Abstract: The theory of quantum critical phenomena is introduced to study some current many-body problems in condensed matter physics. Renormalization group concepts are applied to strongly correlated electronic materials which are close to a zero-temperature instability. These systems have enhanced effective masses and susceptibility. Scaling arguments yield the exponents which govern the critical behavior of these quantities in terms of the usual critical exponents associated with a zero-temperature phase transition. We show the existence of a new energy scale, related to the quantum nature of the many-body instability, which can be generally associated with the setting of Fermi-liquid behavior with decreasing temperature in three-dimensional strongly interacting electronic systems. The theory of quantum critical phenomena is used to investigate the Kondo lattice problem, which provides a model to describe heavy-fermion systems and to introduce a scaling theory of the Mott transition with special emphasis on charge fluctuation effects. However, this report is not a review on heavy fermions and Mott insulators. The microscopic theories of these systems are still controversial and present some of the most challenging and instigating problems in condensed matter physics. This state of affairs stimulated the author to review and extend the scaling approach. The scaling theory we develop provides a powerful tool, based on the notion of universality, to understand the physical properties of correlated systems beyond the mean-field level. This is illustrated by our treatment of the one-dimensional Hubbard model, where, although the Fermi-liquid fixed point does not survive the fluctuations, the scaling approach is still useful. Finally, we discuss briefly how disorder affect our results.

Abstract: Calcium phosphates have a wide range of pH stability, depending on their Ca/P ratio. Under physiological conditions (pH ≈7), the most stable calcium phosphate is hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 . Acidic calcium phosphates, like dicalcium phosphate, CaHPO 4 (monetite) and dicalcium phosphate dihydrate, CaHPO 4 ·2H 2 O (brushite), are thermodynamically unstable under pH values greater than 6–7 and undergo transformation into more stable calcium phosphates. It means that, when placed in vivo (pH ≈7), acidic calcium phosphates convert to hydroxyapatite. In the present study, a coating of crystalline monetite oriented along the [112] axis was electrochemically deposited on titanium substrates. This monetite coating was subsequently converted to hydroxyapatite by immersion in alkaline solutions. The result was a crystalline hydroxyapatite coating oriented along the [002] axis. Different alkaline solutions produced the same result. Studying the effect of immersion time on the transformation indicated that 4 h were required to complete the conversion from monetite to hydroxyapatite. The transformation occurred by a dissolution–reprecipitation mechanism, i.e. the monetite coating was continuously dissolved and reprecipitated as hydroxyapatite. This combined electrochemical deposition and chemical conversion process produced hydroxyapatite coatings with satisfactory adhesion to the substrate and a thickness between 10 and 30 μm.

Abstract: Perfect fluid Friedmann-Robertson-Walker quantum cosmological models for an arbitrary barotropic equation of state $p = \alpha\rho$ are constructed using Schutz's variational formalism. In this approach the notion of time can be recovered. By superposition of stationary states, finite-norm wave-packet solutions to the Wheeler-DeWitt equation are found. The behaviour of the scale factor is studied by applying the many-worlds and the ontological interpretations of quantum mechanics. Singularity-free models are obtained for $\alpha \alpha > - 1$.

Abstract: Human rotavirus strains belonging to genotype G9 or P[9] were detected in a collection of stool specimens from children with diarrhea in two cities of the state of Rio de Janeiro, Brazil, between March 1997 and December 1999. G9 strains were first detected in April 1997 and remained prevalent until the end of the study, at a frequency of 15.9% (n = 157). A high percentage of VP7 nucleotide (99.0 to 99.5%) and deduced amino acid identity (98.6 to 99.1%) was found between three randomly selected Brazilian G9 strains and the American G9 strain US1205. A novel G9:P[4] genotype combination was detected in addition to G9:P[8] and G9:P[6], demonstrating that this G genotype may undergo constant genetic reassortment in nature. The P[9] rotavirus strains constituted 10.2%, the majority of which were detected between April and July 1997. The RNA electrophoretic migration pattern of the G3:P[9] strains resembled that of AU-1 virus (G3:P3[9]), suggesting a genetic similarity between the Brazilian G3:P[9] strains and the Japanese virus, which is similar to a feline rotavirus genetically.

