101 resultados para Architecture and software patterns
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The InterPro database (http://www.ebi.ac.uk/interpro/) is a freely available resource that can be used to classify sequences into protein families and to predict the presence of important domains and sites. Central to the InterPro database are predictive models, known as signatures, from a range of different protein family databases that have different biological focuses and use different methodological approaches to classify protein families and domains. InterPro integrates these signatures, capitalizing on the respective strengths of the individual databases, to produce a powerful protein classification resource. Here, we report on the status of InterPro as it enters its 15th year of operation, and give an overview of new developments with the database and its associated Web interfaces and software. In particular, the new domain architecture search tool is described and the process of mapping of Gene Ontology terms to InterPro is outlined. We also discuss the challenges faced by the resource given the explosive growth in sequence data in recent years. InterPro (version 48.0) contains 36 766 member database signatures integrated into 26 238 InterPro entries, an increase of over 3993 entries (5081 signatures), since 2012.
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The epidemiology of skin cancer shows interplay between host susceptibility, (ultraviolet) environment, socioeconomical conditions and behavioural patterns. Its etiology is not yet fully elucidated and reveals intriguing questions. Fair-skinned populations have experienced over the last 60 years a rapid increase in the incidence of melanoma which is unparalleled by any other cancer, although signs of levelling off and stabilization in incidence have recently been observed in some countries. Despite many primary prevention and early detection campaigns over the last decades in Europe, decreases in melanoma mortality are modest and limited to a few countries. Further, reduction in the incidence of thick melanomas has not yet been evidenced. In this presentation, drivers for the incidence and mortality trends of skin cancer, with a strong focus on melanoma, its most lethal form, will be discussed.
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Hazard mapping in mountainous areas at the regional scale has greatly changed since the 1990s thanks to improved digital elevation models (DEM). It is now possible to model slope mass movement and floods with a high level of detail in order to improve geomorphologic mapping. We present examples of regional multi-hazard susceptibility mapping through two Swiss case studies, including landslides, rockfall, debris flows, snow avalanches and floods, in addition to several original methods and software tools. The aim of these recent developments is to take advantage of the availability of high resolution DEM (HRDEM) for better mass movement modeling. Our results indicate a good correspondence between inventories of hazardous zones based on historical events and model predictions. This paper demonstrates that by adapting tools and methods issued from modern technologies, it is possible to obtain reliable documents for land planning purposes over large areas.
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BACKGROUND AND PURPOSE: To investigate the effect of chronic hyperglycemia on cerebral microvascular remodeling using perfusion computed tomography. METHODS: We retrospectively identified 26 patients from our registry of 2453 patients who underwent a perfusion computed tomographic study and had their hemoglobin A1c (HbA1c) measured. These 26 patients were divided into 2 groups: those with HbA1c>6.5% (n=15) and those with HbA1c≤6.5% (n=11). Perfusion computed tomographic studies were processed using a delay-corrected, deconvolution-based software. Perfusion computed tomographic values were compared between the 2 patient groups, including mean transit time, which relates to the cerebral capillary architecture and length. RESULTS: Mean transit time values in the nonischemic cerebral hemisphere were significantly longer in the patients with HbA1c>6.5% (P=0.033), especially in the white matter (P=0.005). Significant correlation (R=0.469; P=0.016) between mean transit time and HbA1c level was observed. CONCLUSIONS: Our results from a small sample suggest that chronic hyperglycemia may be associated with cerebral microvascular remodeling in humans. Additional prospective studies with larger sample size are required to confirm this observation.
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The QDR (quinidine drug resistance) family of genes encodes transporters belonging to the MFS (major facilitator superfamily) of proteins. We show that QDR transporters, which are localized to the plasma membrane, do not play a role in drug transport. Hence, null mutants of QDR1, QDR2 and QDR3 display no alterations in susceptibility to azoles, polyenes, echinocandins, polyamines or quinolines, or to cell wall inhibitors and many other stresses. However, the deletion of QDR genes, individually or collectively, led to defects in biofilm architecture and thickness. Interestingly, QDR-lacking strains also displayed attenuated virulence, but the strongest effect was observed with qdr2∆, qdr3∆ and in qdr1/2/3∆ strains. Notably, the attenuated virulence and biofilm defects could be reversed upon reintegration of QDR genes. Transcripts profiling confirmed differential expression of many biofilm and virulence-related genes in the deletion strains as compared with wild-type Candida albicans cells. Furthermore, lipidomic analysis of QDR-deletion mutants suggests massive remodelling of lipids, which may affect cell signalling, leading to the defect in biofilm development and attenuation of virulence. In summary, the results of the present study show that QDR paralogues encoding MFS antiporters do not display conserved functional linkage as drug transporters and perform functions that significantly affect the virulence of C. albicans.
