bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing young children’s thinking through learning to write argument
Authors: Riley Jeni , Reedy David
Published: February 2005

This article draws on evidence from a small-scale study carried out in two early years classrooms. The study investigated an approach that appeared to enable very young children to construct and to write an argument. Multi-disciplinary theoretical perspectives are utilized for an explanation of the findings, with the work of Kress (1989) and Andrews (1995, 1997) on the nature of argument itself, Donaldson (1993) and Bereiter and Scardamalia (1993) on the value of writing to structure and develop thinking, being the most prominent. The case studies discussed here show that 5-7 year olds can engage with contentious, real-life issues and if offered structured support, they are able not only to produce written texts in the argument genre but their thinking also develops. A collaboration between professionals from different fields of education which aimed to support children’s learning in literacy reaffirms the impressive competence of early years pupils.
Literacy in the homes of young deaf children: Common and distinct features of spoken language and sign bilingual environments
Authors: Swanwick Ruth , Watson Linda
Published: February 2005

The study of deaf children’s early literacy raises fundamental issues about their access to language, experiences of early interaction and literacy development. However, we currently understand very little about how young deaf children develop literacy skills given their exceptional linguistic circumstances. This review explores early literacy practices in the homes of young deaf children to identify the commonalities and differences apparent in spoken language and sign bilingual homes. The introduction of the Newborn Hearing Screening Programme (NHSP), which is currently taking place, aims to diagnose congenital deafness in the first few weeks of life, followed by immediate involvement of a team of professionals with the child and family, including a teacher of the deaf. This provides a unique opportunity to explore early literacy practices in homes, and identify ways in which teachers and parents/carers can work collaboratively to facilitate deaf children’s early literacy development.
How e-communities extend the concept of exchange in marketing: An application of the motivation, opportunity, ability (MOA) theory
Authors: Gruen Thomas W. , Osmonbekov Talai , Czaplewski Andrew J.
Published: February 2005

Customer-to-customer (C2C) know-how exchanges occur in a variety of contexts, including virtual environments of Internet mediated communities. Exchange of know-how that takes place among the customers of an organization's offering has the potential to create customer value and result in positive outcomes for organizations. This study proposes a model that examines key factors that drive C2C exchanges as well as the outcomes of these exchanges. The model shows how C2C exchanges create value for the marketing organization – that is, value over and above the value that the customer receives directly through exchanges with the organization. C2C exchanges are also proposed to enhance loyalty intentions. Viewing C2C know-how exchange as an information source to the customer, the model adapts and applies the motivation, opportunity, and ability (MOA) theory to explain levels of C2C know-how exchange.
Pre-Modern Property and Self-Ownership Before and After Locke
Authors: Coleman Janet
Published: February 2005

Self-ownership is a central concept not only in Anglo-American liberal/libertarian discourse but also in Marxism. This article investigates what it means to say that a person has fundamental entitlement to full property in himself. It looks at possible moments when pre-modern concepts of the self became modern ones, examining Locke’s Second Treatise and his Essay Concerning Human Understanding. The aim is to focus on continuities and discontinuities in the transition from pre-modern to modern concepts and practices of identity and agency and the role that attitudes to property played within this transition. It also seeks to alert historians to the pitfalls of accepting contemporary conceptions of moral and civic agency found in normative political theory when they study pre-modern contexts and the people who lived their lives within them. It also attempts to expose certain modern limits on our understanding of society and people’s obligations to one another by rejecting the laws of the oikos as currently applied to the political domain.
‘Philosophy’s Gaudy Dress’
Authors: Zerilli Linda M.G.
Published: February 2005

John Locke famously sets the arts of rhetoric at odds with the pursuit of knowledge. Drawing on the work of Ernesto Grassi, this article shows that Locke’s epistemological and political arguments are parasitic on the very tropes and figures he would exclude in any serious discourse. Accordingly, Locke’s attack on the divine right of kings and his famous argument for the social contract is read as exhibiting a rhetorical structure. This structure is crucial to Locke’s critique of heteronomy and his attempt to facilitate the identification of oneself as a free subject.
Savage and Modern Liberty
Authors: Moyn Samuel
Published: February 2005

This article is a study of the trajectory of the contemporary French liberal philosopher Marcel Gauchet from his early, ‘anarchist’ commitments through the 1970s to his discovery and defense of liberalism, notably as expressed in his 1980 revival and interpretation of his 19th-century countryman Benjamin Constant’s post-revolutionary liberalism. Discussed in the article are Gauchet’s devotion to and revision of the portrait of primitive society he inherited from the French anthropologist Pierre Clastres, how his early political and theoretical concerns are transmuted in Gauchet’s reading of Constant, and the relevance of this trajectory for comprehending even Gauchet’s most recent pronouncements about the nature and future of liberal society.
Crime, Criminal Justice and Criminology in Greece
Authors: Lambropoulou Effi
Published: February 2005

