bluuebunny/crossref_metadata_2025 huggingface dataset:
Tripod sign
Authors: Suvarna JC , Keskar VS
Published: October 2009

"Tripod Sign" or "Amoss's Sign" is a sign of meningeal irritation. Although useful in diagnosing meningitis, it is not pathognomic and may be seen in a variety of clinical conditions. Infants < 1 year of age and immunocompromised individuals may not demonstrate signs of meningeal irritation. Since elicitation of the sign requires voluntary sitting up, it is of limited use in patients with marked altered sensorium and young infants.
Microwave Parametric Amplifiers
Authors: Faber Marek T.
Published: October 2009

An outline of the development of microwave parametric amplifiers (paramps) is presented as an introduction. The principle of their operation is explained leading to the classification of parametric amplifiers and frequency converters. (Photoparametric amplification is also referenced.) Varactor diodes are briefly presented in order to discuss in greater detail the operation of the most significant type of paramp—the nondegenerate parametric amplifier—including gain, noise, bandwidth, and stability. Degenerate, multiple‐idler and traveling‐wave parametric amplifiers are also discussed. Then the construction of a 3.25‐GHz nondegenerate parametric amplifier is presented as a representative example.
Automation
Authors: Considine D.M. , Considine Glenn D.
Published: October 2009

Advantages/Limitations of Automation

Applications for Automation Technology

Scientific Foundation for Automation

Contributions of Automation to Engineering and Science

Status of Automation—1990s

Technologies Closely Coupled with Automation

CAD
(Computer‐Aided Design)

CAM
(Computer‐Aided Manufacturing)

Bridging
CAD
and
CAM
Systems

CIM
(Computer‐Integrated Manufacturing)

FMS
(Flexible Manufacturing System)

Motion Control Systems
Battery
Authors: Urry L.F.
Published: October 2009

Cell Electrochemical Systems and Designs

Standard Cells
Biochemical Theories of Aging
Authors: Macauley John B.
Published: October 2009

Free Radicals, Somatic Mutation, and Aging

Glycation
Bioprocess Engineering (Biotechnology)
Authors: Ladisch Michael R.
Published: October 2009

New Biotechnology

Growth of the Fermentation Industries

Growth of the Antibiotic/Pharmaceutical Industry

Growth of the Amino Acid/Acidulant Fermentation Industry

Growth of the Biopharmaceutical Industry

Growth of Industrial Enzymes

The Polymerase Chain Reaction (
PCR
)

Impacts of Biotechnology on Drug Discovery and Biology

Bioprocess Engineering and Economics

Bioseparations and Bioprocess Engineering
Bubonic Plague
Authors: Vickery R.C.
Published: October 2009

The Great Plague
Calorimetry
Authors: Albert H.J.
Published: October 2009

Calorimeters of Historical and Special Interest

Gas Calorimeters
Cell (Biology)
Authors: Baldo, Ann C. De
Published: October 2009

Cell Division

Active Transport in Cells
Cellulose Ester Plastics (Organic)
Authors: Rich R.P.
Published: October 2009

Cellulose Esters

Organic Cellulose Ester Plastics
Chromatography
Authors: Converse J.G. , Villalobos R.
Published: October 2009

Beginnings of Chromatography

Fundamentals of Chromatography

Advancements in Chromatography

Gas Chromatography

Process Gas Chromatography

Liquid‐Column Chromatography
Cloning
(Mammals)
Authors: Love Jamie
Published: October 2009

Potential Uses for Clones
Clouds and Cloud Formation
Authors: Kraght Peter K.
Published: October 2009

Cloud Formation

Cloud Classification

The Ten Cloud Genera

Other Cloud Forms and Terms
Coal Tar and Derivatives
Authors: Romovacek George R. , Lauer G. G.
Published: October 2009

Carbonization Process

Processing of Crude Tar

Tar Acids

Tar Bases

Solvent Naphtha

Naphthalene

Topped Tar

Creosote

Pitch

Roofing Pitch
Computer Vision Syndrome (
CVS
)
Authors:   Vision Rx, Inc.
Published: October 2009

Prevention
Control System Architecture
Authors: Zimmerman Carl K.
Published: October 2009

State‐of‐the‐Art Control Systems

Higher‐Level Process Control

State‐of‐the‐Art Distributed Control Systems

Designing for Plantwide Control

Potential of Artificial Intelligence

Personal Computers
Cosmology
Authors: Wright Edward L. (Ned)
Published: October 2009

Early History

Galaxies

H
ubble's Law

Models of the Universe

Cosmological Principle

Background Radiation

Big Bang Theory

Inflationary Scenario

Dark Matter

Prospects
Desalination
Authors: Sekino Masaaki
Published: October 2009

Distillation

Electrodialysis

Reverse Osmosis

Ion Exchange

Other Processes

Worldwide Installations
Diamond Anvil High Pressure Cell
Authors: Jayaraman A.
Published: October 2009

The Diamond Anvil Cell

Pressure Media

Ultrahigh Pressure Research
Electrolytic Conductivity and Resistivity Measurements
Authors: Sperry Elmer , Nagy John
Published: October 2009

Measurement Fundamentals

Measuring Circuits

Conductivity Cells
Fuel Cells
Authors: Benke J.R. , Rastler D.
Published: October 2009

Early Experience with the
P
hosphoric
A
cid
F
uel
C
ell (
PAFC
)

4.5 
MW
Demonstration Plant

Shift of Emphasis to Solid Oxide Fuel Cells
G
aucher's Disease
Authors:   National Institutes of Health
Published: October 2009

