528 research outputs found

    Spatial and seasonal relationships between Pacific harbor seals (Phoca vitulina richardii) and their prey, at multiple scales

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    Knowing where pinnipeds forage is vital to managing and protecting their populations, and for assessing potential interactions with fisheries. We assessed the spatial relationship between the seasonal distribution of Pacific harbor seals (Phoca vitulina richardii) outfitted with satellite transmitters and the seasonal distributions of potential harbor seal prey species in San Francisco Bay, California. Pearson’s correlation coefficients were calculated between the number of harbor seal locations in an area of the San Francisco Bay and the abundance of specific prey species in the same area. The influence of scale on the analyses was assessed by varying the scale of analysis from 1 to 10 km. There was consistency in the prey species targeted by harbor seals year-round, although there were seasonal differences between the most important prey species. The highest correlations between harbor seals and their prey were found for seasonally abundant benthic species, located within about 10 km of the primary haul-out site. Probable foraging habitat for harbor seals was identified, based on areas with high abundances of prey species that were strongly correlated with harbor seal distribution. With comparable local data inputs, this approach has potential application to pinniped management in other areas, and to decisions about the location of marine reserves designed to protect these species

    Leveraging the online environment to remove barriers to student learning in large first year foundation subjects

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    This work is part of a larger three year project aimed at disseminating good practice in online learning and teaching throughout the Faculty of Science at The University of New South Wales (UNSW). Dissemination is based on a template Blackboard Vista site created for a large first year Materials Science course (Allen, Crosky, McAlpine, Hoffman and Monroe, 2006). A project group comprising members of several schools in the Science Faculty has been formed to manage the overall project and project funds have been used to employ an educational developer to work with academic teaching staff to modify and implement the template into courses from different schools across the faculty. The focus of the group is on large classes with a view to getting maximum impact (improved outcomes for the largest number of students). Fundamentals of Physics is one of the first courses to modify and implement the template as part of this project

    Banner News

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    https://openspace.dmacc.edu/banner_news/1051/thumbnail.jp

    Non-participation during azithromycin mass treatment for trachoma in The Gambia: heterogeneity and risk factors.

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    BACKGROUND: There is concern that untreated individuals in mass drug administration (MDA) programs for neglected tropical diseases can reduce the impact of elimination efforts by maintaining a source of transmission and re-infection. METHODOLOGY/PRINCIPAL FINDINGS: Treatment receipt was recorded against the community census during three MDAs with azithromycin for trachoma in The Gambia, a hypo-endemic setting. Predictors of non-participation were investigated in 1-9 year olds using random effects logistic regression of cross-sectional data for each MDA. Two types of non-participators were identified: present during MDA but not treated (PNT) and eligible for treatment but absent during MDA (EBA). PNT and EBA children were compared to treated children separately. Multivariable models were developed using baseline data and validated using year one and two data, with a priori adjustment for previous treatment status. Analyses included approximately 10000 children at baseline and 5000 children subsequently. There was strong evidence of spatial heterogeneity, and persistent non-participation within households and individuals. By year two, non-participation increased significantly to 10.4% overall from 6.2% at baseline, with more, smaller geographical clusters of non-participating households. Multivariable models suggested household level predictors of non-participation (increased time to water and household head non-participation for both PNT and EBA; increased household size for PNT status only; non-inclusion in a previous trachoma examination survey and younger age for EBA only). Enhanced coverage efforts did not decrease non-participation. Few infected children were detected at year three and only one infected child was EBA previously. Infected children were in communities close to untreated endemic areas with higher rates of EBA non-participation during MDA. CONCLUSIONS/SIGNIFICANCE: In hypo-endemic settings, with good coverage and no association between non-participation and infection, efforts to improve participation during MDA may not be required. Further research could investigate spatial hotspots of infection and non-participation in other low and medium prevalence settings before allocating resources to increase participation

    Chemostat culture systems support diverse bacteriophage communities from human feces

