565 research outputs found

    Autoionization effects in ultraviolet absorption spectra of hot gases Scientific report no. 6

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    Autoionization effects in ultraviolet absorption spectra of hot gase

    I\u27ll Come Back to Dixieland, If You\u27ll Come Back to Me

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    https://digitalcommons.library.umaine.edu/mmb-vp/5546/thumbnail.jp

    Shock Tube Determination of Autoionization Lifetime and Oscillator Strengths of the 352 3P 2Po-353P2 2S1/2 Doublet of Al I Scientific Report No. 2

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    Shock tube measurement of autoionization lifetime and oscillator strengths of states above first ionization potential for aluminu

    Absorption line series and autoionization resonance structure analysis in the ultraviolet spectrum of Sr I

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    Photoelectric spectrometer to measure absorption line series and autoionization resonance in ultraviolet spectrum of strontium vapo

    Cost-effectiveness analysis of endoscopic third ventriculostomy

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    Journal ArticleOBJECTIVE: Endoscopic third ventriculostomy (ETV) is currently the principal alternative to cerebrospinal fluid shunt placement in the management of pediatric hydrocephalus. Cost-effectiveness analysis can help determine the optimal strategy for integrating these different approaches. METHODS: All patients (n = 28) who underwent ETV at British Columbia's Children's Hospital between 1989 and 1998 were matched for age, pathogenesis, and number of previous shunt procedures, with patients treated with cerebrospinal fluid shunts. To perform a cost-effectiveness analysis, hydrocephalus-related resource consumption and outcome (determined as the number of hydrocephalus treatment-free days during follow-up) were then retrospectively identified. Cost data were linked to resource use to provide a total cost for all resources used. Costs and outcomes were discounted annually at 5% by standard economic analysis methods. RESULTS: Twenty-four of 28 ETV patients had obstructive hydrocephalus. Over equivalent follow-up periods (median, 35 mo), the ETV success rate (defined by need for reoperation) was 54%.One hydrocephalus-related death and one hemiparesis occurred in the ETV group. No permanent procedure-related morbidity or mortality was seen in the shunt group. The cost/effect ratios for the two groups were similar. The additional incremental resource use by the shunt group included six readmissions and eight reoperations. ETV mean costs per patient were 10,570±10,570 ± 7628, versus 10,922±10,922 ± 8722 for the shunt group (Canadian dollars for the year 2000). Costs accrued more quickly for the shunt group as time passed. The additional incremental outcome benefit to the endoscopy group was 86 treatment-free days (3.07 d per patient [95% confidence interval, -7.56 to 13.70 d]). Neither of these differences was statistically significant. CONCLUSION: In this matched cohort, ETV was not significantly less costly or more effective over a median 35 months of follow-up, with a 54% initial ETV success rate, even before the additional morbidity and mortality encountered were taken into account. The time course for the accrued costs suggests that a larger cohort, longer follow-up, or higher success rates are needed to demonstrate the cost-effectiveness of this therapy

    Predicting shunt failure on the basis of clinical symptoms and signs in children

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    Journal ArticleObject. In evaluating pediatric patients for shunt malfunction, predictive values for symptoms and signs are important in deciding which patients should undergo an imaging study, whereas determining clinical findings that correlate with a low probability of shunt failure could simplify management. Methods. Data obtained during the recently completed Pediatric Shunt Design Trial (PSDT) were analyzed. Predictive values were calculated for symptoms and signs of shunt failure. To refine predictive capability, a shunt score based on a cluster of signs and symptoms was derived and validated using multivariate methods. Four hundred thirty-one patient encounters after recent shunt insertions were analyzed. For encounters that took place within 5 months after shunt insertion (early encounters), predictive values for symptoms and signs included the following: nausea and vomiting (positive predictive value [PPV] 79%, likelihood ratio [LR] 10.4), irritability (PPV 78%, LR 9.8), decreased level of consciousness (LOC) (PPV 100%), erythema (PPV 100%), and bulging fontanelle (PPV 92%, LR 33.1). Between 9 months and 2 years after shunt insertion (late encounters), only loss of developmental milestones (PPV 83%, LR 36.7) and decreased LOC (PPV 100%) were strongly associated with shunt failure. However, the absence of a symptom or sign still left a 15 to 29% (early encounter group) or 9 to 13% (late encounter group) chance of shunt failure. Using the shunt score developed for early encounters, which sums from 1 to 3 points according to the specific symptoms or signs present, patients with scores of 0, 1, 2, and 3 or greater had shunt failure rates of 4%, 50%, 75%, and 100%, respectively. Using the shunt score derived from late encounters, patients with scores of 0, 1, and 2 or greater had shunt failure rates of 8%, 38%, and 100%, respectively. Conclusions. In children, certain symptoms and signs that occur during the first several months following shunt insertion are strongly associated with shunt failure; however, the individual absence of these symptoms and signs offers the clinician only a limited ability to rule out a shunt malfunction. Combining them in a weighted scoring system improves the ability to predict shunt failure based on clinical findings

