Biomedical subjects

J M Carmona

Publications and source records attributed to J M Carmona.

5 recordsLinked to original sources

PubMed2005

First results from the CERN axion solar telescope.

Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field ("axion helioscope"), they would be transformed into x-rays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling g(agamma)<1.16x10(-10) GeV-1 at 95% C.L. for m(a) less, similar 0.02 eV. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses.

Journal Article↗

PubMed2003

Transient backbending behavior in the Ising model with fixed magnetization.

The physical origin of the backbendings in the equations of state of finite but not necessarily small systems is studied in the Ising model with fixed magnetization (IMFM) by means of the topological properties of the observable distributions and the analysis of the largest cluster with increasing lattice size. Looking at the convexity anomalies of the IMFM thermodynamic potential, it is shown that the order of the transition at the thermodynamic limit can be recognized in finite systems independently of the lattice size. General statistical mechanics arguments and analytical calculations suggest that the backbending in the caloric curve is a transient behavior which should not converge to a plateau in the thermodynamic limit, while the first-order transition (in the Ehrenfest sense) is still signaled by a discontinuity in the magnetization equation of state.

Journal Article↗

PubMed2000

Health promotion in the city: a structured review of the literature on interventions to prevent heart disease, substance abuse, violence and HIV infection in US metropolitan areas, 1980-1995.

To achieve its national public health goals, the US must improve the health of low-income urban populations. To contribute to this process, this study reviewed published reports of health promotion interventions designed to prevent heart disease, HIV infection, substance abuse, and violence in US cities. The study's objectives were to describe the target populations, settings, and program characteristics of these interventions and to assess the extent to which these programs followed accepted principles for health promotion. Investigators searched five computerized databases and references of selected articles for articles published in peer-reviewed journals between 1980 and 1995. Selected articles listed as a main goal primary prevention of one of four index conditions; were carried out within a US city; included sufficient information to characterize the intervention; and organized at least 25% of its activities within a community setting. In general, programs reached a diverse population of low-income city residents in a variety of settings, employed multiple strategies, and recognized at least some of the principles of effective health promotion. Most programs reported a systematic evaluation. However, many programs did not involve participants in planning, intervene to change underlying social causes, last more than a year, or tailor for the subpopulations they targeted, limiting their potential effectiveness. Few programs addressed the unique characteristics of urban communities.

HIV Infections↗

PubMed2000

Effect of the inclusion time of dietary saturated and unsaturated fats before slaughter on the accumulation and composition of abdominal fat in female broiler chickens.

The aim of this experiment was to assess the effects of four different feeding programs designed to include tallow, a saturated fat at 0, 8, 12, and 28 d prior to slaughter on female broiler performance and the deposition, fatty acid profile, and melting point of abdominal fat. The following treatment groups were established according to dietary inclusion--from 21 to 49 d of age--of: sunflower oil (SUN), sunflower oil followed by tallow during the last 8 d (SUN + 8TALL), sunflower oil followed by tallow during the last 12 d (SUN + 12TALL), and tallow (TALL). The diets were designed to be isoenergetic and isonitrogenous. Abdominal fat deposition increased linearly with increasing number of days in which birds were fed the tallow-enriched diet. However, linear and quadratic response patterns were found between days before slaughter in which the birds were fed the tallow-enriched diet and abdominal fat melting points. This result suggested an exponential response in which 85% of the maximum level was already attained when the dietary fat type changed from an unsaturated to a saturated condition during the last 8 d of the feeding period. The use of an unsaturated fat source during the first stages of growth, and the substitution of a saturated fat for a few days before slaughter, may offer the advantage of lower abdominal fat deposition and an acceptable fat fluidity compared with the use of a saturated fat source during the whole growing and finishing period.

Abdomen↗

PubMed1993

[The topography of the skull and brain of the goat].

This study, based on three goats, provides a radiographic projection of a median section of the brain and the skull. The method allows a topographic correlation of brain structures with the skull and surrounding osseous structures. A standard skull position, with the basic horizontal plane passing through the external acoustic meatus, and parallel to the floor of the skull, results in a method of localizing brain structures in specific transverse planes. This stereotaxic method allows investigators to account for variability in topography between animals in the localization of brain structures through external morphology.

Animals↗