6,587 research outputs found
Interjudge Reliability in the Measurement of Pitchmatching
In the clinical analysis and treatment of voice disorders, software packages allow the extraction of acoustic voice parameters, such as fundamental frequency, from patient vocal productions. The utility of such software packages in the clinical situation, however, is dependent upon consistency in their use and in interpretation of the analyses they provide. The present study focused on the extraction and interpretation of voice pitch data. Samples from eight trained singers who were asked to match the pitch of both pure tones and synthesized human voice were submitted to the Kay Elemetrics Computerized Speech Lab for analysis. Estimates of voice pitch were made by three judges, and the inter-rater reliability was measured. Results indicated that judges were very consistent in the estimation of token duration but varied widely in estimates of fundamental frequency. These results have important implications for use of such software packages in clinical diagnosis and treatment.ASC Undergraduate Research ScholarshipSBS Undergraduate Research Scholarshi
From Visit to Action: How Zoo Visitor Characteristics Influence Environmentally-Responsible Behavior
Over the last 30 years, AZA-accredited zoos and aquariums have shifted focus from recreation to become centers of research, conservation and education. As awareness of environmental issues increases, zoos around the world have stepped up the challenge of engaging their visitors in learning experiences to enhance knowledge and awareness of conservation initiatives and eventually evoke action. Evaluation of these educational programs has also shifted from assessing whether a program works to determining for whom it works and why. The purpose of this study is to explore the role of locus of control, motivation, previous life experiences, personal interest and knowledge on the effectiveness of a zoo program designed to stimulate environmentally-responsible behavior (ERB). A web-based survey and mail-back paper survey were used to evaluate the effectiveness of the education program in terms of environmentally-responsible behavior and understand what visitor characteristics influence an individual to participate in ERB. Responses were received from 546 visitors. The survey instrument included an environmentally-themed locus of control scale, questions to understand visit motivation, various assessments of previous life experiences, a personal interest and perceived knowledge scale, and an objective knowledge test. To evaluate these variables in terms of environmentally-responsible behavior, a 21 item list of action behaviors was complied from conservation messages around the zoo. Results indicated significant positive relationships between environmentally-responsible behavior and several independent variables including internal locus of control, educational motivation, attendance at educational attractions, owning a variety of pets, personal interest, higher perceived and objective knowledge of animal and conservation issues, and attendance at special summer exhibits. Program implementation limited the study results due to ineffective distribution of program brochures and less than ideal sign placement. The results indicate that no one variable is so highly correlated that it alone could influence environmentally-responsible behavior. Rather it is a combination of many environmental and conservation-related experiences that prepares a zoo visitor for a meaningful learning experience. Also, Affirmation of environmental attitudes and beliefs plays a large role in encouraging visitors to continue acting in an environmentally-responsible way
Single-Step Charge Transport through DNA over Long Distances
Quantum yields for charge transport across adenine tracts of increasing length have been measured by monitoring hole transport in synthetic oligonucleotides between photoexcited 2-aminopurine, a fluorescent analogue of adenine, and N_2-cyclopropyl guanine. Using fluorescence quenching, a measure of hole injection, and hole trapping by the cyclopropyl guanine derivative, we separate the individual contributions of single- and multistep channels to DNA charge transport and find that with 7 or 8 intervening adenines the charge transport is a coherent, single-step process. Moreover, a transition occurs from multistep to single-step charge transport with increasing donor/acceptor separation, opposite to that generally observed in molecular wires. These results establish that coherent transport through DNA occurs preferentially across 10 base pairs, favored by delocalization over a full turn of the helix
Control of Keratinocyte Division In Vitro
Aqueous extracts of newborn rat epidermis inhibit mitosis of cultivated keratinocytes obtained from guinea pigs and humans. The mitotic activity of cultivated human keratinocytes and fibroblasts obtained from the uninvolved skin of subjects with psoriasis is similar to the mitotic activity of these cells obtained from involved psoriatic skin. This observation is consistent with the model of repression of mitotic activity in normal skin and a derepression of mitotic activity in psoriatic epidermis. Extracts of liver also inhibit mitosis of guinea pig keratinocytes. Cultivated keratinocytes do not exhibit the same specificity of inhibition by epidermal extracts that has been reported for surviving fragments of mouse ear
Contra-rotating marine current turbines : single point tethered floating system - stabilty and performance
The Energy Systems Research Unit within the Department of Mechanical Engineering at the University of Strathclyde has developed a novel contra-rotating tidal turbine (CoRMaT). A series of tank and sea tests have led to the development and deployment of a small stand-alone next generation tidal turbine. Novel aspects of this turbine include its single point compliant mooring system, direct drive open to sea permanent magnet generator, and two contra-rotating sets of rotor blades. The sea testing of the turbine off the west coast of Scotland in the Sound of Islay is described; the resulting stability of a single-point tethered device and power quality from the direct drive generator is reported and evaluated. It is noted that reasonably good moored turbine stability within a real tidal stream can be achieved with careful design; however even quite small instabilities have an effect on the output electrical power quality. Finally, the power take-off and delivery options for a 250kW production prototype are described and assessed
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CRISPR-Cas9 Gene Editing of Hematopoietic Stem Cells from Patients with Friedreich's Ataxia.
Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by expansion of GAA repeats in intron 1 of the frataxin (FXN) gene, leading to significant decreased expression of frataxin, a mitochondrial iron-binding protein. We previously reported that syngeneic hematopoietic stem and progenitor cell (HSPC) transplantation prevented neurodegeneration in the FRDA mouse model YG8R. We showed that the mechanism of rescue was mediated by the transfer of the functional frataxin from HSPC-derived microglia/macrophage cells to neurons/myocytes. In this study, we report the first step toward an autologous HSPC transplantation using the CRISPR-Cas9 system for FRDA. We first identified a pair of CRISPR RNAs (crRNAs) that efficiently removes the GAA expansions in human FRDA lymphoblasts, restoring the non-pathologic level of frataxin expression and normalizing mitochondrial activity. We also optimized the gene-editing approach in HSPCs isolated from healthy and FRDA patients' peripheral blood and demonstrated normal hematopoiesis of gene-edited cells in vitro and in vivo. The procedure did not induce cellular toxic effect or major off-target events, but a p53-mediated cell proliferation delay was observed in the gene-edited cells. This study provides the foundation for the clinical translation of autologous transplantation of gene-corrected HSPCs for FRDA
Comparative frequency of Coagulation Factor II and Coagulation Factor V Alleles among new-born and senior citizens
Resistance to activated protein C is one of the most common inherited disorders associated with hereditary thrombophilia. A missense mutation in the gene coding for coagulation factor V (CF V Leiden) and which renders this procoagulant factor resistant to inactivation by activated protein C results in an inherited risk for venous thrombosis. Recently, another mutation has been identified in the prothrombin gene (CF II G20210A) which was also associated with increased risk for venous thrombosis. In this study, we sought to establish the frequency of the two alleles in a random sample of Maltese newborn and compare these with the frequencies of the same alleles among senior citizens and patients with clinical thrombophilia. The control population of 554 newborn samples processed for the same point mutations gave 13 (2.3%) who were CF V Leiden heterozygotes and 7 (2.7%) who were CF II G20210A heterozygotes. Neither homozygotes nor trans-heterozygotes (i.e. CF V Leden and CF II2 0210A heterozygotes) were observed. The 348 senior citizens gave 9 (2.6%) CF V Leiden heterozygotes and 8 (2.4%) CF II G20210A heterozygotes. Neither homozygotes nor trans-heterozygotes (i.e. CF V Leden and CF II20210A heterozygotes) were observed. The 328 patients referred to the Laboratory of Molecular Genetics, University of Malta, with clinical thrombosis gave 23 (7.01%) CF V Leiden heterozygotes and 24 (7.31%) CF II G20210A heterozygous. One patient was found to be trans-heterozygous for the two mutations. The data suggested that although CF V G1691A and CF II G20210A may increase risk for thrombophilia, they do not impact on the survival of the carriers, but the transheterozygozity may also confer increased risk. The high allele frequency may be best explained by positive natural selection.peer-reviewe
State Dependence of Stimulus-Induced Variability Tuning in Macaque MT
Behavioral states marked by varying levels of arousal and attention modulate
some properties of cortical responses (e.g. average firing rates or pairwise
correlations), yet it is not fully understood what drives these response
changes and how they might affect downstream stimulus decoding. Here we show
that changes in state modulate the tuning of response variance-to-mean ratios
(Fano factors) in a fashion that is neither predicted by a Poisson spiking
model nor changes in the mean firing rate, with a substantial effect on
stimulus discriminability. We recorded motion-sensitive neurons in middle
temporal cortex (MT) in two states: alert fixation and light, opioid
anesthesia. Anesthesia tended to lower average spike counts, without decreasing
trial-to-trial variability compared to the alert state. Under anesthesia,
within-trial fluctuations in excitability were correlated over longer time
scales compared to the alert state, creating supra-Poisson Fano factors. In
contrast, alert-state MT neurons have higher mean firing rates and largely
sub-Poisson variability that is stimulus-dependent and cannot be explained by
firing rate differences alone. The absence of such stimulus-induced variability
tuning in the anesthetized state suggests different sources of variability
between states. A simple model explains state-dependent shifts in the
distribution of observed Fano factors via a suppression in the variance of gain
fluctuations in the alert state. A population model with stimulus-induced
variability tuning and behaviorally constrained information-limiting
correlations explores the potential enhancement in stimulus discriminability by
the cortical population in the alert state.Comment: 36 pages, 18 figure
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