Eight short-range, open-terrain SF
6
tracer tests in low wind speeds were conducted during Phase 2 of Project Sagebrush using continuous releases. Four tests were made during very unstable conditions ...in July and August 2016, and four during very stable conditions in October 2016. All tests featured 10-min averaging and 1-Hz sampling of tracer concentrations together with an extensive suite of meteorological measurements. We find that the uncertainty in well-mixed daytime measurements of tracer concentrations, using the absolute value of the relative percentage difference in collocated duplicate samplers, approaches a downwind limit of about 7–8%. Concentration variability in collocated sampling, due to stochastic factors and independent of measurement uncertainty, increases the total observational uncertainty closer to the source from about 20% (daytime) to 40% (very stable conditions). Longer averaging periods moderately reduce the concentration variability. The data indicate that the large increase in concentration variability is linked with the suppression of turbulent mixing, small eddy length scales, and meandering in very stable conditions. These results should be considered when comparing observations with model predictions in evaluations.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A number of numerical wind flow models have been developed for simulating wind flow at relatively fine spatial resolutions (e.g., ~ 100 m); however, there are very limited observational data ...available for evaluating these high-resolution models. This study presents high-resolution surface wind data sets collected from an isolated mountain and a steep river canyon. The wind data are presented in terms of four flow regimes: upslope, afternoon, downslope, and a synoptically driven regime. There were notable differences in the data collected from the two terrain types. For example, wind speeds on the isolated mountain increased with distance upslope during upslope flow, but generally decreased with distance upslope at the river canyon site during upslope flow. In a downslope flow, wind speed did not have a consistent trend with position on the isolated mountain, but generally increased with distance upslope at the river canyon site. The highest measured speeds occurred during the passage of frontal systems on the isolated mountain. Mountaintop winds were often twice as high as wind speeds measured on the surrounding plain. The highest speeds measured in the river canyon occurred during late morning hours and were from easterly down-canyon flows, presumably associated with surface pressure gradients induced by formation of a regional thermal trough to the west and high pressure to the east. Under periods of weak synoptic forcing, surface winds tended to be decoupled from large-scale flows, and under periods of strong synoptic forcing, variability in surface winds was sufficiently large due to terrain-induced mechanical effects (speed-up over ridges and decreased speeds on leeward sides of terrain obstacles) that a large-scale mean flow would not be representative of surface winds at most locations on or within the terrain feature. These findings suggest that traditional operational weather model (i.e., with numerical grid resolutions of around 4 km or larger) wind predictions are not likely to be good predictors of local near-surface winds on sub-grid scales in complex terrain. Measurement data can be found at http://www.firemodels.org/index.php/windninja-introduction/windninja-publications.
The HeartWare left ventricular assist device (HVAD, HeartWare Inc, Framingham, MA) is the first implantable centrifugal continuous-flow pump approved for use as a bridge to transplantation. An ...infrequent but serious adverse event of LVAD support is thrombus ingestion or formation in the pump. In this study, we analyze the incidence of pump thrombus, evaluate the comparative effectiveness of various treatment strategies, and examine factors pre-disposing to the development of pump thrombus.
The analysis included 382 patients who underwent implantation of the HVAD as part of the HeartWare Bridge to Transplant (BTT) and subsequent Continued Access Protocol (CAP) trial. Descriptive statistics and group comparisons were generated to analyze baseline characteristics, incidence of pump thrombus, and treatment outcomes. A multivariate analysis was performed to assess significant risk factors for developing pump thrombus.
There were 34 pump thrombus events observed in 31 patients (8.1% of the cohort) for a rate of 0.08 events per patient-year. The incidence of pump thrombus did not differ between BTT and CAP. Medical management of pump thrombus was attempted in 30 cases, and was successful in 15 (50%). A total of 16 patients underwent pump exchange, and 2 underwent urgent transplantation. Five patients with a pump thrombus died after medical therapy failed, 4 of whom also underwent a pump exchange. Survival at 1 year in patients with and without a pump thrombus was 69.4% and 85.5%, respectively (p = 0.21). A multivariable analysis revealed that significant risk factors for pump thrombus included a mean arterial pressure > 90 mm Hg, aspirin dose ≤ 81 mg, international normalized ratio ≤ 2, and Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile level of ≥ 3 at implant.