Natural History

Roles of Current Molecular and Enzymatic Assays

Indications for Treatment and Appropriate Modes of Therapy

Goals
Gerontology
Authors: Flurkey Kevin
Published: October 2009

Theories of Senescence

Population Senescence and Evolutionary Biology

Organismal Senescence

Cellular Senescence

Molecular Senescence

Caloric Restriction

Genetic Strategies

Evaluating Aging Theories and Anti‐Aging “Cures”

Conclusion
Glass
Authors: Dietz Earl D. , Hench L.L.
Published: October 2009

Types of Traditional Glass

Lead Glasses

Borosilicate Glasses

Special‐Purpose Traditional Glasses

Traditional Manufacturing Process

Glass Blocks

Sol‐Gel Glass
Hubble Space Telescope (
HST
)
Authors: Villard Ray
Published: October 2009

History

Hubble Operations

Hubble Science

Black Holes

Stellar Environments

Comets

Galaxies

Nebula

Nova

Stars

Planets

Jupiter

Mars

Neptune

Saturn

Uranus
Hygrometry and Psychrometry
Authors: Wiederhold Pieter R.
Published: October 2009

Wet Bulb/Dry Bulb Measurements

Percent Relative Humidity

Dew Point Hygrometry
Insulation (Thermal)
Authors: Shuman E.C.
Published: October 2009

Thermal Insulation Systems and Materials

Selection of Thermal Insulation

Principal Types of Thermal Insulating Materials

Principal Forms of Thermal Insulation
Internet (The History)
Authors: Kleinrock Leonard , Kahn Robert E. , Clark David D. , Cerf Vinton G. , Leiner Barry M. , Lynch Daniel C. , Roberts Lawrence G. , Wolff Stephen
Published: October 2009

Origins of the Internet

The Initial Internetting Concepts

Proving the Ideas

Transition to Widespread Infrastructure

The Role of Documentation

Formation of the Broad Community

Commercialization of the Technology

History of the Future

Conclusion
Lasers (Eye Surgery)
Authors:   Vision Rx, Inc.
Published: October 2009

Types of Lasers and Their Uses
Liquid Crystal Display Technology
Authors:   Stanford Resources, Inc.
Published: October 2009

Liquid Crystal Displays

Basis of
LCD
Operation

LCD
Addressing Schemes

Twisted‐Nematic (
TN
)
LCD
Operation

Multiplexed
TN
‐
LCD
Operation

Passive Matrix
LCD
Operation

Active Matrix Addressed
LCD
s

Other Performance Issues

Amorphous Silicon (a‐Si) Thin‐Film Transistors

Polycrystalline Silicon (Poly‐Si) Thin‐Film Transistors

High‐Temperature Poly‐Si

Low‐Temperature Poly‐Si

Single‐Crystal Silicon Transistors for Displays

Cadmium Selenide (
Cd
Se
) Thin‐Film Transistors

Ferroelectric Liquid Crystal Display (
FLCD
)

Polymer‐Dispersed Liquid Crystal Display (
PDLCD
)

Electronically Controlled Birefringence (
ECB
) Liquid Crystal Displays

Dynamic Scattering Mode (
DSM
) Liquid Crystal Display

Guest‐Host (
GH
) Liquid Crystal Display

Cholesteric Liquid Crystal Display

Liquid‐Crystal‐on‐Silicon (
LCOS
) Devices

Reflective and Transflective Liquid Crystal Displays

Liquid Crystal Materials

Surface Alignment Materials

Color Filters for Displays

Polarizers and Film Compensators for Liquid Crystal Displays
Cerebral Cortex
Authors: Majewska Ania K
Published: October 2009

The cerebral cortex is the surface of the cerebral hemispheres and is the brain area most recently acquired in evolution. The cerebral cortex is involved in many higher‐level functions such as sensory perception, cognition, motor planning and control.
Alkaliphiles
Authors: Horikoshi Koki
Published: October 2009

Alkaliphiles grow optimally or very well at pH values above 9, often between 10 and 12, but cannot grow, or grow only slowly, at more neutral pH values. The enzymology, physiology, ecology, molecular biology and genetics of alkaliphiles, as well as industrial applications of these microorganisms have been investigated extensively and several enzymes have been put to use on an industrial scale.
Archaeal Ecology
Authors: Ferrera Isabel , Takacs‐Vesbach Cristina D , Reysenbach Anna‐Louise
Published: October 2009

The Archaea represent one of the three domains of life and are distinguished from the Bacteria and Eukarya phylogenetically and biochemically. As a group, the Archaea are physiologically diverse and inhabit a wide range of ecosystems, including the most extreme environments on Earth, where they contribute to global energy cycles.
Biogeochemical Cycles
Authors: Oren Aharon
Published: October 2009

Many of the chemical elements are constantly taken up, excreted and/or transformed by living organisms. This is true for those elements that constitute a significant part of the biomass on Earth (carbon, nitrogen, sulfur and phosphorus) as well as for many other elements present in small amounts in living cells, such as iron and many other metals. The biogeochemical cycles qualitatively and quantitatively describe the cycling of the elements between the abiotic terrestrial, marine and atmospheric environment and the biota.
Zygomycota and Glomeromycota
Authors: Moore‐Landecker Elizabeth
Published: October 2009