The article describes the political and social reaction to crime and the response of the criminal justice system. Between 1980 and 1999, there was only a modest increase (of around 27 percent) in all recorded crimes in Greece, although there was a five-fold increase in the most serious crimes (felonies), which however accounted for a very small proportion of the total (1.4 percent in 1999). In formal terms, the sentences of the courts are often severe, but in practice most of these sentences are not carried out: lenient rules, adopted to control prison overcrowding, mean that many prison sentences are converted to fines, and those who are sent to prison are usually released early. Law and order politics, which previously focused on political ‘extremists’, has recently achieved more general legitimacy in Greece. Nevertheless, new laws providing for severe sentences mostly derive from Greece’s international and European commitments. A review of the varied writings of Greek criminologists in recent years suggests that criminology in Greece is at an early stage in attempting to engage systematically and productively with political and public discourse on crime and criminal justice.
Cloning and Characterization of a 5′ Regulatory Region of the Prolactin Receptor-Associated Protein/17β Hydroxysteroid Dehydrogenase 7 Gene
Authors: Risk Michael , Shehu Aurora , Mao Jifang , Stocco Carlos O. , Goldsmith Laura T. , Bowen-Shauver Jennifer M. , Gibori Geula
Published: February 2005

Prolactin receptor-associated protein (PRAP) originally cloned in our laboratory was shown to be a novel, luteal isoform of 17β hydroxysteroid dehydrogenase 7 (17βHSD7). In this study, we cloned the promoter region of rat PRAP/17βHSD7 and investigated the mechanisms regulating both basal activity and LH-induced repression of this promoter. Truncated and site-specific mutants of PRAP/17βHSD7 promoter identified two enhancer regions that contained highly conserved Sp1 binding site and bound Sp1 from nuclear extracts of both corpora lutea and a rat luteal cell line. Repression of PRAP/17βHSD7 expression and promoter activity by human chorionic gonadotropin/forskolin was localized to a −52-bp proximal segment of the promoter. This region contained a conserved CCAAT site and bound nuclear factor Y; binding of this transcription factor was inhibited by human chorionic gonadotropin in vivo. Furthermore, mutation of the nuclear factor Y site in the −52-bp promoter-reporter construct abolished forskolin-mediated inhibition of the promoter in a rat luteal cell line. In summary, we have identified the promoter elements involved in the basal expression of PRAP/17βHSD7. We have also found that LH-mediated repression of this gene is at the level of transcription and involves inhibition of nuclear factor YA binding to the CCAAT site within the proximal promoter.
Modeling of non‐linear systems by FWNNs and their intelligent control
Authors: Srivastava Smriti , Singh Madhusudan , Hanmandlu M. , Jha A. N.
Published: February 2005

By utilizing some of the important properties of wavelets like denoising, compression, multiresolution along with the concepts of fuzzy logic and neural network, two fuzzy wavelet neural networks (FWNNs) are proposed for approximating any arbitrary non‐linear function, hence, identifying a non‐linear system. We have fuzzified the output of DWT block, which receives the given inputs, in the proposed two methods: one using compression property and other using multiresolution property. We present a new type of fuzzy neuron model, each non‐linear synapse of which is characterized by a set of fuzzy implication rules with singleton weights in their consequents.

It is shown that noise and disturbance in the reference signal are reduced with wavelets and also the variation of somatic gain, the parameter that controls the slope of the activation function in the neural network, leads to more accurate output. Identification results are found to be accurate and speed of their convergence is fast.

Next, we simulate a control system for keeping output at a desired level by using the identified models. Two self‐learning controllers are designed in this simulation. One is a self‐learning fuzzy PI controller and other is a NN controller. Simulation results show that the NN controller is more adaptive and fast. Copyright © 2005 John Wiley & Sons, Ltd.
Amish brittle hair syndrome gene maps to 7p14.1
Authors: Seboun Eric , Lemainque Arnaud , Jackson Charles E.
Published: February 2005

The brittle hair syndrome (BHS) is characterized by short stature, intellectual impairment, brittle hair, and decreased fertility in 20 members from a large Amish consanguineous kindred previously reported affected with this syndrome. We mapped the BHS gene by genome scan to chromosome 7p14.1. Evidence of linkage was supported by a maximum multipoint LOD score of 6 obtained with GENEHUNTER for the linkage interval defined by markers D7S484‐D7S2422 distant by 17.2 cM. Two‐point linkage analysis performed with SUPERLINK yielded a LOD score of 9.02 at θ = 0 for marker D7S2497 located within that interval. Analysis of haplotypes homozygous‐by‐descent allowed fine mapping of the BHS gene within a 4.81 cM interval delimited by markers D7S2497 and D7S691, a region that spreads over 3.42 Mb. © 2005 Wiley‐Liss, Inc.
Improved molecular diagnosis of dystrophinopathies in an unselected clinical cohort
Authors: Dent K.M. , Dunn D.M. , von Niederhausern A.C. , Aoyagi A.T. , Kerr L. , Bromberg M.B. , Hart K.J. , Tuohy T. , White S. , den Dunnen J.T. , Weiss R.B. , Flanigan K.M.
Published: February 2005

