1,706 research outputs found

    Light Trap Records of \u3ci\u3ePhyllophaga\u3c/i\u3e (Coleoptera: Scarabaeidae) in Wisconsin, 1984-1987

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    Phyllophaga adults (June beetles) were surveyed from 1984 through 1987 at five locations in Wisconsin using black light traps. Data were collected at each location for three consecutive years. A total of 9,259 specimens representing 13 species were collected during the survey. Species captured, sex ratios, and flight periods for abundant species were recorded for each location. Species abundance differed from previous surveys of Phyllophaga in Wisconsin. Possible reasons for observed shifts in species abundance are discussed

    Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers

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    We demonstrate a new approach for engineering group IV semiconductor-based quantum photonic structures containing negatively charged silicon-vacancy (SiV−^-) color centers in diamond as quantum emitters. Hybrid SiC/diamond structures are realized by combining the growth of nanoand micro-diamonds on silicon carbide (3C or 4H polytype) substrates, with the subsequent use of these diamond crystals as a hard mask for pattern transfer. SiV−^- color centers are incorporated in diamond during its synthesis from molecular diamond seeds (diamondoids), with no need for ionimplantation or annealing. We show that the same growth technique can be used to grow a diamond layer controllably doped with SiV−^- on top of a high purity bulk diamond, in which we subsequently fabricate nanopillar arrays containing high quality SiV−^- centers. Scanning confocal photoluminescence measurements reveal optically active SiV−^- lines both at room temperature and low temperature (5 K) from all fabricated structures, and, in particular, very narrow linewidths and small inhomogeneous broadening of SiV−^- lines from all-diamond nano-pillar arrays, which is a critical requirement for quantum computation. At low temperatures (5 K) we observe in these structures the signature typical of SiV−^- centers in bulk diamond, consistent with a double lambda. These results indicate that high quality color centers can be incorporated into nanophotonic structures synthetically with properties equivalent to those in bulk diamond, thereby opening opportunities for applications in classical and quantum information processing

    Critical windows of exposure to household pesticides and risk of childhood leukemia.

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    The potential etiologic role of household pesticide exposures was examined in the Northern California Childhood Leukemia Study. A total of 162 patients (0-14 years old) with newly diagnosed leukemia were rapidly ascertained during 1995-1999, and 162 matched control subjects were randomly selected from the birth registry. The use of professional pest control services at any time from 1 year before birth to 3 years after was associated with a significantly increased risk of childhood leukemia [odds ratio (OR) = 2.8; 95% confidence interval (CI), 1.4-5.7], and the exposure during year 2 was associated with the highest risk (OR = 3.6; 95% CI, 1.6-8.3). The ORs for exposure to insecticides during the 3 months before pregnancy, pregnancy, and years 1, 2, and 3 were 1.8 (95% CI, 1.1-3.1), 2.1 (95% CI, 1.3-3.5), 1.7 (95% CI, 1.0-2.9), 1.6 (95% CI, 1.0-2.7), and 1.2 (95% CI, 0.7-2.1), respectively. Insecticide exposures early in life appear to be more significant than later exposures, and the highest risk was observed for exposure during pregnancy. Additionally, more frequent exposure to insecticides was associated with a higher risk. In contrast to insecticides, the association between herbicides and leukemia was weak and nonsignificant. Pesticides were also grouped based on where they were applied. Exposure to indoor pesticides was associated with an increased risk, whereas no significant association was observed for exposure to outdoor pesticides. The findings suggest that exposure to household pesticides is associated with an elevated risk of childhood leukemia and further indicate the importance of the timing and location of exposure

    Robust numerical analysis of fibrous composites from X-ray computed tomography image data enabling low resolutions

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    X-ray computed tomography scans can provide detailed information about the state of the material after manufacture and in service. X-ray computed tomography aided engineering (XAE) was recently introduced as an automated process to transfer 3D image data to finite element models. The implementation of a structure tensor code for material orientation analysis in combination with a newly developed integration point-wise fibre orientation mapping allows an easy applicable, computationally cheap, fast, and accurate model set-up. The robustness of the proposed approach is demonstrated on a non-crimp fabric glass fibre reinforced composite for a low resolution case with a voxel size of 64 Îźm corresponding to more than three times the fibre diameter. Even though 99.8% of the original image data is removed, the simulated elastic modulus of the considered non-crimp fabric composite is only underestimated by 4.7% compared to the simulation result based on the original high resolution scan

