title: Clan Mackenzie

text: In what is known as the Skirmish of Alness in 1715 the Earl of Seaforth, chief of Mackenzie led a force of 3000 men that forced the retreat of a smaller force loyal to the British Government, which was commanded by the Earl of Sutherland and included the clans Sutherland, Munro, Ross and Mackay. Much of the Ross's and Munro's lands were ravaged, but they retaliated by raiding the Mackenzie lands in what is known as the Siege of Brahan.


title: Clan Mackenzie

text: The Siege of Inverness (1715) came to an end when the town, which was being held by the Mackenzies was surrendered to Simon Fraser of Lovat. Soon after this Colonel Sir Robert Munro, 6th Baronet of Foulis marched into the town of Inverness with 400 Munros and took over control as governor from Fraser. Government troops arrived in Inverness towards the end of February, and for some months the process of disarming the rebels went on, led by a Munro detachment under George Munro of Culcairn.


title: Clan Mackenzie

text: The clan rivalries which had erupted in rebellion were finding an outlet in local politics. The Mackenzie's position as Earl of Seaforth came to an end in 1716, and it seems to have been arranged that while the Clan Ross held the county seat the Munros would represent the Tain Burghs. To secure the burghs, control of three out of the five was necessary. Ross ascendancy was secure in Tain, and from 1716 to 1745 the Munros controlled Dingwall.


title: Clan Mackenzie

text: The Clan Mackenzie fought at the Battle of Glen Shiel in 1719 where they were defeated by Government forces and the Mackenzie chief was wounded, afterwards retreating to the Western Isles and from there to the Continent. In 1721 the Clan Mackenzie, led by Donald Murchison, defeated Government supporters from the Clan Ross at the Battle of Glen Affric. This was followed by the Battle of Coille Bhan where again, led by Donald Murchison and also his relative Kenneth Murchison, the Clan Mackenzie defeated Government forces. General Wade's report on the Highlands in 1724, estimated the clan strength at 3,000 men.


title: Clan Mackenzie

text: George Mackenzie, 3rd Earl of Cromartie led the Jacobite Mackenzies at the Battle of Falkirk (1746) where they were victorious in helping to defeat British Government forces. The Mackenzies then went on to lay waste to the lands of the Munros who supported the Government and burn down Foulis Castle. They also went on to lay waste to the lands of the Clan Sutherland and the Earl of Sutherland who also supported the Government, and captured Dunrobin Castle, although the Earl of Sutherland himself escaped through a back door. However, soon after this as the Earl of Cromartie and his forces were travelling south to meet Charles Edward Stuart they were attacked by the Mackay and Sutherland Independent Highland Companies who supported the British Government in what became known as the Battle of Littleferry and the Jacobite Mackenzies were prevented from joining the Jacobite army at the Battle of Culloden. Soon after George Mackenzie, 3rd Earl of Cromartie and his son were captured at Dunrobin Castle. The Earl of Cromartie's titles were then forfeited.


title: Clan Mackenzie

text: Other Mackenzies took the side of the British Government: the chief, Kenneth Mackenzie, Lord Fortrose had in fact raised three Independent Highland Companies to support the British Government. In one of the Independent Highland Companies under Captain Colin Mackenzie it is recorded at Shiramore in Badenoch in June 1746 and it included many of them from Kintail as well as more than sixty men from the Clan MacRae.


title: Clan Mackenzie

text: A number of famous regiments have been raised from the Mackenzie clan, including the Highland Light Infantry (raised in 1777), the Seaforth Highlanders (raised in 1778), and the second battalion of the Seaforth Highlanders, known as the Ross-shire Buffs (raised in 1793). All those regiments wore the MacKenzie tartan. Born in 1754, Chief Francis Mackenzie, 1st Baron Seaforth, the last Lord Seaforth raised a regiment for the British Army in 1778, the 72nd, and the clan produced another the 78th in 1793. Both had distinguished records fighting against Napoleon and were later amalgamated into the Queen's Own Highlanders.


title: Clan Mackenzie

text: The 78th Regiment, as it was first called, was raised in 1778 from men on the Seaforth and other Mackenzie estates. The Earl of Seaforth, having raised his men, sailed with them to India in 1781, but died there a few months later. During the Wars in India, Colin Mackenzie (1754–1821) was Surveyor General of India, and an art collector and orientalist. He produced many of the first accurate maps of India, and his research and collections contributed significantly to the field of Asian studies. In 1799, he was part of the British force at the Battle of Seringapatam. He also fought in the Napoleonic Wars.


title: Clan Mackenzie

text: Throughout the 19th century Clan Mackenzie was without a chief that was recognised by the Lord Lyon King of Arms. In 1979, Roderick Grant Francis Blunt-Mackenzie, 4th Earl of Cromartie, legally changed his surname to "Mackenzie" and was widely recognised as Chief of the clan (for example by Clan Mackenzie Societies around the Commonwealth). Although not descended from a "Mackenzie" in the male line (his father was born a "Blunt" and later changed to "Blunt-Mackenzie" after marrying Sibell Lilian Sutherland-Leveson-Gower, Countess of Cromartie), he inherited his titles and "Mackenzie" descent through his mother (even she only claims a "Mackenzie" descent as a great-great-great-great-granddaughter of George Mackenzie, 3rd Earl of Cromartie).


title: Clan Mackenzie

text: On his death in 1990 his son John Ruaridh Mackenzie, 5th Earl of Cromartie succeeded as chief of Clan Mackenzie. The Earl of Cromartie still owns lands in "clan country" however, the largest remaining Mackenzie landowner by some margin is Mackenzie of Gairloch, with an estate which extends to over 50,000 acres (like the clan chief, Mackenzie of Gairloch has inherited his clan name and lands through the female line). The current chief is a member of the Standing Council of Scottish Chiefs.


title: Clan Mackenzie

text: The current chief of Clan Mackenzie lives at Castle Leod, which is thought to date from the 16th century. The chief has leased the unoccupied old tower to the Clan Mackenzie Charitable Trust (CMCT) for 99 years. In 1991 it was announced that the castle was planned to be restored. The restoration was to include a clan genealogical centre that would be open to the public. During the 1990s there was extensive work done on the tower. In 2002 the Highland Buildings Preservation Trust (HBPT) was contacted, to carry out a feasibility study to investigate the potential for the re-use of the upper floor space of the tower, which deemed public funding to be sought to cover the costs of restoration. Because of concerns of physical and legal separation between the clan chief and the tower, the chief decided that the conditions of public funding were too onerous.


title: Clan Mackenzie

text: Clan chief: John Ruaridh Grant Mackenzie, 5th Earl of Cromartie (b. 1948), Viscount Tarbat of Tarbat, Baron Castlehaven, Baron MacLeod of Castle Leod, Chief of Clan Mackenzie. Chiefs of Clan Mackenzie are titled as "Caberféidh" (translation from Scottish Gaelic: "Deer's antlers"). This Gaelic title is derived from the stag's head charge on the former chief, the Earl of Seaforth's Coat of Arms.


title: Clan Mackenzie

text: The surname "Mackenzie" is of Scottish origin and derived from Gaelic. The name is an Anglicised form of the Gaelic "Mac Coinnich", which is a patronymic form of the personal name "Coinneach" meaning "comely" or "handsome". Today personal name "Coinneach" is generally Anglicised as "Kenneth" however "Kenneth" was originally used as an Anglicisation of different Gaelic personal name – "Cionaodh".


title: Clan Mackenzie

text: The Anglicised "Mackenzie" had originally been pronounced ""Mackaingye"" – with a modern English "Y" sound represented with the letter yogh . In the 18th century it became popular to write and pronounce the name with what is the equivalent of a modern English "Z" sound, because of the similarity of the letter "yogh" and letter "Z". There are Lowland Scots words and Scottish names that have been affected in a similar way (example: the surname "Menzies").


title: Clan Mackenzie

text: The Seat of the Clan Mackenzie, Castle Leod is widely considered to be the inspiration behind Castle Leoch, the home of the Clan Mackenzie, in Diana Gabaldon's Outlander series. It was considered as a filming location for the TV series, however, Doune Castle was selected due to its ease of location.


title: Clan Mackenzie

text: Diana Gabaldon told STV that "When the TV show began scouting locations, I suggested Leod as a possibility. It's entirely accurate as to period, of course, and has magnificent grounds, with a park of enormous, exotic trees planted by centuries of MacKenzies and their visitors. (Diana herself planted a "very modest" rowan, as her "own wee contribution" to the history).


title: Clan Mackenzie

text: In the Emberverse series by S.M. Stirling, otherwise known as the 'Change' world, the founder of the Clan Mackenzie, Juniper Mackenzie, is descended from this Scottish clan.


title: Clavulanic acid

text: Clavulanic acid is a β-lactam drug that functions as a mechanism-based β-lactamase inhibitor. While not effective by itself as an antibiotic, when combined with penicillin-group antibiotics, it can overcome antibiotic resistance in bacteria that secrete β-lactamase, which otherwise inactivates most penicillins.


title: Clavulanic acid

text: In its most common preparations, potassium clavulanate (clavulanic acid as a salt of potassium) is combined with:


title: Clavulanic acid

text: Amoxicillin-clavulanic acid is a first-line treatment for many types of infections, including sinus infections, and urinary tract infections, including pyelonephritis. This is, in part, because of its efficacy against gram-negative bacteria which tend to be more difficult to control than gram-positive bacteria with chemotherapeutic antibiotics.


title: Clavulanic acid

text: The use of clavulanic acid with penicillins has been associated with an increased incidence of cholestatic jaundice and acute hepatitis during therapy or shortly after. The associated jaundice is usually self-limiting and very rarely fatal.


title: Clavulanic acid

text: The UK Committee on Safety of Medicines (CSM) recommends that treatments such as amoxicillin/clavulanic acid preparations be reserved for bacterial infections likely to be caused by amoxicillin-resistant β-lactamase-producing strains, and that treatment should not normally exceed 14 days.


