888 research outputs found

    Toward a Third Industrial Divide?

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    Introduction: The Second Divide Revisited The Second Industrial Divide: Possibilities for Prosperity was written in another time of great despair about the future of the American economy. Michael Piore and Charles Sabel described the mid-eighties in terms that seem to fit our own predicament: “The times are troubled indeed when thegood news is almost indistinguishable from the bad. Economic downturns no longer seem mere interruptions in the march to greater prosperity; rather they threaten to destroy the world markets on which economic success has depended since the end of World War II. Meanwhile, upturns avert disaster without solving the problems of unemployment and slow growth, which have become chronic in almost all the advanced countries. No theory seems able to explain recent events, let alone predict what will happen next.” (Piore and Sabel 1984, p. 3)

    Molecular associations of recurrent spontaneous abortion

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    Approximately one in four pregnant women experience one or more miscarriages, making spontaneous abortion the most common pregnancy complication, and of public health importance. Recurrent spontaneous abortion (RSA) can be defined as the loss of two or more pregnancies and affects 1% of couples. This prevalence is higher than expected by chance, suggesting some couples have an underlying systemic cause for RSA. We have chosen to study two immunological aspects of pregnancy loss. The first involves maternal defense against infection in terms of predicted mannose binding lectin (MBL) plasma levels. The second approach is to analyze the human leukocyte antigen-G (HLA-G) gene, which is believed to play a role in maternal recognition of paternal antigens at the maternal-fetal interface. The case population included women having two or more clinically recognized spontaneous abortions as well as having unknown etiology for RSA. Controls subjects were selected from healthy primiparous women with no history of miscarriage. Cases and controls were genotyped for five MBL single nucleotide polymorphisms (SNPs). Both populations genotyped were in Hardy-Weinberg equilibrium, at all five sites. Fisher's exact test of cases and controls was not significant at each of the five sites, p-values > 0.05. No association was observed between MBL genotypes or predicted MBL plasma levels and risk of RSA, or presence of live birth and recurrent pregnancy loss, among women with unexplained RSA. Using the same population, the HLA-G promoter region and 3' untranslated region (UTR) was sequenced in cases and controls. Twenty-three SNPs were observed with a minor allele frequency >0.02 in the promoter region. Linkage disequilibrium was detected throughout 1400 base pairs of the promoter region that were sequenced. While SNP data revealed allele frequency differences between cases and controls, haplotype data proved even more beneficial; one haplotype potentially predicting increased risk of RSA, while the other potentially protecting against risk of RSA. Finally, cases had a higher frequency of individuals homozygous for the 14 base pair insertion in the 3' UTR

    FACS purification and transcriptome analysis of drosophila neural stem cells reveals a role for Klumpfuss in self-renewal

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    Drosophila neuroblasts (NBs) have emerged as a model for stem cell biology that is ideal for genetic analysis but is limited by the lack of cell-type-specific gene expression data. Here, we describe a method for isolating large numbers of pure NBs and differentiating neurons that retain both cell-cycle and lineage characteristics. We determine transcriptional profiles by mRNA sequencing and identify 28 predicted NB-specific transcription factors that can be arranged in a network containing hubs for Notch signaling, growth control, and chromatin regulation. Overexpression and RNA interference for these factors identify Klumpfuss as a regulator of self-renewal. We show that loss of Klumpfuss function causes premature differentiation and that overexpression results in the formation of transplantable brain tumors. Our data represent a valuable resource for investigating Drosophila developmental neurobiology, and the described method can be applied to other invertebrate stem cell lineages as well

    Study of an Acrylamide-based Photopolymer for use as a Holographic Data Storage Medium

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    An acrylamide-based photopolymer formulated in the Centre for Industrial and Engineering Optics has been investigated with a view to further optimisation for holographic optical storage. Series of 15 to 30 gratings were angularly multiplexed in a volume of the photopolymer layers with different thickness at a spatial frequency of 1500 lines/mm. Since the photopolymer is a saturable material, an exposure scheduling method was used to exploit the entire dynamic range of the material and allow equal strength gratings to be recorded. From this investigation the photopolymer layer’s M/# was determined with regard to the recording geometry used. The temporal stability of photopolymer layers was studied in terms of diffraction efficiency and change of the reconstructed angle due to material shrinkage. In addition, the potential of the photopolymer as a holographic data storage medium was demonstrated by recording bit data-pages

