bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Quaternary Structure: Symmetry Patterns
Authors: Stenkamp Ronald E
Published: September 2006

Protein molecules can assemble into larger, multisubunit oligomers that possess unique quaternary structures and biological properties. The symmetry properties of these complexes are described, in particular with respect to the types of subunit–subunit interactions giving rise to the oligomers.
RNA
Structural Motifs
Authors: Tung Chang‐Shung
Published: September 2006

Chemically, ribonucleic acid (RNA) is a close cousin of deoxyribonucleic acid (DNA). RNA is, however, involved in a wide range of cellular activities (e.g. translating genetic information, serving as a structural scaffold, catalysing biological reactions) that often require the molecule to fold into a very specific structure for the purpose of performing its targeted function. Structurally and functionally, it is therefore more closely related to proteins.
Hammerhead Ribozymes
Authors: Rossi John R
Published: September 2006

The hammerhead ribozyme is an RNA‐cleaving, RNA enzyme, derived from single‐stranded RNA viroids, and virusoids, which infect flowering plants. Engineering of hammerhead ribozymes allows these RNA catalysts to be utilized for cleaving virtually any RNA target of choice, thus making them useful tools for both genetic and therapeutic applications.
RNA Structure: Roles of Divalent Metal Ions
Authors: Carter Richard J , Holbrook Stephen R
Published: September 2006

Divalent metal ions play an important role in charge neutralization and incorrectly folding RNA into its three‐dimensional structure. They also play a potentially important role in the catalytic activity of RNA.
Protein–Ligand Interactions: Induced Fit
Authors: Ma Buyong , Kumar Sandeep , Tsai Chung‐Jung , Wolfson Haim , Sinha Neeti , Nussinov Ruth
Published: September 2006

Protein–ligand interactions include two major components: protein folding and binding mechanisms; and hinge bending conformational transitions.
Biological Macromolecules: UV‐visible Spectrophotometry
Authors: Schmid Franz‐Xaver
Published: September 2006

Biological macromolecules such as proteins and nucleic acids absorb light in the UV‐visible region of the spectrum. Absorbance measurements are used for measuring concentrations, for the detection of conformational changes and of ligand binding, and for following enzyme reactions.
Parasitism: the Variety of Parasites
Authors: Phillips R Stephen
Published: September 2006

Parasitism is the association of two different animals (species) in which one benefits at the expense of the other and frequently causes serious harm in the process.
Demographic Concepts
Authors: Ebert Thomas A
Published: September 2006

This article has sections titled

Introduction

Historical Development

Life Tables

Population Growth

The Euler–Lotka Equation

The Reproductive Value Function
Coexistence
Authors: Tokeshi M
Published: September 2006

Coexistence refers to a state in which different organisms persist together in the same locality. Coexistence of species is a fundamental issue in community ecology.
Deep Ocean Ecosystems
Authors: Canganella Francesco , Kato Chiaki
Published: September 2006

The term ‘deep ocean’ typically describes any marine ecosystem located at depths greater than 500 metres. This environment is characterized by an elevated hydrostatic pressure, an average temperature of 2–4°C, the absence of sunlight, and the scarce availability of organic food. Specific organisms are associated with the deepest areas, and pressure‐adapted animals as well as microorganisms inhabit these peculiar ecosystems.
Shallow Seas Ecosystems
Authors: Bianconi Giovanna
Published: September 2006

Shallow seas are defined as marginal or inland extensions of ocean with average depths of about 200 m. They are also called coastal or neritic waters, and described as those lying landward of 200 m depth. Their contour is known as the continental shelf, and their seaward margin is known as the continental edge, which separates shallow waters from the deep ocean. The area of shallow seas accounts for 7.5% of the oceans, 18% of the land above the sea level, and 3% of the Earth's surface.
Plant Growth and Carbon Economy
Authors: Poorter Hendrik
Published: September 2006

Plant growth can be defined as the increase in biomass over time. The rate of growth depends on the daily amount of carbon fixed in photosynthesis, the amount of carbon used for respiration as well as the carbon concentration of the newly formed material.
Nutrient Acquisition, Assimilation and Utilization
Authors: McDonald A James S , Standing Dominic B
Published: September 2006

Plant growth is dependent upon the acquisition, assimilation and utilization of nutrients. Plants show many adaptations that allow for the absorption of nutrients. These adaptations allow different types of plant to survive in diverse habitats.
Ecology of Storage and Allocation of Resources: Animals
Authors: Pond Caroline
Published: September 2006

Storage of energy and other materials is essential to many aspects of animals’ ecology. Many aspects of anatomy, biochemistry and physiology maximize the efficiency of storage materials and tissues and adapt them for use under different ecological conditions.
Hibernation: Poikilotherms
Authors: Storey Kenneth B , Storey Janet M
Published: September 2006

Winter survival by cold‐blooded animals includes strategies to find insulated, secure hibernacula as well as metabolic adaptations that address stresses including low temperature, freezing, oxygen deprivation and desiccation.
Ecology of Water Relations and Thermoregulation
Authors: Houser Dorian S , Crocker Daniel E , Costa Daniel P
Published: September 2006

The interaction between animals, their water use and heat regulation.
Global Change – The Future and the Greenhouse Effect
Authors: Doney Scott C , Schimel David
Published: September 2006