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    BACKGROUND: Most human microbiota studies focus on bacteria inhabiting body surfaces, but these surfaces also are home to large populations of viruses. Many are bacteriophages, and their role in driving bacterial diversity is difficult to decipher without the use of in vitro ecosystems that can reproduce human microbial communities. RESULTS: We used chemostat culture systems known to harbor diverse fecal bacteria to decipher whether these cultures also are home to phage communities. We found that there are vast viral communities inhabiting these ecosystems, with estimated concentrations similar to those found in human feces. The viral communities are composed entirely of bacteriophages and likely contain both temperate and lytic phages based on their similarities to other known phages. We examined the cultured phage communities at five separate time points over 24 days and found that they were highly individual-specific, suggesting that much of the subject-specificity found in human viromes also is captured by this culture-based system. A high proportion of the community membership is conserved over time, but the cultured communities maintain more similarity with other intra-subject cultures than they do to human feces. In four of the five subjects, estimated viral diversity between fecal and cultured communities was highly similar. CONCLUSIONS: Because the diversity of phages in these cultured fecal communities have similarities to those found in humans, we believe these communities can serve as valuable ecosystems to help uncover the role of phages in human microbial communities

    Innovative multi-site photoplethysmography measurement and analysis demonstrating increased arterial stiffness in paediatric heart transplant recipients

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    Objective: It has been documented that heart transplantation in children is often complicated by arterial hypertension and increased arterial stiffness. We use innovative multi-site photoplethysmography (MPPG) pulse measurement and analysis technology to assess changes in arterial stiffness in paediatric heart transplant recipients (HTRs) in comparison with healthy control (HC) children. Approach: A group of 20 HTRs (median age 13.5 years, eight male) were compared to an overall age- and gender-matched group of 161 HCs (median age 11.6 years, 74 male). Peripheral pulse was recorded bilaterally using MPPG at the ear lobe, index finger and great toe sites, along with an electrocardiogram cardiac timing reference. Segmental pulse arrival times between peripheral sites (finger–ear, PATf–e; toe–finger, PATt–f; and toe–ear PATt–e) were calculated as arterial stiffness measures, and differences between subject groups were tested using multivariate analysis. Normalised ear, finger and toe pulse shapes were also studied and compared between groups. Main results: After correction for heart rate and diastolic and mean arterial blood pressures, the HTR group was found to have significantly lower segmental PATt–e and PATt–f measurements, with median values of 150 ms versus 172 ms in the HC group (p  =  0.02), and 104 ms versus 118 ms in the HC group (p  =  0.01), respectively, consistent with increased arterial stiffness in the patient group. The normalised ear, finger and toe sites showed only a mild elongation in each pulse rise time for the transplant group. Significance: This study shows that innovative and easy-to-do MPPG gives further evidence for increased arterial stiffness in children who have undergone successful cardiac transplantation

    Allelic expression analysis of the osteoarthritis susceptibility locus that maps to MICAL3

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    <p>Abstract</p> <p>Background</p> <p>A genome-wide association scan with subsequent replication study that involved over 67,000 individuals of European ancestry has produced evidence of association of single nucleotide polymorphism rs2277831 to primary osteoarthritis (OA) with a P-value of 2.9 × 10<sup>-5</sup>. rs2277831, an A/G transition, is located in an intron of <it>MICAL3</it>. This gene is located on chromosome 22q11.21 and the association signal encompasses two additional genes, <it>BCL2L13 </it>and <it>BID</it>. It is becoming increasingly apparent that many common complex traits are mediated by <it>cis</it>-acting regulatory polymorphisms that influence, in a tissue-specific manner, gene expression or transcript stability.</p> <p>Methods</p> <p>We used total and allelic expression analysis to assess whether the OA association to rs2277831 is mediated by an influence on MICAL3, BCL2L13 or BID expression. Using RNA extracted from joint tissues of 60 patients who had undergone elective joint replacement surgery, we assessed whether rs2277831 correlated with allelic expression of either of the three genes by: 1) measuring the expression of each gene by quantitative PCR and then stratifying the data by genotype at rs2277831 and 2) accurately discriminating and quantifying the mRNA synthesised from the alleles of OA patients using allelic-quantitative PCR.</p> <p>Results</p> <p>We found no evidence for a correlation between gene expression and genotype at rs2277831, with P-values of 0.09 for <it>BCL2L13</it>, 0.07 for <it>BID </it>and 0.33 for <it>MICAL3</it>. In the allelic expression analysis we observed several examples of significant (p < 0.05) allelic imbalances, with an allelic expression ratio of 2.82 observed in <it>BCL2L13 </it>(P = 0.004), 2.09 at <it>BID </it>(P = 0.001) and the most extreme case being at <it>MICAL3</it>, with an allelic expression ratio of 5.47 (P = 0.001). However, there was no correlation observed between the pattern of allelic expression and the genotype at rs2277831.</p> <p>Conclusions</p> <p>In the tissues that we have studied, our data do not support our hypothesis that the association between rs2277831 and OA is due to the effect this SNP has on <it>MICAL3, BCL2L13 </it>or <it>BID </it>gene expression. Instead, our data point towards other functional effects accounting for the OA associated signal.</p

