scholarly journals Confidence Interval Estimation for Quantitative Precipitation Forecasts (QPF) Using Short-Range Ensemble Forecasts (SREF)

2006 ◽  
Vol 21 (1) ◽  
pp. 24-41 ◽  
Author(s):  
Jung-Sun Im ◽  
Keith Brill ◽  
Edwin Danaher
Keyword(s):  
United States ◽  
Confidence Interval ◽  
Lead Time ◽  
Short Range ◽  
Grid Point ◽  
The United States ◽  
Regression Equations ◽  
Ensemble Forecasts ◽  
Forecast Lead Time ◽  
Quantitative Precipitation Forecasts

Abstract The Hydrometeorological Prediction Center (HPC) at the NCEP has produced a suite of deterministic quantitative precipitation forecasts (QPFs) for over 40 yr. While the operational forecasts have proven to be useful in their present form, they offer no information concerning the uncertainties of individual forecasts. The purpose of this study is to develop a methodology to quantify the uncertainty in manually produced 6-h HPC QPFs (HQPFs) using NCEP short-range ensemble forecasts (SREFs). Results presented herein show the SREFs can predict the uncertainty of HQPFs. The correlation between HQPF absolute error (AE) and ensemble QPF spread (SP) is greater than 0.5 at 90.5% of grid points in the continental United States, exceeding 0.8 at 10% of these, for the 6-h forecast in winter. On the basis of the high correlation, the linear regression equations of AE on SP are derived at each point on a grid covering the United States. In addition, the regression equations for data categorized according to the observed and forecasted precipitation amounts are obtained and evaluated. Using the regression model equation parameters for 15 categorized ranges of HQPF at each horizontal grid point for each season and individual forecast lead time, an AE associated with an individual SP is predicted, as is the 95% confidence interval (CI) of the AE. Based on the AE CI forecast and the HQPF itself, the 95% CI of the HQPF is predicted as well. This study introduces an efficient and advanced method, providing an estimate of the uncertainty in the deterministic HQPF. Verification demonstrates the usefulness of the CI forecasts for a variety of classifications, such as season, CI range, HQPF, and forecast lead time.

scholarly journals Comparison of Daily Precipitation Statistics for the United States in Observations and in the NCEP Climate Forecast System

2008 ◽  
Vol 21 (22) ◽  
pp. 5993-6014 ◽  
Author(s):  
R. W. Higgins ◽  
V. B. S. Silva ◽  
V. E. Kousky ◽  
W. Shi
Keyword(s):  
United States ◽  
Lead Time ◽  
Daily Precipitation ◽  
The United States ◽  
Climate Forecast ◽  
Forecast System ◽  
Climate Forecast System ◽  
Station Data ◽  
Forecast Lead Time ◽  
Ncep Climate Forecast System

Abstract An intercomparison of the statistics of daily precipitation within seasonal climate over the conterminous United States is carried out using gridded station data and output from the NCEP Climate Forecast System (CFS). Differences in the occurrence of daily precipitation between the observations and a set of CFS reforecasts are examined as a function of forecast lead time for 1982–2005. Difference patterns show considerable evolution depending on season and lead time, with positive biases in CFS at most locations and leads except along the southern tier of states during the spring and summer months. An examination of differences in daily precipitation statistics by ENSO phase and in the frequencies of wet and dry spells is also conducted using a longer period of gridded daily station data (1948–2006) and a pair of 100-yr CFS coupled simulations. These comparisons expose additional details of the regional and seasonal dependence of the bias in the CFS simulations and reforecasts over the conterminous United States. The analysis motivates additional synoptic studies aimed at improving the linkage between daily precipitation and related circulation features in CFS. Prospects for using this information to develop more reliable ensemble-based probabilistic forecasts in real time at leads of 2–4 weeks (e.g., risks of heavy rain events) are also considered.

scholarly journals Longer Residence in the United States is Associated With More Physical Function Limitations in African Immigrant Older Adults

2020 ◽  
pp. 073346482097760
Author(s):  
Manka Nkimbeng ◽  
Yvonne Commodore-Mensah ◽  
Jacqueline L. Angel ◽  
Karen Bandeen-Roche ◽  
Roland J. Thorpe ◽  
...  
Keyword(s):  
United States ◽  
Older Adults ◽  
Confidence Interval ◽  
Physical Function ◽  
Racial Discrimination ◽  
African Immigrants ◽  
The United States ◽  
African Immigrant ◽  
High Discrimination ◽  
The Mean

