bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phospholipases: Degradation of Membrane Phospholipids
Authors: Fisher Aron B , Jain Mahendra 
Published: September 2006

Abstract
Phospholipases are interfacial enzymes that degrade phospholipids through hydrolytic cleavage. They participate in a broad spectrum of important physiological functions and pathophysiological processes through modification of phospholipids and generation of products that are potent regulators and messengers. These processes are controlled at enzymological and gene expression levels, and thus their effects range over periods of minutes to days.
Sulfide: Biosynthesis from Sulfate
Authors: Verschueren Koen HG , Wilkinson Anthony J 
Published: September 2006

Abstract
The uptake and reduction of inorganic sulfate and its subsequent assimilation into organic biomolecules is an elaborate and energy‐consuming process. This pathway, involving many enzymes, is tightly regulated to control the production of reactive intermediates and to ensure that the flux through the pathway matches the cell's requirements for reduced sulfur.
Fibrinogen and Fibrin
Authors: Doolittle Russell F 
Published: September 2006

Abstract
Fibrinogen is a soluble plasma protein that is converted to fibrin polymer in response to damage to the vascular system. The clotting process is initiated when platelets aggregate at the wound site. Their disruption releases biologically active amines and a proteolytic cascade follows which culminates in the conversion of fibrinogen to fibrin. The fibrin polymer forms the matrix of the tangle of cellular and molecular substances called the blood clot.
Vitamin
K
: Structure and Function
Authors: Booth Sarah L , Saltzman Edward 
Published: September 2006

Abstract
Vitamin K is a cofactor specific to the vitamin K‐dependent γ‐glutamyl carboxylase and the formation of the amino acid γ‐carboxyglutamic acid (Gla). Numerous Gla‐containing proteins have been identified to date, including those involved in blood coagulation, but there are still significant gaps in knowledge about the physiological roles of many of these proteins.
Bacterial Genetics
Authors: Klotz Martin Günter 
Published: September 2006

Abstract
Bacteria have existed on planet Earth for more than 3.7 billion years and, since then, they have conquered virtually every life‐supporting habitat by evolving a wide variety of lifestyles through ongoing changes (by mutation and recombination) in their genomes. The understanding of how the heritable material (genotype) determines structure and function (phenotype) of bacteria is the subject of bacterial genetics.
Bacterial Membrane Transport: Organization of Membrane Activities
Authors: Maloney Peter C 
Published: September 2006

Abstract
Bacteria have transport systems enabling them to accumulate needed nutrients, extrude unwanted byproducts and modify their cytoplasmic content of salts so as to maintain a composition conducive to growth and development. Most bacterial transport systems resemble their counterparts in eukaryotic cells, and similar principles operate in both cell types. Because bacterial transporters are often easier to deal with experimentally, they have become important models for their eukaryotic brethren.
Group Translocation – PEP:PTS
Authors: Maloney Peter C , Postma Pieter 
Published: September 2006

Abstract

The phosphoenolpyruvate (PEP):carbohydrate
phosphotransferase
system (PTS) is a bacterial transport system that phosphorylates its carbohydrate substrates during their transport, leading to intracellular accumulation of the respective phosphoryl esters. In mixtures of carbon sources, preferential growth on PTS substrates often occurs, as the phosphorylation state of PTS proteins coordinates the activity and synthesis of enzymes of intermediary metabolism.
Glycolipids: Distribution and Biological Function
Authors: Brandenburg Klaus , Holst Otto 
Published: September 2006

AbstractGlycolipids are amphiphilic components of cell membranes, composed of a hydrophilic polar sugar headgroup (backbone) and a hydrophobic apolar lipid moiety anchoring the molecule in the membrane. According to their detailed chemical structure, in particular of the sugar part, these compounds may fulfil a variety of biological functions important for many processes in life.
Complement Regulatory Proteins
Authors: Meri Seppo , Jarva Hanna 
Published: September 2006

Abstract
Complement regulatory proteins are plasma and cell membrane molecules that regulate complement activation and protect host cells against complement damage. Certain diseases, such as hereditary angio‐oedema, membranoproliferative glomerulonephritis and paroxysmal nocturnal haemoglobinuria, are caused by complement regulator deficiency.
Hypersensitivity: Stimulatory (Type V)
Authors: Weetman Anthony P 
Published: September 2006