Human activities are causing a significant build‐up of greenhouse gases (e.g. carbon dioxide, methane and nitrous oxide) and aerosols in the atmosphere, which is modulated in part by the land biosphere and ocean. Model projections for the next century suggest that these changes in atmospheric composition will result in substantial global warming and strengthening of the hydrological cycle, with possibly profound impacts on terrestrial and marine ecosystems.
Landscape Ecology
Authors: LaGro James A
Published: September 2006

Landscapes are dynamic assemblages of nested ecosystems that span a broad range of spatial scales. Landscape ecology is a science concerned with the biophysical and cultural patterns and processes that influence landscape structure, function and change.
Integrated Pest Management
Authors: Hoffmann Michael P , Zalom Frank G , Kuhar Thomas P
Published: September 2006

A variety of pests plague agricultural and nonagricultural settings causing economic or ecological losses. The strategy that uses multiple tactics to manage pests in a manner that poses minimal environmental, health and economic risks is integrated pest management.
Biodiversity – Threats
Authors: Sechrest Weston W , Brooks Thomas M
Published: September 2006

Any direct or indirect human activity that threatens the planet's biological diversity in the form of genes, populations, species, ecosystems, or other levels of biological organization is considered a threat to survival.
Conservation of Populations and Species
Authors: Kareiva Peter M
Published: September 2006

The conservation of populations and species requires that we identify how many and which populations have the greatest value, and then determine effective strategies for minimizing the threats to those populations. In many instances human activities have so severely imperilled species, that we must turn to habitat restoration, captive breeding, and large‐scale ecosystem management to accomplish the goal of biodiversity protection.
Mutualistic Symbioses
Authors: Saffo Mary Beth
Published: September 2006

Mutualistic symbioses are symbioses that are beneficial to both (or all) symbiotic partners; they are intricate, complex and variable in their interactions. Widely distributed both geographically and taxonomically, they play an important ecological and evolutionary role in the biosphere.
Human Disease: Effects of Economic Development
Authors: Powles John , McMichael Anthony
Published: September 2006

Economic and technical development since palaeolithic times has had both favourable and unfavourable effects on the burden of disease and injury in human populations. Pre‐modern agrarian populations with universal early marriage probably experienced the least favourable survival patterns and health levels. Over the last couple of centuries, the favourable effects of economic development on health have dramatically outweighed the unfavourable. However, some important unfavourable effects remain to be solved.
Energy Use in Agriculture
Authors: Giampietro M
Published: September 2006

The function of agriculture is to supply food and other biomass to match, in quantity and quality, the demands of population. This requires analysis from various perspectives: energy analysis is one way of describing agricultural performance and technical change, studying future trends, and assessing the human impact on ecological systems aimed at producing crops and livestock.
Physiologically‐structured Populations
Authors: Łomnicki Adam
Published: September 2006

The physiologically structured population is a concept of population ecology that rests on the premise that population properties should be derived from individual properties. Since individuals within a single population differ not only by sex and age but also in body size and food intake, these differences determine population dynamics and other population properties.
Homo neanderthalensis
Authors: Wood Bernard A
Published: September 2006

Homo neanderthalensis
is the extinct hominin species most closely related to modern humans.
Dinosaurs and the Origin of Birds
Authors: Clark James M
Published: September 2006

The close evolutionary relationship between birds and dinosaurs has been debated ever since the discovery of a fossil primitive bird,
Archaeopteryx
.
Developmental Systems Theory
Authors: Griffiths Paul E
Published: September 2006

Developmental systems theory (DST) is a wholeheartedly epigenetic approach to development and evolution. The developmental system of an organism is the entire matrix of resources that are needed to reproduce the life cycle. The range of developmental resources that are properly described as being inherited, and which are subject to natural selection, is far wider than has traditionally been allowed.
Essentialism and Human Nature
Authors: Lloyd Elisabeth A , Crowley Stephen J
Published: September 2006

Current scientific attempts to characterize human nature have roots in a philosophic view of kinds that is inapplicable to any species in the wake of Darwin's work on evolution by natural selection.
Function and Teleology
Authors: Buller David J
Published: September 2006

The biological concept of function appears teleological, implying goal directedness or purpose. Ever since the scientific revolution, however, teleology has appeared inconsistent with fundamental scientific principles. Philosophers of biology have attempted to explicate the concept of function so as to make it simultaneously teleological and scientifically acceptable.
Philosophy of Selection: Units and Levels
Authors: Brandon Robert N
Published: September 2006

A hierarchical approach to natural selection picks out the levels and units of biological organization that causally interact with the selective environment leading to differential reproduction.
Nerve Regeneration: Mammalian
Authors: Seil Fredrick John
Published: September 2006

Nerve regeneration is strictly the regrowth of an axon following injury. The term is also used more broadly, however, to cover collateral sprouting, neural plasticity, protection from secondary tissue injury, reconstitution of supporting tissues and transplantation.
Bioethics of Gene Therapy
Authors: Resnik David B
Published: September 2006

Gene therapy in human beings raises a variety of important ethical and social issues, including risks to patients and future generations, interference with natural human reproduction and the natural human form, the difference between therapy and enhancement, and human subjects protection.
Death and Dying
Authors: Rhodes Rosamond
Published: September 2006

