152 research outputs found

    Detecting fish aggregations from reef habitats mapped with high resolution side scan sonar imagery

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    As part of a multibeam and side scan sonar (SSS) benthic survey of the Marine Conservation District (MCD) south of St. Thomas, USVI and the seasonal closed areas in St. Croix—Lang Bank (LB) for red hind (Epinephelus guttatus) and the Mutton Snapper (MS) (Lutjanus analis) area—we extracted signals from water column targets that represent individual and aggregated fish over various benthic habitats encountered in the SSS imagery. The survey covered a total of 18 km2 throughout the federal jurisdiction fishery management areas. The complementary set of 28 habitat classification digital maps covered a total of 5,462.3 ha; MCDW (West) accounted for 45% of that area, and MCDE (East) 26%, LB 17%, and MS the remaining 13%. With the exception of MS, corals and gorgonians on consolidated habitats were significantly more abundant than submerged aquatic vegetation (SAV) on unconsolidated sediments or unconsolidated sediments. Continuous coral habitat was the most abundant consolidated habitat for both MCDW and MCDE (41% and 43% respectively). Consolidated habitats in LB and MS predominantly consisted of gorgonian plain habitat with 95% and 83% respectively. Coral limestone habitat was more abundant than coral patch habitat; it was found near the shelf break in MS, MCDW, and MCDE. Coral limestone and coral patch habitats only covered LB minimally. The high spatial resolution (0.15 m) of the acquired imagery allowed the detection of differing fish aggregation (FA) types. The largest FA densities were located at MCDW and MCDE over coral communities that occupy up to 70% of the bottom cover. Counts of unidentified swimming objects (USOs), likely representing individual fish, were similar among locations and occurred primarily over sand and shelf edge areas. Fish aggregation school sizes were significantly smaller at MS than the other three locations (MCDW, MCDE, and LB). This study shows the advantages of utilizing SSS in determining fish distributions and density

    Reducing particulate matter emissions from residential wood burning stoves by electrostatic precipitation : a CFD modeling study

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    Emissions of PM2.5 from residential fuel wood heating appliances are a major source of winter air pollution in many parts of North America and northern Europe. This pollution has been linked to respiratory health problems. One possible method of reducing these emissions is via an electrostatic precipitator (ESP) installed at the top of the flue pipe of the appliance. This study investigated the hypothesis that such a device can operate efficiently and contribute to a significant reduction in PM2.5 emissions from fuel wood combustion. A 2-D axisymmetric numerical model of an ESP was created and simulated using commercial computational fluid dynamics software. The model and simulation procedure included several enhancements over similar studies found in the literature such as: the use of a polydisperse particle distribution, the use of a partially developed gas flow velocity profile and the use of a sum-of-charges particle charging model that includes diffusion and field charging mechanisms. The simulation technique was validated using experimental data and provided collection efficiency values within 5% of the experimental values. A reference model based on the dimensions of a standard flue pipe (diameter of 0,15 m) was simulated and found to have an overall collection efficiency of 75%. Based on these results, the emissions of PM2.5 from residential fuel wood combustion in Quebec province could be reduced by 64% in one scenario. Several safety and operational issues need to be resolved before such a device can be launched commercially

    Effect of ion bombardment on in-plane texture, surface morphology, and microstructure of vapor deposited Nb thin films

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    Niobium films were deposited by physical vapor deposition (PVD) and ion-beam-assisted deposition (IBAD) using ion energies of 0, 250, 500 and 1000 eV, and RR ratios (ion-to-atom arrival rate ratio) of 0, 0.1, and 0.4 on (100) silicon, amorphous glass, and (0001) sapphire substrates of thickness 50–1000 nm. Besides a {110} fiber texture, an in-plane texture was created by orienting the ion beam with respect to the substrate. The in-plane texture as measured by the degree of orientation was strongly dependent on both ion-beam energy and the RR ratio. In fact, the degree of orientation in the films followed a linear relationship with the energy per deposited atom, En.En. The grain structure was columnar and the column width increased with normalized energy. The surface morphology depended on both the normalized energy of the ion beam and the film thickness. All films had domelike surface features that were oriented along the ion-beam incident direction. The dimension of these features increased with normalized energy and film thickness. Surface roughness also increased with normalized energy and film thickness, with the root-mean-square roughness increasing from 1.6 nm for the PVD sample (100 nm thick) to 36.7 nm for the IBAD film (1000 eV, R = 0.4,R=0.4, 800 nm thick). Both the surface morphology evolution and in-plane texture development in these films were the result of the different ion sputter rates among differently oriented grains. © 1997 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69738/2/JAPIAU-81-10-6754-1.pd

    Folic acid supplementation increases survival and modulates high risk HPV-induced phenotypes in oral squamous cell carcinoma cells and correlates with p53 mRNA transcriptional down-regulation

