182 resultados para Lorenz energy cycle


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Several neuropsychiatry disorders have shown a sexual dimorphism in their incidence, symptom profile and therapeutic response. A better understanding of the impact of sex hormones in emotional processing sexual dimorphism could bring tight to this important clinical finding. Some studies have provided evidence of sex differences in the identification of emotional faces, however, results are inconsistent and such inconsistency could be related to the lack of experimental control of the sex hormone status of participants. More recently, a few studies evaluated the modulation of facial emotion recognition by the phase of the menstrual cycle and sex hormones, however, none of them directly compared these results with a group of men. We evaluated the accuracy of facial emotion recognition in 40 healthy volunteers. Eleven women were assigned to early follicular group, nine women to the ovulatory group and 10 women to luteal group, depending on the phase of menstrual cycle, and a group of 10 men were also evaluated. Estrogen, progesterone and testosterone levels were assessed. The performance of the groups in the identification of emotional faces varied depending on the emotion. Early follicular group were more accurate to perceive angry faces than all other groups. Sadness was more accurately recognized by early follicular group than by luteal group and regarding the recognition of fearful faces a trend to a better performance and a significantly higher accuracy was observed, respectively, in the early follicular group and in the ovulatory group, in comparison to men. In women, estrogen negatively correlated to the accuracy in perception of angry mate faces. Our results indicate sex hormones to be implicated in a sexual dimorphism in facial emotion recognition, and highlight the importance of estrogen specifically in the recognition of negative emotions such as sadness, anger and fear. (C) 2009 Elsevier Ltd. All rights reserved.

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Studies on children with cancer have suggested that energy expenditure may indeed be greater than predicted for healthy children. Nutritional assessment is important for intervention and for the prevention of complications associated with malnutrition. The present study aimed to describe the nutritional status, energy expenditure, and substrate utilization of children and adolescents with cancer compared to healthy children matched for age, sex, and body mass index. Subjects were evaluated by anthropometry, food intake pattern, and body composition analysis. Energy expenditure and substrate oxidation were measured by indirect calorimetry. Indirect calorimetry data, energy, and macronutrient intake, anthropometry, and body composition parameters showed no significant differences between groups. There was no evidence of increased energy expenditure or of a change in substrate utilization in children with cancer compared to the healthy group. The data regarding usual food consumption showed no significant differences between groups.

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Urinary bladder cancer is the fourth most common malignancy in the Western world. Transitional cell carcinoma (TCC) is the most common subtype, accounting for about 90% of all bladder cancers. The TP53 gene plays an essential role in the regulation of the cell cycle and apoptosis and therefore contributes to cellular transformation and malignancy; however, little is known about the differential gene expression patterns in human tumors that present with the wild-type or mutated TP53 gene. Therefore, because gene profiling can provide new insights into the molecular biology of bladder cancer, the present study aimed to compare the molecular profiles of bladder cancer cell lines with different TP53 alleles, including the wild type (RT4) and two mutants (5637, with mutations in codons 280 and 72; and T24, a TP53 allele encoding an in-frame deletion of tyrosine 126). Unsupervised hierarchical clustering and gene networks were constructed based on data generated by cDNA microarrays using mRNA from the three cell lines. Differentially expressed genes related to the cell cycle, cell division, cell death, and cell proliferation were observed in the three cell lines. However, the cDNA microarray data did not cluster cell lines based on their TP53 allele. The gene profiles of the RT4 cells were more similar to those of T24 than to those of the 5637 cells. While the deregulation of both the cell cycle and the apoptotic pathways was particularly related to TCC, these alterations were not associated with the TP53 status.