Because of technological advances that have enabled medicine to preserve and support life and the advances that have enabled physicians to measure previously unobservable biological activities, a host of social issues involving death and dying have developed. In light of these developments society has to refine its understanding of death and develop acceptable standards for decision‐making surrounding death and dying.
Eugenics
Authors: Allen Garland E
Published: September 2006

The term ‘Eugenics’ refers to a person who is hereditarily endowed with noble qualities, but is associated with improving the hereditary quality of the human species by selective breeding.
Alpine Ecosystems
Authors: Körner Christian
Published: September 2006

Of all land area of the globe (about 151 million km
2
), the alpine life zone covers around 3% or 4.5 million km
2
, which is one‐third less than the area of the vegetated arctic life zone of North America and Eurasia (largely tundra). The alpine life zone (just as the arctic life zone) is treeless, hence its lower boundary is the climatic, high elevation treeline. Its upper boundary is the upper limit of plant life. Both these boundaries are fragmented and represent gradual transition zones. The alpine zone covers a suite of ecosystems (e.g. grass and shrub heathlands), microhabitats (e.g. rock crevices and springs) and isolated outposts of life.
Caspar, Donald L D
Authors: Morgan Gregory J
Published: September 2006

1927

–

American

biophysicist

who

helped determine the structure of
Tobacco mosaic virus
.
Trager, William
Authors: Power Helen J
Published: September 2006

1910

–

American

biologist

, specializing in

experimental protozoology and insect physiology, who developed a simple method for the continuous culture of the malaria parasite
Plasmodium falciparum
in 1976.
Garnham, Percy Cyril Claude
Authors: Power Helen J
Published: September 2006

1901

–

1994

British

protozoologist and malariologist

who with Henry E. Shortt

discovered the exoerythrocytic schizonts or tissue stage of mammalian malaria parasites

.
History of Hookworm
Authors: Power Helen J
Published: September 2006

The history of hookworm is concerned with early incidence of the disease; discovery of hookworms and their role in disease; realization of public health implications; the mode of transmission and life cycle; differentiation of the two species of intestinal nematodes,
Ancylostoma duodenale
and
Necator americanus
; and the Rockefeller campaign against the disease.
Huxley, Julian Sorrell
Authors: Waters C Kenneth
Published: September 2006

(1887–1975) British biologist and science popularizer who influenced the development of evolutionary theory, championed the idea that science should benefit society and served as first director‐general of UNESCO.
Carson, Rachel Louise
Authors: Gardner Kirsten E
Published: September 2006

1907

–

1964

American

writer and marine biologist

who

directed public attention to the misuse of pesticides with her 1962 publication
Silent Spring
.
Gallo, Robert Charles
Authors: Harden Victoria A
Published: September 2006

(b. 1937) American scientist who demonstrated the retroviral cause of AIDS.
Goodall, Jane
Authors: Gardner Kirsten E
Published: September 2006

1934

–

British

ethologist

who

revolutionized behavioural studies of chimpanzees

.
Philosophy of Ecology
Authors: Taylor Peter J , Haila Yrjö
Published: September 2006

A key challenge in conceptualizing ecological complexity is to allow simultaneously for particularity, contingency and structure – structure, moreover, that changes, is internally differentiated, and has problematic boundaries. Given that all organisms live in dynamic ecological contexts, philosophy of ecology raises more general questions about conceptualizing the positionality of humans and other organisms in their intersecting worlds.
Sertürner, Friedrich Wilhelm
Authors: Sneader Walter
Published: September 2006

1783–1841 German apothecary who isolated morphine from opium.
Schmiedeberg, Oswald
Authors: Muscholl E
Published: September 2006

1838–1921 Russian‐born German pharmacologist who established experimental pharmacology as a biological science and brought worldwide recognition to this discipline.
History of Sulfonamides
Authors: Sneader Walter
Published: September 2006

The sulfonamides were the first effective antibacterial drugs. As they were developed a decade before the general introduction of antibiotics, bacteria began to acquire resistance to them as a consequence of their overuse.
Brugada Syndrome
Authors: Brugada Pedro , Brugada Ramon , Brugada Josep
Published: September 2006

The
Brugada syndrome
is a hereditary disease causing sudden cardiac death in apparently healthy individuals with a structurally normal heart. The disease is caused by mutations in the cardiac sodium channel gene
SCN5A
, which result in abnormal electrocardiographic findings. When left untreated, or treated with presently available antiarrhythmic drugs, patients with Brugada syndrome have a high mortality rate (approximately 10% per year). At present, the only effective treatment to prevent sudden death is the implantable defibrillator.
Digestive System of Invertebrates
Authors: Fankboner Peter V
Published: September 2006

Digestion by invertebrates is nominally in two phases: extracellular breakdown of food followed by intracellular digestion; protist invertebrates digest foodstuffs by intracellular means. Invertebrate digestion differs from that of vertebrates in that the former lacks digestive glands opening into the hindgut.
Parent–Offspring and Sibling Conflict
Authors: Kilner Rebecca M
Published: September 2006

Parent–offspring conflict arises when the optimal level of parental care that offspring would choose to receive exceeds the optimal level of parental care that a parent would prefer to provide. For example, when a parent is identically related to the members of its brood, it may prefer to divide resources equally among its young. By contrast, the individual offspring value their own well being more highly than their siblings and so should try to take a disproportionate share of food. By taking resources from their siblings, individual offspring can additionally cause sibling conflict.
Gymnosperms
Authors: Meidinger Del
Published: September 2006

