Assessment of low amounts of meat and bone meal in the diet of laying hens by using stable isotopes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Different tools to trace geographic origin and seasonality of croaker (Micropogonias furnieri)

The aim of this study was to use proximate chemical composition, macro and trace elements, fatty acid profile and stable isotopes as traceability tools to assess geographic origin and seasonality of croaker (Micropogonicts fumieri). Croaker from Parnaiba contained higher ash in July and lower fat content than croaker from Santos. In contrast, croaker from Santos had statistically higher proportion of 16:1n-9+16:1n-7, 20:1n-11, 20:1n-9, MUFA and n-3/n-6 ratio than croaker from Parnaiba. Concerning seasonality, croaker caught in July had significantly higher amounts of 14:0, 15:0, 16:1n-9+16:1n-7 and saturated fatty acids than fish caught in December. Concerning elements, significant differences were also detected between seasons for Cl, Ca, Fe, Sr and S, whereas differences between geographic origins were only observed with K. delta C-13 and delta N-15 were statistically different between geographic origins, whereas differences between seasons were only detected in delta N-15 ratio of croaker from Santos. Fatty acids, minerals and stable isotope are effective methods to trace geographic origin and seasonality of croaker. Nonetheless, further investigation is still required with larger samples of croaker to enable the implementation of fatty acids, elements or stable isotope as authenticity tools by food control agencies. (C) 2014 Elsevier Ltd. All rights reserved.

Nonmesonic weak decay dynamics from proton spectra of Lambda-hypernuclei

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effect of self-adhesive and self-etching resin cements on the bond strength of nonmetallic posts in different root thirds

The purpose of this study was to evaluate the effect of self-adhesive and self-etching resin cements on the bond strength of nonmetallic posts in different root regions. Sixty single-rooted human teeth were decoronated, endodontically treated, post-space prepared, and divided into six groups. Glass-fiber (GF) posts (Exacto, Angelus) and fiber-reinforced composite (FRC) posts (EverStick, StickTeck) were cemented with self-adhesive resin cement (Breeze) (SA) (Pentral Clinical) and self-etching resin cement (Panavia-F) (SE) (Kuraray). Six 1-mm-thick rods were obtained from the cervical (C), middle (M), and apical (A) regions of the roots. The specimens were then subjected to microtensile testing in a special machine (BISCO; Schaumburg, IL, USA) at a crosshead speed of 0.5 mm/min. Microtensile bond strength data were analyzed with two-way ANOVA and Tukey's tests. Means (and SD) of the MPa were: GF/SA/C: 14.32 (2.84), GF/SA/M: 10.69 (2.72), GF/SA/A: 6.77 (2.17), GF/SE/C: 11.56 (4.13), GF/SE/M: 6.49 (2.54), GF/SE/A: 3.60 (1.29), FRC/SA/C: 16.89 (2.66), FRC/SA/M: 13.18 (2.19), FRC/SA/A: 8.45 (1.77), FRC/SE/C: 13.69 (3.26), FRC/SE/M: 9.58 (2.23), FRC/SE/A: 5.62 (2.12). The difference among the regions was statistically significant for all groups (p < 0.05). The self-adhesive resin cement showed better results than the self-etching resin cement when compared to each post (p < 0.05). No statistically significant differences in bond strengths of the resin cements when comparable to each post (p > 0.05). The bond strength values were significantly affected by the resin cement and the highest values were found for self-adhesive resin cement.

Rediscovery and redescription of the unusual subterranean characiform Stygichthys typhlops, with notes on its life history

The rediscovery of the enigmatic subterranean characiform Stygichthys typhlops is reported almost a half-century after the collection of the holotype, the only specimen previously known. Thirty-four specimens were collected in two shallow hand-dug wells at the region of the type locality, c. 13 km south-west of the town of Jaiba, Minas Gerais, Brazil. These specimens provide new information on the morphology of this species, and for the first time on its life history. The conservation status of S. typhlops is discussed. The species is severely threatened by habitat loss caused by exploitation of the aquifer. (C) 2010 The Authors Journal compilation (C) 2010 The Fisheries Society of the British Isles

Paleoenvironmental reconstruction of a Late Quaternary lagoon system in southern Brazil (Jaguaruna region, Santa Catarina state) based on multi-proxy analysis

