293 research outputs found

    A new approach to mass spectrometer measurements of thermospheric density

    Get PDF
    The gas sampling problem in satellite and high velocity probes was investigated by applying the theory of a drifting Maxwellian gas. A lens system using a free stream ion source was developed and experimentally evaluated over the pressure range of 0.00001 to 0.01 N/m sq (approx. 10 to the minus 7th power to 0.0001 torr). The source has high beam transparency, which minimizes gas-surface collisions within, or near, the ionization volume. It is shown that for high ion energy (60 eV), the extracted ion beam has an on-axis energy spread of less than 4 eV, and that 90 percent of the ions are within 2.5 deg of the beam axis. It is concluded that the molecular beam mass spectrometer concept, developed for gas density measurements in the upper atmosphere, substantially reduces gas-surface scattering and gas-surface reactions in the sample, and preserves the integrity of the gas sample during the analysis process. Studies show that both the Scout and Delta launch vehicles have adequate volume, control, velocity, and data acquisition capability necessary to obtain thermospheric number density in real time

    Robotic lobectomy: tips, pitfalls and troubleshooting

    Get PDF
    The robotic approach in thoracic surgery has rapidly gained popularity in recent years. As with the introduction of any new technology, this warrants not only adaptation of the operative technique itself, but also the evolution of appropriate troubleshooting strategies. A selected number of helpful tips and technical procedural manoeuvres have been compiled to prevent intraoperative problems, as well as to overcome challenging situations that can arise during robotic lobectomies. In robotic surgery, as opposed to open surgery or video-assisted thoracic surgery, these tips serve an important purpose for the operating surgeon, as well as the entire surgical team involved in the procedure. All the assembled recommendations have proved their effectiveness and have been successfully used by the authors in many procedures. Furthermore, these manoeuvres have been found to be of great importance in the training and proctoring of thoracic surgeons, fellows and residents (bed-side assistants). This guide of clearly arranged tips and troubleshooting strategies offers surgeons a useful tool to overcome difficult situations in robotic lobectomy and preferably improve the reproducibility and safety of their procedure

    Performance modeling of ultraviolet Raman lidar systems for daytime profiling of atmospheric water vapor

    Get PDF
    We describe preliminary results from a comprehensive computer model developed to guide optimization of a Raman lidar system for measuring daytime profiles of atmospheric water vapor, emphasizing an ultraviolet, solar-blind approach

    Antidepressent Treatment for Depression: Total Charges and Therapy Duration

    Get PDF
    Background: The economic costs of depression are significant, both the direct medical costs of care and the indirect costs of lost productivity. Empirical studies of antidepressant costeffectiveness suggest that the use of selective serotonin reuptake inhibitors (SSRI) may be no more costly than tricyclic antidepressants (TCA), will improve tolerability, and is associated with longer therapy duration. However the success of depression care usually involves multiple factors, including source of care, type of care, and patient characteristics, in addition to drug choice. The cost-effective mix of antidepressant therapy components is unclear. Aims of the Study: Our study evaluates cost and antidepressant-continuity outcomes for depressed patients receiving antidepressant therapy. Specifically, we determined the impact of provider choice for initial care, concurrent psychotherapy, and choice of SSRI versus TCA-based pharmacotherapies on the joint outcome of low treatment cost and continuous antidepressant therapy. Methods: A database of private health insurance claims identifies 2,678 patients who received both a diagnosis of depression and a prescription for an antidepressant during 1990–1994. Patients each fall into one of four groups according to whether their health care charges are high versus low (using the median value as the break point) and by whether their antidepressant usage pattern is continuous versus they discontinued pharmacotherapy early (filling fewer than six prescriptions). A bivariate probit model controlling for patient characteristics, co-morbidities, type of depression and concurrent treatment is the primary multivariate statistical vehicle for cost-effective treatment situation. Results: SSRIs substantially reduce the incidence of patients discontinuing pharmacotherapy while leaving charges largely unchanged. The relative effectiveness of SSRIs in depression treatment is independent of the patient’s personal characteristics and dominates the consequences of other treatment dimensions such as seeing a mental health specialist and receiving concurrent psychotherapy. Initial provider specialty is irrelevant to the continuity of pharmacotherapy, and concurrent psychotherapy creates a tradeoff through reduced pharmacotherapy interruption with higher costs. Discussion: Longer therapy duration is associated with SSRI-based pharmacotherapy (relative to TCA-based pharmacotherapy) and with concurrent psychotherapy. High cost is associated with concurrent psychotherapy and choice of a specialty provider for initial care. In our study cost-effective care includes SSRI-based pharmacotherapy initiated with a non-specialty provider. Previous treatment history and other unobserved factors that might affect antidepressant choice are not included in our model. Implications for Health Care Provision: The decision to use an SSRI-based pharmacotherapy need not consider carefully the patient’s personal characteristics. Shifting depressed patients’ pharmacotherapy away from TCAs to SSRIs has the effect of improving outcomes by lowering the incidence of discontinuation of pharmacotherapy while leaving largely unchanged the likelihood of having high overall health care charges. Targeted use of concurrent psychotherapy may be additionally cost-effective. Implications for Health Policies: The interaction of various components of depression care can alter the cost-effectiveness of antidepressant therapy. Our results demonstrate a role for the non-specialty provider in initiating care and support increased use of SSRIs as first-line therapy for depression as a way of providing cost-effective care that is consistent with APA guidelines for continuous antidepressant treatment. Implications for Further Research: Further research that improves our understanding of how decisions regarding provider choice, concurrent psychotherapy, and drug choice are made will improve our understanding of the effects treatment choices on the cost-effectiveness of depression care. We have suggested that targeted concurrent psychotherapy may prove to be cost-effective; research to determine groups most likely to benefit from the additional treatment would further enable clinicians and healthcare policy makers to form a consensus regarding a model for treating depression

