Metamorphic evolution of a subduction complex, South Shetland Islands, Antarctica

A subduction complex composed of ocean floor material mixed with arc-derived metasediments crops out in the Elephant Island group and at Smith Island, South Shetland Islands, Antarctica, with metamorphic ages of 120-80 Ma and 58-47 Ma? respectively. Seven metamorphic zones (I-VII) mapped on Elephant Island delineate a gradual increase in metamorphic grade from the pumpellyite-actinolite facies, through the crossite-epidote blueschist facies, to the lower amphibolite facies. Geothermometry in garnet-amphibole and garnet-biotite pairs yields temperatures of about 350 degrees C in zone III to about 525 degrees C in zone VII. Pressures were estimated on the basis of Si content in white mica, Al2O3 content in alkali amphibole, Na-M4/Al-IV in sodic-calcic and calcic amphibole, Al-VI/Si in calcic amphibole, and jadeite content in clinopyroxene. Mean values vary from about 6-7.5 kbar in zone II to about 5 kbar in zone VII. Results from the other islands of the Elephant Island group are comparable to those from the main island; Smith Island yielded slightly higher pressures, up to 8 kbar, with temperatures estimated between 300 and 350 degrees C. Zoned minerals and other textural indications locally enable inference of P-T-t trajectories, all with a clockwise evolution. A reconstruction in space and time of these P-T-t paths allows an estimate of the thermal structure in the upper crust during the two ductile deformation phases (D-1 & D-2) that affected the area. This thermal structure is in good agreement with the one expected for a subduction zone. The arrival and collision of thickened oceanic crust may have caused the accretion and preservation of the subduction complex. In this model, D-1 represents the subduction movements expressed by the first vector of the clockwise P-T-t path, D-2 reflects the collision corresponding to the second vector with increasing temperature and decreasing pressure, and D-3 corresponds to isostatic uplift accompanied by erosion, under circumstances of decreasing temperature and pressure.

Protein-energy status and 15N-glycine kinetic study of child a cirrhotic patients fed low- to high-protein energy diets

In five male cirrhotic patients (Child A) and in four age- and sex-matched healthy control subjects, whole-body protein turnover was measured using a single oral dose of N-15-glycine as a tracer and urinary ammonia as end product. Subjects were studied in the fasting and feeding state, with different levels of protein and energy intake. The patients were underweight and presented lower plasma transthyretin and retinol-binding protein levels. When compared with controls, the kinetic studies showed patients to be hypometabolic in the fasting (Do) state and with the control diet [D-1 = (0.85 g of protein/154 kJ). kg(-1). day(-1)]. However, when corrected by body weight, the kinetic differences between groups disappeared, whereas the N-retention in the feeding state showed better results for the patients due mainly to their efficient breakdown decrease. When fed high-level protein or energy diets [D-2 = (0.9 g protein/195 kJ) and D-3 = (1.56 g protein/158 kJ). kg(-1). day(-1)], the patients showed D-0 = D-1 = D-2 < D-3 for N-flux and (D-0 = D-1) < D-3 (D-2 is intermediary) for protein synthesis. Thus, the present data suggest that the remaining mass of the undernourished mild cirrhotic patients has fairly good protein synthesis activity and also that protein, rather than energy intake, would be the limiting factor for increasing their whole-body protein synthesis.

Influence of diet on assimilation and turnover of C-13 in the tissues of broiler chickens

1. The C-13 turnover rates of the liver and thoracic pectoral muscle of growing broilers were determined by feeding diets with varying C-13 content.2. Male chicks ( 1- d- old) were subjected to treatments based on free choice of 5 different mixes of energy and protein sources from plants with C-3 and C-4 photosynthetic pathways that had differing C-13 content. Rice bran ( R) and soybean meal ( S) were the C-3 sources, while maize ( C) and maize gluten meal ( G) were the C-4 sources. Choices were R + S, C + G, R + G, C + S or R + C +G + S. The 6th treatment was a complete feed ( CF) that was similar to a commercial broiler feed.3. The isotopic composition of the birds' tissues was representative of the isotopic composition of the diets. The assimilation was faster for C-3, in both liver and muscle, than for C-4 diets, and give the delta per mil difference between the diet and tissues.4. The liver is the most active metabolic tissue and gave more rapid isotope turnover than in muscle.