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Nine ruminally cannulated cows fed different energy sources were used to evaluate an avian-derived polyclonal antibody preparation (PAP-MV) against the specific ruminal bacteria Streptococcus bovis, Fusobacterium necrophorum, Clostridium aminophilum, Peptostreptococcus anaerobius, and Clostridium stick-landii and monensin (MON) on ruminal fermentation patterns and in vivo digestibility. The experimental design was three 3 x 3 Latin squares distinguished by the main energy source in the diet [dry-ground corn grain (CG), high-moisture corn silage (HMCS), or citrus pulp (CiPu)]. Inside each Latin square, animals received one of the feed additives per period [none (CON), MON, or PAP-MV]. Dry matter intake and ruminal fermentation variables such as pH, total short-chain fatty acids (tSCFA), which included acetate, propionate, and butyrate, as well as lactic acid and NH(3)-N concentration were analyzed in this trial. Total tract DM apparent digestibility and its fractions were estimated using chromic oxide as an external marker. Each experimental period lasted 21 d. Ruminal fluid sampling was carried out on the last day of the period at 0, 2, 4, 6, 8, 10, and 12 h after the morning meal. Ruminal pH was higher (P = 0.006) 4 h postfeeding in MON and PAP-MV groups when compared with CON. Acetate: propionate ratio was greater in PAP-MV compared with MON across sampling times. Polyclonal antibodies did not alter (P > 0.05) tSCFA, molar proportion of acetate and butyrate, or lactic acid and NH(3)-N concentration. Ruminal pH was higher (P = 0.01), 4 h postfeeding in CiPu diets compared with CG and HMCS. There was no interaction between feed additive and energy source (P > 0.05) for any of the digestibility coefficients analyzed. Starch digestibility was less (P = 0.008) in PAP-MV when compared with CON and MON. In relation to energy sources, NDF digestibility was greater (P = 0.007) in CG and CiPu vs. the HMCS diet. The digestibility of ADF was greater (P = 0.002) in CiPu diets followed by CG and HMCS. Feeding PAP-MV or monensin altered ruminal fermentation patterns and digestive function in cows; however, those changes were independent of the main energy source of the diet.

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High energy intake and excessive body fatness impair mammogenesis in prepubertal ruminants. High energy intake and excessive fatness also increase serum leptin. Our objective was to determine if an infusion of leptin decreases proliferation of mammary epithelial cells of prepubertal heifers in vivo. Ovine leptin at 100 mu g/quarter per d with or without 10 mu g of insulin-like growth factor (IGF)-I was infused via the teat canal into mammary glands of prepubertal dairy heifers; contralateral quarters were used as controls. After 7 d of treatment, bromodeoxyuridine was infused intravenously and heifers were slaughtered similar to 2 h later. Tissue from 3 regions of the mammary parenchyma was collected and immunostained for bromodeoxyuridine (BrdU), proliferating cell nuclear antigen (Ki-67), and caspase-3. Leptin decreased the number of mammary epithelial cells in the S-phase of the cell cycle by 48% in IGF-I-treated quarters and by 19% in saline-treated quarters. Leptin did not alter the number of mammary epithelial cells within the cell cycle, as indicated by Ki-67 labeling. Caspase-3 immunostaining within the mammary parenchyma was very low in these heifers, but leptin significantly increased labeling in saline-treated quarters. Leptin enhanced SOCS-3 expression in IGF-I-treated quarters but did not alter SOCS-1 or SOCS-5 expression. We conclude that a high concentration of leptin in the bovine mammary gland reduces proliferation of mammary epithelial cells. The reduced proliferation is accompanied by an increase in SOCS-3 expression, suggesting a possible mechanism for leptin inhibition of IGF-I action. Whether leptin might be a physiological regulator of mammogenesis remains to be determined.

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Recently we conducted the molecular characterization of Rangelia vitalii, a protozoan with high pathogenicity for young dogs in southern Brazil. To date, the descriptions of the disease have been restricted to natural infection cases. Therefore, this study aimed to evaluate the parasitemia, biological cycles and clinical-pathological findings in dogs experimentally infected with R. vitalii in the acute phase of disease, and also aimed to test a therapeutic protocol based on the diminazene aceturate. For this study, we used 12 young dogs (females), separated into two groups. Group A was composed of healthy dogs, not-infected (n = 5), and Group B consisted of animals infected with R. vitalii (n = 7). After infection, the animals were monitored by blood smear examinations, which showed intra-erythrocytic forms of the parasite 5 days post-infection (PI). Parasitemia increased progressively in these animals and had the highest peak of circulating parasites between 9 and 11 days PI. Subsequently, the parasitemia reduced and the protozoan was seen inside the leukocytes in days 17, 19 and 21 PI. The most prominent clinical signs observed at the 20 day PI of experiment were lethargy, fever and anorexia. We observed a decrease of hematocrit of infected animals compared with not-infected dogs, featuring a moderate anemia. Pathological evaluation of one dog in Group B at day 21 PI revealed splenomegaly, hepatomegaly, lymphadenopathy, and hemorrhages at necropsy. Histological examination showed only follicular hyperplasia in the spleen and lymph nodes, and the etiologic agent in the vascular endothelium. At 21 days PI, it was performed the treatment of dogs in Group B (n = 6) with a single dose of diminazene aceturate, which showed a curative efficacy of 100% in cleaning R. vitalii from blood of infected dogs. (C) 2011 Elsevier Inc. All rights reserved.

