A New Approach to Estimate the Age of the Earth and the Age of the Universe

NASA Astrophysics Data System (ADS)

Ben Salem, Kamel

2011-01-01

In a previous article, we proposed estimations for the age of the Universe and for the date of stabilization of its general structure on the basis of a given age of the Earth equal to 4.6 billion years. In the present article, we propose a new approach to estimate more accurately and at the same time, the age of the Earth and that of the Universe, starting from verse 4 of Sura 70 of the Qur'an. The procedure we followed and which is detailed in this article, should in our view, contribute to enlighten the debate on the question. We must add that our approach can in no case be considered as based on "concordism" or conjecture. Indeed, it rests on rigorous mathematical computations.

A revised burial dose estimation procedure for optical dating of youngand modern-age sediments

USGS Publications Warehouse

Arnold, L.J.; Roberts, R.G.; Galbraith, R.F.; DeLong, S.B.

2009-01-01

The presence of genuinely zero-age or near-zero-age grains in modern-age and very young samples poses a problem for many existing burial dose estimation procedures used in optical (optically stimulated luminescence, OSL) dating. This difficulty currently necessitates consideration of relatively simplistic and statistically inferior age models. In this study, we investigate the potential for using modified versions of the statistical age models of Galbraith et??al. [Galbraith, R.F., Roberts, R.G., Laslett, G.M., Yoshida, H., Olley, J.M., 1999. Optical dating of single and multiple grains of quartz from Jinmium rock shelter, northern Australia: Part I, experimental design and statistical models. Archaeometry 41, 339-364.] to provide reliable equivalent dose (De) estimates for young and modern-age samples that display negative, zero or near-zero De estimates. For this purpose, we have revised the original versions of the central and minimum age models, which are based on log-transformed De values, so that they can be applied to un-logged De estimates and their associated absolute standard errors. The suitability of these 'un-logged' age models is tested using a series of known-age fluvial samples deposited within two arroyo systems from the American Southwest. The un-logged age models provide accurate burial doses and final OSL ages for roughly three-quarters of the total number of samples considered in this study. Sensitivity tests reveal that the un-logged versions of the central and minimum age models are capable of producing accurate burial dose estimates for modern-age and very young (<350??yr) fluvial samples that contain (i) more than 20% of well-bleached grains in their De distributions, or (ii) smaller sub-populations of well-bleached grains for which the De values are known with high precision. Our results indicate that the original (log-transformed) versions of the central and minimum age models are still preferable for most routine dating applications, since these age models are better suited to the statistical properties of typical single-grain and multi-grain single-aliquot De datasets. However, the unique error properties of modern-age samples, combined with the problems of calculating natural logarithms of negative or zero-Gy De values, mean that the un-logged versions of the central and minimum age models currently offer the most suitable means of deriving accurate burial dose estimates for very young and modern-age samples. ?? 2009 Elsevier Ltd. All rights reserved.

The 'Own Children' fertility estimation procedure: a reappraisal.

PubMed

Avery, Christopher; St Clair, Travis; Levin, Michael; Hill, Kenneth

2013-07-01

The Full Birth History has become the dominant source of estimates of fertility levels and trends for countries lacking complete birth registration. An alternative, the 'Own Children' method, derives fertility estimates from household age distributions, but is now rarely used, partly because of concerns about its accuracy. We compared the estimates from these two procedures by applying them to 56 recent Demographic and Health Surveys. On average, 'Own Children' estimates of recent total fertility rates are 3 per cent lower than birth-history estimates. Much of this difference stems from selection bias in the collection of birth histories: women with more children are more likely to be interviewed. We conclude that full birth histories overestimate total fertility, and that the 'Own Children' method gives estimates of total fertility that may better reflect overall national fertility. We recommend the routine application of the 'Own Children' method to census and household survey data to estimate fertility levels and trends.

Early Enrollees and Peer Age Effect: First Evidence from INVALSI Data

ERIC Educational Resources Information Center

Ordine, Patrizia; Rose, Giuseppe; Sposato, Daniela

2015-01-01

This paper estimates peer age effect on educational outcomes of Italian pupils attending primary school by exploiting changes in enrollment rules over the last few years. The empirical procedure allows to understand if there is selection in classroom formation, arguing that in the absence of pupils sorting by early age at school entry, it is…

Scores on Riley's stuttering severity instrument versions three and four for samples of different length and for different types of speech material.

PubMed

Todd, Helena; Mirawdeli, Avin; Costelloe, Sarah; Cavenagh, Penny; Davis, Stephen; Howell, Peter

2014-12-01

Riley stated that the minimum speech sample length necessary to compute his stuttering severity estimates was 200 syllables. This was investigated. Procedures supplied for the assessment of readers and non-readers were examined to see whether they give equivalent scores. Recordings of spontaneous speech samples from 23 young children (aged between 2 years 8 months and 6 years 3 months) and 31 older children (aged between 10 years 0 months and 14 years 7 months) were made. Riley's severity estimates were scored on extracts of different lengths. The older children provided spontaneous and read samples, which were scored for severity according to reader and non-reader procedures. Analysis of variance supported the use of 200-syllable-long samples as the minimum necessary for obtaining severity scores. There was no significant difference in SSI-3 scores for the older children when the reader and non-reader procedures were used. Samples that are 200-syllables long are the minimum that is appropriate for obtaining stable Riley's severity scores. The procedural variants provide similar severity scores.

Radiological pitfalls of age estimation in adopted children: a case report.

PubMed

Gibelli, D; De Angelis, D; Cattaneo, C

2015-04-01

Age estimation has a relevant importance in assessing adopted children, also in cases where the age of the minor seems unquestioned, since pathological conditions may radically alter bodily growth. This may lead to an incorrect age evaluation, with consequent social and psychological problems linked to an inadequate collocation in public school. This study aims at exposing a case report concerning age estimation for a newly adopted child from Cambodia; previous clinical documentation reported information suggesting possible malnutrition, which was verified by the observation of a general disalignment of bone and dental structures. This example shows the importance of a thorough forensic evaluation of adopted children from other countries in order to verify the possible environmental modification of physiological growth even where it seems not to be needed, and represents a caveat for clinical and social personnel dealing with adoption procedures.

National hospital discharge survey: 2004 annual summary with detailed diagnosis and procedure data.

PubMed

Kozak, Lola Jean; DeFrances, Carol Jean; Hall, Margaret Jean

2006-10-01

This report presents 2004 national estimates and selected trend data on the use of nonfederal short-stay hospitals in the United States. Estimates are provided by selected patient and hospital characteristics, diagnoses, and surgical and nonsurgical procedures performed. Estimates of diagnoses and procedures are presented according to International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes. The estimates are based on data collected through the National Hospital Discharge Survey (NHDS). The survey has been conducted annually since 1965. In 2004, data were collected for approximately 371,000 discharges. Of the 476 eligible nonfederal short-stay hospitals in the sample, 439 (92 percent) responded to the survey. An estimated 34.9 million inpatients were discharged from nonfederal short-stay hospitals in 2004. They used 167.9 million days of care and had an average length of stay of 4.8 days. Hospital use by age ranged from 4.3 million days of care for patients 5-14 years of age to 31.8 million days of care for 75-84 year olds. Almost a third of patients 85 years and over were discharged from hospitals to long-term care institutions. Diseases of the circulatory system was the leading diagnostic category for males. Childbirth was the leading category for females, followed by circulatory diseases. The proportion of HIV discharges who were 40 years of age and over increased from 40 percent in 1995 to 67 percent in 2004. The rate of cardiac catheterizations was higher for males than for females and higher for patients 65-74 and 75-84 years of age than for older or younger groups. The average length of stay for both vaginal and cesarean deliveries decreased from 1980 through 1995 but stays for vaginal deliveries increased 24 percent during the period from 1995 to 2004.

Estimation of radiation cancer risk in CT-KUB

NASA Astrophysics Data System (ADS)

Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Bradley, D. A.; Ang, W. C.; Bahrudin, N. A.; Mhareb, M. H. A.

2017-08-01

The increased demand for computed tomography (CT) in radiological scanning examinations raises the question of a potential health impact from the associated radiation exposures. Focusing on CT kidney-ureter-bladder (CT-KUB) procedures, this work was aimed at determining organ equivalent dose using a commercial CT dose calculator and providing an estimate of cancer risks. The study, which included 64 patients (32 males and 32 females, mean age 55.5 years and age range 30-80 years), involved use of a calibrated CT scanner (Siemens-Somatom Emotion 16-slice). The CT exposures parameter including tube potential, pitch factor, tube current, volume CT dose index (CTDIvol) and dose-length product (DLP) were recorded and analyzed using CT-EXPO (Version 2.3.1, Germany). Patient organ doses, including for stomach, liver, colon, bladder, red bone marrow, prostate and ovaries were calculated and converted into cancer risks using age- and sex-specific data published in the Biological Effects of Ionizing Radiation (BEIR) VII report. With a median value scan range of 36.1 cm, the CTDIvol, DLP, and effective dose were found to be 10.7 mGy, 390.3 mGy cm and 6.2 mSv, respectively. The mean cancer risks for males and females were estimated to be respectively 25 and 46 out of 100,000 procedures with effective doses between 4.2 mSv and 10.1 mSv. Given the increased cancer risks from current CT-KUB procedures compared to conventional examinations, we propose that the low dose protocols for unenhanced CT procedures be taken into consideration before establishing imaging protocols for CT-KUB.

Usefulness of telomere length in DNA from human teeth for age estimation.

PubMed

Márquez-Ruiz, Ana Belén; González-Herrera, Lucas; Valenzuela, Aurora

2018-03-01

Age estimation is widely used to identify individuals in forensic medicine. However, the accuracy of the most commonly used procedures is markedly reduced in adulthood, and these methods cannot be applied in practice when morphological information is limited. Molecular methods for age estimation have been extensively developed in the last few years. The fact that telomeres shorten at each round of cell division has led to the hypothesis that telomere length can be used as a tool to predict age. The present study thus aimed to assess the correlation between telomere length measured in dental DNA and age, and the effect of sex and tooth type on telomere length; a further aim was to propose a statistical regression model to estimate the biological age based on telomere length. DNA was extracted from 91 tooth samples belonging to 77 individuals of both sexes and 15 to 85 years old and was used to determine telomere length by quantitative real-time PCR. Our results suggested that telomere length was not affected by sex and was greater in molar teeth. We found a significant correlation between age and telomere length measured in DNA from teeth. However, the equation proposed to predict age was not accurate enough for forensic age estimation on its own. Age estimation based on telomere length in DNA from tooth samples may be useful as a complementary method which provides an approximate estimate of age, especially when human skeletal remains are the only forensic sample available.

On the use of regression analysis for the estimation of human biological age.

PubMed

Krøll, J; Saxtrup, O

2000-01-01

The present investigation compares three linear regression procedures for the definition of human biological age (bioage). As a model system for bioage definition is used the variations with age of blood hemoglobin (B-hemoglobin) in males in the age range 50-95 years. The bioage measures compared are: 1: P-bioage; defined from regression of chronological age on B-hemoglobin results. 2: AC-bioage; obtained by indirect regression, using in reverse the equation describing the regression of B-hemoglobin on age in a reference population. 3: BC-bioage; defined by orthogonal regression on the reference regression line of B-hemoglobin on age. It is demonstrated that the P-bioage measure gives an overestimation of the bioage in the younger and an underestimation in the older individuals. This 'regression to the mean' is avoided using the indirect regression procedures. Here the relatively low SD of the BC-bioage measure results from the inclusion of individual chronological age in the orthogonal regression procedure. Observations on male blood donors illustrates the variation of the AC- and BC-bioage measures in the individual.

Reducing uncertainty and increasing consistency: technical improvements to forest carbon pool estimation using the national forest inventory of the US

Treesearch

C.W. Woodall; G.M. Domke; J. Coulston; M.B. Russell; J.A. Smith; C.H. Perry; S.M. Ogle; S. Healey; A. Gray

2015-01-01

The FIA program does not directly measure forest C stocks. Instead, a combination of empirically derived C estimates (e.g., standing live and dead trees) and models (e.g., understory C stocks related to stand age and forest type) are used to estimate forest C stocks. A series of recent refinements in FIA estimation procedures have sought to reduce the uncertainty...

[Forensic age estimation in juveniles and young adults: Reducing the range of scatter in age diagnosis by combining different methods].

PubMed

Schmidt, Sven; Schramm, Danilo; Ribbecke, Sebastian; Schulz, Ronald; Wittschieber, Daniel; Olze, Andreas; Vieth, Volker; Ramsthaler, H Frank; Pfischel, Klaus; Pfeiffer, Heidi; Geserick, Gunther; Schmeling, Andreas

2016-01-01

The dramatic rise in the number of refugees entering Germany means that age estimation for juveniles and young adults whose age is unclear but relevant to legal and official procedures has become more important than ever. Until now, whether and to what extent the combination of methods recommended by the Study Group on Forensic Age Diagnostics has resulted in a reduction of the range of scatter of the summarized age diagnosis has been unclear. Hand skeletal age, third molar mineralization stage and ossification stage of the medial clavicular epiphyses were determined for 307 individuals aged between 10 and 29 at time of death on whom autopsies were performed at the Institutes of Legal Medicine in Berlin, Frankfurt am Main and Hamburg between 2001 and 2011. To measure the range of scatter, linear regression analysis was used to calculate the standard error of estimate for each of the above methods individually and in combination. It was found that combining the above methods led to a reduction in the range of scatter. Due to various limitations of the study, the statistical parameters determined cannot, however, be used for age estimation practice.

Bayes plus Brass: Estimating Total Fertility for Many Small Areas from Sparse Census Data

PubMed Central

Schmertmann, Carl P.; Cavenaghi, Suzana M.; Assunção, Renato M.; Potter, Joseph E.

2013-01-01

Small-area fertility estimates are valuable for analysing demographic change, and important for local planning and population projection. In countries lacking complete vital registration, however, small-area estimates are possible only from sparse survey or census data that are potentially unreliable. Such estimation requires new methods for old problems: procedures must be automated if thousands of estimates are required, they must deal with extreme sampling variability in many areas, and they should also incorporate corrections for possible data errors. We present a two-step algorithm for estimating total fertility in such circumstances, and we illustrate by applying the method to 2000 Brazilian Census data for over five thousand municipalities. Our proposed algorithm first smoothes local age-specific rates using Empirical Bayes methods, and then applies a new variant of Brass’s P/F parity correction procedure that is robust under conditions of rapid fertility decline. PMID:24143946

Applying Deep Learning in Medical Images: The Case of Bone Age Estimation.

PubMed

Lee, Jang Hyung; Kim, Kwang Gi

2018-01-01

A diagnostic need often arises to estimate bone age from X-ray images of the hand of a subject during the growth period. Together with measured physical height, such information may be used as indicators for the height growth prognosis of the subject. We present a way to apply the deep learning technique to medical image analysis using hand bone age estimation as an example. Age estimation was formulated as a regression problem with hand X-ray images as input and estimated age as output. A set of hand X-ray images was used to form a training set with which a regression model was trained. An image preprocessing procedure is described which reduces image variations across data instances that are unrelated to age-wise variation. The use of Caffe, a deep learning tool is demonstrated. A rather simple deep learning network was adopted and trained for tutorial purpose. A test set distinct from the training set was formed to assess the validity of the approach. The measured mean absolute difference value was 18.9 months, and the concordance correlation coefficient was 0.78. It is shown that the proposed deep learning-based neural network can be used to estimate a subject's age from hand X-ray images, which eliminates the need for tedious atlas look-ups in clinical environments and should improve the time and cost efficiency of the estimation process.

The impact of ICD-9 revascularization procedure codes on estimates of racial disparities in ischemic stroke.

PubMed

Boan, Andrea D; Voeks, Jenifer H; Feng, Wuwei Wayne; Bachman, David L; Jauch, Edward C; Adams, Robert J; Ovbiagele, Bruce; Lackland, Daniel T

2014-01-01

The use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) diagnostic codes can identify racial disparities in ischemic stroke hospitalizations; however, inclusion of revascularization procedure codes as acute stroke events may affect the magnitude of the risk difference. This study assesses the impact of excluding revascularization procedure codes in the ICD-9 definition of ischemic stroke, compared with the traditional inclusive definition, on racial disparity estimates for stroke incidence and recurrence. Patients discharged with a diagnosis of ischemic stroke (ICD-9 codes 433.00-434.91 and 436) were identified from a statewide inpatient discharge database from 2010 to 2012. Race-age specific disparity estimates of stroke incidence and recurrence and 1-year cumulative recurrent stroke rates were compared between the routinely used traditional classification and a modified classification of stroke that excluded primary ICD-9 cerebral revascularization procedures codes (38.12, 00.61, and 00.63). The traditional classification identified 7878 stroke hospitalizations, whereas the modified classification resulted in 18% fewer hospitalizations (n = 6444). The age-specific black to white rate ratios were significantly higher in the modified than in the traditional classification for stroke incidence (rate ratio, 1.50; 95% confidence interval [CI], 1.43-1.58 vs. rate ratio, 1.24; 95% CI, 1.18-1.30, respectively). In whites, the 1-year cumulative recurrence rate was significantly reduced by 46% (45-64 years) and 49% (≥ 65 years) in the modified classification, largely explained by a higher rate of cerebral revascularization procedures among whites. There were nonsignificant reductions of 14% (45-64 years) and 19% (≥ 65 years) among blacks. Including cerebral revascularization procedure codes overestimates hospitalization rates for ischemic stroke and significantly underestimates the racial disparity estimates in stroke incidence and recurrence. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

The Hospitalization Costs of Diabetes and Hypertension Complications in Zimbabwe: Estimations and Correlations

PubMed Central

Mutowo, Mutsa P.; Lorgelly, Paula K.; Laxy, Michael; Mangwiro, John C.; Owen, Alice J.

2016-01-01

Objective. Treating complications associated with diabetes and hypertension imposes significant costs on health care systems. This study estimated the hospitalization costs for inpatients in a public hospital in Zimbabwe. Methods. The study was retrospective and utilized secondary data from medical records. Total hospitalization costs were estimated using generalized linear models. Results. The median cost and interquartile range (IQR) for patients with diabetes, $994 (385–1553) mean $1319 (95% CI: 981–1657), was higher than patients with hypertension, $759 (494–1147) mean $914 (95% CI: 825–1003). Female patients aged below 65 years with diabetes had the highest estimated mean costs ($1467 (95% CI: 1177–1828)). Wound care had the highest estimated mean cost of all procedures, $2884 (95% CI: 2004–4149) for patients with diabetes and $2239 (95% CI: 1589–3156) for patients with hypertension. Age below 65 years, medical procedures (amputation, wound care, dialysis, and physiotherapy), the presence of two or more comorbidities, and being prescribed two or more drugs were associated with significantly higher hospitalization costs. Conclusion. Our estimated costs could be used to evaluate and improve current inpatient treatment and management of patients with diabetes and hypertension and determine the most cost-effective interventions to prevent complications and comorbidities. PMID:27403444

Breast cancer risk from different mammography screening practices.

PubMed

Bijwaard, Harmen; Brenner, Alina; Dekkers, Fieke; van Dillen, Teun; Land, Charles E; Boice, John D

2010-09-01

Mammography screening is an accepted procedure for early detection of breast tumors among asymptomatic women. Since this procedure involves the use of X rays, it is itself potentially carcinogenic. Although there is general consensus about the benefit of screening for older women, screening practices differ between countries. In this paper radiation risks for these different practices are estimated using a new approach. We model breast cancer induction by ionizing radiation in a cohort of patients exposed to frequent X-ray examinations. The biologically based, mechanistic model provides a better foundation for the extrapolation of risks to different mammography screening practices than empirical models do. The model predicts that the excess relative risk (ERR) doubles when screening starts at age 40 instead of 50 and that a continuation of screening at ages 75 and higher carries little extra risk. The number of induced fatal breast cancers is estimated to be considerably lower than derived from epidemiological studies and from internationally accepted radiation protection risks. The present findings, if used in a risk-benefit analysis for mammography screening, would be more favorable to screening than estimates currently recommended for radiation protection. This has implications for the screening ages that are currently being reconsidered in several countries.

Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buhl, T.E.; Hansen, W.R.

1984-05-01

Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based onmore » this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, L; Bai, S; Zhang, Y

Purpose: To systematically evaluate imaging doses and cancer risks to organs-at-risk as a Result of cumulative doses from various radiological imaging procedures in image-guided radiotherapy (IGRT) in a large cohort of cancer patients. Methods: With IRB approval, imaging procedures (computed tomography, kilo-voltage portal imaging, megavoltage portal imaging and kilo-voltage cone-beam computed tomography) of 4832 cancer patients treated during 4.5 years were collected with their gender, age and circumference. Correlations between patient’s circumference and Monte Carlo simulated-organ dose were applied to estimate organ doses while the cancer risks were reported as 1+ERR using BEIR VII models. Results: 80 cGy or moremore » doses were deposited to brain, lungs and RBM in 273 patients (maximum 136, 278 and 267 cGy, respectively), due largely to repetitive imaging procedures and non-personalized imaging settings. Regardless of gender, relative cancer risk estimates for brain, lungs, and RBM were 3.4 (n = 55), 2.6 (n = 49), 1.8 (n = 25) for age group of 0–19; 1.2 (n = 87), 1.4 (n = 98), 1.3 (n = 51) for age group of 20–39; 1.0 (n = 457), 1.1 (n = 880), 1.8 (n=360) for age group of 40–59; 1.0 (n = 646), 1.1 (n = 1400), 2.3 (n = 716) for age group of 60–79 and 1.0 (n = 108),1.1 (n = 305),1.6 (n = 147) for age group of 80–99. Conclusion: The cumulative imaging doses and associated cancer risks from multi-imaging procedures were patient-specific and site-dependent, with up to 2.7 Gy imaging dose deposited to critical structures in some pediatric patients. The associated cancer risks in brain and lungs for children of age 0 to 19 were 2–3 times larger than those for adults. This study indicated a pressing need for personalized imaging protocol to maximize its clinical benefits while reducing associated cancer risks. Sichuan University Scholarship.« less

Age estimation by assessment of pulp chamber volume: a Bayesian network for the evaluation of dental evidence.

PubMed

Sironi, Emanuele; Taroni, Franco; Baldinotti, Claudio; Nardi, Cosimo; Norelli, Gian-Aristide; Gallidabino, Matteo; Pinchi, Vilma

2017-11-14

The present study aimed to investigate the performance of a Bayesian method in the evaluation of dental age-related evidence collected by means of a geometrical approximation procedure of the pulp chamber volume. Measurement of this volume was based on three-dimensional cone beam computed tomography images. The Bayesian method was applied by means of a probabilistic graphical model, namely a Bayesian network. Performance of that method was investigated in terms of accuracy and bias of the decisional outcomes. Influence of an informed elicitation of the prior belief of chronological age was also studied by means of a sensitivity analysis. Outcomes in terms of accuracy were adequate with standard requirements for forensic adult age estimation. Findings also indicated that the Bayesian method does not show a particular tendency towards under- or overestimation of the age variable. Outcomes of the sensitivity analysis showed that results on estimation are improved with a ration elicitation of the prior probabilities of age.

Bayesian networks of age estimation and classification based on dental evidence: A study on the third molar mineralization.

PubMed

Sironi, Emanuele; Pinchi, Vilma; Pradella, Francesco; Focardi, Martina; Bozza, Silvia; Taroni, Franco

2018-04-01

Not only does the Bayesian approach offer a rational and logical environment for evidence evaluation in a forensic framework, but it also allows scientists to coherently deal with uncertainty related to a collection of multiple items of evidence, due to its flexible nature. Such flexibility might come at the expense of elevated computational complexity, which can be handled by using specific probabilistic graphical tools, namely Bayesian networks. In the current work, such probabilistic tools are used for evaluating dental evidence related to the development of third molars. A set of relevant properties characterizing the graphical models are discussed and Bayesian networks are implemented to deal with the inferential process laying beyond the estimation procedure, as well as to provide age estimates. Such properties include operationality, flexibility, coherence, transparence and sensitivity. A data sample composed of Italian subjects was employed for the analysis; results were in agreement with previous studies in terms of point estimate and age classification. The influence of the prior probability elicitation in terms of Bayesian estimate and classifies was also analyzed. Findings also supported the opportunity to take into consideration multiple teeth in the evaluative procedure, since it can be shown this results in an increased robustness towards the prior probability elicitation process, as well as in more favorable outcomes from a forensic perspective. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Functional and effective brain connectivity for discrimination between Alzheimer's patients and healthy individuals: A study on resting state EEG rhythms.

PubMed

Blinowska, Katarzyna J; Rakowski, Franciszek; Kaminski, Maciej; De Vico Fallani, Fabrizio; Del Percio, Claudio; Lizio, Roberta; Babiloni, Claudio

2017-04-01

This exploratory study provided a proof of concept of a new procedure using multivariate electroencephalographic (EEG) topographic markers of cortical connectivity to discriminate normal elderly (Nold) and Alzheimer's disease (AD) individuals. The new procedure was tested on an existing database formed by resting state eyes-closed EEG data (19 exploring electrodes of 10-20 system referenced to linked-ear reference electrodes) recorded in 42 AD patients with dementia (age: 65.9years±8.5 standard deviation, SD) and 42 Nold non-consanguineous caregivers (age: 70.6years±8.5 SD). In this procedure, spectral EEG coherence estimated reciprocal functional connectivity while non-normalized directed transfer function (NDTF) estimated effective connectivity. Principal component analysis and computation of Mahalanobis distance integrated and combined these EEG topographic markers of cortical connectivity. The area under receiver operating curve (AUC) indexed the classification accuracy. A good classification of Nold and AD individuals was obtained by combining the EEG markers derived from NDTF and coherence (AUC=86%, sensitivity=0.85, specificity=0.70). These encouraging results motivate a cross-validation study of the new procedure in age- and education-matched Nold, stable and progressing mild cognitive impairment individuals, and de novo AD patients with dementia. If cross-validated, the new procedure will provide cheap, broadly available, repeatable over time, and entirely non-invasive EEG topographic markers reflecting abnormal cortical connectivity in AD patients diagnosed by direct or indirect measurement of cerebral amyloid β and hyperphosphorylated tau peptides. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Surgical procedures and their cost estimates among women with newly diagnosed endometriosis: a US database study.

PubMed

Fuldeore, M; Chwalisz, K; Marx, S; Wu, N; Boulanger, L; Ma, L; Lamothe, K

2011-01-01

This descriptive study assessed the rate and costs of surgical procedures among newly diagnosed endometriosis patients. Utilizing the Medstat MarketScan database, commercially insured women aged 18-45 with endometriosis newly diagnosed during 2006-2007 were identified. Each endometriosis patient was matched to four women without endometriosis (population controls) based on age and region of residence. Surgical procedures received during the 12 months post-diagnosis were assessed. Costs of surgical procedures were the amount paid by the insurance companies. This study identified 15,891 women with newly diagnosed endometriosis and 63,564 population controls. More than 65% of endometriosis patients received an endometriosis-related surgical procedure within 1 year of the initial diagnosis. The most common procedure was therapeutic laparoscopy (31.6%), followed by abdominal hysterectomy (22.1%) and vaginal hysterectomy (6.8%). Prevalence and type of surgery performed varied by patient age, including a hysterectomy rate of approximately 16% in patients younger than 35 and 37% among patients aged 35-45 years. Average costs ranged from $4,289 (standard deviation [SD]: $3,313) for diagnostic laparoscopy to $11,397 (SD: $8,749) for abdominal hysterectomy. Diagnosis of endometriosis cannot be validated against medical records, and information on the severity of endometriosis-related symptoms is not available in administrative claims data. Over 65% of patients had endometriosis-related surgical procedures, including hysterectomy, within 1 year of being diagnosed with endometriosis. The cost of surgical procedures related to endometriosis places a significant financial burden on the healthcare system.

Intracranial Procedures and Expected Frequency of Creutzfeldt-Jakob Disease.

PubMed

Abrams, Joseph Y; Maddox, Ryan A; Schonberger, Lawrence B; Belay, Ermias D

2016-01-01

To assess the frequency and characteristics of intracranial procedures (ICPs) performed and the number of U.S. residents living with a history of ICP. These data are used to calculate the expected annual number of sporadic Creutzfeldt-Jakob disease (CJD) cases among U.S. residents with a history of ICP. The Nationwide Inpatient Sample provided data on the frequency and types of ICPs, and data from the National Center for Health Statistics was used to produce age-adjusted mortality rates. A model was constructed, which estimated long-term survival and sporadic CJD rates among ICP patients based on procedure type and age. There were an estimated 2,070,488 ICPs in the United States from 1998 to 2007, an average of over 200,000 per year. There were an estimated 2,023,726 U.S. residents in 2013 with a history of ICP in the previous 30 years. In 2013, there was expected to be 4.1 sporadic CJD cases (95% CI 1-8) among people with a history of ICP in the past 30 years. The considerable proportion of U.S. residents living with a history of ICP is important information for retrospective assessments of CJD or any other suspected long-term outcome of ICPs. © 2015 S. Karger AG, Basel.

National Hospital Discharge Survey: 2003 annual summary with detailed diagnosis and procedure data.

PubMed

Kozak, Lola Jean; Lees, Karen A; DeFrances, Carol J

2006-05-01

This report presents 2003 national estimates and trend data on the use of non-Federal short-stay hospitals in the United States. Estimates are provided by patient and hospital characteristics, diagnoses, and surgical and nonsurgical procedures performed. Estimates of diagnoses and procedures are presented according to the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes. The estimates are based on data collected through the National Hospital Discharge Survey (NHDS). The survey has been conducted annually since 1965. In 2003, data were collected for approximately 320,000 discharges. Of the 479 eligible non-Federal short-stay hospitals in the sample, 426 (89 percent) responded to the survey. An estimated 34.7 million inpatients were discharged from non-Federal short-stay hospitals in 2003. They used 167.3 million days of care and had an average length of stay of 4.8 days. Females used almost one-third more days of hospital care than males. Patients with five or more diagnoses rose from 29 percent of discharges in 1990 to 57 percent in 2003. The leading diagnostic category was respiratory diseases for children under 15 years, childbirth for 15-44 year olds, and circulatory diseases for patients 45 years of age and over. Only surgical procedures were performed for 27 percent of discharges, 18 percent had surgical and nonsurgical procedures, and 16 percent had only nonsurgical procedures. A total of 664,000 coronary angioplasties were performed, and stents were inserted during 86 percent of these procedures with drug-eluting stents used in 28 percent. The number and rate of total and primary cesarean deliveries rose from 1995 to 2003. The rate of vaginal birth after cesarean delivery dropped 58 percent, from 35.5 in 1995 to 14.8 in 2003.

Hysterectomy trends in Australia, 2000-2001 to 2013-2014: joinpoint regression analysis.

PubMed

Wilson, Louise F; Pandeya, Nirmala; Mishra, Gita D

2017-10-01

Hysterectomy is a common gynecological procedure, particularly in middle and high income countries. The aim of this paper was to describe and examine hysterectomy trends in Australia from 2000-2001 to 2013-2014. For women aged 25 years and over, data on the number of hysterectomies performed in Australia annually were sourced from the National Hospital and Morbidity Database. Age-specific and age-standardized hysterectomy rates per 10 000 women were estimated with adjustment for hysterectomy prevalence in the population. Using joinpoint regression analysis, we estimated the average annual percentage change over the whole study period (2000-2014) and the annual percentage change for each identified trend line segment. A total of 431 162 hysterectomy procedures were performed between 2000-2001 and 2013-2014; an annual average of 30 797 procedures (for women aged 25+ years). The age-standardized hysterectomy rate, adjusted for underlying hysterectomy prevalence, decreased significantly over the whole study period [average annual percentage change -2.8%; 95% confidence interval (CI) -3.5%, -2.2%]. The trend was not linear with one joinpoint detected in 2008-2009. Between 2000-2001 and 2008-2009 there was a significant decrease in incidence (annual percentage change -4.4%; 95% CI -5.2%, -3.7%); from 2008-2009 to 2013-2014 the decrease was minimal and not significantly different from zero (annual percentage change -0.1%; 95% CI -1.7%, 1.5%). A similar change in trend was seen in all age groups. Hysterectomy rates in Australian women aged 25 years and over have declined in the first decade of the 21st century. However, in the last 5 years, rates appear to have stabilized. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Mathematics skills in good readers with hydrocephalus.

PubMed

Barnes, Marcia A; Pengelly, Sarah; Dennis, Maureen; Wilkinson, Margaret; Rogers, Tracey; Faulkner, Heather

2002-01-01

Children with hydrocephalus have poor math skills. We investigated the nature of their arithmetic computation errors by comparing written subtraction errors in good readers with hydrocephalus, typically developing good readers of the same age, and younger children matched for math level to the children with hydrocephalus. Children with hydrocephalus made more procedural errors (although not more fact retrieval or visual-spatial errors) than age-matched controls; they made the same number of procedural errors as younger, math-level matched children. We also investigated a broad range of math abilities, and found that children with hydrocephalus performed more poorly than age-matched controls on tests of geometry and applied math skills such as estimation and problem solving. Computation deficits in children with hydrocephalus reflect delayed development of procedural knowledge. Problems in specific math domains such as geometry and applied math, were associated with deficits in constituent cognitive skills such as visual spatial competence, memory, and general knowledge.

Sample size estimation for alternating logistic regressions analysis of multilevel randomized community trials of under-age drinking.

PubMed

Reboussin, Beth A; Preisser, John S; Song, Eun-Young; Wolfson, Mark

2012-07-01

Under-age drinking is an enormous public health issue in the USA. Evidence that community level structures may impact on under-age drinking has led to a proliferation of efforts to change the environment surrounding the use of alcohol. Although the focus of these efforts is to reduce drinking by individual youths, environmental interventions are typically implemented at the community level with entire communities randomized to the same intervention condition. A distinct feature of these trials is the tendency of the behaviours of individuals residing in the same community to be more alike than that of others residing in different communities, which is herein called 'clustering'. Statistical analyses and sample size calculations must account for this clustering to avoid type I errors and to ensure an appropriately powered trial. Clustering itself may also be of scientific interest. We consider the alternating logistic regressions procedure within the population-averaged modelling framework to estimate the effect of a law enforcement intervention on the prevalence of under-age drinking behaviours while modelling the clustering at multiple levels, e.g. within communities and within neighbourhoods nested within communities, by using pairwise odds ratios. We then derive sample size formulae for estimating intervention effects when planning a post-test-only or repeated cross-sectional community-randomized trial using the alternating logistic regressions procedure.

Predictive values derived from lower wisdom teeth developmental stages on orthopantomograms to calculate the chronological age in adolescence and young adults as a prerequisite to obtain age-adjusted informed patient consent prior to elective surgical procedures in young patients with incomplete or mismatched personal data.

PubMed

Friedrich, Reinhard E; Schmidt, Kirsten; Treszl, András; Kersten, Jan F

2016-01-01

Introduction: Surgical procedures require informed patient consent, which is mandatory prior to any procedure. These requirements apply in particular to elective surgical procedures. The communication with the patient about the procedure has to be comprehensive and based on mutual understanding. Furthermore, the informed consent has to take into account whether a patient is of legal age. As a result of large-scale migration, there are eventually patients planned for medical procedures, whose chronological age can't be assessed reliably by physical inspection alone. Age determination based on assessing wisdom tooth development stages can be used to help determining whether individuals involved in medical procedures are of legal age, i.e., responsible and accountable. At present, the assessment of wisdom tooth developmental stages barely allows a crude estimate of an individual's age. This study explores possibilities for more precise predictions of the age of individuals with emphasis on the legal age threshold of 18 years. Material and Methods: 1,900 dental orthopantomograms (female 938, male 962, age: 15-24 years), taken between the years 2000 and 2013 for diagnosis and treatment of diseases of the jaws, were evaluated. 1,895 orthopantomograms (female 935, male 960) of 1,804 patients (female 872, male 932) met the inclusion criteria. The archives of the Department of Diagnostic Radiology in Dentistry, University Medical Center Hamburg-Eppendorf, and of an oral and maxillofacial office in Rostock, Germany, were used to collect a sufficient number of radiographs. An effort was made to achieve almost equal distribution of age categories in this study group; 'age' was given on a particular day. The radiological criteria of lower third molar investigation were: presence and extension of periodontal space, alveolar bone loss, emergence of tooth, and stage of tooth mineralization (according to Demirjian). Univariate and multivariate general linear models were calculated. Using hierarchical multivariate analyses a formula was derived quantifying the development of the four parameters of wisdom tooth over time. This model took repeated measurements of the same persons into account and is only applicable when a person is assessed a second time. The second approach investigates a linear regression model in order to predict the age. In a third approach, a classification and regression tree (CART) was developed to derive cut-off values for the four parameters, resulting in a classification with estimates for sensitivity and specificity. Results: No statistically significant differences were found between parameters related to wisdom tooth localization (right or left side). In univariate analyses being of legal age was associated with consecutive stages of wisdom tooth development, the obliteration of the periodontal space, and tooth emergence, as well with alveolar bone loss; no association was found with tooth mineralization. Multivariate models without repeated measurements revealed imprecise estimates because of the unknown individual-related variability. The precision of these models is thus not very good, although it improves with advancing age. When calculating a CART-analysis and a receiver operating characteristics - area under the curve of 78% was achieved; when maximizing both specificity and sensitivity, a Youden's index of 47% was achieved (with 73% specificity and 74% sensitivity). Discussion: This study provides a basis to help determine whether a person is 18 years or older in individuals who are assumed to be between 15 and 24 years old. From repeated measurements, we found a linear effect of age on the four parameters in the individuals. However, this information can't be used for prognosis, because of the large intra-individual variability. Thus, although the development of the four parameters can be estimated over time, a direct conclusion with regard to age can't be drawn from the parameters without previous biographic information about a person. While a single parameter is of limited value for calculating the target age of 18 years, combining several findings, that can be determined on a standard radiography, may potentially be a more reliable diagnostic tool for estimating the target age in both sexes. However, a high degree of precision can't be achieved. The reason for persistent uncertainty lies in the wide chronological range of wisdom tooth development, which stretches from well below to above the 18 th life year. The regression approach thus seems not optimal. Although sensitivity and specificity of the CART-model are moderately high, this model is still not reliable as a diagnostic tool. Our findings could have impact, e.g. on elective surgeries for young individuals with unknown biography. However, these results cannot replace social engagement, in particular thorough physical examination of patients and careful registration of their histories. Further studies on the use of this calculation method in different ethnic groups would be desirable.

Molecular pathology and age estimation.

PubMed

Meissner, Christoph; Ritz-Timme, Stefanie

2010-12-15

Over the course of our lifetime a stochastic process leads to gradual alterations of biomolecules on the molecular level, a process that is called ageing. Important changes are observed on the DNA-level as well as on the protein level and are the cause and/or consequence of our 'molecular clock', influenced by genetic as well as environmental parameters. These alterations on the molecular level may aid in forensic medicine to estimate the age of a living person, a dead body or even skeletal remains for identification purposes. Four such important alterations have become the focus of molecular age estimation in the forensic community over the last two decades. The age-dependent accumulation of the 4977bp deletion of mitochondrial DNA and the attrition of telomeres along with ageing are two important processes at the DNA-level. Among a variety of protein alterations, the racemisation of aspartic acid and advanced glycation endproducs have already been tested for forensic applications. At the moment the racemisation of aspartic acid represents the pinnacle of molecular age estimation for three reasons: an excellent standardization of sampling and methods, an evaluation of different variables in many published studies and highest accuracy of results. The three other mentioned alterations often lack standardized procedures, published data are sparse and often have the character of pilot studies. Nevertheless it is important to evaluate molecular methods for their suitability in forensic age estimation, because supplementary methods will help to extend and refine accuracy and reliability of such estimates. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Improvements in prevalence trend fitting and incidence estimation in EPP 2013

PubMed Central

Brown, Tim; Bao, Le; Eaton, Jeffrey W.; Hogan, Daniel R.; Mahy, Mary; Marsh, Kimberly; Mathers, Bradley M.; Puckett, Robert

2014-01-01

Objective: Describe modifications to the latest version of the Joint United Nations Programme on AIDS (UNAIDS) Estimation and Projection Package component of Spectrum (EPP 2013) to improve prevalence fitting and incidence trend estimation in national epidemics and global estimates of HIV burden. Methods: Key changes made under the guidance of the UNAIDS Reference Group on Estimates, Modelling and Projections include: availability of a range of incidence calculation models and guidance for selecting a model; a shift to reporting the Bayesian median instead of the maximum likelihood estimate; procedures for comparison and validation against reported HIV and AIDS data; incorporation of national surveys as an integral part of the fitting and calibration procedure, allowing survey trends to inform the fit; improved antenatal clinic calibration procedures in countries without surveys; adjustment of national antiretroviral therapy reports used in the fitting to include only those aged 15–49 years; better estimates of mortality among people who inject drugs; and enhancements to speed fitting. Results: The revised models in EPP 2013 allow closer fits to observed prevalence trend data and reflect improving understanding of HIV epidemics and associated data. Conclusion: Spectrum and EPP continue to adapt to make better use of the existing data sources, incorporate new sources of information in their fitting and validation procedures, and correct for quantifiable biases in inputs as they are identified and understood. These adaptations provide countries with better calibrated estimates of incidence and prevalence, which increase epidemic understanding and provide a solid base for program and policy planning. PMID:25406747

A proposed method to estimate premorbid full scale intelligence quotient (FSIQ) for the Canadian Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) using demographic and combined estimation procedures.

PubMed

Schoenberg, Mike R; Lange, Rael T; Saklofske, Donald H

2007-11-01

Establishing a comparison standard in neuropsychological assessment is crucial to determining change in function. There is no available method to estimate premorbid intellectual functioning for the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). The WISC-IV provided normative data for both American and Canadian children aged 6 to 16 years old. This study developed regression algorithms as a proposed method to estimate full-scale intelligence quotient (FSIQ) for the Canadian WISC-IV. Participants were the Canadian WISC-IV standardization sample (n = 1,100). The sample was randomly divided into two groups (development and validation groups). The development group was used to generate regression algorithms; 1 algorithm only included demographics, and 11 combined demographic variables with WISC-IV subtest raw scores. The algorithms accounted for 18% to 70% of the variance in FSIQ (standard error of estimate, SEE = 8.6 to 14.2). Estimated FSIQ significantly correlated with actual FSIQ (r = .30 to .80), and the majority of individual FSIQ estimates were within +/-10 points of actual FSIQ. The demographic-only algorithm was less accurate than algorithms combining demographic variables with subtest raw scores. The current algorithms yielded accurate estimates of current FSIQ for Canadian individuals aged 6-16 years old. The potential application of the algorithms to estimate premorbid FSIQ is reviewed. While promising, clinical validation of the algorithms in a sample of children and/or adolescents with known neurological dysfunction is needed to establish these algorithms as a premorbid estimation procedure.

Predictive values derived from lower wisdom teeth developmental stages on orthopantomograms to calculate the chronological age in adolescence and young adults as a prerequisite to obtain age-adjusted informed patient consent prior to elective surgical procedures in young patients with incomplete or mismatched personal data

PubMed Central

Friedrich, Reinhard E.; Schmidt, Kirsten; Treszl, András; Kersten, Jan F.

2016-01-01

Introduction: Surgical procedures require informed patient consent, which is mandatory prior to any procedure. These requirements apply in particular to elective surgical procedures. The communication with the patient about the procedure has to be comprehensive and based on mutual understanding. Furthermore, the informed consent has to take into account whether a patient is of legal age. As a result of large-scale migration, there are eventually patients planned for medical procedures, whose chronological age can’t be assessed reliably by physical inspection alone. Age determination based on assessing wisdom tooth development stages can be used to help determining whether individuals involved in medical procedures are of legal age, i.e., responsible and accountable. At present, the assessment of wisdom tooth developmental stages barely allows a crude estimate of an individual’s age. This study explores possibilities for more precise predictions of the age of individuals with emphasis on the legal age threshold of 18 years. Material and Methods: 1,900 dental orthopantomograms (female 938, male 962, age: 15–24 years), taken between the years 2000 and 2013 for diagnosis and treatment of diseases of the jaws, were evaluated. 1,895 orthopantomograms (female 935, male 960) of 1,804 patients (female 872, male 932) met the inclusion criteria. The archives of the Department of Diagnostic Radiology in Dentistry, University Medical Center Hamburg-Eppendorf, and of an oral and maxillofacial office in Rostock, Germany, were used to collect a sufficient number of radiographs. An effort was made to achieve almost equal distribution of age categories in this study group; ‘age’ was given on a particular day. The radiological criteria of lower third molar investigation were: presence and extension of periodontal space, alveolar bone loss, emergence of tooth, and stage of tooth mineralization (according to Demirjian). Univariate and multivariate general linear models were calculated. Using hierarchical multivariate analyses a formula was derived quantifying the development of the four parameters of wisdom tooth over time. This model took repeated measurements of the same persons into account and is only applicable when a person is assessed a second time. The second approach investigates a linear regression model in order to predict the age. In a third approach, a classification and regression tree (CART) was developed to derive cut-off values for the four parameters, resulting in a classification with estimates for sensitivity and specificity. Results: No statistically significant differences were found between parameters related to wisdom tooth localization (right or left side). In univariate analyses being of legal age was associated with consecutive stages of wisdom tooth development, the obliteration of the periodontal space, and tooth emergence, as well with alveolar bone loss; no association was found with tooth mineralization. Multivariate models without repeated measurements revealed imprecise estimates because of the unknown individual-related variability. The precision of these models is thus not very good, although it improves with advancing age. When calculating a CART-analysis and a receiver operating characteristics – area under the curve of 78% was achieved; when maximizing both specificity and sensitivity, a Youden’s index of 47% was achieved (with 73% specificity and 74% sensitivity). Discussion: This study provides a basis to help determine whether a person is 18 years or older in individuals who are assumed to be between 15 and 24 years old. From repeated measurements, we found a linear effect of age on the four parameters in the individuals. However, this information can't be used for prognosis, because of the large intra-individual variability. Thus, although the development of the four parameters can be estimated over time, a direct conclusion with regard to age can’t be drawn from the parameters without previous biographic information about a person. While a single parameter is of limited value for calculating the target age of 18 years, combining several findings, that can be determined on a standard radiography, may potentially be a more reliable diagnostic tool for estimating the target age in both sexes. However, a high degree of precision can’t be achieved. The reason for persistent uncertainty lies in the wide chronological range of wisdom tooth development, which stretches from well below to above the 18th life year. The regression approach thus seems not optimal. Although sensitivity and specificity of the CART-model are moderately high, this model is still not reliable as a diagnostic tool. Our findings could have impact, e.g. on elective surgeries for young individuals with unknown biography. However, these results cannot replace social engagement, in particular thorough physical examination of patients and careful registration of their histories. Further studies on the use of this calculation method in different ethnic groups would be desirable. PMID:27975042

Motion‐related artifacts in structural brain images revealed with independent estimates of in‐scanner head motion

PubMed Central

Savalia, Neil K.; Agres, Phillip F.; Chan, Micaela Y.; Feczko, Eric J.; Kennedy, Kristen M.

2016-01-01

Abstract Motion‐contaminated T1‐weighted (T1w) magnetic resonance imaging (MRI) results in misestimates of brain structure. Because conventional T1w scans are not collected with direct measures of head motion, a practical alternative is needed to identify potential motion‐induced bias in measures of brain anatomy. Head movements during functional MRI (fMRI) scanning of 266 healthy adults (20–89 years) were analyzed to reveal stable features of in‐scanner head motion. The magnitude of head motion increased with age and exhibited within‐participant stability across different fMRI scans. fMRI head motion was then related to measurements of both quality control (QC) and brain anatomy derived from a T1w structural image from the same scan session. A procedure was adopted to “flag” individuals exhibiting excessive head movement during fMRI or poor T1w quality rating. The flagging procedure reliably reduced the influence of head motion on estimates of gray matter thickness across the cortical surface. Moreover, T1w images from flagged participants exhibited reduced estimates of gray matter thickness and volume in comparison to age‐ and gender‐matched samples, resulting in inflated effect sizes in the relationships between regional anatomical measures and age. Gray matter thickness differences were noted in numerous regions previously reported to undergo prominent atrophy with age. Recommendations are provided for mitigating this potential confound, and highlight how the procedure may lead to more accurate measurement and comparison of anatomical features. Hum Brain Mapp 38:472–492, 2017. © 2016 Wiley Periodicals, Inc. PMID:27634551

Sources of funding for adult and paediatric CT procedures at a metropolitan tertiary hospital: How much do Medicare statistics really cover?

PubMed

Hayton, Anna; Wallace, Anthony; Johnston, Peter

2015-12-01

The radiation dose to the Australian paediatric population as a result of medical imaging is of growing concern, in particular the dose from CT. Estimates of the Australian population dose have largely relied on Medicare Australia statistics, which capture only a fraction of those imaging procedures actually performed. The fraction not captured has been estimated using a value obtained for a survey of the adult population in the mid-1990s. To better quantify the fraction of procedures that are not captured by Medicare Australia, procedure frequency and funding data for adult and paediatric patients were obtained from a metropolitan tertiary teaching and research hospital. Five calendar years of data were obtained with a financial class specified for each individual procedure. The financial classes were grouped to give the percentage of Medicare Australia billable procedures for both adult and paediatric patients. The data were also grouped to align with the Medicare Australia age cohorts. The percentage of CT procedures billable to Medicare Australia increased from 16% to 28% between 2008 and 2012. In 2012, the percentage billable for adult and paediatric patients was 28% and 33%, respectively; however, many adult CT procedures are performed at stand-alone clinics, which bulk bill. Using Medicare Australia statistics alone, the frequency of paediatric CT procedures performed on the Australian paediatric population will be grossly under estimated. A correction factor of 4.5 is suggested for paediatric procedures and 1.5 for adult procedures. The fraction of actual procedures performed that are captured by Medicare Australia will vary with time. © 2015 The Royal Australian and New Zealand College of Radiologists.

Three-dimensional analysis of third molar development to estimate age of majority.

PubMed

Márquez-Ruiz, Ana Belén; Treviño-Tijerina, María Concepción; González-Herrera, Lucas; Sánchez, Belén; González-Ramírez, Amanda Rocío; Valenzuela, Aurora

2017-09-01

Third molars are one of the few biological markers available for age estimation in undocumented juveniles close the legal age of majority, assuming an age of 18years as the most frequent legal demarcation between child and adult status. To obtain more accurate visualization and evaluation of third molar mineralization patterns from computed tomography images, a new software application, DentaVol©, was developed. Third molar mineralization according to qualitative (Demirjian's maturational stage) and quantitative parameters (third molar volume) of dental development was assessed in multi-slice helical computed tomography images of both maxillary arches displayed by DentaVol© from 135 individuals (62 females and 73 males) aged between 14 and 23years. Intra- and inter-observer agreement values were remarkably high for both evaluation procedures and for all third molars. A linear correlation between third molar mineralization and chronological age was found, with third molar maturity occurring earlier in males than in females. Assessment of dental development with both procedures, by using DentaVol© software, can be considered a good indicator of age of majority (18years or older) in all third molars. Our results indicated that virtual computed tomography imaging can be considered a valid alternative to orthopantomography for evaluations of third molar mineralization, and therefore a complementary tool for determining the age of majority. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Operative needs in HIV+ populations: An estimation for sub-Saharan Africa.

PubMed

Cherewick, Megan L; Cherewick, Steven D; Kushner, Adam L

2017-05-01

In 2015, it was estimated that approximately 36.7 million people were living with HIV globally and approximately 25.5 million of those people were living in sub-Saharan Africa. Limitations in the availability and access to adequate operative care require policy and planning to enhance operative capacity. Data estimating the total number of persons living with HIV by country, sex, and age group were obtained from the Joint United Nations Programme on HIV/AIDS (UNAIDS) in 2015. Using minimum proposed surgical rates per 100,000 for 4, defined, sub-Saharan regions of Africa, country-specific and regional estimates were calculated. The total need and unmet need for operative procedures were estimated. A minimum of 1,539,138 operative procedures were needed in 2015 for the 25.5 million persons living with HIV in sub-Saharan Africa. In 2015, there was an unmet need of 908,513 operative cases in sub-Saharan Africa with the greatest unmet need in eastern sub-Saharan Africa (427,820) and western sub-Saharan Africa (325,026). Approximately 55.6% of the total need for operative cases is adult women, 38.4% are adult men, and 6.0% are among children under the age of 15. A minimum of 1.5 million operative procedures annually are required to meet the needs of persons living with HIV in sub-Saharan Africa. The unmet need for operative care is greatest in eastern and western sub-Saharan Africa and will require investments in personnel, infrastructure, facilities, supplies, and equipment. We highlight the need for global planning and investment in resources to meet targets of operative capacity. Copyright © 2016 Elsevier Inc. All rights reserved.

Estimating malaria transmission from humans to mosquitoes in a noisy landscape

PubMed Central

Reiner, Robert C.; Guerra, Carlos; Donnelly, Martin J.; Bousema, Teun; Drakeley, Chris; Smith, David L.

