70 research outputs found

    Statistical diagnostic and correction of a chemistry-transport model for the prediction of total column ozone

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    International audienceIn this paper, we introduce a statistical method for examining and adjusting chemical-transport models. We illustrate the findings with total column ozone predictions, based on the University of Illinois at Urbana-Champaign 2-D (UIUC 2-D) chemical-transport model of the global atmosphere. We propose a general diagnostic procedure for the model outputs in total ozone over the latitudes ranging from 60° South to 60° North to see if the model captures some typical patterns in the data. The method proceeds in two steps to avoid possible collinearity issues. First, we regress the measurements given by a cohesive data set from the SBUV(/2) satellite system on the model outputs with an autoregressive noise component. Second, we regress the residuals of this first regression on the solar flux, the annual cycle, the Antarctic or Arctic Oscillation, and the Quasi Biennial Oscillation. If the coefficients from this second regression are statistically significant, then they mean that the model did not simulate properly the pattern associated with these factors. Systematic anomalies of the model are identified using data from 1979 to 1995, and statistically corrected afterwards. The 1996?2003 validation sample confirms that the combined approach yields better predictions than the direct UIUC 2-D outputs

    An Ethnohistorical Perspective on Cheyenne Demography

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    Administrative censuses of the Southern Cheyenne Indians from 1880,1891, and 1900 permit family reconstitution, identification of residence groups, and comparisons of fertility between monogamous and polygynous women, when the records are approached by ethnohistori cal methods. This approach includes an awareness of the aboriginal adoption practices, kinship system, and naming practices. It is argued that the biases and distortions of administrative records can be effectively corrected to add to our store of information on band and tribal societies.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Prenatal Hypoxic-Ischemic Insult Changes the Distribution and Number of NADPH-Diaphorase Cells in the Cerebellum

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    Astrogliosis, oligodendroglial death and motor deficits have been observed in the offspring of female rats that had their uterine arteries clamped at the 18th gestational day. Since nitric oxide has important roles in several inflammatory and developmental events, here we evaluated NADPH-diaphorase (NADPH-d) distribution in the cerebellum of rats submitted to this hypoxia-ischemia (HI) model. At postnatal (P) day 9, Purkinje cells of SHAM and non-manipulated (NM) animals showed NADPH-d+ labeling both in the cell body and dendritic arborization in folia 1 to 8, while HI animals presented a weaker labeling in both cellular structures. NADPH-d+ labeling in the molecular (ML), and in both the external and internal granular layer, was unaffected by HI at this age. At P23, labeling in Purkinje cells was absent in all three groups. Ectopic NADPH-d+ cells in the ML of folia 1 to 4 and folium 10 were present exclusively in HI animals. This labeling pattern was maintained up to P90 in folium 10. In the cerebellar white matter (WM), at P9 and P23, microglial (ED1+) NADPH-d+ cells, were observed in all groups. At P23, only HI animals presented NADPH-d labeling in the cell body and processes of reactive astrocytes (GFAP+). At P9 and P23, the number of NADPH-d+ cells in the WM was higher in HI animals than in SHAM and NM ones. At P45 and at P90 no NADPH-d+ cells were observed in the WM of the three groups. Our results indicate that HI insults lead to long-lasting alterations in nitric oxide synthase expression in the cerebellum. Such alterations in cerebellar differentiation might explain, at least in part, the motor deficits that are commonly observed in this model

    The spatial structure of lithic landscapes : the late holocene record of east-central Argentina as a case study

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    Fil: Barrientos, Gustavo. División Antropología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Catella, Luciana. División Arqueología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Oliva, Fernando. Centro Estudios Arqueológicos Regionales. Facultad de Humanidades y Artes. Universidad Nacional de Rosario; Argentin

    RBC Transfusions Are Associated with Prolonged Mechanical Ventilation in Pediatric Acute Respiratory Distress Syndrome

