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System Development (system + development)
Kinds of System Development Selected AbstractsDevelopment of a web-based mass transfer processes laboratory: System development and implementationCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 1 2003Yusong Li Abstract A web-based environment is utilized as a means to introduce advanced mass transfer processes concepts in environmental engineering and science courses. System development and implementation is presented, including detailed descriptions of the techniques employed to link software written in high-level computer languages such as C++ and FORTRAN to an internet-based, user-friendly graphical user interface for both program input and output. © 2003 Wiley Periodicals, Inc. Comput Appl Eng Educ 11: 25,39, 2003; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.10036 [source] Cover Picture: Electrophoresis 10'2010ELECTROPHORESIS, Issue 10 2010Article first published online: 18 MAY 2010 Issue no. 10 is a regular issue comprising 19 manuscripts distributed over four distinct parts. Part I is on microfluidics and miniaturized systems and has 5 articles; Part II is on nucleic acids with 4 articles on restriction endonuclease fingerprinting, mutation detection and DNA separation and detection; Part III has 7 articles on monolithic stationary phases for CEC, single walled carbon nanohorns as pseudo-stationary phases for CEC and EKC, MEEKC, cyclodextrin-modified gold nanoparticles for enantioseparations by CEC, use of divalent dipeptides as counter ions in CE and capillary coating for CE of proteins; and Part IV has 3 articles on proteomics methodologies. Featured articles include: Microfluidic preparative free-flow isoelectric focusing in a triangular channel: System development and characterization ((10.1002/elps.200900577)) Separation and recovery of nucleic acids with improved biological activity by acid-degradable polyacrylamide gel electrophoresis ((10.1002/elps.200900783)) Evaluation of the performance of single-walled carbon nanohorns in capillary electrophoresis ((10.1002/elps.200900628)) The inter- and intra-operator variability in manual spot segmentation and its effect on spot quantitation in two dimensional electrophoresis analysis. ((10.1002/elps.200900674)) [source] Hyperthermia in utero due to maternal influenza is an environmental risk factor for schizophreniaCONGENITAL ANOMALIES, Issue 3 2007Marshall J. Edwards ABSTRACT A hypothesis is presented that the association between maternal influenza and other causes of fever during the second trimester of pregnancy and the subsequent development of schizophrenia in the child is due to the damage caused by hyperthermia to the developing amygdalohippocampal complex and associated structures in the fetal brain. Hyperthermia is a known cause of congenital defects of the central nervous system and other organs after sufficiently severe exposures during early organogenesis. The pathogenic mechanisms include death of actively dividing neuroblasts, disruption of cell migration and arborization and vascular damage. In experimental studies, hyperthermia during later stages of central nervous system development also caused damage to the developing brainstem that was associated with functional defects. This damage usually results in hypoplasia of the parts undergoing active development at the time of exposure. Recent studies have shown no evidence of direct invasion of the fetus by the influenza virus. Factors that might interact with hyperthermia include familial liability to schizophrenia, season of birth, maternal nutrition, severe stress and medications used to alleviate the symptoms of fevers. The time of the development of the fetal amygdalohippocampal complex and the changes found in its structure and associated areas of the brain are compatible with the known effects of hyperthermia. [source] Development of the endoderm and gut in medaka, Oryzias latipesDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 5 2006Daisuke Kobayashi We performed an extensive analysis of endodermal development and gut tube morphogenesis in the medaka embryo by histology and in situ hybridization. The markers used in these analyses included sox17, sox32, foxA2, gata-4, -5, -6 and shh. sox17, sox32, foxA2, and gata-5 and -6 are expressed in the early endoderm to the onset of gut tube formation. Sections of medaka embryos hybridized with foxA2, a pan-endodermal marker during gut morphogenesis, demonstrated that gut tube formation is initiated in the anterior portion and that the anterior and mid/posterior gut undergo distinct morphogenetic processes. Tube formation in the anterior endoderm that is fated to the pharynx and esophagus is much delayed and appears to be independent of gut morphogenesis. The overall aspects of medaka gut development are similar to those of zebrafish, except that zebrafish tube formation initiates at both the anterior and posterior portions. Our results therefore describe both molecular and morphological aspects of medaka digestive system development that will be necessary for the characterization of medaka mutants. [source] Environmental complexity and central nervous system development and functionDEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 2 2004Mark H. Lewis Abstract Environmental restriction or deprivation early in development can induce social, cognitive, affective, and motor abnormalities similar to those associated