2015-01-01

A basic quantitative understanding of malaria transmission requires measuring the probability a mosquito becomes infected after feeding on a human. Parasite prevalence in mosquitoes is highly age-dependent, and the unknown age-structure of fluctuating mosquito populations impedes estimation. Here, we simulate mosquito infection dynamics, where mosquito recruitment is modelled seasonally with fractional Brownian noise, and we develop methods for estimating mosquito infection rates. We find that noise introduces bias, but the magnitude of the bias depends on the ‘colour' of the noise. Some of these problems can be overcome by increasing the sampling frequency, but estimates of transmission rates (and estimated reductions in transmission) are most accurate and precise if they combine parity, oocyst rates and sporozoite rates. These studies provide a basis for evaluating the adequacy of various entomological sampling procedures for measuring malaria parasite transmission from humans to mosquitoes and for evaluating the direct transmission-blocking effects of a vaccine. PMID:26400195

The age estimation practice related to illegal unaccompanied minors immigration in Italy.

PubMed

Pradella, F; Pinchi, V; Focardi, M; Grifoni, R; Palandri, M; Norelli, G A

2017-12-01

The migrants arrived to the Italian coasts in 2016 were 181.436, 18% more than the previous year and 6% more than the highest number ever since. An "unaccompanied minor" (UAM) is a third-country national or a stateless person under eighteen years of age, who arrives on the territory of the Member State unaccompanied by an adult responsible for him/her whether by law or by the practice of the Member State concerned, and for as long as he or she is not effectively taken into the care of such a person; it includes a minor who is left unaccompanied after he/she entered the territory of the Member States. As many as 95.985 UAMs applied for international protection in an EU member country just in 2015, almost four times the number registered in the previous year. The UAMs arrived in Italy were 28.283 in 2016; 94% of them were males, 92% unaccompanied, 8% of them under 15; the 53,6% is 17; the individuals between 16 and 17 are instead the 82%. Many of them (50%), 6561 in 2016, escaped from the sanctuaries, thus avoiding to be formally identified and registered in Italy in the attempt to reach more easily northern Europe countries, since The Dublin Regulations (2003) state that the asylum application should be held in the EU country of entrance or where parents reside. The age assessment procedures can therefore be considered as a relevant task that weighs in on the shoulders of the forensic experts with all the related issues and the coming of age is the important threshold. In the EU laws on asylum, the minors are considered as one of the groups of vulnerable persons towards whom Member States have specific obligations. A proper EU common formal regulation in the matter of age estimation procedures still lacks. According to the Italian legal framework in the matter, a medical examination should have been always performed but a new law completely changed the approach to the procedures of age estimation of the migrant (excluding the criminal cases) with a better adherence to the notions and concepts of vulnerability and psychological and social maturity.

Innovative Rehabilitation Technology Demonstration and Evaluation Program

EPA Science Inventory

The needs associated with the aging water infrastructure are immense and have been estimated at more than $1 trillion dollars over the next 20 years for water and wastewater utilities. To meet this growing need, utilities require the use of innovative technologies and procedures...

Physiological frailty index (PFI): quantitative in-life estimate of individual biological age in mice.

PubMed

Antoch, Marina P; Wrobel, Michelle; Kuropatwinski, Karen K; Gitlin, Ilya; Leonova, Katerina I; Toshkov, Ilia; Gleiberman, Anatoli S; Hutson, Alan D; Chernova, Olga B; Gudkov, Andrei V

2017-03-19

The development of healthspan-extending pharmaceuticals requires quantitative estimation of age-related progressive physiological decline. In humans, individual health status can be quantitatively assessed by means of a frailty index (FI), a parameter which reflects the scale of accumulation of age-related deficits. However, adaptation of this methodology to animal models is a challenging task since it includes multiple subjective parameters. Here we report a development of a quantitative non-invasive procedure to estimate biological age of an individual animal by creating physiological frailty index (PFI). We demonstrated the dynamics of PFI increase during chronological aging of male and female NIH Swiss mice. We also demonstrated acceleration of growth of PFI in animals placed on a high fat diet, reflecting aging acceleration by obesity and provide a tool for its quantitative assessment. Additionally, we showed that PFI could reveal anti-aging effect of mTOR inhibitor rapatar (bioavailable formulation of rapamycin) prior to registration of its effects on longevity. PFI revealed substantial sex-related differences in normal chronological aging and in the efficacy of detrimental (high fat diet) or beneficial (rapatar) aging modulatory factors. Together, these data introduce PFI as a reliable, non-invasive, quantitative tool suitable for testing potential anti-aging pharmaceuticals in pre-clinical studies.

Abundance Trends and Status of the Little Colorado River Population of Humpback Chub: An Update Considering 1989-2006 Data

USGS Publications Warehouse

Coggins,, Lewis G.

2008-01-01

EXECUTIVE SUMMARY In 1967, the humpback chub (Gila cypha) (HBC) was added to the federal list of endangered species and is today protected under the Endangered Species Act of 1973. Only six populations of humpback chub are currently known to exist, five in the Colorado River Basin above Lees Ferry, Arizona, and one in Grand Canyon, Arizona. The majority of Grand Canyon humpback chub are found in the Little Colorado River (LCR)-the largest tributary to the Colorado River in Grand Canyon-and the Colorado River near its confluence with the Little Colorado River. Monitoring and research of the Grand Canyon humpback chub population is overseen by the U.S. Geological Survey's (USGS) Grand Canyon Monitoring and Research Center (GCMRC) under the auspices of the Glen Canyon Dam Adaptive Management Program (GCDAMP), a Federal initiative to protect and improve resources downstream of Glen Canyon Dam. This report provides updated information on the status and trends of the LCR population in light of new information and refined assessment methodology. An earlier assessment of the LCR population (Coggins and others, 2006a) used data collected during 1989?2002; the assessment provided here includes that data and additional data collected through 2006. Catch-rate indices, closed population mark-recapture model abundance estimates, results from the original age-structured mark recapture (ASMR) model (Coggins and others, 2006b), and a newly refined ASMR model are presented. This report also seeks to (1) formally evaluate alternative stock assessment models using Pearson residual analyses and information theoretic procedures, (2) use mark-recapture data to estimate the relationship between HBC age and length, (3) translate uncertainty in the assignment of individual fish age to resulting estimates of recruitment and abundance from the ASMR model, and (4) evaluate past and present stock assessments considering the available data sources and analyses, recognizing the limitations inherent in both. A major task of this study was to improve the overall methodology used to conduct HBC stock assessment by addressing concerns identified in an independent review conducted in 2003 (Kitchell and others, 2003). The review report identified that the current technique of assigning age to individual fish based on length was a potential source of bias in ASMR estimates of abundance and recruitment, and called for a more complete examination of this potential error source. Additionally, the review suggested that further work to develop procedures to better arbitrate among alternative assessment models (e.g., ASMR 1?3) would be beneficial. To address the first of the concerns identified by the independent review, this study uses mark-recapture data to develop a temperature-dependent growth model to characterize the relationship between HBC age and length. This model attempts to account for temperature differences resulting from both ontogenetic habitat shifts between the Little Colorado and the mainstem Colorado Rivers as well as seasonal variation in water temperature within the LCR. The resulting growth model is then used to characterize the error in assigning age to individual fish based on length. Results presented in this study suggest that ageing error does not result in large bias in either abundance or recruitment estimates from the ASMR model. However, incorporating ageing error into the assessment does result in less precise estimates, particularly for recruitment. To address the second concern brought forward in the review report related to model selection procedures, this study arbitrated among the competing models by both examining model fit using Pearson residual analyses and considering information theoretic measures. Although adult abundance estimates and trend varied little among all models considered, these procedures identified ASMR 3 as the model whose underlying assumptions were most consistent with the data. Because ASMR 3 is

Estimates of genetic parameters in turkeys. 3. Sexual dimorphism and its implications in selection procedures.

PubMed

Toelle, V D; Havenstein, G B; Nestor, K E; Bacon, W L

1990-10-01

Live, carcass, and skeletal data taken at 16 wk of age on 504 female and 584 male turkeys from 34 sires and 168 dams were utilized to evaluate sex differences in genetic parameter estimates. Data were transformed to common mean and variance to evaluate possible scaling effects. Genetic parameters were estimated from transformed and untransformed data. Further analyses were conducted with a model that included sire by sex and dams within sire by sex interactions, and the variance estimates were used to calculate genetic correlations between the sexes and genetic regression parameters. Heritability estimates from transformed and untransformed data were similar, indicating that sex differences were present in the genetic parameters, but scaling effects were not an important factor. Genetic correlation estimates from paternal (PHS) and maternal (MHS) half-sib estimates were close to unity for BW (1.14, PHS; 1.09, MHS), shank width (.99, PHS; .93, MHS), breast muscle weight (1.23, PHS; 1.04, MHS), and shank length (1.09, PHS; .97, MHS). However, abdominal fat (.79, PHS; .59 MHS), total drumstick muscle weight (.75, PHS; 1.14, MHS), rough cleaned shank weight (.78, PHS; not estimatable, MHS), and shank bone density (1.00, PHS; .53, MHS) estimates were somewhat lower. The estimates suggest that the measurement of these latter "traits" at the same age in the two sexes may, in fact, be measuring different genetic effects and that selection procedures in turkeys need to take these correlations into account in order to make optimum progress. The genetic regression parameters indicated that more intense selection in the sex that has the smaller genetic variation could be practiced to make greater gains in the opposite sex.

Development and Pilot Testing of 24-Hour Multiple-Pass Recall to Assess Dietary Intake of Toddlers of Somali- and Iraqi-Born Mothers Living in Norway

PubMed Central

Grewal, Navnit Kaur; Mosdøl, Annhild; Aunan, Marte Bergsund; Monsen, Carina; Torheim, Liv Elin

2014-01-01

The aim of this study was to develop, test, and evaluate a 24-h recall procedure to assess the dietary intake of toddlers of Somali- and Iraqi-born mothers living in Norway. A protocol for a 24-h multiple-pass recall procedure, registration forms, and visual tools (a picture library for food identification and portion size estimation) was developed and tested in 12 mothers from Somalia and Iraq with children aged 10–21 months. Five female field workers were recruited and trained to conduct the interviews. Evaluation data for the 24-h recall procedure were collected from both the mothers and the field workers. Nutrient intake was calculated using a Norwegian dietary calculation system. Each child’s estimated energy intake was compared with its estimated energy requirement. Both the mothers and the field workers found the method feasible and the visual tools useful. The estimated energy intake corresponded well with the estimated energy requirement for most of the children (within mean ± 2 SD, except for three). The pilot study identified the need for additional foods in the picture library and some crucial aspects in training and supervising the field workers to reduce sources of error in the data collection. PMID:24949548

Indexing the relative abundance of age-0 white sturgeons in an impoundment of the lower Columbia River from highly skewed trawling data

USGS Publications Warehouse

Counihan, T.D.; Miller, Allen I.; Parsley, M.J.

1999-01-01

The development of recruitment monitoring programs for age-0 white sturgeons Acipenser transmontanus is complicated by the statistical properties of catch-per-unit-effort (CPUE) data. We found that age-0 CPUE distributions from bottom trawl surveys violated assumptions of statistical procedures based on normal probability theory. Further, no single data transformation uniformly satisfied these assumptions because CPUE distribution properties varied with the sample mean (??(CPUE)). Given these analytic problems, we propose that an additional index of age-0 white sturgeon relative abundance, the proportion of positive tows (Ep), be used to estimate sample sizes before conducting age-0 recruitment surveys and to evaluate statistical hypothesis tests comparing the relative abundance of age-0 white sturgeons among years. Monte Carlo simulations indicated that Ep was consistently more precise than ??(CPUE), and because Ep is binomially rather than normally distributed, surveys can be planned and analyzed without violating the assumptions of procedures based on normal probability theory. However, we show that Ep may underestimate changes in relative abundance at high levels and confound our ability to quantify responses to management actions if relative abundance is consistently high. If data suggest that most samples will contain age-0 white sturgeons, estimators of relative abundance other than Ep should be considered. Because Ep may also obscure correlations to climatic and hydrologic variables if high abundance levels are present in time series data, we recommend ??(CPUE) be used to describe relations to environmental variables. The use of both Ep and ??(CPUE) will facilitate the evaluation of hypothesis tests comparing relative abundance levels and correlations to variables affecting age-0 recruitment. Estimated sample sizes for surveys should therefore be based on detecting predetermined differences in Ep, but data necessary to calculate ??(CPUE) should also be collected.

Functional Linear Model with Zero-value Coefficient Function at Sub-regions.

PubMed

Zhou, Jianhui; Wang, Nae-Yuh; Wang, Naisyin

2013-01-01

We propose a shrinkage method to estimate the coefficient function in a functional linear regression model when the value of the coefficient function is zero within certain sub-regions. Besides identifying the null region in which the coefficient function is zero, we also aim to perform estimation and inferences for the nonparametrically estimated coefficient function without over-shrinking the values. Our proposal consists of two stages. In stage one, the Dantzig selector is employed to provide initial location of the null region. In stage two, we propose a group SCAD approach to refine the estimated location of the null region and to provide the estimation and inference procedures for the coefficient function. Our considerations have certain advantages in this functional setup. One goal is to reduce the number of parameters employed in the model. With a one-stage procedure, it is needed to use a large number of knots in order to precisely identify the zero-coefficient region; however, the variation and estimation difficulties increase with the number of parameters. Owing to the additional refinement stage, we avoid this necessity and our estimator achieves superior numerical performance in practice. We show that our estimator enjoys the Oracle property; it identifies the null region with probability tending to 1, and it achieves the same asymptotic normality for the estimated coefficient function on the non-null region as the functional linear model estimator when the non-null region is known. Numerically, our refined estimator overcomes the shortcomings of the initial Dantzig estimator which tends to under-estimate the absolute scale of non-zero coefficients. The performance of the proposed method is illustrated in simulation studies. We apply the method in an analysis of data collected by the Johns Hopkins Precursors Study, where the primary interests are in estimating the strength of association between body mass index in midlife and the quality of life in physical functioning at old age, and in identifying the effective age ranges where such associations exist.

Estimation of death rates in US states with small subpopulations.

PubMed

Voulgaraki, Anastasia; Wei, Rong; Kedem, Benjamin

2015-05-20

In US states with small subpopulations, the observed mortality rates are often zero, particularly among young ages. Because in life tables, death rates are reported mostly on a log scale, zero mortality rates are problematic. To overcome the observed zero death rates problem, appropriate probability models are used. Using these models, observed zero mortality rates are replaced by the corresponding expected values. This enables logarithmic transformations and, in some cases, the fitting of the eight-parameter Heligman-Pollard model to produce mortality estimates for ages 0-130 years, a procedure illustrated in terms of mortality data from several states. Copyright © 2014 John Wiley & Sons, Ltd.

National Health and Nutrition Examination Survey: National Youth Fitness Survey Estimation Procedures, 2012.

PubMed

Johnson, Clifford L; Dohrmann, Sylvia M; Kerckove, Van de; Diallo, Mamadou S; Clark, Jason; Mohadjer, Leyla K; Burt, Vicki L

2014-11-01

The National Health and Nutrition Examination Survey's (NHANES) National Youth Fitness Survey (NNYFS) was conducted in 2012 by the Centers for Disease Control and Prevention's National Center for Health Statistics (NCHS). NNYFS collected data on physical activity and fitness levels to evaluate the health and fitness of children aged 3-15 in the United States. The survey comprised three levels of data collection: a household screening interview (or screener), an in-home personal interview, and a physical examination. The screener's primary objective was to determine whether any children in the household were eligible for the interview and examination. Eligibility was determined by preset selection probabilities for desired sex-age subdomains. After selection, the in-home personal interview collected demographic, health, physical activity, and nutrition information about the child as well as information about the household. The examination included physical measurements and fitness tests. This report provides background on the NNYFS program and summarizes the survey's sample design specifications. The report presents NNYFS estimation procedures, including the methods used to calculate survey weights for the full sample as well as a combined NHANES/NNYFS sample for 2012 (accessible only through the NCHS Research Data Center). The report also describes appropriate variance estimation methods. Documentation of the sample selection methods, survey content, data collection procedures, and methods to assess nonsampling errors are reported elsewhere. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

Gap Detection and Temporal Modulation Transfer Function as Behavioral Estimates of Auditory Temporal Acuity Using Band-Limited Stimuli in Young and Older Adults

PubMed Central

Shen, Yi

2015-01-01

Purpose Gap detection and the temporal modulation transfer function (TMTF) are 2 common methods to obtain behavioral estimates of auditory temporal acuity. However, the agreement between the 2 measures is not clear. This study compares results from these 2 methods and their dependencies on listener age and hearing status. Method Gap detection thresholds and the parameters that describe the TMTF (sensitivity and cutoff frequency) were estimated for young and older listeners who were naive to the experimental tasks. Stimuli were 800-Hz-wide noises with upper frequency limits of 2400 Hz, presented at 85 dB SPL. A 2-track procedure (Shen & Richards, 2013) was used for the efficient estimation of the TMTF. Results No significant correlation was found between gap detection threshold and the sensitivity or the cutoff frequency of the TMTF. No significant effect of age and hearing loss on either the gap detection threshold or the TMTF cutoff frequency was found, while the TMTF sensitivity improved with increasing hearing threshold and worsened with increasing age. Conclusion Estimates of temporal acuity using gap detection and TMTF paradigms do not seem to provide a consistent description of the effects of listener age and hearing status on temporal envelope processing. PMID:25087722

Age estimation by modified Demirjian's method (2004) and its applicability in Tibetan young adults: A digital panoramic study.

PubMed

Bijjaragi, Shobha C; Sangle, Varsha A; Saraswathi, F K; Patil, Veerendra S; Ashwini Rani, S R; Bapure, Sunil K

2015-01-01

Estimation of the age is a procedure adopted by anthropologists, archeologists and forensic scientists. Different methods have been undertaken. However none of them meet the standards as Demirjian's method since 1973. Various researchers have applied this method, in both original and modified form (Chaillet and Demirjian in 2004) in different ethnic groups and the results obtained were not satisfactory. To determine the applicability and accuracy of modified Demirjian's method of dental age estimation (AE) in 8-18 year old Tibetan young adults to evaluate the interrelationship between dental and chronological age and the reliability between intra- and inter observer relationship. Clinical setting and computerized design. A total of 300 Tibetan young adults with an age range from 8 to 18 years were recruited in the study. Digital panoramic radiographs (DPRs) were evaluated as per the modified Demirjian's method (2004). Pearson correlation, paired t-test, linear regression analysis. Inter -and intraobserver reliability revealed a strong agreement. A positive and strong association was found between chronological age and estimated dental age (r = 0.839) with P < 0.01. Modified Demirjian method (2004) overestimated the age by 0.04 years (2.04 months)in Tibetan young adults. Results suggest that, the modified Demirjian method of AE is not suitable for Tibetan young adults. Further studies: With larger sample size and comparision with different methods of AE in a given population would be an interesting area for future research.

Global and regional cause-of-death patterns in 1990.

PubMed Central

Murray, C. J.; Lopez, A. D.

1994-01-01

Demographic estimation techniques suggest that worldwide about 50 million deaths occur each year, of which about 39 million are in the developing countries. In countries with adequate registration of vital statistics, the age at death and the cause can be reliably determined. Only about 30-35% of all deaths are captured by vital registration (excluding sample registration schemes); for the remainder, cause-of-death estimation procedures are required. Indirect methods which model the cause-of-death structure as a function of the level of mortality can provide reasonable estimates for broad cause-of-death groups. Such methods are generally unreliable for more specific causes. In this case, estimates can be constructed from community-level mortality surveillance systems or from epidemiological evidence on specific diseases. Some check on the plausibility of the estimates is possible in view of the hierarchical structure of cause-of-death lists and the well-known age-specific patterns of diseases and injuries. The results of applying these methods to estimate the cause of death for over 120 diseases or injuries, by age, sex and region, are described. The estimates have been derived in order to calculate the years of life lost due to premature death, one of the two components of overall disability-adjusted life years (DALYs) calculated for the 1993 World development report. Previous attempts at cause-of-death estimation have been limited to a few diseases only, with little age-specific detail. The estimates reported in detail here should serve as a useful reference for further public health research to support the determination of health sector priorities. PMID:8062402

Estimating malaria transmission from humans to mosquitoes in a noisy landscape.

PubMed

Reiner, Robert C; Guerra, Carlos; Donnelly, Martin J; Bousema, Teun; Drakeley, Chris; Smith, David L

2015-10-06

A basic quantitative understanding of malaria transmission requires measuring the probability a mosquito becomes infected after feeding on a human. Parasite prevalence in mosquitoes is highly age-dependent, and the unknown age-structure of fluctuating mosquito populations impedes estimation. Here, we simulate mosquito infection dynamics, where mosquito recruitment is modelled seasonally with fractional Brownian noise, and we develop methods for estimating mosquito infection rates. We find that noise introduces bias, but the magnitude of the bias depends on the 'colour' of the noise. Some of these problems can be overcome by increasing the sampling frequency, but estimates of transmission rates (and estimated reductions in transmission) are most accurate and precise if they combine parity, oocyst rates and sporozoite rates. These studies provide a basis for evaluating the adequacy of various entomological sampling procedures for measuring malaria parasite transmission from humans to mosquitoes and for evaluating the direct transmission-blocking effects of a vaccine. © 2015 The Authors.

Standard Operating Procedure for the Turbidimetric Determination of Lead in Paint Extracts

EPA Science Inventory

Exposure to lead (Pb) may adversely impact children's brains, nervous systems and many organs. An estimated 310,000 US children ages 1 to 5 have elevated blood leads. In the United States, the major exposure pathway for children to Pb is from deteriorated Pb-based paint (LBP), ...

Economic Valuation of the Global Burden of Cleft Disease Averted by a Large Cleft Charity.

PubMed

Poenaru, Dan; Lin, Dan; Corlew, Scott

2016-05-01

This study attempts to quantify the burden of disease averted through the global surgical work of a large cleft charity, and estimate the economic impact of this effort over a 10-year period. Anonymized data of all primary cleft lip and cleft palate procedures in the Smile Train database were analyzed and disability-adjusted life years (DALYs) calculated using country-specific life expectancy tables, established disability weights, and estimated success of surgery and residual disability probabilities; multiple age weighting and discounting permutations were included. Averted DALYs were calculated and gross national income (GNI) per capita was then multiplied by averted DALYs to estimate economic gains. 548,147 primary cleft procedures were performed in 83 countries between 2001 and 2011. 547,769 records contained complete data available for the study; 58 % were cleft lip and 42 % cleft palate. Averted DALYs ranged between 1.46 and 4.95 M. The mean economic impact ranged between USD 5510 and 50,634 per person. This corresponded to a global economic impact of between USD 3.0B and 27.7B USD, depending on the DALY and GNI values used. The estimated cost of providing these procedures based on an average reimbursement rate was USD 197M (0.7-6.6 % of the estimated impact). The immense economic gain realized through procedures focused on a small proportion of the surgical burden of disease highlights the importance and cost-effectiveness of surgical treatment globally. This methodology can be applied to evaluate interventions for other conditions, and for evidence-based health care resource allocation.

TU-H-CAMPUS-IeP1-03: Comparison of Monte Carlo Simulation and Conversion Factor Based Method On Estimation of Effective Dose in Pediatric Patients Undergoing Interventional Cardiac Procedures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leung, K; Wong, M; Ng, Y

Purpose: Interventional cardiac procedures utilize frequent fluoroscopy and cineangiography, which impose considerable radiation risk to patients, especially pediatric patients. Accurate calculation of effective dose is important in order to estimate cancer risk over the rest of their lifetime. This study evaluates the difference in effective dose calculated by Monte Carlo simulation with those estimated by locally-derived conversion factors (CF-local) and by commonly quoted conversion factors from Karambatsakidou et al (CF-K). Methods: Effective dose (E),of 12 pediatric patients, age between 2.5–19 years old, who had undergone interventional cardiac procedures, were calculated using PCXMC-2.0 software. Tube spectrum, irradiation geometry, exposure parameters andmore » dose-area product (DAP) of each projection were included in the software calculation. Effective doses for each patient were also estimated by two Methods: 1) CF-local: conversion factor derived locally by generalizing results of 12 patients, multiplied by DAP of each patient gives E-local. 2) CF-K: selected factor from above-mentioned literature, multiplied by DAP of each patient gives E-K. Results: Mean of E, E-local and E-K were 16.01 mSv, 16.80 mSv and 22.25 mSv respectively. A deviation of −29.35% to +34.85% between E and E-local, while a greater deviation of −28.96% to +60.86% between E and EK were observed. E-K overestimated the effective dose for patients at age 7.5–19. Conclusion: Effective dose obtained by conversion factors is simple and quick to estimate radiation risk of pediatric patients. This study showed that estimation by CF-local may bear an error of 35% when compared with Monte Carlo calculation. If using conversion factors derived by other studies may result in an even greater error, of up to 60%, due to factors that are not catered for in the estimation, including patient size, projection angles, exposure parameters, tube filtration, etc. Users must be aware of these potential inaccuracies when simple conversion method is employed.« less

Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population.

PubMed

Sequeira, Catarina-Dourado; Teixeira, Alexandra; Caldas, Inês-Morais; Afonso, Américo; Pérez-Mongiovi, Daniel

2014-12-01

The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament.

Dental service trends for older US adults, 1998-2006.

PubMed

Skaar, Daniel D; O'Connor, Heidi

2012-03-01

This study of the Medicare Current Beneficiary Survey (MCBS) updates trends in utilization of dental services between 1998 and 2006 for community-dwelling U.S. adults of age 65 years and older. Bivariate comparisons were made between dependent variables (annual dental visits and types of dental procedures) and independent variables (age, gender, race, income, education, population density, marital status, U.S. Census Bureau regions, and self-reported health). The estimated percentage of community-dwelling Medicare beneficiaries with a dental visit for the years studied increased from 45.0% in 1998 to 46.3% in 2006. The age group of respondents who were 85 years and older had the greatest percentage increase in dental visits. Those reporting visits with preventive procedures increased from 87.8% to 91.2% whereas those reporting visits with nonpreventive procedures declined from 63.9% to 58.4%. The prevalence of dental visits continues to trend upward for this population of older adults. Increasing delivery of preventive services will likely impact the future mix of dental services as U.S. adults live longer. © 2012 Special Care Dentistry Association and Wiley Periodicals, Inc.

Trends in hospital admissions and surgical procedures for degenerative lumbar spine disease in England: a 15-year time-series study.

PubMed

Sivasubramaniam, Vinothan; Patel, Hitesh C; Ozdemir, Baris A; Papadopoulos, Marios C

2015-12-15

Low back pain (LBP), from degenerative lumbar spine disease, represents a significant burden on healthcare resources. Studies worldwide report trends attributable to their country's specific demographics and healthcare system. Considering England's specific medico-socioeconomic conditions, we investigate recent trends in hospital admissions and procedures for LBP, and discuss the implications for the allocation of healthcare resources. Retrospective cohort study using Hospital Episode Statistics data relating to degenerative lumbar spine disease in England, between 1999 and 2013. Regression models were used to analyse trends. Trends in the number of admissions and procedures for LBP, mean patient age, gender and length of stay. Hospital admissions and procedures have increased significantly over the study period, from 127.09 to 216.16 and from 24.5 to 48.83 per 100,000, respectively, (p<0.001). The increase was most marked in the oldest age groups with a 1.9 and 2.33-fold increase in admissions for patients aged 60-74 and ≥ 75 years, respectively, and a 2.8-fold increase in procedures for those aged ≥ 60 years. Trends in hospital admissions were characterised by a widening gender gap, increasing mean patient age, and decreasing mean hospital stay (p<0.001). Trends in procedures were characterised by a narrowing gender gap, increasing mean patient age (p=0.014) and decreasing mean hospital stay (p<0.001). Linear regression models estimate that each hospital admission translates to 0.27 procedures, per 100,000 (95% CI 0.25 to 0.30, r 0.99, p<0.001; r, Pearson's correlation coefficient). Hospital admissions are increasing at 3.5 times the rate of surgical procedures (regression gradient 7.63 vs 2.18 per 100,000/year). LBP represents a significant and increasing workload for hospitals in England. These trends demonstrate an increasing demand for specialists involved in the surgical and non-surgical management of this disease, and highlight the need for services capable of dealing with the increased comorbidity burden associated with an ageing patient group. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Precision of measurement and body size in whole-body air-displacement plethysmography.

PubMed

Wells, J C; Fuller, N J

2001-08-01

To investigate methodological and biological precision for air-displacement plethysmography (ADP) across a wide range of body size. Repeated measurements of body volume (BV) and body weight (WT), and derived estimates of density (BD) and indices of fat mass (FM) and fat-free mass (FFM). Sixteen men, aged 22--48 y; 12 women, aged 24--42 y; 13 boys, aged 5--14 y; 17 girls, aged 5--16 y. BV and WT were measured using the Bodpod ADP system from which estimates of BD, FM and FFM were derived. FM and FFM were further adjusted for height to give fat mass index (FMI) and fat-free mass index (FFMI). ADP is very precise for measuring both BV and BD (between 0.16 and 0.44% of the mean). After removing two outliers from the database, and converting BD to body composition, precision of FMI was <6% in adults and within 8% in children, while precision of FFMI was within 1.5% for both age groups. ADP shows good precision for BV and BD across a wide range of body size, subject to biological artefacts. If aberrant values can be identified and rejected, precision of body composition is also good. Aberrant values can be identified by using pairs of ADP procedures, allowing the rejection of data where successive BD values differed by >0.007 kg/l. Precision of FMI obtained using pairs of procedures improves to <4.5% in adults and <5.5% in children.

Does intraoperative fluid management in spine surgery predict intensive care unit length of stay?

PubMed

Nahtomi-Shick, O; Kostuik, J P; Winters, B D; Breder, C D; Sieber, A N; Sieber, F E

2001-05-01

To determine whether intraoperative fluid management in spine surgery predicts postoperative intensive care unit length of stay (ICU LOS). Retrospective case series. University-affiliated medical center. 103 adult ASA physical status I, II, and III patients undergoing spine surgery. Patients were divided into three LOS groups: no ICU stay (LOS0) (n = 26), 1 day ICU stay (LOS1) (n = 48), and ICU stay > 1 day (LOS2) (n = 29). Measurements were analyzed by groups using the Kruskal-Wallis and Mann-Whitney tests, and linear regression. Demographics, comorbidity, length of surgery, surgical procedure, and intraoperative fluids were recorded. The important differences in perioperative fluid management among the three groups included estimated blood loss (612 +/- 480 mL, 1853 +/- 1175 mL, 2702 +/- 1771 mL, means +/- SD); total crystalloid administration (2715 +/- 1396 mL, 5717 +/- 2574 mL, 7281 +/- 3417 mL); and total blood administration (92 +/- 279 mL, 935 +/- 757 mL, 1542 +/- 1230 mL) in LOS0, LOS1, and LOS2, respectively. The mixture of surgical procedures was similar in LOS1 and LOS2; and differed from LOS0. Predictors of ICU LOS included age, ASA physical status, surgical procedure, total crystalloid administration, and platelet administration. Surgical procedure and total crystalloid administration correlated (Pearson correlation coefficient = 0.441; p = 0.000) and were not related to age or ASA physical status. Total crystalloid administration during spine surgery does predict ICU LOS. In addition, total crystalloid administration is closely related to the surgical procedure. Given that the mixture of surgical procedures was similar in LOS1 and LOS2, but differed in estimated blood loss, total crystalloid administration, and total blood administration; intraoperative fluid management during spine surgery only predicts ICU LOS insofar as total crystalloid administration is related to the surgical procedure.

Bayesian semiparametric estimation of covariate-dependent ROC curves

PubMed Central

Rodríguez, Abel; Martínez, Julissa C.

2014-01-01

Receiver operating characteristic (ROC) curves are widely used to measure the discriminating power of medical tests and other classification procedures. In many practical applications, the performance of these procedures can depend on covariates such as age, naturally leading to a collection of curves associated with different covariate levels. This paper develops a Bayesian heteroscedastic semiparametric regression model and applies it to the estimation of covariate-dependent ROC curves. More specifically, our approach uses Gaussian process priors to model the conditional mean and conditional variance of the biomarker of interest for each of the populations under study. The model is illustrated through an application to the evaluation of prostate-specific antigen for the diagnosis of prostate cancer, which contrasts the performance of our model against alternative models. PMID:24174579

A statistical method for estimating rates of soil development and ages of geologic deposits: A design for soil-chronosequence studies

USGS Publications Warehouse

Switzer, P.; Harden, J.W.; Mark, R.K.

1988-01-01

A statistical method for estimating rates of soil development in a given region based on calibration from a series of dated soils is used to estimate ages of soils in the same region that are not dated directly. The method is designed specifically to account for sampling procedures and uncertainties that are inherent in soil studies. Soil variation and measurement error, uncertainties in calibration dates and their relation to the age of the soil, and the limited number of dated soils are all considered. Maximum likelihood (ML) is employed to estimate a parametric linear calibration curve, relating soil development to time or age on suitably transformed scales. Soil variation on a geomorphic surface of a certain age is characterized by replicate sampling of soils on each surface; such variation is assumed to have a Gaussian distribution. The age of a geomorphic surface is described by older and younger bounds. This technique allows age uncertainty to be characterized by either a Gaussian distribution or by a triangular distribution using minimum, best-estimate, and maximum ages. The calibration curve is taken to be linear after suitable (in certain cases logarithmic) transformations, if required, of the soil parameter and age variables. Soil variability, measurement error, and departures from linearity are described in a combined fashion using Gaussian distributions with variances particular to each sampled geomorphic surface and the number of sample replicates. Uncertainty in age of a geomorphic surface used for calibration is described using three parameters by one of two methods. In the first method, upper and lower ages are specified together with a coverage probability; this specification is converted to a Gaussian distribution with the appropriate mean and variance. In the second method, "absolute" older and younger ages are specified together with a most probable age; this specification is converted to an asymmetric triangular distribution with mode at the most probable age. The statistical variability of the ML-estimated calibration curve is assessed by a Monte Carlo method in which simulated data sets repeatedly are drawn from the distributional specification; calibration parameters are reestimated for each such simulation in order to assess their statistical variability. Several examples are used for illustration. The age of undated soils in a related setting may be estimated from the soil data using the fitted calibration curve. A second simulation to assess age estimate variability is described and applied to the examples. ?? 1988 International Association for Mathematical Geology.

Methods and application of bone densitometry in clinical diagnosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wahner, H.W.; Riggs, B.L.

1986-01-01

With the awareness of osteoporosis as a major health problem for an aging population, there is great interest in early recognition and treatment of abnormal bone loss. Effective prevention of bone loss has to occur prior to the occurrence of irreparable damage. Standard radiographic procedures are not sensitive enough for the task. Therefore, a number of alternative procedures to estimate bone loss have been developed over the years, ranging from efforts to quantitate information obtained from radiographic images to sophisticated procedures such as neutron activation analysis or procedures based on the Compton scatter phenomenon. Only two procedures, photon absorptiometry andmore » computed tomography (CT), have emerged as applicable for routine clinical use. In photon absorptiometry the entire bone mineral (cortical and trabecular bone) of a specific skeletal site is measured. CT allows measuring of bone mineral of trabecular or cortical bone alone. Normally, bone mass reaches a maximum in the third decade and then continuously declines. This age-related bone loss is greater in women in whom an accelerated rate of loss occurs at the menopause. When bone density reaches a critical fracture threshold, skeletal fractures occur (spine, hip, and distal long bones). The age at which this critical fracture threshold is reached depends on the maximal bone mass achieved in early adulthood and the rate of loss with increasing age. With the exception of NaF, present-day therapeutic efforts only retard or prevent bone loss but do not significantly add bone mineral to the skeleton. Recognition of high-risk groups and early treatment are therefore required. 79 references.« less

A general methodology for maximum likelihood inference from band-recovery data

USGS Publications Warehouse

Conroy, M.J.; Williams, B.K.

1984-01-01

A numerical procedure is described for obtaining maximum likelihood estimates and associated maximum likelihood inference from band- recovery data. The method is used to illustrate previously developed one-age-class band-recovery models, and is extended to new models, including the analysis with a covariate for survival rates and variable-time-period recovery models. Extensions to R-age-class band- recovery, mark-recapture models, and twice-yearly marking are discussed. A FORTRAN program provides computations for these models.

The skin aging index: a new approach for documenting anti-aging products or procedures.

PubMed

Nkengne, Alex; Roure, Romain; Rossi, Ana Beatriz; Bertin, Christiane

2013-08-01

The overall appearance of an aged skin is characterized by a combination of several attributes such as wrinkles, brown spots and sagging. Our objective was to develop and validate a statistical framework to assess the overall anti-ageing benefits of products/procedures. Different skin attributes were evaluated by a clinical grader and combined using a Principal Component Analysis (PCA). The Skin Ageing Index was defined as the normalized projection of the clinical grading values on the first PCA axis. Several Skin Indexes were built by grouping specific parameters related to a skin condition such as overall ageing, wrinkles and sagging. The method was validated following two steps. Firstly, a clinical study was performed on 173 Caucasian women and the correlation between the Skin Indexes and the volunteers' real and perceived age was estimated. Secondly, a double-blinded placebo-controlled randomized study was performed on 87 Caucasian women to assess the efficacy of an anti-wrinkle cream containing retinol, hyaluronic acid and dihydroxymethylchromone. Facial wrinkles were clinically evaluated and a Wrinkle Index was built. All indexes were highly correlated with the real and the perceived age (0.57 ≤ Pearson R ≤ 0.92, P-value ≤ 0.05). Finally, the Wrinkle Index provides documented evidence that the tested product significantly reduced the appearance of wrinkles versus the placebo and the baseline assessment (-23.53% after 4 weeks, -27.83% after 8 weeks). Skin ageing Indexes capture information relevant to the visual transformation of facial skin with age, while providing documented product benefits. These tools may enable a simpler and more consistent comparison of anti-ageing products/procedures. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Age validation and growth of bluenose Hyperoglyphe antarctica using the bomb chronometer method of radiocarbon ageing.

PubMed

Horn, P L; Neil, H L; Paul, L J; Marriott, P

2010-11-01

Age validation of bluenose Hyperoglyphe antarctica was sought using the independent bomb chronometer procedure. Radiocarbon ((14) C) levels were measured in core micro-samples from 12 otoliths that had been aged using a zone count method. The core (14) C measurement for each fish was compared with the value on a surface water reference curve for the calculated birth year of the fish. There was good agreement, indicating that the line-count ageing method described here is not substantially biased. A second micro-sample was also taken near the edge of nine of the otolith cross-sections to help define a bomb-carbon curve for waters deeper than 200-300 m. There appears to be a 10 to 15 year lag in the time it takes the (14) C to reach the waters where adult H. antarctica are concentrated. The maximum estimated age of this species was 76 years, and females grow significantly larger than males. Von Bertalanffy growth curves were estimated, and although they fit the available data reasonably well, the lack of aged juvenile fish results in the K and t(0) parameters being biologically meaningless. Consequently, curves that are likely to better represent population growth were estimated by forcing t(0) to be -0·5. © 2010 NIWA. Journal of Fish Biology © 2010 The Fisheries Society of the British Isles.

Results of endoscopic third ventriculostomy in elderly patients ≥65 years of age.

PubMed

Niknejad, Hamid Reza; Depreitere, Bart; De Vleeschouwer, Steven; Van Calenbergh, Frank; van Loon, Johannes

2015-03-01

Endoscopic third ventriculostomy (ETV) has been accepted as the procedure of choice for the treatment of obstructive hydrocephalus in children and adults. The role and outcome of this procedure in the elderly has not been evaluated yet. Over an 11-year interval we retrospectively analyzed data of patients, 65+ years of age, who underwent ETV in our center. Success of the procedure was assessed in terms of symptom relief and/or elimination of the need for shunting. Additionally pre- and postoperative ventricular volumes were estimated using Evan's index (Ei) and fronto-occipital horn ratio (FOR). In our analysis we compared the results of the elderly patients with those of the pediatric and adult age groups treated in our center. We obtained data of 16 elderly cases (11 males, 5 females), mean age 72.8 years (66-83 years) out of the 91 patients treated with ETV in total. The success rate was 75% in this age group; mean follow-up 18.4 months (2-55 months). In 10 patients a mass lesion was the underlying cause of hydrocephalus. Mean ventricular size reduction was 18% and 13.5% (Ei and FOR) in the success group vs. 7.6% and 6.2% in the failure group. Three out of four patients who had shunting pre-EVT, became shunt independent post-operatively. The presence of flow void over the stoma was 100% correlated with success. All 7 patients with a primary or metastatic brain tumor were able to receive radiation therapy. Also in elderly, ETV is a safe and efficient procedure, with success rates similar to the younger population. Further research is required to set up a prognostic scoring system for this age group. Copyright © 2014 Elsevier B.V. All rights reserved.

Modelling survival and mortality risk to 15 years of age for a national cohort of children with serious congenital heart defects diagnosed in infancy.

PubMed

Knowles, Rachel L; Bull, Catherine; Wren, Christopher; Wade, Angela; Goldstein, Harvey; Dezateux, Carol

2014-01-01

Congenital heart defects (CHDs) are a significant cause of death in infancy. Although contemporary management ensures that 80% of affected children reach adulthood, post-infant mortality and factors associated with death during childhood are not well-characterised. Using data from a UK-wide multicentre birth cohort of children with serious CHDs, we observed survival and investigated independent predictors of mortality up to age 15 years. Data were extracted retrospectively from hospital records and death certificates of 3,897 children (57% boys) in a prospectively identified cohort, born 1992-1995 with CHDs requiring intervention or resulting in death before age one year. A discrete-time survival model accounted for time-varying predictors; hazards ratios were estimated for mortality. Incomplete data were addressed through multilevel multiple imputation. By age 15 years, 932 children had died; 144 died without any procedure. Survival to one year was 79.8% (95% confidence intervals [CI] 78.5, 81.1%) and to 15 years was 71.7% (63.9, 73.4%), with variation by cardiac diagnosis. Importantly, 20% of cohort deaths occurred after age one year. Models using imputed data (including all children from birth) demonstrated higher mortality risk as independently associated with cardiac diagnosis, female sex, preterm birth, having additional cardiac defects or non-cardiac malformations. In models excluding children who had no procedure, additional predictors of higher mortality were younger age at first procedure, lower weight or height, longer cardiopulmonary bypass or circulatory arrest duration, and peri-procedural complications; non-cardiac malformations were no longer significant. We confirm the high mortality risk associated with CHDs in the first year of life and demonstrate an important persisting risk of death throughout childhood. Late mortality may be underestimated by procedure-based audit focusing on shorter-term surgical outcomes. National monitoring systems should emphasise the importance of routinely capturing longer-term survival and exploring the mechanisms of mortality risk in children with serious CHDs.

Psychophysics with children: Investigating the effects of attentional lapses on threshold estimates.

PubMed

Manning, Catherine; Jones, Pete R; Dekker, Tessa M; Pellicano, Elizabeth

2018-03-26

When assessing the perceptual abilities of children, researchers tend to use psychophysical techniques designed for use with adults. However, children's poorer attentiveness might bias the threshold estimates obtained by these methods. Here, we obtained speed discrimination threshold estimates in 6- to 7-year-old children in UK Key Stage 1 (KS1), 7- to 9-year-old children in Key Stage 2 (KS2), and adults using three psychophysical procedures: QUEST, a 1-up 2-down Levitt staircase, and Method of Constant Stimuli (MCS). We estimated inattentiveness using responses to "easy" catch trials. As expected, children had higher threshold estimates and made more errors on catch trials than adults. Lower threshold estimates were obtained from psychometric functions fit to the data in the QUEST condition than the MCS and Levitt staircases, and the threshold estimates obtained when fitting a psychometric function to the QUEST data were also lower than when using the QUEST mode. This suggests that threshold estimates cannot be compared directly across methods. Differences between the procedures did not vary significantly with age group. Simulations indicated that inattentiveness biased threshold estimates particularly when threshold estimates were computed as the QUEST mode or the average of staircase reversals. In contrast, thresholds estimated by post-hoc psychometric function fitting were less biased by attentional lapses. Our results suggest that some psychophysical methods are more robust to attentiveness, which has important implications for assessing the perception of children and clinical groups.

Exposure to diagnostic radiation and risk of breast cancer among carriers of BRCA1/2 mutations: retrospective cohort study (GENE-RAD-RISK).

PubMed

Pijpe, Anouk; Andrieu, Nadine; Easton, Douglas F; Kesminiene, Ausrele; Cardis, Elisabeth; Noguès, Catherine; Gauthier-Villars, Marion; Lasset, Christine; Fricker, Jean-Pierre; Peock, Susan; Frost, Debra; Evans, D Gareth; Eeles, Rosalind A; Paterson, Joan; Manders, Peggy; van Asperen, Christi J; Ausems, Margreet G E M; Meijers-Heijboer, Hanne; Thierry-Chef, Isabelle; Hauptmann, Michael; Goldgar, David; Rookus, Matti A; van Leeuwen, Flora E

2012-09-06

To estimate the risk of breast cancer associated with diagnostic radiation in carriers of BRCA1/2 mutations. Retrospective cohort study (GENE-RAD-RISK). Three nationwide studies (GENEPSO, EMBRACE, HEBON) in France, United Kingdom, and the Netherlands, 1993 female carriers of BRCA1/2 mutations recruited in 2006-09. Risk of breast cancer estimated with a weighted Cox proportional hazards model with a time dependent individually estimated cumulative breast dose, based on nominal estimates of organ dose and frequency of self reported diagnostic procedures. To correct for potential survival bias, the analysis excluded carriers who were diagnosed more than five years before completion of the study questionnaire. In carriers of BRCA1/2 mutations any exposure to diagnostic radiation before the age of 30 was associated with an increased risk of breast cancer (hazard ratio 1.90, 95% confidence interval 1.20 to 3.00), with a dose-response pattern. The risks by quarter of estimated cumulative dose <0.0020 Gy, ≥ 0.0020-0.0065 Gy, ≥ 0.0066-0.0173 Gy, and ≥ 0.0174 Gy were 1.63 (0.96 to 2.77), 1.78 (0.88 to 3.58), 1.75 (0.72 to 4.25), and 3.84 (1.67 to 8.79), respectively. Analyses on the different types of diagnostic procedures showed a pattern of increasing risk with increasing number of radiographs before age 20 and before age 30 compared with no exposure. A history of mammography before age 30 was also associated with an increased risk of breast cancer (hazard ratio 1.43, 0.85 to 2.40). Sensitivity analysis showed that this finding was not caused by confounding by indication of family history. In this large European study among carriers of BRCA1/2 mutations, exposure to diagnostic radiation before age 30 was associated with an increased risk of breast cancer at dose levels considerably lower than those at which increases have been found in other cohorts exposed to radiation. The results of this study support the use of non-ionising radiation imaging techniques (such as magnetic resonance imaging) as the main tool for surveillance in young women with BRCA1/2 mutations.

An outcomes analysis of five prenatal screening strategies for trisomy 21 in women younger than 35 years.

PubMed

Biggio, Joseph R; Morris, T Christopher; Owen, John; Stringer, Jeffery S A

2004-03-01

This study was undertaken to examine the cost-effectiveness and procedural-related losses associated with 5 prenatal screening strategies for fetal aneuploidy in women under 35 years old. Five prenatal screening strategies were compared in a decision analysis model: triple screen: maternal age and midtrimester serum alpha-fetoprotein, human chorionic gonadotropin (hCG), and unconjugated estriol; quad screen: triple screen plus serum dimeric inhibin A; first-trimester screen: maternal age, serum pregnancy-associated plasma protein A and free beta-hCG and fetal nuchal translucency at 10 to 14 weeks' gestation; integrated screen: first-trimester screen plus quad screen, but first-trimester results are withheld until the quad screen is completed when a composite result is provided; sequential screen: first-trimester screen plus quad screen, but the first-trimester screen results are provided immediately and prenatal diagnosis offered if positive; later prenatal diagnosis is available if the quad screen is positive. Model estimates were literature derived, and cost estimates also included local sources. The 5 strategies were compared for cost, the numbers of Down syndrome fetuses detected and live births averted, and the number of procedure-related euploid losses. Sensitivity analyses were performed for parameters with imprecise point estimates. In the baseline analysis, sequential screening was the least expensive strategy ($455 million). It detected the most Down syndrome fetuses (n=1213), averted the most Down syndrome live births (n=678), but led to the highest number of procedure-related euploid losses (n=859). The integrated screen had the fewest euploid losses (n=62) and averted the second most Down syndrome live births (n=520). If fewer than 70% of women diagnosed with fetal Down syndrome elect to abort, the quad screen became the least expensive strategy. Although sequential screening was the most cost-effective prenatal screening strategy for fetal trisomy 21, it had the highest procedure-related euploid loss rate. The patient's perspective on detection versus fetal safety may help define the optimal screening strategy.

Multiple Imputation of a Randomly Censored Covariate Improves Logistic Regression Analysis.

PubMed

Atem, Folefac D; Qian, Jing; Maye, Jacqueline E; Johnson, Keith A; Betensky, Rebecca A

2016-01-01

Randomly censored covariates arise frequently in epidemiologic studies. The most commonly used methods, including complete case and single imputation or substitution, suffer from inefficiency and bias. They make strong parametric assumptions or they consider limit of detection censoring only. We employ multiple imputation, in conjunction with semi-parametric modeling of the censored covariate, to overcome these shortcomings and to facilitate robust estimation. We develop a multiple imputation approach for randomly censored covariates within the framework of a logistic regression model. We use the non-parametric estimate of the covariate distribution or the semiparametric Cox model estimate in the presence of additional covariates in the model. We evaluate this procedure in simulations, and compare its operating characteristics to those from the complete case analysis and a survival regression approach. We apply the procedures to an Alzheimer's study of the association between amyloid positivity and maternal age of onset of dementia. Multiple imputation achieves lower standard errors and higher power than the complete case approach under heavy and moderate censoring and is comparable under light censoring. The survival regression approach achieves the highest power among all procedures, but does not produce interpretable estimates of association. Multiple imputation offers a favorable alternative to complete case analysis and ad hoc substitution methods in the presence of randomly censored covariates within the framework of logistic regression.

Comparison of Patient Outcomes in 3725 Overlapping vs 3633 Nonoverlapping Neurosurgical Procedures Using a Single Institution's Clinical and Administrative Database.

PubMed

Zygourakis, Corinna C; Keefe, Malla; Lee, Janelle; Barba, Julio; McDermott, Michael W; Mummaneni, Praveen V; Lawton, Michael T

2017-02-01

Overlapping surgery is a common practice to improve surgical efficiency, but there are limited data on its safety. To analyze the patient outcomes of overlapping vs nonoverlapping surgeries performed by multiple neurosurgeons. Retrospective review of 7358 neurosurgical procedures, 2012 to 2015, at an urban academic hospital. Collected variables: patient age, gender, insurance, American Society of Anesthesiologists score, severity of illness, mortality risk, admission type, transfer source, procedure type, surgery date, number of cosurgeons, presence of neurosurgery resident/fellow/another attending, and overlapping vs nonoverlapping surgery. Outcomes: procedure time, length of stay, estimated blood loss, discharge location, 30-day mortality, 30-day readmission, return to operating room, acute respiratory failure, and severe sepsis. Statistics: univariate, then multivariate mixed-effect models. Overlapping surgery patients (n = 3725) were younger and had lower American Society of Anesthesiologists scores, severity of illness, and mortality risk (P < .0001) than nonoverlapping surgery patients (n = 3633). Overlapping surgeries had longer procedure times (214 vs 172 min; P < .0001), but shorter length of stay (7.3 vs 7.9 d; P = .010) and lower estimated blood loss (312 vs 363 mL’s; P = .003). Overlapping surgery patients were more likely to be discharged home (73.6% vs 66.2%; P < .0001), and had lower mortality rates (1.3% vs 2.5%; P = .0005) and acute respiratory failure (1.8% vs 2.6%; P = .021). In multivariate models, there was no significant difference between overlapping and nonoverlapping surgeries for any patient outcomes, except for procedure duration, which was longer in overlapping surgery (estimate = 23.03; P < .001). When planned appropriately, overlapping surgery can be performed safely within the infrastructure at our academic institution. Copyright © 2017 by the Congress of Neurological Surgeons

The cost of obesity for nonbariatric inpatient operative procedures in the United States: national cost estimates obese versus nonobese patients.

PubMed

Mason, Rodney J; Moroney, Jolene R; Berne, Thomas V

2013-10-01

To evaluate the economic impact of obesity on hospital costs associated with the commonest nonbariatric, nonobstetrical surgical procedures. Health care costs and obesity are both rising. Nonsurgical costs associated with obesity are well documented but surgical costs are not. National cost estimates were calculated from the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS) database, 2005-2009, for the highest volume nonbariatric nonobstetric procedures. Obesity was identified from the HCUP-NIS severity data file comorbidity index. Costs for obese patients were compared with those for nonobese patients. To control for medical complexity, each obese patient was matched one-to-one with a nonobese patient using age, sex, race, and 28 comorbid defined elements. Of 2,309,699 procedures, 439,8129 (19%) were successfully matched into 2 medically equal groups (obese vs nonobese). Adjusted total hospital costs incurred by obese patients were 3.7% higher with a significantly (P < 0.0001) higher per capita cost of $648 (95% confidence interval [CI]: $556-$736) compared with nonobese patients. Of the 2 major components of hospital costs, length of stay was significantly increased in obese patients (mean difference = 0.0253 days, 95% CI: 0.0225-0.0282) and resource utilization determined by costs per day were greater in obese patients due to an increased number of diagnostic and therapeutic procedures needed postoperatively (odds ratio [OR] = 0.94, 95% CI: 0.93-0.96). Postoperative complications were equivalent in both groups (OR = 0.97, 95% CI: 0.93-1.02). Annual national hospital expenditures for the largest volume surgical procedures is an estimated $160 million higher in obese than in a comparative group of nonobese patients.

