964 resultados para Short circuit in stator
Resumo:
BACKGROUND: Comparative genomic hybridization (CGH) is a valuable alternative to fluorescence in situ hybridization (FISH) for preimplantation genetic screening (PGS) because it allows full karyotype analysis. However, this approach requires the cryopreservation of biopsied embryos until results are available. The aim of this study is to reduce the hybridization period of CGH, in order to make this short-CGH technique suitable for PGS of Day-3 embryos, avoiding the cryopreservation step. METHODS: Thirty-two fibroblasts from six aneuploid cell lines (Coriell) and 48 blastomeres from 10 Day-4 embryos, discarded after PGS by FISH with 9 probes (9-chr-FISH), were analysed by short-CGH. A reanalysis by the standard 72 h-CGH and FISH using telomeric probes was performed when no concordant results between short-CGH and FISH diagnosis were observed. The short-CGH was subsequently applied in a clinical case of advanced maternal age. RESULTS: In 100% of the fibroblasts analysed, the characteristic aneuploidies of each cell line were detected by short-CGH. The results of the 48 blastomeres screened by short-CGH were supported by both 72 h-CGH results and FISH reanalysis. The chromosomes most frequently involved in aneuploidy were 22 and 16, but aneuploidies for the other chromosomes, excepting 1, 10 and 13, were also detected. Forty-one of the 94 aneuploid events observed (43.6%) corresponded to chromosomes which are not analysed by 9-chr-FISH. CONCLUSIONS: We have performed a preliminary validation of the short-CGH technique, including one clinical case, suggesting this approach may be applied to Day-3 aneuploidy analysis, thereby avoiding embryo cryopreservation and perhaps helping to improve implantation rate after PGS.
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Background. Hydroxyethylstarch (HES) is a synthetic polymer of glucose that has been suggested for therapeutic use in long-term plasma expansion. The aim of this study was to test the hypothesis that the infusion of a small volume of HES may provide benefits in systemic and regional hemodynamics and metabolism in a brain-dead canine model compared with large volume crystalloid resuscitation. Methods. Fourteen mongrel dogs were subjected to a brain-death protocol by consecutive insufflations of a balloon catheter in the epidural space. One hour after induction of brain-death, the animals were randomly assigned to two groups: NS (0.9% NaCl, 33mL/kg), and HES (6% HES 450/0.7, 17mL/Kg). Systemic and regional hemodynamics were evaluated using Swan-Ganz, ultrasonic flowprobes, and arterial catheters. Serial blood samples were collected for blood gas, electrolyte, and serum chemistry analysis. Systemic, hepatic, and splanchnic O(2)-derived variables were also calculated. Results. Epidural balloon insufflations induced a significant increase in mean arterial pressure, cardiac output (MAP and CO, respectively), regional blood flow, and systemic vascular resistance. Following the hyperdynamic phase, severe hypotension with normalization of systemic and regional blood flow was observed. Fluid resuscitation induced a prompt increase in MAP, CO, and portal vein blood flow, and a significant reduction in systemic and pulmonary vascular resistance. There were no differences between groups in metabolic indices, liver function tests (LFTs), or renal function tests. HES was more effective than NS in restoring cardiac performance in the first 2h after fluid resuscitation (P < 0.05). Both tested solutions partially and temporarily restored systemic and regional oxygen delivery. Conclusion. Small volumes of 6% HES 450/0.7 improved cardiovascular performance and provided the same regional hemodynamic and metabolic benefits of large volumes of isotonic crystalloid solutions. (C) 2011 Elsevier Inc. All rights reserved.
