240 research outputs found
Contribuição dos humanos, cães e gatos à transmissão do Trypanosoma cruzi na Região do Chaco Argentino
Foi determinada a prevalência da infecção por T. cruzi nos humanos, cães e gatos, pertencentes a 47 rancherÃas em três povoados rurais; Guanaco Muerto (Córdoba), La Invernada e Amamás (Santiago del Estero), mediante reações seroldgicas e xenodiagnóstico. Poram examinadas 245 pessoas, 123 cães e 14 gatos. A taxa de prevalência na população foi entre 58,7% (GM) e 49,6% (LI). Foram detectados 76% de cães infectados, o que resultou significativamente superior aos 51% encontrados nos humanos. As porcentagens de cães (64,2%) e gatos (63,6%) com parasitemia foram significativamente superiores à correspondente aos humanos (12,5%). Se bem que 79% dos gatos estavam infectados, sua pequena quantidade e seus hábitos de perambulação determinam que sua participação na transmissão doméstica do T. cruzi seja restrita. Não obstante existir em média um maior número de humanos que de cães em cada lar, tanto de sujeitos sãos como infectados (6,5 vs. 3,3 e 3,4 vs. 2,4, respectivamente), foram detectados também na média mais cães que humanos com parasitemia em cada casa (2,1 vs. 1,0). As altas porcentagens de cães infectados e com parasitemia, além do hábito de repouso intra-domiciliário o qual ocasiona estreito contacto entre eles e os barbeiros determinam que os cães sejam os principais provedores de parásitos à disposição para a transmissão, e os hospedeiros mais importantes para /nanutenção da doença de Chagas na Região do Chaco Argentino.Trypanosoma cruzi prevalence rates of human, dog and cat populations from 47 households of 3 rural localities of the phytogeographical Chaqueña area of Argentina were determined both by serological and xenodiagnostic procedures. Human prevalence rates were uniform and ranged from 49.6 to 58.7%. Overall prevalence rate in dogs (75.0%) was significantly higher than in humans (51.0%). The overall proportion of parasitemic individuals assessed by xenodiagnosis was significantly higher in either dog (64.2%) or cat (63.6%) populations than among humans (12.5%). Although both the average number of resident as well as infected individuals per household was higher for people than for dogs (6.5 vs. 3.3, and 3.4 vs. 2.4, respectively), the reverse was recorded when parasitemic individuals were considered (1.0 vs. 2.1). Results are discussed in relation to dog between dogs and people, and dogs and bugs. In the light of present data, dogs must be considered as the major donors of parasites to vector bugs and thus, principal contributors to transmission in this region of Argentina
VIPERS: An Unprecedented View of Galaxies and Large-Scale Structure Halfway Back in the Life of the Universe
The VIMOS Public Extragalactic Redshift Survey (VIPERS) is an ongoing ESO
Large Programme to map in detail the large-scale distribution of galaxies at
0.5 < z <1.2. With a combination of volume and sampling density that is unique
for these redshifts, it focuses on measuring galaxy clustering and related
cosmological quantities as part of the grand challenge of understanding the
origin of cosmic acceleration. VIPERS has also been designed to guarantee a
broader legacy, allowing detailed investigations of the properties and
evolutionary trends of z~1 galaxies. The survey strategy exploits the specific
advantages of the VIMOS spectrograph at the VLT, aiming at a final sample of
nearly 100,000 galaxy redshifts to iAB = 22.5 mag, which represents the largest
redshift survey ever performed with ESO telescopes. In this introductory
article we describe the survey construction, together with early results based
on a first sample of ~55,000 galaxies.Comment: 6 pages, 8 figures; introductory pape
The AMANDA Neutrino Telescope and the Indirect Search for Dark Matter
With an effective telescope area of order 10^4 m^2, a threshold of ~50 GeV
and a pointing accuracy of 2.5 degrees, the AMANDA detector represents the
first of a new generation of high energy neutrino telescopes, reaching a scale
envisaged over 25 years ago. We describe its performance, focussing on the
capability to detect halo dark matter particles via their annihilation into
neutrinos.Comment: Latex2.09, 16 pages, uses epsf.sty to place 15 postscript figures.