title: Clavulanic acid

text: The β-lactam like structure of clavulanic acid looks structurally similar to penicillin, but the biosynthesis of this molecule involves a different biochemical pathway. Clavulanic acid is produced by the bacterium "Streptomyces clavuligerus", using glyceraldehyde-3-phosphate and -arginine as starting materials. Although each of the intermediates of the pathway are known, the exact mechanism for all of the enzymatic reactions are not fully understood. The process mainly involves 3 enzymes: clavaminate synthase, β-lactam synthetase, and N-(2-carboxyethyl)-L-arginine (CEA) synthase. Clavaminate synthase is a non-heme oxygenase dependent on iron and α-keto-glutarate and is encoded by orf5 of the clavulanic acid gene cluster. The specific mechanism of how this enzyme works is not fully understood, but this enzyme regulates 3 steps in the overall synthesis of clavulanic acid. All 3 steps occur in the same region of the catalytic, iron-containing reaction center, yet do not occur in sequence and affect different areas of the clavulanic acid structure.


title: Clavulanic acid

text: β-lactam synthetase is a 54.5 kDa protein that is encoded by orf3 of the clavulanic acid gene cluster, and shows similarity to asparagine synthase – Class B enzymes. The exact mechanism on how this enzyme works to synthesize the β-lactam is not proven, but is believed to occur in coordination with a CEA synthase and ATP.


title: Clavulanic acid

text: CEA synthase is a 60.9 kDA protein and is the first gene found in the clavulanic acid biosynthesis gene cluster, encoded by orf2 of the clavulanic acid gene cluster. The specific mechanism of how this enzyme works is still under investigation; however, it is known that this enzyme has the ability to couple together glyceraldehyde-3-phosphate with L-arginine in the presence of thiamine diphosphate (TDP or thiamine pyrophosphate), which is the first step of the clavulanic acid biosynthesis.


title: Clavulanic acid

text: Clavulanic acid was discovered around 1974-75 by British scientists working at the drug company Beecham from the bacteria "Streptomyces clavuligerus".


title: Clavulanic acid

text: After several attempts, Beecham finally filed for US patent protection for the drug in 1981, and U.S. Patents 4,525,352, 4,529,720, and 4,560,552 were granted in 1985.


title: Clavulanic acid

text: Clavulanic acid has negligible intrinsic antimicrobial activity, despite sharing the β-lactam ring that is characteristic of β-lactam antibiotics. However, the similarity in chemical structure allows the molecule to interact with the enzyme β-lactamase secreted by certain bacteria to confer resistance to β-lactam antibiotics.


title: Clavulanic acid

text: Clavulanic acid is a suicide inhibitor, covalently bonding to a serine residue in the active site of the β-lactamase. This restructures the clavulanic acid molecule, creating a much more reactive species that attacks another amino acid in the active site, permanently inactivating it, and thus inactivating the enzyme.


title: Clavulanic acid

text: This inhibition restores the antimicrobial activity of β-lactam antibiotics against lactamase-secreting resistant bacteria. Despite this, some bacterial strains that are resistant even to such combinations have emerged.


title: PD-1 and PD-L1 inhibitors

text: PD-1 inhibitors and PD-L1 inhibitors are a group of checkpoint inhibitor anticancer drugs that block the activity of PD-1 and PDL1 immune checkpoint proteins present on the surface of cells. Immune checkpoint inhibitors are emerging as a front-line treatment for several types of cancer.


title: PD-1 and PD-L1 inhibitors

text: PD-1 and PD-L1 inhibitors act to inhibit the association of the programmed death-ligand 1 (PD-L1) with its receptor, programmed cell death protein 1 (PD-1). The interaction of these cell surface proteins is involved in the suppression of the immune system and occurs following infection to limit the killing of bystander host cells and prevent autoimmune disease. This immune checkpoint is also active in pregnancy, following tissue allografts, and in different types of cancer.


title: PD-1 and PD-L1 inhibitors

text: The concept of blocking PD-1 and PD-L1 for the treatment of cancer was first published in 2001. Pharmaceutical companies began attempting to develop drugs to block these molecules, and the first clinical trial was launched in 2006, evaluating nivolumab. As of 2017, more than 500 clinical trials involving PD-1 and PD-L1 inhibitors have been conducted in more than 20,000 patients. By the end of 2017, PD-1/PD-L1 inhibitors had been approved for the treatment of nine forms of cancer.


title: PD-1 and PD-L1 inhibitors

text: In the cancer disease state, the interaction of PD-L1 on the tumor cells with PD-1 on a T-cell reduces T-cell function signals to prevent the immune system from attacking the tumor cells. Use of an inhibitor that blocks the interaction of PD-L1 with the PD-1 receptor can prevent the cancer from evading the immune system in this way. Several PD-1 and PD-L1 inhibitors are being trialled within the clinic for use in advanced melanoma, non-small cell lung cancer, renal cell carcinoma, bladder cancer and Hodgkin lymphoma, amongst other cancer types.


title: PD-1 and PD-L1 inhibitors

text: Immunotherapy with these immune checkpoint inhibitors appears to shrink tumours in a higher number of patients across a wider range of tumour types and is associated with lower toxicity levels than other immunotherapies, with durable responses. However, de-novo and acquired resistance is still seen in a large proportion of patients. Hence PD-L1 inhibitors are considered to be the most promising drug category for many different cancers.


title: PD-1 and PD-L1 inhibitors

text: Not all patients respond to PD-1/PD-L1 inhibitors. The FDA has approved several assays to measure the level of PD-L1 expressed by tumor cells, in order to predict the likelihood of response to an inhibitor. PD-L1 levels have been found to be highly predictive of response. Higher mutation burden is also predictive of response to anti-PD-1/PD-L1 agents.


title: PD-1 and PD-L1 inhibitors

text: PD-1 and PD-L1 inhibitors are closely related to CTLA4 (cytotoxic T-lymphocyte-associated protein 4) inhibitors, such as ipilimumab. PD-1 and CTLA-4 are both expressed on activated T cells, but at different phases of immune response.


title: PD-1 and PD-L1 inhibitors

text: Current clinical trials are evaluating anti-PD-1 and PD-L1 drugs in combination with other immunotherapy drugs blocking LAG3, B7-H3, KIR, OX40, PARP, CD27, and ICOS.


title: PD-1 and PD-L1 inhibitors

text: Pembrolizumab (formerly MK-3475 or lambrolizumab, Keytruda) was developed by Merck and first approved by the Food and Drug Administration in 2014 for the treatment of melanoma. It was later approved for metastatic non-small cell lung cancer and head and neck squamous cell carcinoma. In 2017, it became the first immunotherapy drug approved for use based on the genetic mutations of the tumor rather than the site of the tumor. It was shown, that patients with higher non-synonymous mutation burden in their tumors respond better to the treatment. Both their objective response rate and progression-free survival was shown to be higher than in patients with low non-synonymous mutation burden.


title: PD-1 and PD-L1 inhibitors

text: Nivolumab (Opdivo) was developed by Bristol-Myers Squibb and first approved by the FDA in 2014 for the treatment of melanoma. It was later approved for squamous cell lung cancer, renal cell carcinoma, and Hodgkin's lymphoma.


title: PD-1 and PD-L1 inhibitors

text: Cemiplimab (Libtayo) was developed by Regeneron Pharmaceuticals and first approved by the FDA in 2018 for the treatment of cutaneous squamous cell carcinoma (CSCC) or locally advanced CSCC who are not candidates for curative surgery or curative radiation.


title: PD-1 and PD-L1 inhibitors

text: Dostarlimab (Jemperli) – was developed by GlaxoSmithKline and was first approved for the treatment of mismatch repair deficient (dMMR) recurrent or advanced endometrial cancer by the FDA in April of 2021. On August 17, 2021, the FDA granted accelerated approval for the treatment of mismatch repair deficient (dMMR) recurrent or advanced solid tumors.


title: PD-1 and PD-L1 inhibitors

text: Atezolizumab (Tecentriq) is a fully humanised IgG1 (immunoglobulin 1) antibody developed by Roche Genentech. In 2016, the FDA approved atezolizumab for urothelial carcinoma and non-small cell lung cancer.


title: PD-1 and PD-L1 inhibitors

text: Avelumab (Bavencio) is a fully human IgG1 antibody developed by Merck Serono and Pfizer. Avelumab is FDA approved for the treatment of metastatic merkel-cell carcinoma. It failed phase III clinical trials for gastric cancer.


title: PD-1 and PD-L1 inhibitors

text: Durvalumab (Imfinzi) is a fully human IgG1 antibody developed by AstraZeneca. Durvalumab is FDA approved for the treatment of urothelial carcinoma and unresectable non-small cell lung cancer after chemoradiation.


title: PD-1 and PD-L1 inhibitors

text: Immunotherapies as a group have off-target effects and toxicities common to them. Some of these include interstitial pneumonitis, colitis, hepatitis, thyroiditis, skin reactions, low levels of platelets and white blood cells, inflammation of the brain or spinal cord, neuromuscular adverse events including myositis, Guillain-Barré syndrome, myasthenia gravis; myocarditis and cardiac insufficiency, acute adrenal insufficiency, and nephritis. The most common kidney related changes are acute interstitial nephritis, followed by glomerular diseases and then tubular damage. The detailed mechanism of these adverse effects are not fully elucidated; however, they are clearly different from known autoimmune diseases. Immune-mediated adverse reactions are usually attributed to generalised dysregulation of T cells or development of autoantibodies, although memory T cell responses against occult viral infections might also play a role in some patients with advanced melanoma following combined PD-1/CTLA-4 blockade.


title: PD-1 and PD-L1 inhibitors

text: When compared with standard chemotherapeutic agents, PD-1/PD-L1 inhibitors had a lower reported incidence of fatigue, sensory neuropathy, diarrhea, bone marrow suppression, loss of appetite, nausea, and constipation.


title: Fazlur Rahman Khan

text: Fazlur Rahman Khan (, "Fozlur Rôhman Khan"; 3 April 1929 – 27 March 1982) was a Bangladeshi-American structural engineer and architect, who initiated important structural systems for skyscrapers. Considered the "father of tubular designs" for high-rises, Khan was also a pioneer in computer-aided design (CAD). He was the designer of the Sears Tower, since renamed Willis Tower, the tallest building in the world from 1973 until 1998, and the 100-story John Hancock Center.


title: Fazlur Rahman Khan

text: A partner in the firm Skidmore, Owings & Merrill in Chicago, Khan, more than any other individual, ushered in a renaissance in skyscraper construction during the second half of the 20th century. He has been called the "Einstein of structural engineering" and the "Greatest Structural Engineer of the 20th Century" for his innovative use of structural systems that remain fundamental to modern skyscraper design and construction. In his honor, the Council on Tall Buildings and Urban Habitat established the Fazlur Khan Lifetime Achievement Medal, as one of their CTBUH Skyscraper Awards.


