First-Grade Cognitive Abilities as Long-Term Predictors of Reading Comprehension and Disability Status

PubMed Central

Fuchs, Douglas; Compton, Donald L.; Fuchs, Lynn S.; Bryant, V. Joan; Hamlett, Carol L.; Lambert, Warren

2012-01-01

In a sample of 195 first graders selected for poor reading performance, the authors explored four cognitive predictors of later reading comprehension and reading disability (RD) status. In fall of first grade, the authors measured the children’s phonological processing, rapid automatized naming (RAN), oral language comprehension, and nonverbal reasoning. Throughout first grade, they also modeled the students’ reading progress by means of weekly Word Identification Fluency (WIF) tests to derive December and May intercepts. The authors assessed their reading comprehension in the spring of Grades 1–5. With the four cognitive variables and the WIF December intercept as predictors, 50.3% of the variance in fifth-grade reading comprehension was explained: 52.1% of this 50.3% was unique to the cognitive variables, 13.1% to the WIF December intercept, and 34.8% was shared. All five predictors were statistically significant. The same four cognitive variables with the May (rather than December) WIF intercept produced a model that explained 62.1% of the variance. Of this amount, the cognitive variables and May WIF intercept accounted for 34.5% and 27.7%, respectively; they shared 37.8%. All predictors in this model were statistically significant except RAN. Logistic regression analyses indicated that the accuracy with which the cognitive variables predicted end-of-fifth-grade RD status was 73.9%. The May WIF intercept contributed reliably to this prediction; the December WIF intercept did not. Results are discussed in terms of a role for cognitive abilities in identifying, classifying, and instructing students with severe reading problems. PMID:22539057

First-grade cognitive abilities as long-term predictors of reading comprehension and disability status.

PubMed

Fuchs, Douglas; Compton, Donald L; Fuchs, Lynn S; Bryant, V Joan; Hamlett, Carol L; Lambert, Warren

2012-01-01

In a sample of 195 first graders selected for poor reading performance, the authors explored four cognitive predictors of later reading comprehension and reading disability (RD) status. In fall of first grade, the authors measured the children's phonological processing, rapid automatized naming (RAN), oral language comprehension, and nonverbal reasoning. Throughout first grade, they also modeled the students' reading progress by means of weekly Word Identification Fluency (WIF) tests to derive December and May intercepts. The authors assessed their reading comprehension in the spring of Grades 1-5. With the four cognitive variables and the WIF December intercept as predictors, 50.3% of the variance in fifth-grade reading comprehension was explained: 52.1% of this 50.3% was unique to the cognitive variables, 13.1% to the WIF December intercept, and 34.8% was shared. All five predictors were statistically significant. The same four cognitive variables with the May (rather than December) WIF intercept produced a model that explained 62.1% of the variance. Of this amount, the cognitive variables and May WIF intercept accounted for 34.5% and 27.7%, respectively; they shared 37.8%. All predictors in this model were statistically significant except RAN. Logistic regression analyses indicated that the accuracy with which the cognitive variables predicted end-of-fifth-grade RD status was 73.9%. The May WIF intercept contributed reliably to this prediction; the December WIF intercept did not. Results are discussed in terms of a role for cognitive abilities in identifying, classifying, and instructing students with severe reading problems.

Utilizing spatial and spectral features of photoacoustic imaging for ovarian cancer detection and diagnosis

NASA Astrophysics Data System (ADS)

Li, Hai; Kumavor, Patrick; Salman Alqasemi, Umar; Zhu, Quing

2015-01-01

A composite set of ovarian tissue features extracted from photoacoustic spectral data, beam envelope, and co-registered ultrasound and photoacoustic images are used to characterize malignant and normal ovaries using logistic and support vector machine (SVM) classifiers. Normalized power spectra were calculated from the Fourier transform of the photoacoustic beamformed data, from which the spectral slopes and 0-MHz intercepts were extracted. Five features were extracted from the beam envelope and another 10 features were extracted from the photoacoustic images. These 17 features were ranked by their p-values from t-tests on which a filter type of feature selection method was used to determine the optimal feature number for final classification. A total of 169 samples from 19 ex vivo ovaries were randomly distributed into training and testing groups. Both classifiers achieved a minimum value of the mean misclassification error when the seven features with lowest p-values were selected. Using these seven features, the logistic and SVM classifiers obtained sensitivities of 96.39±3.35% and 97.82±2.26%, and specificities of 98.92±1.39% and 100%, respectively, for the training group. For the testing group, logistic and SVM classifiers achieved sensitivities of 92.71±3.55% and 92.64±3.27%, and specificities of 87.52±8.78% and 98.49±2.05%, respectively.

Analysis of multivariate longitudinal kidney function outcomes using generalized linear mixed models.

PubMed

Jaffa, Miran A; Gebregziabher, Mulugeta; Jaffa, Ayad A

2015-06-14

Renal transplant patients are mandated to have continuous assessment of their kidney function over time to monitor disease progression determined by changes in blood urea nitrogen (BUN), serum creatinine (Cr), and estimated glomerular filtration rate (eGFR). Multivariate analysis of these outcomes that aims at identifying the differential factors that affect disease progression is of great clinical significance. Thus our study aims at demonstrating the application of different joint modeling approaches with random coefficients on a cohort of renal transplant patients and presenting a comparison of their performance through a pseudo-simulation study. The objective of this comparison is to identify the model with best performance and to determine whether accuracy compensates for complexity in the different multivariate joint models. We propose a novel application of multivariate Generalized Linear Mixed Models (mGLMM) to analyze multiple longitudinal kidney function outcomes collected over 3 years on a cohort of 110 renal transplantation patients. The correlated outcomes BUN, Cr, and eGFR and the effect of various covariates such patient's gender, age and race on these markers was determined holistically using different mGLMMs. The performance of the various mGLMMs that encompass shared random intercept (SHRI), shared random intercept and slope (SHRIS), separate random intercept (SPRI) and separate random intercept and slope (SPRIS) was assessed to identify the one that has the best fit and most accurate estimates. A bootstrap pseudo-simulation study was conducted to gauge the tradeoff between the complexity and accuracy of the models. Accuracy was determined using two measures; the mean of the differences between the estimates of the bootstrapped datasets and the true beta obtained from the application of each model on the renal dataset, and the mean of the square of these differences. The results showed that SPRI provided most accurate estimates and did not exhibit any computational or convergence problem. Higher accuracy was demonstrated when the level of complexity increased from shared random coefficient models to the separate random coefficient alternatives with SPRI showing to have the best fit and most accurate estimates.

MIXOR: a computer program for mixed-effects ordinal regression analysis.

PubMed

Hedeker, D; Gibbons, R D

1996-03-01

MIXOR provides maximum marginal likelihood estimates for mixed-effects ordinal probit, logistic, and complementary log-log regression models. These models can be used for analysis of dichotomous and ordinal outcomes from either a clustered or longitudinal design. For clustered data, the mixed-effects model assumes that data within clusters are dependent. The degree of dependency is jointly estimated with the usual model parameters, thus adjusting for dependence resulting from clustering of the data. Similarly, for longitudinal data, the mixed-effects approach can allow for individual-varying intercepts and slopes across time, and can estimate the degree to which these time-related effects vary in the population of individuals. MIXOR uses marginal maximum likelihood estimation, utilizing a Fisher-scoring solution. For the scoring solution, the Cholesky factor of the random-effects variance-covariance matrix is estimated, along with the effects of model covariates. Examples illustrating usage and features of MIXOR are provided.

Low Probability of Intercept Waveforms via Intersymbol Dither Performance Under Multiple Conditions

DTIC Science & Technology

2009-03-01

United States Air Force, Department of Defense, or the United States Government . AFIT/GE/ENG/09-23 Low Probability of Intercept Waveforms via...21 D random variable governing the distribution of dither values 21 p (ct) D (t) probability density function of the...potential performance loss of a non-cooperative receiver compared to a cooperative receiver designed to account for ISI and multipath. 1.3 Thesis

Low Probability of Intercept Waveforms via Intersymbol Dither Performance Under Multipath Conditions

DTIC Science & Technology

2009-03-01

United States Air Force, Department of Defense, or the United States Government . AFIT/GE/ENG/09-23 Low Probability of Intercept Waveforms via...21 D random variable governing the distribution of dither values 21 p (ct) D (t) probability density function of the...potential performance loss of a non-cooperative receiver compared to a cooperative receiver designed to account for ISI and multipath. 1.3 Thesis

Detection of Differential Item Functioning Using the Lasso Approach

ERIC Educational Resources Information Center

Magis, David; Tuerlinckx, Francis; De Boeck, Paul

2015-01-01

This article proposes a novel approach to detect differential item functioning (DIF) among dichotomously scored items. Unlike standard DIF methods that perform an item-by-item analysis, we propose the "LR lasso DIF method": logistic regression (LR) model is formulated for all item responses. The model contains item-specific intercepts,…

Non-medical use of prescription drugs in Bangalore, India.

PubMed

Nattala, Prasanthi; Murthy, Pratima; Kandavel, Thennarasu; Cottler, Linda B

2015-01-01

Non-medical prescription drug use is an ongoing problem in India; however, there is paucity of literature in the Indian population. The objective of the present study is to explore the non-medical use of prescription medicines in urban Bangalore, South India (N = 717). Participants were recruited using a mall-intercept approach, wherein they were intercepted in 5 randomly selected shopping malls, and interviewed on their use of prescription medicines. The mean age of the participants was 28 years (S.D. 5). The non-medical use of different prescription medicine classes over the past 12 months was as follows: anti-inflammatories and analgesics (26%), opioids (17%), antibiotics (13%), and sedatives (12%). The majority reported "use without prescription," while "use in ways other than as prescribed" was also reported. In all cases, chemist shops were the main source of obtaining the drugs non-medically. In multivariate logistic regression analyses, non-medical use was found to be significantly associated with participants' baseline characteristics like gender, education, current employment status, and marital status. Sixty-five percent stated that although "doctor's prescription is not required for common complaints, we can decide ourselves," while 60% stated, "it's okay to deviate from a prescription as needed." One hundred percent said that "using prescription medicines is more socially acceptable, and safer, compared to alcohol or illicit drugs." These findings underscore the need for considering various contextual factors in tailoring preventive interventions for reducing non-medical use of prescription drugs.

Influence of motivation, self-efficacy and situational factors on the teaching quality of clinical educators.

PubMed

Dybowski, Christoph; Sehner, Susanne; Harendza, Sigrid

2017-05-08

Being exposed to good teachers has been shown to enhance students' knowledge and their clinical performance, but little is known about the underlying psychological mechanisms that provide the basis for being an excellent medical teacher. Self-Determination Theory (SDT) postulates that more self-regulated types of motivation are associated with higher performance. Social Cognitive Theory (SCT) focuses on self-efficacy that has been shown to be positively associated with performance. To investigate the influences of different types of teaching motivation, teaching self-efficacy, and teachers' perceptions of students' skills, competencies and motivation on teaching quality. Before the winter semester 2014, physicians involved in bedside teaching in internal medicine at the University Medical Center Hamburg-Eppendorf completed a questionnaire with sociodemographic items and instruments measuring different dimensions of teaching motivation as well as teaching self-efficacy. During the semester, physicians rated their perceptions of the participating students who rated the teaching quality after each lesson. We performed a random intercept mixed-effects linear regression with students' ratings of teaching quality as the dependent variable and students' general interest in a subject as covariate. We explored potential associations between teachers' dispositions and their perceptions of students' competencies in a mixed-effects random intercept logistic regression. 94 lessons given by 55 teachers with 500 student ratings were analyzed. Neither teaching motivation nor teaching self-efficacy were directly associated with students' rating of teaching quality. Teachers' perceptions of students' competencies and students' general interest in the lesson's subject were positively associated with students' rating of teaching quality. Physicians' perceptions of their students' competencies were significantly positively predicted by their teaching self-efficacy. Teaching quality might profit from teachers who are self-efficacious and able to detect their students' competencies. Students' general interest in a lesson's subject needs to be taken into account when they are asked to evaluate teaching quality.

Nutritional status of under-five children in Bangladesh: a multilevel analysis.

PubMed

Alom, Jahangir; Quddus, Md Abdul; Islam, Mohammad Amirul

2012-09-01

The nutritional status of under-five children is a sensitive sign of a country's health status as well as economic condition. This study investigated the differential impact of some demographic, socioeconomic, environmental and health-related factors on the nutritional status among under-five children in Bangladesh using Bangladesh Demographic and Health Survey 2007 data. Two-level random intercept binary logistic regression models were used to identify the determinants of under-five malnutrition. The analyses revealed that 16% of the children were severely stunted and 25% were moderately stunted. Among the children under five years of age 3% were severely wasted and 14% were moderately wasted. Furthermore, 11% of the children were severely underweight and 28% were moderately underweight. The main contributing factors for under-five malnutrition were found to be child's age, mother's education, father's education, father's occupation, family wealth index, currently breast-feeding, place of delivery and division. Significant community-level variations were found in the analyses.

Cluster Analysis of Campylobacter jejuni Genotypes Isolated from Small and Medium-Sized Mammalian Wildlife and Bovine Livestock from Ontario Farms.

PubMed

Viswanathan, M; Pearl, D L; Taboada, E N; Parmley, E J; Mutschall, S K; Jardine, C M

2017-05-01

Using data collected from a cross-sectional study of 25 farms (eight beef, eight swine and nine dairy) in 2010, we assessed clustering of molecular subtypes of C. jejuni based on a Campylobacter-specific 40 gene comparative genomic fingerprinting assay (CGF40) subtypes, using unweighted pair-group method with arithmetic mean (UPGMA) analysis, and multiple correspondence analysis. Exact logistic regression was used to determine which genes differentiate wildlife and livestock subtypes in our study population. A total of 33 bovine livestock (17 beef and 16 dairy), 26 wildlife (20 raccoon (Procyon lotor), five skunk (Mephitis mephitis) and one mouse (Peromyscus spp.) C. jejuni isolates were subtyped using CGF40. Dendrogram analysis, based on UPGMA, showed distinct branches separating bovine livestock and mammalian wildlife isolates. Furthermore, two-dimensional multiple correspondence analysis was highly concordant with dendrogram analysis showing clear differentiation between livestock and wildlife CGF40 subtypes. Based on multilevel logistic regression models with a random intercept for farm of origin, we found that isolates in general, and raccoons more specifically, were significantly more likely to be part of the wildlife branch. Exact logistic regression conducted gene by gene revealed 15 genes that were predictive of whether an isolate was of wildlife or bovine livestock isolate origin. Both multiple correspondence analysis and exact logistic regression revealed that in most cases, the presence of a particular gene (13 of 15) was associated with an isolate being of livestock rather than wildlife origin. In conclusion, the evidence gained from dendrogram analysis, multiple correspondence analysis and exact logistic regression indicates that mammalian wildlife carry CGF40 subtypes of C. jejuni distinct from those carried by bovine livestock. Future studies focused on source attribution of C. jejuni in human infections will help determine whether wildlife transmit Campylobacter jejuni directly to humans. © 2016 Blackwell Verlag GmbH.

Multilevel covariance regression with correlated random effects in the mean and variance structure.

PubMed

Quintero, Adrian; Lesaffre, Emmanuel

2017-09-01

Multivariate regression methods generally assume a constant covariance matrix for the observations. In case a heteroscedastic model is needed, the parametric and nonparametric covariance regression approaches can be restrictive in the literature. We propose a multilevel regression model for the mean and covariance structure, including random intercepts in both components and allowing for correlation between them. The implied conditional covariance function can be different across clusters as a result of the random effect in the variance structure. In addition, allowing for correlation between the random intercepts in the mean and covariance makes the model convenient for skewedly distributed responses. Furthermore, it permits us to analyse directly the relation between the mean response level and the variability in each cluster. Parameter estimation is carried out via Gibbs sampling. We compare the performance of our model to other covariance modelling approaches in a simulation study. Finally, the proposed model is applied to the RN4CAST dataset to identify the variables that impact burnout of nurses in Belgium. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study on Light Interception and Biomass Production of Different Cotton Cultivars

PubMed Central

Mao, Shuchun; Han, Yingchun; Feng, Lu; Wang, Guoping; Yang, Beifang; Zhi, Xiaoyu; Fan, Zhengyi; Lei, Yaping; Du, Wenli; Li, Yabing

2016-01-01

Identifying the characteristics of light interception and utilization is of great significance for improving the potential photosynthetic activity of plants. The present research investigates the differences in absorbing and converting photosynthetically active radiation (PAR) among various cotton cultivars. Field experiments were conducted in 2012, 2013 and 2014 in Anyang, Henan, China. Ten cultivars with different maturity and plant architectures were planted at a density of 60,000 plants ha-1 in randomized blocks, with three replicates. The spatial distribution of light in canopy was measured and quantified with a geo-statistical method, according to which the cumulative amount of intercepted radiation was calculated by Simpson 3/8 rules. Finally, light interception was analyzed in association with the biomass accumulation of different cultivars. The key results were: (1) late-maturing varieties with an incompact plant architecture captured more solar radiation throughout the whole growth period than middle varieties with columnar architecture and even more than early varieties with compact architecture, and they produced more biomass; (2) the highest PAR interception ratio and the maximum biomass accumulation rate occurred during the blossoming and boll-forming stage, when leaf area index (LAI) reached its peak; (3) the distribution within the canopy presented a significant spatial heterogeneity, and at late growing stage, the PAR was mainly intercepted by upper canopies in incompact-type plant communities, but was more homogeneous in columnar-type plants; however, the majority of radiation was transmitted through the canopy in compact-type colonies; (4) there was not a consistent variation relationship between the cumulative intercepted PAR (iPAR) and biomass among these cultivars over the three years of the study. Based on these results, we attempted to clarify the distinction in light spatial distribution within different canopies and the patterns of PAR interception in diverse cotton cultivars with different hereditary characters, thereby providing a significant basis for researchers to select cultivars with appropriate growth period and optimal plant architecture for improvement of light interception and utilization. PMID:27227675

Nonmedical use of sedatives in urban Bengaluru.

PubMed

Nattala, Prasanthi; Murthy, Pratima; Thennarasu, K; Cottler, Linda B

2014-07-01

Nonmedical sedative use is emerging as a serious problem in India. However, there is paucity of literature on the patterns of use in the population. The aim of the present analysis was to explore sedative use patterns in an urban metropolis. Data for the present analysis come from the parent study on nonmedical prescription drug use in Bengaluru, India. Participants (n = 717) were recruited using a mall-intercept approach, wherein they were intercepted in five randomly selected shopping malls, and administered an interview on their use of prescription drugs. Past 12-month nonmedical sedative use was reported by 12%, benzodiazepines being the commonest. Reasons cited for nonmedical use included "sleeplessness, pain relief, stress." A majority (73%) reported sedative use "in ways other than as prescribed," compared to "use without prescription" (27%). All prescriptions were issued by general physicians in private hospitals. About 11% among those who used "in ways other than as prescribed," and 100% of nonprescribed users, reported irregular use (skipping doses/stopping/restarting). Among those who used "in ways other than prescribed," pharmacy stores were the source of obtaining the sedatives. Among "nonprescribed users," family/friends were the main source. Three-percent reported using sedatives and alcohol together in the same use episode. In multivariate logistic regression analyses, nonmedical sedative use was significantly associated with graduation-level education or above (adjusted odds ratio [aOR]: 2.53, 95% confidence interval [CI]: 1.30-4.91), and married status (aOR: 2.32, 95% CI: 1.04-5.18). Findings underscore the need for considering various contextual factors in tailoring preventive interventions for reducing nonmedical sedative use.

Impact of Health Research Systems on Under-5 Mortality Rate: A Trend Analysis.

PubMed

Yazdizadeh, Bahareh; Parsaeian, Mahboubeh; Majdzadeh, Reza; Nikooee, Sima

2016-11-26

Between 1990 and 2015, under-5 mortality rate (U5MR) declined by 53%, from an estimated rate of 91 deaths per 1000 live births to 43, globally. The aim of this study was to determine the share of health research systems in this decrease alongside other influential factors. We used random effect regression models including the 'random intercept' and 'random intercept and random slope' models to analyze the panel data from 1990 to 2010. We selected the countries with U5MRs falling between the first and third quartiles in 1990. We used both the total articles (TA) and the number of child-specific articles (CSA) as a proxy of the health research system. In order to account for the impact of other factors, measles vaccination coverage (MVC) (as a proxy of health system performance), gross domestic product (GDP), human development index (HDI), and corruption perception index (CPI) (as proxies of development), were embedded in the model. Among all the models, 'the random intercept and random slope models' had lower residuals. The same variables of CSA, HDI, and time were significant and the coefficient of CSA was estimated at -0.17; meaning, with the addition of every 100 CSA, the rate of U5MR decreased by 17 per 1000 live births. Although the number of CSA has contributed to the reduction of U5MR, the amount of its contribution is negligible compared to the countries' development. We recommend entering different types of researches into the model separately in future research and including the variable of 'exchange between knowledge generator and user.' © 2017 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

A simplified approach to the pooled analysis of calibration of clinical prediction rules for systematic reviews of validation studies

PubMed Central

Dimitrov, Borislav D; Motterlini, Nicola; Fahey, Tom

2015-01-01

Objective Estimating calibration performance of clinical prediction rules (CPRs) in systematic reviews of validation studies is not possible when predicted values are neither published nor accessible or sufficient or no individual participant or patient data are available. Our aims were to describe a simplified approach for outcomes prediction and calibration assessment and evaluate its functionality and validity. Study design and methods: Methodological study of systematic reviews of validation studies of CPRs: a) ABCD2 rule for prediction of 7 day stroke; and b) CRB-65 rule for prediction of 30 day mortality. Predicted outcomes in a sample validation study were computed by CPR distribution patterns (“derivation model”). As confirmation, a logistic regression model (with derivation study coefficients) was applied to CPR-based dummy variables in the validation study. Meta-analysis of validation studies provided pooled estimates of “predicted:observed” risk ratios (RRs), 95% confidence intervals (CIs), and indexes of heterogeneity (I2) on forest plots (fixed and random effects models), with and without adjustment of intercepts. The above approach was also applied to the CRB-65 rule. Results Our simplified method, applied to ABCD2 rule in three risk strata (low, 0–3; intermediate, 4–5; high, 6–7 points), indicated that predictions are identical to those computed by univariate, CPR-based logistic regression model. Discrimination was good (c-statistics =0.61–0.82), however, calibration in some studies was low. In such cases with miscalibration, the under-prediction (RRs =0.73–0.91, 95% CIs 0.41–1.48) could be further corrected by intercept adjustment to account for incidence differences. An improvement of both heterogeneities and P-values (Hosmer-Lemeshow goodness-of-fit test) was observed. Better calibration and improved pooled RRs (0.90–1.06), with narrower 95% CIs (0.57–1.41) were achieved. Conclusion Our results have an immediate clinical implication in situations when predicted outcomes in CPR validation studies are lacking or deficient by describing how such predictions can be obtained by everyone using the derivation study alone, without any need for highly specialized knowledge or sophisticated statistics. PMID:25931829

[Biodiversity and depressive symptoms in Mexican adults: Exploration of beneficial environmental effects].

PubMed

Duarte-Tagles, Héctor; Salinas-Rodríguez, Aarón; Idrovo, Álvaro J; Búrquez, Alberto; Corral-Verdugo, Víctor

2015-08-01

Depression is a highly prevalent illness among adults, and it is the second most frequently reported mental disorder in urban settings in México. Exposure to natural environments and its components may improve the mental health of the population. To evaluate the association between biodiversity indicators and the prevalence of depressive symptoms among the adult population (20 to 65 years of age) in México. Information from the Encuesta Nacional de Salud y Nutrición 2006 (ENSANUT 2006) and the Compendio de Estadísticas Ambientales 2008 was analyzed. A biodiversity index was constructed based on the species richness and ecoregions in each state. A multilevel logistic regression model was built with random intercepts and a multiple logistic regression was generated with clustering by state. The factors associated with depressive symptoms were being female, self-perceived as indigenous, lower education level, not living with a partner, lack of steady paid work, having a chronic illness and drinking alcohol. The biodiversity index was found to be inversely associated with the prevalence of depressive symptoms when defined as a continuous variable, and the results from the regression were grouped by state (OR=0.71; 95% CI = 0.59-0.87). Although the design was cross-sectional, this study adds to the evidence of the potential benefits to mental health from contact with nature and its components.

Risk Factors for Child Malnutrition in Bangladesh: A Multilevel Analysis of a Nationwide Population-Based Survey.

PubMed

Chowdhury, Mohammad Rocky Khan; Rahman, Mohammad Shafiur; Khan, Mohammad Mubarak Hossain; Mondal, Mohammad Nazrul Islam; Rahman, Mohammad Mosiur; Billah, Baki

2016-05-01

To identify the prevalence and risk factors of child malnutrition in Bangladesh. Data was extracted from the Bangladesh Demographic Health Survey (2011). The outcome measures were stunting, wasting, and underweight. χ(2) analysis was performed to find the association of outcome variables with selected factors. Multilevel logistic regression models with a random intercept at each of the household and community levels were used to identify the risk factors of stunting, wasting, and underweight. From the 2011 survey, 7568 children less than 5 years of age were included in the current analysis. The overall prevalence of stunting, wasting, and underweight was 41.3% (95% CI 39.0-42.9). The χ(2) test and multilevel logistic regression analysis showed that the variables age, sex, mother's body mass index, mother's educational status, father's educational status, place of residence, socioeconomic status, community status, religion, region of residence, and food security are significant factors of child malnutrition. Children with poor socioeconomic and community status were at higher risk of malnutrition. Children from food insecure families were more likely to be malnourished. Significant community- and household-level variations were found. The prevalence of child malnutrition is still high in Bangladesh, and the risk was assessed at several multilevel factors. Therefore, prevention of malnutrition should be given top priority as a major public health intervention. Copyright © 2016 Elsevier Inc. All rights reserved.

Successful customer intercept interview recruitment outside small and midsize urban food retailers.

PubMed

Pelletier, Jennifer E; Caspi, Caitlin E; Schreiber, Liana R N; Erickson, Darin J; Harnack, Lisa; Laska, Melissa N

2016-10-05

Customer intercept interviews are increasingly used to characterize food purchases at retail food outlets and restaurants; however, methodological procedures, logistical issues and response rates using intercept methods are not well described in the food environment literature. The aims of this manuscript were to 1) describe the development and implementation of a customer intercept interview protocol in a large, NIH-funded study assessing food purchases in small and midsize food retailers in Minneapolis and St. Paul, Minnesota, 2) describe intercept interview response rates by store type and environmental factors (e.g., neighborhood socioeconomic status, day/time, weather), and 3) compare demographic characteristics (e.g., gender, race/ethnicity) of participants versus non-participants. After a pilot phase involving 28 stores, a total of 616 interviews were collected from customers exiting 128 stores in fall 2014. The number of eligible customers encountered per hour (a measure of store traffic), participants successfully recruited per hour, and response rates were calculated overall and by store type, neighborhood socio-economic status, day and time of data collection, and weather. Response rates by store type, neighborhood socio-economic status, time and day of data collection, and weather, and characteristics of participants and non-participants were compared using chi-square tests. The overall response rate was 35 %, with significantly higher response rates at corner/small grocery stores (47 %) and dollar stores (46 %) compared to food-gas marts (32 %) and pharmacies (26 %), and for data collection between 4:00-6:00 pm on weekdays (40 %) compared to weekends (32 %). The distribution of race/ethnicity, but not gender, differed between participants and non-participants (p < 0.01), with greater participation rates among those identified as Black versus White. Customer intercept interviews can be successfully used to recruit diverse samples of customers at small and midsize food retailers. Future community-based studies using customer intercept interviews should collect data sufficient to report response rates and consider potential differences between the racial/ethnic composition of the recruited sample and the target population.

Dual-polarized feed antenna apparatus and method of use

NASA Technical Reports Server (NTRS)

Sarehraz, Mohammed (Inventor); Buckle, Kenneth A. (Inventor); Stefanakos, Elias (Inventor); Weller, Thomas (Inventor); Goswami, D. Yogi (Inventor)

2009-01-01

An antenna apparatus and method for the interception of randomly polarized electromagnetic waves utilizing a dual polarized antenna which is excited through a cross-slot aperture using two well-isolated orthogonal feeds.

Dual-polarized feed antenna apparatus and method of use

NASA Technical Reports Server (NTRS)

Sarehraz, Mohammad (Inventor); Buckle, Kenneth A. (Inventor); Stefanakos, Elias (Inventor); Weller, Thomas (Inventor); Goswami, D. Yogi (Inventor)

2008-01-01

An antenna apparatus and method for the interception of randomly polarized electromagnetic waves utilizing a dual polarized antenna which is excited through a cross-slot aperture using two well-isolated orthogonal feeds.

Prediction of random-regression coefficient for daily milk yield after 305 days in milk by using the regression-coefficient estimates from the first 305 days.

PubMed

Yamazaki, Takeshi; Takeda, Hisato; Hagiya, Koichi; Yamaguchi, Satoshi; Sasaki, Osamu

2018-03-13

Because lactation periods in dairy cows lengthen with increasing total milk production, it is important to predict individual productivities after 305 days in milk (DIM) to determine the optimal lactation period. We therefore examined whether the random regression (RR) coefficient from 306 to 450 DIM (M2) can be predicted from those during the first 305 DIM (M1) by using a random regression model. We analyzed test-day milk records from 85690 Holstein cows in their first lactations and 131727 cows in their later (second to fifth) lactations. Data in M1 and M2 were analyzed separately by using different single-trait RR animal models. We then performed a multiple regression analysis of the RR coefficients of M2 on those of M1 during the first and later lactations. The first-order Legendre polynomials were practical covariates of random regression for the milk yields of M2. All RR coefficients for the additive genetic (AG) effect and the intercept for the permanent environmental (PE) effect of M2 had moderate to strong correlations with the intercept for the AG effect of M1. The coefficients of determination for multiple regression of the combined intercepts for the AG and PE effects of M2 on the coefficients for the AG effect of M1 were moderate to high. The daily milk yields of M2 predicted by using the RR coefficients for the AG effect of M1 were highly correlated with those obtained by using the coefficients of M2. Milk production after 305 DIM can be predicted by using the RR coefficient estimates of the AG effect during the first 305 DIM.

