Resumo: Em razão de, em estudos que analisam a relação remodelação cardíaca e estenose aórtica supravalvar: ser importante a detecção precoce da disfunção ventricular; o método hemodinâmico ser ideal para detecção da disfunção, porém inadequado para estudos seqüenciais; a taquipnéia manifestar-se, geralmente, quando há deterioração cardíaca grave e não estar estabelecida a relação entre a capacidade funcional e a função ventricular, torna-se necessário identificar se o(s) primeiro(s) sinal(is) de intolerância ao esforço físico está(ão) relacionado(s) a disfunção ventricular. Assim, este trabalho tem como objetivos avaliar em diferentes períodos, 3, 6, 12 e 18 semanas, após indução de estenose aórtica supravalvar em ratos a: 1) função do ventrículo esquerdo em repouso e as alterações morfológicas cardíacas por meio do ecocardiograma; 2) tolerância ao esforço físico, em teste incremental em esteira; 3) relação entre a tolerância ao esforço físico e a função cardíaca determinada em repouso. Foram utilizados 37 ratos Wistar, jovens, machos divididos em dois grupos: controle operado (GC, n=13) e estenose aórtica supravalvar (GEAo, n=24). O GEAo foi submetido a cirurgia com implantação de um clipe na artéria aorta para a indução da estenose aórtica supravalvar. O GC foi submetido à mesma cirurgia, porém sem a implantação do clipe. Os animais foram mantidos com água e ração e ad libitum, em ambiente com temperatura controlada a 23°C e ciclo de luz invertido. Todos os procedimentos foram realizados no ciclo escuro, com o auxílio de iluminação fluorescente vermelha, cuja emissão de onda, por ser longa, não é percebida pelos animais. Dos 24 ratos do grupo estenose aórtica (GEAo), 10 morreram e dois apresentaram sinais de insuficiência cardíaca ao final do experimento, taquipnéia associada a derrame pleural... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Considering that, in studies analyzing the relationship between cardiac remodeling and supravalvar aortic stenosis, the early detection of ventricular dysfunction is important, the hemodynamic method is ideal to detect such dysfunction although it is inadequate for sequential studies, tachypnea is generally manifested when severe cardiac deterioration exists and that the relationship between functional capacity and ventricular function has not been established, it is necessary to identify whether the first sign(s) of exercise intolerance is(are) related to ventricular dysfunction. Hence, this study aimed at evaluating, in different periods - 3, 6, 12 and 18 weeks - after the induction of supravalvar aortic stenosis in rats, the following aspects: 1) function of the left ventricle at rest and cardiac morphological alterations by means of an echocardiogram; 2) exercise tolerance during an incremental test on a treadmill; 3) relationship between exercise tolerance and cardiac function determined at rest. Thirty-seven young male Wistar rats were used. The animals were separated into two groups: operated control (CG, n=13) and supravalvar aortic stenosis (GEAo, n=24). GEAo was submitted to surgery with the implantation of a clip on the aorta artery for induction of supravalvar aortic stenosis. GC was submitted to the same type of surgery although without clip implantation. The animals were given water and chow ad libitum and maintained in a controlledtemperature environment at 23°C and an inverted light-dark cycle. All the procedures were performed in the dark cycle by using red fluorescent illumination, whose long wave emission is not perceived by the animals. Of the 24 rats in the GEAo ten died and two presented signs of cardiac insufficiency at the end of the experiment, tachypnea associated with pleural stroke, thrombus in the left atrium and hypertrophia in the right ventricle, thus... (Complete abstract click electronic access below) / Orientador: Antônio Carlos Cicogna / Coorientador: Katashi Okoshi / Banca: Leonardo Antonio Mamede Zornoff / Banca: Vilmar Baldissera / Mestre

The demands of future computing, as well as the challenges of nanometer-era VLSI design, will require new design techniques and design styles that are simultaneously high performance, energy-efficient, and robust to noise and process variation. One of the emerging problems concerns the communication mechanisms between the increasing number of blocks, or cores, that can be integrated onto a single chip. The bus-based systems and point-to-point interconnection strategies in use today cannot be easily scaled to accommodate the large numbers of cores projected in the near future. Network-on-chip (NoC) interconnect infrastructures are one of the key technologies that will enable the emergence of many-core processors and systems-on-chip with increased computing power and energy efficiency. This dissertation is focused on testing, yield improvement and fault-tolerance of such NoC infrastructures. A fast, efficient test method is developed for NoCs, that exploits their inherent parallelism to reduce the test time by transporting test data on multiple paths and testing multiple NoC components concurrently. The improvement of test time varies, depending on the NoC architecture and test transport protocol, from 2X to 34X, compared to current NoC test methods. This test mechanism is used subsequently to perform detection of NoC link permanent faults, which are then repaired by an on-chip mechanism that replaces the faulty signal lines with fault-free ones, thereby increasing the yield, while maintaining the same wire delay characteristics. The solution described in this dissertation improves significantly the achievable yield of NoC inter-switch channels â from 4% improvement for an 8-bit wide channel, to a 71% improvement for a 128-bit wide channel. The direct benefit is an improved fault-tolerance and increased yield and long-term reliability of NoC based multicore systems. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

