bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct localised measurement of electrical resistivity profile in rat and embryonic chick retinas using a microprobe
Authors: Kasi Harsha , Meissner Robert , Babalian Alexandre , Lintel Harald van , Bertsch Arnaud , Renaud Philippe
Published: July 2015

We report an alternative technique to perform a direct and local measurement of electrical resistivities in a layered retinal tissue. Information on resistivity changes along the depth in a retina is important for modelling retinal stimulation by retinal prostheses. Existing techniques for resistivity-depth profiling have the drawbacks of a complicated experimental setup, a less localised resistivity probing and/or lower stability for measurements. We employed a flexible microprobe to measure local resistivity with bipolar impedance spectroscopy at various depths in isolated rat and chick embryo retinas for the first time. Small electrode spacing permitted high resolution measurements and the probe flexibility contributed to stable resistivity profiling. The resistivity was directly calculated based on the resistive part of the impedance measured with the Peak Resistance Frequency (PRF) methodology. The resistivity-depth profiles for both rat and chick embryo models are in accordance with previous mammalian and avian studies in literature. We demonstrate that the measured resistivity at each depth has its own PRF signature. Resistivity profiles obtained with our setup provide the basis for the construction of an electric model of the retina. This model can be used to predict variations in parameters related to retinal stimulation and especially in the design and optimisation of efficient retinal implants.
Logan, Utah: A Case Study in Water and Energy Efficiency
Authors: Jones Steven C. , Lindhardt Paul W. , Sowby Robert B.
Published: July 2015

Logan City, Utah, experienced firsthand the water ‐ energy nexus when it undertook a comprehensive water and energy audit to determine its best path forward.
Adapting to Drought in Australia and California: Creative Water Transfers in a Water‐Scarce World
Authors: Langford John , Man Debra C. , Hirsch Steve
Published: July 2015

This column focuses on the use of water exchanges and associated price mechanisms to mitigate the impact of shortages and uncertainty in two geographic areas of these countries ‐ California and southeastern Australia. They are similar in terms of climate and population; California's population is approximately 35 million versus southeastern Australia's population of 20 million, which embodies four out of five of Australia's largest cities. Both California and southeastern Australia share the dilemma of balancing scarce water resources between agricultural uses and the rapidly growing needs of cities and industry ‐ each critical to future prosperity. And in both areas, agricultural water use makes up the overwhelming share of total developed water ‐ approximately 70% in Australia and more than 80% in California.
Eduction, extension, and exhumation of ultrahigh‐pressure rocks in metamorphic core complexes due to subduction initiation
Authors: Petersen Kenni Dinesen , Buck W. Roger
Published: July 2015

The controversy over the exhumation of ultrahigh‐pressure (UHP) rocks centers on whether it involves rising of pieces of crust detached from subducted continental lithosphere or an entire subducted plate that undergoes “eduction,” i.e., reverse subduction. We present a new thermomechanical model of continental subduction showing that these apparently contrasting mechanisms can occur together: crust subducted deep enough is heated and weakened, causing limited diapiric rise, while crust subducted to shallower depths retains strength and is exhumed only by eduction. The model also shows for the first time how eduction followed by seafloor spreading can occur in a zone of regional convergence. This occurs spontaneously when subduction of buoyant crust causes a subduction zone to “lock up” in one place causing a new subduction zone to form in another. The model is consistent with many features of the youngest region of UHP rock exhumation on earth: the D'Entrecasteaux Islands. UHP exhumation and the amount of regional extension, as well as the seismic structure around the islands, can be explained by eduction. Ductile flow fabrics, seen on the islands, would result from exhumation of the most deeply subducted crust heated enough to undergo partial melting. Reversal of motion on the north‐dipping continental subduction zone, required by this model, was likely triggered by initiation of the New Britain Trench, as suggested previously. Our model implies that the crust of Goodenough Basin, south of the islands, was exhumed by eduction in the last 5 Ma and this hypothesis can be tested by drilling.
Borsäure und Tetraborate [BAT Value Documentation in German language, 2015]
Authors: Bolt H.M. , Golka K.
Published: July 2015

Veröffentlicht in der Reihe
Biologische Arbeitsstoff‐Toleranz‐Werte (BAT‐Werte), Expositionsäquivalente für krebserzeugende Arbeitsstoffe (EKA) und Biologische Leitwerte (BLW)
, 22. Lieferung, Ausgabe 2015

Der Artikel enthält folgende Kapitel:

Metabolismus und Toxikokinetik

Kritische Toxizität

Belastung und Beanspruchung

Auswahl der Indikatoren

Untersuchungsmethoden

Hintergrundbelastung

Evaluierung

Interpretation
Addendum zu Benzol [BAT Value Documentation in German language, 2015]
Authors: Weistenhöfer W. , Drexler H.
Published: July 2015

Veröffentlicht in der Reihe
Biologische Arbeitsstoff‐Toleranz‐Werte (BAT‐Werte), Expositionsäquivalente für krebserzeugende Arbeitsstoffe (EKA) und Biologische Leitwerte (BLW)
, 22. Lieferung, Ausgabe 2015
Tubulin and Microtubules
Authors: Amos Linda A
Published: July 2015

