941 research outputs found
Is Social Media like an Onion?: Exploring the Social Penetration Theory as an Explanation for Viral Responses to Intimate Self-Disclosures
A recent public FB post about a personal experience with depression went viral within a week. Within a week this post was reposted on numerous media outlets, and shared by others nearly 500,000 times. This post skipped to the third, affective stage, of the Social Penetration Theory
Initial test results on bolometers for the Planck high frequency instrument
We summarize the fabrication, flight qualification, and dark performance of bolometers completed at the Jet Propulsion Laboratory for the High Frequency Instrument (HFI) of the joint ESA/NASA Herschel/Planck mission to be launched in 2009. The HFI is a multicolor focal plane which consists of 52 bolometers operated at 100 mK. Each bolometer is mounted to a feedhorn-filter assembly which defines one of six frequency bands centered between 100-857 GHz. Four detectors in each of five bands from 143-857 GHz are coupled to both linear polarizations and thus measure the total intensity. In addition, eight detectors in each of four bands (100, 143, 217, and 353 GHz) couple only to a single linear polarization and thus provide measurements of the Stokes parameters, Q and U, as well as the total intensity. The measured noise equivalent power (NEP) of all detectors is at or below the background limit for the telescope and time constants are a few ms, short enough to resolve point sources as the 5 to 9 arc min beams move across the sky at 1 rpm
Constant Size Molecular Descriptors For Use With Machine Learning
A set of molecular descriptors whose length is independent of molecular size
is developed for machine learning models that target thermodynamic and
electronic properties of molecules. These features are evaluated by monitoring
performance of kernel ridge regression models on well-studied data sets of
small organic molecules. The features include connectivity counts, which
require only the bonding pattern of the molecule, and encoded distances, which
summarize distances between both bonded and non-bonded atoms and so require the
full molecular geometry. In addition to having constant size, these features
summarize information regarding the local environment of atoms and bonds, such
that models can take advantage of similarities resulting from the presence of
similar chemical fragments across molecules. Combining these two types of
features leads to models whose performance is comparable to or better than the
current state of the art. The features introduced here have the advantage of
leading to models that may be trained on smaller molecules and then used
successfully on larger molecules.Comment: 18 pages, 5 figure
A novel immunofluorescence flow cytometry technique detects the expansion of brown tides caused by Aureoumbra lagunensis to the Caribbean Sea
Author Posting. © American Society for Microbiology, 2014. This article is posted here by permission of American Society for Microbiology for personal use, not for redistribution. The definitive version was published in Applied and Environmental Microbiology 80 (2014): 4947-4957, doi:10.1128/AEM.00888-14.During the past 3 decades, brown tides caused by the pelagophytes Aureococcus anophagefferens and Aureoumbra lagunensis have caused ecological and economic damage to coastal ecosystems across the globe. While blooms of A. lagunensis had previously been confined to Texas, in 2012, an expansive brown tide occurred on Florida's East Coast, causing widespread disruption within the Indian River and Mosquito Lagoons and generating renewed interest in this organism. A major impediment to detailed investigations of A. lagunensis in an ecosystem setting has been the absence of a rapid and reliable method for cell quantification. The combination of their small size (3 to 5 μm) and nondescript extracellular features makes identification and enumeration of these cells with conventional methods a challenge. Here we report the development of an immunological-based flow cytometry method that uses a fluorescently labeled antibody developed against A. lagunensis. This method is species specific, sensitive (detection limit of 1.5 × 103 cells ml−1), precise (1% relative standard deviation of replicated samples), and accurate (108% ± 8% recovery of spiked samples) over a wide range of cell concentrations. Furthermore, this method effectively quantifies A. lagunensis in both glutaraldehyde- and formalin-preserved samples, yields a high throughput of samples (∼35 samples h−1), and is cost-effective, making it an ideal tool for managers and scientists. This method successfully documented the recurrence of a brown tide bloom in Florida in 2013. Bloom densities were highest in June (>2.0 × 106 cells ml−1) and spanned >60 km from the Ponce de Leon inlet in the northern Mosquito Lagoon south to Titusville in the Indian River Lagoon. Low levels of A. lagunensis cells were found >250 km south of this region. This method also quickly and accurately identified A. lagunensis as the causative agent of a 2013 brown tide bloom in Guantanamo Bay, Cuba, and thus should prove useful for both quantifying the dynamics of ongoing blooms of A. lagunensis as well as documenting new outbreaks of this harmful alga.This research was funded as part of an NOAA ECOHAB Event Response
grant to C.J.G. Support for D.M.A. was provided by the Woods Hole
Center for Oceans and Human Health, a National Science Foundation
grant (OCE-1314642), and a National Institute of Environmental Health
Sciences grant (1-P01-ES021923-01)
Spatial Patterns and Sequential Sampling Plans for Estimating Densities of Stink Bugs (Hemiptera: Pentatomidae) in Soybean in the North Central Region of the United States
Stink bugs are an emerging threat to soybean (Fabales: Fabaceae) in the North Central Region of the United States. Consequently, region-specific scouting recommendations for stink bugs are needed. The aim of this study was to characterize the spatial pattern and to develop sampling plans to estimate stink bug population density in soybean fields. In 2016 and 2017, 125 fields distributed across nine states were sampled using sweep nets. Regression analyses were used to determine the effects of stink bug species [Chinavia hilaris (Say) (Hemiptera: Pentatomidae) and Euschistus spp. (Hemiptera: Pentatomidae)], life stages (nymphs and adults), and field locations (edge and interior) on spatial pattern as represented by variance–mean relationships. Results showed that stink bugs were aggregated. Sequential sampling plans were developed for each combination of species, life stage, and location and for all the data combined. Results for required sample size showed that an average of 40–42 sample units (sets of 25 sweeps) would be necessary to achieve a precision of 0.25 for stink bug densities commonly encountered across the region. However, based on the observed geographic gradient of stink bug densities, more practical sample sizes (5–10 sample units) may be sufficient in states in the southeastern part of the region, whereas impractical sample sizes (\u3e100 sample units) may be required in the northwestern part of the region. Our findings provide research-based sampling recommendations for estimating densities of these emerging pests in soybean