Geometric Modeling of Inclusions as Ellipsoids

NASA Technical Reports Server (NTRS)

Bonacuse, Peter J.

2008-01-01

Nonmetallic inclusions in gas turbine disk alloys can have a significant detrimental impact on fatigue life. Because large inclusions that lead to anomalously low lives occur infrequently, probabilistic approaches can be utilized to avoid the excessively conservative assumption of lifing to a large inclusion in a high stress location. A prerequisite to modeling the impact of inclusions on the fatigue life distribution is a characterization of the inclusion occurrence rate and size distribution. To help facilitate this process, a geometric simulation of the inclusions was devised. To make the simulation problem tractable, the irregularly sized and shaped inclusions were modeled as arbitrarily oriented, three independent dimensioned, ellipsoids. Random orientation of the ellipsoid is accomplished through a series of three orthogonal rotations of axes. In this report, a set of mathematical models for the following parameters are described: the intercepted area of a randomly sectioned ellipsoid, the dimensions and orientation of the intercepted ellipse, the area of a randomly oriented sectioned ellipse, the depth and width of a randomly oriented sectioned ellipse, and the projected area of a randomly oriented ellipsoid. These parameters are necessary to determine an inclusion s potential to develop a propagating fatigue crack. Without these mathematical models, computationally expensive search algorithms would be required to compute these parameters.

Nonmedical use of sedatives in urban Bengaluru

PubMed Central

Nattala, Prasanthi; Murthy, Pratima; Thennarasu, K.; Cottler, Linda B.

2014-01-01

Background: Nonmedical sedative use is emerging as a serious problem in India. However, there is paucity of literature on the patterns of use in the population. Aim: The aim of the present analysis was to explore sedative use patterns in an urban metropolis. Materials and Methods: Data for the present analysis come from the parent study on nonmedical prescription drug use in Bengaluru, India. Participants (n = 717) were recruited using a mall-intercept approach, wherein they were intercepted in five randomly selected shopping malls, and administered an interview on their use of prescription drugs. Results: Past 12-month nonmedical sedative use was reported by 12%, benzodiazepines being the commonest. Reasons cited for nonmedical use included “sleeplessness, pain relief, stress.” A majority (73%) reported sedative use “in ways other than as prescribed,” compared to “use without prescription” (27%). All prescriptions were issued by general physicians in private hospitals. About 11% among those who used “in ways other than as prescribed,” and 100% of nonprescribed users, reported irregular use (skipping doses/stopping/restarting). Among those who used “in ways other than prescribed,” pharmacy stores were the source of obtaining the sedatives. Among “nonprescribed users,” family/friends were the main source. Three-percent reported using sedatives and alcohol together in the same use episode. In multivariate logistic regression analyses, nonmedical sedative use was significantly associated with graduation-level education or above (adjusted odds ratio [aOR]: 2.53, 95% confidence interval [CI]: 1.30-4.91), and married status (aOR: 2.32, 95% CI: 1.04-5.18). Conclusions: Findings underscore the need for considering various contextual factors in tailoring preventive interventions for reducing nonmedical sedative use. PMID:25316935

Parent's social status and children's nutrition influence on the university entrance of young adults in the last two decades in Brazil.

PubMed

Baraldi, Larissa Galastri; Conde, Wolney Lisboa

2014-01-01

The analysis of social indicators and health status of parents and children is a preferred way to estimate the potential for social mobility in different societies or different periods in the same society. To analyze the evolution of educational and nutritional status of the Brazilian families by an intergenerational approach. A representative sample of the Brazilian population, consisting of parents (35 to 65 years old) and young adults (20 to 24 years old) obtained from three national surveys NHNS (1989), HBS (2003 and 2009). We performed a descriptive analysis and, for the sons, we calculated the probability of starting college using the multilevel logistic regression with random intercept model. The advance of the nutritional status of young people was statistically higher than to their parents (p < 0.005). Social conditions experienced in childhood and family status had great influence on their later school success. These data indicate improvements in social status controlled by the nutritional status, initiated in the period of 1989-2003. Although inequality persists in the country, the family's influence declined in the period 2003-2009.

Immunocompromised Travelers: Demographic Characteristics, Travel Destinations, and Pretravel Health Care from the U.S. Global TravEpiNet Consortium

PubMed Central

Schwartz, Brian S.; Rosen, Jessica; Han, Pauline V.; Hynes, Noreen A.; Hagmann, Stefan H.; Rao, Sowmya R.; Jentes, Emily S.; Ryan, Edward T.; LaRocque, Regina C.

2015-01-01

An increasing number of immunocompromised individuals are pursuing international travel, and a better understanding of their international travel patterns and pretravel health care is needed. We evaluated the clinical features, itineraries, and pretravel health care of 486 immunocompromised international travelers seen at Global TravEpiNet sites from January 2009 to June 2012. We used bivariate analyses and logistic regressions using random intercept models to compare demographic and travel characteristics, vaccines administered, and medications prescribed for immunocompromised travelers versus 30,702 immunocompetent travelers. Immunocompromised travelers pursued itineraries that were largely similar to those of immunocompetent travelers, with nearly one-third of such travelers visiting countries with low human development indices. Biological agents, including tumor necrosis factor blockers, were commonly used immunosuppressive medications among immunocompromised travelers. A strong collaboration between travel-medicine specialists, primary care doctors, and specialist physicians is needed to prepare immunocompromised people for international travel. Incorporating routine questioning and planning regarding travel into the primary care visits of immunocompromised people may be useful. PMID:26304922

The relationship between organizational policies and practices and work limitations among hospital patient care workers.

PubMed

Sparer, Emily H; Boden, Leslie I; Sorensen, Glorian; Dennerlein, Jack T; Stoddard, Anne; Wagner, Gregory R; Nagler, Eve M; Hashimoto, Dean M; Hopcia, Karen; Sabbath, Erika L

2018-05-29

We examined relationships between organizational policies and practices (OPPs) (safety practices, ergonomic practices, and people-oriented culture) and work limitations in a sample of hospital workers. We used the 6-item Work Limitations Questionnaire (WLQ) to assess workers' perceptions of health-related work limitations. Self-reported OPPs and the WLQ were collected from workers in Boston, Massachusetts (n = 1277). We conducted random-intercept multi-level logistic regression models for each OPP using stepwise selection of covariates. As the unit-average ergonomic practice score increased by one, the odds of a worker reporting work limitations decreased by approximately 39% (P-value = 0.018), adjusted for job title, age, and body mass index. A similar relationship existed for people-oriented culture (P-value = 0.038). The association between safety practices and work limitations was similar, but not statistically significant. This study demonstrated the importance of workplace OPPs. OPPs that promote positive and supportive environments and that foster improvements in ergonomics may help reduce work limitations. © 2018 Wiley Periodicals, Inc.

Immunocompromised Travelers: Demographic Characteristics, Travel Destinations, and Pretravel Health Care from the U.S. Global TravEpiNet Consortium.

PubMed

Schwartz, Brian S; Rosen, Jessica; Han, Pauline V; Hynes, Noreen A; Hagmann, Stefan H; Rao, Sowmya R; Jentes, Emily S; Ryan, Edward T; LaRocque, Regina C

2015-11-01

An increasing number of immunocompromised individuals are pursuing international travel, and a better understanding of their international travel patterns and pretravel health care is needed. We evaluated the clinical features, itineraries, and pretravel health care of 486 immunocompromised international travelers seen at Global TravEpiNet sites from January 2009 to June 2012. We used bivariate analyses and logistic regressions using random intercept models to compare demographic and travel characteristics, vaccines administered, and medications prescribed for immunocompromised travelers versus 30,702 immunocompetent travelers. Immunocompromised travelers pursued itineraries that were largely similar to those of immunocompetent travelers, with nearly one-third of such travelers visiting countries with low human development indices. Biological agents, including tumor necrosis factor blockers, were commonly used immunosuppressive medications among immunocompromised travelers. A strong collaboration between travel-medicine specialists, primary care doctors, and specialist physicians is needed to prepare immunocompromised people for international travel. Incorporating routine questioning and planning regarding travel into the primary care visits of immunocompromised people may be useful. © The American Society of Tropical Medicine and Hygiene.

Aggressive crime, alcohol and drug use, and concentrated poverty in 24 U.S. urban areas.

PubMed

Valdez, Avelardo; Kaplan, Charles D; Curtis, Russell L

2007-01-01

The nexus between substance use and aggressive crime involves a complex interrelationship among mediating individual and community-level variables. Using multilevel logistic regression models, we investigate how community-level concentration of poverty variables mediate the predictive relationships among individual level social attachment variables and substance use on aggressive crime in a large national sample of male arrestees (N = 20,602) drawn from 24 U.S. urban areas. The findings support our hypothesis that individual social attachments to marriage and the labor force (education and employment) are the principal individual-level pathway mediating the substance abuse/aggression nexus. In the random intercept model, 3.17% of the variation not explained by the individual-level predictor variables is attributable to community-level variation in urban area female-headed households and households receiving welfare. This confirms our hypothesis that social structural conditions of an urban environment differentially expose persons to conditions that predict being arrested for an aggressive crime. Our findings tend to counter the cultural theorists who argue for an indigenous culture of violence in inner-city ghettos and barrios.

Predicting Treatment Effect from Surrogate Endpoints and Historical Trials | Division of Cancer Prevention

Cancer.gov

By Stuart G. Baker, 2017 Introduction This software fits a zero-intercept random effects linear model to data on surrogate and true endpoints in previous trials. Requirement:  Mathematica Version 11 or later. |

A comparison of observation-level random effect and Beta-Binomial models for modelling overdispersion in Binomial data in ecology & evolution.

PubMed

Harrison, Xavier A

2015-01-01

Overdispersion is a common feature of models of biological data, but researchers often fail to model the excess variation driving the overdispersion, resulting in biased parameter estimates and standard errors. Quantifying and modeling overdispersion when it is present is therefore critical for robust biological inference. One means to account for overdispersion is to add an observation-level random effect (OLRE) to a model, where each data point receives a unique level of a random effect that can absorb the extra-parametric variation in the data. Although some studies have investigated the utility of OLRE to model overdispersion in Poisson count data, studies doing so for Binomial proportion data are scarce. Here I use a simulation approach to investigate the ability of both OLRE models and Beta-Binomial models to recover unbiased parameter estimates in mixed effects models of Binomial data under various degrees of overdispersion. In addition, as ecologists often fit random intercept terms to models when the random effect sample size is low (<5 levels), I investigate the performance of both model types under a range of random effect sample sizes when overdispersion is present. Simulation results revealed that the efficacy of OLRE depends on the process that generated the overdispersion; OLRE failed to cope with overdispersion generated from a Beta-Binomial mixture model, leading to biased slope and intercept estimates, but performed well for overdispersion generated by adding random noise to the linear predictor. Comparison of parameter estimates from an OLRE model with those from its corresponding Beta-Binomial model readily identified when OLRE were performing poorly due to disagreement between effect sizes, and this strategy should be employed whenever OLRE are used for Binomial data to assess their reliability. Beta-Binomial models performed well across all contexts, but showed a tendency to underestimate effect sizes when modelling non-Beta-Binomial data. Finally, both OLRE and Beta-Binomial models performed poorly when models contained <5 levels of the random intercept term, especially for estimating variance components, and this effect appeared independent of total sample size. These results suggest that OLRE are a useful tool for modelling overdispersion in Binomial data, but that they do not perform well in all circumstances and researchers should take care to verify the robustness of parameter estimates of OLRE models.

DS/LPI autocorrelation detection in noise plus random-tone interference. [Direct Sequence Low-Probabilty of Intercept

NASA Technical Reports Server (NTRS)

Hinedi, S.; Polydoros, A.

1988-01-01

The authors present and analyze a frequency-noncoherent two-lag autocorrelation statistic for the wideband detection of random BPSK signals in noise-plus-random-multitone interference. It is shown that this detector is quite robust to the presence or absence of interference and its specific parameter values, contrary to the case of an energy detector. The rule assumes knowledge of the data rate and the active scenario under H0. It is concluded that the real-time autocorrelation domain and its samples (lags) are a viable approach for detecting random signals in dense environments.

Analysis of baseline, average, and longitudinally measured blood pressure data using linear mixed models.

PubMed

Hossain, Ahmed; Beyene, Joseph

2014-01-01

This article compares baseline, average, and longitudinal data analysis methods for identifying genetic variants in genome-wide association study using the Genetic Analysis Workshop 18 data. We apply methods that include (a) linear mixed models with baseline measures, (b) random intercept linear mixed models with mean measures outcome, and (c) random intercept linear mixed models with longitudinal measurements. In the linear mixed models, covariates are included as fixed effects, whereas relatedness among individuals is incorporated as the variance-covariance structure of the random effect for the individuals. The overall strategy of applying linear mixed models decorrelate the data is based on Aulchenko et al.'s GRAMMAR. By analyzing systolic and diastolic blood pressure, which are used separately as outcomes, we compare the 3 methods in identifying a known genetic variant that is associated with blood pressure from chromosome 3 and simulated phenotype data. We also analyze the real phenotype data to illustrate the methods. We conclude that the linear mixed model with longitudinal measurements of diastolic blood pressure is the most accurate at identifying the known single-nucleotide polymorphism among the methods, but linear mixed models with baseline measures perform best with systolic blood pressure as the outcome.

Label-noise resistant logistic regression for functional data classification with an application to Alzheimer's disease study.

PubMed

Lee, Seokho; Shin, Hyejin; Lee, Sang Han

2016-12-01

Alzheimer's disease (AD) is usually diagnosed by clinicians through cognitive and functional performance test with a potential risk of misdiagnosis. Since the progression of AD is known to cause structural changes in the corpus callosum (CC), the CC thickness can be used as a functional covariate in AD classification problem for a diagnosis. However, misclassified class labels negatively impact the classification performance. Motivated by AD-CC association studies, we propose a logistic regression for functional data classification that is robust to misdiagnosis or label noise. Specifically, our logistic regression model is constructed by adopting individual intercepts to functional logistic regression model. This approach enables to indicate which observations are possibly mislabeled and also lead to a robust and efficient classifier. An effective algorithm using MM algorithm provides simple closed-form update formulas. We test our method using synthetic datasets to demonstrate its superiority over an existing method, and apply it to differentiating patients with AD from healthy normals based on CC from MRI. © 2016, The International Biometric Society.

Risk and Protective Effects of Sibling Relationships among African American Adolescents

ERIC Educational Resources Information Center

Soli, Anna R.; McHale, Susan M.; Feinberg, Mark E.

2009-01-01

This study investigated associations between sibling relationships and adjustment among 179 African American adolescent siblings (controlling for family factors) and tested moderating effects of familism values and birth order. Two-level random intercept models revealed that familism values moderated sibling relationship-adjustment linkages,…

Modeling the rate of HIV testing from repeated binary data amidst potential never-testers.

PubMed

Rice, John D; Johnson, Brent A; Strawderman, Robert L

2018-01-04

Many longitudinal studies with a binary outcome measure involve a fraction of subjects with a homogeneous response profile. In our motivating data set, a study on the rate of human immunodeficiency virus (HIV) self-testing in a population of men who have sex with men (MSM), a substantial proportion of the subjects did not self-test during the follow-up study. The observed data in this context consist of a binary sequence for each subject indicating whether or not that subject experienced any events between consecutive observation time points, so subjects who never self-tested were observed to have a response vector consisting entirely of zeros. Conventional longitudinal analysis is not equipped to handle questions regarding the rate of events (as opposed to the odds, as in the classical logistic regression model). With the exception of discrete mixture models, such methods are also not equipped to handle settings in which there may exist a group of subjects for whom no events will ever occur, i.e. a so-called "never-responder" group. In this article, we model the observed data assuming that events occur according to some unobserved continuous-time stochastic process. In particular, we consider the underlying subject-specific processes to be Poisson conditional on some unobserved frailty, leading to a natural focus on modeling event rates. Specifically, we propose to use the power variance function (PVF) family of frailty distributions, which contains both the gamma and inverse Gaussian distributions as special cases and allows for the existence of a class of subjects having zero frailty. We generalize a computational algorithm developed for a log-gamma random intercept model (Conaway, 1990. A random effects model for binary data. Biometrics46, 317-328) to compute the exact marginal likelihood, which is then maximized to obtain estimates of model parameters. We conduct simulation studies, exploring the performance of the proposed method in comparison with competitors. Applying the PVF as well as a Gaussian random intercept model and a corresponding discrete mixture model to our motivating data set, we conclude that the group assigned to receive follow-up messages via SMS was self-testing at a significantly lower rate than the control group, but that there is no evidence to support the existence of a group of never-testers. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A randomized, controlled study of a healthy corner store initiative on the purchases of urban, low-income youth

PubMed Central

Lent, Michelle R.; Veur, Stephanie S. Vander; McCoy, Tara A.; Wojtanowski, Alexis C.; Sandoval, Brianna; Sherman, Sandy; Komaroff, Eugene; Foster, Gary D.

2014-01-01

Objective Although many initiatives exist to improve the availability of healthy foods in corner stores, few randomized trials have assessed their effects. This study evaluated, in a randomized, controlled trial, the effects of a first-generation healthy corner store intervention on students’ food and beverage purchases over a two-year period. Design and Methods Participants (n=767) were 4th-6th grade students. Ten schools and their nearby corner stores (n=24) were randomly assigned to the healthy corner store intervention or an assessment-only control. Intercept surveys directly assessed the nutritional characteristics of students’ corner store purchases at baseline, 1 and 2 years. Students’ weight and heights were measured at baseline, 1 and 2 years. Results There were no differences in energy content per intercept purchased from control or intervention schools at year 1 (p=0.12) or 2 (p=0.58). There were no differences between control and intervention students in BMI-z score (year 1, p=0.83; year 2, p=0. 98) or obesity prevalence (year 1, p=0.96; year 2, p=0.58). Conclusions A healthy corner store initiative did not result in significant changes in the energy content of corner store purchases or in continuous or categorical measures of obesity. These data will help to inform future interventions. PMID:25311881

Evaluation of gene expression classification studies: factors associated with classification performance.

PubMed

Novianti, Putri W; Roes, Kit C B; Eijkemans, Marinus J C

2014-01-01

Classification methods used in microarray studies for gene expression are diverse in the way they deal with the underlying complexity of the data, as well as in the technique used to build the classification model. The MAQC II study on cancer classification problems has found that performance was affected by factors such as the classification algorithm, cross validation method, number of genes, and gene selection method. In this paper, we study the hypothesis that the disease under study significantly determines which method is optimal, and that additionally sample size, class imbalance, type of medical question (diagnostic, prognostic or treatment response), and microarray platform are potentially influential. A systematic literature review was used to extract the information from 48 published articles on non-cancer microarray classification studies. The impact of the various factors on the reported classification accuracy was analyzed through random-intercept logistic regression. The type of medical question and method of cross validation dominated the explained variation in accuracy among studies, followed by disease category and microarray platform. In total, 42% of the between study variation was explained by all the study specific and problem specific factors that we studied together.

Travel time to maternity care and its effect on utilization in rural Ghana: a multilevel analysis.

PubMed

Masters, Samuel H; Burstein, Roy; Amofah, George; Abaogye, Patrick; Kumar, Santosh; Hanlon, Michael

2013-09-01

Rates of neonatal and maternal mortality are high in Ghana. In-facility delivery and other maternal services could reduce this burden, yet utilization rates of key maternal services are relatively low, especially in rural areas. We tested a theoretical implication that travel time negatively affects the use of in-facility delivery and other maternal services. Empirically, we used geospatial techniques to estimate travel times between populations and health facilities. To account for uncertainty in Ghana Demographic and Health Survey cluster locations, we adopted a novel approach of treating the location selection as an imputation problem. We estimated a multilevel random-intercept logistic regression model. For rural households, we found that travel time had a significant effect on the likelihood of in-facility delivery and antenatal care visits, holding constant education, wealth, maternal age, facility capacity, female autonomy, and the season of birth. In contrast, a facility's capacity to provide sophisticated maternity care had no detectable effect on utilization. As the Ghanaian health network expands, our results suggest that increasing the availability of basic obstetric services and improving transport infrastructure may be important interventions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of welfare and maternal work on recommended preventive care utilization among low-income children.

PubMed

Holl, Jane L; Oh, Elissa H; Yoo, Joan; Amsden, Laura B; Sohn, Min-Woong

2012-12-01

We examined how maternal work and welfare receipt are associated with children receiving recommended pediatric preventive care services. We identified American Academy of Pediatrics-recommended preventive care visits from medical records of children in the 1999-2004 Illinois Families Study: Child Well-Being. We used Illinois administrative data to identify whether mothers received welfare or worked during the period the visit was recommended, and we analyzed the child visit data using random-intercept logistic regressions that adjusted for child, maternal, and visit-specific characteristics. The 485 children (95%) meeting inclusion criteria made 41% of their recommended visits. Children were 60% more likely (adjusted odds ratios [AOR` = 1.60; 95% confidence interval [CI] = 1.27, 2.01) to make recommended visits when mothers received welfare but did not work compared with when mothers did not receive welfare and did not work. Children were 25% less likely (AOR = 0.75; 95% CI = 0.60, 0.94) to make preventive care visits during periods when mothers received welfare and worked compared with welfare only periods. The Temporary Assistance for Needy Families maternal work requirement may be a barrier to receiving recommended preventive pediatric health care.

Comparison of statistical models to estimate parasite growth rate in the induced blood stage malaria model.

PubMed

Wockner, Leesa F; Hoffmann, Isabell; O'Rourke, Peter; McCarthy, James S; Marquart, Louise

2017-08-25

The efficacy of vaccines aimed at inhibiting the growth of malaria parasites in the blood can be assessed by comparing the growth rate of parasitaemia in the blood of subjects treated with a test vaccine compared to controls. In studies using induced blood stage malaria (IBSM), a type of controlled human malaria infection, parasite growth rate has been measured using models with the intercept on the y-axis fixed to the inoculum size. A set of statistical models was evaluated to determine an optimal methodology to estimate parasite growth rate in IBSM studies. Parasite growth rates were estimated using data from 40 subjects published in three IBSM studies. Data was fitted using 12 statistical models: log-linear, sine-wave with the period either fixed to 48 h or not fixed; these models were fitted with the intercept either fixed to the inoculum size or not fixed. All models were fitted by individual, and overall by study using a mixed effects model with a random effect for the individual. Log-linear models and sine-wave models, with the period fixed or not fixed, resulted in similar parasite growth rate estimates (within 0.05 log 10 parasites per mL/day). Average parasite growth rate estimates for models fitted by individual with the intercept fixed to the inoculum size were substantially lower by an average of 0.17 log 10 parasites per mL/day (range 0.06-0.24) compared with non-fixed intercept models. Variability of parasite growth rate estimates across the three studies analysed was substantially higher (3.5 times) for fixed-intercept models compared with non-fixed intercept models. The same tendency was observed in models fitted overall by study. Modelling data by individual or overall by study had minimal effect on parasite growth estimates. The analyses presented in this report confirm that fixing the intercept to the inoculum size influences parasite growth estimates. The most appropriate statistical model to estimate the growth rate of blood-stage parasites in IBSM studies appears to be a log-linear model fitted by individual and with the intercept estimated in the log-linear regression. Future studies should use this model to estimate parasite growth rates.

The Association Between Sexual Health and Physical, Mental, and Social Health in Adolescent Women.

PubMed

Hensel, Devon J; Nance, Jennifer; Fortenberry, J Dennis

2016-10-01

Developmental models link sexual well-being to physical, mental/emotional, and social well-being, yet little empirical literature evaluates these relationships in adolescents. Better understanding of how and when sexuality complements other aspects of health may yield important points to enhance existing health education and prevention efforts. Data were drawn from a 10-year longitudinal cohort study of sexual relationships and sexual behavior among adolescent women (N = 387; 14-17 years at enrollment). Sexual health data were drawn from quarterly partner-specific interviews and were linked to physical, mental/emotional, and social health information in annual questionnaires. Random intercept, mixed effects linear, ordinal logistic, or binary logistic regression were used to estimate the influence of sexual health on health and well-being outcomes (Stata, v.23, StataCorp, College Station, TX). All models controlled for participant age and race/ethnicity. Higher sexual health was significantly associated with less frequent nicotine and substance use, lower self-reported depression, lower thrill seeking, higher self-esteem, having fewer friends who use substances, higher religiosity, better social integration, lower frequency of delinquent behavior and crime, and more frequent community group membership. Sexual health was not associated with the number of friends who used cigarettes. Positive sexually related experiences in romantic relationships during adolescence may complement physical, mental/emotional, and social health. Addressing specific aspects of healthy sexual development during clinical encounters could dually help primary prevention and health education address other common adolescent health issues. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Do mobile family planning clinics facilitate vasectomy use in Nepal?

PubMed

Padmadas, Sabu S; Amoako Johnson, Fiifi; Leone, Tiziana; Dahal, Govinda P

2014-06-01

Nepal has a distinct topography that makes reproductive health and family planning services difficult to access, particularly in remote mountain and hill regions where over a quarter of modern contraceptive users rely exclusively on vasectomy. A three-level random intercept logistic regression analysis was applied on data from the 2011 Nepal Demographic and Health Survey to investigate the extent of influence of mobile family planning clinics on the odds of a male or a female sterilization, adjusting for relevant characteristics including ecological differences and random effects. The analyses included a sample of 2014 sterilization users, considering responses from currently married women of reproductive ages. The odds of a male sterilization were significantly higher in a mobile clinic than those in a government hospital (odds ratio, 1.65; 95% confidence interval, 1.21-2.25). The effects remained unaltered and statistically significant after adjusting for sociodemographic and clustering effects. Random effects were highly significant, which suggest the extent of heterogeneity in vasectomy use at the community and district levels. The odds of vasectomy use in mobile clinics were significantly higher among couples residing in hill and mountain regions and among those with three or more sons or those with only daughters. Mobile clinics significantly increase the uptake of vasectomy in hard-to-reach areas of Nepal. Reproductive health interventions should consider mobile clinics as an effective strategy to improve access to male-based modern methods and enhance gender equity in family planning. Family planning interventions in hard-to-reach communities could consider mobile clinic as an effective strategy to promote male-based modern methods. Improving access to vasectomy could substantially reduce unmet need for family planning in countries experiencing rapid fertility transition. Copyright © 2014 Elsevier Inc. All rights reserved.

Variable-intercept panel model for deformation zoning of a super-high arch dam.

PubMed

Shi, Zhongwen; Gu, Chongshi; Qin, Dong

2016-01-01

This study determines dam deformation similarity indexes based on an analysis of deformation zoning features and panel data clustering theory, with comprehensive consideration to the actual deformation law of super-high arch dams and the spatial-temporal features of dam deformation. Measurement methods of these indexes are studied. Based on the established deformation similarity criteria, the principle used to determine the number of dam deformation zones is constructed through entropy weight method. This study proposes the deformation zoning method for super-high arch dams and the implementation steps, analyzes the effect of special influencing factors of different dam zones on the deformation, introduces dummy variables that represent the special effect of dam deformation, and establishes a variable-intercept panel model for deformation zoning of super-high arch dams. Based on different patterns of the special effect in the variable-intercept panel model, two panel analysis models were established to monitor fixed and random effects of dam deformation. Hausman test method of model selection and model effectiveness assessment method are discussed. Finally, the effectiveness of established models is verified through a case study.

Randomized Clinical Trial of Interceptive and Comprehensive Orthodontics

PubMed Central

King, G.J.; Spiekerman, C.F.; Greenlee, G.M.; Huang, G.J.

2012-01-01

Focusing public insurance programs on interceptive orthodontics (IO) may increase access for low-income children. This report presents outcomes from a randomized clinical trial (RCT) comparing IO with comprehensive orthodontics (CO) in Medicaid patients. One hundred seventy pre-adolescents with Medicaid-eligible malocclusions were randomized to IO (n = 86) followed by observation (OBS) or OBS followed by CO (n = 84). One hundred thirty-four completed the trial. Models at pre-treatment (baseline) and following ≤ 2 years of intervention and 2 years of OBS (48 mos) were scored by calibrated examiners using the Peer Assessment Rating (PAR) and Index of Complexity, Outcome and Need (ICON). Overall outcomes and clinically meaningful categorical ICON data on need/acceptability, complexity, and improvement were compared. At baseline, groups were balanced by age, gender, ethnicity, and PAR/ICON scores. Most were minorities. Most (77%) were rated as difficult-to-very difficult. Scores improved significantly for both groups, but CO more than IO (PAR, 18.6 [95%CI 15.1, 22.1] vs.10.1 [95%CI 6.7, 13.4]; ICON, 44.8 [95% CI 39.7, 49.9] vs. 35.2 [95%CI 29.7, 40.6], respectively). On average, IO is effective at reducing malocclusions in Medicaid patients, but less than CO. (ClinicalTrials.gov number CT00067379) PMID:22699670

Schema generation in recurrent neural nets for intercepting a moving target.

PubMed

Fleischer, Andreas G

2010-06-01

The grasping of a moving object requires the development of a motor strategy to anticipate the trajectory of the target and to compute an optimal course of interception. During the performance of perception-action cycles, a preprogrammed prototypical movement trajectory, a motor schema, may highly reduce the control load. Subjects were asked to hit a target that was moving along a circular path by means of a cursor. Randomized initial target positions and velocities were detected in the periphery of the eyes, resulting in a saccade toward the target. Even when the target disappeared, the eyes followed the target's anticipated course. The Gestalt of the trajectories was dependent on target velocity. The prediction capability of the motor schema was investigated by varying the visibility range of cursor and target. Motor schemata were determined to be of limited precision, and therefore visual feedback was continuously required to intercept the moving target. To intercept a target, the motor schema caused the hand to aim ahead and to adapt to the target trajectory. The control of cursor velocity determined the point of interception. From a modeling point of view, a neural network was developed that allowed the implementation of a motor schema interacting with feedback control in an iterative manner. The neural net of the Wilson type consists of an excitation-diffusion layer allowing the generation of a moving bubble. This activation bubble runs down an eye-centered motor schema and causes a planar arm model to move toward the target. A bubble provides local integration and straightening of the trajectory during repetitive moves. The schema adapts to task demands by learning and serves as forward controller. On the basis of these model considerations the principal problem of embedding motor schemata in generalized control strategies is discussed.

