Genetic and environmental effects on parturition and lactation intervals in water buffaloes from Brazil

Genetic and environmental effects on parturition interval (PI) and duration of lactation (DL) were evaluated in 107 Jafarabadi, 98 Mediterranean, 1027 Murrah and 624 crossbred buffalo females (n=1856), based on data from the Buffalo Genetic Improvement Program-PROMEBUL from 1980 to 2003. The statistical model included effects of herd, parturition year and month, calf's sex, parturition order and genetic group, composing 11, 34, 12, 2, 12 and 4 classes, respectively. A significant effect over PI was observed (P<0.01) in all classes, excepting sex. Mean parturition intervals per genetic group presented significant differences through SNK test (P<0.05), with mean values of 451.29; 429.47; 406.97 and 389.78 days in Mediterranean, crossbred, Murrah and Jafarabadi, respectively. Mean DL values were 276.68; 270.33; 258.03 and 235.59 days for Mediterranean, Murrah, crossbred and Jafarabadi groups, respectively. No significant differences in DL were observed in relation to genetic groups. However, herd and parturition order, year and month significantly influenced DL (P<0.01). The herd was the main source of variation over DL, followed by parturition year and month. A regression based on parturition month in relation to PI and DL showed that females giving birth in the last months of the year presented higher PI and DL.

Inbreeding and its effects on some productive and reproductive traits in a Murrah buffalo herd

Data concerning genealogy, milk yield, lactation length, caving interval and lac at first calving, obtained from Murrah buffaloes on a farm In São Paulo state, Brazil, were studied in order to determine the presence of inbreeding in the herd and to evaluate its effects as well as the effects of some environmental factors on productive and reproductive traits. The mean inbreeding coefficient estimated for 2414 animals, born from 1965 to 1995 was 2.94%. of these animals, 47% mere considered inbred with a mean inbreeding coefficient equal 6.25%. Milk production, lactation length, calving interval and age at first calving averaged 1493.3 +/- 60.7 kg, 271.0 +/- 37.3 days, 385.0 +/- 53.4 days and 33.05 +/- 6.05 months, respectively. Among all four traits, only lactation length was affected by inbreeding.

Novel allosteric conformation of human HB revealed by the hydration and anion effects on O-2 binding

The effect of anions on the stability of different functional conformations of Hb is examined through the determination of the dependence of O-2 affinity on water activity (a(w)). The control of a(w) is effected by varying the sucrose osmolal concentration in the bathing solution according to the osmotic stress method. Thus, the hydration change following Hb oxygenation is determined as a function of Cl- and of DPG concentration. We find that only similar to 25 additional water molecules bind to human Hb during the deoxy-to-oxy conformation transition in the absence of anions, in contrast with similar to 72 that bind in the presence of more than 50 mM Cl- or more than 15 mu M DPG. We demonstrate that the increase in the hydration change linked with oxygenation is coupled with anion binding to the deoxy-Hb. Hence, we propose that the deoxy-Hb coexists in two allosteric conformations which depend on whether anion is bound or not: the tense T-state, with low oxygen affinity and anion bound, or a new allosteric P-state, with intermediate oxygen affinity and free of bound anions. The intrinsic oxygen affinity of this unforeseen P-state and the differential binding of Cl-, DPG, and H2O between states P and T and P and R are characteristics which are consistent with those expected for a putative intermediate allosteric state of Hb. These findings represent a new opportunity to explore the structure-function relationships of hemoglobin regulation.

Use of Yucca schidigera extract in broiler diets and its effects on performance results obtained with different coccidiosis control methods

A trial was conducted to assess the effects of the dietary supplement Yucca schidigera extract on the performance of broilers subjected to different coccidiosis control methods. Six hundred male broiler chicks were randomly allocated to 1 of 5 treatments with 4 replicates each. The treatments were as follows: T1, vaccinated against coccidiosis; T2, nonvaccinated, a dietary coccidiostat; T3, vaccinated against coccidiosis, diet supplemented with Y. schidigera extract (0.01%); T4, coccidiostat plus Y. schidigera extract added to feed (0.01%); and T5, nonvaccinated, nonsupplemented control. The parameters analyzed were bird performance and morphology of the intestinal mucosal surface. The intestinal villi were higher at 6 d of age in broilers treated with coccidiostats or vaccinated against coccidiosis and supplemented with Y. schidigera extract compared with groups receiving the vaccine only or no treatment. Addition of the Y. schidigera extract to the diet of vaccinated birds improved average daily gain and feed conversion rate at 42 d of age compared with the other treatments, suggesting there might be a beneficial, synergistic effect between the coccidiosis vaccine and the Y. schidigera extract.