This paper provides a paleoenvironmental reconstruction of a Late Quaternary lagoon system in the Jaguaruna region of Santa Catarina state, southern Brazil. Integrated results of bulk sedimentary organic matter characterization (delta C-13, delta N-15 and C/N), microfossil (pollen and diatom) and grain-size analysis from three shallow cores (similar to 2.5m depth) allowed us to propose an evolving paleogeographic scenario in this coastal region for the last ca. 5500 cal a BP. The lagoonal system in this area was more extensive during the mid-Holocene than today, with a gradual and continuous lagoon-sea disconnection until the present. We add to the debate regarding relative sea-level (RSL) variations for the Brazilian coast during the Holocene and discuss the importance of sedimentary dynamics for interpreting changes in coastal ecosystems. The multi-proxy analysis suggests that changes in coastal ecosystems could be directly related to local sedimentary processes, which are not necessarily linked to RSL fluctuations and/or to climatic variations. Copyright (c) 2011 John Wiley & Sons, Ltd.

Dyspeptic symptoms and delayed gastric emptying of solids in patients with inactive Crohn's disease

Background: Patients with Crohn's disease (CD) have been shown to present dyspeptic symptoms more frequently than the general population. Some of these symptoms could be related to motility disorders to some degree. Then, we propose to investigate whether gastric emptying of solids in patients with inactive CD is delayed and to determine the relationships between gastric emptying and dyspeptic symptoms in inactive CD. Methods: Twenty-six patients with inactive Crohn's disease, as defined by a Crohn's Disease Activity Index (CDAI) < 150, underwent a gastric emptying test by breath test using C-13 octanoic acid coupled to a solid meal and answered a validated questionnaire (The Porto Alegre Dyspeptic Symptoms Questionnaire) to assess dyspeptic symptoms. Patients with scores >= 6 were considered to have dyspepsia. The control group was composed by 19 age-and sex-matched healthy volunteers. Results: Patients with CD had a significantly longer t 1/2 and t lag (p<0.05) than the controls. CD patients with dyspepsia had significantly (p<0.05) prolonged gastric emptying when compared to patients without dyspeptic symptoms. When the individual symptom patterns were analyzed, only vomiting was significantly associated with delayed gastric emptying (p<0.05). There was no difference between the subgroups of patients with respect to gender, CDAI scores, disease location, clinical behavior (obstructive/obstructive) or previous gastrointestinal surgery. Conclusion: Delayed gastric emptying in inactive Crohn's disease patients seems to be associated with dyspeptic symptoms, particularly vomiting, even without any evidence of gastrointestinal obstruction.

Permeability of riparian forest strips in agricultural, small subtropical watersheds in south-eastern Brazil

If riparian buffer zones are ineffective in preventing C-4 plant carbon from upland areas reaching the stream sediment, the composition of stream fauna can be significantly altered. The permeability of riparian forest strips in agricultural, small subtropical watersheds in south-eastern Brazil was measured in nine watersheds categorised according to the predominant land cover of the legally required 30-m buffer riparian zone. Four watersheds with well preserved riparian forest along the 30-m buffer zone were designated as FOREST watersheds; three watersheds, with a predominance of C-4 grasses from sugarcane to pasture, mixed with preserved riparian forests, were designated MIXED watersheds; and two watersheds were termed PASTURE-SUGAR because their entire 30-m buffer zone was covered by C-4 plants. Stable carbon (delta C-13) isotopes were used as tracers of upland C-4 carbon in sediments, suspended particulate organic carbon, terrestrial and aquatic invertebrates and two species of neotropical fish. Although the intact 30-m buffer zone of riparian forests did not entirely prevent the input of C-4 to the river environment and food web, there was a significant increase in C-4 carbon in those watersheds where the buffer zone was not covered by riparian forests. These findings emphasise the importance of riparian forests in mitigating disturbance in streams and support efforts to preserve such riparian corridors.

Factors controlling water-column respiration in rivers of the central and southwestern Amazon Basin