    Steady and Transient Radio Emission from Ultracool Dwarfs

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    We detect radio emission in an additional two epochs of the ultracool dwarf binary LP 349- 25, finding that the observed emission is broadband and steady on timescales between 10s and 10.7 hours, as well as on timescales of 0.6 and 1.6 years. This system is unusual for ultracool dwarfs with detectable radio emission, in exhibiting a lack of any large scale variability, particularly the bursting (periodic or aperiodic) behavior exhibited by the other objects with detectable levels of radio emission. We explore the constraints that the lack of variability on long and short timescales, and flat spectral index, imply about the radio-emitting structures and mechanism. The temporal constraints argue for a high latitude emitting region with a large inclination so that it is always in view, and survives for at least 0.6 year. Temporal constraints also limit the plasma conditions, implying that the electron density be n_e <4x10^5 cm-3 and B < 130 G in order not to see time variations due to collisional or radiative losses from high energy particles. The observations and constraints provided by them are most compatible with a nonthermal radio emission mechanism, likely gyrosynchrotron emission from a spatially homogeneous or inhomogeneous source. This indicates that, similar to behaviors noted for chromospheric, transition region, and coronal plasmas in ultracool dwarfs, the magnetic activity patterns observed in active higher mass stars can survive to the substellar boundary. We also present new epochs of multi-frequency radio observations for the the ultracool dwarfs 2MASS 05233822-140322 and 2MASS14563831-2809473(=LHS 3003); each has been detected in at least one previous epoch but are not detected in the epochs reported here.Comment: 28 pages, two figures, accepted for publication in Ap

    Amblyomma hebraeum is the predominant tick species on goats in the Mnisi Community Area of Mpumalanga Province South Africa and is co-infected with Ehrlichia ruminantium and Rickettsia africae

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    BACKGROUND : In sub-Saharan Africa, Amblyomma ticks are vectors of heartwater disease in domestic ruminants, caused by the rickettsial pathogen Ehrlichia ruminantium. Immature tick stages often bite humans, whereby they act as vectors of tick-bite fever caused by Rickettsia africae. Moreover, Amblyomma ticks cause damage to livestock due to their feeding behaviour. In South Africa, we studied the abundance of Amblyomma hebraeum ticks on goats of emerging farmers in Mpumalanga Province. A selected number of A. hebraeum nymphs and adult ticks was tested for co-infection with E. ruminantium and R. africae. METHODS : A total of 630 indigenous goats, belonging to farmers in the Mnisi Community area, were examined for ticks in 2013 and 2014. All ticks were identified, and a selected number was tested by PCR with reverse line blot hybridisation. RESULTS : In total, 13,132 ticks were collected from goats distributed over 17 different households. Amblyomma hebraeum was the predominant species, followed by R. microplus. Rhipicephalus appendiculatus, R. simus and R. zambeziensis were also identified. Amblyomma hebraeum was present throughout the year, with peak activity of adults in summer (November) and nymphs in winter (July). The ratio between adults and nymphs ranged from 1:2.7 in summer to 1:55.1 in winter. The mean prevalence of infection for E. ruminantium by PCR/RLB in adult ticks was 17.4% (31/178), whereas 15.7% (28/178) were infected with R. africae. In pooled nymphs, 28.4% were infected with E. ruminantium and 38.8% carried R. africae infection. Co-infections of E. ruminantium and R. africae in adult and pooled nymphal ticks were 3.9% (7/178) and 10% (14.9), respectively. Lameness of goats due to predilection of ticks for the interdigital space of their feet was observed in 89% of the households. CONCLUSIONS : Goats act as important alternative hosts for cattle ticks, which underscored the necessity to include goats in control programs. It is suggested to use acaricide-impregnated leg-bands as a sustainable method to kill ticks and prevent lameness in goats. The challenge of goats by considerable numbers of E. ruminantium-infected ticks is a major obstacle for upgrading the indigenous goat breeds. Humans may be at risk to contract tick-bite fever in this area.The Faculty of Veterinary Medicine of Utrecht University and the Faculty of Veterinary Science of the University of Pretoria.http://www.parasitesandvectors.comhj2020Veterinary Tropical Disease