    Monitoramento do lençol freático sob influência da irrigação com águas residuárias.

    Get PDF
    A aplicação de águas residuárias provenientes de Estações de Tratamento de Esgoto (ETE) na agricultura torna-se uma excelente opção como forma direta de preservação dos recursos hídricos e como fonte de água e nutrientes às culturas agrícolas. Entretanto existe pouco conhecimento sobre a infiltração dessas águas nos solos tropicais e o potencial de contaminação na zona saturada do sub-solo. O presente trabalho teve como objetivo monitorar o lençol freático sob diferentes lâminas de irrigação com efluente de ETE em área cultivada com cana-de-açúcar no município de Piracicaba-SP. O monitoramento foi realizado no período 12/ 2008 a 12/ 2009, com frequência bimestral, através de quatro poços de monitoramento (PM) distribuídos ao longo da área experimental. Foram avaliados os parâmetros considerados indicadores de poluição pela legislação vigente (N-NO3-, Al, B, Cd, Cr, Cu, Fe, Mn, Ni, Pb e Zn), além de carbono orgânico (DOC) e inorgânico (DIC) dissolvido, Cl, CE, P-PO4, N-NO2-, SO4 e Na. Dos resultados obtidos nenhum parâmetro apresentou valor superior aos considerados com necessidade de intervenção. Entretanto, de maneira geral, as maiores concentrações DIC, DOC, Cl, Na, SO4 e CE foram observadas no PM sob contribuição das maiores lâminas de efluentes aplicadas, sugerindo a importância de se aplicar uma lâmina ideal à cultura

    Keeper-animal interactions: differences between the behaviour of zoo animals affect stockmanship

    Get PDF
    Stockmanship is a term used to describe the management of animals with a good stockperson someone who does this in a in a safe, effective, and low-stress manner for both the stock-keeper and animals involved. Although impacts of unfamiliar zoo visitors on animal behaviour have been extensively studied, the impact of stockmanship i.e familiar zoo keepers is a new area of research; which could reveal significant ramifications for zoo animal behaviour and welfare. It is likely that different relationships are formed dependant on the unique keeper-animal dyad (human-animal interaction, HAI). The aims of this study were to (1) investigate if unique keeper-animal dyads were formed in zoos, (2) determine whether keepers differed in their interactions towards animals regarding their attitude, animal knowl- edge and experience and (3) explore what factors affect keeper-animal dyads and ultimately influence animal behaviour and welfare. Eight black rhinoceros (Diceros bicornis), eleven Chapman’s zebra (Equus burchellii), and twelve Sulawesi crested black macaques (Macaca nigra) were studied in 6 zoos across the UK and USA. Subtle cues and commands directed by keepers towards animals were identified. The animals latency to respond and the respective behavioural response (cue-response) was recorded per keeper-animal dyad (n=93). A questionnaire was constructed following a five-point Likert Scale design to record keeper demographic information and assess the job satisfaction of keepers, their attitude towards the animals and their perceived relationship with them. There was a significant difference in the animals’ latency to appropriately respond after cues and commands from different keepers, indicating unique keeper-animal dyads were formed. Stockmanship style was also different between keepers; two main components contributed equally towards this: “attitude towards the animals” and “knowledge and experience of the animals”. In this novel study, data demonstrated unique dyads were formed between keepers and zoo animals, which influenced animal behaviour
    • …
    corecore