A SAXS study of kinetics of aggregation of TEOS-derived sonogels at different temperatures

The kinetics of aggregation of tetraethoxysilane (TEOS)-derived silica sols, produced by acid-catalyzed and ultrasound-stimulated hydrolysis, were studied by 'in situ' measurements of small-angle X-ray scattering (SAXS) at the temperatures 40 degreesC, 60 degreesC and 70 degreesC. The results were analyzed in terms of the evolution with time (t) of the SAXS intensity probing the mass fractal characteristics of the system, the average radius of gyration (Rc,) of the clusters and the number of primary particles per cluster. The aggregation process yields mass fractal structures which exhibit a scattering exponent (alpha) practically equal to 2, in the probed length scale range (5.3 nm < 1/q < 0.22 nm), beneath and even far beyond the gel point. This suggests that a is a direct measure of the real mass fractal dimension (D) of the structure. The precursor sol (pH = 2) exhibits I nm mean sized clusters with mass fractal dimension D similar to 1.9. Increasing the pH to 4.5, the cluster mean size and the number of primary particles per cluster increase but the system keeps a more opened structure (D similar to 1.4). In the first aggregation stages, D increases up to similar to2 by incorporating primary particles to the clusters without changing their mean size. From this stage, the aggregation progresses following a thermally activated scaling law well described by R-G similar tot(1/D) in all cases. This is indicative of a diffusion-controlled cluster-cluster aggregation process. The activation energy of the process was found to be 91.7 kJ/mol. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Morphological characterization of follicle deviation in Nelore (Bos indicus) heifers and cows

Follicle diameter deviation is defined as the beginning of the differential change in growth rates between the largest and next largest follicles subsequent to wave emergence and is considered a key component of follicle selection. Follicle selection has been extensively studied in European breeds of cattle (Bos taurus) but has not been critically studied in Zebu breeds (Bos indicus). The objectives of the present study were to determine and compare the morphological characteristics of deviation associated with the first post-ovulatory wave (Wave 1) of the estrous cycle in Nelore heifers (n = 8) and nonlactating cows (n = 11). Beginning on the day of ovulation (day 0), the three largest follicles (F1-F3, respectively) were individually tracked every 12 h for 6 d using transrectal ultrasonography. In individual animals, deviation was determined graphically using visual inspection of the diameter profiles of F1, F2 and sometimes F3 (observed deviation) and mathematically using segmented regression analysis of the diameter differences between F1 and F2 or sometimes F3 (calculated deviation). Mean day of emergence of Wave 1 when F1 reached >3 rum (approximately 1 d after ovulation) and growth rate of F1 during deviation (approximately 1.4 mm/d) were not significantly different between heifers and cows. The results of determining the beginning of deviation within heifers and cows using the observed and calculated methods were not significantly different. Averaged over both methods, diameter deviation occurred 2.8 d after ovulation when F1 reached 5.7 mm in heifers, and 2.4 d after ovulation when F1 reached 6.1 mm in cows. In conclusion, the emergence of Wave 1 and growth rates and diameters of the future dominant follicles at the beginning of deviation were similar in Nelore heifers and nonlactating cows, regardless of the methods used to determine deviation. Relative to Holstein cattle, emergence of Wave 1 appeared to occur about 1 d later and diameter of the future dominant follicle at the beginning of deviation was about 2 turn smaller in Nelore. (C) 2004 Elsevier B.V. All rights reserved.