What affects response rates in primary healthcare-based programmes? An analysis of individual and unit-related factors associated with increased odds of non-response based on HCV screening in the general population in Poland

PubMed Central

Parda, Natalia; Stępień, Małgorzata; Zakrzewska, Karolina; Madaliński, Kazimierz; Kołakowska, Agnieszka; Godzik, Paulina; Rosińska, Magdalena

2016-01-01

Objectives Response rate in public health programmes may be a limiting factor. It is important to first consider their delivery and acceptability for the target. This study aimed at determining individual and unit-related factors associated with increased odds of non-response based on hepatitis C virus screening in primary healthcare. Design Primary healthcare units (PHCUs) were extracted from the Register of Health Care Centres. Each of the PHCUs was to enrol adult patients selected on a random basis. Data on the recruitment of PHCUs and patients were analysed. Multilevel modelling was applied to investigate individual and unit-related factors associated with non-response. Multilevel logistic model was developed with fixed effects and only a random intercept for the unit. Preliminary analysis included a random effect for unit and each of the individual or PHCU covariates separately. For each of the PHCU covariates, we applied a two-level model with individual covariates, unit random effect and a single fixed effect of this unit covariate. Setting This study was conducted in primary care units in selected provinces in Poland. Participants A total of 242 PHCUs and 24 480 adults were invited. Of them, 44 PHCUs and 20 939 patients agreed to participate. Both PHCUs and patients were randomly selected. Results Data on 44 PHCUs and 24 480 patients were analysed. PHCU-level factors and recruitment strategies were important predictors of non-response. Unit random effect was significant in all models. Larger and private units reported higher non-response rates, while for those with a history of running public health programmes the odds of non-response was lower. Proactive recruitment, more working hours devoted to the project and patient resulted in higher acceptance of the project. Higher number of personnel had no such effect. Conclusions Prior to the implementation of public health programme, several factors that could hinder its execution should be addressed. PMID:27927665

What affects response rates in primary healthcare-based programmes? An analysis of individual and unit-related factors associated with increased odds of non-response based on HCV screening in the general population in Poland.

PubMed

Parda, Natalia; Stępień, Małgorzata; Zakrzewska, Karolina; Madaliński, Kazimierz; Kołakowska, Agnieszka; Godzik, Paulina; Rosińska, Magdalena

2016-12-07

Response rate in public health programmes may be a limiting factor. It is important to first consider their delivery and acceptability for the target. This study aimed at determining individual and unit-related factors associated with increased odds of non-response based on hepatitis C virus screening in primary healthcare. Primary healthcare units (PHCUs) were extracted from the Register of Health Care Centres. Each of the PHCUs was to enrol adult patients selected on a random basis. Data on the recruitment of PHCUs and patients were analysed. Multilevel modelling was applied to investigate individual and unit-related factors associated with non-response. Multilevel logistic model was developed with fixed effects and only a random intercept for the unit. Preliminary analysis included a random effect for unit and each of the individual or PHCU covariates separately. For each of the PHCU covariates, we applied a two-level model with individual covariates, unit random effect and a single fixed effect of this unit covariate. This study was conducted in primary care units in selected provinces in Poland. A total of 242 PHCUs and 24 480 adults were invited. Of them, 44 PHCUs and 20 939 patients agreed to participate. Both PHCUs and patients were randomly selected. Data on 44 PHCUs and 24 480 patients were analysed. PHCU-level factors and recruitment strategies were important predictors of non-response. Unit random effect was significant in all models. Larger and private units reported higher non-response rates, while for those with a history of running public health programmes the odds of non-response was lower. Proactive recruitment, more working hours devoted to the project and patient resulted in higher acceptance of the project. Higher number of personnel had no such effect. Prior to the implementation of public health programme, several factors that could hinder its execution should be addressed. 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/.

Community mass treatment with azithromycin for trachoma: Factors associated with change in participation of children from the first to the second round

PubMed Central

Ssemanda, Elizabeth N.; Mkocha, Harran; Levens, Joshua; Munoz, Beatriz; West, Sheila K.

2013-01-01

Background Mass drug administration (MDA) with azithromycin is an important part of trachoma control programs. Maintaining high participation among children is challenging. Aim We assessed factors identifying households with a child who changed participation from the first MDA to the second MDA compared to households where all children participated at both MDAs. Methods Two case-control comparisons were conducted in 11 Tanzanian communities, which underwent MDA in 2008 and 2009. The first case group (n=165) was a random sample of households with a child who changed from a 2008 non-participant to a 2009 participant (delayed participant). The second case group (n=165) was a random sample of households with a child who went from a 2008 participant to a 2009 non-participant (change to non-participant). Controls (n=330) were a random sample of households where all children participated in both rounds. Risk factors were assessed using questionnaires asked of children’s guardians. Logistic models with a random-intercept were used to estimate odds ratios and 95% confidence intervals. Results Households with delayed participation were more likely to be in communities with fewer treatment days (OR=2.98, 95% CI=1.80–4.92) and assigned to Community Treatment Assistants (CTA) with a wide area to cover (OR=1.88, 95% CI=1.09–3.23). Households with change to non-participation were more likely to live further from the distribution site (OR=3.17, 95% CI=1.19–8.46), have the guardian born outside the village with short-term residency (OR=2.64, 95% CI=1.32–5.31), and be assigned to a male CTA (OR=1.75, 95% CI=1.08–2.83). Conclusions Factors related to program accessibility were associated with delayed participation and maintaining participation. PMID:26462290

Early blood pressure, anti-hypotensive therapy and outcomes at 18 to 22 month corrected age in extremely preterm infants

PubMed Central

Batton, Beau; Li, Lei; Newman, Nancy S.; Das, Abhik; Watterberg, Kristi L.; Yoder, Bradley A.; Faix, Roger G.; Laughon, Matthew M.; Stoll, Barbara J.; Higgins, Rosemary D.; Walsh, Michele C.

2016-01-01

Objective Investigate relationships between early blood pressure (BP) changes, receipt of anti-hypotensive therapy, and 18 – 22 month corrected age (CA) outcomes for extremely preterm infants. Design Prospective observational study of infants 230/7 – 266/7 weeks gestational age (GA). Hourly BP values and anti-hypotensive therapy exposure in the first 24 hours were recorded. Four groups were defined: infants who did or did not receive anti-hypotensive therapy in whom BP did or did not rise at the expected rate (defined as an increase in the mean arterial BP of ≥5 mmHg/day). Random-intercept logistic modeling controlling for center clustering, GA, and illness severity was used to investigate the relationship between BP, anti-hypotensive therapies, and infant outcomes. Setting Sixteen academic centers of the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Main Outcome Measures Death or neurodevelopmental impairment / developmental delay (NIDD) at 18 – 22 months CA. Results Of 367 infants, 203 (55%) received an anti-hypotensive therapy, 272 (74%) survived to discharge, and 331 (90%) had a known outcome at 18 – 22 months CA. With logistic regression, there was an increased risk of death/NIDD with anti-hypotensive therapy versus no treatment (odds ratio: 1.836, 95% confidence interval: 1.092 – 3.086), but not NIDD alone (odds ratio: 1.53, 95% confidence interval: 0.708 – 3.307). Conclusion Independent of early BP changes, anti-hypotensive therapy exposure was associated with an increased risk of death/NIDD at 18 to 22 months CA when controlling for risk factors known to affect survival and neurodevelopment. PMID:26567120

Complementary nonparametric analysis of covariance for logistic regression in a randomized clinical trial setting.

PubMed

Tangen, C M; Koch, G G

1999-03-01

In the randomized clinical trial setting, controlling for covariates is expected to produce variance reduction for the treatment parameter estimate and to adjust for random imbalances of covariates between the treatment groups. However, for the logistic regression model, variance reduction is not obviously obtained. This can lead to concerns about the assumptions of the logistic model. We introduce a complementary nonparametric method for covariate adjustment. It provides results that are usually compatible with expectations for analysis of covariance. The only assumptions required are based on randomization and sampling arguments. The resulting treatment parameter is a (unconditional) population average log-odds ratio that has been adjusted for random imbalance of covariates. Data from a randomized clinical trial are used to compare results from the traditional maximum likelihood logistic method with those from the nonparametric logistic method. We examine treatment parameter estimates, corresponding standard errors, and significance levels in models with and without covariate adjustment. In addition, we discuss differences between unconditional population average treatment parameters and conditional subpopulation average treatment parameters. Additional features of the nonparametric method, including stratified (multicenter) and multivariate (multivisit) analyses, are illustrated. Extensions of this methodology to the proportional odds model are also made.

Universality properties of school-based preventive intervention targeted at cannabis use.

PubMed

Miovský, Michal; Voňková, Hana; Gabrhelík, Roman; Šťastná, Lenka

2015-02-01

This study aims to examine the effect of school-based preventive intervention on cannabis use in Czech adolescents with different levels of risk factors and provide evidence of its universality. A randomized controlled prevention trial with six waves was conducted over a period of 33 months. We used a two-level logistic random-intercept model for panel data; we first looked at the statistical significance of the effect of the intervention on cannabis use, controlling for the characteristics of the children and time dummies. Then we analyzed the effects of the interactions between the intervention and the characteristics of the children on cannabis use and related it to the definition of universal preventive interventions. The setting for the study was in basic schools in the Czech Republic in the years 2007-2010. A total of 1,874 sixth-graders (mean age 11.82 years) who completed the baseline testing. According to our results, the prevention intervention was effective. We found all the selected characteristics of the children to be relevant in relation to cannabis use, except their relationships with their friends. We showed empirically that the intervention is universal in two dimensions for the selected characteristics of the children. First, all adolescents who undergo the intervention are expected to benefit. Second, with respect to the effect of the intervention on cannabis use, the total level of individual risk of cannabis use is superior to the composition of the risk factors in the individual risk profile. We present indicative evidence that the drug prevention intervention may be considered a true universal preventive intervention.

Welfare, maternal work, and on-time childhood vaccination rates.

PubMed

Sohn, Min-Woong; Yoo, Joan; Oh, Elissa H; Amsden, Laura B; Holl, Jane L

2011-12-01

To examine effects of Temporary Assistance for Needy Families welfare cash assistance and maternal work requirements on "on-time" childhood vaccination rates. A stratified random sample of Illinois children from low-income families affected by welfare reform was monitored from 1997 to 2004. Medical records from pediatricians' offices and Medicaid claims data were used to identify the timeliness of 18 recommended vaccinations. Random-intercept logistic models were used to estimate on-time vaccine administration as a function of welfare receipt and maternal work with adjustment for characteristics of the children and mothers and time-varying covariates pertaining to the administration window for each recommended vaccine dose. Of all recommended vaccinations, 55.9% were administered on time. On-time vaccination rates were higher when families were receiving welfare than not (57.4% vs 52.8%). Children in families that either were receiving welfare or had working mothers were 1.7 to 2.1 times more likely to receive vaccinations on time compared with children in families that were not receiving welfare and did not have working mothers. When vaccine doses were stratified according to welfare status, maternal work was associated with decreased on-time vaccination rates (odds ratio: 0.73 [95% confidence interval: 0.59-0.90]) when families received welfare but increased on-time vaccination rates (odds ratio: 1.68 [95% confidence interval: 1.27-2.22]) when they did not receive welfare. These results indicate that maternal work requirements of Temporary Assistance for Needy Families had negative effects on timely administration of childhood vaccinations, although receipt of welfare itself was associated with increased on-time rates.

Isolating the cow-specific part of residual energy intake in lactating dairy cows using random regressions.

PubMed

Fischer, A; Friggens, N C; Berry, D P; Faverdin, P

2018-07-01

The ability to properly assess and accurately phenotype true differences in feed efficiency among dairy cows is key to the development of breeding programs for improving feed efficiency. The variability among individuals in feed efficiency is commonly characterised by the residual intake approach. Residual feed intake is represented by the residuals of a linear regression of intake on the corresponding quantities of the biological functions that consume (or release) energy. However, the residuals include both, model fitting and measurement errors as well as any variability in cow efficiency. The objective of this study was to isolate the individual animal variability in feed efficiency from the residual component. Two separate models were fitted, in one the standard residual energy intake (REI) was calculated as the residual of a multiple linear regression of lactation average net energy intake (NEI) on lactation average milk energy output, average metabolic BW, as well as lactation loss and gain of body condition score. In the other, a linear mixed model was used to simultaneously fit fixed linear regressions and random cow levels on the biological traits and intercept using fortnight repeated measures for the variables. This method split the predicted NEI in two parts: one quantifying the population mean intercept and coefficients, and one quantifying cow-specific deviations in the intercept and coefficients. The cow-specific part of predicted NEI was assumed to isolate true differences in feed efficiency among cows. NEI and associated energy expenditure phenotypes were available for the first 17 fortnights of lactation from 119 Holstein cows; all fed a constant energy-rich diet. Mixed models fitting cow-specific intercept and coefficients to different combinations of the aforementioned energy expenditure traits, calculated on a fortnightly basis, were compared. The variance of REI estimated with the lactation average model represented only 8% of the variance of measured NEI. Among all compared mixed models, the variance of the cow-specific part of predicted NEI represented between 53% and 59% of the variance of REI estimated from the lactation average model or between 4% and 5% of the variance of measured NEI. The remaining 41% to 47% of the variance of REI estimated with the lactation average model may therefore reflect model fitting errors or measurement errors. In conclusion, the use of a mixed model framework with cow-specific random regressions seems to be a promising method to isolate the cow-specific component of REI in dairy cows.

Nurses' but not supervisors' safety practices are linked with job satisfaction.

PubMed

Hurtado, David A; Kim, Seung-Sup; Subramanian, S V; Dennerlein, Jack T; Christiani, David C; Hashimoto, Dean M; Sorensen, Glorian

2017-10-01

To test the associations of safety practices as reported by nurses and their respective unit supervisors with job satisfaction. Psychosocial workplace factors are associated with job satisfaction; however, it is unknown whether nurses and supervisors accounts of safety practices are differentially linked to this outcome. Cross-sectional study design including nurses (n = 1052) nested in 94 units in two hospitals in Boston (MA, USA). Safety practices refer to the identification and control of occupational hazards at the unit. Safety practices were measured aggregating nurses' responses per unit, and supervisory levels. Individual's job satisfaction for each nurse was the response variable. Supervisors assessed safety practices more favourably than their unit nursing staff. Adjusted random intercept logistic regressions showed that the odds of higher job satisfaction were higher for nurses at units with better safety practices (OR: 1.67, 95% CI: 1.04, 2.68) compared with nurses at units that averaged lower safety practices. Supervisors' reports of safety practices were not correlated with the job satisfaction of their staff. Adequate safety practices might be a relevant managerial role that enhances job satisfaction among nurses. Nursing supervisors should calibrate their safety assessments with their nursing staff to improve nurses' job satisfaction. © 2017 John Wiley & Sons Ltd.

Neighborhood Racial Diversity and Metabolic Syndrome: 2003-2008 National Health and Nutrition Examination Survey.

PubMed

Li, Kelin; Wen, Ming; Fan, Jessie X

2018-03-30

This study investigated the independent association between neighborhood racial/ethnic diversity and metabolic syndrome among US adults, and focused on how this association differed across individual and neighborhood characteristics (i.e., race/ethnicity, sex, age, urbanity, neighborhood poverty). Objectively-measured biomarker data from 2003 to 2008 National Health and Nutrition Examination Survey were linked to census-tract profiles from 2000 decennial census (N = 10,122). Multilevel random intercept logistic regression models were estimated to examine the contextual effects of tract-level racial/ethnic diversity on individual risks of metabolic syndrome. Overall, more than 20% of the study population were identified as having metabolic syndrome, although the prevalence also varied across demographic subgroups and specific biomarkers. Multilevel analyses showed that increased racial/ethnic diversity within a census tract was associated with decreased likelihood of having metabolic syndrome (OR 0.71, 95% CI 0.52-0.96), particularly among female (OR 0.64; 95% CI 0.43-0.96), young adults (OR 0.60; 95% CI 0.39-0.93), and residents living in urban (OR 0.67; 95% CI 0.48-0.93) or poverty neighborhoods (OR 0.54; 95% CI 0.31-0.95). The findings point to the potential benefits of neighborhood racial/ethnic diversity on individual health risks.

Effects of Welfare and Maternal Work on Recommended Preventive Care Utilization Among Low-Income Children

PubMed Central

Holl, Jane L.; Oh, Elissa H.; Yoo, Joan; Amsden, Laura B.

2012-01-01

Objectives. We examined how maternal work and welfare receipt are associated with children receiving recommended pediatric preventive care services. Methods. We identified American Academy of Pediatrics–recommended preventive care visits from medical records of children in the 1999–2004 Illinois Families Study: Child Well-Being. We used Illinois administrative data to identify whether mothers received welfare or worked during the period the visit was recommended, and we analyzed the child visit data using random-intercept logistic regressions that adjusted for child, maternal, and visit-specific characteristics. Results. The 485 children (95%) meeting inclusion criteria made 41% of their recommended visits. Children were 60% more likely (adjusted odds ratios [AOR` = 1.60; 95% confidence interval [CI] = 1.27, 2.01) to make recommended visits when mothers received welfare but did not work compared with when mothers did not receive welfare and did not work. Children were 25% less likely (AOR = 0.75; 95% CI = 0.60, 0.94) to make preventive care visits during periods when mothers received welfare and worked compared with welfare only periods. Conclusion. The Temporary Assistance for Needy Families maternal work requirement may be a barrier to receiving recommended preventive pediatric health care. PMID:23078495

Rates and Implications of Rainfall Interception in a Coastal Redwood Forest

Treesearch

Leslie M. Reid; Jack Lewis

2007-01-01

Throughfall was measured for a year at five-min intervals in 11 collectors randomly located on two plots in a second-growth redwood forest at the Caspar Creek Experimental Watersheds. Monitoring at one plot continued two more years, during which stemflow from 24 trees was also measured. Comparison of throughfall and stemflow to rainfall measured in adjacent clearings...

Generalized SAMPLE SIZE Determination Formulas for Investigating Contextual Effects by a Three-Level Random Intercept Model.

PubMed

Usami, Satoshi

2017-03-01

Behavioral and psychological researchers have shown strong interests in investigating contextual effects (i.e., the influences of combinations of individual- and group-level predictors on individual-level outcomes). The present research provides generalized formulas for determining the sample size needed in investigating contextual effects according to the desired level of statistical power as well as width of confidence interval. These formulas are derived within a three-level random intercept model that includes one predictor/contextual variable at each level to simultaneously cover various kinds of contextual effects that researchers can show interest. The relative influences of indices included in the formulas on the standard errors of contextual effects estimates are investigated with the aim of further simplifying sample size determination procedures. In addition, simulation studies are performed to investigate finite sample behavior of calculated statistical power, showing that estimated sample sizes based on derived formulas can be both positively and negatively biased due to complex effects of unreliability of contextual variables, multicollinearity, and violation of assumption regarding the known variances. Thus, it is advisable to compare estimated sample sizes under various specifications of indices and to evaluate its potential bias, as illustrated in the example.

Causal mediation analysis for longitudinal data with exogenous exposure

PubMed Central

Bind, M.-A. C.; Vanderweele, T. J.; Coull, B. A.; Schwartz, J. D.

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. PMID:26272993

Unitary Suprathreshold Color-Difference Metrics of Legibility for CRT Raster Imagery.

DTIC Science & Technology

1986-09-01

observers possessing norma vision could accurately read random numeral strings of one color displayed DD J 4-73 EDITION OF C 6S IS OBSOLETE - SEURT CLSIICTO...34 Table 2, continued. SAE (L*,u*,v*) : .909 .940 Intercept 1. 8581 1. 8022 " N -0. 3980 -0.3655 m .AE 0. 1217 0. 1206-" =, E -0. 0019 -0. 0017 * all t > 3

Longitudinal Change of Self-Perceptions of Aging and Mortality

PubMed Central

2014-01-01

Objective. To understand the association between self-perceptions of aging (SPA) and mortality in late life. Method. The sample (n = 1,507) was drawn from the Australian Longitudinal Study of Aging (baseline age = 65–103 years). We used joint growth curve and survival models on 5 waves of data for a period of 16 years to investigate the random intercept and slope of SPA for predicting all-cause mortality. Results. The unadjusted model revealed that poor SPA at baseline, as well as decline in SPA, increased the risk of mortality (SPA intercept hazard ratio [HR] = 1.21, 95% confidence interval [CI] = 1.13, 1.31; SPA slope HR = 1.17, 95% CI = 1.02, 1.33). This relationship remained significant for the SPA intercept after adjusting for other risk factors including demographics, physical health, cognitive functioning, and well-being. Conclusion. These findings suggest that a single measurement of SPA in late life may be very informative of future long-term vulnerability to health decline and mortality. Furthermore, a dynamic measure of SPA may be indicative of adaptation to age-related changes. This supports a “self-fulfilling” hypothesis, whereby SPA is a lens through which age-related changes are interpreted, and these interpretations can affect future health and health behaviors. PMID:23419867

Ultrasonic RF time series for early assessment of the tumor response to chemotherapy.

PubMed

Lin, Qingguang; Wang, Jianwei; Li, Qing; Lin, Chunyi; Guo, Zhixing; Zheng, Wei; Yan, Cuiju; Li, Anhua; Zhou, Jianhua

2018-01-05

Ultrasound radio-frequency (RF) time series have been shown to carry tissue typing information. To evaluate the potential of RF time series for early prediction of tumor response to chemotherapy, 50MCF-7 breast cancer-bearing nude mice were randomized to receive cisplatin and paclitaxel (treatment group; n = 26) or sterile saline (control group; n = 24). Sequential ultrasound imaging was performed on days 0, 3, 6, and 8 of treatment to simultaneously collect B-mode images and RF data. Six RF time series features, slope, intercept, S1, S2, S3 , and S4 , were extracted during RF data analysis and contrasted with microstructural tumor changes on histopathology. Chemotherapy administration reduced tumor growth relative to control on days 6 and 8. Compared with day 0, intercept, S1 , and S2 were increased while slope was decreased on days 3, 6, and 8 in the treatment group. Compared with the control group, intercept, S1, S2, S3 , and S4 were increased, and slope was decreased, on days 3, 6, and 8 in the treatment group. Tumor cell density decreased significantly in the latter on day 3. We conclude that ultrasonic RF time series analysis provides a simple way to noninvasively assess the early tumor response to chemotherapy.

Causal mediation analysis for longitudinal data with exogenous exposure.

PubMed

Bind, M-A C; Vanderweele, T J; Coull, B A; Schwartz, J D

2016-01-01

Mediation analysis is a valuable approach to examine pathways in epidemiological research. Prospective cohort studies are often conducted to study biological mechanisms and often collect longitudinal measurements on each participant. Mediation formulae for longitudinal data have been developed. Here, we formalize the natural direct and indirect effects using a causal framework with potential outcomes that allows for an interaction between the exposure and the mediator. To allow different types of longitudinal measures of the mediator and outcome, we assume two generalized mixed-effects models for both the mediator and the outcome. The model for the mediator has subject-specific random intercepts and random exposure slopes for each cluster, and the outcome model has random intercepts and random slopes for the exposure, the mediator, and their interaction. We also expand our approach to settings with multiple mediators and derive the mediated effects, jointly through all mediators. Our method requires the absence of time-varying confounding with respect to the exposure and the mediator. This assumption is achieved in settings with exogenous exposure and mediator, especially when exposure and mediator are not affected by variables measured at earlier time points. We apply the methodology to data from the Normative Aging Study and estimate the direct and indirect effects, via DNA methylation, of air pollution, and temperature on intercellular adhesion molecule 1 (ICAM-1) protein levels. Our results suggest that air pollution and temperature have a direct effect on ICAM-1 protein levels (i.e. not through a change in ICAM-1 DNA methylation) and that temperature has an indirect effect via a change in ICAM-1 DNA methylation. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Centre-related variability in hospital admissions of patients with spondyloarthritis.

PubMed

Andrés, Mariano; Sivera, Francisca; Pérez-Vicente, Sabina; Carmona, Loreto; Vela, Paloma

2016-09-01

The aim of this study was to explore the variability in hospital admissions of patients with spondyloarthritis (SpA) in Spain, and the centre factors that may influence that variability. Descriptive cross-sectional study, part of the emAR II study, performed in Spain (2009-2010). Health records of patients with a diagnosis of SpA and at least one visit to the rheumatology units within the previous 2 years were reviewed. Variables related to hospital admissions, to the SpA, and to the patient and centre were collected. A multilevel logistic regression analysis of random intercept with non-random slopes was performed to assess variability between centres. From 45 centres, 1168 patients' health records were reviewed. Main SpA forms were ankylosing spondylitis (55.2 %) and psoriatic arthritis (22.2 %). A total of 248 admissions were registered for 196 patients (19.2 %, n = 1020). An adjusted variability of 17.6 % in hospitalizations between centres was noted. The following hospital-related factors showed a significant association with admissions: the total number of admissions of the centre, the existence of electronic admission, and the availability of ultrasound in rheumatology. However, these factors only explained 42.9 % of the inter-centre variability. The risk of a patient with SpA of being admitted could double (median OR 2.09), depending on the hospital where the patient was being managed. Hospital admissions of patients with SpA varied between hospitals due to centre characteristics. Further studies are needed to ascertain which specific factors may be causing the variation, as studied variables explained less than half of the variability.

HIV-related knowledge, perceptions, attitudes, and utilisation of HIV counselling and testing: a venue-based intercept commuter population survey in the inner city of Johannesburg, South Africa.

PubMed

Chimoyi, Lucy; Tshuma, Ndumiso; Muloongo, Keith; Setswe, Geoffrey; Sarfo, Bismark; Nyasulu, Peter S

2015-01-01

HIV counselling and testing (HCT) and knowledge about HIV have been key strategies utilised in the prevention and control of HIV/AIDS worldwide. HIV knowledge and uptake of HCT services in sub-Saharan Africa are still low. This study was conducted to determine factors associated with HCT and HIV/AIDS knowledge levels among a commuter population in Johannesburg, South Africa. To identify the factors associated with HCT uptake among the commuter population. A simple random sampling method was used to select participants in a venue-based intercept survey at a taxi rank in the Johannesburg Central Business District. Data were collected using an electronic questionnaire. Logistic regression analysis assessed factors associated with HIV testing stratified by gender. 1,146 respondents were interviewed, the maority (n=579, 50.5%) were females and (n=780, 68.1%) were over 25 years of age. Overall HCT knowledge was high (n=951, 83%) with more females utilising HCT facilities. There was a significant difference in HIV testing for respondents living closer to and further away from health facilities. Slightly more than half of the respondents indicated stigma as one of the barriers for testing (n=594, 52%, p-value=0.001). For males, living with a partner (aOR: 1.68, 95% CI: 1.02-2.78, p-value: 0.041) and possessing a post-primary education were positively associated with testing (aOR: 2.00, 95% CI: 1.15-3.47, p-value: 0.014), whereas stigma and discrimination reduced the likelihood of testing (aOR: 0.40, 95% CI: 0.31-0.62, p-value: <0.001). For females, having one sexual partner (aOR: 2.65, 95% CI: 1.19-5.90, p-value: 0.017) and a low perceived benefit for HIV testing (aOR: 0.54, 95% CI: 0.30-0.96, p-value: 0.035) were associated with HIV testing. The overall HIV/AIDS knowledge was generally high. Gender-specific health education and HIV intervention programmes are needed for improved access to HCT services. One favourable intervention would be the use of home-based HCT programmes.

Mixed-effects models for estimating stand volume by means of small footprint airborne laser scanner data.

Treesearch

J. Breidenbach; E. Kublin; R. McGaughey; H.-E. Andersen; S. Reutebuch

2008-01-01

For this study, hierarchical data sets--in that several sample plots are located within a stand--were analyzed for study sites in the USA and Germany. The German data had an additional hierarchy as the stands are located within four distinct public forests. Fixed-effects models and mixed-effects models with a random intercept on the stand level were fit to each data...

Multilevel Models for Intensive Longitudinal Data with Heterogeneous Autoregressive Errors: The Effect of Misspecification and Correction with Cholesky Transformation

PubMed Central

Jahng, Seungmin; Wood, Phillip K.

2017-01-01

Intensive longitudinal studies, such as ecological momentary assessment studies using electronic diaries, are gaining popularity across many areas of psychology. Multilevel models (MLMs) are most widely used analytical tools for intensive longitudinal data (ILD). Although ILD often have individually distinct patterns of serial correlation of measures over time, inferences of the fixed effects, and random components in MLMs are made under the assumption that all variance and autocovariance components are homogenous across individuals. In the present study, we introduced a multilevel model with Cholesky transformation to model ILD with individually heterogeneous covariance structure. In addition, the performance of the transformation method and the effects of misspecification of heterogeneous covariance structure were investigated through a Monte Carlo simulation. We found that, if individually heterogeneous covariances are incorrectly assumed as homogenous independent or homogenous autoregressive, MLMs produce highly biased estimates of the variance of random intercepts and the standard errors of the fixed intercept and the fixed effect of a level 2 covariate when the average autocorrelation is high. For intensive longitudinal data with individual specific residual covariance, the suggested transformation method showed lower bias in those estimates than the misspecified models when the number of repeated observations within individuals is 50 or more. PMID:28286490

Optimal Interception of a Maneuvering Long-range Missile

NASA Astrophysics Data System (ADS)

X. Vinh, Nguyen; T. Kabamba, Pierre; Takehira, Tetsuya

2001-01-01

In a Newtonian central force field, the minimum-fuel interception of a satellite, or a ballistic missile, in elliptic trajectory can be obtained via Lawden's theory of primer vector. To secure interception when the target performs evasive maneuvers, a new control law, with explicit solutions, is implemented. It is shown that by a rotation of coordinate system, the problem of three-dimensional interception is reduced to a planar problem. The general case of planar interception of a long-range ballistic missile is then studied. Examples of interception at a specified time, head-on interception and minimum-fuel interception are presented. In each case, the requirement for the thrust acceleration is expressed explicitly as a function of time.

Internal models of target motion: expected dynamics overrides measured kinematics in timing manual interceptions.

