1000 resultados para Conglomerati bituminosi tiepidiPressa GiratoriaITSMITFTCreep Test
Resumo:
We assessed motor laterality in sheep to explore species-specific brain hemi-field dominance and how this could be affected by genetic or developmental factors. Further, we investigated whether directionality and strength of laterality could be linked to emotional stress in ewes and their lambs during partial separation. Forty-three ewes and their singleton lambs were scored on the (left/right) direction of turn in a y-maze to rejoin a conspecific (laterality test). Further, their behavioural response (i.e. time spent near the fence, vocalisations, and activity level) during forced separation by an open-mesh fence was assessed (separation test). Individual laterality was recorded for 44.2 % ewes (significant right bias) and 81.4 % lambs (equally biased to the left and the right). There was no significant association in side bias between dams and offspring. The Chi-squared test revealed a significant population bias for both groups (p < 0.05). Evolutionary adaptive strategies or stimuli-related visual laterality may provide explanation for this decision-making process. Absolute strength of laterality (irrespective of side) was high (Kolmogorov–Smirnov test, dams: D = 0.2; p < 0.001; lambs: D = 0.36, p < 0.0001). The Wilcoxon test showed that lateralised lambs and dams spent significantly more time near each other during separation than non-lateralised animals (p < 0.05), and that lateralised dams were also more active than non-lateralised ones. Arguably, the lateralised animals showed a greater attraction to their pair because they were more disturbed and thus required greater reassurance. The data show that measures of laterality offer a potential novel non-invasive indicator of separation stress.
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PURPOSE:
To determine the test-retest variability in perimetric, optic disc, and macular thickness parameters in a cohort of treated patients with established glaucoma.
PATIENTS AND METHODS:
In this cohort study, the authors analyzed the imaging studies and visual field tests at the baseline and 6-month visits of 162 eyes of 162 participant in the Glaucoma Imaging Longitudinal Study (GILS). They assessed the difference, expressed as the standard error of measurement, of Humphrey field analyzer II (HFA) Swedish Interactive Threshold Algorithm fast, Heidelberg retinal tomograph (HRT) II, and retinal thickness analyzer (RTA) parameters between the two visits and assumed that this difference was due to measurement variability, not pathologic change. A statistically significant change was defined as twice the standard error of measurement.
RESULTS:
In this cohort of treated glaucoma patients, it was found that statistically significant changes were 3.2 dB for mean deviation (MD), 2.2 for pattern standard deviation (PSD), 0.12 for cup shape measure, 0.26 mm for rim area, and 32.8 microm and 31.8 microm for superior and inferior macular thickness, respectively. On the basis of these values, it was estimated that the number of potential progression events detectable in this cohort by the parameters of MD, PSD, cup shape measure, rim area, superior macular thickness, and inferior macular thickness was 7.5, 6.0, 2.3, 5.7, 3.1, and 3.4, respectively.
CONCLUSIONS:
The variability of the measurements of MD, PSD, and rim area, relative to the range of possible values, is less than the variability of cup shape measure or macular thickness measurements. Therefore, the former measurements may be more useful global measurements for assessing progressive glaucoma damage.
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PURPOSE: To clarify the risk parameters measured by anterior segment optical coherence tomography (AS-OCT) for elevated intraocular pressures (IOP) provoked by the darkroom test and to provide recommendations for its clinical usage. METHODS: Subjects aged >40 years and whose peripheral anterior chambers were ≤1/4 corneal thickness were recruited. The anterior segment of the eye was imaged in sitting position and under both light and dark conditions and biometry was performed using anterior segment optical coherence tomography. The analyzed parameters were: (1) central anterior chamber depth (ACD); (2) anterior chamber width; (3) pupil diameter; (4) iris curvature; (5) lens thickness; and (6) number of meridians with closed angles (NCA). Then the darkroom test was performed and a positive provocative test result was defined as a rise in IOP ≥8 mm Hg after the test. Statistical analyses included: (1) the difference in parameters between positive and negative eyes; (2) the association between posttest IOP and the parameters; and (3) the difference in parameters between the 2 eyes in subjects with the asymmetric results. RESULTS: A total of 70 subjects were recruited. ACD (P=0.022), NCA in light (P<0.001), and NCA in dark (P<0.001) were different significantly between eyes with positive and negative results. There was a strong association between NCA in dark (r=0.755, P<0.001) and the posttest IOP. Among subjects with asymmetric results between the 2 eyes, the ACD was shallower and the lens thickness was larger in the positive eye. CONCLUSIONS: The posttest IOP is determined by the extent of functionally closed angles in the dark. The test may be useful in the early diagnosis of primary angle closure. At the same time, angle configuration should be evaluated to remove false positive result.