Myocardial pathology induced by aldosterone is dependent on non-canonical activities of G protein-coupled receptor kinases
Hyper-aldosteronism is associated with myocardial dysfunction including induction of cardiac fibrosis and maladaptive hypertrophy. Mechanisms of these cardiotoxicities are not fully understood. Here we show that mineralocorticoid receptor (MR) activation by aldosterone leads to pathological myocardial signalling mediated by mitochondrial G protein-coupled receptor kinase 2 (GRK2) pro-death activity and GRK5 pro-hypertrophic action. Moreover, these MR-dependent GRK2 and GRK5 non-canonical activities appear to involve cross-talk with the angiotensin II type-1 receptor (AT1R). Most importantly, we show that ventricular dysfunction caused by chronic hyper-aldosteronism in vivo is completely prevented in cardiac Grk2 knockout mice (KO) and to a lesser extent in Grk5 KO mice. However, aldosterone-induced cardiac hypertrophy is totally prevented in Grk5 KO mice. We also show human data consistent with MR activation status in heart failure influencing GRK2 levels. Therefore, our study uncovers GRKs as targets for ameliorating pathological cardiac effects associated with high-aldosterone levels
The Association Between Persistent White-Matter Abnormalities and Repeat Injury After Sport-Related Concussion
Objective: A recent systematic review determined that the physiological effects of concussion may persist beyond clinical recovery. Preclinical models suggest that ongoing physiological effects are accompanied by increased cerebral vulnerability that is associated with risk for subsequent, more severe injury. This study examined the association between signal alterations on diffusion tensor imaging following clinical recovery of sport-related concussion in athletes with and without a subsequent second concussion. Methods: Average mean diffusivity (MD) was calculated in a region of interest (ROI) in which concussed athletes (n = 82) showed significantly elevated MD acutely after injury (<48 h), at an asymptomatic time point, 7 days post-return to play (RTP), and 6 months relative to controls (n = 69). The relationship between MD in the identified ROI and likelihood of sustaining a subsequent concussion over a 1-year period was examined with a binary logistic regression (re-injured, yes/no). Results: Eleven of 82 concussed athletes (13.4%) sustained a second concussion within 12 months of initial injury. Mean MD at 7 days post-RTP was significantly higher in those athletes who went on to sustain a repeat concussion within 1 year of initial injury than those who did not (p = 0.048; d = 0.75). In this underpowered sample, the relationship between MD at 7 days post-RTP and likelihood of sustaining a secondary injury approached significance [χ2 (1) = 4.17, p = 0.057; B = 0.03, SE = 0.017; OR = 1.03, CI = 0.99, 1.07]. Conclusions: These preliminary findings raise the hypothesis that persistent signal abnormalities in diffusion imaging metrics at RTP following concussion may be predictive of a repeat concussion. This may reflect a window of cerebral vulnerability or increased susceptibility following concussion, though understanding the clinical significance of these findings requires further study
Maximal Oxidative Capacity during Exercise Is Associated with Skeletal Muscle Fuel Selection and Dynamic Changes in Mitochondrial Protein Acetylation
SummaryMaximal exercise-associated oxidative capacity is strongly correlated with health and longevity in humans. Rats selectively bred for high running capacity (HCR) have improved metabolic health and are longer-lived than their low-capacity counterparts (LCR). Using metabolomic and proteomic profiling, we show that HCR efficiently oxidize fatty acids (FAs) and branched-chain amino acids (BCAAs), sparing glycogen and reducing accumulation of short- and medium-chain acylcarnitines. HCR mitochondria have reduced acetylation of mitochondrial proteins within oxidative pathways at rest, and there is rapid protein deacetylation with exercise, which is greater in HCR than LCR. Fluxomic analysis of valine degradation with exercise demonstrates a functional role of differential protein acetylation in HCR and LCR. Our data suggest that efficient FA and BCAA utilization contribute to high intrinsic exercise capacity and the health and longevity benefits associated with enhanced fitness
Impact of PNKP mutations associated with microcephaly, seizures and developmental delay on enzyme activity and DNA strand break repair
Microcephaly with early-onset, intractable seizures and developmental delay (MCSZ) is a hereditary disease caused by mutations in polynucleotide kinase/phosphatase (PNKP), a DNA strand break repair protein with DNA 5'-kinase and DNA 3'-phosphatase activity. To investigate the molecular basis of this disease, we examined the impact of MCSZ mutations on PNKP activity in vitro and in cells. Three of the four mutations currently associated with MCSZ greatly reduce or ablate DNA kinase activity of recombinant PNKP at 30°C (L176F, T424Gfs48X and exon15Δfs4X), but only one of these mutations reduces DNA phosphatase activity under the same conditions (L176F). The fourth mutation (E326K) has little impact on either DNA kinase or DNA phosphatase activity at 30°C, but is less stable than the wild-type enzyme at physiological temperature. Critically, all of the MCSZ mutations identified to date result in ∼10-fold reduced cellular levels of PNKP protein, and reduced rates of chromosomal DNA strand break repair. Together, these data suggest that all four known MCSZ mutations reduce the cellular stability and level of PNKP protein, with three mutations likely ablating cellular DNA 5'-kinase activity and all of the mutations greatly reducing cellular DNA 3'-phosphatase activity
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