211 research outputs found

    Organic farming enhances parasitoid diversity at the local and landscape scales

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    1. The magnitude of the benefits derived from organic farming within contrasting managed landscapes remains unclear and, in particular, the potential scale-dependent response of insect parasitoids is relatively unexplored. Identifying the scale at which parasitoids are affected by organic farming will be an important step to enhance their conservation. 2. We sampled tachinid parasitoids at the centre and margin of arable and grassland fields on paired organic and conventional farms located in landscapes with different proportions of organic land. A total of 192 fields were sampled in two biogeographical regions of the UK. 3. We found that the positive effect of organic farming on tachinid parasitoid diversity can be observed at multiple spatial scales. At the local scale, we found higher abundance and species richness of tachinid parasitoids on organic than on conventional farms and on field margins than on field centres. At the landscape scale, the diversity of tachinids was higher in landscapes with higher proportions of organic land. At both scales, the positive effect of organic farming was clear for arable fields, while it was almost neutral for grasslands. 4. Synthesis and applications. Any attempt to enhance parasitoid diversity in agricultural landscapes needs to consider the local management in relation to the habitat type, location within the field and agricultural management in the surrounding landscape. To restore parasitoid diversity, the promotion of organic agriculture should aim to increase both the total extent of organic farming and the connectivity of individual farms. As the benefits of organic farming to biodiversity clearly spread beyond individual farm boundaries, any assessment of organic farming should consider these positive externalities

    Ocular Point-of-Care Ultrasonography to Diagnose Posterior Chamber Abnormalities: A Systematic Review and Meta-analysis

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    Importance: Diagnosing posterior chamber ocular abnormalities typically requires specialist assessment. Point-of-care ultrasonography (POCUS) performed by nonspecialists, if accurate, could negate the need for urgent ophthalmologist evaluation. Objective: This meta-analysis sought to define the diagnostic test characteristics of emergency practitioner-performed ocular POCUS to diagnose multiple posterior chamber abnormalities in adults. Data sources: PubMed (OVID), MEDLINE, EMBASE, Cochrane, CINAHL, and SCOPUS were searched from inception through June 2019 without restrictions. Conference abstracts and trial registries were also searched. Bibliographies of included studies and relevant reviews were manually searched, and experts in the field were queried. Study selection: Included studies compared ocular POCUS performed by emergency practitioners with a reference standard of ophthalmologist evaluation. Pediatric studies were excluded. All 116 studies identified during abstract screening as potentially relevant underwent full-text review by multiple authors, and 9 studies were included. Data extraction and synthesis: In accordance with PRISMA guidelines, multiple authors extracted data from included studies. Results were meta-analyzed for each diagnosis using a bivariate random-effects model. Data analysis was performed in July 2019. Main outcomes and measures: The outcomes of interest were diagnostic test characteristics of ocular POCUS for the following diagnoses: retinal detachment, vitreous hemorrhage, vitreous detachment, intraocular foreign body, globe rupture, and lens dislocation. Results: Nine studies (1189 eyes) were included. All studies evaluated retinal detachment, but up to 5 studies assessed each of the other diagnoses of interest. For retinal detachment, sensitivity was 0.94 (95% CI, 0.88-0.97) and specificity was 0.94 (95% CI, 0.85-0.98). Sensitivity and specificity were 0.90 (95% CI, 0.65-0.98) and 0.92 (95% CI, 0.75-0.98), respectively, for vitreous hemorrhage and were 0.67 (95% CI, 0.51-0.81) and 0.89 (95% CI, 0.53-0.98), respectively, for vitreous detachment. Sensitivity and specificity were high for lens dislocation (0.97 [95% CI, 0.83-0.99] and 0.99 [95% CI, 0.97-1.00]), intraocular foreign body (1.00 [95% CI, 0.81-1.00] and 0.99 [95% CI, 0.99-1.00]), and globe rupture (1.00 [95% CI, 0.63-1.00] and 0.99 [95% CI, 0.99-1.00]). Results were generally unchanged in sensitivity analyses of studies with low risk of bias. Conclusions and relevance: This study suggests that emergency practitioner-performed ocular POCUS is an accurate test to assess for retinal detachment in adults. Its utility in diagnosing other posterior chamber abnormalities is promising but needs further study

