1,070 research outputs found

    Physics Beyond the Standard Model: Focusing on the Muon Anomaly

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    We present a model based on the implication of an exceptional E_{6}-GUT symmetry for the anomalous magnetic moment of the muon. We follow a particular chain of breakings with Higgses in the 78 and 351 representations. We analyse the radiative correction contributions to the muon mass and the effects of the breaking of the so-called Weinberg symmetry. We also estimate the range of values of the parameters of our model.Comment: 14 RevTeX pages, 5 figure

    Isolamento de Toxoplasma gondii a partir de cérebro e músculo de gatos serologicamente positivos utilizando culturas celulares

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    O isolamento de Toxoplasma gondii é imprescindível quer para efeitos de diagnóstico definitivo da infecção, quer para estudos visando a genotipagem de estirpes circulantes, tanto nos animais como no ser humano. O bioensaio é presentemente considerado o método de eleição para isolamento de T. gondii de amostras biológicas, no entanto, para além de eticamente questionável, a inoculação em ratinho é dispendiosa e laboriosa. O ensaio in vitro utilizando culturas celulares é frequentemente mencionado como alternativa, contudo o investimento nesta área tem sido diminuto, sendo raros os trabalhos que referem o recurso a este método para isolamento de T. gondii a partir de tecidos animais. Este estudo teve como objectivo testar diferentes métodos de isolamento de T. gondii em culturas de células. Para a preparação dos inóculos, colhemos amostras de tecido cerebral e muscular (coração e membros) de 16 gatos serologicamente positivos, durante a necrópsia. O tecido cerebral foi homogeneizado com agulha e seringa em meio de cultura e o tecido muscular digerido numa solução de ácido clorídrico e pepsina. A inoculação dos homogeneizados de cérebro e músculo em culturas de células Vero resultou, respectivamente, numa taxa de isolamento de 37,5% (6/16) e 62,5% (10/16). A visualização microscópica de taquizoítos nas culturas celulares foi possível 5-14 dias pós-inoculação, utilizando homogeneizados de cérebro e 7-32 dias pós-inoculação, utilizando homogeneizados de tecido muscular. Todos os isolados foram confirmados por n-PCR visando a região ITS1 do rDNA de T. gondii

    A possible origin of superconducting currents in cosmic strings

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    The scattering and capture of right-handed neutrinos by an Abelian cosmic string in the SO(10) grand unification model are considered. The scattering cross-section of neutrinos per unit length due to the interaction with the gauge and Higgs fields of the string is much larger in its scaling regime than in the friction one because of the larger infrared cutoff of the former.The probability of capture in a zero mode of the string accompanied by the emission of a gauge or Higgs boson shows a resonant peak for neutrino momentum of the order of its mass. Considering the decrease of number of strings per unit comoving volume in the scaling epoch the cosmological consequences of the superconducting strings formed in this regime will be much smaller than those which could be produced already in the friction one.Comment: 14 pages Latex, 4 figues/ep

    A key role for iron-bound phosphorus in authigenic apatite formation in North Atlantic continental platform sediments

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    A combination of pore water and solid phase analysis was used to determine whether authigenic carbonate fluorapatite (CFA) is currently forming in the sediment at two locations (OMEX I and II) on the North Atlantic continental platform Goban Spur (southwest of Ireland). Results of selective P extractions suggest that an early diagenetic redistribution of Fe-bound P to an authigenic P phase may be occurring at both stations. A steady-state diagenetic model describing the depth profiles of pore water HPO42− and three solid phase forms of P (organic P, Fe-bound P and authigenic P) was developed and applied to the data of station OMEX-I. The model results indicate that CFA formation can account for the observed increase of authigenic P with depth at this station. Furthermore, the results show that an intense cycling of P between Fe-bound P and pore water HPO42− at the redox interface can create conditions beneficial for CFA formation. This internal P cycle is driven by downward, bioturbational transport of mainly in-situ-formed Fe-bound P into the reduced sediment zone. Losses from the internal P cycle due to CFA formation and HPO42− diffusion are compensated for by sorption of HPO42− released from organic matter to Fe oxides in the oxidized surface sediment. Fe-bound P thus acts as an intermediate between organic P and CFA. CFA can account for between 25 and 70% of the total burial flux of reactive P at station OMEX-I and thus may act as an important sink for P in this low sedimentation, continental margin environment

    Hand disinfection in a neonatal intensive care unit: continuous electronic monitoring over a one-year period