title: Fazlur Rahman Khan

text: Although best known for skyscrapers, Khan was also an active designer of other kinds of structures, including the Hajj airport terminal, the McMath–Pierce solar telescope and several stadium structures.


title: Fazlur Rahman Khan

text: Fazlur Rahman Khan was born on 3 April 1929 to a Bengali Muslim family in Dacca, Bengal Presidency (present-day Bangladesh). He was from and brought up in the Khan Bari of Bhandarikandi in Madaripur, Faridpur District. His father, Khan Bahadur Abdur Rahman Khan, was a high school mathematics teacher and textbook author who eventually became the Director of Public Instruction in Bengal and after retirement served as the first Principal of Jagannath College. His mother, Khadijah Khatun, was the daughter of Abdul Basit Chowdhury, the Zamindar (aristocratic landowner) of Dulai in Pabna who traced his ancestry to a migrant from Samarkand in Turkestan. Khan's paternal uncle, Abdul Hakim Khan, was the son-in-law of Syed Abdul Jabbar, a "zamindar" based in Comilla.


title: Fazlur Rahman Khan

text: Khan attended Armanitola Government High School, in Dhaka. After that, he studied Civil Engineering in Bengal Engineering and Science University, Shibpur (present day Indian Institute of Engineering Science and Technology, Shibpur), Kolkata, India, and then received his Bachelor of Civil Engineering degree from Ahsanullah Engineering College, (now Bangladesh University of Engineering and Technology). He received a Fulbright Scholarship and a government scholarship, which enabled him to travel to the United States in 1952. There he studied at the University of Illinois at Urbana–Champaign. In three years Khan earned two master's degrees – one in structural engineering and one in theoretical and applied mechanics – and a PhD in structural engineering with thesis titled "Analytical Study of Relations Among Various Design Criteria for Rectangular Prestressed Concrete Beams".


title: Fazlur Rahman Khan

text: His hometown in Dhaka did not have any buildings taller than three stories. He did not view his first skyscraper in person until the age of 21 years old, and he had not stepped inside a mid-rise building until he moved to the United States for graduate school. Despite this, the environment of his hometown in Dhaka later influenced his tube building concept, which was inspired by the bamboo that sprouted around Dhaka. He found that a hollow tube, like the bamboo in Dhaka, lent a high-rise vertical durability.


title: Fazlur Rahman Khan

text: In 1955, employed by the architectural firm Skidmore, Owings & Merrill (SOM), he began working in Chicago. He was made a partner in 1966. He worked the rest of his life side by side with fellow architect Bruce Graham. Khan introduced design methods and concepts for efficient use of material in building architecture. His first building to employ the tube structure was the Chestnut De-Witt apartment building. During the 1960s and 1970s, he became noted for his designs for Chicago's 100-story John Hancock Center and 110-story Sears Tower, since renamed Willis Tower, the tallest building in the world from 1973 until 1998.


title: Fazlur Rahman Khan

text: He believed that engineers needed a broader perspective on life, saying, "The technical man must not be lost in his own technology; he must be able to appreciate life, and life is art, drama, music, and most importantly, people."


title: Fazlur Rahman Khan

text: Khan's personal papers, most of which were in his office at the time of his death, are held by the Ryerson & Burnham Libraries at the Art Institute of Chicago. The Fazlur Khan Collection includes manuscripts, sketches, audio cassette tapes, slides and other materials regarding his work.


title: Fazlur Rahman Khan

text: For enjoyment, Khan loved singing Rabindranath Tagore's poetic songs in Bengali. He and his wife, Liselotte, who immigrated from Austria, had one daughter who was born in 1960. In 1967, he elected to become a United States citizen.


title: Fazlur Rahman Khan

text: Khan discovered that the rigid steel frame structure that had long dominated tall building design was not the only system fitting for tall buildings, marking the start of a new era of skyscraper construction.


title: Fazlur Rahman Khan

text: Khan's central innovation in skyscraper design and construction was the idea of the "tube" structural system for tall buildings, including the "framed tube", "trussed tube", and "bundled tube" variants. His "tube concept", using all the exterior wall perimeter structure of a building to simulate a thin-walled tube, revolutionized tall building design. Most buildings over 40 stories constructed since the 1960s now use a tube design derived from Khan's structural engineering principles.


title: Fazlur Rahman Khan

text: Lateral loads (horizontal forces) such as wind forces, seismic forces, etc., begin to dominate the structural system and take on increasing importance in the overall building system as the building height increases. Wind forces become very substantial, and forces caused by earthquakes, etc. are important as well. The tubular designs resist such forces for tall buildings. Tube structures are stiff and have significant advantages over other framing systems. They not only make the buildings structurally stronger and more efficient, but also significantly reduce the structural material requirements. The reduction of material makes the buildings economically more efficient and reduces environmental impact. The tubular designs enable buildings to reach even greater heights. Tubular systems allow greater interior space and further enable buildings to take on various shapes, offering added freedom to architects. These new designs opened an economic door for contractors, engineers, architects, and investors, providing vast amounts of real estate space on minimal plots of land. Khan was among a group of engineers who encouraged a rebirth in skyscraper construction after a hiatus of over thirty years.


title: Fazlur Rahman Khan

text: The tubular systems have yet to reach their limit when it comes to height. Another important feature of the tubular systems is that buildings can be constructed using steel or reinforced concrete, or a composite of the two, to reach greater heights. Khan pioneered the use of lightweight concrete for high-rise buildings, at a time when reinforced concrete was used for mostly low-rise construction of only a few stories in height. Most of Khan's designs were conceived considering pre-fabrication and repetition of components so projects could be quickly built with minimal errors.


title: Fazlur Rahman Khan

text: The population explosion, starting with the baby boom of the 1950s, created widespread concern about the amount of available living space, which Khan solved by building upward. More than any other 20th-century engineer, Fazlur Rahman Khan made it possible for people to live and work in "cities in the sky". Mark Sarkisian (Director of Structural and Seismic Engineering at Skidmore, Owings & Merrill) said, "Khan was a visionary who transformed skyscrapers into sky cities while staying firmly grounded in the fundamentals of engineering."


title: Fazlur Rahman Khan

text: Since 1963, the new structural system of framed tubes became highly influential in skyscraper design and construction. Khan defined the framed tube structure as "a three dimensional space structure composed of three, four, or possibly more frames, braced frames, or shear walls, joined at or near their edges to form a vertical tube-like structural system capable of resisting lateral forces in any direction by cantilevering from the foundation." Closely spaced interconnected exterior columns form the tube. Horizontal loads, for example from wind and earthquakes, are supported by the structure as a whole. About half the exterior surface is available for windows. Framed tubes allow fewer interior columns, and so create more usable floor space. The bundled tube structure is more efficient for tall buildings, lessening the penalty for height. The structural system also allows the interior columns to be smaller and the core of the building to be free of braced frames or shear walls that use valuable floor space. Where larger openings like garage doors are required, the tube frame must be interrupted, with transfer girders used to maintain structural integrity.


title: Fazlur Rahman Khan

text: The first building to apply the tube-frame construction was the DeWitt-Chestnut Apartment Building, since renamed Plaza on DeWitt, building that Bruce Graham designed and Khan did the engineering for was completed in Chicago in 1963. This laid the foundations for the framed tube structure used in the construction of the World Trade Center.


title: Fazlur Rahman Khan

text: Khan pioneered several other variants of the tube structure design. One of these was the concept of applying X-bracing to the exterior of the tube to form a "trussed tube". X-bracing reduces the lateral load on a building by transferring the load into the exterior columns, and the reduced need for interior columns provides a greater usable floor space. Khan first employed exterior X-bracing on his engineering of the John Hancock Center in 1965, and this can be clearly seen on the building's exterior, making it an architectural icon.


title: Fazlur Rahman Khan

text: In contrast to earlier steel frame structures, such as the Empire State Building (1931), which required about 206 kilograms of steel per square meter and One Chase Manhattan Plaza (1961), which required around 275 kilograms of steel per square meter, the John Hancock Center was far more efficient, requiring only 145 kilograms of steel per square meter. The trussed tube concept was applied to many later skyscrapers, including the Onterie Center, Citigroup Center and Bank of China Tower.


title: Fazlur Rahman Khan

text: One of Khan's most important variants of the tube structure concept was the "bundled tube", which was used for the Willis Tower and One Magnificent Mile. The bundled tube design was not only the most efficient in economic terms, but it was also "innovative in its potential for versatile formulation of architectural space. Efficient towers no longer had to be box-like; the tube-units could take on various shapes and could be bundled together in different sorts of groupings."


title: Fazlur Rahman Khan

text: Tube-in-tube system takes advantage of core shear wall tubes in addition to exterior tubes. The inner tube and outer tube work together to resist gravity loads and lateral loads and to provide additional rigidity to the structure to prevent significant deflections at the top. This design was first used in One Shell Plaza. Later buildings to use this structural system include the Petronas Towers.


title: Fazlur Rahman Khan

text: The outrigger and belt truss system is a lateral load resisting system in which the tube structure is connected to the central core wall with very stiff outriggers and belt trusses at one or more levels. BHP House was the first building to use this structural system followed by the First Wisconsin Center, since renamed U.S. Bank Center, in Milwaukee. The center rises 601 feet, with three belt trusses at the bottom, middle and top of the building. The exposed belt trusses serve aesthetic and structural purposes. Later buildings to use this include Shanghai World Financial Center.


title: Fazlur Rahman Khan

text: The last major buildings engineered by Khan were the One Magnificent Mile and Onterie Center in Chicago, which employed his bundled tube and trussed tube system designs respectively. In contrast to his earlier buildings, which were mainly steel, his last two buildings were concrete. His earlier DeWitt-Chestnut Apartments building, built in 1963 in Chicago, was also a concrete building with a tube structure. Trump Tower in New York City is also another example that adapted this system.


title: Fazlur Rahman Khan

text: Khan developed the shear wall frame interaction system for mid high-rise buildings. This structural system uses combinations of shear walls and frames designed to resist lateral forces. The first building to use this structural system was the 35-stories Brunswick Building. The Brunswick building was completed in 1965 and became the tallest reinforced concrete structure of its time. The structural system of Brunswick Building consists of a concrete shear wall core surrounded by an outer concrete frame of columns and spandrels. Apartment buildings up to 70 stories high have successfully used this concept.


