941 resultados para Bank of Upper Canada


Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper presents the development and evaluation of a method for enabling quantitative and automatic scoring of alternating tapping performance of patients with Parkinson’s disease (PD). Ten healthy elderly subjects and 95 patients in different clinical stages of PD have utilized a touch-pad handheld computer to perform alternate tapping tests in their home environments. First, a neurologist used a web-based system to visually assess impairments in four tapping dimensions (‘speed’, ‘accuracy’, ‘fatigue’ and ‘arrhythmia’) and a global tapping severity (GTS). Second, tapping signals were processed with time series analysis and statistical methods to derive 24 quantitative parameters. Third, principal component analysis was used to reduce the dimensions of these parameters and to obtain scores for the four dimensions. Finally, a logistic regression classifier was trained using a 10-fold stratified cross-validation to map the reduced parameters to the corresponding visually assessed GTS scores. Results showed that the computed scores correlated well to visually assessed scores and were significantly different across Unified Parkinson’s Disease Rating Scale scores of upper limb motor performance. In addition, they had good internal consistency, had good ability to discriminate between healthy elderly and patients in different disease stages, had good sensitivity to treatment interventions and could reflect the natural disease progression over time. In conclusion, the automatic method can be useful to objectively assess the tapping performance of PD patients and can be included in telemedicine tools for remote monitoring of tapping.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

OBJECTIVES: To develop a method for objective assessment of fine motor timing variability in Parkinson’s disease (PD) patients, using digital spiral data gathered by a touch screen device. BACKGROUND: A retrospective analysis was conducted on data from 105 subjects including65 patients with advanced PD (group A), 15 intermediate patients experiencing motor fluctuations (group I), 15 early stage patients (group S), and 10 healthy elderly subjects (HE) were examined. The subjects were asked to perform repeated upper limb motor tasks by tracing a pre-drawn Archimedes spiral as shown on the screen of the device. The spiral tracing test was performed using an ergonomic pen stylus, using dominant hand. The test was repeated three times per test occasion and the subjects were instructed to complete it within 10 seconds. Digital spiral data including stylus position (x-ycoordinates) and timestamps (milliseconds) were collected and used in subsequent analysis. The total number of observations with the test battery were as follows: Swedish group (n=10079), Italian I group (n=822), Italian S group (n = 811), and HE (n=299). METHODS: The raw spiral data were processed with three data processing methods. To quantify motor timing variability during spiral drawing tasks Approximate Entropy (APEN) method was applied on digitized spiral data. APEN is designed to capture the amount of irregularity or complexity in time series. APEN requires determination of two parameters, namely, the window size and similarity measure. In our work and after experimentation, window size was set to 4 and similarity measure to 0.2 (20% of the standard deviation of the time series). The final score obtained by APEN was normalized by total drawing completion time and used in subsequent analysis. The score generated by this method is hence on denoted APEN. In addition, two more methods were applied on digital spiral data and their scores were used in subsequent analysis. The first method was based on Digital Wavelet Transform and Principal Component Analysis and generated a score representing spiral drawing impairment. The score generated by this method is hence on denoted WAV. The second method was based on standard deviation of frequency filtered drawing velocity. The score generated by this method is hence on denoted SDDV. Linear mixed-effects (LME) models were used to evaluate mean differences of the spiral scores of the three methods across the four subject groups. Test-retest reliability of the three scores was assessed after taking mean of the three possible correlations (Spearman’s rank coefficients) between the three test trials. Internal consistency of the methods was assessed by calculating correlations between their scores. RESULTS: When comparing mean spiral scores between the four subject groups, the APEN scores were different between HE subjects and three patient groups (P=0.626 for S group with 9.9% mean value difference, P=0.089 for I group with 30.2%, and P=0.0019 for A group with 44.1%). However, there were no significant differences in mean scores of the other two methods, except for the WAV between the HE and A groups (P<0.001). WAV and SDDV were highly and significantly correlated to each other with a coefficient of 0.69. However, APEN was not correlated to neither WAV nor SDDV with coefficients of 0.11 and 0.12, respectively. Test-retest reliability coefficients of the three scores were as follows: APEN (0.9), WAV(0.83) and SD-DV (0.55). CONCLUSIONS: The results show that the digital spiral analysis-based objective APEN measure is able to significantly differentiate the healthy subjects from patients at advanced level. In contrast to the other two methods (WAV and SDDV) that are designed to quantify dyskinesias (over-medications), this method can be useful for characterizing Off symptoms in PD. The APEN was not correlated to none of the other two methods indicating that it measures a different construct of upper limb motor function in PD patients than WAV and SDDV. The APEN also had a better test-retest reliability indicating that it is more stable and consistent over time than WAV and SDDV.