    Elections and Ethnic Civil War

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    Existing research on how democratization may influence the risk of civil war tends to consider only changes in the overall level of democracy and rarely examines explicitly the postulated mechanisms relating democratization to incentives for violence. The authors argue that typically highlighted key mechanisms imply that elections should be especially likely to affect ethnic groups’ inclination to resort to violence. Distinguishing between types of conflict and the order of competitive elections, the authors find that ethnic civil wars are more likely to erupt after competitive elections, especially after first and second elections following periods of no polling. When disaggregating to the level of individual ethnic groups and conflicts over territory or government, the authors find some support for the notion that ethno-nationalist mobilization and sore-loser effects provoke postelectoral violence. More specifically, although large groups in general are more likely to engage in governmental conflicts, they are especially likely to do so after noncompetitive elections. Competitive elections, however, strongly reduce the risk of conflict. </jats:p

    Keck Interferometer autoaligner: algorithms and techniques

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    The Keck Interferometer includes an autoalignment system consisting of pop-up targets located at strategic locations along the beam trains of each arm of the instrument along with a sensor and control system. We briefly describe the hardware of the system and then proceed to a description of the two operational modes of the system. These are: 1) to provide an initial alignment of the coude paths in each arm, and 2) to recover coude alignments between changes of the static delay sled positions. For the initial alignment mode, we review the system performance requirements along with the software used for image acquisition and centroiding. For coudĂŠ alignment recovery, we describe beam-train surveys through the static delay (Long Delay Line) and criteria for a successful recovery of a coudĂŠ alignment. Finally, we describe the results of testing of the autoalignment system

    Comparing Competing Theories on the Causes of Mandate Perceptions

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    The discussion of presidential mandates is as certain as a presidential election itself. Journalists inevitably discuss whether the president-elect has a popular mandate. Because they see elections as too complex to allow the public to send a unitary signal, political scientists are more skeptical of mandates. Mandates, however, have received new attention by scholars asking whether perceptions of mandate arise and lead representatives to act as if voters sent a policy directive. Two explanations have emerged to account for why elected officials might react to such perceptions. One focuses on the President’s strategic decision to declare a mandate, the second on how members of Congress read signals of changing preferences in the electorate from their own election results. We test these competing views to see which more accurately explains how members of Congress act in support of a perceived mandate. The results indicate that members respond more to messages about changing preferences than to the president’s mandate declaration

    A metagenomic study of diet-dependent interaction between gut microbiota and host in infants reveals differences in immune response

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    BACKGROUND: Gut microbiota and the host exist in a mutualistic relationship, with the functional composition of the microbiota strongly affecting the health and well-being of the host. Thus, it is important to develop a synthetic approach to study the host transcriptome and the microbiome simultaneously. Early microbial colonization in infants is critically important for directing neonatal intestinal and immune development, and is especially attractive for studying the development of human-commensal interactions. Here we report the results from a simultaneous study of the gut microbiome and host epithelial transcriptome of three-month-old exclusively breast- and formula-fed infants. RESULTS: Variation in both host mRNA expression and the microbiome phylogenetic and functional profiles was observed between breast- and formula-fed infants. To examine the interdependent relationship between host epithelial cell gene expression and bacterial metagenomic-based profiles, the host transcriptome and functionally profiled microbiome data were subjected to novel multivariate statistical analyses. Gut microbiota metagenome virulence characteristics concurrently varied with immunity-related gene expression in epithelial cells between the formula-fed and the breast-fed infants. CONCLUSIONS: Our data provide insight into the integrated responses of the host transcriptome and microbiome to dietary substrates in the early neonatal period. We demonstrate that differences in diet can affect, via gut colonization, host expression of genes associated with the innate immune system. Furthermore, the methodology presented in this study can be adapted to assess other host-commensal and host-pathogen interactions using genomic and transcriptomic data, providing a synthetic genomics-based picture of host-commensal relationships

    Is democracy an option for the realist?

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    In Democracy for Realists, Christopher Achen and Larry Bartels argue that the depressingly well-established fact that people are woefully ignorant on politically relevant matters renders democratic ideals mere “fairy tales.” However, this iconoclasm stands in deep tension with the prescriptions they themselves end up offer-ing towards the end of the book, which coincide to a surprising extent with those that have been offered by democrats for decades. This is a problem because, if we take seriously the type of data that Achen and Bartels rely on (and add to)—data that should make us realists in the sense of the book’s title—it is not clear that democracy in any recognizable sense remains an option for the realist

    Does compulsory voting increase support for leftist policy?

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    Citizens unequally participate in referendums, and this may systematically bias policy in favor of those who vote. Some view compulsory voting as an important tool to alleviate this problem, whereas others worry about its detrimental effects on the legitimacy and quality of democratic decision making. So far, however, we lack systematic knowledge about the causal effect of compulsory voting on public policy. We argue that sanctioned compulsory voting mobilizes citizens at the bottom of the income distribution and that this translates into an increase in support for leftist policies. We empirically explore the effects of a sanctioned compulsory voting law on direct-democratic decision making in Switzerland. We find that compulsory voting significantly increases electoral support for leftist policy positions in referendums by up to 20 percentage points. We discuss the implications of these results for our understanding of the policy consequences of electoral institutions
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