Radiation doses for pediatric nuclear medicine studies: comparing the North American consensus guidelines and the pediatric dosage card of the European Association of Nuclear Medicine.

PubMed

Grant, Frederick D; Gelfand, Michael J; Drubach, Laura A; Treves, S Ted; Fahey, Frederic H

2015-04-01

Estimated radiation dose is important for assessing and communicating the risks and benefits of pediatric nuclear medicine studies. Radiation dose depends on the radiopharmaceutical, the administered activity, and patient factors such as age and size. Most radiation dose estimates for pediatric nuclear medicine have not been based on administered activities of radiopharmaceuticals recommended by established practice guidelines. The dosage card of the European Association of Nuclear Medicine (EANM) and the North American consensus guidelines each provide recommendations of administered activities of radiopharmaceuticals in children, but there are substantial differences between these two guidelines. For 12 commonly performed pediatric nuclear medicine studies, two established pediatric radiopharmaceutical administration guidelines were used to calculate updated radiation dose estimates and to compare the radiation exposure resulting from the recommendations of each of the guidelines. Estimated radiation doses were calculated for 12 common procedures in pediatric nuclear medicine using administered activities recommended by the dosage card of the EANM (version 1.5.2008) and the 2010 North American consensus guidelines for radiopharmaceutical administered activities in pediatrics. Based on standard models and nominal age-based weights, radiation dose was estimated for typical patients at ages 1, 5, 10 and 15 years and adult. The resulting effective doses were compared, with differences greater than 20% considered significant. Following either the EANM dosage card or the 2010 North American guidelines, the highest effective doses occur with radiopharmaceuticals labeled with fluorine-18 and iodine-123. In 24% of cases, following the North American consensus guidelines would result in a substantially higher radiation dose. The guidelines of the EANM dosage card would lead to a substantially higher radiation dose in 39% of all cases, and in 62% of cases in which patients were age 5 years or younger. For 12 commonly performed pediatric nuclear medicine studies, updated radiation dose estimates can guide efforts to reduce radiation exposure and provide current information for discussing radiation exposure and risk with referring physicians, patients and families. There can be substantial differences in radiation exposure for the same procedure, depending upon which of these two guidelines is followed. This discordance identifies opportunities for harmonization of the guidelines, which may lead to further reduction in nuclear medicine radiation doses in children.

40 CFR 98.385 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. You must follow the procedures for estimating missing data in § 98... estimating missing data for petroleum products in § 98.395 also applies to coal-to-liquid products. ...

40 CFR 98.385 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. You must follow the procedures for estimating missing data in § 98... estimating missing data for petroleum products in § 98.395 also applies to coal-to-liquid products. ...

40 CFR 98.385 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. You must follow the procedures for estimating missing data in § 98... estimating missing data for petroleum products in § 98.395 also applies to coal-to-liquid products. ...

40 CFR 98.385 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. You must follow the procedures for estimating missing data in § 98... estimating missing data for petroleum products in § 98.395 also applies to coal-to-liquid products. ...

40 CFR 98.385 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. You must follow the procedures for estimating missing data in § 98... estimating missing data for petroleum products in § 98.395 also applies to coal-to-liquid products. ...

Estimating increment-decrement life tables with multiple covariates from panel data: the case of active life expectancy.

PubMed

Land, K C; Guralnik, J M; Blazer, D G

1994-05-01

A fundamental limitation of current multistate life table methodology-evident in recent estimates of active life expectancy for the elderly-is the inability to estimate tables from data on small longitudinal panels in the presence of multiple covariates (such as sex, race, and socioeconomic status). This paper presents an approach to such an estimation based on an isomorphism between the structure of the stochastic model underlying a conventional specification of the increment-decrement life table and that of Markov panel regression models for simple state spaces. We argue that Markov panel regression procedures can be used to provide smoothed or graduated group-specific estimates of transition probabilities that are more stable across short age intervals than those computed directly from sample data. We then join these estimates with increment-decrement life table methods to compute group-specific total, active, and dependent life expectancy estimates. To illustrate the methods, we describe an empirical application to the estimation of such life expectancies specific to sex, race, and education (years of school completed) for a longitudinal panel of elderly persons. We find that education extends both total life expectancy and active life expectancy. Education thus may serve as a powerful social protective mechanism delaying the onset of health problems at older ages.

Mallard age and sex determination from wings

USGS Publications Warehouse

Carney, S.M.; Geis, A.D.

1960-01-01

This paper describes characters on the wing plumage of the mallard that indicate age and sex. A key outlines a logical order in which to check age and sex characters on wings. This method was tested and found to be more than 95 percent reliable, although it was found that considerable practice and training with known-age specimens was required to achieve this level of accuracy....The implications of this technique and the sampling procedure it permits are discussed. Wing collections could provide information on production, and, if coupled with a banding program could permit seasonal population estimates to be calculated. In addition, representative samples of wings would provide data to check the reliability of several other waterfowl surveys.

Topics on distance correlation, feature screening and lifetime expectancy with application to Beaver Dam eye study data

NASA Astrophysics Data System (ADS)

Kong, Jing

This thesis includes 4 pieces of work. In Chapter 1, we present the work with a method for examining mortality as it is seen to run in families, and lifestyle factors that are also seen to run in families, in a subpopulation of the Beaver Dam Eye Study that has died by 2011. We find significant distance correlations between death ages, lifestyle factors, and family relationships. Considering only sib pairs compared to unrelated persons, distance correlation between siblings and mortality is, not surprisingly, stronger than that between more distantly related family members and mortality. Chapter 2 introduces a feature screening procedure with the use of distance correlation and covariance. We demonstrate a property for distance covariance, which is incorporated in a novel feature screening procedure based on distance correlation as a stopping criterion. The approach is further implemented to two real examples, namely the famous small round blue cell tumors data and the Cancer Genome Atlas ovarian cancer data Chapter 3 pays attention to the right censored human longevity data and the estimation of lifetime expectancy. We propose a general framework of backward multiple imputation for estimating the conditional lifetime expectancy function and the variance of the estimator in the right censoring setting and prove the properties of the estimator. In addition, we apply the method to the Beaver Dam eye study data to study human longevity, where the expected human lifetime are modeled with smoothing spline ANOVA based on the covariates including baseline age, gender, lifestyle factors and disease variables. Chapter 4 compares two imputation methods for right censored data, namely the famous Buckley-James estimator and the backward imputation method proposed in Chapter 3 and shows that backward imputation method is less biased and more robust with heterogeneity.

Hospitalizations in pediatric patients with immune thrombocytopenia in the United States

PubMed Central

Tarantino, Michael D.; Danese, Mark; Klaassen, Robert J.; Duryea, Jennifer; Eisen, Melissa; Bussel, James

2016-01-01

Abstract To examine utilization and outcomes in pediatric immune thrombocytopenia (ITP) hospitalizations, we used ICD-9 code 287.31 to identify hospitalizations in patients with ITP in the 2009 HCUP KID, an all-payer sample of pediatric hospitalizations from US community hospitals. Diagnosis and procedure codes were used to estimate rates of ITP-related procedures, comorbidity prevalence, costs, length of stay (LOS), and mortality. In 2009, there were an estimated 4499 hospitalizations in children aged 6 months–17 years with ITP; 43% in children aged 1–5 years; and 47% with emergency department encounters. The mean hospitalization cost was $5398, mean LOS 2.0 days, with 0.3% mortality (n = 13). With any bleeding (15.2%, including gastrointestinal 2.0%, hematuria 1.3%, intracranial hemorrhage [ICH] 0.6%), mean hospitalization cost was $7215, LOS 2.5 days, with 1.5% mortality. For ICH (0.6%, n = 27), mean cost was $40 209, LOS 8.5 days, with 21% mortality. With infections (14%, including upper respiratory 5.2%, viral 4.9%, bacterial 1.9%), the mean cost was $6928, LOS 2.9 days, with 0.9% mortality. Septic shock was reported in 0.3% of discharges. Utilization included immunoglobulin administration (37%) and splenectomies (2.3%). Factors associated with higher costs included age >6 years, ICH, hematuria, transfusion, splenectomy, and bone marrow diagnostics (p < 0.05). In conclusion, of the 4499 hospitalizations with ITP, mortality rates of 1.5%, 21%, and 0.9% were seen with any bleeding, ICH, and infection, respectively. Higher costs were associated with clinically significant bleeding and procedures. Future analyses may reveal effects of the implementation of more recent ITP guidelines and use of additional treatments. PMID:26941022

40 CFR 98.435 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Gases Contained in Pre-Charged Equipment or Closed-Cell Foams § 98.435 Procedures for estimating missing data. Procedures for estimating missing data are not provided for importers and exporters of...

40 CFR 98.435 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... Gases Contained in Pre-Charged Equipment or Closed-Cell Foams § 98.435 Procedures for estimating missing data. Procedures for estimating missing data are not provided for importers and exporters of...

40 CFR 98.435 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... Gases Contained in Pre-Charged Equipment or Closed-Cell Foams § 98.435 Procedures for estimating missing data. Procedures for estimating missing data are not provided for importers and exporters of...

40 CFR 98.435 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... Gases Contained in Pre-Charged Equipment or Closed-Cell Foams § 98.435 Procedures for estimating missing data. Procedures for estimating missing data are not provided for importers and exporters of...

40 CFR Appendix Ix to Part 86 - Experimentally Determining the R-Factor for Bench Aging Durability Procedures

Code of Federal Regulations, 2014 CFR

2014-07-01

... catalyst. Calculate the least-squared best-fit line through the data. For the data set to be useful for this purpose the data should have an approximately common intercept between 0 and 4000 miles. See the... data between one- and two-times the standard. 2. Estimate the value of R and calculate the effective...

'Micro-hole' optical dating of quartz from HOTRAX-05 Arctic Ocean cores

NASA Astrophysics Data System (ADS)

Berger, G. W.; Polyak, L. V.

2011-12-01

For Quaternary Arctic Ocean cores, numeric dating methods are needed spanning and exceeding the age range of the widely used radiocarbon (C-14) method. Previously, luminescence sediment dating of 4-11 μm diameter quartz and feldspar grains from core tops has often produced large burial-age overestimates (e.g., by >7 kyr) due to failure to resolve mixed-age histories. However, application of micro-focused-laser ('micro-hole') photon-stimulated-luminescence (PSL) applied to quartz grains of 11-90 μm diameters from the tops (upper 2 cm) of high-sedimentation- rate HOTRAX-05 multi-cores at the Alaska margin provides expected near zero ages (0-200 a), thus overcoming the earlier problem of large PSL age over-estimation. This micro-hole PSL dating approach has also been applied to >11 μm quartz grains from multi-cores at two sites on the central Lomonosov Ridge. For a core top within a perched basin, a burial-age estimate of ~2 ka for 11-62 μm quartz was obtained, in accord with published C-14 age estimates from foraminifera, demonstrating the efficacy of the micro-hole approach to this ridge area. At a nearby 'erosive' ridge-top site, the micro-hole PSL approach paradoxically produces two different burial-age estimates from the same core-top horizon. The >90 μm quartz grains yield a burial age of ~25 ka, in accord with a C-14 age estimate of ~26 ka from >250 μm foraminifers from the same horizon. However, the 11-90 μm quartz produces a burial-age estimate of ~9 ka, indicating a differently preserved burial history for the medium silt grains than for the sand grains within a single horizon. This unexpected result provides a unique insight into past, complicated, depositional processes on this ridge top over a time range spanning the LGM. These results from the micro-hole PSL approach thus indicate a clear potential for dating times of detrital quartz deposition at other ridge tops in the Arctic Ocean, and for providing perhaps new insights into local preservation of burial ages. These PSL procedures are being applied also to sediment above and below a diamicton in a HOTRAX-05 core from the Northwind Ridge, with the aim of dating indirectly the diamicton. Preliminary results from this core will be presented.

Attention-deficit/hyperactivity disorder and phonological working memory: Methodological variability affects clinical and experimental performance metrics.

PubMed

Tarle, Stephanie J; Alderson, R Matt; Patros, Connor H G; Lea, Sarah E; Hudec, Kristen L; Arrington, Elaine F

2017-05-01

Despite promising findings in extant research that suggest impaired working memory (WM) serves as a central neurocognitive deficit or candidate endophenotype of attention-deficit/hyperactivity disorder (ADHD), findings from translational research have been relatively underwhelming. This study aimed to explicate previous equivocal findings by systematically examining the effect of methodological variability on WM performance estimates across experimental and clinical WM measures. Age-matched boys (ages 8-12 years) with (n = 20) and without (n = 20) ADHD completed 1 experimental (phonological) and 2 clinical (digit span, letter-number sequencing) WM measures. The use of partial scoring procedures, administration of greater trial numbers, and high central executive demands yielded moderate-to-large between-groups effect sizes. Moreover, the combination of these best-case procedures, compared to worst-case procedures (i.e., absolute scoring, administration of few trials, use of discontinue rules, and low central executive demands), resulted in a 12.5% increase in correct group classification. Collectively, these findings explain inconsistent ADHD-related WM deficits in previous reports, and highlight the need for revised clinical measures that utilize best-case procedures. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Comparing adaptive procedures for estimating the psychometric function for an auditory gap detection task.

PubMed

Shen, Yi

2013-05-01

A subject's sensitivity to a stimulus variation can be studied by estimating the psychometric function. Generally speaking, three parameters of the psychometric function are of interest: the performance threshold, the slope of the function, and the rate at which attention lapses occur. In the present study, three psychophysical procedures were used to estimate the three-parameter psychometric function for an auditory gap detection task. These were an up-down staircase (up-down) procedure, an entropy-based Bayesian (entropy) procedure, and an updated maximum-likelihood (UML) procedure. Data collected from four young, normal-hearing listeners showed that while all three procedures provided similar estimates of the threshold parameter, the up-down procedure performed slightly better in estimating the slope and lapse rate for 200 trials of data collection. When the lapse rate was increased by mixing in random responses for the three adaptive procedures, the larger lapse rate was especially detrimental to the efficiency of the up-down procedure, and the UML procedure provided better estimates of the threshold and slope than did the other two procedures.

The economic implications of a multimodal analgesic regimen for patients undergoing major orthopedic surgery: a comparative study of direct costs.

PubMed

Duncan, Christopher M; Hall Long, Kirsten; Warner, David O; Hebl, James R

2009-01-01

Total knee and total hip arthoplasty (THA) are 2 of the most common surgical procedures performed in the United States and represent the greatest single Medicare procedural expenditure. This study was designed to evaluate the economic impact of implementing a multimodal analgesic regimen (Total Joint Regional Anesthesia [TJRA] Clinical Pathway) on the estimated direct medical costs of patients undergoing lower extremity joint replacement surgery. An economic cost comparison was performed on Mayo Clinic patients (n = 100) undergoing traditional total knee or total hip arthroplasty using the TJRA Clinical Pathway. Study patients were matched 1:1 with historical controls undergoing similar procedures using traditional anesthetic (non-TJRA) techniques. Matching criteria included age, sex, surgeon, type of procedure, and American Society of Anesthesiologists (ASA) physical status (PS) classification. Hospital-based direct costs were collected for each patient and analyzed in standardized inflation-adjusted constant dollars using cost-to-charge ratios, wage indexes, and physician services valued using Medicare reimbursement rates. The estimated mean direct hospital costs were compared between groups, and a subgroup analysis was performed based on ASA PS classification. The estimated mean direct hospital costs were significantly reduced among TJRA patients when compared with controls (cost difference, 1999 dollars; 95% confidence interval, 584-3231 dollars; P = 0.0004). A significant reduction in hospital-based (Medicare Part A) costs accounted for the majority of the total cost savings. Use of a comprehensive, multimodal analgesic regimen (TJRA Clinical Pathway) in patients undergoing lower extremity joint replacement surgery provides a significant reduction in the estimated total direct medical costs. The reduction in mean cost is primarily associated with lower hospital-based (Medicare Part A) costs, with the greatest overall cost difference appearing among patients with significant comorbidities (ASA PS III-IV patients).

Risk of Hemorrhage Attributed to Underlying Chronic Diseases and Uninterrupted Aspirin Therapy of Patients Undergoing Minor Oral Surgical Procedures: A Retrospective Cohort Study.

PubMed

Rojanaworarit, Chanapong; Limsawan, Soontaree

2017-01-01

This study aimed to estimate the risk of bleeding following minor oral surgical procedures and uninterrupted aspirin therapy in high-risk patients or patients with existing chronic diseases compared to patients who did not use aspirin during minor oral surgery at a public hospital. This retrospective cohort study analyzed the data of 2912 patients, aged 20 years or older, who underwent 5251 minor oral surgical procedures at a district hospital in Thailand. The aspirin group was comprised of patients continuing aspirin therapy during oral surgery. The non-aspirin group (reference) included all those who did not use aspirin during surgery. Immediate and late-onset bleeding was evaluated in each procedure. The risk ratio of bleeding was estimated using a multilevel Poisson regression. The overall cumulative incidence of immediate bleeding was 1.3% of total procedures. No late-onset bleeding was found. A significantly greater incidence of bleeding was found in the aspirin group (5.8% of procedures, p<0.001). After adjusting for covariates, a multilevel Poisson regression model estimated that the bleeding risk in the aspirin group was 4.5 times higher than that of the non-aspirin group (95% confidence interval, 2.0 to 10.0; p<0.001). However, all bleeding events were controlled by simple hemostatic measures. High-risk patients or patients with existing chronic diseases who continued aspirin therapy following minor oral surgery were at a higher risk of hemorrhage than general patients who had not used aspirin. Nonetheless, bleeding complications were not life-threatening and could be promptly managed by simple hemostatic measures. The procedures could therefore be provided with an awareness of increased bleeding risk, prepared hemostatic measures, and postoperative monitoring, without the need for discontinuing aspirin, which could lead to more serious complications.

Utilization of apical vaginal support procedures at time of inpatient hysterectomy performed for benign conditions: a national estimate.

PubMed

Ross, Whitney Trotter; Meister, Melanie R; Shepherd, Jonathan P; Olsen, Margaret A; Lowder, Jerry L

2017-10-01

Apical vaginal support is considered the keystone of pelvic organ support. Level I evidence supports reestablishment of apical support at time of hysterectomy, regardless of whether the hysterectomy is performed for prolapse. National rates of apical support procedure performance at time of inpatient hysterectomy have not been well described. We sought to estimate trends and factors associated with use of apical support procedures at time of inpatient hysterectomy for benign indications in a large national database. The National (Nationwide) Inpatient Sample was used to identify hysterectomies performed from 2004 through 2013 for benign indications. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to select both procedures and diagnoses. The primary outcome was performance of an apical support procedure at time of hysterectomy. Descriptive and multivariable analyses were performed. There were 3,509,230 inpatient hysterectomies performed for benign disease from 2004 through 2013. In both nonprolapse and prolapse groups, there was a significant decrease in total number of annual hysterectomies performed over the study period (P < .0001). There were 2,790,652 (79.5%) hysterectomies performed without a diagnosis of prolapse, and an apical support procedure was performed in only 85,879 (3.1%). There was a significant decrease in the proportion of hysterectomies with concurrent apical support procedure (high of 4.0% in 2004 to 2.5% in 2013, P < .0001). In the multivariable logistic regression model, increasing age, hospital type (urban teaching), hospital bed size (large and medium), and hysterectomy type (vaginal and laparoscopically assisted vaginal) were associated with performance of an apical support procedure. During the study period, 718,578 (20.5%) inpatient hysterectomies were performed for prolapse diagnoses and 266,743 (37.1%) included an apical support procedure. There was a significant increase in the proportion of hysterectomies with concurrent apical support procedure (low of 31.3% in 2005 to 49.3% in 2013, P < .0001). In the multivariable logistic regression model, increasing age, hospital type (urban teaching), hospital bed size (medium and large), and hysterectomy type (total laparoscopic and laparoscopic supracervical) were associated with performance of an apical support procedure. This national database study demonstrates that apical support procedures are not routinely performed at time of inpatient hysterectomy regardless of presence of prolapse diagnosis. Educational efforts are needed to increase awareness of the importance of reestablishing apical vaginal support at time of hysterectomy regardless of indication. Copyright © 2017 Elsevier Inc. All rights reserved.

Massachusetts health reform and disparities in joint replacement use: difference in differences study

PubMed Central

Kapoor, Alok; Katz, Jeffrey N; McCormick, Danny; Lasser, Karen E; Feng, Chen; Manze, Meredith G; Kressin, Nancy R

2015-01-01

Objective To estimate the impact of the insurance expansion in 2006 on use of knee and hip replacement procedures by race/ethnicity, area income, and the use of hospitals that predominantly serve poor people (“safety net hospitals”). Design Quasi-experimental difference in differences study examining change after reform in the share of procedures performed in safety net hospitals by race/ethnicity and area income, with adjustment for patients’ residence, demographics, and comorbidity. Setting State of Massachusetts, United States. Participants Massachusetts residents aged 40-64 as the target beneficiaries of reform and similarly aged residents of New Jersey, New York, and Pennsylvania as the comparison (control) population. Main outcomes measures Number of knee and hip replacement procedures per 10 000 population and use of safety net hospitals. Procedure counts from state discharge data for 2.5 years before and after reform, and multivariate difference in differences. Poisson regression was used to adjust for demographics, economic conditions, secular time, and geographic factors to estimate the change in procedure rate associated with health reform by race/ethnicity and area income. Results Before reform, the number of procedures (/10 000) in Massachusetts was lower among Hispanic people (12.9, P<0.001) than black people (28.1) and white people (30.1). Overall, procedure use increased 22.4% during the 2.5 years after insurance expansion; reform in Massachusetts was associated with a 4.7% increase. The increase associated with reform was significantly higher among Hispanic people (37.9%, P<0.001) and black people (11.4%, P<0.05) than among white people (2.8%). Lower income was not associated with larger increases in procedure use. The share of knee and hip replacement procedures performed in safety net hospitals in Massachusetts decreased by 1.0% from a level of 12.7% before reform. The reduction was larger among Hispanic people (−6.4%, P<0.001) than white people (−1.0%), and among low income residents (−3.9%, p<0.001) than high income residents (0%). Conclusions Insurance expansion can help reduce disparities by race/ethnicity but not by income in access to elective surgical care and could shift some elective surgical care away from safety net hospitals. PMID:25700849

Risk factor assessment to anticipate performance in the National Developmental Screening Test in children from a disadvantaged area.

PubMed

Montes, Alejandro; Pazos, Gustavo

2016-02-01

Identifying children at risk of failing the National Developmental Screening Test by combining prevalences of children suspected of having inapparent developmental disorders (IDDs) and associated risk factors (RFs) would allow to save resources. 1. To estimate the prevalence of children suspected of having IDDs. 2. To identify associated RFs. 3. To assess three methods developed based on observed RFs and propose a pre-screening procedure. The National Developmental Screening Test was administered to 60 randomly selected children aged between 2 and 4 years old from a socioeconomically disadvantaged area from Puerto Madryn. Twenty-four biological and socioenvironmental outcome measures were assessed in order to identify potential RFs using bivariate and multivariate analyses. The likelihood of failing the screening test was estimated as follows: 1. a multivariate logistic regression model was developed; 2. a relationship was established between the number of RFs present in each child and the percentage of children who failed the test; 3. these two methods were combined. The prevalence of children suspected of having IDDs was 55.0% (95% confidence interval: 42.4%-67.6%). Six RFs were initially identified using the bivariate approach. Three of them (maternal education, number of health checkups and Z scores for height-for-age, and maternal age) were included in the logistic regression model, which has a greater explanatory power. The third method included in the assessment showed greater sensitivity and specificity (85% and 79%, respectively). The estimated prevalence of children suspected of having IDDs was four times higher than the national standards. Seven RFs were identified. Combining the analysis of risk factor accumulation and a multivariate model provides a firm basis for developing a sensitive, specific and practical pre-screening procedure for socioeconomically disadvantaged areas. Sociedad Argentina de Pediatría.

Real-ear-to-coupler difference predictions as a function of age for two coupling procedures.

PubMed

Bagatto, Marlene P; Scollie, Susan D; Seewald, Richard C; Moodie, K Shane; Hoover, Brenda M

2002-09-01

The predicted real-ear-to-coupler difference (RECD) values currently used in pediatric hearing instrument prescription methods are based on 12-month age range categories and were derived from measures using standard acoustic immittance probe tips. Consequently, the purpose of this study was to develop normative RECD predicted values for foam/acoustic immittance tips and custom earmolds across the age continuum. To this end, RECD data were collected on 392 infants and children (141 with acoustic immittance tips, 251 with earmolds) to develop normative regression equations for use in deriving continuous age predictions of RECDs for foam/acoustic immittance tips and earmolds. Owing to the substantial between-subject variability observed in the data, the predictive equations of RECDs by age (in months) resulted in only gross estimates of RECD values (i.e., within +/- 4.4 dB for 95% of acoustic immittance tip measures; within +/- 5.4 dB in 95% of measures with custom earmolds) across frequency. Thus, it is concluded that the estimates derived from this study should not be used to replace the more precise individual RECD measurements. Relative to previously available normative RECD values for infants and young children, however, the estimates derived through this study provide somewhat more accurate predicted values for use under those circumstances for which individual RECD measurements cannot be made.

Safety and complications of percutaneous kidney biopsies in 715 children and 8573 adults in Norway 1988-2010.

PubMed

Tøndel, Camilla; Vikse, Bjørn Egil; Bostad, Leif; Svarstad, Einar

2012-10-01

Skepticism about performing renal biopsies is often because of uncertainty regarding risk of complications. The aim of this study was to evaluate safety and relevant complications of renal biopsies in pediatric and adult patients in a large national registry study. Kidney biopsies reported in the Norwegian Kidney Biopsy Registry from 1988 to 2010 were included. Risk factors for major complications (blood transfusion and/or surgical or catheter intervention) were analyzed using logistic regression statistics. Of the 9288 biopsies included, 715 were from children, and 8573 were from adults (≥18 years). Median age was 49 years (range=2 weeks to 94 years). Gross hematuria appeared after biopsy in 1.9% of the patients; 0.9% of patients needed blood transfusion, and 0.2% of patients needed surgical intervention/catheterization. The frequencies were 1.9%, 0.9%, and 0.2% in adults and 1.7%, 0.1% and 0.1% in children, respectively; 97.9% of the biopsies were without complications. In unadjusted analyses, risk factors for major complications were age>60 years, estimated GFR<60 ml/min per 1.73 m(2), systolic hypertension, acute renal failure, and smaller clinical center size (<30 biopsies/yr). Adjusted analyses (adjusted for age and/or estimated GFR) showed higher odds ratios (OR) only for smaller clinical center (OR=1.60 [1.02-2.50]) and low estimated GFR (estimated GFR=30-59 ml/min per 1.73 m(2) [OR=4.90 (1.60-14.00)] and estimated GFR<30 ml/min per 1.73 m(2) [OR 15.50 (5.60-43.00)]). Percutaneous renal biopsy is a low-risk procedure in all ages. Reduced estimated GFR and smaller center size are associated with an increased risk of major complications.

Comparison of Patient Outcomes and Cost of Overlapping Versus Nonoverlapping Spine Surgery.

PubMed

Zygourakis, Corinna C; Sizdahkhani, Saman; Keefe, Malla; Lee, Janelle; Chou, Dean; Mummaneni, Praveen V; Ames, Christopher P

2017-04-01

Overlapping surgery recently has gained significant media attention, but there are limited data on its safety and efficacy. To date, there has been no analysis of overlapping surgery in the field of spine. Our goal was to compare overlapping versus nonoverlapping spine surgery patient outcomes and cost. A retrospective review was undertaken of 2319 spine surgeries (n = 848 overlapping; 1471 nonoverlapping) performed by 3 neurosurgery attendings from 2012 to 2015 at the University of California San Francisco. Collected variables included patient age, sex, insurance, American Society of Anesthesiology score, severity of illness, risk of mortality, procedure type, surgeon, day of surgery, source of transfer, admission type, overlapping versus nonoverlapping surgery (≥1 minute of overlapping procedure time), Medicare-Severity Diagnosis-Related Group, osteotomy, and presence of another attending/fellow/resident. Univariate, then multivariate mixed-effect models were used to evaluate the effect of the collected variables on the following outcomes: procedure time, estimated blood loss, length of stay, discharge status, 30-day mortality, 30-day unplanned readmission, unplanned return to OR, and total hospital cost. Urgent spine cases were more likely to be done in an overlapping fashion (all P < 0.01). After we adjusted for patient demographics, clinical indicators, and procedure characteristics, overlapping surgeries had longer procedure times (estimate = 26.17; P < 0.001) and lower rates of discharge to home (odds ratio 0.65; P < 0.001), but equivalent rates of 30-day mortality, readmission, return to the operating room, estimated blood loss, length of stay, and total hospital cost (all P = ns). Overlapping spine surgery may be performed safely at our institution, although continued monitoring of patient outcomes is necessary. Overlapping surgery does not lead to greater hospital costs. Copyright © 2017 Elsevier Inc. All rights reserved.

40 CFR Appendix Ix to Part 86 - Experimentally Determining the R-Factor for Bench Aging Durability Procedures

Code of Federal Regulations, 2013 CFR

2013-07-01

... for each catalyst. Calculate the least-squared best-fit line through the data. For the data set to be useful for this purpose the data should have an approximately common intercept between 0 and 4000 miles... testing yields data between one- and two-times the standard. 2. Estimate the value of R and calculate the...

40 CFR Appendix Ix to Part 86 - Experimentally Determining the R-Factor for Bench Aging Durability Procedures

Code of Federal Regulations, 2010 CFR

2010-07-01

... for each catalyst. Calculate the least-squared best-fit line through the data. For the data set to be useful for this purpose the data should have an approximately common intercept between 0 and 4000 miles... testing yields data between one- and two-times the standard. 2. Estimate the value of R and calculate the...

40 CFR Appendix Ix to Part 86 - Experimentally Determining the R-Factor for Bench Aging Durability Procedures

Code of Federal Regulations, 2011 CFR

2011-07-01

... for each catalyst. Calculate the least-squared best-fit line through the data. For the data set to be useful for this purpose the data should have an approximately common intercept between 0 and 4000 miles... testing yields data between one- and two-times the standard. 2. Estimate the value of R and calculate the...

40 CFR Appendix Ix to Part 86 - Experimentally Determining the R-Factor for Bench Aging Durability Procedures

Code of Federal Regulations, 2012 CFR

2012-07-01

... for each catalyst. Calculate the least-squared best-fit line through the data. For the data set to be useful for this purpose the data should have an approximately common intercept between 0 and 4000 miles... testing yields data between one- and two-times the standard. 2. Estimate the value of R and calculate the...

Agents affecting health of mother and child in a rural area of Kenya. III. The epidemiology of measles.

PubMed

Voorhoeve, A M; Muller, A S; Schulpen, T W; Gemert, W; Valkenburg, H A; Ensering, H E

1977-12-01

Between April 1974 and March 1976 surveillance of measles has been conducted by 12 fieldworkers making fortnightly home visits among a total population of 24,000 living in nearly 4000 households scattered in variable density throughout an area of 87 sq km in the northern division of the Machakos district, Kenya. The diagnosis of measles was verified by one of the project's physicians according to standardized procedures and was, whenever possible, supported by virus isolation and serum antibody level determination. Because not all reported patients were actually seen during the period of clinical manifestations, the diagnosis remained doubtful in a number of cases. Incidence and mortality figures have been estimated with 95% confidence limits based on the assumption that doubtful cases represent a probability of measles of .33 and probable cases a probability of .67. The estimated attack rate for the susceptible population 0-15 years of age was 13.5%. When related to all children--susceptible or not--the attack rate was highest in the 1-2 years age group (11%). Almost 15% of cases occurred below the age of one year, 1% below 6 months of age and 6% between 6 and 8 months. The estimated case fatality rate was 6.5%, fatality being highest between 1 and 2 years of age. For the age group 0-15 years measles accounted for 16.7% of all deaths. The estimated death rate per 100,000 total population was 113. The epidemiological pattern of measles suggests continuous re-introduction of the measles virus in a dispersed population causing micro-outbreaks of the disease in geographically widely separated spots throughout the year which tends to keep the proportion of susceptibles down and the attack rate during a protracted epidemic relatively low.

Dental age estimation in living individuals using 3.0 T MRI of lower third molars.

PubMed

Guo, Yucheng; Olze, Andreas; Ottow, Christian; Schmidt, Sven; Schulz, Ronald; Heindel, Walter; Pfeiffer, Heidi; Vieth, Volker; Schmeling, Andreas

2015-11-01

In order to increase the validity of age estimation in adolescents and young adults when there is no legitimation for X-ray examinations, it seems desirable to be able to assess the mineralization of third molars using X-ray-free imaging procedures. In the present study, the mineralization stages of lower third molars were determined prospectively in 269 male and 248 female individuals aged 12 to 24 years using 3.0 T MRI. The classification system of Demirjian et al. was used to determine the stages. This study presents the minima and maxima, means and standard deviations, median values, and lower and upper quartiles separately for both sexes, for the mineralization stages B-H. Statistically significant sex differences were observed for the mineralization stages C, E, F, and G, and a faster developmental rate was observed for males. It was concluded that magnetic resonance imaging is an X-ray-free alternative to orthopantomography when assessing mineralization of third molars.

Dose limits for astronauts

NASA Technical Reports Server (NTRS)

Sinclair, W. K.

2000-01-01

Radiation exposures to individuals in space can greatly exceed natural radiation exposure on Earth and possibly normal occupational radiation exposures as well. Consequently, procedures limiting exposures would be necessary. Limitations were proposed by the Radiobiological Advisory Panel of the National Academy of Sciences/National Research Council in 1970. This panel recommended short-term limits to avoid deterministic effects and a single career limit (of 4 Sv) based on a doubling of the cancer risk in men aged 35 to 55. Later, when risk estimates for cancer had increased and were recognized to be age and sex dependent, the NCRP, in Report No. 98 in 1989, recommended a range of career limits based on age and sex from 1 to 4 Sv. NCRP is again in the process of revising recommendations for astronaut exposure, partly because risk estimates have increased further and partly to recognize trends in limiting radiation exposure occupationally on the ground. The result of these considerations is likely to be similar short-term limits for deterministic effects but modified career limits.

Predicting the need for vascular surgeons in Canada.

PubMed

Lotfi, Shamim; Jetty, Prasad; Petrcich, William; Hajjar, George; Hill, Andrew; Kubelik, Dalibor; Nagpal, Sudhir; Brandys, Tim

2017-03-01

With the introduction of direct entry (0+5) residency programs in addition to the traditional (5+2) programs, the number of vascular surgery graduates across Canada is expected to increase significantly during the next 5 to 10 years. Society's need for these newly qualified surgeons is unclear. This study evaluated the predicted requirement for vascular surgeons across Canada to 2021. A program director survey was also performed to evaluate program directors' perceptions of the 0+5 residency program, the expected number of new trainees, and faculty recruitment and retirement. The estimated and projected Canadian population numbers for each year between 2013 and 2021 were determined by the Canadian Socio-economic Information and Management System (CANSIM), Statistics Canada's key socioeconomic database. The number of vascular surgery procedures performed from 2008 to 2012 stratified by age, gender, and province was obtained from the Canadian Institute for Health Information Discharge Abstract Database. The future need for vascular surgeons was calculated by two validated methods: (1) population analysis and (2) workload analysis. In addition, a 12-question survey was sent to each vascular surgery program director in Canada. The estimated Canadian population in 2013 was 35.15 million, and there were 212 vascular surgeons performing a total of 98,339 procedures. The projected Canadian population by 2021 is expected to be 38.41 million, a 9.2% increase from 2013; however, the expected growth rate in the age group 60+ years, who are more likely to require vascular procedures, is expected to be 30% vs 3.4% in the age group <60 years. Using population analysis modeling, there will be a surplus of 10 vascular surgeons in Canada by 2021; however, using workload analysis modeling (which accounts for the more rapid growth and larger proportion of procedures performed in the 60+ age group), there will be a deficit of 11 vascular surgeons by 2021. Program directors in Canada have a positive outlook on graduating 0+5 residents' skill, and the majority of programs will be recruiting at least one new vascular surgeon during the next 5 years. Although population analysis projects a potential surplus of surgeons, workload analysis predicts a deficit of surgeons because it accounts for the rapid growth in the 60+ age group in which the majority of procedures are performed, thus more accurately modeling future need for vascular surgeons. This study suggests that there will be a need for newly graduating vascular surgeons in the next 5 years, which could have an impact on resource allocation across training programs in Canada. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Evaluation of algorithms to identify incident cancer cases by using French health administrative databases.

PubMed

Ajrouche, Aya; Estellat, Candice; De Rycke, Yann; Tubach, Florence

2017-08-01

Administrative databases are increasingly being used in cancer observational studies. Identifying incident cancer in these databases is crucial. This study aimed to develop algorithms to estimate cancer incidence by using health administrative databases and to examine the accuracy of the algorithms in terms of national cancer incidence rates estimated from registries. We identified a cohort of 463 033 participants on 1 January 2012 in the Echantillon Généraliste des Bénéficiaires (EGB; a representative sample of the French healthcare insurance system). The EGB contains data on long-term chronic disease (LTD) status, reimbursed outpatient treatments and procedures, and hospitalizations (including discharge diagnoses, and costly medical procedures and drugs). After excluding cases of prevalent cancer, we applied 15 algorithms to estimate the cancer incidence rates separately for men and women in 2012 and compared them to the national cancer incidence rates estimated from French registries by indirect age and sex standardization. The most accurate algorithm for men combined information from LTD status, outpatient anticancer drugs, radiotherapy sessions and primary or related discharge diagnosis of cancer, although it underestimated the cancer incidence (standardized incidence ratio (SIR) 0.85 [0.80-0.90]). For women, the best algorithm used the same definition of the algorithm for men but restricted hospital discharge to only primary or related diagnosis with an additional inpatient procedure or drug reimbursement related to cancer and gave comparable estimates to those from registries (SIR 1.00 [0.94-1.06]). The algorithms proposed could be used for cancer incidence monitoring and for future etiological cancer studies involving French healthcare databases. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Estimating multilevel logistic regression models when the number of clusters is low: a comparison of different statistical software procedures.

PubMed

Austin, Peter C

2010-04-22

Multilevel logistic regression models are increasingly being used to analyze clustered data in medical, public health, epidemiological, and educational research. Procedures for estimating the parameters of such models are available in many statistical software packages. There is currently little evidence on the minimum number of clusters necessary to reliably fit multilevel regression models. We conducted a Monte Carlo study to compare the performance of different statistical software procedures for estimating multilevel logistic regression models when the number of clusters was low. We examined procedures available in BUGS, HLM, R, SAS, and Stata. We found that there were qualitative differences in the performance of different software procedures for estimating multilevel logistic models when the number of clusters was low. Among the likelihood-based procedures, estimation methods based on adaptive Gauss-Hermite approximations to the likelihood (glmer in R and xtlogit in Stata) or adaptive Gaussian quadrature (Proc NLMIXED in SAS) tended to have superior performance for estimating variance components when the number of clusters was small, compared to software procedures based on penalized quasi-likelihood. However, only Bayesian estimation with BUGS allowed for accurate estimation of variance components when there were fewer than 10 clusters. For all statistical software procedures, estimation of variance components tended to be poor when there were only five subjects per cluster, regardless of the number of clusters.

Procedures for ambient-pressure and tympanometric tests of aural acoustic reflectance and admittance in human infants and adults

PubMed Central

Keefe, Douglas H.; Hunter, Lisa L.; Feeney, M. Patrick; Fitzpatrick, Denis F.

2015-01-01

Procedures are described to measure acoustic reflectance and admittance in human adult and infant ears at frequencies from 0.2 to 8 kHz. Transfer functions were measured at ambient pressure in the ear canal, and as down- or up-swept tympanograms. Acoustically estimated ear-canal area was used to calculate ear reflectance, which was parameterized by absorbance and group delay over all frequencies (and pressures), with substantial data reduction for tympanograms. Admittance measured at the probe tip in adults was transformed into an equivalent admittance at the eardrum using a transmission-line model for an ear canal with specified area and ear-canal length. Ear-canal length was estimated from group delay around the frequency above 2 kHz of minimum absorbance. Illustrative measurements in ears with normal function are described for an adult, and two infants at 1 month of age with normal hearing and a conductive hearing loss. The sensitivity of this equivalent eardrum admittance was calculated for varying estimates of area and length. Infant-ear patterns of absorbance peaks aligned in frequency with dips in group delay were explained by a model of resonant canal-wall mobility. Procedures will be applied in a large study of wideband clinical diagnosis and monitoring of middle-ear and cochlear function. PMID:26723319

Demirjian approach of dental age estimation: Abridged for operator ease.

PubMed

Jain, Vanshika; Kapoor, Priyanka; Miglani, Ragini

2016-01-01

Present times have seen an alarming increase in incidence of crimes by juveniles and of mass destruction that Highlight the preponderance of individual age estimation. Of the numerous techniques employed for age assessment, dental age estimation (DAE) and its correlation with chronological age (CA) have been of great significance in the recent past. Demirjian system, considered as gold standard in DAE is a simple and convenient method for DAE, though,, although, referring to multiple tables make it cumbersome and less eco friendly due to excessive paper load. The present study was aimed to develop a comprehensive chart (DAEcc) inclusive of all Demirjian tables and developmental stages of teeth and also to as well as to test the operator ease of 50 undergraduate dental students in performing DAE using this chart. The study was performed in two stages, wherein the first stage was aimed at formulation of the comprehensive chart (DAE CC ) which included pictorial representation of calcification stages, the Federation Dentaire Internationale notation of the teeth, and the corresponding scores for each stage with a concluding column at the end to enter the total score. The second stage assessed the applicability of the ease of DAE by DAE CC , whereby fifty 2 nd year BDS students were asked to trace the calcification stages of the seven permanent left mandibular teeth on a panorex, identify the correct stage, assign the corresponding score, and to calculate the total score for subsequent dental age assessment. showed that average time taken by the students for tracing seven mandibular teeth was 5 min and for assessment of dental age was 7 min. The total time taken for DAE was approximately 12 min, thus making the procedure less time consuming. Hence, this study proposes the use of DAEcc for age estimation due to ease in comprehension and execution of Demirjian system.

Age validation of quillback rockfish (Sebastes maliger) using bomb radiocarbon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerr, L A; Andrews, A H; Munk, K

2005-01-05

Rockfishes (Sebastes spp.) support one of the most economically important fisheries of the Pacific Northwest and it is essential for sustainable management that age estimation procedures be validated for these species. Atmospheric testing of thermonuclear devices during the 1950s and 1960s created a global radiocarbon ({sup 14}C) signal in the ocean environment that scientists have identified as a useful tracer and chronological marker in natural systems. In this study, we first demonstrated that fewer samples are necessary for age validation using the bomb-generated {sup 14}C signal by emphasizing the utility of the time-specific marker created by the initial rise ofmore » bomb-{sup 14}C. Second, the bomb-generated {sup 14}C signal retained in fish otoliths was used to validate the age and age estimation methodology of the quillback rockfish (Sebastes maliger) in the waters of southeast Alaska. Radiocarbon values from the first year's growth of quillback rockfish otoliths were plotted against estimated birth year producing a {sup 14}C time series spanning 1950 to 1985. The initial rise of bomb-{sup 14}C from pre-bomb levels ({approx} -90 {per_thousand}) occurred in 1959 {+-} 1 year and {sup 14}C levels rose relatively rapidly to peak {Delta}{sup 14}C values in 1967 (+105.4 {per_thousand}), with a subsequent declining trend through the end of the record in 1985 (+15.4 {per_thousand}). The agreement between the year of initial rise of {sup 14}C levels from the quillback rockfish record and the chronometer determined for the waters of southeast Alaska from yelloweye rockfish (S. ruberrimus) otoliths validated the ageing methodology for the quillback rockfish. The concordance of the entire quillback rockfish {sup 14}C record with the yelloweye rockfish time series demonstrated the effectiveness of this age validation technique, confirmed the longevity of the quillback rockfish up to a minimum of 43 years, and strongly supports higher age estimates of up to 90 years.« less

Transarterial Coil-Augmented Onyx Embolization for Brain Arteriovenous Malformation

PubMed Central

Gao, Xu; Liang, Guobiao; Li, Zhiqing; Wang, Xiaogang; Yu, Chunyong; Cao, Peng; Chen, Jun; Li, Jingyuan

2014-01-01

Summary Onyx has been widely adopted for the treatment of arteriovenous malformations (AVMs). However, its control demands operators accumulate a considerable learning curve. We describe our initial experience using a novel injection method for the embolization of AVMs. We retrospectively reviewed the data of all 22 patients with brain AVMs (12 men, 10 women; age range, 12-68 years; mean age, 43.2 years) treated by the transarterial coil-augmented Onyx injection technique. The size of the AVMs ranged from 25 mm to 70 mm (average 35.6 mm). The technical feasibility of the procedure, procedure-related complications, angiographic results, and clinical outcome were evaluated. In every case, endovascular treatment (EVT) was completed. A total of 31 sessions were performed, with a mean injection volume of 6.1 mL (range, 1.5-16.0 mL). An average of 96.7% (range 85%-100%) estimated size reduction was achieved, and 18 AVMs could be completely excluded by EVT alone. The results remained stable on follow-up angiograms. A procedural complication occurred in one patient, with permanent mild neurologic deficit. Our preliminary series demonstrated that the coil-augmented Onyx injection technique is a valuable adjunct achieving excellent nidal penetration and improving the safety of the procedure. PMID:24556304

40 CFR 98.425 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) Whenever the quality assurance procedures in § 98.424(a)(1) of this subpart... following missing data procedures shall be followed: (1) A quarterly CO2 mass flow or volumetric flow value...

40 CFR 98.445 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. A complete record of all measured parameters used in the GHG... following missing data procedures: (a) A quarterly flow rate of CO2 received that is missing must be...

40 CFR Appendix C to Part 75 - Missing Data Estimation Procedures

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Missing Data Estimation Procedures C... (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. C Appendix C to Part 75—Missing Data Estimation Procedures 1. Parametric Monitoring Procedure for Missing SO2 Concentration or NOX Emission Rate Data 1...

40 CFR 98.425 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. (a) Whenever the quality assurance procedures in § 98.424(a) of this subpart cannot... following missing data procedures shall be followed: (1) A quarterly CO2 mass flow or volumetric flow value...

40 CFR Appendix C to Part 75 - Missing Data Estimation Procedures

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Missing Data Estimation Procedures C... (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. C Appendix C to Part 75—Missing Data Estimation Procedures 1. Parametric Monitoring Procedure for Missing SO2 Concentration or NOX Emission Rate Data 1...

40 CFR Appendix C to Part 75 - Missing Data Estimation Procedures

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Missing Data Estimation Procedures C... (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. C Appendix C to Part 75—Missing Data Estimation Procedures 1. Parametric Monitoring Procedure for Missing SO2 Concentration or NOX Emission Rate Data 1...

40 CFR 98.425 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. (a) Whenever the quality assurance procedures in § 98.424(a)(1) of this subpart... following missing data procedures shall be followed: (1) A quarterly CO2 mass flow or volumetric flow value...

40 CFR 98.425 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) Whenever the quality assurance procedures in § 98.424(a)(1) of this subpart... following missing data procedures shall be followed: (1) A quarterly CO2 mass flow or volumetric flow value...

40 CFR 98.425 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) Whenever the quality assurance procedures in § 98.424(a)(1) of this subpart... following missing data procedures shall be followed: (1) A quarterly CO2 mass flow or volumetric flow value...

40 CFR Appendix C to Part 75 - Missing Data Estimation Procedures

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Missing Data Estimation Procedures C... (CONTINUED) CONTINUOUS EMISSION MONITORING Pt. 75, App. C Appendix C to Part 75—Missing Data Estimation Procedures 1. Parametric Monitoring Procedure for Missing SO2 Concentration or NOX Emission Rate Data 1...

40 CFR 98.235 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. A complete record of all estimated and/or measured parameters used in... sources as soon as possible, including in the subsequent calendar year if missing data are not discovered...

40 CFR 98.235 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. A complete record of all estimated and/or measured parameters used in... sources as soon as possible, including in the subsequent calendar year if missing data are not discovered...

40 CFR 98.235 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. A complete record of all estimated and/or measured parameters used in... sources as soon as possible, including in the subsequent calendar year if missing data are not discovered...

40 CFR 98.235 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. A complete record of all estimated and/or measured parameters used in... sources as soon as possible, including in the subsequent calendar year if missing data are not discovered...

A Class of Factor Analysis Estimation Procedures with Common Asymptotic Sampling Properties

ERIC Educational Resources Information Center

Swain, A. J.

1975-01-01

Considers a class of estimation procedures for the factor model. The procedures are shown to yield estimates possessing the same asymptotic sampling properties as those from estimation by maximum likelihood or generalized last squares, both special members of the class. General expressions for the derivatives needed for Newton-Raphson…

Plastic surgeons’ self-reported operative infection rates at a Canadian academic hospital

PubMed Central

Ng, Wendy KY; Kaur, Manraj Nirmal; Thoma, Achilleas

2014-01-01

BACKGROUND: Surgical site infection rates are of great interest to patients, surgeons, hospitals and third-party payers. While previous studies have reported hospital-acquired infection rates that are nonspecific to all surgical services, there remain no overall reported infection rates focusing specifically on plastic surgery in the literature. OBJECTIVE: To estimate the reported surgical site infection rate in plastic surgery procedures over a 10-year period at an academic hospital in Canada. METHODS: A review was conducted on reported plastic surgery surgical site infection rates from 2003 to 2013, based on procedures performed in the main operating room. For comparison, prospective infection surveillance data over an eight-year period (2005 to 2013) for nonplastic surgery procedures were reviewed to estimate the overall operative surgical site infection rates. RESULTS: A total of 12,183 plastic surgery operations were performed from 2003 to 2013, with 96 surgical site infections reported, corresponding to a net operative infection rate of 0.79%. There was a 0.49% surgeon-reported infection rate for implant-based procedures. For non-plastic surgery procedures, surgical site infection rates ranged from 0.04% for cataract surgery to 13.36% for high-risk abdominal hysterectomies. DISCUSSION: The plastic surgery infection rate at the study institution was found to be <1%. This rate was equal to, or somewhat less than, surgical site infection rates. However, these results do not report patterns of infection rates germane to procedures, season, age groups or sex. To provide more in-depth knowledge of this topic, multicentre studies should be conducted. PMID:25535460

Comparisons between consumption estimates from bioenergetics simulations and field measurements for walleyes from Oneida Lake, New York

USGS Publications Warehouse

Lantry, B.F.; Rudstam, L. G.; Forney, J.L.; VanDeValk, A.J.; Mills, E.L.; Stewart, D.J.; Adams, J.V.

2008-01-01

Daily consumption was estimated from the stomach contents of walleyes Sander vitreus collected weekly from Oneida Lake, New York, during June-October 1975, 1992, 1993, and 1994 for one to four age-groups per year. Field rations were highly variable between weeks, and trends in ration size varied both seasonally and annually. The coefficient of variation for weekly field rations within years and ages ranged from 45% to 97%. Field estimates were compared with simulated consumption from a bioenergetics model. The simulation averages of daily ration deviated from those of the field estimates by -20.1% to +70.3%, with a mean across all simulations of +14.3%. The deviations for each time step were much greater than those for the simulation averages, ranging from -92.8% to +363.6%. A systematic trend in the deviations was observed, the model producing overpredictions at rations less than 3.7% of body weight. Analysis of variance indicated that the deviations were affected by sample year and week but not age. Multiple linear regression using backwards selection procedures and Akaike's information criterion indicated that walleye weight, walleye growth, lake temperature, prey energy density, and the proportion of gizzard shad Dorosoma cepedianum in the diet significantly affected the deviations between simulated and field rations and explained 32% of the variance. ?? Copyright by the American Fisheries Society 2008.

Incorporating diverse data and realistic complexity into demographic estimation procedures for sea otters

USGS Publications Warehouse

Tinker, M. Timothy; Doak, Daniel F.; Estes, James A.; Hatfield, Brian B.; Staedler, Michelle M.; Gross, Arthur

2006-01-01

Reliable information on historical and current population dynamics is central to understanding patterns of growth and decline in animal populations. We developed a maximum likelihood-based analysis to estimate spatial and temporal trends in age/sex-specific survival rates for the threatened southern sea otter (Enhydra lutris nereis), using annual population censuses and the age structure of salvaged carcass collections. We evaluated a wide range of possible spatial and temporal effects and used model averaging to incorporate model uncertainty into the resulting estimates of key vital rates and their variances. We compared these results to current demographic parameters estimated in a telemetry-based study conducted between 2001 and 2004. These results show that survival has decreased substantially from the early 1990s to the present and is generally lowest in the north-central portion of the population's range. The greatest temporal decrease in survival was for adult females, and variation in the survival of this age/sex class is primarily responsible for regulating population growth and driving population trends. Our results can be used to focus future research on southern sea otters by highlighting the life history stages and mortality factors most relevant to conservation. More broadly, we have illustrated how the powerful and relatively straightforward tools of information-theoretic-based model fitting can be used to sort through and parameterize quite complex demographic modeling frameworks. ?? 2006 by the Ecological Society of America.