Gymnosperms are a diverse group of plants with the common characteristic of having a ‘naked’, or unprotected, seed. Historically common, today only about 900 species exist worldwide. Though found in a wide variety of habitats, gymnosperms dominate many northern hemisphere landscapes.
Angiosperms
Authors: Chase Mark W
Published: September 2006

The angiosperms or flowering plants are the largest group of terrestrial, photosynthetic organisms, with perhaps 250 000–300 000 species occurring on all continents, including within the Arctic Circle and Antarctica.
Eudicots
Authors: Soltis Douglas E , Soltis Pamela S
Published: September 2006

A major clade of flowering plants, comprising approximately 75% of all flowering plants and characterized by pollen having three apertures (lines of weakness).
Magnoliales
Authors: Sampson F Bruce
Published: September 2006

The order Magnoliales is a member of the most basal sub‐class of angiosperms, the Magnoliidae, and is made up of three families, the relatively large family Magnoliaceae and two small families, Himantandraceae and Degeneriaceae.
Poales (Grasses)
Authors: Jacobs Surrey WL , Wilson Karen L
Published: September 2006

The Poales include the well‐known and economically important grass family (Gramineae), the well‐known sedge family (Cyperaceae), the colourful bromeliads (Bromeliaceae) and several less well‐known families of plants. All belong to the group of flowering plants known as the monocotyledons.
Malpighiales
Authors: Hoffmann Petra
Published: September 2006

The order Malpighiales belongs to the eurosid I clade of the eudicots in the angiosperms (flowering plants). It contains about 30 to 40 plant families (depending on the taxonomic concept adopted),
c
.725 genera and 16 000 to 17 000 species.
Brassicales (Mustard)
Authors: Rodman James Eric
Published: September 2006

The eudicot order Brassicales comprises the mustards (Brassicaceae), capers (Capparaceae) and several smaller families, and also includes the genomic model
Arabidopsis
. The name Capparales is common in older taxonomic literature.
Malvales (Mallow)
Authors: Whitlock Barbara A
Published: September 2006

Malvales are a large and diverse group of trees and shrubs found mostly in the tropics and subtropics.
Gentianales (Coffees, Dogbanes, Gentians and Milkweeds)
Authors: Struwe Lena
Published: September 2006

The angiosperm order Gentianales includes the Apocynaceae (dogbanes and milkweeds), Gelsemiaceae, Gentianaceae (gentians), Loganiaceae (strychnine plants) and Rubiaceae (coffee and madder plants). They are found worldwide in most climates, but are most abundant in the tropics.
Dipsacales (Honeysuckle)
Authors: Backlund Anders
Published: September 2006

The plant order Dipsacales comprises about 2000 species belonging to the eight core families Adoxaceae, Caprifoliaceae, Collumelliaceae, Diervillaceae, Dipsacaceae, Linnaeceae, Morinaceae and Valerianaceae. It includes many ornamental plants such as honeysuckle and weigela.
Electrophoresis and Blotting of
DNA
Authors: Tamber Sandeep , Hancock Robert EW
Published: September 2006

DNA electrophoresis and blotting are techniques commonly used to visualize DNA. Electrophoresis uses gels to separate DNA molecules on the basis of size; whereas blotting allows researchers to identify specific DNA fragments on the basis of their sequences.
Transformation of Competent Bacterial Cells: Electroporation
Authors: Anthony R
Published: September 2006

Electroporation has become a valuable technique for the transfer of DNA into eukaryotic and prokaryotic cells. It is currently the most efficient means of transferring DNA, with efficiencies 20 times higher than obtained with maximally competent cells prepared with calcium chloride (CaCl
2
). Chemical transformation using CaCl
2
is generally used for routine transformation when the DNA sample is not limiting. Electroporation is particularly useful in applications where high transformation efficiencies are specifically required. In essence, fast growing cells are centrifuged and washed in ice‐cold water. They are placed in a cuvette with the DNA and a high‐voltage pulse is applied. Cells are then plated out and selected for on agar.
Protein Quantitation: Lowry Protocol
Authors: Gebauer W
Published: September 2006

Protein quantitation according to the protocol of Lowry.
Isolation of DNA from Low Gelling Temperature Agarose
Authors: Southern Edwin M
Published: September 2006

One of the advantages of the use of low gelling temperature agarose for gel electrophoresis is that it is easy to recover DNA and RNA from the gel by melting it and extracting it with phenol.
Long‐range PCR
Authors: Wilton S
Published: September 2006

The polymerase chain reaction (PCR) has been used extensively in the amplification of DNA fragments where there is a general size preference for products less than 1000 bp. Larger products may be synthesized at low or inefficient levels and then normally after considerable effort in reaction optimization. While
Taq
DNA polymerase has remained the thermostable polymerase of choice for most PCRs, this enzyme is not efficient in the amplification of large DNA fragments. This limitation is thought to be due to the error‐prone nature of the
Taq
polymerase, whereby those transcripts that end in an error (a misincorporated base) are not efficiently reinitiated and extended. The combination of two thermostable DNA polymerases such as
Taq
and another enzyme with superior editing (proof‐reading) ability minimizes misincorporation and facilitates the amplification of long (reportedly over 40 kb) PCR products.
Immunofluorescence: Protocol
Authors: Liddell JE
Published: September 2006