Abstract: Mafic rocks representative of the alkaline magmatism of the Alto Paranaiba Province in southwestern Minas Gerais, Brazil were studied by means of petrography, mineral, whole-rock and isotope geochemistry with the objective of better understanding this Cretaceous magmatism and the characteristics of the magma sources. Because of the variety and complexity of lithotypes examined in this research and the paucity of detailed studies of these Brazilian rocks in the literature, this study also attempts to establish parameters that allow for a clear distinction between kimberlite and kamafugite. Fifty-two occurrences are described and classified as kimberlite or kamafugite. Among the kamafugites, both ugandite (characterized by the presence of leucite) and mafurite (with kalsilite) end members have been characterized. Mineral compositions were found to be efficient in distinguishing between kimberlites, mafurites and ugandites in the province, primarily on the basis of phlogopite composition. The Re-Os isotope systematics permitted a better understanding of the relation of the sublithospheric mantle source to the magmatism in the region. Kimberlites, mafurites and ugandites have different 187Os/188Os ratios (0.117 to 0.129, 0.127 to 0.145 and 0.142 to 0.147, respectively). The Rb-Sr and Sm-Nd isotope systematics failed to indicate first-order differences between kamafugites and kimberlites, whilst 206Pb/204Pb ratios for the kimberlites are higher than those for the other rock types. Kimberlite and kamafugite isotopic compositions appear to be related to the mixture of at least two dominant mantle components: one with an isotopic signature similar to that of lithospheric peridotites, i.e., with 187Os/188Os ratios of the order of 0.118, similar to those observed in mantle-derived xenoliths entrained in kimberlites intruded in the Kaapvaal, Wyoming, and Siberian cratons; another with higher 187Os/188Os ratios of the order of 0.135, within the range of ratios reported for pyroxenite veins in alpine-type peridotites and ocean island basalts. Different melting depths of heterogeneous lithospheric sources by a mantle plume are suggested to explain the isotopic characteristics of the Alto Paranaiba Alkaline Province alkaline rocks.

Abstract: The School Feeding Program has been mostly concerned with the provision of snacks or meals in school break. However, there are possibilities, which can be used by the Program nutritionist for developing educational activities related to nutrition, aiming at health promotion of the school community. These activities require the revision of the Program functions to use this space for discussions about conditioning factors of feeding habits, influencing factors of acquisition, cooking and ingestion of food, among other issues. To consider all the school activities also as educational ones would foster integration among students, teachers and other school workers, such as nutritionists and cooks. The promotion of openings to discuss health conditions at the workplace would contribute to the production of knowledge and to the development of continuing education practices, an essential activity in a time of rapid changes.

Abstract: There is now compelling evidence that, in addition to signaling to the central nervous system (CNS), leptin also exerts its metabolic effects acting directly on peripheral tissues. It has been demonstrated by in vivo and in vitro studies, that leptin increases glucose and fatty acid metabolism in skeletal muscle. These direct leptin effects are supported by the presence of the long form of the leptin receptor, considered to be capable of performing intracellular signaling, in peripheral tissues, including skeletal muscle. The exposure of soleus muscle to supra-physiological leptin concentrations stimulate the activity of both the pyruvate-dehydrogenase (PDH) complex and Krebs cycle. This could be due to a direct stimulation of PDH and krebs cycle by leptin or a consequence of an indirect effect of this hormone activating the mitochondrial uncoupling process. In addition, in soleus and extensor digitorum longus (EDL) muscles, leptin and insulin had opposite effects on lipid metabolism, with leptin favoring lipid oxidation and insulin favoring lipid storage as triglycerides (TG). The leptin effects on free fatty acid (FFA) oxidation were more pronounced in soleus than in EDL. The differences in response of soleus compared with that of EDL was probably due to differences in fiber type composition and metabolic characteristics. It has been demonstrated that leptin reduces the TG content of skeletal. When tissue TG content is severely depleted by hyperleptinemia in normal rats, there is a dramatic increase in insulin sensitivity. This lipopenic effect of leptin may protect from the development of insulin resistance and diabetes in animals. In humans, obesity is also associated with an increase in insulin resistance and the development of Type II diabetes, however, contrary to rats and mice, there is abundance of leptin, indicating a state of resistance to this hormone in humans. Future studies are necessary to investigate the reasons why lean subjects seem to respond properly to endogenous leptin while obese ones don't. The understanding of the putative direct leptin signaling pathway in skeletal muscle could be an important step towards the utilization of leptin or a leptin receptor agonist as therapeutic tools to treat obesity and its related metabolic disorders.