with autism. Conversely, rearing animals in larger, more complex environments results in enhanced brain structure and function, including increased brain weight, dendritic branching, neurogenesis, gene expression, and improved learning and memory. Moreover, in animal models of CNS insult (e.g., gene deletion), a more complex environment has attenuated or prevented the sequelae of the insult. Of relevance is the prevention of seizures and attenuation of their neuropathological sequelae as a consequence of exposure to a more complex environment. Relatively little attention, however, has been given to the issue of sensitive periods associated with such effects, the relative importance of social versus inanimate stimulation, or the unique contribution of exercise. Our studies have examined the effects of environmental complexity on the development of the restricted, repetitive behavior commonly observed in individuals with autism. In this model, a more complex environment substantially attenuates the development of the spontaneous and persistent stereotypies observed in deer mice reared in standard laboratory cages. Our findings support a sensitive period for such effects and suggest that early enrichment may have persistent neuroprotective effects after the animal is returned to a standard cage environment. Attenuation or prevention of repetitive behavior by environmental complexity was associated with increased neuronal metabolic activity, increased dendritic spine density, and elevated neurotrophin (BDNF) levels in brain regions that are part of cortical,basal ganglia circuitry. These effects were not observed in limbic areas such as the hippocampus. MRDD Research Reviews 2004;10:91,95. © 2004 Wiley-Liss, Inc. [source] Tulp3 is a critical repressor of mouse hedgehog signalingDEVELOPMENTAL DYNAMICS, Issue 5 2009Don A. Cameron Abstract Precise regulation of the morphogen sonic hedgehog (Shh) and modulation of the Shh signaling pathway is required for proper specification of cell fate within the developing limbs and neural tube, and resultant tissue morphogenesis. Tulp3 (tubby-like protein 3) is a protein of unknown function which has been implicated in nervous system development through gene knockout studies. We demonstrate here that mice lacking the Tulp3 gene develop abnormalities of both the neural tube and limbs consistent with improper regulation of Shh signaling. Tulp3,/, embryos show expansion of Shh target gene expression and display a ventralization of neural progenitor cells in the caudal neural tube. We further show that Tulp3,/,/Shh,/, compound mutant embryos resemble Tulp3 mutants, and express Shh target genes in the neural tube and limbs which are not expressed in Shh,/, embryos. This work uncovers a novel role for Tulp3 as a negative regulatory factor in the Hh pathway. Developmental Dynamics 238:1140,1149, 2009. © 2009 Wiley-Liss, Inc. [source] Cardiac expression patterns of endothelin-converting enzyme (ECE): Implications for conduction system developmentDEVELOPMENTAL DYNAMICS, Issue 6 2008David Sedmera Abstract The spatiotemporal distribution of the endothelin-converting enzyme (ECE) protein in the embryonic chick heart and the association of this polypeptide with the developing cardiac conduction system is described here for the first time. Further, we show how cardiac hemodynamic load directly affects ECE level and distribution. Endothelin (ET) is a cytokine involved in the inductive recruitment of Purkinje fibers. ET is produced by proteolytic cleavage of Big-ET by ECE. We generated an antibody against chick ECE recognizing a single band at ,70 kD to correlate the cardiac expression of this protein with that reported previously for its mRNA. ECE protein expression was more widespread compared to its mRNA, being present in endothelial cells, mesenchymal cells, and myocytes, and particularly enriched in the trabeculae and nascent ventricular conduction system. The myocardial expression was significantly modified under experimentally altered hemodynamic loading. In vivo, ET receptor blockade with bosentan delayed activation sequence maturation. These data support a role for ECE in avian cardiac conduction system differentiation and maturation. Developmental Dynamics 237:1746,1753, 2008. © 2008 Wiley-Liss, Inc. [source] Six cadm/synCAM genes are expressed in the nervous system of developing zebrafishDEVELOPMENTAL DYNAMICS, Issue 1 2008Thomas Pietri Abstract The Cadm (cell adhesion molecule) family of cell adhesion molecules (also known as IGSF4, SynCAM, Necl and TSLC) has been implicated in a multitude of physiological and pathological processes, such as spermatogenesis, synapse formation and lung cancer. The precise mechanisms by which these adhesion molecules mediate these diverse functions remain unknown. To investigate mechanisms of action of these molecules during development, we have identified zebrafish orthologs of Cadm family members and have examined their expression patterns during development and in the adult. Zebrafish possess six cadm genes. Sequence comparisons and phylogenetic analysis suggest that four of the zebrafish cadm genes represent duplicates of two tetrapod Cadm genes, whereas the other two cadm genes are single orthologs of tetrapod Cadm genes. All six zebrafish cadms are expressed throughout the nervous system both during development and in the adult. The spatial and temporal patterns of expression suggest multiple roles for Cadms during nervous system