Abstract
Type V hypersensitivity is the final type of hypersensitivity in which antibodies are produced with the property of stimulating specific cell targets. The clearest example is Graves disease caused by antibodies that stimulate the thyroid‐stimulating hormone receptor, leading to overactivity of the thyroid gland.
Immunization of experimental animals
Authors: de Souza J Brian 
Published: September 2006

AbstractEffective vaccines are urgently required for some of the major killer diseases such as human immunodeficiency virus (HIV), tuberculosis (TB), malaria and cancer. This challenge can only be realized through a better understanding of the interplay between pathogen (or tumour) and the host's immune system. While epidemiological surveys and variousin vitrostudies provide useful leads, experimental animals are powerful tools for the manipulation of the immune responsein vivoand remain central to our understanding of the body's response to infection. They afford a means of analysing the different roles played by the various components of the immune system in providing protection against disease and of devising methods of enhancing and accelerating this protection by immunization.
Chromosome Mechanics
Authors: Moore Charleen M , Best Robert G 
Published: September 2006

Abstract
Chromosome mechanics describes the processes of chromosome replication and behaviour as they relate to somatic cell division and gametogenesis. Mitosis produces identical diploid somatic cells, whereas meiosis produces haploid germ cells with recombination of parental alleles. Aberrations occur in these processes that include chromosomal nondisjunction leading to numerical abnormalities and unrepaired DNA damage resulting in chromosomal breakage and structural rearrangements.
Chromosomal Genetic Disease: Numerical Aberrations
Authors: Robinson Wendy P , McFadden Deborah E 
Published: September 2006

Abstract
Numerical aberrations represent a significant proportion of chromosomal changes found in humans. These errors can occur in meiosis or mitosis and therefore be constitutive (present in all cells) or mosaic (present in some cells). They represent a significant cause of pregnancy loss as well as abnormalities found in livebirths.
Sickle Cell Anaemia
Authors: Nagel Ronald L 
Published: September 2006

Abstract
Sickle cell anaemia is a genetic disease, whose indispensable feature is the presence of a mutation in the beta globin gene that specifies one of the chains of haemoglobin. This mutation endows the haemoglobin with a new property: the capacity of polymerizing when deoxygenated. This mutation has several untoward consequences: haemolytic anaemia, acute chest syndrome, stroke, renal insufficiency, leg ulcers, osteonecrosis, etc. Lifespan is compromised and the only accepted treatment is hydroxyurea, which is capable of ameliorating the phenotype and extending the life of the patient.
Genetic Disease: Nonmendelian
Authors: Lightowlers Robert N , Selwood Simon P , Chrzanowska‐Lightowlers Zofia MA 
Published: September 2006

Abstract
The mitochondrial genome is an essential source of extranuclear deoxyribonucleic acid (DNA) in mammalian cells. Mitochondrial DNA (mtDNA) is inherited solely from the mother and encodes several polypeptides that are fundamental for cell respiration. There are many known pathogenic mutations of mtDNA which underlie a series of clinical disorders known as mitochondrial cytopathies or encephalomyopathies.
Expanding Mutations/Genetic Anticipation
Authors: Chiurazzi Pietro , Oostra Ben A 
Published: September 2006

Abstract
Expanding or dynamic mutations are caused by the abnormal expansion of simple repetitive sequences, which are scattered throughout the genome. The phenotypic effects will depend on the localization of the unstable sequence (exonic, intronic, in the promoter or intergenic region), on the size of the expansion, on the lack of interruptions and on the sequence of the repeat unit, which may favour the formation of secondary structures. More than 20 genetic disorders due to expanding (or ‘dynamic’) mutations have been reported to date.
Genetic Screening and Testing
Authors: Rowley Peter T , Saller Devereux N 
Published: September 2006

Abstract
Genetic screening is the systematic search in a population for individuals of certain 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. This suspicion may arise because of suggestive clinical features or a genetic relationship to a person known to have the genetic abnormality in question.
TransferRNAin Decoding and the Wobble Hypothesis
Authors: Tuite Mick F 
Published: September 2006

