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Prenatal trio exome sequencing (ES) has become integrated into the care for pregnant women when the fetus has structural anomalies. Details regarding optimizing indications for prenatal exome sequencing, its detection rates with different categories of fetal anomalies, and principles of interpretation of pathogenicity of sequence variants are still under investigation. However, there is now growing consensus about its benefits for finding the cause of fetal structural anomalies. What is not established, is whether exome or genome sequencing (GS) has a place in the care of all pregnant women. This report is a summary of the debate on this topic at the 26th International Conference on Prenatal Diagnosis and Therapy. Both expert debaters considered the advantages and disadvantages. Advantages include the ability to diagnose serious childhood conditions without a prenatally observable phenotype, which creates the potential of early treatments. Disadvantages include difficulties with variant classification, counseling complexities, healthcare cost, and the burden on healthcare systems and families, in particular with the discovery of adult-onset disorders or variants of uncertain significance. Although both debaters weighed the balance of these conflicting arguments differently, they agreed that more research is needed to further explore the clinical utility and ethical aspects of GS for all pregnant women. 相似文献
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The stability of kerosene in soils as affected by volatization was determined in a laboratory column experiment by following the losses in the total concentration and the change in composition of the residuals in a dune sand, a loamy sand, and a silty loam soil during a 50-day period. Seven major compounds ranging between C9 and C15 were selected from a large variety of hydrocarbons forming kerosene and their presence in the remaining petroleum product was determined. The change in composition of kerosene during the experimental period was determined by gas chromatography and related to the seven major compounds selected. The experimental conditions — air-dairy soil and no subsequent addition of water—excluded both biodegradative and leaching. losses.The losses of kerosene in air-dried soil columns during the 50-day experimental period and the changes in the composition of the remaining residues due to volatilization are reported. The volatilization of all the components determined was greater from the dune sand and loamy sand soils than from the silty loam soil. It was assumed that the reason for this behavior was that the dune sand and the loamy sand soils contain a greater proportion of large pores (>4.5 μm) than the silty loam soil, even though the total porosity of the loamy sand and the silty loam is similar. In all the soils in the experiment, the components with a high carbon number formed the main fraction of the kerosene residues after 50 days of incubation. 相似文献
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Ronni Gamzu Yaron Zalel Jeffrey M. Jacobson Leticia Screiber Reuven Achiron 《黑龙江环境通报》2002,22(11):1040-1043
A single umbilical artery resulting from absence of the umbilical arteries and persistence of the vitelline artery that arises directly from the abdominal aorta has been described only in malformed fetuses with sirenomelia or caudal regression. Such an aberrant artery was suggested to be the etiology of sirenomelia caused by a ‘steal’ mechanism of blood flow from the caudal end of the embryo. We present a case in which prenatal ultrasound showed a similar aberrant single artery arising from the abdominal aorta in an otherwise normal fetus with a normal course of pregnancy. This vessel, a continuation of the superior mesenteric artery (SMA), corresponds to a persistent vitelline artery assuming the function of the umbilical arteries. The etiology of such a finding and its possible consequences are discussed. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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This study investigates learning disability (LD) as an individual‐differences variable predicting leadership emergence, role occupancy, and effectiveness. We hypothesize that individuals with LD are less likely to occupy leadership roles, and that informal group processes (leadership emergence) will mediate the relationship between LD and leadership role occupancy. We also hypothesized that, among leaders promoted and selected for leadership training, there would be a negative relationship between LD and effective leadership. We first checked for LD in a sample of 1076 soldiers, measuring cognitive ability with a geometric‐analogies test as a control. Some months later, during the soldiers' basic training, we measured leadership emergence. We then identified those who were selected for leadership training, recording, and measuring their effectiveness according to supervisory and peer evaluations. Leadership emergence was found to mediate the negative relationship between LD and leadership role occupancy. There were no significant differences among leaders (n = 308) with and without LD in regard to leadership effectiveness. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Dominance relationships among species play a major role in the structure of animal communities. Yet, dominant species with
different trade-offs in resource exploitation and monopolization could affect community structure in variable ways. In ants,
dominant species could be classified into either behavioral dominants that exhibit territorial aggression or numerical dominants
that exhibit high biomass or frequency of occurrence. While each class of dominance has generally been found to negatively
affect the foraging activity of species in ant communities, the concurrent effect of both classes of species has never been
tested. Here, we examined the effects of two behaviorally dominant species, Crematogaster inermis and Monomorium salomonis, and a numerically dominant species, Messor arenarius, on the foraging behavior of seed-eating species in a desert ant assemblage. In a 1-year study, the foraging activity of
the ant species was assessed using seed baits, which were sampled during night and day. While the numerically dominant species
exhibited high foraging efficiency and negatively affected the ability of other seed-eating species to obtain seeds, significantly
more seeds remained at baits that were occupied the previous night by each of the two behaviorally dominant species, possibly
due to aggressive exclusion of M. arenarius foragers from the baits. This exclusion also facilitated greater foraging activity of the seed-eating species. Our results
demonstrate how these two types of dominance could differently affect the foraging activity of ant species in the community. 相似文献
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Habitat loss reduces species diversity, but the effect of habitat fragmentation on number of species is less clear because fragmentation generally accompanies loss of habitat. We compared four methods that aim to decouple the effects of fragmentation from the effects of habitat loss. Two methods are based on species-area relations, one on Fisher's alpha index of diversity, and one on plots of cumulative number of species detected against cumulative area sampled. We used these methods to analyze the species diversity of spiders in 2, 3.2 × 4 km agricultural landscapes in Southern Judea Lowlands, Israel. Spider diversity increased as fragmentation increased with all four methods, probably not because of the additive within-patch processes, such as edge effect and heterogeneity. The positive relation between fragmentation and species diversity might reflect that most species can disperse through the fields during the wheat-growing season. We suggest that if a given area was designated for the conservation of spiders in Southern Judea Lowlands, Israel, a set of several small patches may maximize species diversity over time. 相似文献