development. Developmental Dynamics 237:233,246, 2008. © 2007 Wiley-Liss, Inc. [source] The basic helix-loop-helix factor Hand2 regulates autonomic nervous system developmentDEVELOPMENTAL DYNAMICS, Issue 3 2005Yuka Morikawa Abstract Mammalian autonomic nervous system (ANS) development requires the combinatorial action of a number of transcription factors, which include Mash1, Phox2b, and GATA3. Here we show that the bHLH transcription factor, Hand2 (dHAND), is expressed concurrently with Mash1 during sympathetic nervous system (SNS) development and that the expression of Hand2 is not dependent on Mash1. This suggests that these two bHLH factors work in parallel during SNS development. We also show that ectopic expression of Hand2 activates the neuronal program and promotes the acquisition of a phenotype corresponding to peripheral neurons including neurons of the SNS lineage in P19 embryonic carcinoma cells. We propose that Hand2 works in parallel with other members of the transcriptional network to regulate ANS developmental but can ectopically activate the program by a cross-regulatory mechanism that includes the activation of Mash1. We show that this function is dependent on its interaction with the histone acetyltransferase p300/CBP, indicating that Hand2 functions to promote ANS development as part of a larger transcriptional complex. Developmental Dynamics 234:613,621, 2005. © 2005 Wiley-Liss, Inc. [source] Hoxb3 vagal neural crest-specific enhancer element for controlling enteric nervous system developmentDEVELOPMENTAL DYNAMICS, Issue 2 2005Kwok Keung Chan Abstract The neural and glial cells of the intrinsic ganglia of the enteric nervous system (ENS) are derived from the hindbrain neural crest at the vagal level. The Hoxb3 gene is expressed in the vagal neural crest and in the enteric ganglia of the developing gut during embryogenesis. We have identified a cis -acting enhancer element b3IIIa in the Hoxb3 gene locus. In this study, by transgenic mice analysis, we examined the tissue specificity of the b3IIIa enhancer element using the lacZ reporter gene, with emphasis on the vagal neural crest cells and their derivatives in the developing gut. We found that the b3IIIa-lacZ transgene marks only the vagal region and not the trunk or sacral region. Using cellular markers, we showed that the b3IIIa-lacZ transgene was expressed in a subset of enteric neuroblasts during early development of the gut, and the expression was maintained in differentiated neurons of the myenteric plexus at later stages. The specificity of the b3IIIa enhancer in directing gene expression in the developing ENS was further supported by genetic analysis using the Dom mutant, a spontaneous mouse model of Hirschsprung's disease characterized by the absence of enteric ganglia in the distal gut. The colonization of lacZ -expressing cells in the large intestine was incomplete in all the Dom/b3IIIa-lacZ hybrid mutants we examined. To our knowledge, this is the only vagal neural crest-specific genetic regulatory element identified to date. This element could be used for a variety of genetic manipulations and in establishing transgenic mouse models for studying the development of the ENS. Developmental Dynamics 233:473,483, 2005. © 2005 Wiley-Liss, Inc. [source] Vascular gene expression and phenotypic correlation during differentiation of human embryonic stem cellsDEVELOPMENTAL DYNAMICS, Issue 2 2005Sharon Gerecht-Nir Abstract The study of the cascade of events of induction and sequential gene activation that takes place during human embryonic development is hindered by the unavailability of postimplantation embryos at different stages of development. Spontaneous differentiation of human embryonic stem cells (hESCs) can occur by means of the formation of embryoid bodies (EBs), which resemble certain aspects of early embryos to some extent. Embryonic vascular formation, vasculogenesis, is a sequential process that involves complex regulatory cascades. In this study, changes of gene expression along the development of human EBs for 4 weeks were studied by large-scale gene screening. Two main clusters were identified,one of down-regulated genes such as POU5, NANOG, TDGF1/Cripto (TDGF, teratocarcinoma-derived growth factor-1), LIN28, CD24, TERF1 (telomeric repeat binding factor-1), LEFTB (left,right determination, factor B), and a second of up-regulated genes such as TWIST, WNT5A, WT1, AFP, ALB, NCAM1. Focusing on the vascular system development, genes known to be involved in vasculogenesis and angiogenesis were explored. Up-regulated genes include vasculogenic growth factors such as VEGFA, VEGFC, FIGF (VEGFD), ANG1, ANG2, TGF,3, and PDGFB, as well as the related receptors FLT1, FLT4, PDGFRB, TGF,R2, and TGF,R3, other markers such as CD34, VCAM1, PECAM1, VE-CAD, and transcription factors TAL1, GATA2, and GATA3. The reproducibility of the array data was verified independently and illustrated that many genes known to be involved in vascular development are activated during the differentiation of hESCs in culture. Hence, the analysis of the vascular system can be extended to other differentiation pathways, allocating human EBs as an in vitro model to study early human development. Developmental Dynamics 232:487,497, 2005. © 2004 Wiley-Liss, Inc. [source] Development of the corticospinal system and hand motor function: central conduction times and motor performance testsDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 4 2000U M Fietzek