51 research outputs found

    High Availability in the Future Internet

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    With the evolution of the Internet, a huge number of real- time applications, like Voice over IP, has started to use IP as primary transmission medium. These services require high availability, which is not amongst the main features of today’s heterogeneous Internet where fail- ures occur frequently. Unfortunately, the primary fast resilience scheme implemented in IP routers, Loop-Free Alternates (LFA), usually does not provide full protection against failures. Consequently, there has been a growing interest in LFA-based network optimization methods, aimed at tuning some aspect of the underlying IP topology to maximize the ratio of failure cases covered by LFA. The main goal of this chapter is to give a comprehensive overview of LFA and survey the related LFA network op- timization methods, pointing out that these optimization tools can turn LFA into an easy-to-deploy yet highly effective IP fast resilience scheme

    Pathogenic variants in the DEAH-box RNA helicase DHX37 are a frequent cause of 46,XY gonadal dysgenesis and 46,XY testicular regression syndrome

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    PURPOSE: XY individuals with disorders/differences of sex development (DSD) are characterized by reduced androgenization caused, in some children, by gonadal dysgenesis or testis regression during fetal development. The genetic etiology for most patients with 46,XY gonadal dysgenesis and for all patients with testicular regression syndrome (TRS) is unknown. METHODS: We performed exome and/or Sanger sequencing in 145 individuals with 46,XY DSD of unknown etiology including gonadal dysgenesis and TRS. RESULTS: Thirteen children carried heterozygous missense pathogenic variants involving the RNA helicase DHX37, which is essential for ribosome biogenesis. Enrichment of rare/novel DHX37 missense variants in 46,XY DSD is highly significant compared with controls (P value = 5.8 × 10-10). Five variants are de novo (P value = 1.5 × 10-5). Twelve variants are clustered in two highly conserved functional domains and were specifically associated with gonadal dysgenesis and TRS. Consistent with a role in early testis development, DHX37 is expressed specifically in somatic cells of the developing human and mouse testis. CONCLUSION: DHX37 pathogenic variants are a new cause of an autosomal dominant form of 46,XY DSD, including gonadal dysgenesis and TRS, showing that these conditions are part of a clinical spectrum. This raises the possibility that some forms of DSD may be a ribosomopathy

    The First Post-Kepler Brightness Dips of KIC 8462852

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    We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <<1um, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process

    The First Post-Kepler Brightness Dips of KIC 8462852

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    Update in Molecular Biology for Teachers from Public Schools: a Knowledge Exchange Experience.

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    One  of the goals of the graduate Program in Molecular Biology from UNIFESP (PrMB -UNIFESP) is to contribute for continuing education of biology teachers from public high schools. A close relation between university and public schools is an important channel for dissemination of scientific knowledge. Thus, a 40h Molecular Biology updating course was offered to 20 high school teachers. The objective was to discuss genomic and proteomic advances and their application. The course was organized by graduate students  from PrMB -UNIFESP. Three groups ofstudents were formed, two being responsible for theorical and practical classes and one for global logistic including searching for financial support. The themes presented to the teachers were flow of genetic information,  recombinant DNA, gene cloning, transgenic plants and animals, mutation, super bacteria and stem cell. The teachers also had hands-on classes including DNA extraction, PCR, gene cloning and SDS-PAGE. The teachers received an assignment to go back to their s chools and do some activity with their students that would be related to the themes discussed. The students produced videos, discussions, posters, theater, experimental models and pratical classes related to the course themes. After 3 months the teachers r eturned to show their students’ work.  We conclude that information was transmitted to the teachers, updating them, and to high school students, that learned science in a entertaining way. Also, the graduate students had an experience on how to organize a c ourse including all its responsibilities

    Y-chromosome markers in Turner syndrome: Screening of 130 patients

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    BACKGROUND: The presence of Y-chromosome material in patients with Turner syndrome (TS) is a risk factor for the development of gonadoblastoma. Cytogenetic analysis detects Y-chromosome mosaicism in about 5% of Turner patients. However, if Y-chromosome sequences are present in only a few cells, they may be missed by routine analysis. The use of molecular techniques to detect the presence of Y-chromosome fragments in such patients is becoming increasingly important. AIM: The objective of our study was to analyze cryptic Y-chromosome derivatives in Hungarian TS patient population by real-time PCR (RT-PCR). SUBJECTS AND METHODS: Cytogenetic and RT-PCR methods were used to examine peripheral blood DNA of 130 Hungarian patients with TS for the presence of Y-chromosome. With RT-PCR, 4 regions throughout the Y-chromosome were analyzed. RESULTS: Initial cytogenetic karyotyping assessing 10-50 metaphases revealed 3 patients with Y-chromosome positivity. RT-PCR revealed further 6 patients with Y-chromosome, who were initially considered as Y-negatives by standard kayotyping. The consecutive cytogenetic analysis of a large number (about 100) of metaphases (in 5 patients) and/or FISH (in 6 patients) however, also confirmed the presence of the Y-chromosome in these patients. Prophylactic gonadectomy was carried out in all 9 patients and 1 of them was diagnosed as having bilateral gonadoblastoma without clinical symptoms. CONCLUSIONS: We recommend a routine molecular screening for hidden Y-chromosome sequences in Turner patients, who are negative for Y-chromosome by conventional cytogenetic analysis, in order to calculate the future risk of developing gonadoblastoma

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