652 research outputs found

    Adjustment of a Coastal Buoyant Outflow Under Tidal and Wind Forcing

    Get PDF
    The discharge of brackish water from estuaries typically forms distinct coastal plumes, often visible through their color signature due to sediment load and particulate matter from rivers. The processes of mixing and dispersion of coastal plumes are subjected to natural variations in the magnitude and timing of freshwater inflows, tides and meteorological conditions. This study presents shipboard observation of the bulge region of a buoyant plume off Winyah Bay, SC. The observation comprises downward looking 600 and 1200 kHz ADCP (Acoustic Doppler Current Profiler) and CTD measurements. Along with standard CTD casts, water samples were collected to analyze and determine mass sediment concentration using standard filtering techniques. Auxiliary data such as wind, river discharge and coastal sea level measurements were collected from WeatherFlow, USGS streamflow and NOAA tide gauge stations, respectively. The study addresses the evolution of bulge region of the plume under the conditions of low freshwater discharge and light wind forcing. The study also examines the fate of the suspended sediments under high discharge condition. The spatial and temporal salinity and temperature structures from CTD measurements are analyzed to inspect the evolution of the bulge region. The impact of suspended sediments on modifying the density anomaly within the plume is also assessed. Gradient Richardson number is calculated to examine the influence of suspended sediments on the mixing processes within the plume. Analysis of the observations demonstrate that the buoyant water was not dispersed by the wind forcing but formed a well pronounced baroclinic jet with associated front. The buoyant outflow occurring at semidiurnal tidal frequency first propagated northward with the wind-driven currents, but then turned anticyclonically and continued southward, against the wind-driven current. However, this baroclinic jet never reached the coastline to form a coastal current. Due to wind forcing, the frontal zone width exceeded the baroclinic Rossby radius, and in some cases multiple frontal structures were observed. Overall, the results demonstrate that under certain forcing conditions all buoyant outflow is deflected into a growing bulge and ultimately spreads offshore contributing to the cross-shelf exchange processes

    Investigating the Synthesis and Characterization of a Novel “Green” H<sub>2</sub>O<sub>2</sub>-Assisted, Water-Soluble Chitosan/Polyvinyl Alcohol Nanofiber for Environmental End Uses

    Get PDF
    The present work highlights the formation of a novel green nanofiber based on H2O2-assisted water-soluble chitosan/polyvinyl alcohol (WSCHT/PVA) by using water as an ecofriendly solvent and genipin used as a nontoxic cross-linker. The 20/80 blend ratio was found to have the most optimum uniform fiber morphology. WSCHT retained the same structure as WISCHT. The prepared nanofibers were characterized by Scanning electron microscopy (SEM), Fourier transform spectroscopy (FTIR), Thermo gravimetric analysis (TGA), Differential scanning calorimeter (DSC), X-ray diffraction (XRD), Water Contact Angle (WCA) and Ultraviolet-visible spectroscopy (UV-vis). During electrospinning, the crystalline microstructure of the WSCHT/PVA underwent better solidification and after cross-linking there was an increase in the melting temperature of the fiber. Swelling ratio studies revealed noticeable increase in hydrophilicity with increase of WSCHT, which was further demonstrated by the decrease of contact angle from 64.74&deg; to 14.68&deg;. WSCHT/PVA nanofiber mats exhibit excellent UV blocking protection with less than 5% transmittance value and also showed improved in vitro drug release properties with stable release for longer duration (cross-linked fibers) and burst release for shorter duration (uncross linked) fibers. Finally our experimental data demonstrates excellent adsorption ability of Colour Index (C.I.) reactive black 5 (RB5) due to protonated amino groups

    Risk of Depression in a Suburban Primary Care Setting Before and During the COVID-19 Pandemic.

    Get PDF
    INTRODUCTION: Major depression is a common disorder affecting millions of adults each year. Many population-based surveys showed an increase in the number people with symptoms of depression at the onset of the COVID-19 pandemic. Our aim was to determine and compare the prevalence of depression risk in a primary care setting before and during the COVID-19 pandemic. METHODS: We conducted a cross-sectional study based on retrospective review of medical records from a large suburban primary care clinic. Records of adults 18 years and older, seen between January 1, 2019 and December 31, 2020 and who had also been screened for depression using the 9-item Patient Health Questionnaire (PHQ-9) were analyzed. RESULTS: Adults 18 years and older who completed the PHQ-9 assessment in 2019 and 2020 were 5078 and 4338, respectively. Risk of depression was 18.2% in 2019 and 14.8% in 2020 ( CONCLUSION: Although our results did not reflect the published literature reporting a higher prevalence of depression during the COVID-19 pandemic, they were consistent with reports of increased risk in females and younger adults

    Biomarkers of Tuberculosis Severity and Treatment Effect: A Directed Screen of 70 Host Markers in a Randomized Clinical Trial.