Maturation of the corticospinal (CS) tract and hand motor function provide paradigms for central nervous system development. In this study, involving 112 participants (aged from 0.2 to 30 years), we evaluated central motor conduction times (CMCT) obtained with transcranial magnetic stimulation (TMS) during preinnervation conditions of facilitation and relaxation. Auditory reaction time, velocity of a ballistic movement of the arm, finger tapping, diadochokinesis, and fine motor visuomanual tracking were also examined. The maturation profiles for every parameter were calculated. CMCTs for the different preinnervation conditions reached adult values at different times and this could be explained by maturation of excitability at the cortical and spinal level. A stable phase for CMCTs and reaction time was reached during childhood. Parameters which measured motor speed and skill indicated that the development of these continued into adulthood. The maturation of the fast CS tract seems to be completed before the acquisition of the related motor performance has been accomplished. In conclusion, we could demonstrate that data from several neurophysiological methods can be combined and used to study the maturation of the function of the nervous system. This approach could allow appraisal of pathological conditions that show parallels with omissions or lack of developmental progress. [source] Roles of glutamate and GABA receptors in setting the developmental timing of spontaneous synchronized activity in the developing mouse cortexDEVELOPMENTAL NEUROBIOLOGY, Issue 12 2007Annette K. McCabe Abstract Spontaneous, synchronized electrical activity (SSA) plays important roles in nervous system development, but it is not clear what causes it to start and stop at the appropriate times. In previous work, we showed that when SSA in neonatal mouse cortex is blocked by TTX in cultured slices during its normal time of occurrence (E17,P3), it fails to stop at P3 as it does in control cultured slices, but instead persists through at least P10. This indicates that SSA is self-extinguishing. Here we use whole-cell recordings and [Ca2+]i imaging to compare control and TTX-treated slices to isolate the factors that normally extinguish SSA on schedule. In TTX-treated slices, SSA bursts average 4 s in duration, and have two components. The first, lasting about 1 s, is mediated by AMPA receptors; the second, which extends the burst to 4 s and is responsible for most of the action potential generation during the burst, is mediated by NMDA receptors. In later stage (P5,P9) control slices, after SSA has declined to about 4% of its peak frequency, bursts lack this long NMDA component. Blocking this NMDA component in P5,P9 TTX-treated slices reduces SSA frequency, but not to the low values found in control slices, implying that additional factors help extinguish SSA. GABAA inhibitors restore SSA in control slices, indicating that the emergence of GABAA -mediated inhibition is another major factor that helps terminate SSA. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Mechanisms of morphogen movementDEVELOPMENTAL NEUROBIOLOGY, Issue 4 2005Maura Strigini Abstract Morphogens are defined as signaling molecules that are produced locally, yet act directly at a distance to pattern the surrounding field of cells in a concentration-dependent manner. In recent years many laboratories have devoted their attention to how morphogens actually reach distant cells. Several models have been proposed, including diffusion in the extracellular space and planar transcytosis. A combination of genetic, developmental, and cell-biological approaches have been taken to tackle this issue. I will present the models and discuss the types of experiments that have been designed to test them. It stands out that most of the work has been carried out in Drosophila. Morphogens contribute to patterning of the vertebrate nervous system, and the same signaling molecules have recently been shown to play important, possibly instructive, roles in axon guidance. Little, if anything, is known about the movement of morphogens in the context of nervous system development. The long-standing tradition of biophysical studies on diffusion in the brain extracellular space, along with the sophisticated in vitro culture systems developed in neurobiology laboratories, may provide new tools and ideas to test these models in a new context. © 2005 Wiley Periodicals, Inc. J Neurobiol 64: 324,333, 2005 [source] Accelerated nervous system development contributes to behavioral efficiency in the laboratory mouse: A behavioral review and theoretical proposalDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2001Ian Q. Whishaw Abstract The emergence of the laboratory mouse as a favored species for genetic research has posed a number of problems for scientists interested in the reflection of genetic influences in mouse behavior. It is commonly thought that rat behavior, which has been studied more extensively than mouse behavior, could be easily generalized to mice. In this article, a number of categories of behavior displayed by the mouse (motor, spatial, defensive, social) are reviewed and contrasted with the same categories of behavior displayed by the rat. The comparison suggests that mouse behavior is simpler and more dependent upon elementary actions than the behavior of the rat. We suggest that the behavioral simplification in the mouse adapts it for a different ecological niche than that occupied by the rat. We propose that this simplification may be mediated by accelerated brain maturation during development. We further propose that this developmental acceleration in the mouse renders it less dependent upon complex social behavior and plastic nervous system changes associated with learning than the rat. This difference poses problems for the development of relevant methods of behavioral analysis and interpretation. Since the mouse's biological adaptations will be reflected in laboratory behavior, suggestions are made for behavioral approaches to the study and interpretation of mouse behavior. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 151,170, 2001 [source] A review of drug prevention system development in Romania and its impact on youth drug consumption trends, 1995,2005DRUG AND ALCOHOL REVIEW, Issue 4 2009CSABA L. DÉGI Abstract Issues. A tremendous growth occurred in the reported drug use and abuse in Romania from 1995 to 1999. Lack of concern by government and little policy attention contributed to the surprising delay of drug policy and drug prevention system development. General public stigmatize drug users and drug consumption is considered a matter of personal fault and responsibility. There is some but not sufficient research and evaluation on drug use, abuse problem. Approach. Drug use, abuse and prevention are discussed from research-based, user-focused and prevention system development perspectives. Prevalence and trends of drug use, abuse in the past decade (1995,2005) are summarized. Prevention issues are discussed based on research data from adolescents, parents and teachers. The Romanian primary drug prevention system has been evaluated based on our experiences in drug use prevention activities carried out in schools and recreational environments. Key Findings. Public and scientific perspectives on drug consumption in Romania, between 1995 and 1999, were dominated by an idealistic, non-realistic perception. Since 1995, drug use among adolescents increased almost four times in less than 4 years. The first law against drug traffic and consumption was issued only in 2000. Now primary drug prevention strategies are in action, but in general they are lacking standard evaluation procedures. Implications/Conclusion. Conclusions are drafted for new perspectives in prevention activities. More long-term, user-focused, demand-centred prevention activities should be carried out in more and more diversified settings and evaluation should be thoroughly considered.[Dégi CL. A review of drug prevention system development in Romania and its impact on youth drug consumption trends, 1995,2005. Drug Alcohol Rev 2009;28:419,425] [source] Gully processes and gully dynamicsEARTH SURFACE PROCESSES AND LANDFORMS, Issue 14 2009M. J. Kirkby Abstract This synthetic review of gully morphology and genesis focuses on incised semi-permanent gully systems rather than on shallow ephemeral gullies. It examines the conditions for gully formation; a sharp step to initiate a headcut, a sufficiently low effective bedload fraction to evacuate eroded material, and the potential to maintain steep sidewalls, usually dominated by mass movement processes. Gully formation is also favoured by an indurated surface layer which maintains steep sideslopes, often with armouring material from the capping layer, and a sharp headcut which does not diffuse away. Two different approaches towards the areal modelling of gully system development agree in treating the ratio of advective (channel) to diffusive (sideslope) processes as a key determinant of the morphology of a gully system as it evolves. Implications for gully prevention and remediation are briefly discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Structure of Banking Systems in Developed and Transition EconomiesEUROPEAN FINANCIAL MANAGEMENT, Issue 2 2001Dwight Jaffee The paper empirically analyses the determinants of banking system structure (as measured by bank assets, number, branches and employees) for 26 developed OECD countries. The estimated regressions are then applied to 23 transition economies, to obtain benchmarks for the efficient structure of their banking systems. The actual and benchmark measures of banking structure are compared to evaluate the state of banking system development, including the computation of a measure of ,banking system convergence'. The results are objective and replicable multidimensional measures of banking system development for the transition economies. [source] The spatio-temporal and subcellular expression of the candidate Down syndrome gene Mnb/Dyrk1A in the developing mouse brain suggests distinct sequential roles in neuronal developmentEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2008Barbara Hämmerle Abstract It is widely accepted that the neurological alterations in Down syndrome (DS) are principally due to modifications in developmental processes. Accordingly, a large part of the research on DS in recent years has focused on chromosome 21 genes that influence brain development. MNB/DYRK1A is one of the genes on human chromosome 21 that has raised most interest, due to its relationship with the brain functions that are altered in DS. Although a number of interesting experimental mouse models for DS are being developed, we still know little about the expression of Mnb/Dyrk1A during mouse brain development. Here, we report that Mnb/Dyrk1A displays a rather dynamic spatio-temporal expression