Pump thrombus is a clinically important adverse event in patients receiving an HVAD, occurring at a rate of 0.08 events per patient-year. Significant risk factors for pump thrombosis include elevated blood pressure and sub-optimal anti-coagulation and anti-platelet therapies. This suggests that pump thrombus event rates could be reduced through careful adherence to patient management guidelines.
Antimicrobial resistance results in increased morbidity, mortality, and costs of health care. Prevention of the emergence of resistance and the dissemination of resistant microorganisms will reduce ...these adverse effects and their attendant costs. Appropriate antimicrobial stewardship that includes optimal selection, dose, and duration of treatment, as well as control of antibiotic use, will prevent or slow the emergence of resistance among microorganisms. A comprehensively applied infection control program will interdict the dissemination of resistant strains.
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Project Sagebrush Finn, D.; Clawson, K. L.; Eckman, R. M. ...
Journal of applied meteorology and climatology,
06/2016, Volume:
55, Issue:
6
Journal Article
Peer reviewed
Open access
The first phase of an atmospheric tracer experiment program, designated Project Sagebrush, was conducted at the Idaho National Laboratory in October 2013. The purpose was to reevaluate the results of ...classical field experiments in short-range plume dispersion (e.g., Project Prairie Grass) using the newer technologies that are available for measuring both turbulence levels and tracer concentrations. All releases were conducted during the daytime with atmospheric conditions ranging from neutral to unstable. The key finding was that the values of the horizontal plume spread parameter σy
tended to be larger, by up to a factor of ∼2, than those measured in many previous field studies. The discrepancies tended to increase with downwind distance. The values of the ratio σy/σθ
, where σθ
is the standard deviation of the horizontal wind direction, also trend near the upper limit or above the range of values determined in earlier studies. There was also evidence to suggest that the value of σy
began to be independent of σθ
for σθ
greater than 18°. It was also found that the commonly accepted range of values for σθ
in different stability conditions might be limiting, at best, and might possibly be unrealistically low, especially at night in low wind speeds. The results raise questions about the commonly accepted magnitudes of σy
derived from older studies. These values are used in the parameterization and validation of both older stability-class dispersion models as well as newer models that are based on Taylor's equation and modern PBL theory.
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BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
Objectives
To assess current knowledge of National Heart, Lung and Blood Institutes (NHLBI) and Thalassemia International Federation (TIF) recommendations, blood banking practices and ...perceived challenges among transfusion services in the management of patients with haemoglobinopathies.
Background
Previous reports have demonstrated variations in transfusion practices for sickle cell disease (SCD) and thalassemia patients. Recently, NHLBI/TIF have provided transfusion recommendations for patients with haemoglobinopathies.
Methods
A cross‐sectional survey was conducted of transfusion services from the state of Georgia previously identified as having SCD/thalassemia populations. The survey assessed transfusion service practices in pre‐transfusion testing and blood product selection; awareness/implementation of NHLBI/TIF transfusion‐based recommendations and perceived challenges in transfusing haemoglobinopathy patients.
Results
Responses were received from 35 of 49 (71%) institutions. Only institutions indicating transfusing SCD or thalassemia patients (32) were included in analysis. Seventy‐one percent of non‐sickle cell treatment centres (SCTCs) and 20% of non‐thalassemia treatment centres follow NHLBI and TIF recommendations to perform a red blood cell phenotype beyond ABO/Rh(D) and provide Rh and Kell prophylactically matched units for SCD and thalassemia patients, respectively. Forty percent of institutions (33% of non‐SCTCs) employ RBC genotyping to evaluate the red cell phenotype for SCD patients. Over 77% of institutions do not utilise a reliable method to identify SCD patients prior to transfusion, such as a required question/answer field on type/screen or crossmatch orders.
Conclusion
Many healthcare systems' transfusion practices for haemoglobinopathy patients are discordant with NHLBI/TIF recommendations. Efforts are needed to increase awareness and implementation of current recommendations among all transfusion services seeing these patients.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Sickle cell disease is a group of disorders, the majority of which are detected through state newborn screening programs. There is limited knowledge of disease prevalence in the U.S. ...population. We report 20 years of case finding and laboratory data for sickle cell disease and trait to assist in: planning for health services delivery; providing data for researchers; aiding in tracking health outcome trends; and assessing sickle gene prevalence in the newborn population. During the 20-year period, there were 39,422 confirmed cases of sickle cell disease among 76,527,627 newborn births screened (1:1941) and 1,107,875 laboratory reports of probable sickle trait among 73,951,175 newborn births screened (1:67). The highest sickle cell disease incidence during the 20 years was in the District of Columbia (1:437) followed by Mississippi (1:683) and South Carolina (1:771). For sickle cell trait, the highest incidences were in the District of Columbia (1:22), Mississippi (1:26), and South Carolina (1:31).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Blood trauma caused by continuous-flow left ventricular assist devices (CF-LVADs) has been associated with device thrombosis and anemia. Accurate in vivo quantification of erythrocyte turnover and ...its contribution to CF-LVAD complications have yet to be elucidated.