title: Fazlur Rahman Khan

text: Khan's seminal work of developing tall building structural systems are still used today as the starting point when considering design options for tall buildings. Tube structures have since been used in many skyscrapers, including the construction of the World Trade Center, Aon Center, Petronas Towers, Jin Mao Building, Bank of China Tower and most other buildings in excess of 40 stories constructed since the 1960s. The strong influence of tube structure design is also evident in the world's current tallest skyscraper, the Burj Khalifa in Dubai. According to Stephen Bayley of "The Daily Telegraph":


title: Fazlur Rahman Khan

text: Khan and Mark Fintel conceived ideas of shock absorbing soft-stories, for protecting structures from abnormal loading, particularly strong earthquakes, over a long period of time. This concept was a precursor to modern seismic isolation systems. The structures are designed to behave naturally during earthquakes where traditional concepts of material ductility are replaced by mechanisms that allow for movement during ground shaking while protecting material elasticity.


title: Fazlur Rahman Khan

text: Khan designed several notable structures that are not skyscrapers. Examples include the Hajj terminal of King Abdulaziz International Airport, completed in 1981, which consists of tent-like roofs that are folded up when not in use. The project received several awards, including the Aga Khan Award for Architecture, which described it as an "outstanding contribution to architecture for Muslims". The tent-like tensile structures advanced the theory and technology of fabric as a structural material and led the way to its use for other types of terminals and large spaces.


title: Fazlur Rahman Khan

text: Khan also designed the King Abdulaziz University, the United States Air Force Academy in Colorado Springs and the Hubert H. Humphrey Metrodome in Minneapolis. With Bruce Graham, Khan developed a cable-stayed roof system for the Baxter Travenol Laboratories in Deerfield, Illinois.


title: Fazlur Rahman Khan

text: In the 1970s, engineers were just starting to use computer structural analysis on a large scale. SOM was at the center of these new developments, with undeniable contributions from Khan. Graham and Khan lobbied SOM partners to purchase a mainframe computer, a risky investment at a time, when new technologies were just starting to form. The partners agreed, and Khan began programming the system to calculate structural engineering equations, and later, to develop architectural drawings.


title: Fazlur Rahman Khan

text: Among Khan's other accomplishments, he received the Wason Medal (1971) and Alfred Lindau Award (1973) from the American Concrete Institute (ACI); the Thomas Middlebrooks Award (1972) and the Ernest Howard Award (1977) from ASCE; the Kimbrough Medal (1973) from the American Institute of Steel Construction; the Oscar Faber medal (1973) from the Institution of Structural Engineers, London; the International Award of Merit in Structural Engineering (1983) from the International Association for Bridge and Structural Engineering IABSE; the AIA Institute Honor for Distinguished Achievement (1983) from the American Institute of Architects; and the John Parmer Award (1987) from Structural Engineers Association of Illinois and Illinois Engineering Hall of Fame from Illinois Engineering Council (2006).


title: Fazlur Rahman Khan

text: Khan was cited five times by "Engineering News-Record" as among those who served the best interests of the construction industry, and in 1972 he was honored with "ENR" Man of the Year award. In 1973 he was elected to the National Academy of Engineering. He received honorary doctorates from Northwestern University, Lehigh University, and the Swiss Federal Institute of Technology Zürich (ETH Zurich).


title: Fazlur Rahman Khan

text: The Council on Tall Buildings and Urban Habitat named one of their CTBUH Skyscraper Awards the Fazlur Khan Lifetime Achievement Medal after him, and other awards have been established in his honor, along with a chair at Lehigh University. Promoting educational activities and research, the Fazlur Rahman Khan Endowed Chair of Structural Engineering and Architecture honors Khan's legacy of engineering advancement and architectural sensibility. Dan Frangopol is the first holder of the chair.


title: Fazlur Rahman Khan

text: Khan was mentioned by President Obama in 2009 in his speech in Cairo, Egypt when he cited the achievements of America's Muslim citizens.


title: Fazlur Rahman Khan

text: Khan was the subject of the Google Doodle on 3 April 2017, marking what would have been his 88th birthday.


title: Fazlur Rahman Khan

text: In 2021, director Laila Kazmi began production on a feature-length documentary film to be called "Reaching New Heights: Fazlur Rahman Khan and the Skyscraper" on the life and legacy of Khan. The film is produced by Kazmi's production company Kazbar Media, with development support from ITVS, which provides co-production support to independent documentaries on PBS. The film is helmed by director and producer Laila Kazmi, with associate producer Arnila Guha, and New York-based art director Begoña Lopez. It is fiscally sponsored by Film Independent.


title: Fazlur Rahman Khan

text: In 1971 the Bangladesh Liberation War broke out. Khan was heavily involved with creating public opinion and garnering emergency funding for Bengali people during the war. He created the Chicago-based Bangladesh Emergency Welfare Appeal organization.


title: Fazlur Rahman Khan

text: Khan died of a heart attack on 27 March 1982 while on a trip in Jeddah, Saudi Arabia, at the age of 52. He was a general partner in SOM. His body was returned to the United States and was buried in Graceland Cemetery in Chicago.


title: Soft On Demand

text: , often known as SOD, is a Japanese adult video group of companies which has its headquarters in the Nakano ward of Tokyo. SOD was founded in December 1995 by Ganari Takahashi, who retired from the company in March 2005 and is currently working in agriculture. The company is one of the largest adult video companies in Japan and is notable for its creative approach to adult videos.


title: Soft On Demand

text: In 2009, the company, under president Chie Sugawara (菅原 千恵), had 128 employees (27 male and 101 female) and a capital of 100 million yen (about US$1.1 million). For the fiscal year ending March 31, 2009, SOD had total sales of 14.9 billion yen (about US$165 million) and a profit of 670 million yen (about US$7.4 million). For 2007 the figures were sales of 13.5 billion yen (about US$120 million) and profit of 900 million yen (about US$8 million). SOD has been a fast-growing company since its foundation, going from sales of 300 million yen in 1996 to 1.5 billion in 1998 to 4.1 billion in 2000, 7.8 billion in 2003, and 9 billion in 2005. In spite of its rapid growth, it was overtaken in sales volume in the early 2000s by rival AV producer Hokuto, which also absorbed some of SOD's former companies. After peaking in 2008, Hokuto sales have plunged while annual income at SOD has stayed level at about 15 billion yen (about US$150 million) for the 2008-2010 period allowing it to become once again the largest adult video group in Japan.


title: Soft On Demand

text: One director has described their product this way: "SOD's porno is ridiculous. There's nothing really sordid about it" and "different to anything else in the porno world". Some of its most notable approaches have been quiz shows that tested the knowledge of AV (adult video) actresses with challenging questions, CFNM (clothed female, naked male) videos that have women studying a man's penis (the "Uniforms, Undies and All Naked School Multi-Story" series), and plots where women are put under hypnosis. There have also been nude sports series, the senior citizen epic "All Naked Nursing Home for the Elderly", Company Sex Parties, Summer Festivals (a festival focused on penises and not to be confused with the actual Shinto festival dealing with fertility) and Sex Camps.


title: Soft On Demand

text: One of their releases from May 2006, "500 Person Sex" ("500人SEX"), features 250 couples having sex (apart from each other but in the same room) in an impressive synchronized way, and thus got some raised eyebrows from occidental adult sites. The video received a special jury award at the 2006 AV Open.


title: Soft On Demand

text: By 2003, SOD was releasing more than 1,000 adult video titles per year. SOD also works with a number of companies in other areas and has thus become a group (zaibatsu) of companies mainly in the area of producing adult videos. Besides producing videos the company also produces condoms and lubricant lotions, PC games (aka hentai games), and adult anime.


title: Soft On Demand

text: Outside of the adult area, SOD is also involved in producing softcore and genre movies, idol videos and TV programs. Among their mainstream movies, some have featured SOD AV actresses including the 2008 horror film "Yoroi Samurai Zombie" with Nana Natsume and the 2006 comedy-drama "Tokyo Daigaku Monogatari", directed by Tatsuya Egawa and featuring Sasa Handa. A third entry was the 2014 science fiction film "Danger Dolls", with SOD star Mana Sakura making an appearance.


title: Soft On Demand

text: In 2004, the company announced plans to produce an adaptation of the Shougakukan "Big Comic Original" manga series "Ajisai no Uta" ("Song of Hydrangea") as an original video animation (OVA) for a general audience. Volume 1 of the series was released in August 2004 and the fourth and final volume came out in December of that year.


title: Soft On Demand

text: Internally, SOD outsources work to its individual units, original video production being done by SOD Create Inc. () headed by Daisuke Kasai (). This affiliate, founded in March 1999, was originally called and changed its name to SOD Create in 2001.


title: Soft On Demand

text: Package design for SOD is the realm of another division, SOD Artworks (SODアートワークス), founded in 2004, and under the leadership of Yoshino Toshimitsu ().


title: Soft On Demand

text: Since its inception, SOD has produced over 7,500 movies starring some of the most prominent JAV actresses. The company has also made a significant shift towards producing more virtual reality content in recent years, and even went as far as to build an adult theme park in the heart of Tokyo, also known as SOD Land.


title: Soft On Demand

text: For the past several years, SOD has run a campaign to bring attention to the rise of sexually transmitted diseases (STD) in Japan and to increase the use of condoms. The program, called STOP! STD, has used former SOD star Nana Natsume as a spokeswoman.


title: Soft On Demand

text: From 2002 to 2006, the company held the SOD AV Awards, an annual ceremony to present a series of awards to honor actresses, directors, and staff of companies in the SOD group. In 2006, the company also sponsored, along with Tokyo Sports, a wider award contest called the AV Open. Sixteen companies competed for a total prize pool of 25 Million yen with the winner being decided by sales of the videos entered in the contest.


title: Soft On Demand

text: In the second year of the AV Open competition, 19 companies participated and the SOD entry won by a large margin. But it was subsequently discovered that SOD had used company funds to buy thousands of their own videos. SOD was disqualified and the discredited AV Open was replaced the next year by the Hokuto Corporation sponsored AV Grand Prix.


