979 resultados para Skinner, Brian
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African-American composers within the field of classical music have made very profound contributions to the literature. In the field of chamber music, Scott Joplin, William Grant Still, Adolphus Hailstork and other composers illustrious composers have created an established and well-documented body of repertoire for many orchestral wind instruments. The saxophone repertoire, however, has not been developed as fully due to its limited tradition as an orchestral instrument and its prominence in the tradition of jazz and popular music. African-American composers in particular appear to be significantly under-represented within the standard concert saxophone literature. My personal experiences with saxophone repertoire in academic settings, solo recitals, conferences and in surveys of standard repertoire from nationally-recognized saxophone teachers support this assertion. There are many African-American composers who have made substantial contributions to the body of repertoire for the concert saxophone. This dissertation examines the works of three prolific African-American composers for the concert saxophone; Dr. Yusef A. Lateef, Andrew N. White III, and Dr. David N. Baker. All have composed more than five separate works featuring the concert saxophone. This project comprises three recitals, each dedicated to one of the three composers selected for this dissertation. Each recital presented will present their compositions featuring the saxophone as a soloist with various types of accompaniment. The project also includes newly-created piano reductions of Dr. David Baker's works for saxophone and orchestra made collaboratively with Baker and arranger John Leszczynski.
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Biogas is a mixture of methane and other gases. In its crude state, it contains carbon dioxide (CO2) that reduces its energy efficiency and hydrogen sulfide (H2S) that is toxic and highly corrosive. Because chemical methods of removal are expensive and environmentally hazardous, this project investigated an algal-based system to remove CO2 from biogas. An anaerobic digester was used to mimic landfill biogas. Iron oxide and an alkaline spray were used to remove H2S and CO2 respectively. The CO2-laden alkali solution was added to a helical photobioreactor where the algae metabolized the dissolved CO2 to generate algal biomass. Although technical issues prevented testing of the complete system for functionality, cost analysis was completed and showed that the system, in its current state, is not economically feasible. However, modifications may reduce operation costs.
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In 2014 alone, over 12,000 women are expected to be diagnosed with cervical cancer. Of these women who are diagnosed, about 3,909 will result in death. Despite developments in prevention methods, cervical cancer remains a major health concern for women. Growing evidence suggests that Salvianolic acid B (Sal B), a major component of the Chinese herb Danshen, may inhibit cancer cell growth and help fight against cervical cancer. This study characterizes the potential of Sal B as a cervical cancer drug through in vitro testing on HeLa cells. We hypothesized that application of Sal B to HeLa cells will result in decreased cell viability and increased apoptosis in a dose dependent manner. HeLa cells were treated with varying concentrations of Sal B: 25µM, 50µM, 100µM, and 200µM. Cell viability was determined through colony formation assay, cell death ELISA, and nuclear morphology. An inhibitor study was also conducted for further apoptosis pathway analysis. Colony formation assay demonstrated a significant decrease in cell viability with increasing concentrations of Sal B with 75% viability at 50µM down to 0% viability at 200µM. Cell death ELISA and the analysis of nuclear morphology via Hoechst staining reported significant levels of apoptosis at concentrations equal to 50µM and greater. Furthermore, experiments using caspase inhibitors indicated that Sal B’s apoptotic effects are caspase-8 dependent. In conclusion, our results demonstrate that Sal B inhibits cancer cell growth by a mechanism that involves apoptosis induction through the extrinsic pathway.
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Prenatal nicotine exposure (PNE) is linked to a large number of psychiatric disorders, including attention deficit hyperactivity disorder (ADHD). Current literature suggests that core deficits observed in ADHD reflect abnormal inhibitory control governed by the prefrontal cortex (PFC) of the brain. The PFC is structurally altered by PNE, but it is still unclear how neural firing is affected during tasks that test behavioral inhibition, such as the stop-signal task, or if neural correlates related to inhibitory control are affected after PNE in awake behaving animals. To address these questions, we recorded from single medial PFC (mPFC) neurons in control rats and PNE rats as they performed our stopsignal task. We found that PNE rats were faster for all trial types and were less likely to inhibit the behavioral response on STOP trials. Neurons in mPFC fired more strongly on STOP trials and were correlated with accuracy and reaction time. Although the number of neurons exhibiting significant modulation during task performance did not differ between groups, overall activity in PNE was reduced. We conclude that PNE makes rats impulsive and reduces firing in mPFC neurons that carry signals related to response inhibition.