The phylum Zygomycota is an ecologically diverse and economically important group of fungi, containing two classes, the Zygomycetes and Trichomycetes. The phylum Glomeromycota, a group of mycorrhizal fungi, is derived from the Zygomycota.
Bacterial Evolution
Authors: Maniloff Jack
Published: October 2009

The Earth formed about 4600 million years ago and, 400–700 million years later, chemical evolution began, leading to living entities with metabolic pathways, catalysts, information storage molecules and, finally, membrane‐enclosed ‘organisms’. Evolution continued, with high levels of mutation and lateral gene transfer, to produce microbial anaerobic heterotrophs, autotrophs, lithotrophs, phototrophs (anoxygenic and later oxygenic) and, by 2200 million years ago, aerobes.
Gram‐type Positive Bacteria
Authors: Wiegel Juergen , Byrer Dorothy E , Onyenwoke Rob
Published: October 2009

Gram‐type positive bacteria, composed of the two phyla
Firmicutes
and
Actinobacteria
, are characterized by the presence of a thick peptidoglycan layer and the absence of lipopolysaccharide and an outer membrane. Though closely related phylogenetically, these bacteria are diverse in habitat, metabolism and medical and industrial importance. Although not observed for all, the
Firmicutes
(low G+C mol% group) represent endospore‐formers while the
Actinobacteria
(high G+C mol% group) taxa form actinospores (
Actinoplanes
), conidiospores (
Streptomyces
) or hyphae‐fragmentation into short cells without formation of conidia (
Nocardia
).
Immunity to Fungi
Authors: Killingley Ben , Kibbler Chris
Published: October 2009

The medically important fungi are a diverse group of pathogens that employ a variety of virulence strategies to establish themselves in the host. Successful host defence against fungi requires collaboration between the innate and acquired immune systems. Knowledge of the mechanisms involved is leading to advances in therapeutics.
Complement: The Alternative Pathway
Authors: Zipfel Peter F , Skerka Christine
Published: October 2009

The alternative pathway of complement is a powerful and evolutionarily old defence system of innate immunity that inactivates invading microorganisms and modified self cells. For survival in an immunocompetent host, pathogenic microbes must provide means to interfere with alternative pathway activation at their surface. Recent evidence shows that mutations and sequence variations of important regulators of this pathway cause a variety of disease including age‐related macular degeneration (AMD) of the eye and kidney diseases in the form of haemolytic uraemic syndrome (HUS) and membranoproliferative glomerulonephritis (MPGN).
Viruses of the Archaea
Authors: Basta Tamara , Garrett Roger A , Prangishvili David
Published: October 2009

Double‐strandeddeoxyribonucleic acid(DNA) viruses that infect members of the third domain of life, the Archaea, are diverse and exceptional in both their morphotypes and their genomic properties. The majority of characterized species infect hyperthermophilic hosts and carry morphological features which have not been observed for viruses from the other domains of life, the Bacteria and the Eukarya. This exceptional status of the archaeal viruses is reinforced by the finding that a large majority of their predicted genes yield no sequence matches in public sequence databases, and their functions remain unknown. One of the viruses, the bicaudavirus ATV (Acidianustwo‐tailed virus), is quite unique in that it undergoes a major morphological change, growing long tail structures, extracellularly. A small minority of archaeal viruses, which exclusively infect mesophilic or moderately thermophilic hosts, are morphologically similar to head‐tail DNA viruses of bacteria.
Transfer
RNA
Authors: Goldman Emanuel
Published: October 2009

Transfer ribonucleic acid (tRNA) is the class of molecules that decode the genetic code and link the coded information to their attached amino acids. These become constituents of the protein specified by the gene.
RNA
Interactions in
m
RNA
Splicing
Authors: Newman Andrew J
Published: October 2009

Complex ribonucleoprotein machines called spliceosomes remove introns from nuclear messenger ribonucleic acid (mRNA) precursors by mRNA splicing. A dynamic network of RNA interactions in the spliceosome plays crucial roles in splice site recognition and provides a structural framework for the catalytic steps of mRNA splicing.
Fc Receptors
Authors: Boross Peter , van de Poel Kees , Van de Winkel Jan GJ , Leusen Jeanette HW
Published: October 2009

Receptors for the Fc region of immunoglobulins link humoral responses to cellular activities within the immune system. Leucocyte Fc receptors exist as hetero‐oligomeric complexes with unique ligand‐binding α chains and promiscuous accessory subunits.
Transforming Growth Factor Beta: Role in Cell Growth and Differentiation
Authors: Serra Rosa
Published: October 2009

Transforming growth factor beta (TGFβ) is the prototype for a family of multifunctional secreted peptides that control many aspects of growth and development in a cell‐type‐specific manner.
Genetic Engineering: Reporter Genes
Authors: Lawler Joseph F , Hyland Edel M , Boeke Jef D
Published: October 2009

Reporter genes are easily measured surrogates for a molecule of interest.
Hepatitis E Virus
Authors: Kamili Saleem , Krawczynski Krzysztof
Published: October 2009

Hepatitis E virus

(HEV) is a nonenveloped
ribonucleic acid
(RNA) virus that is responsible for large epidemics and sporadic cases of self‐limiting, enterically transmitted, acute viral hepatitis in developing countries.
Centromeres
Authors: Kalitsis Paul
Published: October 2009

The centromere is a eukaryotic chromosomal substructure that ensures the accurate segregation of newly replicated chromosomes to daughter cells. It carries out this essential cell cycle process via multiple functions such as, spindle microtubule attachment, mitotic checkpoint control, sister‐chromatid cohesion and release and cytokinesis. This article explores the structure and function of the centromere in many well‐studied eukaryotic organisms.
Platelets
Authors: Chiang Thomas M , Dietcher Steven R
Published: October 2009