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The objective of this study was to evaluate duodenocecostomy in horses performed through a ventral midline laparotomy and report its influence oil body weight, glucose absorption, serum components, and characteristics of jejunum, cecum, and large colon histology. Four horses were submitted to the duodenocecostomy technique through a ventral midline laparotomy with animals in dorsal recumbency under inhalation anesthesia, followed by abdominal exploration. A side-to-side anastomosis was performed between the duodenojejunal flexure and the base of the cecum with two simple continuous suture lines of the serosal and muscular layers. The size of the opening created was approximately 2 cm in diameter. The mucosa layer was not Sutured. After 30 days, animals were submitted to a second laparotomy to check the patency of the duodenocaecal fistula. During both laparotomy procedures, excisional biopsies of different segments of the gastrointestinal tract were performed. Information on physical examination findings, results of hematologic and histopathologic evaluations, and oral glucose absorption test were recorded. The horses did not have significant weight loss from baseline, and absorption curve of glucose did not significantly vary from baseline. Only triglycerides had significant alterations. Histologic evaluation of jejunum, cecum, and large colon did not show alterations of intestinal structure and morphology. We concluded that the proposed technique, principally in relation to the fistula size and not suturing the mucosa layer, allowed partial or total Occlusion of the fistulae without the necessity of a second surgery and avoided the permanent bypass of ingesta and weight loss.
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Subclinical mastitis is a common and easily disseminated disease in dairy herds. Its routine diagnosis via bacterial culture and biochemical identification is a difficult and time-consuming process. In this work, we show that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows bacterial identification with high confidence and speed (1 d for bacterial growth and analysis). With the use of MALDI-TOF MS, 33 bacterial culture isolates from milk of different dairy cows from several farms were analyzed, and the results were compared with those obtained by classical biochemical methods. This proof-of-concept case demonstrates the reliability of MALDI-TOF MS bacterial identification, and its increased selectivity as illustrated by the additional identification of coagulase-negative Staphylococcus species and mixed bacterial cultures. Matrix-assisted laser desorption-ionization mass spectrometry considerably accelerates the diagnosis of mastitis pathogens, especially in cases of subclinical mastitis. More immediate and efficient animal management strategies for mastitis and milk quality control in the dairy industry can therefore be applied.
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Cows fed high-protein diets may have impaired reproductive performance. Although the pathogenesis has not been completely elucidated, it appears that not only the uterus, but also the follicle and oocyte, are affected by excessive plasma urea nitrogen (PUN) concentrations. Thus, the objective was to determine the effects of short-term urea feeding on the competence of bovine oocytes. Forty crossbred heifers (Bos indicus vs Bos taurus) were allocated to two groups, namely CONTROL (maintenance diet) and UREA (maintenance diet supplemented with 75 g of urea/day), following a cross-over design. Heifers received their respective diets for 6 d (without adaptation). On the sixth day, blood samples were harvested both before and 3 h after feeding, and cumulus oocyte complexes (COCs) were collected by ovum pick-up. Although PUN concentrations were higher in UREA than CONTROL heifers (31.31 mg/dL +/- 1.13 vs 22.12 mg/dL +/- 0.86; mean +/- SEM), neither the number of COCs recovered (8.8 +/- 1.0 vs 9.2 +/- 0.8, UREA vs CONTROL, respectively) nor their quality (based on morphology) differed significantly between groups. Next, oocytes were fertilized and cultured in vitro to assess developmental rates. There was an absence of significant differences between groups for rates of cleavage (Day 3) or blastocyst formation (Days 6, 7 and 9), but the hatched blastocyst rate on Day 11 after fertilization was lower (P < 0.05) in the UREA than the CONTROL groups (64.3 vs 83.5%). Therefore, we inferred that the effects of urea were only manifest later in development. In conclusion, high PUN concentrations decreased oocyte competence in heifers, reinforcing the hypothesis that poor reproductive performance in cows with high PUN was due, at least in part, to a deleterious effect on oocytes. (C) 2011 Elsevier Inc. All rights reserved.