Photopatternable di-ureasil-zirconium oxocluster organic-inorganic hybrids as cost effective integrated optical substrates

Organic-inorganic hybrids containing methacrylic acid (McOH, CH(2)= C(CH(3))COOH)) modified zirconium tetrapropoxide, Zr(OPr(n))(4), classed as di-ureasil-zirconium oxo-cluster hybrids, have been prepared and structurally characterized by X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), Fourier transform infrared (FT-IR) and Raman (FT-Raman) spectroscopies, Si and C nuclear magnetic resonance (NMR), and atomic force microscopy (AFM). XRD and SAXS results have pointed out the presence of Si- and Zr-based nanobuilding blocks (NBBs) dispersed into the organic phase. Inter-NBBs correlation distances have been estimated for the pure di-ureasil and a model compound obtained. by hydrolysis/condensation of Zr(OPr(n))(4):McOH (molar ratio 1: 1): d(Si) approximate to 26 +/- 1 angstrom and d(Zr) approximate to 16 +/- 1 angstrom, respectively. In the case of the di-ureasil-zirconium oxo-cluster hybrids, these distances depend on the Zr relative molar percentage (rel. mol. Zr %) (d(Si) ranges from 18 to 25 angstrom and d(Zr) from 14 to 23 angstrom, as the rel. mol. Zr % increases from 5 to 75), suggesting that the Si- and Zr-based clusters are interconstrained. Complementary data from FT-IR, FT-Raman, (29)Si and (13)C NMR, and AFM support to a structural model where McOH-modified Zr-based NBBs (Zr-OMc) are present over the whole range of composition. At low Zr-OMc contents (rel. mol. Zr % <30) the clusters are well-dispersed within the di-ureasil host, whereas segregation occurs at the 0.1 mu m scale at high Zr-OMc concentration (rel. mol. Zr % = 50). No Zr-O-Si heterocondensation has been discerned. Monomode waveguides, diffractions gratings, and Fabry-Perot cavities have been written through the exposure of the hybrid monoliths to UV light. FT-Raman has shown that the chemical process that takes place under illumination is the polymerization of the methacrylate groups of the Zr-OMc NBBs. The guidance region in patterned channels is a Gaussian section located below the exposed surface with typical dimensions of 320 mu m wide and 88 mu m deep. The effective refractive index is 1.5162 (maximum index contrast on the order of 1 x 10(-4)) and the reflection coeficient of the Fabry-Perot cavity (formed by a grating patterned into a 0.278 cm channel) is 0.042 with a free spectral range value of 35.6 GHz.

Controlling the growth of zirconia needles precursor from a liquid crystal template

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of timing of induced luteolysis in embryo donor mares on reproductive performance and pregnancy rate in recipient mares

The objective was to evaluate the effects of giving prostaglandin F(2 alpha) (PGF) to donor mares 48 h prior to embryo collection. Non-lactating donor mares (n = 20 estrous cycles in 10 mares), ranging from 2.5 to 10 y of age and 400 to 500 kg of body weight were used from September 2004 to February 2005 in the southern hemisphere (Brazil). Donor mares were randomly assigned in a cross-over design study. During a Treated cycle, 7.5 mg PGF was given 48 h prior to embryo collection, whereas in the Control cycle, 7.5 mg PGF was given at embryo collection. In Treated Cycles, serum progesterone concentrations decreased between the day of PGF treatment and the day of embryo collection (13.9 +/- 5.4 and 0.5 +/- 0.3 ng/mL, respectively; P < 0.05). In Treated versus Control cycles, the interovulatory interval was shorter (14.9 +/- 0.9 vs 17.5 +/- 1.1 d, P < 0.05). However, there was no significant difference between these groups for the interval from PGF to ovulation (average, 9.8 d), embryo recovery rate (average, 75%), embryo quality, uterine protein concentration, and pregnancy rate in recipient mares (average, 87% at 15 d after ovulation, with no pregnancy loss detected by 60 d). In conclusion, giving donor mares PGF 48 h prior to embryo collection reduced the average interovulatory interval by approximately 2.5 d, thereby potentially increasing the numbers of embryos that could be collected during a breeding season, with no deleterious effects on embryo recovery rate, embryo quality, or pregnancy rate in recipient mares. (c) 2011 Elsevier B.V. All rights reserved.