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A field study was conducted at ARC - Grain Crops Institute, Potchefstroom Experimental Farm and at Taung Crop Production Center during 2006/07 summer growing season. Twenty sorghum genotypes were planted in two separate blocks, under full irrigation and rain fed conditions with plot size of 4 rows x 5 m x 0.9 m giving a density of 55 555 plants ha-1. The experiment was laid out in a randomised complete block design replicated three times. The irrigated block received scheduled irrigation from planting until maturity, while the rain fed block received irrigation prior to germination only. Agronomic traits measured were plant height, stem diameter, biomass, flowering date, panicle exertion, panicle length, leaf area, grain yield, and thousand seed mass at Potchefstroom and Taung experiments. Drought susceptibility index (DSI) was quantified using the formula: DSI = [1 - (Ydi/ Ypi)]/ [1 - (YD/YP)] and %yield reduction (%YR) was calculated using the formula: %YR = (Ypi –Ydi)/ Ypi x 100. Significant variations among genotypes with regard to grain yield (GYLD), plant height (PH), panicle length (PL), biomass (BM), stem diameter (SD), panicle exertion (PEx), and 1000 seed mass (TSM) were observed at Potchefstroom under rain fed conditions, while under irrigated conditions significant variations were only observed for GYLD, PH, PL, BM, days to 50% flowering (DF), SD, leaf area (LA), PEx and TSM. At Potchefstroom genotypes varied significantly with regard to PH, PL, BM, DF, SD, LA, PEx and TSM under rain fed conditions, while under irrigated conditions genotypes varied with all traits measured with exception of harvest index (HI) and relative water content (RWC). At Potchefstroom, soil water deficits significantly affected GYLD, PH, HI, PEx and RWC, while at Potchefstroom soil water deficits significantly affected GYLD, PH, SD, LA, PEx, TSM and RWC. Genotypes varied with their level of resistance/ susceptibility to soil water deficits at both Potchefstroom and Taung. Some remarkable correlations among traits measured were observed under rain fed and irrigated conditions and across the treatments at both Potchefstroom and Taung. At Potchefstroom, significant correlation was only observed between drought susceptibility index (DSI) and PH under rain fed conditions, while at Potchefstroom negative and significant correlation was only observed between DSI and GYLD under rain fed conditions. At Potchefstroom, GYLD under rain fed significantly related to GYLD under irrigated conditions and across the treatments. However, GYLD under irrigated conditions significantly related to GYLD across the treatments. At Potchefstroom, GYLD under rain fed conditions significantly correlated with GYLD across soil water regimes, while GYLD under irrigated conditions significantly correlated with GYLD across the treatments. Genotypes that exhibited the combination of high yield potential and resistant traits were recommended. Genotypes that exhibited high resistant traits with low yield potential were recommended for breeders to incorporate those traits into susceptible genotypes with high yield potential. / Dissertation (MInstAgrar)--University of Pretoria, 2010. / Plant Production and Soil Science / unrestricted

Diabetes associated complications make management during exercise complex (Brugnara, Vinaixa, Murillo, Samino, Rodriguez, Beltran, Lerin, Davison, Correig & Novials, 2012). Research on the prevention of such challenges is of paramount importance. The aim of this study was to determine the effects of three different carbohydrate supplementation protocols on blood glucose levels after every 10 minutes of a 60 minute exercise bout at 65 to 75 % HRR on the treadmill as well as every half hour during a two hour post exercise recovery period. The three protocols implemented after a standardized pre-exercise meal were: control protocol (no carbohydrate supplementation), protocol 1 (one carbohydrate supplementation of 15 grams given at 30 minutes) and protocol 2 (two carbohydrate supplementation of 15 grams given at 30 minutes and 45 minutes). A total of 32 participants took part in the study (Mean age: 32.84 ±12.12). All participants were submitted to all three protocols. Statistical and practical significant differences were found between blood glucose levels of protocol 0 and protocol 1 (MDIF = 2.62 ± 3.99 mmol.L--‐1) at 20 minutes of the exercise duration (p=.024;d=0.42). Statistical and practical significant differences in blood glucose levels with protocol 0 rendering the higher glucose values were also found between protocols 0 and 2 at 10 minutes (MDIF = 3.44 ± 5.54 mmol.L--‐1; p=.001;d=0.62), 20 minutes (MDIF = 3.32 ± 5.23 mmol.L--‐1; p=.001;d=0.63) and 30 minutes of exercise (MDIF = 2.81 ± 5.40 mmol.L--‐1; p=.006;d=0.52) as well as between the mean minimum (M0 = 9.49 ± 4.51 mmol.L--‐1 and M2 = 7.28 ± 4.07 mmol.L--‐1; p=.013;d=0.46), mean maximum (M0 = 12.73 ± 5.51 mmol.L--‐1 and M2 = 10.07 ± 4.63 mmol.L--‐1; p=.015;d=0.46) and overall mean (M0 = 9.07 ± 4.88 mmol.L--‐1 and M2 = 8.53 ± 4.25 mmol.L--‐1; p=.011;d=0.48) with protocol 0 rendering the higher glucose values in all these comparisons. It was concluded that carbohydrate supplementation during exercise affects blood glucose levels positively particularly considering the significant difference found between protocol 0 and 2. Whilst protocol 2 also resulted in less fluctuations in the blood glucose levels during exercise and minimum, overall mean and maximum blood glucose values were closer to “normal/safe” range, there was no conclusive evidence that protocol 2 was better than protocol 1.