AbstractThe translation of the genetic code stored in messenger RNA requires significantly fewer tranfer RNAs than there are codons. This is achieved through an increased flexibility in the allowable base‐pair interactions between the mRNA and tRNA involving the third position of the codon. The rules governing the allowable base‐pair interactions were originally summarized in Crick's ‘wobble hypothesis’.
Site‐specific Recombination in Chromosome Function
Authors: Sherratt David J 
Published: September 2006

AbstractSite‐specific recombination leads to the integration, deletion or inversion of defined DNA segments by conservative breakage–rejoining reactions at defined recombination sites. It functions to integrate and excise extrachromosomal elements into and out of genomes, to maintain circular replicons at the correct copy number in a monomeric state, and to mediate inversion gene switches.
Caenorhabditis elegans: Determination of Germ Cell Fate
Authors: Schierenberg Einhard 
Published: September 2006

AbstractConsiderable differences exist between germ cells and somatic cells with respect to developmental programmes and control of gene expression. During germ cell formation several decisions have to be made. Recent progress has helped to elucidate the control of developmental choices, such as those between proliferation or differentiation, mitotis or meiosis, life or programmed cell death, sperm or oocyte.
DrosophilaEmbryo: Cell Signalling and Segmental Patterning
Authors: Vincent Jean‐Paul , Alexandre Cyrille 
Published: September 2006

AbstractExpression of the primary segment polarity geneswinglessandhedgehogestablishes a signalling centre at each parasegment boundary of theDrosophilaembryo. As a result, epidermal cells within each segment acquire a specific fate and polarity along the anterior–posterior axis.
Caenorhabditis elegans
Embryo: Establishment of Asymmetry
Authors: Basham Stephen E , Rose Lesilee S 
Published: September 2006

Abstract

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.
Drosophila
Retinal Patterning
Authors: Spencer Susan , Brachmann Carrie , Cagan Ross 
Published: September 2006

Abstract

The
Drosophila
retina is a compound apposition eye
composed of some 750 self‐contained eye units with lens, retina and
photoreceptors. Study of the
Drosophila
retina is useful in
understanding the general problems of cell cycle regulation, local cell
signalling, expression of determinative factors, control of programmed cell
death and rearrangement of cells within epithelia.
Sea Urchin Embryo: Specification of Cell Fate
Authors: Angerer Robert C , Angerer Lynne M 
Published: September 2006

Abstract
Specification of cell fate in sea urchin embryos involves
initial asymmetric distribution of maternal molecules that establish vegetal
and nonvegetal domains of transcription activity. Subsequently, fates of most
blastomeres are regulated by cell–cell interactions involving signalling
ligands and cell surface receptors.
Geological Time: History of Ideas
Authors: Bowler Peter J 
Published: September 2006

AbstractEarly estimates of the Earth's age were restricted by literal interpretations of Genesis, but the geological time scale had been greatly extended by the early nineteenth century. Calculations by physicists gave rise to very limited estimates of the Earth's age in the late nineteenth century, and it was only after the discovery of radioactivity that it became possible both to extend the scale of geological time and develop techniques for providing exact dates.
Evolution: History
Authors: Bowler Peter J 
Published: September 2006

Abstract

The modern theory of evolution was founded by Charles Darwin,
but an overview of the history of evolutionism shows that ideas of the
transformation of species predated Darwin, and that even following the
publication of Darwin's
Origin of Species
in 1859, a complex
series of developments was needed to create the genetical theory of natural
selection accepted by most biologists today.
Phylogeny and Stratigraphy Comparison
Authors: Wagner Peter 
Published: September 2006

Abstract
Phylogenetic relationships among taxa can be estimated in a number of ways. Given known fossil records, phylogenetic estimates implicitly hypothesize the latest possible origination times of taxa. These hypotheses can be used to evaluate the quality of the fossil record. Alternatively, these hypotheses can be tested using various methods in order to test the assumptions yielding the initial phylogenetic estimate.
Cephalochordata (Lancelets)
Authors: Jefferies Richard PS 
Published: September 2006

Abstract

The Cephalochordata constitute one of the three traditionally recognized subphyla of the Chordata, the other two being the Tunicata (Urochordata) and the Craniata (including the Vertebrata). They are also known as Acraniata or lancelets. There are only two extant genera,
Branchiostoma
(amphioxus) and
Epigonichthys
(
Asymmetron
).
Placodermi (Armoured Fishes)
Authors: Goujet Daniel F 
Published: September 2006