Abstract: This paper reviews the most relevant aspects of measuring basal metabolic rate (BMR). The authors discuss individual and lifestyle factors (age, anthropometry, smoking, physical activity, diet, menses, and ethnicity) as well as possible environmental factors at time of measurement which may alter BMR values. Various available predictive equations, especially those recommended by the World Health Organization in 1985, and subsequent validation studies, particularly in populations living in the tropics, are presented. The review indicates the need for more information on BMR from populations living in different parts of the world so that better estimates can be provided for clinicians and epidemiologists.

Abstract: In order to analyze some controversies on the equivalence between ballistic deposition (BD) and the Kardar-Parisi-Zhang (KPZ) theory, we simulated the BD model in one and two dimensions. Effective exponents betaL were obtained in the growth regions, which were rigorously determined for various lengths L. Effective exponents alphaL were obtained from saturation widths in the steady-state regimes. In d=1 we found betaL=beta+AL(-lambda) and alphaL=alpha+BL(-delta), with asymptotic exponents consistent with the KPZ values beta=1/3 and alpha=1/2, and correction-to-scaling exponents 0.2 < or approximately = lambda < or approximately = 0.4 and 0.6 < or approximately = delta < or approximately = 0.8. These strong finite-size corrections explain the previous discrepancies between numerical estimates for BD and the exact KPZ results. In d=2 we could only obtain reliable estimates of alphaL, which are consistent with KPZ values if finite-size corrections with delta approximately 0.4 are considered.

Abstract: Investigation of metal distribution in preserved areas is highly relevant due to the present-day lack of reliable databases against which to assess contamination. 23 samples of surface sediments from the Ribeira Bay, Rio de Janeiro State, Brazil, were analyzed by ICP/AES for Ti, Ca, Mg, Fe, Al, Sr, La, V, Y, Ni, Cu, Cr, Mn and Zn. Hg concentrations were determined by CVAAS. With respect to Al, metals were classified as strongly correlated, correlated, inversely correlated and non-correlated. Cluster analysis of the concentration data confirmed this, except for Hg. Cluster analysis of the sampling sites produced three groups, on the basis of grainsize, continental input, and marine input. Climatic and hydrodynamic factors, as well as soil characteristics, are important controls of the metal distribution in this region. The Ribeira Bay has a natural background metal content, when compared with average shales and with other impacted and non-impacted regions.

