957 resultados para finite-sample test
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We report oxygen and carbon stable isotope analyses of foraminifers, primarily planktonic, sampled at low resolution in the Cretaceous and Paleogene sections from Sites 1257, 1258, and 1260. Data from two samples from Site 1259 are also reported. The very low resolution of the data only allows us to detect climate-driven isotopic events on the timescale of more than 500 k.y. A several million-year-long interval of overall increase in planktonic 18O is seen in the Cenomanian at Site 1260. Before and after this interval, foraminifers from Cenomanian and Turonian black shales have d18O values in the range -4.2 per mil to -5.0 per mil, suggestive of upper ocean temperatures higher than modern tropical values. The d18O values of upper ocean dwelling Paleogene planktonics exhibit a long-term increase from the early Eocene to the middle Eocene. During shipboard and postcruise processing, it proved difficult to extract well-preserved foraminifer tests from black shales by conventional techniques. Here, we report results of a test of procedures for cleaning foraminifers in Cretaceous organic-rich mudstone sediments using various combinations of soaking in bleach, Calgon/hydrogen peroxide, or Cascade, accompanied by drying, repeat soaking, or sonication. A procedure that used 100% bleach, no detergent, and no sonication yielded the largest number of clean, whole individual foraminifers with the shortest preparation time. We found no significant difference in d18O or d13C values among sets of multiple samples of the planktonic foraminifer Whiteinella baltica extracted following each cleaning procedure.
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The utilization of symptom validity tests (SVTs) in pediatric assessment is receiving increasing empirical support. The Rey 15-Item Test (FIT) is an SVT commonly used in adult assessment, with limited research in pediatric populations. Given that FIT classification statistics across studies to date have been quite variable, Boone, Salazar, Lu, Warner-Chacon, and Razani (2002) developed a recognition trial to use with the original measure to enhance accuracy. The current study aims to assess the utility of the FIT and recognition trial in a pediatric mild traumatic brain injury (TBI) sample (N = 112; M = 14.6 years), in which a suboptimal effort base rate of 17% has been previously established (Kirkwood & Kirk, 2010). All participants were administered the FIT as part of an abbreviated neuropsychological evaluation; failure on the Medical Symptom Validity Test (MSVT) was used as the criterion for suspect effort. The traditional adult cut-off score of(99%), but poor sensitivity (6%). When the recognition trial was also utilized, a combination score of(sensitivity = 64%, specificity = 93%). Results indicate that the FIT with recognition trial may be useful in the assessment of pediatric suboptimal effort, at least among relatively high functioning children following mild TBI.
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"The Social Science component will be administered to students in grades 4 and 7 during April of the year 2001."--P. 2.
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Understanding the feasibility of applying the Team Climate Inventory (TCI) in non-Western cultures is essential for researchers attempting to understand the influence of culture on workers' perceived climate. This study describes the application of the TCI in such a setting using data from 203 administrators employed in a Taiwanese medical center. Reliability and factor analyses were performed to establish the feasibility and psychometric properties of the TCI Taiwan version. Reliabilities of both the four- and five-factor solutions exceeded .80. Factor analyses indicated a satisfactory four-factor structure, despite some variations in comparison with the U.K. version. The TCI Taiwan version is feasible and has acceptable psychometric properties. Further research is warranted regarding the degree to which disparities result from cultural differences and the specific nature of organizational systems in Chinese communities.
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This study is based on rock mechanical tests of samples from platform carbonate strata to document their petrophysical properties and determine their potential for porosity loss by mechanical compaction. Sixteen core-plug samples, including eleven limestones and five dolostones, from Miocene carbonate platforms on the Marion Plateau, offshore northeast Australia, were tested at vertical effective stress, sigma1', of 0-70 MPa, as lateral strain was kept equal to zero. The samples were deposited as bioclastic facies in platform-top settings having paleo-water depths of <10-90 m. They were variably cemented with low-Mg calcite and five of the samples were dolomitized before burial to present depths of 39-635 m below sea floor with porosities of 8-46%. Ten samples tested under dry conditions had up to 0.22% strain at sigma1' = 50 MPa, whereas six samples tested saturated with brine, under drained conditions, had up to 0.33% strain. The yield strength was reached in five of the plugs. The measured strains show an overall positive correlation with porosity. Vp ranges from 3640 to 5660 m/s and Vs from 1840 to 3530 m/s. Poisson coefficient is 0.20-0.33 and Young's modulus at 30 MPa ranged between 5 and 40 GPa. Water saturated samples had lower shear moduli and slightly higher P- to S-wave velocity ratios. Creep at constant stress was observed only in samples affected by pore collapse, indicating propagation of microcracks. Although deposited as loose carbonate sand and mud, the studied carbonates acquired reef-like petrophysical properties by early calcite and dolomite cementation. The small strains observed experimentally at 50 MPa indicate that little mechanical compaction would occur at deeper burial. However, as these rocks are unlikely to preserve their present high porosities to 4-5 km depth, further porosity loss would proceed mainly by chemical compaction and cementation.
