4,537 research outputs found

    Bisphenol A exposure in Mexico City and risk of prematurity: a pilot nested case control study

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    Abstract Background Presence of Bisphenol A (BPA) has been documented worldwide in a variety of human biological samples. There is growing evidence that low level BPA exposure may impact placental tissue development and thyroid function in humans. The aim of this present pilot study was to determine urinary concentrations of BPA during the last trimester of pregnancy among a small subset of women in Mexico City, Mexico and relate these concentrations to risk of delivering prematurely. Methods A nested case-control subset of 60 participants in the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) study in Mexico City, Mexico were selected based on delivering less than or equal to 37 weeks of gestation and greater than 37 weeks of gestation. Third trimester archived spot urine samples were analyzed by online solid phase extraction coupled with high performance liquid chromatography isotope dilution tandem mass spectrometry. Results BPA was detected in 80.0% (N = 48) of the urine samples; total concentrations ranged from < 0.4 μg/L to 6.7 μg/L; uncorrected geometric mean was 1.52 μg/L. The adjusted odds ratio of delivering less than or equal to 37 weeks in relation to specific gravity adjusted third trimester BPA concentration was 1.91 (95%CI 0.93, 3.91, p-value = 0.08). When cases were further restricted to births occurring prior to the 37th week (n = 12), the odds ratio for specific-gravity adjusted BPA was larger and statistically significant (p < 0.05). Conclusions This is the first study to document measurable levels of BPA in the urine of a population of Mexican women. This study also provides preliminary evidence, based on a single spot urine sample collected during the third trimester, that pregnant women who delivered less than or equal to 37 weeks of gestation and prematurely (< 37 weeks) had higher urinary concentrations of BPA compared to women delivering after 37 weeks.http://deepblue.lib.umich.edu/bitstream/2027.42/78251/1/1476-069X-9-62.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78251/2/1476-069X-9-62.pdfPeer Reviewe

    Telepresence and the Role of the Senses

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    The telepresence experience can be evoked in a number of ways. A well-known example is a player of videogames who reports about a telepresence experience, a subjective experience of being in one place or environment, even when physically situated in another place. In this paper we set the phenomenon of telepresence into a theoretical framework. As people react subjectively to stimuli from telepresence, empirical studies can give more evidence about the phenomenon. Thus, our contribution is to bridge the theoretical with the empirical. We discuss theories of perception with an emphasis on Heidegger, Merleau-Ponty and Gibson, the role of the senses and the Spinozian belief procedure. The aim is to contribute to our understanding of this phenomenon. A telepresence-study that included the affordance concept is used to empirically study how players report sense-reactions to virtual sightseeing in two cities. We investigate and explore the interplay of the philosophical and the empirical. The findings indicate that it is not only the visual sense that plays a role in this experience, but all senses

    An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core

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    Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles

    Geographic distribution at subspecies resolution level: closely related Rhodopirellula species in European coastal sediments.

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    Members of the marine genus Rhodopirellula are attached living bacteria and studies based on cultured Rhodopirellula strains suggested that three closely related species R. baltica, 'R. europaea' and 'R. islandica' have a limited geographic distribution in Europe. To address this hypothesis, we developed a nested PCR for a single gene copy detection of a partial acetyl CoA synthetase (acsA) from intertidal sediments collected all around Europe. Furthermore, we performed growth experiments in a range of temperature, salinity and light conditions. A combination of Basic Local Alignment Search Tool (BLAST) and Minimum Entropy Decomposition (MED) was used to analyze the sequences with the aim to explore the geographical distribution of the species and subspecies. MED has been mainly used for the analysis of the 16S rRNA gene and here we propose a protocol for the analysis of protein-coding genes taking into account the degeneracy of the codons and a possible overestimation of functional diversity. The high-resolution analysis revealed differences in the intraspecies community structure in different geographic regions. However, we found all three species present in all regions sampled and in agreement with growth experiments we demonstrated that Rhodopirellula species do not have a limited geographic distribution in Europe

    Small but crucial : the novel small heat shock protein Hsp21 mediates stress adaptation and virulence in Candida albicans

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    Day clinics and hospitals - a cost comparison

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    Objective. To determine the types of surgical procedures currently undertaken in day clinics and to compare the number of procedures, the average in-facility cost, and the pre- and post-discharge costs for each procedure or group of procedures.Design. A retrospective descriptive study of medical aid claims data.Setting. Department of Family Medicine, University of the Witwatersrand, Johannesburg.Subject. Three private sector medical aid schemes with in excess of 170 000 principal members (380 000 lives).Outcome measures. For each surgical procedure. the following were compared: (i) the total number of procedures done; (ii) the average total in-facility cost; and (iii) the cost of professional fees and medicines for 7 days before admission, during admission, and for 14 days after discharge.Results. During 1997, 89 216 patients underwent surgery. Day clinics and hospitals accounted for 5 490 and 83 726 admissions respectively. Fifty-one different types of procedures were identified that met the inclusion criteria.On average the in-facility costs for 45 (88%) of the 51 compared procedures were lower in day clinics compared with hospitals. Average costs can be as much as 90% lower in day clinics. Some procedures, particularly certain dental operations, cost more in day clinics. The professional fees of attending doctors and the cost of medicines are generally higher when the procedure is undertaken in a hospital.Conclusion. In South Africa, as is the case in the USA, day clinics have the potential to reduce the cost of surgical procedures

