507 research outputs found
Unconventional high-energy-state contribution to the Cooper pairing in under-doped copper-oxide superconductor HgBaCaCuO
We study the temperature-dependent electronic B1g Raman response of a
slightly under-doped single crystal HgBaCaCuO with a
superconducting critical temperature Tc=122 K. Our main finding is that the
superconducting pair-breaking peak is associated with a dip on its
higher-energy side, disappearing together at Tc. This result hints at an
unconventional pairing mechanism, whereas spectral weight lost in the dip is
transferred to the pair-breaking peak at lower energies. This conclusion is
supported by cellular dynamical mean-field theory on the Hubbard model, which
is able to reproduce all the main features of the B1g Raman response and
explain the peak-dip behavior in terms of a nontrivial relationship between the
superconducting and the pseudo gaps.Comment: 7 pages 4 figure
A computational framework for immiscible three-phase flow in deformable porous media
Several soil decontamination processes and enhanced oil recovery techniques involve the co-existence of three immiscible fluids, such as water, a nonaqueous phase liquid and a gas. In this work, a computational framework based on the individual mass balance of each phase is developed, aimed at simulating three-phase flow in a deformable rock through the finite element method, without resorting to specific simplifications that are usually required by standard numerical schemes. Key ingredients of the model are: expression of the residual in terms of mass contents, consistent lumping of the storage terms in the residual and algorithmic (tangent) matrix, consistent integration rules, the use of a minimum relative permeability and a time marching scheme based on trapezoidal integration. Special convective boundary conditions are adopted for pressures to be consistent with the assumed rock wettability properties during co-current imbibition. The resulting numerical scheme can deal with arbitrary saturation and/or pressure boundary conditions. The model is tested by simulating gas injection tests, and both co- and counter-current water imbibition tests, in a deformable core. To assess the performance and robustness of the whole framework, sensitivity analyses are performed upon varying key constitutive, loading and numerical parameters
Prevalence and diversity of Chlamydiales and other amoeba-resisting bacteria in domestic drinking water systems.
A growing number of human infections incriminate environmental bacteria that have evolved virulent mechanisms to resist amoebae and use them as a replicative niche. These bacteria are designated amoeba-resisting bacteria (ARB). Despite the isolation of these ARB in various human clinical samples, the possible source of infection remains undetermined in most cases. However, it is known that the ARB Legionella pneumophila, for instance, causes a respiratory infection in susceptible hosts after inhalation of contaminated water aerosols from various sources. The Chlamydiales order contains many ARB, such as Parachlamydia acanthamoebae or Simkania negevensis, previously implicated in human respiratory infections with no identified contamination sources. We thus investigated whether domestic water systems are a potential source of transmission of these Chlamydiales to humans by using amoebal culture and molecular methods. Other important ARB such as mycobacteria and Legionella were also investigated, as were their possible amoebal hosts. This work reports for the first time a very high prevalence and diversity of Chlamydiales in drinking water, being detected in 35 (72.9%) of 48 investigated domestic water systems, with members of the Parachlamydiaceae family being dominantly detected. Furthermore, various Legionella and mycobacteria species were also recovered, some species of which are known to be causal agents of human infections
Association between television viewing and obesity in Peruvian women
OBJECTIVE: To assess the association between frequency of television viewing, overweight and obesity in a nationally representative sample of Peruvian women. METHODS: Secondary analysis of the Demographic and Health Survey 2008 including women aged from 15 to 49 years old. The outcome variables were obesity (body mass index >30 kg/m²) and overweight (body mass index >25 butOBJETIVO: Evaluar la asociación entre frecuencia de ver televisión, sobrepeso y obesidad en una muestra representativa de mujeres peruanas a nivel nacional. MÉTODOS: Análisis secundario de la Encuesta Nacional Demográfica y de Salud Familiar incluyendo mujeres de 15 a 49 años. Las variables resultados fueron obesidad (índice de masa corporal >30 kg/m²) y sobrepeso (>25 pesoOBJETIVO: Analisar a associação entre frequência de assistir televisão com sobrepeso e obesidade em uma amostra representativa