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Since the first anti-doping tests in the 1960s, the analytical aspects of the testing remain challenging. The evolution of the analytical process in doping control is discussed in this paper with a particular emphasis on separation techniques, such as gas chromatography and liquid chromatography. These approaches are improving in parallel with the requirements of increasing sensitivity and selectivity for detecting prohibited substances in biological samples from athletes. Moreover, fast analyses are mandatory to deal with the growing number of doping control samples and the short response time required during particular sport events. Recent developments in mass spectrometry and the expansion of accurate mass determination has improved anti-doping strategies with the possibility of using elemental composition and isotope patterns for structural identification. These techniques must be able to distinguish equivocally between negative and suspicious samples with no false-negative or false-positive results. Therefore, high degree of reliability must be reached for the identification of major metabolites corresponding to suspected analytes. Along with current trends in pharmaceutical industry the analysis of proteins and peptides remains an important issue in doping control. Sophisticated analytical tools are still mandatory to improve their distinction from endogenous analogs. Finally, indirect approaches will be discussed in the context of anti-doping, in which recent advances are aimed to examine the biological response of a doping agent in a holistic way.
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The objective of this study was to assess breeding and dispersal patterns of both males and females in a monogyne (a single queen per colony) population of ants. Monogyny is commonly associated with extensive nuptial flights, presumably leading to considerable gene flow over large areas. Opposite to these expectations we found evidence of both inbreeding and sex-biased gene flow in a monogyne population of Formica exsecta. We found a significant degree of population subdivision at a local scale (within islands) for queens (females heading established colonies) and workers, but not for colony fathers (the males mated to the colony queens). However, we found little evidence of population subdivision at a larger scale (among islands). More conclusive support for sex-biased gene flow comes from the analysis of isolation by distance on the largest island, and from assignment tests revealing differences in female and male philopatry. The genetic similarity between pairs of queens decreased significantly when geographical distance increased, demonstrating limited dispersal and isolation by distance in queens. By contrast, we found no such pattern for colony fathers. Furthermore, a significantly greater fraction of colony queens were assigned as having originated from the population of residence, as compared to colony fathers. Inbreeding coefficients were significantly positive for workers, but not for mother queens. The queen-male relatedness coefficient of 0.23 (regression relatedness) indicates that mating occurs between fairly close relatives. These results suggest that some monogyne species of ants have complex dispersal and mating systems that can result in genetic isolation by distance over small geographical scales. More generally, this study also highlights the importance of identifying the relevant scale in analyses of population structure and dispersal.
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Introduction: Recently, mesenchymal stem cells (MSC) of perivascular origin have been identified in several organs not including the heart. Using a novel cell isolation protocol, we have isolated cells sharing common characteristics from mouse hearts and pancreas. The aim of the present study was to characterize these cells in vitro.Methods: Cells were isolated from neonatal and adult mouse hearts and pancreas and cultured for more than 6 months. Surface marker expression was analyzed by flow cytometry and immunocytochemistry. Cell differentiation was tested using multiple differentiation media. Insulin production by pancreas-derived cells was tested by dithizone staining.Results: Cells showing a similar, distinctive morphology were obtained from the heart and pancreas after 4-8 weeks of culture. Cells from the two organs also showed a very similar immunophenotype, characterized by expression of c-kit (stem cell factor receptor), CD44, the common leukocyte marker CD45, and the monocytic markers CD11b and CD14. A significant proportion of cardiac and pancreatic cells expressed NG2, a marker for pericytes and other vascular cells. A significant proportion of cardiac, but not of pancreatic cells expressed stem cell antigen-1 (Sca-1). However, cells did not express T, B or dendritic cell markers. Cells of both cardiac and pancreatic origin spontaneously formed "spheres" (spherical cell aggregates similar to "neurospheres" formed by neural stem cells) in vitro. Cardiosphere formation was enhanced by TNF-alpha. Several cardiospheres (but no "pancreatospheres") derived from neonatal (but not adult) cells showed spontaneous rhythmic contractions, thus demonstrating cardiac differentiation (this was confirmed by immunostaining for alpha-sarcomeric actinin). Beating activity was enhanced by low serum conditions. Cells from both organs formed adipocytes, osteocytes and osteocytes under appropriate conditions, the typical differentiation pattern of MSCs. Pancreas-derived cells also formed dithizonepositive insulin-producing cells.Conclusions: We have defined cardiac and pancreatic cell populations that share a common morphology, growth characteristics, and a unique immunophenotype. Expression of perivascular and monocytic markers, along with stem/priogenitor cell markers by these cells suggests a relationship with pericytes-mesoangioblasts and so-called multipotent monocytes. Cells show MSC-typical growth and differentiation patterns, together with tissue-specific differentiation potential: cardiomyocytes for cardiac-derived cells and insulinproducing cells for pancreas-derived cells.
