712 research outputs found
Data base formation and assessment of biotic and abiotic parameters associated with artificial reefs
There is a critical need for accurate data in order to make decisions regarding the construction, emplacement, and further development of artificial reefs in the State of Florida.
This study looked a biotic and abiotic parameters of articifial reefs. A data matrix listing reefs on the vertical axis and the associated biotic and a biotic data or attributes available from published and non-pub1ished sources on the horizontal axis created: 1) a compilation of what data were available; 2) an indication of the completeness and extensiveness of the data; 3) a summary of the descriptive statistics of the data; 4) a preliminary
analysis of the relationship among the biotic and abiotic parameters through correlation analysis; 5) some preliminary modeling of the artificial reefs to form the basis of prediction through stepwise and multiple linear
regression analysis. (29pp.
Commentary on comparison of MODIS snow cover and albedo products with ground observations over the mountainous terrain of Turkey
International audienceThe MODerate-resolution Imaging Spectroradiometer (MODIS) snow cover product was evaluated by Parajka and Blösch (2006) over the territory of Austria. The spatial and temporal variability of the MODIS snow product classes are analyzed, the accuracy of the MODIS snow product against numerous in situ snow depth data are examined and the main factors that may influence the MODIS classification accuracy are identified in their studies. The authors of this paper would like to provide more discussion to the scientific community on the "Validation of MODIS snow cover images" when similar methodology is applied to mountainous regions covered with abundant snow but with limited number of ground survey and automated stations. Daily snow cover maps obtained from MODIS images are compared with ground observations in mountainous terrain of Turkey for the winter season of 2002?2003 and 2003?2004 during the accumulation and ablation periods of snow. Snow depth and density values are recorded to determine snow water equivalent (SWE) values at 19 points in and around the study area in Turkey. Comparison of snow maps with in situ data show good agreement with overall accuracies in between 62 to 82 percent considering a 2-day shift during cloudy days. Studies show that the snow cover extent can be used for forecasting of runoff hydrographs resulting mostly from snowmelt for a mountainous basin in Turkey. MODIS-Terra snow albedo products are also compared with ground based measurements over the ablation stage of 2004 using the automated weather operating stations (AWOS) records at fixed locations as well as from the temporally assessed measuring sites during the passage of the satellite. Temporarily assessed 20 ground measurement sites are randomly distributed around one of the AWOS stations and both MODIS and ground data were aggregated in GIS for analysis. Reduction in albedo is noticed as snow depth decreased and SWE values increased
The confusion assessment method for the intensive care unit in patients with cirrhosis
In the intensive care unit (ICU), delirium is routinely measured with the widely-used, validated Confusion Assessment Method for the ICU (CAM-ICU), but CAM-ICU has not been studied in patients with cirrhosis. We studied a group of patients with cirrhosis to determine the relationship between delirium measured by CAM-ICU and clinical outcomes. Consecutive patients with cirrhosis admitted to the ICU from 2009 to 2012 were included in a retrospective cohort study. Patients were screened twice daily for coma and delirium during their ICU stay using the Richmond Agitation Sedation Scale (RASS) and CAM-ICU. The association between delirium/coma and mortality was determined using multiple logistic regression. RASS and CAM-ICU were also compared to a retrospective assessment of hepatic encephalopathy (HE). Of 91 patients with cirrhosis, 26 (28.6 %) developed delirium/coma. RASS/CAM-ICU had fair agreement with the HE assessment (κ 0.38). Patients with delirium/coma had numerically greater mortality in-hospital (23.1 vs. 7.7 %, p = 0.07) and at 90 days (30.8 vs. 18.5 %, p = 0.26), and they also had longer hospital length of stay (median 19.5 vs. 6 days, p < 0.001). Delirium/coma was associated with increased inpatient mortality, independent of disease severity (unadjusted OR 3.6; 95 % CI, 0.99-13.1; MELD-adjusted OR 5.4; 95 % CI, 1.3-23.8; acute physiology score-adjusted OR 2.2; 95 % CI, 0.53-8.9). Delirium/coma was also associated with longer length of stay after adjusting for disease severity. In critically ill patients with cirrhosis, delirium/coma as measured by the RASS and CAM-ICU is associated with increased mortality and hospital length of stay. For these patients, these measures provide valuable information and may be useful tools for clinical care. RASS and CAM-ICU need to be compared to HE-specific measures in future studies
Paracentesis is Associated with Reduced Mortality in Patients Hospitalized with Cirrhosis and Ascites
Diagnostic paracentesis is recommended for patients with cirrhosis admitted to the hospital for ascites or encephalopathy. However, it is not known if clinicians in the United States adhere to this recommendation; a relationship between paracentesis and clinical outcome has not been reported. We analyzed a US database to determine the frequency of paracentesis and its association with mortality.