title: Soft On Demand

text: The Japanese AV industry has several different "ethics groups", which are voluntary organizations to assure adherence with Japanese pornography laws and to regulate content and copyrights. The earliest of these organizations was founded by the major AV companies in 1972 and is known as the Nihon Ethics of Video Association (NEVA). In response, SOD in 1996 began its own regulatory group known as the . Medirin was composed of "indie" companies, independent AV studios which explored porn themes forbidden by NEVA rules and which used a smaller-pixeled censorship mosaic for their videos. Medirin was re-organized in 2005 to form the to review and regulate adult videos and adult game software. The CSA had more than 65 members among AV producers comprising most of the SOD group and some other major companies. In November 2010, the organization was dissolved and the Ethics Organization of Video took its place.


title: Jackhammer

text: A jackhammer (pneumatic drill or demolition hammer in British English) is a pneumatic or electro-mechanical tool that combines a hammer directly with a chisel. It was invented by William Mcreavy, who then sold the patent to Charles Brady King. Hand-held jackhammers are generally powered by compressed air, but some are also powered by electric motors. Larger jackhammers, such as rig-mounted hammers used on construction machinery, are usually hydraulically powered. These tools are typically used to break up rock, pavement, and concrete.


title: Jackhammer

text: A jackhammer operates by driving an "internal" hammer up and down. The hammer is first driven down to strike the chisel and then back up to return the hammer to the original position to repeat the cycle. The effectiveness of the jackhammer is dependent on how much force is applied to the tool. It is generally used like a hammer to break the hard surface or rock in construction works and it is not considered under earth moving equipment, along with its accessories (i.e., pusher leg, lubricator).


title: Jackhammer

text: The first steam-powered drill was patented by Samuel Miller in 1806. The drill used steam only for raising the drill. Pneumatic drills were developed in response to the needs of mining, quarrying, excavating, and tunneling. A pneumatic drill was proposed by a C. Brunton in 1844. In 1846, a percussion drill that could be worked by steam, or atmospheric pressure obtained from a vacuum, was patented in Britain by Thomas Clarke, Mark Freeman, and John Varley. The first American "percussion drill" was made in 1848, and patented in 1849 by Jonathan J. Couch of Philadelphia, Pennsylvania. In that drill, the drill bit passed through the piston of a steam engine. The piston snagged the drill bit and hurled it against the rock face. It was an experimental model. In 1849, Couch's assistant, Joseph W. Fowle, filed a patent caveat for a percussion drill of his own design. In Fowle's drill, the drill bit was connected directly to the piston in the steam cylinder; specifically, the drill bit was connected to the piston's crosshead. The drill also had a mechanism for turning the drill bit around its axis between strokes and for advancing the drill as the hole deepened. By 1850 or 1851, Fowle was using compressed air to drive his drill, making it the first true pneumatic drill.


title: Jackhammer

text: The demand for pneumatic drills was driven especially by miners and tunnelers, because steam engines needed fires to operate and the ventilation in mines and tunnels was inadequate to vent the fires' fumes. As well, mines and tunnels might contain flammable explosive gases such as methane. There was also no way to convey steam over long distances, such as from the surface to the bottom of a mine, without it condensing. By contrast, compressed air could be conveyed over long distances without loss of its energy, and after the compressed air had been used to power equipment, it could ventilate a mine or tunnel.


title: Jackhammer

text: In Europe since the late 1840s, the king of Sardinia, Carlo Alberto, had been contemplating the excavation of a tunnel through Mount Fréjus to create a rail link between Italy and France, which would cross his realm. The need for a mechanical rock drill was obvious and that sparked research in Europe on pneumatic rock drills. A Frenchman, François Cavé (), designed a rock drill that used compressed air, which he patented in 1851. However, the air had to be admitted manually to the cylinder during each stroke, so it was not successful.


title: Jackhammer

text: In 1854, in England, Thomas Bartlett made and then patented (1855) a rock drill, the bit of which was connected directly to the piston of a steam engine. In 1855, Bartlett demonstrated his drill, powered by compressed air, to officials of the Mount Fréjus tunnel project. (In 1855, a German, Schumann, invented a similar pneumatic rock drill in Freiburg, Germany.) By 1861, Bartlett’s drill had been refined by the Savoy-born engineer Germain Sommeiller (1815-1871) and his colleagues, Grandis and Grattoni. Thereafter, many inventors refined the pneumatic drill. Sommeiller took his drill to the lengthy Gotthard Pass Tunnel, then being built to link railways between Switzerland and Italy under the Alps. From there, mining and railway tunnelling expanded.


title: Jackhammer

text: Two equipment manufacturing companies, Atlas Copco and Ingersoll Rand, became dominant in the provision of compressed air drilling apparatus in Europe and America respectively, each holding significant patents.


title: Jackhammer

text: The word "jackhammer" is used in North American English and Australia, while "pneumatic drill" is used colloquially elsewhere in the English speaking world, although strictly speaking a "pneumatic drill" refers to a pneumatically driven jackhammer.


title: Jackhammer

text: In Britain, electromechanical versions are colloquially known by the name of "Kangos". The term comes from the former British brand name now owned by Milwaukee tools.


title: Jackhammer

text: A full-sized portable jackhammer is impractical for use against walls and steep slopes, except by a very strong person, as the user would have to both support the weight of the tool, and push the tool back against the work after each blow. A technique developed by experienced workers is a two-man team to overcome this obstacle of gravity: one operates the hammer and the second assists by holding the hammer either on his shoulders or cradled in his arms. Both use their combined weight to push the bit into the workface. This method is commonly referred to as horizontal jackhammering.


title: Jackhammer

text: Another method is overhead jackhammering, requiring strength conditioning and endurance to hold a smaller jackhammer, called a rivet buster, over one's head. To make overhead work safer, a platform can be used. One such platform is a positioner–actuator–manipulator (PAM). This unit takes all the weight and vibration from the user.


title: Jackhammer

text: A pneumatic jackhammer, also known as a ' or ', is a jackhammer that uses compressed air as the power source. The air supply usually comes from a portable air compressor driven by a diesel engine. Reciprocating compressors were formerly used. The unit comprised a reciprocating compressor driven, through a centrifugal clutch, by a diesel engine. The engine's governor provided only two speeds:


title: Jackhammer

text: Modern versions use rotary compressors and have more sophisticated variable governors. The unit is usually mounted on a trailer and sometimes includes an electrical generator to supply lights or electric power tools.


title: Jackhammer

text: Additionally, some users of pneumatic jackhammers may use a pneumatic lubricator which is placed in series with the air hose powering the air hammer. This increases the life and performance of the jackhammer.


title: Jackhammer

text: An electropneumatic hammer is often called a rotary hammer, because it has an electric motor, which rotates a crank. The hammer has two pistons – a drive piston and a free-flight piston. The crank moves the drive piston back and forth in the same cylinder as the flight piston. The drive piston never touches the flight piston. Instead, the drive piston compresses air in the cylinder, which then propels the flight piston against a striker, which contacts the drill bit.


title: Jackhammer

text: Electric powered tools come in a variety of sizes, about . They require an external power source, but do not require a compressor. Although in the past these tools did not have the power of an air or pneumatic hammer, this is changing with newer brushless-motor tools coming close to the power of a pneumatic tool and in some cases even matching it. Electric-powered tools are useful for locations where access to a compressor is limited or impractical, such as inside a building, in a crowded construction site, or in a remote location and it is not uncommon under earth moving equipment or tool.


title: Jackhammer

text: Electropneumatic tools use a variety of chucks for attaching chisels, but the most common are SDS-max, 7/8 in hex, TE-S, and 1+1/8 in hex. The connection end size is also related to the breaking energy of the tool. For example, the Bosch and Hilti tools both use SDS-max, while the Bosch, Hilti, and Makita tools all use 1+1/8 in hex connection. See hammer drills for more on electropneumatic hammering.


title: Jackhammer

text: A hydraulic breaker may be fitted to heavy equipment such as an excavator or backhoe, and is widely used for roadwork, quarrying, construction sitework, and general demolition. These larger machine mounted breakers are known as rig mounted, or machine mounted breakers. Such tools can be used horizontally, as they do not require the assist of gravity to do their work. They typically use a hydraulic motor driving a sealed pneumatic hammer system, as a hydraulically activated hammer would both develop a low strike speed and potentially transfer unacceptable shock loads to the pump system. Contrast this with a steam, mechanical, or hydraulically driven pile driver.


title: Jackhammer

text: Advances in technology have allowed for portable hydraulic breakers. The jackhammer is connected with hydraulic hoses to a portable hydraulic powerpack: either a petrol or diesel engine driving a hydraulic pump; or a mini-excavator or skid-steer via a power take-off driveshaft to the machine's hydraulic system. Hydraulic power sources are more efficient than air compressors, making the kit smaller, cheaper or more powerful than a comparable pneumatic version.


title: Jackhammer

text: Pneumatic or hydraulic tools are particularly likely to be used in underground mines where there is an explosion risk (such as with coal), since they do not required high-voltage electricity to work, eliminating much of the danger of spark-induced detonation.


title: Jackhammer

text: Sharpening: chisels may be resharpened in a shop or with an angle grinder with grinding disc. After resharpening, they must then be heat treated to restore the integrity of the steel before use. Self-sharpening polygon and flat chisels are also available.


title: Jackhammer

text: The sound of the hammer blows, combined with the explosive air exhaust, makes pneumatic jackhammers dangerously loud, emitting more than 120 dB SPL near the operator’s ears. Sound-blocking earmuffs and earplugs must be worn by the operator to prevent a form of hearing loss, of which tinnitus is the main symptom. Although some pneumatic jackhammers now have a silencer around the barrel of the tool, loud air exhaust, hammer blows themselves, and compressor engine sounds remain unmuffled.


title: Jackhammer

text: Use has been linked to Raynaud syndrome; in particular, prolonged exposure to the pronounced vibration conducted by the tool can lead to a secondary form of the syndrome known as vibration white finger. Applying athletic tape is not very effective in preventing white finger but seems to help alleviate some of its discomfort. Pneumatic drill usage can also lead to a predisposition for the development of carpal tunnel syndrome.