Mutations in the DMD gene result in Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). Readily available clinical tests detect only deletions of one exon or greater, which are found in approximately 60% of cases. Mutational analysis of other types of DMD mutations, such as premature stop codons and small frameshifting insertions or deletions, has historically been hampered by the large size of the gene. We have recently reported a method that allows the rapid and economical sequencing of the entire coding region of the DMD gene, and that is more sensitive than methods based on single‐strand conformational polymorphism (SSCP) screening or other preliminary screening steps. Here we use single condition amplification/internal primer (SCAIP) sequencing analysis, in combination with multiplex amplifiable probe hybridization (MAPH) analysis of duplications, to report the frequency of mutations in a large cohort of unselected dystrophinopathy patients from a single clinic. Our results indicate that 7% of dystrophinopathy patients do not have coding region mutations, suggesting that intronic mutations are not uncommon. The availability of rapid and thorough mutation analysis from peripheral blood samples, along with an improved estimate of the percentage of non‐coding region mutations, will be of benefit for improved genetic counseling and in identification of cohorts for clinical trials. © 2005 Wiley‐Liss, Inc.
Is multicenter collaborative research in clinical genetics dead and, if so, what killed it?
Authors: Hunter Alasdair G.W.
Published: February 2005

This study describes the course of a clinical trial designed to investigate the possible role of thrombophilic factors in limb reduction defects, which was abandoned after 1 year because lack of progress of the project through ethics review and the failure to make significant inroads in patient recruitment. Factors that are thought to have contributed to the failure are discussed, in the hope that others can avoid some of the pitfalls. © 2005 Wiley‐Liss, Inc.
Use of targeted array‐based CGH for the clinical diagnosis of chromosomal imbalance: Is less more?
Authors: Bejjani Bassem A. , Saleki Reza , Ballif Blake C. , Rorem Emily A. , Sundin Kyle , Theisen Aaron , Kashork Catherine D. , Shaffer Lisa G.
Published: February 2005

Chromosome analysis is an important component to the diagnosis of congenital anomalies, developmental delay, and mental retardation. Routine chromosome analysis identifies aneuploidy and structural rearrangements greater than 5 Mb but cannot identify abnormalities of the telomeric regions or microdeletions reliably. Molecular cytogenetic techniques were developed to overcome these limitations. High‐resolution comparative genomic hybridization (CGH)‐based microarrays (array CGH) were developed to increase the resolution of chromosomal studies and to provide a comprehensive assay by using large‐insert clones as the target for analysis. We constructed a microarray for the clinical diagnosis of medically significant and relatively common chromosomal alterations. Nine hundred six bacterial artificial chromosome (BAC) clones were chosen, the chromosomal locations of which were confirmed by fluorescence in situ hybridization (FISH). FISH‐testing showed that 7% of the clones were mismapped based on map locations obtained from two publicly available databases (58 mapped to the wrong chromosome and three mapped to a different locus on the same chromosome), 16% cross‐hybridized to other chromosomes, and 12% did not hybridize or showed poor hybridization signals under uniform FISH conditions. Thus, from a total of 906 BAC clones that were evaluated, only 589 (65%) were deemed adequate for arraying on this clinical device. The performance of this array was tested in a set of blinded experiments on a cohort of phenotypically normal individuals and on individuals with known chromosome abnormalities. The array identified deletion/duplication polymorphisms not seen by FISH in the phenotypically normal individuals and detected single copy dosage differences in all of the cases with known chromosomal abnormalities. All abnormalities detected by the array were confirmed by FISH with BACs from the appropriate loci. Our data demonstrate that the rigorous assessment of BACs and their use in array CGH is especially important when the microarray is used for clinical diagnosis. In addition, this study illustrates that when constructed carefully with proper attention to the quality of the BACs that are arrayed, array CGH is an effective and efficient tool for delineating chromosomal aberrations and an important adjunct to FISH and conventional cytogenetics. © 2005 Wiley‐Liss, Inc.
Mosaic tetrasomy 14pter‐q13 due to a supernumerary isodicentric derivate of proximal chromosome 14q
Authors: Eggermann Thomas , Gamerdinger Ulrike , Bosse Kristin , Heidrich‐Kaul Christiane , Raff Ruth , Meyer Esther , Heil Ingeborg , Schüler Herdit , Korsch Eckhard , Schwanitz Gesa
Published: February 2005

Tetrasomy of proximal 14q is an extremely rare condition and has never been reported to be associated with survival. We here report on the first case of mosaic tetrasomy of 14pter‐q13 due to a de‐novo supernumerary pseudoisodicentric chromosome in a 2‐year‐old boy with multiple dysmorphisms and malformations. The marker was detectable in nearly 25% of lymphocytes as well as in cells from buccal mucosa. Detailed fluorescence in situ hybridization (FISH) analyses allowed the characterization of the marker to entirely consist of proximal 14q material and to be symmetric. The pattern of clinical features in our patient only slightly correspond to that of patients with trisomy of proximal 14q, but further cases are needed to define whether tetrasomy of proximal 14q is a separate entity. © 2005 Wiley‐Liss, Inc.
Carpal and tarsal synostoses and transverse reduction defects of the toes in two brothers heterozygous for a double de novo NOGGIN mutation
Authors: Debeer Philippe , Huysmans Christel , Van de Ven Wim J.M. , Fryns Jean‐Pierre , Devriendt Koen
Published: February 2005