Methods
The 2009 Nationwide Inpatient Sample (which contains data from approximately 8 million hospital discharges each year) was used to identify patients with cirrhosis and ascites admitted with a primary diagnosis of ascites or encephalopathy. In-hospital mortality, length of stay, and hospital charges were compared for those who did and did not undergo paracentesis. Outcomes were compared for those who received an early paracentesis (within 1 day of admission) and those who received one later.
Results
Of 17,711 eligible admissions, only 61% underwent paracentesis. In-hospital mortality was reduced by 24% among patients who underwent paracentesis (6.5% vs 8.5%, adjusted odds ratio [OR], 0.55; 95% confidence interval [CI], 0.41–0.74). Most paracenteses (66%) occurred ≤1 day after admission. In-hospital mortality was lower among patients who received early paracentesis than those who received it later (5.7% vs 8.1%; P=.049), although this difference was not significant after adjustment for confounders (OR, 1.26; 95% CI, 0.78–2.02). Among patients who underwent paracentesis, the mean hospital stay was 14% longer, and hospital charges were 29% greater than for patients that did not receive the procedure.
Conclusions
Paracentesis is underused for patients admitted to the hospital with ascites; the procedure is associated with increased short-term survival. These data support practice guidelines derived from expert opinion. Studies are needed to identify barriers to guideline adherence
Harnessing Higher-Order (Meta-)Logic to Represent and Reason with Complex Ethical Theories
The computer-mechanization of an ambitious explicit ethical theory, Gewirth's
Principle of Generic Consistency, is used to showcase an approach for
representing and reasoning with ethical theories exhibiting complex logical
features like alethic and deontic modalities, indexicals, higher-order
quantification, among others. Harnessing the high expressive power of Church's
type theory as a meta-logic to semantically embed a combination of quantified
non-classical logics, our work pushes existing boundaries in knowledge
representation and reasoning. We demonstrate that intuitive encodings of
complex ethical theories and their automation on the computer are no longer
antipodes.Comment: 14 page
Predicting Liver Transplant Capacity Using Discrete Event Simulation
The number of liver transplants (LTs) performed in the US increased until 2006 but has since declined despite an ongoing increase in demand. This decline may be due in part to decreased donor liver quality and increasing discard of poor-quality livers. We constructed a discrete event simulation (DES) model informed by current donor characteristics to predict future LT trends through the year 2030. The data source for our model is the United Network for Organ Sharing database, which contains patient-level information on all organ transplants performed in the US. Previous analysis showed that liver discard is increasing and that discarded organs are more often from donors who are older, are obese, have diabetes, and donated after cardiac death. Given that the prevalence of these factors is increasing, the DES model quantifies the reduction in the number of LTs performed through 2030. In addition, the model estimatesthe total number of future donors needed to maintain the current volume of LTs and the effect of a hypothetical scenario of improved reperfusion technology.We also forecast the number of patients on the waiting list and compare this with the estimated number of LTs to illustrate the impact that decreased LTs will have on patients needing transplants. By altering assumptions about the future donor pool, this model can be used to develop policy interventions to prevent a further decline in this lifesaving therapy. To our knowledge, there are no similar predictive models of future LT use based on epidemiological trends
Substitution and diffusion of Cr²⁺ and Cr ³⁺ in synthetic forsterite and natural olivine at 1200–1500 °C and 1 bar
Investigation of polymorphisms on abcg2, aa-nat and fabp3 genes in the kıvırcık sheep reared in three different provinces of turkey
Trends in Characteristics of Patients Listed for Liver Transplantation Will Lead to Higher Rates of Waitlist Removal Due to Clinical Deterioration
BACKGROUND:
Changes in the epidemiology of end-stage liver disease may lead to increased risk of dropout from the liver transplant waitlist. Anticipating the future of liver transplant waitlist characteristics is vital when considering organ allocation policy.
METHODS:
We performed a discrete event simulation to forecast patient characteristics and rate of waitlist dropout. Estimates were simulated from 2015 to 2025. The model was informed by data from the Organ Procurement and Transplant Network, 2003 to 2014. National data are estimated along with forecasts for 2 regions.
RESULTS:
Nonalcoholic steatohepatitis will increase from 18% of waitlist additions to 22% by 2025. Hepatitis C will fall from 30% to 21%. Listings over age 60 years will increase from 36% to 48%. The hazard of dropout will increase from 41% to 46% nationally. Wait times for transplant for patients listed with a Model for End-Stage Liver Disease (MELD) between 22 and 27 will double. Region 5, which transplants at relatively higher MELD scores, will experience an increase from 53% to 64% waitlist dropout. Region 11, which transplants at lower MELD scores, will have an increase in waitlist dropout from 30% to 44%.
CONCLUSIONS:
The liver transplant waitlist size will remain static over the next decade due to patient dropout. Liver transplant candidates will be older, more likely to have nonalcoholic steatohepatitis and will wait for transplantation longer even when listed at a competitive MELD score. There will continue to be significant heterogeneity among transplant regions where some patients will be more likely to drop out of the waitlist than receive a transplant
- …