    Agency, qualia and life: connecting mind and body biologically

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    Many believe that a suitably programmed computer could act for its own goals and experience feelings. I challenge this view and argue that agency, mental causation and qualia are all founded in the unique, homeostatic nature of living matter. The theory was formulated for coherence with the concept of an agent, neuroscientific data and laws of physics. By this method, I infer that a successful action is homeostatic for its agent and can be caused by a feeling - which does not motivate as a force, but as a control signal. From brain research and the locality principle of physics, I surmise that qualia are a fundamental, biological form of energy generated in specialized neurons. Subjectivity is explained as thermodynamically necessary on the supposition that, by converting action potentials to feelings, the neural cells avert damage from the electrochemical pulses. In exchange for this entropic benefit, phenomenal energy is spent as and where it is produced - which precludes the objective observation of qualia

    Association between average daily gain, faecal dry matter content and concentration of Lawsonia intracellularis in faeces

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    <p>Abstract</p> <p>Background</p> <p>The objective of this study was to investigate the association between average daily gain and the number of <it>Lawsonia intracellularis</it> bacteria in faeces of growing pigs with different levels of diarrhoea.</p> <p>Methods</p> <p>A longitudinal field study (<it>n</it> = 150 pigs) was performed in a Danish herd from day 29 to 47 post weaning. Every third day all pigs were weighed, subjected to a clinical examination and faecal samples were obtained. Faecal samples were subjected to dry matter determination and absolute quantification by PCR for <it>L. intracellularis</it> and porcine circovirus type 2 (PCV2). Association between average daily gain, faecal dry matter content, numbers of <it>L. intracellularis</it> bacteria and PCV2 genome copies in faeces was investigated in a multilevel mixed-effects linear model.</p> <p>Results</p> <p>Increasing numbers of <it>L. intracellularis</it> log<sub>10</sub> bacteria/g faeces were significantly associated with decreasing average daily gain (<it>P</it> < 0.001). The association was decreasing with increasing faecal dry matter content (<it>P</it> < 0.01). The number of PCV2 log<sub>10</sub> copies/g faeces was not significantly associated with average daily gain of the pigs (<it>P</it> > 0.5).</p> <p>Conclusion</p> <p>The results suggest a potential application of a PCR quantifying <it>L. intracellularis</it> in growing pigs. Faecal dry matter content must be taken into consideration in interpretation of such test results.</p

    Missed treatment opportunities and barriers to comprehensive treatment for sexual violence survivors in Kenya: a mixed methods study

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    Background In Kenya, most sexual violence survivors either do not access healthcare, access healthcare late or do not complete treatment. To design interventions that ensure optimal healthcare for survivors, it is important to understand the characteristics of those who do and do not access healthcare. In this paper, we aim to: compare the characteristics of survivors who present for healthcare to those of survivors reporting violence on national surveys; understand the healthcare services provided to survivors; and, identify barriers to treatment. Methods A mixed methods approach was used. Hospital records for survivors from two referral hospitals were compared with national-level data from the Kenya Demographic and Health Survey 2014, and the Violence Against Children Survey 2010. Descriptive summaries were calculated and differences in characteristics of the survivors assessed using chi-square tests. Qualitative data from six in-depth interviews with healthcare providers were analysed thematically. Results Among the 543 hospital respondents, 93.2% were female; 69.5% single; 71.9% knew the perpetrator; and 69.2% were children below 18 years. Compared to respondents disclosing sexual violence in nationally representative datasets, those who presented at hospital were less likely to be partnered, male, or assaulted by an intimate partner. Data suggest missed opportunities for treatment among those who did present to hospital: HIV PEP and other STI prophylaxis was not given to 30 and 16% of survivors respectively; 43% of eligible women did not receive emergency contraceptive; and, laboratory results were missing in more than 40% of the records. Those aged 18 years or below and those assaulted by known perpetrators were more likely to miss being put on HIV PEP. Qualitative data highlighted challenges in accessing and providing healthcare that included stigma, lack of staff training, missing equipment and poor coordination of services. Conclusions Nationally, survivors at higher risk of not accessing healthcare include older survivors; partnered or ever partnered survivors; survivors experiencing sexual violence from intimate partners; children experiencing violence in schools; and men. Interventions at the community level should target survivors who are unlikely to access healthcare and address barriers to early access to care. Staff training and specific clinical guidelines/protocols for treating children are urgently needed
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