836 research outputs found
Condições do mercado de trabalho e organização do trabalho nas plantações na economia cafeeira de São Paulo, 1885-1915: uma análise preliminar
Este trabalho se inclui no debate atual sobre o papel do imigrante nas fazendas de café no fim do século passado. Sua conclusão básica é que as condições do mercado cafeeiro e do mercado de trabalho permitiram ao colono médio melhorar sua posição econômica e ascender verticalmente na sociedade brasileira. Para tanto, o autor utiliza-se de dados primários obtidos em fontes ainda não muito exploradas como a Estatística Agrícola e Zootécnica, 1904-05. Estas informações revelam a estrutura do mercado de mão-de-obra, e indicam em vários períodos uma situação de escassez relativa de trabalho
Experiential Learning Programs for the Future of Engineering Education
The need for 21st century engineers to be educated as creative innovators is discussed. Three complementary experiential learning programs that help engineering students learn to stretch beyond their comfort zones are described: a multidisciplinary design program; an entrepreneurship program; and an international engineering program. These three interdisciplinary programs each address common educational needs: to create flexible, creative, self-actualized change agents. The approaches we are taking to implement and institutionalize these in a large, comprehensive, research oriented university are described.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86757/1/Sick5.pd
Bromine measurements in ozone depleted air over the Arctic Ocean
In situ measurements of ozone, photochemically active bromine compounds, and other trace gases over the Arctic Ocean in April 2008 are used to examine the chemistry and geographical extent of ozone depletion in the arctic marine boundary layer (MBL). Data were obtained from the NOAA WP-3D aircraft during the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) study and the NASA DC-8 aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) study. Fast (1 s) and sensitive (detection limits at the low pptv level) measurements of BrCl and BrO were obtained from three different chemical ionization mass spectrometer (CIMS) instruments, and soluble bromide was measured with a mist chamber. The CIMS instruments also detected Br2. Subsequent laboratory studies showed that HOBr rapidly converts to Br2 on the Teflon instrument inlets. This detected Br2 is identified as active bromine and represents a lower limit of the sum HOBr + Br2. The measured active bromine is shown to likely be HOBr during daytime flights in the arctic. In the MBL over the Arctic Ocean, soluble bromide and active bromine were consistently elevated and ozone was depleted. Ozone depletion and active bromine enhancement were confined to the MBL that was capped by a temperature inversion at 200–500 m altitude. In ozone-depleted air, BrO rarely exceeded 10 pptv and was always substantially lower than soluble bromide that was as high as 40 pptv. BrCl was rarely enhanced above the 2 pptv detection limit, either in the MBL, over Alaska, or in the arctic free troposphere
Chronic administration of R-flurbiprofen attenuates learning impairments in transgenic amyloid precursor protein mice
<p>Abstract</p> <p>Background</p> <p>Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced incidence of Alzheimer's disease (AD). We and others have shown that certain NSAIDs reduce secretion of Aβ42 in cell culture and animal models, and that the effect of NSAIDs on Aβ42 is independent of the inhibition of cyclooxygenase by these compounds. Since Aβ42 is hypothesized to be the initiating pathologic molecule in AD, the ability of these compounds to lower Aβ42 selectively may be associated with their protective effect. We have previously identified <it>R</it>-flurbiprofen (tarenflurbil) as a selective Aβ42 lowering agent with greatly reduced cyclooxygenase activity that shows promise for testing this hypothesis. In this study we report the effect of chronic <it>R</it>-flurbiprofen treatment on cognition and Aβ loads in Tg2576 APP mice.</p> <p>Results</p> <p>A four-month preventative treatment regimen with <it>R</it>-flurbiprofen (10 mg/kg/day) was administered to young Tg2576 mice prior to robust plaque or Aβ pathology. This treatment regimen improved spatial learning as assessed by the Morris water maze, indicated by an increased spatial bias during the third probe trial and an increased utilization of a place strategy to solve the water maze. These results are consistent with an improvement in hippocampal- and medial temporal lobe-dependent memory function. A modest, though not statistically significant, reduction in formic acid-soluble levels of Aβ was also observed. To determine if R-flurbiprofen could reverse cognitive deficits in Tg2576 mice where plaque pathology was already robust, a two-week therapeutic treatment was given to older Tg2576 mice with the same dose of <it>R</it>-flurbiprofen. This approach resulted in a significant decrease in Aβ plaque burden but no significant improvement in spatial learning.</p> <p>Conclusion</p> <p>We have found that chronic administration of <it>R</it>-flurbiprofen is able to attenuate spatial learning deficits if given prior to plaque deposition in Tg2576 mice. Given its ability to selectively target Aβ42 production and improve cognitive impairments in transgenic APP mice, as well as promising data from a phase 2 human clinical trial, future studies are needed to investigate the utility of <it>R</it>-flurbiprofen as an AD therapeutic and its possible mechanisms of action.</p