Microtubules are found in almost all types of eukaryotic cell. Their principal constituents are the highly conserved proteins of the tubulin family, in the form of longitudinal protofilaments of tubulin heterodimers. The conserved lateral interactions produce a characteristic 2D lattice. Tubulin structure and conformational changes are now known to atomic resolution. Its GTP‐dependent dynamic self‐assembly and disassembly is modulated by a host of other proteins. This dynamic activity and a more passive role as tracks for interaction with motor proteins, kinesin and dynein, allow microtubules to perform vital roles in various forms of cell motility. They are an essential component of cell division, provide oriented tracks for the transport of cellular organelles and vesicles and are responsible for the relative positioning of cellular compartments. Thus, they are important targets in the control of cancer cells, as their essential activity is severely affected by a variety of drugs.

Key Concepts

Tubulin heterodimers, consisting of highly homologous α‐ and β‐tubulin monomers, self‐assemble into a unique lattice with polar longitudinal ‘protofilaments’

The assembled sheet has a slightly variable curvature, producing microtubules, with around 13 protofilaments but not strictly defined unless they are grown from a γ‐tubulin template or given a curvature appropriate to exactly 13 protofilaments by accessory proteins

The structure of microtubules has been solved to near‐atomic level both with GTP homologues bound to β‐tubulin and with GDP bound; also a depolymerised protofilament structure in a longitudinally curved conformation is known

Hydrolysis of bound GTP enables microtubules to assemble with ‘dynamic instability’, behaviour that depends on stochastic disassembly when the GTP ‘cap’ is lost from a growing end

Microtubule behaviour is modified by many different accessory proteins that may act just at the tips or everywhere on the lattice wall

To play different roles according to their positions in cells, the properties of microtubules may vary owing to different tubulin isotypes and be modified by a wide range of associated proteins

Changes can also vary with time (‘ageing’) as a result of post‐translational modification of tubulin and of some accessory proteins

Microtubules are employed in axonemes of cilia and flagella, where the motor protein dynein interacts with them to produce beating while other linking components help control the wave‐form

Cytoplasmic microtubules provide tracks for vesicles and other cargoes driven by kinesins and cytoplasmic dynein

Mitotic and meiotic spindles are assembled from microtubules, which interact with kinetochores and with multiple motor proteins

Microtubules are susceptible to many small molecules that depolymerise or hyperstabilise them and thus serve as anti‐cancer drugs.
Immunogenicity
Authors: Galson Jacob D , O'Connor Daniel
Published: July 2015

An antigen refers to a molecule that is able to bind to the cells of the immune system. If an antigen can also stimulate an immune response, it is termed an immunogen. Immunogenicity is a measure of this ability to activate the immune response: that is, the B and T cells underlying humoral and cell‐mediated immunity. Understanding the concept of immunogenicity is therefore vital in understanding the field of immunology as a whole. The determinants of immunogenicity are complex, but much research has been conducted in this area in the context of vaccination and protein therapeutics, where understanding immunogenicity is of key clinical significance. While obtaining accurate measures of immunogenicity is difficult, a range of techniques to both predict the immunogenicity of a substance and to measure immunogenicity based on B and T cell activation have been developed.

Key Concepts

Immunogenicity is defined as the ability of a substance to elicit an adaptive immune response.

The immunogenicity of a substance depends on multiple factors relating to the properties of the substance itself, the biological system, and how the substance is delivered to the biological system.

Immunogenicity is necessary for our body to respond to and destroy pathogens, as well as to remove tumourogenic and dying cells.

Understanding immunogenicity is important for pharmaceutical development, where it is sometimes necessary to either increase (vaccination) or decrease (protein therapeutics) the immunogenicity of a product.

Experimental model systems, and more recently, computational tools, are being developed to predict immunogenicity.

Immunogenicity can be measured empirically by assessing the numbers of activated T or B cells, or antibody levels during a response to the substance.
Antibody Synthesis
In Vitro
Authors: Iborra Antoni , Martínez Paz , Palacio José Ramón
Published: July 2015

Antibodies are specific proteins that recognise nearly any chemical structure. During
in vivo
immunisation B cells are activated by antigen. Antigen‐specific cells proliferate and some differentiate into antibody‐secreting plasma cells. Monoclonal antibody technology was first reported by Köhler and Milstein in 1975. Briefly, B cells with specificity for a known antigen were fused with myeloma to make them immortal. Hybridomas grow in culture indefinitely and secrete monoclonal antibodies (mAbs) of a desired specificity. Hybridoma technology and antibody engineering have contributed in Biomedicine to the diagnosis of malignancies, tissue typing, identification of individual cell types, detection of cytokines, growth factors and hormones. The mAbs have become important in human immunotherapy and diagnosis. Murine mAbs have limited potential in human therapeutic applications due to human immune response to the murine antibodies. Several strategies for human mAbs production for immunotherapy are described in this article. Monoclonal antibodies have also a wide range of applications in Health and Food Sciences, Environmental Sciences, Technology and Experimental Sciences among others.