The development of tolerance to anticonvulsant drug effects has traditionally been studied in terms of pharmacological variables associated with the drug itself ; for example, the dose or the schedule of administration. This type of tolerance is referred to as pharmacologic drug tolerance. In contrast, we have demonstrated that the development of tolerance to ethanol's anticonvulsant effect is contingent upon the adminstration of convulsive stimulation during periods of ethanol exposure; we refer to this as contingent drug tolerance. The purpose of the first two experiments in the present thesis was to extend the phenomenon of contingent tolerance to the anticonvulsant effects of three clinically relevant antiepileptic drugs: carbamazepine (CBZ), diazepam (DZP), and sodium valproate (VPA). In Experiment 1, kindled rats that received an injection of CBZ (70 mg/kg, IP), DZP (2 mg/kg, IP), or VPA (250 mg/kg, IP) 1 hr before each of 10 bidaily (one every 48 hr) convulsive stimulations displayed a significant amount of tolerance to the drugs' anticonvulsant effects on the tolerance test trial ; in contrast, there was no evidence of tolerance in the rats from the three vehicle control groups. In Experiment 2, the development of tolerance to the anticonvulsant effects of CBZ, DZP, and VPA, administered on a bidaily basis, was shown to be contingent upon the administration of convulsive stimulation during the periods of drug exposure. Kindled rats in the three drug-before-stimulation groups rapidly developed tolerance to the anticonvulsant effects of CBZ, DZP, and VPA; in contrast, there was no evidence of tolerance i n the respective drug-afterstimulation groups, despite the fact that they had the same drug history. The purpose of the final three experiments was to compare contingent and pharmacologic tolerance to the anticonvulsant effects of DZP. Experiment 3 replicated earlier demonstrations of pharmacologic tolerance to DZP's anticonvulsant effect; kindled rats that received chronic DZP (2 mg/kg, every 8 hr, for 10 days) developed tolerance to the drug's anticonvulsant effect even though they did not receive convulsive stimulation during the periods of drug exposure. In Experiment 4, the rate of dissipation of pharmacologic and contingent tolerance to DZP's anticonvulsant effect was compared. Pharmacologic tolerance gradually dissipated over the 16-day retention interval ; in contrast, there was no evidence of dissipation of contingent tolerance after 16 days of drug withdrawal. These data suggest that different physiological changes are responsible for pharmacologic and contingent tolerance to DZP's anticonvulsant effect. This conclusion was supported by the results of Experiment 5, in which a single injection of the benzodiazepine receptor antagonist RO 15-1788 24 hr prior to a tolerance-retention test trial significantly reduced the expression of pharmacologic tolerance, but not contingent tolerance, to DZP's anticonvulsant effect. The results of these five experiments make two general points. First, concurrent convulsive stimulation can have an important effect on the development of tolerance to the anticonvulsant effects of antiepileptic drugs. And second, there are significant differences in the physiological changes responsible for the development and the dissipation of contingent and pharmacologic tolerance to DZP's anticonvulsant effect. Because traditional theories do not address these differences, a new model of contingent and pharmacologic tolerance is presented. / Arts, Faculty of / Psychology, Department of / [title page not included] / Graduate

The reniform nematode is a major pest affecting common upland cotton in the United States. Management of this pest in cotton fields only gives partial control and is sometimes neither economical nor profitable. Past research has shown no resistance to the reniform nematode in currently available commercial cotton cultivars. Screenings of several currently available cotton cultivars for tolerance to the reniform nematode were conducted in the growing seasons of 2006 and 2007 at the Delta Branch Experiment Station in Stoneville MS. Several cultivars were identified as tolerant and productive including ‘Croplan Genetics 3520 B2RF,’ ‘DynaGrow 2520 B2RF,’ and ‘Stoneville 5242 BR.’ Other cultivars were tolerant but less productive, including ‘Deltapine 488 BG/RR,’ ‘Fibermax 960 B2R,’ and ‘Stoneville 5599 BR.’ ‘Deltapine 455 BG/RR,’ ‘Phytogen 370,’ and ‘Phytogen 485’ were shown to be productive, but not tolerant to the reniform nematode.