Finding the breech: Influence of breech presentation on mode of delivery based on timing of diagnosis, attempt at external cephalic version, and provider success with version.

PubMed

Andrews, Suzanne; Leeman, Lawrence; Yonke, Nicole

2017-09-01

Breech presentation affects 3-4% of pregnancies at term and malpresentation is the primary indication for 10-15% of cesarean deliveries. External cephalic version is an effective intervention that can decrease the need for cesarean delivery; however, timely identification of breech presentation is required. We hypothesized that women with a fetus in a breech presentation that is diagnosed after 38 weeks' estimated gestational age have a decreased likelihood of external cephalic version attempted and an increased likelihood of cesarean delivery. This was a retrospective cohort study. A chart review was performed for 251 women with breech presentation at term presenting to our tertiary referral university hospital for external cephalic version, cesarean for breech presentation, or vaginal breech delivery. Vaginal delivery was significantly more likely (31.1% vs 12.5%; P<.01) in women with breech presentation diagnosed before 38 weeks' estimated gestational age as external cephalic version was offered, and subsequently attempted in a greater proportion of women diagnosed before 38 weeks. External cephalic version was more successful when performed by physicians with greater procedural volume during the 3.5 year period of the study (59.1% for providers performing at least 10 procedures vs 31.3% if performing fewer than 10 procedures, P<.01). Results support the need for interventions to increase timely diagnosis of breech presentation as well as improved patient counseling and use of experienced providers for external cephalic version. © 2017 Wiley Periodicals, Inc.

Multiple testing with discrete data: Proportion of true null hypotheses and two adaptive FDR procedures.

PubMed

Chen, Xiongzhi; Doerge, Rebecca W; Heyse, Joseph F

2018-05-11

We consider multiple testing with false discovery rate (FDR) control when p values have discrete and heterogeneous null distributions. We propose a new estimator of the proportion of true null hypotheses and demonstrate that it is less upwardly biased than Storey's estimator and two other estimators. The new estimator induces two adaptive procedures, that is, an adaptive Benjamini-Hochberg (BH) procedure and an adaptive Benjamini-Hochberg-Heyse (BHH) procedure. We prove that the adaptive BH (aBH) procedure is conservative nonasymptotically. Through simulation studies, we show that these procedures are usually more powerful than their nonadaptive counterparts and that the adaptive BHH procedure is usually more powerful than the aBH procedure and a procedure based on randomized p-value. The adaptive procedures are applied to a study of HIV vaccine efficacy, where they identify more differentially polymorphic positions than the BH procedure at the same FDR level. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Population Health Implications of Medical Tourism.

PubMed

Adabi, Kian; Stern, Carrie S; Weichman, Katie E; Garfein, Evan S; Pothula, Aravind; Draper, Lawrence; Tepper, Oren M

2017-07-01

Fifteen million U.S. patients each year seek medical care abroad; however, there are no data on outcomes and follow-up of these procedures. This study aims to identify, evaluate, and survey patients presenting with complications from aesthetic procedures abroad and estimate their cost to the U.S. health care system. A single-center retrospective review was conducted. A cohort of patients presenting with complications from aesthetic procedures performed abroad was generated. Demographic, complication, and cost data were compiled. Patients were surveyed to assess their overall experience. Over a 36-month period, 42 patients met inclusion criteria (one man and 41 women), with an average age of 35 ± 11.4 years (range, 20 to 60 years). Comorbidities included four active smokers, two patients with hypertension, and one patient with diabetes. Average body mass index was 29 ± 4.4 kg/m (range, 22 to 38 kg/m). Procedures performed abroad included abdominoplasty (n = 28), liposuction (n = 20), buttock augmentation (n = 10), and breast augmentation (n = 7), with several patients undergoing combined procedures. Eleven patients presented with abscesses and eight presented with wound dehiscence. Eight of the 18 patients who were surveyed were not pleased with their results and 11 would not go abroad again for subsequent procedures. Average cost of treating the complications was $18,211, with an estimated cost to the U.S. health care system of $1.33 billion. The main payer group was Medicaid. Complications from patients seeking aesthetic procedures abroad will continues to increase. Patients should be encouraged to undergo cosmetic surgery in the United States to improve patient outcomes and satisfaction and because it is economically advantageous. Therapeutic, IV.

The Polls-Review: Inaccurate Age and Sex Data in the Census Pums Files: Evidence and Implications.

PubMed

Alexander, J Trent; Davern, Michael; Stevenson, Betsey

2010-01-01

We discover and document errors in public-use microdata samples ("PUMS files") of the 2000 Census, the 2003-2006 American Community Survey, and the 2004-2009 Current Population Survey. For women and men age 65 and older, age- and sex-specific population estimates generated from the PUMS files differ by as much as 15 percent from counts in published data tables. Moreover, an analysis of labor-force participation and marriage rates suggests the PUMS samples are not representative of the population at individual ages for those age 65 and over. PUMS files substantially underestimate labor-force participation of those near retirement age and overestimate labor-force participation rates of those at older ages. These problems were an unintentional byproduct of the misapplication of a newer generation of disclosure-avoidance procedures carried out on the data. The resulting errors in the public-use data could significantly impact studies of people age 65 and older, particularly analyses of variables that are expected to change by age.

40 CFR Appendix Viii to Part 86 - Aging Bench Equipment and Procedures

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 20 2013-07-01 2013-07-01 false Aging Bench Equipment and Procedures.... 86, App. VIII Appendix VIII to Part 86—Aging Bench Equipment and Procedures This appendix provides specifications for standard aging bench equipment and aging procedures which may be used to conduct bench aging...

40 CFR Appendix Viii to Part 86 - Aging Bench Equipment and Procedures

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Aging Bench Equipment and Procedures.... VIII Appendix VIII to Part 86—Aging Bench Equipment and Procedures This appendix provides specifications for standard aging bench equipment and aging procedures which may be used to conduct bench aging...

40 CFR Appendix Viii to Part 86 - Aging Bench Equipment and Procedures

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Aging Bench Equipment and Procedures.... 86, App. VIII Appendix VIII to Part 86—Aging Bench Equipment and Procedures This appendix provides specifications for standard aging bench equipment and aging procedures which may be used to conduct bench aging...

The prevalence and causes of blindness in the Sultanate of Oman: the Oman Eye Study (OES)

PubMed Central

Khandekar, R; Mohammed, A J; Negrel, A D; Al Riyami, A

2002-01-01

Aims: To estimate the magnitude and the causes of blindness through a community based nationwide survey in Oman. This was conducted in 1996–7. Methods: A stratified cluster random sampling procedure was used to select 12 400 people. The WHO/PBD standardised survey methodology was used, with suitable adaptation. The major causes of blindness were identified among those found blind. Results: A total of 11 417 people were examined (response rate 91.8%) The prevalence of blindness in the Omani population was estimated to be 1.1% (95% CI 0.9 to 1.3), blindness being defined according to the WHO Tenth Revision of the International Classification of Diseases. Prevalence of blindness was clearly related to increasing age, with estimates of 0.08% for the 0–14 age group, 0.1% for the 15–39 age group, 2.3% for the 40–59 age group, and 16.8% for the group aged 60 +. There was a statistically significant difference between the prevalence in females (1.4%) and males (0.8%). The northern and central regions had a higher prevalence of blindness (1.3% to 3%). The major causes of blindness were unoperated cataract (30.5%), trachomatous corneal opacities (23.7%), and glaucoma (11.5%) Conclusions: Despite an active eye healthcare programme, blindness due to cataract and trachoma remains a public health problem of great concern in several regions of the sultanate. These results highlight the need, when planning effective intervention strategies, to target the eye healthcare programme to the ageing population, with special emphasis on women. PMID:12185115

Variation in quality of care after emergency general surgery procedures in the elderly.

PubMed

Ingraham, Angela M; Cohen, Mark E; Raval, Mehul V; Ko, Clifford Y; Nathens, Avery B

2011-06-01

The elderly (age ≥65 years) comprise an increasing proportion of patients undergoing emergency general surgery (EGS) procedures and have distinct needs compared with the young. We postulated that the needs of the elderly require different processes of care than those required for the young to assure optimal outcomes. To explore this hypothesis, we evaluated 30-day outcomes following EGS procedures in the young and the elderly and determined whether hospital performance was consistent across these 2 age strata. With data from the American College of Surgeons National Surgical Quality Improvement Program (2005 to 2008), regression models were constructed for serious morbidity and mortality for all patients undergoing EGS procedures and separately for young and elderly patients. These models allowed for estimation of the risk of adverse outcomes associated with advanced age and the generation of hospital-level observed to expected (O/E) ratios. We evaluated the correlation between hospital O/E ratios for the young and the elderly and the concordance of outlier status (hospitals with CIs of O/E ratios excluding 1) with weighted κ across these 2 age groups. Among 68,003 procedures at 186 hospitals, elderly patients had a higher crude and adjusted risk for serious morbidity (27.9% versus 9.7%, p < 0.0001; odds ratio 1.17, 95% CI 1.10 to 1.24) and mortality (15.2% versus 2.5%, p < 0.0001; odds ratio 2.29, 95% CI 2.09 to 2.51). When outcomes for elderly versus younger patients were compared, there was fair to moderate agreement on hospital performance for serious morbidity (r = 0.43; κ = 0.30) but not for mortality (r = 0.10; κ = 0.17). Elderly patients are at substantially greater risk for adverse events following EGS procedures. Hospitals had only slight agreement in mortality outcomes in the elderly compared with those in young patients. Processes of care that may account for this disparity should be further investigated. Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

A Normalized Direct Approach for Estimating the Parameters of the Normal Ogive Three-Parameter Model for Ability Tests.

ERIC Educational Resources Information Center

Gugel, John F.

A new method for estimating the parameters of the normal ogive three-parameter model for multiple-choice test items--the normalized direct (NDIR) procedure--is examined. The procedure is compared to a more commonly used estimation procedure, Lord's LOGIST, using computer simulations. The NDIR procedure uses the normalized (mid-percentile)…

On the relative ages of galactic globular clusters. A new observable, a semi-empirical calibration and problems with the theoretical isochrones

NASA Astrophysics Data System (ADS)

Buonanno, R.; Corsi, C. E.; Pulone, L.; Fusi Pecci, F.; Bellazzini, M.

1998-05-01

A new procedure is described to derive homogeneous relative ages from the Color-Magnitude Diagrams (CMDs) of Galactic globular clusters (GGCs). It is based on the use of a new observable, Delta V(0.05) , namely the difference in magnitude between an arbitrary point on the upper main sequence (V_{+0.05} -the V magnitude of the MS-ridge, 0.05 mag redder than the Main Sequence (MS) Turn-off, (TO)) and the horizontal branch (HB). The observational error associated to Delta V(0.05) is substantially smaller than that of previous age-indicators, keeping the property of being strictly independent of distance and reddening and of being based on theoretical luminosities rather than on still uncertain theoretical temperatures. As an additional bonus, the theoretical models show that Delta V(0.05) has a low dependence on metallicity. Moreover, the estimates of the relative age so obtained are also sufficiently invariant (to within ~ +/- 1 Gyr) with varying adopted models and transformations. Since the difference in the color difference Delta (B-V)_{TO,RGB} (VandenBerg, Bolte and Stetson 1990 -VBS, Sarajedini and Demarque 1990 -SD) remains the most reliable technique to estimate relative cluster ages for clusters where the horizontal part of the HB is not adequately populated, we have used the differential ages obtained via the "vertical" Delta V(0.05) parameter for a selected sample of clusters (with high quality CMDs, well populated HBs, trustworthy calibrations) to perform an empirical calibration of the "horizontal" observable in terms of [Fe/H] and age. A direct comparison with the corresponding calibration derived from the theoretical models reveals the existence of clear-cut discrepancies, which call into question the model scaling with metallicity in the observational planes. Starting from the global sample of considered clusters, we have thus evaluated, within a homogeneous procedure, relative ages for 33 GGCs having different metallicity, HB-morphologies, and galactocentric distances. These new estimates have also been compared with previous latest determinations (Chaboyer, Demarque and Sarajedini 1996, and Richer {et al. } 1996). The distribution of the cluster ages with varying metallicity and galactocentric distance are briefly discussed: (a) there is no direct indication for any evident age-metallicity relationship; (b) there is some spread in age (still partially compatible with the errors), and the largest dispersion is found for intermediate metal-poor clusters; (c) older clusters populate both the inner and the outer regions of the Milky Way, while the younger globulars are present only in the outer regions, but the sample is far too poor to yield conclusive evidences.

Relative crater production rates on planets

NASA Technical Reports Server (NTRS)

Hartmann, W. K.

1977-01-01

The relative numbers of impacts on different planets, estimated from the dynamical histories of planetesimals in specified orbits (Wetherill, 1975), are converted by a described procedure to crater production rates. Conversions are dependent on impact velocity and surface gravity. Crater retention ages can then be derived from the ratio of the crater density to the crater production rate. The data indicate that the terrestrial planets have crater production rates within a factor ten of each other. As an example, for the case of Mars, least-squares fits to crater-count data suggest an average age of 0.3 to 3 billion years for two types of channels. The age of Olympus Mons is discussed, and the effect of Tharsis volcanism on channel formation is considered.

The Music Attentiveness Screening Assessment, Revised (MASA-R): A Study of Technical Adequacy.

PubMed

Waldon, Eric G; Lesser, Alexander; Weeden, Lydia; Messick, Emily

2016-01-01

Evidence suggests that attention is an important consideration when designing procedural support interventions for children undergoing distressing medical procedures. As such, the extent to which children can attend to musical stimuli used during music-based procedural support interventions would seem important. The Music Attentiveness Screening Assessment (MASA) was designed to assess a child's ability to attend to musical stimuli, but further revisions were deemed necessary to improve administration, test-retest reliability, and interobserver agreement for the measure's items. This study investigated the technical adequacy of the Music Attentiveness Screening Assessment, Revised (MASA-R), with a non-clinical sample of children aged 4 to 9 years by examining (a) Construct validity using comparator instruments measuring auditory attention; (b) Test-retest reliability following a two-week delay; and (c) Interobserver agreement when administered by two independent examiners. This non-clinical sample included 69 children who were administered both items from MASA-R and two comparator instruments: the Auditory Attention subtest from the NEPSY-II (NII-AA) for children aged 5 to 9 years (n = 47); and the Auditory Attention subtest from the Woodcock-Johnson Tests of Cognitive Abilities, 3rd ed. (WJIII-AA), for children aged 4 years (n = 22). A significant proportion of score variance was shared by both MASA-R items and the comparator measures: R (2) = .16, F(2, 66) = 6.30, p = .003. MASA-R score estimates with regard to test-retest reliability (Item I, intra-class correlation [ICC] = .88; Item II, ICC = .91) and interobserver agreement (Item I, ICC = .99; Item II, ICC = .98) also fell into acceptable ranges. Estimates of MASA-R score construct validity, test-retest reliability, and interobserver agreement appear improved over its predecessor, MASA. While findings are promising, additional investigation of its use with a clinical sample is needed before it can be confidently used in pediatrics. © the American Music Therapy Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Estimating acreage by double sampling using LANDSAT data

NASA Technical Reports Server (NTRS)

Pont, F.; Horwitz, H.; Kauth, R. (Principal Investigator)

1982-01-01

Double sampling techniques employing LANDSAT data for estimating the acreage of corn and soybeans was investigated and evaluated. The evaluation was based on estimated costs and correlations between two existing procedures having differing cost/variance characteristics, and included consideration of their individual merits when coupled with a fictional 'perfect' procedure of zero bias and variance. Two features of the analysis are: (1) the simultaneous estimation of two or more crops; and (2) the imposition of linear cost constraints among two or more types of resource. A reasonably realistic operational scenario was postulated. The costs were estimated from current experience with the measurement procedures involved, and the correlations were estimated from a set of 39 LACIE-type sample segments located in the U.S. Corn Belt. For a fixed variance of the estimate, double sampling with the two existing LANDSAT measurement procedures can result in a 25% or 50% cost reduction. Double sampling which included the fictional perfect procedure results in a more cost effective combination when it is used with the lower cost/higher variance representative of the existing procedures.

Long-term follow-up of Fontan completion in adults and adolescents.

PubMed

Fuchigami, Tai; Nagashima, Mitsugi; Hiramatsu, Takeshi; Matsumura, Goki; Tateishi, Minori; Masuda, Noriyasu; Yamazaki, Kenji

2017-07-01

The Fontan procedure is rarely performed in adults and adolescents in the present era. We review our results with the Fontan procedure in adolescents and young adults. Between 1974 and 2010, 79 consecutive patients underwent the Fontan procedure at an age ≥ 15 years (mean age at Fontan operation, 20.3 years ± 4.5 years). Forty-five patients underwent atriopulmonary connection, 11 underwent the Bjork procedure, and 23 underwent total cavopulmonary connection. Ten hospital deaths (HDs) and/or early Fontan takedowns (TDs) occurred. The median follow-up period was 18.2 years (range, 0.6-37.6 years). The estimated freedom from death or TD rates was 79.7% at 5 years, 77.0% at 10 years, 73.9% at 15 years, and 63.9% at 20 years. Age was not a predictor of HD and/or TD. Freedom from death or TD after 1998 was 69.1% at 5 years, 69.1% at 10 years, and 69.1% at 15 years, and before 1997 was 82.3% at 5 years, 79.0% at 10 years, 75.5% at 15 years, and 65.1% at 20 years; there were no significant differences between the two groups. In 19 late-death patients, nine (47.4%) experienced sudden death. Among these patients, five had known arrhythmias before sudden death. In patients who were ≥15 years old, the surgical results of the Fontan operation were acceptable. Approximately half of the late deaths were sudden deaths, mainly occurring 10-20 years postoperatively. © 2017 Wiley Periodicals, Inc.

A numerical procedure for recovering true scattering coefficients from measurements with wide-beam antennas

NASA Technical Reports Server (NTRS)

Wang, Qinglin; Gogineni, S. P.

1991-01-01

A numerical procedure for estimating the true scattering coefficient, sigma(sup 0), from measurements made using wide-beam antennas. The use of wide-beam antennas results in an inaccurate estimate of sigma(sup 0) if the narrow-beam approximation is used in the retrieval process for sigma(sup 0). To reduce this error, a correction procedure was proposed that estimates the error resulting from the narrow-beam approximation and uses the error to obtain a more accurate estimate of sigma(sup 0). An exponential model was assumed to take into account the variation of sigma(sup 0) with incidence angles, and the model parameters are estimated from measured data. Based on the model and knowledge of the antenna pattern, the procedure calculates the error due to the narrow-beam approximation. The procedure is shown to provide a significant improvement in estimation of sigma(sup 0) obtained with wide-beam antennas. The proposed procedure is also shown insensitive to the assumed sigma(sup 0) model.

Is employer-based health insurance a barrier to entrepreneurship?

PubMed

Fairlie, Robert W; Kapur, Kanika; Gates, Susan

2011-01-01

The focus on employer-provided health insurance in the United States may restrict business creation. We address the limited research on the topic of "entrepreneurship lock" by using recent panel data from matched Current Population Surveys. We use difference-in-difference models to estimate the interaction between having a spouse with employer-based health insurance and potential demand for health care. We find evidence of a larger negative effect of health insurance demand on business creation for those without spousal coverage than for those with spousal coverage. We also take a new approach in the literature to examine the question of whether employer-based health insurance discourages business creation by exploiting the discontinuity created at age 65 through the qualification for Medicare. Using a novel procedure of identifying age in months from matched monthly CPS data, we compare the probability of business ownership among male workers in the months just before turning age 65 and in the months just after turning age 65. We find that business ownership rates increase from just under age 65 to just over age 65, whereas we find no change in business ownership rates from just before to just after for other ages 55-75. We also do not find evidence from the previous literature and additional estimates that other confounding factors such as retirement, partial retirement, social security and pension eligibility are responsible for the increase in business ownership in the month individuals turn 65. Our estimates provide some evidence that "entrepreneurship lock" exists, which raises concerns that the bundling of health insurance and employment may create an inefficient level of business creation. Copyright © 2010 Elsevier B.V. All rights reserved.

Estimating the probability for major gene Alzheimer disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farrer, L.A.; Cupples, L.A.

1994-02-01

Alzheimer disease (AD) is a neuropsychiatric illness caused by multiple etiologies. Prediction of whether AD is genetically based in a given family is problematic because of censoring bias among unaffected relatives as a consequence of the late onset of the disorder, diagnostic uncertainties, heterogeneity, and limited information in a single family. The authors have developed a method based on Bayesian probability to compute values for a continuous variable that ranks AD families as having a major gene form of AD (MGAD). In addition, they have compared the Bayesian method with a maximum-likelihood approach. These methods incorporate sex- and age-adjusted riskmore » estimates and allow for phenocopies and familial clustering of age on onset. Agreement is high between the two approaches for ranking families as MGAD (Spearman rank [r] = .92). When either method is used, the numerical outcomes are sensitive to assumptions of the gene frequency and cumulative incidence of the disease in the population. Consequently, risk estimates should be used cautiously for counseling purposes; however, there are numerous valid applications of these procedures in genetic and epidemiological studies. 41 refs., 4 figs., 3 tabs.« less

The effect of sampling, diagnostic criteria and assessment procedures on the observed prevalence of DSM-III-R personality disorders among treated alcoholics.

PubMed

Verheul, R; Hartgers, C; Van den Brink, W; Koeter, M W

1998-03-01

OBJECTIVE. In a recent review of empirical studies on the prevalence of DSM-III-R personality disorders among substance abusers, wide ranges of prevalence rates for overall Axis II, antisocial personality disorder (APD) and borderline personality disorder (BPD) were shown. Utilizing subsamples from within a single study population, the current report explores the effect of sampling, diagnostic criteria and assessment procedures on the observed prevalence of DSM-III-R personality disorders among treated alcoholics. Personality disorders were assessed with the Personality Diagnostic Questionnaire Revised (PDQR) at two times of measurement (Time 1 n = 459; Time 2 n = 90). In addition, APD was measured with the Composite International Diagnostic Interview (CIDI; n = 587). Finally, an unselected subgroup (n = 136) was interviewed with the International Personality Disorder Examination (IPDE). There were few differences between inpatients or outpatients or between males and females. Using the IPDE, the exclusion of substance-related pathology did not affect the prevalence estimate. However, the prevalence rates according to the PDQR varied greatly across age groups. In a representative subsample (n = 109), the prevalence rates also varied greatly across assessment methods (PDQR, 52% vs IPDE, 31%). The prevalence estimate of APD according to the CIDI was related to setting, gender, age group and the applied time-frame. These findings indicate the examined factors to be necessary qualifiers of prevalence estimates and, consequently, support the use of a multiple-criteria/multimethod assessment battery in research as well as in clinical work.

Estimating Body Composition in Adolescent Sprint Athletes: Comparison of Different Methods in a 3 Years Longitudinal Design

PubMed Central

Aerenhouts, Dirk

2015-01-01

A recommended field method to assess body composition in adolescent sprint athletes is currently lacking. Existing methods developed for non-athletic adolescents were not longitudinally validated and do not take maturation status into account. This longitudinal study compared two field methods, i.e., a Bio Impedance Analysis (BIA) and a skinfold based equation, with underwater densitometry to track body fat percentage relative to years from age at peak height velocity in adolescent sprint athletes. In this study, adolescent sprint athletes (34 girls, 35 boys) were measured every 6 months during 3 years (age at start = 14.8 ± 1.5yrs in girls and 14.7 ± 1.9yrs in boys). Body fat percentage was estimated in 3 different ways: 1) using BIA with the TANITA TBF 410; 2) using a skinfold based equation; 3) using underwater densitometry which was considered as the reference method. Height for age since birth was used to estimate age at peak height velocity. Cross-sectional analyses were performed using repeated measures ANOVA and Pearson correlations between measurement methods at each occasion. Data were analyzed longitudinally using a multilevel cross-classified model with the PROC Mixed procedure. In boys, compared to underwater densitometry, the skinfold based formula revealed comparable values for body fatness during the study period whereas BIA showed a different pattern leading to an overestimation of body fatness starting from 4 years after age at peak height velocity. In girls, both the skinfold based formula and BIA overestimated body fatness across the whole range of years from peak height velocity. The skinfold based method appears to give an acceptable estimation of body composition during growth as compared to underwater densitometry in male adolescent sprinters. In girls, caution is warranted when interpreting estimations of body fatness by both BIA and a skinfold based formula since both methods tend to give an overestimation. PMID:26317426

Impact of concentration of ellagitannins in oak wood on their levels and organoleptic influence in red wine.

PubMed

Michel, Julien; Jourdes, Michael; Silva, Maria A; Giordanengo, Thomas; Mourey, Nicolas; Teissedre, Pierre-Louis

2011-05-25

Some wood substances such as ellagitannins can be extracted during wine aging in oak barrels. The level of these hydrolyzable tannins in wine depends of some parameters of oak wood. Their impact on the organoleptic perception of red wine is poorly known. In our research, oak staves were classified in three different groups according to their level of ellagitannins estimated by NIRS (near infrared spectroscopy) online procedure (Oakscan). First, the ellagitannin level and composition were determine for each classified stave and an excellent correlation between the NIRS classification (low, medium and high potential level of ellagitannin) and the ellagitannin content estimated by HPLC-UV was found. Each different group of NIRS classified staves was then added to red wine during its aging in a stainless tank, and the extraction and evolution of the ellagitannins were monitored. A good correlation between the NIRS classification and the concentration of ellagitannins in red wine aging in contact with the classified staves was observed. The influence of levels of ellagitannins on the resulting wine perception was estimated by a trained judge's panel, and it reveals that the level of ellagitannins in wine has an impact on the roundness and amplitude of the red wine.

Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ubeda, Carlos, E-mail: cubeda@uta.cl; Miranda, Patricia; Vano, Eliseo

Purpose: To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Methods: Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-areamore » product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Results: Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for <1 yr; 213 for 1 to <5 yr; 82 for 5 to <10 yr; and 102 for 10 to <16 yr. The third quartile values obtained for DAP by diagnostic and therapeutic procedures and age range were 1.17 and 1.11 Gy cm{sup 2} for <1 yr; 1.74 and 1.90 Gy cm{sup 2} for 1 to <5 yr; 2.83 and 3.22 Gy cm{sup 2} for 5 to <10 yr; and 7.34 and 8.68 Gy cm{sup 2} for 10 to <16 yr, respectively. The third quartile value obtained for the DAP/body weight ratio for the full sample of procedures was 0.17 (Gy cm{sup 2}/kg) for diagnostic and therapeutic procedures. Conclusions: The data presented in this paper are an initial attempt at establishing local DRLs in pediatric interventional cardiology, from a large sample of procedures for the standard age bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there may be large differences in child size. These DRLs were obtained at the largest pediatric hospital in Chile, with an active optimization program, and could be used by other hospitals in the Latin America region to compare their current patient dose values and determine whether corrective action is appropriate.« less

Local patient dose diagnostic reference levels in pediatric interventional cardiology in Chile using age bands and patient weight values.

PubMed

Ubeda, Carlos; Miranda, Patricia; Vano, Eliseo

2015-02-01

To present the results of a patient dose evaluation program in pediatric cardiology and propose local diagnostic reference levels (DRLs) for different types of procedure and age range, in addition to suggesting approaches to correlate patient dose values with patient weight. This study was the first conducted in Latin America for pediatric interventional cardiology under the auspices of the International Atomic Energy Agency. Over three years, the following data regarding demographic and patient dose values were collected: age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time (FT), and two dosimetric quantities, dose-area product (DAP) and cumulative dose (CD), at the patient entrance reference point. The third quartile values for FT, DAP, CD, number of cine series, and the DAP/body weight ratio were proposed as the set of quantities to use as local DRLs. Five hundred and seventeen patients were divided into four age groups. Sample sizes by age group were 120 for <1 yr; 213 for 1 to <5 yr; 82 for 5 to <10 yr; and 102 for 10 to <16 yr. The third quartile values obtained for DAP by diagnostic and therapeutic procedures and age range were 1.17 and 1.11 Gy cm 2 for <1 yr; 1.74 and 1.90 Gy cm 2 for 1 to <5 yr; 2.83 and 3.22 Gy cm 2 for 5 to <10 yr; and 7.34 and 8.68 Gy cm 2 for 10 to <16 yr, respectively. The third quartile value obtained for the DAP/body weight ratio for the full sample of procedures was 0.17 (Gy cm 2 /kg) for diagnostic and therapeutic procedures. The data presented in this paper are an initial attempt at establishing local DRLs in pediatric interventional cardiology, from a large sample of procedures for the standard age bands used in Europe, complemented with the values of the ratio between DAP and patient weight. This permits a rough estimate of DRLs for different patient weights and the refining of these values for the age bands when there may be large differences in child size. These DRLs were obtained at the largest pediatric hospital in Chile, with an active optimization program, and could be used by other hospitals in the Latin America region to compare their current patient dose values and determine whether corrective action is appropriate. © 2015 American Association of Physicists in Medicine.

Estimating times of surgeries with two component procedures: comparison of the lognormal and normal models.

PubMed

Strum, David P; May, Jerrold H; Sampson, Allan R; Vargas, Luis G; Spangler, William E

2003-01-01

Variability inherent in the duration of surgical procedures complicates surgical scheduling. Modeling the duration and variability of surgeries might improve time estimates. Accurate time estimates are important operationally to improve utilization, reduce costs, and identify surgeries that might be considered outliers. Surgeries with multiple procedures are difficult to model because they are difficult to segment into homogenous groups and because they are performed less frequently than single-procedure surgeries. The authors studied, retrospectively, 10,740 surgeries each with exactly two CPTs and 46,322 surgical cases with only one CPT from a large teaching hospital to determine if the distribution of dual-procedure surgery times fit more closely a lognormal or a normal model. The authors tested model goodness of fit to their data using Shapiro-Wilk tests, studied factors affecting the variability of time estimates, and examined the impact of coding permutations (ordered combinations) on modeling. The Shapiro-Wilk tests indicated that the lognormal model is statistically superior to the normal model for modeling dual-procedure surgeries. Permutations of component codes did not appear to differ significantly with respect to total procedure time and surgical time. To improve individual models for infrequent dual-procedure surgeries, permutations may be reduced and estimates may be based on the longest component procedure and type of anesthesia. The authors recommend use of the lognormal model for estimating surgical times for surgeries with two component procedures. Their results help legitimize the use of log transforms to normalize surgical procedure times prior to hypothesis testing using linear statistical models. Multiple-procedure surgeries may be modeled using the longest (statistically most important) component procedure and type of anesthesia.

Indirect estimation of the tectonic evolution of magnetic structures along the Indiavaí-Lucialva Shear Zone, Mato Grosso, Brazil

NASA Astrophysics Data System (ADS)

Louro, V. H.; Ribeiro, V. B.; Mantovani, M. S.; Geolit Team

2013-05-01

The Indiavaí-Lucialva Shear Zone (ILSZ) has a notorious cinematic standard, moving from SW to NE, juxtaposing the Santa Helena Granitic Batholith to the metavolcanosedimentary sets and orthogneisses from the Jauru Domain basement. Along the ILSZ, a sequence of magnetic anomalies of high interference, with each other, and varied polarities occurs, what suggests the presence of different lithologies or times of (re)crystallization of the ferromagnetic minerals from these magnetic structures. In its southernmost portion, the sequence of magnetic anomalies splits in two directions, SW and SE, with the first invading the limits of the Santa Helena batholith and, the latest, accompanying the ILSZ. This study aimed for the comprehension of complex tectonic setting of this region. It analyzed the set of anomalies estimating their lateral limits, depths and directions of total magnetization, with the Enhanced Horizontal Derivatives (EHD), its extrapolation for depth estimative (EHD-Depth), and through an iterative reduction to the magnetic pole, respectively. This procedure allowed the composition of initial models for further inversions of magnetic data which, results, indicate contrasts of magnetic susceptibility in sub-surface. Once known the approximated 3-D shape of the magnetic structures along the ILSZ, the total magnetization intensity of each anomaly was recovered, what consequently allowed, by vector subtraction, to estimate their individual remnant magnetization. The remnant magnetization's inclinations and declinations of the anomalies sources and their latitudes and longitudes permitted the calculus of their respective virtual magnetic paleopoles. When confronted with the South American paleopole wander path and the datings linked to this path, available in the literature, it was possible to have an indirect approximation of the age of (re)crystallization of each magnetic structure near the ILSZ. This procedure indicated an increasing of the ages of the structures from SE (1298 Ma) to NW (1439 Ma). The southwestern anomalies invading the Santa Helena batholith showed ages of approximately 1419 Ma, what allows to infer their allocation with the rest of the intrusion of the batholith.; Total magnetic field map of the region of the ILSZ, locating the studied anomalies, mineral occurences and tectonic limits.

40 CFR 98.455 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... § 98.455 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

40 CFR 98.155 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG...), a substitute data value for the missing parameter shall be used in the calculations, according to...

40 CFR 98.155 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG...), a substitute data value for the missing parameter shall be used in the calculations, according to...

40 CFR 98.35 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. Whenever a quality-assured value of a required parameter is... substitute data value for the missing parameter shall be used in the calculations. (a) For all units subject...

40 CFR 98.35 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. Whenever a quality-assured value of a required parameter is... substitute data value for the missing parameter shall be used in the calculations. (a) For all units subject...

40 CFR 98.155 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG...), a substitute data value for the missing parameter shall be used in the calculations, according to...

40 CFR 98.305 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... Use § 98.305 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

40 CFR 98.305 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... Use § 98.305 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

40 CFR 98.35 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. Whenever a quality-assured value of a required parameter is... substitute data value for the missing parameter shall be used in the calculations. (a) For all units subject...

40 CFR 98.455 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... § 98.455 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

40 CFR 98.455 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... § 98.455 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

40 CFR 98.305 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Use § 98.305 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

40 CFR 98.35 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. Whenever a quality-assured value of a required parameter is... substitute data value for the missing parameter shall be used in the calculations. (a) For all units subject...

40 CFR 98.305 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... Use § 98.305 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

40 CFR 98.155 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG...), a substitute data value for the missing parameter shall be used in the calculations, according to...

40 CFR 98.35 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. Whenever a quality-assured value of a required parameter is... substitute data value for the missing parameter shall be used in the calculations. (a) For all units subject...

40 CFR 98.155 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG...), a substitute data value for the missing parameter shall be used in the calculations, according to...

40 CFR 98.455 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... § 98.455 Procedures for estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations is required. Replace missing data, if needed, based on data from...

DOES MEDICARE SAVE LIVES?*

PubMed Central

Card, David; Dobkin, Carlos; Maestas, Nicole

2009-01-01

Health insurance characteristics shift at age 65 as most people become eligible for Medicare. We measure the impacts of these changes on patients who are admitted to hospitals through emergency departments for conditions with similar admission rates on weekdays and weekends. The age profiles of admissions and comorbidities for these patients are smooth at age 65, suggesting that the severity of illness is similar on either side of the Medicare threshold. In contrast, the number of procedures performed in hospitals and total list charges exhibit small but statistically significant discontinuities, implying that patients over 65 receive more services. We estimate a nearly 1-percentage-point drop in 7-day mortality for patients at age 65, equivalent to a 20% reduction in deaths for this severely ill patient group. The mortality gap persists for at least 9 months after admission. PMID:19920880

European breast cancer service screening outcomes: a first balance sheet of the benefits and harms.

PubMed

Paci, Eugenio; Broeders, Mireille; Hofvind, Solveig; Puliti, Donella; Duffy, Stephen William

2014-07-01

A recent comprehensive review has been carried out to quantify the benefits and harms of the European population-based mammographic screening programs. Five literature reviews were conducted on the basis of the observational published studies evaluating breast cancer mortality reduction, breast cancer overdiagnosis, and false-positive results. On the basis of the studies reviewed, the authors present a first estimate of the benefit and harm balance sheet. For every 1,000 women screened biennially from ages 50 to 51 years until ages 68 to 69 years and followed up until age 79 years, an estimated seven to nine breast cancer deaths are avoided, four cases are overdiagnosed, 170 women have at least one recall followed by noninvasive assessment with a negative result, and 30 women have at least one recall followed by invasive procedures yielding a negative result. The chance of a breast cancer death being avoided by population-based mammography screening of appropriate quality is more than that of overdiagnosis by screening. These outcomes should be communicated to women offered service screening in Europe. ©2014 American Association for Cancer Research.

Summary of the evidence of breast cancer service screening outcomes in Europe and first estimate of the benefit and harm balance sheet.

PubMed

Paci, Eugenio

2012-01-01

To construct a European 'balance sheet' of key outcomes of population-based mammographic breast cancer screening, to inform policy-makers, stakeholders and invited women. From the studies reviewed, the primary benefit of screening, breast cancer mortality reduction, was compared with the main harms, over-diagnosis and false-positive screening results (FPRs). Pooled estimates of breast cancer mortality reduction among invited women were 25% in incidence-based mortality studies and 31% in case-control studies (38% and 48% among women actually screened). Estimates of over-diagnosis ranged from 1% to 10% of the expected incidence in the absence of screening. The combined estimate of over-diagnosis for screened women, from European studies correctly adjusted for lead time and underlying trend, was 6.5%. For women undergoing 10 biennial screening tests, the estimated cumulative risk of a FPR followed by non-invasive assessment was 17%, and 3% having an invasive assessment. For every 1000 women screened biennially from age 50-51 until age 68-69 and followed up to age 79, an estimated seven to nine lives are saved, four cases are over-diagnosed, 170 women have at least one recall followed by non-invasive assessment with a negative result and 30 women have at least one recall followed by invasive procedures yielding a negative result. The chance of saving a woman's life by population-based mammographic screening of appropriate quality is greater than that of over-diagnosis. Service screening in Europe achieves a mortality benefit at least as great as the randomized controlled trials. These outcomes should be communicated to women offered service screening in Europe.

Capsule Endoscopy in the Assessment of Obscure Gastrointestinal Bleeding: An Economic Analysis

PubMed Central

Palimaka, S; Blackhouse, Gord; Goeree, Ron

2015-01-01

Background Small-bowel capsule endoscopy is a tool used to visualize the small bowel to identify the location of bleeds in obscure gastrointestinal bleeding (OGIB). Capsule endoscopy is currently funded in Ontario in cases where there has been a failure to identify a source of bleeding via conventional diagnostic procedures. In Ontario, capsule endoscopy is a diagnostic option for patients whose findings on esophagogastroduodenoscopy, colonoscopy, and push enteroscopy have been negative (i.e., the source of bleeding was not found). Objectives This economic analysis aims to estimate the budget impact of different rates of capsule endoscopy use as a complement to push enteroscopy procedures in patients aged 18 years and older. Data Sources Population-based administrative databases for Ontario were used to identify patients receiving push enteroscopy and small-bowel capsule endoscopy in the fiscal years 2008 to 2012. Review Methods A systematic literature search was performed to identify economic evaluations of capsule endoscopy for the investigation of OGIB. Studies were assessed for their methodological quality and their applicability to the Ontarian setting. An original budget impact analysis was performed using data from Ontarian administrative sources and published literature. The budget impact was estimated for different levels of use of capsule endoscopy as a complement to push enteroscopy due to the uncertain clinical utility of the capsule based on current clinical evidence. The analysis was conducted from the provincial public payer perspective. Results With varying rates of capsule endoscopy use, the budgetary impact spans from savings of $510,000,1 when no (0%) push enteroscopy procedures are complemented with capsule endoscopy, to $2,036,000, when all (100%) push enteroscopy procedures are complemented with capsule endoscopy. A scenario where 50% of push enteroscopy procedures are complemented with capsule endoscopy (expected use based on expert opinion) would result in additional expenditure of about $763,000. Limitations In the literature on OGIB, estimates of rebleeding rates after endoscopic procedures or spontaneous cessation rates are unreliable, with a lack of data. Rough estimates from expert consultation can provide an indication of expected additional use of capsule endoscopy; however, a wide range of capsule uses was explored. Conclusions The budgetary impact in the first year in Ontario of capsule endoscopy use to complement push enteroscopy procedures ranges from $510,000 in savings to an additional expenditure of $2,036,000 (at 0% and 100% push enteroscopy procedures complemented, respectively). The expected scenario of 50% of push enteroscopy procedures likely to benefit from the use of capsule endoscopy, based on expert opinion, would result in additional expenditures of $763,000 in the first year. PMID:26355732

Caesarean section greatly increases risk of scar endometriosis.

PubMed

Nominato, Nilo Sérgio; Prates, Luis Felipe Victor Spyer; Lauar, Isabela; Morais, Jaqueline; Maia, Laura; Geber, Selmo

2010-09-01

To estimate the incidence of scar endometriosis after different surgical procedures. A retrospective study of 72 patients diagnosed with scar endometriosis between 1978 and 2003 was performed. Patient age, site of endometriosis, previous operations, time-gap between last surgery and onset of symptoms, nodule characteristics, and recurrence were evaluated. Age ranged from 16 to 48 years. Location varied according to the previous surgery: 46 caesarean section, one hysterectomy, one in abdominal surgery, 19 episiotomy, one was a relapse and two pelvic floor procedures, two women with no previous surgery. The incidence of scar endometriosis after caesarean section was significantly higher than after episiotomy (0.2 and 0.06%, respectively: p<0.00001) with a relative risk of 3.3. Pain was the most frequent symptom. The mean time between surgery and onset of symptoms was 3.7 years. Our findings confirm that scar endometriosis is a rare condition and indicate, probably for the first time, that caesarean section greatly increases the risk of developing scar endometriosis. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Endoscopic Injection of Low Dose Triamcinolone: a Simple, Minimally Invasive and Effective Therapy for Interstitial Cystitis with Hunner Lesions.

PubMed

Funaro, Michael G; King, Alexandra N; Stern, Joel N H; Moldwin, Robert M; Bahlani, Sonia

2018-05-18

To investigate the efficacy of low dose triamcinolone injection for effectiveness and durability in interstitial cystitis/bladder pain syndrome (IC/BPS) patients with Hunner Lesions (HL). Clinical data from patients with HL who underwent endoscopic submucosal injection of triamcinolone were reviewed: Demographics, pre/post operative pain and nocturia scores, and long-term clinical outcomes were assessed. Duration of response was estimated by time to repeat procedure. Kaplan-Meier estimator was used to evaluate time to repeat procedure. 36 patients who received injections of triamcinolone between 2011 and 2015 were included. Median age±SD of patients was 61.5±12.0 years 23; 28 (77.8%) of patients were female and 8 (22.2%) were male. 26 patients (72.2%) received only 1 set of injections, 8 (22.2%) received 2 sets of injections, and 2 (5.56%) received 3 or more sets of injections. Average time between injections in those receiving more than one set of injections was 344.9 days (median: 313.5, range: 77-714). Pre-procedural pain scores were 8.3±1.2 (mean±SD) on Likert pain scale (0-10), and mean post-procedural pain scores at approximately one month were 3.8±2.2 p<0.001. Mean pre-procedural nocturia bother scores were 7.5±2.0 and mean post-procedural nocturia bother scores were 5.1±2.5) p<0.001. Endoscopic submucosal injection of low dose triamcinolone in IC/BPS patients with HL is an effective and durable adjunct to existing treatment modalities. This approach is associated with low morbidity and can be performed on an outpatient basis. Copyright © 2018. Published by Elsevier Inc.

[Impact of 3 years of contract implementation on the quality of cataract surgery].

PubMed

Begiristain, J; Elizalde, B; Ibarluzea, J; Mendicute, J; Sola, C

1999-01-01

To assess the adequacy to clinical practice of cataract procedures contracted in the Gipuzkoa Health Area (in public as well as concerted hospitals) from 1995. A second aim is to identify the achievements obtained three years after its implementation comparing the data with those of 1994, a year before. Before its implementation a multidisciplinar team established the number of surgical procedures to be contracted each year by age and sex, as well as the technical and quality conditions (out-patient surgery, loco-regional anaesthetic, facoemulsification, etc.). Data used for the assessment: Cataracts Registry of the Ophthalmologic Unit, Patient Management Categories and surgical waiting lists. During the period studied, 8,073 cataract operations were performed, 9% higher than expected. The distribution by age and sex was as estimated. Technical and quality standards were fulfilled, except for the surgical waiting list, in at least 75% of the procedures. The surgical technique mainly used was facoenmulsification, increasing from 15% in 1994 to 76.5% in 1997. The contracting of cataract surgery has allowed the assessment, reordering, and establishment of standards of care for all the professionals involved in the process. There were improvements in clinical practice during the period studied. This has given raise to the homogenisation of care in all the units following technical and quality standards, meaning better equity for the patients in need of the procedure.

A Comparison of Ambulatory Surgery Center Production Costs and Medicare Payments: Evidence on Colonoscopy and Endoscopy.

PubMed

Mitchell, Jean M; Carey, Kathleen

2016-02-01

Ambulatory surgery centers (ASCs) are freestanding facilities that specialize in surgical and diagnostic procedures that do not require an overnight stay. While it is generally assumed that ASCs are less costly than hospital outpatient surgery departments, there is sparse empirical evidence regarding their relative production costs. To estimate ASC production costs using financial and claims records for procedures performed by surgery centers that specialize in gastroenterology procedures (colonoscopy and endoscopy). We estimate production costs in ASCs that specialize in gastroenterology procedures using financial cost and patient discharge data from Pennsylvania for the time period 2004-2013. We focus on the 2 primary procedures (colonoscopies and endoscopies) performed at each ASC. We use our estimates to predict average costs for each procedure and then compare predicted costs to Medicare ACS payments for these procedures. Comparisons of the costs of each procedure with 2013 national Medicare ASC payment rates suggest that Medicare payments exceed production costs for both colonoscopy and endoscopy. This study demonstrated that it is feasible to estimate production costs for procedures performed in freestanding surgery centers. The procedure-specific cost estimates can then be compared with ASC payment rates to ascertain if payments are aligned with costs. This approach can serve as an evaluation template for CMS and private insurers who are concerned that ASC facility payments for specific procedures may be excessive.

Single center experience in selecting the laparoscopic Frey procedure for chronic pancreatitis.

PubMed

Tan, Chun-Lu; Zhang, Hao; Li, Ke-Zhou

2015-11-28

To share our experience regarding the laparoscopic Frey procedure for chronic pancreatitis (CP) and patient selection. All consecutive patients undergoing duodenum-preserving pancreatic head resection from July 2013 to July 2014 were reviewed and those undergoing the Frey procedure for CP were included in this study. Data on age, gender, body mass index (BMI), American Society of Anesthesiologists score, imaging findings, inflammatory index (white blood cells, interleukin (IL)-6, and C-reaction protein), visual analogue score score during hospitalization and outpatient visit, history of CP, operative time, estimated blood loss, and postoperative data (postoperative mortality and morbidity, postoperative length of hospital stay) were obtained for patients undergoing laparoscopic surgery. The open surgery cases in this study were analyzed for risk factors related to extensive bleeding, which was the major reason for conversion during the laparoscopic procedure. Age, gender, etiology, imaging findings, amylase level, complications due to pancreatitis, functional insufficiency, and history of CP were assessed in these patients. Nine laparoscopic and 37 open Frey procedures were analyzed. Of the 46 patients, 39 were male (85%) and seven were female (16%). The etiology of CP was alcohol in 32 patients (70%) and idiopathic in 14 patients (30%). Stones were found in 38 patients (83%). An inflammatory mass was found in five patients (11%). The time from diagnosis of CP to the Frey procedure was 39 ± 19 (9-85) mo. The BMI of patients in the laparoscopic group was 20.4 ± 1.7 (17.8-22.4) kg/m(2) and was 20.6 ± 2.9 (15.4-27.7) kg/m(2) in the open group. All patients required analgesic medication for abdominal pain. Frequent acute pancreatitis or severe abdominal pain due to acute exacerbation occurred in 20 patients (43%). Pre-operative complications due to pancreatitis were observed in 18 patients (39%). Pancreatic functional insufficiency was observed in 14 patients (30%). Two laparoscopic patients (2/9) were converted. In seven successful laparoscopic cases, the mean operative time was 323 ± 29 (290-370) min. Estimated intra-operative blood loss was 57 ± 14 (40-80) mL. One patient had a postoperative complication, and no mortality was observed. Postoperative hospital stay was 7 ± 2 (5-11) d. Multiple linear regression analysis of 37 open Frey procedures showed that an inflammatory mass (P < 0.001) and acute exacerbation (P < 0.001) were risk factors for intra-operative blood loss. The laparoscopic Frey procedure for CP is feasible but only suitable in carefully selected patients.

The Pediatric Anesthesiology Workforce: Projecting Supply and Trends 2015-2035.

PubMed

Muffly, Matthew K; Singleton, Mark; Agarwal, Rita; Scheinker, David; Miller, Daniel; Muffly, Tyler M; Honkanen, Anita

2018-02-01

A workforce analysis was conducted to predict whether the projected future supply of pediatric anesthesiologists is balanced with the requirements of the inpatient pediatric population. The specific aims of our analysis were to (1) project the number of pediatric anesthesiologists in the future workforce; (2) project pediatric anesthesiologist-to-pediatric population ratios (0-17 years); (3) project the mean number of inpatient pediatric procedures per pediatric anesthesiologist; and (4) evaluate the effect of alternative projections of individual variables on the model projections through 2035. The future number of pediatric anesthesiologists is determined by the current supply, additions to the workforce, and departures from the workforce. We previously compiled a database of US pediatric anesthesiologists in the base year of 2015. The historical linear growth rate for pediatric anesthesiology fellowship positions was determined using the Accreditation Council for Graduate Medical Education Data Resource Books from 2002 to 2016. The future number of pediatric anesthesiologists in the workforce was projected given growth of pediatric anesthesiology fellowship positions at the historical linear growth rate, modeling that 75% of graduating fellows remain in the pediatric anesthesiology workforce, and anesthesiologists retire at the current mean retirement age of 64 years old. The baseline model projections were accompanied by age- and gender-adjusted anesthesiologist supply, and sensitivity analyses of potential variations in fellowship position growth, retirement, pediatric population, inpatient surgery, and market share to evaluate the effect of each model variable on the baseline model. The projected ratio of pediatric anesthesiologists to pediatric population was determined using the 2012 US Census pediatric population projections. The projected number of inpatient pediatric procedures per pediatric anesthesiologist was determined using the Kids' Inpatient Database historical data to project the future number of inpatient procedures (including out of operating room procedures). In 2015, there were 5.4 pediatric anesthesiologists per 100,000 pediatric population and a mean (±standard deviation [SD]) of 262 ±8 inpatient procedures per pediatric anesthesiologist. If historical trends continue, there will be an estimated 7.4 pediatric anesthesiologists per 100,000 pediatric population and a mean (±SD) 193 ±6 inpatient procedures per pediatric anesthesiologist in 2035. If pediatric anesthesiology fellowship positions plateau at 2015 levels, there will be an estimated 5.7 pediatric anesthesiologists per 100,000 pediatric population and a mean (±SD) 248 ±7 inpatient procedures per pediatric anesthesiologist in 2035. If historical trends continue, the growth in pediatric anesthesiologist supply may exceed the growth in both the pediatric population and inpatient procedures in the 20-year period from 2015 to 2035.

Single center experience in selecting the laparoscopic Frey procedure for chronic pancreatitis

PubMed Central

Tan, Chun-Lu; Zhang, Hao; Li, Ke-Zhou

2015-01-01

AIM: To share our experience regarding the laparoscopic Frey procedure for chronic pancreatitis (CP) and patient selection. METHODS: All consecutive patients undergoing duodenum-preserving pancreatic head resection from July 2013 to July 2014 were reviewed and those undergoing the Frey procedure for CP were included in this study. Data on age, gender, body mass index (BMI), American Society of Anesthesiologists score, imaging findings, inflammatory index (white blood cells, interleukin (IL)-6, and C-reaction protein), visual analogue score score during hospitalization and outpatient visit, history of CP, operative time, estimated blood loss, and postoperative data (postoperative mortality and morbidity, postoperative length of hospital stay) were obtained for patients undergoing laparoscopic surgery. The open surgery cases in this study were analyzed for risk factors related to extensive bleeding, which was the major reason for conversion during the laparoscopic procedure. Age, gender, etiology, imaging findings, amylase level, complications due to pancreatitis, functional insufficiency, and history of CP were assessed in these patients. RESULTS: Nine laparoscopic and 37 open Frey procedures were analyzed. Of the 46 patients, 39 were male (85%) and seven were female (16%). The etiology of CP was alcohol in 32 patients (70%) and idiopathic in 14 patients (30%). Stones were found in 38 patients (83%). An inflammatory mass was found in five patients (11%). The time from diagnosis of CP to the Frey procedure was 39 ± 19 (9-85) mo. The BMI of patients in the laparoscopic group was 20.4 ± 1.7 (17.8-22.4) kg/m2 and was 20.6 ± 2.9 (15.4-27.7) kg/m2 in the open group. All patients required analgesic medication for abdominal pain. Frequent acute pancreatitis or severe abdominal pain due to acute exacerbation occurred in 20 patients (43%). Pre-operative complications due to pancreatitis were observed in 18 patients (39%). Pancreatic functional insufficiency was observed in 14 patients (30%). Two laparoscopic patients (2/9) were converted. In seven successful laparoscopic cases, the mean operative time was 323 ± 29 (290-370) min. Estimated intra-operative blood loss was 57 ± 14 (40-80) mL. One patient had a postoperative complication, and no mortality was observed. Postoperative hospital stay was 7 ± 2 (5-11) d. Multiple linear regression analysis of 37 open Frey procedures showed that an inflammatory mass (P < 0.001) and acute exacerbation (P < 0.001) were risk factors for intra-operative blood loss. CONCLUSION: The laparoscopic Frey procedure for CP is feasible but only suitable in carefully selected patients. PMID:26640341

Percutaneous cryoablation of metastatic renal cell carcinoma for local tumor control: feasibility, outcomes, and estimated cost-effectiveness for palliation.