Key Concepts

Antigen is a molecule that binds specifically to B cell receptor (BCR) or soluble antibodies. T cell receptor (TCR) recognise processed antigen presented by MHC (major histocompatibility complex).

Epitope or antigenic determinant is part of an antigen that is recognised specifically by TCR‐MHC or by BCR or by soluble antibodies.

Immunogen is an antigen that generates a cellular and humoral immune response.

Antibody is an immunoglobulin that recognises specifically a particular antigenic epitope.

Antibody affinity is the strength of binding between a single binding site of an antibody and a single antigenic determinant or epitope.

Plasma B cells are differentiated B cells that, after binding to an antigen, secrete soluble antibodies.

Hybridoma is a hybrid cell line obtained by cell fusion of an immortalised lymphocyte tumor line, or myeloma, and B lymphocytes with defined antigen specificities.

Monoclonal antibody is an immunoglobulin with specificity for one antigenic determinant or epitope, derived from a single B‐clone.

Antibody immunotherapy is applied in immunopathology and in cancer. The main therapeutic agents are human or humanised monoclonal antibodies.
Antibody Engineering
Authors: Paul Sudhir , Planque Stephanie , Massey Richard
Published: July 2015

Antibodies contain sites in the heavy and light chain variable domains (V domains) with antigen‐binding activity largely independent of their constant domains (C domains). Recombinant antibodies that bind with pathological proteins are used widely as drugs. In addition, antibodies containing V domain nucleophilic sites that bind protein targets irreversibly or catalyse target breakdown. Target‐specific therapeutic antibodies can be obtained by inducing adaptive B cell development in transgenic animal or by test‐tube affinity maturation of cloned antibody V domain repertoires. The V domains are recloned as full‐length antibodies to improve their pharmacokinetic behaviour, restore the C domain‐dependent catalytic activity and incorporate effector functions residing in the C domains. Assembly of the V domains into multivalent constructs improves the binding avidity. Linkage to enzymes, toxins or delivery proteins imparts novel functions to the constructs. Uptake of antibodies by internalisation of membrane‐bound antigen forms can render intracellular antigens sensitive to antibody targeting.

Key Concepts

Antibodies are highly adaptive structures. They are encoded by germline genes that have diversified over evolutionary time and then undergo further antigen‐driven adaptive development over the life time of an individual organism.

The antigen combining site is composed of the antibody light and heavy chain subunit variable domains. The constant domain contributes effector functions such as complement activation and Fc receptor binding.

Monoclonal IgG antibodies that bind protein target reversibly have emerged as a major class of biological drugs for various diseases. The efficacy and safety of antibody drugs depend on their antigen recognition affinity, specificity andin vivopharmacokinetics.

Understanding the natural process underlying adaptive sequence diversification has permitted isolation of monoclonal antibodies, meeting the criteria for therapeutic applications. Antibody display and cloning methods have enabled identification of individual antibodies with defined antigenic specificities from vast repertoires.

Improvement of IgG antibody functions can be attained in the test tube by rational or random mutagenesis coupled with directed selection of the mutants.

The new electrophilic immunisation approach has enabled on‐demand production of next‐generation monoclonal IgGs with superior protein target neutralisation capacity made possible by irreversible target binding.

Combined innate and adaptive immunity algorithms have been applied to produce monoclonal IgM, IgA and V domains that rapidly and specifically catalyse the degradation of disease‐associated protein targets, making feasible the development of more efficacious and safer therapeutic antibodies.
Anaemia: Overview
Authors: Houston Brett L , Houston Donald S , Zarychanski Ryan
Published: July 2015

Anaemia, a decrease in erythrocyte mass that is reflected in a reduction in the haemoglobin concentration in the peripheral blood, is the most common haematologic condition for which medical attention is sought. Erythrocytes are critical to tissue oxygenation and carbon dioxide removal, and severe anaemia may lead to tissue hypoxia and organ dysfunction. Erythropoiesis is a highly regulated process controlled by erythropoietin. Adaptive mechanisms permit moderate anaemia to be well tolerated, and the clinical importance of mild to moderate anaemia is its representation of an underlying disease. Mild to moderate anaemia may be one of the first clues of an underlying disease. Although many of the signs and symptoms of anaemia are nonspecific, a pragmatic classification of anaemia based on integration of kinetic and morphologic characteristics of erythrocytes allows efficient investigation of the underlying aetiology.