Acculturation and racial discrimination have been independently associated with physical function limitations in immigrant and United States (U.S.)-born populations. This study examined the relationships among acculturation, racial discrimination, and physical function limitations in N = 165 African immigrant older adults using multiple linear regression. The mean age was 62 years ( SD = 8 years), and 61% were female. Older adults who resided in the United States for 10 years or more had more physical function limitations compared with those who resided here for less than 10 years ( b = −2.62, 95% confidence interval [CI] = [–5.01, –0.23]). Compared to lower discrimination, those with high discrimination had more physical function limitations ( b = −2.51, 95% CI = [–4.91, –0.17]), but this was no longer significant after controlling for length of residence and acculturation strategy. Residing in the United States for more than 10 years is associated with poorer physical function. Longitudinal studies with large, diverse samples of African immigrants are needed to confirm these associations.

scholarly journals Economic Impact from Unrestricted Spread of Potato Cyst Nematodes in Australia

2009 ◽  
Vol 99 (12) ◽  
pp. 1387-1393 ◽  
Author(s):  
M. Hodda ◽  
D. C. Cook
Keyword(s):  
United States ◽  
Confidence Interval ◽  
Economic Impact ◽  
Annual Cost ◽  
The United States ◽  
Economic Consequences ◽  
Potato Cyst Nematodes ◽  
Cyst Nematodes ◽  
Model Predictions ◽  
Alternative Responses

Potato cyst nematodes (PCN) (Globodera spp.) are quarantine pests with serious potential economic consequences. Recent new detections in Australia, Canada, and the United States have focussed attention on the consequences of spread and economic justifications for alternative responses. Here, a full assessment of the economic impact of PCN spread from a small initial incursion is presented. Models linking spread, population growth, and economic impact are combined to estimate costs of spread without restriction in Australia. Because the characteristics of the Australian PCN populations are currently unknown, the known ranges of parameters were used to obtain cost scenarios, an approach which makes the model predictions applicable generally. Our analysis indicates that mean annual costs associated with spread of PCN would increase rapidly initially, associated with increased testing. Costs would then increase more slowly to peak at over AUD$20 million per year ≈10 years into the future. Afterward, this annual cost would decrease slightly due to discounting factors. Mean annual costs over 20 years were $18.7 million, with a 90% confidence interval between AUD$11.9 million and AUD$27.0 million. Thus, cumulative losses to Australian agriculture over 20 years may exceed $370 million without action to prevent spread of PCN and entry to new areas.

15. The Return to Confrontation, 1979–80

2013 ◽  
Author(s):  
John W. Young ◽  
John Kent
Keyword(s):  
United States ◽  
Soviet Union ◽  
Nuclear Weapons ◽  
Short Range ◽  
The United States ◽  
Arms Race ◽  
The Soviet Union ◽  
Slow Progress ◽  
The Cold War ◽  
East West

This chapter examines why the United States and the Soviet Union returned to confrontation during the period 1979–1980. Despite the slow progress of the Strategic Arms Limitation Talks (SALT II), there were at least some efforts to control strategic weapons. Short-range and intermediate-range nuclear weapons, in contrast, continued to grow in number and sophistication, particularly in Europe, where NATO and Warsaw Pact forces still prepared for war against each other, despite détente. The failure to control theatre nuclear weapons led to a new twist in the European arms race at the end of the 1970s which helped to undermine recent improvements in East–West relations. The chapter first considers NATO’s ‘dual track’ decision regarding theatre nuclear weapons before discussing the Iranian Revolution and the Soviet intervention in Afghanistan. It concludes with an assessment of the revival of the Cold War, focusing on the so-called Carter Doctrine.

scholarly journals Racial and Ethnic Variations in Mortality Rates for Patients Undergoing Maintenance Dialysis Treated in US Territories Compared with the US 50 States