title: Jackhammer

text: Some manufacturers of electro-pneumatic tools now offer vibration reduction systems to reduce the vibration felt by the operator. For example, Hilti manufactures a jackhammer model that has approximately the same impact energy of a pneumatic hammer, but the vibration felt by the operator is significantly less (7 m/s). Other manufacturers such as Makita, DeWalt and Bosch also offer electric tools with vibration dampening.


title: Jackhammer

text: In addition, using a jackhammer to break up concrete pavement may expose the operator to hazardous dust containing respirable crystalline silica that may induce silicosis. The operator and those in the vicinity of the jackhammer operations should wear personal protective equipment, including an OSHA-approved respirator (US).


title: Cunard-White Star Line

text: The company was created to control the joint shipping assets of the Cunard Line and the White Star Line after both companies experienced financial difficulties during the Great Depression. Cunard White Star controlled a total of twenty-five ocean liners (with Cunard contributing fifteen ships and White Star ten). Both Cunard and White Star were in dire financial trouble, and were looking to complete enormous liners: White Star had Hull 844 – – and Cunard had Hull 534, which would later become . In 1933, the British government agreed to provide assistance to the two competitors on the condition that they merge their North Atlantic operations. The agreement was completed on 30 December 1933. The merger took place on 10 May 1934, creating Cunard-White Star Limited. White Star contributed ten ships to the new company while Cunard contributed fifteen. Due to this arrangement, and since Hull 534 was Cunard's ship, Cunard owned 62% of the new company, with White Star owning the remaining 38%. White Star vessels flew the White Star flag over the Cunard flag while Cunard vessels flew the Cunard flag over the White Star flag.


title: Cunard-White Star Line

text: Being in a better financial and operating state than White Star, Cunard began absorbing White Star assets and as a result, most of the White Star vessels were quickly disposed of or sent to the shipbreakers. White Star's Australia and New Zealand service ships were transferred to the Shaw, Savill & Albion Line in 1934 and was retired and sold for scrap the following year, along with Cunard's . White Star's flagship , the largest ship in the world until 1935, was sold in 1936.


title: Cunard-White Star Line

text: In 1947, Cunard acquired White Star’s 38% share in the company and on 31 December 1949 the company had dropped the White Star name and was renamed "Cunard Line". Both the Cunard and White Star house flags were flown on the company's liners at the time of the merger and thereafter. However, the Cunard flag was flown over the White Star flag on the last two White Star liners, and . "Georgic" was scrapped in 1956, while "Britannic" made the final Liverpool–New York crossing of any White Star vessel from New York on 25 November 1960, and returned to Liverpool for the final time before sailing under her own power to the ship breakers. She was the last White Star liner in existence, leaving the passenger tender , which was also owned by the company until 1934, as the last White Star Line ship afloat.


title: Cunard-White Star Line

text: Despite this, all Cunard Line ships flew both the Cunard and White Star Line house flags on their masts until late 1968. This was most likely because "Nomadic" remained in service with Cunard until 4 November 1968, and was sent to the breakers' yard, only to be bought for use as a floating restaurant. After this, the White Star flag was no longer flown, the White Star name was removed from Cunard operations and all remnants of both White Star Line and Cunard-White Star Line were retired. Cunard operated as a separate entity until 1999, when it was fully acquired by Carnival Corporation.


title: Frenum piercing

text: A frenum piercing is a type of body piercing located on the underside of the shaft of the penis. A series of parallel frenum piercings is known as a frenum ladder. A frenum ladder may be extended to include lorum piercings, hafada piercings and guiche piercings.


title: Frenum piercing

text: Frenum piercings generally require from two to five weeks to heal fully. Depending on the placement it may be a surface piercing, but due to both the vascular, fast healing nature of the penis, and loose nature of the skin in that area, frenum piercings rarely reject if pierced properly, although they may migrate.


title: Frenum piercing

text: Those wishing to stretch this piercing to accommodate larger gauge jewelry should wait until at least two weeks after the initial piercing has fully healed. It is common for a frenum piercing to start to close soon after the jewelry has been removed. A fairly recent piercing may start to close in less than an hour. Temporary removal and replacement (for example, to accommodate a partner who finds it uncomfortable) may mean reinserting with a smaller gauge and then restretching to get back to the original, larger gauge. This tendency for the piercing to close up will diminish over time.


title: Frenum piercing

text: Both barbells and rings can be worn in frenum piercings, both as initial jewellery and on an ongoing basis. Sometimes, when rings are worn, the diameter of the ring is specifically chosen so that the ring can be worn encircling the penis. A wide variety of chastity devices make use of frenum piercings to secure themselves to the penis, as part of fetish or BDSM activities.


title: Frenum piercing

text: The earliest literary reference to frenum piercings occurs in 1884 in "Zeitschrift für Ethnologie" which states: "Amongst the Timorese of Indonesia, the Frenulum beneath the glans penis is pierced with brass rings...the function of the ring is to enhance stimulation during sex." Anecdotal piercing lore associates this piercing (along with many other male genital piercings) with various chastity devices that have been used throughout history, although there is little hard data to back up this claim.


title: Frenum piercing

text: In contemporary society, frenum piercings were primarily found amongst the members of gay BDSM subcultures, until body piercing became re-introduced to mainstream society in the late 1970s and early 1980s.


title: Frenum piercing

text: Frenum piercings are often intended to provide sexual pleasure to both the bearer and the person they are having sexual intercourse with. They may also be used to attach chastity devices to the bearer, denying them sexual pleasure.


title: Frenum piercing

text: A Frenum Ladder, also known as a Jacob's Ladder, consists of a series of frenum piercings often extending from below the head of the penis and as far as the base of the shaft of the penis.


title: Frenum piercing

text: Sometimes, a frenum ladder will be accompanied by a hafada ladder and/or a guiche ladder. Due to the relatively easy healing of these piercings it is not uncommon for several, or even all of them to be performed at the same time.


title: Planetary boundaries

text: Planetary boundaries is a concept highlighting human-caused perturbations of Earth systems making them relevant in a way not accommodated by the environmental boundaries separating the three ages within the Holocene epoch. Crossing a planetary boundary comes at the risk of abrupt environmental change. The framework is based on scientific evidence that human actions, especially those of industrialized societies since the Industrial Revolution, have become the main driver of global environmental change. According to the framework, "transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental-scale to planetary-scale systems."


title: Planetary boundaries

text: The normative component of the framework is that human societies have been able to thrive under the comparatively stable climatic and ecological conditions of the Holocene. To the extent that these Earth system process boundaries have not been crossed, they mark the “safe zone” for human societies on the planet. The concept has since become influential in the international community (e.g. United Nations Conference on Sustainable Development), including governments at all levels, international organizations, civil society and the scientific community. The framework consists of nine global change processes. In 2009, according to Rockström and others, two boundaries were already crossed, while others were in imminent danger of being crossed.


title: Planetary boundaries

text: In 2015, several of the scientists in the original group published an update, bringing in new co-authors and new model-based analysis. According to this update, four of the boundaries were crossed: climate change, loss of biosphere integrity, land-system change, altered biogeochemical cycles (phosphorus and nitrogen). The scientists also changed the name of the boundary "Loss of biodiversity" to "Change in biosphere integrity" to emphasize that not only the number of species but also the functioning of the biosphere as a whole is important for Earth system stability. Similarly, the "Chemical pollution" boundary was renamed to "Introduction of novel entities," widening the scope to consider different kinds of human-generated materials that disrupt Earth system processes.


title: Planetary boundaries

text: In 2022, based on available literature, the introduction of novel entities was concluded to be the 5th transgressed planetary boundary.


title: Planetary boundaries

text: The basic idea of the Planetary Boundaries framework is that maintaining the observed resilience of the Earth system in the Holocene is a precondition for humanity’s pursuit of long-term social and economic development. The Planetary Boundaries framework contributes to an understanding of global sustainability because it brings a planetary scale and a long timeframe into focus.


title: Planetary boundaries

text: The framework described nine "planetary life support systems" essential for maintaining a “desired Holocene state”, and attempted to quantify how far seven of these systems had been pushed already. Boundaries were defined to help define a "safe space for human development", which was an improvement on approaches aiming at minimizing human impacts on the planet.


title: Planetary boundaries

text: The framework is based on scientific evidence that human actions, especially those of industrialized societies since the Industrial Revolution, have become the main driver of global environmental change. According to the framework, "transgressing one or more planetary boundaries may be deleterious or even catastrophic due to the risk of crossing thresholds that will trigger non-linear, abrupt environmental change within continental-scale to planetary-scale systems." The framework consists of nine global change processes. In 2009, two boundaries were already crossed, while others were in imminent danger of being crossed. Later estimates indicated that three of these boundaries—climate change, biodiversity loss, and the biogeochemical flow boundary—appear to have been crossed.


title: Planetary boundaries

text: The scientists outlined how breaching the boundaries increases the threat of functional disruption, even collapse, in Earth’s biophysical systems in ways that could be catastrophic for human wellbeing. While they highlighted scientific uncertainty, they indicated that breaching boundaries could “trigger feedbacks that may result in crossing thresholds that drastically reduce the ability to return within safe levels”. The boundaries were "rough, first estimates only, surrounded by large uncertainties and knowledge gaps" which interact in complex ways that are not yet well understood.


title: Planetary boundaries

text: The planetary boundaries framework lays the groundwork for a shifting approach to governance and management, away from the essentially sectoral analyses of limits to growth aimed at minimizing negative externalities, toward the estimation of the safe space for human development. Planetary boundaries demarcate, as it were, the "planetary playing field" for humanity if major human-induced environmental change on a global scale is to be avoided.


title: Planetary boundaries

text: The authors of this framework was a group of Earth System and environmental scientists in 2009 led by Johan Rockström from the Stockholm Resilience Centre and Will Steffen from the Australian National University. They collaborated with 26 leading academics, including Nobel laureate Paul Crutzen, Goddard Institute for Space Studies climate scientist James Hansen, oceanographer Katherine Richardson, geographer Diana Liverman and the German Chancellor's chief climate adviser Hans Joachim Schellnhuber.


title: Planetary boundaries

text: Most of the contributing scientists were involved in strategy-setting for the Earth System Science Partnership, the precursor to the international global change research network Future Earth. The group wanted to define a "safe operating space for humanity" for the wider scientific community, as a precondition for sustainable development.