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The life cycle of Ixodes luciae was evaluated for five consecutive generations in the laboratory. Wild mice Calomys callosus and laboratory rats Rattus norvegicus were used as hosts for larvae and nymphs. For adult ticks, opossums Didelphis aurita were used as hosts. Off-host developmental periods were observed in an incubator at 27A degrees C and 95% RH. The life cycle of I. luciae lasted 95-97 days, excluding prefeeding periods. C. callosus, one of the natural host species for I. luciae immature stages, was shown to be much more suitable than the artificial host R. norvegicus. Significantly (P < 0.05), more larvae and nymphs successfully fed on C. callosus than on R. norvegicus. When tick-na < ve C. callosus were exposed to three consecutive larval infestations at 24-day intervals, recovery of engorged larvae were greater in the second and third infestations, indicating that previous infestations did not induce acquired resistance to ticks. Larval feeding period typically varied from 5 to 10 days on R. norvegicus, but was significantly (P < 0.05), longer on C. callosus (range, 7-34 days). The majority (71.7%) of I. luciae adult females successfully fed and oviposited after exposed to D. aurita. Mean engorged weight (581.9 mg; range, 237.1-796.0 mg) of these females were much higher than those previously reported for other New World Ixodes species. Our results are in accordance to the current literature that appoints opossums Didelphidae and small rodents (e.g., C. callosus) natural hosts for I. luciae immature and adult stages, respectively.

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In this paper, we consider solutions to the three-dimensional Schrodinger equation of the form psi(r) = u(r)/r, where u(0) not equal 0. The expectation value of the kinetic energy operator for such wavefunctions diverges. We show that it is possible to introduce a potential energy with an expectation value that also diverges, exactly cancelling the kinetic energy divergence. This renormalization procedure produces a self-adjoint Hamiltonian. We solve some problems with this new Hamiltonian to illustrate its usefulness.

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Amblyomma incisum Neumann is a major tick species in the Atlantic Forest of Brazil. Tapir is the main host for adult ticks and a high aggressiveness of nymphs to humans has been reported. In this work data on the biology and life cycle of this tick species is presented for the first time. It was shown that horse is a suitable host for A. incisum adults and rabbit for larvae and nymphs. It was also shown that A. incisum is a big tick species (mean engorged female weight of 1.96 g) with a long life cycle which lasts 262.3 days when maintained at 27A degrees C and 85% RH. These laboratory conditions were, however, inappropriate and egg hatching rate (1.2%) was very low. Nevertheless egg hatching of ticks in a forest patch increased considerably (72.2%) indicating that this A. incisum population is highly dependent on a forest-like environment.

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Nuclear transfer of domestic cat can be used as a tool to develop reproductive biotechnologies in wild felids. The importance of cell cycle phase during the nuclear transfer has been a matter of debate since the first mammalian clone was produced. The cell cycle phase of donor cells interferes on maintenance of correct ploidy and genetic reprogramming of the reconstructed embryo. The use of G0/G1 arrested donor cells has been shown to improve nuclear transfer efficiency. The present study was conducted to test the hypothesis that domestic cat foetal fibroblasts cultured up to the fifth passage and submitted to full confluency provide a higher percentage of cells at G0/G1 stage than fibroblasts cultured in serum starved media. Results demonstrated that serum starvation increased (p < 0.05) the percentage of G0/G1 fibroblasts when compared with control. Moreover, the combined protocol using confluency and serum starvation was more efficient (p < 0.05) synchronizing cells at G0/G1 stage than serum starvation or confluency alone for the first 3 days of treatment. In conclusion, serum starvation and full confluency act in a synergistic manner to improve domestic cat foetal fibroblast cell cycle synchronization at the G0/G1 stage.