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    Copyright © 2017 by the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies. Blood products are often transfused in critically ill children, although recent studies have recognized their potential for harm. Translatability to pediatric acute respiratory distress syndrome is unknown given that hypoxemia has excluded pediatric acute respiratory distress syndrome patients from clinical trials. We aimed to determine whether an association exists between blood product transfusion and survival or duration of ventilation in pediatric acute respiratory distress syndrome. Design: Retrospective analysis of prospectively enrolled cohort. Setting: Large, academic PICU. Patients: Invasively ventilated children meeting Berlin Acute Respiratory Distress Syndrome and Pediatric Acute Lung Injury Consensus Conference Pediatric Acute Respiratory Distress Syndrome criteria from 2011 to 2015. Interventions: We recorded transfusion of RBC, fresh frozen plasma, and platelets within the first 3 days of pediatric acute respiratory distress syndrome onset. Each product was tested for independent association with survival (Cox) and duration of mechanical ventilation (competing risk regression with extubation as primary outcome and death as competing risk). A sensitivity analysis using 1:1 propensity matching was also performed. Measurements and Main Results: Of 357 pediatric acute respiratory distress syndrome patients, 155 (43%) received RBC, 82 (23%) received fresh frozen plasma, and 92 (26%) received platelets. Patients who received RBC, fresh frozen plasma, or platelets had higher severity of illness score, lower Pao2/Fio2, and were more often immunocompromised (all p \u3c 0.05). Patients who received RBC, fresh frozen plasma, or platelets had worse survival and longer duration of ventilation by univariate analysis (all p \u3c 0.05). After multivariate adjustment for above confounders, no blood product was associated with survival. After adjustment for the same confounders, RBC were associated with decreased probability of extubation (subdistribution hazard ratio, 0.65; 95% CI, 0.51-0.83). The association between RBC and prolonged ventilation was confirmed in propensity-matched subgroup analysis. Conclusions: RBC transfusion was independently associated with longer duration of mechanical ventilation in pediatric acute respiratory distress syndrome. Hemoglobin transfusion thresholds should be tested specifically within pediatric acute respiratory distress syndrome to establish whether a more restrictive transfusion strategy would improve outcomes

    Cardiac manifestations of Alstrom syndrome: echocardiographic findings.

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    BACKGROUND: Alstrom syndrome is an extremely rare autosomal recessive genetic disorder characterized by infantile-onset cardiomyopathy (CMP), blindness, hearing impairment/loss, and obesity. Prior reports have demonstrated that the dilated CMP of Alstrom syndrome occurs in about 62% of patients with this syndrome. To date, there have been no reports examining the echocardiographic features of Alstrom-related heart disease. METHODS: Eleven patients diagnosed with Alstrom syndrome who underwent one or more transthoracic echocardiograms from 1994 to 2003 were retrospectively evaluated. A total of 16 transthoracic echocardiograms were comprehensively reviewed with an emphasis on chamber sizes, wall thickness, left ventricular (LV) and right ventricular (RV) systolic function, and valve function. RESULTS: Four of 11 patients (36%) had evidence of global LV systolic dysfunction (quantitative ejection fraction [EF] range 9%-29%). Three of these 4 patients also had severe generalized RV systolic dysfunction, whereas one had normal RV systolic function. LV and RV dilation was present in 3 of 4. All patients with low EF had an apically tethered mitral valve closure pattern although only one of 4 had more than mild mitral regurgitation. Although 3 of 4 patients with low EF had an apically tethered tricuspid valve closure pattern, none had more than mild tricuspid regurgitation. Reduced EF was not associated with regional wall-motion abnormalities. Three of 11 patients (27%) overall and two of 4 of the patients with low EF (50%) had pericardial effusions. CONCLUSIONS: The Alstrom CMP in this cohort of patients was typically dilated and nonsegmental with predominantly biventricular involvement. It was infrequently associated with myocardial hypertrophy. Apically tethered mitral and tricuspid valve closure patterns were visualized, although severe functional valvular insufficiency was not present. LV and left atrial dilation was observed in a number of patients without reduced EF, and may be an early stage in the development of the CMP
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