87 resultados para Threshold concept theory
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We assessed the responses of hematological parameters and their relationship to the anaerobic threshold of Brazilian soccer players during a training program. Twelve athletes were evaluated at the beginning (week 0, T1), in the middle (week 6, T2), and at the end (week 12, T3) of the soccer training program. On the first day at 7:30 AM, before collecting the blood sample at rest for the determination of the hematological parameters, the athletes were conducted to the anthropometric evaluation. On the second day at 8:30 AM, the athletes had their anaerobic threshold measured. Analysis of variance with Newman-Keuls`post hoc was used for statistical comparisons between the parameters measured during the soccer training program. Correlations between the parameters analyzed were determined using the Pearson`s correlation coefficient. Erythrocytes concentration, hemoglobin, and hematocrit were significantly increased from T1 to T2. The specific soccer training program led to a rise in erythrocytes, hemoglobin, and hematocrit from T1 to T2. We assumed that these results occurred due to the plasma volume reduction and may be explained by the soccer training program characteristics. Furthermore, we did not observe any correlation between the anaerobic threshold and the hematological parameters.
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Background: Attention deficit hyperactivity disorder (ADHD) is a clinically significant disorder in adulthood, but current diagnostic criteria and instruments do not seem to adequately capture the complexity of the disorder in this developmental phase. Accordingly, there are limited data on the proportion of adults affected by the disorder, specially in developing countries. Method: We assessed a representative household sample of the Brazilian population for ADHD with the Adult ADHD Self-report Scale (ASRS) Screener, and evaluated the instrument according to the Rasch model of item response theory. Results: The sample was comprised by 3007 individuals, and the overal prevalence of positive screeners for ADHD was 5.8% [95% confidence interval (CI), 4.8-7.0]. Rasch analyses revealed the misfitt of the overall sample to expectations of the model. The evaluation of the sample stratified by age revealed that data for adolescents showed a signficant fittnes to the model expectations, while items completed by adults were not adequated. Conclusions: The lack of fitness to the model for adult respondents challenges the possibility of a linear transformation of the ordinal data into interval measures and the utilization of parametric analyses of data. This result suggests that diagnostic criteria and instruments for adult ADHD must take into account a developmental perspective. Moreover, it calls for further evaluation of currently employed research methods in light of modern theories of psychometrics. Copyright (C) 2010 John Wiley & Sons, Ltd.
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Objective: The purpose of this study was to investigate regional structural abnormalities in the brains of five patients with refractory obsessive-compulsive disorder (OCD) submitted to gamma ventral capsulotomy. Methods: We acquired morphometric magnetic resonance imaging (MRI) data before and after 1 year of radiosurgery using a 1.5-T MRI scanner. Images were spatially normalized and segmented using optimized voxel-based morphometry (VBM) methods. Voxelwise statistical comparisons between pre- and post-surgery MRI scans were performed using a general linear model. Findings in regions predicted a priori to show volumetric changes (orbitofrontal cortex, anterior cingulate gyrus, basal ganglia and thalamus) were reported as significant if surpassing a statistical threshold of p<0.001 (uncorrected for multiple comparisons). Results: We detected a significant regional postoperative increase in gray matter volume in the right inferior frontal gyri (Brodmann area 47, BA47) when comparing all patients pre and postoperatively. Conclusions: Our results support the current theory of frontal-striatal-thalamic-cortical (FSTC) circuitry involvement in OCD pathogenesis. Gamma ventral capsulotomy is associated with neurobiological changes in the inferior orbitofrontal cortex in refractory OCD patients. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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Motor unit action potentials (MUAPs) evoked by repetitive, low-intensity transcranial magnetic stimulation can be modeled as a Poisson process. A mathematical consequence of such a model is that the ratio of the variance to the mean of the amplitudes of motor evoked potentials (MEPs) should provide an estimate of the mean size of the individual MUAPs that summate to generate each MEP. We found that this is, in fact, the case. Our finding thus supports the use of the Poisson distribution to model MEP generation and indicates that this model enables characterization of the motor unit population that contributes to near-threshold MEPs. Muscle Nerve 42: 825-828, 2010
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Background: Widespread use of prostate-specific antigen screening has resulted in younger and healthier men being diagnosed with prostate cancer. Their demands and expectations of surgical intervention are much higher and cannot be adequately addressed with the classic trifecta outcome measures. Objective: A new and more comprehensive method for reporting outcomes after radical prostatectomy, the pentafecta, is proposed. Design, setting, and participants: From January 2008 through September 2009, details of 1111 consecutive patients who underwent robot-assisted radical prostatectomy performed by a single surgeon were retrospectively analyzed. Of 626 potent men, 332 who underwent bilateral nerve sparing and who had 1 yr of follow-up were included in the study group. Measurements: In addition to the traditional trifecta outcomes, two perioperative variables were included in the pentafecta: no postoperative complications and negative surgical margins. Patients who attained the trifecta and concurrently the two additional outcomes were considered as having achieved the pentafecta. A logistic regression model was created to evaluate independent factors for achieving the pentafecta. Results and limitations: Continence, potency, biochemical recurrence-free survival, and trifecta rates at 12 mo were 96.4%, 89.8%, 96.4%, and 83.1%, respectively. With regard to the perioperative outcomes, 93.4% had no postoperative complication and 90.7% had negative surgical margins. The pentafecta rate at 12 mo was 70.8%. On multivariable analysis, patient age (p = 0.001) was confirmed as the only factor independently associated with the pentafecta. Conclusions: A more comprehensive approach for reporting prostate surgery outcomes, the pentafecta, is being proposed. We believe that pentafecta outcomes more accurately represent patients` expectations after minimally invasive surgery for prostate cancer. This approach may be beneficial and may be used when counseling patients with clinically localized disease. (C) 2011 European Association of Urology. Published by Elsevier B. V. All rights reserved.