Degradation of tetracycline by photo-Fenton process - Solar irradiation and matrix effects

The degradation of the antibiotic tetracycline (TC) by the photo-Fenton process was evaluated under black-light and solar irradiation. The influences of iron source (Fe(NO3)(3) or ferrioxalate), hydrogen peroxide and matrix (pure water, surface water and a sewage treatment plant effluent-STP) were evaluated. Under black-light irradiation, TC degradation was favored in the presence of Fe(NO3)(3), achieving total degradation after 1 min irradiation, while under solar light the use of ferrioxalate favors the degradation. Nevertheless, no significant difference in total organic carbon removal was observed between these two iron sources, achieving a residual concentration of around 5 mg L-1 under black-light and 2 mg L-1 under solar light irradiation. No decrease of the degradation efficiency relative to pure water was observed when TC was irradiated in a sample of surface water, under either black-light or solar irradiation. However, lower efficiency was obtained under black-light when TC was present in a sample of STP effluent, indicating the interference of the constituents of this sample on the overall efficiency of the process. on the other hand, under solar irradiation in the presence of ferrioxalate, no influence of the matrix was observed, even in the sample of STP effluent, achieving total degradation of TC in 1.5 min. (c) 2006 Elsevier B.V. All rights reserved.

Influence of temperature upon paralyzing and myotoxic effects of bothropstoxin-I on mouse neuromuscular preparations

Bothropstoxin-I (BthTX-I), from B. jararacussu venom, is a phospholipase A(2) (PLA(2)) homologue devoid of enzymatic activity. Besides inducing severe myonecrosis, BthTX-I promotes paralysis of both directly and indirectly evoked contractions in isolated neuromuscular preparations. We applied an experimental paradigm in order to characterize the steps involved in the toxic effects of BthTX-I on mouse neuromuscular junction. Myotoxicity was assessed by microscopic analysis of extensor digitorum longus muscles; paralyzing activity was evaluated through the recording of isolated contractions indirectly evoked in phrenic-diaphragm preparations. After 90 min at 35 degreesC, BthTX-I induced complete and irreversible paralysis, and damaged 30.3 +/- 2.7% of muscle fibers. In contrast, no effect was observed when tissues were incubated with BthTX-I at 10degreesC for 60 min and subsequently washed with toxin-free solution and maintained at 35 degreesC. These results indicate that the binding of BthTX-I to the cellular tissue surface is very weak at low temperature and that an additional factor is necessary. However, when tissues were submitted to BthTX-I (10degreesC for 60 min), and the temperature was elevated to 35 degreesC, omitting the washing step, it was observed muscle paralysis and damage in 39.04 +/- 4.2% of muscle fibers. These results indicate that a temperature-dependent step is necessary for BthTX-I to promote both its myotoxic and paralyzing activities. (C) 2004 Elsevier B.V.. All rights reserved.

EVALUATION of COVERING MATERIALS IN INDIVIDUAL SHELTERS and ITS EFFECTS on PHYSIOLOGICAL RESPONSES and PERFORMANCE of DAIRY CALVES

In Tropical regions, the animal performance is often affected by climate conditions. This study aimed to evaluate covering materials in individual shelters, normally used to house dairy calves, and its influence on the calves physiology and performance. The design used was completely randomized, with a 2x3 factorial arrangement to compare the averages of 5% through the Tukey's test, i.e., both genders-and three types of covering in the shelters (Z - zinc; AC - asbestos cement; and WPAC - white-painted asbestos cement). Parameters evaluated included daily weight gain (DWG), dry matter intake (DMI), feed conversion (FC), rectal temperature (RT), and respiratory frequency (RF). Results showed significant differences (P < 0.05) among males (1.04kg/day) and females (0.74kg/day) for DWG and interaction between gender and treatment (P < 0.05) for zinc covering (0.562kg/day for females and 1.120kg/day for males). Significant differences were also observed in FI of animals housed under shelters with the covering of zinc (48.35kgDM/day for females and 96.91 kgDM/day for males). There were no significant differences (P > 0.05) in the FC and the RT, and there were significant differences (P < 0.05) for RF in the Z treatments (56.9 mov.min(-1)), WPAC (62.2 mov.min(-1)) and FC (70.25 mov.min-1). It was concluded that different covering materials did not affect performance and dry matter intake of dairy calves. However, the animals' physiology of thermoregulation was altered by the different covering materials used in individual shelters.

