267 research outputs found

    Influence of previous crops and nematicide treatments on root lesion nematode populations and crop yields

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    Nous avons Ă©tudiĂ© au champ l'influence du prĂ©cĂ©dent cultural, de la sĂ©quence culturelle et de traitements Ă  l'aldicarbe sur les populations de nematodes des nodositĂ©s et sur les rendements de diverses cultures Ă  l'Ăźle-du Prince-Édouard. La culture prĂ©cĂ©dente a eu le plus grand impact sur le nombre de nematodes. Les sĂ©quences des cultures ont parfois eu une influence sur les populations de nematodes des nodositĂ©s (principalement Pratylenchus penetrans) et sur les rendements. Dans les champs commerciaux d'orge (Hordeum vulgare), les nematodes des nodositĂ©s Ă©taient plus nombreux lorsque l'orge suivait une culture combinĂ©e de trĂšfle rouge (Trifolium pratense) et de flĂ©ole (Phleum pratense) et les nematodes du rabougrissement (Tylenchorynchus spp., principalement T. dubiuset Merlinius spp.) Ă©taient plus nombreux quand l'orge Ă©tait semĂ©e pendant deux annĂ©es consĂ©cutives. La masse de la matiĂšre sĂšche combinĂ©e du feuillage et du grain Ă©tait plus importante lorsque l'orge Ă©tait semĂ©e auprĂšs des pommes de terre (Solanum tuberosum) et cette masse Ă©tait plus faible avec deux cultures successives d’orge ou avec un mĂ©lange de trĂšfle rouge et de flĂ©ole. En conditions expĂ©rimentales au champ, les populations de nĂ©matodes des nodositĂ©s Ă©taient plus Ă©levĂ©es dans les racines d’orge lorsque celle-ci Ă©tait cultivĂ©e aprĂšs des pommes de terre et les rendements en grain Ă©taient plus faibles lorsque l’orge Ă©tait cultivĂ©e pendant deux annĂ©es consĂ©cutives. Les changements dans les populations de nĂ©matodes chez la pomme de terre n’étaient pas associĂ©s aux sĂ©quences dĂ©butant avec le blĂ© (Triticum aestivum) ou l’orge que dans les sĂ©quences dĂ©butant avec les pommes de terre ou le soya (Glycine max). L’aldicarbe a rĂ©duit le nombre de nĂ©matodes des nodositĂ©s en plus d’accroĂźtre les rendements en pommes de terre et en soya.A field study assessing the influence of the previous crop, the crop sequence, and aldicarb treatments on root lesion nematode populations and crop yields was carried out in Prince-Edward-Island, Canada. The most recent crop had the greatest impact on nematode numbers. The crop sequences had an influence in some cases on root lesion nematode populations (primarily Pratylenchus penetrans) and on crop yields. In commercial barley (Hordeum vulgare) fields, root lesion nematodes in roots were greatest when barley followed a red clover (Trifolium pratense) timothy (Phleum pratense) ley, and stunt nematodes (Tylenchorhynchus spp., primarily T. dubius, and Merlinius spp.) were more common when barley followed barley. The combined dry weight of foliage and grain was larger when barley was planted after potato (Solanumtuberosum) and smaller when barley followed barley or a red clover-timothy mixture. Under experimental field conditions, root lesion nematode populations were largest in barley roots when barley followed potato and grain yields were smallest when barley followed barley. Changes in nematode populations in potato were not associated with crop sequences. Potato tuber yields were higher in the sequences that began with wheat (Triticum aestivum) or barley than in the sequences that began with potato or soybean (Glycine max). Aldicarb reduced the numbers of root lesion nematodes in roots with concomitant yield increases in potato and soybean

    Respiratory viruses, symptoms, and inflammatory markers in acute exacerbations and stable chronic obstructive pulmonary disease

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    The effects of respiratory viral infection on the time course of chronic obstructive pulmonary disease (COPD) exacerbation were examined by monitoring changes in systemic inflammatory markers in stable COPD and at exacerbation. Eighty-three patients with COPD (mean [SD] age, 66.6 [7.1] yr, FEV1, 1.06 [0.61] L) recorded daily peak expiratory flow rate and any increases in respiratory symptoms. Nasal samples and blood were taken for respiratory virus detection by culture, polymerase chain reaction, and serology, and plasma fibrinogen and serum interleukin-6 (IL-6) were determined at stable baseline and exacerbation. Sixty-four percent of exacerbations were associated with a cold occurring up to 18 d before exacerbation. Seventy-seven viruses (39 [58.2%] rhinoviruses) were detected in 66 (39.2%) of 168 COPD exacerbations in 53 (64%) patients. Viral exacerbations were associated with frequent exacerbators, colds with increased dyspnea, a higher total symptom count at presentation, a longer median symptom recovery period of 13 d, and a tendency toward higher plasma fibrinogen and serum IL-6 levels. Non-respiratory syncytial virus (RSV) respiratory viruses were detected in 11 (16%), and RSV in 16 (23.5%), of 68 stable COPD patients, with RSV detection associated with higher inflammatory marker levels. Respiratory virus infections are associated with more severe and frequent exacerbations, and may cause chronic infection in COPD. Prevention and early treatment of viral infections may lead to a decreased exacerbation frequency and morbidity associated with COPD

    Lift, Drag and Thrust Measurement in a Hypersonic Impulse Facility

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    This paper reports the extension of the stress wave force balance to the measurement of forces on models which are non-axisymmetric or which have non-axisymmetric load distributions. Recent results are presented which demonstrate the performance of the stress wave force balance for drag measurement, for three-component force measurement and preliminary results for thrust measurement on a two-dimensional scramjet nozzle. In all cases, the balances respond within a few hundred microseconds