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BACKGROUND: Dolutegravir (S/GSK1349572), a once-daily, unboosted integrase inhibitor, was recently approved in the United States for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in combination with other antiretroviral agents. Dolutegravir, in combination with abacavir-lamivudine, may provide a simplified regimen. METHODS: We conducted a randomized, double-blind, phase 3 study involving adult participants who had not received previous therapy for HIV-1 infection and who had an HIV-1 RNA level of 1000 copies per milliliter or more. Participants were randomly assigned to dolutegravir at a dose of 50 mg plus abacavir-lamivudine once daily (DTG-ABC-3TC group) or combination therapy with efavirenz-tenofovir disoproxil fumarate (DF)-emtricitabine once daily (EFV-TDF-FTC group). The primary end point was the proportion of participants with an HIV-1 RNA level of less than 50 copies per milliliter at week 48. Secondary end points included the time to viral suppression, the change from baseline in CD4+ T-cell count, safety, and viral resistance. RESULTS: A total of 833 participants received at least one dose of study drug. At week 48, the proportion of participants with an HIV-1 RNA level of less than 50 copies per milliliter was significantly higher in the DTG-ABC-3TC group than in the EFV-TDF-FTC group (88% vs. 81%, P = 0.003), thus meeting the criterion for superiority. The DTG-ABC-3TC group had a shorter median time to viral suppression than did the EFV-TDF-FTC group (28 vs. 84 days, P<0.001), as well as greater increases in CD4+ T-cell count (267 vs. 208 per cubic millimeter, P<0.001). The proportion of participants who discontinued therapy owing to adverse events was lower in the DTG-ABC-3TC group than in the EFV-TDF-FTC group (2% vs. 10%); rash and neuropsychiatric events (including abnormal dreams, anxiety, dizziness, and somnolence) were significantly more common in the EFV-TDF-FTC group, whereas insomnia was reported more frequently in the DTG-ABC-3TC group. No participants in the DTG-ABC-3TC group had detectable antiviral resistance; one tenofovir DF-associated mutation and four efavirenz-associated mutations were detected in participants with virologic failure in the EFV-TDF-FTC group. CONCLUSIONS: Dolutegravir plus abacavir-lamivudine had a better safety profile and was more effective through 48 weeks than the regimen with efavirenz-tenofovir DF-emtricitabine. Copyright © 2013 Massachusetts Medical Society.
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Supercontinua generated in microstructure fiber can exhibit significant excess amplitude noise. We present experimental and numerical studies of the origins of this excess noise and its dependence on the input laser pulse parameters.
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Broadband supercontinuum spectra are generated in a microstructured fiber using femtosecond laser pulses. Noise properties of these spectra are studied through experiments and numerical simulations based on a generalized stochastic nonlinear Schrödinger equation. In particular, the relative intensity noise as a function of wavelength across the supercontinuum is measured over a wide range of input pulse parameters, and experimental results and simulations are shown to be in good quantitative agreement. For certain input pulse parameters, amplitude fluctuations as large as 50% are observed. The simulations clarify that the intensity noise on the supercontinuum arises from the amplification of two noise inputs during propagation - quantum-limited shot noise on the input pulse, and spontaneous Raman scattering in the fiber. The amplification factor is a sensitive function of the input pulse parameters. Short input pulses are critical for the generation of very broad supercontinua with low noise.
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SCOPUS: er.j
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Conferencia leída con motivo del proyecto TIEM98 patrocinado por el Centr de Recerca Matemàtica del Institut d’Estudis Catalans.
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Me gustaría empezar haciendo un bosquejo de mis propias experiencias en el aprendizaje y enseñanza de la geometría. A lo largo de mi educación secundaria me enseñaron la geometría como una materia separada de la aritmética y del álgebra, a cargo de profesores diferentes y no formando parte de una asignatura integra llamada matemáticas.
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This paper presents a reified temporal logic for representing and reasoning about temporal and non-temporal relationships between non-temporal assertions. A clear syntax and semantics for the logic is formally provided. Three types of predicates, temporal predicates, non-temporal predicates and meta-predicates, are introduced. Terms of the proposed language are partitioned into three types, temporal terms, non-temporal terms and propositional terms. Reified propositions consist of formulae with each predicate being either a temporal predicate or a meta-predicate. Meta-predicates may take both temporal terms and propositional terms together as arguments or take propositional terms alone. A standard formula of the classical first-order language with each predicate being a non-temporal predicate taking only non-temporal terms as arguments is reified as just a propositional term. A general time ontology has been provided which can be specialized to a variety of existing temporal systems. The new logic allows one to predicate and quantify over propositional terms while according a special status of time; for example, assertions such as ‘effects cannot precede their causes’ is ensured in the logic, and some problematic temporal aspects including the delay time between events and their effects can be conveniently expressed. Applications of the logic are presented including the characterization of the negation of properties and their contextual sentences, and the expression of temporal relations between actions and effects.
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In this paper, a knowledge-based approach is proposed for the management of temporal information in process control. A common-sense theory of temporal constraints over processes/events, allowing relative temporal knowledge, is employed here as the temporal basis for the system. This theory supports duration reasoning and consistency checking, and accepts relative temporal knowledge which is in a form normally used by human operators. An architecture for process control is proposed which centres on an historical database consisting of events and processes, together with the qualitative temporal relationships between their occurrences. The dynamics of the system is expressed by means of three types of rule: database updating rules, process control rules, and data deletion rules. An example is provided in the form of a life scheduler, to illustrate the database and the rule sets. The example demonstrates the transitions of the database over time, and identifies the procedure in terms of a state transition model for the application. The dividing instant problem for logical inference is discussed with reference to this process control example, and it is shown how the temporal theory employed can be used to deal with the problem.