8,468 research outputs found
Mammalia, Chiroptera, Molossidae, <i>Molossops temminckii</i> (Burmeister, 1854), and Vespertilionidae, <i>Eptesicus furinalis</i> (dOrbigny and Gervais, 1847): New locality record and distribution extension in Cordoba Province, Argentina
During a field trip to the Ramsar site “Bañados del Río Dulce y Laguna Mar Chiquita” we captured three specimensof Molossops temminckii (Burmeister, 1854) and two of Eptesicus furinalis (d’Orbigny and Gervais, 1847). Molossopstemminckii has a wide distribution in Argentina, but this new record represents the second mention of the species for theCordoba Province after 13 years. The specimens of E. furinalis represent the tenth record for Cordoba and the second for RíoPrimero Department. This new information reflects the scarcity of systematic studies on bats in Cordoba Province
Phenomenological Models of Socio-Economic Network Dynamics
We study a general set of models of social network evolution and dynamics.
The models consist of both a dynamics on the network and evolution of the
network. Links are formed preferentially between 'similar' nodes, where the
similarity is defined by the particular process taking place on the network.
The interplay between the two processes produces phase transitions and
hysteresis, as seen using numerical simulations for three specific processes.
We obtain analytic results using mean field approximations, and for a
particular case we derive an exact solution for the network. In common with
real-world social networks, we find coexistence of high and low connectivity
phases and history dependence.Comment: 11 pages, 8 figure
Mujeres que son pareja de un varón infectado por el VIH: descripción de sus características y valoración del riesgo
ObjetivoDescribir las situaciones de riesgo y la prevalencia del virus de la inmunodeficiencia humana (VIH) en mujeres con pareja heterosexual infectada por el VIH.DiseñoEstudio descriptivo y transversal.EmplazamientoCentro ambulatorio de diagnóstico del VIH de Madrid.PacientesSe incluyó en el estudio a 229 mujeres atendidas por primera vez entre 1993 y 2002 por tener una pareja heterosexual estable diagnosticada de infección por el VIH, sin otra exposición de riesgo.Mediciones principalesInformación sociodemográfica, historial reproductivo, conducta sexual, datos clínicos y analíticos de ambos miembros de la pareja.ResultadosEl 66% de las parejas mantenían relaciones sexuales desde hacía más de un año. Las mujeres tenían menor edad media (29,6 años) que los varones. El 29% de las mujeres tenían hijos y el 5,2% estaban embarazadas. Entre los varones, el 82% se había inyectado drogas, pero sólo el 13% mantenía esta práctica. El 73% estaba diagnosticado de infección por el VIH desde hacía más de 6 meses, el 16% presentaba criterios de sida y el 35% recibía tratamiento antirretroviral. El 60% de los varones que conocían previamente su infección habían evitado sistemáticamente los coitos sin preservativo, frente al 33% de los que no se sabían infectados (p < 0,001). El 19% había tenido accidentes en el uso del preservativo. La seroprevalencia del VIH en las mujeres fue del 6,1% (intervalo de confianza del 95%, 3,5-10,3%).ConclusionesLa atención a las personas con VIH debe incluir la asistencia a la pareja sexual, ofreciendo información, apoyo psicológico, consejo preventivo y reproductivo, además del diagnóstico del VIH y de otras infecciones de transmisión sexual.ObjectiveTo describe the situations of risk and the prevalence of HIV in women with a heterosexual partner infected by HIV.DesignCross-sectional descriptive study.SettingOut-patient HIV diagnosis centre in Madrid.Patients229 women seen for the first time between 1993 and 2002 because they had a stable heterosexual partner diagnosed with HIV, and who were exposed to no other risk.Main measurementsSocial and personal details, reproduction history, sexual conduct, clinical, and analytic data of both partners.Results66% of couples had maintained sexual relations for over a year.Women were on average younger (29.6 years old) than the men. 29% of the women had children and 5.2% were pregnant. 82% of men had injected drugs, but only 13% still did. 73% had been diagnosed with HIV for over 6 months, 16% had AIDS criteria, and 35% were taking retroviral treatment. 60% of the men who knew of their infection had systematically avoided sex without condoms, against 33% of those who did not know they were infected (P<.001). 19% had had accidents in use of the condom.HIV seroprevalence in the women was 6.1% (95% CI, 3.5%-10.3%).ConclusionsHealth care of people with HIV must include care of their sexual partner, involving information, psychological support, preventive and reproductive advice, as well as diagnosis of HIV or other sexually transmitted diseases
De Novo Generation of Infectious Prions In Vitro Produces a New Disease Phenotype