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The majority of small-cell lung cancers (SCLCs) express p16 but not pRb, Given our previous study showing loss of pRb in Merkel cell carcinoma (MCC)/neuroendocrine carcinoma of the skin and the clinicopathological similarities between SCLC acid MCC, we wished to determine if this was also the case in MCC, Twenty-nine MCC specimens from 23 patients were examined for deletions at 10 loci on 9p and I on 9p. No loss of heterozygosity (LO H) was peen in 9 patients including 2 for which tumour and cell line DNAs were examined. Four patients had LOH for all informative loci on 9p, Ten tumours showed more limited regions of loss on 9p, and from these 2 common regions of deletion were determined, Half of all informative cases had LOH at D95168, the most telomeric marker examined, and 3 specimens showed loss of only D9S168, A second region (InFNA-D9S126) showed L0H in 10(44%) cases, and case MCC26 showed LOH for only D9S126, implicating genes centromeric of the CDKN2A locus. No mutations in the coding regions of p16 were seen in 7 cell lines tested, and reactivity to anti-p16 antibody was seen in all Il tumour specimens examined and in 6 of 7 cell lines from 6 patients. Furthermore, all cell lines examined reacted with anti-p 14' antibody, These results suggest that neither transcript of the CDKN2A locus is the target of deletions on 9p in MCC and imply the existence of tumour-suppressor genes mapping both centromeric and telomeric of this locus. (C) 2001 Wiley-Liss, Inc.
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Non-steroidal anti-inflammatory drugs (NSAIDs) have been used for pain relief in orthodontics, but clinical studies reported that they may reduce tooth movement (TM). By other side, TM seems to activate brain structures related to nociception, but the effects of NSAIDs in this activation have not been studied yet. We analyzed the effect of short-term treatment with acetaminophen or celecoxib in the separation of rat upper incisors, as well as in neuronal activation of the spinal trigeminal nucleus, following tooth movement. Thirty rats (400-420 g) were pretreated through oral gavage (1 ml/dose)with acetaminophen (200 mg/kg), celecoxib (50 mg/kg) or vehicle (carboxymethylcellulose 0.4%). After 30 min, they received an activated (30 g) orthodontic appliance for TM. In controls, this appliance was immediately removed after its introduction. Rats received ground food, and every 12 h, one of the drugs or vehicle. After 48 h, they were anesthetized, maxilla was radiographed, and were perfused with 4% paraformaldehyde. Brains were further processed for Fos immunohistochemistry. TM induced incisor distalization (p < 0.05) and neuronal activation of the spinal trigeminal nucleus. Treatment with both drugs did not affect tooth movement, but reduced c-fos expression in the caudalis subnucleus. No changes in c-fos expression were seen in the oralis and interpolaris subnuclei. We conclude that neither celecoxib nor acetaminophen seems to affect tooth movement, when used for 2 days, but both drugs are able to reduce the activation of brain structures related to nociception. Short-term treatment with celecoxib, thus, may be a therapeutic alternative to acetaminophen when the latter is contra indicated. (C) 2009 Elsevier Inc. All rights reserved.
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Previous genetic analyses of psychosis proneness have been limited by their small sample size. For the purposes of large-scale screening, a 12-item questionnaire was developed through a two-stage process of reduction from the full Chapman and Chapman scales. 3685 individuals (including 1438 complete twin pairs) aged 18–25 years and enrolled in the volunteer Australian Twin Registry returned a mail questionnaire which included this psychosis proneness scale and the Eysenck Personality Questionnaire. Despite the brevity of the questionnaire, item and factor analysis identified four unambiguous and essentially uncorrelated scales. There were (1) Perceptual Aberration – Magical Ideation; (2) Hypomania – Impulsivity/Nonconformity; (3) Social Anhedonia and (4) Physical Anhedonia. Model-fitting analyses showed additive genetic and specific environmental factors were sufficient for three of the four scales, with the Social Anhedonia scale requiring also a parameter for genetic dominance. There was no evidence for the previously hypothesised sex differences in the genetic determination of psychosis-proneness. The potential value of multivariate genetic analysis to examine the relationship between these four scales and dimensions of personality is discussed. The growing body of longitudinal evidence on psychosis-proneness suggests the value of incorporating this brief measure into developmental twin studies.