de mulheres peruanas em nível nacional. MÉTODOS: Análise secundária da Pesquisa Nacional Demográfica e de Saúde Familiar incluindo 27.712 mulheres de 15 a 49 anos em 2008. As variáveis-desfecho foram obesidade (índice de massa corporal >; 30 kg/m2) e sobrepeso (entre 25 e 30 kg/m2); a variável de exposição foi a frequência de assistir televisão (nunca, ocasionalmente, quase todos os dias). Foi utilizada regressão logística para amostras complexas, ajustada por potenciais confundidores. Os resultados foram apresentados como odds ratios ajustados (ORa) com seus respectivos intervalos de 95% de confiança. RESULTADOS: A prevalência de sobrepeso foi de 34,7% (IC95% 33,8;35,7) e de obesidade, 14,3% (IC95% 13,6;5,1). Mulheres que assistiam televisão ocasionalmente e quase todos os dias tiveram maior probabilidade de ter obesidade em comparação às que não assistiam: ORa = 1,7 (IC95% 1,3;2,3) e ORa 2,6 (IC95% 2,0;3,5), respectivamente. A magnitude da associação foi menor para o sobrepeso: ORa 1,2 (IC95% 1,3;2,3) e ORa 1,6 (IC95% 1,1;1,4), respectivamente. A associação foi mais forte na área urbana. CONCLUSÕES: A frequência de assistir televisão esteve associada à apresentar obesidade e sobrepeso entre mulheres peruanas, e a força da associação variou de acordo com a área de residência. Estes achados podem auxiliar estratégias de prevenção da obesidade no contexto peruano
Effect of preterm birth on growth and blood pressure in adulthood in the Pelotas 1993 cohort
BACKGROUND: Preterm birth has been associated with increased risk of hypertension and cardiovascular disease later in adulthood, attributed to cardiovascular and metabolic alterations in early life. However, there is paucity of evidence from low- and middle-income countries (LMICs). METHODS: We investigated the differences between preterm (<37 weeks gestational age) and term-born individuals in birth length and weight as well as adult (18 and 20 years) height, weight and blood pressure in the Brazilian 1993 Pelotas birth cohort using linear regressions. Analyses were adjusted for the maternal weight at the beginning of pregnancy and maternal education and family income at childbirth. Additional models were adjusted for body mass index (BMI) and birthweight. Separate analyses were run for males and females. The complete sample was analysed with an interaction term for sex. RESULTS: Of the 3585 babies included at birth, 3010 were followed up in adulthood at 22 years. Preterm participants had lower length and weight at birth. This difference remained for male participants in adulthood, but female participants were no shorter than their term counterparts by 18 years of age. At 22 years, females born preterm had lower blood pressures (systolic blood pressure -1.00 mmHg, 95%CI -2.7, 0.7 mmHg; diastolic blood pressure -1.1 mmHg, 95%CI -2.4, 0.3 mmHg) than females born at term. These differences were not found in male participants. CONCLUSIONS: In this Brazilian cohort we found contrasting results regarding the association of preterm birth with blood pressure in young adulthood, which may be unique to an LMIC
Effect of preterm birth on growth and blood pressure in adulthood in the Pelotas 1993 cohort
Background
Preterm birth has been associated with increased risk of hypertension and cardiovascular disease later in adulthood, attributed to cardiovascular and metabolic alterations in early life. However, there is paucity of evidence from low- and middle-income countries (LMICs).
Methods
We investigated the differences between preterm (<37 weeks gestational age) and term-born individuals in birth length and weight as well as adult (18 and 20 years) height, weight and blood pressure in the Brazilian 1993 Pelotas birth cohort using linear regressions. Analyses were adjusted for the maternal weight at the beginning of pregnancy and maternal education and family income at childbirth. Additional models were adjusted for body mass index (BMI) and birthweight. Separate analyses were run for males and females. The complete sample was analysed with an interaction term for sex.
Results
Of the 3585 babies included at birth, 3010 were followed up in adulthood at 22 years. Preterm participants had lower length and weight at birth. This difference remained for male participants in adulthood, but female participants were no shorter than their term counterparts by 18 years of age. At 22 years, females born preterm had lower blood pressures (systolic blood pressure −1.00 mmHg, 95%CI −2.7, 0.7 mmHg; diastolic blood pressure −1.1 mmHg, 95%CI −2.4, 0.3 mmHg) than females born at term. These differences were not found in male participants.
Conclusions
In this Brazilian cohort we found contrasting results regarding the association of preterm birth with blood pressure in young adulthood, which may be unique to an LMIC
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