title: Planetary boundaries

text: The 2009 study identified nine planetary boundaries and, drawing on current scientific understanding, the researchers proposed quantifications for seven of them. These are:


title: Planetary boundaries

text: For one process in the planetary boundaries framework, the scientists have not specified a global boundary quantification:


title: Planetary boundaries

text: The quantification of individual planetary boundaries is based on the observed dynamics of the interacting Earth system processes included in the framework. The control variables were chosen because together they provide an effective way to track the human-caused shift away from Holocene conditions.


title: Planetary boundaries

text: For some of Earth’s dynamic processes, historic data display clear thresholds between comparatively stable conditions. For example, past ice-ages show that during peak glacial conditions, the atmospheric concentration of CO was ~180-200 ppm. In interglacial periods (including the Holocene), CO concentration has fluctuated around 280 ppm. To know what were like with an atmosphere with over 350 ppm CO, scientists need to look back about 3 million years. The paleo record of climatic, ecological and biogeochemical changes shows that the Earth system has experienced tipping points, when a very small increment for a control variable (like CO) triggers a larger, possibly catastrophic, change in the response variable (global warming) through feedbacks in the natural Earth System itself.


title: Planetary boundaries

text: For several of the processes in the planetary boundaries framework, it is difficult to locate individual points that mark the threshold shift away from Holocene-like conditions. This is because the Earth system is complex and the scientific evidence base is still partial and fragmented. Instead, the planetary boundaries framework identifies many Earth system thresholds at multiple scales that will be influenced by increases in the control variables. Examples include shifts in monsoon behavior linked to the aerosol loading and freshwater use planetary boundaries.


title: Planetary boundaries

text: The planetary boundaries framework proposes a range of values for its control variables. This range is supposed to span the threshold between a 'safe operating space' where Holocene-like dynamics can be maintained and a highly uncertain, poorly predictable world where Earth system changes likely increase risks to societies. The "boundary" is defined as the lower end of that range. If the boundaries are persistently crossed, the world goes further into a danger zone.


title: Planetary boundaries

text: It is difficult to restore a 'safe operating space' for humanity that is described by the planetary boundary concept. Even if past biophysical changes could be mitigated, the predominant paradigms of social and economic development appear largely indifferent to the looming possibilities of large scale environmental disasters triggered by human actions. Legal boundaries can help keep human activities in check, but are only as effective as the political will to make and enforce them.


title: Planetary boundaries

text: Understanding the Earth system is fundamentally about understanding interactions among environmental change processes. The planetary boundaries are defined with reference to dynamic conditions of the Earth system, but scientific discussions about how different planetary boundaries relate to each other are often philosophically and analytically muddled. Clearer definitions of the basic concepts and terms might help give clarity.


title: Planetary boundaries

text: There are many many interactions among the processes in planetary boundaries the framework. While these interactions can create both stabilizing and destabilizing feedbacks in the Earth system, the authors suggested that a transgressed planetary boundary will reduce the safe operating space for other processes in the framework rather than expand it from the proposed boundary levels. They give the example that the land use boundary could “shift downward” if the freshwater boundary is breached, causing lands to become arid and unavailable for agriculture. At a regional level, water resources may decline in Asia if deforestation continues in the Amazon. That way of framing the interactions shifts from the framework’s biophysical definition of boundaries based on Holocene-like conditions to an anthropocentric definition (demand for agricultural land). Despite this conceptual slippage, considerations of known Earth system interactions across scales suggest the need for "extreme caution in approaching or transgressing any individual planetary boundaries."


title: Planetary boundaries

text: Another example has to do with coral reefs and marine ecosystems: In 2009, researchers showed that, since 1990, calcification in the reefs of the Great Barrier that they examined decreased at a rate unprecedented over the last 400 years (14% in less than 20 years). Their evidence suggests that the increasing temperature stress and the declining ocean saturation state of aragonite is making it difficult for reef corals to deposit calcium carbonate. Multiple stressors, such as increased nutrient loads and fishing pressure, moves corals into less desirable ecosystem states. Ocean acidification will significantly change the distribution and abundance of a whole range of marine life, particularly species "that build skeletons, shells, and tests of biogenic calcium carbonate. Increasing temperatures, surface UV radiation levels and ocean acidity all stress marine biota, and the combination of these stresses may well cause perturbations in the abundance and diversity of marine biological systems that go well beyond the effects of a single stressor acting alone."


title: Planetary boundaries

text: In 2012, Steven Running suggested a tenth boundary, the annual net global primary production of all terrestrial plants, as an easily determinable measure integrating many variables that will give "a clear signal about the health of ecosystems".


title: Planetary boundaries

text: In 2015, a second paper was published in "Science" to update the Planetary Boundaries concept. The update concluded four boundaries had now been transgressed: climate, biodiversity, land use and biogeochemical cycles. The 2015 paper emphasized interactions of the nine boundaries and identified climate change and loss of biodiversity integrity as ‘core boundaries’ of central importance to the framework because the interactions of climate and the biosphere are what scientifically defines Earth system conditions.


title: Planetary boundaries

text: In 2017, some authors argued that marine systems are underrepresented in the framework. Their proposed remedy was to include the seabed as a component of the earth surface change boundary. They also wrote that the framework should account for "changes in vertical mixing and ocean circulation patterns".


title: Planetary boundaries

text: A 2018 study calls into question the adequacy of efforts to limit warming to 2 degrees above pre-industrial temperatures, as set out in the Paris Agreement. The scientists raise the possibility that even if greenhouse gas emissions are substantially reduced to limit warming to 2 degrees, that might exceed the "threshold" at which self-reinforcing climate feedbacks add additional warming until the climate system stabilizes in a hothouse climate state. This would make parts of the world uninhabitable for people, raise sea levels by up to 60 metres (200 ft), and raise temperatures by 4–5 °C (7.2–9.0 °F) to levels that are higher than any interglacial period in the past 1.2 million years.


title: Planetary boundaries

text: According to the biologist Cristián Samper, a "boundary that expresses the probability of families of species disappearing over time would better reflect our potential impacts on the future of life on Earth." The biodiversity boundary has also been criticized for framing biodiversity solely in terms of the extinction rate. The global extinction rate has been highly variable over the Earth's history, and thus using it as the only biodiversity variable can be of limited usefulness.


title: Planetary boundaries

text: The biogeochemist William Schlesinger thinks waiting until we near some suggested limit for nitrogen deposition and other pollutions will just permit us to continue to a point where it is too late. He says the boundary suggested for phosphorus is not sustainable, and would exhaust the known phosphorus reserves in less than 200 years.


title: Planetary boundaries

text: The ocean chemist Peter Brewer queries whether it is "truly useful to create a list of environmental limits without serious plans for how they may be achieved ... they may become just another stick to beat citizens with. Disruption of the global nitrogen cycle is one clear example: it is likely that a large fraction of people on Earth would not be alive today without the artificial production of fertilizer. How can such ethical and economic issues be matched with a simple call to set limits? ... food is not optional."


title: Planetary boundaries

text: Peak phosphorus is a concept to describe the point in time at which the maximum global phosphorus production rate is reached. Phosphorus is a scarce finite resource on earth and means of production other than mining are unavailable because of its non-gaseous environmental cycle. According to some researchers, Earth's phosphorus reserves are expected to be completely depleted in 50–100 years and peak phosphorus to be reached by approximately 2030.


title: Planetary boundaries

text: Surface ocean acidity is clearly interconnected with the climate change boundaries, since the concentration of carbon dioxide in the atmosphere is also the underlying control variable for the ocean acidification boundary.


title: Planetary boundaries

text: The ocean chemist Peter Brewer thinks "ocean acidification has impacts other than simple changes in pH, and these may need boundaries too."


title: Planetary boundaries

text: Across the planet, forests, wetlands and other vegetation types are being converted to agricultural and other land uses, impacting freshwater, carbon and other cycles, and reducing biodiversity. In the year 2015 the boundary was defined as 75% of forests rested intact, including 85% of boreal forests, 50% of temperate forests and 85% of tropical forests. The boundary is crossed because only 62% of forests rested intact as of the year 2015.


title: Planetary boundaries

text: The boundary for land use has been criticized as follows: "The boundary of 15 per cent land-use change is, in practice, a premature policy guideline that dilutes the authors' overall scientific proposition. Instead, the authors might want to consider a limit on soil degradation or soil loss. This would be a more valid and useful indicator of the state of terrestrial health."


title: Planetary boundaries

text: The freshwater cycle is another boundary significantly affected by climate change. Overexploitation of freshwater occurs if a water resource is mined or extracted at a rate that exceeds the recharge rate. Water pollution and saltwater intrusion can also turn much of the world's underground water and lakes into finite resources with "peak water" usage debates similar to oil.


title: Planetary boundaries

text: The hydrologist David Molden stated in 2009 that planetary boundaries are a welcome new approach in the "limits to growth" debate but said "a global limit on water consumption is necessary, but the suggested planetary boundary of 4,000 cubic kilometres per year is too generous."


title: Planetary boundaries

text: A study concludes that the 'Freshwater use' boundary should be renamed to the 'Freshwater change', composed of "green" and "blue" water components. 'Green water' refers to disturbances of terrestrial precipitation, evaporation and soil moisture. Water scarcity can have substantial effects in agriculture.<ref name="10.1029/2021EF002567"></ref> When measuring and projecting water scarcity in agriculture for climate change scenarios, both "green water" and "blue water" are of relevance.


title: Planetary boundaries

text: In April 2022, scientists proposed and preliminarily evaluated 'green water' in the water cycle as a likely transgressed planetary boundary, as measured by root-zone soil moisture deviation from Holocene variability.<ref name="10.1038/s43017-022-00287-8"></ref>


title: Planetary boundaries

text: The stratospheric ozone layer protectively filters ultraviolet radiation (UV) from the Sun, which would otherwise damage biological systems. The actions taken after the Montreal Protocol appeared to be keeping the planet within a safe boundary.


title: Planetary boundaries

text: The Nobel laureate in chemistry, Mario Molina, says "five per cent is a reasonable limit for acceptable ozone depletion, but it doesn't represent a tipping point".


title: Planetary boundaries

text: Worldwide each year, aerosol particles result in about 800,000 premature deaths from air pollution. Aerosol loading is sufficiently important to be included among the planetary boundaries, but it is not yet clear whether an appropriate safe threshold measure can be identified.