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CONTEXT AND OBJECTIVES: A multicentric study was set up to assess the feasibility for Swiss cancer registries of actively retrieving 3 additional variables of epidemiological and a etiological relevance for melanoma, and of potential use for the evaluation of prevention campaigns. MATERIAL AND METHODS: The skin type, family history of melanoma and precise anatomical site were retrieved for melanoma cases registered in 5 Swiss cantons (Neuchâtel, St-Gall and Appenzell, Vaud and Wallis) over 3 to 6 consecutive years (1995-2002). Data were obtained via a short questionnaire administered by the physicians - mostly dermatologists - who originally excised the lesions. As the detailed body site was routinely collected in Ticino, data from this Cancer Registry were included in the body site analysis. Relative melanoma density (RMD) was computed by the ratio of observed to expected numbers of melanomas allowing for body site surface areas, and further adjusted for site-specific melanocyte density. RESULTS: Of the 1,645 questionnaires sent, 1,420 (86.3%) were returned. The detailed cutaneous site and skin type were reliably obtained for 84.7% and 78.7% of questionnaires, and family history was known in 76% of instances. Prevalence of sun-sensitive subjects and patients with melanoma affected first-degree relatives, two target groups for early detection and surveillance campaigns were 54.1% and 3.4%, respectively. After translation into the 4th digit of the International Classification of Diseases for Oncology, the anatomical site codes from printed (original information) and pictorial support (body chart from the questionnaire) concurred for 94.6% of lesions. Discrepancies occurred mostly for lesions on the upper, outer part of the shoulder for which the clinician's textual description was "shoulder blade". This differential misclassification suggests under-estimation by about 10% of melanomas of the upper limbs and an over-estimation of 5% for truncal melanomas. Sites of highest melanoma risk were the face, the shoulder and the upper arm for sexes, the back for men and the leg for women. Three major features of this series were: (1) an unexpectedly high RMD for the face in women (6.2 vs 4.2 in men), (2) the absence of a male predominance for melanomas on the ears, and (3) for the upper limbs, a steady gradient of increasing melanoma density with increasing proximity to the trunk, regardless of sex. DISCUSSION AND CONCLUSION: The feasibility of retrieving the skin type, the precise anatomical location and family history of melanoma in a reliable manner was demonstrated thanks to the collaboration of Swiss dermatologists. Use of a schematic body drawing improves the quality of the anatomical site data and facilitate the reporting task of doctors. Age and sex patterns of RMD paralleled general indicators of sun exposure and behaviour, except for the hand (RMD=0.2). These Swiss results support some site or sun exposure specificity in the aetiology of melanoma.
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This paper reports on the purpose, design, methodology and target audience of E-learning courses in forensic interpretation offered by the authors since 2010, including practical experiences made throughout the implementation period of this project. This initiative was motivated by the fact that reporting results of forensic examinations in a logically correct and scientifically rigorous way is a daily challenge for any forensic practitioner. Indeed, interpretation of raw data and communication of findings in both written and oral statements are topics where knowledge and applied skills are needed. Although most forensic scientists hold educational records in traditional sciences, only few actually followed full courses that focussed on interpretation issues. Such courses should include foundational principles and methodology - including elements of forensic statistics - for the evaluation of forensic data in a way that is tailored to meet the needs of the criminal justice system. In order to help bridge this gap, the authors' initiative seeks to offer educational opportunities that allow practitioners to acquire knowledge and competence in the current approaches to the evaluation and interpretation of forensic findings. These cover, among other aspects, probabilistic reasoning (including Bayesian networks and other methods of forensic statistics, tools and software), case pre-assessment, skills in the oral and written communication of uncertainty, and the development of independence and self-confidence to solve practical inference problems. E-learning was chosen as a general format because it helps to form a trans-institutional online-community of practitioners from varying forensic disciplines and workfield experience such as reporting officers, (chief) scientists, forensic coordinators, but also lawyers who all can interact directly from their personal workplaces without consideration of distances, travel expenses or time schedules. In the authors' experience, the proposed learning initiative supports participants in developing their expertise and skills in forensic interpretation, but also offers an opportunity for the associated institutions and the forensic community to reinforce the development of a harmonized view with regard to interpretation across forensic disciplines, laboratories and judicial systems.