We describe two siblings with carpal and tarsal synostoses associated with transverse deficiencies of the toes. Mutation analysis of the NOG gene revealed a double missense mutation in both boys resulting in Pro42Ala and Pro50Arg. The parents were clinically unaffected, and these two mutations were not detected in their white blood cells or buccal mucosa. This indicates the presence of gonadal mosaicism or a low level of somatic mosaicism in one of the parents. © 2005 Wiley‐Liss, Inc.
Hetero‐Aggregate Compounds of Aryl and Alkyl Lithium Reagents: A Structurally Intriguing Aspect of Organolithium Chemistry
Authors: Gossage Robert A. , Jastrzebski Johann T. B. H. , van Koten Gerard
Published: February 2005

Organolithium compounds are often depicted as mononuclear species. However, such compounds are in fact aggregated species and can form hetero‐aggregates containing different organic groups, including heteroatom groups. In reactions involving organolithium reagents, the “pure” homo‐aggregate organolithium compound can change into a hetero‐aggregate, which has a different structure and reactivity to the homo‐aggregate. This fact is often overlooked. When there are chiral centers in the organolithium reagent or the substrate, diastereoselective self‐assembly (the preferential formation of a particular diastereoisomeric aggregate) plays a role. The importance of these contributions in understanding the structure and reactivity patterns of organolithium reagents is the focus of this Minireview.
Synthesis and properties of ultraviolet/moisture dual‐curable polysiloxane acrylates
Authors: Qi Yusong , Meng Xing , Yang Jianwen , Zeng Zhaohua , Chen Yonglie
Published: February 2005

Ultraviolet (UV)/moisture dual‐curable polysiloxane acrylates (PSAs) were prepared from N,N‐bis[3‐(triethoxysilyl)propyl]amine (G402) and ethoxylated trimethylolpropane triacrylate (EB160) through Michael addition. The obtained prepolymers were characterized by 1H‐NMR and FTIR. The rheological behavior of the prepolymers exhibited the properties of a Bingham fluid and the apparent viscosity was directly correlated with molecular weight. The photocuring kinetics of PSA were studied using photo‐DSC and all the polymerization conversions were high. With increasing content of tertiary amine in the prepolymer, the photocuring rate in air increased as well. The moisture‐curing kinetics of the prepolymers was studied using FTIR. It was found that the curing mechanism may be described as the transforming of SiOC into SiOSi structure, which was consistent with the theoretical expectation. DSC and TGA were used to characterize the glass‐transition temperatures and the thermomechanical stability of the prepolymers. Measurements of physical properties showed excellent gloss, impact strength, and high electric resistance for both UV‐ and moisture‐cured films, but poor adhesion for UV‐cured films and lower hardness for moisture‐cured films. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 846–853, 2005
Molecular transport of n‐alkanes through diol chain‐extended polyurethane membranes
Authors: Swamy B. K. Kendaganna , Siddaramaiah  , Naidu B. Vijaya Kumar , Mallikarjuna N. N. , Aminabahvi T. M.
Published: February 2005

Molecular transport of n‐alkanes was investigated by calculating sorption, diffusion, and permeation of liquids through the diol chain‐extended polyurethane (PU) membranes in the temperature interval 25–60°C. Sorption experiments were performed gravimetrically. Diffusion coefficients were calculated from Fick's equation. These results showed a dependency on the nature and size of interacting n‐alkane molecules as well as morphology of the chain‐extended PUs. Transport kinetics followed an anomalous trend. Using the temperature‐dependent transport parameters, activation energies were calculated for diffusion and permeation processes using an Arrhenius equation. The van't Hoff relationship was used to obtain enthalpy and entropy of sorption. Concentration profiles of liquids through PU membranes were computed using Fick's equation, solved under appropriate initial and boundary conditions. A correlation was attempted between transport properties of liquids and physicomechanical properties of PU membranes. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 874–882, 2005
Cell detection at far ranges: supporting Tb—Z relationships
Authors: Calheiros R.V. , Machado R. , Lima M.A.
Published: February 2005

The Bauru radar detects inner cores of deep convective storm cells at long range, but relevant cell areas are left undetected. A procedure is in development to generate a more complete three‐dimensional representation of the cell structure for cost‐beneficial hydrological use at larger distances. A set of satellite microwave brightness temperature (Tb)—radar reflectivity (Z) relationships, basic to the retrieval procedure, has been derived. Copyright © 2005 Royal Meteorological Society
What the papers say: Metabolic compartmentation and ‘soluble’ metabolic pathways
Authors: Clegg James
Published: February 2005

Studies on individual enzymes in dilute solutions have largely provided the basis for many of the current views on metabolism and its control in intact cells. An increasing body of evidence from studies made on intact cells suggests that this approach may require re‐evaluation. One recent example of this evidence is briefly reviewed and related to other work that bears on the matter.
Molecular biology of herbicides
Authors: Hardy R. W. F. , Giaquinta R. T.
Published: February 2005

One of the most dynamic areas of plant molecular biology is the investigation of the actions of three classes of herbicides: s‐triazines (atrazine, simazine), glyphosate, and sulfonylureas (chlorsulfuron, sulfometuron methyl) (Figure 1). The results of this work are expected to provide the first significant applications of plant biotechnology: directly, in the genetic engineering of crop plants resistant to specific herbicides and, indirectly, in providing a molecular basis for the rational design of new herbicides for specific biological targets.