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    <p>Abstract</p> <p>Background</p> <p>Although the primary risk factors for developing oral cancers are well understood, less is known about the relationship among the secondary factors that may modulate the progression of oral cancers, such as high-risk human papillomavirus (HPV) infection and folic acid (FA) supplementation. This study examined high-risk HPV and FA supplementation effects, both singly and in combination, to modulate the proliferative phenotypes of the oral cancer cell lines CAL27, SCC25 and SCC15.</p> <p>Results</p> <p>Using a comprehensive series of integrated <it>in vitro </it>assays, distinct effects of HPV infection and FA supplementation were observed. Both high-risk HPV strains 16 and 18 induced robust growth-stimulating effects in CAL27 and normal HGF-1 cells, although strain-specific responses were observed in SCC25 and SCC15 cells. Differential effects were also observed with FA administration, which significantly altered the growth rate of the oral cancer cell lines CAL27, SCC15, and SCC25, but not HGF-1 cells. Unlike HPV, FA administration induced broad, general increases in cell viability among all cell lines that were associated with <it>p53 </it>mRNA transcriptional down-regulation. None of these cell lines were found to harbor the common C677T mutation in methylenetetrahydrofolate reductase (<it>MTHFR</it>), which can reduce FA availability and may increase oral cancer risk.</p> <p>Conclusion</p> <p>Increased FA utilization and DNA hypermethylation are common features of oral cancers, and in these cell lines, specifically. The results of this study provide further evidence that FA antimetabolites, such as Fluorouracil (f5U or 5-FU) and Raltitrexed, may be alternative therapies for tumors resistant to other therapies. Moreover, since the incidence of oral HPV infection has been increasing, and can influence oral cancer growth, the relationship between FA bioavailability and concomitant HPV infection must be elucidated. This study is among the first pre-clinical studies to evaluate FA- and HPV-induced effects in oral cancers, both separately and in combination, which provides additional rationale for clinical screening of HPV infection prior to treatment.</p

    Global Prevalence of Gestational Diabetes Mellitus: A Systematic Review and Meta-Analysis

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    1. Abstract 1.1. Background: Evidence suggests that diabetes in all forms are on the rise especially gesta-tional diabetes mellitus which increases the risk of maternal and neonatal morbidities; however global prevalence rates and geographical distribution of GDM remain uncertain. The aim of this study is to examine the global burden of gestational diabetes mellitus. 1.2. Methods: A systematic review and meta-analysis of studies reporting Randomised Clinical Trials (RCTs) in pregnant women who have GDM was conducted. Cochrane (Central), PubMed, Scopus, JBI, Medline, EMBASE and reference lists of retrieved studies were searched from inception to March 2019. Publications on prevalence of GDM irrespective of the baseline criteria used to diagnose GDM were included in the study. Studies were limited to English language, randomised control trials and women aged between 19-44 years inclusive. 1.3. Results: Eleven RCTs met the inclusion criteria for this review. The included studies collectively reported GDM rates of 13,450 pregnant women from 7 countries. The diagnostic criteria used in the studies were World Health Organisation (WHO) 1985 and 1999, International Association of Diabetes, Pregnancy Study Group (IADPSG), National Diabetes Data Group (NDDG), Carpenter-Coustan (C&C) and O'Sullivan's criteria. Seven RCTs screened for GDM in comparison with different diagnostic criteria in the same population while three studies used the same criteria for different groups. One study compared 100g, 3h OGTT to 75g, 2h OGTT for diagnosing GDM using Carpenter and Coustan criteria. All seven RCTs that compared different diagnostic criteria in the same population detected different prevalence rates of GDM. Three RCTs measured prevalence of GDM in the same population using WHO 1999 and IADPSG 2013 criteria. Using random effect model, data from three studies that compared IADPSG criteria to WHO 1999 showed an Odds Ratio (OR) of 0.52(0.15, 1.84), 95% Confidence Interval (CI) and high heterogeneity of 99%. In all three studies, prevalence of GDM measured by IADPSG criteria was higher than WHO 1999 criteria, although not significant (p= 0.31). Combining all the studies gave a global estimated prevalence of GDM to be 10.13% (95% CI, 7.33-12.94) with moderate heterogeneity of 27%. The highest prevalence of GDM wit

    Anti-phospholipid human monoclonal antibodies inhibit CCR5-tropic HIV-1 and induce β-chemokines

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    Traditional antibody-mediated neutralization of HIV-1 infection is thought to result from the binding of antibodies to virions, thus preventing virus entry. However, antibodies that broadly neutralize HIV-1 are rare and are not induced by current vaccines. We report that four human anti-phospholipid monoclonal antibodies (mAbs) (PGN632, P1, IS4, and CL1) inhibit HIV-1 CCR5-tropic (R5) primary isolate infection of peripheral blood mononuclear cells (PBMCs) with 80% inhibitory concentrations of <0.02 to ∼10 µg/ml. Anti-phospholipid mAbs inhibited PBMC HIV-1 infection in vitro by mechanisms involving binding to monocytes and triggering the release of MIP-1α and MIP-1β. The release of these β-chemokines explains both the specificity for R5 HIV-1 and the activity of these mAbs in PBMC cultures containing both primary lymphocytes and monocytes