    The female menstrual cycle does not influence testosterone concentrations in male partners

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    <p>Abstract</p> <p>Background</p> <p>The time of ovulation has since long been believed to be concealed to male heterosexual partners. Recent studies have, however, called for revision of this notion. For example, male testosterone concentrations have been shown to increase in response to olfactory ovulation cues, which could be biologically relevant by increasing sexual drive and aggressiveness. However, this phenomenon has not previously been investigated in real-life human settings. We therefore thought it of interest to test the hypothesis that males' salivary testosterone concentrations are influenced by phases of their female partners' menstrual cycle; expecting a testosterone peak at ovulation.</p> <p>Methods</p> <p>Thirty young, healthy, heterosexual couples were recruited. During the course of 30-40 days, the women registered menses and ovulation, while the men registered sexual activity, physical exercise, alcohol intake and illness (confounders), and obtained daily saliva samples for testosterone measurements. All data, including the registered confounders, were subjected to multiple regression analysis.</p> <p>Results</p> <p>In contrast to the hypothesis, the ovulation did not affect the testosterone levels, and the resulting testosterone profile during the menstrual cycle was on the average flat. The specific main hypothesis, that male testosterone levels on the day of ovulation would be higher than day 4 of the cycle, was clearly contradicted by a type II error(β)-analysis (< 14.3% difference in normalized testosterone concentration; β = 0.05).</p> <p>Conclusions</p> <p>Even though an ovulation-related salivary testosterone peak was observed in individual cases, no significant effect was found on a group level.</p

    Accuracy of Continuous Glucose Monitoring During Three Closed-Loop Home Studies Under Free-Living Conditions.

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    OBJECTIVES: Closed-loop (CL) systems modulate insulin delivery based on glucose levels measured by a continuous glucose monitor (CGM). Accuracy of the CGM affects CL performance and safety. We evaluated the accuracy of the Freestyle Navigator(®) II CGM (Abbott Diabetes Care, Alameda, CA) during three unsupervised, randomized, open-label, crossover home CL studies. MATERIALS AND METHODS: Paired CGM and capillary glucose values (10,597 pairs) were collected from 57 participants with type 1 diabetes (41 adults [mean±SD age, 39±12 years; mean±SD hemoglobin A1c, 7.9±0.8%] recruited at five centers and 16 adolescents [mean±SD age, 15.6±3.6 years; mean±SD hemoglobin A1c, 8.1±0.8%] recruited at two centers). Numerical accuracy was assessed by absolute relative difference (ARD) and International Organization for Standardization (ISO) 15197:2013 15/15% limits, and clinical accuracy was assessed by Clarke error grid analysis. RESULTS: Total duration of sensor use was 2,002 days (48,052 h). Overall sensor accuracy for the capillary glucose range (1.1-27.8 mmol/L) showed mean±SD and median (interquartile range) ARD of 14.2±15.5% and 10.0% (4.5%, 18.4%), respectively. Lowest mean ARD was observed in the hyperglycemic range (9.8±8.8%). Over 95% of pairs were in combined Clarke error grid Zones A and B (A, 80.1%, B, 16.2%). Overall, 70.0% of the sensor readings satisfied ISO criteria. Mean ARD was consistent (12.3%; 95% of the values fall within ±3.7%) and not different between participants (P=0.06) within the euglycemic and hyperglycemic range, when CL is actively modulating insulin delivery. CONCLUSIONS: Consistent accuracy of the CGM within the euglycemic-hyperglycemic range using the Freestyle Navigator II was observed and supports its use in home CL studies. Our results may contribute toward establishing normative CGM performance criteria for unsupervised home use of CL.Juvenile Diabetes Research Foundation (#22-2009-802), Diabetes UK (BDA07/0003549) and Seventh Framework Programme of the European Union (Grant Agreement number 247138) with additional support for the Artificial Pancreas work by National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK085621), Wellcome Strategic Award (100574/Z/12/Z), and National Institute for Health Research Cambridge Biomedical Research Centre.This is the final version of the article. It first appeared from Mary Ann Liebert via http://dx.doi.org/10.1089/dia.2015.006
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