PubMed

Bang, Hyun J; Littrup, Peter J; Goodrich, Dylan J; Currier, Brandt P; Aoun, Hussein D; Heilbrun, Lance K; Vaishampayan, Ulka; Adam, Barbara; Goodman, Allen C

2012-06-01

To assess complications, local tumor recurrences, overall survival (OS), and estimates of cost-effectiveness for multisite cryoablation (MCA) of oligometastatic renal cell carcinoma (RCC). A total of 60 computed tomography- and/or ultrasound-guided percutaneous MCA procedures were performed on 72 tumors in 27 patients (three women and 24 men). Average patient age was 63 years. Tumor location was grouped according to common metastatic sites. Established surgical selection criteria graded patient status. Median OS was determined by Kaplan-Meier method and defined life-years gained (LYGs). Estimates of MCA costs per LYG were compared with established values for systemic therapies. Total number of tumors and cryoablation procedures for each anatomic site are as follows: nephrectomy bed, 11 and 11; adrenal gland, nine and eight; paraaortic, seven and six; lung, 14 and 13; bone, 13 and 13; superficial, 12 and nine; intraperitoneal, five and three; and liver, one and one. A mean of 2.2 procedures per patient were performed, with a median clinical follow-up of 16 months. Major complication and local recurrence rates were 2% (one of 60) and 3% (two of 72), respectively. No patients were graded as having good surgical risk, but median OS was 2.69 years, with an estimated 5-year survival rate of 27%. Cryoablation remained cost-effective with or without the presence of systemic therapies according to historical cost comparisons, with an adjunctive cost-effectiveness ratio of $28,312-$59,554 per LYG. MCA was associated with very low morbidity and local tumor recurrence rates for all anatomic sites, with apparent increased OS. Even as an adjunct to systemic therapies, MCA appeared cost-effective for palliation of oligometastatic RCC. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

An automatic calibration procedure for remote eye-gaze tracking systems.

PubMed

Model, Dmitri; Guestrin, Elias D; Eizenman, Moshe

2009-01-01

Remote gaze estimation systems use calibration procedures to estimate subject-specific parameters that are needed for the calculation of the point-of-gaze. In these procedures, subjects are required to fixate on a specific point or points at specific time instances. Advanced remote gaze estimation systems can estimate the optical axis of the eye without any personal calibration procedure, but use a single calibration point to estimate the angle between the optical axis and the visual axis (line-of-sight). This paper presents a novel automatic calibration procedure that does not require active user participation. To estimate the angles between the optical and visual axes of each eye, this procedure minimizes the distance between the intersections of the visual axes of the left and right eyes with the surface of a display while subjects look naturally at the display (e.g., watching a video clip). Simulation results demonstrate that the performance of the algorithm improves as the range of viewing angles increases. For a subject sitting 75 cm in front of an 80 cm x 60 cm display (40" TV) the standard deviation of the error in the estimation of the angles between the optical and visual axes is 0.5 degrees.

40 CFR 98.285 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.283(b), a complete record of all...) For each missing value of the monthly carbon content of petroleum coke, the substitute data value...

40 CFR 98.415 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable (e.g., if a meter malfunctions), a substitute data value for the missing parameter shall be used...

40 CFR 98.315 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.313(b), a complete record of all... substitute data value for the missing parameter shall be used in the calculations as specified in the...

40 CFR 98.415 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable (e.g., if a meter malfunctions), a substitute data value for the missing parameter shall be used...

40 CFR 98.285 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.283(b), a complete record of all...) For each missing value of the monthly carbon content of petroleum coke, the substitute data value...

40 CFR 98.285 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.283(b), a complete record of all...) For each missing value of the monthly carbon content of petroleum coke, the substitute data value...

40 CFR 98.245 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. For missing feedstock flow rates, product flow rates, and carbon contents, use the same procedures as for missing flow rates and carbon contents for fuels as specified in § 98.35. ...

40 CFR 98.315 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.313(b), a complete record of all... substitute data value for the missing parameter shall be used in the calculations as specified in the...

40 CFR 98.315 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.313(b), a complete record of all... substitute data value for the missing parameter shall be used in the calculations as specified in the...

40 CFR 98.245 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. For missing feedstock flow rates, product flow rates, and carbon contents, use the same procedures as for missing flow rates and carbon contents for fuels as specified in § 98.35. ...

40 CFR 98.315 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.313(b), a complete record of all... substitute data value for the missing parameter shall be used in the calculations as specified in the...

40 CFR 98.245 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. For missing feedstock flow rates, product flow rates, and carbon contents, use the same procedures as for missing flow rates and carbon contents for fuels as specified in § 98.35. ...

40 CFR 98.285 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.283(b), a complete record of all...) For each missing value of the monthly carbon content of petroleum coke, the substitute data value...

40 CFR 98.285 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. For the petroleum coke input procedure in § 98.283(b), a complete record of all...) For each missing value of the monthly carbon content of petroleum coke, the substitute data value...

40 CFR 98.245 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. For missing feedstock and product flow rates, use the same procedures as for missing... contents and missing molecular weights for fuels as specified in § 98.35(b)(1). For missing flare data...

40 CFR 98.195 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. For the procedure in § 98.193(b)(1), a complete record of all measured parameters... all available process data or data used for accounting purposes. (b) For missing values related to the...

40 CFR 98.415 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable (e.g., if a meter malfunctions), a substitute data value for the missing parameter shall be used...

40 CFR 98.415 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable (e.g., if a meter malfunctions), a substitute data value for the missing parameter shall be used...

40 CFR 98.415 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... Procedures for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable (e.g., if a meter malfunctions), a substitute data value for the missing parameter shall be used...

40 CFR 98.245 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. For missing feedstock flow rates, product flow rates, and carbon contents, use the same procedures as for missing flow rates and carbon contents for fuels as specified in § 98.35. ...

A Comparison of a Bayesian and a Maximum Likelihood Tailored Testing Procedure.

ERIC Educational Resources Information Center

McKinley, Robert L.; Reckase, Mark D.

A study was conducted to compare tailored testing procedures based on a Bayesian ability estimation technique and on a maximum likelihood ability estimation technique. The Bayesian tailored testing procedure selected items so as to minimize the posterior variance of the ability estimate distribution, while the maximum likelihood tailored testing…

A Demographic Analysis of Suicide Among U.S. Navy Personnel

DTIC Science & Technology

1997-08-01

estimates of a Poisson- distributed variable according to the procedure described in Lilienfeld and Lilienfeld .27 Based on averaged age-specific rates of...n suicides, the total number of pairs will be n(n- 1)/2). The Knox method tests the null hypothesis that the event of a pair of suicides being close...significantly differ. It is likely, however, that the military’s required suicide prevention programs and psychological autopsies help to ascertain as

Costs of Clostridium difficile infection in pediatric operations: A propensity score-matching analysis.

PubMed

Kulaylat, Afif N; Rocourt, Dorothy V; Podany, Abigail B; Engbrecht, Brett W; Twilley, Marianne; Santos, Mary C; Cilley, Robert E; Hollenbeak, Christopher S; Dillon, Peter W

2017-05-01

The purpose of this analysis was to assess the burden of Clostridium difficile infection in the hospitalized pediatric surgical population and to characterize its influence on the costs of care. There were 313,664 patients age 1-18 years who underwent a general thoracic or abdominal procedure in the Kids' Inpatient Database during 2003, 2006, 2009, and 2012. Logistic regression was used to model factors associated with the development of C difficile infection. A propensity score-matching analysis was performed to evaluate the influence of C difficile infection on mortality, duration of stay, and costs in similar patient cohorts. Population weights were used to estimate the national excess burden of C difficile infection on these outcomes. The overall prevalence of C difficile infection in the sampled cohort was 0.30%, with an increasing trend of C difficile infection over time in non-children's hospitals (P < .001). C difficile infection was associated with younger age, nonelective procedures, increasing comorbidities, and urban teaching hospital status (P < .001). An estimated 1,438 children developed C difficile infection after operation. After propensity score matching, the mean excess duration of stay and costs attributable to C difficile infection were 5.8 days and $12,801 (P < .001), accounting for 8,295 days spent in the hospital and $18.4 million (2012 USD) in spending annually. C difficile infection is a relatively uncommon but costly complication after pediatric operative procedures. Given the increasing trend of C difficile infection among hospitalized surgical patients, there is substantial opportunity for reduction of inpatient burden and associated costs in this potentially preventable nosocomial infection. Copyright © 2016 Elsevier Inc. All rights reserved.

Statistical Cost Estimation in Higher Education: Some Alternatives.

ERIC Educational Resources Information Center

Brinkman, Paul T.; Niwa, Shelley

Recent developments in econometrics that are relevant to the task of estimating costs in higher education are reviewed. The relative effectiveness of alternative statistical procedures for estimating costs are also tested. Statistical cost estimation involves three basic parts: a model, a data set, and an estimation procedure. Actual data are used…

Partial report and other sampling procedures overestimate the duration of iconic memory.

PubMed

Appelman, I B

1980-03-01

In three experiments, subjects estimated the duration of a brief visual image (iconic memory) either directly by adjusting onset of a click to offset of the visual image, or indirectly with a Sperling partial report (sampling) procedure. The results indicated that partial report and other sampling procedures may reflect other brief phenomena along with iconic memory. First, the partial report procedure yields a greater estimate of the duration of iconic memory than the more direct click method. Second, the partial report estimate of the duration of iconic memory is affected if the subject is required to simultaneously retain a list of distractor items (memory load), while the click method estimate of the duration of iconic memory is not affected by a memory load. Finally, another sampling procedure based on visual cuing yields different estimates of the duration of iconic memory depending on how many items are cued. It was concluded that partial report and other sampling procedures overestimate the duration of iconic memory.

40 CFR 98.195 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. For the procedure in § 98.193(b)(1), a complete record of all measured parameters... available process data or data used for accounting purposes. (b) For missing values related to the CaO and...

40 CFR 98.195 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. For the procedure in § 98.193(b)(1), a complete record of all measured parameters... available process data or data used for accounting purposes. (b) For missing values related to the CaO and...

40 CFR 98.195 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. For the procedure in § 98.193(b)(2), a complete record of all measured parameters... process data or data used for accounting purposes. (b) For missing values related to the CaO and MgO...

40 CFR 98.195 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. For the procedure in § 98.193(b)(1), a complete record of all measured parameters... available process data or data used for accounting purposes. (b) For missing values related to the CaO and...

UK population norms for the modified dental anxiety scale with percentile calculator: adult dental health survey 2009 results

PubMed Central

2013-01-01

Background A recent UK population survey of oral health included questions to assess dental anxiety to provide mean and prevalence estimates of this important psychological construct. Methods A two-stage cluster sample was used for the survey across England, Wales, and Northern Ireland. The survey took place between October-December 2009, and January-April 2010. All interviewers were trained on survey procedures. Within the 7,233 households sampled there were 13,509 adults who were asked to participate in the survey and 11,382 participated (84%). Results The scale was reliable and showed some evidence of unidimensionality. Estimated proportion of participants with high dental anxiety (cut-off score = 19) was 11.6%. Percentiles and confidence intervals were presented and can be estimated for individual patients across various age ranges and gender using an on-line tool. Conclusions The largest reported data set on the MDAS from a representative UK sample was presented. The scale’s psychometrics is supportive for the routine assessment of patient dental anxiety to compare against a number of major demographic groups categorised by age and sex. Practitioners within the UK have a resource to estimate the rarity of a particular patient’s level of dental anxiety, with confidence intervals, when using the on-line percentile calculator. PMID:23799962

Minilaparotomy with a gasless laparoscopic-assisted procedure by abdominal wall lifting for ileorectal anastomosis in patients with slow transit constipation.

PubMed

Tomita, Ryouichi; Fujisak, Shigeru

2009-01-01

Total colectomy with ileorectal anastomosis (IRA) is the most widely adopted procedure. The aim of this study was to introduce a minimally invasive procedure, i.e., minilaparotomy with laparoscopic-assisted procedure, by abdominal wall lifting for IRA in patients with slow transit constipation (STC). Six STC patients (6 women, aged 40-69 years, mean age 56.3 years) underwent minilaparotomy with gasless laparoscopic-assisted approach by abdominal wall lifting for IRA. The present procedure involved a 7-cm lower abdominal median incision made at the beginning of the operation. 12 mm ports were also placed in the right and left upper abdominal quadrant positions. The upper abdominal wall was lifted by a subcutaneous Kirshner wire. The small wound was pulled upward and/or laterally by retractors (abdominal lifting) and conventional surgical instruments were used through the wound. Occasionally laparoscopic assistance was employed. The terminal ileum with total colon was brought out through the small wound and transected, approximately 5 cm from the ileocecal valve. The colon was also resected at the level of promontrium. Then, IRA was performed in the instruments. The total surgical time was 197.7 +/- 33.9 min and the mean estimated blood loss was 176.8 +/- 42.2 ml. There was no surgical mortality. Post-operative hospitalization was 8.1 +/- 2.1 days. Six months after surgery, they defecated 1.8 +/- 2.1 times daily, have no abdominal distension, pain, and incontinence. The patients also take no laxatives. All subjects were satisfied with this procedure. Minilaparotomy with gasless laparoscopic-assisted IRA by abdominal wall lifting could be a safe and efficient technique in the treatment of STC.

Effects of Estimation Bias on Multiple-Category Classification with an IRT-Based Adaptive Classification Procedure

ERIC Educational Resources Information Center

Yang, Xiangdong; Poggio, John C.; Glasnapp, Douglas R.

2006-01-01

The effects of five ability estimators, that is, maximum likelihood estimator, weighted likelihood estimator, maximum a posteriori, expected a posteriori, and Owen's sequential estimator, on the performances of the item response theory-based adaptive classification procedure on multiple categories were studied via simulations. The following…

Improvements in estimating proportions of objects from multispectral data

NASA Technical Reports Server (NTRS)

Horwitz, H. M.; Hyde, P. D.; Richardson, W.

1974-01-01

Methods for estimating proportions of objects and materials imaged within the instantaneous field of view of a multispectral sensor were developed further. Improvements in the basic proportion estimation algorithm were devised as well as improved alien object detection procedures. Also, a simplified signature set analysis scheme was introduced for determining the adequacy of signature set geometry for satisfactory proportion estimation. Averaging procedures used in conjunction with the mixtures algorithm were examined theoretically and applied to artificially generated multispectral data. A computationally simpler estimator was considered and found unsatisfactory. Experiments conducted to find a suitable procedure for setting the alien object threshold yielded little definitive result. Mixtures procedures were used on a limited amount of ERTS data to estimate wheat proportion in selected areas. Results were unsatisfactory, partly because of the ill-conditioned nature of the pure signature set.

Laparoscopic Choledochoduodenostomy.

PubMed

Cuendis-Velázquez, Adolfo; E Trejo-Ávila, Mario; Rosales-Castañeda, Enrique; Cárdenas-Lailson, Eduardo; E Rojano-Rodríguez, Martin; Romero-Loera, Sujey; A Sanjuan-Martínez, Carlos; Moreno-Portillo, Mucio

Today's options for biliary bypass procedures, for difficult choledocholithiasis, range from open surgery to laparo-endoscopic hybrid procedures. The aim of this study was to analyze the outcomes of patients with difficult choledocholithiasis treated with laparoscopic choledochoduodenostomy. We performed a prospective observational study from March 2011 to June 2016. We included patients with difficult common bile duct stones (recurrent or unresolved by ERCP) in which a biliary bypass procedure was required. We performed a laparoscopic bile duct exploration with choledochoduodenostomy and intraoperative cholangioscopy. A total of 19 patients were included. We found female predominance (78.9%), advanced mean age (72.4±12 years) and multiple comorbidities. Most patients with previous episodes of choledocholitiasis or cholangitis, mode 1 (min-max: 1-7). Mean common bile duct diameter 24.9±7mm. Mean operative time 218.5±74min, estimated blood loss 150 (30-600)mL, resume of oral intake 3.2±1 days, postoperative length of stay 4.9±2 days. We found a median of 18 (12-32) months of follow-up. All patients with normalization of liver enzymes during follow-up. One patient presented with sump syndrome and one patient died due to nosocomial pneumonia. Laparoscopic choledochoduodenostomy with intraoperative cholangioscopy seems to be safe and effective treatment for patients with difficult common bile duct stones no resolved by endoscopic procedures. This procedure is a good option for patients with advanced age and multiple comorbidities. We offer all the advantages of minimally invasive surgery to these patients. Copyright © 2017 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

Enrollment in HIV Care Two Years after HIV Diagnosis in the Kingdom of Swaziland: An Evaluation of a National Program of New Linkage Procedures.

PubMed

MacKellar, Duncan A; Williams, Daniel; Storer, Nosipho; Okello, Velephi; Azih, Charles; Drummond, Jennifer; Nuwagaba-Biribonwoha, Harriet; Preko, Peter; Morgan, Rebecca L; Dlamini, Makhosazana; Byrd, Johnita; Agolory, Simon; Baughman, Andrew L; McNairy, Margaret L; Sahabo, Ruben; Ehrenkranz, Peter

2016-01-01

To improve early enrollment in HIV care, the Swaziland Ministry of Health implemented new linkage procedures for persons HIV diagnosed during the Soka Uncobe male circumcision campaign (SOKA, 2011-2012) and the Swaziland HIV Incidence Measurement Survey (SHIMS, 2011). Abstraction of clinical records and telephone interviews of a retrospective cohort of HIV-diagnosed SOKA and SHIMS clients were conducted in 2013-2014 to evaluate compliance with new linkage procedures and enrollment in HIV care at 92 facilities throughout Swaziland. Of 1,105 clients evaluated, within 3, 12, and 24 months of diagnosis, an estimated 14.0%, 24.3%, and 37.0% enrolled in HIV care, respectively, after adjusting for lost to follow-up and non-response. Kaplan-Meier functions indicated lower enrollment probability among clients 14-24 (P = 0.0001) and 25-29 (P = 0.001) years of age compared with clients >35 years of age. At 69 facilities to which clients were referred for HIV care, compliance with new linkage procedures was low: referral forms were located for less than half (46.8%) of the clients, and few (9.6%) were recorded in the appointment register or called either before (0.3%) or after (4.9%) their appointment. Of over one thousand clients newly HIV diagnosed in Swaziland in 2011 and 2012, few received linkage services in accordance with national procedures and most had not enrolled in HIV care two years after their diagnosis. Our findings are a call to action to improve linkage services and early enrollment in HIV care in Swaziland.

Prevalence of Total Hip and Knee Replacement in the United States.

PubMed

Maradit Kremers, Hilal; Larson, Dirk R; Crowson, Cynthia S; Kremers, Walter K; Washington, Raynard E; Steiner, Claudia A; Jiranek, William A; Berry, Daniel J

2015-09-02

Descriptive epidemiology of total joint replacement procedures is limited to annual procedure volumes (incidence). The prevalence of the growing number of individuals living with a total hip or total knee replacement is currently unknown. Our objective was to estimate the prevalence of total hip and total knee replacement in the United States. Prevalence was estimated using the counting method by combining historical incidence data from the National Hospital Discharge Survey and the Healthcare Cost and Utilization Project (HCUP) State Inpatient Databases from 1969 to 2010 with general population census and mortality counts. We accounted for relative differences in mortality rates between those who have had total hip or knee replacement and the general population. The 2010 prevalence of total hip and total knee replacement in the total U.S. population was 0.83% and 1.52%, respectively. Prevalence was higher among women than among men and increased with age, reaching 5.26% for total hip replacement and 10.38% for total knee replacement at eighty years. These estimates corresponded to 2.5 million individuals (1.4 million women and 1.1 million men) with total hip replacement and 4.7 million individuals (3.0 million women and 1.7 million men) with total knee replacement in 2010. Secular trends indicated a substantial rise in prevalence over time and a shift to younger ages. Around 7 million Americans are living with a hip or knee replacement, and consequently, in most cases, are mobile, despite advanced arthritis. These numbers underscore the substantial public health impact of total hip and knee arthroplasties. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Estimating Surgical Procedure Times Using Anesthesia Billing Data and Operating Room Records.

PubMed

Burgette, Lane F; Mulcahy, Andrew W; Mehrotra, Ateev; Ruder, Teague; Wynn, Barbara O

2017-02-01

The median time required to perform a surgical procedure is important in determining payment under Medicare's physician fee schedule. Prior studies have demonstrated that the current methodology of using physician surveys to determine surgical times results in overstated times. To measure surgical times more accurately, we developed and validated a methodology using available data from anesthesia billing data and operating room (OR) records. We estimated surgical times using Medicare 2011 anesthesia claims and New York Statewide Planning and Research Cooperative System 2011 OR times. Estimated times were validated using data from the National Surgical Quality Improvement Program. We compared our time estimates to those used by Medicare in the fee schedule. We estimate surgical times via piecewise linear median regression models. Using 3.0 million observations of anesthesia and OR times, we estimated surgical time for 921 procedures. Correlation between these time estimates and directly measured surgical time from the validation database was 0.98. Our estimates of surgical time were shorter than the Medicare fee schedule estimates for 78 percent of procedures. Anesthesia and OR times can be used to measure surgical time and thereby improve the payment for surgical procedures in the Medicare fee schedule. © Health Research and Educational Trust.

Empirical best linear unbiased prediction method for small areas with restricted maximum likelihood and bootstrap procedure to estimate the average of household expenditure per capita in Banjar Regency

NASA Astrophysics Data System (ADS)

Aminah, Agustin Siti; Pawitan, Gandhi; Tantular, Bertho

2017-03-01

So far, most of the data published by Statistics Indonesia (BPS) as data providers for national statistics are still limited to the district level. Less sufficient sample size for smaller area levels to make the measurement of poverty indicators with direct estimation produced high standard error. Therefore, the analysis based on it is unreliable. To solve this problem, the estimation method which can provide a better accuracy by combining survey data and other auxiliary data is required. One method often used for the estimation is the Small Area Estimation (SAE). There are many methods used in SAE, one of them is Empirical Best Linear Unbiased Prediction (EBLUP). EBLUP method of maximum likelihood (ML) procedures does not consider the loss of degrees of freedom due to estimating β with β ^. This drawback motivates the use of the restricted maximum likelihood (REML) procedure. This paper proposed EBLUP with REML procedure for estimating poverty indicators by modeling the average of household expenditures per capita and implemented bootstrap procedure to calculate MSE (Mean Square Error) to compare the accuracy EBLUP method with the direct estimation method. Results show that EBLUP method reduced MSE in small area estimation.

The numerical evaluation of maximum-likelihood estimates of the parameters for a mixture of normal distributions from partially identified samples

NASA Technical Reports Server (NTRS)

Walker, H. F.

1976-01-01

Likelihood equations determined by the two types of samples which are necessary conditions for a maximum-likelihood estimate were considered. These equations suggest certain successive approximations iterative procedures for obtaining maximum likelihood estimates. The procedures, which are generalized steepest ascent (deflected gradient) procedures, contain those of Hosmer as a special case.

Procedure M - A framework for stratified area estimation. [in multispectral scanner data processing

NASA Technical Reports Server (NTRS)

Kauth, R. J.; Cicone, R. C.; Malila, W. A.

1980-01-01

This paper describes Procedure M, a systematic approach to processing multispectral scanner data for classification and acreage estimation. A general discussion of the rationale and development of the procedure is given in the context of large-area agricultural applications. Specific examples are given in the form of test results on acreage estimation of spring small grains.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR CALCULATING INGESTION EXPOSURE ESTIMATING INGESTION EXPOSURE, THE INDIRECT METHOD OF EXPOSURE ESTIMATION (IIT-A-7.0)

EPA Science Inventory

The purpose of this SOP is to describe the procedures undertaken for calculating ingestion exposure using the indirect method of exposure estimation. This SOP uses This SOP uses data that have been properly coded and certified with appropriate QA/QC procedures by the University ...

Notes on testing equality and interval estimation in Poisson frequency data under a three-treatment three-period crossover trial.

PubMed

Lui, Kung-Jong; Chang, Kuang-Chao

2016-10-01

When the frequency of event occurrences follows a Poisson distribution, we develop procedures for testing equality of treatments and interval estimators for the ratio of mean frequencies between treatments under a three-treatment three-period crossover design. Using Monte Carlo simulations, we evaluate the performance of these test procedures and interval estimators in various situations. We note that all test procedures developed here can perform well with respect to Type I error even when the number of patients per group is moderate. We further note that the two weighted-least-squares (WLS) test procedures derived here are generally preferable to the other two commonly used test procedures in the contingency table analysis. We also demonstrate that both interval estimators based on the WLS method and interval estimators based on Mantel-Haenszel (MH) approach can perform well, and are essentially of equal precision with respect to the average length. We use a double-blind randomized three-treatment three-period crossover trial comparing salbutamol and salmeterol with a placebo with respect to the number of exacerbations of asthma to illustrate the use of these test procedures and estimators. © The Author(s) 2014.

Contraceptive prescriptions for US servicewomen, 2008-2013.

PubMed

Witkop, Catherine T; Webber, Bryant J; Chu, Kasi M; Clark, Leslie L

2017-07-01

To determine the proportion and characteristics of US servicewomen who were prescribed contraception between 2008 and 2013 and to estimate the prevalence of contraceptive utilization among women who deployed during the surveillance period. This is a descriptive study of all servicewomen of child-bearing potential serving in the active component of the US armed forces at any time between 2008 and 2013. We estimated contraceptive utilization status using pharmacy, procedural and diagnostic codes as recorded in the Defense Medical Surveillance System and Pharmacy Data Transaction Service. Estimates of contraceptive utilization were compared by demographic and military variables, including deployment status. Poisson regression with robust error variance was used to estimate adjusted prevalence ratios and 95% confidence intervals. Among eligible servicewomen (N=375,847), 68.7% received at least one form of contraception during the surveillance period. Contraceptive methods included short acting only (55.6%), long-acting (11.9%), permanent (1.0%) and barrier methods (0.2%). An additional 8.2% received counseling services only without an associated procedure or prescription. After adjusting by several demographic variables, receipt of contraception was highest among women aged 25-29 years and lowest among those aged 17-19 and 45-49 years. Receipt of any contraception was similar across racial/ethnic groups, although Hispanic and black, non-Hispanic women were more likely to receive long-acting reversible contraception. Of those who deployed (N=131,597), 53.6% received contraception before or during their deployment, with 7.9% using long-acting contraception. US servicewomen utilize contraception at high levels, with few demographic disparities. Gaps still exist, especially among the youngest women and around the time of deployment. US servicewomen are prescribed contraception at high levels, but utilization is lower in the youngest servicewomen and around the time of deployment. Such data provide opportunities for development and evaluation of interventions designed to improve access to contraceptive services for all servicewomen and to reduce the rate of unintended pregnancy. Published by Elsevier Inc.

Estimating parasitic sea lamprey abundance in Lake Huron from heterogenous data sources

USGS Publications Warehouse

Young, Robert J.; Jones, Michael L.; Bence, James R.; McDonald, Rodney B.; Mullett, Katherine M.; Bergstedt, Roger A.

2003-01-01

The Great Lakes Fishery Commission uses time series of transformer, parasitic, and spawning population estimates to evaluate the effectiveness of its sea lamprey (Petromyzon marinus) control program. This study used an inverse variance weighting method to integrate Lake Huron sea lamprey population estimates derived from two estimation procedures: 1) prediction of the lake-wide spawning population from a regression model based on stream size and, 2) whole-lake mark and recapture estimates. In addition, we used a re-sampling procedure to evaluate the effect of trading off sampling effort between the regression and mark-recapture models. Population estimates derived from the regression model ranged from 132,000 to 377,000 while mark-recapture estimates of marked recently metamorphosed juveniles and parasitic sea lampreys ranged from 536,000 to 634,000 and 484,000 to 1,608,000, respectively. The precision of the estimates varied greatly among estimation procedures and years. The integrated estimate of the mark-recapture and spawner regression procedures ranged from 252,000 to 702,000 transformers. The re-sampling procedure indicated that the regression model is more sensitive to reduction in sampling effort than the mark-recapture model. Reliance on either the regression or mark-recapture model alone could produce misleading estimates of abundance of sea lampreys and the effect of the control program on sea lamprey abundance. These analyses indicate that the precision of the lakewide population estimate can be maximized by re-allocating sampling effort from marking sea lampreys to trapping additional streams.

Models and analysis for multivariate failure time data

NASA Astrophysics Data System (ADS)

Shih, Joanna Huang

The goal of this research is to develop and investigate models and analytic methods for multivariate failure time data. We compare models in terms of direct modeling of the margins, flexibility of dependency structure, local vs. global measures of association, and ease of implementation. In particular, we study copula models, and models produced by right neutral cumulative hazard functions and right neutral hazard functions. We examine the changes of association over time for families of bivariate distributions induced from these models by displaying their density contour plots, conditional density plots, correlation curves of Doksum et al, and local cross ratios of Oakes. We know that bivariate distributions with same margins might exhibit quite different dependency structures. In addition to modeling, we study estimation procedures. For copula models, we investigate three estimation procedures. the first procedure is full maximum likelihood. The second procedure is two-stage maximum likelihood. At stage 1, we estimate the parameters in the margins by maximizing the marginal likelihood. At stage 2, we estimate the dependency structure by fixing the margins at the estimated ones. The third procedure is two-stage partially parametric maximum likelihood. It is similar to the second procedure, but we estimate the margins by the Kaplan-Meier estimate. We derive asymptotic properties for these three estimation procedures and compare their efficiency by Monte-Carlo simulations and direct computations. For models produced by right neutral cumulative hazards and right neutral hazards, we derive the likelihood and investigate the properties of the maximum likelihood estimates. Finally, we develop goodness of fit tests for the dependency structure in the copula models. We derive a test statistic and its asymptotic properties based on the test of homogeneity of Zelterman and Chen (1988), and a graphical diagnostic procedure based on the empirical Bayes approach. We study the performance of these two methods using actual and computer generated data.

Determination of SB2 masses and age: introduction of the mass ratio in the Bayesian analysis

NASA Astrophysics Data System (ADS)

Giarrusso, M.; Leone, F.; Tognelli, E.; Degl'Innocenti, S.; Prada Moroni, P. G.

2018-04-01

Stellar age assignment still represents a difficult task in Astrophysics. This unobservable fundamental parameter can be estimated only through indirect methods, as well as generally the mass. Bayesian analysis is a statistical approach largely used to derive stellar properties by taking into account the available information about the quantities we are looking for. In this paper we propose to apply the method to the double-lined spectroscopic binaries (SB2), for which the only available information about masses is the observed mass ratio of the two components. We validated the method on a synthetic sample of Pre-Main Sequence (PMS) SB2 systems showing the capability of the technique to recover the simulated age and masses. Then, we applied our procedure to the PMS eclipsing binaries Parenago 1802 and RX J0529.4+0041 A, whose masses of both components are known, by treating them as SB2 systems. The estimated masses are in agreement with those dynamically measured. We conclude that the method, if based on high resolution and high signal-to-noise spectroscopy, represents a robust way to infer the masses of the very numerous SB2 systems together with their age, allowing to date the hosting astrophysical environments.

Determination of SB2 masses and age: introduction of the mass ratio in the Bayesian analysis

NASA Astrophysics Data System (ADS)

Giarrusso, M.; Leone, F.; Tognelli, E.; Degl'Innocenti, S.; Prada Moroni, P. G.

2018-07-01

Stellar age assignment still represents a difficult task in Astrophysics. This unobservable fundamental parameter can be estimated only through indirect methods, as well as generally the mass. Bayesian analysis is a statistical approach largely used to derive stellar properties by taking into account the available information about the quantities we are looking for. In this paper, we propose to apply the method to the double-lined spectroscopic binaries (SB2), for which the only available information about masses is the observed mass ratio of the two components. We validated the method on a synthetic sample of pre-main-sequence (PMS) SB2 systems showing the capability of the technique to recover the simulated age and masses. Then, we applied our procedure to the PMS eclipsing binaries Parenago 1802 and RX J0529.4+0041 A, whose masses of both components are known, by treating them as SB2 systems. The estimated masses are in agreement with those dynamically measured. We conclude that the method, if based on high resolution and high signal-to-noise spectroscopy, represents a robust way to infer the masses of the very numerous SB2 systems together with their age, allowing to date the hosting astrophysical environments.

Estimating equations estimates of trends

USGS Publications Warehouse

Link, W.A.; Sauer, J.R.

1994-01-01

The North American Breeding Bird Survey monitors changes in bird populations through time using annual counts at fixed survey sites. The usual method of estimating trends has been to use the logarithm of the counts in a regression analysis. It is contended that this procedure is reasonably satisfactory for more abundant species, but produces biased estimates for less abundant species. An alternative estimation procedure based on estimating equations is presented.

Evaluation of Bayesian Sequential Proportion Estimation Using Analyst Labels

NASA Technical Reports Server (NTRS)

Lennington, R. K.; Abotteen, K. M. (Principal Investigator)

1980-01-01

The author has identified the following significant results. A total of ten Large Area Crop Inventory Experiment Phase 3 blind sites and analyst-interpreter labels were used in a study to compare proportional estimates obtained by the Bayes sequential procedure with estimates obtained from simple random sampling and from Procedure 1. The analyst error rate using the Bayes technique was shown to be no greater than that for the simple random sampling. Also, the segment proportion estimates produced using this technique had smaller bias and mean squared errors than the estimates produced using either simple random sampling or Procedure 1.

Process dissociation analyses of memory changes in healthy aging, preclinical, and very mild Alzheimer disease: Evidence for isolated recollection deficits.

PubMed

Millar, Peter R; Balota, David A; Maddox, Geoffrey B; Duchek, Janet M; Aschenbrenner, Andrew J; Fagan, Anne M; Benzinger, Tammie L S; Morris, John C

2017-10-01

Recollection and familiarity are independent processes that contribute to memory performance. Recollection is dependent on attentional control, which has been shown to be disrupted in early stage Alzheimer's disease (AD), whereas familiarity is independent of attention. The present longitudinal study examines the sensitivity of recollection estimates based on Jacoby's (1991) process dissociation procedure to AD-related biomarkers in a large sample of well-characterized cognitively normal middle-aged and older adults (N = 519) and the extent to which recollection discriminates these individuals from individuals with very mild symptomatic AD (N = 64). Participants studied word pairs (e.g., knee bone), then completed a primed, explicit, cued fragment-completion memory task (e.g., knee b_n_). Primes were either congruent with the correct response (e.g., bone), incongruent (e.g., bend), or neutral (e.g., &). This design allowed for the estimation of independent contributions of recollection and familiarity processes, using the process dissociation procedure. Recollection, but not familiarity, was impaired in healthy aging and in very mild AD. Recollection discriminated cognitively normal individuals from the earliest detectable stage of symptomatic AD above and beyond standard psychometric tests. In cognitively normal individuals, baseline CSF measures indicative of AD pathology were related to lower initial recollection and less practice-related improvement in recollection over time. Finally, presence of amyloid plaques, as imaged by PIB-PET, was also related to less improvement in recollection over time. These findings suggest that attention-demanding memory processes, such as recollection, may be particularly sensitive to both symptomatic and preclinical AD pathology. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Consistency of Rasch Model Parameter Estimation: A Simulation Study.

ERIC Educational Resources Information Center

van den Wollenberg, Arnold L.; And Others

1988-01-01

The unconditional--simultaneous--maximum likelihood (UML) estimation procedure for the one-parameter logistic model produces biased estimators. The UML method is inconsistent and is not a good alternative to conditional maximum likelihood method, at least with small numbers of items. The minimum Chi-square estimation procedure produces unbiased…

An Evaluation of Hierarchical Bayes Estimation for the Two- Parameter Logistic Model.

ERIC Educational Resources Information Center

Kim, Seock-Ho

Hierarchical Bayes procedures for the two-parameter logistic item response model were compared for estimating item parameters. Simulated data sets were analyzed using two different Bayes estimation procedures, the two-stage hierarchical Bayes estimation (HB2) and the marginal Bayesian with known hyperparameters (MB), and marginal maximum…

14 CFR 151.24 - Procedures: Application; information on estimated project costs.

Code of Federal Regulations, 2014 CFR

2014-01-01

... estimated project costs. 151.24 Section 151.24 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Development Projects § 151.24 Procedures: Application; information on estimated project costs. (a) If any part of the estimated project costs consists of the value of donated land, labor, materials, or equipment...

14 CFR 151.24 - Procedures: Application; information on estimated project costs.

Code of Federal Regulations, 2012 CFR

2012-01-01

... estimated project costs. 151.24 Section 151.24 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Development Projects § 151.24 Procedures: Application; information on estimated project costs. (a) If any part of the estimated project costs consists of the value of donated land, labor, materials, or equipment...

14 CFR 151.24 - Procedures: Application; information on estimated project costs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... estimated project costs. 151.24 Section 151.24 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Development Projects § 151.24 Procedures: Application; information on estimated project costs. (a) If any part of the estimated project costs consists of the value of donated land, labor, materials, or equipment...

14 CFR 151.24 - Procedures: Application; information on estimated project costs.

Code of Federal Regulations, 2013 CFR

2013-01-01

... estimated project costs. 151.24 Section 151.24 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Development Projects § 151.24 Procedures: Application; information on estimated project costs. (a) If any part of the estimated project costs consists of the value of donated land, labor, materials, or equipment...

14 CFR 151.24 - Procedures: Application; information on estimated project costs.

Code of Federal Regulations, 2011 CFR

2011-01-01

... estimated project costs. 151.24 Section 151.24 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Development Projects § 151.24 Procedures: Application; information on estimated project costs. (a) If any part of the estimated project costs consists of the value of donated land, labor, materials, or equipment...

Development of methodologies for the estimation of thermal properties associated with aerospace vehicles

NASA Technical Reports Server (NTRS)

Scott, Elaine P.

1993-01-01

Thermal stress analyses are an important aspect in the development of aerospace vehicles such as the National Aero-Space Plane (NASP) and the High-Speed Civil Transport (HSCT) at NASA-LaRC. These analyses require knowledge of the temperature within the structures which consequently necessitates the need for thermal property data. The initial goal of this research effort was to develop a methodology for the estimation of thermal properties of aerospace structural materials at room temperature and to develop a procedure to optimize the estimation process. The estimation procedure was implemented utilizing a general purpose finite element code. In addition, an optimization procedure was developed and implemented to determine critical experimental parameters to optimize the estimation procedure. Finally, preliminary experiments were conducted at the Aircraft Structures Branch (ASB) laboratory.

Development of methodologies for the estimation of thermal properties associated with aerospace vehicles

NASA Astrophysics Data System (ADS)

Scott, Elaine P.

1993-12-01

Thermal stress analyses are an important aspect in the development of aerospace vehicles such as the National Aero-Space Plane (NASP) and the High-Speed Civil Transport (HSCT) at NASA-LaRC. These analyses require knowledge of the temperature within the structures which consequently necessitates the need for thermal property data. The initial goal of this research effort was to develop a methodology for the estimation of thermal properties of aerospace structural materials at room temperature and to develop a procedure to optimize the estimation process. The estimation procedure was implemented utilizing a general purpose finite element code. In addition, an optimization procedure was developed and implemented to determine critical experimental parameters to optimize the estimation procedure. Finally, preliminary experiments were conducted at the Aircraft Structures Branch (ASB) laboratory.

40 CFR 98.335 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... missing data. For the carbon input procedure in § 98.333(b), a complete record of all measured parameters... average carbon contents of inputs according to the procedures in § 98.335(b) if data are missing. (b) For...

40 CFR 98.335 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... missing data. For the carbon input procedure in § 98.333(b), a complete record of all measured parameters... average carbon contents of inputs according to the procedures in § 98.335(b) if data are missing. (b) For...

40 CFR 98.335 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... missing data. For the carbon input procedure in § 98.333(b), a complete record of all measured parameters... average carbon contents of inputs according to the procedures in § 98.335(b) if data are missing. (b) For...

40 CFR 98.335 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... missing data. For the carbon input procedure in § 98.333(b), a complete record of all measured parameters... average carbon contents of inputs according to the procedures in § 98.335(b) if data are missing. (b) For...

40 CFR 98.335 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... missing data. For the carbon input procedure in § 98.333(b), a complete record of all measured parameters... average carbon contents of inputs according to the procedures in § 98.335(b) if data are missing. (b) For...

Trends in Hysteropexy and Apical Support for Uterovaginal Prolapse in the United States from 2002 to 2012.

PubMed

Madsen, Annetta M; Raker, Christina; Sung, Vivian W

Our objective was to describe trends in hysteropexy and apical support for uterovaginal prolapse (UVP) from 2002 to 2012 in the United States. We identified patient and hospital variables associated with hysteropexy and apical support. We used the Nationwide Inpatient Sample and International Classification of Diseases, Ninth Revision codes to identify a population of women 18 years or older with UVP undergoing pelvic organ prolapse surgery from January 1, 2002, to December 31, 2012. Procedures were categorized as (1) hysteropexy, (2) obliterative with uterine preservation, (3) hysterectomy with apical support, (4) hysterectomy without apical support, and (5) other reconstruction without apical support. Categories were dichotomized into those with and without apical support. We used survey weights to obtain nationally representative estimates; χ and linear and logistic regression compared procedure groups. An estimated 815,184 hospital discharges of pelvic organ prolapse procedures for UVP occurred from 2002 to 2012. During this time, hysteropexies increased from 1.81% to 5.00% (P < 0.0001). From 2002 to 2012, hysterectomies with apical support increased (10.07% to 32.51%, P < 0.0001), hysterectomy without apical support decreased (27.14% to 17.12%, P < 0.0001), and reconstruction without apical support decreased (59.07% to 40.48%, P < 0.0001). In most recent years 2011 to 2012, 60% of women with UVP underwent inpatient surgery without an apical procedure. Age 52 years or older, Medicare payment, Northeast region, and urban teaching hospitals were associated with increased odds of apical support for UVP (P < 0.001 for all). Hysteropexy significantly increased in the United States from 2002 to 2012, although the overall proportion remains low. While hysterectomy without apical support is decreasing, approximately 60% of inpatient procedures performed for UVP do not address the apex.

Concurrent orthopedic and neurosurgical procedures in pediatric patients with spinal deformity.

PubMed

Mooney, James F; Glazier, Stephen S; Barfield, William R

2012-11-01

The management of pediatric patients with complex spinal deformity often requires both an orthopedic and a neurosurgical intervention. The reasons for multiple subspecialty involvement include, but are not limited to, the presence of a tethered cord requiring release or a syrinx requiring decompression. It has been common practice to perform these procedures in a staged manner, although there is little evidence in the literature to support separate interventions. We reviewed a series of consecutive patients who underwent spinal deformity correction and a neurosurgical intervention concurrently in an attempt to assess the safety, efficacy, and possible complications associated with such an approach. Eleven patients were reviewed who underwent concurrent orthopedic and neurosurgical procedures. Data were collected for patient demographics, preoperative diagnosis, procedures performed, intraoperative and perioperative complications, as well as any unexpected return to the operating room for any reason. Operative notes and anesthesia records were reviewed to determine estimated blood loss, surgical time, and the use of intraoperative neurological monitoring. Patient diagnoses included myelodysplasia (N=6), congenital scoliosis and/or kyphosis (N=4), and scoliosis associated with Noonan syndrome (N=1). Age at the time of surgery averaged 9 years 2 months (range=14 months to 17 years 2 months). Estimated blood loss averaged 605 ml (range=50-3000 ml). The operative time averaged 313 min (range=157-477 min). There were no intraoperative complications, including incidental dural tears or deterioration in preoperative neurological status. One patient developed a sore associated with postoperative cast immobilization that led to a deep wound infection. It appears that concurrent orthopedic and neurosurgical procedures in pediatric patients with significant spinal deformities can be performed safely and with minimal intraoperative and postoperative complications when utilizing modern surgical and neuromonitoring techniques. Level of evidence=Level IV. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

External validation of a forest inventory and analysis volume equation and comparisons with estimates from multiple stem-profile models

Treesearch

Christopher M. Oswalt; Adam M. Saunders

2009-01-01

Sound estimation procedures are desideratum for generating credible population estimates to evaluate the status and trends in resource conditions. As such, volume estimation is an integral component of the U.S. Department of Agriculture, Forest Service, Forest Inventory and Analysis (FIA) program's reporting. In effect, reliable volume estimation procedures are...

Male orthopaedic surgeons and anaesthetists: equally good at estimating fluid volumes (and changing light bulbs) but equally poor at estimating procedure duration.

PubMed

Chua, Weiliang; Kong, Chee Hoe; Murphy, Diarmuid Paul

2015-05-01

How many orthopods does it take to change a light bulb? One - to refer to the medics for 'Darkness ?Cause'. Additionally, anaesthetists and surgeons often disagree on the estimated blood loss during surgery and the estimated procedure duration. We designed this study to compare the ability of orthopaedic surgeons and anaesthetists in: (a) estimating fluid volumes; (b) estimating procedure durations; and (c) changing light bulbs. Participants had to either be a specialist in anaesthesia or orthopaedic surgery, or a trainee in that specialty for at least two years. Three different fluid specimens were used for volume estimation (44 mL, 88 mL and 144 mL). Two videos of different lengths (140 seconds and 170 seconds), showing the suturing of a banana skin, were used for procedure duration estimation. To determine the ability at changing light bulbs, the participants had to match eight different light sockets to their respective bulbs. 30 male anaesthetists and trainees and 31 male orthopaedic surgeons and trainees participated in this study. Orthopaedic surgeons underestimated the three fluid volumes by 3.9% and anaesthetists overestimated by 5.1% (p = 0.925). Anaesthetists and orthopaedic surgeons overestimated the duration of the two procedures by 21.2% and 43.1%, respectively (p = 0.006). Anaesthetists had a faster mean time in changing light bulbs (70.1 seconds vs. 74.1 seconds, p = 0.319). In an experimental environment, male orthopaedic surgeons are as good as male anaesthetists in estimating fluid volumes (in commonly seen surgical specimens) and in changing light bulbs. Both groups are poor at estimating procedure durations.

Three ages of Venus

NASA Technical Reports Server (NTRS)

Wood, Charles A.; Coombs, Cassandra R.

1989-01-01

A central question for any planet is the age of its surface. Based on comparative planetological arguments, Venus should be as young and active as the Earth (Wood and Francis). The detection of probable impact craters in the Venera radar images provides a tool for estimating the age of the surface of Venus. Assuming somewhat different crater production rates, Bazilevskiy et al. derived an age of 1 + or - 0.5 billion years, and Schaber et al. and Wood and Francis estimated an age of 200 to 400 million years. The known impact craters are not randomly distributed, however, thus some area must be older and others younger than this average age. Ages were derived for major geologic units on Venus using the Soviet catalog of impact craters (Bazilevskiy et al.), and the most accessible geologic unit map (Bazilevskiy). The crater counts are presented for (diameters greater than 20 km), areas, and crater densities for the 7 terrain units and coronae. The procedure for examining the distribution of craters is superior to the purely statistical approaches of Bazilevskiy et al. and Plaut and Arvidson because the bins are larger (average size 16 x 10(6) sq km) and geologically significant. Crater densities define three distinct groups: relatively heavily cratered (Lakshmi, mountain belts), moderately cratered (smooth and rolling plains, ridge belts, and tesserae), and essentially uncratered (coronae and domed uplands). Following Schaber et al., Grieve's terrestrial cratering rate of 5.4 + or - 2.7 craters greater than 20 km/10(9) yrs/10(6) sq km was used to calculate ages for the geologic units on Venus. To improve statistics, the data was aggregated into the three crater density groups, deriving the ages. For convenience, the three similar age groups are given informal time stratigraphic unit names, from youngest to oldest: Ulfrunian, Sednaian, Lakshmian.

Three ages of Venus

NASA Astrophysics Data System (ADS)

Wood, Charles A.; Coombs, Cassandra R.

A central question for any planet is the age of its surface. Based on comparative planetological arguments, Venus should be as young and active as the Earth (Wood and Francis). The detection of probable impact craters in the Venera radar images provides a tool for estimating the age of the surface of Venus. Assuming somewhat different crater production rates, Bazilevskiy et al. derived an age of 1 + or - 0.5 billion years, and Schaber et al. and Wood and Francis estimated an age of 200 to 400 million years. The known impact craters are not randomly distributed, however, thus some area must be older and others younger than this average age. Ages were derived for major geologic units on Venus using the Soviet catalog of impact craters (Bazilevskiy et al.), and the most accessible geologic unit map (Bazilevskiy). The crater counts are presented for (diameters greater than 20 km), areas, and crater densities for the 7 terrain units and coronae. The procedure for examining the distribution of craters is superior to the purely statistical approaches of Bazilevskiy et al. and Plaut and Arvidson because the bins are larger (average size 16 x 10(6) sq km) and geologically significant. Crater densities define three distinct groups: relatively heavily cratered (Lakshmi, mountain belts), moderately cratered (smooth and rolling plains, ridge belts, and tesserae), and essentially uncratered (coronae and domed uplands). Following Schaber et al., Grieve's terrestrial cratering rate of 5.4 + or - 2.7 craters greater than 20 km/10(9) yrs/10(6) sq km was used to calculate ages for the geologic units on Venus. To improve statistics, the data was aggregated into the three crater density groups, deriving the ages. For convenience, the three similar age groups are given informal time stratigraphic unit names, from youngest to oldest: Ulfrunian, Sednaian, Lakshmian.

A nondestructive method for estimation of the fracture toughness of CrMoV rotor steels based on ultrasonic nonlinearity.

PubMed

Jeong, Hyunjo; Nahm, Seung-Hoon; Jhang, Kyung-Young; Nam, Young-Hyun

2003-09-01

The objective of this paper is to develop a nondestructive method for estimating the fracture toughness (K(IC)) of CrMoV steels used as the rotor material of steam turbines in power plants. To achieve this objective, a number of CrMoV steel samples were heat-treated, and the fracture appearance transition temperature (FATT) was determined as a function of aging time. Nonlinear ultrasonics was employed as the theoretical basis to explain the harmonic generation in a damaged material, and the nonlinearity parameter of the second harmonic wave was the experimental measure used to be correlated to the fracture toughness of the rotor steel. The nondestructive procedure for estimating the K(IC) consists of two steps. First, the correlations between the nonlinearity parameter and the FATT are sought. The FATT values are then used to estimate K(IC) using the K(IC) versus excess temperature (i.e., T-FATT) correlation that is available in the literature for CrMoV rotor steel.

Cholesterol Curves to Identify Population Norms by Age and Sex in Healthy Weight Children

PubMed Central

Skinner, Asheley Cockrell; Steiner, Michael J.; Chung, Arlene E.; Perrin, Eliana M.

2012-01-01

Objective Develop clinically applicable charts of lipid values illustrating fluctuations throughout childhood and by sex among healthy weight children. Methods The National Health and Nutrition Examination Survey (1999–2008) was used to estimate total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides by age and sex in healthy weight children age 3 to 17 years. Using LMS procedures, the authors created smoothed curves demonstrating population-based 50th percentile for age and the 75th and 95th percentiles. Results The curves were based on 7681 children meeting inclusion criteria. Total cholesterol, HDL, and LDL demonstrated peaks at approximately 8 to 12 years for boys. Similar peaks were evident for girls at slightly younger ages, approximately 7 to 11 years. Triglycerides showed peaks for girls, but values were similar across ages for boys. Conclusions The use of fixed lipid value cutoffs in established guidelines regardless of age or sex likely mislabels many children as abnormal. The authors’ charts may allow for a more nuanced interpretation based on population norms. PMID:22157422

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions, Addendum

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1975-01-01

New results and insights concerning a previously published iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions were discussed. It was shown that the procedure converges locally to the consistent maximum likelihood estimate as long as a specified parameter is bounded between two limits. Bound values were given to yield optimal local convergence.

Procedures used to estimate hardwood lumber consumption from 1963 to 2002

Treesearch

William Luppold; Matthew Bumgardner

2008-01-01

This paper presents an explanation for and procedures used to estimate hardwood lumber consumption by secondary hardwood processing industries from 1963 to 2002. This includes: classification of industry and industry groups, development of proxy prices used to estimate lumber consumption, assumptions used to convert dimension purchases to lumber consumption, estimation...

[Cognitive aging mechanism of signaling effects on the memory for procedural sentences].