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BACKGROUND: Primary angle-closure glaucoma (PACG) is a major cause of visual morbidity in East Asia. Dark-room provocative test (DRPT) has been used to determine which narrow angles have the risk to develop angle closure. However, the accuracy of DRPT might be altered because that after emerging from the dark room, the configuration of the angle is affected by the light of the slit-lamp and the appositionally closed angle reopens. The aim of this study was to examine the pupillary diameter in different light conditions and use it as a parameter to assess the accuracy of dark-room provocative test. METHODS: Patients with suspected primary angle-closure glaucoma undergoing DRPT were recruited. The anterior chamber angle was examined by anterior segment optical coherence tomography under the following conditions: (1) in standard room illumination; (2) after short-term dark-adaptation and (3) after DRPT. Mean values of pupil size and numbers of appositionally closed angle under different conditions were compared. RESULTS: A total of 47 eyes of 47 patients were analyzed. The pupil size after DRPT was smaller than that after short-term dark-adaptation (P < 0.001) and smaller than that in standard room illumination (P = 0.026). The numbers of appositionally closed angles after short-term dark-adaptation were significantly larger than those after DRPT (P < 0.001). There was no significant difference between the numbers of appositionally closed angles in standard room illumination and after DRPT (P = 0.157). CONCLUSIONS: Constriction of pupil size immediately after prolonged dark room provocative test may lead to change in the angle configuration, which may lead to false negative results. We suggest a modified protocol of recording intraocular pressure immediately after DRPT and performing gonioscopy following short-term dark adaptation to improve the accuracy of angle closure assessment.
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The evaporation of exoplanetary atmospheres is thought to be driven by high-energy irradiation. However, the actual mass loss rates are not well constrained. Co-I Kipping has recently discovered that the star KOI-314, an M1V dwarf at 65 pc distance, is orbited by two earth-sized planets, the inner one of them rocky and the outer one gaseous (P_orb = 14d and 23d). Other recent works have shown an abundance of small rocky planets in very close orbits around their host stars, suggesting that the stellar high-energy irradiation evaporates away gaseous envelopes. KOI-314 is the first nearby system in which earth-sized planets of both types are detected, allowing us to constrain the efficiency of planetary evaporation if the stellar X-ray irradiation is measured. We therefore propose a 10 ks Chandra ACIS-S pointing to determine the stellar X-ray luminosity and hardness ratio. The accuracy of the orbital solution decreases quickly due to Transit-Timing Variations, which is why we ask for DDT.
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The KongTM ball test has been used extensively to assess lateral bias in the domestic dog. Implicit in this challenge is the assumption that dogs use their dominant paw to stabilise the ball. This study examined whether or not this is the case. A comparative approach was adopted, exploring limb use in dogs and humans. In Experiment 1, the paw preference of 48 dogs was assessed on the KongTM ball test. Analysis revealed an equal distribution of paw use, although significantly more dogs were paw-preferent than ambilateral. Significantly more male dogs were classified as right-pawed, while more females were ambilateral. There was no significant effect of canine sex or castration status on the dogs’ paw preferences. In Experiment 2, 94 adult humans were assessed on their ability to remove a piece of paper from a KongTM ball with their mouth, using their left, right or both hands to stabilise the ball. 76% of the right-handed people used their left hand, and 82% of the left-handed participants used their right hand, to hold the KongTM steady. It is concluded that dogs, like humans, are most likely using their non-dominant limb to stabilise the KongTM ball and their dominant side for postural support. This has potential applied implications from an animal welfare perspective.