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AbstractIn addition to genetic changes affecting the function of gene products, changes in gene expression have been suggested to underlie many or even most of the phenotypic differences among mammals. However, detailed gene expression comparisons were, until recently, restricted to closely related species, owing to technological limitations. Thus, we took advantage of the latest technologies (RNA-Seq) to generate extensive qualitative and quantitative transcriptome data for a unique collection of somatic and germline tissues from representatives of all major mammalian lineages (placental mammals, marsupials and monotremes) and birds, the evolutionary outgroup.In the first major project of my thesis, we performed global comparative analyses of gene expression levels based on these data. Our analyses provided fundamental insights into the dynamics of transcriptome change during mammalian evolution (e.g., the rate of expression change across species, tissues and chromosomes) and allowed the exploration of the functional relevance and phenotypic implications of transcription changes at a genome-wide scale (e.g., we identified numerous potentially selectively driven expression switches).In a second project of my thesis, which was also based on the unique transcriptome data generated in the context of the first project we focused on the evolution of alternative splicing in mammals. Alternative splicing contributes to transcriptome complexity by generating several transcript isoforms from a single gene, which can, thus, perform various functions. To complete the global comparative analysis of gene expression changes, we explored patterns of alternative splicing evolution. This work uncovered several general and unexpected patterns of alternative splicing evolution (e.g., we found that alternative splicing evolves extremely rapidly) as well as a large number of conserved alternative isoforms that may be crucial for the functioning of mammalian organs.Finally, the third and final project of my PhD consisted in analyzing in detail the unique functional and evolutionary properties of the testis by exploring the extent of its transcriptome complexity. This organ was previously shown to evolve rapidly both at the phenotypic and molecular level, apparently because of the specific pressures that act on this organ and are associated with its reproductive function. Moreover, my analyses of the amniote tissue transcriptome data described above, revealed strikingly widespread transcriptional activity of both functional and nonfunctional genomic elements in the testis compared to the other organs. To elucidate the cellular source and mechanisms underlying this promiscuous transcription in the testis, we generated deep coverage RNA-Seq data for all major testis cell types as well as epigenetic data (DNA and histone methylation) using the mouse as model system. The integration of these complete dataset revealed that meiotic and especially post-meiotic germ cells are the major contributors to the widespread functional and nonfunctional transcriptome complexity of the testis, and that this "promiscuous" spermatogenic transcription is resulting, at least partially, from an overall transcriptionally permissive chromatin state. We hypothesize that this particular open state of the chromatin results from the extensive chromatin remodeling that occurs during spermatogenesis which ultimately leads to the replacement of histones by protamines in the mature spermatozoa. Our results have important functional and evolutionary implications (e.g., regarding new gene birth and testicular gene expression evolution).Generally, these three large-scale projects of my thesis provide complete and massive datasets that constitute valuables resources for further functional and evolutionary analyses of mammalian genomes.
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PURPOSE OF REVIEW: We present an overview of recent concepts in mechanisms underlying cognitive decline associated with brain aging and neurodegeneration from the perspective of MRI. RECENT FINDINGS: Recent findings challenge the established link between neuroimaging biomarkers of neurodegeneration and age-related or disease-related cognitive decline. Amyloid burden, white matter hyperintensities and local patterns of brain atrophy seem to have differential impact on cognition, particularly on episodic and working memory - the most vulnerable domains in 'normal aging' and Alzheimer's disease. Studies suggesting that imaging biomarkers of neurodegeneration are independent of amyloid-β give rise to new hypothesis regarding the pathological cascade in Alzheimer's disease. Findings in patients with autosomal-dominant Alzheimer's disease confirm the notion of differential temporal trajectory of amyloid deposition and brain atrophy to add another layer of complexity on the basic mechanisms of cognitive aging and neurodegeneration. Finally, the concept of cognitive reserve in 'supernormal aging' is questioned by evidence for the preservation of neurochemical, structural and functional brain integrity in old age rather than recruitment of 'reserves' for maintaining cognitive abilities. SUMMARY: Recent advances in clinical neuroscience, brain imaging and genetics challenge pathophysiological hypothesis of neurodegeneration and cognitive aging dominating the field in the last decade and call for reconsidering the choice of therapeutic window for early intervention.
