15 resultados para Brown, Daniel

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Temporal and spatial fluctuations of environmental parameters are normally assigned as causes of variations in morpho-phenological characters of seaweeds and in their epibionts, but formal tests of such hypotheses are lacking, especially in narrow gradients. The present study evaluated the influence of a very small depth gradient (1 to 3 m) and of subtle seasonality characteristic of tropical areas on morpho-phenological traits and on the occurrence of sessile epiphytic organisms using a controlled orthogonal sampling design in a sublittoral population of the tropical brown alga Sargassum cymosum. Four temporal samples were obtained over a one-year period at three depths using nine replicates. The wet weight, maximum length, number of primary and secondary branches, and proportion of secondary branches with receptacles were recorded. Epibiosis was estimated by visual evaluation of percentage cover on secondary branches. Algal morphology varied as a function of the period of the year (weaker effect) and depth (stronger effect) but in different ways for each variable analysed. In general, fronds tended to be shorter, heavier, and more ramified in shallower areas. In relation to time, the morphological characters tended mostly to present higher values in January (summer) and/or April (autumn). Frequency of receptacles did not depend on algal morphology and depth at all but varied in time, although only in the deepest area. Epibiosis also did not depend on algal morphology but varied in relation to time (stronger effect) and, to a lesser extent, depth (weaker effect). The effect of time upon epibiosis also depended on the biological group analysed. These data support the hypothesis that algal morphology varies in relation to period of the year and depth, even under small temporal and spatial environmenal gradients.

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We have previously shown that a high-protein, carbohydrate-free diet can decrease the production of glycerol-3-phosphate (G3P) from glucose and increase glyceroneogenesis in both brown (BAT) and epididymal (EAT) adipose tissue. Here, we utilized an in-vivo approach to examine the hypothesis that there is reciprocal regulation in the G3P synthesis from glucose (via glycolysis) and glyceroneogenesis in BAT, EAT and liver of fasted rats and cafeteria diet-fed rats. Glyceroneogenesis played a prominent role in the generation of G3P in the liver (similar to 70 %) as well as in BAT and EAT (similar to 80 %) in controls rats. The cafeteria diet induced an increase in the total glyceride-glycerol synthesis and G3P synthesis from glucose and a decrease in glyceroneogenesis in BAT; this diet did not affect either the total glyceride-glycerol synthesis or G3P generation from glyceroneogenesis or glycolysis in the liver or EAT. Fasting induced an increase in total glyceride-glycerol synthesis and glyceroneogenesis and a decrease in G3P synthesis from glucose in the liver but did not affect either the total glyceride-glycerol synthesis or G3P synthesis from glyceroneogenesis in BAT and EAT, despite a reduction in glycolysis in these tissues. These data demonstrate that reciprocal changes in the G3P generation from glucose and from glyceroneogenesis in the rat liver and BAT occur only when the synthesis of glycerides-glycerol is increased. Further, our data suggest that this increase may be essential for the systemic recycling of fatty acids by the liver from fasted rats and for the maintenance of the thermogenic capacity of BAT from cafeteria diet-fed rats.

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With the objective to establish the best metabolizable energy (ME) intake for layers, and the best dietary vegetable oil addition level to optimize egg production, an experiment was carried out with 432 30-week-old Hisex Brown layers. Birds were distributed into nine treatments with six replicates of eight birds each according to a 3 x 3 factorial arrangement, consisting of three daily metabolizable energy intake (280, 300 or 320 kcal/bird/day) and three oil levels (0.00; 0.75 and 1.50 g/bird/day). Daily feed intake was limited to 115, 110 and 105 g/bird in order to obtain the desired energy and oil intake in each treatment. The following parameters were evaluated: initial weight, final weight, body weight change, egg production, egg mass, feed conversion ratio per dozen eggs and per egg mass and energy conversion. There was no influence of the treatments on egg production (%) or egg mass (g/bird/day). Final weight and body weight change were significantly affected by increasing energy intake. Feed conversion ratio per egg mass, feed conversion ratio per dozen eggs and energy conversion significantly worsened as a function of the increase in daily energy intake. An energy intake of 280 kcal/bird/day with no addition of dietary oil does not affect layer performance.

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Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargue and averaged monthly models, the utility of the GDAS data is shown. (C) 2012 Elsevier B.V. All rights reserved.