Platelets are small, anucleate, disc‐shaped blood cells derived from bone marrow megakaryocytes which serve several critical roles in normal haemostasis and participate in both health and disease.
Blood Groups and Transfusion Science
Authors: Reid Marion E
Published: October 2009

Determination of blood group antigens is an integral part of safe blood transfusion and of the management of pregnancy. The antigens are on the surface of erythrocytes and, thus, can elicit an immune response in a recipient who has a different profile of antigens (only identical twins will have erythrocytes with the same profile).
Meiosis
Authors: Kohli Jürg , Hartsuiker Edgar
Published: October 2009

Meiosis is the process leading to formation of the haploid gametes from diploid cells.
Bacterial Fermentation
Authors: Müller Volker
Published: October 2009

Under anaerobic conditions, in the dark and in the absence of electron acceptors, organic compounds are catabolized by strictly anaerobic or facultatively anaerobic bacteria by internally balanced oxidation–reduction reactions, a process called fermentation. In fermentation, the organic compound serves as both electron donor and acceptor, and adenosine triphosphate is synthesized by substrate‐level phosphorylation.
Human Chromosome Evolution
Authors: Holmquist Gerald P , Wienberg Johannes
Published: October 2009

During mammalian genome evolution, nuclear DNA content remained more or less unchanged and the chromosomal banding pattern was maintained with the exception of occasional chromosomal rearrangements. Chromosomal rearrangements occur frequently in individuals but only occasionally are they fixed into the common karyotype of a new species. The fixed rearrangements are passed on during evolution and unambiguously reveal how mammalian species are related to each other.
Molecular Phylogeny Reconstruction
Authors: Kumar Sudhir , Filipski Alan
Published: October 2009

Molecular phylogenetics deals with the inference of evolutionary relationships among individuals, populations, species and higher taxonomic entities using molecular data. By modelling patterns of molecular change in protein anddeoxyribonucleic acid(DNA) sequences over time, scientists now routinely reconstruct evolutionary histories of species and evaluate confidence levels of the inferences. Molecular phylogenetic inferences have been not only supportive of traditional phylogenies, but also instrumental in resolving some difficult questions regarding branching orders within many evolutionary lineages. Because of the vast and growing databases of molecular sequence information, this area promises to be an important key to understanding the history and relationships of all life forms on this planet.
Darwinian Medicine
Authors: Williams George C
Published: October 2009

Modern concepts of evolutionary biology can provide important insights into human vulnerability to disease and suggest ways of reducing that vulnerability and treating the diseases. They also suggest some urgently needed research.
Human Populations: Origins and Evolution
Authors: Harding Rosalind M , Relethford John H
Published: October 2009

The origins of modern human diversity have been debated within a framework set by two hypotheses: ‘Out of Africa’ versus multiregional evolution. For a better understanding of how human populations evolved, a new framework for analysis of genetic polymorphism is needed.
Molecular Evolution: Patterns and Rates
Authors: Bromham Lindell
Published: October 2009

The pace of
deoxyribonucleic acid
(DNA) evolution varies across the genome and between species, determined by the balance between mutation, selection and drift.
Molecular Evolution: Rates
Authors: Bromham Lindell
Published: October 2009

The pace of molecular change is generally more even than morphological evolution, yet there is clearly variation in molecular evolution rate between biological lineages. The causes of this rate variation are still largely unknown, but may be influenced by species characteristics, population structure and evolutionary processes.
Sequencing the Human Genome: Novel Insights into its Structure and Function
Authors: Kehrer‐Sawatzki Hildegard , Cooper David N
Published: October 2009

The availability of the human genome sequence has had an enormous impact on biomedical research. New discoveries emanating directly from the elucidation of the human genome sequence have included the unexpectedly low total number of genes, the existence of numerous transcribed but noncoding sequences and the multiplicity of low‐copy repeats and segmental duplications. The Human Genome Project has also spawned new research projects such as Encyclopedia of DNA Elements (ENCODE) and Haplotype Map (HapMap) which together are helping to reveal the remarkable complexity of the human genome. Finally, comparison of the human genome sequence with the genome sequences of other higher organisms has opened up numerous research avenues in evolutionary biology.
Apical Meristems
Authors: Francis Dennis
Published: October 2009

Apical meristems are regarded generically, as the growing tips of the higher plant. However, neither the shoot apical meristem (SAM) nor the root apical meristem (RAM) is apical, the former is protected by young unexpanded leaves and the RAM by the root cap. The SAM is an exponentially growing morphogenetic centre, it initiates leaves, flowers, nodes and internodes and in culture can regenerate a whole plant. Genes that regulate the SAM include the homeodomain genes,WUSCHEL(WUS),SHOOTMERISTEMLESS(KNOTTED), KNOTTED‐like genes and the WUS‐relatedWOX9together with the nonhomeodomainCLAVATAgene family. Leaf initiation, an event characterized by an early change in the plane of cell division on the flanks of the SAM, is characterized by the expression ofMGOUNwhileAINTEGUMENTAexpression is restricted to the primordium. The RAM shows steady‐state growth kinetics and roots in culture form more roots.QUIESCENT CENTRE HOMOBOX(QHB) is a gene expressed in the quiescent centre, a population of slowly dividing founder cells that is located at the pole of the RAM.QHBmay function in a manner analogous toWUS. However,ROOTMERISTEMLESSis a nonhomeodomain gene that is also central to normal function of theRAM.
Archaeal Chromosome
Authors: Lundgren Magnus
Published: October 2009