We investigated the age (lifespan) of circulating erythrocytes in subjects with CF-LVAD. Erythrocyte lifespan is a quantitative indicator of in vivo erythrocyte turnover that can be accurately derived from measurement of the exhaled carbon monoxide (CO) level. Sixty non-smoking subjects were prospectively enrolled: 25 had a CF-LVAD without thrombosis; 10 had a CF-LVAD with thrombosis; and 25 were normal controls. End-tidal breath CO levels were measured and used to calculate erythrocyte lifespan.
The mean erythrocyte lifespan was significantly shorter in CF-LVAD subjects with (29.7 ± 14.9 days) compared to those without (65.0 ± 17.3 days) device thrombosis (p < 0.0001). The lifespans in these 2 groups were significantly shorter compared with normal controls (96.0 ± 24.9 days, both p < 0.0001). A receiver operator curve demonstrated high sensitivity-specificity for use of erythrocyte lifespan to detect device thrombosis (AUC = 0.94). In addition, all CF-LVAD subjects had low hemoglobin (11.8 ± 2.0 g/dl), and their anemia was normochromic normocytic with elevated mean reticulocyte counts. Erythrocyte lifespan correlated significantly with mean corpuscular hemoglobin concentration (r = 0.56, p = 0.0005) and red cell distribution width (r = -0.65, p < 0.001), but not with reticulocyte count (r = 0.27, p = 0.32).
Erythrocyte lifespan is substantially reduced in subjects with a CF-LVAD, which was more pronounced in the presence of device thrombosis. The etiology of anemia in CF-LVAD was primarily due to accelerated erythrocyte aging. Further studies are needed to determine whether erythrocyte lifespan could provide a practical means of detecting subtle pre-clinical thrombosis.
Large, rapid, and intermittent changes in wind direction were commonly observed in low–wind speed conditions in the very stable boundary layer during the phase 2 of the Project Sagebrush field tracer ...study. This paper investigates the occurrence and magnitude of these wind direction changes in the very stable boundary layer and explores their associated meteorological factors. The evidence indicates that these wind direction changes occur mainly at wind speeds of less than 1.5 m s−1 and are associated with momentum and sensible heat fluxes approaching zero in low–wind shear conditions. This results in complete vertical decoupling. They are only weakly dependent on the magnitude of turbulence. The magnitude of the wind direction changes is generally greatest near the surface, because of the greater prevalence of low wind speeds there, and decreases upward.
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BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Two substrates of insulin-degrading enzyme (IDE), amyloid β-protein (Aβ) and insulin, are critically important in the pathogenesis of Alzheimer's disease (AD) and type 2 diabetes mellitus (DM2), ...respectively. We previously identified IDE as a principal regulator of Aβ levels in neuronal and microglial cells. A small chromosomal region containing a mutant IDE allele has been associated with hyperinsulinemia and glucose intolerance in a rat model of DM2. Human genetic studies have implicated the IDE region of chromosome 10 in both AD and DM2. To establish whether IDE hypofunction decreases Aβ and insulin degradation in vivo and chronically increases their levels, we characterized mice with homozygous deletions of the IDE gene (IDE -/-). IDE deficiency resulted in a >50% decrease in Aβ degradation in both brain membrane fractions and primary neuronal cultures and a similar deficit in insulin degradation in liver. The IDE -/- mice showed increased cerebral accumulation of endogenous Aβ, a hallmark of AD, and had hyperinsulinemia and glucose intolerance, hallmarks of DM2. Moreover, the mice had elevated levels of the intracellular signaling domain of the β-amyloid precursor protein, which was recently found to be degraded by IDE in vitro. Together with emerging genetic evidence, our in vivo findings suggest that IDE hypofunction may underlie or contribute to some forms of AD and DM2 and provide a mechanism for the recently recognized association among hyperinsulinemia, diabetes, and AD.
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