A randomised controlled trial of breast cancer genetics services in South East Scotland:Psychological impact
This study compared the psychological impact of two models of breast cancer genetics services in South East Scotland. One hundred and seventy general practices were randomised to refer patients to the existing standard regional service or the novel community based service. Participants completed postal questionnaires at baseline (n¼373), 4 weeks (n¼276) and 6 months (n¼263) to assess perceived risk of breast cancer, subjective and objective understanding of genetics and screening issues, general psychological\ud
distress, cancer worry and health behaviours. For participants in both arms of the trial, there were improvements in subjective and objective understanding up to 4 weeks which were generally sustained up to 6 months. However, improvements in subjective understanding for the women at low risk of breast cancer (i.e. not at significantly increased risk) in the standard service arm did not reach statistical significance. Cancer worry was significantly reduced at 6 months for participants in both arms of the trial. The two models of cancer genetics services tested were generally comparable in terms of the participants’ psychological outcomes. Therefore,\ud
decisions regarding the implementation of the novel community-based service should be based on the resources required and client satisfaction with the service
Ethical and methodological issues in engaging young people living in poverty with participatory research methods
This paper discusses the methodological and ethical issues arising from a project that focused on conducting a qualitative study using participatory techniques with children and young people living in disadvantage. The main aim of the study was to explore the impact of poverty on children and young people's access to public and private services. The paper is based on the author's perspective of the first stage of the fieldwork from the project. It discusses the ethical implications of involving children and young people in the research process, in particular issues relating to access and recruitment, the role of young people's advisory groups, use of visual data and collection of data in young people's homes. The paper also identifies some strategies for addressing the difficulties encountered in relation to each of these aspects and it considers the benefits of adopting participatory methods when conducting research with children and young people
UBF levels determine the number of active ribosomal RNA genes in mammals
In mammals, the mechanisms regulating the number of active copies of the ∼200 ribosomal RNA (rRNA) genes transcribed by RNA polymerase I are unclear. We demonstrate that depletion of the transcription factor upstream binding factor (UBF) leads to the stable and reversible methylation-independent silencing of rRNA genes by promoting histone H1–induced assembly of transcriptionally inactive chromatin. Chromatin remodeling is abrogated by the mutation of an extracellular signal-regulated kinase site within the high mobility group box 1 domain of UBF1, which is required for its ability to bend and loop DNA in vitro. Surprisingly, rRNA gene silencing does not reduce net rRNA synthesis as transcription from remaining active genes is increased. We also show that the active rRNA gene pool is not static but decreases during differentiation, correlating with diminished UBF expression. Thus, UBF1 levels regulate active rRNA gene chromatin during growth and differentiation
Analysis of patient safety event report categories at one large academic hospital
Given the persistent safety incidents in operating rooms (ORs) nationwide (approx. 4000 preventable harmful surgical errors per year), there is a need to better analyze and understand reported patient safety events. This study describes the results of applying the Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS) supported by the Teamwork Evaluation of Non-Technical Skills (TENTS) instrument to analyze patient safety event reports at one large academic medical center. Results suggest that suboptimal behaviors stemming from poor communication, lack of situation monitoring, and inappropriate task prioritization and execution were implicated in most reported events. Our proposed methodology offers an effective way of programmatically sorting and prioritizing patient safety improvement efforts
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