    Optical genome mapping and revisiting short-read genome sequencing data reveal previously overlooked structural variants disrupting retinal disease-associated genes

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    Purpose: Structural variants (SVs) play an important role in inherited retinal diseases (IRD). Although the identification of SVs significantly improved upon the availability of genome sequencing, it is expected that involvement of SVs in IRDs is higher than anticipated. We revisited short-read genome sequencing data to enhance the identification of gene-disruptive SVs. Methods: Optical genome mapping was performed to improve SV detection in short-read genome sequencing-negative cases. In addition, reanalysis of short-read genome sequencing data was performed to improve the interpretation of SVs and to re-establish SV prioritization criteria. Results: In a monoallelic USH2A case, optical genome mapping identified a pericentric inversion (173 megabase), with 1 breakpoint disrupting USH2A. Retrospectively, the variant could be observed in genome sequencing data but was previously deemed false positive. Reanalysis of short-read genome sequencing data (427 IRD cases) was performed which yielded 30 pathogenic SVs affecting, among other genes, USH2A (n = 15), PRPF31 (n = 3), and EYS (n = 2). Eight of these (>25%) were overlooked during previous analyses. Conclusion: Critical evaluation of our findings allowed us to re-establish and improve our SV prioritization and interpretation guidelines, which will prevent missing pathogenic events in future analyses. Our data suggest that more attention should be paid to SV interpretation and the current contribution of SVs in IRDs is still underestimated

    Cataclysmic Variables from SDSS II. The Second Year

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    The first full year of operation following the commissioning year of the Sloan Digital Sky Survey has revealed a wide variety of newly discovered cataclysmic variables. We show the SDSS spectra of forty-two cataclysmic variables observed in 2002, of which thirty-five are new classifications, four are known dwarf novae (CT Hya, RZ Leo, T Leo and BZ UMa), one is a known CV identified from a previous quasar survey (Aqr1) and two are known ROSAT or FIRST discovered CVs (RX J09445+0357, FIRST J102347.6+003841). The SDSS positions, colors and spectra of all forty-two systems are presented. In addition, the results of follow-up studies of several of these objects identify the orbital periods, velocity curves and polarization that provide the system geometry and accretion properties. While most of the SDSS discovered systems are faint (>18th mag) with low accretion rates (as implied from their spectral characteristics), there are also a few bright objects which may have escaped previous surveys due to changes in the mass transfer rate.Comment: Accepted for publication in The Astronomical Journal, Vol. 126, Sep. 2003, 44 pages, 25 figures (now with adjacent captions), AASTeX v5.

    Diversity among Equals: Educational Opportunity and the State of Affirmative Admissions in New England

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    This report reviews the practice of Affirmative Admissions as a strategy for achieving diversity within New England colleges and universities. It shows how educational leaders perceive Affirmative Admissions, the nature of regional Affirmative Admissions policies, and the numbers of student affected by current enrollment strategies. This report is part of a larger series on educational access and opportunity in New England. Research was organized into five components: (1) analysis of pertinent legal issues related to postsecondary access and equity; (2) interviews with postsecondary campus and state leaders (n=104); (3) interviews with K-12 leaders and educators at state, district, and school levels (n=45); (4) a survey of 221 postsecondary education institutions in New England; and (5) econometric analyses of student data. The focus was on groups of institutions, 18 groups clustered by admissions policies and restrictions. The most compelling conclusion is that there is no significant evidence that colleges have reduced standards to admit greater numbers of minority students. By increasing educational access to a broader segment of the population, the regions higher education institutions have taken crucial steps toward assuring the vitality and vibrancy of New Englands future economy and civic life. The study also indicates that the pool of qualified minority students is much too small, highlighting the need to improve the preparation of minority students. Three appendixes contain details about survey methodology, participating institutions, and regression coefficients. Prepared by the Center for Education Policy (CEP) and Massachusetts Institute for Social and Economic Research (MISER), University of Massachusetts at Amherst. Sponsored by the Nellie Mae Education Foundation
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