6 resultados para Subjective perception of the context

em DigitalCommons@University of Nebraska - Lincoln


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This paper investigates postgraduate students' perceptions of the Internet as an enabler of scholarship.The specific objectives of the study are: to ascertain the perception held by the postgraduate students on the Internet usage as an enabler of scholarship, and to determine what interventions are necessary to facilitate postgraduate students' adoption of the Internet as a tool for learning and research. The subjects of study are the postgraduate students of the University of Ibadan, Nigeria. A random sample of 100 students was selected with representation from each faculty of the university. A questionnaire instrument with a 12-item scale was designed and administered. Data analysis was done using the chi-square statistical method. The results show that majority of the postgraduate students have positive perceptions of the Internet as an enabler of information sourcing for learning and research. However some of these students have low self-efficacy in Internet use for information sourcing.

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This study investigated the influence of top-down and bottom-up information on speech perception in complex listening environments. Specifically, the effects of listening to different types of processed speech were examined on intelligibility and on simultaneous visual-motor performance. The goal was to extend the generalizability of results in speech perception to environments outside of the laboratory. The effect of bottom-up information was evaluated with natural, cell phone and synthetic speech. The effect of simultaneous tasks was evaluated with concurrent visual-motor and memory tasks. Earlier works on the perception of speech during simultaneous visual-motor tasks have shown inconsistent results (Choi, 2004; Strayer & Johnston, 2001). In the present experiments, two dual-task paradigms were constructed in order to mimic non-laboratory listening environments. In the first two experiments, an auditory word repetition task was the primary task and a visual-motor task was the secondary task. Participants were presented with different kinds of speech in a background of multi-speaker babble and were asked to repeat the last word of every sentence while doing the simultaneous tracking task. Word accuracy and visual-motor task performance were measured. Taken together, the results of Experiments 1 and 2 showed that the intelligibility of natural speech was better than synthetic speech and that synthetic speech was better perceived than cell phone speech. The visual-motor methodology was found to demonstrate independent and supplemental information and provided a better understanding of the entire speech perception process. Experiment 3 was conducted to determine whether the automaticity of the tasks (Schneider & Shiffrin, 1977) helped to explain the results of the first two experiments. It was found that cell phone speech allowed better simultaneous pursuit rotor performance only at low intelligibility levels when participants ignored the listening task. Also, simultaneous task performance improved dramatically for natural speech when intelligibility was good. Overall, it could be concluded that knowledge of intelligibility alone is insufficient to characterize processing of different speech sources. Additional measures such as attentional demands and performance of simultaneous tasks were also important in characterizing the perception of different kinds of speech in complex listening environments.

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Artificial selection for starvation resistance provided insight into the relationships between evolved physiological and life history trait responses following exposure to biologically induced stress. Investigations of alterations to body composition, metabolic rate, movement, and life history traits including development time, female egg production, and longevity in response to brief periods of starvation were conducted on genetically based starvation-resistant and control lines of Drosophila melanogaster. Analysis of the starvation-resistant lines indicated increased energy storage with increased triglyceride deposition and conversion of carbohydrates to lipid, as identified by respiratory quotient values. Correlations between reductions in metabolic rates and movement in the starvation-resistant lines, suggested the presence of an evolved physiological response resulting in energy conservation. Investigations of life history traits in the starvation-resistant lines indicated no significant differences in development time or reproduction between the selected and control lines. Measurements of longevity, however, indicated a significant reduction in starvation-resistant D. melanogaster lifespan. These results suggested that elevated lipid concentrations, similar to that observed with obesity, were correlated with premature mortality. Exposure of the starvation-resistant and control lines to diets supplemented with glucose, palmitic acid, and a 2:1 mixture of casein to albumin were used to investigate alterations in body composition, movement, and life history traits. Results obtained from this study indicated that increased sugar in the diet led to increased carbohydrate, glycogen, total sugar, trehalose, and triglyceride concentrations, while increased fat and protein in the diet resulted in increased soluble protein, carbohydrate, glycogen, total sugar, and trehalose concentrations. Examination of life history trait responses indicated reduced fecundity in females exposed to increased glucose concentrations. Increased supplementations of palmitic acid was consistently correlated with an overall reduction in lifespan in both the starvation-resistant and control Drosophila lines, while measurements of movement indicated increased female activity levels in flies exposed to diets supplemented with fat and protein. Analyses of the physiological and life history trait responses to starvation and dietary supplementation on Drosophila melanogaster used in the present study has implications for investigating the mechanisms underlying the development and persistence of human obesity and associated metabolic disorders.