Abstract
Placoderms are a group of fossil true jawed fishes restricted to the Middle Palaeozoic period (Silurian and Devonian). They were the dominant forms in the seas of this time with more than 300 species. They show adaptations to various modes of life including the first active vertebrate predators and numerous bottom‐feeders.
Sauria (Lizards)
Authors: Benton Michael J 
Published: September 2006

Abstract

Lizards are generally small fast‐moving four‐legged slender terrestrial animals. The group of 3440 species of lizards, however, contains some exceptions: the large predatory Komodo dragon, the marine Galapagos iguana, the gliding
Draco
, various limbless forms, and burrowers.
Lagomorpha (Rabbits, Hares and Pikas)
Authors: Montuire Sophie 
Published: September 2006

Abstract
Lagomorphs comprise the pikas, hares and rabbits. The members of this order have a head and body length between 0.125 and 0.75 m, and adults weigh from 0.1 to 5 kg. All are terrestrial. Pikas are mostly diurnal whereas rabbits and hares are active mainly in the evening and night. They can be strong runners.
Proboscidea (Elephants)
Authors: Shoshani Jeheskel 
Published: September 2006

AbstractProboscidea – the living elephants and their fossil relatives – are of ungulate origin, dating to the late Palaeocene of northeast Africa and spread to all continents except Australia and Antarctica. The earliest proboscideans were characterized by the presence of a prominent and hooked coracoid process on the scapula (shoulder blade), and a medial process on the astragalus (ankle bone). Advanced proboscideans have pneumatized bones in the cranium, a developed proboscis (trunk), horizontal (rather than the usual vertical) tooth displacement, tusks that exhibit Schreger pattern in a cross‐section, and possess a temporal gland. The estimated number of fossil and living species and subspecies of proboscideans is 165, of which only three are alive today.
Sirenia (Dugongs and Manatees)
Authors: Domning Daryl P 
Published: September 2006

Abstract
The Sirenia is an order of large, aquatic, plant‐eating, mostly tropical placental mammals that includes the modern seacows (dugongs and manatees) and their extinct relatives. Their nearest living relatives are the Proboscidea (elephants). Together with some extinct orders (Desmostylia and Embrithopoda), the Sirenia and Proboscidea make up a group known as Tethytheria, after their likely origin along the shores of the ancient Tethys Seaway in the Old World.
Cnidaria (Coelenterates)
Authors: Shostak Stanley 
Published: September 2006

Abstract

Cnidaria (Gr.,
cnidae
, nettle) is a phylum of mostly marine Metazoa distinguished by cnidocysts, subcellular encapsulated tubules capable of everting and, in some cases, discharging venom. Sexual reproduction results in solid planula embryos that develop into columnar polyps. Asexual reproduction results in clones of polyps, polypoidal colonies or disk‐shaped to bell‐shaped sexual medusas (jellyfish).
Rotifera
Authors: Wallace Robert Lee 
Published: September 2006

Abstract

Rotifera are minute, bilaterally symmetrical, unsegmented animals that live predominantly in freshwaters. The phylum name (Latin,
rota
, wheel;
ferre
, to bear) was first used by Cuvier in 1798; this refers to the anterior end which, in many species, resembles a rotating wheel due to the sequential beat of its cilia.
Cycliophora
Authors: Kristensen Reinhardt Møbjerg 
Published: September 2006

Abstract

The cycliophorans are the recently discovered group of microscopic marine animals with an asexual and sexual life cycle. The only described species
Symbion pandora
lives on the mouth appendages of marine lobsters and have so far only been found in the Northern hemisphere. The phylogenetic position in the Animal Kingdom is still uncertain. Cycliophorans have been considered a sister group to Entoprocta and Ectoprocta or Rotifera and Acanthocephala.
Mollusca (Molluscs)
Authors: Haszprunar Gerhard 
Published: September 2006

Abstract
Mollusca are bilateral (or secondarily asymmetrical) coelomate Protostomia with spiral cleavage and mostly a (often modified) trochophore‐like larva. Most species are provided with spicule or shell (plates), a mantle cavity with gills, a ciliary or muscular gliding sole (foot), a visceral portion with heart and excretory organs and alimentary tract with rasping tongue (radula).
Trilobita (Trilobites)
Authors: Clarkson Euan NK 
Published: September 2006