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    <p>Abstract</p> <p>Background</p> <p>Good hand hygiene compliance is essential to prevent nosocomial infections in healthcare settings. Direct observation of hand hygiene compliance is the gold standard but is time consuming. An electronic dispenser with built-in wireless recording equipment allows continuous monitoring of its usage. The purpose of this study was to monitor the use of alcohol-based hand rub dispensers with a built-in electronic counter in a neonatal intensive care unit (NICU) setting and to determine compliance with hand hygiene protocols by direct observation.</p> <p>Methods</p> <p>A one-year observational study was conducted at a 27 bed level III NICU at a university hospital. All healthcare workers employed at the NICU participated in the study. The use of bedside dispensers was continuously monitored and compliance with hand hygiene was determined by random direct observations.</p> <p>Results</p> <p>A total of 258,436 hand disinfection events were recorded; i.e. a median (interquartile range) of 697 (559–840) per day. The median (interquartile range) number of hand disinfection events performed per healthcare worker during the day, evening, and night shifts was 13.5 (10.8 - 16.7), 19.8 (16.3 - 24.1), and 16.6 (14.2 - 19.3), respectively. In 65.8% of the 1,168 observations of patient contacts requiring hand hygiene, healthcare workers fully complied with the protocol.</p> <p>Conclusions</p> <p>We conclude that the electronic devices provide useful information on frequency, time, and location of its use, and also reveal trends in hand disinfection events over time. Direct observations offer essential data on compliance with the hand hygiene protocol. In future research, data generated by the electronic devices can be supplementary used to evaluate the effectiveness of hand hygiene promotion campaigns.</p

    Fortalezas del carácter y autorregulación emocional en trabajadores brasileños

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    Character strengths and emotion self-regulation are relevant psychological resources to help workers cope with current demands in the workplace. The present investigation aimed to test the association with and the predictive power of the character strengths regarding emotion self-regulation. A total of 203 participants aged 18 to 68 years answered the sociodemographic questionnaire, Character Strength Scale –Brief (CSS-Brief), and the Emotion Self-Regulation Scale –Adult (ESRS-AD). The findings indicated weak to strong associations between the CSS-Brief and ESRS-AD factors. The intrapersonal strength and the intellectual and interpersonal strengths predicted the emotion self-regulation strategies likely to be adopted by the workers. The gathered evidence suggested significant differences in the ESRS-AD and CSS-Brief regarding the participants’ sociodemographic features. These results have occurred regardless of the workers’ hierarchical level and job department.Las fortalezas del carácter y la autorregulación de las emociones son recursos psicológicos relevantes para ayudar a los trabajadores a hacer frente a las demandas actuales en trabajo. La presente investigación tuvo como objetivo probar la asociación y el poder predictivo de las fortalezas del carácter con respecto a la autorregulación emocional. Un total de 203 participantes con edades entre 18 y 68 años respondieron el cuestionario sociodemográfico, la Escala de Fortaleza del Carácter -Breve (EFC-Breve) y la Escala de Autorregulación Emocional -Adulto (EARE-AD). Los resultados indicaron asociaciones de débiles a fuertes entre los factores CSS-Brief y ESRS-AD. La fortaleza intrapersonal y las fortalezas intelectuales e interpersonales predijeron las estrategias de autorregulación emocional susceptibles de ser adoptadas por los trabajadores. La evidencia recopilada sugirió diferencias significativas en ESRS-AD y CSS-Brief con respecto a las características sociodemográficas de los participantes. Estos resultados se han producido independientemente del nivel jerárquico y del departamento de trabajo de los trabajadore

    Investigation of intervertebral disc degeneration using multivariate FTIR spectroscopic imaging

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    Traditionally tissue samples are analysed using protein or enzyme specific stains on serial sections to build up a picture of the distribution of components contained within them. In this study we investigated the potential of multivariate curve resolution-alternating least squares (MCR-ALS) to deconvolute 2nd derivative spectra of Fourier transform infrared (FTIR) microscopic images measured in transflectance mode of goat and human paraffin embedded intervertebral disc (IVD) tissue sections, to see if this methodology can provide analogous information to that provided by immunohistochemical stains and bioassays but from a single section. MCR-ALS analysis of non-degenerate and enzymatically in vivo degenerated goat IVDs reveals five matrix components displaying distribution maps matching histological stains for collagen, elastin and proteoglycan (PG), as well as immunohistochemical stains for collagen type I and II. Interestingly, two components exhibiting characteristic spectral and distribution profiles of proteoglycans were found, and relative component/tissue maps of these components (labelled PG1 and PG2) showed distinct distributions in non-degenerate versus mildly degenerate goat samples. MCR-ALS analysis of human IVD sections resulted in comparable spectral profiles to those observed in the goat samples, highlighting the inter species transferability of the presented methodology. Multivariate FTIR image analysis of a set of 43 goat IVD sections allowed the extraction of semi-quantitative information from component/tissue gradients taken across the IVD width of collagen type I, collagen type II, PG1 and PG2. Regional component/tissue parameters were calculated and significant correlations were found between histological grades of degeneration and PG parameters (PG1: p = 0.0003, PG2: p < 0.0001); glycosaminoglycan (GAG) content and PGs (PG1: p = 0.0055, PG2: p = 0.0001); and MRI T2* measurements and PGs (PG1: p = 0.0021, PG2: p < 0.0001). Additionally, component/tissue parameters for collagen type I and II showed significant correlations with total collagen content (p = 0.0204, p = 0.0127). In conclusion, the presented findings illustrate, that the described multivariate FTIR imaging approach affords the necessary chemical specificity to be considered an important tool in the study of IVD degeneration in goat and human IVDs
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