525 research outputs found
Elastic properties of graphyne-based nanotubes
Graphyne nanotubes (GNTs) are nanostructures obtained from rolled up graphyne
sheets, in the same way carbon nanotubes (CNTs) are obtained from graphene
ones. Graphynes are 2D carbon-allotropes composed of atoms in sp and sp2
hybridized states. Similarly to conventional CNTs, GNTs can present different
chiralities and electronic properties. Because of the acetylenic groups (triple
bonds), GNTs exhibit large sidewall pores that influence their mechanical
properties. In this work, we studied the mechanical response of GNTs under
tensile stress using fully atomistic molecular dynamics simulations and density
functional theory (DFT) calculations. Our results show that GNTs mechanical
failure (fracture) occurs at larger strain values in comparison to
corresponding CNTs, but paradoxically with smaller ultimate strength and
Young's modulus values. This is a consequence of the combined effects of the
existence of triple bonds and increased porosity/flexibility due to the
presence of acetylenic groups
SEROLOGICAL DETECTION OF HEPATITIS A VIRUS IN FREE-RANGING NEOTROPICAL PRIMATES (Sapajus spp., Alouatta caraya) FROM THE PARANĂ RIVER BASIN, BRAZIL
Nonhuman primates are considered as the natural hosts of Hepatitis A virus (HAV), as well as other pathogens, and can serve as natural sentinels to investigate epizootics and endemic diseases that are of public health importance. During this study, blood samples were collected from 112 Neotropical primates (NTPs) (Sapajus nigritus and S. cay, n = 75; Alouatta caraya, n = 37) trap-captured at the ParanĂĄ River basin, Brazil, located between the States of ParanĂĄ and Mato Grosso do Sul. Anti-HAV IgG antibodies were detected in 4.5% (5/112) of NTPs, specifically in 6.7% (5/75) of Sapajus spp. and 0% (0/37) of A. caraya. In addition, all samples were negative for the presence of IgM anti-HAV antibodies. These results suggest that free-ranging NTPs were exposed to HAV within the geographical regions evaluated
Comparte la felicidad, educando sobre sexualidad con ciudadanos y ciudadanas habitantes de calle
Curso de Especial InterĂ©sLos habitantes de calle (en adelante CHC) se han convertido en una problemĂĄtica social debido a la desarticulaciĂłn, violencia y pobreza de la sociedad colombiana. A partir de esta situaciĂłn se diseñó y elaborĂł la cartilla âComparte la felicidad, educando sobre sexualidad con Ciudadanos y Ciudadanas Habitantes de calleâ que aborda los cuatro holones de la sexualidad: VinculaciĂłn afectiva, erotismo, gĂ©nero y reproductividad, con el objetivo de promover la salud sexual y reproductiva, y la prevenciĂłn de Infecciones de transmisiĂłn sexual, incluido el VIH/SIDA. Para identificar el contenido de la cartilla se realizĂł una entrevista estructurada de la cual se obtuvo la informaciĂłn a incluir en la cartilla, posteriormente validada en la unidad OASIS.Curso de Especial InterĂ©s1. Resumen
2. JustificaciĂłn
3. Marco teĂłrico
4. Objetivos de la investigaciĂłn
5. MĂ©todologĂa
6. Estudio de mercado
7. Resultados
8. DiscusiĂłn
9. Conclusiones
10. Recomendaciones
11. Referencias
12. ApéndicesPregradoPsicólog
Cortical stimulation of language fields under local anesthesia: optimizing removal of brain lesions adjacent to speech areas
Bionomics of Anopheles aquasalis Curry 1932, in GuaraĂ, state of Rio de Janeiro, southeastern Brazil: I. Seasonal distribution and parity rates
Mutation Size Optimizes Speciation in an Evolutionary Model
The role of mutation rate in optimizing key features of evolutionary dynamics has recently been investigated in various computational models. Here, we address the related question of how maximum mutation size affects the formation of species in a simple computational evolutionary model. We find that the number of species is maximized for intermediate values of a mutation size parameter Ό; the result is observed for evolving organisms on a randomly changing landscape as well as in a version of the model where negative feedback exists between the local population size and the fitness provided by the landscape. The same result is observed for various distributions of mutation values within the limits set by Ό. When organisms with various values of Ό compete against each other, those with intermediate Ό values are found to survive. The surviving values of Ό from these competition simulations, however, do not necessarily coincide with the values that maximize the number of species. These results suggest that various complex factors are involved in determining optimal mutation parameters for any population, and may also suggest approaches for building a computational bridge between the (micro) dynamics of mutations at the level of individual organisms and (macro) evolutionary dynamics at the species level
Physics, Astrophysics and Cosmology with Gravitational Waves
Gravitational wave detectors are already operating at interesting sensitivity
levels, and they have an upgrade path that should result in secure detections
by 2014. We review the physics of gravitational waves, how they interact with
detectors (bars and interferometers), and how these detectors operate. We study
the most likely sources of gravitational waves and review the data analysis
methods that are used to extract their signals from detector noise. Then we
consider the consequences of gravitational wave detections and observations for
physics, astrophysics, and cosmology.Comment: 137 pages, 16 figures, Published version
<http://www.livingreviews.org/lrr-2009-2
Anthropometric indices and exclusive breastfeeding in the first six months of life: a comparison with reference standards NCHS, 1977 and WHO, 2006
Factors affecting commencement and cessation of smoking behaviour in Malaysian adults
<p>Abstract</p> <p>Background</p> <p>Tobacco consumption peak in developed countries has passed, however, it is on the increase in many developing countries. Apart from cigarettes, consumption of local hand-rolled cigarettes such as <it>bidi </it>and <it>rokok daun </it>are prevalent in specific communities. Although factors associated with smoking initiation and cessation has been investigated elsewhere, the only available data for Malaysia is on prevalence. This study aims to investigate factors associated with smoking initiation and cessation which is imperative in designing intervention programs.</p> <p>Methods</p> <p>Data were collected from 11,697 adults by trained recording clerks on sociodemographic characteristics, practice of other risk habit and details of smoking such as type, duration and frequency. Smoking commencement and cessation were analyzed using the Kaplan-Meier estimates and log-rank tests. Univariate and multivariate Cox proportional hazard regression models were used to calculate the hazard rate ratios.</p> <p>Results</p> <p>Males had a much higher prevalence of the habit (61.7%) as compared to females (5.8%). Cessation was found to be most common among the Chinese and those regularly consuming alcoholic beverages. Kaplan-Meier plot shows that although males are more likely to start smoking, females are found to be less likely to stop. History of betel quid chewing and alcohol consumption significantly increase the likelihood of commencement (p < 0.0001), while cessation was least likely among Indians, current quid chewers and kretek users (p < 0.01).</p> <p>Conclusions</p> <p>Gender, ethnicity, history of quid chewing and alcohol consumption have been found to be important factors in smoking commencement; while ethnicity, betel quid chewing and type of tobacco smoked influences cessation.</p
Study of decays to the final state and evidence for the decay
A study of decays is performed for the first time
using data corresponding to an integrated luminosity of 3.0
collected by the LHCb experiment in collisions at centre-of-mass energies
of and TeV. Evidence for the decay
is reported with a significance of 4.0 standard deviations, resulting in the
measurement of
to
be .
Here denotes a branching fraction while and
are the production cross-sections for and mesons.
An indication of weak annihilation is found for the region
, with a significance of
2.4 standard deviations.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-022.html,
link to supplemental material inserted in the reference
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