4,349 research outputs found

    Genomic and toxigenic heterogeneity of bacillus cereus sensu lato Isolated from ready-to-eat foods and powdered milk in day care centers in Colombia

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    Bacillus cereus sensu lato (s.l.) is a group of bacteria commonly found in diverse environments, including foods, with potential to cause emesis and diarrhea. In Colombia, it is one of the main foodborne pathogens. The aim of this study was to determine the genomic and toxigenic heterogeneity of B. cereus s.l. isolated from ready-to-eat foods and powdered milk collected in day care centers of Medellin, Colombia. Of 112 B. cereus s.l. isolates obtained, 94% were beta-hemolytic. Toxigenic heterogeneity was established by the presence of nheABC, hblCDAB, cytK2, entFM, and cesB toxigenic genes. The nheABC operon and entFM gene were most frequently detected in the isolates, whereas the cesB gene was not found. According to the toxin genes content, nine toxigenic profiles were identified. A 44% of isolates had profiles with all genes for nonhemolytic enterotoxin, hemolysin BL, and enterotoxin FM production (profiles II and IV). Pulsed-field gel electrophoresis analysis indicated a high genomic heterogeneity among the B. cereus s.l., with 68 isolates grouping into 16 clusters and 33 placed separately in the dendrogram. This study provides useful information on the safety of ready-to-eat foods and powdered milk in day care centers where children, a susceptible population, are exposed and it should incentive for more studies to understand the distribution of different toxin-encoding genes among B. cereus s.l. isolates, enabling detailed risk assessment

    Towards photonic biosensing using a three-port mach-zehnder interferometer in a silicon nitride platform

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    Integrated photonics enables sensitive and label-free optical biosensors for the detection of chemical and biological substances and is therefore promising for future lab-on-chip solutions. In this article we present our current development of silicon nitride based integrated photonic biosensing devices working at telecom wavelengths. Our approach of three-port based interferometric sensing circumvents the issues of conventional Mach-Zehnder interferometers, providing a constant sensitivity, and allowing to use a fixed wavelength sensing scheme. Preliminary experimental results show that the fabricated devices work as expected from simulations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Estrogenic activity, race/ethnicity, and Indigenous American ancestry among San Francisco Bay Area women.

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    Estrogens play a significant role in breast cancer development and are not only produced endogenously, but are also mimicked by estrogen-like compounds from environmental exposures. We evaluated associations between estrogenic (E) activity, demographic factors and breast cancer risk factors in Non-Latina Black (NLB), Non-Latina White (NLW), and Latina women. We examined the association between E activity and Indigenous American (IA) ancestry in Latina women. Total E activity was measured with a bioassay in plasma samples of 503 women who served as controls in the San Francisco Bay Area Breast Cancer Study. In the univariate model that included all women with race/ethnicity as the independent predictor, Latinas had 13% lower E activity (p = 0.239) and NLBs had 35% higher activity (p = 0.04) compared to NLWs. In the multivariable model that adjusted for demographic factors, Latinas continued to show lower E activity levels (26%, p = 0.026), but the difference between NLBs and NLWs was no longer statistically significant (p = 0.431). An inverse association was observed between E activity and IA ancestry among Latina women (50% lower in 0% vs. 100% European ancestry, p = 0.027) consistent with our previously reported association between IA ancestry and breast cancer risk. These findings suggest that endogenous estrogens and exogenous estrogen-like compounds that act on the estrogen receptor and modulate E activity may partially explain racial/ethnic differences in breast cancer risk

    Immunoanalytical Approach for Detecting and Identifying Ancestral Peptide Biomarkers in Early Earth Analogue Environments