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction Performance in cross-country skiing is influenced by the skier’s ability to continuously produce propelling forces and force magnitude in relation to the net external forces. A surrogate indicator of the “power supply” in cross-country skiing would be a physiological variable that reflects an important performance-related capability, whereas the body mass itself is an indicator of the “power demand” experienced by the skier. To adequately evaluate an elite skier’s performance capability, it is essential to establish the optimal ratio between the physiological variable and body mass. The overall aim of this doctoral thesis was to investigate the importance of body-mass exponent optimization for the evaluation of performance capability in cross-country skiing. Methods In total, 83 elite cross-country skiers (56 men and 27 women) volunteered to participate in the four studies. The physiological variables of maximal oxygen uptake (V̇O2max) and oxygen uptake corresponding to a blood-lactate concentration of 4 mmol∙l-1 (V̇O2obla) were determined while treadmill roller skiing using the diagonal-stride technique; mean oxygen uptake (V̇O2dp) and upper-body power output (Ẇ) were determined during double-poling tests using a ski-ergometer. Competitive performance data for elite male skiers were collected from two 15-km classical-technique skiing competitions and a 1.25-km sprint prologue; additionally, a 2-km double-poling roller-skiing time trial using the double-poling technique was used as an indicator of upper-body performance capability among elite male and female junior skiers. Power-function modelling was used to explain the race and time-trial speeds based on the physiological variables and body mass. Results The optimal V̇O2max-to-mass ratios to explain 15-km race speed were V̇O2max divided by body mass raised to the 0.48 and 0.53 power, and these models explained 68% and 69% of the variance in mean skiing speed, respectively; moreover, the 95% confidence intervals (CI) for the body-mass exponents did not include either 0 or 1. For the modelling of race speed in the sprint prologue, body mass failed to contribute to the models based on V̇O2max, V̇O2obla, and V̇O2dp. The upper-body power output-to-body mass ratio that optimally explained time-trial speed was Ẇ ∙ m-0.57 and the model explained 63% of the variance in speed. Conclusions The results in this thesis suggest that V̇O2max divided by the square root of body mass should be used as an indicator of performance in 15-km classical-technique races among elite male skiers rather than the absolute or simple ratio-standard scaled expression. To optimally explain an elite male skier’s performance capability in sprint prologues, power-function models based on oxygen-uptake variables expressed absolutely are recommended. Moreover, to evaluate elite junior skiers’ performance capabilities in 2-km double-poling roller-skiing time trials, it is recommended that Ẇ divided by the square root of body mass should be used rather than absolute or simple ratio-standard scaled expression of power output.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Climate change has resulted in substantial variations in annual extreme rainfall quantiles in different durations and return periods. Predicting the future changes in extreme rainfall quantiles is essential for various water resources design, assessment, and decision making purposes. Current Predictions of future rainfall extremes, however, exhibit large uncertainties. According to extreme value theory, rainfall extremes are rather random variables, with changing distributions around different return periods; therefore there are uncertainties even under current climate conditions. Regarding future condition, our large-scale knowledge is obtained using global climate models, forced with certain emission scenarios. There are widely known deficiencies with climate models, particularly with respect to precipitation projections. There is also recognition of the limitations of emission scenarios in representing the future global change. Apart from these large-scale uncertainties, the downscaling methods also add uncertainty into estimates of future extreme rainfall when they convert the larger-scale projections into local scale. The aim of this research is to address these uncertainties in future projections of extreme rainfall of different durations and return periods. We plugged 3 emission scenarios with 2 global climate models and used LARS-WG, a well-known weather generator, to stochastically downscale daily climate models’ projections for the city of Saskatoon, Canada, by 2100. The downscaled projections were further disaggregated into hourly resolution using our new stochastic and non-parametric rainfall disaggregator. The extreme rainfall quantiles can be consequently identified for different durations (1-hour, 2-hour, 4-hour, 6-hour, 12-hour, 18-hour and 24-hour) and return periods (2-year, 10-year, 25-year, 50-year, 100-year) using Generalized Extreme Value (GEV) distribution. By providing multiple realizations of future rainfall, we attempt to measure the extent of total predictive uncertainty, which is contributed by climate models, emission scenarios, and downscaling/disaggregation procedures. The results show different proportions of these contributors in different durations and return periods.