1,512 research outputs found

    A genome-wide survey of segmental duplications that mediate common human genetic variation of chromosomal architecture.

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    Recent studies have identified a small number of genomic rearrangements that occur frequently in the general population. Bioinformatics tools are now available for systematic genome-wide surveys of higher-order structures predisposing to such common variations in genomic architecture. Segmental duplications (SDs) constitute up to 5 per cent of the genome and play an important role in generating additional rearrangements and in disease aetiology. We conducted a genome-wide database search for a form of SD, palindromic segmental duplications (PSDs), which consist of paired, inverted duplications, and which predispose to inversions, duplications and deletions. The survey was complemented by a search for SDs in tandem orientation (TSDs) that can mediate duplications and deletions but not inversions. We found more than 230 distinct loci with higher-order genomic structure that can mediate genomic variation, of these about 180 contained a PSD. A number of these sites were previously identified as harbouring common inversions or as being associated with specific genomic diseases characterised by duplication, deletions or inversions. Most of the regions, however, were previously unidentified; their characterisation should identify further common rearrangements and may indicate localisations for additional genomic disorders. The widespread distribution of complex chromosomal architecture suggests a potentially high degree of plasticity of the human genome and could uncover another level of genetic variation within human populations

    Experimental demonstration of a novel heterogeneously integrated III-V on Si microlaser

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    In this work we present the first experimental demonstration of a novel class of heterogeneously integrated III-V-on-silicon microlasers. We first show that by coupling a silicon cavity to a III-V wire, the interaction between the propagating mode in the III-V wire and the cavity mode in the silicon resonator results in high, narrow band reflection back into the III-V waveguide, forming a so-called resonant mirror. By combining two such mirrors and providing optical gain in the III-V wire in between these 2 mirrors, laser operation can be realized. We simulate the reflectivity spectrum of such a resonant mirror using 3D FDTD and discuss the results. We also present experimental results of the very first optically pumped heterogeneously integrated resonant mirror laser. The fabricated device measures 55 mu m by 2 mu m and shows single mode laser emission with a side-mode suppression ratio of 37 dB

    Accuracy of predicting milk yield from alternative milk recording schemes

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    peer-reviewedThe effect of reducing the frequency of official milk recording and the number of recorded samples per test-day on the accuracy of predicting daily yield and cumulative 305-day yield was investigated. A control data set consisting of 58 210 primiparous cows with milk test-day records every 4 weeks was used to investigate the influence of reduced milk recording frequencies. The accuracy of prediction of daily yield with one milk sample per test-day was investigated using 41 874 testday records from 683 cows. Results show that five or more test-day records taken at 8-weekly intervals (A8) predicted 305-day yield with a high level of accuracy. Correlations between 305-day yield predicted from 4-weekly recording intervals (A4) and from 8-weekly intervals were 0.99, 0.98 and 0.98 for milk, fat and protein, respectively. The mean error in estimating 305-day yield from the A8 scheme was 6.8 kg (s.d. 191 kg) for milk yield, 0.3 kg (s.d. 10 kg) for fat yield, and −0.3 kg (s.d. 7 kg) for protein yield, compared with the A4 scheme. Milk yield and composition taken during either morning (AM) or evening (PM) milking predicted 24-h yield with a high degree of accuracy. Alternating between AM and PM sampling every 4 weeks predicted 305-day yield with a higher degree of accuracy than either all AM or all PM sampling. Alternate AM-PM recording every 4 weeks and AM + PM recording every 8 weeks produced very similar accuracies in predicting 305-day yield compared with the official AM + PM recording every 4 weeks

    Delineation of Gambel\u27s Quail Habitat in the Trans-Pecos, Texas

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    Gambel’s quail (Callipepla gambelii) are a common quail species in southwestern states of the United States and the northwestern states of Mexico. In Texas this species occurs in the Trans-Pecos region, are underutilized, and could become an important game bird and source of income for ranchers in the Chihuahuan Desert region of Texas. Salt cedar (Tamarisk spp.), introduced from Asia for ornamental and erosion purposes, is invasive in the western part of the Rio Grande corridor that generally creates monocultures that choke out the native vegetation of the region. Knowing this, the objectives of this study were to: (1) delineate salt cedar and native riparian habitats along the Rio Grande corridor in the Trans-Pecos; (2) evaluate those habitats based on the known distribution of Gambel’s quail in the Trans-Pecos; and (3) estimate the amount of suitable habitat for Gambel’s quail in Trans-Pecos, Texas. Although dominant along the Rio Grande, native riparian vegetation was more prevalent than salt cedar communities when combining primary creeks in all counties. Brewster County was the area with a higher percentage of salt cedar occurrence (21.2%) vs. native riparian vegetation (78.8%). The largest extension of salt cedar occurred in Presidio County with an extension of 6,656.3 ha but this only represented 12.7% of our analyzed area. Hudspeth County had an occurrence of salt cedar of 2,905.2 ha representing 6.8% of the estimated riparian area of the Rio Grande corridor in this county. El Paso County’s total urban area-agricultural fields area is a total of 90,682.9184 ha