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The aim of this research was to analyze oestrogen receptor-alpha (ER alpha), ER beta and progesterone receptor (PR) gene expression in the canine oocyte and cumulus cells throughout the oestrous cycle. Ovaries from 38 bitches were recovered after ovariohysterectomy and sliced. The phase of the oestrous cycle was determined by vaginal cytology, vaginoscopy and serum hormonal measurements. Oocytes were mechanically denuded by repeated pipetting. For each phase of the cycle, a sample was composed by a pool of 50 oocytes (sample number: prooestrus = 3, oestrus = 8, dioestrus = 5 and anoestrus = 5) or a pool of cumulus cells (prooestrus = 4, oestrus = 7, dioestrus = 4 and anoestrus = 6). Oocyte and cumulus cells` total RNA was isolated and reverse transcription was conducted to perform real-time PCR. Oestrogen receptor-alpha was expressed throughout the cycle in the oocyte (33.33%, 25.0%, 20.0% and 60.0% for prooestrus, oestrus, dioestrus and anoestrus, respectively) and cumulus cells (50.0%, 47.14%, 25.0% and 66.67% for prooestrus, oestrus, dioestrus and anoestrus, respectively). In the oocyte, the ER beta was also expressed in all phases of the cycle (33.33%, 50.0%, 20.0% and 60.0% for prooestrus, oestrus, dioestrus and anoestrus, respectively), whereas in cumulus cells, ER beta was only expressed during prooestrus (50%) and oestrus (14.29%). Interestingly, while the oocyte PR was not detected in any phase of the cycle, this receptor was expressed during prooestrus (50%), oestrus (42.86%) and anoestrus (16.67%) in cumulus cells. In conclusion, canine oocytes express ER alpha and ER beta throughout the oestrous cycle, however, there is a lack of PR expression in all these phases. Moreover, in cumulus cells, only ER alpha was expressed throughout the oestrous cycle.

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The Santa Ines, a Brazilian hair sheep, has a non-seasonal breeding activity. Data regarding the duration of the postpartum anestrous period in Santa Ines lactating ewes is lacking and the objective of this trial was to determine the effects of replacing neutral detergent fibre (NDF) provided by coastcross (Cynodon sp.) hay with NDF contained in soybean hulls (SH) on the postpartum ovarian activity-as measured by the serum progesterone (P(4)) concentration. Fifty-six lactating ewes (body weight 56.1 +/- 6.8 kg) were individually penned and used in a randomized complete block design with 14 blocks and four treatments. The SH NDF replaced 33 (SH33), 67 (SH67), or 100% (SH100) of the NDF contributed by coastcross hay in the control diet (SHO). This resulted in a SH inclusion at rates of 0, 25, 54, and 85% of the dietary dry matter (DM). Blood samples were collected twice weekly from the 14th to 84th day postpartum and the serum P(4) concentrations determined by radioimmunoassay (RIA). It was estimated that the 1st postpartum ovulation occurred 6 days before the date that a serum P(4) >= 1 ng/ml concentration was first recorded. The mean body condition score (BCS; 0-5 scale) was 3.0 +/- 0.19 on day 14 postpartum and the mean BCS at day 56 postpartum increased linearly (P<0.01) with the inclusion levels of SH (3.09, 3.24, 3.34, and 3.36, respectively). Treatments did not differ significantly in the induction of postpartum days to the resumption of ovarian luteal activity (34.1 +/- 15.3 days postpartum). On days 25, 50, and 75 postpartum 36.80, and 100% of the ewes had resumed ovarian activity, respectively. Nonesterified fatty acid concentration decreased quadratically (P<0.05) with the SH inclusion, with values of 0.323, 0.244, 0.204, and 0.216 mequiv./l for the SHO, SH33, SH67, and SH100 treatments being recorded, respectively. Replacement of the NDF provided by coastcross hay with the NDF from the SH did not influence the duration of the postpartum anestrous period in Santa Ines lactating ewes. Considering a 150-day gestation period and the 34 days postpartum anestrous demonstrated in the present study, the current production system of a lambing interval of 8 months (3 lambing events in 2 years) may not be optimizing the production potential and a system in which the lambing interval is shortened by at least 1 month may be feasible. (C) 2008 Elsevier B.V. All rights reserved.