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Esta tese se dedica ao estudo de modelos de fixação de preços e suas implicações macroeconômicas. Nos primeiros dois capítulos analiso modelos em que as decisões das firmas sobre seus preços praticados levam em conta custos de menu e de informação. No Capítulo 1 eu estimo tais modelos empregando estatísticas de variações de preços dos Estados Unidos, e concluo que: os custos de informação são significativamente maiores que os custos de menu; os dados claramente favorecem o modelo em que informações sobre condições agregadas são custosas enquanto que as idiossincráticas têm custo zero. No Capítulo 2 investigo as consequências de choques monetários e anúncios de desinflação usando os modelos previamente estimados. Mostro que o grau de não-neutralidade monetária é maior no modelo em que parte da informação é grátis. O Capítulo 3 é um artigo em conjunto com Carlos Carvalho (PUC-Rio) e Antonella Tutino (Federal Reserve Bank of Dallas). No artigo examinamos um modelo de fixação de preços em que firmas estão sujeitas a uma restrição de fluxo de informação do tipo Shannon. Calibramos o modelo e estudamos funções impulso-resposta a choques idiossincráticos e agregados. Mostramos que as firmas vão preferir processar informações agregadas e idiossincráticas conjuntamente ao invés de investigá-las separadamente. Este tipo de processamento gera ajustes de preços mais frequentes, diminuindo a persistência de efeitos reais causados por choques monetários.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Theory: A classic question in political science concems ",hat deteImines the number of parties that compete in a given polity. Broadly speaking, there are two approaches to answering this question, one that emphasizes the role of electorallaws in structuring coalitional incentives, another that emphasizes the importance of pre-existing social cleavages. In tbis paper, we view the number of parties as a product of the interaction between these two forces, following Powell (1982) and Ordeshook and Shvetsova (1994). Hypotheses: The effective number of parties in a polity should be a multiplicative rather than an additive function ofthe peImissiveness ofthe electoral system and the heterogeneity ofthe society. Methods: Multiple regression on cross-sectional aggregate electoral statistics. Unlike previous studies, we (1) do not confine attention to developed democracies; (2) explicitly control for the influence of presidential elections, taking account of whether they are concurrent or nonconcurrent, and ofthe effective number ofpresidential candidates; and (3) also control for the presence and operation of upper tiers in legislative elections. Results: The hypothesis is confiImed, both as regards the number of legislative and the number of presidential parties .

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper presents a methodology to estimate and identify different kinds of economic interaction, whenever these interactions can be established in the form of spatial dependence. First, we apply the semi-parametric approach of Chen and Conley (2001) to the estimation of reaction functions. Then, the methodology is applied to the analysis financial providers in Thailand. Based on a sample of financial institutions, we provide an economic framework to test if the actual spatial pattern is compatible with strategic competition (local interactions) or social planning (global interactions). Our estimates suggest that the provision of commercial banks and suppliers credit access is determined by spatial competition, while the Thai Bank of Agriculture and Agricultural Cooperatives is distributed as in a social planner problem.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Alternaria alternata, the causal agent of Alternaria brown spot (ABS), causes necrosis on leaves, twigs, and fruit, reducing the productivity and quality of fruits. Tangerines and their hybrids are highly susceptible to the disease. Species, hybrids, and cultivars of Citrus from the germplasm bank of the Estacao Experimental de Citricultura de Bebedouro, São Paulo, Brazil, were evaluated in 2004 and 2005 with respect to their resistance to A. alternata, both through natural infection and by inoculation. Detached leaves were also used to demonstrate susceptibility or resistance to the disease. Ten cultivars of Satsumas (Citrus unshiu), and 14 cultivars of Clementine mandarin (C. clementina) did not show any symptoms of the disease in their leaves, either through natural infection or when inoculated in the field. The Burguess SRA-412, Wallent SRA-438, Carvalhais, Ampefy SRA-459, Ananas SRA, and Macaque SRA-426 mandarin hybrids (C. reticulata) did not show symptoms of the disease under natural or artificial infection in the field. Some cultivars of C. deliciosa, C. tangerina, C. erythrosa, and C. temple showed symptoms of the disease, even though no previous record of their susceptibility to Alternaria brown spot had been previously reported. The hybrids Fairchild, Nova, Page, Fortune, and Sunburst were susceptible to the disease. However, Fremont mandarin (a crossing between C. clementina and C. reticulata), Encore (C. nobilis x C. deliciosa), and Fallglo (C. reticulata x C. paradisi) did not show symptoms in field, and few symptoms were verified in detached leaves. These materials are promising for the cultivation of tangerines, and will enable genetic improvement for the development of cultivars resistant to Alternaria brown spot. (c) 2007 Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Alternaria Brown Spot, caused by Alternaria alternata, is a major fungal disease in some kinds of tangerines, tangor, mandarins and pomelos. In Brazil as well as worldwide, A. alternata can cause necrosis in fruits, branches and leaves, causing substantial profit loss. In the present research, in laboratory conditions and in the field, we evaluated the resistance to the fungus, in leaves and fruits, for 22 varieties and hybrids of tangerines. To this end, we evaluated genotypes belonging to the