441 research outputs found

    Identification of chromosomes involved in a Robertsonian translocation in cattle

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    Summary- The chromosomes involved in the robertsonian translocation described after classical Giemsa staining by Darre et al. (1974), were determined using G(GTG), R(RBA) and C(CBG) banding techniques. The chromosomes in question were identified as chromosomes 9 and 23. cattle- chromosome- robertsonian translocation Résumé- Les chromosomes impliqués dans une translocation robertsonienne décrite, tout d’abord, en coloration conventionnelle par Darre et al. (1974) ont été déterminés à l’aide des techniques de marquage G(GTG), R(RBA) et C(CBG). sont le 9 et le 23. boeuf- chromosome- translocation robertsonienne Les chromosomes concerné

    Cytogenetic investigation in Saanen and Alpine artificial insemination bucks. Identification of a Robertsonian translocation

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    The cytogenetic study of 224 AI Saanen and Alpine he-goats revealed the presence of a Saanen animal carrying a Robertsonian translocation. The chromosomes involved in this translocation were determined using G (GTG) and C (CBG) banding techniques. The chromosomes in question were identified as chromosomes 6 and 15.L’étude cytogénétique de 224 boucs d’insémination artificielle de races Saanen et Alpine a permis de mettre en évidence la présence d’un animal de race Saanen porteur d’une translocation robertsonienne. Les chromosomes impliqués dans cette translocation ont été déterminés à l’aide des techniques de marquage G (GTG) et C (CBG). Les chromosomes concernés sont le 6 et le 15

    Rhetoric, organizational category dynamics and institutional change : a study of the UK Welfare State

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    Accounts of institutional change and categorization conventionally assume that high-status change agents can impose change, even to stable category systems, which lower-status actors accommodate in order to ensure social approval and material resources. By exploring the UK Conservative-Liberal Coalition's rhetorical efforts to reform the welfare state, how welfare providers are categorized and the subsequent response of implicated category members, we offer instead an account of institutional change that exposes the agentic limitations of high-status actors. Whilst governments may well be in a position to impose changes in the formal rules of the game through manipulation of material resources (fiscal contraction, privatization, open markets, deregulation), we find that they cannot necessarily monopolize symbolic resources (identities/cultural features). We also find that deviation from cultural expectations is not only available to large, high-status organizations, low-status actors too have discretion over their responses to institutional pressures regarding how they are categorized and subsequently judged

    Influence of the initial chemical conditions on the rational design of silica particles

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    The influence of the water content in the initial composition on the size of silica particles produced using the Stöber process is well known. We have shown that there are three morphological regimes defined by compositional boundaries. At low water levels (below stoichiometric ratio of water:tetraethoxysilane), very high surface area and aggregated structures are formed; at high water content (>40 wt%) similar structures are also seen. Between these two boundary conditions, discrete particles are formed whose size are dictated by the water content. Within the compositional regime that enables the classical Stöber silica, the structural evolution shows a more rapid attainment of final particle size than the rate of formation of silica supporting the monomer addition hypothesis. The clearer understanding of the role of the initial composition on the output of this synthesis method will be of considerable use for the establishment of reliable reproducible silica production for future industrial adoption

    Genetic determinants of co-accessible chromatin regions in activated T cells across humans.

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    Over 90% of genetic variants associated with complex human traits map to non-coding regions, but little is understood about how they modulate gene regulation in health and disease. One possible mechanism is that genetic variants affect the activity of one or more cis-regulatory elements leading to gene expression variation in specific cell types. To identify such cases, we analyzed ATAC-seq and RNA-seq profiles from stimulated primary CD4+ T cells in up to 105 healthy donors. We found that regions of accessible chromatin (ATAC-peaks) are co-accessible at kilobase and megabase resolution, consistent with the three-dimensional chromatin organization measured by in situ Hi-C in T cells. Fifteen percent of genetic variants located within ATAC-peaks affected the accessibility of the corresponding peak (local-ATAC-QTLs). Local-ATAC-QTLs have the largest effects on co-accessible peaks, are associated with gene expression and are enriched for autoimmune disease variants. Our results provide insights into how natural genetic variants modulate cis-regulatory elements, in isolation or in concert, to influence gene expression

    Liquid-gas phase transition in nuclear multifragmentation

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    The equation of state of nuclear matter suggests that at suitable beam energies the disassembling hot system formed in heavy ion collisions will pass through a liquid-gas coexistence region. Searching for the signatures of the phase transition has been a very important focal point of experimental endeavours in heavy ion collisions, in the last fifteen years. Simultaneously theoretical models have been developed to provide information about the equation of state and reaction mechanisms consistent with the experimental observables. This article is a review of this endeavour.Comment: 63 pages, 27 figures, submitted to Adv. Nucl. Phys. Some typos corrected, minor text change

    Wordless intervention for epilepsy in learning disabilities (WIELD):study protocol for a randomized controlled feasibility trial

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    Epilepsy is the most common neurological problem that affects people with learning disabilities. The high seizure frequency, resistance to treatments, associated skills deficit and co-morbidities make the management of epilepsy particularly challenging for people with learning disabilities. The Books Beyond Words booklet for epilepsy uses images to help people with learning disabilities manage their condition and improve quality of life. Our aim is to conduct a randomized controlled feasibility trial exploring key methodological, design and acceptability issues, in order to subsequently undertake a large-scale randomized controlled trial of the Books Beyond Words booklet for epilepsy

    45S rDNA Regions Are Chromosome Fragile Sites Expressed as Gaps In Vitro on Metaphase Chromosomes of Root-Tip Meristematic Cells in Lolium spp

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    BACKGROUND: In humans, chromosome fragile sites are regions that are especially prone to forming non-staining gaps, constrictions or breaks in one or both of the chromatids on metaphase chromosomes either spontaneously or following partial inhibition of DNA synthesis and have been well identified. So far, no plant chromosome fragile sites similar to those in human chromosomes have been reported. METHODS AND RESULTS: During the course of cytological mapping of rDNA on ryegrass chromosomes, we found that the number of chromosomes plus chromosome fragments was often more than the expected 14 in most cells for Lolium perenne L. cv. Player by close cytological examination using a routine chromosome preparation procedure. Further fluorescent in situ hybridization (FISH) using 45S rDNA as a probe indicated that the root-tip cells having more than a 14-chromosome plus chromosome fragment count were a result of chromosome breakage or gap formation in vitro (referred to as chromosome lesions) at 45S rDNA sites, and 86% of the cells exhibited chromosome breaks or gaps and all occurred at the sites of 45S rDNA in Lolium perenne L. cv. Player, as well as in L. multiflorum Lam. cv. Top One. Chromatin depletion or decondensation occurred at various locations within the 45S rDNA regions, suggesting heterogeneity of lesions of 45S rDNA sites with respect to their position within the rDNA region. CONCLUSIONS: The chromosome lesions observed in this study are very similar cytologically to that of fragile sites observed in human chromosomes, and thus we conclude that the high frequency of chromosome lesions in vitro in Lolium species is the result of the expression of 45S rDNA fragile sites. Possible causes for the spontaneous expression of fragile sites and their potential biological significance are discussed
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