Abstract: The purpose of this study was to determine the effect of the oral administration of pyridostigmine bromide on indices of heart rate variability (HRV) in healthy young volunteers. Seventeen healthy participants (11 men, 6 women; aged 27 +/- 8 y) submitted to a randomized, crossover, double-blind protocol, in which they received 30 mg pyridostigmine bromide (PYR) or placebo orally at 8-hour intervals for 24 hours, on two separate days. Venous blood samples were collected 2 and 24 hours after the first dose for determination of serum cholinesterase activity. Holter tapes were recorded during the 24-hour period and analyzed using a semiautomatic technique to evaluate time- and frequency-domain indices of HRV and to build three-dimensional return maps for later quantification. Symptoms were mild and occurred similarly during administration of PYR and placebo (p = 0.140). Serum cholinesterase activity was reduced by 15% at 2 hours (p = 0.013) and by 14% at 24 hours (p = 0.010) after the first dose of PYR, but not after administration of placebo. Pyridostigmine administration caused a significant increase in the mean 24-hour R-R interval (placebo: 814 +/- 20 msec; PYR: 844 +/- 18 msec; p = 0.003) and in time-domain indices of HRV, such as the standard deviation of all R-R intervals (SDNN; placebo: 151 +/- 9 msec; PYR: 164 +/- 9 msec; p = 0.017), and the percentage of pairs of adjacent R-R intervals differing by more than 50 msec (pNN50; placebo: 12.8 +/- 1.8%; PYR: 13.9 +/- 1.5%; p = 0.029). Pyridostigmine had no significant effect on frequency-domain indices of HRV, but resulted in significant increase in P2, a parasympathetic index derived from the three-dimensional return map (placebo: 93 +/- 13 msec; PYR: 98 +/- 13 ms; p = 0.029). In conclusion, low-dose pyridostigmine reduced mean heart rate and increased HRV during a 24-hour period in healthy young subjects.

Abstract: To study the distribution of triggers of migraine in a selected population, 100 patients who fulfilled the diagnostic criteria for migraine without aura as proposed by the International Headache Society were evaluated by means of a personal interview. Stress was the most cited trigger, triggering migraine in 76%. Afterwards, in descending order of frequency, were cited sensorial stimuli (75%), sleep deprivation (49%), hunger (48%), environmental factors (47%), food (46%), menses (39%), fatigue (35%), alcohol (28%), sleep excess (27%), cafeine (22%), physical exertion (20%), head trauma (20%), trips (4%), sexual activity (3%), medications (2%), neck movements (2%), smoking (1%) and the use of a low pillow (1%). It is concluded that certain factors seem to play an important role in the triggering of migraine.

Abstract: This article presents reflections on how alcohol consumption is conceived as a sociological object, including proscribed forms linked to the definition of diseases or disregard for moral norms. Through considerations on the accumulated investment in a research process currently under way, the author highlights the ethical and epistemological dilemmas faced by anthropologists who focus on this issue.

Abstract: Varios derivados de 1,4-naftoquinonas contendo um grupo hidrazino como cadeia lateral foram sintetizados a partir do 3-diazo-naftaleno-1,2,4-triona e foram avaliados como potenciais agentes antimicrobianos. Os derivados naftoquinonicos 2-[N'-(1-acetil-2-oxo-propilideno)-hidrazino]-3-hidroxi-[1,4]naftoquinona, 2-[(3-hidroxi-1,4-dioxo-1,4-diidro-naftaleno-2-il)-hidrazono]-3-oxo -butirato de etila, 2-[(3-hidroxi-1,4-dioxo-1,4-diidro-naftaleno-2-il)-hidrazono]-3-oxo-butirato de t-butila, 3-hidroxi-2-[(di-O-isopropilideno-malonato)-hidrazino]-1,4-naftoquinona e 2-[(3-hidroxi-1,4-dioxo-1,4-diidro-naftaleno-2-il)-hidrazono]-malonato de etila mostraram maior atividade antibacteriana, ao nivel de teste preliminar em disco, que o lapachol (1), uma 1,4-naftoquinona muito conhecida pelas suas variadas atividades biologicas. Estudo sobre a concentracao minima inibitoria (MIC) para o Staphylococcus aureus mostrou que 2-[(3-hidroxi-1,4-dioxo-1,4-diidro-naftaleno-2-il)-hidrazono]-malonato de etila tem uma atividade duas vezes maior que 1. Da mesma forma, o estudo da densidade otica em cultura de S. aureus com esta substância mostrou uma atividade similar a da vancomicina na concentracao de 2xMIC.