PubMed

Zago, Myrka; Bosco, Gianfranco; Maffei, Vincenzo; Iosa, Marco; Ivanenko, Yuri P; Lacquaniti, Francesco

2004-04-01

Prevailing views on how we time the interception of a moving object assume that the visual inputs are informationally sufficient to estimate the time-to-contact from the object's kinematics. Here we present evidence in favor of a different view: the brain makes the best estimate about target motion based on measured kinematics and an a priori guess about the causes of motion. According to this theory, a predictive model is used to extrapolate time-to-contact from expected dynamics (kinetics). We projected a virtual target moving vertically downward on a wide screen with different randomized laws of motion. In the first series of experiments, subjects were asked to intercept this target by punching a real ball that fell hidden behind the screen and arrived in synchrony with the visual target. Subjects systematically timed their motor responses consistent with the assumption of gravity effects on an object's mass, even when the visual target did not accelerate. With training, the gravity model was not switched off but adapted to nonaccelerating targets by shifting the time of motor activation. In the second series of experiments, there was no real ball falling behind the screen. Instead the subjects were required to intercept the visual target by clicking a mousebutton. In this case, subjects timed their responses consistent with the assumption of uniform motion in the absence of forces, even when the target actually accelerated. Overall, the results are in accord with the theory that motor responses evoked by visual kinematics are modulated by a prior of the target dynamics. The prior appears surprisingly resistant to modifications based on performance errors.

15 CFR 742.13 - Communications intercepting devices; software and technology for communications intercepting...

Code of Federal Regulations, 2013 CFR

2013-01-01

...; software and technology for communications intercepting devices. 742.13 Section 742.13 Commerce and Foreign... Communications intercepting devices; software and technology for communications intercepting devices. (a) License... wire, oral, or electronic communications (ECCNs 5A001.i and 5A980); and for related “software...

A Mixed-Methods Evaluation of the Choose Less, Weigh Less Portion Size Health Marketing Campaign in Los Angeles County.

PubMed

Gase, Lauren N; Barragan, Noel C; Robles, Brenda; Leighs, Michael; Kuo, Tony

2015-01-01

To assess the impact of the Choose Less, Weigh Less portion size health marketing campaign. A mixed-methods, cross-sectional evaluation. A quantitative Internet panel survey was administered through an online sampling vendor and qualitative interviews were conducted by street intercept. The panel survey included 796 participants, weighted to represent Los Angeles County. Street intercept interviews were conducted with 50 other participants. The Choose Less, Weigh Less campaign included print media on transit shelters, bus and rail cars, and billboards; radio and online advertising; and Web site content and social media outreach. The panel survey measured self-reported campaign exposure and outcomes, including knowledge of recommended daily calorie limits, attitudes toward portion sizes, and intent to reduce calories and portion size. Intercept interviews assessed campaign appeal, clarity, and utility. Weighted survey data were analyzed using logistic regression to assess the association between campaign exposure and outcomes. Interview data were analyzed for themes. The campaign reached 19.7% of the Los Angeles County population. Significant differences were seen for 2 of the 10 outcomes assessed. Participants who saw the campaign were more likely than those who did not to report fast-food portion sizes as being too large (adjusted odds ratio [Adj. OR]: 1.89; 95% confidence interval [CI]: 1.16, 3.07) and intention to choose a smaller portion (Adj. OR: 1.99; 95% CI: 1.20, 3.31). Qualitative data revealed three themes about appeal, clarity, and utility. Health marketing efforts targeting portion size can have relatively broad reach and limited but positive impacts on consumer attitudes and intent to select smaller portions.

Consumption of key food groups during the postpartum period in low-income, non-Hispanic black mothers.

PubMed

Kay, Melissa C; Wasser, Heather; Adair, Linda S; Thompson, Amanda L; Siega-Riz, Anna Maria; Suchindran, Chirayath M; Bentley, Margaret E

2017-10-01

The postpartum period can impact diet quality and subsequently place women at greater risk for overweight or obesity. This study examined consumption of key food groups during the first 2 years postpartum among low income, non-Hispanic black, first-time mothers. Data were from the Infant Care, Feeding and Risk of Obesity Study, a cohort of 217 mother-infant dyads, followed from 3 to 18 months postpartum, collected from 2003 to 2007. At each study visit (3, 6, 9, 12, and 18 months) 24-h dietary recalls were collected. Consumption levels were compared to those recommended from the 2010 Dietary Guidelines for Americans (DGAs) for each of the following food groups: fruits, vegetables, grains, whole grains, protein foods and dairy, as well as an estimated upper limit for sugar-sweetened beverage (SSB) consumption. At each time point, mothers met recommended intake levels for grains and protein foods only. In random-intercept logistic regression models, no demographic or household characteristics were associated with a likelihood of consuming recommended levels for any of the food groups according to the DGAs. Given the low intake of fruits, vegetables, whole grains and lean protein foods and high intake of SSBs and refined grains, interventions targeting women's diet during the postpartum period are warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

All part of the job? The contribution of the psychosocial and physical work environment to health inequalities in Europe and the European health divide.

PubMed

Toch, Marlen; Bambra, Clare; Lunau, Thorsten; van der Wel, Kjetil A; Witvliet, Margot I; Dragano, Nico; Eikemo, Terje A

2014-01-01

This study is the first to examine the contribution of both psychosocial and physical risk factors to occupational inequalities in self-assessed health in Europe. Data from 27 countries were obtained from the 2010 European Working Conditions Survey for men and women aged 16 to 60 (n = 21,803). Multilevel logistic regression analyses (random intercept) were applied, estimating odds ratios of reporting less than good health. Analyses indicate that physical working conditions account for a substantial proportion of occupational inequalities in health in both Central/Eastern and Western Europe. Physical, rather than psychosocial, working conditions seem to have the largest effect on self-assessed health in manual classes. For example, controlling for physical working conditions reduced the inequalities in the prevalence of"less than good health" between the lowest (semi- and unskilled manual workers) and highest (higher controllers) occupational groups in Europe by almost 50 percent (Odds Ratio 1.87, 95% Confidence Interval 1.62-2.16 to 1.42, 1.23-1.65). Physical working conditions contribute substantially to health inequalities across "post-industrial" Europe, with women in manual occupations being particularly vulnerable, especially those living in Central/Eastern Europe. An increased political and academic focus on physical working conditions is needed to explain and potentially reduce occupational inequalities in health.

A Daily Diary Analysis of Condom Breakage and Slippage During Vaginal Sex or Anal Sex Among Adolescent Women.

PubMed

Hensel, Devon J; Selby, Sarah; Tanner, Amanda E; Fortenberry, J Dennis

2016-09-01

Adolescent women are disproportionately impacted by the adverse outcomes associated with sexual activity, including sexually transmitted infections (STI). Condoms as a means of prevention relies on use that is free of usage failure, including breakage and/or slippage. This study examined the daily prevalence of and predictors of condom breakage and/or slippage during vaginal sex and during anal sex among adolescent women. Adolescent women (N = 387; 14 to 17 years) were recruited from primary care clinics for a longitudinal cohort study of STIs and sexual behavior. Data were daily partner-specific sexual diaries. Random intercept mixed-effects logistic regression was used to estimate the fixed effect of each predictor on condom breakage/slippage during vaginal or during anal sex (Stata, 13.0), adjusting model coefficients for the correlation between repeated within-participant diary entries. Condom slippage and/or breakage varied across sexual behaviors and was associated with individual-specific (eg, age and sexual interest) and partner-specific factors (eg, negativity). Recent behavioral factors (eg, experiencing slippage and/or breakage in the past week) were the strongest predictors of current condom slippage and/or breakage during vaginal or anal sex. Factors associated with young women's condom breakage/slippage during vaginal or during anal sex should be integrated as part of STI prevention efforts and should be assessed as part of ongoing routine clinical care.

Factors associated with married women's support of male circumcision for HIV prevention in Uganda: a population based cross-sectional study.

PubMed

Mati, Komi; Adegoke, Korede K; Salihu, Hamisu M

2016-08-02

Despite the protective effect of male circumcision (MC) against HIV in men, the acceptance of voluntary MC in priority countries for MC scale-up such as Uganda remains limited. This study examined the role of women's sociodemographic characteristics, knowledge of HIV and sexual bargaining power as determinants of women's support of male circumcision (MC). Data from the Uganda AIDS Indicator Survey, 2011 were analyzed (n = 4,874). Bivariate and multivariate logistic regression analyses with random intercept were conducted to identify factors that influence women's support of MC. Overall, 67.0 % (n = 3,276) of the women in our sample were in support of MC but only 28.0 % had circumcised partners. Women who had the knowledge that circumcision reduces HIV risk were about 6 times as likely to support MC than women who lacked that knowledge [AOR (adjusted odds ratio) = 5.85, 95 % CI (confidence interval) = 4.83-7.10]. The two indicators of women's sexual bargaining power (i.e., ability to negotiate condom use and ability to refuse sex) were also positively associated with support of MC. Several sociodemographic factors particularly wealth index were also positively associated with women's support of MC. The findings in this study will potentially inform intervention strategies to enhance uptake of male circumcision as a strategy to reduce HIV transmission in Uganda.

The association between the density of retail tobacco outlets, individual smoking status, neighbourhood socioeconomic status and school locations in New South Wales, Australia.

PubMed

Marashi-Pour, Sadaf; Cretikos, Michelle; Lyons, Claudine; Rose, Nick; Jalaludin, Bin; Smith, Joanne

2015-01-01

We explored the association between the density of tobacco outlets and neighbourhood socioeconomic status, and between neighbourhood tobacco outlet density and individual smoking status. We also investigated the density of tobacco outlets around primary and secondary schools in New South Wales (NSW). We calculated the mean density of retail tobacco outlets registered in NSW between 2009 and 2011, using kernel density estimation with an adaptive bandwidth. We used generalised ordered logistic regression model to explore the association between socioeconomic status and density of tobacco outlets. The association between neighbourhood tobacco outlet density and individuals' current smoking status was investigated using random-intercept generalised linear mixed models. We also calculated the median tobacco outlet density around NSW schools. More disadvantaged Census Collection Districts (CDs) were significantly more likely to have higher tobacco outlet densities. After adjusting for neighbourhood socioeconomic status and participants' age, sex, country of birth and Aboriginal status, neighbourhood mean tobacco outlet density was significantly and positively associated with individuals' smoking status. The median of tobacco outlet density around schools was significantly higher than the state median. Policymakers could consider exploring a range of strategies that target tobacco outlets in proximity to schools, in more disadvantaged neighbourhoods and in areas of existing high tobacco outlet density. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

A Health-Based Metric for Evaluating the Effectiveness of Noise Barrier Mitigation Associated With Transport Infrastructure Noise.

PubMed

Prendergast, Geoffrey P; Staff, Michael

2017-01-01

This study examines the use of the number of night-time sleep disturbances as a health-based metric to assess the cost effectiveness of rail noise mitigation strategies for situations, wherein high-intensity noises dominate such as freight train pass-bys and wheel squeal. Twenty residential properties adjacent to the existing and proposed rail tracks in a noise catchment area of the Epping to Thornleigh Third Track project were used as a case study. Awakening probabilities were calculated for individual's awakening 1, 3 and 5 times a night when subjected to 10 independent freight train pass-by noise events using internal maximum sound pressure levels (LAFmax). Awakenings were predicted using a random intercept multivariate logistic regression model. With source mitigation in place, the majority of the residents were still predicted to be awoken at least once per night (median 88.0%), although substantial reductions in the median probabilities of awakening three and five times per night from 50.9 to 29.4% and 9.2 to 2.7%, respectively, were predicted. This resulted in a cost-effective estimate of 7.6-8.8 less people being awoken at least three times per night per A$1 million spent on noise barriers. The study demonstrates that an easily understood metric can be readily used to assist making decisions related to noise mitigation for large-scale transport projects.

The Association of Health-Related Fitness and Chronic Absenteeism Status in New York City Middle School Youth.

PubMed

D'Agostino, Emily M; Day, Sophia E; Konty, Kevin J; Larkin, Michael; Saha, Subir; Wyka, Katarzyna

2018-03-23

Extensive research demonstrates the benefits of fitness on children's health and academic performance. Although decreases in health-related fitness may increase school absenteeism, multiple years of prospective, child-level data are needed to examine whether fitness changes predict subsequent chronic absenteeism status. Six cohorts of New York City public school students were followed from grades 5-8 (2006/2007-2012/2013; N = 349,381). A longitudinal 3-level logistic generalized linear mixed model with random intercepts was used to test the association of individual children's changes in fitness and 1-year lagged chronic absenteeism. The odds of chronic absenteeism increased 27% [odds ratio (OR) 95% confidence interval (CI), 1.25-1.30], 15% (OR 95% CI, 1.13-1.18), 9% (OR 95% CI, 1.07-1.11), and 1% (OR 95% CI, 0.98-1.04), for students who had a >20% decrease, 10%-20% decrease, <10% increase or decrease, and 10%-20% increase in fitness, respectively, compared with >20% fitness increase. These findings contribute important longitudinal evidence to a cross-sectional literature, demonstrating reductions in youth fitness may increase absenteeism. Given only 25% of youth aged 12-15 years achieve the recommended daily 60 minutes or more of moderate to vigorous physical activity, future work should examine the potential for youth fitness interventions to reduce absenteeism and foster positive attitudes toward lifelong physical activity.

15 CFR 742.13 - Communications intercepting devices; software and technology for communications intercepting...

Code of Federal Regulations, 2014 CFR

2014-01-01

...; software and technology for communications intercepting devices. 742.13 Section 742.13 Commerce and Foreign... Communications intercepting devices; software and technology for communications intercepting devices. (a) License... wire, oral, or electronic communications (ECCNs 5A001.f.1 and 5A980); and for related “software...

Rainfall interception by tree crown and leaf litter: an interactive process

Treesearch

Xiang Li; Qingfu Xiao; Jianzhi Niu; Salli Dymond; E. Gregory McPherson; Natalie van Doorn; Xinxiao Yu; Baoyuan Xie; Kebin Zhang; Jiao Li

2017-01-01

Rainfall interception research in forest ecosystems usually focuses on interception by either tree crown or leaf litter, although the 2 components interact when rainfall occurs. A process-based study was conducted to jointly measure rainfall interception by crown and litter and the interaction between the 2 interception processes for 4 tree species (...

New Directions in Software Quality Assurance Automation

DTIC Science & Technology

2009-06-01

generation process. 4.1 Parameterized Safety Analysis We can do a qualitative analysis as well and ask questions like “ what has contributed to this...the probability of interception p1 in the previous example, we can determine what impact those parameters have on the probability of hazardous...assumed that the AEG is traversed top-down and left-to-right and only once to produce a particular event trace Randomized decisions about what

Eye movements and manual interception of ballistic trajectories: effects of law of motion perturbations and occlusions.

PubMed

Delle Monache, Sergio; Lacquaniti, Francesco; Bosco, Gianfranco

2015-02-01

Manual interceptions are known to depend critically on integration of visual feedback information and experience-based predictions of the interceptive event. Within this framework, coupling between gaze and limb movements might also contribute to the interceptive outcome, since eye movements afford acquisition of high-resolution visual information. We investigated this issue by analyzing subjects' head-fixed oculomotor behavior during manual interceptions. Subjects moved a mouse cursor to intercept computer-generated ballistic trajectories either congruent with Earth's gravity or perturbed with weightlessness (0 g) or hypergravity (2 g) effects. In separate sessions, trajectories were either fully visible or occluded before interception to enforce visual prediction. Subjects' oculomotor behavior was classified in terms of amounts of time they gazed at different visual targets and of overall number of saccades. Then, by way of multivariate analyses, we assessed the following: (1) whether eye movement patterns depended on targets' laws of motion and occlusions; and (2) whether interceptive performance was related to the oculomotor behavior. First, we found that eye movement patterns depended significantly on targets' laws of motion and occlusion, suggesting predictive mechanisms. Second, subjects coupled differently oculomotor and interceptive behavior depending on whether targets were visible or occluded. With visible targets, subjects made smaller interceptive errors if they gazed longer at the mouse cursor. Instead, with occluded targets, they achieved better performance by increasing the target's tracking accuracy and by avoiding gaze shifts near interception, suggesting that precise ocular tracking provided better trajectory predictions for the interceptive response.

[Canopy interception characteristics of main vegetation types in Liupan Mountains of China].

PubMed

Xu, Li-hong; Shi, Zhong-jie; Wang, Yan-hui; Xiong, Wei; Yu, Peng-tao

2010-10-01

Based on field observation and modeling analysis, this paper studied the canopy interception, interception capacity, and some parameters for interception modeling of main forest types in Liupan Mountains of China. For the test main forest types, the ratio of their canopy interception to precipitation ranged from 8.59% to 17.94%, throughfall was more than 80%, and stemflow ranged from 0.23% to 3.10%. The canopy interception capacity was 0.78-1.88 mm, among which, leaf interception capacity was 0.62-1.63 mm, and stem interception capacity was 0.13-0.29 mm. Conifer forest had a higher canopy interception capacity than broad-leaved forest. The modified model considering the change of leaf area index, which was used in this paper, had a higher simulating precision than the interception model used before. The simulation results for Betula albo-sinensis forest, Pinus armandii forest, Prunus shrub, and Quercus liaotungensis-Tilia paucicostata forest were good, but those for Quercus liaotungensis forest, Pinus tabulaeformis forest, and Acer tetramerum and Euonymus sanguineus shrub were bad, which might be related to the differences in canopy structure, leaf area index, and precipitation characteristics.

Elevated dry-season malaria prevalence associated with fine-scale spatial patterns of environmental risk: a case-control study of children in rural Malawi.

PubMed

Townes, Lindsay R; Mwandama, Dyson; Mathanga, Don P; Wilson, Mark L

2013-11-11

Understanding the role of local environmental risk factors for malaria in holo-endemic, poverty-stricken settings will be critical to more effectively implement- interventions aimed at eventual elimination. Household-level environmental drivers of malaria risk during the dry season were investigated in rural southern Malawi among children < five years old in two neighbouring rural Traditional Authority (TA) regions dominated by small-scale agriculture. Ten villages were randomly selected from TA Sitola (n = 6) and Nsamala (n = 4). Within each village, during June to August 2011, a census was conducted of all households with children under-five and recorded their locations with a geographic position system (GPS) device. At each participating house, a nurse administered a malaria rapid diagnostic test (RDT) to children under five years of age, and a questionnaire to parents. Environmental data were collected for each house, including land cover within 50-m radius. Variables found to be significantly associated with P. falciparum infection status in bivariate analysis were included in generalized linear models, including multivariate logistic regression (MLR) and multi-level multivariate logistic regression (MLLR). Spatial clustering of RDT status, environmental factors, and Pearson residuals from MLR and MLLR were analysed using the Getis-Ord Gi* statistic. Of 390 children enrolled from six villages in Sitola (n = 162) and four villages in Nsamala (n = 228), 45.6% tested positive (n = 178) for Plasmodium infection by RDT. The MLLR modelled the statistical relationship of Plasmodium positives and household proximity to agriculture (<25-m radius), controlling for the child sex and age (in months), bed net ownership, elevation, and random effects intercepts for village and TA-level unmeasured factors. After controlling for area affects in MLLR, proximity to active agriculture remained a significant predictor of positive RDT result (OR 2.80, 95% CI 1.41-5.55). Mapping of Pearson residuals from MLR showed significant clustering (Gi* z > 2.58, p < 0.01) predominantly within TA Sitola, while residuals from MLLR showed no such clustering. This study provides evidence for significant, dry-season heterogeneity of malaria prevalence strongly linked to peridomestic land use, and particularly of elevated risk associated with nearby crop production.

[Canopy interception of sub-alpine dark coniferous communities in western Sichuan, China].

PubMed

Lü, Yu-liang; Liu, Shi-rong; Sun, Peng-sen; Liu, Xing-liang; Zhang, Rui-pu

2007-11-01

Based on field measurements of throughfall and stemflow in combination with climatic data collected from the meteorological station adjacent to the studied sub-alpine dark coniferous forest in Wolong, Sichuan Province, canopy interception of sub-alpine dark coniferous forests was analyzed and modeled at both stand scale and catchment scale. The results showed that monthly interception rate of Fargesia nitida, Bashania fangiana--Abies faxoniana old-growth ranged from 33% Grass to 72%, with the average of 48%. In growing season, there was a linear or powerful or exponential relationship between rainfall and interception an. a negative exponential relationship between rainfall and interception rate. The mean maximum canopy interception by the vegetation in the catchment of in.44 km was 1.74 ment and the significant differences among the five communities occurred in the following sequence: Moss-Fargesia nitida, Bashan afanglana-A. faxoniana stand > Grass-F. nitida, B. fangiana-A. faxoniana stand > Moss-Rhododendron spp.-A. faxoniana stand > Grass-Rh. spp.-A. faxoniana stand > Rh. spp. shrub. In addition, a close linear relationship existed between leaf area index (LAI) and maximum canopy interception. The simulated value of canopy interception rate, maximum canopy interception rate and addition interception rate of the vegetation in the catchment were 39%, 25% and 14%, respectively. Simulation of the canopy interception model was better at the overall growing season scale, that the mean relative error was 9%-14%.

A cluster-randomised quality improvement study to improve two inpatient stroke quality indicators.

PubMed

Williams, Linda; Daggett, Virginia; Slaven, James E; Yu, Zhangsheng; Sager, Danielle; Myers, Jennifer; Plue, Laurie; Woodward-Hagg, Heather; Damush, Teresa M

2016-04-01

Quality indicator collection and feedback improves stroke care. We sought to determine whether quality improvement training plus indicator feedback was more effective than indicator feedback alone in improving inpatient stroke indicators. We conducted a cluster-randomised quality improvement trial, randomising hospitals to quality improvement training plus indicator feedback versus indicator feedback alone to improve deep vein thrombosis (DVT) prophylaxis and dysphagia screening. Intervention sites received collaborative-based quality improvement training, external facilitation and indicator feedback. Control sites received only indicator feedback. We compared indicators pre-implementation (pre-I) to active implementation (active-I) and post-implementation (post-I) periods. We constructed mixed-effect logistic models of the two indicators with a random intercept for hospital effect, adjusting for patient, time, intervention and hospital variables. Patients at intervention sites (1147 admissions), had similar race, gender and National Institutes of Health Stroke Scale scores to control sites (1017 admissions). DVT prophylaxis improved more in intervention sites during active-I period (ratio of ORs 4.90, p<0.001), but did not differ in post-I period. Dysphagia screening improved similarly in both groups during active-I, but control sites improved more in post-I period (ratio of ORs 0.67, p=0.04). In logistic models, the intervention was independently positively associated with DVT performance during active-I period, and negatively associated with dysphagia performance post-I period. Quality improvement training was associated with early DVT improvement, but the effect was not sustained over time and was not seen with dysphagia screening. External quality improvement programmes may quickly boost performance but their effect may vary by indicator and may not sustain over time. 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/

Incidence and predictors of suicide attempts in bipolar I and II disorders: A 5-year follow-up study.

PubMed

Pallaskorpi, Sanna; Suominen, Kirsi; Ketokivi, Mikko; Valtonen, Hanna; Arvilommi, Petri; Mantere, Outi; Leppämäki, Sami; Isometsä, Erkki

2017-02-01

Few long-term studies on bipolar disorder (BD) have investigated the incidence and risk factors of suicide attempts (SAs) specifically related to illness phases. We examined the incidence of SAs during different phases of BD in a long-term prospective cohort of bipolar I (BD-I) and bipolar II (BD-II) patients, and risk factors specifically for SAs during major depressive episodes (MDEs). In the Jorvi Bipolar Study (JoBS), 191 BD-I and BD-II patients were followed using life-chart methodology. Prospective information on SAs of 177 patients (92.7%) during different illness phases was available up to 5 years. The incidence of SAs and their predictors were investigated using logistic and Poisson regression models. Analyses of risk factors for SAs occurring during MDEs were conducted using two-level random-intercept logistic regression models. During the 5 years of follow-up, 90 SAs per 718 patient-years occurred. The incidence was highest, over 120-fold higher than in euthymia, during mixed states (765/1000 person-years; 95% confidence interval [CI] 461-1269 person-years), and also very high in MDEs, almost 60-fold higher than in euthymia (354/1000 person-years; 95% CI 277-451 person-years). For risk of SAs during MDEs, the duration of MDEs, severity of depression, and cluster C personality disorders were significant predictors. We confirmed in this long-term study that the highest incidences of SAs occur in mixed and major depressive illness phases. The variations in incidence rates between euthymia and illness phases were remarkably large, suggesting that the question "when" rather than "who" may be more relevant for suicide risk in BD. However, risk during MDEs is likely also influenced by personality factors. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Evaluation of cardiac surgery mortality rates: 30-day mortality or longer follow-up?

PubMed

Siregar, Sabrina; Groenwold, Rolf H H; de Mol, Bas A J M; Speekenbrink, Ron G H; Versteegh, Michel I M; Brandon Bravo Bruinsma, George J; Bots, Michiel L; van der Graaf, Yolanda; van Herwerden, Lex A

2013-11-01

The aim of our study was to investigate early mortality after cardiac surgery and to determine the most adequate follow-up period for the evaluation of mortality rates. Information on all adult cardiac surgery procedures in 10 of 16 cardiothoracic centres in Netherlands from 2007 until 2010 was extracted from the database of Netherlands Association for Cardio-Thoracic Surgery (n = 33 094). Survival up to 1 year after surgery was obtained from the national death registry. Survival analysis was performed using Kaplan-Meier and Cox regression analysis. Benchmarking was performed using logistic regression with mortality rates at different time points as dependent variables, the logistic EuroSCORE as covariate and a random intercept per centre. In-hospital mortality was 2.94% (n = 972), 30-day mortality 3.02% (n = 998), operative mortality 3.57% (n = 1181), 60-day mortality 3.84% (n = 1271), 6-month mortality 5.16% (n = 1707) and 1-year mortality 6.20% (n = 2052). The survival curves showed a steep initial decline followed by stabilization after ∼60-120 days, depending on the intervention performed, e.g. 60 days for isolated coronary artery bypass grafting (CABG) and 120 days for combined CABG and valve surgery. Benchmark results were affected by the choice of the follow-up period: four hospitals changed outlier status when the follow-up was increased from 30 days to 1 year. In the isolated CABG subgroup, benchmark results were unaffected: no outliers were found using either 30-day or 1-year follow-up. The course of early mortality after cardiac surgery differs across interventions and continues up to ∼120 days. Thirty-day mortality reflects only a part of early mortality after cardiac surgery and should only be used for benchmarking of isolated CABG procedures. The follow-up should be prolonged to capture early mortality of all types of interventions.

Recovery of high speed memory scanning after transient global amnesia: a case report.

PubMed

Okura, M; Tomotake, M; Mori, K; Ikuta, T

1996-12-01

We described the case of a 59 year old female with transient global amnesia (TGA) who had been examined neuropsychologically using Sternberg's paradigm and a random number generation (RNG) task on the following day, 1 week and 4 weeks after a TGA episode. The slope value of the linear function, a measure of cognitive memory scanning speed, decreased with time and showed a marked decrease 1 week after TGA, suggesting that the stage of serial and exhaustive scanning recovered within 1 week. The zero-intercept value, on the other hand, increased during 1 week but decreased 4 weeks later and was not related directly to recovery from TGA. The performance in RNG task improved 1 week later, but deteriorated 4 weeks after the episode. Such a change in RNG was in accordance with that of the zero-intercept value, predicting a relationship. It is concluded that the subclinical memory deficit, detected with these tasks, persisted longer than clinical recovery from TGA.

REGRES: A FORTRAN-77 program to calculate nonparametric and ``structural'' parametric solutions to bivariate regression equations

NASA Astrophysics Data System (ADS)

Rock, N. M. S.; Duffy, T. R.

REGRES allows a range of regression equations to be calculated for paired sets of data values in which both variables are subject to error (i.e. neither is the "independent" variable). Nonparametric regressions, based on medians of all possible pairwise slopes and intercepts, are treated in detail. Estimated slopes and intercepts are output, along with confidence limits, Spearman and Kendall rank correlation coefficients. Outliers can be rejected with user-determined stringency. Parametric regressions can be calculated for any value of λ (the ratio of the variances of the random errors for y and x)—including: (1) major axis ( λ = 1); (2) reduced major axis ( λ = variance of y/variance of x); (3) Y on Xλ = infinity; or (4) X on Y ( λ = 0) solutions. Pearson linear correlation coefficients also are output. REGRES provides an alternative to conventional isochron assessment techniques where bivariate normal errors cannot be assumed, or weighting methods are inappropriate.

Eye movement accuracy determines natural interception strategies.

PubMed

Fooken, Jolande; Yeo, Sang-Hoon; Pai, Dinesh K; Spering, Miriam

2016-11-01

Eye movements aid visual perception and guide actions such as reaching or grasping. Most previous work on eye-hand coordination has focused on saccadic eye movements. Here we show that smooth pursuit eye movement accuracy strongly predicts both interception accuracy and the strategy used to intercept a moving object. We developed a naturalistic task in which participants (n = 42 varsity baseball players) intercepted a moving dot (a "2D fly ball") with their index finger in a designated "hit zone." Participants were instructed to track the ball with their eyes, but were only shown its initial launch (100-300 ms). Better smooth pursuit resulted in more accurate interceptions and determined the strategy used for interception, i.e., whether interception was early or late in the hit zone. Even though early and late interceptors showed equally accurate interceptions, they may have relied on distinct tactics: early interceptors used cognitive heuristics, whereas late interceptors' performance was best predicted by pursuit accuracy. Late interception may be beneficial in real-world tasks as it provides more time for decision and adjustment. Supporting this view, baseball players who were more senior were more likely to be late interceptors. Our findings suggest that interception strategies are optimally adapted to the proficiency of the pursuit system.

Recurrent bridgehead effects accelerate global alien ant spread.