Immunocytochemistry is the only immunoassay in which antigen can be localized to its position
in vivo
in cells and tissues.
Separation of RNA and DNA in Methylmercuric Hydroxide Denaturing Agarose Gels
Authors: Southern Edwin M
Published: September 2006

RNA molecules tend to aggregate in solution and adopt a range of conformations that can affect the mobility of molecules. In addition, nuclease nicks are often not revealed by nondenaturing electrophoresis. For this reason, it is often preferable to separate nucleic acids as denatured molecules. The use of gels containing millimolar amounts of methylmercuric (II) hydroxide as the denaturing agent is described. Heating and other operations must be carried out in an efficient fume hood because methylmercury (II) hydroxide is extremely poisonous, and it should be used and disposed of in accordance with the supplier's instructions.
Denaturation of RNA Using Glyoxal
Authors: Southern Edwin M
Published: September 2006

RNA normally exhibits a high degree of secondary structure and aggregation. By treating RNA with glyoxal the RNA molecules can be completely denatured and assume random coil configurations.
Site‐directed Mutagenesis of Double‐stranded Plasmids
Authors: Jones P
Published: September 2006

Site‐directed mutagenesis can be used to mutate DNA fragments inserted into plasmid vectors using one oligonucleotide and three restriction enzymes.
Preparation of Nuclei from Rat Liver using Sucrose
Authors: Graham John M
Published: September 2006

Nuclei can be prepared from rat liver using sucrose.
Somitogenesis in Vertebrate Development
Authors: Takahashi Yoshiko
Published: September 2006

Somites are transient embryonic structures that undergo periodic segmentation and that form skeletal muscles, dermis and axial bones (vertebral column and ribs). Recent studies have revealed the molecular mechanisms underlying the specification and differentiation of the somitic cells as well as giving an understanding of how their segmental periodicity is generated.
Alternative Splicing: Cell‐type‐specific and Developmental Control
Authors: Valcárcel Juan , Smith Christopher WJ
Published: September 2006

Alternative splicing is a process that allows individual genes to produce multiple functionally distinct protein isoforms. The production of alternatively spliced isoforms is usually controlled in a cell type or developmentally regulated manner.
Genetic Screening and Testing
Authors: Rowley Peter T , Saller Devereux N , Shapiro Robert E
Published: September 2006

Genetic screening is the systematic search in a population for individuals with a particular genetic disease or genotypes. The usual purpose is to detect persons who themselves are at risk or whose offspring are at risk for a genetic disease or a genetically determined susceptibility to an environmental agent. Genetic testing is performed to determine the genotype of an individual suspected of having a mutation because of suggestive clinical features or a genetic relationship to a person known to have the genetic abnormality in question.
Prostate Cancer
Authors: Evans Christopher P , Busby J Erik
Published: September 2006

The prostate is a walnut‐sized gland located between the bladder and external urinary sphincter through which the urethra passes. The primary function of the prostate is to produce the fluid that accompanies the ejaculate; hence, it is important in reproduction. Adenocarcinoma of the prostate is the fourth most commonly diagnosed cancer in men worldwide.
Ageing Genes: Gerontogenes
Authors: Rattan Suresh IS
Published: September 2006

The idea of gerontogenes is in line with the evolutionary explanation of the ageing process as being caused by the absence of maintenance and repair, rather than an active, evolutionarily selected process. The term ‘gerontogenes’, therefore, refers to an altered state of those genes that influence ageing and longevity.
Ribosomal Proteins in Eukaryotes
Authors: Bommer Ulrich‐Axel , Stahl Joachim
Published: September 2006

About 80 different ribosomal proteins are involved in the biogenesis and functioning of eukaryotic ribosomes. Genome sequencing efforts have contributed to our knowledge on their evolution, and recent progress in the structural analysis of the ribosome has considerably improved our understanding of the localization and function of individual ribosomal proteins, some of which are also involved in extraribosomal functions.
Meiotic Recombination Pathways
Authors: Bishop Douglas K
Published: September 2006

Reciprocal recombination between homologous chromosomes in meiosis plays a critical role in promoting accurate reductional chromosome regulation. Meiotic recombination is highly regulated to ensure that at least one reciprocal crossover event occurs between each pair of homologous chromosomes.
Glycolysis Regulation
Authors: Lopaschuk Gary D , Dyck Jason RB
Published: September 2006

Glycolysis provides an important source of energy for most cells as well as a source of substrate for a number of other metabolic pathways. Its regulation is complex, involving allosteric control, phosphorylation control and transcriptional control of glycolytic enzymes. Modulation of fructose 2,6‐bisphosphate has emerged as one of the key sites at which glycolysis is controlled.
Iron Cofactors: Nonhaem
Authors: Fox Brian G
Published: September 2006

Proteins and enzymes with nonhaem iron centres display many functions: metal centres with primarily sulfur ligation are involved in electron transfer, electrophilic activation of hydroxyl groups, regulation of gene expression and fixation of N
2
; mononuclear and diiron centres with oxygen and nitrogen ligation have roles in various reactions with O
2
and in hydrolysis. The principles of their mechanisms of action are beginning to emerge from the considerable experimental data obtained on these proteins. Future research will attempt to extend this mechanistic understanding and to manipulate the enzymes to extend their already substantial catalytic capabilities.
Termination of Replication in Bacteria
Authors: Duggin Iain G , Wilce Jackie A
Published: September 2006