We examined the factors controlling the variability in water-column respiration rates in Amazonian rivers. Our objectives were to determine the relationship between respiration rates and the in situ concentrations of the size classes of organic carbon (OC), and the biological source (C-3 and C-4 plants and phytoplankton) of organic matter (OM) supporting respiration. Respiration was measured along with OC size fractions and dissolved oxygen isotopes (delta O-18-O-2) in rivers of the central and southwestern Amazon Basin. Rates ranged from 0.034 mu mol O-2 L-1 h(-1) to 1.78 mu mol O-2 L-1 h(-1), and were four-fold higher in rivers with evidence of photosynthetic production (demonstrated by delta O-18-O-2<24.2 parts per thousand) as compared to rivers lacking such evidence (delta O-18-O-2>24.2 parts per thousand; 1.35 +/- 0.22 vs. 0.30 +/- 0.29 mu mol L-1 h(-1)). Rates were likely elevated in the former rivers, which were all sampled during low water, due to the stimulation of heterotrophic respiration via the supply of a labile, algal-derived substrate and/or the occurrence of autotrophic respiration. The organic composition of fine particulate OM (FPOM) of these rivers is consistent with a phytoplankton origin. Multiple linear regression analysis indicates that [FPOC], C:N-FPOC ratios, and [O-2] account for a high amount of the variability in respiration rates (r(2) = 0.80). Accordingly, FPOC derived from algal sources is associated with elevated respiration rates. The delta C-13 of respiration-derived CO2 indicates that the role of phytoplankton, C-3 plants, and C-4 grasses in supporting respiration is temporally and spatially variable. Future scaling work is needed to evaluate the significance of phytoplankton production to basin-wide carbon cycling.

A trophic study of the sympatric Amazonian freshwater turtles Podocnemis unifilis and Podocnemis expansa (Testudines, Podocnemidae) using carbon and nitrogen stable isotope analyses

The Yellow-spotted River Turtle (Podocnemis unifilis Troschel, 1848) and the South American River Turtle (Podocnemis expansa (Schweigger, 1812)) are two turtles species that are widely distributed and have ecological, economic, and cultural importance in the Amazon basin. Although sympatric regarding most of their distribution, few studies have addressed the coexistence of these two species. To examine this, we analyzed the trophic level and the primary carbon source from the diets of both species in Baixo Araguaia, Tocantins, Brazil, using stable isotope analyses of carbon (delta C-13) and nitrogen (delta N-15). We also verified possible intraspecific variations (related to sex and body mass) in the trophic levels and primary carbon sources of their diets. Podocnemis unifilis had higher values of delta N-15 than P. expansa, averaging 7.59 parts per thousand and 5.06 parts per thousand, respectively, a difference which may indicate a possible trophic change owing to exploiting different food resources. No differences were found between the two species in relation to delta C-13 (mean values of -26.2 parts per thousand and -26.1 parts per thousand, respectively). The similarity between delta C-13 values suggests that the sources of their basal feeding are the same, consisting mainly of C-3 plants. There was no intraspecific variation in the values of delta C-13 and delta N-15.

Carbon isotope fractionation during calcium carbonate precipitation induced by urease-catalysed hydrolysis of urea

Stable carbon isotopic fractionation during calcium carbonate precipitation induced by urease-catalysed hydrolysis of urea was experimentally investigated in artificial water at a constant temperature of 30 degrees C. Carbon isotope fractionation during urea hydrolysis follows a Rayleigh distillation trend characterized by a C-13-enrichment factor of -20 to -22 parts per thousand. CaCO3 precipitate is up to 17.9 parts per thousand C-13-depleted relative to the urea substrate (-48.9 +/- 0.07 parts per thousand). Initial CaCO3 precipitate forms close to isotopic equilibrium with dissolved inorganic carbon. Subsequent precipitation occurs at -2 to -3 parts per thousand offset from isotopic equilibrium, suggesting that the initial delta C-13 value of CaCO3 is reset through dissolution followed by reprecipitation with urease molecules playing a role in offsetting the delta C-13 value of CaCO3 from isotopic equilibrium. Potentially, this isotopic systematics may provide a tool for the diagnosis of ureolytically-formed carbonate cements used as sealing agent. Moreover, it may serve as a basis to develop a carbon isotope tool for the quantification of ureolytically-induced CO2 sequestration. Finally, it suggests carbon isotope disequilibrium as a hallmark of past enzymatic activity in ancient microbial carbonate formation. (C) 2012 Elsevier B.V. All rights reserved.

Biosynthesis of Two Dihydropyrrole-Polyketides from a Marine-Derived Penicillium citrinum

Feeding experiments with C-13-labeled precursors were performed in order to establish the biosynthesis of two N-acylated dihydropyrroles, (8E)-1-(2,3-dihydro-1H-pyrrol-1-yl)-2- methyldec-8-ene-1,3-dione (1) and 1-(2,3-dihydro-1H-pyrrol-1-yl)-2- methyldecane-1,3-dione (2), isolated from the cultures of a marine-derived Penicillium citrinum. The biosynthesis of both, 1 and 2, involves the incorporation of acetate, methionine and ornithine.

Do changes in carbon allocation account for the growth response to potassium and sodium applications in tropical Eucalyptus plantations?