The Archaea is one of the three domains of life, and the least known. Sequencing of many archaeal chromosomes has shown that archaea display many eukaryotic features, despite sharing their appearance and range of genome size with bacteria. Chromatin organization, replication and transcription are similar to eukaryotes while operon organization and transcription regulation are similar to bacteria.
Amyloidosis
Authors: Benson Merrill D
Published: October 2009

The amyloidoses are a group of β‐structure protein deposition diseases that may be systemic or localized, sporadic, hereditary or associated with chronic inflammation. Pathology is the result of displacement of normal tissue structures.
Neutropenia
Authors: Dale David C
Published: October 2009

Neutropenia is a decrease in the number of neutrophilic leucocytes in the blood. Clinically neutropenia is defined as an absolute blood neutrophil count (total white blood cells per litre multiplied by the percentage of neutrophils) more than two standard deviations below the normal mean.
Implantable Pumps and Ports
Authors: Buchwald Henry , Rohde Thomas D
Published: October 2009

An implantable pump is a device that can be implanted within the body to deliver a drug or other substance to the same location or another site in the body. In addition to a reservoir and pumping mechanism, an implantable pump usually has a refill septum so that it can be refilled

in situ

and a catheter for remote delivery; an implantable port also has a refill septum and a delivery catheter but lacks a reservoir and an intrinsic pump.
Vries, Hugo de
Authors: Dröscher Ariane
Published: October 2009

de Vries (1848–1935), a Dutch botanist, who pioneered research on osmosis, rediscovered Mendel's laws and developed an influential hereditary theory.
Cell Senescence
In Vitro
Authors: Rattan Suresh IS
Published: October 2009

Cell senescence
in vitro
refers to the physiological, structural, biochemical and molecular changes that occur progressively during serial subcultivation of normal diploid cells during their limited proliferative lifespan in laboratory conditions.
Réaumur, René Antoine Ferchault de
Authors: Ratcliff Marc J
Published: October 2009

A mathematician turned naturalist, experimentalist and engineer, Réaumur tackled a wide variety of subjects. He was the head of a network of scholars whose seminal works set new standards for experimentation in the life sciences during the 1740s.
Hounsfield, Godfrey Newbold
Authors: Sutton Michael A
Published: October 2009

Godfrey Hounsfield (1919–2004), a British physicist who pioneered Computer Axial Tomography (CAT) scanning, using computer analysis of X‐ray data to produce three‐dimensional body images.
Lorenz, Konrad Zacharias
Authors: Burkhardt Richard W
Published: October 2009

Konrad Lorenz (1903–1989), an Austrian biologist whose comparative studies of animal behaviour provided the foundations for the science of ethology.
Foraging
Authors: Roitberg Bernard D , Roitberg Gabi
Published: October 2009

This article deals with foraging theory, a subdiscipline of Behavioural Ecology that elucidates why and how animals exploit food. In particular, it seeks to explain the adaptive significance of foraging strategies wherein individuals employ particular suites of tactics that lead to maximizing Darwinian fitness via accessing and assimilating foodstuffs. These rules involve methods that animals use for searching for foodstuffs as well as for discriminating among foodstuffs based upon energetic profitability.
Max Planck Gesellschaft/Society
Authors: Hergersberg Peter
Published: October 2009

The Max Planck Society for the Advancement of Science is an independent, nonprofit, research organization. It supports excellence in research, principally in its own Institutes. Max Planck Institutes carry out basic research in the public interest in the natural, biological and social sciences, as well as in the humanities. Although it is largely financed by the state, the Max Planck Society is not a state institution, but a registered society. The members of the Max Planck Society include more than 840 Supporting Members, the Honorary Members and the

ex officio

members. Scientific Members appointed to the Max Planck Society are also members of the association and are, generally, Directors at the Max Planck Institutes.
Bioethics – Overview
Authors: Chadwick Ruth F
Published: October 2009

Bioethics is a multidisciplinary field of study including ethical, legal and social aspects of developments in life sciences and medicine. There are multiple approaches to it and this gives rise to controversy about its aims, objectives and methodologies.
Centre National de la Recherche Scientifique (
CNRS
)
Authors: Picard (translation W. H. Schneider) Jean‐Francois
Published: October 2009

The CNRS or Centre National de la Recherche Scientifique is the largest publicly funded French research organization, working under the authority of the French Ministry of Research.
Cold‐shock Response in Microorganisms
Authors: Schumann Wolfgang , Inouye Masayori , Phadtare Sangita
Published: October 2009

Several species of bacteria are capable of mounting what is known as the cold‐shock response. This is induced upon a sudden decrease in external temperature and results in the transiently enhanced synthesis of a set of proteins, termed cold‐shock proteins, which allow the bacteria to adapt to low temperature.
Trager, William
Authors: Power Helen J
Published: October 2009

William Trager (1910–2005), an American biologist and specialist in experimental protozoology and insect physiology, developed a simple method for the continuous culture of the malaria parasite

Plasmodium falciparum

in 1976.
Goldberger, Joseph
Authors: Power Helen J
Published: October 2009

American physician and epidemiologist, who was responsible for identifying the link between dietary deficiency and pellagra.
Steptoe, Patrick
Authors: Power Helen J
Published: October 2009

