RESUMO

Developmental malnourishment impacts the energetic metabolism control throughout life. In rat offspring, a 0% protein diet during the first 10 days of lactation results in leptin resistance and in alterations in: feeding behavior, serum leptin and neuropeptide Y (NPY) levels in the hypothalamic arcuate nucleus (ARC)/paraventricular (PVN) pathway. Here, the distributions of alpha-melanocyte stimulating hormone (α-MSH) and cocaine and amphetamine regulated transcript (CART), anorexigenic molecules, were immunohistochemically assessed in the ARC, PVN and lateral hypothalamus (LH) nuclei. Rat dams were subjected to one of the following diet protocols from postnatal day (P) 1-10: 1) Protein-free (PFG, 0% protein chow); 2) Pair-fed (UFG, normoprotein chow); 3) Control group (CG, normoprotein chow). PFG, UFG and CG male offspring were analyzed at different time points, from P5 to P180. In the ARC, PFG α-MSH and CART were increased from P10 to P45 when compared to CG and UFG. In the PVN, α-MSH and CART peaks in PFG animals were delayed from P20 to P30 when compared to CG. In the LH, CART was more intense in PFG animals than in UFG and CG ones by P20, and, by P30, UFG immunostaining became less intense than in CG. In conclusion, aproteic diet altered the ontogenetic distribution of both anorexigenic molecules. In the PVN, the peak was delayed to P30, which coincides with the leptin peak and follows the previously described NPY (orexigenic) peak in this model. The permanent LH CART and α-MSH increase may be associated with the previously observed PFG hypophagia.

Assuntos

RESUMO

Bioleaching is a mature technology, which is widely employed commercially in the leaching of primary sources of metals (ores, concentrates, and mine residues). The current work discussed the effects of aluminum sulfate additions to the growth medium, PLS recirculation and bleeding on the column bioleaching of secondary copper sulfide ores with a significant content of fluoride-containing minerals. Fluoride is toxic to bacteria at the pH of bioleaching but its toxicity may be overcome in the presence of soluble aluminum and ferric iron. Therefore, experiments were carried out in 10 × 100 cm height aerated columns, loaded with 10 kg of crushed and agglomerated copper ore and inoculated with Sulfobacillus thermosulfidooxidans. Initially, fluoride concentrations of up to 2.5 g/L in the pregnant leach solution were observed due to the fast dissolution of fluoride-bearing minerals. Aluminum was added to the leaching solution to reduce the Al/F ratio so that the concentration of HF (the main toxic species) was decreased, but while the total fluoride concentration was higher than that of aluminum, the bacterial population as low. Therefore, the current work emphasizes that it is possible to set up conditions to enable bioleaching even at high fluoride concentrations. Following this approach, copper extractions above 90% were achieved for a H2SO4 consumption ranging from 128.8 to 206.1 Kg/ton.

RESUMO

This collection of articles provides an account of the papers delivered at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP)(held in New Orleans, LA, USA, from 10 to 14 August 2003) in a symposium session on assessing the burden of Taenia solium cysticercosis and echinococcosis organised and chaired by A. Lee Willingham III from the WHO/FAO Collaborating Center for Research and Training on Emerging and other Parasitic Zoonoses in Denmark and Peter M. Schantz from the Parasitic Diseases Division of the US Centers for Disease Control and Prevention, USA. The focus was on the persistence of the zoonotic parasitic diseases cysticercosis, caused by the pork tapeworm T. solium, and echinococcosis,caused by species of the tapeworm Echinococcus, and why these diseases are given very little attention on the national and international agendas in spite of the availability of tools to detect, treat,control and prevent them when it is quite clear in most instances that they are clearly associated with and help perpetuate poverty. A major reason for this is that in many endemic areas the presence and impact of these diseases are not known due to the lack of investigation and information thus policymakers are not aware of their burden and benefits of their control. Documentation is also needed to help increase awareness of the international community and hopefully result in financial and technical support being made available. Thus, burden assessments of cysticercosis and echinococcosis provide an essential evidence base for securing political will and financial and technical support as well as providing a basis for cost-benefit analysis of prevention and control efforts. In order to make an appropriate and full burden assessment one must consider the health, agricultural, social and other impacts of these parasitic zoonoses comprehensively. During the symposium presentations were given concerning current ongoing initiatives to assess the burden of cysticercosis and echinococcosis and examples of the impact of these diseases in both developing and developed countries were provided. In addition, cost factors related to vaccines for these cestode diseases were discussed and the possibilities for technical and financial support from multilateral agencies for assessments and interventions presented.

Assuntos