Abstract
Trilobites are extinct marine arthropods in which the body is divided transversely into a head (cephalon), a thorax of articulated segments, and a tail (pygidium). The body is also divided longitudinally into a raised axis and two lateral lobes. Mature individuals range from about 1 mm in length to 700 mm.
Chaetognatha (Arrow Worms)
Authors: Bone Quentin 
Published: September 2006

Abstract
Chaetognaths are elongate bilaterally symmetrical marine animals, ranging from 0.2 to 12 cm long. They have a distinct head bearing grasping spines, and a tail fin together with one or two paired fins. The bipartite body and head contain powerful rapidly contracting muscles, but apart from gut and gonads, internal organs are absent; there is no heart or blood system.
Geological Time: Dating Techniques
Authors: Prothero Donald R 
Published: September 2006

AbstractNumerical dating (‘absolute dating’) of geological events allows us to place time estimates on geological and biological phenomena of the past. A number of techniques are used, most of which use the process of radioactive decay as a clock. From the latest dates, we have discovered that many evolutionary processes and events took place either much faster or much more slowly than previously imagined.
International Time Scale
Authors: Berggren William A 
Published: September 2006

Abstract
An ITS is a calendar of magnetic reversals and palaeontological events. The elements of an ITS consist of: (1) a Global Polarity Time Scale (GPTS) based on distances between magnetic anomalies on the sea floor; (2) analytically precise radioisotopic ages used to calibrate the GPTS; (3) precise magnetobiostratigraphic correlations from which a biochronology is derived (including the correct correlation between magnetozones and sea floor anomalies).
Earth: Changes Through Time
Authors: Prothero Donald R 
Published: September 2006

Abstract
Over the past 4600 million years since its formation, the Earth has undergone many changes. From a barren planet with a molten surface constantly churned by meteorites and volcanoes, and no free oxygen in its atmosphere, the Earth has evolved into a planet with large slow‐moving continents covered in vegetation that provides an oxygen‐rich atmosphere.
Cambrian Radiation
Authors: Valentine James W 
Published: September 2006

Abstract
It is consistent with the fossil record that all living phyla had evolved by the end of Early Cambrian time, over half a billion years ago. Many phyla first appear as marine fossils during a 10‐million‐year period in the Early Cambrian known as the Cambrian explosion, and radiated rapidly to produce marine communities analogous to those of today.
Human Evolution: Early Radiations
Authors: Wood Bernard A 
Published: September 2006

Abstract

Fossil evidence suggests that African ancestors exclusively ancestral to modern humans (such as the genera
Ardipithecus
,
Australopithecus
and
Paranthropus
) had emerged by at least 4.5 million years ago, and subsequently diversified.
Homo habilis
and
Homo rudolfensis
are adaptively and cladistically closer to this early hominin radiation than they are to later
Homo
taxa.
Plant Plasma Membrane
Authors: Larsson Christer , Sommarin Marianne , Pical Christophe , Kjellbom Per , Widell Susanne 
Published: September 2006

Abstract
The plasma membrane of the cell encloses the cell contents and
acts as a barrier between the cell and its environment. The plasma membrane
allows the exchange of ions and solutes with the rest of the organism and its
surroundings, and plays an important role in plant development, pathogen
resistance and frost‐hardiness.
Plant Endoplasmic Reticulum
Authors: Denecke Jurgen 
Published: September 2006

Abstract
The plant endoplasmic reticulum is responsible for the synthesis
and often storage of a large group of proteins and lipids that enter the
secretory pathway. This multifunctional organelle, which also represents one
of the calcium storage compartments in plant cells, has currently received
considerable interest in the research community because of features unique to
plants that make it particularly interesting for biotechnology.
Plant Vacuoles
Authors: Neuhaus Jean‐Marc , Martinoia Enrico 
Published: September 2006

Abstract
Most plant cells contain one or several vacuoles, which may
occupy up to 95% of the cellular space. The vacuoles often appear empty
under a light microscope (hence their name), except when they contain pigments
or precipitated substances. The vacuole is delimited from the cytosol by the
vacuolar membrane, which is also called tonoplast.