In the case of a circular bacterial chromosome, termination of DNA replication occurs when the two replication forks, progressing in opposite directions, meet and fuse in a specific region of the chromosome, which is generally diametrically opposed to the site of initiation of DNA replication. Most research has focused on the systems utilized by the rod‐shaped Gram‐negative
Escherichia coli
and Gram‐positive
Bacillus subtilis
.
Protein–DNA Interactions
Authors: Rooman Marianne , Wintjens René
Published: September 2006

The control of the information stored in the genome is managed by DNA‐binding proteins, which are therefore of fundamental importance to cellular life. A wide diversity of such proteins, exhibiting various DNA‐binding modes, specificities and functions, is observed in all living organisms.
Urea Cycle
Authors: Tuchman Mendel
Published: September 2006

The mammalian urea cycle, discovered by Krebs and Henseleit in 1932, takes place in the liver. It is the main chemical pathway used by ureotelic species to dispose of ammonium nitrogen by converting it into urea, which is much less toxic and efficiently excreted by the kidneys.
Uric Acid Metabolism
Authors: Skinner Kelly A , Parks Dale A , Khoo Nicholas H
Published: September 2006

Nitrogenous compounds are continuously derived from digestion of proteins in ingested food, degradation of nucleic acids, purine salvage pathways,
de novo
purine biosynthesis, and purine nucleotide interconversion. Nitrogenous waste products are highly toxic; therefore, efficient mechanisms of elimination have evolved, that are optimally suited for the particular class of organism. All animals excrete three main nitrogenous products – ammonia, urea and uric acid – as well as minor nitrogen excretory products.
RecA Protein
Authors: Bianco Piero R , Kowalczykowski Stephen C
Published: September 2006

The RecA protein ofEscherichia coliis the prototypic deoxyribonucleic acid (DNA) strand exchange protein. It assembles on single‐stranded DNA to form a helical nucleoprotein filament that is the active species for all RecA protein‐dependent functions. This protein–DNA complex is responsible for three mutually exclusive functions: DNA recombination, induction of the DNA‐damage SOS response and SOS‐induced mutagenesis.
Gluconeogenesis
Authors: Wallace John C , Barritt Greg J
Published: September 2006

The gluconeogenic pathway, which is found in the liver and kidney, involves the synthesis of glucose from three‐carbon precursors such as lactate, alanine and glycerol. The main function of gluconeogenesis is to supply glucose to tissues, such as the brain and red blood cells, that depend on glucose as their main or sole energy source.
Eukaryotic Ribosomes: Assembly
Authors: Raué Hendrik A
Published: September 2006

Eukaryotic ribosomes contain one copy of each of four different RNA species and about 80 different proteins. These components are assembled into ribosomal subunits in an ordered manner as the precursor ribosomal RNA is processed into the mature form. Pre‐rRNA processing and assembly takes place largely in the nucleolus with later stages occurring in the nucleoplasm and finally the cytoplasm. It requires numerous accessory factors, including a large number of small nucleolar ribonucleoprotein particles (snoRNPs).
Apoptosis: Morphological Criteria and Other Assays
Authors: Gobé Glenda , Harmon Brian
Published: September 2006

Apoptosis is a morphologically and biochemically distinct mode of cell death that uses the cell's own genetic control for death to occur. It is central to many normal physiological processes such as morphogenesis, homeostasis and differentiation and, in disease, ‘apoptosis’ is responsible for loss of functioning tissue as well as the control of proliferation in disorders such as neoplasias and cancers.
Vaccination
Authors: Nossal Gustav JV
Published: September 2006

Vaccination is the generic term for immunization procedures. Immunization is a procedure whereby living or nonliving materials are introduced into the body in order to stimulate the defence system, namely the lymphoid tissues, with a view to rendering a person or animal immune to a disease.
Antigens: Lipids
Authors: Matsuda Kazuhiro
Published: September 2006

Phospholipids and glycolipids are the major components of biomembranes. Immune responses against them are implicated in several human diseases and in recognition by higher organisms of microbial infections. Structural analysis of lipid antigens is important for understanding the mechanisms of molecular interactions and the pathogenesis of immune abnormalities.
Antibody Classes
Authors: Wingren Christer , Alkner Ulf , Hansson Ulla‐Britt
Published: September 2006

Antibodies are glycoproteins belonging to the immunoglobulin family. The immunoglobulins have a common four‐chain structure (two identical light chains and two identical heavy chains) and they can be divided into different classes (and subclasses) according to the isotype of the heavy chain. The heavy chain isotype will confer different structural and functional properties on each antibody class, so that each isotype will occupy a specific site in the body and have a specific role to play in the immune system.
Major Histocompatibility Complex (MHC)
Authors: Penn Dustin J , Ilmonen Petteri
Published: September 2006

The major histocompatibility complex (MHC) contains the most diverse genes known in vertebrates, the class I and II loci. These highly polymorphic genes encode cell surface receptors that play a central role in controlling immunological self/nonself recognition, and subsequently, tissue rejection, autoimmunity and immune responses to infectious diseases. The polymorphisms of MHC genes have been maintained by natural selection over long periods of evolutionary time.
Plasminogen Activation System
Authors: Andreasen Peter A
Published: September 2006