    Association of Checklist Use in Endotracheal Intubation With Clinically Important Outcomes: A Systematic Review and Meta-analysis

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    Importance: The ε4 allele of the apolipoprotein E (APOE) gene and lower apolipoprotein E (apoE) protein levels in plasma are risk factors for Alzheimer disease, but the underlying biological mechanisms are not fully understood. Half of plasma apoE circulates on high-density lipoproteins (HDLs). Higher apoE levels in plasma HDL were previously found to be associated with lower coronary heart disease risk, but the coexistence of another apolipoprotein, apoC3, modified this lower risk. Objective: To investigate associations between the presence of apoE in different lipoproteins with cognitive function, particularly the risk of dementia. Design, Setting, and Participants: This prospective case-cohort study embedded in the Ginkgo Evaluation of Memory Study (2000-2008) analyzed data from 1351 community-dwelling participants 74 years and older. Of this group, 995 participants were free of dementia at baseline (recruited from September 2000 to June 2002) and 521 participants were diagnosed with incident dementia during follow-up until 2008. Data analysis was performed from January 2018 to December 2019. Exposures: Enzyme-linked immunosorbent assay–measured concentration of apoE in whole plasma, HDL-depleted plasma (non-HDL), HDL, and HDL subspecies that contain or lack apoC3 or apoJ. Main Outcomes and Measures: Adjusted hazard ratios for risk of dementia and Alzheimer disease during follow-up and adjusted differences (β coefficients) in Alzheimer Disease Assessment–Cognitive Subscale (ADAS-cog) and Modified Mini-Mental State Examination scores at baseline. Results: Among 1351 participants, the median (interquartile range) age was 78 (76-81) years; 639 (47.3%) were women. The median (interquartile range) follow-up time was 5.9 (3.7-6.5) years. Higher whole plasma apoE levels and higher apoE levels in HDL were associated with better cognitive function assessed by ADAS-cog (whole plasma, β coefficient, −0.15; 95% CI, −0.24 to −0.06; HDL, β coefficient, −0.20; 95% CI, −0.30 to −0.10) but were unassociated with dementia or Alzheimer disease risk. When separated by apoC3, a higher apoE level in HDL that lacks apoC3 was associated with better cognitive function (ADAS-cog per SD: β coefficient, 0.17; 95% CI, −0.27 to −0.07; Modified Mini-Mental State Examination score per SD: β coefficient, 0.25; 95% CI, 0.07 to 0.42) and lower risk of dementia (hazard ratio per SD, 0.86; 95% CI, 0.76 to 0.99). In contrast, apoE levels in HDL that contains apoC3 were unassociated with any of these outcomes. Conclusions and Relevance: In a prospective cohort of older adults with rigorous follow-up of dementia, the apoE level in HDL that lacked apoC3 was associated with better cognitive function and lower dementia risk. This finding suggests that the cardioprotective associations of this novel lipoprotein extend to dementia

    Evidence for Spatial Separation of Galactic Dust Components

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    We present an implementation of a Bayesian mixture model using Hamiltonian Monte Carlo (HMC) techniques to search for spatial separation of Galactic dust components. Utilizing intensity measurements from \Planck High Frequency Instrument (HFI), we apply this model to high-latitude Galactic dust emission. Our analysis reveals a strong preference for a spatially-varying two-population dust model in intensity, with each population being well characterized by a single-component dust spectral-energy distribution (SED). While no spatial information is built into the likelihood, our investigation unveils spatially coherent structures with high significance, pointing to a physical origin for the observed spatial separation. These results are robust to our choice of likelihood and of input data. Furthermore, they are favored over a single-component dust model by Bayesian evidence calculations. Incorporating \IRAS 100\,μm\mu m to constrain the Wein-side of the blackbody function, we find the dust populations differ at the 2.5σ2.5\sigma level on the spectral index (βd\beta_d) vs. temperature (Td)(T_d) plane. The presence of a multi-population dust has implications for component separation techniques frequently employed in the recovery of the Cosmic Microwave Background.Comment: 16 pages, 8 figures. Submitted to Ap