Talk presented at the 3rd International Symposium on Sources and Detection of
Dark Matter in the Universe (DM98), Santa Monica, California, Feb. 199
Physicochemical and Biological Characterisation of Diclofenac Oligomeric Poly(3-hydroxyoctanoate) Hybrids as β-TCP Ceramics Modifiers for Bone Tissue Regeneration
Nowadays, regenerative medicine faces a major challenge in providing new, functional materials that will meet the characteristics desired to replenish and grow new tissue. Therefore, this study presents new ceramic-polymer composites in which the matrix consists of tricalcium phosphates covered with blends containing a chemically bounded diclofenac with the biocompatible polymer-poly(3-hydroxyoctanoate), P(3HO). Modification of P(3HO) oligomers was confirmed by NMR, IR and XPS. Moreover, obtained oligomers and their blends were subjected to an in-depth characterisation using GPC, TGA, DSC and AFM. Furthermore, we demonstrate that the hydrophobicity and surface free energy values of blends decreased with the amount of diclofenac modified oligomers. Subsequently, the designed composites were used as a substrate for growth of the pre-osteoblast cell line (MC3T3-E1). An in vitro biocompatibility study showed that the composite with the lowest concentration of the proposed drug is within the range assumed to be non-toxic (viability above 70%). Cell proliferation was visualised using the SEM method, whereas the observation of cell penetration into the scaffold was carried out by confocal microscopy. Thus, it can be an ideal new functional bone tissue substitute, allowing not only the regeneration and restoration of the defect but also inhibiting the development of chronic inflammation
Care, laboratory beagles and affective utopia
A caring approach to knowledge production has been portrayed as epistemologically radical, ethically vital and as fostering continuous responsibility between researchers and research-subjects. This article examines these arguments through focusing on the ambivalent role of care within the first large-scale experimental beagle colony, a self-professed ‘beagle utopia’ at the University of California, Davis, (1951-1986). We argue that care was at the core of the beagle colony; the lived environment was re-shaped in response to animals ‘speaking back’ to researchers, and ‘love’ and ‘kindness’ were important considerations during staff recruitment. Ultimately, however, we show that care-relations were used to manufacture compliancy, preventing the predetermined ends of the experiment from being troubled. Rather than suggesting Davis would have been less ethically troubling, or more epistemologically radical, with ‘better’ care, however, we suggest the case troubles existing care theory and argue that greater attention needs to be paid to histories, contexts, and exclusions
The AMANDA Neutrino Telescope
With an effective telescope area of order m for TeV neutrinos, a
threshold near 50 GeV and a pointing accuracy of 2.5 degrees per muon
track, the AMANDA detector represents the first of a new generation of high
energy neutrino telescopes, reaching a scale envisaged over 25 years ago. We
describe early results on the calibration of natural deep ice as a particle
detector as well as on AMANDA's performance as a neutrino telescope.Comment: 12 pages, Latex2.09, uses espcrc2.sty and epsf.sty, 13 postscript
files included. Talk presented at the 18th International Conference on
Neutrino Physics and Astrophysics (Neutrino 98), Takayama, Japan, June 199
The AMANDA Neutrino Telescope: Principle of Operation and First Results
AMANDA is a high-energy neutrino telescope presently under construction at
the geographical South Pole. In the Antarctic summer 1995/96, an array of 80
optical modules (OMs) arranged on 4 strings (AMANDA-B4) was deployed at depths
between 1.5 and 2 km. In this paper we describe the design and performance of
the AMANDA-B4 prototype, based on data collected between February and November
1996. Monte Carlo simulations of the detector response to down-going
atmospheric muon tracks show that the global behavior of the detector is
understood. We describe the data analysis method and present first results on
atmospheric muon reconstruction and separation of neutrino candidates. The
AMANDA array was upgraded with 216 OMs on 6 new strings in 1996/97
(AMANDA-B10), and 122 additional OMs on 3 strings in 1997/98.Comment: 36 pages, 23 figures, submitted to Astroparticle Physic
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