Prions are the proteinaceous infectious agents responsible for Transmissible Spongiform Encephalopathies. Compelling evidence supports the hypothesis that prions are composed exclusively of a misfolded version of the prion protein (PrPSc) that replicates in the body in the absence of nucleic acids by inducing the misfolding of the cellular prion protein (PrPC). The most common form of human prion disease is sporadic, which appears to have its origin in a low frequency event of spontaneous misfolding to generate the first PrPSc particle that then propagates as in the infectious form of the disease. The main goal of this study was to mimic an early event in the etiology of sporadic disease by attempting de novo generation of infectious PrPSc in vitro. For this purpose we analyzed in detail the possibility of spontaneous generation of PrPSc by the protein misfolding cyclic amplification (PMCA) procedure. Under standard PMCA conditions, and taking precautions to avoid cross-contamination, de novo generation of PrPSc was never observed, supporting the use of the technology for diagnostic applications. However, we report that PMCA can be modified to generate PrPSc in the absence of pre-existing PrPSc in different animal species at a low and variable rate. De novo generated PrPSc was infectious when inoculated into wild type hamsters, producing a new disease phenotype with unique clinical, neuropathological and biochemical features. Our results represent additional evidence in support of the prion hypothesis and provide a simple model to study the mechanism of sporadic prion disease. The findings also suggest that prion diversity is not restricted to those currently known, and that likely new forms of infectious protein foldings may be produced, resulting in novel disease phenotypes
Age-specific vaccine effectiveness of seasonal 2010/2011 and pandemic influenza A(H1N1) 2009 vaccines in preventing influenza in the United Kingdom
An analysis was undertaken to measure age-specific vaccine effectiveness (VE) of 2010/11 trivalent seasonal influenza vaccine (TIV) and monovalent 2009 pandemic influenza vaccine (PIV) administered in 2009/2010. The test-negative case-control study design was employed based on patients consulting primary care. Overall TIV effectiveness, adjusted for age and month, against confirmed influenza A(H1N1)pdm 2009 infection was 56% (95% CI 42–66); age-specific adjusted VE was 87% (95% CI 45–97) in <5-year-olds and 84% (95% CI 27–97) in 5- to 14-year-olds. Adjusted VE for PIV was only 28% (95% CI x6 to 51) overall and 72% (95% CI 15–91) in <5-year-olds. For confirmed influenza B infection, TIV effectiveness was 57% (95% CI 42–68) and in 5- to 14-year-olds 75% (95% CI 32–91). TIV provided moderate protection against the main circulating strains in 2010/2011, with higher protection in children. PIV administered during the previous season provided residual protection after 1 year, particularly in the <5 years age group
Processes structuring macrophyte metacommunities in Mediterranean ponds: combining novel methods to disentangle the role of dispersal limitation, species sorting and spatial scales
Experimental measurements and diffusion in Harbor and coastal zones
Experimental results of turbulent flows in the sea surface near the coastline have been performed using both Lagrangian and Eulerian methods, field tests are presented using video recordings and velocity sensors. The spatial and
temporal resolution is limited by the measuring instruments, which results in “filtering” out the very small scales. The experimental field-results obtained during
the large-scale surf zone experiments carried out in the Ebro Delta, (Spain), under spilling/plunging breaking waves are compared with experiments performed at the Barcelona harbour. The field-measurements include several tests across the surf zone with high vertical resolution. The measured turbulent properties are compared with macroturbulence characteristics and length parameterisations. Diffusion is measured and related to the local velocity spectra so that a generalized Richardson
law may be used
Elementary excitations, exchange interaction and spin-Peierls transition in CuGeO
The microscopic description of the spin-Peierls transition in pure and doped
CuGeO_3 is developed taking into account realistic details of crystal
structure. It it shown that the presence of side-groups (here Ge) strongly
influences superexchange along Cu-O-Cu path, making it antiferromagnetic.
Nearest-neighbour and next-nearest neighbour exchange constants and
are calculated. Si doping effectively segments the CuO_2-chains
leading to or even slightly ferromagnetic. Strong
sensitivity of the exchange constants to Cu-O-Cu and (Cu-O-Cu)-Ge angles may be
responsible for the spin-Peierls transition itself (``bond-bending mechanism''
of the transition). The nature of excitations in the isolated and coupled
spin-Peierls chains is studied and it is shown that topological excitations
(solitons) play crucial role. Such solitons appear in particular in doped
systems (Cu_{1-x}Zn_xGeO_3, CuGe_{1-x}Si_xO_3) which can explain the
phase diagram.Comment: 7 pages, revtex, 7 Postscript figure
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