PubMed

Bertelsmeier, Cleo; Ollier, Sébastien; Liebhold, Andrew M; Brockerhoff, Eckehard G; Ward, Darren; Keller, Laurent

2018-05-22

Biological invasions are a major threat to biological diversity, agriculture, and human health. To predict and prevent new invasions, it is crucial to develop a better understanding of the drivers of the invasion process. The analysis of 4,533 border interception events revealed that at least 51 different alien ant species were intercepted at US ports over a period of 70 years (1914-1984), and 45 alien species were intercepted entering New Zealand over a period of 68 years (1955-2013). Most of the interceptions did not originate from species' native ranges but instead came from invaded areas. In the United States, 75.7% of the interceptions came from a country where the intercepted ant species had been previously introduced. In New Zealand, this value was even higher, at 87.8%. There was an overrepresentation of interceptions from nearby locations (Latin America for species intercepted in the United States and Oceania for species intercepted in New Zealand). The probability of a species' successful establishment in both the United States and New Zealand was positively related to the number of interceptions of the species in these countries. Moreover, species that have spread to more continents are also more likely to be intercepted and to make secondary introductions. This creates a positive feedback loop between the introduction and establishment stages of the invasion process, in which initial establishments promote secondary introductions. Overall, these results reveal that secondary introductions act as a critical driver of increasing global rates of invasions.

Amotosalen: Allogeneic Cellular Immunotherapies system, INTERCEPT Plasma System, INTERCEPT Platelet System, S 59.

PubMed

2003-01-01

Adis CommentsCerus Corporation is developing a variety of pathogen-inactivation systems, based on its Helinx technology. Three of the systems include amotosalen [S 59] as the inactivation compound. Amotosalen is a light-activated, DNA-, RNA-crosslinking psoralen compound, which is used to neutralise pathogens. The systems that utilise amotosalen are called the INTERCEPT Platelet System, the INTERCEPT Plasma System and the Allogeneic Cellular Immunotherapies (ACIT) system. The INTERCEPT Platelet System and INTERCEPT Plasma System are two of the systems that make up Cerus' INTERCEPT Blood Systems. The other system is the INTERCEPT Red Blood Cell System, which contains S 303 as the inactivation compound rather than amotosalen. Cerus' Helinx technology is able to prevent replication of DNA or RNA that is present in pathogens but not in the blood components being treated (e.g. platelets and plasma). When added to the blood components, the inactivation agent (in this case amotosalen) crosses the membrane or cell wall of the pathogen. When activated by light, amotosalen binds to the nucleic acid of the pathogen and prevents replication. This process prevents infection. INTERCEPT Platelet System: Cerus developed its INTERCEPT Platelet System, in collaboration with Baxter Healthcare, for use in blood centres. Platelets are an essential component of the coagulation process and may be required by patients undergoing surgery, cancer chemotherapy, transplantation or with bleeding disorders. The system is made up of an illuminator device, a compound absorption device and a processing kit containing amotosalen. In October 2002, the two companies announced that CE Mark approval had been received for the illuminator device for the INTERCEPT trade mark Blood System. Application of this technology to platelets is the first to be approved. As it is a new technology, the system is currently undergoing process validation in accordance with European Blood Bank GMP requirements. This validation process is currently being conducted in Denmark, France, Germany, Sweden and the UK. Marketing approval applications for the INTERCEPT Platelet System have also been submitted in Australia and Canada. In addition, the regulatory submission process has begun in the US. A phase III trial (EuroSPRITE) has been conducted in 103 patients in Europe with pooled random donor platelets. The platelets were collected using the buffy coat process. Another two 20-patient clinical trials have also been conducted in Europe, as well as a 40-patient trial using platelets collected by an apheresis collection system. Cerus has also conducted a phase III trial (SPRINT) in the US. The trial was conducted in 671 patients and used platelets collected by Baxter's apheresis collection system. INTERCEPT Plasma System: Cerus is also developing the INTERCEPT Plasma System in collaboration with Baxter Healthcare. The system also combines amotosalen, an illumination device and a compound absorption device. The two companies are currently preparing regulatory applications for the INTERCEPT Plasma System for the US. This application will be followed by a submission for CE Mark designation in Europe. Patients undergoing surgery, or transplantation, or with bleeding disorders, may require transfusions of plasma, often to control bleeding. The type of plasma is stored in frozen form and is called fresh frozen plasma (FFP). The INTERCEPT Plasma System is currently in phase IIIc development in the US. Patient enrolment in the trial is still ongoing. The trial is comparing INTERCEPT trade mark Plasma System treated versus untreated FFP in 30 patients with thrombotic thrombocytopenic purpura. Allogeneic Cellular Immunotherapies system: Cerus is also investigating the potential of its Helinx technology to improve the outcome of bone marrow transplantation procedures (used to treat leukaemia and lymphoma) through the treatmatment for many forms of leukaemia and is most effective when the donor is very closely matched to the patient for the major human leucocyte antigen (HLA) groups. As part of the transplant procedure, patients receive donor T cells to improve engraftment of the bone marrow transplant and strengthen the patient's immune system. However, donor T cells expose the patient to a high risk of contracting graft-versus-host disease (GVHD) caused by the proliferation of donor T cells, which attack the patient's healthy tissue. GVHD has a high mortality rate. Cerus' ACIT system has been developed to decrease the stringency of matching donors to patients and to inhibit the ability of donor T cells to cause GVHD. Light-activated amotosalen binds and permanently crosslinks DNA, preventing replication and thus stopping proliferation of donor T cells. Phase I development is currently being conducted in this area in the US using amotosalen as the neutralising agent. Cerus completed a phase I study investigating the safety and tolerability of its ACIT system in 2001. The study was conducted in patients receiving closely matched allogeneic bone marrow transplants for leukaemia. The company is currently collaborating with the National Marrow Donor Program in order to conduct further clinical studies in patients receiving bone marrow transplants from unmatched donors. Cerus has development, manufacturing and marketing agreements with Baxter covering the INTERCEPT Blood Systems, which includes the INTERCEPT Platelet system, the INTERCEPT Plasma System, and the INTERCEPT Red Blood Cell System. Under the terms of the agreements the two companies usually share the very early development activities. Cerus then conducts preclinical and clinical trials, while Baxter is responsible for the development of the systems disposables and devices. Following commercialisation Cerus will supply amotosalen and Baxter will supply the other components of the system and market, sell and distribute the system In January 2001, Cereus announced that it has entered into a collaborative agreement with the Pharmaceutical Division of Kirin Brewery in Japan to develop and market products for stem cell transplantation based on Cerus' proprietary Helinx technology. Under terms of the agreement, Cerus and Kirin will jointly develop the products. Cerus has received an initial license fee of US dollar 1 million. In addition it may receive up to US dollar 11 million in future payments upon achievement of development milestones. Kirin will also fund all development expenses for the Asia-Pacific region and a portion of Cerus' development activities aimed at obtaining product approval in the US. Kirin will market the products in the Asia-Pacific region, including Japan, China, Korea and Australia, and Cerus will receive a specified share of product revenues. Cerus will retain marketing rights in the rest of the world, including the US and Europe.

How is rainfall interception in urban area affected by meteorological parameters?

NASA Astrophysics Data System (ADS)

Zabret, Katarina; Rakovec, Jože; Mikoš, Matjaž; Šraj, Mojca

2017-04-01

Rainfall interception is part of the hydrological cycle. Precipitation, which hits vegetation, is retained on the leaves and branches, from which it eventually evaporates into the atmosphere (interception) or reaches the ground by dripping from the canopy, falling through the gaps (throughfall) and running down the stems (stemflow). The amount of rainfall reaching the ground depends on various meteorological and vegetation parameters. Rainfall, throughfall and stemflow have been measured in the city of Ljubljana, Slovenia since the beginning of 2014. Manual and automatic measurements are performed regularly under Betula pendula and Pinus nigra trees in urban area. In 2014, there were detected 178 rainfall events with total amount of 1672.1 mm. In average B. pendula intercepted 44% of rainfall and P. nigra intercepted 72% of rainfall. In 2015 we have detected 117 events with 1047.4 mm of rainfall, of which 37% was intercepted by B. pendula and 60% by P. nigra. The effect of various meteorological parameters on the rainfall interception was analysed in the study. The parameters included in the analysis were rainfall rate, rainfall duration, drop size distribution (average drop velocity and diameter), average wind speed, and average temperature. The results demonstrate decreasing rainfall interception with longer rainfall duration and higher rainfall intensity although the impact of the latter one is not statistically significant. In the case of very fast or very slow rainfall drops, the interception is higher than for the mean rain drop velocity values. In the case of P. nigra the impact of the rain drop diameter on interception is similar to the one of rain drop velocity while for B. pendula increasing of drop diameter also increases the interception. As expected, interception is higher for warmer events. This trend is more evident for P. nigra than for B. pendula. Furthermore, the amount of intercepted rainfall also increases with wind although it could be relatively high in case of very low wind speeds.

Pseudo-random bit generator based on lag time series

NASA Astrophysics Data System (ADS)

García-Martínez, M.; Campos-Cantón, E.

2014-12-01

In this paper, we present a pseudo-random bit generator (PRBG) based on two lag time series of the logistic map using positive and negative values in the bifurcation parameter. In order to hidden the map used to build the pseudo-random series we have used a delay in the generation of time series. These new series when they are mapped xn against xn+1 present a cloud of points unrelated to the logistic map. Finally, the pseudo-random sequences have been tested with the suite of NIST giving satisfactory results for use in stream ciphers.

Biomechanical factors contributing to self-organization in seagrass landscapes

USGS Publications Warehouse

Fonseca, M.S.; Koehl, M.A.R.; Kopp, B.S.

2007-01-01

Field observations have revealed that when water flow is consistently from one direction, seagrass shoots align in rows perpendicular to the primary axis of flow direction. In this study, live Zostera marina shoots were arranged either randomly or in rows perpendicular to the flow direction and tested in a seawater flume under unidirectional flow and waves to determine if shoot arrangement: a) influenced flow-induced force on individual shoots, b) differentially altered water flow through the canopy, and c) influenced light interception by the canopy. In addition, blade breaking strength was compared with flow-induced force to determine if changes in shoot arrangement might reduce the potential for damage to shoots. Under unidirectional flow, both current velocity in the canopy and force on shoots were significantly decreased when shoots were arranged in rows as compared to randomly. However, force on shoots was nearly constant with downstream distance, arising from the trade-off of shoot bending and in-canopy flow reduction. The coefficient of drag was higher for randomly-arranged shoots at low velocities (< 30 cm s- 1) but converged rapidly among the two shoot arrangements at higher velocities. Shoots arranged in rows tended to intercept slightly more light than those arranged randomly. Effects of shoot arrangement under waves were less clear, potentially because we did not achieve the proper plant size?row spacing ratio. At this point, we may only suggest that water motion, as opposed to light capture, is the dominant physical mechanism responsible for these shoot arrangements. Following a computation of the Environmental Stress Factor, we concluded that even photosynthetically active blades may be damaged or broken under frequently encountered storm conditions, irrespective of shoot arrangement. We hypothesize that when flow is generally from one direction, seagrass bed patterns over multiple scales of consideration may arise as a cumulative effect of individual shoot self-organization driven by reduced force and drag on the shoots and somewhat improved light capture.

Automated Neuropsychological Assessment Metrics Version 4 (ANAM4): Select Psychometric Properties and Administration Procedures

DTIC Science & Technology

2012-12-01

month no- cost extension for this study was approved on 7 November 2012, extending study activities through December 2013. A modified statement of work...approved as part of the no- cost extension and currently pending approval by the USARIEM HURC (Amendment #14), is presented in Table 2. 5...ptjournal.apta.org/Downloaded from 13     time. SAS 9.2 was used to perform a mixed model analysis with random individual intercept to account for

Seasonality on the rainfall partitioning of a fast-growing tree plantation under Mediterranean conditions

NASA Astrophysics Data System (ADS)

molina, antonio; llorens, pilar; biel, carme

2014-05-01

Studies on rainfall interception in fast-growing tree plantations are less numerous than those in natural forests. Trees in these plantations are regularly distributed, and the canopy cover is clumped but changes quickly, resulting on high variability in the volume and composition of water that reach the soil. In addition, irrigation supply is normally required in semiarid areas to get optimal wood production; consequently, knowing rainfall interception and its yearly evolution is crucial to manage the irrigation scheme properly. This work studies the rainfall partitioning seasonality in a cherry tree (Prunus avium) plantation orientated to timber production under Mediterranean conditions. The monitoring design started on March 2012 and consists of a set of 58 throughfall tipping buckets randomly distributed (based on a 1x1 m2 grid) in a plot of 128 m2 with 8 trees. Stemflow is measured in all the trees with 2 tipping buckets and 6 accumulative collectors. Canopy cover is regularly measured throughout the study period, in leaf and leafless periods, by mean of sky-orientated photographs taken 50 cm above the center of each tipping bucket. Others tree biometrics are also measured such as diameter and leaf area index. Meteorological conditions are measured at 2 m above the forest cover. This work presents the first analyses describing the rainfall partitioning and its dependency on canopy cover, distance to tree and meteorological conditions. The modified Gash' model for rainfall interception in dispersed vegetation is also preliminary evaluated.

Eye movements in interception with delayed visual feedback.

PubMed

Cámara, Clara; de la Malla, Cristina; López-Moliner, Joan; Brenner, Eli

2018-07-01

The increased reliance on electronic devices such as smartphones in our everyday life exposes us to various delays between our actions and their consequences. Whereas it is known that people can adapt to such delays, the mechanisms underlying such adaptation remain unclear. To better understand these mechanisms, the current study explored the role of eye movements in interception with delayed visual feedback. In two experiments, eye movements were recorded as participants tried to intercept a moving target with their unseen finger while receiving delayed visual feedback about their own movement. In Experiment 1, the target randomly moved in one of two different directions at one of two different velocities. The delay between the participant's finger movement and movement of the cursor that provided feedback about the finger movements was gradually increased. Despite the delay, participants followed the target with their gaze. They were quite successful at hitting the target with the cursor. Thus, they moved their finger to a position that was ahead of where they were looking. Removing the feedback showed that participants had adapted to the delay. In Experiment 2, the target always moved in the same direction and at the same velocity, while the cursor's delay varied across trials. Participants still always directed their gaze at the target. They adjusted their movement to the delay on each trial, often succeeding to intercept the target with the cursor. Since their gaze was always directed at the target, and they could not know the delay until the cursor started moving, participants must have been using peripheral vision of the delayed cursor to guide it to the target. Thus, people deal with delays by directing their gaze at the target and using both experience from previous trials (Experiment 1) and peripheral visual information (Experiment 2) to guide their finger in a way that will make the cursor hit the target.

Associations between Stress Biology Indicators and Overweight across Toddlerhood

PubMed Central

Miller, Alison L.; Kaciroti, Niko; Sturza, Julie; Retzloff, Lauren; Rosenblum, Katherine; Vazquez, Delia M.; Lumeng, Julie C.

2017-01-01

Biological stress responses are proposed as a pathway through which stress exposure can “get under the skin” and lead to health problems, specifically obesity. Yet, it is not clear when such associations may emerge or whether they are bidirectional. Cortisol and salivary alpha amylase (sAA) were considered indicators of the biological stress response. We tested the longitudinal association between cortisol and sAA and weight in 215 low-income children at ages 21, 27, and 33 months (52% male; 46% non-Hispanic white). sAA and cortisol intercept and slope (representing morning level and rate of change across the day) were calculated for each age point using random effect models. Children were weighed and length measured and categorized as overweight versus normal weight (overweight defined as weight-for-length z-score ≥ 85th percentile for age and sex). Cross-lagged models stratified by sex and controlling for birthweight z-score tested the concurrent and cross-lagged associations between each of 4 indices of stress biology individually (cortisol and sAA intercept and slope) and overweight. Overweight status was correlated across time. Cortisol and sAA were correlated across occasions of measurement, though somewhat less strongly in boys. There were no concurrent associations between stress indicators and overweight. sAA at 27 months predicted greater risk of overweight at 33 months in girls, such that both lower sAA intercept and more rapidly increasing sAA at 27 months predicted greater risk of overweight at 33 months (β=−0.64, p<.05 and β=1.09, p<.05, respectively). For boys only, overweight at 21 months predicted lower sAA intercept at 27 months (β=−0.35, p<.05). Findings suggest that longitudinal associations of stress biology and weight status may be present only on a limited basis very early in the lifespan. PMID:28273588

Interception loss, throughfall and stemflow in a maritime pine stand. II. An application of Gash's analytical model of interception

NASA Astrophysics Data System (ADS)

Loustau, D.; Berbigier, P.; Granier, A.

1992-10-01

Interception, throughfall and stemflow were determined in an 18-year-old maritime pine stand for a period of 30 months. This involved 71 rainfall events, each corresponding either to a single storm or to several storms. Gash's analytical model of interception was used to estimate the sensitivity of interception to canopy structure and climatic parameters. The seasonal cumulative interception loss corresponded to 12.6-21.0% of the amount of rainfall, whereas throughfall and stemflow accounted for 77-83% and 1-6%, respectively. On a seasonal basis, simulated data fitted the measured data satisfactorily ( r2 = 0.75). The rainfall partitioning between interception, throughfall and stemflow was shown to be sensitive to (1) the rainfall regime, i.e. the relative importance of light storms to total rainfall, (2) the climatic parameters, rainfall rate and average evaporation rate during storms, and (3) the canopy structure parameters of the model. The low interception rate of the canopy was attributed primarily to the low leaf area index of the stand.

Calculation of intercepted runoff depth based on stormwater quality and environmental capacity of receiving waters for initial stormwater pollution management.

PubMed

Peng, Hai-Qin; Liu, Yan; Gao, Xue-Long; Wang, Hong-Wu; Chen, Yi; Cai, Hui-Yi

2017-11-01

While point source pollutions have gradually been controlled in recent years, the non-point source pollution problem has become increasingly prominent. The receiving waters are frequently polluted by the initial stormwater from the separate stormwater system and the wastewater from sewage pipes through stormwater pipes. Consequently, calculating the intercepted runoff depth has become a problem that must be resolved immediately for initial stormwater pollution management. The accurate calculation of intercepted runoff depth provides a solid foundation for selecting the appropriate size of intercepting facilities in drainage and interception projects. This study establishes a separate stormwater system for the Yishan Building watershed of Fuzhou City using the InfoWorks Integrated Catchment Management (InfoWorks ICM), which can predict the stormwater flow velocity and the flow of discharge outlet after each rainfall. The intercepted runoff depth is calculated from the stormwater quality and environmental capacity of the receiving waters. The average intercepted runoff depth from six rainfall events is calculated as 4.1 mm based on stormwater quality. The average intercepted runoff depth from six rainfall events is calculated as 4.4 mm based on the environmental capacity of the receiving waters. The intercepted runoff depth differs when calculated from various aspects. The selection of the intercepted runoff depth depends on the goal of water quality control, the self-purification capacity of the water bodies, and other factors of the region.

Intercepting virtual balls approaching under different gravity conditions: evidence for spatial prediction.

PubMed

Russo, Marta; Cesqui, Benedetta; La Scaleia, Barbara; Ceccarelli, Francesca; Maselli, Antonella; Moscatelli, Alessandro; Zago, Myrka; Lacquaniti, Francesco; d'Avella, Andrea

2017-10-01

To accurately time motor responses when intercepting falling balls we rely on an internal model of gravity. However, whether and how such a model is also used to estimate the spatial location of interception is still an open question. Here we addressed this issue by asking 25 participants to intercept balls projected from a fixed location 6 m in front of them and approaching along trajectories with different arrival locations, flight durations, and gravity accelerations (0 g and 1 g ). The trajectories were displayed in an immersive virtual reality system with a wide field of view. Participants intercepted approaching balls with a racket, and they were free to choose the time and place of interception. We found that participants often achieved a better performance with 1 g than 0 g balls. Moreover, the interception points were distributed along the direction of a 1 g path for both 1 g and 0 g balls. In the latter case, interceptions tended to cluster on the upper half of the racket, indicating that participants aimed at a lower position than the actual 0 g path. These results suggest that an internal model of gravity was probably used in predicting the interception locations. However, we found that the difference in performance between 1 g and 0 g balls was modulated by flight duration, the difference being larger for faster balls. In addition, the number of peaks in the hand speed profiles increased with flight duration, suggesting that visual information was used to adjust the motor response, correcting the prediction to some extent. NEW & NOTEWORTHY Here we show that an internal model of gravity plays a key role in predicting where to intercept a fast-moving target. Participants also assumed an accelerated motion when intercepting balls approaching in a virtual environment at constant velocity. We also show that the role of visual information in guiding interceptive movement increases when more time is available. Copyright © 2017 the American Physiological Society.

Comparison between students and residents on determinants of willingness to separate waste and waste separation behaviour in Zhengzhou, China.

PubMed

Dai, Xiaoping; Han, Yuping; Zhang, Xiaohong; Hu, Wei; Huang, Liangji; Duan, Wenpei; Li, Siyi; Liu, Xiaolu; Wang, Qian

2017-09-01

A better understanding of willingness to separate waste and waste separation behaviour can aid the design and improvement of waste management policies. Based on the intercept questionnaire survey data of undergraduate students and residents in Zhengzhou City of China, this article compared factors affecting the willingness and behaviour of students and residents to participate in waste separation using two binary logistic regression models. Improvement opportunities for waste separation were also discussed. Binary logistic regression results indicate that knowledge of and attitude to waste separation and acceptance of waste education significantly affect the willingness of undergraduate students to separate waste, and demographic factors, such as gender, age, education level, and income, significantly affect the willingness of residents to do so. Presence of waste-specific bins and attitude to waste separation are drivers of waste separation behaviour for both students and residents. Improved education about waste separation and facilities are effective to stimulate waste separation, and charging on unsorted waste may be an effective way to improve it in Zhengzhou.

Validation of prediction models: examining temporal and geographic stability of baseline risk and estimated covariate effects

PubMed Central

Austin, Peter C.; van Klaveren, David; Vergouwe, Yvonne; Nieboer, Daan; Lee, Douglas S.; Steyerberg, Ewout W.

2018-01-01

Background Stability in baseline risk and estimated predictor effects both geographically and temporally is a desirable property of clinical prediction models. However, this issue has received little attention in the methodological literature. Our objective was to examine methods for assessing temporal and geographic heterogeneity in baseline risk and predictor effects in prediction models. Methods We studied 14,857 patients hospitalized with heart failure at 90 hospitals in Ontario, Canada, in two time periods. We focussed on geographic and temporal variation in baseline risk (intercept) and predictor effects (regression coefficients) of the EFFECT-HF mortality model for predicting 1-year mortality in patients hospitalized for heart failure. We used random effects logistic regression models for the 14,857 patients. Results The baseline risk of mortality displayed moderate geographic variation, with the hospital-specific probability of 1-year mortality for a reference patient lying between 0.168 and 0.290 for 95% of hospitals. Furthermore, the odds of death were 11% lower in the second period than in the first period. However, we found minimal geographic or temporal variation in predictor effects. Among 11 tests of differences in time for predictor variables, only one had a modestly significant P value (0.03). Conclusions This study illustrates how temporal and geographic heterogeneity of prediction models can be assessed in settings with a large sample of patients from a large number of centers at different time periods. PMID:29350215

Relationships between community social capital and injury in Canadian adolescents: a multilevel analysis

PubMed Central

Vafaei, Afshin; Pickett, William; Alvarado, Beatriz E

2015-01-01

Background Characteristics of social environments are potential risk factors for adolescent injury. Impacts of social capital on the occurrence of such injuries have rarely been explored. Methods General health questionnaires were completed by 8910 youth aged 14 years and older as part of the 2010 Canadian Health Behaviour in School-Aged Children study. These were supplemented with community-level data from the 2006 Canada Census of Population. Multilevel logistic regression models with random intercepts were fit to examine associations of interest. The reliability and validity of variables used in this analysis had been established in past studies, or in new analyses that employed factor analysis. Results Between school differences explained 2% of the variance in the occurrence of injuries. After adjustment for all confounders, community social capital did not have any impact on the occurrence of injuries in boys: OR: 1.01, 95% CI 0.80 to 1.29. However, living in areas with low social capital was associated with lower occurrence of injuries in girls (OR 0.78, 95% CI 0.63 to 0.96). Other factors that were significantly related to injuries in both genders were younger age, engagement in more risky behaviours, and negative behavioural influences from peers. Conclusions After simultaneously taking into account the influence of community-level and individual-level factors, community levels of social capital remained a relatively strong predictor of injury among girls but not boys. Such gender effects provide important clues into the social aetiology of youth injury. PMID:26294708

Is religiosity positively associated with school connectedness: evidence from high school students in Atlantic Canada?

PubMed

Azagba, Sunday; Asbridge, Mark; Langille, Donald B

2014-12-01

School connectedness (SC) is associated with decreased student risk behavior and better health and social outcomes. While a considerable body of research has examined the factors associated with SC, there is limited evidence about the particular role of religiosity in shaping levels of SC. Employing data reported by junior and senior high school students from Atlantic Canada, this study examines whether religiosity is positively associated with SC and whether such associations differ by gender. We tested the association between SC and religiosity using a random intercept multilevel logistic regression. The between-school variability in SC was first determined by our estimating a null or empty model; three different model specifications that included covariates were estimated: in Model 1 we adjusted for gender, age, academic performance, parental education, and living arrangement; in Model 2 for sensation seeking and subjective social status in addition to Model 1 variables; and in Model 3 we added substance use to the analysis. Our multilevel regression analyses showed that religiosity was protectively associated with lower SC across the three model specifications when both genders were examined together. In gender-stratified analyses we found similar protective associations of religiosity, with lower SC for both males and females in all three models. Given the overwhelming positive impact of SC on a range of health, social and school outcomes, it is important to understand the role of religiosity, among other factors, that may be modified to enhance student's connectedness to school.

A Daily Diary Analysis of Condom Breakage and Slippage during Vaginal Sex or Anal Sex among Adolescent Women

PubMed Central

Hensel, Devon J.; Selby, Sarah; Tanner, Amanda E.; Fortenberry, J. Dennis

2016-01-01

Background Adolescent women Adolescent women are disproportionately impacted by the adverse outcomes associated with sexual activity, including sexually transmitted infections (STI). Condoms as a means of prevention relies upon use that is free of usage failure, including breakage and/or slippage. This study examined the daily prevalence of and predictors of condom breakage and/or slippage during vaginal sex and during anal sex among adolescent women. Methods Adolescent women (N=387; 14 to 17 years) were recruited from primary care clinics for a longitudinal cohort study of STIs and sexual behavior. Data were daily partner-specific sexual diaries. Random intercept mixed effects logistic regression was used to estimate the fixed effect of each predictor on condom breakage/slippage during vaginal or during anal sex (Stata, 13.0), adjusting model coefficients for the correlation between repeated within-participant diary entries. Results Condom slippage and/or breakage varied across sexual behaviors and was associated with individual-specific (e.g., age and sexual interest) and partner-specific factors (e.g., negativity). Recent behavioral factors (e.g., experiencing slippage and/or breakage in the past week) were the strongest predictors of current condom slippage and/or breakage during vaginal or anal sex Conclusion Factors associated with young women’s condom breakage/slippage during vaginal or during anal sex should be integrated as part of STI prevention efforts, and should be assessed as part of ongoing routine clinical care. PMID:27513377

Continuing care and long-term substance use outcomes in managed care: early evidence for a primary care-based model.

PubMed

Chi, Felicia W; Parthasarathy, Sujaya; Mertens, Jennifer R; Weisner, Constance M

2011-10-01

How best to provide ongoing services to patients with substance use disorders to sustain long-term recovery is a significant clinical and policy question that has not been adequately addressed. Analyzing nine years of prospective data for 991 adults who entered substance abuse treatment in a private, nonprofit managed care health plan, this study aimed to examine the components of a continuing care model (primary care, specialty substance abuse treatment, and psychiatric services) and their combined effect on outcomes over nine years after treatment entry. In a longitudinal observational study, follow-up measures included self-reported alcohol and drug use, Addiction Severity Index scores, and service utilization data extracted from the health plan databases. Remission, defined as abstinence or nonproblematic use, was the outcome measure. A mixed-effects logistic random intercept model controlling for time and other covariates found that yearly primary care, and specialty care based on need as measured at the prior time point, were positively associated with remission over time. Persons receiving continuing care (defined as having yearly primary care and specialty substance abuse treatment and psychiatric services when needed) had twice the odds of achieving remission at follow-ups (p<.001) as those without. Continuing care that included both primary care and specialty care management to support ongoing monitoring, self-care, and treatment as needed was important for long-term recovery of patients with substance use disorders.

Association of socio-economic, gender and health factors with common mental disorders in women: a population-based study of 5703 married rural women in India.

PubMed

Shidhaye, Rahul; Patel, Vikram

2010-12-01

There are few population-based studies from low- and middle-income countries that have described the association of socio-economic, gender and health factors with common mental disorders (CMDs) in rural women. Population-based study of currently married rural women in the age group of 15-39 years. The baseline data are from the National Family Health Survey-II conducted in 1998. A follow-up study was conducted 4 years later in 2002-03. The outcome of CMD was assessed using the 12-item General Health Questionnaire (GHQ-12). Due to the hierarchical nature and complex survey design, data were analysed using mixed-effect logistic regression with random intercept model. A total of 5703 women (representing 83.5% of eligible women) completed follow-up. The outcome of CMD was observed in 609 women (10.7%, 95% confidence interval 9.8-11.6). The following factors were independently associated with the outcome of CMD in the final multivariable model: higher age, low education, low standard of living, recent intimate partner violence (IPV), husband's unsatisfactory reaction to dowry, husband's alcohol use and women's own tobacco use. Socio-economic and gender disadvantage factors are independently associated with CMDs in this population of women. Strategies that address structural determinants, for example to promote women's education and reduce their exposure to IPV, may reduce the burden of CMDs in women.

A Health-Based Metric for Evaluating the Effectiveness of Noise Barrier Mitigation Associated With Transport Infrastructure Noise

PubMed Central

Prendergast, Geoffrey P.; Staff, Michael

2017-01-01

Introduction: This study examines the use of the number of night-time sleep disturbances as a health-based metric to assess the cost effectiveness of rail noise mitigation strategies for situations, wherein high-intensity noises dominate such as freight train pass-bys and wheel squeal. Materials and Methods: Twenty residential properties adjacent to the existing and proposed rail tracks in a noise catchment area of the Epping to Thornleigh Third Track project were used as a case study. Awakening probabilities were calculated for individual’s awakening 1, 3 and 5 times a night when subjected to 10 independent freight train pass-by noise events using internal maximum sound pressure levels (LAFmax). Results: Awakenings were predicted using a random intercept multivariate logistic regression model. With source mitigation in place, the majority of the residents were still predicted to be awoken at least once per night (median 88.0%), although substantial reductions in the median probabilities of awakening three and five times per night from 50.9 to 29.4% and 9.2 to 2.7%, respectively, were predicted. This resulted in a cost-effective estimate of 7.6–8.8 less people being awoken at least three times per night per A$1 million spent on noise barriers. Conclusion: The study demonstrates that an easily understood metric can be readily used to assist making decisions related to noise mitigation for large-scale transport projects. PMID:29192613

More than just a question of technology: factors related to hospitals' adoption and implementation of health information exchange.

