C. Garcia

Study of environmental burden of lead in children using teeth as bioindicator

The south region of Sao Paulo city hosts the Guarapiranga dam, responsible for water supply to 25% of the city population. Their surroundings have been subject to intense and irregular occupation by people from very low socioeconomics classes. Measurements undertaken on sediment and particulate materials in the dam revealed concentrations of lead, copper, zinc and cadmium above internationally accepted limits. Epidemiological and toxicological studies undertaken by the World Health Organization in individuals exhibiting lead concentrations in blood, near or below the maximum recommended (10 microg dl(-1)), surprisingly revealed that toxic effects are more intense in individuals belonging to low socioeconomics classes. Motivated by these facts, we aimed at the investigation of chronic incorporation of lead, as well as the use of our BIOKINETICS code, which is based on an accepted ICRP biokinetics model for lead, in order to extrapolate the results from teeth to other organs. The focus of our data taking was children from poor families, living in a small, restrict and allegedly contaminated area in São Paulo city. Thus, a total of 74 human teeth were collected. The average concentration of lead in teeth of children 5 to 10 years old was determined by means of a high-resolution inductively coupled plasma mass spectrometer (ICP-MS). For standardization of the measurements, an animal bone certified material (H-Animal Bone), from the International Atomic Energy Agency, was analyzed. The amount of lead in children living in the surroundings of the dam, was approximately 40% higher than those from the control region, and the average lead concentration was equal to 1.3 microg g(-1) approximately. Grouping the results in terms of gender, tooth type and condition, it was concluded that a carious molar of boys is a much more efficient contamination pathway for lead, resulting in concentrations 70% higher than in the control region. We also inferred the average concentrations of lead in other organs of these children, by making use of our BIOKINETIC code.

Avaliação nutricional dos profissionais do serviço de nutrição e dietética de um hospital terciário de Porto Alegre

Abstract This study aimed to identify anthropometric and biochemical status and to analyze the weight gain of collaborators of nutrition and dietetics services of Hospital de Clinicas de Porto Alegre (HCPA). This was a retrospective longitudinal study enrolled 190 employees. Nutritional assessment and clinical analysis was measurement. A structured questionnaire was applied all employ-ees. The prevalence of excess weight was 60.8%. Weight gain was significantly associated to length of service, working shift and physical activity. The study showed that an additional year of work was associated with weight gain around 500 g, the shift in average gain of 4 kg and physical activity with average weight loss of 3.3 kg. The association between weight gain, work-ing time and working shift in employees refers to the need to create nutrition intervention program aiming to promote healthy eating habits. Keywords: antropometry; occupational groups; weight gain. Avaliacao nutricional dos profissionais do servico de nutricao e dietetica de um hospital terciario de Porto Alegre

Nuclear Photoproduction of Pseudoscalar Mesons at Forward Angles up to 6.0 GeV

The nuclear incoherent π0 photoproduction cross section from 12C is evaluated at forward angles in the 4.0 to 6.0 GeV energy range using the multicollisional intranuclear cascade model MCMC. The model incorporates some improvements in comparison with previous versions associated with the momentum distribution (MD) for light nuclei—extracted from the available (e,e′p) data—as well as the evaluation of the shadowing effects during the photo‐nucleus interaction. The final results of the single and double differential cross sections at forward angles are very sensitive to the MD parameterizations due to the Pauli principle, which largely suppresses the cross sections for low momentum transfer. The attenuation of the nuclear cross section due to pion—nucleus final state interactions is approximately 40% (without nuclear shadowing), which is in nice agreement with the predictions from the Glauber model. The single and double π0 differential cross sections are presented for possible applications for the interpre...

Photon-induced multiple particle emissions of {sup 90}Zr and {sup nat}Zr from 10 to 140 MeV

A comprehensive analysis of electrodisintegration yields of protons on {sup 90}Zr is proposed taking into account the giant dipole resonance, isovector giant quadrupole resonance (IVGQR), and quasideuteron contributions to the total photoabsorption cross section from 10 to 140 MeV. The calculation applies the MCMC intranuclear cascade to address the direct and pre-equilibrium emissions and another Monte Carlo-based algorithm to describe the evaporation step. The final results of the total photoabsorption cross section for {sup 90}Zr and relevant decay channels are obtained by fitting the (e,p) measurements from the National Bureau of Standards and show that multiple proton emissions dominate the photonuclear reactions at higher energies. These results provide a consistent explanation for the exotic and steady increase of the (e,p) yield and also a strong evidence of a IVGQR with a strength parameter compatible with the E2 energy-weighted sum rule. The inclusive photoneutron cross sections for {sup 90}Zr and {sup nat}Zr, derived from these results and normalized with the (e,p) data, are in agreement within 10% with both Livermore and Saclay data up to 140 MeV.

The nuclear matter effects in π0 photoproduction at high energies

The in-medium influence on p0 photoproduction from spin zero nuclei is carefully studied in the GeV range using a straightforward Monte Carlo analysis. The calculation takes into account the relativistic nuclear recoil for coherent mechanisms (electromagnetic and nuclear amplitudes) plus a time dependent multi-collisional intranuclear cascade approach (MCMC) to describe the transport properties of mesons produced in the surroundings of the nucleon. A detailed analysis of the meson energy spectra for the photoproduction on 12C at 5.5 GeV indicates that both the Coulomb and nuclear coherent events are associated with a small energy transfer to the nucleus (

Photon-induced multiple particle emissions of Zr90 and natZr from 10 to 140 MeV

lesssim

Incoherent {pi}{sup 0} photoproduction from complex nuclei

5 MeV), while the contribution of the nuclear incoherent mechanism is vanishing small within this kinematical range. The angular distributions are dominated by the Primakoff peak at extreme forward angles, with the nuclear incoherent process being the most important contribution above

Nuclear incoherent photoproduction of pi(0) and eta from 4 to 12 GeV

theta_{pi^{0}}gtrsim2^{0}

Avaliação nutricional dos profissionais do serviço de nutrição e dietética de um hospital terciário de Porto Alegre Nutritional evaluation of employees on a nutritional and dietary service of a tertiary hospital in Porto Alegre

. Such consistent Monte Carlo approach provides a suitable method to clean up nuclear backgrounds in some recent high precision experiments, such as the PrimEx experiment at the Jefferson Laboratory Facility.