Key Concepts

Anaemia is the most common haematologic condition encountered in medical practice

Erythrocytes are critical to tissue oxygenation and carbon dioxide removal

Physiologic compensatory mechanisms allow mild to moderate anaemia to be well tolerated; severe anaemia may be associated with tissue hypoxia and organ dysfunction

Erythropoiesis, the production of erythrocytes, is a tightly regulated process controlled predominantly by the synthesis of erythropoietin in response to hypoxia

The clinical significance of mild–moderate anaemia lies in its association with an underlying systemic disease; the finding of anaemia should prompt consideration of additional investigations

Classification of anaemia based on kinetic and morphologic erythrocyte characteristics allows pragmatic segregation into microcytic, macrocytic or normocytic anaemia, further directing the investigation of an underlying disease
Alcohol and Pregnancy and the Foetal Alcohol Syndrome
Authors: Bonthius Daniel J
Published: July 2015

Foetal alcohol syndrome is a specific pattern of birth defects caused by prenatal alcohol exposure. The syndrome's components include somatic growth restrictions, characteristic midface abnormalities and brain dysfunction. ‘Foetal alcohol spectrum disorders’ (FASDs) includes the broad range of offspring effects caused by prenatal alcohol exposure. Alcohol is a teratogenic drug to which the developing brain is particularly vulnerable. Alcohol induces brain injury and dysfunction in the offspring through a variety of mechanisms, one of the most important of which is neuronal death. Alcohol‐induced neurodevelopmental sequelae most often include learning disorders, attention deficits and behaviour problems. These deficits can range from mild to severe, depending on dose and timing of the alcohol exposure, maternal and foetal genetics and other conditions of exposure. Because alcohol use is so prevalent and because the developing brain is so vulnerable, FASD is the most important preventable cause of cognitive deficiency in the western world.

Key Concepts

Foetal alcohol syndrome (FAS) is a constellation of developmental abnormalities that results from maternal alcohol abuse during pregnancy.

Components of FAS include prenatal and postnatal growth restrictions, a characteristic set of midface abnormalities and central nervous system dysfunction.

‘Foetal alcohol spectrum disorders’ (FASD) is an umbrella term that encompasses the full range of adverse effects of alcohol on the offspring.

Many children who were prenatally exposed to alcohol have FASD, which most commonly manifests as neurodevelopmental problems, without having the full FAS syndrome.

The brain is the most vulnerable of the foetal organs to alcohol‐induced damage.

Alcohol damages the developing brain in a variety of ways, one of the most important of which is neuronal death.

The vulnerability of developing neurons to alcohol‐induced injury depends on a variety of factors, including the dose and timing of alcohol exposure.

Not all foetuses are equally vulnerable to alcohol‐induced injury; some possess certain genes that can increase or decrease their susceptibility to alcohol teratogenesis.

The most common neurodevelopmental problems induced by prenatal alcohol exposure are learning disorders, attention deficits and behaviour problems.

People with FASD are often particularly disabled by severe deficits in executive functions, a group of cognitive integrative behaviours that reflect the ability to self‐regulate, effectively plan, organise, keep focused on and carry out goal‐directed activity.
Frosch, Paul
Authors: Berger Silvia
Published: July 2015

Paul Frosch (1860–1928) was a German bacteriologist and a pioneer of animal virology. He worked at the Institute for Infectious Diseases in Berlin as a close co‐worker of Robert Koch, the leading figure of medical bacteriology, and became later appointed professor at the veterinary school in Berlin. On the basis of a study on typhoid, Frosch introduced the term ‘infection carrier’ for infected persons without manifest symptoms, and emphasised the role they played in spreading the epidemic. The concept subsequently became the cornerstone of epidemic control for a variety of infectious diseases in Germany. In 1898, Frosch pioneered virus research when he described the aetiological agent of the foot‐and‐mouth disease together with Friedrich Loeffler, characterising it as an ultravisible, filterable substance.
Comparative Cytogenetics
Authors: Breen Matthew
Published: July 2015

In the pre‐genomics era, the field of comparative cytogenetics was restricted to the comparison of banded chromosome preparations of the species being studied. Subsequent application of molecular biology tools to cytogenetics facilitated the development of molecular cytogenetics. In particular, fluorescence
in situ
hybridisation (
FISH
) improved our ability to compare genomes at the chromosomal and subchromosomal levels, leading to much more defined knowledge about the processes of gross chromosomal rearrangements that have occurred during evolution. In the past few years, as more whole genomes have been sequenced, the new wealth of genome information alongside enhanced technologies has advanced cytogenetic studies to a resolution far beyond that of the light microscope. This convergence of genome‐integrated resources with conventional cytogenetics catalysed the emergence of cytogenomics. Using a variety of analytical platforms, cytogenomics provides more detailed study of chromosome changes within and between species, with resolution of just a few kilobases. Within the broader field of comparative genomics, comparative cytogenetics has provided opportunities to understand more about our own genome architecture and function, in the context of the dynamic process of speciation and evolutionary change. In the biomedical arena, the field of One Medicine has embraced a comparative approach to expedite gene discovery using appropriate animal models of disease. This article briefly summarises some of the work that has resulted in a greater understanding of the comparative cytogenetics of mammals, especially in the context of their relationship to the human karyotype.

Key Concepts

Genomes of different species are organised into different chromosome numbers, sizes and morphologies (karyotypes).

While karyotypes differ, cytogenetic approaches may be used to make direct comparisons.

The emergence of high‐quality genome sequences for numerous species provides new tools to make higher resolution comparisons of the chromosome of such species.

Breakpoints along chromosomes that occur in cancer cells may be similar to those associated with speciation.

