3,459 research outputs found

    Particle Sensor Using Solidly Mounted Resonators

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    This paper describes the development of a novel particle sensing system employing zinc oxide based solidly mounted resonator (SMR) devices for the detection of airborne fine particles (i.e., PM2.5 and PM10). The system operates in a dual configuration in which two SMR devices are driven by Colpitts-type oscillators in a differential mode. Particles are detected by the frequency shift caused by the mass of particles present on one resonator with while the other acts as a reference channel. Experimental validation of the system was performed inside an environmental chamber using a dust generator with the particles of known size and concentration. A sensor sensitivity of 4.6 Hz per ÎŒg/m3 was demonstrated for the SMRs resonating at a frequency of 970 MHz. Our results demonstrate that the SMR-based system has the potential to be implemented in CMOS technology as a low-cost, miniature smart particle detector for the real-time monitoring of airborne particles

    Genomic analysis of urogenital and rectal Neisseria meningitidis isolates reveals encapsulated hyperinvasive meningococci and coincident multidrug-resistant gonococci.

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    OBJECTIVE: Invasive meningococcal disease (IMD) outbreaks in men who have sex with men (MSM) have been associated with meningococcal colonisation of the urethra and rectum, but little is known about this colonisation or co-colonisation with the closely related gonococcus. Whole genome sequencing (WGS) was employed to explore these phenomena. METHODS: Meningococci isolated from the urogenital tract and rectum (n=23) and coincident gonococci (n=14) were analysed by WGS along with contemporary meningococci from IMD (n=11). All isolates were obtained from hospital admissions in Brighton, UK, 2011-2013. Assembled WGS were deposited in the PubMLST/neisseria database (http://pubmlst.org/neisseria) and compared at genomic loci common to gonococci or meningococci. RESULTS: As expected, most meningococci from IMD were encapsulated and belonged to hyperinvasive lineages. So too were meningococci found in the urogenital tract and rectum, contrasting to those asymptomatically carried in the nasopharynx where such meningococci are rare. Five hyperinvasive meningococcal lineages and four distinct gonococcal genotypes were recovered, including multiresistant ST-1901 (NG MAST-1407) gonococci. CONCLUSIONS: These data were consistent with a predisposition for potentially virulent encapsulated hyperinvasive meningococci to colonise the urethra and rectum, which suggests their involvement in MSM IMD outbreaks. The coincidence of multiresistant gonococci raises wider public health concerns

    Whole genome sequencing of Neisseria gonorrhoeae reveals transmission clusters involving patients of mixed HIV serostatus.

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    OBJECTIVES: Prevention and control of gonorrhoea depends on understanding the nature of sexual networks and risk factors for infection. We aimed to use high-resolution typing (whole genome sequencing (WGS)) of Neisseria gonorrhoeae isolates plus patient questionnaire data to gain insights into transmission patterns in a high prevalence setting. METHODS: During a 9-month period (July 2014-March 2015), patients diagnosed with gonorrhoea attending sexual health service in Brighton, UK, were invited to provide anonymised detailed information by questionnaire about risk factors for infection. Questionnaire data plus WGS data from cultured isolates were analysed to yield information about sexual networks and risk factors for infection. RESULTS: 104/149 individuals who consented to participate in the study were culture positive. 97/104 (93%) were male. 80 self-reported to be men who have sex with men (MSM). 35/104 (34%) of patients were HIV positive. 51/104 (49%) individuals reported using geosocial networking applications to facilitate contact. Sex under the influence of drugs was reported by 16/34 (46%) of HIV-positive MSM, 17/41 (41%) of HIV-negative MSM and 5/15 (31%) of heterosexuals. WGS data were available for 100 isolates from 83 patients. 55 isolates (66%) belonged to genetically related subtypes involving one or more patients, who could be plausibly linked through recent direct or indirect transmission. Four transmission clusters containing 3-12 individuals were composed of MSM of mixed HIV serostatus. CONCLUSIONS: We show that data obtained from WGS of N. gonorrhoeae and enhanced epidemiological data obtained from patient questionnaires are mutually supportive and reveal insights into sexual networks. Our findings suggest that serosorting may have declined as a practice and indicate the importance of designing public health interventions that target infection risks associated with recreational drug use and contact made using geosocial networking applications

    Persistent near real-time passive acoustic monitoring for baleen whales from a moored buoy: System description and evaluation