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A number of studies have recently investigated personality traits in non-human species, with the dog gaining popularity as a subject species for research in this area. Recent research has shown the consistency of personality traits across both context and time for adult dogs, both when using questionnaire based methods of investigation and behavioural analyses of the dogs' behaviour. However, only a few studies have assessed the correspondence between these two methods, with results varying considerably across studies. Furthermore, most studies have focused on adult dogs, despite the fact that an understanding of personality traits in young puppies may be important for research focusing on the genetic basis of personality traits. In the current study, we sought to evaluate the correspondence between a questionnaire based method and the in depth analyses of the behaviour of 2-month old puppies in an open-field test in which a number of both social and non-social stimuli were presented to the subjects. We further evaluated consistency of traits over time by re-testing a subset of puppies. The correspondence between methods was high and test-retest consistency (for the main trait) was also good using both evaluation methods. Results showed clear factors referring to the two main personality traits 'extroversion,' (i.e. the enthusiastic, exuberant approach to the stimuli) and 'neuroticism,' (i.e. the more cautious and fearful approach to the stimuli), potentially similar to the shyness-boldness dimension found in previous studies. Furthermore, both methods identified an 'amicability' dimension, expressing the positive interactions the pups directed at the humans stranger, and a 'reservedness' dimension which identified pups who largely chose not to interact with the stimuli, and were defined as quiet and not nosey in the questionnaire.
Design of a Virtual Reality Framework for Maintainability and assemblability test of complex systems
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This paper presents a unique environment whose features are able to satisfy requirements for both virtual maintenance and virtual manufacturing through the conception of original virtual reality (VR) architecture. Virtual Reality for the Maintainability and Assemblability Tests (VR_MATE) encompasses VR hardware and software and a simulation manager which allows customisation of the architecture itself as well as interfacing with a wide range of devices employed in the simulations. Two case studies are presented to illustrate VR_MATE's unique ability to allow for both maintainability tests and assembly analysis of an aircraft carriage and a railway coach cooling system respectively. The key impact of this research is the demonstration of the potentialities of using VR techniques in industry and its multiple applications despite the subjective character within the simulation. VR_MATE has been presented as a framework to support the strategic and operative objectives of companies to reduce product development time and costs whilst maintaining product quality for applications which would be too expensive to simulate and evaluate in the real world.
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Since 1999, the rapid, inexpensive and non-destructive use of Th/K and Th/U ratios from spectral gamma ray measurements have been used as a proxy for changes in palaeo-hinterland weathering. This model is tested here by analysis of in situ palaeoweathering horizons where clay mineral contents are well-known. A residual palaeoweathered horizon of Palaeogene laterite (developed on basalt) has been logged at 14 locations across N. Ireland using spectral gamma ray detectors. The results are compared to published elemental and mineralogical data. While the model of K and U loss during the early stages of weathering to smectite and kaolinite is supported, the formation (during progressively more advanced weathering) of gibbsite and iron oxides has reversed the predicted pattern and caused U and Th retention in the weathering profile. The severity (duration, humidity) of weathering and palaeoweathering may be estimated using Th/K ratios as a proxy. The use of Th/U ratios is more problematic should detrital gibbsite (or similar clays) or iron oxides be detected. Mineralogical analysis is needed in order to evaluate the hosts for K, U and Th: nonetheless, the spectral gamma ray machine offers a real-time, inexpensive and effective tool for the preliminary or conjunctive assessment of degrees of weathering or palaeoweathering.
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This paper, written in English and Spanish, tells what a pap test is and what the test results mean.