s‐Triazines affect photosynthesis by inhibiting the binding of quinones to the chloroplast membrane QB protein. An s‐triazine resistant QB protein isolated from weeds in fields consistently treated with the herbicide has a serine in place of a glycine in this highly conserved protein. Glyphosate inhibits 5‐enolpyruvyl‐shikimate‐3‐phosphate synthase (EPSP synthase), an enzyme in the aromatic amino acid biosynthetic pathway. Mutagenized bacteria produce a resistant EPSP synthase with a substitution of serine for proline. Sulfonylureas inhibit the acetolactate synthase (ALS) of bacteria, yeast, and higher plants; this enzyme catalyzes the first step in the synthesis of branched chain amino acids. Resistant ALS has been found in bacteria, yeast and tobacco with a proline substituted by serine in yeast ALS. These findings provide a strong basis for developing projected plant biotechnology applications.
Genetic manipulation and analysis of higher plant plasmagenes using somatic cell fusion
Authors: Gleba Yuri Yu. , Meshkiene Irute
Published: February 2005

The majority of higher plants (including almost all important crops) demonstrate strict uniparental maternal inheritance of plasmagenes in the process of conventional sexual crossing; it is therefore impossible to generate heterozygosity for these genes with standard crossing procedures. However, recent experiments have shown that hybrid plants can be produced by somatic cell fusion and that these contain the cytoplasmic genes of both parents. The phenotypic and genetic properties of these hybrid plants are described here.
The heat shock genes: A family of highly conserved genes with a superbly complex expression pattern
Authors: Voellmy Richard
Published: February 2005

The heat shock genes (hsp genes) are a family of truly ubiquitous genes which have been highly conserved throughout evolution. The protein products of these genes, the heat shock proteins (hsps) are thought to play a protective role in cells (although this may not be their only function). The genes and their products have been the subjects of intense research both at the cellular and molecular levels over the past few years. This review deals with the conservation of the heat shock response and with the expression of the hsp genes under different conditions: they are usually activated as a group by different forms of stress, but can be expressed individually or in subsets at different stages during normal development and the expression of one of them is evoked by the products of different transforming genes. Experimental approaches which have provided information or which have led to hypotheses regarding the molecular details of the mechanisms regulating the expression of the genes are discussed.
What the papers say: Differential roles of paternal and maternal genomes during embryogenesis in the mouse
Authors: Surani M. Azim H.
Published: February 2005

Although female and male gametes are presumably equivalent in their genetic contribution to embryos, they carry specific information, perhaps reversibly imprinted into the genomes during oogenesis and spermatogenesis, as to their maternal or paternal origin. This information is crucial for embryogenesis and, in the absence of at least one haploid set of chromosomes from each parent, embryos do not develop to term. The paternal genome is probably required for proliferation of extraembryonic tissues and the maternal genome for some stages of embryogeneis. Furthermore, the effects of certain mutations are determined by the paternal or maternal origin of the inheritance.
Metamorphosis of a protein
Authors: Ryan Robert O. , Law John H.
Published: February 2005

All insects appear to have a transport lipoprotein in the hemolymph (blood) that is responsible for moving hydrophobic materials through aqueous compartments. This has been called lipophorin because it is believed to be a reversible transport shuttle. Since most insects undergo some degree of metamorphosis from larval stages to the adult, the need to transport hydrophobic materials or the nature of these materials may change in the course of the life span. This is especially marked in the case of the holometabolous insects – those which undergo drastic change of form, e.g. caterpillar‐pupa‐adult moth. We have found that lipophorin undergoes a molecular metamorphosis paralleling that of the insect.
New insights into the origin of biological chirality
Authors: Blumenthal Steven J.
Published: February 2005

Life is characterized by a selectivity for asymmetric molecules. A great deal of theoretical and experimental work has yet to explain why living organisms utilize only L‐amino acids in proteins and D‐sugars in RNA and DNA. Also unknown is how a form of life based on asymmetric molecules evolved from an environment containing a racemic mixture of prebiotic molecules. By what mechanism did this selectivity for asymmetric molecules take place?
Radioimmunoassay and molecular phylogeny
Authors: Lowenstein Jerold M.
Published: February 2005

Traditionally, phylogenetic relations among living and extinct species have been estimated from their morphology, particularly that of the bones and teeth. During the past two decades, molecular comparisons of DNA, RNA and proteins have increasingly influenced the taxonomy of living forms. Recently, radio‐immunoassay (RIA) has been applied to the resolution of phylogenetic disputes by testing the relationships of residual fossil proteins with those of living organisms.
Roots: Molecular basis of gene expression: Origins from the Pajama experiment
Authors: Pardee Arthur B.
Published: February 2005

The Pajama (Pardee, Jacob, Monod) experiment provided a breakthrough in our understanding of the molecular mechanisms by which gene expression is regulated. Today, twenty‐five years later it provides a paradigm for thinking about problems of gene expression, such as growth regulation and differentiation. From this experiment emerged entities such as repressors, regulatory genes, the operon as a group of jointly controlled genes, and messenger RNA.
Education: Transdisciplinary science and the graduate curriculum
Authors: Lawson Robert B.
Published: February 2005