PubMed

Vest, Joshua R

2010-12-01

The provisions of the American Recovery & Reinvestment Act increased the likelihood of more widespread health information exchange (HIE), the electronic transfer of patient-level information between organizations, by essentially mandating the use of electronic health record systems. While important, the sparse body of research on HIE efforts and anecdotal reports indicate the barriers to HIE adoption and implementation include factors beyond simply the presence or absence of a specific technology. This paper examines those technological, organizational, and environmental factors that are associated with both HIE adoption and implementation in a sample of 4830 U.S. hospitals. Factors associated with adoption and implementation were modeled using random-intercept logistic regression. Consistent with a perspective that adoption and implementation are different phenomena, many factors associated with an increased odds of adoption, were unassociated with implementation and vice versa. Non-profit status, public hospitals, more live and operation applications, more emergency room visits, network membership, and the presence of physician portals all increased hospitals' odds of HIE adoption. However, only network membership increased the odds of HIE implementation, whereas competition decreased those odds significantly. This study agreed with earlier case-studies and anecdotal reports that factors beyond technology were important to both adoption and implementation. While current U.S. policy on healthcare information technology adoption focuses on technological barriers, many other non-technological factors may ultimately hinder effective HIE. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Factors motivating and affecting health information exchange usage

PubMed Central

Zhao, Hongwei; Jaspserson, 'Jon; Gamm, Larry D; Ohsfeldt, Robert L

2011-01-01

Objective Health information exchange (HIE) is the process of electronically sharing patient-level information between providers. However, where implemented, reports indicate HIE system usage is low. The aim of this study was to determine the factors associated with different types of HIE usage. Design Cross-sectional analysis of clinical data from emergency room encounters included in an operational HIE effort linked to system user logs using crossed random-intercept logistic regression. Measurements Independent variables included factors indicative of information needs. System usage was measured as none, basic usage, or a novel pattern of usage. Results The system was accessed for 2.3% of all encounters (6142 out of 271 305). Novel usage patterns were more likely for more complex patients. The odds of HIE usage were lower in the face of time constraints. In contrast to expectations, system usage was lower when the patient was unfamiliar to the facility. Limitations Because of differences between HIE efforts and the fact that not all types of HIE usage (ie, public health) could be included in the analysis, results are limited in terms of generalizablity. Conclusions This study of actual HIE system usage identifies patients and circumstances in which HIE is more likely to be used and factors that are likely to discourage usage. The paper explores the implications of the findings for system redesign, information integration across exchange partners, and for meaningful usage criteria emerging from provisions of the Health Information Technology for Economic & Clinical Health Act. PMID:21262919

The Link Between Community-Based Violence and Intimate Partner Violence: the Effect of Crime and Male Aggression on Intimate Partner Violence Against Women.

PubMed

Kiss, Ligia; Schraiber, Lilia Blima; Hossain, Mazeda; Watts, Charlotte; Zimmerman, Cathy

2015-08-01

Both intimate partner violence (IPV) and community violence are prevalent globally, and each is associated with serious health consequences. However, little is known about their potential links or the possible benefits of coordinated prevention strategies. Using aggregated data on community violence from the São Paulo State Security Department (INFOCRIM) merged with WHO multi-country study on women's health and domestic violence data, random intercept models were created to assess the effect of crime on women's probability of experiencing IPV. The association between IPV and male aggression (measured by women's reports of their partner's fights with other men) was examined using logistic regression models. We found little variation in the likelihood of male IPV perpetration related to neighborhood crime level but did find an increased likelihood of IPV experiences among women whose partners were involved in male-to-male violence. Emerging evidence on violence prevention has suggested some promising avenues for primary prevention that address common risk factors for both perpetration of IPV and male interpersonal violence. Strategies such as early identification and effective treatment of emotional disorders, alcohol abuse prevention and treatment, complex community-based interventions to change gender social norms and social marketing campaigns designed to modify social and cultural norms that support violence may work to prevent simultaneously male-on-male aggression and IPV. Future evaluations of these prevention strategies should simultaneously assess the impact of interventions on IPV and male interpersonal aggression.

Which dogs with appendicular osteosarcoma benefit most from chemotherapy after surgery? Results from an individual patient data meta-analysis.

PubMed

Schmidt, A F; Groenwold, R H H; Amsellem, P; Bacon, N; Klungel, O H; Hoes, A W; de Boer, A; Kow, K; Maritato, K; Kirpensteijn, J; Nielen, M

2016-03-01

Osteosarcoma (OS) is a malignant tumor of mesenchymal origin that produces osteoid. Given that the prognosis can vary considerably between dogs, we aimed to explore whether treatment could be tailored towards patient subgroups, characterized by their predicted risk of mortality. For the current study, a subset of five nonrandomized studies (400 subjects of whom 88 were dead at 5 months follow-up) was used from a previously published 20 study individual patient data meta-analysis. Missing data was dependent on observed variables and was imputed to correct for this dependency. Based on a previously published multivariable prognostic model, the 5-month mortality risk was predicted. Subsequently, in surgically treated dogs, using a logistic regression model with a random intercept for a study indicator, we explored whether chemotherapy effectiveness depended on predicted 5-month mortality risk. After adjustment for potential confounders the main effect of any chemotherapy was 0.48 (odds ratio) (95%CI 0.30; 0.78). Testing for chemotherapy by predicted 5-month mortality risk interaction revealed that the effects of any chemotherapy decreased with increasing predicted risk; interaction OR 3.41 (1.07; 10.84). Results from individually comparing carboplatin, cisplatin, doxorubicin and doxorubicin combination therapy to no chemotherapy, were similar in magnitude and direction. These results indicate that the main treatment effects of chemotherapy do not necessarily apply to all patients. Copyright © 2015 Elsevier B.V. All rights reserved.

Genetic Parameter Estimates for Metabolizing Two Common Pharmaceuticals in Swine.

PubMed

Howard, Jeremy T; Ashwell, Melissa S; Baynes, Ronald E; Brooks, James D; Yeatts, James L; Maltecca, Christian

2018-01-01

In livestock, the regulation of drugs used to treat livestock has received increased attention and it is currently unknown how much of the phenotypic variation in drug metabolism is due to the genetics of an animal. Therefore, the objective of the study was to determine the amount of phenotypic variation in fenbendazole and flunixin meglumine drug metabolism due to genetics. The population consisted of crossbred female and castrated male nursery pigs ( n = 198) that were sired by boars represented by four breeds. The animals were spread across nine batches. Drugs were administered intravenously and blood collected a minimum of 10 times over a 48 h period. Genetic parameters for the parent drug and metabolite concentration within each drug were estimated based on pharmacokinetics (PK) parameters or concentrations across time utilizing a random regression model. The PK parameters were estimated using a non-compartmental analysis. The PK model included fixed effects of sex and breed of sire along with random sire and batch effects. The random regression model utilized Legendre polynomials and included a fixed population concentration curve, sex, and breed of sire effects along with a random sire deviation from the population curve and batch effect. The sire effect included the intercept for all models except for the fenbendazole metabolite (i.e., intercept and slope). The mean heritability across PK parameters for the fenbendazole and flunixin meglumine parent drug (metabolite) was 0.15 (0.18) and 0.31 (0.40), respectively. For the parent drug (metabolite), the mean heritability across time was 0.27 (0.60) and 0.14 (0.44) for fenbendazole and flunixin meglumine, respectively. The errors surrounding the heritability estimates for the random regression model were smaller compared to estimates obtained from PK parameters. Across both the PK and plasma drug concentration across model, a moderate heritability was estimated. The model that utilized the plasma drug concentration across time resulted in estimates with a smaller standard error compared to models that utilized PK parameters. The current study found a low to moderate proportion of the phenotypic variation in metabolizing fenbendazole and flunixin meglumine that was explained by genetics in the current study.

Genetic Parameter Estimates for Metabolizing Two Common Pharmaceuticals in Swine

PubMed Central

Howard, Jeremy T.; Ashwell, Melissa S.; Baynes, Ronald E.; Brooks, James D.; Yeatts, James L.; Maltecca, Christian

2018-01-01

In livestock, the regulation of drugs used to treat livestock has received increased attention and it is currently unknown how much of the phenotypic variation in drug metabolism is due to the genetics of an animal. Therefore, the objective of the study was to determine the amount of phenotypic variation in fenbendazole and flunixin meglumine drug metabolism due to genetics. The population consisted of crossbred female and castrated male nursery pigs (n = 198) that were sired by boars represented by four breeds. The animals were spread across nine batches. Drugs were administered intravenously and blood collected a minimum of 10 times over a 48 h period. Genetic parameters for the parent drug and metabolite concentration within each drug were estimated based on pharmacokinetics (PK) parameters or concentrations across time utilizing a random regression model. The PK parameters were estimated using a non-compartmental analysis. The PK model included fixed effects of sex and breed of sire along with random sire and batch effects. The random regression model utilized Legendre polynomials and included a fixed population concentration curve, sex, and breed of sire effects along with a random sire deviation from the population curve and batch effect. The sire effect included the intercept for all models except for the fenbendazole metabolite (i.e., intercept and slope). The mean heritability across PK parameters for the fenbendazole and flunixin meglumine parent drug (metabolite) was 0.15 (0.18) and 0.31 (0.40), respectively. For the parent drug (metabolite), the mean heritability across time was 0.27 (0.60) and 0.14 (0.44) for fenbendazole and flunixin meglumine, respectively. The errors surrounding the heritability estimates for the random regression model were smaller compared to estimates obtained from PK parameters. Across both the PK and plasma drug concentration across model, a moderate heritability was estimated. The model that utilized the plasma drug concentration across time resulted in estimates with a smaller standard error compared to models that utilized PK parameters. The current study found a low to moderate proportion of the phenotypic variation in metabolizing fenbendazole and flunixin meglumine that was explained by genetics in the current study. PMID:29487615

Biological monitoring of environmental quality: The use of developmental instability

USGS Publications Warehouse

Freeman, D.C.; Emlen, J.M.; Graham, J.H.; Hough, R. A.; Bannon, T.A.

1994-01-01

Distributed robustness is thought to influence the buffering of random phenotypic variation through the scale-free topology of gene regulatory, metabolic, and protein-protein interaction networks. If this hypothesis is true, then the phenotypic response to the perturbation of particular nodes in such a network should be proportional to the number of links those nodes make with neighboring nodes. This suggests a probability distribution approximating an inverse power-law of random phenotypic variation. Zero phenotypic variation, however, is impossible, because random molecular and cellular processes are essential to normal development. Consequently, a more realistic distribution should have a y-intercept close to zero in the lower tail, a mode greater than zero, and a long (fat) upper tail. The double Pareto-lognormal (DPLN) distribution is an ideal candidate distribution. It consists of a mixture of a lognormal body and upper and lower power-law tails.

Sex drugs, peer connections, and HIV: Use and risk among African American, Latino, and Multiracial young men who have sex with men (YMSM) in Los Angeles and New York.

PubMed

Mutchler, Matt G; McKay, Tara; Candelario, Norman; Liu, Honghu; Stackhouse, Bill; Bingham, Trista; Ayala, George

2011-01-01

African American and Latino young men who have sex with men are at high risk for HIV infection. We administered brief intercept surveys (N=416) at 18 Black and Latino gay pride events in Los Angeles and New York in 2006 and 2007. Ordinal logistic regressions were used to model the effects of substance use during sex, peer connectedness, relationship status, and homelessness on condom use. Alcohol use, crystal use, homelessness, and having a primary relationship partner were negatively associated with condom use, while peer connectedness and marijuana use during sex were positively associated with condom use. Implications for service providers and future research are discussed.

The critical distance in laser-induced plasmas: an operative definition

NASA Astrophysics Data System (ADS)

Delle Side, D.; Giuffreda, E.; Nassisi, V.

2016-05-01

We propose a method to estimate a precise value for the critical distance Lcr after which three-body recombination stops to produce charge losses in an expanding laser-induced plasma. We show in particular that the total charge collected has a ``reversed sigmoid'' shape as a function of the target-to-detector distance. Fitting the total charge data with a logistic related function, we could consider as Lcr the intercept of the tangent to this curve in its inflection point. Furthermore, this value scales well with theoretical predictions. From the application point of view, this could be of great practical interest, since it provide a reliable way to precisely determine the geometry of the extraction system in Laser Ion Sources.

Effects of the interception of litterfall by the understory on carbon cycling in eucalyptus plantations of South China.

PubMed

Yang, Long; Wang, Jun; Huang, Yuhui; Hui, Dafeng; Wen, Meili

2014-01-01

For the purposes of forest restoration, carbon (C) fixation, and economic improvement, eucalyptus (Eucalyptus urophylla) has been widely planted in South China. The understory of eucalyptus plantations is often occupied by a dense community of the fern Dicranopteris dichotoma, which intercepts tree canopy leaf litter before it reaches the ground. To understand the effects of this interception of litterfall on C cycling in eucalyptus plantations, we quantified the mass of intercepted litter and the influences of litterfall interception on litter decomposition and soil respiration. The total mass of E. urophylla litterfall collected on the understory was similar to that collected by the traditional litter trap method. All of the eucalyptus litterfall is intercepted by the D. dichotoma canopy. Of the litterfall that was intercepted by D. dichotoma, 20-40% and 60-80% was intercepted by the top (50-100 cm) and bottom (0-50 cm) of the understory canopy, respectively. Intercepted litterfall decomposed faster at the bottom of understory canopy (at the base of the plants) than at the top, and decomposition was slower on the soil surface in the absence of understory than on any location in the understory canopy. Soil respiration was highest when both the understory and litter were present and was lowest when both the understory and litter were absent. These results indicate that litterfall interception changed carbon flow between aboveground and belowground through litter decomposition and soil respiration, which changed carbon cycling in eucalyptus plantations. The effects of the understory on litter decomposition and soil respiration should be considered in ecosystem carbon models.

Intrastorm scale rainfall interception dynamics in a mature coniferous forest stand

NASA Astrophysics Data System (ADS)

Iida, Shin'ichi; Levia, Delphis F.; Shimizu, Akira; Shimizu, Takanori; Tamai, Koji; Nobuhiro, Tatsuhiko; Kabeya, Naoki; Noguchi, Shoji; Sawano, Shinji; Araki, Makoto

2017-05-01

Canopy interception of rainfall is an important process in the water balance of forests. The intrastorm dynamics of canopy interception is less well understood than event scale interception. Accordingly, armed with measurements of hourly interception intensity (i) from the field, this study is among the first to examine the differences in canopy interception dynamics between the first and second halves of rainfall events to quantify dynamic storage values for a coniferous forest in Japan. At this site, experimental results demonstrated that: (1) the relationship between interception loss (I) and gross rainfall (GR) at the event scale is better explained by a parabolic curve than a linear relationship, and there is a low correlation between rainfall intensity (gr) and i; (2) the ratio of accumulated i during the first half (IF) to that of gr (GRF) was larger than the second half (IS/GRS), with no significant correlations between potential evaporation during first half (PEF) vs IF or the second half (PES) vs IS; and (3) water storage capacity was similar to the magnitude of maximum I. By emphasizing the comparison between IF and IS, this study concludes that the water storage on tree surface is more important than losses by wet canopy evaporation and splash during rain. This study also adds insights into intrastorm interception dynamics of coniferous forests which are necessary to better model and forecast interception losses.

Aerial surveys adjusted by ground surveys to estimate area occupied by black-tailed prairie dog colonies

USGS Publications Warehouse

Sidle, John G.; Augustine, David J.; Johnson, Douglas H.; Miller, Sterling D.; Cully, Jack F.; Reading, Richard P.

2012-01-01

Aerial surveys using line-intercept methods are one approach to estimate the extent of prairie dog colonies in a large geographic area. Although black-tailed prairie dogs (Cynomys ludovicianus) construct conspicuous mounds at burrow openings, aerial observers have difficulty discriminating between areas with burrows occupied by prairie dogs (colonies) versus areas of uninhabited burrows (uninhabited colony sites). Consequently, aerial line-intercept surveys may overestimate prairie dog colony extent unless adjusted by an on-the-ground inspection of a sample of intercepts. We compared aerial line-intercept surveys conducted over 2 National Grasslands in Colorado, USA, with independent ground-mapping of known black-tailed prairie dog colonies. Aerial line-intercepts adjusted by ground surveys using a single activity category adjustment overestimated colonies by ≥94% on the Comanche National Grassland and ≥58% on the Pawnee National Grassland. We present a ground-survey technique that involves 1) visiting on the ground a subset of aerial intercepts classified as occupied colonies plus a subset of intercepts classified as uninhabited colony sites, and 2) based on these ground observations, recording the proportion of each aerial intercept that intersects a colony and the proportion that intersects an uninhabited colony site. Where line-intercept techniques are applied to aerial surveys or remotely sensed imagery, this method can provide more accurate estimates of black-tailed prairie dog abundance and trends

Transport of intercepted snow from trees during snow storms

Treesearch

David H. Miller

1966-01-01

Five principal processes by which intercepted snow in trees is removed during snow storms are described and evaluated as far as data permit: vapor flux from melt water, vapor flux from bodies of snow, stem flow and dripping of melt water, sliding of bodies of intercepted snow from branches, and wind erosion and transport of intercepted snow. Further research is...

Calibrating random forests for probability estimation.

PubMed

Dankowski, Theresa; Ziegler, Andreas

2016-09-30

Probabilities can be consistently estimated using random forests. It is, however, unclear how random forests should be updated to make predictions for other centers or at different time points. In this work, we present two approaches for updating random forests for probability estimation. The first method has been proposed by Elkan and may be used for updating any machine learning approach yielding consistent probabilities, so-called probability machines. The second approach is a new strategy specifically developed for random forests. Using the terminal nodes, which represent conditional probabilities, the random forest is first translated to logistic regression models. These are, in turn, used for re-calibration. The two updating strategies were compared in a simulation study and are illustrated with data from the German Stroke Study Collaboration. In most simulation scenarios, both methods led to similar improvements. In the simulation scenario in which the stricter assumptions of Elkan's method were not met, the logistic regression-based re-calibration approach for random forests outperformed Elkan's method. It also performed better on the stroke data than Elkan's method. The strength of Elkan's method is its general applicability to any probability machine. However, if the strict assumptions underlying this approach are not met, the logistic regression-based approach is preferable for updating random forests for probability estimation. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Intercepting a moving target: On-line or model-based control?

PubMed

Zhao, Huaiyong; Warren, William H

2017-05-01

When walking to intercept a moving target, people take an interception path that appears to anticipate the target's trajectory. According to the constant bearing strategy, the observer holds the bearing direction of the target constant based on current visual information, consistent with on-line control. Alternatively, the interception path might be based on an internal model of the target's motion, known as model-based control. To investigate these two accounts, participants walked to intercept a moving target in a virtual environment. We degraded the target's visibility by blurring the target to varying degrees in the midst of a trial, in order to influence its perceived speed and position. Reduced levels of visibility progressively impaired interception accuracy and precision; total occlusion impaired performance most and yielded nonadaptive heading adjustments. Thus, performance strongly depended on current visual information and deteriorated qualitatively when it was withdrawn. The results imply that locomotor interception is normally guided by current information rather than an internal model of target motion, consistent with on-line control.

A Multilevel AR(1) Model: Allowing for Inter-Individual Differences in Trait-Scores, Inertia, and Innovation Variance.

PubMed

Jongerling, Joran; Laurenceau, Jean-Philippe; Hamaker, Ellen L

2015-01-01

In this article we consider a multilevel first-order autoregressive [AR(1)] model with random intercepts, random autoregression, and random innovation variance (i.e., the level 1 residual variance). Including random innovation variance is an important extension of the multilevel AR(1) model for two reasons. First, between-person differences in innovation variance are important from a substantive point of view, in that they capture differences in sensitivity and/or exposure to unmeasured internal and external factors that influence the process. Second, using simulation methods we show that modeling the innovation variance as fixed across individuals, when it should be modeled as a random effect, leads to biased parameter estimates. Additionally, we use simulation methods to compare maximum likelihood estimation to Bayesian estimation of the multilevel AR(1) model and investigate the trade-off between the number of individuals and the number of time points. We provide an empirical illustration by applying the extended multilevel AR(1) model to daily positive affect ratings from 89 married women over the course of 42 consecutive days.

Using ecological momentary assessment to test the effectiveness of a web-based brief alcohol intervention over time among heavy-drinking students: randomized controlled trial.

PubMed

Voogt, Carmen; Kuntsche, Emmanuel; Kleinjan, Marloes; Poelen, Evelien; Engels, Rutger

2014-01-08

Web-based brief alcohol interventions are effective in reducing alcohol use among students when measured at limited follow-up time points. To date, no studies have tested Web-based brief alcohol intervention effectiveness over time by using a large number of measurements. Testing whether the What Do You Drink (WDYD) Web-based brief alcohol intervention can sustain a reduction in alcohol use among heavy-drinking students aged 18-24 years at 1-, 3-, and 6-month follow-up intervals. A purely Web-based, 2-arm, parallel-group randomized controlled trial applying an ecological momentary assessment approach with 30 weekly measurements was conducted in the Netherlands (2010-2011). Participants were recruited offline and online. A total of 907 participants were randomized into the experimental condition (n=456) including the single-session and fully automated WDYD intervention, or into the control condition (n=451) including assessment only. Weekly alcohol consumption and frequency of binge drinking were the self-assessed outcome measures. Attrition rates of the 907 participants were 110 (12.1%), 130 (14.3%), and 162 (17.9%) at 1-, 3-, and 6-month follow-up intervals, respectively. Latent growth curve analyses according to the intention-to-treat principle revealed that participants in the experimental condition had significantly lower weekly alcohol consumption compared to participants in the control condition that was sustained at 3-month follow-up (intercept=-2.60, P<.001; slope=0.16, P=.08). Additional linear regression analyses indicated that this intercept difference resulted from significantly higher levels of alcohol units per week for participants in the control condition compared to those in the experimental condition at 1-month (beta=-2.56, SE 0.74, Cohen's d=0.20, P=.001), 3-month (beta=-1.76, SE 0.60, Cohen's d=0.13, P=.003), and 6-month (beta=-1.21, SE 0.58, Cohen's d=0.09, P=.04) follow-up intervals. Latent growth curve analyses further indicated that participants in the experimental condition had a significantly lower frequency of binge drinking compared to participants in the control condition that was sustained at 6-month follow-up (intercept=-0.14, P=.01; slope=0.004, P=.19). This intercept difference resulted from higher levels in this outcome for participants in the control condition relative to participants in the experimental condition at 1-month (beta=-1.15, SE 0.06, Cohen's d=0.16, P=.01), 3-month (beta=-0.12, SE 0.05, Cohen's d=0.09, P=.01), and 6-month (beta=-0.09, SE 0.05, Cohen's d=0.03, P=.045) follow-up intervals. The WDYD intervention was shown to be effective in preventing an increase in weekly alcohol consumption and frequency of binge drinking directly after the intervention. This effect was sustained 3 and 6 months after the intervention. Netherlands Trial Register NTR2665; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2665 (Archived by WebCite at http://webcitation.org/6LuQVn12M).

Midday Depression vs. Midday Peak in Diurnal Light Interception: Contrasting Patterns at Crown and Leaf Scales in a Tropical Evergreen Tree.

PubMed

Ventre-Lespiaucq, Agustina; Flanagan, Nicola S; Ospina-Calderón, Nhora H; Delgado, Juan A; Escudero, Adrián

2018-01-01

Crown architecture usually is heterogeneous as a result of foraging in spatially and temporally heterogeneous light environments. Ecologists are only beginning to identify the importance of temporal heterogeneity for light acquisition in plants, especially at the diurnal scale. Crown architectural heterogeneity often leads to a diurnal variation in light interception. However, maximizing light interception during midday may not be an optimal strategy in environments with excess light. Instead, long-lived plants are expected to show crown architectures and leaf positions that meet the contrasting needs of light interception and avoidance of excess light on a diurnal basis. We expected a midday depression in the diurnal course of light interception both at the whole-crown and leaf scales, as a strategy to avoid the interception of excessive irradiance. We tested this hypothesis in a population of guava trees ( Psidium guajava L.) growing in an open tropical grassland. We quantified three crown architectural traits: intra-individual heterogeneity in foliage clumping, crown openness, and leaf position angles. We estimated the diurnal course of light interception at the crown scale using hemispheric photographs, and at the leaf scale using the cosine of solar incidence. Crowns showed a midday depression in light interception, while leaves showed a midday peak. These contrasting patterns were related to architectural traits. At the crown scale, the midday depression of light interception was linked to a greater crown openness and foliage clumping in crown tops than in the lateral parts of the crown. At the leaf scale, an average inclination angle of 45° led to the midday peak in light interception, but with a huge among-leaf variation in position angles. The mismatch in diurnal course of light interception at crown and leaf scales can indicate that different processes are being optimized at each scale. These findings suggest that the diurnal course of light interception may be an important dimension of the resource acquisition strategies of long-lived woody plants. Using a temporal approach as the one applied here may improve our understanding of the diversity of crown architectures found across and within environments.

Midday Depression vs. Midday Peak in Diurnal Light Interception: Contrasting Patterns at Crown and Leaf Scales in a Tropical Evergreen Tree

PubMed Central

Ventre-Lespiaucq, Agustina; Flanagan, Nicola S.; Ospina-Calderón, Nhora H.; Delgado, Juan A.; Escudero, Adrián

2018-01-01

Crown architecture usually is heterogeneous as a result of foraging in spatially and temporally heterogeneous light environments. Ecologists are only beginning to identify the importance of temporal heterogeneity for light acquisition in plants, especially at the diurnal scale. Crown architectural heterogeneity often leads to a diurnal variation in light interception. However, maximizing light interception during midday may not be an optimal strategy in environments with excess light. Instead, long-lived plants are expected to show crown architectures and leaf positions that meet the contrasting needs of light interception and avoidance of excess light on a diurnal basis. We expected a midday depression in the diurnal course of light interception both at the whole-crown and leaf scales, as a strategy to avoid the interception of excessive irradiance. We tested this hypothesis in a population of guava trees (Psidium guajava L.) growing in an open tropical grassland. We quantified three crown architectural traits: intra-individual heterogeneity in foliage clumping, crown openness, and leaf position angles. We estimated the diurnal course of light interception at the crown scale using hemispheric photographs, and at the leaf scale using the cosine of solar incidence. Crowns showed a midday depression in light interception, while leaves showed a midday peak. These contrasting patterns were related to architectural traits. At the crown scale, the midday depression of light interception was linked to a greater crown openness and foliage clumping in crown tops than in the lateral parts of the crown. At the leaf scale, an average inclination angle of 45° led to the midday peak in light interception, but with a huge among-leaf variation in position angles. The mismatch in diurnal course of light interception at crown and leaf scales can indicate that different processes are being optimized at each scale. These findings suggest that the diurnal course of light interception may be an important dimension of the resource acquisition strategies of long-lived woody plants. Using a temporal approach as the one applied here may improve our understanding of the diversity of crown architectures found across and within environments. PMID:29904391

Examining the canopy interception at a forest field site using cosmic-ray neutron detection

NASA Astrophysics Data System (ADS)

Andreasen, M.; Looms, M.; Christiansen, J. R.; Sonnenborg, T. O.; Stisen, S.; Jensen, K. H.

2017-12-01

Canopy interception, the amount of precipitation captured by the surface of plants and trees, is a key component of the water cycle as it constrains the water flux to the ground below vegetation. Forests have especially high interception capacities and therefore the interception loss often forms a considerable part of the total evapotranspiration. The canopy interception capacity is dependent on the size and structure of the vegetation, and the interception loss can vary substantial in time and space. Measuring the canopy interception loss directly is challenging and current methodologies only represent small areas and rely on indirect approaches. Improving methods to estimate canopy interception loss directly will forward the basic understanding of how vegetation structure interacts with the water cycle and hence prediction of evapotranspiration. The intensity of low-energy neutrons produced by cosmic-rays, measured above the ground surface, is sensitive to the hydrogen content in the upper decimeters of the ground and hence the soil moisture content from a radius of hundreds of meters in the horizontal direction. In order to advance the cosmic-ray neutron (CRN) soil moisture method and extend the application of the CRN method more research has recently focused on the signal of other hydrogen pools on the neutron intensity (e.g., vegetation and canopy interception). A recent study, based on neutron transport modeling, found that the ground level thermal neutron intensity (energy < 1 eV), and as a consequence also the thermal-to-epithermal neutron (T/E) ratio (epithermal energy > 1 eV), increased with increasing canopy interception. In this study, we test whether CRN measurements can be used to provide a direct measure of the canopy interception. Four sets of CR2000/B systems were installed below the canopy in an oak forest stand in Denmark. Each system holds a bare (primarily measuring thermal neutrons) and a moderated detector (primarily measuring epithermal neutrons). The measured T/E ratios are compared to independent canopy interception measurements, obtained from throughfall and precipitation measurements. Furthermore, T/E ratios are related to measurements from leaf wetness sensors, CRN soil moisture estimates, and the biomass density in the canopy derived from a mobile terrestrial laser scanner.

Context effects on smooth pursuit and manual interception of a disappearing target.