pattern during mouse central nervous system development. Our data indicate that Mnb/Dyrk1A is specifically expressed in four sequential developmental phases: transient expression in preneurogenic progenitors, cell cycle-regulated expression in neurogenic progenitors, transient expression in recently born neurones, and persistent expression in late differentiating neurones. Our results also suggest that the subcellular localization of MNB/DYRK1A, including its translocation to the nucleus, is finely regulated. Thus, the MNB/DYRK1A protein kinase could be a key element in the molecular machinery that couples sequential events in neuronal development. This rich repertoire of potential functions in the developing central nervous system is suitable to be linked to the neurological alterations in DS through the use of mouse experimental models. [source] LRRN6A/LERN1 (leucine-rich repeat neuronal protein 1), a novel gene with enriched expression in limbic system and neocortexEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2003Laura Carim-Todd Abstract Human chromosome 15q24-q26 is a very complex genomic region containing several blocks of segmental duplications to which susceptibility to anxiety disorders has been mapped (Gratacos et al., 2001, Cell, 106, 367,379; Pujana et al., 2001, Genome Res., 11, 98,111). Through an in silico gene content analysis of the 15q24-q26 region we have identifie1d a novel gene, LRRN6A (leucine-rich repeat neuronal 6A), and confirmed its location to the centromeric end of this complex region. LRRN6A encodes a transmembrane leucine-rich repeat protein, LERN1 (leucine-rich repeat neuronal protein 1), with similarity to proteins involved in axonal guidance and migration, nervous system development and regeneration processes. The identification of homologous genes to LRRN6A on chromosomes 9 and 19 and the orthologous genes in the mouse genome and other organisms suggests that LERN proteins constitute a novel subfamily of LRR (leucine-rich repeat)-containing proteins. The LRRN6A expression pattern is specific to the central nervous system, highly and broadly expressed during early stages of development and gradually restricted to forebrain structures as development proceeds. Expression level in adulthood is lower in general but remains stable and significantly enriched in the limbic system and cerebral cortex. Taken together, the confirmation of LRRN6A's expression profile, its predicted protein structure and its similarity to nervous system-expressed LRR proteins with essential roles in nervous system development and maintenance suggest that LRRN6A is a novel gene of relevance in the molecular and cellular neurobiology of vertebrates. [source] FMRFamide gene and peptide expression during central nervous system development of the cephalopod mollusk, Idiosepius notoidesEVOLUTION AND DEVELOPMENT, Issue 2 2010Tim Wollesen SUMMARY Mollusks are a showcase of brain evolution represented by several classes with a varying degree of nervous system centralization. Cellular and molecular processes involved in the evolution of the highly complex cephalopod brain from a simple, monoplacophoran-like ancestor are still obscure and homologies on the cellular level are poorly established. FMRFamide (Phe-Ile-Arg-Phe-NH2)-related peptides (FaRPs) constitute an evolutionarily conserved and diverse group of neuropeptides in the central nervous system (CNS) of many metazoans. Herein, we provide a detailed description of the developing FMRFamide-like immunoreactive (Fa-lir) CNS of the pygmy squid Idiosepius notoides using gene expression analyses and immunocytochemistry. The open reading frame of the I. notoides FMRFamide gene InFMRF predicts one copy each of FIRFamide, FLRFamide (Phe-Leu-Arg-Phe-NH2), ALSGDAFLRFamide (Ala-Leu-Ser-Gly-Asp-Ala-Phe-Leu-Arg-Phe-NH2), and 11 copies of FMRFamide. Applying matrix-assisted laser desorption/ionization time-of-flight (ToF) mass spectrometry-based peptide profiling, we characterized all predicted FaRPs except ALSGDAFLRFamide. Two cell clusters express InFMRF and show FMRFamide-like-immunoreactivity within the palliovisceral ganglia, that is, the future posterior subesophageal mass, during the lobe differentiation phase. They project neurites via ventral axonal tracts, which form the scaffold of the future subesophageal mass. In the supraesophageal mass, InFMRF is first expressed during mid-embryogenesis in the superior and inferior buccal lobes. A neurite of the peduncle commissure represents the first Fa-lir element. Later, the sub- and supraesophageal mass interconnect via Fa-lir neurites and more brain lobes express InFMRF and FMRFamide-like peptides. InFMRF expression was observed in fewer brain lobes than Fa-lir elements. The early expression of InFMRF and FMRFamide-lir peptides in the visceral system and not the remaining CNS of the cephalopod I. notoides resembles the condition found in the majority of investigated gastropods. [source] Genetic and clinical aspects of X-linked hydrocephalus (L1 disease): Mutations in the L1CAM geneHUMAN MUTATION, Issue 1 2001Sabine Weller Abstract L1 disease is a group of overlapping clinical phenotypes including X-linked hydrocephalus, MASA syndrome, spastic paraparesis type 1, and X-linked agenesis of corpus callosum. The patients are characterized by hydrocephalus, agenesis or hypoplasia of corpus callosum and corticospinal tracts, mental retardation, spastic paraplegia, and adducted thumbs. The responsible