    Microbiota‐Dependent Metabolite Trimethylamine N‐Oxide and Coronary Artery Calcium in the Coronary Artery Risk Development in Young Adults Study (CARDIA)

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    BACKGROUND: Clinical studies implicate trimethylamine N-oxide (TMAO; a gut microbiota-dependent nutrient metabolite) in cardiovascular disease risk. There is a lack of population-based data on the role of TMAO in advancing early atherosclerotic disease. We tested the prospective associations between TMAO and coronary artery calcium (CAC) and carotid intima-media thickness (cIMT). METHODS AND RESULTS: Data were from the Coronary Artery Risk Development in Young Adults Study (CARDIA), a biracial cohort of US adults recruited in 1985-1986 (n=5115). We randomly sampled 817 participants (aged 33-55 years) who attended examinations in 2000-2001, 2005-2006, and 2010-2011, at which CAC was measured by computed tomography and cIMT (2005-2006) by ultrasound. TMAO was quantified using liquid chromotography mass spectrometry on plasma collected in 2000-2001. Outcomes were incident CAC, defined as Agatston units=0 in 2000-2001 and >0 over 10-year follow-up, CAC progression (any increase over 10-year follow-up), and continuous cIMT. Over the study period, 25% (n=184) of those free of CAC in 2000-2001 (n=746) developed detectable CAC. In 2000-2001, median (interquartile range) TMAO was 2.6 (1.8-4.2) μmol/L. In multivariable-adjusted models, TMAO was not associated with 10-year CAC incidence (rate ratio=1.03; 95% CI: 0.71-1.52) or CAC progression (0.97; 0.68-1.38) in Poisson regression, or cIMT (beta coefficient: -0.009; -0.03 to 0.01) in linear regression, comparing the fourth to the first quartiles of TMAO. CONCLUSIONS: In this population-based study, TMAO was not associated with measures of atherosclerosis: CAC incidence, CAC progression, or cIMT. These data indicate that TMAO may not contribute significantly to advancing early atherosclerotic disease risk among healthy early-middle-aged adults

    Organic Cation Transporter 3 and the Dopamine Transporter Differentially Regulate Catecholamine Uptake in the Basolateral Amygdala and Nucleus Accumbens

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    Regional alterations in kinetics of catecholamine uptake are due in part to variations in clearance mechanisms. The rate of clearance is a critical determinant of the strength of catecholamine signaling. Catecholamine transmission in the nucleus accumbens core (NAcc) and basolateral amygdala (BLA) is of particular interest due to involvement of these regions in cognition and motivation. Previous work has shown that catecholamine clearance in the NAcc is largely mediated by the dopamine transporter (DAT), but clearance in the BLA is less DAT‐dependent. A growing body of literature suggests that organic cation transporter 3 (OCT3) also contributes to catecholamine clearance in both regions. Consistent with different clearance mechanisms between regions, catecholamine clearance is more rapid in the NAcc than in the BLA, though mechanisms underlying this have not been resolved. We compared the expression of DAT and OCT3 and their contributions to catecholamine clearance in the NAcc and BLA. We found DAT protein levels were ~ 4‐fold higher in the NAcc than in the BLA, while OCT3 protein expression was similar between the two regions. Immunofluorescent labeling of the two transporters in brain sections confirmed these findings. Ex vivo voltammetry demonstrated that the magnitude of catecholamine release was greater, and the clearance rate was faster in the NAcc than in the BLA. Additionally, catecholamine clearance in the BLA was more sensitive to the OCT3 inhibitor corticosterone, while clearance in the NAcc was more cocaine sensitive. These distinctions in catecholamine clearance may underlie differential effects of catecholamines on behavioral outputs mediated by these regions