Patrick Steptoe (1913–1988), a British gynaecologist who with Robert Edwards created the first ‘test‐tube baby’ born followingin vitrofertilization.
Philosophy of Ecology
Authors: Taylor Peter J
Published: October 2009

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 – humans included – 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.
Collectins
Authors: Ip WK Eddie , Takahashi Kazue
Published: October 2009

Collectins are proteins of the innate immune system, circulating pattern‐recognition molecules involved in recognizing and clearing pathogens and dying or damaged cells of self in an antibody‐independent manner. Collectins consist of a cysteine‐rich domain, a collagen‐like domain, a neck region and a carbohydrate‐recognition domain that bind certain molecular motifs exposed on the surface of pathogens and diseased or damaged cells.
Major Histocompatibility Complex Genes: Mouse H‐2
Authors: Hatina Jiří
Published: October 2009

Mouse major histocompatibility complex genes are arranged in a complex gene cluster – the H2 complex, coding for proteins either directly performing or associated with antigen presentation to T lymphocytes. The principal level of the regulation of the expression of H2 genes is the level of transcription. The major histocompatibility complex genes are the most polymorphic genes known, both within the coding and regulatory sequences. The genetic manipulation of H2 genes is very useful for creating mouse models of human immune‐related functions and pathologies. H2‐associated disease susceptibility is used as a model to understand similar human diseases.
Human and Chimpanzee Nucleotide Diversity
Authors: Kaessmann Henrik
Published: October 2009

Nucleotide diversity is a measure of
deoxyribonucleic acid
(DNA) polymorphism in a population that is based on pairwise DNA sequence comparisons. The extent of nucleotide diversity is shaped by the mutation rate and selection but also by the demographic history of a population. Thus, studies of nucleotide diversity in humans and their closest evolutionary relative, the chimpanzee, shed light on the population history of these species.
Introns: Phase Compatibility
Authors: Patthy László
Published: October 2009

Introns that lie between coding regions of protein‐coding genes may be assigned to three different phase classes, depending on their position relative to the reading frame of the translated protein: phase 0 (located between two codons), phase 1 (splitting codons between the first and second nucleotides) or phase 2 (splitting codons between the second and third nucleotides). In the case of protein‐coding genes with a unique pattern of pre‐messengerribonucleic acid(mRNA) splicing (and a unique protein product), the 5′ and 3′ splice junctions of an intron always belong to the same phase class (as defined by the unique protein product).
Alternative Splicing: Evolution
Authors: Patthy László
Published: October 2009

Alternative splicing of pre‐messengerribonucleic acid(pre‐mRNA) allows the generation of different mRNAs from the same gene. Evolution of alternative splicing affecting translated regions of mRNAs permits the synthesis of different proteins from a single gene, significantly increasing the diversity of the protein repertoire.
Exons and Protein Modules
Authors: Patthy László
Published: October 2009

Modules are versatile protein domains that are frequently used as building blocks in the construction of diverse multidomain proteins. The assembly of multidomain proteins from modules is facilitated by recombination in introns flanking the exons that encode the modules, but it may also occur by recombination in exons or through cotranscription of tandem genes.
Exons: Shuffling
Authors: Patthy László
Published: October 2009

Exon shuffling through recombination in spliceosomal introns had a major role in the evolution of multidomain proteins associated with multicellularity of metazoa.
Mutational Change in Evolution
Authors: Graur Dan
Published: October 2009

Evolution is the process of change in the genetic make‐up of populations. Two evolutionary forces are known to cause changes in gene frequencies with time: selection and random genetic drift.
Single‐base Mutation
Authors: Graur Dan
Published: October 2009

Deoxyribonucleic acid(DNA) sequences are normally copied exactly during the process of chromosome replication; however, new sequences are formed if errors in either DNA replication or DNA repair occur. These errors are called mutations.
Evolution: Views of
Authors: Crow James F
Published: October 2009

Darwin's original theory of evolution by natural selection is now almost universally accepted by biologists. It has been broadened by the inclusion of Mendelian inheritance and a mathematical formulation, called the new synthesis. Nevertheless, with more detailed study, different views of various aspects of the process have emerged and these are the subject of this article.
Molecular Clocks
Authors: Li Wen‐Hsiung , Makova Kateryna D
Published: October 2009

The molecular clock hypothesis postulates that the rate of evolution in a macromolecule is approximately constant per year over time and among different evolutionary lineages. While local clocks in closely related organisms with similar generation times can be useful for dating evolutionary events, strong evidence now suggests that no global or universal clock exists in mammals.
Hox
Genes and Body Plan: Evolution
Authors: Tour Ella , McGinnis William
Published: October 2009

The development of diverse structures on the anterior–posterior axis of animal embryos is dependent on homeotic or

Hox

genes. The expression and function of the

Hox

genes varies during evolution and underlies some of the morphological differences in different animal taxa.
Pax
Genes: Evolution and Function
Authors: Bouchard Maxime , Schleiffer Alexander , Eisenhaber Frank , Busslinger Meinrad
Published: October 2009

The transcription factors of the Pax protein family have been conserved throughout metazoan evolution and play essential roles in brain development and organogenesis. Loss‐of‐function and gain‐of‐function mutations in

PAX

genes cause inherited disease syndromes and tumor formation respectively.
Coevolution: Molecular
Authors: Adkins Ronald M
Published: October 2009

Molecular coevolution is an ongoing process by which a change in the sequence or function of a nucleic acid or protein molecule alters the selective effect of substitutions in another molecule or at other sites in the same molecule or of changes in the function of another molecule.
Pseudogenes: Age
Authors: Rhoads Allen R , Friedberg Felix
Published: October 2009