Chromosome changes in cancers may be shared between species, suggestive of an evolutionarily conserved pathogenetic mechanism.
New‐Generation Vaccine Adjuvants
Authors: O'Hagan Derek T
Published: July 2015

The currently available vaccines represent an outstanding success story in modern medicine, as they are responsible for a huge reduction in morbidity and mortality worldwide. However, it is clear that new approaches are necessary to enable the development of vaccines against more difficult pathogens, which are not yet under control, including human immunodeficiency virus (HIV), malaria and Methicillin‐resistantStaphylococcal aureus(MRSA). In addition, vaccines are necessary to counter emerging pathogen threats such as pandemic influenza and Ebola viruses. Potential improvements to current vaccines may include the addition of new adjuvants, which are able to induce more potent immune responses, more rapid responses or responses with an expanded breadth of pathogen coverage. New‐generation adjuvants are now becoming available which may enable the development of new and improved vaccines, and this is currently a very active area of research and development.

Key Concepts

Vaccines are safe and effective and have had a major impact on reducing the impact of infectious diseases in the twentieth century and continue to do so early in the twenty‐first century.

Adjuvants are included in vaccines to increase the immune response to the vaccine antigens.

Vaccine adjuvants are often necessary to enable vaccines to be effective.

Most currently available childhood vaccines contain insoluble aluminium salts as adjuvants.

To enable the development of vaccines against some more difficult pathogens, such as HIV and malaria, more potent adjuvants will be required.

New‐generation adjuvants normally comprise several components combined together to achieve the best immune response to the vaccine.

New vaccine adjuvants will have to undergo extensive safety testing before they will ever be included in licensed vaccines.

Recently, it was identified that traditional small molecular weight drugs could perform as adjuvants, opening up the possibility of discovering many more new adjuvant‐active compounds.

Formulation science is a key contributor to allow the development of safe and effective vaccine adjuvants.

It is becoming increasingly important to fully understand the mechanism of action of vaccine adjuvants, how they work is important.
Autoimmune Disease: Mechanisms
Authors: Fairweather DeLisa , Root‐Bernstein Robert
Published: July 2015

The immune system provides protection against infections and repairs tissue damage induced by physical trauma. Autoimmune disease occurs when the immune response inadvertently inflicts damage to tissues in the body. Similar features between autoimmune diseases suggest that common pathogenic mechanisms could lead to the development of autoimmune disease in genetically susceptible individuals. Activation of specific innate immune pathways is a characteristic of many autoimmune diseases. Innate immune cell activation directs antigen‐specific autoimmune T and B cells to cause tissue pathology under the influence of sex hormones. Thus, most autoimmune diseases occur predominantly in one sex or the other such as type I diabetes, Crohn's disease and myocarditis in men vs. thyroiditis, rheumatoid arthritis and lupus in women. Importantly, at least 80% of all autoimmune diseases occur in women. Current research targets these common immune mechanisms in an effort to develop better therapies and to prevent autoimmune disease.

Key Concepts

Genes and the environment contribute to the development of autoimmune diseases.

Nearly 80% of autoimmune diseases occur in women.

Sex hormones regulate inflammation and alter autoimmune disease in animal models.

Estrogens increase auto‐antibodies, which are key diagnostic criteria for most autoimmune diseases.

Many theories exist for how infections and chemicals could cause autoimmune diseases.

Microbial and/or chemical activation of innate immunity must occur at the same time as damage to self‐tissues in order for autoimmune disease to develop.

Dysregulation of peripheral immunoregulatory mechanisms is a key characteristic of autoimmune diseases.

Successful treatment of autoimmune diseases might require the targeting of multiple effector pathways.
MicroRNA
s in Cardiovascular Development and Diseases
Authors: Mishra Shivangi , Yadav Tanuja , Rani Anshu , Rani Vibha
Published: July 2015

Small molecule microribonucleic acids (miRNAs) are coming up with a huge impact on the scientific world of therapeutics and diagnostics. These 22–24 nucleotide small noncoding RNAs acting as negative gene regulators are found to be involved in a broad range of homeostasis process. One of the major health‐related concerns in current scenario is the development of heart problems leading to cardiomyopathy and heart failure in extreme conditions. The disease condition is associated with both lifestyle and genetic factors. The role of miRNAs governing the regulation of the genes involved in heart development and diseases is being studied extensively. Some of the miRNAs present abundantly in heart and regulating the process of cardiovascular development and diseases are miR‐1, miR‐133, miR‐499, miR‐208 and miR‐199b. This article presents a brief review on the roles of these miRNAs in cardiac development and diseases along with their potential in heart regeneration.

Key Concepts

A large fraction of miRNAs are expressed in heart regulating the gene expression.

miR‐1/133b, miR‐208/499 and miR‐17‐92 clusters are majorly involved in the cardiovascular systems.

An imbalance or downregulation of the crucial miRNAs is associated with the development of cardiac diseases.