    Management of shunt infections: a multicenter pilot study

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    Journal ArticleObject. Approximately 10% of cerebrospinal fluid (CSF) shunt operations are associated with infection and require removal or externalization of the shunt, in-hospital treatment with antibiotic agents, and insertion of a new shunt. In a previous survey, the authors identified substantial variation in the duration of antibiotic therapy as well as the duration of hospital stay. The present multicenter pilot study was undertaken to evaluate current strategies in the treatment of shunt infection. Methods. Patients were enrolled in the study if they had a successful treatment of a CSF shunt infection proved by culture of a CSF specimen. Details of their care and the incidence of culture-proved reinfection were recorded. Seventy patients from 10 centers were followed up for 1 year after their CSF shunt infection. The initial management of the infection was shunt externalization in 17 patients, shunt removal and external ventricular drain insertion in 50, and antibiotic treatment alone in three. Reinfection occurred in 18 patients (26%). Twelve of the 18 reinfections were caused by the same organism and six were due to new organisms. The treatment time varied from 4 to 47 days, with a mean of 17.4 days for those who later experienced a reinfection compared with 16.2 days for those who did not. The most common organism (Staphylococcus epidermidis, 34 patients) was associated with a reinfection rate of 29% and a mean treatment time of 12.8 days for those who suffered reinfection and 12.5 days for those who did not. Conclusions. Reinfection after treatment of a CSF shunt infection is alarmingly common. According to the data available, the incidence of reinfection does not appear to be related to the duration of antibiotic therapy

    The relative contribution of climate to changes in lesser prairie-chicken abundance

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    Citation: Ross, B. E., Haukos, D., Hagen, C., & Pitman, J. (2016). The relative contribution of climate to changes in lesser prairie-chicken abundance. Ecosphere, 7(6), 11. doi:10.1002/ecs2.1323Managing for species using current weather patterns fails to incorporate the uncertainty associated with future climatic conditions; without incorporating potential changes in climate into conservation strategies, management and conservation efforts may fall short or waste valuable resources. Understanding the effects of climate change on species in the Great Plains of North America is especially important, as this region is projected to experience an increased magnitude of climate change. Of particular ecological and conservation interest is the lesser prairie-chicken (Tympanuchus pallidicinctus), which was listed as "threatened" under the U.S. Endangered Species Act in May 2014. We used Bayesian hierarchical models to quantify the effects of extreme climatic events (extreme values of the Palmer Drought Severity Index [PDSI]) relative to intermediate (changes in El Nino Southern Oscillation) and long-term climate variability (changes in the Pacific Decadal Oscillation) on trends in lesser prairie-chicken abundance from 1981 to 2014. Our results indicate that lesser prairie-chicken abundance on leks responded to environmental conditions of the year previous by positively responding to wet springs (high PDSI) and negatively to years with hot, dry summers (low PDSI), but had little response to variation in the El Nino Southern Oscillation and the Pacific Decadal Oscillation. Additionally, greater variation in abundance on leks was explained by variation in site relative to broad-scale climatic indices. Consequently, lesser prairie-chicken abundance on leks in Kansas is more strongly influenced by extreme drought events during summer than other climatic conditions, which may have negative consequences for the population as drought conditions intensify throughout the Great Plains
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