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Background: Social Phobia (SP) is an anxiety disorder that frequently co-occurs with obsessive-compulsive disorder (OCD); however, studies that evaluate clinical factors associated with this specific comorbidity are rare. The aim was to estimate the prevalence of SP in a large multicenter sample of OCD patients and compare the characteristics of individuals with and without SP. Method: A cross-sectional study with 1001 patients of the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders using several assessment instruments, including the Dimensional Yale-Brown Obsessive-Compulsive Scale and the Structured Clinical Interview for DSM-IV Axis I Disorders. Univariate analyses were followed by logistic regression. Results: Lifetime prevalence of SP was 34.6% (N=346). The following variables remained associated with SP comorbidity after logistic regression: male sex, lower socioeconomic status, body dysmorphic disorder, specific phobia, dysthymia, generalized anxiety disorder, agoraphobia, Tourette syndrome and binge eating disorder. Limitations: The cross-sectional design does not permit the inference of causal relationships; some retrospective information may have been subject to recall bias; all patients were being treated in tertiary services, therefore generalization of the results to other samples of OCD sufferers should be cautious. Despite the large sample size, some hypotheses may not have been confirmed due to the small number of cases with these characteristics (type 2 error). Conclusion: SP is frequent among OCD patients and co-occurs with other disorders that have common phenomenological features. These findings have important implications for clinical practice, indicating the need for broader treatment approaches for individuals with this profile. (C) 2012 Elsevier B.V. All rights reserved.

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The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal.

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The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10(17) eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or "rapid") monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction.

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Festuccia WT, Blanchard PG, Oliveira TB, Magdalon J, Paschoal VA, Richard D, Deshaies Y. PPAR gamma activation attenuates cold-induced upregulation of thyroid status and brown adipose tissue PGC-1 alpha and D2. Am J Physiol Regul Integr Comp Physiol 303: R1277-R1285, 2012. First published October 24, 2012; doi:10.1152/ajpregu.00299.2012.-Here, we investigated whether pharmacological PPAR gamma activation modulates key early events in brown adipose tissue (BAT) recruitment induced by acute cold exposure with the aim of unraveling the interrelationships between sympathetic and PPAR gamma signaling. Sprague-Dawley rats treated or not with the PPAR gamma ligand rosiglitazone (15 mg.kg(-1).day(-1), 7 days) were kept at 23 degrees C or exposed to cold (5 degrees C) for 24 h and evaluated for BAT gene expression, sympathetic activity, thyroid status, and adrenergic signaling. Rosiglitazone did not affect the reduction in body weight gain and the increase in feed efficiency, VO2, and BAT sympathetic activity induced by 24-h cold exposure. Rosiglitazone strongly attenuated the increase in serum total and free T4 and T3 levels and BAT iodothyronine deiodinase type 2 (D2) and PGC-1 alpha mRNA levels and potentiated the reduction in BAT thyroid hormone receptor (THR) beta mRNA levels induced by cold. Administration of T3 to rosiglitazone-treated rats exacerbated the cold-induced increase in energy expenditure but did not restore a proper activation of D2 and PGC-1 alpha, nor further increased uncoupling protein 1 expression. Regarding adrenergic signaling, rosiglitazone did not affect the changes in BAT cAMP content and PKA activity induced by cold. Rosiglitazone alone or in combination with cold increased CREB binding to DNA, but it markedly reduced the expression of one of its major coactivators, CREB binding protein. In conclusion, pharmacological PPAR gamma activation impairs short-term cold elicitation of BAT adrenergic and thyroid signaling, which may result in abnormal tissue recruitment and thermogenic activity.

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The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E-nu between 10(17) eV and 10(20) eV from point-like sources across the sky south of +55 degrees and north of -65 degrees declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of similar to 3.5 years of a full surface detector array for the Earth-skimming channel and similar to 2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k(PS) . E-nu(-2). from a point-like source, 90% confidence level upper limits for k(PS) at the level of approximate to 5x10(-7) and 2.5x10(-6) GeV cm(-2) s(-1) have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively.

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A thorough search of the sky exposed at the Pierre Auger Cosmic Ray Observatory reveals no statistically significant excess of events in any small solid angle that would be indicative of a flux of neutral particles from a discrete source. The search covers from -90 degrees to +15 degrees in declination using four different energy ranges above 1 EeV (10(18) eV). The method used in this search is more sensitive to neutrons than to photons. The upper limit on a neutron flux is derived for a dense grid of directions for each of the four energy ranges. These results constrain scenarios for the production of ultrahigh energy cosmic rays in the Galaxy.

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Background The prevalence, sociodemographic aspects, and clinical features of body dysmorphic disorder (BDD) in patients with obsessivecompulsive disorder (OCD) have been previously addressed in primarily relatively small samples. Methods We performed a cross-sectional demographic and clinical assessment of 901 OCD patients participating in the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders. We used the Structured Clinical Interview for DSM-IV Axis I Disorders; Yale-Brown Obsessive-Compulsive Scale; Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS); Brown Assessment of Beliefs Scale; Clinical Global Impression Scale; and Beck Depression and Anxiety Inventories. Results The lifetime prevalence of BDD was 12.1%. The individuals with comorbid BDD (OCD-BDD; n = 109) were younger than were those without it. In addition, the proportions of single and unemployed patients were greater in the OCD-BDD group. This group of patients also showed higher rates of suicidal behaviors; mood, anxiety, and eating disorders; hypochondriasis; skin picking; Tourette syndrome; and symptoms of the sexual/religious, aggressive, and miscellaneous dimensions. Furthermore, OCD-BDD patients had an earlier onset of OC symptoms; greater severity of OCD, depression, and anxiety symptoms; and poorer insight. After logistic regression, the following features were associated with OCD-BDD: current age; age at OCD onset; severity of the miscellaneous DY-BOCS dimension; severity of depressive symptoms; and comorbid social phobia, dysthymia, anorexia nervosa, bulimia nervosa, and skin picking. Conclusions Because OCD patients might not inform clinicians about concerns regarding their appearance, it is essential to investigate symptoms of BDD, especially in young patients with early onset and comorbid social anxiety, chronic depression, skin picking, or eating disorders. Depression and Anxiety 29: 966-975, 2012. (C) 2012 Wiley Periodicals, Inc.