Hemophilia A (HA) is a hemorrhagic disorder caused by a decrease/absence of coagulation Factor VIII (FVIII) in circulation. Management involves administration of FVIII to prevent bleeding episodes. The most serious complication of this replacement therapy is the development of inhibitory anti-FVIII antibodies which neutralize the infused FVIII. Low zone tolerance (LZT) is a state in which the immune system is unresponsive to an antigen induced by repeated prior exposure to low doses of said antigen. Previous animal studies exploring LZT demonstrated successful T-cell tolerance induction by this mechanism. This study investigated whether the administration of low-dose FVIII could induce immune tolerance to FVIII in a HA mouse model. HA mice received intravenous FVIII at doses ranging from 0.01 IU/kg - 5 IU/kg to determine the most promising doses (0.25 IU/kg, 2.5 IU/Kg) to further investigate. Naïve mice were treated with 0.25 IU/kg or 2.5 IU/kg weekly for 6 weeks, then immunized with 25 IU/kg FVIII weekly for 4 weeks. Following a two-week rest period (week 12), all mice received a 25 IU/Kg booster shot. Blood was collected on weeks 7, 11 and 13 and anti-FVIII antibody concentrations were measured by ELISA. Control mice received phosphate buffered saline (PBS) during weeks 1-6 of the experiment, followed by identical immunizations as stated above. Within the 2.5 IU/Kg FVIII treatment group, 11% of the mice developed tolerance to the treatment, indicated by undetectable anti-FVIII IgG titer by ELISA. The remaining 89% of these mice developed high titer antibodies, therefore they were not tolerized to FVIII. In the PBS treatment group, 62% of the mice developed high anti-FVIII antibodies. Conversely, 50% of the mice treated with 0.25 IU/kg were tolerized to FVIII and the remaining mice had significantly reduced antibody titers when compared to the controls. Moreover, upon booster dose injection, 100% of 0.25 IU/kg and 2.5 IU/Kg treated mice that were previously tolerized retained tolerance, suggesting that tolerance through low-dose injections is maintained upon FVIII re-exposure. The LZT experiment conducted here shines light on a new approach to preventing FVIII inhibitors. This study suggests that frequently administering low doses of FVIII effectively induces tolerance to FVIII in HA mice. Moreover, treatment through LZT induction may confer long lasting protection against inhibitor development as indicated by the retention of tolerance in mice subjected to a rest period and post-treatment booster shot. / Thesis / Master of Science (MSc)

According to a conditioning analysis of tolerance, pharmacological conditional responses (CRs) contribute to tolerance. It has previously been reported that, as expected on the basis of this model, tolerance to the hypothermic effect of ethanol is attenuated by "external inhibition," i e., by the presentation of a novel stimulus (a strobe light). However, results of more recent research indicate that novel stimuli augment the hypothermic effect of ethanol in rats receiving the drug for the first time It is possible, therefore, that a novel stimulus apparently attenuates ethanol tolerance because it augments ethanol-hypothermia, rather than because it functions as an external inhibitor. Results presented in this thesis confirm reports that ethanol-induced hypothermia is augmented by a novel stimulus, thus prior demonstrations of external inhibition of ethanol tolerance is equivocal Further experiments in this thesis evaluated external inhibition tolerance to another effect of ethanol — ataxia Although the initial ataxic effect of ethanol (unlike the hypothermic effect) is not enhanced by a novel stimulus (a strobe light/white noise combination), the stimulus reinstated ethanol-induced ataxia in tolerant rats. Tolerance was also disrupted by the novel omission of the strobe/noise stimulus Thus, experiments in this thesis demonstrate external inhibition of ethanol tolerance in a preparation not confounded by the effects of the novel stimulus on initial responding to ethanol. Experiments reported in this thesis also demonstrate that tolerance to the ataxic effect of ethanol is mediated by a compensatory CR, termed "hypertaxia " The compensatory CR was disrupted by the novel addition and novel omission of the strobe/noise stimulus providing converging evidence that the attenuation of tolerance by a novel stimulus results from external inhibition of Pavlovian conditioning Finally, external inhibition of ethanol tolerance was not evident when there was a long delay between tolerance development sessions and testing These data are consistent with an associative analysis of tolerance which suggests that contextual control of tolerance should be minimized as the interval between training and testing is increased / Thesis / Doctor of Philosophy (PhD)

No description available.