Does the 6-minute walk test predicts functional capacity in a sample of elderly women? A pilot study
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Introduction: Functional capacity is the capacity to conduct daily activities in an independent way. It can be estimated with the 6-minutes’ walk test (6MWT) and other validated functional tests. Objectives: Verify associations between functional capacity measured with two different instruments (6MWT and Composite Physical Function (CPF) scale) and levels of physical activity and between those and characterization variables. Methods: This sample consisted of 30 apparently healthy elderly women from Loures municipality. Essentially they should be independent and community-dwelling. Characterization data were collected, containing characterization of physical activity levels and anthropometric data. Functional capacity was assessed with CPF scale and distance walked by the 6MWT. Results were analysed using a SPSS v21.0 through correlation tests. Results: The walked distance in 6MWT was positively associated with height (r = 0.406; p = 0.026), physical activity level (r = 0.594; p = 0.001) and functional capacity (r = 0.682; p = 0.000). For each point more obtained in CPF, the distance walked increases on average by 7.5 meters. Relatively to sedentary participants, being insufficiently active increases, on average, the distance walked in 85.8 meters; and being active increases, on average, the distance walked in 108.8 meters. No other associations were observed in our sample. Conclusion: Based on the collected sample, walked distance in 6MWT has a high correlation with results in CPF scale, so this test can be used to predict functional capacity. More attention should be taken to promote strategies to increase walking in older adults.
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Introduction. Test of Everyday Attention for Children (TEA-Ch) has been validated in different countries demonstrating that it is an instrument with a correct balance between reliability and duration. Given the shortage of trustworthy instruments of evaluation in our language for infantile population we decide to explore the Spanish version of the TEA-Ch. Methods. We administered TEA-Ch (version A) to a sample control of 133 Spanish children from 6 to 11 years enrolled in school in the Community of Madrid. Four children were selected at random by course of Primary Education, distributing the sex of equivalent form. Descriptive analysis and comparison by ages and sex in each of the TEA-Ch's subtests were conducted to establish a profile of the sample. In order to analyze the effect of the age, subjects were grouped in six sub-samples: 6, 7, 8, 9, 10 and 11 years-old. Results. This first descriptive analysis demonstrates age exerted a significant effect on each measure, due to an important "jump" in children's performance between 6 and 7 years-old. The effect of sex was significant only in two visual attention measures (Sky Search & Map) and interaction age and sex exerted a significant effect only in the dual task (Score DT). Conclusions. The results suggest that the Spanish version of the TEA-Ch (A) might be a useful instrument to evaluate attentional processes in Spanish child population.
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Our aim was to determine the normative reference values of cardiorespiratory fitness (CRF) and to establish the proportion of subjects with low CRF suggestive of future cardio-metabolic risk.
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This study sought to analyse the behaviour of the average spinal posture using a novel investigative procedure in a maximal incremental effort test performed on a treadmill. Spine motion was collected via stereo-photogrammetric analysis in thirteen amateur athletes. At each time percentage of the gait cycle, the reconstructed spine points were projected onto the sagittal and frontal planes of the trunk. On each plane, a polynomial was fitted to the data, and the two-dimensional geometric curvature along the longitudinal axis of the trunk was calculated to quantify the geometric shape of the spine. The average posture presented at the gait cycle defined the spine Neutral Curve. This method enabled the lateral deviations, lordosis, and kyphosis of the spine to be quantified noninvasively and in detail. The similarity between each two volunteers was a maximum of 19% on the sagittal plane and 13% on the frontal (p<0.01). The data collected in this study can be considered preliminary evidence that there are subject-specific characteristics in spinal curvatures during running. Changes induced by increases in speed were not sufficient for the Neutral Curve to lose its individual characteristics, instead behaving like a postural signature. The data showed the descriptive capability of a new method to analyse spinal postures during locomotion; however, additional studies, and with larger sample sizes, are necessary for extracting more general information from this novel methodology.
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This study evaluated the effect of specimens' design and manufacturing process on microtensile bond strength, internal stress distributions (Finite Element Analysis - FEA) and specimens' integrity by means of Scanning Electron Microscopy (SEM) and Laser Scanning Confocal Microscopy (LCM). Excite was applied to flat enamel surface and a resin composite build-ups were made incrementally with 1-mm increments of Tetric Ceram. Teeth were cut using a diamond disc or a diamond wire, obtaining 0.8 mm² stick-shaped specimens, or were shaped with a Micro Specimen Former, obtaining dumbbell-shaped specimens (n = 10). Samples were randomly selected for SEM and LCM analysis. Remaining samples underwent microtensile test, and results were analyzed with ANOVA and Tukey test. FEA dumbbell-shaped model resulted in a more homogeneous stress distribution. Nonetheless, they failed under lower bond strengths (21.83 ± 5.44 MPa)c than stick-shaped specimens (sectioned with wire: 42.93 ± 4.77 MPaª; sectioned with disc: 36.62 ± 3.63 MPa b), due to geometric irregularities related to manufacturing process, as noted in microscopic analyzes. It could be concluded that stick-shaped, nontrimmed specimens, sectioned with diamond wire, are preferred for enamel specimens as they can be prepared in a less destructive, easier, and more precise way.