Upconversion luminescence and thermal effects in terbium-ytterbium codoped fluorogermanate glass-ceramic

Cooperative energy transfer upconversion luminescence is investigated in Tb(3+)/Yb(3+)-codoped PbGeO(3)-PbF(2)-CdF(2) glass-ceramic and its precursor glass under resonant and off resonance infrared excitation. Bright UV-visible emission signals around 384, 415, 438 nm, and 473-490, 545, 587, and 623 nm are identified as due to the (5)D(3)((5)G(6))->(7)F(1) (J=6,5,4) and (5)D(4)->(7)F(1) (J=6,5,4,3) transitions, respectively, and readily observed. The results indicate that cooperative energy transfer between ytterbium and terbium. ions followed by excited state absorption are the dominant upconversion excitation mechanisms involved. Comparison of the upconversion process in a glass-ceramic sample and its glassy precursor revealed that the former present much higher upconversion efficiency. The dependence of the upconversion emission upon pump power, temperature, and doping content is also examined.

Photoexpansion and photobleaching effects in oxysulfide thin films of the GeS2+Ga2O3 system

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

Oxygen plasma treatment of sisal fibers and polypropylene: Effects on mechanical properties of composites

Polypropylene powder and sisal fibers were oxygen plasma treated, and the mechanical properties of their composites were tested. Two main effects were investigated: the incorporation of oxygen polar groups in the polypropylene surface and the surface degradation and chain scission of both polypropylene and sisal fibers. Prior to these treatments, three reactor configurations were tested to investigate the best condition for both effects to occur in PP film. Results showed that polypropylene-cellulose adhesion forces are about an order of magnitude higher for PP film treatments at 13.56 MHz than at 40 kHz owing to much higher chain scission at lower frequencies, although it probably also occurs at high frequency and high power. Polypropylene powder treated with oxygen plasma in optimum conditions for polar group incorporation did not result in improvement in any composite mechanical property, probably owing to the polymer melting. Sisal fibers and PP powder treated In conditions of surface degradation did not improve flexural or tensile properties but resulted in higher impact resistance, comparable to the improvement obtained with the addition of compatibilizer.

Magnetic-field and confinement effects on the effective Land, g factor in AlxGa1-xAs parabolic quantum wells

The magnetic-field and confinement effects on the Land, factor in AlxGa1-xAs parabolic quantum wells under magnetic fields applied parallel or perpendicular to the growth direction are theoretically studied. Calculations are performed in the limit of low temperatures and low electron density in the heterostructure. The g factor is obtained by taking into account the effects of non-parabolicity and anisotropy of the conduction band through the 2 x 2 Ogg-McCombe Hamiltonian, and by including the cubic Dresselhaus spin-orbit term. A simple formula describing the magnetic-field dependence of the effective Land, factor is analytically derived by using the Rayleigh-Schrodinger perturbation theory, and it is found in good agreement with previous experimental studies devoted to understand the behavior of the g factor, as a function of an applied magnetic field, in semiconductor heterostructures. Present numerical results for the effective Land, factor are shown as functions of the quantum-well parameters and magnetic-field strength, and compared with available experimental measurements.

Early cytotoxic and genotoxic effects of atrazine on Wistar rat liver: A morphological, immunohistochemical, biochemical, and molecular study

Risk assessments suggest that intermediate and long-term exposure to triazine herbicides and its metabolites through water can cause severe damage to human health. The objective of this study was to investigate the possible effects of atrazine on Wistar rats submitted to subacute treatment. For this purpose, the activity of catalase and alanine aminotransferase was quantified, and the effect of the herbicide on cell membranes was examined based on the measurement of lipid peroxidation and consequent formation of malondialdehyde and on the mRNA expression of antioxidant enzymes (Mn-superoxide dismutase [SOD] and GSTM1) and connexins. In addition, we evaluated histopathological alterations in the liver, cellular expression of SOD and glutathione (GST), activation of heat shock proteins (HSPs) by immunohistochemistry, and the induction of apoptosis. The genotoxic potential of the herbicide was investigated by the micronucleus test in bone marrow smears. Adult male Wistar rats were treated with an aqueous solution of atrazine at a concentration of 400 mg/kg/day, by gavage, for 14 consecutive days. Control groups were also included. The results showed an increase of catalase levels and maintenance of the expression of antioxidant enzymes (SOD and GST). In addition, lipid peroxidation, hepatic tissue degeneration, activation of HSP90, increased levels of connexin mRNA, and genotoxicity were observed. In conclusion, atrazine induced early hepatic oxidative stress that triggered defense mechanisms to maintain the morphophysiological integrity of the liver. Further studies are needed to better understand the effects of this herbicide on human health. (C) 2011 Elsevier B.V. All rights reserved.

Cellular and tissue effects induced by photogemA (R) and red LED in photodynamic therapy

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