Germplasm Bank of the Estacao Experimental de Citricultura de Bebedouro. The resistant genetic materials (found in leaves and fruits) represented four varieties of clementines (Citrus clementina); six varieties of mandarins (two belonging to C. reticulata, two to C. tangerina, one to C. deliciosa and one to C. nobilis); one tangelo (C. tangerina x C. paradisi); two mandarin hybrids (one resulting from crossing C nobilis x C. deliciosa and the other from crossing C. clementina x C. reticulata); one tangor hybrid (C. clementina) and two satsuma hybrids (C. unshiu x C. deliciosa). We also determined a relation between the inoculation of leaves and fruits. The resistance and susceptibility following inoculation in leaves and fruits supports a relationship between these organs and the physiological responses observed for the evaluated genotypes. (C) 2009 Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

O trabalho teve como objetivo a caracterização físico-química de frutos de mangostão amarelo (Garcinia xanthochymus Hook). Seis amostras de 25 frutos cada foram colhidas em plantas de mangostão amarelo do Banco Ativo de Germoplasma da Universidade Estadual Paulista e caracterizadas pela avaliação de diâmetro e altura, peso, percentagem e número de sementes por fruto, percentagem de casca, percentagem de polpa, sólidos solúveis (SS), acidez titulável (AT), vitamina C e relação SS/AT. O mangostão amarelo tem boas qualidades tecnológicas e é uma fonte intermediária de vitamina C com conteúdo médio de 120,33 mg/100g de fruta fresca.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of the study was to determine the percentage of crude protein, crude fiber and crude fat (ether extract) of 25 genotypes of kale from the Germplasm Bank of Instituto Agronomico de Campinas and of one genotype grown in the region of Jaboticabal-SP. The plants were cultivated in the field, and the leaves after collection were pre-dried in a convection oven at 65 degrees C for 72 h. Afterward, the leaves were analyzed for crude protein, crude fiber and crude fat (ether-soluble materials). Significant differences were detected among the different genotypes for all the characteristics examined. of the genotypes studied, six showed more than 30% crude protein: HS-20 (32.56%), Comum (31.70%), Couve de Arthur Nogueira 2 (31.16%), Pires 2 de Campinas (30.63%), Manteiga 1-916 (30.36%), and Manteiga de Ribeirao Pires I-2446 (30.03%). In relation to crude fiber, the highest percentage was seen in the genotype Manteiga de Mococa (10.92%), differing significantly from the other genotypes studied. With regard to crude fat, the highest percentage was found in the genotype HS-20 (3.72%), and Pires 1 de Campinas (3.34%). of the genotypes tested, HS-20 stood out among the others, showing both the highest percentage of protein and fat.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects and animal and maternal permanent environmental effects as random. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of age (cubic regression) were considered as random covariate. The random effects were modeled using B-spline functions considering linear, quadratic and cubic polynomials for each individual segment. Residual variances were grouped in five age classes. Direct additive genetic and animal permanent environmental effects were modeled using up to seven knots (six segments). A single segment with two knots at the end points of the curve was used for the estimation of maternal genetic and maternal permanent environmental effects. A total of 15 models were studied, with the number of parameters ranging from 17 to 81. The models that used B-splines were compared with multi-trait analyses with nine weight traits and to a random regression model that used orthogonal Legendre polynomials. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most appropriate and parsimonious model to describe the covariance structure of the data. Selection for higher weight, such as at young ages, should be performed taking into account an increase in mature cow weight. Particularly, this is important in most of Nellore beef cattle production systems, where the cow herd is maintained on range conditions. There is limited modification of the growth curve of Nellore cattle with respect to the aim of selecting them for rapid growth at young ages while maintaining constant adult weight.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

PURPOSE: To investigate if tests used in the preoperative period of upper abdominal or thoracic surgeries are able to differentiate the patients that presented cardiopulmonary postoperative complications. METHODS: Seventy eight patients, 30 submitted to upper abdominal surgery and 48 to thoracic surgery were evaluated. Spirometry, respirometry, manovacuometry, six-minute walk test and stair-climbing test were performed. Complications from immediate postoperative to discharge from hospital were registered. RESULTS: The postoperative complications rate was 17% in upper abdominal surgery and 10% in thoracic surgery. In the univariate regression, the only variable that kept the correlation with postoperative complications in the upper abdominal surgery was maximal expiratory pressure. In thoracic surgery, the maximal voluntary ventilation, six-minute walk test and time in stair-climbing test presented correlation with postoperative complications. After multiple regression only stair-climbing test continued as an important risk predictor in thoracic surgery. CONCLUSION: The respiratory pressure could differentiate patients with complications in upper abdominal surgery, whereas in thoracic surgery, only spirometric values and exercise tests could differentiate them.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

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