Heart regeneration can be achieved by the exogenous supply of deregulated miRNAs.
Coronaviruses
Authors: Steffen Imke , Simmons Graham
Published: July 2015

Coronaviruses are important human and animal pathogens causing respiratory and gastrointestinal infections ranging from mild to severe. Two highly pathogenic human coronaviruses with high fatality rates, SARS‐CoV and MERS‐CoV, have emerged in different parts of the world in the recent past causing major public health concerns. Several unique features of coronaviruses make them likely the candidates for zoonotic transmissions into the human population: (1) their exceptionally large RNA genomes allow for increased plasticity and diversity, (2) their presence in mammalian (bat) and avian reservoir species with specialised immune functions and increased mobility facilitates their geographical spread and (3) their sophisticated molecular mechanisms of viral entry, replication and assembly involving a number of poorly studied viral accessory proteins complicates the development of suitable therapeutic strategies.

Key Concepts

Coronaviruses contain the largest known viral RNA genomes.

Bats and birds are major reservoirs for coronaviruses.

Two highly pathogenic human coronaviruses, SARS‐CoV and MERS‐CoV, have emerged since the early 2000s.

Coronavirus spike proteins are activated by a variety of proteases, often in a two‐step proteolysis process.

Many coronaviruses utilise exopeptidases as primary cellular receptors.
Hypothesis Testing in Palaeoanthropology
Authors: Makedonska Jana A , Strait David S
Published: July 2015

Hypothesis testing is used to guide scientific research by narrowing down possible explanations for a phenomenon, using the principle of elimination of alternative scenarios. Thus, scientists test hypotheses by attempting to falsify them. A hypothesis is deduced from observed patterns and aims at linking those patterns to the factors proposed to have caused it. Hypothesis testing is frequently accompanied by statistical tests of null hypotheses, focusing on the inferential analysis of sample properties such as the mean and the variance. For instance, if there is less than a 5% chance that two samples are drawn from the same entity, we reject the null hypothesis and claim that these samples are significantly different. A salient point to keep in mind when testing hypotheses is that a successful evaluation of a hypothesis depends critically on the manner in which it was formulated. Hypotheses pertaining to the origin of modern humans are reviewed and evaluated.

Key Concepts

A hypothesis links observed patterns to the factors proposed to have caused it.

Scientists do not attempt to prove that a hypothesis is true.

Hypothesis testing guides scientific research by narrowing down possible explanations for a phenomenon, using the principle of elimination of alternative scenarios.

Statistical tests assess the probability that a hypothesis is true or false.

It is important for hypotheses to specify testable predictions.

Several hypotheses have been proposed to explain the origin of modern humans.

Hypotheses explaining modern human origins each make several predictions, some of which can be readily tested using paleontological and genetic data.
Sound Bite
Authors: Bas Ozen , Grabe Maria Elizabeth
Published: July 2015

A sound bite is an audiovisual segment in which one can see and hear a speaker. In an image bite we see people without hearing them speak—instead a reporter's voiceover narration is heard. The average duration of candidate sound bites in US presidential election campaigns has shrunk from 40 seconds in the 1960s to below 10 seconds, while image bites are growing as a proportion of election coverage. These changes in size of image and sound bites have led to concerns about the media's role in presenting political candidates, in their own words, to the electorate.
Distributed Energy Systems Based on Water Electrolysis Driven by Renewable Electricity
Authors: Zhang Dongke , Zeng Kai
Published: July 2015

Renewable electricity such as wind and solar power provides a meaningful sustainable energy source for remote regions, but its intermittency in nature and inherently low power intensities and energy densities require suitable energy storage mechanisms to make it viable. Alkaline water electrolysis can serve as such a means of energy storage. This article outlines a distributed energy system concept involving water electrolysis. The promises of the distributed energy system are discussed in terms of the development and research of water electrolysis. The technical studies for water electrolysis were evaluated and assessed with current literature. By analyzing the opportunities and limitations of water electrolysis in matching their power scales with feasible renewable electricity sources, this work showed that a distributed energy system with a capacity of 200 kWis technically and economically feasible using currently available technologies, indicating the potential of this distributed system for energy supply for remote communities. This work also identifies several key areas where further R&D effort is needed in order to help deploy water electrolysis and hydrogen fuel cell technologies in the utilization of renewable energy.
Solid Oxide Fuel Cell (
SOFC
)
Authors: Desideri Umberto , Barelli Linda
Published: July 2015

Significant are the potentials of solid oxide fuel cells (
SOFCs
) for high efficiency energy generation, also through renewable sources exploitation (syngas and biogas). For these reasons, they can represent a promising technology in the transition to a low carbon economy. Nevertheless, critical technological issues affecting their durability and reliability, beyond the high cost, still impede their widespread. To deeply analyze the potentials relative to high efficiency generation, different architectures for system integration of
SOFC
and their performance are analyzed, whereas a deep analysis is provided relative to degradation mechanisms limiting the durability of cells.
Combined Heat and Power
Authors: Thorin Eva , Sandberg Jan , Yan Jinyue
Published: July 2015

Combined heat and power (CHP) is the simultaneous production of useful heat and power in an integrated process with common fuel or energy source. By integrating heat and power production, it is possible to use the energy source in a more efficient way and by that to reduce the environmental impact includingCO2emissions.