Pseudogenes present valuable evolutionary markers since they undergo neutral evolution. Determination of the age of pseudogenes over relatively short distances of time can confirm the order of evolutionary emergence and provide evidence for common ancestry.
Gene Families: Multigene Families and Superfamilies
Authors: Ohta Tomoko
Published: October 2009

Multigene families are defined as groups of genes with sequence homology and related overlapping functions, whereas superfamilies are defined as a group of proteins or genes of common origin with nonoverlapping functions. If a group of proteins or genes contains a domain of common origin, it is a superfamily; a protein or a gene may belong to two or more superfamilies.
Concerted Evolution
Authors: Liao Daiqing
Published: October 2009

Concerted evolution is a genetic process by which repetitive deoxyribonucleic acid (DNA) sequences are homogenized so that the sequence of a given multigene family within a species shares much higher sequence identity than that of the homologous gene family between two different species. Concerted evolution occurs in all living organisms, from bacteria to humans. DNA recombination mechanisms, especially unequal crossover and gene conversion, are responsible for concerted evolution.
Major Histocompatibility Complex (
MHC
) Genes: Evolution
Authors: Hughes Austin L
Published: October 2009

The major histocompatibility complex is a family of genes whose products play a key role in the immune system, presenting peptides to T cells. This family includes the most polymorphic loci known in animals.
Globin Genes: Evolution
Authors: Hardison Ross C
Published: October 2009

Hemoglobins carry oxygen from the lungs to other tissues and are encoded by a family of globin genes that are differentially expressed during development. Defects in expression of these globin genes lead to inherited anemias called thalassemias. Other globin genes encode proteins involved in oxygen storage and other functions.
Ancient
DNA
: Phylogenetic Applications
Authors: Knapp Michael , Vigilant Linda , Hofreiter Michael
Published: October 2009

Studies of ancient human
deoxyribonucleic acid
(DNA) attempt to shed light on the genetic relationships among individuals representing archaic or extinct human populations, and between these individuals and modern humans. These studies are limited by several factors, including the contamination of ancient samples with modern human DNA, the limited availability of nuclear DNA and difficulties in interpretation of results, due to the fact that modern, typically geographically defined human populations are not associated with diagnostic mitochondrial DNA (mtDNA) sequences.
Insurance and Human Genetics: Approaches to Regulation
Authors: Lemmens Trudo
Published: October 2009

The potential use of genetics for insurance purposes raises concerns about genetic discrimination. Regulatory strategies to curb genetic discrimination exist in several countries. These regulations aim at promoting a just distribution of insurance, which has multiple meanings in different social contexts, determining the potential impact of genetic discrimination.
Gene Structure: Evolution
Authors: Ohta Tomoko
Published: October 2009

Two fundamental processes in the evolution of gene structure in populations are the production of variations by mutations and the natural selection that filters these variations. Mutations occur randomly in genomes of germ cell lineages and are rejected or selected for, so that genes perform needed functions. As a result of minute effects of most mutations, both genetic drift and natural selection influence their fate in a population.
Long Interspersed Nuclear Elements (LINEs): Evolution
Authors: Furano Anthony V , Boissinot Stéphane
Published: October 2009

LINE‐1 (long interspersed nuclear element‐1, L1) repeateddeoxyribonucleic acid(DNA) elements are non‐long terminal repeat (LTR) group of retrotransposons that replicate by copying (reverse transcribing) theirribonucleic acid(RNA) transcript into genomic DNA. LINE‐1 elements, which can also copy other RNAs into genomic DNA, are the dominant (and in some species the only) active clade of retrotransposons in mammals, where they have been replicating and evolving since before the mammalian radiation approximately 100 million years ago.
Risks to Relatives
Authors: Hopper John L , Dite Gillian S , Byrnes Graham B
Published: October 2009

Studying risks to relatives can reveal important information on the likely causes of diseases. Even a modest increased risk for relatives of individuals with the disease (affected probands) compared with relatives of individuals without the disease (unaffected probands) cannot exist without there being strong underlying familial risk factors. Studying risks to relatives as a function of the strength of genetic, environmental and cohabitational relationships to the probands can help resolve whether the familial risk factors are likely to have a genetic and/or environmental aetiology, the more so if specific genes and environmental exposures are measured for one or more of the family members. Because only a small proportion of the familial aggregations of common diseases can be explained by known genes and other familial causes, there is scope for greatly expanding our knowledge of disease aetiology through information that can be gained from studying risks to relatives.
Linkage Disequilibrium
Authors: Croucher Peter JP
Published: October 2009

When two or more polymorphic loci are studied in a population, the interaction between the loci is often expressed in terms of linkage disequilibrium (LD). The loci are in LD if their respective alleles do not associate independently (randomly). The degree of over‐ or underrepresentation of the expected haplotypes measures the extent of LD. Recombination acts to reduce LD.
Fitness and Selection
Authors: Charlesworth Brian
Published: October 2009

When genotypes differ in their fitnesses, selection will affect the genetic composition of a population. Precise mathematical definitions of fitness have been developed and can be applied to the estimation of genotypic fitnesses in human populations.
Genetics of Large Populations and Association Studies
Authors: Garnier‐Géré Pauline Hélène , Chikhi Lounès
Published: October 2009