PubMed

Kreyenmeier, Philipp; Fooken, Jolande; Spering, Miriam

2017-07-01

In our natural environment, we interact with moving objects that are surrounded by richly textured, dynamic visual contexts. Yet most laboratory studies on vision and movement show visual objects in front of uniform gray backgrounds. Context effects on eye movements have been widely studied, but it is less well known how visual contexts affect hand movements. Here we ask whether eye and hand movements integrate motion signals from target and context similarly or differently, and whether context effects on eye and hand change over time. We developed a track-intercept task requiring participants to track the initial launch of a moving object ("ball") with smooth pursuit eye movements. The ball disappeared after a brief presentation, and participants had to intercept it in a designated "hit zone." In two experiments ( n = 18 human observers each), the ball was shown in front of a uniform or a textured background that either was stationary or moved along with the target. Eye and hand movement latencies and speeds were similarly affected by the visual context, but eye and hand interception (eye position at time of interception, and hand interception timing error) did not differ significantly between context conditions. Eye and hand interception timing errors were strongly correlated on a trial-by-trial basis across all context conditions, highlighting the close relation between these responses in manual interception tasks. Our results indicate that visual contexts similarly affect eye and hand movements but that these effects may be short-lasting, affecting movement trajectories more than movement end points. NEW & NOTEWORTHY In a novel track-intercept paradigm, human observers tracked a briefly shown object moving across a textured, dynamic context and intercepted it with their finger after it had disappeared. Context motion significantly affected eye and hand movement latency and speed, but not interception accuracy; eye and hand position at interception were correlated on a trial-by-trial basis. Visual context effects may be short-lasting, affecting movement trajectories more than movement end points. Copyright © 2017 the American Physiological Society.

Effects of the Interception of Litterfall by the Understory on Carbon Cycling in Eucalyptus Plantations of South China

PubMed Central

Huang, Yuhui; Hui, Dafeng; Wen, Meili

2014-01-01

For the purposes of forest restoration, carbon (C) fixation, and economic improvement, eucalyptus (Eucalyptus urophylla) has been widely planted in South China. The understory of eucalyptus plantations is often occupied by a dense community of the fern Dicranopteris dichotoma, which intercepts tree canopy leaf litter before it reaches the ground. To understand the effects of this interception of litterfall on C cycling in eucalyptus plantations, we quantified the mass of intercepted litter and the influences of litterfall interception on litter decomposition and soil respiration. The total mass of E. urophylla litterfall collected on the understory was similar to that collected by the traditional litter trap method. All of the eucalyptus litterfall is intercepted by the D. dichotoma canopy. Of the litterfall that was intercepted by D. dichotoma, 20–40% and 60–80% was intercepted by the top (50–100 cm) and bottom (0–50 cm) of the understory canopy, respectively. Intercepted litterfall decomposed faster at the bottom of understory canopy (at the base of the plants) than at the top, and decomposition was slower on the soil surface in the absence of understory than on any location in the understory canopy. Soil respiration was highest when both the understory and litter were present and was lowest when both the understory and litter were absent. These results indicate that litterfall interception changed carbon flow between aboveground and belowground through litter decomposition and soil respiration, which changed carbon cycling in eucalyptus plantations. The effects of the understory on litter decomposition and soil respiration should be considered in ecosystem carbon models. PMID:24959853

Interception of spray drift by border structures. Part 1: wind tunnel experiments.

PubMed

De Schampheleire, M; Nuyttens, D; Dekeyser, D; Verboven, P; Cornelis, W; Gabriels, D; Spanoghe, P

2008-01-01

This research investigated the drift-intercepting potential of structures surrounding the field borders, like artificial screens and crops, which are not yet a part of the drift mitigation measures for field crop sprayers in Belgium. Drift-interception experiments were performed in the wind tunnel of the International Centre for Eremology (Ghent University, Belgium) with various interception structures: Artificial screens with heights of 0.5, 0.75 and 1 m and screen open areas of 16, 36 and 63%; a row of plastic Christmas trees with heights of 0.5 and 0.75 m; and a potato canopy. The interception structure was positioned at 1 m from the field border. From the results it was found that type of border structure has a pronounced effect on the drift interception, while the height of the border structure had no significant effect.

Cannabis use in children with individualized risk profiles: Predicting the effect of universal prevention intervention.

PubMed

Miovský, Michal; Vonkova, Hana; Čablová, Lenka; Gabrhelík, Roman

2015-11-01

To study the effect of a universal prevention intervention targeting cannabis use in individual children with different risk profiles. A school-based randomized controlled prevention trial was conducted over a period of 33 months (n=1874 sixth-graders, baseline mean age 11.82). We used a two-level random intercept logistic model for panel data to predict the probabilities of cannabis use for each child. Specifically, we used eight risk/protective factors to characterize each child and then predicted two probabilities of cannabis use for each child if the child had the intervention or not. Using the two probabilities, we calculated the absolute and relative effect of the intervention for each child. According to the two probabilities, we also divided the sample into a low-risk group (the quarter of the children with the lowest probabilities), a moderate-risk group, and a high-risk group (the quarter of the children with the highest probabilities) and showed the average effect of the intervention on these groups. The differences between the intervention group and the control group were statistically significant in each risk group. The average predicted probabilities of cannabis use for a child from the low-risk group were 4.3% if the child had the intervention and 6.53% if no intervention was provided. The corresponding probabilities for a child from the moderate-risk group were 10.91% and 15.34% and for a child from the high-risk group 25.51% and 32.61%. School grades, thoughts of hurting oneself, and breaking the rules were the three most important factors distinguishing high-risk and low-risk children. We predicted the effect of the intervention on individual children, characterized by their risk/protective factors. The predicted absolute effect and relative effect of any intervention for any selected risk/protective profile of a given child may be utilized in both prevention practice and research. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pollen concentrations and prevalence of asthma and allergic rhinitis in Italy: Evidence from the GEIRD study.

PubMed

Marchetti, Pierpaolo; Pesce, Giancarlo; Villani, Simona; Antonicelli, Leonardo; Ariano, Renato; Attena, Francesco; Bono, Roberto; Bellisario, Valeria; Fois, Alessandro; Gibelli, Nadia; Nicolis, Morena; Olivieri, Mario; Pirina, Pietro; Scopano, Eugenio; Siniscalco, Consolata; Verlato, Giuseppe; Marcon, Alessandro

2017-04-15

Pollen exposure has acute adverse effects on sensitized individuals. Information on the prevalence of respiratory diseases in areas with different pollen concentrations is scanty. We performed an ecologic analysis to assess whether the prevalence of allergic rhinitis and asthma in young adults varied across areas with different pollen concentrations in Italy. A questionnaire on respiratory diseases was delivered to random samples of 20-44year-old subjects from six centers in 2005-2010. Data on the daily air concentrations of 7 major allergologic pollens (Poaceae, Urticaceae, Oleaceae, Cupressaceae, Coryloideae, Betula and Ambrosia) were collected for 2007-2008. Center-specific pollen exposure indicators were calculated, including the average number of days per year with pollens above the low or high concentration thresholds defined by the Italian Association of Aerobiology. Associations between pollen exposure and disease prevalence, adjusted for potential confounders, were estimated using logistic regression models with center as a random-intercept. Overall, 8834 subjects (56.8%) filled in the questionnaire. Allergic rhinitis was significantly less frequent in the centers with longer periods with high concentrations of at least one (OR per 10days=0.989, 95%CI: 0.979-0.999) or at least two pollens (OR=0.974, 95%CI: 0.951-0.998); associations with the number of days with at least one (OR=0.988, 95%CI: 0.972-1.004) or at least two (OR=0.985, 95%CI: 0.970-1.001) pollens above the low thresholds were borderline significant. Asthma prevalence was not associated with pollen concentrations. Our study does not support that the prevalence of allergic rhinitis and asthma is greater in centers with higher pollen concentrations. It is not clear whether the observed ecologic associations hold at the individual level. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-Term Improvements in Knowledge and Psychosocial Factors of a Teen Pregnancy Prevention Intervention Implemented in Group Homes.

PubMed

Green, Jennifer; Oman, Roy F; Lu, Minggen; Clements-Nolle, Kristen D

2017-06-01

Youth in out-of-home care have higher rates of sexual risk behaviors and pregnancy than youth nationally. This study aimed to determine if Power Through Choices (PTC), a teen pregnancy prevention program developed for youth in out-of-home care, significantly improves knowledge and psychosocial outcomes regarding HIV and sexually transmitted infections (STIs), sexual activity and contraception methods, long term. A cluster randomized controlled trial was conducted with 1,036 ethnically diverse youths (aged 13-18 years) recruited from 44 residential group homes in three states. Intervention participants received the 10-session PTC intervention; control participants received usual care. Participants were administered self-report surveys at baseline, after intervention, 6 and 12 months after the intervention. Survey items assessed knowledge, attitudes, self-efficacy, and behavioral intentions regarding HIV and STIs, sexual activity and contraception methods. Random intercept logistic regression analyses were used to assess differences between the intervention and control groups. Compared with youth in the control group, youth in the PTC intervention demonstrated significant improvements in knowledge about anatomy and fertility (adjusted odds ratio [AOR] = 1.07, 95% confidence interval [CI] = 1.03-1.11), HIV and STIs (AOR = 1.03, 95% CI = 1.002-1.07), and methods of protection (AOR = 1.06, 95% CI = 1.03-1.09), as well as self-efficacy regarding self-efficacy to communicate with a partner (AOR = 1.14, 95% CI = 1.04-1.26), plan for protected sex and avoid unprotected sex (AOR = 1.16, 95% CI = 1.04-1.28), and where to get methods of birth control (AOR = 1.13, 95% CI = 1.01-1.26) 12 months after the intervention. Findings suggest that the PTC intervention can have positive long-term knowledge and psychosocial effects regarding contraception methods on youth in out-of-home care. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Prevalence of drug use during sex amongst MSM in Europe: Results from a multi-site bio-behavioural survey.

PubMed

Rosińska, Magdalena; Gios, Lorenzo; Nöstlinger, Christiana; Vanden Berghe, Wim; Marcus, Ulrich; Schink, Susanne; Sherriff, Nigel; Jones, Anna-Marie; Folch, Cinta; Dias, Sonia; Velicko, Inga; Mirandola, Massimo

2018-05-01

Substance use has been consistently reported to be more prevalent amongst Men who have Sex with Men (MSM) compared to the general population. Substance use, in particular polydrug use, has been found to be influenced by social and contextual factors and to increase the risk of unprotected intercourse among MSM. The objective of this analysis was to investigate the prevalence and predictors of drug use during a sexual encounter and to identify specific prevention needs. A multi-site bio-behavioural cross-sectional survey was implemented in 13 European cities, targeting MSM and using Time-Location Sampling and Respondent-Driven Sampling methods Multivariable multi-level logistic random-intercept model (random effect of study site) was estimated to identify factors associated with the use of alcohol, cannabis, party drugs, sexual performance enhancement drugs and chemsex drugs. Overall, 1261 (30.0%) participants reported drug use, and 436 of 3706 (11.8%) reported the use of two or more drugs during their last sexual encounter. By drug class, 966 (23.0%) reported using sexual performance enhancement drugs, 353 (8.4%) - party drugs, and 142 (3.4%) the use of chemsex drugs. Respondents who reported drug use were more frequently diagnosed with HIV (10.5% vs. 3.9%) before and with other STIs during the 12 months prior to the study (16.7% vs. 9.2%). The use of all the analysed substances was significantly associated with sexual encounter with more than one partner. Substance and polydrug use during sexual encounters occurred amongst sampled MSM across Europe although varying greatly between study sites. Different local social norms within MSM communities may be important contextual drivers of drug use, highlighting the need for innovative and multi-faceted prevention measures to reduce HIV/STI risk in the context of drug use. Copyright © 2018 Elsevier B.V. All rights reserved.

EZSCAN for undiagnosed type 2 diabetes mellitus: A systematic review and meta-analysis.

PubMed

Bernabe-Ortiz, Antonio; Ruiz-Alejos, Andrea; Miranda, J Jaime; Mathur, Rohini; Perel, Pablo; Smeeth, Liam

2017-01-01

The EZSCAN is a non-invasive device that, by evaluating sweat gland function, may detect subjects with type 2 diabetes mellitus (T2DM). The aim of the study was to conduct a systematic review and meta-analysis including studies assessing the performance of the EZSCAN for detecting cases of undiagnosed T2DM. We searched for observational studies including diagnostic accuracy and performance results assessing EZSCAN for detecting cases of undiagnosed T2DM. OVID (Medline, Embase, Global Health), CINAHL and SCOPUS databases, plus secondary resources, were searched until March 29, 2017. The following keywords were utilized for the systematic searching: type 2 diabetes mellitus, hyperglycemia, EZSCAN, SUDOSCAN, and sudomotor function. Two investigators extracted the information for meta-analysis and assessed the quality of the data using the Revised Version of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) checklist. Pooled estimates were obtained by fitting the logistic-normal random-effects model without covariates but random intercepts and using the Freeman-Tukey Arcsine Transformation to stabilize variances. Heterogeneity was also assessed using the I2 measure. Four studies (n = 7,720) were included, three of them used oral glucose tolerance test as the gold standard. Using Hierarchical Summary Receiver Operating Characteristic model, summary sensitivity was 72.0% (95%CI: 60.0%- 83.0%), whereas specificity was 56.0% (95%CI: 38.0%- 74.0%). Studies were very heterogeneous (I2 for sensitivity: 79.2% and for specificity: 99.1%) regarding the inclusion criteria and bias was present mainly due to participants selection. The sensitivity of EZSCAN for detecting cases of undiagnosed T2DM seems to be acceptable, but evidence of high heterogeneity and participant selection bias was detected in most of the studies included. More studies are needed to evaluate the performance of the EZSCAN for undiagnosed T2DM screening, especially at the population level.

Gross rainfall amount and maximum rainfall intensity in 60-minute influence on interception loss of shrubs: a 10-year observation in the Tengger Desert.

PubMed

Zhang, Zhi-Shan; Zhao, Yang; Li, Xin-Rong; Huang, Lei; Tan, Hui-Juan

2016-05-17

In water-limited regions, rainfall interception is influenced by rainfall properties and crown characteristics. Rainfall properties, aside from gross rainfall amount and duration (GR and RD), maximum rainfall intensity and rainless gap (RG), within rain events may heavily affect throughfall and interception by plants. From 2004 to 2014 (except for 2007), individual shrubs of Caragana korshinskii and Artemisia ordosica were selected to measure throughfall during 210 rain events. Various rainfall properties were auto-measured and crown characteristics, i.e., height, branch and leaf area index, crown area and volume of two shrubs were also measured. The relative interceptions of C. korshinskii and A. ordosica were 29.1% and 17.1%, respectively. Rainfall properties have more contributions than crown characteristics to throughfall and interception of shrubs. Throughfall and interception of shrubs can be explained by GR, RI60 (maximum rainfall intensities during 60 min), RD and RG in deceasing importance. However, relative throughfall and interception of two shrubs have different responses to rainfall properties and crown characteristics, those of C. korshinskii were closely related to rainfall properties, while those of A. ordosica were more dependent on crown characteristics. We highlight long-term monitoring is very necessary to determine the relationships between throughfall and interception with crown characteristics.

On interception modelling of a lowland coastal rainforest in northern Queensland, Australia

NASA Astrophysics Data System (ADS)

Wallace, Jim; McJannet, Dave

2006-10-01

SummaryRecent studies of the water balance of tropical rainforests in northern Queensland have revealed that large fractions of rainfall, up to 30%, are intercepted by the canopy and lost as evaporation. These loss rates are much higher than those reported for continental rainforests, for example, in the Amazon basin, where interception is around 9% of rainfall. Higher interception losses have been found in coastal and mountain rainforests and substantial advection of energy during rainfall is proposed to account for these results. This paper uses a process based model of interception to analyse the interception losses at Oliver Creek, a lowland coastal rainforest site in northern Queensland with a mean annual rainfall of 3952 mm. The observed interception loss of 25% of rainfall for the period August 2001 to January 2004 can be reproduced by the model with a suitable choice of the three key controlling variables, the canopy storage capacity, mean rainfall rate and mean wet canopy evaporation rate. Our analyses suggest that the canopy storage capacity of the Oliver Creek rainforest is between 3.0 and 3.5 mm, higher than reported for most other rainforests. Despite the high canopy capacity at our site, the interception losses can only be accounted for with energy advection during rainfall in the range 40-70% of the incident energy.

Estimation of Stormwater Interception Rate for various LID Facilities

NASA Astrophysics Data System (ADS)

Kim, S.; Lee, O.; Choi, J.

2017-12-01

In this study, the stormwater interception rate is proposed to apply in the design of LID facilities. For this purpose, EPA-SWMM is built with some areas of Noksan National Industrial Complex where long-term observed stormwater data were monitored and stormwater interception rates for various design capacities of various LID facilities are estimated. While the sensitivity of stormwater interception rate according to design specifications of bio-retention and infiltration trench facilities is not large, the sensitivity of stormwater interception rate according to local rainfall characteristics is relatively big. As a result of comparing the present rainfall interception rate estimation method which is officially operated in Korea with the one proposed in this study, it will be presented that the present method is highly likely to overestimate the performance of the bio-retention and infiltration trench facilities. Finally, a new stormwater interception rate formulas for the bio-retention and infiltration trench LID facilities will be proposed. Acknowledgement This research was supported by a grant (2016000200002) from Public Welfare Technology Development Program funded by Ministry of Environment of Korean government.

Physiological and Technical Demands of No Dribble Game Drill in Young Basketball Players.

PubMed

Conte, Daniele; Favero, Terence G; Niederhausen, Meike; Capranica, Laura; Tessitore, Antonio

2015-12-01

This study assessed the physiological and technical demands of no dribble game drill (NDGD) in comparison with a regular drill (RD). Twenty-three young basketball players performed RDs and NDGDs in a random order. All basketball rules were followed for RDs, whereas dribbling was not permitted for NDGDs. The independent variable was the drill condition, and the dependent variables were percentage of maximal heart rate (%HRmax), rate of perceived exertion (RPE), Edwards training load (TL), and the following technical actions (TAs): pass (total, correct, wrong, and percent of correct passes), shot (total, scored, missed, and percent of made shots), interception, steal, turnover, and rebound. Wilcoxon signed-rank tests were applied to assess differences between NDGD and RD conditions for each dependent variable, and the level of statistical significance was set at p ≤ 0.05. Results showed higher values for %HRmax (p = 0.007), Edwards TL (p = 0.006), and RPE (p = 0.027) in NDGD compared with RD condition. Technical action analysis revealed higher values in NDGD than RD for total (p = 0.000), correct (p = 0.000), and wrong pass (p = 0.005), and interception (p = 0.001), whereas no significant differences were found for the other TAs. The main finding of this study was that NDGD condition elicited a greater physiological demand and a higher number of passes and interceptions than the RD one. Basketball coaches should consider the NDGD as a viable method to increase the physiological load of their training sessions and to teach passing skills in a game-based situation.

Process-based rainfall interception by small trees in Northern China: The effect of rainfall traits and crown structure characteristics

Treesearch

Xiang Li; Qingfu Xiao; Jianzhi Niu; Salli Dymond; Natalie S. van Doorn; Xinxiao Yu; Baoyuan Xie; Xizhi Lv; Kebin Zhang; Jiao Li

2016-01-01

Rainfall interception by a tree's crown is one of the most important hydrological processes in an ecosystem, yet the mechanisms of interception are not well understood. A process-based experiment was conducted under five simulated rainfall intensities (from 10 to 150 mm h−1) to directly quantify tree crown interception and examine the effect...

Intercepted photosynthetically active radiation in wheat canopies estimated by spectral reflectance. [Phoenix, Arizona

NASA Technical Reports Server (NTRS)

Hatfield, J. L.; Asrar, G.; Kanemasu, E. T.

1982-01-01

The interception of photosynthetically active radiation (PAR) was evaluated relative to greenness and normalized difference (MSS 7-5/7+5) for five planting dates of wheat for 1978-79 and 1979-80 in Phoenix. Intercepted PAR was calculated from a model driven by leaf area index and stage of growth. Linear relationships were found between greenness and normalized difference with a separate model representing growth and senescence of the crop. Normalized difference was a significantly better model and would be easier to apply than the empirically derived greenness parameter. For the leaf area growth portion of the season the model between PAR interception and normalized difference was the same over years, however, for the leaf senescence the models showed more variability due to the lack of data on measured interception in sparse canopies. Normalized difference could be used to estimate PAR interception directly for crop growth models.

Basic Diagnosis and Prediction of Persistent Contrail Occurrence using High-resolution Numerical Weather Analyses/Forecasts and Logistic Regression. Part I: Effects of Random Error

NASA Technical Reports Server (NTRS)

Duda, David P.; Minnis, Patrick

2009-01-01

Straightforward application of the Schmidt-Appleman contrail formation criteria to diagnose persistent contrail occurrence from numerical weather prediction data is hindered by significant bias errors in the upper tropospheric humidity. Logistic models of contrail occurrence have been proposed to overcome this problem, but basic questions remain about how random measurement error may affect their accuracy. A set of 5000 synthetic contrail observations is created to study the effects of random error in these probabilistic models. The simulated observations are based on distributions of temperature, humidity, and vertical velocity derived from Advanced Regional Prediction System (ARPS) weather analyses. The logistic models created from the simulated observations were evaluated using two common statistical measures of model accuracy, the percent correct (PC) and the Hanssen-Kuipers discriminant (HKD). To convert the probabilistic results of the logistic models into a dichotomous yes/no choice suitable for the statistical measures, two critical probability thresholds are considered. The HKD scores are higher when the climatological frequency of contrail occurrence is used as the critical threshold, while the PC scores are higher when the critical probability threshold is 0.5. For both thresholds, typical random errors in temperature, relative humidity, and vertical velocity are found to be small enough to allow for accurate logistic models of contrail occurrence. The accuracy of the models developed from synthetic data is over 85 percent for both the prediction of contrail occurrence and non-occurrence, although in practice, larger errors would be anticipated.

Gross rainfall amount and maximum rainfall intensity in 60-minute influence on interception loss of shrubs: a 10-year observation in the Tengger Desert

PubMed Central

Zhang, Zhi-Shan; Zhao, Yang; Li, Xin-Rong; Huang, Lei; Tan, Hui-Juan

2016-01-01

In water-limited regions, rainfall interception is influenced by rainfall properties and crown characteristics. Rainfall properties, aside from gross rainfall amount and duration (GR and RD), maximum rainfall intensity and rainless gap (RG), within rain events may heavily affect throughfall and interception by plants. From 2004 to 2014 (except for 2007), individual shrubs of Caragana korshinskii and Artemisia ordosica were selected to measure throughfall during 210 rain events. Various rainfall properties were auto-measured and crown characteristics, i.e., height, branch and leaf area index, crown area and volume of two shrubs were also measured. The relative interceptions of C. korshinskii and A. ordosica were 29.1% and 17.1%, respectively. Rainfall properties have more contributions than crown characteristics to throughfall and interception of shrubs. Throughfall and interception of shrubs can be explained by GR, RI60 (maximum rainfall intensities during 60 min), RD and RG in deceasing importance. However, relative throughfall and interception of two shrubs have different responses to rainfall properties and crown characteristics, those of C. korshinskii were closely related to rainfall properties, while those of A. ordosica were more dependent on crown characteristics. We highlight long-term monitoring is very necessary to determine the relationships between throughfall and interception with crown characteristics. PMID:27184918

Fog interception by Ball moss (Tillandsia recurvata)

NASA Astrophysics Data System (ADS)

Guevara-Escobar, A.; Cervantes-Jiménez, M.; Suzán-Azpiri, H.; González-Sosa, E.; Hernández-Sandoval, L.; Malda-Barrera, G.; Martínez-Díaz, M.

2011-08-01

Interception losses are a major influence in the water yield of vegetated areas. For most storms, rain interception results in less water reaching the ground. However, fog interception can increase the overall water storage capacity of the vegetation and once the storage is exceeded, fog drip is a common hydrological input. Fog interception is disregarded in water budgets of semiarid regions, but for some plant communities, it could be a mechanism offsetting evaporation losses. Tillandsia recurvata is a cosmopolitan epiphyte adapted to arid habitats where fog may be an important water source. Therefore, the interception storage capacity by T. recurvata was measured in controlled conditions and applying simulated rain or fog. Juvenile, vegetative specimens were used to determine the potential upperbound storage capacities. The storage capacity was proportional to dry weight mass. Interception storage capacity (Cmin) was 0.19 and 0.56 mm for rainfall and fog respectively. The coefficients obtained in the laboratory were used together with biomass measurements for T. recurvata in a xeric scrub to calculate the depth of water intercepted by rain. T. recurvata contributed 20 % to the rain interception capacity of their shrub hosts: Acacia farnesiana and Prosopis laevigata and; also potentially intercepted 4.8 % of the annual rainfall. Nocturnal stomatic opening in T. recurvata is not only relevant for CO2 but for water vapor, as suggested by the higher weight change of specimens wetted with fog for 1 h at dark in comparison to those wetted during daylight (543 ± 77 vs. 325 ± 56 mg, p = 0.048). The storage capacity of T. recurvata leaf surfaces could increase the amount of water available for evaporation, but as this species colonise montane forests, the effect could be negative on water recharge, because potential storage capacity is very high, in the laboratory experiments it took up to 12 h at a rate of 0.26 l h-1 to reach saturation conditions when fog was applied.

Fitting rainfall interception models to forest ecosystems of Mexico

NASA Astrophysics Data System (ADS)

Návar, José

2017-05-01

Models that accurately predict forest interception are essential both for water balance studies and for assessing watershed responses to changes in land use and the long-term climate variability. This paper compares the performance of four rainfall interception models-the sparse Gash (1995), Rutter et al. (1975), Liu (1997) and two new models (NvMxa and NvMxb)-using data from four spatially extensive, structurally diverse forest ecosystems in Mexico. Ninety-eight case studies measuring interception in tropical dry (25), arid/semi-arid (29), temperate (26), and tropical montane cloud forests (18) were compiled and analyzed. Coefficients derived from raw data or published statistical relationships were used as model input to evaluate multi-storm forest interception at the case study scale. On average empirical data showed that, tropical montane cloud, temperate, arid/semi-arid and tropical dry forests intercepted 14%, 18%, 22% and 26% of total precipitation, respectively. The models performed well in predicting interception, with mean deviations between measured and modeled interception as a function of total precipitation (ME) generally <5.8% and Nash-Sutcliffe efficiency E estimators >0.66. Model fitting precision was dependent on the forest ecosystem. Arid/semi-arid forests exhibited the smallest, while tropical montane cloud forest displayed the largest ME deviations. Improved agreement between measured and modeled data requires modification of in-storm evaporation rate in the Liu; the canopy storage in the sparse Gash model; and the throughfall coefficient in the Rutter and the NvMx models. This research concludes on recommending the wide application of rainfall interception models with some caution as they provide mixed results. The extensive forest interception data source, the fitting and testing of four models, the introduction of a new model, and the availability of coefficient values for all four forest ecosystems are an important source of information and a benchmark for future investigations in this area of hydrology.

Sex drugs, peer connections, and HIV: Use and risk among African American, Latino, and Multiracial young men who have sex with men (YMSM) in Los Angeles and New York

PubMed Central

Mutchler, Matt G.; McKay, Tara; Candelario, Norman; Liu, Honghu; Stackhouse, Bill; Bingham, Trista; Ayala, George

2011-01-01

African American and Latino young men who have sex with men are at high risk for HIV infection. We administered brief intercept surveys (N=416) at 18 Black and Latino gay pride events in Los Angeles and New York in 2006 and 2007. Ordinal logistic regressions were used to model the effects of substance use during sex, peer connectedness, relationship status, and homelessness on condom use. Alcohol use, crystal use, homelessness, and having a primary relationship partner were negatively associated with condom use, while peer connectedness and marijuana use during sex were positively associated with condom use. Implications for service providers and future research are discussed. PMID:21731406

Global canopy interception from satellite observations

USDA-ARS?s Scientific Manuscript database

A new methodology for retrieving rainfall interception rates from multi satellite observations is presented. The approach makes use of the daily productof the Global Precipitation Climatology Project (GPCP) as driving data and applies Gash’s analytical model to derive interception rates at global sc...

The narrow-leaf syndrome: a functional and evolutionary approach to the form of fog-harvesting rosette plants.

PubMed

Martorell, Carlos; Ezcurra, Exequiel

2007-04-01

Plants that use fog as an important water-source frequently have a rosette growth habit. The performance of this morphology in relation to fog interception has not been studied. Some first-principles from physics predict that narrow leaves, together with other ancillary traits (large number and high flexibility of leaves, caudices, and/or epiphytism) which constitute the "narrow-leaf syndrome" should increase fog-interception efficiency. This was tested using aluminum models of rosettes that differed in leaf length, width and number and were exposed to artificial fog. The results were validated using seven species of Tillandsia and four species of xerophytic rosettes. The total amount of fog intercepted in rosette plants increased with total leaf area, while narrow leaves maximized interception efficiency (measured as interception per unit area). The number of leaves in the rosettes is physically constrained because wide-leafed plants can only have a few blades. At the limits of this constraint, net fog interception was independent of leaf form, but interception efficiency was maximized by large numbers of narrow leaves. Atmospheric Tillandsia species show the narrow-leaf syndrome. Their fog interception efficiencies were correlated to the ones predicted from aluminum-model data. In the larger xerophytic rosette species, the interception efficiency was greatest in plants showing the narrow-leaf syndrome. The adaptation to fog-harvesting in several narrow-leaved rosettes was tested for evolutionary convergence in 30 xerophytic rosette species using a comparative method. There was a significant evolutionary tendency towards the development of the narrow-leaf syndrome the closer the species grew to areas where fog is frequently available. This study establishes convergence in a very wide group of plants encompassing genera as contrasting as Tillandsia and Agave as a result of their dependence on fog.

Estimating Vegetation Rainfall Interception Using Remote Sensing Observations at Very High Resolution

NASA Astrophysics Data System (ADS)

Cui, Y.; Zhao, P.; Hong, Y.; Fan, W.; Yan, B.; Xie, H.