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    Several mass spectrometry and spectroscopic techniques have been used in the search for molecular biomarkers on Mars. A major constraint is their capability to detect and identify large and complex compounds such as peptides or other biopolymers. Multiplex immunoassays can detect these com-pounds, but antibodies must be produced for a large number of sequence-dependent molecular targets. Ancestral Sequence Re-construction (ASR) followed by protein "resurrection" in the lab can help to narrow the selection of targets. Herein, we propose an immunoanalytical method to identify ancient and universally conserved protein/peptide sequences as targets for identifying ancestral biomarkers in nature. We have developed, tested, and validated this approach by producing antibodies to eight previously described ancestral resurrected proteins (three beta-lactamases, three thioredoxins, one Elongation Factor Tu, and one RuBisCO, all of them theoretically dated as Precambrian), and used them as a proxy to search for any potential feature of them that could be present in current natural environments. By fluorescent sandwich microarray immunoassays (FSMI), we have detected positive immunoreactions with antibodies to the oldest beta-lactamase and thioredoxin proteins (ca. 4 Ga) in samples from a hydrothermal environment. Fine epitope mapping and inhibitory immunoassays allowed the identification of well-conserved epitope peptide sequences that resulted from ASR and were present in the sample. We corroborated these results by metagenomic sequencing and found several genes encoding analogue proteins with significant matches to the peptide epitopes identified with the antibodies. The results demonstrated that peptides inferred from ASR studies have true counterpart analogues in Nature, which validates and strengthens the well-known ASR/protein resurrection technique and our immunoanalytical approach for investigating ancient environments and metabolisms on Earth and elsewhere

    The Comparability of Men Who Have Sex With Men Recruited From Venue-Time-Space Sampling and Facebook: A Cohort Study

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    Background: Recruiting valid samples of men who have sex with men (MSM) is a key component of the US human immunodeficiency virus (HIV) surveillance and of research studies seeking to improve HIV prevention for MSM. Social media, such as Facebook, may present an opportunity to reach broad samples of MSM, but the extent to which those samples are comparable with men recruited from venue-based, time-space sampling (VBTS) is unknown. Objective: The objective of this study was to assess the comparability of MSM recruited via VBTS and Facebook. Methods: HIV-negative and HIV-positive black and white MSM were recruited from June 2010 to December 2012 using VBTS and Facebook in Atlanta, GA. We compared the self-reported venue attendance, demographic characteristics, sexual and risk behaviors, history of HIV-testing, and HIV and sexually transmitted infection (STI) prevalence between Facebook- and VTBS-recruited MSM overall and by race. Multivariate logistic and negative binomial models estimated age/race adjusted ratios. The Kaplan-Meier method was used to assess 24-month retention. Results: We recruited 803 MSM, of whom 110 (34/110, 30.9% black MSM, 76/110, 69.1% white MSM) were recruited via Facebook and 693 (420/693, 60.6% black MSM, 273/693, 39.4% white MSM) were recruited through VTBS. Facebook recruits had high rates of venue attendance in the previous month (26/34, 77% among black and 71/76, 93% among white MSM; between-race P=.01). MSM recruited on Facebook were generally older, with significant age differences among black MSM (P=.02), but not white MSM (P=.14). … See full text for complete abstract

    Vaccination of nulliparous gilts against porcine epidemic diarrhoea can result in low neutralising antibody titres and high litter mortality