In the accompanying article contributed by Robert B. Lawson, proposals are made for revising the curriculum for doctoral students in biology in order to enhance a transdisciplinary awareness of biological science. The article is written mainly in the context of Dr Lawson's role as a scientist and educator in the United States. BioEssays will welcome articles along similar lines from educators in other countries. These should be sent to the Staff Editor, Dr Adam S. Wilkins.
Molecular biology and biophysics of ion channels
Authors: Keynes Richard D.
Published: February 2005

The transmission of electrical impulses in nerve and muscle cells depends fundamentally on the operation of specific ion channels in their membranes. Recent technical advances in electrical recording from cell membranes have permitted the analysis of the properties of single ion channels and the measurement of gating currents. The results have revealed considerable complexities, in particular in the operation of voltage‐gated sodium channels, and in the relationships between the several open and closed states of the channels. An important new development is the cloning and analysis of the structural genes for the acetylcholine receptor and sodium channel protein, which promises to yield fresh insights into the functioning of these proteins.
Molecular biology of blood coagulation disorders
Authors: Peake Ian R.
Published: February 2005

Current research into the molecular biology of blood‐clotting factors suggests that the basis of inherited bleeding disorders may soon be understood. In addition, the expression of cloned genes for the factors in mammalian cell lines provides the hope of pure factors being available for replacement therapy, uncontaminated with the causative agents for Hepatitis and Acquired Immune Deficiency Syndrome (AIDS), identified in the blood products at present available. The recent findings on the molecular biology of several of the key blood clotting genes are described here.
The molecular biology of the sphingolipid hydrolases
Authors: Ginns Edward I.
Published: February 2005

Our understanding of the sphingolipidoses has improved as a result of the investigation of molecular mechanisms causing clinical heterogeneity. This knowledge, derived from both the protein and gene structures, should bring therapy for these inherited disorders closer to a realistic possibility.
Eukaryotic DNA replication
Authors: Denhardt David T. , Faust Emanuel A.
Published: February 2005

Several factors are contributing to an increased air of excitement about the eukaryotic DNA replication problem: new insights into the nature of origins of replication, a better appreciation of the factors that control initiation, and studies of a DNA polymerase α‐primase enzyme complex. In this review, recent research on the initiation, elongation and termination phases of DNA replication is critically examined and a coherent picture is formulated. In the not‐far‐distant future we expect to reproduce these processes in biochemically defined systems.
Splicing of messenger RNA precursors
Authors: Patwardhan Satish , Kaltwasser Gustavo , Dimaria Peter R. , Goldenberg Carlos J.
Published: February 2005

The splicing of pre‐mRNAs in vitro is accomplished by formation of RNA intermediates in a lariat form. Lariat RNAs have been recently identified in vivo supporting the validity of the proposed pathway for processing pre‐mRNAs in vitro.

We have recently reported20 a partial purification scheme for a pre‐mRNA splicing activity. Purification of the individual components and eventually reconstitution of the reaction with purified activities will firmly establish the pathways for pre‐mRNA splicing and help to elucidate the detailed biochemical mechanism of the several reactions involved in mRNA splicing.
What the papers say: Early steps in T lymphocyte development within the thymus
Authors: Shortman Kenneth
Published: February 2005

The differentiation of T lymphocytes, the cells that are responsible for cell‐mediated immunity, takes place within the thymus, but details of the developmental pathway have long been obscure. Although distinct subpopulations of thymocytes had been characterized, they acted like separate developmental streams rather than sequential differentiation stages. Recently, a minor subgroup of thymocytes representing an earlier blast population has been identified, offering the hope that the key developmental events will be discerned by focus on this new population of precursor cells.
Two mechanisms for escape from immune surveillance by neurotropic retroviruses
Authors: Clements Janice E. , Narayan Opendra
Published: February 2005

The mechanism(s) by which lentiviruses and related non‐oncogenic retroviruses (e.g. HTLV‐III, the etiologic agent of AIDS) escape immune surveillance, and thereby create long term progressive disease conditions, has been unknown until recently. Studies with two lentiviruses have begun to illuminate the mechanisms. In one, antigenic drift in the virus appears to be the primary mechanism of escape from immune surveillance; in the second, selective masking of the viral envelope glycoprotein epitope, which normally elicits neutralizing anti‐body, appears to provide the means of escape.
Fertilization and the cytoskeleton in the mouse
Authors: Maro Bernard
Published: February 2005

The behaviour and roles of the microtubule network and the microfilaments following fertilization in the mouse oocyte are described. The microtubule network is organized by multiple microtubule organizing centres (MTOCs) and these play a major role in establishing spindle structure and pronuclear movement following fertilization; in contrast to sea urchin and frog eggs, the sperm centriole plays little part in organization of the post‐fertilization spindle. The microfilaments are required for spindle rotation, polar body formation, certain changes in the egg cortex, and also for pronuclear movement. Influences of the chromosomes on microtubule and microfilament organisation are also discussed.
Gene amplification in multidrug‐resistant cells: Molecular and karyotypic events
Authors: Gudkov Andrey , Kopnin Boris
Published: February 2005