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Baumgartner, M. F., Bonnell, J., Van Parijs, S. M., Corkeron, P. J., Hotchkin, C., Ball, K., Pelletier, L., Partan, J., Peters, D., Kemp, J., Pietro, J., Newhall, K., Stokes, A., Cole, T. V. N., Quintana, E., & Kraus, S. D. Persistent near real-time passive acoustic monitoring for baleen whales from a moored buoy: System description and evaluation. Methods in Ecology and Evolution, 10(9), (2019): 1476-1489, doi: 10.1111/2041-210X.13244.1. Managing interactions between human activities and marine mammals often relies on an understanding of the real‐time distribution or occurrence of animals. Visual surveys typically cannot provide persistent monitoring because of expense and weather limitations, and while passive acoustic recorders can monitor continuously, the data they collect are often not accessible until the recorder is recovered. 2. We have developed a moored passive acoustic monitoring system that provides near real‐time occurrence estimates for humpback, sei, fin and North Atlantic right whales from a single site for a year, and makes those occurrence estimates available via a publicly accessible website, email and text messages, a smartphone/tablet app and the U.S. Coast Guard's maritime domain awareness software. We evaluated this system using a buoy deployed off the coast of Massachusetts during 2015–2016 and redeployed again during 2016–2017. Near real‐time estimates of whale occurrence were compared to simultaneously collected archived audio as well as whale sightings collected near the buoy by aerial surveys. 3. False detection rates for right, humpback and sei whales were 0% and nearly 0% for fin whales, whereas missed detection rates at daily time scales were modest (12%–42%). Missed detections were significantly associated with low calling rates for all species. We observed strong associations between right whale visual sightings and near real‐time acoustic detections over a monitoring range 30–40 km and temporal scales of 24–48 hr, suggesting that silent animals were not especially problematic for estimating occurrence of right whales in the study area. There was no association between acoustic detections and visual sightings of humpback whales. 4. The moored buoy has been used to reduce the risk of ship strikes for right whales in a U.S. Coast Guard gunnery range, and can be applied to other mitigation applications.We thank Annamaria Izzi, Danielle Cholewiak and Genevieve Davis of the NOAA NEFSC for assistance in developing the analyst protocol. We are grateful to the NOAA NEFSC aerial survey observers (Leah Crowe, Pete Duley, Jen Gatzke, Allison Henry, Christin Khan and Karen Vale) and the NEAq aerial survey observers (Angela Bostwick, Marianna Hagbloom and Paul Nagelkirk). Danielle Cholewiak and three anonymous reviewers provided constructive criticism on earlier drafts of the manuscript. Funding for this project was provided by the NOAA NEFSC, NOAA Advanced Sampling Technology Work Group, Environmental Security Technology Certification Program of the U.S. Department of Defense, the U.S. Navy's Living Marine Resources Program, Massachusetts Clean Energy Center and the Bureau of Ocean Energy Management. Funding from NOAA was facilitated by the Cooperative Institute for the North Atlantic Region (CINAR) under Cooperative Agreement NA14OAR4320158

    Resistance to Mucosal Lysozyme Compensates for the Fitness Deficit of Peptidoglycan Modifications by Streptococcus pneumoniae

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    The abundance of lysozyme on mucosal surfaces suggests that successful colonizers must be able to evade its antimicrobial effects. Lysozyme has a muramidase activity that hydrolyzes bacterial peptidoglycan and a non-muramidase activity attributable to its function as a cationic antimicrobial peptide. Two enzymes (PgdA, a N-acetylglucosamine deacetylase, and Adr, an O-acetyl transferase) that modify different sites on the peptidoglycan of Streptococcus pneumoniae have been implicated in its resistance to lysozyme in vitro. Here we show that the antimicrobial effect of human lysozyme is due to its muramidase activity and that both peptidoglycan modifications are required for full resistance by pneumococci. To examine the contribution of lysozyme and peptidoglycan modifications during colonization of the upper respiratory tract, competition experiments were performed with wild-type and pgdAadr mutant pneumococci in lysozyme M-sufficient (LysM+/+) and -deficient (LysM−/−) mice. The wild-type strain out-competed the double mutant in LysM+/+, but not LysM−/− mice, indicating the importance of resistance to the muramidase activity of lysozyme during mucosal colonization. In contrast, strains containing single mutations in either pgdA or adr prevailed over the wild-type strain in both LysM+/+ and LysM−/− mice. Our findings demonstrate that individual peptidoglycan modifications diminish fitness during colonization. The competitive advantage of wild-type pneumococci in LysM+/+ but not LysM−/− mice suggests that the combination of peptidoglycan modifications reduces overall fitness, but that this is outweighed by the benefits of resistance to the peptidoglycan degrading activity of lysozyme

    Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays

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    We report evidence for direct CP violation in the decay B0 -> K+-pi-+ with 253/fb of data collected with the Belle detector at the KEKB e+e- collider. Using 275 million B B_bar pairs we observe a B -> K+-pi-+ signal with 2140+-53 events. The measured CP violating asymmetry is Acp(K+-pi-+) = -0.101+-0.025 (stat)+-0.005 (syst), corresponding to a significance of 3.9 sigma including systematics. We also search for CP violation in the decays B+- -> K+-pi0 and B+- -> pi+-pi0. The measured CP violating asymmetries are Acp(K+-pi0) = 0.04+-0.05(stat)+-0.02(syst) and Acp(pi+-pi0) = -0.02+-0.10(stat)+-0.01(syst), corresponding to the intervals -0.05 < Acp(K+-pi0) < 0.13 and -0.18<Acp(pi+-pi0)<0.14 at 90% confidence level.Comment: 9 pages, 3 figures. submitted to Physical Review Letter