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The Neotropical genus Coprophanaeus Olsoufieff (1924), as classified here, comprises 38 species distributed among three subgenera (Megaphanaeus Olsoufieff, Metallophanaeus Olsoufieff, and Coprophanaeus s. str. ) and eight species groups. Keys presented help to identify supraspecific and species taxa, all of which are illustrated and diagnosed. Lectotypes are designated for Phanaeus ignecinctus Felsche and Phanaeus ohausi Felsche. Coprophanaeus corythus (Harold), formerly regarded as a subspecies of C. telamon (Erichson), assumes species status. Coprophanaeus magnoi Arnaud, described as a subspecies of C. milon (Blanchard), is raised to species status. New taxonomic interpretations result in 10 new subjective synonymies (junior synonym listed first): Phanaeus machadoi Pereira and d’Andretta = Coprophanaeus saphirinus (Perty); Phanaeus costatus Olsoufieff = Coprophanaeus cyanescens (Olsoufieff); Phanaeus worontzowi Pessôa and Lane = Coprophanaeus cyanescens (Olsoufieff); Coprophanaeus kohlmanni Arnaud = Coprophanaeus morenoi Arnaud; Coprophanaeus pluto nogueirai Arnaud = Coprophanaeus pluto (Harold); Coprophanaeus edmondsi Arnaud = Coprophanaeus conocephalus (Olsoufieff); Coprophanaeus uhleri Malý and Pokorný = Coprophanaeus chiriquensis (Olsoufieff); Coprophanaeus henryi Malý and Pokorný = Coprophanaeus gilli Arnaud; Phanaeus perseus Harold = Coprophanaeus corythus (Harold); Coprophanaeus telamon nevinsoni Arnaud and Gámez = Coprophanaeus corythus; and Coprophanaeus florenti Arnaud = Coprophanaeus ohausi (Felsche). The status of the following names remains unresolved: Phanaeus strandi Balthasar; Coprophanaeus rigoutorum Arnaud; C. terrali Arnaud; C. lichyi Arnaud; C. lecromi Arnaud; C. larseni Arnaud; and C. vazdemeloi Arnaud.

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Anchitherine horses are a subfamily of equids that are abundantly represented in the late Eocene and early Oligocene of North America. This group has been heavily studied in the past, but important questions still remain. Some studies have focused on the Eocene-Oligocene boundary and have used these equids along with other taxa to study mammalian diet and climate change through this interval. I reexamine two anchitherine genera, Mesohippus and Miohippus, from stratigraphic sequences of the White River Group in western Nebraska and southwestern South Dakota. These sequences span the Chadronian (late Eocene), Orellan (early Oligocene), and Whitneyan (early Oligocene) North American land-mammal ages. The most recent revision of these genera was done by Prothero and Shubin (1989). I review the characters used for taxonomic identification. This includes characters such as the hypostyle, the articular facet on the third metatarsal, and dental dimensions. To avoid possible biases caused by combining specimens from different stratigraphic levels, specimens were separated by location and stratigraphic level. The length and width of cheek teeth, and tooth rows were measured on 488 specimens. First molar area serves as a proxy for body mass in horses and other mammals, and can be useful for distinguishing among species. Results indicate that the characters used by Prothero and Shubin were highly variable in anchitherine horses and are not useful for distinguishing between these genera. The development of the articular facet on the third metatarsal may be a function of body size and therefore may be of no more utility than first molar area. Variability in first molar area suggests the presence of three species in the medial and late Chadronian, two species in the Orellan, and at least two species in the Whitneyan. Due to a lack of objective criteria separating Mesohippus from Miohippus, I recommend synonymy of these genera, making Mesohippus a junior subjective synonym.

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Acoustic conditions in hospitals have been shown to influence a patient’s physical and psychological health. Noise levels in an Omaha, Nebraska, hospital were measured and compared between various times: before, during, and after renovations of a hospital wing. The renovations included cosmetic changes and the installation of new in-room patient audio-visual systems. Sound pressure levels were logged every 10-seconds over a four-day period in three different locations: at the nurses' station, in the hallway, and in a nearby patient’s room. The resulting data were analyzed in terms of the hourly A-weighted equivalent sound pressure levels (