gene, L1CAM, encodes the L1 protein which is a member of the immunoglobulin superfamily of neuronal cell adhesion molecules. The L1 protein is expressed in neurons and Schwann cells and seems to be essential for nervous system development and function. The patients' gene mutations are distributed over the functional protein domains. The exact mechanisms by which these mutations cause a loss of L1 protein function are unknown. There appears to be a relationship between the patients' clinical phenotype and the genotype. Missense mutations in extracellular domains or mutations in cytoplasmic regions cause milder phenotypes than those leading to truncation in extracellular domains or to non-detectable L1 protein. Diagnosis of patients and carriers, including prenatal testing, is based on the characteristic clinical picture and DNA mutation analyses. At present, there is no therapy for the prevention or cure of patients' neurological disabilities. Hum Mutat 18:1,12, 2001. © 2001 Wiley-Liss, Inc. [source] Impact of an extreme melt event on the runoff and hydrology of a high Arctic glacierHYDROLOGICAL PROCESSES, Issue 6 2003Sarah Boon Abstract On 28,30 July 2000, an extreme melt event was observed at John Evans Glacier (JEG), Ellesmere Island (79° 40,N, 74° 00,W). Hourly melt rates during this event fell in the upper 4% of the distribution of melt rates observed at the site during the period 1996,2000. Synoptic conditions during the event resulted in strong east-to-west flow over the northern sector of the Greenland Ice Sheet, with descending flow on the northwest side reaching Ellesmere Island. On JEG, wind speeds during the event averaged 8·1 m s,1 at 1183 m a.s.l., with hourly mean wind speeds peaking at 11·6 m s,1. Air temperatures reached 8°C, and rates of surface lowering measured by an ultrasonic depth gauge averaged 56 mm day,1. Calculations with an energy balance model suggest that increased turbulent fluxes contributed to melt enhancement at all elevations on the glacier, while snow albedo feedback resulted in increased melting due to net radiation at higher elevations. The event was responsible for 30% of total summer melt at 1183 m a.s.l. and 15% at 850 m a.s.l. Conditions similar to those during the event occurred on only 0·1% of days in the period 1948,2000, but 61% of events occurred in the summer months and there was an apparent clustering of events in the 1950s and 1980s. Such events have the potential to impact significantly on runoff, mass balance and drainage system development at high Arctic glaciers, and changes in their incidence could play a role in determining how high Arctic glaciers respond to climate change and variability. Copyright © 2003 John Wiley & Sons, Ltd. [source] The fundamental contribution of Robert A. Good to the discovery of the crucial role of thymus in mammalian immunityIMMUNOLOGY, Issue 3 2006Domenico Ribatti Summary Robert Alan Good was a pioneer in the field of immunodeficiency diseases. He and his colleagues defined the cellular basis and functional consequences of many of the inherited immunodeficiency diseases. His was one of the groups that discovered the pivotal role of the thymus in the immune system development and defined the separate development of the thymus-dependent and bursa-dependent lymphoid cell lineages and their responsibilities in cell-mediated and humoral immunity. [source] The Hypothesis,Testing Ordering System: A New Competitive Weapon of Japanese Convenience Stores in a New Digital EraINDUSTRIAL RELATIONS, Issue 4 2002Susumu OgawaArticle first published online: 17 DEC 200 This study focuses on the store,ordering system practiced by Japanese convenience stores. The article examines (1) the conceptual categorization of such ordering systems, (2) the history of the system development at three major convenience stores, and (3) the characteristics of 7,Eleven's development that led the way toward an innovative ordering system. [source] A taxonomy of political processes in systems developmentINFORMATION SYSTEMS JOURNAL, Issue 5 2010Rajiv Sabherwal Abstract Significant resources invested in information system development (ISD) are wasted due to political manoeuvres. Prior research on ISD politics has contributed mainly through theoretical development and case studies. This has enhanced understanding of relevant concepts, political tactics and conditions facilitating politics. However, there is limited understanding of the different processes through which politics unfold. This paper uses 89 ISD projects to develop a taxonomy of political processes in ISD. The taxonomy includes three distinct processes: Tug of War, wherein multiple parties strive to gain project control; Obstacle Race, which involves efforts to resist and pursue the project; and Empire Building, wherein the project is used as an instrument to enhance political or resource bases. The taxonomy is explained using the non-proponents' view of the project and the balance of power between system's proponents and non-proponents. We also discuss the emergent taxonomy's implications for how politics can be managed and studied. [source] Client-Led Information System Creation (CLIC): navigating the gapINFORMATION SYSTEMS JOURNAL, Issue 3 2005Donna Champion Abstract., This paper offers a new framework to facilitate an interpretive approach to client-led information system development, referred to as CLIC (Client-Led Information System Creation). The challenge of moving seamlessly through a process