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A better understanding of a species` reproductive physiology can help conservation programs to manage primates in the wild and develop assisted reproductive technologies in captivity. We investigated whether measurements of fecal progestin and estrogen metabolites obtained by a radioimmunoassay could be used to monitor the ovarian cycle of Alouatta caraya. We also compared the occurrence of vaginal bleeding with the hormone profiles. We collected fecal samples from 3 adult and 1 subadult captive female over 5 mo and performed vaginal cytology for the adults. The interval between fecal progestin surges in the adult females was 19.11 +/- 2.14 d (n = 18 cycles). Fecal progestin concentrations remained at basal values for 9.83 +/- 2.21 d (n = 18) and rose to elevated values for 9.47 +/- 0.72 d (n = 19). The subadult female showed basal levels of fecal estrogen and progestin concentrations throughout the study, suggesting that our hormone measurements are valid to monitor the ovarian cycle. Bleeding periods coincided with basal levels of fecal estrogens and progestin at intervals of 19.8 +/- 0.9 d and lasted for 4.1 +/- 1.0 d. Although we obtained these data from only 3 individuals, the results indicate that this species likely has a menstrual-type ovarian cycle. These data provide the first endocrine profile for the Alouatta caraya ovarian cycle and are similar to results obtained for other howler species. This similarity is important for comparative studies of howlers, allowing for a better understanding of their reproductive physiology and contributing to a critical information base for managing Alouatta species.

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The bovine maternal epithelium is composed of cuboidal cells interspersed with low columnar cells having centrally located nuclei. Bovine trophoblast is composed of two cell types: mononuclear trophoblastic and giant trophoblastic cells that can have two or more nuclei. Number of apoptotic cells and proliferative cells are variable in both cell populations. This study compared tissue growth and apoptosis by flow cytometry in the cell population found at distinct placental regions (central region of placentomes, <= 1-cm microplacentomes and the interplacentomal region) between normal and cloned near-term bovine pregnancies. After a morphological comparison between regions and groups (controls vs. clones), a lesser proportion of diploid to tetraploid cells was observed in the central region of placentomes and in microplacentomes from cloned-derived pregnancies. In addition, cloned animals had a fewer apoptotic cells in the central region of the placentome and in interplacentomal region and a greater proliferative capacity in all regions (cells in G(2)/M) near term as opposed to control animals. These results may reveal the existence of a relationship between such changes in the proportions of uterine and trophoblastic epithelial cells at the end of pregnancy and normal placental function. This could be related to faulty placentation in early pregnancy, placental insufficiency during pregnancy or lack of placental and/or fetal maturation in late pregnancy, which may contribute to someof the abnormalities after in vitro embryo manipulations, such as poor preparation and initiation of parturition, prolonged gestation and lesser post-natal survival in some cloned animals. (C) 2008 Elsevier B.V. All rights reserved.

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Objective. This study evaluated the degree of conversion (DC), maximum rate of cure (R(p)(max)), and polymerization stress (PS) developed by an experimental dental composite subjected to different irradiant energies (3,6,12, 24, or 48J/cm(2)) under constant irradiance (500 mw/cm(2)). Methods. DC and R(p)(max) were monitored for 10 min on the bottom surface of 2-mm thick disks and on 150-mu m thick films (representing the top of the specimen) using ATR-FTIR. PS was monitored for 10 min in 2-mm thick disks bonded to two glass rods (O = 5 mm) attached to a universal testing machine. One-way ANOVA/Tukey tests were used and differences in DC and R(p)(max) between top and bottom surfaces were examined using Student`s t-test. Statistical testing was performed at a pre-set alpha of 0.05. Results. For a given surface, DC showed differences among all groups, except at the top between 24 and 48 J/cm(2). R(p)(max) was similar among all groups at the same surface and statistically higher at the top surface. PS also showed significant differences among all groups. Data for 48 J/cm(2) were not obtained due to specimen failure at the glass/composite interface. Significance. Increases in irradiant exposure led to significant increases in DC and PS, but had no effect on R(p)(max) (c) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.