Effects of bovine Herpesvirus Type 5 on development of in vitro-produced bovine embryos

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

Surface-plasmon-enhanced frequency upconversion in Pr(3+) doped tellurium-oxide glasses containing silver nanoparticles

A frequency upconversion process in Pr(3+) doped TeO(2)-ZnO glasses containing silver nanoparticles is studied under excitation with a nanosecond laser operating at 590 nm, in resonance with the (3)H(4)-->(1)D(2) transition. The excited Pr(3+) ions exchange energy in the presence of the nanoparticles, originating efficient conversion from orange to blue. The enhancement in the intensity of the luminescence at similar to 482 nm, corresponding to the (3)P(0)-->(3)H(4) transition, is due to the influence of the large local field on the Pr(3+) ions, which are located near the metallic nanoparticles. (C) 2008 American Institute of Physics.

Frequency upconversion in a Pr(3+) doped chalcogenide glass containing silver nanoparticles

We report on orange-to-blue frequency upconversion (UC) in Pr(3+) doped chalcogenide glass (Ga(10)Ge(25)S(65)) doped with Ag(2)S and heat treated under different conditions to nucleate silver nanoparticles (NPs). The experiments were performed using 7 ns pulses from a dye laser that operates at similar to 590 nm, in resonance with the (3)H(4)->(1)D(2) transition of Pr(3+) ions. The enhancement observed in the UC emission at similar to 494 nm, ascribed as (3)P(0)->(3)H(4) transition of the Pr(3+) ion, is attributed to the large local field acting on the emitting ions due to the presence of the metallic NPs. (C) 2008 American Institute of Physics.

Use of Rubidium to Label Lysiphlebus testaceipes (Hymenoptera: Braconidae), a Parasitoid of Greenbugs (Homoptera: Aphididae), for Dispersal Studies

A reliable method of labeling is needed to study dispersal of the braconid parasitoid, Lysiphlebus testaceipes (Cresson), an important biological control of greenbugs, Schizaphis graminum (Rondani), on grain sorghum, Sorghum bicolor (L.) Moench. The feasibility of using aqueous solutions of rubidium chloride (RbCl) applied as a foliar spray or soil drench to label greenbugs and L. testaceipes developing within greenbugs was studied. Laboratory and field studies were conducted to identify the minimal concentration of RbCl to assure labeling of greenbugs and wasps, persistence of Rb throughout the wasp's life span, mobility of Rb to unsprayed sorghum leaves, and feasibility of studying dispersal using a release-recapture technique with Rb-labeled wasps. Both greenbugs and wasps could be labeled using RbCl at concentrations of 2,500-10,000 ppm. Rubidium content in labeled wasps did not significantly vary during the first 7 d after emergence. Greenbugs feeding on unsprayed leaves were labeled up to 4 wk after leaves were sprayed. Rb-labeled wasps were found at the maximum trap distance from the release site (60 m) within 1 d after release.

First massive state of the superstring in superspace

Using the manifestly spacetime supersymmetric description of the four-dimensional open superstring, we construct the vertex operator in superspace for the first massive state. This construction provides an N = 1 D = 4 superspace representation of the massive spin-2 multiplet. © 1997 Published by Elsevier Science B.V.

Superspace action for the first massive states of the superstring

Using the manifestly spacetime-supersymmetric version of open superstring field theory, we construct the free action for the first massive states of the open superstring compactified to four dimensions. This action is in N = 1 D = 4 superspace and describes a massive spin-2 multiplet coupled to two massive scalar multiplets. © 1999 Published by Elsevier Science B.V. All rights reserved.

The Ramond sector of open superstring field theory

Although the equations of motion for the Neveu-Schwarz (NS) and Ramond (R) sectors of open superstring field theory can be covariantly expressed in terms of one NS and one R string field, picture-changing problems prevent the construction of an action involving these two string fields. However, a consistent action can be constructed by dividing the NS and R states into three string fields which are real, chiral and antichiral. The open superstring field theory action includes a WZW-like term for the real field and holomorphic Chern-Simons-like terms for the chiral and antichiral fields. Different versions of the action can be constructed with either manifest d = 8 Lorentz covariance or manifest TV = 1 d = 4 super-Poincaré covariance. The lack of a manifestly d = 10 Lorentz covariant action is related to the self-dual five-form in the type-IIB R-R sector.