of information systems (IS) design is still the subject of much research in the IS field. Attempts to address the difficulties of ,bridging the gap' between a client's business needs and an information system definition have hitherto not provided a coherent and practical approach. Rather than attempting to bridge the gap, this paper describes an approach to managing this gap by facilitating the clients' navigating through the information system design process (or inquiry process) in a coherent manner. The framework has been developed through practice, and the paper provides an example of navigating through the design phase taken from an Action Research field study in a major UK bank. [source] Sonographic study of the development of fetal corpus callosum in a Chinese populationJOURNAL OF CLINICAL ULTRASOUND, Issue 2 2009Hai-chun Zhang MM Abstract Purpose The observation of fetal corpus callosum (CC) is important for the prenatal sonographic assessment of fetal central nervous system development. The aim of this study was to investigate the development of normal Chinese fetal CC. Method CC measurements were performed using high-resolution transabdominal sonography on 622 Chinese fetuses between 16 and 39 weeks' gestation. The correlation between CC size and gestational age was investigated. Results The fetal CC length increased in a linear fashion during pregnancy. The length of the CC as a function of gestational age was expressed by the following regression equation: length (mm) = ,9.567 + 1.495 × gestational age (weeks) (r = 0.932, p < 0.001). Conclusion Knowledge of normal CC appearance may help identify developmental anomalies and enable accurate prenatal counseling. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009 [source] Isoflurane enhances spontaneous Ca2+ oscillations in developing rat hippocampal neurons in vitroACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009Q. XIANG Background: During the nervous system development, spontaneous synchronized Ca2+ oscillations are thought to possess integrative properties because their amplitude and frequency can influence the patterning of neuronal connection, neuronal differentiation, axon outgrowth, and long-distance wiring. Accumulating studies have confirmed that some drugs such as volatile anesthetic isoflurane produced histopathologic changes in the central nervous system in juvenile animal models. Because the hippocampus plays an important role in learning and memory, the present work was designed to characterize the Ca2+ oscillations regulated by volatile anesthetic isoflurane in primary cultures of developing hippocampal neurons (5-day-cultured). Methods: Primary cultures of rat hippocampal neurons (5-day-cultured) were loaded with the Ca2+ indicator Fluo-4AM (4 ,M) and were studied with a confocal laser microscope. Results: Approximately 22% of 5-day-cultured hippocampal neurons exhibited typical Ca2+ oscillations. These oscillations were dose-dependently enhanced by isoflurane (EC50 0.5 MAC, minimum alveolar concentration) and this effect could be reverted by bicuculline (50 ,M), a specific ,-aminobutyric acid (GABAA) receptor antagonist. Conclusion: Unlike its depressant effect on the Ca2+ oscillations in adult neurons in previous researches, isoflurane dose-dependently enhanced calcium oscillations in developing hippocampal neurons by activating GABAA receptors, a major excitatory receptor in synergy with N -methyl- d -aspartate receptors at the early stages of development. It may be involved in the mechanism of an isoflurane-induced neurotoxic effect in the developing rodent brain. [source] Science and technology capacity building and partnership in African agriculture: perspectives on Mali and EgyptJOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 5 2005Seife Ayele Science and technology (S&T) have long been seen as key for development. This paper considers the issue of capacity building in the light of recent reconceptualization of the role of science and technology in development. Reconceptualization suggests that science and technology are better seen as key elements of innovation systems, which are themselves the means of gaining value from knowledge creation; and, that innovation, knowledge and development are tightly knit elements of a system of organisations and institutions that must function coherently for improved knowledge and innovation systems to emerge. Developing such systems requires linkages of many types. The paper describes and discusses the conceptual basis for capacity building interventions, using partnership-based capacity building initiatives in new agricultural technologies from Mali and Egypt. The empirical analysis from both countries shows evidence of research capacity building in the form of recruitment, training of scientific staff and provision of research infrastructure. Unsurprisingly, given the S&T knowledge base, the Malian case illustrates the difficulty of moving beyond basic forms of research capacity building. In Egypt, with significant S&T capacity, there is evidence of organizational and institutional innovation towards broader knowledge, and innovation system development in agri-biotechnology. The role of partnerships, and government as ,systems-builder', are shown to be important. Lessons are drawn from these (and other) cases about the relationship between partnerships, S&T and innovation capacity building. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||||||||||||||