The basic process of aCHPplant can be a thermal energy process based on heat engines or a fuel cell process based on electrochemical energy conversion. The capacity can range from several hundreds of megawatts of fuel input to plants delivering electricity and heat through a district heating network of a whole city down to microCHPplants on kilowatt level supplying a one‐family house. The operating load is determined by the heat demand. For systems using a district heating network as the heat load, introducing also other heat demanding processes can be a way to increase the full‐load operating time and the yearly production of electricity from biomass.

The balance between the output of power and the heat supply is an important parameter for the performance of the plant. This is described by the ratio between the electric power and the heat power (the so‐called α‐value).

Several barriers, related both to the market and regulations, exist for implementation ofCHPand policies are necessary to be able to develop the potential in the world. TheCHPis a cost effective and important solution for reduction ofCO2emissions.
Control and Stability of Future Transmission Networks
Authors: Milano Federico
Published: July 2015

This work discusses control aspects and stability issues of future transmission networks. With this aim, several scenarios are considered, and their behavior is compared with that of a standard power system. In particular, voltage, transient, and frequency stability issues are examined. Scenarios involve changes in the generation devices, transmission lines, and transient behavior of loads. In future power networks, generators are assumed to be distributed and decoupled from the grid through voltage source converters. While AC transmission lines cannot be realistically fully substituted with other transmission devices, a high penetration of VSC‐HVDC devices and superconducting corridors is considered. Finally, loads are considered “active,” that is, able to regulate the frequency and equipped with local energy resources and storage systems. The case study, which is based on the IEEE 14‐bus system, provides a comprehensive comparison of the behavior and the stability of the conventional and future power systems.
Optimal Dispatch and Design of Microgrid System
Authors: Wang Chengshan , Guo Li , Li Peng
Published: July 2015

Microgrid, an effective organization form of distributed generation (DG), improves the operation efficiency ofDGwhile mitigating the negative impacts brought by high penetration ofDG. To achieve these goals, equipment types and capacities should be optimized at the design stage, and optimal dispatch is also essential to ensure the economical construction and operation of microgrid. Optimal dispatch and design is one of the most important research fields in the development of microgrid. Dispatch strategies can be divided into two categories: one is to obtain the optimal operation schedule based on the dispatch optimization model composed of various objective functions and constraints; the other is to adopt fixed strategies including a set of operation modes under a set of typical conditions to dispatch the microgrid in a simpler way. As the microgrid dispatch and design are strongly coupled, the effects of dispatch strategies should be considered at the design stage. Meanwhile, dispatch strategies are significantly affected by the results of the design stage. To deal with the coupling, dispatch and design of microgrid are considered simultaneously in the two‐stage optimization model of microgrid.
Carbon Trading and Carbon Market
Authors: Feng Zhen‐Hua
Published: July 2015

The Kyoto Protocol aims to present three flexible implementation mechanisms in an effort to address climate change, and thus generate a market incorporating carbon emissions as a product: joint implementation (JI); a clean development mechanism (CDM); and an international emissions trade (IET). The carbon market has rapidly developed and expanded to become the new star of global trade: in 2011, trading volume stood at 10.3 billiontCO2, with transactions amounting to $176 billion. Some current regional carbon markets include the European Union Emission Trading Scheme (EU ETS), the New South Wales (NSW), and the Regional Greenhouse Gas Initiative (RGGI); China has also tried to establish a domestic carbon trading market and has been piloting a carbon emission trading scheme since 2011. Carbon pricing lies at the heart of carbon market operation; therefore, this article analyzes challenging issues in today's carbon markets, including allowances, energy prices, and special events and also provides policy recommendations for establishing a carbon trading market.
Clean Development Mechanism Development in
C
hina
Authors: Duan Maosheng
Published: July 2015

China is the most important clean development mechanism (
CDM
) host country, accounting for more than half of registered project numbers, issued certified emissions reductions (
CERs
), and expected annual emission reductions of the registered projects. The successful development of
CDM
in China is the result of many factors, including, inter alia, significant emission reduction potential, clear domestic rules, clear and special procedures, solution‐oriented priorities at different stages, capacity building on all domestic actors, continuous capacity building, free capacity building activities, successful examples, crucial role of the
DNA
, strong domestic technical capacities, and joint efforts by various stakeholders. The development of
CDM
projects in China has generated many positive impacts in China, besides the implementation of specific mitigation activities. These impacts include but are not limited to promotion of mitigation efforts by the private sector, promotion of the development of the renewable sector, promotion of public awareness on climate change, promotion of consideration of climate change in decision making, improvement of internal management of companies, improvement of monitoring, reporting, and verification capacities, promotion of the development of low carbon technical capacities, generation of local cobenefits, and establishment of
CDM
Fund. The development of
CDM
projects in China also contributed significantly to the development of pilot carbon emissions trading systems in China.
Impacts of Impurities onCO2Pipeline Transportation
Authors: Tan Yewen , Zheng Ligang
Published: July 2015