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Background: The purpose of this study was to evaluate the effect of long-term use of oral contraceptives (DC) containing 0.20 mg of ethinylestradiol (EE) combined with 0.15 mg of gestodene (GEST) on the peak aerobic capacity and at the anaerobic threshold (AT) level in active and sedentary young women. Study Design: Eighty-eight women (23 +/- 2.1 years old) were divided into four groups active-OC (G1), active-NOC (G2), sedentary-OC (G3) and sedentary-NOC (G4) and were submitted to a continuous ergospirometric incremental test on a cycloergometer with 20 to 25 W min(-1) increments. Data were analyzed by two-way ANOVA with Tukey post hoc test. Level of significance was set at 5%. Results: The OC use effect for the variables relative and absolute oxygen uptake VO(2) mL kg(-1) min(-1); VO(2), L min(-1), respectively), carbon dioxide output (VCO(2), L min(-1)), ventilation (VE, L min(-1)), heart rate (HR, bpm), respiratory exchange ratio (RER) and power output (W) data, as well as the interaction between OC use and exercise effect on the peak of test and at the AT level did not differ significantly between the active groups (G1 and G2) and the sedentary groups (G3 and G4). As to the exercise effect, for all variables studied, it was noted that the active groups presented higher values for the variables VO(2), VCO(2), VE and power output (p<.05) than the sedentary groups. The RER and HR were similar (p>.05) at the peak and at the AT level between G1 vs. G3 and G2 vs. G4. Conclusions: Long-term use of OC containing EE 0.20 mg plus GEST 0.15 mg does not affect aerobic capacity at the peak and at the AT level of exercise tests. (C) 2010 Elsevier Inc. All rights reserved.
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The aim of this study was to compare the intra-and inter-rater reliability of pressure pain threshold (PPT) and manual palpation (MP) of orofacial structures in symptomatic and symptom-free children for temporomandibular disorders (TMD). Fourteen children reporting pain in masticatory muscles or the temporomandibular joint and 16 symptom-free children were randomly assessed on three different occasions: by rater-1 in the first and third session and by rater-2 in the second session. The trained raters applied algometry and MP as recommended by the Research Diagnostic Criteria for TMD. Intraclass correlation coefficients and the Kappa statistic were used to assess the levels of reliability of PPT and MP, respectively. Excellent intra-and inter-rater reliability levels were observed for PPT values at most of the examined sites for symptom-free children and excellent and moderate reliability levels for children reporting pain. For MP, moderate and poor intra-rater and inter-rater reliability levels were observed for most sites in both groups. Algometry showed higher reliability levels for both groups of children and is recommended for pain assessment in children in association with MP. (C) 2010 Elsevier Ltd. All rights reserved.
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Objective: To propose an electronic method for sensitivity evaluation in leprosy and to compare it to the Semmes-Weinstein monofilaments. Methods:Thirty patients attending the Dermatology outpatient clinic of HCFMRP-USP were consecutively evaluated by both the electronic aesthesiometer and Semmes-Weinstein monofilaments on hand and foot test points. The intraclass correlation coefficient (ICC) was calculated to determine the variability of the electronic measures and the Kappa coefficient was calculated to determine the agreement between methods according to their categories (altered and non-altered tactile sensitivity). Results: The ICC was approximately 1, demonstrating repeatability. The Kappa coefficient showed more than 75 and 63% agreement on the hand and foot points, respectively. The mean agreement between the 2 methods for the 7 points of the right and left hand was 77.14 and 75.71%, respectively. The mean agreement for all 10 points was 74.33 and 63.66% on the right and left foot, respectively. In cases of disagreement the detection of altered tactile sensitivity by the electronic esthesiometer on the right and left foot was 90.91 and 84.25%, respectively, with no detection by the monofilaments. Conclusion: The results suggest that the electronic esthesiometer is a reliable and easy application, capable of evaluating alterations of tactile sensitivity in leprosy patients. (C) 2009 Elsevier B.V. All rights reserved.