The plasminogen activation system is a vertebrate extracellular enzyme system consisting of serine proteases, protease inhibitors of the serpin family and various binding proteins. The plasminogen activation system generates extracellular proteolytic activity for physiological and pathophysiological fibrinolysis and tissue remodelling.
Immunological Synapse
Authors: Valitutti Salvatore , Espagnolle Nicolas
Published: September 2006

The immunological synapse is a specialized signalling domain formed at the contact site between cells of the immune system characterized by large‐scale clustering and segregation of surface molecules and intracellular signalling components. The molecular dynamics taking place at the immunological synapse is the manifestation of a sustained and elaborate cell–cell information transfer.
T Lymphocytes: Regulatory
Authors: Fehervari Zoltan , Sakaguchi Shimon
Published: September 2006

Regulatory T cells play a central role in the immune system by potently controlling the responses of other immunocytes. Their activity appears to be essential not only for the maintenance of immunological tolerance but also in the control of all physiological immune responses whether against normal self proteins, microbes or cancerous cells.
Plasma Cells
Authors: Minges Wols Heather A
Published: September 2006

Plasma cells are terminally differentiated B lymphocytes that provide protective immunity through the continuous secretion of antibodies. Antibody‐secreting cells develop in secondary lymphoid tissue following antigen stimulation and may enter a short‐lived plasma cell population that reside primarily in the nonlymphoid area of the spleen or lymph nodes, or instead may migrate to the bone marrow where the majority enter a long‐lived population of plasma cells.
Bird Song: Steroid Hormones and Plasticity
Authors: Wade Juli
Published: September 2006

In many species of birds, males sing to court females and to defend territories or nest sites, whereas females sing little, if at all. This behavioural sex difference is paralleled by sexual dimorphisms in neural and peripheral structures involved in song production. In adulthood, singing is generally activated by gonadal steroids, such as testosterone, but the role that these hormones play in the natural development of the structural and functional sex differences is at present an intriguing mystery.
Nicotinic Acetylcholine Receptors in Neurons
Authors: Dani John A , Lester Robin AJ
Published: September 2006

Nicotinic acetylcholine receptors are members of a superfamily of ligand‐gated ion channels, all of which play a key role in synaptic transmission throughout the nervous system.
Nervous and Immune System Interactions
Authors: Dunn Adrian J
Published: September 2006

Several mechanisms by which the nervous and immune systems might interact have now been recognized. The nervous system may affect immune function via direct innervation of immune organs and by secretion of hormones from the pituitary and other endocrine organs. Conversely, cells of the immune system may influence nervous system function by secretion of a variety of chemical messengers, among which cytokines are the best recognized. Also, although classically the brain was considered ‘immunologically privileged’, it is now recognized that cells of the immune system may be active in the brain, and that this may be an important factor in many central nervous system (CNS) diseases.
Cluster Headache
Authors: Jay Gary W
Published: September 2006

Cluster headache is an excruciatingly painful problem, a ‘suicide headache’. It is secondary to various manifestations of autonomic nervous system dysfunction. Correct diagnosis is clinically mandatory and must be followed with appropriate abortive and prophylactic medications.
Benzodiazepines
Authors: Möhler Hanns
Published: September 2006

Benzodiazepines are a group of drugs with wide application as tranquillizers, hypnotics, muscle relaxants and anticonvulsants. They act by enhancing γ‐aminobutyric acid (GABA)ergic synaptic inhibition in the brain.
Microglia
Authors: Stoll Guido , Jander Sebastian
Published: September 2006

Microglia are resident brain macrophages that respond to even minor pathological events in the central nervous system. Microglia phagocytose debris, present antigens to T cells and contribute to brain damage by production of neurotoxic factors.
Repetitive Action Potential Firing
Authors: Canavier CC , Baxter DA , Byrne JH
Published: September 2006

The biophysical basis of repetitive action potential firing can be understood in terms of the opposing positive and negative feedback processes that generate the repetitive activity. The relative time scales of these processes, which can include ion channel activation and inactivation as well as ion accumulation within a cell, are a key factor in the generation of repetitive single‐spike firing, intrinsic burst firing and network burst firing.
Adrenaline and Noradrenaline: Introduction
Authors: Stanford S Clare
Published: September 2006

Adrenaline and noradrenaline are found in the adrenal gland and in neurons of the peripheral (autonomic) and central nervous systems. Synthesis of these catecholamines is tightly regulated and ensures that their supply is coupled to the rate of their release. Both adrenaline and noradrenaline help to maintain internal body state (‘homeostasis’) but, in the brain, they are thought also to influence arousal and mood.
Oestrogen Regulation of Sexual Behaviour, Mood and Cognition
Authors: Almeida OFX , Condé GL , Sousa N
Published: September 2006

Oestrogens are steroid hormones that act through specific receptors in the brain to influence sexual behaviour, as well as mood and cognition. Oestrogen actions include alterations of neuronal excitability, neurotransmitter synthesis and metabolism, neuronal circuitry and neuronal survival, one or all of which may contribute to their effects on mood and cognition.
Identification of Protein–Protein Interactions
Authors: Mitchell Julie C
Published: September 2006

Protein–protein interactions are the mechanisms underlying many important biological processes. Prediction of protein–protein interactions is performed using a variety of computational methods that employ both ‘first principles’ biophysical calculations as well as knowledge‐based informatics techniques.
Crustacea (Crustaceans)
Authors: Blackstone Neil W
Published: September 2006