2019 ◽  
Vol 15 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Guofen Yan ◽  
Jenny I. Shen ◽  
Rubette Harford ◽  
Wei Yu ◽  
Robert Nee ◽  
...  
Keyword(s):  
United States ◽  
Confidence Interval ◽  
Ethnic Group ◽  
Proportional Hazards ◽  
The United States ◽  
Mortality Rates ◽  
American Samoa ◽  
Cox Proportional Hazards ◽  
Maintenance Dialysis ◽  
Racial Ethnic

Background and objectivesIn the United States mortality rates for patients treated with dialysis differ by racial and/or ethnic (racial/ethnic) group. Mortality outcomes for patients undergoing maintenance dialysis in the United States territories may differ from patients in the United States 50 states.Design, setting, participants, & measurementsThis retrospective cohort study of using US Renal Data System data included 1,547,438 adults with no prior transplantation and first dialysis treatment between April 1, 1995 and September 28, 2012. Cox proportional hazards regression was used to calculate hazard ratios (HRs) of death for the territories versus 50 states for each racial/ethnic group using the whole cohort and covariate-matched samples. Covariates included demographics, year of dialysis initiation, cause of kidney failure, comorbid conditions, dialysis modality, and many others.ResultsOf 22,828 patients treated in the territories (American Samoa, Guam, Puerto Rico, Virgin Islands), 321 were white, 666 were black, 20,299 were Hispanic, and 1542 were Asian. Of 1,524,610 patients in the 50 states, 838,736 were white, 444,066 were black, 182,994 were Hispanic, and 58,814 were Asian. The crude mortality rate (deaths per 100 patient-years) was lower for whites in the territories than the 50 states (14 and 29, respectively), similar for blacks (18 and 17, respectively), higher for Hispanics (27 and 16, respectively), and higher for Asians (22 and 15). In matched analyses, greater risks of death remained for Hispanics (HR, 1.65; 95% confidence interval, 1.60 to 1.70; P<0.001) and Asians (HR, 2.01; 95% confidence interval, 1.78 to 2.27; P<0.001) living in the territories versus their matched 50 states counterparts. There were no significant differences in mortality among white or black patients in the territories versus the 50 states.ConclusionsMortality rates for patients undergoing dialysis in the United States territories differ substantially by race/ethnicity compared with the 50 states. After matched analyses for comparable age and risk factors, mortality risk no longer differed for whites or blacks, but remained much greater for territory-dwelling Hispanics and Asians.

scholarly journals Estimation of the Incidence of Guillain-Barré Syndrome During Pregnancy in the United States

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Tanya R Myers ◽  
Natalie L McCarthy ◽  
Lakshmi Panagiotakopoulos ◽  
Saad B Omer
Keyword(s):  
United States ◽  
Adverse Event ◽  
Confidence Interval ◽  
The United States ◽  
Guillain Barre Syndrome ◽  
Rare Occurrence ◽  
Guillain Barré Syndrome ◽  
Safety Assessments ◽  
Few Data ◽  
Guillain Barré

Abstract Guillain-Barré syndrome (GBS) is an adverse event of interest after vaccination, yet few data are available for background rates during pregnancy. We confirmed 2 cases of incident GBS and estimated an incidence of 2.8 confirmed GBS cases per million person-years (95% confidence interval, 0.5–9.3), indicating rare occurrence. Our findings will help inform safety assessments of Zika vaccines in pregnant populations.

scholarly journals Comparative effectiveness of oral prostacyclin pathway drugs on hospitalization in patients with pulmonary hypertension in the United States: a retrospective database analysis

2020 ◽  
Vol 10 (4) ◽  
pp. 204589402091183
Author(s):  
John W. McConnell ◽  
Yuen Tsang ◽  
Janis Pruett ◽  
William Drake III
Keyword(s):  
United States ◽  
Pulmonary Hypertension ◽  
Confidence Interval ◽  
Lower Risk ◽  
Rate Ratio ◽  
Index Date ◽  
The United States ◽  
Hospitalization Rate ◽  
Hazard Ratio ◽  
Administrative Claims