Multidrug resistance (MDR) is developed in a population of somatic mammalian cells in vivo or in vitro when they are selected for resistance to each of a large group of drugs (colchicine, adriamycin, actinomycin D, etc.). It is produced by the amplification of some unknown gene(s) whose product(s) evidently change(s) the plasma membrane permeability of a cell to a selective agent and to other unrelated compounds. A large specific genomic region (150–250 kbp) undergoes amplification in MDR cells selected for the resistance to different drugs. Amplified DNA is located in homogeneously staining regions of chromosomes, double minute chromosomes and small chromatin bodies – episome‐like structures that replicate out of the S‐phase of a cell cycle. The selection of MDR cell variants is accompanied by regular karyotypic evolution specific for this type of drug resistance.
Science and society: Prospects for and impact of biotechnology: An overview with special reference to China
Authors: Tian‐qin Cao
Published: February 2005

Science and Society presents comments on some of the social and economic implications of the new biology. Here, Cao Tian‐qin presents a perspective from China on recent developments in biotechnology.
Education: Implementing the ‘GPEP report’
Authors: Jason Hilliard , Westberg Jane
Published: February 2005

In the April, 1985 issue of Bio Essays, F. Vella presented an evaluation of the recent GPEP report, concerning medical school education in the United States. Here, Hilliard Jason and Jane Westberg present an additional discussion of the issues.
The molecular genetics of collagen
Authors: Sykes Bryan
Published: February 2005

In their Bioessays review ‘Current views of collagen degradation’, Gillian Murphy and John Reynolds gave an outline of the molecular structure of the members of the collagen family and described their traditional role in providing stable tissue frameworks.1 This short review considers the relationship between the different members of that family and what gene structure reveals about their evolution. Mutation of the collagen structural genes has been discovered in patients suffering from brittle‐bone syndrome and other inherited connective tissue disorders, and here I attempt to rationalize these results into an overall concept of collagen gene mutation and evolution.
Histones in perspective
Authors: von Holt Claus
Published: February 2005

Histones occur in equal amounts to DNA in the cell nucleus and are largely responsible for the compaction of the genome into chromatin via the formation of nucleosomes and higher‐order structures. Whereas two of the five histone types exhibit little structural variation, the remaining three occur in many variant tissue‐ or species‐specific forms. Multiple postsynthetic enzymatic modifications accompanying virtually any type of genome activity, together with the programmed appearance of many histone variants during sea urchin embryogenesis (and other differentiation events in a number of organisms) make histones a challenging enigma in eukaryotic molecular biology.
What the papers say: Short odds for malaria vaccines
Authors: Mitchell G. F.
Published: February 2005

The immunology of falciparum malaria, the lethal type of human malaria, has been transformed by two developments. First, a culture system for the asexual blood stages of Plasmodium falciparum.1 Secondly, the cloning and expression of genes coding for a large number of the protein antigens of this malaria parasite over the past two years. Data on proteins, protein antigens and epitopes of P. falciparum supplied by gene cloning techniques have been supplemented by monoclonal antibody approaches, peptide synthesis, and high‐resolution immunochemistry.
Gene transfer and expression in plants: Implications and potential
Authors: Thomas Terry L. , Hall Timothy C.
Published: February 2005

This review provides a current perspective on the insertion of genes into plants. Some of the knowledge on the structure and control of plant genes gained recently from genetic engineering approaches is described, together with developments that can be expected to emerge from further exploitation of gene transfer techniques.
Plant transposable elements
Authors: Döring Hans‐Peter
Published: February 2005

Biochemical and genetical analysis of plant transposons has shown that these elements can induce unstable mutations and also that the transposon structure can be altered in different ways. Upon insertion, a transposon can give rise to a variety of chromosomal changes in the vicinity of the insertion site. The alterations range from the nucleotide level to large‐scale rearrangements.
Roots: Chloroplast genetics
Authors: Sager Ruth
Published: February 2005

The existence and properties of the chloroplast genome were established by a combination of genetic methods which identified chloroplast mutations and placed them into a linear sequence or map; and by chemical methods, CsCl density gradient ultracentrifugation and base analysis, which identified non‐nuclear DNA extracted from isolated chloroplasts. These studies, carried out in the 1950s and 1960s, primarily with Chlamydomonas, as well as parallel studies of mitochondrial DNA with yeast and Neurospora, laid the framework for distinguishing organelle and nuclear genomes. On this basis, the coding and regulatory functions of three genomes – nuclear, chloroplast, and mitochondrial – are being addressed in modern plant molecular biology.
Analysis of development and differentiation with tumour cell glycoproteins
Authors: Koch Gordon , Smith Michael
Published: February 2005

The repertoire of acceptor glycoproteins for concanavalin A expressed by a cultured tumour cell reflects the normal developmental lineage from which it was derived, as well as the degree of maturation along that lineage. Antibodies to this particular set of glycoproteins show a considerable specificity towards normal differentiation antigens which are often preferentially associated with the less mature intermediates of the corresponding pathway. In addition, comparisons between ‘immature’ and ‘mature’ tumour cells can be used to identify glycoproteins associated with specific differentiated functions such as secretion. Thus tumour cell glycoproteins provide useful probes for analysis of the molecular biology of development and differentiation.
Transposon‐induced events at gene loci
Authors: Peterson Peter A.
Published: February 2005