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Sequence data from regions of five vertebrate vitellogenin genes were used to examine the frequency, distribution, and mutability of the dinucleotide CpG, the preferred modification site for eukaryotic DNA methyltransferases. The observed level of the CpG dinucleotide in all five genes was markedly lower than that expected from the known mononucleotide frequencies. CpG suppression was greater in introns than in exons. CpG-containing codons were found to be avoided in the vitellogenin genes, but not completely despite the redundancy of the genetic code. Frequency and distribution patterns of this dinucleotide varied dramatically among these otherwise closely related genes. Dense clusters of CpG dinucleotides tended to appear in regions of either functional or structural interest (e.g., in the transposon-like Vi-element of Xenopus) and these clusters contained 5-methylcytosine (5 mC). 5 mC is known to undergo deamination to form thymidine, but the extent to which this transition occurs in the heavily methylated genomes of vertebrates and its contribution to CpG suppression are still unclear. Sequence comparison of the methylated vitellogenin gene regions identified C----T and G----A substitutions that were found to occur at relatively high frequencies. The predicted products of CpG deamination, TpG and CpA, were elevated. These findings are consistent with the view that CpG distribution and methylation are interdependent and that deamination of 5 mC plays an important role in promoting evolutionary change at the nucleotide sequence level.
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Molecular chaperones are central to cellular protein homeostasis. In mammals, protein misfolding diseases and aging cause inflammation and progressive tissue loss, in correlation with the accumulation of toxic protein aggregates and the defective expression of chaperone genes. Bacteria and non-diseased, non-aged eukaryotic cells effectively respond to heat shock by inducing the accumulation of heat-shock proteins (HSPs), many of which molecular chaperones involved in protein homeostasis, in reducing stress damages and promoting cellular recovery and thermotolerance. We performed a meta-analysis of published microarray data and compared expression profiles of HSP genes from mammalian and plant cells in response to heat or isothermal treatments with drugs. The differences and overlaps between HSP and chaperone genes were analyzed, and expression patterns were clustered and organized in a network. HSPs and chaperones only partly overlapped. Heat-shock induced a subset of chaperones primarily targeted to the cytoplasm and organelles but not to the endoplasmic reticulum, which organized into a network with a central core of Hsp90s, Hsp70s, and sHSPs. Heat was best mimicked by isothermal treatments with Hsp90 inhibitors, whereas less toxic drugs, some of which non-steroidal anti-inflammatory drugs, weakly expressed different subsets of Hsp chaperones. This type of analysis may uncover new HSP-inducing drugs to improve protein homeostasis in misfolding and aging diseases.
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BACKGROUND: Over the last 4 decades, childhood cancer mortality declined in most developed areas of the world. However, scant information is available from middle-income and developing countries. The authors analyzed and compared patterns in childhood cancer mortality in 24 developed and middle-income countries in America, Asia, and Oceania between 1970 and 2007. METHODS: Childhood age-standardized annual mortality rates were derived from the World Health Organization (WHO) database for all neoplasms, bone and kidney cancer, non-Hodgkin lymphoma (NHL), and leukemias. RESULTS: Since 1970, rates for all childhood cancers dropped from approximately 8 per 100,000 boys to 3 per 100,000 boys and from 6 per 100,000 girls to 2 per 100,000 girls in North America and Japan. Latin American countries registered rates of approximately 5 per 100,000 boys and 4 per 100,000 girls for 2005 through 2007, similar to the rates registered in more developed areas in the early 1980s. Similar patterns were observed for leukemias, for which the mortality rates were 0.81 per 100,000 boys and 0.55 per 100,000 girls in North America, 0.86 per 100,000 boys and 0.68 per 100,000 girls in Japan, and 1.98 per 100,000 boys and 1.65 per 100,000 girls in Latin America for 2005 through 2007. Bone cancer rates for 2005 through 2007 were approximately 2-fold higher in Argentina than in the United States. During the same period, Mexico registered the highest rate for kidney cancer and Colombia registered the highest rate for NHL, whereas the lowest rates were registered by Japan for kidney and by Japan and the United States for NHL. CONCLUSIONS: Improvements in the adoption of current integrated treatment protocols in Latin American and other lower- and middle-income countries worldwide would avoid a substantial proportion of childhood cancer deaths.