    Modulation of hepatic PPAR expression during Ft LVS LPS-induced protection from Francisella tularensis LVS infection

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    <p>Abstract</p> <p>Background</p> <p>It has been shown previously that administration of <it>Francisella tularensis </it>(<it>Ft</it>) Live Vaccine Strain (LVS) lipopolysaccharide (LPS) protects mice against subsequent challenge with <it>Ft </it>LVS and blunts the pro-inflammatory cytokine response.</p> <p>Methods</p> <p>To further investigate the molecular mechanisms that underlie <it>Ft </it>LVS LPS-mediated protection, we profiled global hepatic gene expression following <it>Ft </it>LVS LPS or saline pre-treatment and subsequent <it>Ft </it>LVS challenge using Affymetrix arrays.</p> <p>Results</p> <p>A large number of genes (> 3,000) were differentially expressed at 48 hours post-infection. The degree of modulation of inflammatory genes by infection was clearly attenuated by pre-treatment with <it>Ft </it>LVS LPS in the surviving mice. However, <it>Ft </it>LVS LPS alone had a subtle effect on the gene expression profile of the uninfected mice. By employing gene set enrichment analysis, we discovered significant up-regulation of the fatty acid metabolism pathway, which is regulated by peroxisome proliferator activated receptors (PPARs).</p> <p>Conclusions</p> <p>We hypothesize that the LPS-induced blunting of pro-inflammatory response in mouse is, in part, mediated by PPARs (α and γ).</p

    Wherever I may roam-Human activity alters movements of red deer (Cervus elaphus) and elk (Cervus canadensis) across two continents

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    Human activity and associated landscape modifications alter the movements of animals with consequences for populations and ecosystems worldwide. Species performing long-distance movements are thought to be particularly sensitive to human impact. Despite the increasing anthropogenic pressure, it remains challenging to understand and predict animals' responses to human activity. Here we address this knowledge gap using 1206 Global Positioning System movement trajectories of 815 individuals from 14 red deer (Cervus elaphus) and 14 elk (Cervus canadensis) populations spanning wide environmental gradients, namely the latitudinal range from the Alps to Scandinavia in Europe, and the Greater Yellowstone Ecosystem in North America. We measured individual-level movements relative to the environmental context, or movement expression, using the standardized metric Intensity of Use, reflecting both the directionality and extent of movements. We expected movement expression to be affected by resource (Normalized Difference Vegetation Index, NDVI) predictability and topography, but those factors to be superseded by human impact. Red deer and elk movement expression varied along a continuum, from highly segmented trajectories over relatively small areas (high intensity of use), to directed transitions through restricted corridors (low intensity of use). Human activity (Human Footprint Index, HFI) was the strongest driver of movement expression, with a steep increase in Intensity of Use as HFI increased, but only until a threshold was reached. After exceeding this level of impact, the Intensity of Use remained unchanged. These results indicate the overall sensitivity of Cervus movement expression to human activity and suggest a limitation of plastic responses under high human pressure, despite the species also occurring in human-dominated landscapes. Our work represents the first comparison of metric-based movement expression across widely distributed populations of a deer genus, contributing to the understanding and prediction of animals' responses to human activit

    Wherever I may roam—Human activity alters movements of red deer (Cervus elaphus) and elk (Cervus canadensis) across two continents

    Get PDF
    Human activity and associated landscape modifications alter the movements of ani-mals with consequences for populations and ecosystems worldwide. Species perform-ing long-distance movements are thought to be particularly sensitive to human impact. Despite the increasing anthropogenic pressure, it remains challenging to understand and predict animals' responses to human activity. Here we address this knowledge gap using 1206 Global Positioning System movement trajectories of 815 individuals from 14 red deer (Cervus elaphus) and 14 elk (Cervus canadensis) populations spanning wide environmental gradients, namely the latitudinal range from the Alps to Scandinavia in Europe, and the Greater Yellowstone Ecosystem in North America. We measured individual-level movements relative to the environmental context, or movement ex-pression, using the standardized metric Intensity of Use, reflecting both the directional-ity and extent of movements. We expected movement expression to be affected by resource (Normalized Difference Vegetation Index, NDVI) predictability and topogra-phy, but those factors to be superseded by human impact. Red deer and elk movement expression varied along a continuum, from highly segmented trajectories over relatively small areas (high intensity of use), to directed transitions through restricted corridors (low intensity of use). Human activity (Human Footprint Index, HFI) was the strong-est driver of movement expression, with a steep increase in Intensity of Use as HFI increased, but only until a threshold was reached. After exceeding this level of impact, the Intensity of Use remained unchanged. These results indicate the overall sensitivity of Cervus movement expression to human activity and suggest a limitation of plastic responses under high human pressure, despite the species also occurring in human-dominated landscapes. Our work represents the first comparison of metric- based movement expression across widely distributed populations of a deer genus, contribut-ing to the understanding and prediction of animals' responses to human activity.publishedVersio
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