    Paternal and joint parental occupational pesticide exposure and spina bifida in the National Birth Defects Prevention Study, 1997 to 2002

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    Background: Because of persistent concerns over the association between pesticides and spina bifida, we examined the role of paternal and combined parental occupational pesticide exposures in spina bifida in offspring using data from a large population-based study of birth defects. Methods: Occupational information from fathers of 291 spina bifida cases and 2745 unaffected live born control infants with estimated dates of delivery from 1997 to 2002 were collected by means of maternal report. Two expert industrial hygienists estimated exposure intensity and frequency to insecticides, herbicides, and fungicides. Multivariable logistic regression models were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for exposure to any pesticide and to any class of pesticide (yes/no; and by median), and exposure to combinations of pesticides (yes/no) and risk of spina bifida. Adjusted odds ratios were also estimated by parent exposed to pesticides (neither, mother only, father only, both parents). RESULTS: Joint parental occupational pesticide exposure was positively associated with spina bifida (aOR, 1.5; 95% CI, 0.9–2.4) when compared with infants with neither maternal nor paternal exposures; a similar association was not observed when only one parent was exposed. There was a suggested positive association between combined paternal insecticide and fungicide exposures and spina bifida (aOR, 1.5; 95% CI, 0.8–2.8), however, nearly all other aORs were close to unity. Conclusion: Overall, there was little evidence paternal occupational pesticide exposure was associated with spina bifida. However, the small numbers make it difficult to precisely evaluate the role of pesticide classes, individually and in combination. Birth Defects Research (Part A) 106:963–971, 2016

    Discovery and characterization of a specific inhibitor of serine-threonine kinase cyclin-dependent kinase-like 5 (CDKL5) demonstrates role in hippocampal CA1 physiology

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    Pathological loss-of-function mutations in cyclin-dependent kinase-like 5 (CDKL5) cause CDKL5 deficiency disorder (CDD), a rare and severe neurodevelopmental disorder associated with severe and medically refractory early-life epilepsy, motor, cognitive, visual, and autonomic disturbances in the absence of any structural brain pathology. Analysis of genetic variants in CDD has indicated that CDKL5 kinase function is central to disease pathology. CDKL5 encodes a serine-threonine kinase with significant homology to GSK3ÎČ, which has also been linked to synaptic function. Further, Cdkl5 knock-out rodents have increased GSK3ÎČ activity and often increased long-term potentiation (LTP). Thus, development of a specific CDKL5 inhibitor must be careful to exclude cross-talk with GSK3ÎČ activity. We synthesized and characterized specific, high-affinity inhibitors of CDKL5 that do not have detectable activity for GSK3ÎČ. These compounds are very soluble in water but blood-brain barrier penetration is low. In rat hippocampal brain slices, acute inhibition of CDKL5 selectively reduces postsynaptic function of AMPA-type glutamate receptors in a dose-dependent manner. Acute inhibition of CDKL5 reduces hippocampal LTP. These studies provide new tools and insights into the role of CDKL5 as a newly appreciated key kinase necessary for synaptic plasticity. Comparisons to rodent knock-out studies suggest that compensatory changes have limited the understanding of the roles of CDKL5 in synaptic physiology, plasticity, and human neuropathology

    Infrared target and background radiometric measurements--concepts units and techniques

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    This report discusses concepts units and techniques for making and describing measurements of radiation from targets and backgrounds.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32197/1/0000256.pd

    Food System Resilience: Concepts, Issues, and Challenges

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    Food system resilience has multiple dimensions. We draw on food system and resilience concepts and review resilience framings of different communities. We present four questions to frame food system resilience (Resilience of what? Resilience to what? Resilience from whose perspective? Resilience for how long?) and three approaches to enhancing resilience (robustness, recovery, and reorientation—the three “Rs”). We focus on enhancing resilience of food system outcomes and argue this will require food system actors adapting their activities, noting that activities do not change spontaneously but in response to a change in drivers: an opportunity or a threat. However, operationalizing resilience enhancement involves normative choices and will result in decisions having to be negotiated about trade-offs among food system outcomes for different stakeholders. New approaches to including different food system actors’ perceptions and goals are needed to build food systems that are better positioned to address challenges of the future. Expected final online publication date for the Annual Review of Environment and Resources, Volume 47 is October 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates

    African-specific improvement of a polygenic hazard score for age at diagnosis of prostate cancer

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    Polygenic hazard score (PHS) models are associated with age at diagnosis of prostate cancer. Our model developed in Europeans (PHS46) showed reduced performance in men with African genetic ancestry. We used a cross-validated search to identify single nucleotide polymorphisms (SNPs) that might improve performance in this population. Anonymized genotypic data were obtained from the PRACTICAL consortium for 6253 men with African genetic ancestry. Ten iterations of a 10-fold cross-validation search were conducted to select SNPs that would be included in the final PHS46+African model. The coefficients of PHS46+African were estimated in a Cox proportional hazards framework using age at diagnosis as the dependent variable and PHS46, and selected SNPs as predictors. The performance of PHS46 and PHS46+African was compared using the same cross-validated approach. Three SNPs (rs76229939, rs74421890 and rs5013678) were selected for inclusion in PHS46+African. All three SNPs are located on chromosome 8q24. PHS46+African showed substantial improvements in all performance metrics measured, including a 75% increase in the relative hazard of those in the upper 20% compared to the bottom 20% (2.47-4.34) and a 20% reduction in the relative hazard of those in the bottom 20% compared to the middle 40% (0.65-0.53). In conclusion, we identified three SNPs that substantially improved the association of PHS46 with age at diagnosis of prostate cancer in men with African genetic ancestry to levels comparable to Europeans
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