    Evidence of Key Tinnitus-Related Brain Regions Documented by a Unique Combination of Manganese-Enhanced MRI and Acoustic Startle Reflex Testing

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    Animal models continue to improve our understanding of tinnitus pathogenesis and aid in development of new treatments. However, there are no diagnostic biomarkers for tinnitus-related pathophysiology for use in awake, freely moving animals. To address this disparity, two complementary methods were combined to examine reliable tinnitus models (rats repeatedly administered salicylate or exposed to a single noise event): inhibition of acoustic startle and manganese-enhanced MRI. Salicylate-induced tinnitus resulted in wide spread supernormal manganese uptake compared to noise-induced tinnitus. Neither model demonstrated significant differences in the auditory cortex. Only in the dorsal cortex of the inferior colliculus (DCIC) did both models exhibit supernormal uptake. Therefore, abnormal membrane depolarization in the DCIC appears to be important in tinnitus-mediated activity. Our results provide the foundation for future studies correlating the severity and longevity of tinnitus with hearing loss and neuronal activity in specific brain regions and tools for evaluating treatment efficacy across paradigms

    Mortality Among Adults With Cancer Undergoing Chemotherapy or Immunotherapy and Infected With COVID-19

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    Importance: Large cohorts of patients with active cancers and COVID-19 infection are needed to provide evidence of the association of recent cancer treatment and cancer type with COVID-19 mortality. // Objective: To evaluate whether systemic anticancer treatments (SACTs), tumor subtypes, patient demographic characteristics (age and sex), and comorbidities are associated with COVID-19 mortality. // Design, Setting, and Participants: The UK Coronavirus Cancer Monitoring Project (UKCCMP) is a prospective cohort study conducted at 69 UK cancer hospitals among adult patients (≥18 years) with an active cancer and a clinical diagnosis of COVID-19. Patients registered from March 18 to August 1, 2020, were included in this analysis. // Exposures: SACT, tumor subtype, patient demographic characteristics (eg, age, sex, body mass index, race and ethnicity, smoking history), and comorbidities were investigated. // Main Outcomes and Measures: The primary end point was all-cause mortality within the primary hospitalization. // Results: Overall, 2515 of 2786 patients registered during the study period were included; 1464 (58%) were men; and the median (IQR) age was 72 (62-80) years. The mortality rate was 38% (966 patients). The data suggest an association between higher mortality in patients with hematological malignant neoplasms irrespective of recent SACT, particularly in those with acute leukemias or myelodysplastic syndrome (OR, 2.16; 95% CI, 1.30-3.60) and myeloma or plasmacytoma (OR, 1.53; 95% CI, 1.04-2.26). Lung cancer was also significantly associated with higher COVID-19–related mortality (OR, 1.58; 95% CI, 1.11-2.25). No association between higher mortality and receiving chemotherapy in the 4 weeks before COVID-19 diagnosis was observed after correcting for the crucial confounders of age, sex, and comorbidities. An association between lower mortality and receiving immunotherapy in the 4 weeks before COVID-19 diagnosis was observed (immunotherapy vs no cancer therapy: OR, 0.52; 95% CI, 0.31-0.86). // Conclusions and Relevance: The findings of this study of patients with active cancer suggest that recent SACT is not associated with inferior outcomes from COVID-19 infection. This has relevance for the care of patients with cancer requiring treatment, particularly in countries experiencing an increase in COVID-19 case numbers. Important differences in outcomes among patients with hematological and lung cancers were observed

    Structural and spectroscopic characterisation of a heme peroxidase from sorghum

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    A cationic class III peroxidase from Sorghum bicolor was purified to homogeneity. The enzyme contains a high-spin heme, as evidenced by UV-visible spectroscopy and EPR. Steady state oxidation of guaiacol was demonstrated and the enzyme was shown to have higher activity in the presence of calcium ions. A Fe(III)/Fe(II) reduction potential of -266 mV vs NHE was determined. Stopped-flow experiments with H2O2 showed formation of a typical peroxidase Compound I species, which converts to Compound II in the presence of calcium. A crystal structure of the enzyme is reported, the first for a sorghum peroxidase. The structure reveals an active site that is analogous to those for other class I heme peroxidase, and a substrate binding site (assigned as arising from binding of indole-3-acetic acid) at the γ-heme edge. Metal binding sites are observed in the structure on the distal (assigned as a Na(+) ion) and proximal (assigned as a Ca(2+)) sides of the heme, which is consistent with the Ca(2+)-dependence of the steady state and pre-steady state kinetics. It is probably the case that the structural integrity (and, thus, the catalytic activity) of the sorghum enzyme is dependent on metal ion incorporation at these positions
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