title: Planetary boundaries

text: Some chemicals, such as persistent organic pollutants, heavy metals and radionuclides, have potentially irreversible additive and synergic effects on biological organisms, reducing fertility and resulting in permanent genetic damage. Sublethal uptakes are drastically reducing marine bird and mammal populations. This boundary seems important, although it is hard to quantify. In 2019, it was suggested that novel entities could include genetically modified organisms, pesticides and even artificial intelligence.


title: Planetary boundaries

text: A Bayesian emulator for persistent organic pollutants has been developed which can potentially be used to quantify the boundaries for chemical pollution. To date, critical exposure levels of polychlorinated biphenyls (PCBs) above which mass mortality events of marine mammals are likely to occur, have been proposed as a chemical pollution planetary boundary.


title: Planetary boundaries

text: There are at least 350,000 artificial chemicals in the world. They are coming from "plastics, pesticides, industrial chemicals, chemicals in consumer products, antibiotics and other pharmaceuticals". They have mostly "negative effects on planetary health". Their production increased 50 times since 1950 and expected to increase 3 times more by 2050. Plastic alone contain more than 10,000 chemicals and create large problems. The researchers are calling for limit on chemical production and shift to circular economy, meaning to products that can be reused and recycled.


title: Planetary boundaries

text: In January 2022 a group of scientists concluded that this planetary boundary is already exceeded, which puts in risk the stability of the Earth system. They integrated the literature information on how production and release of a number of novel entities, including plastics and hazardous chemicals, have rapidly increased in the last decades with significant impact on the planetary processes.


title: Planetary boundaries

text: In August 2022, scientists concluded that the (overall transgressed) boundary is a placeholder for multiple different boundaries for NEs that may emerge, reporting that PFAS pollution is one such new boundary. They show that levels of these so-called "forever chemicals" in rainwater are ubiquitously, and often greatly, above guideline safe levels worldwide. There are some moves to restrict and replace their use.


title: Planetary boundaries

text: Planetary integrity, also called "earth’s life-support systems" or "ecological integrity", needs to be maintained for long-term sustainability. The notion of planetary integrity derives from its root term "ecological integrity", which was initially developed to describe the declining state of biodiversity on a sub-global scale. In this context, "integrity" is a way of thinking about ecological health affected by human activities. The concept of planetary integrity is becoming popular at several levels of analysis. It is, for example, implied in the notion of planetary boundaries.


title: Planetary boundaries

text: An expert Panel on Ecological Integrity in 1998 has defined ecological integrity as follows: "An ecosystem has integrity when it is deemed characteristic for its natural region, including the composition and abundance of native species and biological communities, rates of change and supporting processes. In plain language, ecosystems have integrity when they have their native components (plants, animals and other organisms) and processes (such as growth and reproduction) intact.".


title: Planetary boundaries

text: There now seems to be general agreement that planetary integrity is being impacted in unprecedented ways, and that deliberate and thoroughgoing steering mechanisms, such as through the Sustainable Development Goals, are urgently needed. The signs of decaying planetary integrity are apparent from the negative human impacts on the environment and predictions showing that we are fast approaching global tipping points.


title: Planetary boundaries

text: The idea that there are limits to the burden placed upon our planet by human activities has been around for a long time. The Planetary Boundaries framework acknowledges the influence of the 1972 study, "The Limits to Growth", that presented a model in which exponential growth in world population, industrialization, pollution, food production, and resources depletion outstrip the ability of technology to increase resources availability. Subsequently, the report was widely dismissed, particularly by economists and business people, and it has often been claimed that history has proved the projections to be incorrect. In 2008, Graham Turner from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) published "A comparison of "The Limits to Growth" with thirty years of reality". "The Limits to Growth" has been widely discussed, both by critics of the modelling approach and its conclusions and by analysts who argue that the insight that societies do not live in an unlimited world and that historical data since the 1970s support the report’s findings. The "Limits to Growth" approach explores how the socio-technical dynamics of the world economy may limit humanity’s opportunities and introduce risks of collapse. In contrast, the Planetary Boundaries framework focuses on the biophysical dynamics of the Earth system.


title: Planetary boundaries

text: "Our Common Future" was published in 1987 by United Nations' World Commission on Environment and Development. It tried to recapture the spirit of the Stockholm Conference. Its aim was to interlock the concepts of development and environment for future political discussions. It introduced the famous definition for sustainable development:


title: Planetary boundaries

text: Another key idea influencing the Planetary Boundaries framework is the Gaia theory or hypothesis. In the 1970s, James Lovelock and microbiologist Lynn Margulis presented the idea that all organisms and their inorganic surroundings on Earth are integrated into a single self-regulating system. The system has the ability to react to perturbations or deviations, much like a living organism adjusts its regulation mechanisms to accommodate environmental changes such as temperature (homeostasis). Nevertheless, this capacity has limits. For instance, when a living organism is subjected to a temperature that is lower or higher than its living range, it can perish because its regulating mechanism cannot make the necessary adjustments. Similarly the Earth may not be able to react to large deviations in critical parameters. In Lovelock's book "The Revenge of Gaia", he suggests that the destruction of rainforests and biodiversity, compounded with global warming resulting from the increase of greenhouse gases made by humans, could shift feedbacks in the Earth system away from a self-regulating balance to a positive (intensifying) feedback loop.


title: Planetary boundaries

text: Scientists have affirmed that the planet has entered a new epoch, the Anthropocene. In the Anthropocene, humans have become the main agents of not only change to the Earth System but also the driver of Earth System "rupture", disruption of the Earth System's ability to be resilient and recover from that change, potentially ultimately threatening planetary habitability. The previous geological epoch, the Holocene began about 10,000 years ago. It is the current interglacial period, and was a relatively stable environment of the Earth. There have been natural environmental fluctuations during the Holocene, but the key atmospheric and biogeochemical parameters have remained within relatively narrow bounds. This stability has allowed societies to thrive worldwide, developing agriculture, large-scale settlements and complex networks of trade.


title: Planetary boundaries

text: According to Rockström "et al.", we "have now become so dependent on those investments for our way of life, and how we have organized society, technologies, and economies around them, that we must take the range within which Earth System processes varied in the Holocene as a scientific reference point for a desirable planetary state."


title: Planetary boundaries

text: Various biophysical processes that are important in maintaining the resilience of the Earth system are also undergoing large and rapid change because of human actions. For example, since the advent of the Anthropocene, the rate at which species are going extinct has increased over 100 times, and humans are now the driving force altering global river flows as well as water vapor flows from the land surface. Continuing perturbation of Earth system processes by human activities raises the possibility that further pressure could be destabilizing, leading to non-linear, abrupt, large-scale or irreversible environmental change responses by the Earth system within continental- to planetary-scale systems.


title: Planetary boundaries

text: The 2009 report was presented to the General Assembly of the Club of Rome in Amsterdam. An edited summary of the report was published as the featured article in a special 2009 edition of "Nature" alongside invited critical commentary from leading academics like Nobel laureate Mario J. Molina and biologist Cristián Samper.


title: Planetary boundaries

text: Development studies scholars have been critical of aspects of the framework and constraints that its adoption could place on the Global South. Proposals to conserve a certain proportion of Earth's remaining forests can be seen as rewarding the countries such as those in Europe that have already economically benefitted from exhausting their forests and converting land for agriculture. In contrast, countries that have yet to industrialize are asked to make sacrifices for global environmental damage they may have had little role in creating.


title: Planetary boundaries

text: The biogeochemist William Schlesinger queries whether thresholds are a good idea for pollutions at all. He thinks waiting until we near some suggested limit will just permit us to continue to a point where it is too late. "Management based on thresholds, although attractive in its simplicity, allows pernicious, slow and diffuse degradation to persist nearly indefinitely."


title: Planetary boundaries

text: Several studies have assessed environmental footprints of nations based on planetary boundaries: for Sweden, Switzerland, the Netherlands, the European Union, India, many of Belt and Road Initiative countries as well as for the world’s most important economies. While the metrics and allocation approaches applied varied, there is a converging outcome that resource use of wealthier nations – if extrapolated to world population – is not compatible with planetary boundaries.


title: Planetary boundaries

text: Human activities related to agriculture and nutrition globally contribute to the transgression of four out of nine planetary boundaries. Surplus nutrient flows (N, P) into aquatic and terrestrial ecosystems are of highest importance, followed by excessive land-system change and biodiversity loss. Whereas in the case of biodiversity loss, P cycle and land-system change, the transgression is in the zone of uncertainty—indicating an increasing risk (yellow circle in the figure), the N boundary related to agriculture is more than 200% transgressed—indicating a high risk (red marked circle in the figure). Here, nutrition includes food processing and trade as well as food consumption (preparation of food in households and gastronomy). Consumption-related environmental impacts are not quantified at the global level for the planetary boundaries of freshwater use, atmospheric aerosol loading (air pollution) and stratospheric ozone depletion.


title: Planetary boundaries

text: Broadly described proposed solution-approaches based on a general a framework of ecological limits include (transferable) personal carbon allowances and "legislated" national greenhouse gas emissions limits. Consumers would have freedom in their (informed) choice within (the collective) boundaries.


title: Planetary boundaries

text: The United Nations secretary general Ban Ki-moon endorsed the concept of planetary boundaries on 16 March 2012, when he presented the key points of the report of his High Level Panel on Global Sustainability to an informal plenary of the UN General Assembly. Ban stated: "The Panel’s vision is to eradicate poverty and reduce inequality, to make growth inclusive and production and consumption more sustainable, while combating climate change and respecting a range of other planetary boundaries." The concept was incorporated into the so-called "zero draft" of the outcome of the United Nations Conference on Sustainable Development to be convened in Rio de Janeiro 20–22 June 2012. However, the use of the concept was subsequently withdrawn from the text of the conference, "partly due to concerns from some poorer countries that its adoption could lead to the sidelining of poverty reduction and economic development. It is also, say observers, because the idea is simply too new to be officially adopted, and needed to be challenged, weathered and chewed over to test its robustness before standing a chance of being internationally accepted at UN negotiations."


title: Planetary boundaries

text: In 2011, at their second meeting, the High-level Panel on Global Sustainability of the United Nations had incorporated the concept of planetary boundaries into their framework, stating that their goal was: "To eradicate poverty and reduce inequality, make growth inclusive, and production and consumption more sustainable while combating climate change and respecting the range of other planetary boundaries."