CO2transport is an integral part in the wholeCCS(carbon capture and storage) chain. One of the most important factors affecting this part is the quality ofCO2that is being transported. This is a challenging issue because impurities inCO2vary greatly in quantity and in quality depending on the sources ofCO2. Moreover, the requirement for impurity limits also varies depending on the destination of theCO2. Currently, there is no existing regulation forCO2standard for transport. Yet, this issue could have significant impacts onCO2capture and transportation. This article reviews the operating experiences of the current existingCO2pipelines, outlinesCO2quality guidelines from different institutions, analyzes variousCO2capture technologies and related impurities, explores impurities impacts on pipeline transportation, and outlines the issues facing theCO2transport that need to be solved.
Photovoltaics: Comparison of
PV
Cell Types
Authors: Fraas Lewis M.
Published: July 2015

Photovoltaic (
PV
) cells can be categorized according to application, cell material and structure, and cost within the system application context. The three application areas are terrestrial solar, space solar, and non‐solar. For example, thermophotovoltaic (
TPV
) systems use artificial infrared energy sources at night. The three alternative cell structures are large crystallite silicon cells (mono‐ and multi‐crystal Si), small grain size or amorphous thin film cells (
CdTe
,
CIGS
, and a‐Si), and very high efficiency high power density cells (
InGaP
.
GaInAs
/Ge multijunction cells and
GaSb IR
cells). Cell and module cost are very dependent on production scale, and cell conversion efficiency is very important at the system level. Silicon cells are now dominant in the residential terrestrial solar arena. Thin film cells have intrinsic efficiency limitations because of their noncrystalline nature and have been losing market share to silicon. Multijunction solar cells now have conversion efficiencies over 40% but must be integrated into more complicated concentrator photovoltaic (
CPV
) sunlight systems.
CPV
is very promising for lower cost solar electricity for utility systems in sunny locations at the 100 MW scale but still require production volume and component supply‐chain integration. Infrared sensitive
TPV
cells can be used at night and in cold climates in residential furnaces for combined heat and power (
CHP
) complimenting solar modules on the home rooftop.
Solar Water Heating
Authors: Boehm Robert F.
Published: July 2015

One of the most durable applications of solar energy for over 100 years has been the use of the Sun to heat water. In this article, a number of topics relevant to this general thrust are given. Included are discussions of various types of collectors, how their performance can be assessed, and sources of performance information on commercial units.
Solar Thermal Power Systems inCSPApplications
Authors: Hale Mary Jane
Published: July 2015

The focus of this article is solar thermal power systems (STPS) and their role as part of concentrating solar power (CSP) technology. TheSTPSis defined as the portion of aCSPsystem where the Sun's thermal energy is converted into mechanical and electric energy. This article discussesSTPStechnologies and configurations that are appropriate for utility‐scale electricity generation, where utility scale is defined as 1 MWe, or greater. Because theCSPsolar field produces thermal energy, all sources for electricity generation considered in this article are heat engines, in particular Rankine and Brayton cycles.

The concepts of anSTPSare the same as any “conventional” power cycle incorporating a heat engine. Instead of fuel from a fossil source, for example, coal or natural gas, the solar field provides the fuel. The solar field provides fuel in the form of high‐temperature heat transfer fluid. The details of how this is done depend on the solar field technology and configuration, as well as the power cycle. This article discusses both direct and indirect system configurations of the solar field and theSTPS,as well as challenges and benefits presented by the different configurations. Included are areas of investigation in advanced cycles, primarily supercriticalCO2, forSTPSapplications.

While the focus is on theSTPS, this article emphasizes the importance of considering performance from a system level and, therefore, the influence of different solar field technologies and parameters on theSTPS.
Sustainability Assessment for Energy Technologies
Authors: Hirschberg Stefan , Burgherr Peter
Published: July 2015

Striving for sustainability enjoys a wide support. It is easy to agree that energy technologies that are climate friendly, have small impacts on human health and ecosystems, are characterized by low accident risks, are resource‐saving, exhibit high reliability of supply, are economically affordable, and have broad social acceptance come close to satisfying the basic sustainability requirements. Are such technologies available today? If not, will they be available in short, middle, or long terms? Are there transparent, scientific approaches that allow us to measure the sustainability of the various options?

The basis for comprehensive quantitative sustainability assessment is a framework for systematic comparative evaluation of energy technologies. This covers economic, environmental, and social dimensions of sustainability. Consistent, measurable, technology‐specific performance indicators are considered, for example, pollutant emissions, generation costs, and the consequences of possible accidents. The representative quantitative indicators are derived, using a variety of methods including life cycle assessment, impact pathway approach, and probabilistic safety assessment. The methodological framework is supported by large databases. Using multi‐criteria decision analysis, the derived, knowledge‐based indicators can be combined with subjective preferences of the various stakeholders. Of interest are also total costs, that is, aggregated internal and external costs.

Recent full scope applications of the framework demonstrate that the indicator‐based assessment is highly suitable for guiding in a structured manner the debate on the future energy supply and for supporting informed decisions. Sensitivity patterns with regard to such preferences are an important element of the analysis.