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The magnitude of the basic reproduction ratio R(0) of an epidemic can be estimated in several ways, namely, from the final size of the epidemic, from the average age at first infection, or from the initial growth phase of the outbreak. In this paper, we discuss this last method for estimating R(0) for vector-borne infections. Implicit in these models is the assumption that there is an exponential phase of the outbreaks, which implies that in all cases R(0) > 1. We demonstrate that an outbreak is possible, even in cases where R(0) is less than one, provided that the vector-to-human component of R(0) is greater than one and that a certain number of infected vectors are introduced into the affected population. This theory is applied to two real epidemiological dengue situations in the southeastern part of Brazil, one where R(0) is less than one, and other one where R(0) is greater than one. In both cases, the model mirrors the real situations with reasonable accuracy.
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The stress intensity factor threshold (K(IO)) is related to the stress level at which cracks start to grow stably, causing the weakening of porcelain prostheses during their use. The values of K(IO) of seven dental porcelains (with and without reinforcing leucite crystal, KAlSi(2)O(6)) stored in air (22 degrees C, 60% relative humidity) and artificial saliva (37 degrees C) were determined by measuring the crack growth velocity of radial cracks generated at the corner of Vickers indentations. The results of K(IO) were correlated with the leucite content, fracture toughness (K(Ic)), and chemical composition of the porcelains. It was observed that K(IO) increased with the increase of leucite content (only for the leucite-based porcelains) and with the increase of K(Ic). The increase in Al(2)O(3) content or the decrease in the alkali oxide (K(2)O and Na(2)O) content of the material`s glassy matrix tended to increase the K(IO) values. Storage media (air and saliva) did not significantly affect the K(IO) of porcelains tested, indicating that the control parameter of K(IO) value was not the water content of the storage media.
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The purpose of this study was to evaluate the influence of stress and anxiety on the pressure pain threshold (PPT) of masticatory muscles and on the subjective pain report. Forty-five women, students, with mean age of 19.75 years, were divided into two groups: group 1:29 presenting with masticatory myofascial pain (MFP), according to the Research Diagnostic Criteria for Temporomandibular Disorders and group 2: 16 asymptomatic controls. An electronic algometer registered the pain thresholds on four different occasions throughout the academic year. To measure levels of stress, anxiety and pain, the Beck Anxiety Inventory, Lipp Stress Symptoms Inventory and Visual Analog Scale (VAS) were used. Three-way anova and Tukey`s tests were used to verify differences in PPT between groups, times and sites. Levels of anxiety and VAS were compared using Mann-Whitney test, while Friedman`s test was used for the within-groups comparison at different times (T1 to T4). The chi-squared and Cochran tests were performed to compare groups for the proportion of subjects with stress (alpha = 0.05). Differences in PPT recordings between time (P = 0.001) and sites (P < 0.001) were detected. Higher levels of anxiety and lower PPT figures were detected at T2 (academic examination) (P = 0.001). There was no difference between groups for anxiety and stress at any time (P > 0.05). The MFP group also has shown significant increase of VAS at the time of academic examination (P < 0.001). External stressors such as academic examinations have a potential impact on masticatory muscle tenderness, regardless of the presence of a previous condition such as masticatory myofascial pain.
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Objective. The aim of this study was to investigate the influence of the menstrual cycle and oral contraceptive (OC) intake on the pressure pain threshold (PPT) of masticatory muscles in patients with masticatory myofascial pain (MFP). Study design. The sample was composed of 36 women, divided into 4 groups, according to the presence of MFP and the intake of OC (15 patients had MFP [7 taking OC] and 21 were pain-free controls [8 taking OC]). The algometer-based PPT of masseter and temporalis, and the record of subjective pain by visual analog scale (VAS) were determined during 2 consecutives menstrual cycles at 4 phases (menstrual, follicular, periovulatory, and luteal). A 3-way ANOVA for repeated measurements, Kruskal-Wallis, Friedman, and Dunn tests, with a 5% significant level analyzed the data. Results. PPT was significantly lower in MFP patients when compared with controls throughout the experiment (P < .001). The menstrual phases did not influence PPT (P > .05), while the intake of OC seems to raise PPT levels for the left temporalis (P = .01) and right masseter (P = .04). VAS was, in general, higher at the menstrual phase Conclusions. Different phases of the menstrual cycle have no influence on PPT values, regardless of the presence of a previous condition, as masticatory myofascial pain, while the intake of OC is associated with decreased levels of reported pain.