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Dans le domaine des centres d’appels, l’affectation d’agents au service à la clientèle efficaces et satisfaits représente une activité cruciale pour toute direction dédiée aux ressources humaines de ces unités d’affaires. Or, pour parvenir à prendre de bonnes décisions d’embauche et de rejet, des instruments de mesure et d’évaluation des compétences sont souvent mis à contribution. À cet effet, les tests de jugement situationnel (TJS) sont de plus en plus utilisés pour la sélection du personnel. L’objet de cette thèse est donc de vérifier l’efficacité relative des différentes méthodes d’élaboration des grilles de correction des TJS. En effet, jusqu’à présent, trois méthodes ont été privilégiées par les concepteurs de tests (Weekley, Ployhart, & Holtz, 2006) : (1) l’approche rationnelle ou théorique (2) l’approche empirique et (3) le recours à des experts. La possibilité qu’une combinaison de ces différentes approches puisse conduire à de meilleurs résultats est également explorée. Pour y parvenir, le résultat total obtenu à un TJS a été mis en lien avec une évaluation du rendement global effectuée par un supérieur immédiat en y appliquant huit grilles de correction différentes. Au total, un échantillon de 312 employés œuvrant dans des emplois de téléopérateurs au sein d’une grande institution financière québécoise ont participé à cette recherche. Dans l’ensemble, les résultats indiquent qu’une approche empirique permet généralement d’obtenir de meilleures statistiques descriptives en termes de distribution et de dispersion des scores pour un processus de sélection. Cependant, des analyses corrélationnelles indiquent qu’une approche multiple ou méthode hybride, basée sur une intégration des informations fournies par différentes sources d’informations (empirique, théorique et basé sur les experts) pour l’élaboration d’une grille de correction d’un TJS, permet de mieux prédire le rendement des employés (r=0,247**) comparativement à l’utilisation de la théorie pour définir les attentes (r=0,162**), le recours à des experts de contenu œuvrant dans le domaine de pratique (r=0,164**) ou l’utilisation d’une approche empirique (r=0,154*). Mots clés : Test de jugement situationnel, grilles de correction, validité critériée, centre d’appels.
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The aims of this study were to 1) determine the relationship between performance on the court-based TIVRE-Basket® test and peak aerobic power determined from a criterion lab-based incremental treadmill test and 2) to examine the test-retest reliability of the TIVRE-Basket® test in elite male basketball players. To address aim 1, 36 elite male basketball players (age 25.2 + 4.7 years, weight 94.1 + 11.4 kg, height 195.83 + 9.6 cm) completed a graded treadmill exercise test and the TIVRE-Basket® within 72 hours. Mean distance recorded during the TIVRE-Basket® test was 4001.8 + 176.4m, and mean VO2 peak was 54.7 + 2.8 ml.kg.min-1, and the correlation between the two parameters was r=0.824 (P= <0.001). Linear regression analysis identified TIVRE-Basket® distance (m) as the only unique predictor of VO2 peak in a single variable plus constant model: VO2 peak = 2.595 + ((0.13* TIVRE-Basket® distance (m)). Performance on the TIVRE-Basket® test accounted for 67.8% of the variance in VO2 peak (t=8.466, P=<.001, 95% CI 0.01 - 0.016, SEE 1.61). To address aim 2, 20 male basketball players (age 26.7±4.2; height 1.94±0.92; weight 94.0±9.1) performed the TIVRE-Basket® test on two occasions. There was no significant difference in total distance covered between Trial 1 (4138.8 + 677.3m) and Trial 2 (4188.0 + 648.8m; t = 0.5798, P = 0.5688). Mean difference between trials was 49.2 + 399.5m, with an ICC of 0.85 suggesting a moderate level of reliability. Standardised TEM was 0.88%, representing a moderate degree of trial to trial error, and the CV was 6.3%. The TIVRE-Basket® test therefore represents a valid and moderately reliable court-based sport-specific test of aerobic power for use with individuals and teams of elite level male basketball players. Future research is required to ascertain its validity and reliability in other basketball populations e.g. across age groups, at different levels of competition, in females and in different forms of the game e.g. wheelchair basketball.
Resumo:
Tese de mestrado em Química Tecnológica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2016