    The balloon-borne large-aperture submillimeter telescope for polarimetry: BLAST-Pol

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    The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLAST-Pol) is a suborbital mapping experiment designed to study the role played by magnetic fields in the star formation process. BLAST-Pol is the reconstructed BLAST telescope, with the addition of linear polarization capability. Using a 1.8 m Cassegrain telescope, BLAST-Pol images the sky onto a focal plane that consists of 280 bolometric detectors in three arrays, observing simultaneously at 250, 350, and 500 um. The diffraction-limited optical system provides a resolution of 30'' at 250 um. The polarimeter consists of photolithographic polarizing grids mounted in front of each bolometer/detector array. A rotating 4 K achromatic half-wave plate provides additional polarization modulation. With its unprecedented mapping speed and resolution, BLAST-Pol will produce three-color polarization maps for a large number of molecular clouds. The instrument provides a much needed bridge in spatial coverage between larger-scale, coarse resolution surveys and narrow field of view, and high resolution observations of substructure within molecular cloud cores. The first science flight will be from McMurdo Station, Antarctica in December 2010.Comment: 14 pages, 9 figures Submitted to SPIE Astronomical Telescopes and Instrumentation Conference 201

    Design of 280 GHz feedhorn-coupled TES arrays for the balloon-borne polarimeter SPIDER

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    We describe 280 GHz bolometric detector arrays that instrument the balloon-borne polarimeter SPIDER. A primary science goal of SPIDER is to measure the large-scale B-mode polarization of the cosmic microwave background in search of the cosmic-inflation, gravitational-wave signature. 280 GHz channels aid this science goal by constraining the level of B-mode contamination from galactic dust emission. We present the focal plane unit design, which consists of a 16×\times16 array of conical, corrugated feedhorns coupled to a monolithic detector array fabricated on a 150 mm diameter silicon wafer. Detector arrays are capable of polarimetric sensing via waveguide probe-coupling to a multiplexed array of transition-edge-sensor (TES) bolometers. The SPIDER receiver has three focal plane units at 280 GHz, which in total contains 765 spatial pixels and 1,530 polarization sensitive bolometers. By fabrication and measurement of single feedhorns, we demonstrate 14.7^{\circ} FHWM Gaussian-shaped beams with <<1% ellipticity in a 30% fractional bandwidth centered at 280 GHz. We present electromagnetic simulations of the detection circuit, which show 94% band-averaged, single-polarization coupling efficiency, 3% reflection and 3% radiative loss. Lastly, we demonstrate a low thermal conductance bolometer, which is well-described by a simple TES model and exhibits an electrical noise equivalent power (NEP) = 2.6 ×\times 1017^{-17} W/Hz\sqrt{\mathrm{Hz}}, consistent with the phonon noise prediction.Comment: Proceedings of SPIE Astronomical Telescopes + Instrumentation 201

    A cryogenic rotation stage with a large clear aperture for the half-wave plates in the Spider instrument

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    We describe the cryogenic half-wave plate rotation mechanisms built for and used in Spider, a polarization-sensitive balloon-borne telescope array that observed the Cosmic Microwave Background at 95 GHz and 150 GHz during a stratospheric balloon flight from Antarctica in January 2015. The mechanisms operate at liquid helium temperature in flight. A three-point contact design keeps the mechanical bearings relatively small but allows for a large (305 mm) diameter clear aperture. A worm gear driven by a cryogenic stepper motor allows for precise positioning and prevents undesired rotation when the motors are depowered. A custom-built optical encoder system monitors the bearing angle to an absolute accuracy of +/- 0.1 degrees. The system performed well in Spider during its successful 16 day flight.Comment: 11 pages, 7 figures, Published in Review of Scientific Instruments. v2 includes reviewer changes and longer literature revie
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