PubMed

Yamamoto, Hiroki; Shimada, Hideaki

2006-08-01

The aim of this study was to clarify the cognitive aging mechanism of signaling effects on the memory for procedural sentences. Participants were 60 younger adults (college students) and 60 older adults. Both age groups were assigned into two groups; half of each group was presented with procedural sentences with signals that highlighted their top-level structure and the other half with procedural sentences without them. Both groups were requested to perform the sentence arrangement task and the reconstruction task. Each task was composed of procedural sentences with or without signals. Results indicated that signaling supported changes in strategy utilization during the successive organizational processes and that changes in strategy utilization resulting from signaling improved the memory for procedural sentences. Moreover, age-related factors interfered with these signaling effects. This study clarified the cognitive aging mechanism of signaling effects in which signaling supports changes in the strategy utilization during organizational processes at encoding and this mediation promotes memory for procedural sentences, though disuse of the strategy utilization due to aging restrains their memory for procedural sentences.

The search for causal inferences: using propensity scores post hoc to reduce estimation error with nonexperimental research.

PubMed

Tumlinson, Samuel E; Sass, Daniel A; Cano, Stephanie M

2014-03-01

While experimental designs are regarded as the gold standard for establishing causal relationships, such designs are usually impractical owing to common methodological limitations. The objective of this article is to illustrate how propensity score matching (PSM) and using propensity scores (PS) as a covariate are viable alternatives to reduce estimation error when experimental designs cannot be implemented. To mimic common pediatric research practices, data from 140 simulated participants were used to resemble an experimental and nonexperimental design that assessed the effect of treatment status on participant weight loss for diabetes. Pretreatment participant characteristics (age, gender, physical activity, etc.) were then used to generate PS for use in the various statistical approaches. Results demonstrate how PSM and using the PS as a covariate can be used to reduce estimation error and improve statistical inferences. References for issues related to the implementation of these procedures are provided to assist researchers.

Supplemental materials for the analysis of capture-recapture data for polar bears in Western Hudson Bay, Canada, 1984-2004

USGS Publications Warehouse

Regehr, Eric V.; Lunn, Nicholas J.; Amstrup, Steven C.; Stirling, Ian

2007-01-01

Regehr and others (2007, Survival and population size of polar bears in western Hudson Bay in relation to earlier sea ice breakup: Journal of Wildlife Management, v. 71, no. 8) evaluated survival in relation to climatic conditions and estimated population size for polar bears (Ursus maritimus) in western Hudson Bay, Canada. Here, we provide supplemental materials for the analyses in Regehr and others (2007). We demonstrate how tag-return data from harvested polar bears were used to adjust estimates of total survival for human-caused mortality. We describe the sex and age composition of the capture and harvest samples and provide results for goodness-of-fit tests applied to capture-recapture models. We also describe the capture-recapture model selection procedure and the structure of the most supported model, which was used to estimate survival and population size.

Myopia Stabilization and Associated Factors Among Participants in the Correction of Myopia Evaluation Trial (COMET)

PubMed Central

2013-01-01

Purpose. To use the Gompertz function to estimate the age and the amount of myopia at stabilization and to evaluate associated factors in the Correction of Myopia Evaluation Trial (COMET) cohort, a large ethnically diverse group of myopic children. Methods. The COMET enrolled 469 ethnically diverse children aged 6 to younger than 12 years with spherical equivalent refraction between −1.25 and −4.50 diopters (D). Noncycloplegic refraction was measured semiannually for 4 years and annually thereafter. Right eye data were fit to individual Gompertz functions in participants with at least 6 years of follow-up and at least seven refraction measurements over 11 years. Function parameters were estimated using a nonlinear least squares procedure. Associated factors were evaluated using linear regression. Results. In total, 426 participants (91%) had valid Gompertz curve fits. The mean (SD) age at myopia stabilization was 15.61 (4.17) years, and the mean (SD) amount of myopia at stabilization was −4.87 (2.01) D. Ethnicity (P < 0.0001) but not sex or the number of myopic parents was associated with the age at stabilization. Ethnicity (P = 0.02) and the number of myopic parents (P = 0.01) but not sex were associated with myopia magnitude at stabilization. At stabilization, African Americans were youngest (mean age, 13.82 years) and had the least myopia (mean, −4.36 D). Participants with two versus no myopic parents had approximately 1.00 D more myopia at stabilization. The age and the amount of myopia at stabilization were correlated (r = −0.60, P < 0.0001). Conclusions. The Gompertz function provides estimates of the age and the amount of myopia at stabilization in an ethnically diverse cohort. These findings should provide guidance on the time course of myopia and on decisions regarding the type and timing of interventions. PMID:24159085

Trends in the surgical management of stress urinary incontinence among female Medicare beneficiaries, 2002-2007.

PubMed

Rogo-Gupta, Lisa; Litwin, Mark S; Saigal, Christopher S; Anger, Jennifer T

2013-07-01

To describe trends in the surgical management of female stress urinary incontinence (SUI) in the United States from 2002 to 2007. As part of the Urologic Diseases of America Project, we analyzed data from a 5% national random sample of female Medicare beneficiaries aged 65 and older. Data were obtained from the Centers for Medicare and Medicaid Services carrier and outpatient files from 2002 to 2007. Women who were diagnosed with urinary incontinence identified by the International Classification of Diseases, Ninth Edition (ICD-9) diagnosis codes and who underwent surgical management identified by Current Procedural Terminology, Fourth Edition (CPT-4) procedure codes were included in the analysis. Trends were analyzed over the 6-year period. Unweighted procedure counts were multiplied by 20 to estimate the rate among all female Medicare beneficiaries. The total number of surgical procedures remained stable during the study period, from 49,340 in 2002 to 49,900 in 2007. Slings were the most common procedure across all years, which increased from 25,840 procedures in 2002 to 33,880 procedures in 2007. Injectable bulking agents were the second most common procedure, which accounted for 14,100 procedures in 2002 but decreased to 11,320 in 2007. Procedures performed in ambulatory surgery centers and physician offices increased, although those performed in inpatient settings declined. Hospital outpatient procedures remained stable. The surgical management of women with SUI shifted toward a dominance of procedures performed in ambulatory surgery centers from 2002 to 2007, although the overall number of procedures remained stable. Slings remained the dominant surgical procedure, followed by injectable bulking agents, both of which are easily performed in outpatient settings. Copyright © 2013 Elsevier Inc. All rights reserved.

Pediatric cleft palate patients show a 3- to 5-fold increase in cumulative radiation exposure from dental radiology compared with an age- and gender-matched population: a retrospective cohort study.

PubMed

Jacobs, Reinhilde; Pauwels, Ruben; Scarfe, William C; De Cock, Carl; Dula, Karl; Willems, Guy; Verdonck, An; Politis, Constantinus

2018-05-01

The objective of the study was to compare estimates of pediatric cumulative exposure and lifetime attributable risk (LAR) of radiation-induced cancer from dental radiology between cleft palate (CP) subjects and age- and gender-matched controls (non-CP), with and without orthodontic treatment. The radiation exposure frequency of CP subjects and non-CP controls with and without orthodontic treatment was compared for two-dimensional radiography (intra-oral, panoramic and cephalometric radiography), computed tomography (CT), and cone-beam CT (CBCT) using cumulative radiation dose as an estimate. From this dose estimate, the age- and gender-dependent risk for radiation-induced stochastic effects was calculated for each patient group. CP patients received more radiographic examinations than non-CP controls, with the exception of intra-oral radiographs. The cumulative dose to CP patients was considerably higher (1963 μSv at the age of 20 years) than non-CP patients with (597 μSv) and without (383 μSv) orthodontic treatment, primarily due to the higher frequency of CT scanning. Accordingly, CP patients had a three to five times higher LAR than non-CP patients. This study suggests a significantly higher lifetime radiation exposure to CP patients than non-CP controls from dental radiographic procedures. Diagnostic benefits from the use of CT and CBCT in children must be justified and appropriate dose optimization strategies implemented. The present study indicates the need for proper justification and optimization of pediatric exposures in dentistry, with a special focus on high-risk groups.

Analysis of half diallel mating designs I: a practical analysis procedure for ANOVA approximation.

Treesearch

G.R. Johnson; J.N. King

1998-01-01

Procedures to analyze half-diallel mating designs using the SAS statistical package are presented. The procedure requires two runs of PROC and VARCOMP and results in estimates of additive and non-additive genetic variation. The procedures described can be modified to work on most statistical software packages which can compute variance component estimates. The...

40 CFR 98.75 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data. 98.75 Section 98.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.75 Procedures for...

40 CFR 98.75 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data. 98.75 Section 98.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.75 Procedures for...

40 CFR 98.75 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data. 98.75 Section 98.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.75 Procedures for...

40 CFR 98.75 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data. 98.75 Section 98.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.75 Procedures for...

40 CFR 98.75 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data. 98.75 Section 98.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Ammonia Manufacturing § 98.75 Procedures for...

40 CFR 98.45 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data. 98.45 Section 98.45 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.45 Procedures for...

40 CFR 98.45 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data. 98.45 Section 98.45 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.45 Procedures for...

40 CFR 98.45 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data. 98.45 Section 98.45 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.45 Procedures for...

40 CFR 98.45 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data. 98.45 Section 98.45 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.45 Procedures for...

40 CFR 98.45 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data. 98.45 Section 98.45 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Electricity Generation § 98.45 Procedures for...

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1978-01-01

This paper addresses the problem of obtaining numerically maximum-likelihood estimates of the parameters for a mixture of normal distributions. In recent literature, a certain successive-approximations procedure, based on the likelihood equations, was shown empirically to be effective in numerically approximating such maximum-likelihood estimates; however, the reliability of this procedure was not established theoretically. Here, we introduce a general iterative procedure, of the generalized steepest-ascent (deflected-gradient) type, which is just the procedure known in the literature when the step-size is taken to be 1. We show that, with probability 1 as the sample size grows large, this procedure converges locally to the strongly consistent maximum-likelihood estimate whenever the step-size lies between 0 and 2. We also show that the step-size which yields optimal local convergence rates for large samples is determined in a sense by the 'separation' of the component normal densities and is bounded below by a number between 1 and 2.

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions, 2

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1976-01-01

The problem of obtaining numerically maximum likelihood estimates of the parameters for a mixture of normal distributions is addressed. In recent literature, a certain successive approximations procedure, based on the likelihood equations, is shown empirically to be effective in numerically approximating such maximum-likelihood estimates; however, the reliability of this procedure was not established theoretically. Here, a general iterative procedure is introduced, of the generalized steepest-ascent (deflected-gradient) type, which is just the procedure known in the literature when the step-size is taken to be 1. With probability 1 as the sample size grows large, it is shown that this procedure converges locally to the strongly consistent maximum-likelihood estimate whenever the step-size lies between 0 and 2. The step-size which yields optimal local convergence rates for large samples is determined in a sense by the separation of the component normal densities and is bounded below by a number between 1 and 2.

Optimum strata boundaries and sample sizes in health surveys using auxiliary variables

PubMed Central

2018-01-01

Using convenient stratification criteria such as geographical regions or other natural conditions like age, gender, etc., is not beneficial in order to maximize the precision of the estimates of variables of interest. Thus, one has to look for an efficient stratification design to divide the whole population into homogeneous strata that achieves higher precision in the estimation. In this paper, a procedure for determining Optimum Stratum Boundaries (OSB) and Optimum Sample Sizes (OSS) for each stratum of a variable of interest in health surveys is developed. The determination of OSB and OSS based on the study variable is not feasible in practice since the study variable is not available prior to the survey. Since many variables in health surveys are generally skewed, the proposed technique considers the readily-available auxiliary variables to determine the OSB and OSS. This stratification problem is formulated into a Mathematical Programming Problem (MPP) that seeks minimization of the variance of the estimated population parameter under Neyman allocation. It is then solved for the OSB by using a dynamic programming (DP) technique. A numerical example with a real data set of a population, aiming to estimate the Haemoglobin content in women in a national Iron Deficiency Anaemia survey, is presented to illustrate the procedure developed in this paper. Upon comparisons with other methods available in literature, results reveal that the proposed approach yields a substantial gain in efficiency over the other methods. A simulation study also reveals similar results. PMID:29621265

Optimum strata boundaries and sample sizes in health surveys using auxiliary variables.

PubMed

Reddy, Karuna Garan; Khan, Mohammad G M; Khan, Sabiha

2018-01-01

Using convenient stratification criteria such as geographical regions or other natural conditions like age, gender, etc., is not beneficial in order to maximize the precision of the estimates of variables of interest. Thus, one has to look for an efficient stratification design to divide the whole population into homogeneous strata that achieves higher precision in the estimation. In this paper, a procedure for determining Optimum Stratum Boundaries (OSB) and Optimum Sample Sizes (OSS) for each stratum of a variable of interest in health surveys is developed. The determination of OSB and OSS based on the study variable is not feasible in practice since the study variable is not available prior to the survey. Since many variables in health surveys are generally skewed, the proposed technique considers the readily-available auxiliary variables to determine the OSB and OSS. This stratification problem is formulated into a Mathematical Programming Problem (MPP) that seeks minimization of the variance of the estimated population parameter under Neyman allocation. It is then solved for the OSB by using a dynamic programming (DP) technique. A numerical example with a real data set of a population, aiming to estimate the Haemoglobin content in women in a national Iron Deficiency Anaemia survey, is presented to illustrate the procedure developed in this paper. Upon comparisons with other methods available in literature, results reveal that the proposed approach yields a substantial gain in efficiency over the other methods. A simulation study also reveals similar results.

Laparoendoscopic single site surgery in pediatric urology: does it require specialized tools?

PubMed Central

Patel, Nishant; Santomauro, Michael; Marietti, Sarah; Chiang, George

2016-01-01

ABSTRACT Purpose: To describe our experience utilizing Laparoendoscopic single site (LESS) surgery in pediatric urology. Materials and Methods: Retrospective chart review was performed on LESS urologic procedures from November 2009 through March 2013. A total of 44 patients underwent 54 procedures including: nephrectomy (23), orchiopexy (14), varicocelectomy (9), orchiectomy (2), urachal cyst excision (3), and antegrade continence enema (3) (ACE). Results: Median patient age was 6.9 years old. Estimated blood loss (EBL), ranged from less than 5cc to 47cc for a bilateral nephrectomy. Operative time varied from 56 mins for varicocelectomy to a median of 360 minutes for a bilateral nephroureterectomy. Incision length ranged between 2 and 2.5cm. In our initial experience we used a commercial port. However, as we progressed, we were able to perform the majority of our procedures via adjacent fascial punctures for instrumentation at the single incision site. One patient did require conversion to an open procedure as a result of bleeding. Three complications were noted (6.8%), with two Clavien Grade 3b complications. Two patients required additional procedures at 1-year follow-up. Conclusions: The use of LESS applies to many pediatric urologic procedures, ideally for ablative procedures or simple reconstructive efforts. The use of adjacent fascial puncture sites for instrumentation can obviate the need for a commercial port or multiple trocars. PMID:27256182

Developing a method to derive alcohol-attributable fractions for HIV/AIDS mortality based on alcohol's impact on adherence to antiretroviral medication

PubMed Central

2011-01-01

Background Alcohol consumption is causally linked to nonadherence to antiretroviral treatment that in turn causes an increase in HIV/AIDS mortality. This article presents a method to calculate the percentage of HIV/AIDS deaths attributable to alcohol consumption and the associated uncertainty. Methods By combining information on risk relations from a number of published sources, we estimated alcohol-attributable fractions (AAFs) of HIV/AIDS in a stepwise procedure. First, we estimated the effect of alcohol consumption on adherence to antiretroviral treatment, and then we combined this estimate with the impact of nonadherence on death. The 95% uncertainty intervals were computed by estimating the variance of the AAFs using Taylor series expansions of one and multiple variables. AAFs were determined for each of the five Global Burden of Disease regions of Africa, based on country-specific treatment and alcohol consumption data from 2005. Results The effects of alcohol on HIV/AIDS in the African Global Burden of Disease regions range from 0.03% to 0.34% for men and from 0% to 0.17% for women, depending on region and age category. The detrimental effect of alcohol consumption was statistically significant in every region and age category except for the North Africa/Middle East region. Conclusions Although the method has its limitations, it was shown to be feasible and provided estimates of the impact of alcohol use on the mortality outcome of HIV/AIDS. PMID:21320310

Longitudinal changes of telomere length and epigenetic age related to traumatic stress and post-traumatic stress disorder.

PubMed

Boks, Marco P; van Mierlo, Hans C; Rutten, Bart P F; Radstake, Timothy R D J; De Witte, Lot; Geuze, Elbert; Horvath, Steve; Schalkwyk, Leonard C; Vinkers, Christiaan H; Broen, Jasper C A; Vermetten, Eric

2015-01-01

Several studies have reported an association between traumatic stress and telomere length suggesting that traumatic stress has an impact on ageing at the cellular level. A newly derived tool provides an additional means to investigate cellular ageing by estimating epigenetic age based on DNA methylation profiles. We therefore hypothesise that in a longitudinal study of traumatic stress both indicators of cellular ageing will show increased ageing. We expect that particularly in individuals that developed symptoms of post-traumatic stress disorder (PTSD) increases in these ageing parameters would stand out. From an existing longitudinal cohort study, ninety-six male soldiers were selected based on trauma exposure and the presence of symptoms of PTSD. All military personnel were deployed in a combat zone in Afghanistan and assessed before and 6 months after deployment. The Self-Rating Inventory for PTSD was used to measure the presence of PTSD symptoms, while exposure to combat trauma during deployment was measured with a 19-item deployment experiences checklist. These groups did not differ for age, gender, alcohol consumption, cigarette smoking, military rank, length, weight, or medication use. In DNA from whole blood telomere length was measured and DNA methylation levels were assessed using the Illumina 450K DNA methylation arrays. Epigenetic ageing was estimated using the DNAm age estimator procedure. The association of trauma with telomere length was in the expected direction but not significant (B=-10.2, p=0.52). However, contrary to our expectations, development of PTSD symptoms was associated with the reverse process, telomere lengthening (B=1.91, p=0.018). In concordance, trauma significantly accelerated epigenetic ageing (B=1.97, p=0.032) and similar to the findings in telomeres, development of PTSD symptoms was inversely associated with epigenetic ageing (B=-0.10, p=0.044). Blood cell count, medication and premorbid early life trauma exposure did not confound the results. Overall, in this longitudinal study of military personnel deployed to Afghanistan we show an acceleration of ageing by trauma. However, development of PTSD symptoms was associated with telomere lengthening and reversed epigenetic ageing. These findings warrant further study of a perhaps dysfunctional compensatory cellular ageing reversal in PTSD. Copyright © 2014 Elsevier Ltd. All rights reserved.

Estimation of whole body fat from appendicular soft tissue from peripheral quantitative computed tomography in adolescent girls

PubMed Central

Lee, Vinson R.; Blew, Rob M.; Farr, Josh N.; Tomas, Rita; Lohman, Timothy G.; Going, Scott B.

2013-01-01

Objective Assess the utility of peripheral quantitative computed tomography (pQCT) for estimating whole body fat in adolescent girls. Research Methods and Procedures Our sample included 458 girls (aged 10.7 ± 1.1y, mean BMI = 18.5 ± 3.3 kg/m2) who had DXA scans for whole body percent fat (DXA %Fat). Soft tissue analysis of pQCT scans provided thigh and calf subcutaneous percent fat and thigh and calf muscle density (muscle fat content surrogates). Anthropometric variables included weight, height and BMI. Indices of maturity included age and maturity offset. The total sample was split into validation (VS; n = 304) and cross-validation (CS; n = 154) samples. Linear regression was used to develop prediction equations for estimating DXA %Fat from anthropometric variables and pQCT-derived soft tissue components in VS and the best prediction equation was applied to CS. Results Thigh and calf SFA %Fat were positively correlated with DXA %Fat (r = 0.84 to 0.85; p <0.001) and thigh and calf muscle densities were inversely related to DXA %Fat (r = −0.30 to −0.44; p < 0.001). The best equation for estimating %Fat included thigh and calf SFA %Fat and thigh and calf muscle density (adj. R2 = 0.90; SEE = 2.7%). Bland-Altman analysis in CS showed accurate estimates of percent fat (adj. R2 = 0.89; SEE = 2.7%) with no bias. Discussion Peripheral QCT derived indices of adiposity can be used to accurately estimate whole body percent fat in adolescent girls. PMID:25147482

Patient doses in the healing arts

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Determinations of radiation doses to patients from x-ray procedures and radiopharmaceuticals are detailed in this chapter. Instructions are given for estimating doses from x-ray procedures. For selected pediatric procedures, the methodology developed by the Food and Drug Administration is presented. The effect of testicular and ovarian shielding is illustrated in tabular form. Estimates of the Genetically Significant Dose (GSD) and mean annual bone marrow dose from diagnostic x-ray examinations are presented for the US populations (1990). This chapter also provides tables of patient doses from selected nuclear medicine procedures and estimates of fetal doses from {sup 131}I.

OCCUPATIONAL RADIATION DOSES TO OPERATORS PERFORMING FLUOROSCOPICALLY-GUIDED PROCEDURES

PubMed Central

Kim, Kwang Pyo; Miller, Donald L.; de Gonzalez, Amy Berrington; Balter, Stephen; Kleinerman, Ruth A.; Ostroumova, Evgenia; Simon, Steven L.; Linet, Martha S.

2012-01-01

In the past 30 years, the numbers and types of fluoroscopically-guided (FG) procedures have increased dramatically. The objective of the present study is to provide estimated radiation doses to physician specialists, other than cardiologists, who perform FG procedures. We searched Medline to identify English-language journal articles reporting radiation exposures to these physicians. We then identified several primarily therapeutic FG procedures that met specific criteria: well-defined procedures for which there were at least five published reports of estimated radiation doses to the operator, procedures performed frequently in current medical practice, and inclusion of physicians from multiple medical specialties. These procedures were percutaneous nephrolithotomy (PCNL), vertebroplasty, orthopedic extremity nailing for treatment of fractures, biliary tract procedures, transjugular intrahepatic portosystemic shunt creation (TIPS), head/neck endovascular therapeutic procedures, and endoscopic retrograde cholangiopancreatography (ERCP). We abstracted radiation doses and other associated data, and estimated effective dose to operators. Operators received estimated doses per patient procedure equivalent to doses received by interventional cardiologists. The estimated effective dose per case ranged from 1.7 – 56μSv for PCNL, 0.1 – 101 μSv for vertebroplasty, 2.5 – 88μSv for orthopedic extremity nailing, 2.0 – 46μSv for biliary tract procedures, 2.5 – 74μSv for TIPS, 1.8 – 53μSv for head/neck endovascular therapeutic procedures, and 0.2 – 49μSv for ERCP. Overall, mean operator radiation dose per case measured over personal protective devices at different anatomic sites on the head and body ranged from 19 – 800 (median = 113) μSv at eye level, 6 – 1180 (median = 75)μSv at the neck, and 2 – 1600 (median = 302) μSv at the trunk. Operators’ hands often received greater doses than the eyes, neck or trunk. Large variations in operator doses suggest that optimizing procedure protocols and proper use of protective devices and shields might reduce occupational radiation dose substantially. PMID:22647920

Effect of protocol-related variables and women's characteristics on the cumulative false-positive risk in breast cancer screening

PubMed Central

Román, R.; Sala, M.; Salas, D.; Ascunce, N.; Zubizarreta, R.; Castells, X.

2012-01-01

Background: Reducing the false-positive risk in breast cancer screening is important. We examined how the screening-protocol and women's characteristics affect the cumulative false-positive risk. Methods: This is a retrospective cohort study of 1 565 364 women aged 45–69 years who underwent 4 739 498 screening mammograms from 1990 to 2006. Multilevel discrete hazard models were used to estimate the cumulative false-positive risk over 10 sequential mammograms under different risk scenarios. Results: The factors affecting the false-positive risk for any procedure and for invasive procedures were double mammogram reading [odds ratio (OR) = 2.06 and 4.44, respectively], two mammographic views (OR = 0.77 and 1.56, respectively), digital mammography (OR = 0.83 for invasive procedures), premenopausal status (OR = 1.31 and 1.22, respectively), use of hormone replacement therapy (OR = 1.03 and 0.84, respectively), previous invasive procedures (OR = 1.52 and 2.00, respectively), and a familial history of breast cancer (OR = 1.18 and 1.21, respectively). The cumulative false-positive risk for women who started screening at age 50–51 was 20.39% [95% confidence interval (CI) 20.02–20.76], ranging from 51.43% to 7.47% in the highest and lowest risk profiles, respectively. The cumulative risk for invasive procedures was 1.76% (95% CI 1.66–1.87), ranging from 12.02% to 1.58%. Conclusions: The cumulative false-positive risk varied widely depending on the factors studied. These findings are relevant to provide women with accurate information and to improve the effectiveness of screening programs. PMID:21430183

Hospital costs estimation and prediction as a function of patient and admission characteristics.

PubMed

Ramiarina, Robert; Almeida, Renan Mvr; Pereira, Wagner Ca

2008-01-01

The present work analyzed the association between hospital costs and patient admission characteristics in a general public hospital in the city of Rio de Janeiro, Brazil. The unit costs method was used to estimate inpatient day costs associated to specific hospital clinics. With this aim, three "cost centers" were defined in order to group direct and indirect expenses pertaining to the clinics. After the costs were estimated, a standard linear regression model was developed for correlating cost units and their putative predictors (the patients gender and age, the admission type (urgency/elective), ICU admission (yes/no), blood transfusion (yes/no), the admission outcome (death/no death), the complexity of the medical procedures performed, and a risk-adjustment index). Data were collected for 3100 patients, January 2001-January 2003. Average inpatient costs across clinics ranged from (US$) 1135 [Orthopedics] to 3101 [Cardiology]. Costs increased according to increases in the risk-adjustment index in all clinics, and the index was statistically significant in all clinics except Urology, General surgery, and Clinical medicine. The occupation rate was inversely correlated to costs, and age had no association with costs. The (adjusted) per cent of explained variance varied between 36.3% [Clinical medicine] and 55.1% [Thoracic surgery clinic]. The estimates are an important step towards the standardization of hospital costs calculation, especially for countries that lack formal hospital accounting systems.

Has Metal-On-Metal Resurfacing Been a Cost-Effective Intervention for Health Care Providers?-A Registry Based Study.

PubMed

Pulikottil-Jacob, Ruth; Connock, Martin; Kandala, Ngianga-Bakwin; Mistry, Hema; Grove, Amy; Freeman, Karoline; Costa, Matthew; Sutcliffe, Paul; Clarke, Aileen

2016-01-01

Total hip replacement for end stage arthritis of the hip is currently the most common elective surgical procedure. In 2007 about 7.5% of UK implants were metal-on-metal joint resurfacing (MoM RS) procedures. Due to poor revision performance and concerns about metal debris, the use of RS had declined by 2012 to about a 1% share of UK hip procedures. This study estimated the lifetime cost-effectiveness of metal-on-metal resurfacing (RS) procedures versus commonly employed total hip replacement (THR) methods. We performed a cost-utility analysis using a well-established multi-state semi-Markov model from an NHS and personal and social services perspective. We used individual patient data (IPD) from the National Joint Registry (NJR) for England and Wales on RS and THR surgery for osteoarthritis recorded from April 2003 to December 2012. We used flexible parametric modelling of NJR RS data to guide identification of patient subgroups and RS devices which delivered revision rates within the NICE 5% revision rate benchmark at 10 years. RS procedures overall have an estimated revision rate of 13% at 10 years, compared to <4% for most THR devices. New NICE guidance now recommends a revision rate benchmark of <5% at 10 years. 60% of RS implants in men and 2% in women were predicted to be within the revision benchmark. RS devices satisfying the 5% benchmark were unlikely to be cost-effective compared to THR at a standard UK willingness to pay of £20,000 per quality-adjusted life-year. However, the probability of cost effectiveness was sensitive to small changes in the costs of devices or in quality of life or revision rate estimates. Our results imply that in most cases RS has not been a cost-effective resource and should probably not be adopted by decision makers concerned with the cost effectiveness of hip replacement, or by patients concerned about the likelihood of revision, regardless of patient age or gender.

40 CFR 98.185 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... facility that estimate annual process CO2 emissions using the carbon mass balance procedure in § 98.183(b... best available estimate of the mass of the material from all available process data or data used for accounting purposes (such as purchase records). ...

An iterative procedure for obtaining maximum-likelihood estimates of the parameters for a mixture of normal distributions

NASA Technical Reports Server (NTRS)

Peters, B. C., Jr.; Walker, H. F.

1975-01-01

A general iterative procedure is given for determining the consistent maximum likelihood estimates of normal distributions. In addition, a local maximum of the log-likelihood function, Newtons's method, a method of scoring, and modifications of these procedures are discussed.

Accuracy of gestational age estimation from last menstrual period among women seeking abortion in South Africa, with a view to task sharing: a mixed methods study.

PubMed

Constant, Deborah; Harries, Jane; Moodley, Jennifer; Myer, Landon

2017-08-22

The requirement for ultrasound to establish gestational age among women seeking abortion can be a barrier to access. Last menstrual period dating without clinical examination should be a reasonable alternative among selected women, and if reliable, can be task-shared with non-clinicians. This study determines the accuracy of gestational age estimation using last menstrual period (LMP) assessed by community health care workers (CHWs), and explores providers' and CHWs' perspectives on task sharing this activity. The study purpose is to expand access to early medical abortion services. We conducted a multi-center cross-sectional study at four urban non-governmental reproductive health clinics in South Africa. CHWs interviewed women seeking abortion, recorded their LMP and gestational age from a pregnancy wheel if within 63 days. Thereafter, providers performed a standard examination including ultrasound to determine gestational age. Lastly, investigators calculated gestational age for all LMP dates recorded by CHWs. We compared mean gestational age from LMP dates to mean gestational age by ultrasound using t-tests and calculated proportions for those incorrectly assessed as eligible for medical abortion from LMP. In addition, in-depth interviews were conducted with six providers and seven CHWs. Mean gestational age was 5 days (by pregnancy wheel) and 9 days (by LMP calculation) less than ultrasound gestational age. Twelve percent of women were eligible for medical abortion by LMP calculation but ineligible by ultrasound. Uncertainty of LMP date was associated with incorrect assessment of gestational age eligibility for medical abortion (p = 0.015). For women certain their LMP date was within 56 days, 3% had ultrasound gestational ages >70 days. In general, providers and CHWs were in favour of task sharing screening and referral for abortion, but were doubtful that women reported accurate LMP dates. Different perspectives emerged on how to implement task sharing gestational age eligibility for medical abortion. If LMP recall is within 56 days, most women will be eligible for early medical abortion and LMP can substitute for ultrasound dating. Task sharing gestational age estimation is feasible in South Africa, but its implementation should meet women's privacy needs and address healthcare workers' concerns on managing any procedural risk.

Measuring automatic retrieval: a comparison of implicit memory, process dissociation, and speeded response procedures.

PubMed

Horton, Keith D; Wilson, Daryl E; Vonk, Jennifer; Kirby, Sarah L; Nielsen, Tina

2005-07-01

Using the stem completion task, we compared estimates of automatic retrieval from an implicit memory task, the process dissociation procedure, and the speeded response procedure. Two standard manipulations were employed. In Experiment 1, a depth of processing effect was found on automatic retrieval using the speeded response procedure although this effect was substantially reduced in Experiment 2 when lexical processing was required of all words. In Experiment 3, the speeded response procedure showed an advantage of full versus divided attention at study on automatic retrieval. An implicit condition showed parallel effects in each study, suggesting that implicit stem completion may normally provide a good estimate of automatic retrieval. Also, we replicated earlier findings from the process dissociation procedure, but estimates of automatic retrieval from this procedure were consistently lower than those from the speeded response procedure, except when conscious retrieval was relatively low. We discuss several factors that may contribute to the conflicting outcomes, including the evidence for theoretical assumptions and criterial task differences between implicit and explicit tests.

A baseline-free procedure for transformation models under interval censorship.

PubMed

Gu, Ming Gao; Sun, Liuquan; Zuo, Guoxin

2005-12-01

An important property of Cox regression model is that the estimation of regression parameters using the partial likelihood procedure does not depend on its baseline survival function. We call such a procedure baseline-free. Using marginal likelihood, we show that an baseline-free procedure can be derived for a class of general transformation models under interval censoring framework. The baseline-free procedure results a simplified and stable computation algorithm for some complicated and important semiparametric models, such as frailty models and heteroscedastic hazard/rank regression models, where the estimation procedures so far available involve estimation of the infinite dimensional baseline function. A detailed computational algorithm using Markov Chain Monte Carlo stochastic approximation is presented. The proposed procedure is demonstrated through extensive simulation studies, showing the validity of asymptotic consistency and normality. We also illustrate the procedure with a real data set from a study of breast cancer. A heuristic argument showing that the score function is a mean zero martingale is provided.

Robust estimation of the proportion of treatment effect explained by surrogate marker information.

PubMed

Parast, Layla; McDermott, Mary M; Tian, Lu

2016-05-10

In randomized treatment studies where the primary outcome requires long follow-up of patients and/or expensive or invasive obtainment procedures, the availability of a surrogate marker that could be used to estimate the treatment effect and could potentially be observed earlier than the primary outcome would allow researchers to make conclusions regarding the treatment effect with less required follow-up time and resources. The Prentice criterion for a valid surrogate marker requires that a test for treatment effect on the surrogate marker also be a valid test for treatment effect on the primary outcome of interest. Based on this criterion, methods have been developed to define and estimate the proportion of treatment effect on the primary outcome that is explained by the treatment effect on the surrogate marker. These methods aim to identify useful statistical surrogates that capture a large proportion of the treatment effect. However, current methods to estimate this proportion usually require restrictive model assumptions that may not hold in practice and thus may lead to biased estimates of this quantity. In this paper, we propose a nonparametric procedure to estimate the proportion of treatment effect on the primary outcome that is explained by the treatment effect on a potential surrogate marker and extend this procedure to a setting with multiple surrogate markers. We compare our approach with previously proposed model-based approaches and propose a variance estimation procedure based on a perturbation-resampling method. Simulation studies demonstrate that the procedure performs well in finite samples and outperforms model-based procedures when the specified models are not correct. We illustrate our proposed procedure using a data set from a randomized study investigating a group-mediated cognitive behavioral intervention for peripheral artery disease participants. Copyright © 2015 John Wiley & Sons, Ltd.

Menarcheal age of girls from dysfunctional families.

PubMed

Toromanović, Alma; Tahirović, Husref

2004-07-01

The objective of the present study was to determine median age at menarche and the influence of familial instability on maturation. The sample included 7047 girls between the ages of 9 and 17 years from Tuzla Canton. The girls were divided into two groups. Group A (N=5230) comprised girls who lived in families free of strong traumatic events. Group B (N=1817) included girls whose family dysfunction exposed them to prolonged distress. Probit analysis was performed to estimate mean menarcheal age using the Probit procedure of SAS package. The mean menarcheal age calculated by probit analysis for all the girls studied was 13.07 years. In girls from dysfunctional families a very clear shift toward earlier maturation was observed. The mean age at menarche for group B was 13.0 years, which was significantly lower that that for group A, 13.11 years (t=2.92, P<0.01). The results surveyed here lead to the conclusion that girls from dysfunctional families mature not later but even earlier than girls from normal families. This supports the hypothesis that stressful childhood life events accelerate maturation of girls.

The Payer and Patient Cost Burden of Open Breast Conserving Procedures Following Percutaneous Breast Biopsy.

PubMed

Kimball, Chloe C; Nichols, Christine I; Vose, Joshua G

2018-01-01

Percutaneous core-needle biopsy (PCNB) is the standard of care to biopsy and diagnose suspicious breast lesions. Dependent on histology, many patients require additional open procedures for definitive diagnosis and excision. This study estimated the payer and patient out-of-pocket (OOP) costs, and complication risk, among those requiring at least 1 open procedure following PCNB. This retrospective study used the Truven Commercial database (2009-2014). Women who underwent PCNB, with continuous insurance, and no history of cancer, chemotherapy, radiation, or breast surgery in the prior year were included. Open procedures were defined as open biopsy or lumpectomy. Study follow-up ended at chemotherapy, radiation, mastectomy, or 90 days-whichever occurred first. In total, 143 771 patients (mean age 48) met selection criteria; 85.1% underwent isolated PCNB, 12.4% one open procedure, and 2.5% re-excision. Incidence of complications was significantly lower among those with PCNB alone (9.2%) vs 1 open procedure (15.6%) or re-excision (25.3%, P  < .001). Mean incremental commercial payments were US $13 190 greater among patients with 1 open procedure vs PCNB alone (US $17 125 vs US $3935, P  < .001), and US $4767 greater with re-excision (US $21 892) relative to 1 procedure. Mean patient OOP cost was US $858 greater for 1 open procedure vs PCNB alone (US $1527 vs US $669), and US $247 greater for re-excision vs 1 procedure. A meaningful proportion of patients underwent open procedure(s) following PCNB which was associated with increased complication risk and costs to both the payer and the patient. These results suggest a need for technologies to reduce the proportion of cases requiring open surgery and, in some cases, re-excision.

Retroperitoneal versus direct femoral artery approach for thoracic endovascular aortic repair access: a case-control study.

PubMed

Etezadi, Vahid; Katzen, Barry T; Benenati, James F; Alehashemi, Sara; Tsoukas, Athanassios I; Puente, Orlando A

2011-04-01

Many individuals who are candidates for thoracic endovascular aortic repair (TEVAR) are found to have iliac artery anatomy and/or disease that preclude transfemoral endovascular access and require retroperitoneal surgical approach through more proximal arteries. This relatively more invasive technique could potentially affect the procedural outcomes. This study compares the retroperitoneal with transfemoral access used for TEVAR in a single center. In this study, 133 consecutive patients (96 men; mean age ± SD: 69.5 ± 14.7 years) who underwent TEVAR between 1994 and 2009 in a single center were retrospectively evaluated. The type of endovascular access was identified in all the patients. The basic demographics, access method, endograft type, 30-day morbidity and mortality rates, as well as procedure recordings including fluoroscopic and procedure duration, estimated blood loss, and duration of hospitalization were compared between the TEVAR procedures performed using a surgical retroperitoneal approach and those using the standard femoral access. Retroperitoneal access was used in 19 (14.3%; 13 women; mean age ± SD: 71 ± 12.2 years) and direct femoral access in 114 (85.7%; 24 women; mean age ± SD: 69 ± 15.4 years) patients. Two of the retroperitoneal accesses were obtained after failure of femoral approach. Techniques that were used included iliac artery conduit (seven patients), aortic artery conduit (eight patients), aortobifemoral artery graft conduit (one patient), and direct sheath introduction through the distal aorta (two patients) or common iliac artery (one patient). Retroperitoneal approach was used more frequently in women (35%) as compared with men (6%) (p = 0.0001). In all, 79% of the retroperitoneal approaches were associated with use of delivery sheath sizes larger than 24F (p = 0.049). TEVAR technical success was 100% with retroperitoneal and 97.3% with femoral access (p > 0.05). Thirty-day mortality rates were 0% and 8.8% and the rates of access artery injury were 5.3% and 4.4% in retroperitoneal and femoral access groups, respectively (p > 0.05). The incidence of retroperitoneal hematoma was significantly higher with retroperitoneal access (21% vs. 2.6%, p = 0.008). Additionally, retroperitoneal access was associated with significant increase in estimated blood loss and duration of hospitalization (p < 0.05). Type of access does not affect TEVAR success and the early mortality rate. Retroperitoneal approach is a valuable alternative technique in cases involving failed or impossible femoral access. However, this approach is associated with higher chances of retroperitoneal bleeding and longer procedural time and duration of hospitalization. Thoracic endografts with smaller delivery systems could minimize the need for this approach in the future. Copyright © 2011 Annals of Vascular Surgery Inc. All rights reserved.

Radiation exposure to eye lens and operator hands during endovascular procedures in hybrid operating rooms.

PubMed

Attigah, Nicolas; Oikonomou, Kyriakos; Hinz, Ulf; Knoch, Thomas; Demirel, Serdar; Verhoeven, Eric; Böckler, Dittmar

2016-01-01

The purpose of this study was to evaluate the radiation exposure of vascular surgeons' eye lens and fingers during complex endovascular procedures in modern hybrid operating rooms. Prospective, nonrandomized multicenter study design. One hundred seventy-one consecutive patients (138 male; median age, 72.5 years [interquartile range, 65-77 years]) underwent an endovascular procedure in a hybrid operating room between March 2012 and July 2013 in two vascular centers. The dose-area product (DAP), fluoroscopy time, operating time, and amount of contrast dye were registered prospectively. For radiation dose recordings, single-use dosimeters were attached at eye level and to the ring finger of the hand next to the radiation field of the operator for each endovascular procedure. Dose recordings were evaluated by an independent institution. Before the study, precursory investigations were obtained to simulate the radiation dose to eye lens and fingers with an Alderson phantome (RSD, Long Beach, Calif). Interventions were classified into six treatment categories: endovascular repair of infrarenal abdominal aneurysm (n = 65), thoracic endovascular aortic repair (n = 32), branched endovascular aortic repair for thoracoabdominal aneurysms (n = 17), fenestrated endovascular aortic repair for complex abdominal aortic aneurysm, (n = 25), iliac branched device (n = 8), and peripheral interventions (n = 24). There was a significant correlation in DAP between both lens (P < .01; r = 0.55) and finger (P < .01; r = 0.56) doses. The estimated fluoroscopy time to reach a radiation threshold of 20 mSv/y was 1404.10 minutes (90% confidence limit, 1160, 1650 minutes). According to correlation of the lens dose with the DAP an estimated cumulative DAP of 932,000 mGy/m(2) (90% confidence limit, 822,000, 1,039,000) would be critical for a threshold of 20 mSv/y for the eyes. Radiation protection is a serious issue for vascular surgeons because most complex endovascular procedures are delivering measurable radiation to the eyes. With the correlation of the DAP obtained in standard endovascular procedures a critical threshold of 20 mSv/y to the eyes can be predicted and thus an estimate of a potential harmful exposure to the eyes can be obtained. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Factors associated with variations in hospital expenditures for acute heart failure in the United States.

PubMed

Ziaeian, Boback; Sharma, Puza P; Yu, Tzy-Chyi; Johnson, Katherine Waltman; Fonarow, Gregg C

2015-02-01

Relatively little contemporary data are available that describe differences in acute heart failure (AHF) hospitalization expenditures as a function of patient and hospital characteristics, especially from a population-based investigation. This study aimed to evaluate factors associated with variations in hospital expenditures for AHF in the United States. A cross-sectional analysis using discharge data from the 2011 Nationwide Inpatient Sample, Healthcare Cost and Utilization Project, was conducted. Discharges with primary International Classification of Diseases, Ninth Revision, Clinical Modification, diagnosis codes for AHF in adults were included. Costs were estimated by converting Nationwide Inpatient Sample charge data using the Healthcare Cost and Utilization Project Cost-to-Charge Ratio File. Discharges with highest (≥80th percentile) versus lowest (≤20th percentile) costs were compared for patient characteristics, hospital characteristics, utilization of procedures, and outcomes. Of the estimated 1 million AHF hospital discharges, the mean cost estimates were $10,775 per episode. Younger age, higher percentage of obesity, atrial fibrillation, pulmonary disease, fluid/electrolyte disturbances, renal insufficiency, and greater number of cardiac/noncardiac procedures were observed in stays with highest versus lowest costs. Highest-cost discharges were more likely to be observed in urban and teaching hospitals. Highest-cost AHF discharges also had 5 times longer length of stay, were 9 times more costly, and had higher in-hospital mortality (5.6% vs 3.5%) compared with discharges with lowest costs (all P < .001). Acute heart failure hospitalizations are costly. Expenditures vary markedly among AHF hospitalizations in the United States, with substantial differences in patient and hospital characteristics, procedures, and in-hospital outcomes among discharges with highest compared with lowest costs. Copyright © 2014 Elsevier Inc. All rights reserved.

On the impact of different approaches to classify age-related macular degeneration: Results from the German AugUR study.

PubMed

Brandl, Caroline; Zimmermann, Martina E; Günther, Felix; Barth, Teresa; Olden, Matthias; Schelter, Sabine C; Kronenberg, Florian; Loss, Julika; Küchenhoff, Helmut; Helbig, Horst; Weber, Bernhard H F; Stark, Klaus J; Heid, Iris M

2018-06-06

While age-related macular degeneration (AMD) poses an important personal and public health burden, comparing epidemiological studies on AMD is hampered by differing approaches to classify AMD. In our AugUR study survey, recruiting residents from in/around Regensburg, Germany, aged 70+, we analyzed the AMD status derived from color fundus images applying two different classification systems. Based on 1,040 participants with gradable fundus images for at least one eye, we show that including individuals with only one gradable eye (n = 155) underestimates AMD prevalence and we provide a correction procedure. Bias-corrected and standardized to the Bavarian population, late AMD prevalence is 7.3% (95% confidence interval = [5.4; 9.4]). We find substantially different prevalence estimates for "early/intermediate AMD" depending on the classification system: 45.3% (95%-CI = [41.8; 48.7]) applying the Clinical Classification (early/intermediate AMD) or 17.1% (95%-CI = [14.6; 19.7]) applying the Three Continent AMD Consortium Severity Scale (mild/moderate/severe early AMD). We thus provide a first effort to grade AMD in a complete study with different classification systems, a first approach for bias-correction from individuals with only one gradable eye, and the first AMD prevalence estimates from a German elderly population. Our results underscore substantial differences for early/intermediate AMD prevalence estimates between classification systems and an urgent need for harmonization.

On the existence of maximum likelihood estimates for presence-only data

USGS Publications Warehouse

Hefley, Trevor J.; Hooten, Mevin B.

2015-01-01

It is important to identify conditions for which maximum likelihood estimates are unlikely to be identifiable from presence-only data. In data sets where the maximum likelihood estimates do not exist, penalized likelihood and Bayesian methods will produce coefficient estimates, but these are sensitive to the choice of estimation procedure and prior or penalty term. When sample size is small or it is thought that habitat preferences are strong, we propose a suite of estimation procedures researchers can consider using.

Personal Distress and Sympathy Differentially Influence Health Care Professional and Parents' Estimation of Child Procedure-Related Pain.

PubMed

Caes, Line; Goubert, Liesbet; Devos, Patricia; Verlooy, Joris; Benoit, Yves; Vervoort, Tine

2017-02-01

Caregivers’ pain estimations may have important implications for pediatric pain management decisions. Affective responses elicited by facing the child in pain are considered key in understanding caregivers’ estimations of pediatric pain experiences. Theory suggests differential influences of sympathy versus personal distress on pain estimations; yet empirical evidence on the impact of caregivers’ feelings of sympathy versus distress upon estimations of pediatric pain experiences is lacking. The current study explored the role of caregiver distress versus sympathy in understanding caregivers’ pain estimates of the child’s pain experience. Using a prospective design in 31 children undergoing consecutive lumbar punctures and/or bone marrow aspirations at Ghent University Hospital, caregivers’ (i.e., parents, physicians, nurses, and child life specialists) distress and sympathy were assessed before each procedure; estimates of child pain were obtained immediately following each procedure. Results indicated that the child’s level of pain behavior in anticipation of the procedure had a strong influence on all caregivers’ pain estimations. Beyond the impact of child pain behavior, personal distress explained parental and physician’s estimates of child pain, but not pain estimates of nurses and child life specialists. Specifically, higher level of parental and physician’s distress was related to higher child pain estimates. Caregiver sympathy was not associated with pain estimations. The current findings highlight the important role of caregivers’ felt personal distress when faced with child pain, rather than sympathy, in influencing their pain estimates. Potential implications for pain management are discussed.

Unbiased Estimates of Variance Components with Bootstrap Procedures

ERIC Educational Resources Information Center

Brennan, Robert L.

2007-01-01

This article provides general procedures for obtaining unbiased estimates of variance components for any random-model balanced design under any bootstrap sampling plan, with the focus on designs of the type typically used in generalizability theory. The results reported here are particularly helpful when the bootstrap is used to estimate standard…

40 CFR 98.275 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.365 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.365 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.175 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.345 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.465 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.355 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter must be used in the calculations, according to the following...

40 CFR 98.265 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) For each missing value of the inorganic carbon content of phosphate rock or... immediately preceding and immediately following the missing data incident. You must document and keep records...

40 CFR 98.215 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.55 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.125 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... unavailable, a substitute data value for the missing parameter must be used in the calculations as specified...

40 CFR 98.265 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.175 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.125 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... unavailable, a substitute data value for the missing parameter must be used in the calculations as specified...

40 CFR 98.275 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.215 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.345 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.345 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.115 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.325 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.175 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.215 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.55 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.325 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.275 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.215 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.355 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter must be used in the calculations, according to the following...

40 CFR 98.275 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.365 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.65 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations, according to the following...

40 CFR 98.65 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations, according to the following...

40 CFR 98.265 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) For each missing value of the inorganic carbon content of phosphate rock or... immediately preceding and immediately following the missing data incident. You must document and keep records...

40 CFR 98.115 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.115 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.265 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) For each missing value of the inorganic carbon content of phosphate rock or... immediately preceding and immediately following the missing data incident. You must document and keep records...

40 CFR 98.115 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.225 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.175 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.115 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.125 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... unavailable, a substitute data value for the missing parameter must be used in the calculations as specified...

40 CFR 98.355 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter must be used in the calculations, according to the following...

40 CFR 98.465 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.325 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.365 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.465 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.225 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.345 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.65 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations, according to the following...

40 CFR 98.125 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... unavailable, a substitute data value for the missing parameter must be used in the calculations as specified...

40 CFR 98.55 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.55 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.65 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations, according to the following...

40 CFR 98.265 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter must be used in the calculations as specified in paragraphs...

40 CFR 98.355 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter must be used in the calculations, according to the following...

40 CFR 98.345 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... for estimating missing data. A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

40 CFR 98.215 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... for estimating missing data. (a) A complete record of all measured parameters used in the GHG... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.325 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.465 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, in accordance with...

40 CFR 98.175 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.225 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.65 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations, according to the following...

40 CFR 98.225 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... substitute data value for the missing parameter shall be used in the calculations as specified in paragraphs...

40 CFR 98.365 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emissions... substitute data value for the missing parameter shall be used in the calculations, according to the...

Estimating Slope and Level Change in N = 1 Designs

ERIC Educational Resources Information Center

Solanas, Antonio; Manolov, Rumen; Onghena, Patrick

2010-01-01

The current study proposes a new procedure for separately estimating slope change and level change between two adjacent phases in single-case designs. The procedure eliminates baseline trend from the whole data series before assessing treatment effectiveness. The steps necessary to obtain the estimates are presented in detail, explained, and…

Item Selection and Ability Estimation Procedures for a Mixed-Format Adaptive Test

ERIC Educational Resources Information Center

Ho, Tsung-Han; Dodd, Barbara G.

2012-01-01

In this study we compared five item selection procedures using three ability estimation methods in the context of a mixed-format adaptive test based on the generalized partial credit model. The item selection procedures used were maximum posterior weighted information, maximum expected information, maximum posterior weighted Kullback-Leibler…

Procedure for estimating orbital debris risks

NASA Technical Reports Server (NTRS)

Crafts, J. L.; Lindberg, J. P.

1985-01-01

A procedure for estimating the potential orbital debris risk to the world's populace from payloads or spent stages left in orbit on future missions is presented. This approach provides a consistent, but simple, procedure to assess the risk due to random reentry with an adequate accuracy level for making programmatic decisions on planned low Earth orbit missions.

Elderly poverty and Supplemental Security Income.

PubMed

Nicholas, Joyce; Wiseman, Michael

2009-01-01

In the United States, poverty is generally assessed on the basis of income, as reported in the Current Population Survey's (CPS's) Annual Social and Economic Supplement (ASEC), using an official poverty standard established in the 1960s. The prevalence of receipt of means-tested transfers is underreported in the CPS, with uncertain consequences for the measurement of poverty rates by both the official standard and by using alternative "relative" measures linked to the contemporaneous income distribution. The article reports results estimating the prevalence of poverty in 2002. We complete this effort by using a version of the 2003 CPS/ASEC for which a substantial majority (76 percent) of respondents have individual records matching administrative data from the Social Security Administration on earnings and receipt of income from the Old-Age, Survivors, and Disability Insurance and Supplemental Security Income (SSI) programs. Adjustment of the CPS income data with administrative data substantially improves coverage of SSI receipt. The consequence for general poverty is sensitive to the merge procedures employed, but under both sets of merge procedures considered, the estimated poverty rate among all elderly persons and among elderly SSI recipients is substantially less than rates estimated using the unadjusted CPS. The effect of the administrative adjustment is less significant for perception of relative poverty than for absolute poverty. We emphasize the effect of these adjustments on perception of poverty among the elderly in general and elderly SSI recipients in particular.

A reexamination of age-related variation in body weight and morphometry of Maryland nutria

USGS Publications Warehouse

Sherfy, M.H.; Mollett, T.A.; McGowan, K.R.; Daugherty, S.L.