In the October issue of BioEssays (vol. 3, no. 4), H. P. Döring reviewed the general molecular biology of transposable elements in plants. In this review by P. A. Peterson, the effects of transposable genetic elements are considered, with special attention being paid to investigation of mobile‐element‐induced mutations at loci that control identifiable enzymes, and the specific alterations in enzyme properties that result. Together with DNA sequence analysis, these studies have begun to reveal the complexity of insertion/excision events, and their potential in protein evolution.
Using molecular mimicry to produce anti‐receptor antibodies
Authors: Linthicum D. Scott , Bolger Michael B.
Published: February 2005

An innovative approach to the production of anti‐receptor antibodies is now being fully exploited for a number of different cell receptors. This approach employs the concept that antibodies directed against pharmacologically active ligands have a three‐dimensional binding site which is somewhat analogous to the natural receptor. Consequently, when anti‐idiotype antibodies are produced against these anti‐ligand antibodies, some of the anti‐idiotypes will comprise a positive three‐dimensional shape which mimics the original ligand. The anti‐idiotypic antibodies generated in this fashion are able to bind to cell surface receptors. This approach has now been successfully applied to peptide hormones, small bio‐active peptides, interferon, viral hemagglutinins, and a number of small neurotransmitter ligands. So far, the boundaries for this working ‘molecular engineering’ concept have not been reached. This concept may also shed light on the processes which take place in the generation of anti‐receptor antibodies in several autoimmune diseases.
Roots: Activated intermediates: The unexpected may sometimes carry a message
Authors: Lipmann Fritz
Published: February 2005

In this Roots essay, Fritz Lipmann reviews the ways in which a number of activated metabolic intermediates were discovered, and where, not infrequently, he himself played a leading role. The concept of ‘squiggle‐P’ (∼ P) to denote the controversially named ‘high‐energy bond’, the discoveries of acetylphosphate, the activation of carboxylic acids and of amino acids, and of acetyl coenzyme A, are reviewed. In addition, carbamoyl phosphate as perhaps the earliest activated phosphate donor to evolve, and active sulfate, in phosphoadenosine phosphosulfate, are discussed, as well as the remarkable earlier discovery by Buchner and Hahn of how to prepare a yeast extract that fermented carbohydrate to ethanol; this discovery is viewed by Lipmann as the opening chapter in the new sciences of biochemistry and molecular biology.
Transforming mutations in protein—tyrosine kinase genes
Authors: Cooper Jonathan A.
Published: February 2005

Oncogenes are altered forms of normal cellular genes known as proto‐oncogenes. Several oncogenes encode enzymes that phosphorylate substrate proteins at tyrosine. In most of these cases the oncogene differs from its proto‐oncogene by multiple mutations that alter the structure of the encoded protein product. Here we discuss how structural changes might effect the regulation and substrate specificity of the protein kinase product of a protooncogene so that it gains the potential to transform cells.
The molecular biology of the polycyclic aromatic hydrocarbon inducible cytochrome P‐450; the past is prologue
Authors: Iversen P. L. , Hines R. N. , Bresnick Edward
Published: February 2005

The heme‐containing cytochromes P‐450 are a ubiquitous family of monooxygenase isozymes responsible for the oxidative metabolism of a wide variety of endogenous as well as exogenous compounds. Many of the compounds metabolized by this enzyme system are effectively detoxified and converted to derivatives more easily eliminated from the organism. However, some compounds can be activated to reactive species capable of eliciting a cascade of toxic lesions, including cancer. Since its discovery nearly 30 years ago, the cytochrome P‐450 enzyme system has received a great deal of attention, particularly in the areas of their mechanisms of metabolism, range of substrate specificity, the purification and characterization of the multiple isozymes and, more recently, the regulation of expression of specific forms. This review will discuss current notions concerning the expression of at least one cytochrome P‐450 isozyme and future directions that should lead to a more complete understanding of cytochrome P‐450 gene expression in general, particularly as it impacts upon biochemical pharmacology.
Inborn errors of GABA metabolism
Authors: Gibson Kenneth M. , Nyhan William L. , Jaeken Jaak
Published: February 2005

Defects in man in four steps of 4‐aminobutyric acid (GABA) metabolism may interefere with the function of this major inhibitory neurotransmitter. Glutamic acid decarboxylase, 4‐aminobutyric acid aminotransferase, succinic semialdehyde dehydrogenase, and homocarnosinase are closely identified with the brain, but two of these enzymes are expressed in cultured peripheral cells, which may permit novel approaches to the study of the metabolism and regulation of GABA.
Trichothecenes and yellow rain: Possible biological warfare agents
Authors: Dashek W. V. , Mayfield J. E. , Llewellyn G. C. , O'Rear C. E. , Bata A.
Published: February 2005

‘Yellow Rain’, an alleged biological warfare agent thought to be utilized in parts of both South East Asia and Afghanistan, may be composed in part of the mycotoxins, trichothecenes. However, more recent analyses suggest that the ‘Rain’ was mainly honey bee excreta. The history of the controversy together with the biological effects, chemistry as well as the fungi producing these mycotoxins and agricultural commodities affected by trichothecenes are reviewed.