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Shiftwork is a major source of stress for many worker's. This study highlights the role that organizational and psychosocial variables play in alleviating the negative health effects of 10 and 14-h shifts. It examines the direct and mediated effects of coping strategies, social support and control of shifts on work/non-work conflict and subjective health. Participants are 60 ambulance workers, aged 22 to SS years. A structural equation model with good fit demonstrates complex effects of social support from various sources (supervisors, co-workers and family), coping and control on work/non-work conflict and subjective health., Conceptually, the research contributes to the development of a theoretical framework that can assist in explaining how key psychosocial and organizational variables influence the psychological and physical symptoms experienced by shiftworkers. Copyright (C) 2002 John Wiley Sons, Ltd.
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The efficacy of chloroquine treatment of uncomplicated Plasmodium falciparum malaria in East Timor was investigated via molecular tools. Genotyping of the polymorphic markers msp1 and msp2 was performed to investigate the number and type of parasite alleles in pre- and posttreatment blood samples collected from 48 patients. Patients were infected with a minimum of 8 msp1 and 14 msp2 allelic types of parasite, and 43% of the patients had more than one allelic type before treatment. The genotyping also revealed that 66.7% of the patients were infected with at least one identical allelic type of parasite before and after treatment and therefore were likely to have experienced recrudescence. All parasites in pre- and posttreatment blood samples carried the K76T mutation in pfcrt, regardless of the clinical response to chloroquine. The sequence polymorphism patterns in pfcrt in the majority of parasites examined were identical to those observed in Bougainville, Papua New Guinea.
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Distinct Echinococcus granulosus life cycle patterns have been described in North America: domestic and sylvatic. Gene sequences of the sylvatic E. granulosus indicate that it represents a separate variant. Case-based data have suggested that the course of sylvatic disease is less severe than that of domestic disease. which led to the recommendation to treat cystic echinococcosis patients in the Arctic by careful medical management rather than by aggressive surgery. We recently reported the first two documented E. granalosus human cases in Alaska with accompanying severe sequelae. Here we describe the results of molecular genetic analysis of the cyst material of one of the subjects that supported identification of the parasite as the sylvatic (cervid) strain and not the domestic (common sheep strain), which was initially thought to be implicated in these unusually severe Alaskan cases.
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This paper examines the statistical and economic significance of short-term autocorrelation in Australian equities. We document large negative first-order autocorrelation in individual stock returns. Preliminary results suggest this autocorrelation is economically significant, as two simple trading strategies based on the autocorrelation structure appear to yield large risk-adjusted returns. Further analysis, however, shows that these results are driven by the inclusion of small-capitalisation and low-priced stocks which are vulnerable to a number of market-microstructure-related problems. After revising the dataset to mitigate these problems, little evidence of economic significance remains.
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This study aimed to analyze the economic viability of the third milking in production systems using mechanical milking in a closed circuit, aiming to provide technicians and farmers with information to assist them in decision-making. Specifically, it intended: (a) to estimate the cost of one milking; (b) to estimate the cost of the third milking; (c) to develop a mathematical equation to estimate the minimum amount of milk produced with two milkings, from which it would be economically feasible to do the third milking. Data were collected from three dairy farms, from November 2010 to March 2011, keeping a twice-a-day milking frequency, with three data collections in each farm, totalizing nine collections. Considering the average data, it would be feasible to do the third milking if the average milk yield per day of lactating cows in a twice-a-day milking frequency was greater than or equal to 24.43 kg of milk.
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The increased integration of wind power into the electric grid, as nowadays occurs in Portugal, poses new challenges due to its intermittency and volatility. Wind power prediction plays a key role in tackling these challenges. The contribution of this paper is to propose a new hybrid approach, combining particle swarm optimization and adaptive-network-based fuzzy inference system, for short-term wind power prediction in Portugal. Significant improvements regarding forecasting accuracy are attainable using the proposed approach, in comparison with the results obtained with five other approaches.
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This paper presents an artificial neural network approach for short-term wind power forecasting in Portugal. The increased integration of wind power into the electric grid, as nowadays occurs in Portugal, poses new challenges due to its intermittency and volatility. Hence, good forecasting tools play a key role in tackling these challenges. The accuracy of the wind power forecasting attained with the proposed approach is evaluated against persistence and ARIMA approaches, reporting the numerical results from a real-world case study.