2006-01-01

Age-related variation in morphometry has been documented for many species. Knowledge of growth patterns can be useful for modeling energetics, detecting physiological influences on populations, and predicting age. These benefits have shown value in understanding population dynamics of invasive species, particularly in developing efficient control and eradication programs. However, development and evaluation of descriptive and predictive models is a critical initial step in this process. Accordingly, we used data from necropsies of 1,544 nutria (Myocastor coypus) collected in Maryland, USA, to evaluate the accuracy of previously published models for prediction of nutria age from body weight. Published models underestimated body weights of our animals, especially for ages <3. We used cross-validation procedures to develop and evaluate models for describing nutria growth patterns and for predicting nutria age. We derived models from a randomly selected model-building data set (n = 192-193 M, 217-222 F) and evaluated them with the remaining animals (n = 487-488 M, 642-647 F). We used nonlinear regression to develop Gompertz growth-curve models relating morphometric variables to age. Predicted values of morphometric variables fell within the 95% confidence limits of their true values for most age classes. We also developed predictive models for estimating nutria age from morphometry, using linear regression of log-transformed age on morphometric variables. The evaluation data set corresponded with 95% prediction intervals from the new models. Predictive models for body weight and length provided greater accuracy and less bias than models for foot length and axillary girth. Our growth models accurately described age-related variation in nutria morphometry, and our predictive models provided accurate estimates of ages from morphometry that will be useful for live-captured individuals. Our models offer better accuracy and precision than previously published models, providing a capacity for modeling energetics and growth patterns of Maryland nutria as well as an empirical basis for determining population age structure from live-captured animals.

Relative age effect and Yo-Yo IR1 in youth soccer.

PubMed

Deprez, D; Vaeyens, R; Coutts, A J; Lenoir, M; Philippaerts, R

2012-12-01

The aims of the study were to investigate the presence of a relative age effect and the influence of birth quarter on anthropometric characteristics, an estimation of biological maturity and performance in the Yo-Yo Intermittent Recovery Test level 1 in 606 elite, Flemish youth soccer players. The sample was divided into 5 chronological age groups (U10-U19), each subdivided into 4 birth quarters. Players had their APHV estimated and height, weight and Yo-Yo IR1 performance were assessed. Differences between quarters were investigated using uni- and multivariate analyses. Overall, significantly (P<0.001) more players were born in the first quarter (37.6%) compared to the last (13.2%). Further, no significant differences in anthropometric variables and Yo-Yo IR1 performance were found between the 4 birth quarters. However, there was a trend for players born in the first quarter being taller and heavier than players born in the fourth quarter. Players born in the last quarter tended to experience their peak in growth earlier, this may have enabled them to compete physically with their relatively older peers. Our results indicated selection procedures which are focused on the formation of strong physical and physiological homogeneous groups. Relative age and individual biological maturation should be considered when selecting adolescent soccer players. © Georg Thieme Verlag KG Stuttgart · New York.

Estimation procedures to measure and monitor failure rates of components during thermal-vacuum testing

NASA Technical Reports Server (NTRS)

Williams, R. E.; Kruger, R.

1980-01-01

Estimation procedures are described for measuring component failure rates, for comparing the failure rates of two different groups of components, and for formulating confidence intervals for testing hypotheses (based on failure rates) that the two groups perform similarly or differently. Appendix A contains an example of an analysis in which these methods are applied to investigate the characteristics of two groups of spacecraft components. The estimation procedures are adaptable to system level testing and to monitoring failure characteristics in orbit.

The multicategory case of the sequential Bayesian pixel selection and estimation procedure

NASA Technical Reports Server (NTRS)

Pore, M. D.; Dennis, T. B. (Principal Investigator)

1980-01-01

A Bayesian technique for stratified proportion estimation and a sampling based on minimizing the mean squared error of this estimator were developed and tested on LANDSAT multispectral scanner data using the beta density function to model the prior distribution in the two-class case. An extention of this procedure to the k-class case is considered. A generalization of the beta function is shown to be a density function for the general case which allows the procedure to be extended.

Time from cervical conization to pregnancy and preterm birth.

PubMed

Himes, Katherine P; Simhan, Hyagriv N

2007-02-01

To estimate whether the time interval between cervical conization and subsequent pregnancy is associated with risk of preterm birth. Our study is a case control study nested in a retrospective cohort. Women who underwent colposcopic biopsy or conization with loop electrosurgical excision procedure, large loop excision of the transformation zone, or cold knife cone and subsequently delivered at our hospital were identified with electronic databases. Variables considered as possible confounders included maternal race, age, marital status, payor status, years of education, self-reported tobacco use, history of preterm delivery, and dimensions of cone specimen. Conization was not associated with preterm birth or any subtypes of preterm birth. Among women who underwent conization, those with a subsequent preterm birth had a shorter conization-to-pregnancy interval (337 days) than women with a subsequent term birth (581 days) (P=.004). The association between short conization-to-pregnancy interval and preterm birth remained significant when controlling for confounders including race and cone dimensions. The effect of short conization-to-pregnancy interval on subsequent preterm birth was more persistent among African Americans when compared with white women. Women with a short conization-to-pregnancy interval are at increased risk for preterm birth. Women of reproductive age who must have a conization procedure can be counseled that conceiving within 2 to 3 months of the procedure may be associated with an increased risk of preterm birth. II.

Diagnostic Nuclear Medicine for Paediatric Patients in Australia: Assessing the Individual's Dose Burden.

PubMed

Bartlett, Marissa L; Forsythe, Anna; Brady, Zoe; Mathews, John D

2018-05-01

We report data for all Australians aged 0-19 y who underwent publicly funded nuclear medicine studies between 1985 and 2005, inclusive. Radiation doses were estimated for individual patients for 95 different types of studies. There were 374 848 occasions of service for 277 511 patients with a collective effective dose of 1123 Sievert (Sv). Most services were either bone scans (45%) or renal scans (29%), with renal scans predominating at younger ages and bone scans at older ages. This pattern persisted despite a 4-fold increase in the annual number of procedures. Younger children were more likely to experience multiple scans, with the third quartile of scans per patient dropping from two to one with patient age. The median effective dose per patient ranged from 1.3 mSv (4-7 y old) to 2.8 mSv (13-16 y old). This large data set provides valuable information on nuclear medicine services for young Australians in the period 1985-2005.

40 CFR 98.145 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Glass Production § 98.145 Procedures for estimating... carbonate-based raw materials charged to any continuous glass melting furnace use the best available...

40 CFR 98.145 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Glass Production § 98.145 Procedures for estimating... carbonate-based raw materials charged to any continuous glass melting furnace use the best available...

15 CFR 90.4 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... OF COMMERCE PROCEDURE FOR CHALLENGING POPULATION ESTIMATES § 90.4 General. This part provides a procedure for a governmental unit to request a challenge of a population estimate of the Census Bureau. The...

Using age on clothes size label to estimate weight in emergency paediatric patients.

PubMed

Elgie, Laura D; Williams, Andrew R

2012-10-01

To study formulae that estimate children's weight using their actual age. To determine whether using the age on their clothes size label in these formulae can estimate weight when their actual age is unknown. The actual age and age on the clothes labels of 188 children were inserted into formulae that estimate children's weight. These estimates were compared with their actual weight. Bland-Altman plots calculated the precision and accuracy of each of these estimates. In all formulae, using age on the clothes sizes label provided a more precise estimate than the child's actual age. In emergencies where a child's age is unknown, use of the age on their clothes label in weight-estimating formulae yields acceptable weight estimates. Even in situations where a child's age is known, the age on their clothes label may provide a more accurate and precise weight estimate than the actual age.

Preschool predictors of mathematics in first grade children with autism spectrum disorder.

PubMed

Titeca, Daisy; Roeyers, Herbert; Josephy, Haeike; Ceulemans, Annelies; Desoete, Annemie

2014-11-01

Up till now, research evidence on the mathematical abilities of children with autism spectrum disorder (ASD) has been scarce and provided mixed results. The current study examined the predictive value of five early numerical competencies for four domains of mathematics in first grade. Thirty-three high-functioning children with ASD were followed up from preschool to first grade and compared with 54 typically developing children, as well as with normed samples in first grade. Five early numerical competencies were tested in preschool (5-6 years): verbal subitizing, counting, magnitude comparison, estimation, and arithmetic operations. Four domains of mathematics were used as outcome variables in first grade (6-7 years): procedural calculation, number fact retrieval, word/language problems, and time-related competences. Children with ASD showed similar early numerical competencies at preschool age as typically developing children. Moreover, they scored average on number fact retrieval and time-related competences and higher on procedural calculation and word/language problems compared to the normed population in first grade. When predicting first grade mathematics performance in children with ASD, both verbal subitizing and counting seemed to be important to evaluate at preschool age. Verbal subitizing had a higher predictive value in children with ASD than in typically developing children. Whereas verbal subitizing was predictive for procedural calculation, number fact retrieval, and word/language problems, counting was predictive for procedural calculation and, to a lesser extent, number fact retrieval. Implications and directions for future research are discussed. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Estimation of methane emission rate changes using age-defined waste in a landfill site.

PubMed

Ishii, Kazuei; Furuichi, Toru

2013-09-01

Long term methane emissions from landfill sites are often predicted by first-order decay (FOD) models, in which the default coefficients of the methane generation potential and the methane generation rate given by the Intergovernmental Panel on Climate Change (IPCC) are usually used. However, previous studies have demonstrated the large uncertainty in these coefficients because they are derived from a calibration procedure under ideal steady-state conditions, not actual landfill site conditions. In this study, the coefficients in the FOD model were estimated by a new approach to predict more precise long term methane generation by considering region-specific conditions. In the new approach, age-defined waste samples, which had been under the actual landfill site conditions, were collected in Hokkaido, Japan (in cold region), and the time series data on the age-defined waste sample's methane generation potential was used to estimate the coefficients in the FOD model. The degradation coefficients were 0.0501/y and 0.0621/y for paper and food waste, and the methane generation potentials were 214.4 mL/g-wet waste and 126.7 mL/g-wet waste for paper and food waste, respectively. These coefficients were compared with the default coefficients given by the IPCC. Although the degradation coefficient for food waste was smaller than the default value, the other coefficients were within the range of the default coefficients. With these new coefficients to calculate methane generation, the long term methane emissions from the landfill site was estimated at 1.35×10(4)m(3)-CH(4), which corresponds to approximately 2.53% of the total carbon dioxide emissions in the city (5.34×10(5)t-CO(2)/y). Copyright © 2013 Elsevier Ltd. All rights reserved.

Estimating the probability of rare events: addressing zero failure data.

PubMed

Quigley, John; Revie, Matthew

2011-07-01

Traditional statistical procedures for estimating the probability of an event result in an estimate of zero when no events are realized. Alternative inferential procedures have been proposed for the situation where zero events have been realized but often these are ad hoc, relying on selecting methods dependent on the data that have been realized. Such data-dependent inference decisions violate fundamental statistical principles, resulting in estimation procedures whose benefits are difficult to assess. In this article, we propose estimating the probability of an event occurring through minimax inference on the probability that future samples of equal size realize no more events than that in the data on which the inference is based. Although motivated by inference on rare events, the method is not restricted to zero event data and closely approximates the maximum likelihood estimate (MLE) for nonzero data. The use of the minimax procedure provides a risk adverse inferential procedure where there are no events realized. A comparison is made with the MLE and regions of the underlying probability are identified where this approach is superior. Moreover, a comparison is made with three standard approaches to supporting inference where no event data are realized, which we argue are unduly pessimistic. We show that for situations of zero events the estimator can be simply approximated with 1/2.5n, where n is the number of trials. © 2011 Society for Risk Analysis.

Percutaneous closure of patent foramen ovale and atrial septal defect in adults: the impact of clinical variables and hospital procedure volume on in-hospital adverse events.

PubMed

Opotowsky, Alexander R; Landzberg, Michael J; Kimmel, Stephen E; Webb, Gary D

2009-05-01

Percutaneous closure of patent foramen ovale/atrial septal defect (PFO/ASD) is an increasingly common procedure perceived as having minimal risk. There are no population-based estimates of in-hospital adverse event rates of percutaneous PFO/ASD closure. We used nationally representative data from the 2001-2005 Nationwide Inpatient Sample to identify patients >or-=20 years old admitted to an acute care hospital with an International Classification of Diseases, Ninth Revision code designating percutaneous PFO/ASD closure on the first or second hospital day. Variables analyzed included age, sex, number of comorbidities, year, same-day use of intracardiac or other echocardiography, same-day left heart catheterization, hospital size and teaching status, PFO/ASD procedural volume, and coronary intervention volume. Outcomes of interest included length of stay, charges, and adverse events. The study included 2,555 (weighted to United States population: 12,544 +/- 1,987) PFO/ASD closure procedures. Mean age was 52.0 +/- 0.4 years, and 57.3% +/- 1.0% were women. Annual hospital volume averaged 40.8 +/- 7.7 procedures (range, 1-114). Overall, 8.2 +/- 0.8% of admissions involved an adverse event. Older patients and those with comorbidities were more likely to sustain adverse events. Use of intracardiac echocardiography was associated with fewer adverse events. The risk of adverse events was inversely proportional to annual hospital volume (odds ratio [OR] 0.91, 95% confidence interval [CI] 0.86-0.96, per 10 procedures), even after limiting the analysis to hospitals performing >or=10 procedures annually (OR 0.91, 95% CI 0.85-0.98). Adverse events were more frequent at hospitals in the lowest volume quintile as compared with the highest volume quintile (13.3% vs 5.4%, OR 2.42, 95% CI 1.55-3.78). The risk of adverse events of percutaneous PFO/ASD closure is inversely correlated with hospital volume. This relationship applies even to hospitals meeting the current guidelines, performing >or=10 procedures annually.

Incidence of acute postoperative infections requiring reoperation after arthroscopic shoulder surgery.

PubMed

Yeranosian, Michael G; Arshi, Armin; Terrell, Rodney D; Wang, Jeffrey C; McAllister, David R; Petrigliano, Frank A

2014-02-01

An acute infection after arthroscopic shoulder surgery is a rare but serious complication. Previous studies estimating the incidence of infections after arthroscopic surgery have been conducted, but the majority of these had either relatively small study groups or were not specific to shoulder arthroscopic surgery. To investigate the incidence of acute infections after arthroscopic shoulder surgery and compare infection rates by age group, sex, geographic region, and specific procedures. Case series; Level of evidence, 4. A retrospective review of a large insurance company database was performed for all shoulder arthroscopic surgeries performed in the United States between 2004 and 2009 that required additional surgery for infections within 30 days. The data were stratified by sex, age group, and region. Data were also stratified for specific procedures (capsulorrhaphy, treatment for superior labrum anterior-posterior tears, claviculectomy, decompression, and rotator cuff repair) and used to assess the variation in the incidence of infections across different arthroscopic shoulder procedures. Linear regression was used to determine the significance of differences in the data from year to year. χ(2) analysis was used to assess the statistical significance of variations among all groups. Poisson regression analysis with exposure was used to determine significant differences in a pairwise comparison between 2 groups. The total number of arthroscopic shoulder surgeries performed was 165,820, and the number of infections requiring additional surgery was 450, resulting in an overall infection rate of 0.27%. The incidence of infections varied significantly across age groups (P < .001); the infection rate was highest in the ≥60-year age group (0.36%) and lowest in the 10- to 39-year age group (0.18%). The incidence of infections also varied by region (P < .001); the incidence was highest in the South (0.37%) and lowest in the Midwest (0.11%). The incidence of infection treatments was also significantly different between different arthroscopic procedures (P < .01) and was highest for rotator cuff repair (0.29%) and lowest for capsulorrhaphy (0.16%). The incidence did not significantly vary by year or sex. The overall infection rate for all arthroscopic shoulder procedures was 0.27%. The incidence was highest in elderly patients, in the South, and for rotator cuff repair. The incidence was lowest in young patients, in the Midwest, and for capsulorrhaphy. In general, shoulder arthroscopic surgery in this study population had a low rate of reoperation in the acute period.

Habit and recollection in healthy aging, mild cognitive impairment, and Alzheimer's disease.

PubMed

Guerdoux, Estelle; Dressaire, Déborah; Martin, Sophie; Adam, Stéphane; Brouillet, Denis

2012-07-01

This study aimed to create a new French version of the Hay and Jacoby habit-training procedure (1996; 1999) and apply it to novel populations to determine the degree to which habit and recollection were affected. 36 young, 32 middle-aged, and 37 older adults participated in Experiment 1. 17 controls, 17 patients with amnestic Mild Cognitive Impairment (a-MCI), and 17 patients with Alzheimer's disease (AD) were involved in Experiment 2. Participants were assessed across a variety of demographic, neuropsychological and psychopathological variables (e.g., depressive affects, subjective experience of cognitive failures, interference sensitivity). The habit-training process-dissociation was used to explore the cognitive mechanisms underlying memory slips to separate the contribution of habit and recollection to memory performance. The data show a very clear pattern of decreased recollection with age, F(2, 102) = 25.12, p < .001, η²(p) = .197, and age-related neurological impairment, F(2, 48) = 39.22, p < .001, η²(p) = .62, with intact use of habit-based memory. Additional evidence for the validity of the process estimates is provided by theoretically meaningful correlations between the process estimates and measures of attentional control (Stroop test: r = -0.40) and subjective memory complaint (r = -0.45). Although likely not the same as familiarity, the data add to a growing literature suggesting that controlled forms of memory decline with age and in age-related neurological conditions (MCI and AD) whereas more automatic forms of memory (habit) remain intact. This research should improve understanding of memory complaints, preclinical and clinical dementia, and help target processes for rehabilitation.

Assessment of MRI-Based Automated Fetal Cerebral Cortical Folding Measures in Prediction of Gestational Age in the Third Trimester.

PubMed

Wu, J; Awate, S P; Licht, D J; Clouchoux, C; du Plessis, A J; Avants, B B; Vossough, A; Gee, J C; Limperopoulos, C

2015-07-01

Traditional methods of dating a pregnancy based on history or sonographic assessment have a large variation in the third trimester. We aimed to assess the ability of various quantitative measures of brain cortical folding on MR imaging in determining fetal gestational age in the third trimester. We evaluated 8 different quantitative cortical folding measures to predict gestational age in 33 healthy fetuses by using T2-weighted fetal MR imaging. We compared the accuracy of the prediction of gestational age by these cortical folding measures with the accuracy of prediction by brain volume measurement and by a previously reported semiquantitative visual scale of brain maturity. Regression models were constructed, and measurement biases and variances were determined via a cross-validation procedure. The cortical folding measures are accurate in the estimation and prediction of gestational age (mean of the absolute error, 0.43 ± 0.45 weeks) and perform better than (P = .024) brain volume (mean of the absolute error, 0.72 ± 0.61 weeks) or sonography measures (SDs approximately 1.5 weeks, as reported in literature). Prediction accuracy is comparable with that of the semiquantitative visual assessment score (mean, 0.57 ± 0.41 weeks). Quantitative cortical folding measures such as global average curvedness can be an accurate and reliable estimator of gestational age and brain maturity for healthy fetuses in the third trimester and have the potential to be an indicator of brain-growth delays for at-risk fetuses and preterm neonates. © 2015 by American Journal of Neuroradiology.

Effects of trimming weight-for-height data on growth-chart percentiles1–3

PubMed Central

Flegal, Katherine M; Carroll, Margaret D; Ogden, Cynthia L

2016-01-01

Background Before estimating smoothed percentiles of weight-for-height and BMI-for-age to construct the WHO growth charts, WHO excluded observations that were considered to represent unhealthy weights for height. Objective The objective was to estimate the effects of similar data trimming on empirical percentiles from the CDC growth-chart data set relative to the smoothed WHO percentiles for ages 24–59 mo. Design We used the nationally representative US weight and height data from 1971 to 1994, which was the source data for the 2000 CDC growth charts. Trimming cutoffs were calculated on the basis of weight-for-height for 9722 children aged 24–71 mo. Empirical percentiles for 7315 children aged 24–59 mo were compared with the corresponding smoothed WHO percentiles. Results Before trimming, the mean empirical percentiles for weight-for-height in the CDC data set were higher than the corresponding smoothed WHO percentiles. After trimming, the mean empirical 95th and 97th percentiles of weight-for-height were lower than the WHO percentiles, and the proportion of children in the CDC data set above the WHO 95th percentile decreased from 7% to 5%. The findings were similar for BMI-for-age. However, for weight-for-age, which had not been trimmed by the WHO, the empirical percentiles before trimming agreed closely with the upper percentiles from the WHO charts. Conclusion WHO data-trimming procedures may account for some of the differences between the WHO growth charts and the 2000 CDC growth charts. PMID:22990032

Procedure-related risk of miscarriage following amniocentesis and chorionic villus sampling: a systematic review and meta-analysis.

PubMed

Akolekar, R; Beta, J; Picciarelli, G; Ogilvie, C; D'Antonio, F

2015-01-01

To estimate procedure-related risks of miscarriage following amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and a meta-analysis. A search of MEDLINE, EMBASE, CINHAL and The Cochrane Library (2000-2014) was performed to review relevant citations reporting procedure-related complications of amniocentesis and CVS. Only studies reporting data on more than 1000 procedures were included in this review to minimize the effect of bias from smaller studies. Heterogeneity between studies was estimated using Cochran's Q, the I(2) statistic and Egger bias. Meta-analysis of proportions was used to derive weighted pooled estimates for the risk of miscarriage before 24 weeks' gestation. Incidence-rate difference meta-analysis was used to estimate pooled procedure-related risks. The weighted pooled risks of miscarriage following invasive procedures were estimated from analysis of controlled studies including 324 losses in 42 716 women who underwent amniocentesis and 207 losses in 8899 women who underwent CVS. The risk of miscarriage prior to 24 weeks in women who underwent amniocentesis and CVS was 0.81% (95% CI, 0.58-1.08%) and 2.18% (95% CI, 1.61-2.82%), respectively. The background rates of miscarriage in women from the control group that did not undergo any procedures were 0.67% (95% CI, 0.46-0.91%) for amniocentesis and 1.79% (95% CI, 0.61-3.58%) for CVS. The weighted pooled procedure-related risks of miscarriage for amniocentesis and CVS were 0.11% (95% CI, -0.04 to 0.26%) and 0.22% (95% CI, -0.71 to 1.16%), respectively. The procedure-related risks of miscarriage following amniocentesis and CVS are much lower than are currently quoted. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Ergonomic task analysis of ultrasound-guided femoral nerve block: a pilot study.

PubMed

Ajmal, Muhammad; Power, Susan; Smith, Tim; Shorten, George D

2011-02-01

To apply ergonomic task analysis to the performance of ultrasound-guided (US-guided) femoral nerve block (FNB) in an acute hospital setting. Pilot prospective observational study. Orthopedic operating room of a regional trauma hospital. 15 anesthesiologists of various levels of experience in US-guided FNB (estimated minimum experience < 10 procedures; maximum about 50 procedures, and from basic trainees to consultants); and 15 patients (5 men and 10 women), aged 77 ± 15 (mean ± SD yrs) years. MEASUREMENTS/OBSERVATIONS: A data capture "tool", which was modified from one previously developed for ergonomic study of spinal anesthesia, was studied. Patient, operator, and heterogeneous environmental factors related to ergonomic performance of US-guided FNB were identified. The observation period started immediately before commencement of positioning the patient and ended on completion of perineural injection. Data were acquired using direct observations, photography, and application of a questionnaire. The quality of ergonomic performance was generally suboptimal and varied greatly among operators. Eight (experience < 10 procedures) of 15 operators excessively rotated their head, neck, and/or back to visualize the image on the ultrasound machine. Eight operators (experience < 10 procedures) performed the procedure with excessive thoracolumbar flexion. Performance of US-guided FNB presents ergonomic challenges and was suboptimal during most of the procedures observed. Formal training in US-guided peripheral nerve blockade should include reference to ergonomic factors. Copyright © 2011 Elsevier Inc. All rights reserved.

Ngram time series model to predict activity type and energy cost from wrist, hip and ankle accelerometers: implications of age

PubMed Central

Strath, Scott J; Kate, Rohit J; Keenan, Kevin G; Welch, Whitney A; Swartz, Ann M

2016-01-01

To develop and test time series single site and multi-site placement models, we used wrist, hip and ankle processed accelerometer data to estimate energy cost and type of physical activity in adults. Ninety-nine subjects in three age groups (18–39, 40–64, 65 + years) performed 11 activities while wearing three triaxial accelereometers: one each on the non-dominant wrist, hip, and ankle. During each activity net oxygen cost (METs) was assessed. The time series of accelerometer signals were represented in terms of uniformly discretized values called bins. Support Vector Machine was used for activity classification with bins and every pair of bins used as features. Bagged decision tree regression was used for net metabolic cost prediction. To evaluate model performance we employed the jackknife leave-one-out cross validation method. Single accelerometer and multi-accelerometer site model estimates across and within age group revealed similar accuracy, with a bias range of −0.03 to 0.01 METs, bias percent of −0.8 to 0.3%, and a rMSE range of 0.81–1.04 METs. Multi-site accelerometer location models improved activity type classification over single site location models from a low of 69.3% to a maximum of 92.8% accuracy. For each accelerometer site location model, or combined site location model, percent accuracy classification decreased as a function of age group, or when young age groups models were generalized to older age groups. Specific age group models on average performed better than when all age groups were combined. A time series computation show promising results for predicting energy cost and activity type. Differences in prediction across age group, a lack of generalizability across age groups, and that age group specific models perform better than when all ages are combined needs to be considered as analytic calibration procedures to detect energy cost and type are further developed. PMID:26449155

Mortality in Code Blue; can APACHE II and PRISM scores be used as markers for prognostication?

PubMed

Bakan, Nurten; Karaören, Gülşah; Tomruk, Şenay Göksu; Keskin Kayalar, Sinem

2018-03-01

Code blue (CB) is an emergency call system developed to respond to cardiac and respiratory arrest in hospitals. However, in literature, no scoring system has been reported that can predict mortality in CB procedures. In this study, we aimed to investigate the effectiveness of estimated APACHE II and PRISM scores in the prediction of mortality in patients assessed using CB to retrospectively analyze CB calls. We retrospectively examined 1195 patients who were evaluated by the CB team at our hospital between 2009 and 2013. The demographic data of the patients, diagnosis and relevant de-partments, reasons for CB, cardiopulmonary resuscitation duration, mortality calculated from the APACHE II and PRISM scores, and the actual mortality rates were retrospectively record-ed from CB notification forms and the hospital database. In all age groups, there was a significant difference between actual mortality rate and the expected mortality rate as estimated using APACHE II and PRISM scores in CB calls (p<0.05). The actual mortality rate was significantly lower than the expected mortality. APACHE and PRISM scores with the available parameters will not help predict mortality in CB procedures. Therefore, novels scoring systems using different parameters are needed.

Loudness perception and speech intensity control in Parkinson's disease.

PubMed

Clark, Jenna P; Adams, Scott G; Dykstra, Allyson D; Moodie, Shane; Jog, Mandar

2014-01-01

The aim of this study was to examine loudness perception in individuals with hypophonia and Parkinson's disease. The participants included 17 individuals with hypophonia related to Parkinson's disease (PD) and 25 age-equivalent controls. The three loudness perception tasks included a magnitude estimation procedure involving a sentence spoken at 60, 65, 70, 75 and 80 dB SPL, an imitation task involving a sentence spoken at 60, 65, 70, 75 and 80 dB SPL, and a magnitude production procedure involving the production of a sentence at five different loudness levels (habitual, two and four times louder and two and four times quieter). The participants with PD produced a significantly different pattern and used a more restricted range than the controls in their perception of speech loudness, imitation of speech intensity, and self-generated estimates of speech loudness. The results support a speech loudness perception deficit in PD involving an abnormal perception of externally generated and self-generated speech intensity. Readers will recognize that individuals with hypophonia related to Parkinson's disease may demonstrate a speech loudness perception deficit involving the abnormal perception of externally generated and self-generated speech intensity. Copyright © 2014 Elsevier Inc. All rights reserved.

Rates of surgery for frozen shoulder: an experience in England.

PubMed

Kwaees, Tariq A; Charalambous, Charalambos P

2015-01-01

the aim of this study was to identify the incidence of surgical treatment for frozen shoulder in a western population. patients included in this study all resided within a well-defined area in the North West of England, all had surgery for frozen shoulder over a 3-year period and were identified from theatre logbooks of two local hospitals. Cases having surgery for shoulder stiffness other than frozen shoulder were excluded. Local and national population size estimates were based on data obtained from the UK Office for National Statistics. 117 patients underwent surgery for frozen shoulder during the period examined; of these 101 had arthroscopic arthrolysis and 16 had manipulation under anaesthesia. The overall incidence of frozen shoulder surgery was calculated at 2.67 procedures per 10,000 general population per year, and at 7.55 for those aged 40-60. surgical intervention for frozen shoulder is common, estimated at over 14,180 cases per year in England. Given the variation in costs associated with arthroscopic arthrolysis and manipulation under anaesthesia, comparative studies of the cost effectiveness of the two procedures would be of great value. 2C (outcome research).

Annual update of data for estimating ESALs.

DOT National Transportation Integrated Search

2006-10-01

A revised procedure for estimating equivalent single axleloads (ESALs) was developed in 1985. This procedure used weight, classification, and traffic volume data collected by the Transportation Cabinet's Division of Planning. : Annual updates of data...

40 CFR 98.445 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... quantities calculations is required. Whenever the monitoring procedures cannot be followed, you must use the...) A quarterly mass or volume of contents in containers received that is missing must be estimated as...

40 CFR 98.445 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... quantities calculations is required. Whenever the monitoring procedures cannot be followed, you must use the...) A quarterly mass or volume of contents in containers received that is missing must be estimated as...

40 CFR 98.445 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... quantities calculations is required. Whenever the monitoring procedures cannot be followed, you must use the...) A quarterly mass or volume of contents in containers received that is missing must be estimated as...

40 CFR 98.95 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) Except as provided in paragraph (b) of this section, a complete record of all... required. (b) If you use fluorinated heat transfer fluids at your facility and are missing data for one or...

40 CFR 98.205 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emission... substitute data value for the missing parameter will be used in the calculations as specified in paragraph (b...

40 CFR 98.255 - Procedures for estimating missing data.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... during unit operation or if a required fuel sample is not taken), a substitute data value for the missing...

40 CFR 98.295 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. For the emission calculation methodologies in § 98.293(b)(2) and (b)(3), a complete... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.95 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) Except as provided in paragraph (b) of this section, a complete record of all... required. (b) If you use fluorinated heat transfer fluids at your facility and are missing data for one or...

40 CFR 98.205 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emission... substitute data value for the missing parameter will be used in the calculations as specified in paragraph (b...

40 CFR 98.255 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... during unit operation or if a required fuel sample is not taken), a substitute data value for the missing...

40 CFR 98.205 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emission... substitute data value for the missing parameter will be used in the calculations as specified in paragraph (b...

40 CFR 98.255 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... during unit operation or if a required fuel sample is not taken), a substitute data value for the missing...

40 CFR 98.205 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. (a) A complete record of all measured parameters used in the GHG emission... substitute data value for the missing parameter will be used in the calculations as specified in paragraph (b...

40 CFR 98.295 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. For the emission calculation methodologies in § 98.293(b)(2) and (b)(3), a complete... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.95 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. (a) Except as provided in paragraph (b) of this section, a complete record of all... required. (b) If you use fluorinated heat transfer fluids at your facility and are missing data for one or...

40 CFR 98.255 - Procedures for estimating missing data.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... during unit operation or if a required fuel sample is not taken), a substitute data value for the missing...

40 CFR 98.295 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. For the emission calculation methodologies in § 98.293(b)(2) and (b)(3), a complete... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.295 - Procedures for estimating missing data.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Procedures for estimating missing data... estimating missing data. For the emission calculation methodologies in § 98.293(b)(2) and (b)(3), a complete... unavailable, a substitute data value for the missing parameter shall be used in the calculations as specified...

40 CFR 98.255 - Procedures for estimating missing data.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Procedures for estimating missing data... estimating missing data. A complete record of all measured parameters used in the GHG emissions calculations... during unit operation or if a required fuel sample is not taken), a substitute data value for the missing...

Statistical Analysis and Time Series Modeling of Air Traffic Operations Data From Flight Service Stations and Terminal Radar Approach Control Facilities : Two Case Studies

DOT National Transportation Integrated Search

1981-10-01

Two statistical procedures have been developed to estimate hourly or daily aircraft counts. These counts can then be transformed into estimates of instantaneous air counts. The first procedure estimates the stable (deterministic) mean level of hourly...

A Procedure for Calculating the Vertical Space Height of the Sacrum When Determining Skeletal Height for Use in the Anatomical Method of Adult Stature Estimation.

PubMed

Hayashi, Atsuko; Emanovsky, Paul D; Pietrusewsky, Michael; Holland, Thomas D

2016-03-01

Estimating stature from skeletonized remains is one of the essential parameters in the development of a biological profile. A new procedure for determining skeletal height (SKH) incorporating the vertical space height (VSH) from the anterior margin of the sacral promontory to the superior margins of the acetabulae for use in the anatomical method of stature estimation is introduced. Regression equations for stature estimation were generated from measurements of 38 American males of European ancestry from the William M. Bass Donated Skeletal Collection. The modification to the procedure results in a SKH that is highly correlated with stature (r = 0.925-0.948). Stature estimates have low standard errors of the estimate ranging from 21.79 to 25.95 mm, biases from to 0.50 to 0.94 mm, and accuracy rates from 17.71 mm to 19.45 mm. The procedure for determining the VSH, which replaces "S1 height" in traditional anatomical method models, is a key improvement to the method. © 2016 American Academy of Forensic Sciences.

Southern forest inventory and analysis volume equation user’s guide

Treesearch

Christopher M. Oswalt; Roger C. Conner

2011-01-01

Reliable volume estimation procedures are fundamental to the mission of the Forest Inventory and Analysis (FIA) program. Moreover, public access to FIA program procedures is imperative. Here we present the volume estimation procedures used by the southern FIA program of the U.S. Department of Agriculture Forest Service Southern Research Station. The guide presented...

Observed Score and True Score Equating Procedures for Multidimensional Item Response Theory

ERIC Educational Resources Information Center

Brossman, Bradley Grant

2010-01-01

The purpose of this research was to develop observed score and true score equating procedures to be used in conjunction with the Multidimensional Item Response Theory (MIRT) framework. Currently, MIRT scale linking procedures exist to place item parameter estimates and ability estimates on the same scale after separate calibrations are conducted.…

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR ESTIMATING INHALATION EXPOSURES TO CHLORPYRIFOS AND DIAZINON (IIT-A-5.0)

EPA Science Inventory

The purpose of this SOP is to describe the procedures undertaken for estimating inhalation exposures to chlorpyrifos and Diazinon. This SOP uses data that have been properly coded and certified with appropriate QA/QC procedures by the University of Arizona NHEXAS and Battelle La...

Rapid estimation of high-parameter auditory-filter shapes

PubMed Central

Shen, Yi; Sivakumar, Rajeswari; Richards, Virginia M.

2014-01-01

A Bayesian adaptive procedure, the quick-auditory-filter (qAF) procedure, was used to estimate auditory-filter shapes that were asymmetric about their peaks. In three experiments, listeners who were naive to psychoacoustic experiments detected a fixed-level, pure-tone target presented with a spectrally notched noise masker. The qAF procedure adaptively manipulated the masker spectrum level and the position of the masker notch, which was optimized for the efficient estimation of the five parameters of an auditory-filter model. Experiment I demonstrated that the qAF procedure provided a convergent estimate of the auditory-filter shape at 2 kHz within 150 to 200 trials (approximately 15 min to complete) and, for a majority of listeners, excellent test-retest reliability. In experiment II, asymmetric auditory filters were estimated for target frequencies of 1 and 4 kHz and target levels of 30 and 50 dB sound pressure level. The estimated filter shapes were generally consistent with published norms, especially at the low target level. It is known that the auditory-filter estimates are narrower for forward masking than simultaneous masking due to peripheral suppression, a result replicated in experiment III using fewer than 200 qAF trials. PMID:25324086

National Hospital Discharge Survey: 2002 annual summary with detailed diagnosis and procedure data.

PubMed

Kozak, Lola J; Owings, Maria F; Hall, Margaret J

2005-03-01

This report presents 2002 national estimates and selected trend data on the use of non-Federal short-stay hospitals in the United States. Estimates are provided by selected patient and hospital characteristics, diagnoses, and surgical and nonsurgical procedures performed. Estimates of diagnoses and procedures are presented according to International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) codes. The estimates are based on data collected through the National Hospital Discharge Survey (NHDS). The survey has been conducted annually since 1965. In 2002, data were collected for approximately 327,000 discharges. Of the 474 eligible non-Federal short-stay hospitals in the sample, 445 (94 percent) responded to the survey. An estimated 33.7 million inpatients were discharged from non-Federal short-stay hospitals in 2002. They used 164.2 million days of care and had an average length of stay of 4.9 days. Common first-listed discharge diagnoses included delivery, ischemic heart disease, psychoses, pneumonia, and malignant neoplasms. Inpatients had 6.8 million cardiovascular procedures and 6.6 million obstetric procedures. Males had higher rates for cardiac procedures such as cardiac catheterization and coronary artery bypass graft, but males and females had similar rates of pacemaker procedures. The number and rate of all cesarean deliveries, primary and repeat, rose from 1995 to 2002; the rate of vaginal birth after cesarean delivery dropped from 35.5 in 1995 to 15.8 in 2002.

Nonlinear, discrete flood event models, 1. Bayesian estimation of parameters

NASA Astrophysics Data System (ADS)

Bates, Bryson C.; Townley, Lloyd R.

1988-05-01

In this paper (Part 1), a Bayesian procedure for parameter estimation is applied to discrete flood event models. The essence of the procedure is the minimisation of a sum of squares function for models in which the computed peak discharge is nonlinear in terms of the parameters. This objective function is dependent on the observed and computed peak discharges for several storms on the catchment, information on the structure of observation error, and prior information on parameter values. The posterior covariance matrix gives a measure of the precision of the estimated parameters. The procedure is demonstrated using rainfall and runoff data from seven Australian catchments. It is concluded that the procedure is a powerful alternative to conventional parameter estimation techniques in situations where a number of floods are available for parameter estimation. Parts 2 and 3 will discuss the application of statistical nonlinearity measures and prediction uncertainty analysis to calibrated flood models. Bates (this volume) and Bates and Townley (this volume).

Adjoint-Based, Three-Dimensional Error Prediction and Grid Adaptation

NASA Technical Reports Server (NTRS)

Park, Michael A.

2002-01-01

Engineering computational fluid dynamics (CFD) analysis and design applications focus on output functions (e.g., lift, drag). Errors in these output functions are generally unknown and conservatively accurate solutions may be computed. Computable error estimates can offer the possibility to minimize computational work for a prescribed error tolerance. Such an estimate can be computed by solving the flow equations and the linear adjoint problem for the functional of interest. The computational mesh can be modified to minimize the uncertainty of a computed error estimate. This robust mesh-adaptation procedure automatically terminates when the simulation is within a user specified error tolerance. This procedure for estimating and adapting to error in a functional is demonstrated for three-dimensional Euler problems. An adaptive mesh procedure that links to a Computer Aided Design (CAD) surface representation is demonstrated for wing, wing-body, and extruded high lift airfoil configurations. The error estimation and adaptation procedure yielded corrected functions that are as accurate as functions calculated on uniformly refined grids with ten times as many grid points.

Sampling design optimization for spatial functions

USGS Publications Warehouse

Olea, R.A.

1984-01-01

A new procedure is presented for minimizing the sampling requirements necessary to estimate a mappable spatial function at a specified level of accuracy. The technique is based on universal kriging, an estimation method within the theory of regionalized variables. Neither actual implementation of the sampling nor universal kriging estimations are necessary to make an optimal design. The average standard error and maximum standard error of estimation over the sampling domain are used as global indices of sampling efficiency. The procedure optimally selects those parameters controlling the magnitude of the indices, including the density and spatial pattern of the sample elements and the number of nearest sample elements used in the estimation. As an illustration, the network of observation wells used to monitor the water table in the Equus Beds of Kansas is analyzed and an improved sampling pattern suggested. This example demonstrates the practical utility of the procedure, which can be applied equally well to other spatial sampling problems, as the procedure is not limited by the nature of the spatial function. ?? 1984 Plenum Publishing Corporation.

Advanced techniques for modeling avian nest survival

USGS Publications Warehouse

Dinsmore, S.J.; White, Gary C.; Knopf, F.L.

2002-01-01

Estimation of avian nest survival has traditionally involved simple measures of apparent nest survival or Mayfield constant-nest-survival models. However, these methods do not allow researchers to build models that rigorously assess the importance of a wide range of biological factors that affect nest survival. Models that incorporate greater detail, such as temporal variation in nest survival and covariates representative of individual nests represent a substantial improvement over traditional estimation methods. In an attempt to improve nest survival estimation procedures, we introduce the nest survival model now available in the program MARK and demonstrate its use on a nesting study of Mountain Plovers (Charadrius montanus Townsend) in Montana, USA. We modeled the daily survival of Mountain Plover nests as a function of the sex of the incubating adult, nest age, year, linear and quadratic time trends, and two weather covariates (maximum daily temperature and daily precipitation) during a six-year study (1995–2000). We found no evidence for yearly differences or an effect of maximum daily temperature on the daily nest survival of Mountain Plovers. Survival rates of nests tended by female and male plovers differed (female rate = 0.33; male rate = 0.49). The estimate of the additive effect for males on nest survival rate was 0.37 (95% confidence limits were 0.03, 0.71) on a logit scale. Daily survival rates of nests increased with nest age; the estimate of daily nest-age change in survival in the best model was 0.06 (95% confidence limits were 0.04, 0.09) on a logit scale. Daily precipitation decreased the probability that the nest would survive to the next day; the estimate of the additive effect of daily precipitation on the nest survival rate was −1.08 (95% confidence limits were −2.12, −0.13) on a logit scale. Our approach to modeling daily nest-survival rates allowed several biological factors of interest to be easily included in nest survival models and allowed us to generate more biologically meaningful estimates of nest survival.

Survival and re-operation rates after neurosurgical procedures in Scotland: implications for targeted surveillance of sub-clinical variant Creutzfeldt-Jakob disease.

PubMed

Bird, Sheila M; Merrall, Elizabeth L C; Ward, Hester J T; Will, Robert G

2009-01-01

To assess the feasibility of post-mortem surveillance for subclinical variant Creutzfeldt-Jakob disease (vCJD) at least 5 years after neurosurgical procedures. Using Scottish record linkage, we estimated 5-year survival and re-operation rates after 4 neurosurgical procedures performed during 1993-2001 and identified as high or medium risk for transmitting vCJD: [B] drainage of extra- or subdural haematoma, [E] primary or revisional decompression operations and [H] creation of other ventricular shunts were classified as high risk; [C] operations on cerebral aneurysm (clipping) were classified as medium risk. Fatality rate at 1 year depended strongly on procedure, weakly or not at all on sex and era, and increased with age. Procedure rates differed by sex. The rate of subsequent neurosurgical operations was highest for procedure [H] (sole: 21%; multiple: 28%). Each year, the UK has a new cohort of some 5,000 5-year survivors after a high- or medium-risk neurosurgical procedure, whose subsequent annual mortality is at least 3%. Even if half the surviving 5-year survivors of neurosurgery since 1996 gave consent-in-life for vCJD-informative testing at post-mortem, there would be too few relevant post-mortems in 2008-2010 (around 1,600) for 'nil detections' to exclude a 1 in 1,000 subclinical vCJD rate. Autopsy surveillance beyond 2010, or among 5-year survivors of non-neurosurgical at-risk operations, would be needed. (c) 2009 S. Karger AG, Basel.

Sick leave and its determinants in professional soldiers of the Slovenian Armed Forces.

PubMed

Selič, Polona; Petek, Davorina; Serec, Maša; Rus Makovec, Maja

2010-12-01

To assess whether demographic characteristics, self-rated health status, coping behaviors, satisfaction with important interpersonal relationships, financial situation, and current overall quality of life are determinants of sick leave duration in professional soldiers of the Slovenian Armed Forces. In 2008, 448 military personnel on active duty in the Slovenian Armed Forces were invited to participate in the study and 390 returned the completed questionnaires (response rate 87%). The questionnaires used were the self-rated health scale, sick leave scale, life satisfaction scale, Folkman-Lazarus' Ways of Coping Questionnaire, and a demographic data questionnaire. To partition the variance across a wide variety of indicators of participants' experiences, ordinal modeling procedures were used. A multivariate ordinal regression model, explaining 24% of sick leave variance, showed that the following variables significantly predicted longer sick leave duration: female sex (estimate, 1.185; 95% confidence interval [CI], 0.579-1.791), poorer self-rated health (estimate, 3.243; 95% CI, 1.755-4.731), lower satisfaction with relationships with coworkers (estimate, 1.333; 95% CI, 0.399-2.267), and lower education (estimate, 1.577; 95% CI, 0.717-2.436). The impact of age and coping mechanisms was not significant. Longer sick leave duration was found in women and respondents less satisfied with their relationships with coworkers, and these are the groups to which special attention should be awarded when planning supervision, work procedures, and gender equality policy of the Armed Forces. A good way of increasing the quality of interpersonal relationships at work would be to teach such skills in teaching programs for commanding officers.

Motion estimation using point cluster method and Kalman filter.

PubMed

Senesh, M; Wolf, A

2009-05-01

The most frequently used method in a three dimensional human gait analysis involves placing markers on the skin of the analyzed segment. This introduces a significant artifact, which strongly influences the bone position and orientation and joint kinematic estimates. In this study, we tested and evaluated the effect of adding a Kalman filter procedure to the previously reported point cluster technique (PCT) in the estimation of a rigid body motion. We demonstrated the procedures by motion analysis of a compound planar pendulum from indirect opto-electronic measurements of markers attached to an elastic appendage that is restrained to slide along the rigid body long axis. The elastic frequency is close to the pendulum frequency, as in the biomechanical problem, where the soft tissue frequency content is similar to the actual movement of the bones. Comparison of the real pendulum angle to that obtained by several estimation procedures--PCT, Kalman filter followed by PCT, and low pass filter followed by PCT--enables evaluation of the accuracy of the procedures. When comparing the maximal amplitude, no effect was noted by adding the Kalman filter; however, a closer look at the signal revealed that the estimated angle based only on the PCT method was very noisy with fluctuation, while the estimated angle based on the Kalman filter followed by the PCT was a smooth signal. It was also noted that the instantaneous frequencies obtained from the estimated angle based on the PCT method is more dispersed than those obtained from the estimated angle based on Kalman filter followed by the PCT method. Addition of a Kalman filter to the PCT method in the estimation procedure of rigid body motion results in a smoother signal that better represents the real motion, with less signal distortion than when using a digital low pass filter. Furthermore, it can be concluded that adding a Kalman filter to the PCT procedure substantially reduces the dispersion of the maximal and minimal instantaneous frequencies.

Cross-national comparability of burden of disease estimates: the European Disability Weights Project.

PubMed Central

Essink-Bot, Marie-Louise; Pereira, Joaquin; Packer, Claire; Schwarzinger, Michael; Burstrom, Kristina

2002-01-01

OBJECTIVE: To investigate the sources of cross-national variation in disability-adjusted life-years (DALYs) in the European Disability Weights Project. METHODS: Disability weights for 15 disease stages were derived empirically in five countries by means of a standardized procedure and the cross-national differences in visual analogue scale (VAS) scores were analysed. For each country the burden of dementia in women, used as an illustrative example, was estimated in DALYs. An analysis was performed of the relative effects of cross-national variations in demography, epidemiology and disability weights on DALY estimates. FINDINGS: Cross-national comparison of VAS scores showed almost identical ranking orders. After standardization for population size and age structure of the populations, the DALY rates per 100000 women ranged from 1050 in France to 1404 in the Netherlands. Because of uncertainties in the epidemiological data, the extent to which these differences reflected true variation between countries was difficult to estimate. The use of European rather than country-specific disability weights did not lead to a significant change in the burden of disease estimates for dementia. CONCLUSIONS: Sound epidemiological data are the first requirement for burden of disease estimation and relevant between-countries comparisons. DALY estimates for dementia were relatively insensitive to differences in disability weights between European countries. PMID:12219156

Ovarian Cancer Incidence Corrected for Oophorectomy

PubMed Central

Baldwin, Lauren A.; Chen, Quan; Tucker, Thomas C.; White, Connie G.; Ore, Robert N.; Huang, Bin

2017-01-01

Current reported incidence rates for ovarian cancer may significantly underestimate the true rate because of the inclusion of women in the calculations who are not at risk for ovarian cancer due to prior benign salpingo-oophorectomy (SO). We have considered prior SO to more realistically estimate risk for ovarian cancer. Kentucky Health Claims Data, International Classification of Disease 9 (ICD-9) codes, Current Procedure Terminology (CPT) codes, and Kentucky Behavioral Risk Factor Surveillance System (BRFSS) Data were used to identify women who have undergone SO in Kentucky, and these women were removed from the at-risk pool in order to re-assess incidence rates to more accurately represent ovarian cancer risk. The protective effect of SO on the population was determined on an annual basis for ages 5–80+ using data from the years 2009–2013. The corrected age-adjusted rates of ovarian cancer that considered SO ranged from 33% to 67% higher than age-adjusted rates from the standard population. Correction of incidence rates for ovarian cancer by accounting for women with prior SO gives a better understanding of risk for this disease faced by women. The rates of ovarian cancer were substantially higher when SO was taken into consideration than estimates from the standard population. PMID:28368298

Hybrid method to estimate two-layered superficial tissue optical properties from simulated data of diffuse reflectance spectroscopy.

PubMed

Hsieh, Hong-Po; Ko, Fan-Hua; Sung, Kung-Bin

2018-04-20

An iterative curve fitting method has been applied in both simulation [J. Biomed. Opt.17, 107003 (2012)JBOPFO1083-366810.1117/1.JBO.17.10.107003] and phantom [J. Biomed. Opt.19, 077002 (2014)JBOPFO1083-366810.1117/1.JBO.19.7.077002] studies to accurately extract optical properties and the top layer thickness of a two-layered superficial tissue model from diffuse reflectance spectroscopy (DRS) data. This paper describes a hybrid two-step parameter estimation procedure to address two main issues of the previous method, including (1) high computational intensity and (2) converging to local minima. The parameter estimation procedure contained a novel initial estimation step to obtain an initial guess, which was used by a subsequent iterative fitting step to optimize the parameter estimation. A lookup table was used in both steps to quickly obtain reflectance spectra and reduce computational intensity. On simulated DRS data, the proposed parameter estimation procedure achieved high estimation accuracy and a 95% reduction of computational time compared to previous studies. Furthermore, the proposed initial estimation step led to better convergence of the following fitting step. Strategies used in the proposed procedure could benefit both the modeling and experimental data processing of not only DRS but also related approaches such as near-infrared spectroscopy.

Robust estimation for partially linear models with large-dimensional covariates

PubMed Central

Zhu, LiPing; Li, RunZe; Cui, HengJian

2014-01-01

We are concerned with robust estimation procedures to estimate the parameters in partially linear models with large-dimensional covariates. To enhance the interpretability, we suggest implementing a noncon-cave regularization method in the robust estimation procedure to select important covariates from the linear component. We establish the consistency for both the linear and the nonlinear components when the covariate dimension diverges at the rate of o(n), where n is the sample size. We show that the robust estimate of linear component performs asymptotically as well as its oracle counterpart which assumes the baseline function and the unimportant covariates were known a priori. With a consistent estimator of the linear component, we estimate the nonparametric component by a robust local linear regression. It is proved that the robust estimate of nonlinear component performs asymptotically as well as if the linear component were known in advance. Comprehensive simulation studies are carried out and an application is presented to examine the finite-sample performance of the proposed procedures. PMID:24955087

Mixed model approaches for diallel analysis based on a bio-model.

PubMed

Zhu, J; Weir, B S

1996-12-01

A MINQUE(1) procedure, which is minimum norm quadratic unbiased estimation (MINQUE) method with 1 for all the prior values, is suggested for estimating variance and covariance components in a bio-model for diallel crosses. Unbiasedness and efficiency of estimation were compared for MINQUE(1), restricted maximum likelihood (REML) and MINQUE theta which has parameter values for the prior values. MINQUE(1) is almost as efficient as MINQUE theta for unbiased estimation of genetic variance and covariance components. The bio-model is efficient and robust for estimating variance and covariance components for maternal and paternal effects as well as for nuclear effects. A procedure of adjusted unbiased prediction (AUP) is proposed for predicting random genetic effects in the bio-model. The jack-knife procedure is suggested for estimation of sampling variances of estimated variance and covariance components and of predicted genetic effects. Worked examples are given for estimation of variance and covariance components and for prediction of genetic merits.

Robust estimation for partially linear models with large-dimensional covariates.

PubMed

Zhu, LiPing; Li, RunZe; Cui, HengJian

2013-10-01

We are concerned with robust estimation procedures to estimate the parameters in partially linear models with large-dimensional covariates. To enhance the interpretability, we suggest implementing a noncon-cave regularization method in the robust estimation procedure to select important covariates from the linear component. We establish the consistency for both the linear and the nonlinear components when the covariate dimension diverges at the rate of [Formula: see text], where n is the sample size. We show that the robust estimate of linear component performs asymptotically as well as its oracle counterpart which assumes the baseline function and the unimportant covariates were known a priori. With a consistent estimator of the linear component, we estimate the nonparametric component by a robust local linear regression. It is proved that the robust estimate of nonlinear component performs asymptotically as well as if the linear component were known in advance. Comprehensive simulation studies are carried out and an application is presented to examine the finite-sample performance of the proposed procedures.