    Get PDF
    More efficacious treatment regimens are needed for tuberculosis, however, drug development is impeded by a lack of reliable biomarkers of disease severity and of treatment effect. We conducted a directed screen of host biomarkers in participants enrolled in a tuberculosis clinical trial to address this need. Serum samples from 319 protocol-correct, culture-confirmed pulmonary tuberculosis patients treated under direct observation as part of an international, phase 2 trial were screened for 70 markers of infection, inflammation, and metabolism. Biomarker assays were specifically developed for this study and quantified using a novel, multiplexed electrochemiluminescence assay. We evaluated the association of biomarkers with baseline characteristics, as well as with detailed microbiologic data, using Bonferroni-adjusted, linear regression models. Across numerous analyses, seven proteins, SAA1, PCT, IL-1β, IL-6, CRP, PTX-3 and MMP-8, showed recurring strong associations with markers of baseline disease severity, smear grade and cavitation; were strongly modulated by tuberculosis treatment; and had responses that were greater for patients who culture-converted at 8weeks. With treatment, all proteins decreased, except for osteocalcin, MCP-1 and MCP-4, which significantly increased. Several previously reported putative tuberculosis-associated biomarkers (HOMX1, neopterin, and cathelicidin) were not significantly associated with treatment response. In conclusion, across a geographically diverse and large population of tuberculosis patients enrolled in a clinical trial, several previously reported putative biomarkers were not significantly associated with treatment response, however, seven proteins had recurring strong associations with baseline radiographic and microbiologic measures of disease severity, as well as with early treatment response, deserving additional study

    COVID-19 Outbreak: Effect of an Educational Intervention Based on Health Belief Model on Nursing Students' Awareness and Health Beliefs at Najran University, Kingdom of Saudi Arabia

    Get PDF
    This study aimed to investigate the effect of an educational intervention based on the health belief model (HBM) about COVID-19 on nursing&nbsp; students' awareness and health beliefs. A true-experimental research design was conducted at nursing college, Najran University, KSA. A&nbsp; comprehensive sampling was followed to include all female students at the colleges (164 students). The sample was divided randomly into&nbsp; intervention (82) and control group (82). The educational intervention was designed and conducted based on the HBM through four sequential phases: assessment, planning, implementation, and evaluation. The current study results indicated no statistically significant differences between intervention and control groups concerning their demographic characteristic, awareness, and health beliefs before intervention. After intervention, significant differences (p&lt; 0.05) were observed between intervention and control groups in their awareness and all HBM constructs regarding COVID19. There were positive, statistically significant correlations (P&lt; 0.05) between participants' total HBM score and their total awareness score. This study concluded that HBM is effective in increasing nursing students' awareness regarding COVID-19. It also increases their perceived&nbsp; susceptibility, severity, and benefits. Besides, it may increase their self-efficacy to overcome perceived barriers to practice protective and preventive actions while dealing with COVID-19. Keywords: Awareness, COVID-19, Health belief model, Nursing students, Saudi Arabia &nbsp; Cette étude visait à étudier l'effet d'une intervention éducative basée sur le modèle de croyance en santé (HBM) à propos du COVID-19 sur la sensibilisation des étudiants en soins infirmiers et leurs croyances en matière de santé. Une conception de recherche véritablement expérimentale a été menée au collège d'infirmières de l'Université de Najran, en Arabie Saoudite. Un échantillonnage complet a été suivi pour inclure toutes les étudiantes des collèges (164 étudiantes). L'échantillon a été divisé au hasard en groupe d'intervention (82) et groupe témoin (82). L'intervention éducative a été conçue et menée sur la base du HBM à travers quatre phases séquentielles: évaluation, planification, mise en oeuvre et évaluation. Les résultats de l'étude actuelle n'ont indiqué aucune différence statistiquement significative entre les groupes d'intervention et de contrôle concernant leurs caractéristiques démographiques, leur sensibilisation et leurs croyances en matière de santé avant l'intervention. Aprèsl'intervention, des&nbsp; différences significatives (p &lt;0,05) ont été observées entre les groupes d'intervention et de contrôle dans leur connaissance et tutes les constructions HBM concernant COVID19. Il y avait des corrélations positives et statistiquement significatives (P &lt;0,05) entre le score HBM total des participants et leur score total de sensibilisation. Cette étude a conclu que HBM est efficace pour sensibiliser les étudiants en sciences infirmières au COVID-19. Cela augmente également leur sensibilité, leur gravité et leurs avantages perçus. En outre, cela peut augmenter leur efficacité personnelle pour surmonter les obstacles perçus à la pratique d'actions de protection et de prévention tout en traitant le COVID-19. Mots-clés: Sensibilisation, COVID-19, modèle de croyance en matière de santé, étudiants en sciences infirmières, Arabie saoudit