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    Porcine epidemic diarrhoea (PED) is a disease caused by an alphacoronavirus and the symptoms include watery diarrhoea and vomiting, with more than 80% mortality amongst newborn piglets. The placentation in sows hinders the transference of antibodies to the foetus, therefore, the vaccination of pregnant females and transference of antibodies to piglets through colostrum are essential to protect them against virus particles. The aim of the study was to determine whether vaccination of nulliparous gilts could induce a high colostrum antibody titre and lower litter mortality, in comparison with vaccinated multiparous sows previously exposed to the virus. Samples of colostrum were obtained from 11 nulliparous gilts with two previous vaccinations (inactivated vaccine) and from 9 multiparous sows with three or more vaccinations (inactivated vaccine) that had been exposed to the virus. The IgG antibody titre was determined through anti-PED enzyme-linked immunosorbent assays (ELISA) and the neutralisation of antibodies was evaluated through plaque reduction neutralisation tests (PRNT). The colostrum of nulliparous gilts, when compared to the multiparous sows, presented a lower anti-PED IgG antibody titre as well as fewer neutralising antibodies. Furthermore, the piglets of multiparous sows experienced higher survival in comparison with those of nulliparous gilts (P<0.01), and mortality was dependent on the ‘farrowing’ variable (P<0.01). In conclusion, these results show that vaccinating nulliparous gilts does not increase the survival of their piglets in comparison with multiparous sows and that the IgG titres and neutralising antibodies are significantly lower in the former. These results suggest that a modified vaccine strategy is needed for nulliparous gilts to increase piglet protection

    Heteropolycompounds as catalysts for biomass product transformations

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    [EN] In the present review we show a variety of biomass product transformations through catalysis by both bulk and supported heteropolycompounds. The biomass sources considered include carbohydrates, oils and fats, and terpenes as main starting material groups. The products obtained and their applications are presented.We thank CONICET (PIP 003), Agencia Nacional de Promocion Cientifica y Tecnologica (Argentina) (PICT 0406), and Universidad Nacional de La Plata for financial support. GPR and HJT are members of CONICET. MJC and SI thank to Spanish Government-MINECO through Consolider Ingenio 2010-Multicat project for financial support.Sanchez, LM.; Thomas, HJ.; Climent Olmedo, MJ.; Romanelli, GP.; Iborra Chornet, S. (2016). Heteropolycompounds as catalysts for biomass product transformations. Catalysis Reviews: Science and Engineering. 58(4):497-586. doi:10.1080/01614940.2016.1248721S49758658

    Competencias emocionales en estudiantes del Grado en Criminología

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    La adquisición de competencias profesionales es un objetivo prioritario dentro del marco del Espacio Europeo de Educación Superior. El abordaje de la inteligencia emocional en el profesional en Criminología es importante, ya que en el desempeño de sus funciones requiere de una elevada fortaleza emocional. En este sentido, la competencia emocional que el estudiante del Grado en Criminología adquiera en su proceso de enseñanza-aprendizaje es un elemento clave en su futura práctica profesional. El objetivo del presente estudio es evaluar la capacidad de reconocer, comprender y regular los estados emocionales en estudiantes en Criminología. Ha participado una muestra representativa de 52 estudiantes universitarios matriculados en la asignatura optativa Profiling: perfil psicológico del delincuente de cuarto curso del Grado en Criminología de la Universidad de Alicante. Los instrumentos utilizados son el autoinforme Trait Meta-Mood Scale (TMMS-24) y el programa Facial Action Coding System (FACS). Se presentan los resultados obtenidos de la evaluación de las competencias emocionales del alumnado con el propósito de detectar las necesidades formativas en este ámbito

    Diseño de metodologías docentes innovadoras para el desarrollo de competencias emocionales en estudiantes universitarios

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    El Espacio Europeo de Educación Superior (EEES) incorpora al proceso de enseñanza-aprendizaje competencias genéricas y específicas con el objetivo de preparar a los futuros profesionales. El profesional en Criminología requiere de una elevada fortaleza emocional para el correcto desempeño de sus actividades profesionales. El objetivo de esta red es el diseño de nuevas metodologías y prácticas docentes, entre asignaturas de diferentes niveles de enseñanza, para potenciar el desarrollo de las competencias emocionales en el alumnado. Se presentan los resultados obtenidos de la evaluación en competencias emocionales de una muestra representativa de alumnos/as de último curso en el Grado en Criminología, con el propósito de detectar las necesidades formativas en este ámbito, y se describe el diseño de nuevas metodologías y prácticas docentes en asignaturas de primer y último año del Grado en Criminología
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