    Milk protein oxidation in healthy subjects:A preliminary study

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    The role of protein oxidation in the regulation of whole body protein metabolism is unknown. Previously, it was observed that vigorous exercise led to increased protein oxidation. To further characterise 13C-milk protein oxidation in healthy subjects, the oxidation of ingested 13C-protein after an overnight fast was measured using a non-invasive 13C-protein breath test. This approach enables the analysis of 13C-protein oxidation kinetics and the effect of interfering factors. It was found that the estimated maximal 13C-milk protein oxidation was 0.07 g min−1, corresponding to a theoretical maximal oxidation capacity of ≈1.4 g kg body weight−1 d−1. No indications were found for preferential oxidation of non-essential amino acids. Combined ingestion of 30 g 13C-whey protein with 30 g glucose resulted in a 19% decrease of 13C-whey protein oxidation. It was concluded that exogenous 13C-whey protein oxidation can be affected by other co-ingested nutrients like glucose

    Feasibility of controlling hookworm infection through preventive chemotherapy: a simulation study using the individual-based WORMSIM modelling framework

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    Background: Globally, hookworms infect 440 million people in developing countries. Especially children and women of childbearing age are at risk of developing anaemia as a result of infection. To control hookworm infection and disease (i.e. reduce the prevalence of medium and heavy infection to <1 %), the World Health Organization has set the target to provide annual or semi-annual preventive chemotherapy (PC) with albendazole (ALB) or mebendazole (MEB) to at least 75 % of all children and women of childbearing age in endemic areas by 2020. Here, we predict the feasibility of achieving <1 % prevalence of medium and heavy infection, based on simulations with an individual-based model. Methods: We developed WORMSIM, a new generalized individual-based modelling framework for transmission and control of helminths, and quantified it for hookworm transmission based on published data. We simulated the impact of standard and more intense PC strategies on trends in hookworm infection, and explored the potential additional impact of interventions that improve access to water, sanitation, and hygiene (WASH). The individual-based framework allowed us to take account of inter-individual heterogeneities in exposure and contribution to transmission of infection, as well as in participation in successive PC rounds. Results: We predict that in low and medium endemic areas, current PC strategies (including targeting of WCBA) will achieve control of hookworm infection (i.e. the parasitological target) within 2 years. In highly endemic areas, control can be achieved with semi-annual PC with ALB at 90 % coverage, combined with interventions that reduce host contributions to the environmental reservoir of infection by 50 %. More intense PC strategies (high frequency and coverage) can help speed up control of hookworm infection, and may be necessary in some extremely highly endemic settings, but are not a panacea against systematic non-participation to PC. Conclusions: Control of hookworm infection by 2020 is feasible with current PC strategies (including targeting of WCBA). In highly endemic areas, PC should be combined with health education and/or WASH interventions

    40 Gbit/s silicon-organic hybrid (SOH) phase modulator

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    A 40 Gbit/s electro-optic modulator is demonstrated. The modulator is based on a slotted silicon waveguide filled with an organic material. The silicon organic hybrid (SOH) approach allows combining highly nonlinear electro-optic organic materials with CMOS-compatible silicon photonics technology

    Melhoramento genético de erva-mate nativa do estado de Mato Grosso do Sul.

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    O presente estudo objetivou avaliar geneticamente as melhores progĂȘnies de erva-mate, quanto aos caracteres de crescimento, provenientes de plantas nativas da ĂĄrea indĂ­gena de CaarapĂł, Mato Grosso do Sul. O teste de progĂȘnie foi instalado sob delineamento de blocos ao acaso com 30 tratamentos, 5 repetiçÔes e 10 plantas por parcela em linhas simples, no espaçamento 3 x 2 m. Aos 14 meses de idade, as progĂȘnies foram avaliadas quanto aos caracteres altura total das mudas e diĂąmetro do coleto. A herdabilidade individual no sentido restrito para os caracteres estudados pode ser considerada de mĂ©dia a alta magnitude (0,15 e 0,28), respectivamente, para altura e diĂąmetro. Os ganhos genĂ©ticos estimados com a seleção individual variaram para altura de 5,23 a 8,51 cm e para diĂąmetro de 2,08 a 3,15 mm. Os valores genĂ©ticos preditos com propagação sexuada e assexuada indicam maiores possibilidades de ganhos com a implantação de plantios clonais. Na avaliação da sobreposição de geração, pelos resultados verifica-se que, em geral, os indivĂ­duos da geração atual tendem a ser melhores do que aqueles provenientes da geração anterior
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