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A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 10(18) eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and right ascension in several energy ranges above 10(18) eV, and reported in terms of dipolar and quadrupolar coefficients. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Assuming that any cosmic-ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived. These upper limits allow us to test the origin of cosmic rays above 10(18) eV from stationary Galactic sources densely distributed in the Galactic disk and predominantly emitting light particles in all directions.

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A previous study from our laboratory showed that maternal food restriction (MFR) delays thermoregulation in newborn rats. In neonates brown adipose tissue (BAT) is essential for thermogenesis due to the presence of uncoupling proteins (UCPs). The aim of this study was to evaluate the influence of MFR on the UCPs mRNA and protein expression in BAT and skeletal muscle (SM) of the newborn rat. Female Wistar EPM-1 control rats (CON) received chow ad libitum during pregnancy, whereas food-restricted dams (RES) received 50% of the amount ingested by CON. Fifteen hours after birth, the litters were weighed and sacrificed. Blood was collected for hormonal analysis. BAT and SM were used for determination of UCPs mRNA and protein expression, and Ca2+-ATPase sarcoplasmic reticulum (SERCA1). RES pups showed a significant reduction in body weight and fat content at birth. MFR caused a significant increase in the expression of UCP1 and UCP2 in BAT, without changes in UCP3 and SERCA1 expression in BAT and SM. No differences between groups were found for leptin, T4 and glucose levels. RES pups showed increased insulin and decreased T3 levels. The delay in development of thermoregulation previously described in RES animals appears not to result from impairment in thermogenesis, but from an increase in heat loss, since MFR caused low birth weight in pups, leading to greater surface/volume ratio. The higher expression of UCP1 and UCP2 in BAT suggests a compensatory mechanism to increased thermogenesis. (C) 2011 Elsevier Ltd. All rights reserved.

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The composition and seasonal variation of brachyuran and anomuran species associated with mussel farms were evaluated at Praia da Cocanha, Sao Paulo between May 2007 and February 2008. Nine mussel ropes were sampled at random in each quarter, and 1,208 organisms were identified, comprising five families and 28 species. The most numerous species was the porcellanid Pachycheles laevidactylus (18.5%), followed by the xanthids Acantholobulus schmitti (16.6%), Hexapanopeus paulensis (11.3%), Panopeus americanus (10.2%), and Menippe nodifrons (8.4%). The exotic crab Charybdis hellerii was recorded throughout the study period. The ecological descriptors, except Pielou evenness index, varied significantly over the time. The highest abundance and diversity of the species were recorded during November and February. This pattern was reversed for Berger-Parker dominance, with the lowest values recorded in February. The development of epifauna was correlated with the different stages of the mussel farms, since the mean size of mussels and consequently the abundance of epibiotic organisms and the structural complexity on the mussel ropes increased from May (seeding) until February (harvest). Despite this, the temporal population variations in recruitment patterns of the different epibionts should not be overlooked. The results indicated that the mussel farms provided favorable conditions for the development of these crustacean groups, which could be used in environmental monitoring programs and / or be exploited for the aquarium trade.

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The composition and seasonal variation of brachyuran and anomuran species associated with mussel farms were evaluated at Praia da Cocanha, São Paulo between May 2007 and February 2008. Nine mussel ropes were sampled at random in each quarter, and 1,208 organisms were identified, comprising five families and 28 species. The most numerous species was the porcellanid Pachycheles laevidactylus (18.5%), followed by the xanthids Acantholobulus schmitti (16.6%), Hexapanopeus paulensis (11.3%), Panopeus americanus (10.2%), and Menippe nodifrons (8.4%). The exotic crab Charybdis hellerii was recorded throughout the study period. The ecological descriptors, except Pielou evenness index, varied significantly over the time. The highest abundance and diversity of the species were recorded during November and February. This pattern was reversed for Berger-Parker dominance, with the lowest values recorded in February. The development of epifauna was correlated with the different stages of the mussel farms, since the mean size of mussels and consequently the abundance of epibiotic organisms and the structural complexity on the mussel ropes increased from May (seeding) until February (harvest). Despite this, the temporal population variations in recruitment patterns of the different epibionts should not be overlooked. The results indicated that the mussel farms provided favorable conditions for the development of these crustacean groups, which could be used in environmental monitoring programs and / or be exploited for the aquarium trade.