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Effects of climate change on mammalian fauna composition and structure during the advent of North American continental glaciation in the PlioceneRuez, Dennis Russell, 1973- 28 August 2008 (has links)
The cooling preceding the beginning of North American continental glaciation is beautifully represented by the thick fluvial and lacustrine sequences of the Pliocene Glenns Ferry Formation at the Hagerman Fossil Beds National Monument (HAFO), Idaho. This time interval is commonly studied because it contains the elevated global temperatures predicted to result from continued anthropogenic warming. The fossil mammals at HAFO were examined to see the effects of climate change on past mammalian assemblages. The nature of the fossiliferous localities at HAFO was documented to establish which localities could be considered in situ. Additionally, the structural architecture of the beds was mapped to establish an idealized stratigraphic datum to which localities were tied. This facilitated temporal comparison of the widespread localities at HAFO. Second, a high-resolution record of climate change was created using global climate models to predict which oceanic areas varied in temperature in concert with HAFO during the middle Pliocene. Data from deep-sea cores from those oceanic areas were combined to create a proxy temperature pattern; such a detailed record from terrestrial data in the Glenns Ferry Formation is not currently possible. Selected mammalian groups, carnivorans, insectivorans, and leporids, were examined in light of the established climatic patterns. The cooling through the lower portion of the Glenns Ferry Formation corresponds to variation in the morphology of individual species, the relative abundance of species, and the species-level diversity of mammalian groups. There is a return to warm temperatures near the top of the section at HAFO, and the mammals returned to the conditions exhibited before the cool-temperature extreme. This faunal resilience, however, occurred over hundreds of thousands of years. The final paleoecologic approach established correlations between the species diversity of groups of modern mammals and modern climatic values. Many modern groups were found to be highly-significantly correlated to climate, but when the established predictive equations were applied to HAFO, the results were variable. Estimates of annual precipitation varied widely, depending on the taxonomic group, and also deviated from precipitation estimates from sedimentology. Temperature patterns were more consistent with each other and with the pattern of the deep-sea core proxy. / text
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Ostracodes as indicators of the Paleoenvironment in the Pliocene Glenns Ferry Formation, Glenns Ferry Lake, IdahoDennison-Budak, Cordelia W. 19 April 2010 (has links)
No description available.
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Is there a correlation between the ability to recognise speech-in-noise and sensory memory?Svedberg, Stella January 2023 (has links)
Recently, research has begun to pay more attention to the cognitive functions associated with auditory perception. In this study, two tests are performed to investigate the correlation between the ability to recognise speech-in-noise and the performance of sensory memory, as well as to investigate whether the performance would improve during the sensory memory test. For measuring speech-in-noise, the Hagerman test was used. A random noise test to detect deviant noises was used to measure sensory memory. In total 16 participantstook part in the study (mean age=24.8125, SD=3.14), half of the group began with the Hagerman test, and the other half with the random noise test. Two different statistical analyses were performed on the data. For examining the correlation between the performance on the Hagerman test and the random noise test, a Pearson correlation was used. The results were as follows: p = 0.4962, r = -0.1835734. Observing the results, the tests did indicate a slight negative correlation regarding the r-value, but not a significant correlation. Thus, the analysis did not derive any significant results. The second analysis was a dependent t-test to examine whether there was an improvement in performance during the random noise test, as it was divided into four separate blocks. The analysis showed the following results: t = 1.0266, df = 28.943, p = 0.3131. These results were not significant, though observing the block graph might indicate a tendency for improvement. For further studies, the random noise test should perhaps be modified into an easier version. This is based upon the data, as many of the participants merely got a score above, or even below, chance. Further studiesshould also use a higher number of participants as well to increase the chance of receiving significant results from the tests.
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