    Cultural Theories of Postpartum Bleeding in Matlab, Bangladesh: Implications for Community Health Intervention

    Get PDF
    Early recognition can reduce maternal disability and deaths due to postpartum haemorrhage. This study identified cultural theories of postpartum bleeding that may lead to inappropriate recognition and delayed care-seeking. Qualitative and quantitative data obtained through structured interviews with 149 participants living in Matlab, Bangladesh, including women aged 18-49 years, women aged 50+ years, traditional birth attendants (TBAs), and skilled birth attendants (SBAs), were subjected to cultural domain. General consensus existed among the TBAs and lay women regarding signs, causes, and treatments of postpartum bleeding (eigenvalue ratio 5.9, mean competence 0.59, and standard deviation 0.15). Excessive bleeding appeared to be distinguished by flow characteristics, not colour or quantity. Yet, the TBAs and lay women differed significantly from the SBAs in beliefs about normalcy of blood loss, causal role of the retained placenta and malevolent spirits, and care practices critical to survival. Cultural domain analysis captures variation in theories with specificity and representativeness necessary to inform community health intervention

    Traffic-Related Air Pollution and All-Cause Mortality during Tuberculosis Treatment in California.

    Get PDF
    BackgroundAmbient air pollution and tuberculosis (TB) have an impact on public health worldwide, yet associations between the two remain uncertain.ObjectiveWe determined the impact of residential traffic on mortality during treatment of active TB.MethodsFrom 2000-2012, we enrolled 32,875 patients in California with active TB and followed them throughout treatment. We obtained patient data from the California Tuberculosis Registry and calculated traffic volumes and traffic densities in 100- to 400-m radius buffers around residential addresses. We used Cox models to determine mortality hazard ratios, controlling for demographic, socioeconomic, and clinical potential confounders. We categorized traffic exposures as quintiles and determined trends using Wald tests.ResultsParticipants contributed 22,576 person-years at risk. There were 2,305 deaths during treatment for a crude mortality rate of 1,021 deaths per 10,000 person-years. Traffic volumes and traffic densities in all buffers around patient residences were associated with increased mortality during TB treatment, although the findings were not statistically significant in all buffers. As the buffer size decreased, fifth-quintile mortality hazards increased, and trends across quintiles of traffic exposure became more statistically significant. Increasing quintiles of nearest-road traffic volumes in the 100-m buffer were associated with 3%, 14%, 19%, and 28% increased risk of death during TB treatment [first quintile, referent; second quintile hazard ratio (HR)=1.03 [95% confidence interval (CI): 0.86, 1.25]; third quintile HR=1.14 (95% CI: 0.95, 1.37); fourth quintile HR=1.19 (95% CI: 0.99, 1.43); fifth quintile HR=1.28 (95% CI: 1.07, 1.53), respectively; p-trend=0.002].ConclusionsResidential proximity to road traffic volumes and traffic density were associated with increased all-cause mortality in patients undergoing treatment for active tuberculosis even after adjusting for multiple demographic, socioeconomic, and clinical factors, suggesting that TB patients are susceptible to the adverse health effects of traffic-related air pollution. https://doi.org/10.1289/EHP1699

    Standalone and RTK GNSS on 30,000 km of North American Highways

    Full text link
    There is a growing need for vehicle positioning information to support Advanced Driver Assistance Systems (ADAS), Connectivity (V2X), and Automated Driving (AD) features. These range from a need for road determination (<5 meters), lane determination (<1.5 meters), and determining where the vehicle is within the lane (<0.3 meters). This work examines the performance of Global Navigation Satellite Systems (GNSS) on 30,000 km of North American highways to better understand the automotive positioning needs it meets today and what might be possible in the near future with wide area GNSS correction services and multi-frequency receivers. This includes data from a representative automotive production GNSS used primarily for turn-by-turn navigation as well as an Inertial Navigation System which couples two survey grade GNSS receivers with a tactical grade Inertial Measurement Unit (IMU) to act as ground truth. The latter utilized networked Real-Time Kinematic (RTK) GNSS corrections delivered over a cellular modem in real-time. We assess on-road GNSS accuracy, availability, and continuity. Availability and continuity are broken down in terms of satellite visibility, satellite geometry, position type (RTK fixed, RTK float, or standard positioning), and RTK correction latency over the network. Results show that current automotive solutions are best suited to meet road determination requirements at 98% availability but are less suitable for lane determination at 57%. Multi-frequency receivers with RTK corrections were found more capable with road determination at 99.5%, lane determination at 98%, and highway-level lane departure protection at 91%.Comment: Accepted for the 32nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2019), Miami, Florida, September 201
    corecore