Two oral medications targeting the prostacyclin pathway are available to treat pulmonary arterial hypertension in the United States: oral treprostinil and selexipag. We compared real-world hospitalization in patients receiving these medications. A retrospective administrative claims study was conducted using the Optum® Clinformatics® Data Mart database. Patients with pulmonary hypertension were identified using diagnostic codes. Cohort inclusion required age ≥ 18 years, first oral treprostinil or selexipag prescription between 1 January 2015 and 30 September 2017 (index date), and continuous enrollment in the prior ≥6 months. Patients who switched index drug were excluded. Follow-up was from index date until the first of end of index drug exposure, end of continuous enrollment, death, or 31 December 2017. Multivariable Cox proportional hazard and Poisson regression were used to compare risk and rate, respectively, of hospitalization associated with oral treprostinil vs. selexipag, adjusting for potential confounders. The study cohort included 99 patients receiving oral treprostinil and 123 receiving selexipag. Mean age was 61 years, and most patients were females (71%). Compared with oral treprostinil, selexipag was associated with a 46% lower risk of all-cause hospitalization (hazard ratio 0.54, 95% confidence interval 0.31, 0.92; P = 0.02), a 47% lower risk of pulmonary hypertension-related hospitalization (hazard ratio 0.53, 95% confidence interval 0.31, 0.93; P = 0.03), a 42% lower all-cause hospitalization rate (rate ratio 0.58, 95% confidence interval 0.39, 0.87; P = 0.01), and a 46% lower pulmonary hypertension-related hospitalization rate (rate ratio 0.54, 95% confidence interval 0.35, 0.82; P = 0.004). This study suggests that selexipag is associated with lower hospitalization risk and rate than oral treprostinil.

scholarly journals Comparison of Multilocus Sequence Typing and the Xpert C. difficile/Epi Assay for Identification of Clostridium difficile 027/NAP1/BI

2015 ◽  
Vol 54 (3) ◽  
pp. 775-778 ◽  
Author(s):  
Tracy McMillen ◽  
Mini Kamboj ◽  
N. Esther Babady
Keyword(s):  
United States ◽  
Clostridium Difficile ◽  
Confidence Interval ◽  
Multilocus Sequence Typing ◽  
The United States ◽  
Content Type ◽  
Presumptive Identification ◽  
Good Agreement

Clostridium difficile027/NAP1/BI is the most commonC. difficilestrain in the United States. The XpertC. difficile/Epi assay allows rapid, presumptive identification ofC. difficileNAP1. We compared XpertC. difficile/Epi to multilocus sequence typing for identification ofC. difficileNAP1 and found “very good” agreement at 97.9% (κ = 0.86; 95% confidence interval, 0.80 to 0.91).

scholarly journals External Validation of the Secondary Intracerebral Hemorrhage Score in The Netherlands

Stroke ◽  
2013 ◽  
Vol 44 (10) ◽  
pp. 2904-2906 ◽  
Author(s):  
Charlotte J.J. van Asch ◽  
Birgitta K. Velthuis ◽  
Jacoba P. Greving ◽  
Peter Jan van Laar ◽  
Gabriël J.E. Rinkel ◽  
...  
Keyword(s):  
United States ◽  
Computed Tomography ◽  
The Netherlands ◽  
Confidence Interval ◽  
Intracerebral Hemorrhage ◽  
The United States ◽  
Pathological Examination ◽  
Discriminative Ability ◽  
Ich Score ◽  
Noncontrast Computed Tomography

Background and Purpose— We aimed to validate externally in a setting outside the United States the secondary intracerebral hemorrhage (ICH) score that was developed to predict the probability of macrovascular causes in patients with nontraumatic ICH. Methods— Patients with nontraumatic ICH admitted to the University Medical Center Utrecht, the Netherlands, between 2003 and 2011 were included if an angiographic examination, neurosurgical inspection, or pathological examination had been performed. Secondary ICH score performance was assessed by calibration (agreement between predicted and observed outcomes) and discrimination (separation of those with and without macrovascular cause). Results— Forty-eight of 204 patients (23.5%) had a macrovascular cause. The secondary ICH score showed modest calibration ( P =0.06) and modest discriminative ability ( c -statistic 0.73; 95% confidence interval, 0.65–0.80). Discrimination improved slightly using only noncontrast computed tomography categorization ( c -statistic 0.79; 95% confidence interval, 0.72–0.86). Conclusions— The discriminative ability and calibration of the secondary ICH score are moderate in a university hospital setting outside the United States. Clues on noncontrast computed tomography are the strongest predictor of a macrovascular cause in patients with ICH.

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