Understanding the underlying mechanisms that account for the impact of potassium (K) fertilization and its replacement by sodium (Na) on tree growth is key to improving the management of forest plantations that are expanding over weathered tropical soils with low amounts of exchangeable bases. A complete randomized block design was planted with Eucalyptus grandis (W. Hill ex Maiden) to quantify growth, carbon uptake and carbon partitioning using a carbon budget approach. A combination of approaches including the establishment of allometric relationships over the whole rotation and measurements of soil CO2 efflux and aboveground litterfall at the end of the rotation were used to estimate aboveground net production (ANPP), total belowground carbon flux and gross primary production (GPP). The stable carbon isotope (delta C-13) of stem wood alpha-cellulose produced every year was used as a proxy for stomatal limitation of photosynthesis. Potassium fertilization increased GPP and decreased the fraction of carbon allocated belowground. Aboveground net production was strongly enhanced, and because leaf lifespan increased, leaf biomass was enhanced without any change in leaf production, and wood production (P-W) was dramatically increased. Sodium application decreased the fraction of carbon allocated belowground in a similar way, and enhanced GPP, ANPP and P-W, but to a lesser extent compared with K fertilization. Neither K nor Na affected delta C-13 of stem wood alpha-cellulose, suggesting that water-use efficiency was the same among the treatments and that the inferred increase in leaf photosynthesis was not only related to a higher stomatal conductance. We concluded that the response to K fertilization and Na addition on P-W resulted from drastic changes in carbon allocation.

O comportamento de instrução dos trinadores de jovens de futebol em competição

[POR] O objetivo deste estudo centra-se na análise do comportamento de instrução dos treinadores de jovens em competição. O segundo objetivo é efetuar a comparação entre treinadores que orientam equipas na etapa direção (n=6) e especialização (n=3) da formação de jovens jogadores. Os nove treinadores observados, dirigiam equipas de juniores “A” (17-18 anos), “B” (15-16 anos) e “C” (13-14 anos).

Large-scale coupled-cluster calculations

Coupled-cluster theory provides one of the most successful concepts in electronic-structure theory. This work covers the parallelization of coupled-cluster energies, gradients, and second derivatives and its application to selected large-scale chemical problems, beside the more practical aspects such as the publication and support of the quantum-chemistry package ACES II MAB and the design and development of a computational environment optimized for coupled-cluster calculations. The main objective of this thesis was to extend the range of applicability of coupled-cluster models to larger molecular systems and their properties and therefore to bring large-scale coupled-cluster calculations into day-to-day routine of computational chemistry. A straightforward strategy for the parallelization of CCSD and CCSD(T) energies, gradients, and second derivatives has been outlined and implemented for closed-shell and open-shell references. Starting from the highly efficient serial implementation of the ACES II MAB computer code an adaptation for affordable workstation clusters has been obtained by parallelizing the most time-consuming steps of the algorithms. Benchmark calculations for systems with up to 1300 basis functions and the presented applications show that the resulting algorithm for energies, gradients and second derivatives at the CCSD and CCSD(T) level of theory exhibits good scaling with the number of processors and substantially extends the range of applicability. Within the framework of the ’High accuracy Extrapolated Ab initio Thermochemistry’ (HEAT) protocols effects of increased basis-set size and higher excitations in the coupled- cluster expansion were investigated. The HEAT scheme was generalized for molecules containing second-row atoms in the case of vinyl chloride. This allowed the different experimental reported values to be discriminated. In the case of the benzene molecule it was shown that even for molecules of this size chemical accuracy can be achieved. Near-quantitative agreement with experiment (about 2 ppm deviation) for the prediction of fluorine-19 nuclear magnetic shielding constants can be achieved by employing the CCSD(T) model together with large basis sets at accurate equilibrium geometries if vibrational averaging and temperature corrections via second-order vibrational perturbation theory are considered. Applying a very similar level of theory for the calculation of the carbon-13 NMR chemical shifts of benzene resulted in quantitative agreement with experimental gas-phase data. The NMR chemical shift study for the bridgehead 1-adamantyl cation at the CCSD(T) level resolved earlier discrepancies of lower-level theoretical treatment. The equilibrium structure of diacetylene has been determined based on the combination of experimental rotational constants of thirteen isotopic species and zero-point vibrational corrections calculated at various quantum-chemical levels. These empirical equilibrium structures agree to within 0.1 pm irrespective of the theoretical level employed. High-level quantum-chemical calculations on the hyperfine structure parameters of the cyanopolyynes were found to be in excellent agreement with experiment. Finally, the theoretically most accurate determination of the molecular equilibrium structure of ferrocene to date is presented.