Association studies aim to discover the genetic basis of genetic diseases or drug responses through the comparison of unrelated affected and nonaffected individuals in large populations assumed to be at Hardy–Weinberg equilibrium (HWE). The HWE principle and the main causes of departures are first described with a focus on population stratification (Wahlund effect), which is one of the major problems in association studies. Recent statistical methods developed to detect and control for it are briefly reviewed.
Polymorphisms: Origins and Maintenance
Authors: Weiss Kenneth M
Published: October 2009

Polymorphism is variation in specific locations in the
deoxyribonucleic acid
(DNA) sequence. Some authors use the term only for variant alleles with at least 1% frequency in a population. This shows the population dependence of the concept itself. Variation arises initially by some form of mutation in a single individual but, because DNA is transmitted from parent to offspring, over time the frequency and geographical distribution of a genetic variant is essentially a population concept that depends on history.
Migration
Authors: Barbujani Guido
Published: October 2009

Migration is the movement of individuals in geographic space. When that movement has genetic consequences, migration determines gene flow. By introducing new genes where they were previously absent, migration increases genetic diversity within populations and reduces the differences among them. As a rule, groups that dwell close to each other tend to exchange more migrants than distant or isolated groups. But there are exceptions, especially during demographic expansions and when the populations are subdivided by geographic or cultural barriers. Rates and patterns of migration can be reconstructed from the analysis of genetic data.
Human Genome Project: Importance in Clinical Genetics
Authors: Little Peter FR , Williams Rohan BH
Published: October 2009

The Human Genome Project is impacting upon clinical genetics by defining the complexity of genes in humans, by developing technology at ‘genome‐wide’ scale, by underpinning the search for the genetic origins of complex disorders and by driving the development of new sequencing technologies of great power. Here we review these developments and argue that the greatest benefit of the Human Genome Project is yet to come.
Deafness: Hereditary
Authors: Hardelin Jean‐Pierre , Levilliers Jacqueline , Petit Christine
Published: October 2009

There are 45 genes known to cause nonsyndromic hearing impairment, and more are expected to be discovered in the next few years. However, difficulties in genetic linkage analysis, coupled with the possible involvement of environmental causes, have prevented the characterization of the main genes that are causative or predisposing to the late‐onset forms of deafness.
Pharmacogenetics and Pharmacogenomics
Authors: Nebert Daniel W
Published: October 2009

Between 1930 and 1990, several dozen
high‐penetrance predominantly monogenic
(hPpM) disorders in drug metabolism were identified and characterized, leading many to expect that the field of pharmacogenetics would very soon be able to provide us with ‘individualized drug therapy’. However, then came the Human Genome Project and the field of pharmacogenomics. We now realize that the genome is exceedingly complex and that the likelihood of ever achieving individualized drug therapy – for every person and every drug – is not scientifically or financially feasible. Perhaps genomics – in combination with transcriptomics, proteomics and metabonomics – will provide some degree of success, within the next several decades.
Codes of Ethics for Genetics Professionals
Authors: Wurzman Rachel , FitzGerald Kevin
Published: October 2009

Codes of ethics in genetics exist but need further development to keep pace with the rapid evolution of Genetic Technology. Government involvement in regulating genetics must be accompanied by professional codes of ethics to adequately protect users of this knowledge.
Genetic Screening Programmes
Authors: Williamson Shanti
Published: October 2009

Genetic screening programmes may benefit individuals, their families and society, but they may also cause harm. As such, screening programmes should meet certain important requirements before they are routinely implemented.
Clinical Genetic Services in the United Kingdom
Authors: Fryer Alan
Published: October 2009

The aim of Clinical Genetic Services is to help individuals or families with, or at risk of, conditions which may have a genetic basis to live and reproduce as normally as possible. In the UK, such specialist genetic services have, in general, developed as a network of Regional Genetics Centres, each serving populations of approximately 2–5 million people. Clinical geneticists work within these regional centres in multidisciplinary teams together with genetic counsellors and laboratory scientists. The clinical services are delivered through a network of central and district clinics and, in some cases, joint clinics with other specialists.
Newborn Screening Programmes
Authors: Parsons Evelyn P , Bradley Don M
Published: October 2009

Newborn screening programmes are used to detect diseases in neonates by analysing a blood sample collected by heel‐prick, usually during the first week of life. Whereas early programmes were started with the aim of preventing mental retardation, advances in technology now mean that a variety of disorders, where treatment is more problematic, or even nonexistent, can be identified. This has broadened the scope of newborn screening and presents service providers with an increasing need to address issues about consent.
Synthetic Nucleic Acid Delivery Systems in Gene Therapy
Authors: Miller Andrew David
Published: October 2009

Synthetic nucleic acid delivery systems also known as synthetic nonviral vectors, are prepared primarily using synthetic organic chemistry expertise for the delivery of therapeutic nucleic acids to cells
in vitro
,
ex vivo
and
in vivo
. In clinical trials, simple cationic liposomes/micelles or simple cationic polymers have been the most widely used synthetic nucleic acid delivery systems. Problems were encountered and solutions are now in development. Consequently, there is no currently marketed gene therapy that makes use of synthetic nucleic acid delivery systems (synthetic nonviral vectors). Given latest developments, this situation should be reversed given time.
Telomere
Authors: Martin Christa Lese , Ledbetter David H
Published: October 2009

Telomeres, the ‘caps’ at the ends of human chromosomes, consist of specialized DNA and protein complexes that help to protect chromosomes from degradation. Other unique characteristics of telomeric DNA include the sequence homology shared between subtelomeric DNA regions, a high gene density and an increased frequency of chromosomal imbalances.