Accuracy of using Diagnosis Procedure Combination administrative claims data for estimating the amount of opioid consumption among cancer patients in Japan.

PubMed

Iwamoto, Momoko; Higashi, Takahiro; Miura, Hiroki; Kawaguchi, Takahiro; Tanaka, Shigeyuki; Yamashita, Itsuku; Yoshimoto, Tetsusuke; Yoshida, Shigeaki; Matoba, Motohiro

2015-11-01

The state of opioid consumption among cancer patients has never been comprehensively investigated in Japan. The Diagnosis Procedure Combination claims data may be used to measure and monitor opioid consumption among cancer patients, but the accuracy of using the Diagnosis Procedure Combination data for this purpose has never been tested. We aimed to ascertain the accuracy of using the Diagnosis Procedure Combination claims data for estimating total opioid analgesic consumption by cancer patients compared with electronic medical records at Aomori Prefectural Central Hospital. We calculated percent differences between estimates obtained from electronic medical records and Diagnosis Procedure Combination claims data by month and drug type (morphine, oxycodone, fentanyl, buprenorphine, codeine and tramadol) between 1 October 2012 and 30 September 2013, and further examined the causes of discrepancy by reviewing medical and administrative charts between April and July 2013. Percent differences varied by month for drug types with small prescription volumes, but less so for drugs with larger prescription volumes. Differences also tended to diminish when consumption was compared for a year instead of a month. Total percent difference between electronic medical records and Diagnosis Procedure Combination data during the study period was -0.1% (4721 mg per year per hospital), as electronic medical records as baseline. Half of the discrepancy was caused by errors in data entry. Our study showed that Diagnosis Procedure Combination claims data can be used to accurately estimate opioid consumption among a population of cancer patients, although the same conclusion cannot be made for individual estimates or when making estimates for a group of patients over a short period of time. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet

PubMed Central

URIBARRI, JAIME; WOODRUFF, SANDRA; GOODMAN, SUSAN; CAI, WEIJING; CHEN, XUE; PYZIK, RENATA; YONG, ANGIE; STRIKER, GARY E.; VLASSARA, HELEN

2013-01-01

Modern diets are largely heat-processed and as a result contain high levels of advanced glycation end products (AGEs). Dietary advanced glycation end products (dAGEs) are known to contribute to increased oxidant stress and inflammation, which are linked to the recent epidemics of diabetes and cardiovascular disease. This report significantly expands the available dAGE database, validates the dAGE testing methodology, compares cooking procedures and inhibitory agents on new dAGE formation, and introduces practical approaches for reducing dAGE consumption in daily life. Based on the findings, dry heat promotes new dAGE formation by >10- to 100-fold above the uncooked state across food categories. Animal-derived foods that are high in fat and protein are generally AGE-rich and prone to new AGE formation during cooking. In contrast, carbohydrate-rich foods such as vegetables, fruits, whole grains, and milk contain relatively few AGEs, even after cooking. The formation of new dAGEs during cooking was prevented by the AGE inhibitory compound aminoguanidine and significantly reduced by cooking with moist heat, using shorter cooking times, cooking at lower temperatures, and by use of acidic ingredients such as lemon juice or vinegar. The new dAGE database provides a valuable instrument for estimating dAGE intake and for guiding food choices to reduce dAGE intake. PMID:20497781

Age, body mass, and gender as predictors of masters olympic weightlifting performance.

PubMed

Thé, Dwight J; Ploutz-Snyder, Lori

2003-07-01

The purpose of this study was to examine previously collected performance scores from the 2000 World Masters Weightlifting Championships to 1). determine the extent to which age and body mass are related to and predictive of indirect estimates of absolute and relative muscular power, and 2). assess possible gender differences in these associations. Dependent variables were absolute load (ABS = heaviest snatch [kg] + heaviest clean and jerk [kg]) and relative load (REL = ABS [kg]/body mass [kg]), representing indirect estimates of absolute and relative muscular power, respectively. Predictor variables were age (yr) and body mass (kg). Linear regression and various diagnostic procedures were used to analyze the data. The linear model provided an adequate fit for the data because no departures from the usual assumptions of normally distributed variables and homoscedastic error variance were observed. All predictor variables were significantly (P < 0.05) predictive of the dependent variables, but the magnitude of associations (e.g., R(ABS|BM) = 0.18 among females vs R(ABS|BM) = 0.57 among males) and extent of predictive ability (e.g., R(adj)2 for regression of ABS on age and body mass was 0.18-0.58 among females vs 0.74-0.83 among males) were significantly (P < 0.05) higher among males versus females. The extent to which age and body mass explain differences in muscular power differs between female and male masters weightlifters, but the rate of decline (%.yr-1) in power with advancing age is similar and is in agreement with previous reports for world record holders, other masters athletes, and healthy, untrained individuals, suggesting the importance of the aging process itself over physical activity history.

Annual update of data for estimating ESALs : draft.

DOT National Transportation Integrated Search

2008-10-01

A revised procedure for estimating equivalent single axleloads (ESALs) was developed in 1985. This procedure used weight, classification, and traffic volume data collected by the Transportation Cabinet's Division of Planning. : Annual updates of data...

The feasibility of transvaginal robotic surgery in the repair of pelvic organ prolapse.

PubMed

Yaghnam, Ibrahim; Thomas, Dominique; Rosenblatt, Peter; Chughtai, Bilal

2017-08-01

Pelvic organ prolapse (POP), the descent of one or more pelvic organs, occurs in an estimated 40 to 60% of parous women. Conventional transvaginal surgery for POP has been plagued with high failure rates. The purpose was to determine the safety and feasibility of robotic transvaginal POP surgery. The da Vinci Surgical Robot, SI was used in the POP surgical procedures. There were two cadavers (aged 18 and 78 years of age; BMI 17.2 and 19.2 respectively). POP-Q scores before intervention were stage 1 for both cadavers. The visualization of anatomical landmarks and the placement of sutures at these locations were successful. Robotic transvaginal POP is a feasible option for POP surgery. Further studies are warranted to determine the role of robotic transvaginal POP repair.

Fuel Burn Estimation Using Real Track Data

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.

2011-01-01

A procedure for estimating fuel burned based on actual flight track data, and drag and fuel-flow models is described. The procedure consists of estimating aircraft and wind states, lift, drag and thrust. Fuel-flow for jet aircraft is determined in terms of thrust, true airspeed and altitude as prescribed by the Base of Aircraft Data fuel-flow model. This paper provides a theoretical foundation for computing fuel-flow with most of the information derived from actual flight data. The procedure does not require an explicit model of thrust and calibrated airspeed/Mach profile which are typically needed for trajectory synthesis. To validate the fuel computation method, flight test data provided by the Federal Aviation Administration were processed. Results from this method show that fuel consumed can be estimated within 1% of the actual fuel consumed in the flight test. Next, fuel consumption was estimated with simplified lift and thrust models. Results show negligible difference with respect to the full model without simplifications. An iterative takeoff weight estimation procedure is described for estimating fuel consumption, when takeoff weight is unavailable, and for establishing fuel consumption uncertainty bounds. Finally, the suitability of using radar-based position information for fuel estimation is examined. It is shown that fuel usage could be estimated within 5.4% of the actual value using positions reported in the Airline Situation Display to Industry data with simplified models and iterative takeoff weight computation.

Cost-effectiveness analyses of elective orthopaedic surgical procedures in patients with inflammatory arthropathies.

PubMed

Osnes-Ringen, H; Kvamme, M K; Kristiansen, I S; Thingstad, M; Henriksen, J E; Kvien, T K; Dagfinrud, H

2011-03-01

To examine the costs per quality-adjusted life year (QALY) gained for surgical interventions in patients with inflammatory arthropathies, and to compare the costs per QALY gained for replacement versus non-replacement surgical interventions. In total, 248 patients [mean age 57 (SD 13) years, 77% female] with inflammatory arthropathies underwent orthopaedic surgical treatment and responded to mail surveys at baseline and during follow-up (3, 6, 9, and 12 months). Questionnaires included the quality-of-life EuroQol-5D (EQ-5D) and Short Form-6D (SF-6D) utility scores. The health benefit from surgery was subsequently translated into QALYs. The direct treatment costs in the first year were, for each patient, derived from the hospital's cost per patient accounting system (KOSPA). The costs per QALY were estimated and future costs and benefits were discounted at 4%. Improvement in utility at 1-year follow-up was 0.10 with EQ-5D and 0.03 with SF-6D (p < 0.05). The estimated 10-year cost per QALY gained was EUR 5000 for hip replacement surgery (EUR18 600 using SF-6D) and EUR 10 500 (EUR 48 500 using SF-6D) for all replacement procedures. The 5-year cost per QALY was EUR 17 800 for non-replacement surgical procedures measured by EQ-5D (SF-6D: EUR 67 500). Elective orthopaedic surgery in patients with inflammatory arthropathies was cost-effective when measured with EQ-5D, and some procedures were also cost-effective when SF-6D was used in the economic evaluations. Hip replacement surgery was most cost-effective, irrespective of the method of analysis.

Fitting a three-parameter lognormal distribution with applications to hydrogeochemical data from the National Uranium Resource Evaluation Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kane, V.E.

1979-10-01

The standard maximum likelihood and moment estimation procedures are shown to have some undesirable characteristics for estimating the parameters in a three-parameter lognormal distribution. A class of goodness-of-fit estimators is found which provides a useful alternative to the standard methods. The class of goodness-of-fit tests considered include the Shapiro-Wilk and Shapiro-Francia tests which reduce to a weighted linear combination of the order statistics that can be maximized in estimation problems. The weighted-order statistic estimators are compared to the standard procedures in Monte Carlo simulations. Bias and robustness of the procedures are examined and example data sets analyzed including geochemical datamore » from the National Uranium Resource Evaluation Program.« less

40 CFR 98.95 - Procedures for estimating missing data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Procedures for estimating missing data... estimating missing data. (a) Except as provided in paragraph (b) of this section, a complete record of all... required. (b) If you use heat transfer fluids at your facility and are missing data for one or more of the...

Marginal Maximum A Posteriori Item Parameter Estimation for the Generalized Graded Unfolding Model

ERIC Educational Resources Information Center

Roberts, James S.; Thompson, Vanessa M.

2011-01-01

A marginal maximum a posteriori (MMAP) procedure was implemented to estimate item parameters in the generalized graded unfolding model (GGUM). Estimates from the MMAP method were compared with those derived from marginal maximum likelihood (MML) and Markov chain Monte Carlo (MCMC) procedures in a recovery simulation that varied sample size,…

Lake Erie Yellow perch age estimation based on three structures: Precision, processing times, and management implications

USGS Publications Warehouse

Vandergoot, C.S.; Bur, M.T.; Powell, K.A.

2008-01-01

Yellow perch Perca flavescens support economically important recreational and commercial fisheries in Lake Erie and are intensively managed. Age estimation represents an integral component in the management of Lake Erie yellow perch stocks, as age-structured population models are used to set safe harvest levels on an annual basis. We compared the precision associated with yellow perch (N = 251) age estimates from scales, sagittal otoliths, and anal spine sections and evaluated the time required to process and estimate age from each structure. Three readers of varying experience estimated ages. The precision (mean coefficient of variation) of estimates among readers was 1% for sagittal otoliths, 5-6% for anal spines, and 11-13% for scales. Agreement rates among readers were 94-95% for otoliths, 71-76% for anal spines, and 45-50% for scales. Systematic age estimation differences were evident among scale and anal spine readers; less-experienced readers tended to underestimate ages of yellow perch older than age 4 relative to estimates made by an experienced reader. Mean scale age tended to underestimate ages of age-6 and older fish relative to otolith ages estimated by an experienced reader. Total annual mortality estimates based on scale ages were 20% higher than those based on otolith ages; mortality estimates based on anal spine ages were 4% higher than those based on otolith ages. Otoliths required more removal and preparation time than scales and anal spines, but age estimation time was substantially lower for otoliths than for the other two structures. We suggest the use of otoliths or anal spines for age estimation in yellow perch (regardless of length) from Lake Erie and other systems where precise age estimates are necessary, because age estimation errors resulting from the use of scales could generate incorrect management decisions. ?? Copyright by the American Fisheries Society 2008.

Costs and Outcomes of Increasing Access to Bariatric Surgery: Cohort Study and Cost-Effectiveness Analysis Using Electronic Health Records.

PubMed

Gulliford, Martin C; Charlton, Judith; Prevost, Toby; Booth, Helen; Fildes, Alison; Ashworth, Mark; Littlejohns, Peter; Reddy, Marcus; Khan, Omar; Rudisill, Caroline

2017-01-01

To estimate costs and outcomes of increasing access to bariatric surgery in obese adults and in population subgroups of age, sex, deprivation, comorbidity, and obesity category. A cohort study was conducted using primary care electronic health records, with linked hospital utilization data, for 3,045 participants who underwent bariatric surgery and 247,537 participants who did not undergo bariatric surgery. Epidemiological analyses informed a probabilistic Markov model to compare bariatric surgery, including equal proportions with adjustable gastric banding, gastric bypass, and sleeve gastrectomy, with standard nonsurgical management of obesity. Outcomes were quality-adjusted life-years (QALYs) and net monetary benefits at a threshold of £30,000 per QALY. In a UK population of 250,000 adults, there may be 7,163 people with morbid obesity including 1,406 with diabetes. The immediate cost of 1,000 bariatric surgical procedures is £9.16 million, with incremental discounted lifetime health care costs of £15.26 million (95% confidence interval £15.18-£15.36 million). Patient-years with diabetes mellitus will decrease by 8,320 (range 8,123-8,502). Incremental QALYs will increase by 2,142 (range 2,032-2,256). The estimated cost per QALY gained is £7,129 (range £6,775-£7,506). Net monetary benefits will be £49.02 million (range £45.72-£52.41 million). Estimates are similar for subgroups of age, sex, and deprivation. Bariatric surgery remains cost-effective if the procedure is twice as costly, or if intervention effect declines over time. Diverse obese individuals may benefit from bariatric surgery at acceptable cost. Bariatric surgery is not cost-saving, but increased health care costs are exceeded by health benefits to obese individuals. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

TETRA-COM: a comprehensive SPSS program for estimating the tetrachoric correlation.

PubMed

Lorenzo-Seva, Urbano; Ferrando, Pere J

2012-12-01

We provide an SPSS program that implements descriptive and inferential procedures for estimating tetrachoric correlations. These procedures have two main purposes: (1) bivariate estimation in contingency tables and (2) constructing a correlation matrix to be used as input for factor analysis (in particular, the SPSS FACTOR procedure). In both cases, the program computes accurate point estimates, as well as standard errors and confidence intervals that are correct for any population value. For purpose (1), the program computes the contingency table together with five other measures of association. For purpose (2), the program checks the positive definiteness of the matrix, and if it is found not to be Gramian, performs a nonlinear smoothing procedure at the user's request. The SPSS syntax, a short manual, and data files related to this article are available as supplemental materials from brm.psychonomic-journals.org/content/supplemental.

A posteriori noise estimation in variable data sets. With applications to spectra and light curves

NASA Astrophysics Data System (ADS)

Czesla, S.; Molle, T.; Schmitt, J. H. M. M.

2018-01-01

Most physical data sets contain a stochastic contribution produced by measurement noise or other random sources along with the signal. Usually, neither the signal nor the noise are accurately known prior to the measurement so that both have to be estimated a posteriori. We have studied a procedure to estimate the standard deviation of the stochastic contribution assuming normality and independence, requiring a sufficiently well-sampled data set to yield reliable results. This procedure is based on estimating the standard deviation in a sample of weighted sums of arbitrarily sampled data points and is identical to the so-called DER_SNR algorithm for specific parameter settings. To demonstrate the applicability of our procedure, we present applications to synthetic data, high-resolution spectra, and a large sample of space-based light curves and, finally, give guidelines to apply the procedure in situation not explicitly considered here to promote its adoption in data analysis.

Estimation of descriptive statistics for multiply censored water quality data

USGS Publications Warehouse

Helsel, Dennis R.; Cohn, Timothy A.

1988-01-01

This paper extends the work of Gilliom and Helsel (1986) on procedures for estimating descriptive statistics of water quality data that contain “less than” observations. Previously, procedures were evaluated when only one detection limit was present. Here we investigate the performance of estimators for data that have multiple detection limits. Probability plotting and maximum likelihood methods perform substantially better than simple substitution procedures now commonly in use. Therefore simple substitution procedures (e.g., substitution of the detection limit) should be avoided. Probability plotting methods are more robust than maximum likelihood methods to misspecification of the parent distribution and their use should be encouraged in the typical situation where the parent distribution is unknown. When utilized correctly, less than values frequently contain nearly as much information for estimating population moments and quantiles as would the same observations had the detection limit been below them.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miraglia, Roberto, E-mail: rmiraglia@ismett.edu; Maruzzelli, Luigi; Tuzzolino, Fabio

Purpose: The aim of this study was to estimate radiation exposure in pediatric liver transplants recipients who underwent biliary interventional procedures and to compare radiation exposure levels between biliary interventional procedures performed using an image intensifier-based angiographic system (IIDS) and a flat panel detector-based interventional system (FPDS). Materials and Methods: We enrolled 34 consecutive pediatric liver transplant recipients with biliary strictures between January 2008 and March 2013 with a total of 170 image-guided procedures. The dose-area product (DAP) and fluoroscopy time was recorded for each procedure. The mean age was 61 months (range 4-192), and mean weight was 17 kgmore » (range 4-41). The procedures were classified into three categories: percutaneous transhepatic cholangiography and biliary catheter placement (n = 40); cholangiography and balloon dilatation (n = 55); and cholangiography and biliary catheter change or removal (n = 75). Ninety-two procedures were performed using an IIDS. Seventy-eight procedures performed after July 2010 were performed using an FPDS. The difference in DAP between the two angiographic systems was compared using Wilcoxon rank-sum test and a multiple linear regression model. Results: Mean DAP in the three categories was significantly greater in the group of procedures performed using the IIDS compared with those performed using the FPDS. Statistical analysis showed a p value = 0.001 for the PTBD group, p = 0.0002 for the cholangiogram and balloon dilatation group, and p = 0.00001 for the group with cholangiogram and biliary catheter change or removal. Conclusion: In our selected cohort of patients, the use of an FPDS decreases radiation exposure.« less

Finite-error metrological bounds on multiparameter Hamiltonian estimation

NASA Astrophysics Data System (ADS)

Kura, Naoto; Ueda, Masahito

2018-01-01

Estimation of multiple parameters in an unknown Hamiltonian is investigated. We present upper and lower bounds on the time required to complete the estimation within a prescribed error tolerance δ . The lower bound is given on the basis of the Cramér-Rao inequality, where the quantum Fisher information is bounded by the squared evolution time. The upper bound is obtained by an explicit construction of estimation procedures. By comparing the cases with different numbers of Hamiltonian channels, we also find that the few-channel procedure with adaptive feedback and the many-channel procedure with entanglement are equivalent in the sense that they require the same amount of time resource up to a constant factor.

A procedure to estimate proximate analysis of mixed organic wastes.

PubMed

Zaher, U; Buffiere, P; Steyer, J P; Chen, S

2009-04-01

In waste materials, proximate analysis measuring the total concentration of carbohydrate, protein, and lipid contents from solid wastes is challenging, as a result of the heterogeneous and solid nature of wastes. This paper presents a new procedure that was developed to estimate such complex chemical composition of the waste using conventional practical measurements, such as chemical oxygen demand (COD) and total organic carbon. The procedure is based on mass balance of macronutrient elements (carbon, hydrogen, nitrogen, oxygen, and phosphorus [CHNOP]) (i.e., elemental continuity), in addition to the balance of COD and charge intensity that are applied in mathematical modeling of biological processes. Knowing the composition of such a complex substrate is crucial to study solid waste anaerobic degradation. The procedure was formulated to generate the detailed input required for the International Water Association (London, United Kingdom) Anaerobic Digestion Model number 1 (IWA-ADM1). The complex particulate composition estimated by the procedure was validated with several types of food wastes and animal manures. To make proximate analysis feasible for validation, the wastes were classified into 19 types to allow accurate extraction and proximate analysis. The estimated carbohydrates, proteins, lipids, and inerts concentrations were highly correlated to the proximate analysis; correlation coefficients were 0.94, 0.88, 0.99, and 0.96, respectively. For most of the wastes, carbohydrate was the highest fraction and was estimated accurately by the procedure over an extended range with high linearity. For wastes that are rich in protein and fiber, the procedure was even more consistent compared with the proximate analysis. The new procedure can be used for waste characterization in solid waste treatment design and optimization.

Quantile Regression Models for Current Status Data

PubMed Central

Ou, Fang-Shu; Zeng, Donglin; Cai, Jianwen

2016-01-01

Current status data arise frequently in demography, epidemiology, and econometrics where the exact failure time cannot be determined but is only known to have occurred before or after a known observation time. We propose a quantile regression model to analyze current status data, because it does not require distributional assumptions and the coefficients can be interpreted as direct regression effects on the distribution of failure time in the original time scale. Our model assumes that the conditional quantile of failure time is a linear function of covariates. We assume conditional independence between the failure time and observation time. An M-estimator is developed for parameter estimation which is computed using the concave-convex procedure and its confidence intervals are constructed using a subsampling method. Asymptotic properties for the estimator are derived and proven using modern empirical process theory. The small sample performance of the proposed method is demonstrated via simulation studies. Finally, we apply the proposed method to analyze data from the Mayo Clinic Study of Aging. PMID:27994307

Methodology for the evaluation of vascular surgery manpower in France.

PubMed

Berger, L; Mace, J M; Ricco, J B; Saporta, G

2013-01-01

The French population is growing and ageing. It is expected to increase by 2.7% by 2020, and the number of individuals over 65 years of age is expected to increase by 3.3 million, a 33% increase, between 2005 and 2020. As the number of vascular surgery procedures is closely associated with the age of a population, it is anticipated that there will be a significant increase in the workload of vascular surgeons. A model is presented to predict changes in vascular surgery activity according to population ageing, including other parameters that could affect workload evolution. Three types of arterial procedures were studied: infrarenal abdominal aortic aneurysm (AAA) surgery, peripheral arterial occlusive disease (PAOD) procedures and carotid artery (CEA) procedures. Data were selected and extracted from the national PMSI (Medical Information System Program) database. Data obtained from 2000 were used to predict data based on an ageing population for 2008. From this model, a weighted index was defined for each group by comparing expected and observed workloads. According to the model, over this 8-year period, there was an overall increase in vascular procedures of 52.2%, with an increase of 89% in PAOD procedures. Between 2000 and 2009, the total increase was 58.0%, with 3.9% for AAA procedures, 101.7% for PAOD procedures and 13.2% for CEA procedures. The weighted model based on an ageing population and corrected by a weighted factor predicted this increase. This weighted model is able to predict the workload of vascular surgeons over the coming years. An ageing population and other factors could result in a significant increase in demand for vascular surgical services. Copyright © 2012 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Compound estimation procedures in reliability

NASA Technical Reports Server (NTRS)

Barnes, Ron

1990-01-01

At NASA, components and subsystems of components in the Space Shuttle and Space Station generally go through a number of redesign stages. While data on failures for various design stages are sometimes available, the classical procedures for evaluating reliability only utilize the failure data on the present design stage of the component or subsystem. Often, few or no failures have been recorded on the present design stage. Previously, Bayesian estimators for the reliability of a single component, conditioned on the failure data for the present design, were developed. These new estimators permit NASA to evaluate the reliability, even when few or no failures have been recorded. Point estimates for the latter evaluation were not possible with the classical procedures. Since different design stages of a component (or subsystem) generally have a good deal in common, the development of new statistical procedures for evaluating the reliability, which consider the entire failure record for all design stages, has great intuitive appeal. A typical subsystem consists of a number of different components and each component has evolved through a number of redesign stages. The present investigations considered compound estimation procedures and related models. Such models permit the statistical consideration of all design stages of each component and thus incorporate all the available failure data to obtain estimates for the reliability of the present version of the component (or subsystem). A number of models were considered to estimate the reliability of a component conditioned on its total failure history from two design stages. It was determined that reliability estimators for the present design stage, conditioned on the complete failure history for two design stages have lower risk than the corresponding estimators conditioned only on the most recent design failure data. Several models were explored and preliminary models involving bivariate Poisson distribution and the Consael Process (a bivariate Poisson process) were developed. Possible short comings of the models are noted. An example is given to illustrate the procedures. These investigations are ongoing with the aim of developing estimators that extend to components (and subsystems) with three or more design stages.

Estimating Commercial Truck VMT of Interstate Motor Carriers: Data Evaluation

DOT National Transportation Integrated Search

1989-11-01

The objectives of this study were to document and evaluate existing data sources and procedures that estimate the VMT (vehicle miles traveled) of commercial vehicles operating in interstate commerce; to recommend and develop the best procedures that ...

Evaluation of DOTD's Existing Queue Estimation Procedures : Research Project Capsule

DOT National Transportation Integrated Search

2017-10-01

The primary objective of this study is to evaluate the effectiveness of DOTDs queue estimation procedures by comparing results with those obtained directly from site observations through video camera footage or other means. Actual queue start time...

Epidemiologic Analysis of Elective Operative Procedures in Infants Less Than 6 Months of Age in the United States.

PubMed

Einhorn, Lisa M; Young, Brian J; Routh, Jonathan C; Allori, Alexander C; Tracy, Elisabeth T; Greene, Nathaniel H

2017-11-01

This study uses publicly available data to analyze the total number of elective, potentially deferrable operative procedures involving infants <6 months of age in the United States. We investigated the factors associated with the performance of these procedures in this population. The State Ambulatory Surgery Database was used to identify patients in California, North Carolina, New York, and Utah during the years of 2007-2010 who were younger than 6 months of age at the time that they underwent outpatient (ambulatory) surgery. Operations that could reasonably be postponed until 6 months of age were classified as potentially deferrable procedures. Hernia repairs were analyzed separately from other deferrable procedures. Primary outcomes included the total number of elective procedures and the number and rates of potentially deferrable procedures per state per year in this population. Over the study period, a total of 27,540 procedures were identified as meeting inclusion criteria; of those, 7832 (28%) were classified as potentially deferrable, 4315 of which were hernia repairs. The average rates of potentially deferrable nonhernia procedures in California, North Carolina, New York, and Utah were 8.3, 43.8, 30.0, and 11.7 per 10,000 person-years, respectively. In multivariable analysis, private insurance (odds ratio [OR] = 1.36), self-pay status (OR = 1.50), and treatment in a different state (OR = 0.48-3.16) were independent predictors of a potentially deferrable procedure being performed on an infant younger than 6 months. Potentially deferrable procedures are still performed in infants <6 months of age. There appears to be significant variation in timing of these procedures among states. Insurance status and geography may be independent predictors of a procedure being potentially deferrable.

Procedures for estimating the frequency of commercial airline flights encountering high cabin ozone levels

NASA Technical Reports Server (NTRS)

Holdeman, J. D.

1979-01-01

Three analytical problems in estimating the frequency at which commercial airline flights will encounter high cabin ozone levels are formulated and solved: namely, estimating flight-segment mean levels, estimating maximum-per-flight levels, and estimating the maximum average level over a specified flight interval. For each problem, solution procedures are given for different levels of input information - from complete cabin ozone data, which provides a direct solution, to limited ozone information, such as ambient ozone means and standard deviations, with which several assumptions are necessary to obtain the required estimates. Each procedure is illustrated by an example case calculation that uses simultaneous cabin and ambient ozone data obtained by the NASA Global Atmospheric Sampling Program. Critical assumptions are discussed and evaluated, and the several solutions for each problem are compared. Example calculations are also performed to illustrate how variations in lattitude, altitude, season, retention ratio, flight duration, and cabin ozone limits affect the estimated probabilities.

[Efficacy of physiotherapy and hygienic procedures in treatment of adults and children with chronic blepharitis and dry eye syndrome].

PubMed

Prozornaia, L P; Brzhevskiĭ, V V

2013-01-01

110 patients aged from 3 to 42 years old were examined to estimate the efficacy of chronic blepharitis treatment: 50 patients with chronic blepharitis and dry eye syndrome (DES), 28 with DES due to computer vision syndrome and 32 with isolated chronic blepharitis. All patients received eyelid massage. If the secretion was too thick and difficult to evacuate from meibomian glands then duct probing was performed. In addition a complex of hygienic procedures was performed using phytoproducts ("Geltec-Medika", Russia): blepharoshampoo, blepharolotion, blepharogel 1 and 2. Moist warm pads (with blepharolotion and calendula extraction) were applied on the eyelids in 25 patients. Massage and probing of meibomian gland ducts and hygienic procedures were showed to be effective in management of clinical signs of chronic blepharitis including coexisting DES. Moist warm pads improve efficacy of background therapy in patients with meibomian gland hypofunction and have no effect in blepharitis with excessive meibomian gland secretion. Eyelid hygiene was showed to be effective in adults and children as well including infants.

[Incidence of surgical site infection in ambulatory surgery: results of the INCISCO surveillance network in 1999-2000].

PubMed

Sewonou, A; Rioux, C; Golliot, F; Richard, L; Massault, P P; Johanet, H; Cherbonnel, G; Botherel, A H; Farret, D; Astagneau, P

2002-04-01

To estimate the incidence of surgical-site infections (SSI) in ambulatory surgery and to identify risk factors based on the surveillance network INCISO in 1999-2000. Annually, during a three-month period, each surgical ward had to include 200 consecutive operations. Patients were surveyed over the month following surgery. For each patient, data including peri-operative factors, type of procedure and SSI occurrence were collected on a standardized form by a surgical staff committed for the study. Of the 5,183 patients who underwent an ambulatory surgery, the SSI incidence ratio was 0.4% (95% CI [0.3-0.7]). Orthopedic, gynecologic/obstetrics, head and neck, skin and soft tissues surgery accounted for 83% of all ambulatory procedures. 93% of patients belonged to the 0 risk category of the National Nosocomial Infections Surveillance system (NNIS) index. Emergency, age, american anesthesia risk score (ASA), Altemeier wound class, and procedure duration were not found to be risk factors for SSI in ambulatory surgery. Based on these surveillance data, infectious risk was low in ambulatory surgery and was not associated with known SSI risk factors.

Estimation of skeletal muscle mass from body creatine content

NASA Technical Reports Server (NTRS)

Pace, N.; Rahlmann, D. F.

1982-01-01

Procedures have been developed for studying the effect of changes in gravitational loading on skeletal muscle mass through measurements of the body creatine content. These procedures were developed for studies of gravitational scale effects in a four-species model, comprising the hamster, rat, guinea pig, and rabbit, which provides a sufficient range of body size for assessment of allometric parameters. Since intracellular muscle creatine concentration varies among species, and with age within a given species, the concentration values for metabolically mature individuals of these four species were established. The creatine content of the carcass, skin, viscera, smooth muscle, and skeletal muscle was determined for each species. In addition, the skeletal muscle mass of the major body components was determined, as well as the total and fat-free masses of the body and carcass, and the percent skeletal muscle in each. It is concluded that these procedures are particularly useful for studying the effect of gravitational loading on the skeletal muscle content of the animal carcass, which is the principal weight-bearing organ of the body.

High sodium and low potassium intake among Italian children: relationship with age, body mass and blood pressure.

PubMed

Campanozzi, Angelo; Avallone, Sonia; Barbato, Antonio; Iacone, Roberto; Russo, Ornella; De Filippo, Gianpaolo; D'Angelo, Giuseppina; Pensabene, Licia; Malamisura, Basilio; Cecere, Gaetano; Micillo, Maria; Francavilla, Ruggiero; Tetro, Anna; Lombardi, Giuliano; Tonelli, Lisa; Castellucci, Giuseppe; Ferraro, Luigi; Di Biase, Rita; Lezo, Antonella; Salvatore, Silvia; Paoletti, Silvia; Siani, Alfonso; Galeone, Daniela; Strazzullo, Pasquale

2015-01-01

Hypertension is the leading cause of death in developed countries and reduction of salt intake is recommended as a key preventive measure. To assess the dietary sodium and potassium intakes in a national sample of Italian children and adolescents and to examine their relationships with BMI and blood pressure (BP) in the framework of the MINISAL survey, a program supported by the Italian Ministry of Health. The study population included 1424 healthy subjects (766 boys, 658 girls) aged 6-18 years (mean age: 10.1±2.9) who were consecutively recruited in participating National Health Service centers in 10 Italian regions. Electrolyte intake was estimated from 24 hour urine collections tested for completeness by the concomitant measurement of creatinine content. Anthropometric indices and BP were measured with standardized procedures. The average estimated sodium intake was 129 mmol (7.4 g of salt) per day among boys and 117 mmol (6.7 g of salt) among girls. Ninety-three percent of the boys and 89% of the girls had a consumption higher than the recommended age-specific standard dietary target. The estimated average daily potassium intakes were 39 mmol (1.53 g) and 36 mmol (1.40 g), respectively, over 96% of the boys and 98% of the girls having a potassium intake lower than the recommended adequate intake. The mean sodium/potassium ratio was similar among boys and girls (3.5 and 3.4, respectively) and over 3-fold greater than the desirable level. Sodium intake was directly related to age, body mass and BP in the whole population. The Italian pediatric population is characterized by excessive sodium and deficient potassium intake. These data suggest that future campaigns should focus on children and adolescents as a major target in the framework of a population strategy of cardiovascular prevention.

Changes in the Treatment of Pediatric Femoral Fractures: 15-Year Trends From United States Kids' Inpatient Database (KID) 1997 to 2012.

PubMed

Naranje, Sameer M; Stewart, Matthew G; Kelly, Derek M; Jones, Tamekia L; Spence, David D; Warner, William C; Beaty, James H; Sawyer, Jeffrey R

2016-01-01

The options for treating femoral fractures in children and adolescents have evolved over the last 2 decades to include a variety of nonoperative and operative methods. The purpose of this study was to identify changes in the types of treatment for pediatric femoral fractures in the United States from 1997 to 2012. From discharge estimates for 1997, 2000, 2003, 2006, 2009, and 2012 in the Kids' Inpatient Database, data were extracted using the International Classification of Diseases, 9th revision, and Clinical Modification for pediatric femoral fracture treatments. Patients included were 0 to 17 years old and were categorized into 5 age groups: younger than 1, 1 to 4, 5 to 9, 10 to 14, and 15 to 17 years. A total of 74,483 estimated discharges were recorded for pediatric patients with femoral fractures in the database for years 1997, 2000, 2003, 2006, 2009, and 2012. A total of 12,986 pediatric femoral fractures were estimated for 1997 and 9813 for 2012, which was statistically different (P<0.0001). Significantly fewer fractures were treated with closed reduction alone in 2012 than in 1997 in age groups 5 to 9, 10 to 14, and 15 to 17 years. Children aged 5 to 9 had more frequent open reduction and internal fixation in 2012 than in 1997, whereas adolescents aged 15 to 17 had less frequent open reduction and internal fixation in 2012 than in 1997. Although the number of femoral shaft fractures overall has decreased, the frequency of operative treatment has increased significantly in patients 5 to 9 years of age. Knowledge of these trends can guide educational efforts and resource allocation, but further study is necessary to determine procedure-specific (eg, nailing, plating, external fixation) trends and their clinical and economic impacts. Level III-case series.

Estimating medical costs of gastroenterological diseases

PubMed Central

Chou, Li-Fang

2004-01-01

AIM: To estimate the direct medical costs of gastroenterological diseases within the universal health insurance program among the population of local residents in Taiwan. METHODS: The data sources were the first 4 cohort datasets of 200 000 people from the National Health Insurance Research Database in Taipei. The ambulatory, inpatient and pharmacy claims of the cohort in 2001 were analyzed. Besides prevalence and medical costs of diseases, both amount and costs of utilization in procedures and drugs were calculated. RESULTS: Of the cohort with 183 976 eligible people, 44.2% had ever a gastroenterological diagnosis during the year. The age group 20-39 years had the lowest prevalence rate (39.2%) while the elderly had the highest (58.4%). The prevalence rate was higher in women than in men (48.5% vs. 40.0%). Totally, 30.4% of 14 888 inpatients had ever a gastroenterological diagnosis at discharge and 18.8% of 51 359 patients at clinics of traditional Chinese medicine had such a diagnosis there. If only the principal diagnosis on each claim was considered, 16.2% of admissions, 8.0% of outpatient visits, and 10.1% of the total medical costs (8 469 909 US dollars/ 83 830 239 US dollars) were attributed to gastroenterological diseases. On average, 46.0 US dollars per insured person in a year were spent in treating gastroenterological diseases. Diagnostic procedures related to gastroenterological diseases accounted for 24.2% of the costs for all diagnostic procedures and 2.3% of the total medical costs. Therapeutic procedures related to gastroenterological diseases accounted for 4.5% of the costs for all therapeutic procedures and 1.3% of the total medical costs. Drugs related to gastroenterological diseases accounted for 7.3% of the costs for all drugs and 1.9% of the total medical costs. CONCLUSION: Gastroenterological diseases are prevalent among the population of local residents in Taiwan, accounting for a tenth of the total medical costs. Further investigations are needed to differentiate costs in screening, ruling out, confirming, and treating. PMID:14716838

Estimating medical costs of gastroenterological diseases.

PubMed

Chou, Li-Fang

2004-01-15

To estimate the direct medical costs of gastroenterological diseases within the universal health insurance program among the population of local residents in Taiwan. The data sources were the first 4 cohort datasets of 200,000 people from the National Health Insurance Research Database in Taipei. The ambulatory, inpatient and pharmacy claims of the cohort in 2001 were analyzed. Besides prevalence and medical costs of diseases, both amount and costs of utilization in procedures and drugs were calculated. Of the cohort with 183,976 eligible people, 44.2% had ever a gastroenterological diagnosis during the year. The age group 20-39 years had the lowest prevalence rate (39.2%) while the elderly had the highest (58.4%). The prevalence rate was higher in women than in men (48.5% vs. 40.0%). Totally, 30.4% of 14,888 inpatients had ever a gastroenterological diagnosis at discharge and 18.8% of 51,359 patients at clinics of traditional Chinese medicine had such a diagnosis there. If only the principal diagnosis on each claim was considered, 16.2% of admissions, 8.0% of outpatient visits, and 10.1% of the total medical costs (8,469,909 US dollars/83,830,239 US dollars) were attributed to gastroenterological diseases. On average, 46.0 US dollars per insured person in a year were spent in treating gastroenterological diseases. Diagnostic procedures related to gastroenterological diseases accounted for 24.2% of the costs for all diagnostic procedures and 2.3% of the total medical costs. Therapeutic procedures related to gastroenterological diseases accounted for 4.5% of the costs for all therapeutic procedures and 1.3% of the total medical costs. Drugs related to gastroenterological diseases accounted for 7.3% of the costs for all drugs and 1.9% of the total medical costs. Gastroenterological diseases are prevalent among the population of local residents in Taiwan, accounting for a tenth of the total medical costs. Further investigations are needed to differentiate costs in screening, ruling out, confirming, and treating.

Standard and goodness-of-fit parameter estimation methods for the three-parameter lognormal distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kane, V.E.

1982-01-01

A class of goodness-of-fit estimators is found to provide a useful alternative in certain situations to the standard maximum likelihood method which has some undesirable estimation characteristics for estimation from the three-parameter lognormal distribution. The class of goodness-of-fit tests considered include the Shapiro-Wilk and Filliben tests which reduce to a weighted linear combination of the order statistics that can be maximized in estimation problems. The weighted order statistic estimators are compared to the standard procedures in Monte Carlo simulations. Robustness of the procedures are examined and example data sets analyzed.

Laparoscopic donor nephrectomy increases the supply of living donor kidneys: a center-specific microeconomic analysis.

PubMed

Kuo, P C; Johnson, L B

2000-05-27

A tenet of microeconomics is that new technology will shift the supply curve to the right. Laparoscopic donor nephrectomy (LDN) is a new technique for removal of living donor kidneys. Centers performing this procedure have noted an increased number of patients presenting for donor evaluation. This has not been previously studied. The records of all LDN performed from May 1998 to February 1999 were reviewed. The following variables were examined: sex, age, related vs. unrelated donation, estimated blood loss, i.v. analgesia, length of stay, and time out of work. Donors undergoing traditional open donor nephrectomy during January 1997 to May 1998 served as the control group. A composite cost index was constructed. LDN significantly decreased length of stay, pain, and time out of work; the supply function shifted to the right. Telephone interviews revealed that 47% donated solely because of the LDN procedure. LDN increases the supply of living donor kidneys.

Extracting information on the spatial variability in erosion rate stored in detrital cooling age distributions in river sands

NASA Astrophysics Data System (ADS)

Braun, Jean; Gemignani, Lorenzo; van der Beek, Peter

2018-03-01

One of the main purposes of detrital thermochronology is to provide constraints on the regional-scale exhumation rate and its spatial variability in actively eroding mountain ranges. Procedures that use cooling age distributions coupled with hypsometry and thermal models have been developed in order to extract quantitative estimates of erosion rate and its spatial distribution, assuming steady state between tectonic uplift and erosion. This hypothesis precludes the use of these procedures to assess the likely transient response of mountain belts to changes in tectonic or climatic forcing. Other methods are based on an a priori knowledge of the in situ distribution of ages to interpret the detrital age distributions. In this paper, we describe a simple method that, using the observed detrital mineral age distributions collected along a river, allows us to extract information about the relative distribution of erosion rates in an eroding catchment without relying on a steady-state assumption, the value of thermal parameters or an a priori knowledge of in situ age distributions. The model is based on a relatively low number of parameters describing lithological variability among the various sub-catchments and their sizes and only uses the raw ages. The method we propose is tested against synthetic age distributions to demonstrate its accuracy and the optimum conditions for it use. In order to illustrate the method, we invert age distributions collected along the main trunk of the Tsangpo-Siang-Brahmaputra river system in the eastern Himalaya. From the inversion of the cooling age distributions we predict present-day erosion rates of the catchments along the Tsangpo-Siang-Brahmaputra river system, as well as some of its tributaries. We show that detrital age distributions contain dual information about present-day erosion rate, i.e., from the predicted distribution of surface ages within each catchment and from the relative contribution of any given catchment to the river distribution. The method additionally allows comparing modern erosion rates to long-term exhumation rates. We provide a simple implementation of the method in Python code within a Jupyter Notebook that includes the data used in this paper for illustration purposes.

Assessing the short term impact of air pollution on mortality: a matching approach.

PubMed

Baccini, Michela; Mattei, Alessandra; Mealli, Fabrizia; Bertazzi, Pier Alberto; Carugno, Michele

2017-02-10

The opportunity to assess short term impact of air pollution relies on the causal interpretation of the exposure-response association. However, up to now few studies explicitly faced this issue within a causal inference framework. In this paper, we reformulated the problem of assessing the short term impact of air pollution on health using the potential outcome approach to causal inference. We considered the impact of high daily levels of particulate matter ≤10 μm in diameter (PM 10 ) on mortality within two days from the exposure in the metropolitan area of Milan (Italy), during the period 2003-2006. Our research focus was the causal impact of a hypothetical intervention setting daily air pollution levels under a pre-fixed threshold. We applied a matching procedure based on propensity score to estimate the total number of attributable deaths (AD) during the study period. After defining the number of attributable deaths in terms of difference between potential outcomes, we used the estimated propensity score to match each high exposure day, namely each day with a level of exposure higher than 40 μg/m 3 , with a day with similar background characteristics but a level of exposure lower than 40 μg/m 3 . Then, we estimated the impact by comparing mortality between matched days. During the study period daily exposures larger than 40 μg/m 3 were responsible for 1079 deaths (90% CI: 116; 2042). The impact was more evident among the elderly than in the younger age classes. Exposures ≥ 40 μg/m 3 were responsible, among the elderly, for 1102 deaths (90% CI: 388, 1816), of which 797 from cardiovascular causes and 243 from respiratory causes. Clear evidence of an impact on respiratory mortality was found also in the age class 65-74, with 87 AD (90% CI: 11, 163). The propensity score matching turned out to be an appealing method to assess historical impacts in this field, which guarantees that the estimated total number of AD can be derived directly as sum of either age-specific or cause-specific AD, unlike the standard model-based procedure. For this reason, it is a promising approach to perform surveillance focusing on very specific causes of death or diseases, or on susceptible subpopulations. Finally, the propensity score matching is free from issues concerning the exposure-confounders-mortality modeling and does not involve extrapolation. On the one hand this enhances the internal validity of our results; on the other, it makes the approach scarcely appropriate for estimating future impacts.

Administrative Costs Associated With Physician Billing and Insurance-Related Activities at an Academic Health Care System.

PubMed

Tseng, Phillip; Kaplan, Robert S; Richman, Barak D; Shah, Mahek A; Schulman, Kevin A

2018-02-20

Administrative costs in the US health care system are an important component of total health care spending, and a substantial proportion of these costs are attributable to billing and insurance-related activities. To examine and estimate the administrative costs associated with physician billing activities in a large academic health care system with a certified electronic health record system. This study used time-driven activity-based costing. Interviews were conducted with 27 health system administrators and 34 physicians in 2016 and 2017 to construct a process map charting the path of an insurance claim through the revenue cycle management process. These data were used to calculate the cost for each major billing and insurance-related activity and were aggregated to estimate the health system's total cost of processing an insurance claim. Estimated time required to perform billing and insurance-related activities, based on interviews with management personnel and physicians. Estimated billing and insurance-related costs for 5 types of patient encounters: primary care visits, discharged emergency department visits, general medicine inpatient stays, ambulatory surgical procedures, and inpatient surgical procedures. Estimated processing time and total costs for billing and insurance-related activities were 13 minutes and $20.49 for a primary care visit, 32 minutes and $61.54 for a discharged emergency department visit, 73 minutes and $124.26 for a general inpatient stay, 75 minutes and $170.40 for an ambulatory surgical procedure, and 100 minutes and $215.10 for an inpatient surgical procedure. Of these totals, time and costs for activities carried out by physicians were estimated at a median of 3 minutes or $6.36 for a primary care visit, 3 minutes or $10.97 for an emergency department visit, 5 minutes or $13.29 for a general inpatient stay, 15 minutes or $51.20 for an ambulatory surgical procedure, and 15 minutes or $51.20 for an inpatient surgical procedure. Of professional revenue, professional billing costs were estimated to represent 14.5% for primary care visits, 25.2% for emergency department visits, 8.0% for general medicine inpatient stays, 13.4% for ambulatory surgical procedures, and 3.1% for inpatient surgical procedures. In a time-driven activity-based costing study in a large academic health care system with a certified electronic health record system, the estimated costs of billing and insurance-related activities ranged from $20 for a primary care visit to $215 for an inpatient surgical procedure. Knowledge of how specific billing and insurance-related activities contribute to administrative costs may help inform policy solutions to reduce these expenses.

Analysis of Ageing Effect on Li-Polymer Batteries

PubMed Central

Barcellona, Simone; Brenna, Morris; Foiadelli, Federica; Longo, Michela; Piegari, Luigi

2015-01-01

Lithium-ion batteries are a key technology for current and future energy storage in mobile and stationary application. In particular, they play an important role in the electrification of mobility and therefore the battery lifetime prediction is a fundamental aspect for successful market introduction. Numerous studies developed ageing models capable of predicting battery life span. Most of the previous works compared the effect of the ageing factors to a battery's cycle life. These cycles are identical, which is not the case for electric vehicles applications. Indeed, most of the available information is based on results from laboratory testing, under very controlled environments, and using ageing protocols, which may not correctly reflect the actual utilization. For this reason, it is important to link the effect of duty cycles with the ageing of the batteries. This paper proposes a simple method to investigate the effect of the duty cycle on the batteries lifetime through tests performed on different cells for different kinds of cycle. In this way, a generic complex cycle can be seen as a composition of elemental cycles by means of Rainflow procedures. Consequently, the ageing due to any cycle can be estimated starting from the knowledge of simpler cycles. PMID:26236775

Test Equality between Three Treatments under an Incomplete Block Crossover Design.

PubMed

Lui, Kung-Jong

2015-01-01

Under a random effects linear additive risk model, we compare two experimental treatments with a placebo in continuous data under an incomplete block crossover trial. We develop three test procedures for simultaneously testing equality between two experimental treatments and a placebo, as well as interval estimators for the mean difference between treatments. We apply Monte Carlo simulations to evaluate the performance of these test procedures and interval estimators in a variety of situations. We note that the bivariate test procedure accounting for the dependence structure based on the F-test is preferable to the other two procedures when there is only one of the two experimental treatments has a non-zero effect vs. the placebo. We note further that when the effects of the two experimental treatments vs. a placebo are in the same relative directions and are approximately of equal magnitude, the summary test procedure based on a simple average of two weighted-least-squares (WLS) estimators can outperform the other two procedures with respect to power. When one of the two experimental treatments has a relatively large effect vs. the placebo, the univariate test procedure with using Bonferroni's equality can be still of use. Finally, we use the data about the forced expiratory volume in 1 s (FEV1) readings taken from a double-blind crossover trial comparing two different doses of formoterol with a placebo to illustrate the use of test procedures and interval estimators proposed here.

Detecting stages of needle penetration into tissues through force estimation at needle tip using fiber Bragg grating sensors

NASA Astrophysics Data System (ADS)

Kumar, Saurabh; Shrikanth, Venkoba; Amrutur, Bharadwaj; Asokan, Sundarrajan; Bobji, Musuvathi S.

2016-12-01

Several medical procedures involve the use of needles. The advent of robotic and robot assisted procedures requires dynamic estimation of the needle tip location during insertion for use in both assistive systems as well as for automatic control. Most prior studies have focused on the maneuvering of solid flexible needles using external force measurements at the base of the needle holder. However, hollow needles are used in several procedures and measurements of forces in proximity of such needles can eliminate the need for estimating frictional forces that have high variations. These measurements are also significant for endoscopic procedures in which measurement of forces at the needle holder base is difficult. Fiber Bragg grating sensors, due to their small size, inert nature, and multiplexing capability, provide a good option for this purpose. Force measurements have been undertaken during needle insertion into tissue mimicking phantoms made of polydimethylsiloxane as well as chicken tissue using an 18-G needle instrumented with FBG sensors. The results obtained show that it is possible to estimate the different stages of needle penetration including partial rupture, which is significant for procedures in which precise estimation of needle tip position inside the organ or tissue is required.

The use of oral sucrose for procedural pain relief in infants up to six months of age: a randomized controlled trial.

PubMed

Wilson, Sally; Bremner, Alexandra P; Mathews, Judy; Pearson, Diane

2013-12-01

The aim of this study was to evaluate the effectiveness of oral sucrose in decreasing pain during minor procedures in infants of 1-6 months corrected age. A blinded randomized controlled trial with infants aged 4-26 weeks who underwent venipuncture, heel lance or intravenous cannulation were stratified by corrected age into > 4-12 weeks and > 12-26 weeks. They received 2 mL of either 25% sucrose or sterile water orally 2 minutes before the painful procedure. Nonnutritional sucking and parental comfort, provided in adherence to hospital guidelines, were recorded. Pain behavior was recorded using a validated 10 point scale at baseline, during and following the procedure. Data collectors were blinded to the intervention. A total of 21 and 20 infants received sucrose and water, respectively, in the > 4-12-week age group, and 21 and 22, respectively, in the > 12-26-week age group. No statistical differences were found in pain scores between treatment and control groups at any data collection points in either age group. Infants aged > 4-12 weeks who did nonnutritional sucking showed statistically significantly lower median pain scores at 1, 2, and 3 minutes after the procedure than those who did not suck. Infants aged > 4-26 weeks exhibited pain behavior scores that indicated moderate to large pain during painful procedures; however, there was insufficient evidence to show that 2 mL 25% sucrose had a statistically significant effect in decreasing pain. Infants should be offered nonnutritional sucking in compliance with the Baby Friendly Health Initiative during painful procedures. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Estimating Selected Streamflow Statistics Representative of 1930-2002 in West Virginia

USGS Publications Warehouse

Wiley, Jeffrey B.

2008-01-01

Regional equations and procedures were developed for estimating 1-, 3-, 7-, 14-, and 30-day 2-year; 1-, 3-, 7-, 14-, and 30-day 5-year; and 1-, 3-, 7-, 14-, and 30-day 10-year hydrologically based low-flow frequency values for unregulated streams in West Virginia. Regional equations and procedures also were developed for estimating the 1-day, 3-year and 4-day, 3-year biologically based low-flow frequency values; the U.S. Environmental Protection Agency harmonic-mean flows; and the 10-, 25-, 50-, 75-, and 90-percent flow-duration values. Regional equations were developed using ordinary least-squares regression using statistics from 117 U.S. Geological Survey continuous streamflow-gaging stations as dependent variables and basin characteristics as independent variables. Equations for three regions in West Virginia - North, South-Central, and Eastern Panhandle - were determined. Drainage area, precipitation, and longitude of the basin centroid are significant independent variables in one or more of the equations. Estimating procedures are presented for determining statistics at a gaging station, a partial-record station, and an ungaged location. Examples of some estimating procedures are presented.