The Crustacea is a subphylum of arthropods defined by the nauplius larva, two pairs of antennae and biramous second antennae.
Messel
Authors: Schaal Stephan
Published: September 2006

The Messel site became famous with the discovery of its extraordinarily well‐preserved fossils of Middle Eocene age. The fauna and flora suggest a European subtropical rainforest 47 million years ago (Mya). The spectrum of fossil species at this site is unusually extensive.
Extinction
Authors: MacLeod Norman
Published: September 2006

Extinction is the act or process of dying‐out of a species or evolutionary lineage. It is one of the commonest of all ecological/evolutionary processes and represents the inevitable corollary of natural selection. Information on extinction comes from many sources, including laboratory experiments, field studies and the fossil record. The causes of short‐term extinctions involving few species can, in principle, be well understood. The causes of long‐term extinction events, such as those preserved in the fossil record, remain controversial.
Extinction: End‐Permian Mass Extinction
Authors: Erwin Douglas H
Published: September 2006

The end‐Permian mass extinction was the most pervasive biotic crisis in the history of life. About 90% of marine species and some 70% of land species became extinct in two pulses separated by about 10 million years.
Population Genetics: Multilocus
Authors: Shpak Max , Gavrilets Sergey
Published: September 2006

Multilocus population genetics is the study of the distribution and dynamics of genetic variation at several loci in biological populations.
Signal Transduction Pathways in Development and Immunity: Rel Pathways
Authors: Gilmore Thomas D , Ip Y Tony
Published: September 2006

The Rel signal transduction pathway is conserved from insects to humans and controls a variety of processes involved primarily in immunity and development. Misregulation of this pathway has also been implicated in several human disease states.
New World Monkeys
Authors: Hartwig Walter Carl , Rosenberger Alfred L
Published: September 2006

New World monkeys are the living (nonhuman) primates of South and Central America.
Primates (Lemurs, Lorises, Tarsiers, Monkeys and Apes)
Authors: Rosenberger Alfred L , Hartwig Walter C
Published: September 2006

Primates are an order of mammals characterized by a generalized arboreal anatomy and relatively large brains. Primates are found throughout the tropics and temperate latitudes of the world and are among the most endangered of all mammalian orders.
Regeneration of Vertebrate Tissues: Model Systems
Authors: Stocum David L
Published: September 2006

The three mechanisms of tissue regeneration in vertebrates are exemplified by several regenerating tissues used as experimental models in mammals and amphibians. Several strategies can be used to restore tissues that do not normally regenerate.
Caenorhabditis elegans Embryo: Establishment of Asymmetry
Authors: Rose Lesilee S , Basham Stephen E
Published: September 2006

In
Caenorhabditis elegans
, anterior/posterior asymmetry is established in the one‐cell embryo in response to the sperm's position. Polarity proteins become localized in cortical domains and function to produce asymmetric expression patterns of regulators of developmental fate.
Viruses and Plant Disease
Authors: Plumb Roger T
Published: September 2006

Viruses are sublight‐microscopic infectious particles, often spread by a range of invertebrate species, especially insects, which can cause disease in plants. Plants can be killed but more often show a range of symptoms including leaf variegation and discoloration, mottle, mosaic, distortion and stunting.
Mumps Virus
Authors: Duprex W Paul , Rima Bertus K
Published: September 2006

Mumps virus
is a nonsegmented negative‐stranded ribonucleic acid (RNA) virus belonging to the family
Paramyxoviridae
, which causes a childhood disease characterized by swelling of the salivary glands (parotitis) and the testes (orchitis).
Syphilis
Authors: Wright David JM , Norris Steven J
Published: September 2006

Syphilis is a sexually transmitted disease caused by the bacterium
Treponema pallidum
subspecies
pallidum
. It is usually classified as having an infectious phase, primary and secondary lesions, and the now less common noninfectious late stages. Diseases transmitted by nonsexual skin‐to‐skin contact (usually during childhood or adolescence) are caused by the closely related organisms
T. pallidum
subsp.
pertenue
(which causes yaws),
T. pallidum
subsp.
endemicum
(endemic syphilis) and
T. carateum
(pinta).
Luteoviruses
Authors: Brault Véronique , Herrbach Etienne
Published: September 2006

Luteoviruses are plant viruses which can infect a wide range of host plants. They have icosahedral particles, are limited to the phloem tissue of the plant and are only transmitted by aphids.
Reoviruses
Authors: Tran Anh T , Coombs Kevin M
Published: September 2006

Reoviruses are infectious agents, transmitted by respiratory and faecal–oral routes, which are not major human pathogens. The viruses are distinguished by having a genome of 10 segments of double‐stranded ribonucleic acid (dsRNA) that is located inside a double‐layered, spherical nonenveloped protein capsid. The capsid is incompletely uncoated during viral replication.
Bornaviruses
Authors: Lipkin W Ian , Briese Thomas
Published: September 2006

Borna disease virus
is a neurotropic, nonsegmented negative‐strand ribonucleic acid (RNA) virus that is currently the only known member of the family
Bornaviridae
within the order
Mononegavirales
. It appears to be distributed worldwide and has the potential to infect most, if not all, warm‐blooded hosts, causing disorders of the central nervous system.