2017-12-01

Abstract: As an important compont of evapotranspiration, vegetation rainfall interception is the proportion of gross rainfall that is intercepted, stored and subsequently evaporated from all parts of vegetation during or following rainfall. Accurately quantifying the vegetation rainfall interception at a high resolution is critical for rainfall-runoff modeling and flood forecasting, and is also essential for understanding its further impact on local, regional, and even global water cycle dynamics. In this study, the Remote Sensing-based Gash model (RS-Gash model) is developed based on a modified Gash model for interception loss estimation using remote sensing observations at the regional scale, and has been applied and validated in the upper reach of the Heihe River Basin of China for different types of vegetation. To eliminate the scale error and the effect of mixed pixels, the RS-Gash model is applied at a fine scale of 30 m with the high resolution vegetation area index retrieved by using the unified model of bidirectional reflectance distribution function (BRDF-U) for the vegetation canopy. Field validation shows that the RMSE and R2 of the interception ratio are 3.7% and 0.9, respectively, indicating the model's strong stability and reliability at fine scale. The temporal variation of vegetation rainfall interception loss and its relationship with precipitation are further investigated. In summary, the RS-Gash model has demonstrated its effectiveness and reliability in estimating vegetation rainfall interception. When compared to the coarse resolution results, the application of this model at 30-m fine resolution is necessary to resolve the scaling issues as shown in this study. Keywords: rainfall interception; remote sensing; RS-Gash analytical model; high resolution

Evaporation of impact water droplets in interception processes: Historical precedence of the hypothesis and a brief literature overview

NASA Astrophysics Data System (ADS)

Dunkerley, David L.

2009-10-01

SummaryIntra-storm evaporation depths exceed post-storm evaporation depths in the interception of rainfall on plant canopies. An important fraction of the intra-storm evaporation may involve the small impact (or splash) droplets produced when raindrops, and perhaps gravity drops (drips released from plant parts), collide with wet plant surfaces. This idea has been presented as a new conception by Murakami [Murakami, S., 2006. A proposal for a new forest canopy interception mechanism: splash droplet evaporation. Journal of Hydrology 319, 72-82; Murakami, S., 2007a. Application of three canopy interception models to a young stand of Japanese cypress and interpretation in terms of interception mechanism. Journal of Hydrology 342, 305-319; Murakami, S., 2007b. A follow-up for the splash droplet evaporation hypothesis of canopy interception and remaining problems: why is humidity unsaturated during rainfall? In: Proceedings of the 20th Annual Conference. Japan Society of Hydrology and Water Resources (in Japanese). < http://www.jstage.jst.go.jp/article/jshwr/20/0/20_62/_article>] but was in fact advanced by Dunin [Dunin, F.X., O'Loughlin, E.M., Reyenga, W., 1988. Interception loss from eucalypt forest: lysimeter determination of hourly rates for long term evaluation. Hydrological Processes 2, 315-329] more than 20 years ago. In addition, Dunin et al. considered that canopy ventilation might be enhanced in intense rain. This note draws attention to the historical precedence of the work of Dunin et al. and also presents a short review of literature on impact droplet production, highlighting areas where data are still required for the full exploration of the role of droplet evaporation in canopy interception. Droplet production needs to be properly parameterised and included in models of interception processes and landsurface-atmosphere interactions.

Beyond discrimination: A comparison of calibration methods and clinical usefulness of predictive models of readmission risk.

PubMed

Walsh, Colin G; Sharman, Kavya; Hripcsak, George

2017-12-01

Prior to implementing predictive models in novel settings, analyses of calibration and clinical usefulness remain as important as discrimination, but they are not frequently discussed. Calibration is a model's reflection of actual outcome prevalence in its predictions. Clinical usefulness refers to the utilities, costs, and harms of using a predictive model in practice. A decision analytic approach to calibrating and selecting an optimal intervention threshold may help maximize the impact of readmission risk and other preventive interventions. To select a pragmatic means of calibrating predictive models that requires a minimum amount of validation data and that performs well in practice. To evaluate the impact of miscalibration on utility and cost via clinical usefulness analyses. Observational, retrospective cohort study with electronic health record data from 120,000 inpatient admissions at an urban, academic center in Manhattan. The primary outcome was thirty-day readmission for three causes: all-cause, congestive heart failure, and chronic coronary atherosclerotic disease. Predictive modeling was performed via L1-regularized logistic regression. Calibration methods were compared including Platt Scaling, Logistic Calibration, and Prevalence Adjustment. Performance of predictive modeling and calibration was assessed via discrimination (c-statistic), calibration (Spiegelhalter Z-statistic, Root Mean Square Error [RMSE] of binned predictions, Sanders and Murphy Resolutions of the Brier Score, Calibration Slope and Intercept), and clinical usefulness (utility terms represented as costs). The amount of validation data necessary to apply each calibration algorithm was also assessed. C-statistics by diagnosis ranged from 0.7 for all-cause readmission to 0.86 (0.78-0.93) for congestive heart failure. Logistic Calibration and Platt Scaling performed best and this difference required analyzing multiple metrics of calibration simultaneously, in particular Calibration Slopes and Intercepts. Clinical usefulness analyses provided optimal risk thresholds, which varied by reason for readmission, outcome prevalence, and calibration algorithm. Utility analyses also suggested maximum tolerable intervention costs, e.g., $1720 for all-cause readmissions based on a published cost of readmission of $11,862. Choice of calibration method depends on availability of validation data and on performance. Improperly calibrated models may contribute to higher costs of intervention as measured via clinical usefulness. Decision-makers must understand underlying utilities or costs inherent in the use-case at hand to assess usefulness and will obtain the optimal risk threshold to trigger intervention with intervention cost limits as a result. Copyright © 2017 Elsevier Inc. All rights reserved.

Logistic random effects regression models: a comparison of statistical packages for binary and ordinal outcomes.

PubMed

Li, Baoyue; Lingsma, Hester F; Steyerberg, Ewout W; Lesaffre, Emmanuel

2011-05-23

Logistic random effects models are a popular tool to analyze multilevel also called hierarchical data with a binary or ordinal outcome. Here, we aim to compare different statistical software implementations of these models. We used individual patient data from 8509 patients in 231 centers with moderate and severe Traumatic Brain Injury (TBI) enrolled in eight Randomized Controlled Trials (RCTs) and three observational studies. We fitted logistic random effects regression models with the 5-point Glasgow Outcome Scale (GOS) as outcome, both dichotomized as well as ordinal, with center and/or trial as random effects, and as covariates age, motor score, pupil reactivity or trial. We then compared the implementations of frequentist and Bayesian methods to estimate the fixed and random effects. Frequentist approaches included R (lme4), Stata (GLLAMM), SAS (GLIMMIX and NLMIXED), MLwiN ([R]IGLS) and MIXOR, Bayesian approaches included WinBUGS, MLwiN (MCMC), R package MCMCglmm and SAS experimental procedure MCMC.Three data sets (the full data set and two sub-datasets) were analysed using basically two logistic random effects models with either one random effect for the center or two random effects for center and trial. For the ordinal outcome in the full data set also a proportional odds model with a random center effect was fitted. The packages gave similar parameter estimates for both the fixed and random effects and for the binary (and ordinal) models for the main study and when based on a relatively large number of level-1 (patient level) data compared to the number of level-2 (hospital level) data. However, when based on relatively sparse data set, i.e. when the numbers of level-1 and level-2 data units were about the same, the frequentist and Bayesian approaches showed somewhat different results. The software implementations differ considerably in flexibility, computation time, and usability. There are also differences in the availability of additional tools for model evaluation, such as diagnostic plots. The experimental SAS (version 9.2) procedure MCMC appeared to be inefficient. On relatively large data sets, the different software implementations of logistic random effects regression models produced similar results. Thus, for a large data set there seems to be no explicit preference (of course if there is no preference from a philosophical point of view) for either a frequentist or Bayesian approach (if based on vague priors). The choice for a particular implementation may largely depend on the desired flexibility, and the usability of the package. For small data sets the random effects variances are difficult to estimate. In the frequentist approaches the MLE of this variance was often estimated zero with a standard error that is either zero or could not be determined, while for Bayesian methods the estimates could depend on the chosen "non-informative" prior of the variance parameter. The starting value for the variance parameter may be also critical for the convergence of the Markov chain.

Rainfall interception of three trees in Oakland, California

Treesearch

Qingfu Xiao; E. Gregory McPherson

2011-01-01

A rainfall interception study was conducted in Oakland, California to determine the partitioning of rainfall and the chemical composition of precipitation, throughfall, and stemflow. Rainfall interception measurements were conducted on a gingko (Ginkgo biloba) (13.5 m tall deciduous tree), sweet gum (Liquidambar styraciflua) (8...

A Three-dimensional Statistical Reconstruction Model of Grapevine (Vitis vinifera) Simulating Canopy Structure Variability within and between Cultivar/Training System Pairs

PubMed Central

Louarn, Gaëtan; Lecoeur, Jérémie; Lebon, Eric

2008-01-01

Background and Aims In grapevine, canopy-structure-related variations in light interception and distribution affect productivity, yield and the quality of the harvested product. A simple statistical model for reconstructing three-dimensional (3D) canopy structures for various cultivar–training system (C × T) pairs has been implemented with special attention paid to balance the time required for model parameterization and accuracy of the representations from organ to stand scales. Such an approach particularly aims at overcoming the weak integration of interplant variability using the usual direct 3D measurement methods. Model This model is original in combining a turbid-medium-like envelope enclosing the volume occupied by vine shoots with the use of discrete geometric polygons representing leaves randomly located within this volume to represent plant structure. Reconstruction rules were adapted to capture the main determinants of grapevine shoot architecture and their variability. Using a simplified set of parameters, it was possible to describe (1) the 3D path of the main shoot, (2) the volume occupied by the foliage around this path and (3) the orientation of individual leaf surfaces. Model parameterization (estimation of the probability distribution for each parameter) was carried out for eight contrasting C × T pairs. Key Results and Conclusions The parameter values obtained in each situation were consistent with our knowledge of grapevine architecture. Quantitative assessments for the generated virtual scenes were carried out at the canopy and plant scales. Light interception efficiency and local variations of light transmittance within and between experimental plots were correctly simulated for all canopies studied. The approach predicted these key ecophysiological variables significantly more accurately than the classical complete digitization method with a limited number of plants. In addition, this model accurately reproduced the characteristics of a wide range of individual digitized plants. Simulated leaf area density and the distribution of light interception among leaves were consistent with measurements. However, at the level of individual organs, the model tended to underestimate light interception. PMID:18202006

Stable estimate of primary OC/EC ratios in the EC tracer method

NASA Astrophysics Data System (ADS)

Chu, Shao-Hang

In fine particulate matter studies, the primary OC/EC ratio plays an important role in estimating the secondary organic aerosol contribution to PM2.5 concentrations using the EC tracer method. In this study, numerical experiments are carried out to test and compare various statistical techniques in the estimation of primary OC/EC ratios. The influence of random measurement errors in both primary OC and EC measurements on the estimation of the expected primary OC/EC ratios is examined. It is found that random measurement errors in EC generally create an underestimation of the slope and an overestimation of the intercept of the ordinary least-squares regression line. The Deming regression analysis performs much better than the ordinary regression, but it tends to overcorrect the problem by slightly overestimating the slope and underestimating the intercept. Averaging the ratios directly is usually undesirable because the average is strongly influenced by unrealistically high values of OC/EC ratios resulting from random measurement errors at low EC concentrations. The errors generally result in a skewed distribution of the OC/EC ratios even if the parent distributions of OC and EC are close to normal. When measured OC contains a significant amount of non-combustion OC Deming regression is a much better tool and should be used to estimate both the primary OC/EC ratio and the non-combustion OC. However, if the non-combustion OC is negligibly small the best and most robust estimator of the OC/EC ratio turns out to be the simple ratio of the OC and EC averages. It not only reduces random errors by averaging individual variables separately but also acts as a weighted average of ratios to minimize the influence of unrealistically high OC/EC ratios created by measurement errors at low EC concentrations. The median of OC/EC ratios ranks a close second, and the geometric mean of ratios ranks third. This is because their estimations are insensitive to questionable extreme values. A real world example is given using the ambient data collected from an Atlanta STN site during the winter of 2001-2002.

Novel solutions for an old disease: diagnosis of acute appendicitis with random forest, support vector machines, and artificial neural networks.

PubMed

Hsieh, Chung-Ho; Lu, Ruey-Hwa; Lee, Nai-Hsin; Chiu, Wen-Ta; Hsu, Min-Huei; Li, Yu-Chuan Jack

2011-01-01

Diagnosing acute appendicitis clinically is still difficult. We developed random forests, support vector machines, and artificial neural network models to diagnose acute appendicitis. Between January 2006 and December 2008, patients who had a consultation session with surgeons for suspected acute appendicitis were enrolled. Seventy-five percent of the data set was used to construct models including random forest, support vector machines, artificial neural networks, and logistic regression. Twenty-five percent of the data set was withheld to evaluate model performance. The area under the receiver operating characteristic curve (AUC) was used to evaluate performance, which was compared with that of the Alvarado score. Data from a total of 180 patients were collected, 135 used for training and 45 for testing. The mean age of patients was 39.4 years (range, 16-85). Final diagnosis revealed 115 patients with and 65 without appendicitis. The AUC of random forest, support vector machines, artificial neural networks, logistic regression, and Alvarado was 0.98, 0.96, 0.91, 0.87, and 0.77, respectively. The sensitivity, specificity, positive, and negative predictive values of random forest were 94%, 100%, 100%, and 87%, respectively. Random forest performed better than artificial neural networks, logistic regression, and Alvarado. We demonstrated that random forest can predict acute appendicitis with good accuracy and, deployed appropriately, can be an effective tool in clinical decision making. Copyright © 2011 Mosby, Inc. All rights reserved.

Effects of barbell deadlift training on submaximal motor unit firing rates for the vastus lateralis and rectus femoris.

PubMed

Stock, Matt S; Thompson, Brennan J

2014-01-01

Previous investigations that have studied motor unit firing rates following strength training have been limited to small muscles, isometric training, or interventions involving exercise machines. We examined the effects of ten weeks of supervised barbell deadlift training on motor unit firing rates for the vastus lateralis and rectus femoris during a 50% maximum voluntary contraction (MVC) assessment. Twenty-four previously untrained men (mean age  = 24 years) were randomly assigned to training (n = 15) or control (n = 9) groups. Before and following the intervention, the subjects performed isometric testing of the right knee extensors while bipolar surface electromyographic signals were detected from the two muscles. The signals were decomposed into their constituent motor unit action potential trains, and motor units that demonstrated accuracy levels less than 92.0% were not considered for analysis. One thousand eight hundred ninety-two and 2,013 motor units were examined for the vastus lateralis and rectus femoris, respectively. Regression analyses were used to determine the linear slope coefficients (pulses per second [pps]/% MVC) and y-intercepts (pps) of the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. Deadlift training significantly improved knee extensor MVC force (Cohen's d = .70), but did not influence force steadiness. Training had no influence on the slopes and y-intercepts for the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. In agreement with previous cross-sectional comparisons and randomized control trials, our findings do not support the notion that strength training affects the submaximal control of motor units.

The relationship between energy expenditure and speed during pedestrian locomotion in birds: a morphological basis for the elevated y-intercept?

PubMed

Halsey, Lewis G

2013-06-01

The slope of the typically linear relationship between metabolic rate and walking speed represents the net cost of transport (NCOT). The extrapolated y-intercept is often greater than resting metabolic rate, thus representing a fixed cost associated with pedestrian transport including body maintenance costs. The full cause of the elevated y-intercept remains elusive and it could simply represent experimental stresses. The present literature-based study compares the mass-independent energetic cost of pedestrian locomotion in birds (excluding those with an upright posture, i.e. penguins), represented by the y-intercept, to a known predictor of cost of transport, hip height. Both phylogenetically informed and non-phylogenetically informed analyses were undertaken to determine if patterns of association between hip height, body mass, and the y-intercept are robust with respect to the method of analysis. Body mass and hip height were significant predictors of the y-intercept in the best phylogenetically-informed and non-phylogenetically informed models. Thus there is evidence that, in birds at least, the elevated y-intercept is a legitimate component of locomotion energy expenditure. Hip height is probably a good proxy of effective limb length and thus perhaps birds with greater hip heights have lower y-intercepts because their longer legs more efficiently accommodate body motion and/or because their limbs are more aligned with the ground reaction forces. Copyright © 2013 Elsevier Inc. All rights reserved.

Mortality risk prediction in burn injury: Comparison of logistic regression with machine learning approaches.

PubMed

Stylianou, Neophytos; Akbarov, Artur; Kontopantelis, Evangelos; Buchan, Iain; Dunn, Ken W

2015-08-01

Predicting mortality from burn injury has traditionally employed logistic regression models. Alternative machine learning methods have been introduced in some areas of clinical prediction as the necessary software and computational facilities have become accessible. Here we compare logistic regression and machine learning predictions of mortality from burn. An established logistic mortality model was compared to machine learning methods (artificial neural network, support vector machine, random forests and naïve Bayes) using a population-based (England & Wales) case-cohort registry. Predictive evaluation used: area under the receiver operating characteristic curve; sensitivity; specificity; positive predictive value and Youden's index. All methods had comparable discriminatory abilities, similar sensitivities, specificities and positive predictive values. Although some machine learning methods performed marginally better than logistic regression the differences were seldom statistically significant and clinically insubstantial. Random forests were marginally better for high positive predictive value and reasonable sensitivity. Neural networks yielded slightly better prediction overall. Logistic regression gives an optimal mix of performance and interpretability. The established logistic regression model of burn mortality performs well against more complex alternatives. Clinical prediction with a small set of strong, stable, independent predictors is unlikely to gain much from machine learning outside specialist research contexts. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Information content versus word length in random typing

NASA Astrophysics Data System (ADS)

Ferrer-i-Cancho, Ramon; Moscoso del Prado Martín, Fermín

2011-12-01

Recently, it has been claimed that a linear relationship between a measure of information content and word length is expected from word length optimization and it has been shown that this linearity is supported by a strong correlation between information content and word length in many languages (Piantadosi et al 2011 Proc. Nat. Acad. Sci. 108 3825). Here, we study in detail some connections between this measure and standard information theory. The relationship between the measure and word length is studied for the popular random typing process where a text is constructed by pressing keys at random from a keyboard containing letters and a space behaving as a word delimiter. Although this random process does not optimize word lengths according to information content, it exhibits a linear relationship between information content and word length. The exact slope and intercept are presented for three major variants of the random typing process. A strong correlation between information content and word length can simply arise from the units making a word (e.g., letters) and not necessarily from the interplay between a word and its context as proposed by Piantadosi and co-workers. In itself, the linear relation does not entail the results of any optimization process.

Mental illness disclosure decision making.

PubMed

Pahwa, Rohini; Fulginiti, Anthony; Brekke, John S; Rice, Eric

2017-01-01

Disclosure related to mental illness has been linked to various positive outcomes, including better mental health. However, many individuals with serious mental illness (SMI) continue to practice non-disclosure. Even though disclosure inherently occurs within the context of one's social relationships, research has generally conceptualized mental illness disclosure as an individual level phenomenon and neglected to consider preferences concerning to whom an individual discloses and the factors that influence this decision. The current study uses the disclosure decision-making model (DD-MM) by Greene (2009) to better understand the processes of mental illness disclosure preference and selective disclosure for individuals with SMI (n = 60) using multivariate random intercept logistic regression with an emphasis on the constituent factors of disclosure preference at both individual and relational levels. The majority of participants were found to practice selective disclosure, with 68% of the participants identifying at least 1 network member to whom they could disclose. Family members and friends were central to the selective disclosure process, comprising the greatest proportion of network members who, both were and were not identified as preferred confidants. Women were found to show higher odds of preference for mental illness disclosure than men. Having lower perceived social support was associated with lower odds of disclosure preference. Among relational factors, greater relationship availability and lower dyadic tangible social support were associated with lower odds of disclosure preference. Practice and research implications of using social network analysis to get a deeper understanding of disclosure and disclosure preference are discussed, including implications for future interventions targeting stigma reduction. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Gender Differences in Factors Related to HIV Risk Behaviors among People Who Inject Drugs in North-East India

PubMed Central

McFall, Allison M.; Solomon, Sunil S.; Srikrishnan, Aylur K.; Vasudevan, Canjeevaram K.; Anand, Santhanam; Celentano, David D.; Mehta, Shruti H.; Kumar, Suresh; Lucas, Gregory M.

2017-01-01

People who inject drugs (PWID) in India are at high risk for HIV, with women being at elevated risk. Using a socio-ecological framework, this study assessed whether factors associated with HIV transmission risk behaviors differed across men and women PWID. Data for this cross-sectional study were collected from 6449 PWID in 7 cities in Northeast India. Men (n = 5653) and women (n = 796) PWID were recruited using respondent-driven sampling (RDS). We assessed sex differences in two recent HIV transmission risk behaviors: multiple sex partners and needle/syringe sharing. We used multi-level logistic regression models, which incorporated sampling weights and random intercepts for city, to assess factors associated with these HIV risks, separately among men and women. The prevalence of HIV was significantly higher among women than men (53% vs 18.4%, p<0.01). Nearly 13% of men and 8% of women (p = .30) had multiple partners. Employment in men and relationship status and stigma in women were significantly associated with multiple partners. Approximately 25% of men and 19% of women engaged in needle sharing (p = .16). Younger age in women and depression symptoms in men were significantly associated with increased risk for sharing needles. We found that sexual and drug related risk behaviors were common among PWID in Northeast India, and there were differences between men and women in the socio-ecologic correlates of these behaviors. Contextually-integrated and gender-specific HIV prevention and intervention efforts are needed that consider factors at individual, interpersonal- and community-levels that uniquely impact HIV risks among PWID. PMID:28099458

Effect of Length of Stay on Smoking among Turkish and Eastern European Immigrants in Germany--Interpretation in the Light of the Smoking Epidemic Model and the Acculturation Theory.

PubMed

Reiss, Katharina; Schunck, Reinhard; Razum, Oliver

2015-12-15

We analyzed changes in smoking by length of stay among immigrants in Germany and related them to the "smoking epidemic" model and the acculturation theory. We used data from a longitudinal survey (German Socio-economic Panel). Immigrants were identified by country of birth (Turkey: respondents n = 828, observations n = 3871; Eastern Europe: respondents n = 2009, observations n = 7202; non-immigrants: respondents n = 34,011, observations n = 140,701). Smoking status data was available for nine years between 1998 and 2012. Length of stay (LOS, in years) was used as proxy for acculturation. We calculated smoking prevalences, prevalence ratios and a random intercept multilevel logistic regression model. With each year spent in Germany, smoking prevalence increases among Turkish women (OR = 1.14 (95%CI = 1.06-1.21)) and slightly decreases among men. Recently immigrated Turkish women smoke less than non-immigrant women (0-5 years: SPR = 0.25 (95%CI = 0.10-0.57)); prevalences converge with increasing LOS (31+ years: SPR = 1.25 (95%CI = 1.06-1.48)). Among Eastern European immigrants no significant changes were apparent. Immigrants from Turkey "import" their smoking prevalence from a country which is in the earlier stages of the "smoking epidemic". With increasing LOS (thus, advancing acculturation), they "move" to the later stages. Anti-smoking interventions should consider different smoking attitudes in Turkey/Germany and need to discourage women from initiating smoking. Future research should also identify reasons for the possible differences between immigrant groups.

Disparities in Hypertension Prevalence, Awareness, Treatment and Control between Bouyei and Han: Results from a Bi-Ethnic Health Survey in Developing Regions from South China.

PubMed

Dong, Fen; Wang, Dingming; Pan, Li; Yu, Yangwen; Wang, Ke; Li, Ling; Wang, Li; Liu, Tao; Zeng, Xianjia; Sun, Liangxian; Zhu, Guangjin; Feng, Kui; Zhang, Biao; Xu, Ke; Pang, Xinglong; Chen, Ting; Pan, Hui; Ma, Jin; Zhong, Yong; Ping, Bo; Shan, Guangliang

2016-02-19

Hypertension is highly prevalent in low-income population. This study aims to investigate ethnic disparities in hypertension and identify modifiable factors related to its occurrence and control in developing regions in South China. Blood pressure was measured in the Bouyei and Han populations during a community-based health survey in Guizhou, 2012. A multistage stratified sampling method was adopted to recruit Bouyei and Han aged from 20 to 80 years. Taking mixed effects into consideration, multilevel logistic models with random intercept were used for data analysis. The prevalence rates of hypertension were 35.3% for the Bouyei and 33.7% for the Han. Among the hypertensive participants, 30.1% of the Bouyei and 40.2% of the Han were aware of their hypertensive conditions, 19.7% of the Bouyei and 31.1% of the Han were receiving treatment, and only 3.6% of the Bouyei and 9.9% of the Han had their blood pressure under control. Age-sex standardized rates of awareness, treatment, and control were consistently lower in the Bouyei than the Han. Such ethnic disparities were more evident in the elderly population. Avoidance of excessive alcohol consumption and better education were favorable lifestyle for reduction in risk of hypertension. Moderate physical activity improved control of hypertension in Bouyei patients under treatment. Conclusively, hypertension awareness, treatment, and control were substantially lower in Bouyei than Han, particularly in the elderly population. Such ethnic disparities indicate that elderly Bouyei population should be targeted for tailored interventions in the future.

Health Insurance Enrollment and Availability of Medications for Substance Use Disorders.

PubMed

Abraham, Amanda J; Rieckmann, Traci; Andrews, Christina M; Jayawardhana, Jayani

2017-01-01

Medications for treatment of substance use disorders are underutilized in treatment programs in the United States. Little is known about how insurance enrollment within states affects treatment program decisions about whether to offer medications. The primary objective of the study was to examine the impact of health insurance enrollment on availability of substance use disorder medications among treatment programs. Data from the 2012 National Survey of Substance Abuse Treatment Services, National Survey on Drug Use and Health, American Community Survey, Area Health Resource File, and the Substance Abuse and Mental Health Services Administration were combined to examine the impact of state insurance enrollment on availability of substance use disorder medications in treatment programs (N=9,888). A two-level, random-intercept logistic regression model was estimated to account for potential unobserved heterogeneity among treatment programs nested in states. The percentage of state residents with employer-based insurance and Medicaid was associated with greater odds of offering at least one medication among treatment programs. A 5% increase in the rate of private insurance enrollment was associated with a 7.7% increase in the probability of offering at least one medication, and a 5% increase in the rate of state Medicaid enrollment was associated with a 9.3% increase in the probability of offering at least one medication. Results point to the potential significance of health insurance enrollment in shaping the availability of substance use disorder medications. Significant expansions in health insurance enrollment spurred by the Affordable Care Act have the potential to increase access to medications for many Americans.

The statistics of Pearce element diagrams and the Chayes closure problem

NASA Astrophysics Data System (ADS)

Nicholls, J.

1988-05-01

Pearce element ratios are defined as having a constituent in their denominator that is conserved in a system undergoing change. The presence of a conserved element in the denominator simplifies the statistics of such ratios and renders them subject to statistical tests, especially tests of significance of the correlation coefficient between Pearce element ratios. Pearce element ratio diagrams provide unambigous tests of petrologic hypotheses because they are based on the stoichiometry of rock-forming minerals. There are three ways to recognize a conserved element: 1. The petrologic behavior of the element can be used to select conserved ones. They are usually the incompatible elements. 2. The ratio of two conserved elements will be constant in a comagmatic suite. 3. An element ratio diagram that is not constructed with a conserved element in the denominator will have a trend with a near zero intercept. The last two criteria can be tested statistically. The significance of the slope, intercept and correlation coefficient can be tested by estimating the probability of obtaining the observed values from a random population of arrays. This population of arrays must satisfy two criteria: 1. The population must contain at least one array that has the means and variances of the array of analytical data for the rock suite. 2. Arrays with the means and variances of the data must not be so abundant in the population that nearly every array selected at random has the properties of the data. The population of random closed arrays can be obtained from a population of open arrays whose elements are randomly selected from probability distributions. The means and variances of these probability distributions are themselves selected from probability distributions which have means and variances equal to a hypothetical open array that would give the means and variances of the data on closure. This hypothetical open array is called the Chayes array. Alternatively, the population of random closed arrays can be drawn from the compositional space available to rock-forming processes. The minerals comprising the available space can be described with one additive component per mineral phase and a small number of exchange components. This space is called Thompson space. Statistics based on either space lead to the conclusion that Pearce element ratios are statistically valid and that Pearce element diagrams depict the processes that create chemical inhomogeneities in igneous rock suites.

47 CFR 1.20003 - Policies and procedures for employee supervision and control.

Code of Federal Regulations, 2010 CFR

2010-10-01

... or employee responsible for ensuring that any interception of communications or access to call... to implement the interception of communications or access to call-identifying information; (2) An... description of how long it will maintain its records of each interception of communications or access to call...

Exploring the potential of the cosmic-ray neutron method to measure interception storage dynamics

NASA Astrophysics Data System (ADS)

Jakobi, Jannis; Bogena, Heye; Huisman, Johan Alexander; Diekkrüger, Bernd; Vereecken, Harry

2017-04-01

Cosmic-ray neutron soil moisture probes are an emerging technology that relies on the negative correlation between near-surface fast neutron counts and soil moisture content. Hydrogen atoms in the soil, which are mainly present as water, moderate the secondary neutrons on the way back to the surface. Any application of this method needs to consider the sensitivity of the neutron counts to additional sources of hydrogen (e.g. above- and below-ground biomass, humidity of the lower atmosphere, lattice water of the soil minerals, organic matter and water in the litter layer, intercepted water in the canopy, and soil organic matter). In this study, we analyzed the effects of canopy-intercepted water on the cosmic-ray neutron counts. For this, an arable field cropped with sugar beet was instrumented with several cosmic-ray neutron probes and a wireless sensor network with more than 140 in-situ soil moisture sensors. Additionally rainfall interception was estimated using a new approach coupling throughfall measurements and leaf wetness sensors. The derived interception storage was used to correct for interception effects on cosmic ray neutrons to enhance soil water content prediction. Furthermore, the potential for a simultaneous prediction of above- and below-ground biomass, soil moisture and interception was tested.

Fog interception by Sequoia sempervirens (D. Don) crowns decouples physiology from soil water deficit.

PubMed

Simonin, Kevin A; Santiago, Louis S; Dawson, Todd E

2009-07-01

Although crown wetting events can increase plant water status, leaf wetting is thought to negatively affect plant carbon balance by depressing photosynthesis and growth. We investigated the influence of crown fog interception on the water and carbon relations of juvenile and mature Sequoia sempervirens trees. Field observations of mature trees indicated that fog interception increased leaf water potential above that of leaves sheltered from fog. Furthermore, observed increases in leaf water potential exceeded the maximum water potential predicted if soil water was the only available water source. Because field observations were limited to two mature trees, we conducted a greenhouse experiment to investigate how fog interception influences plant water status and photosynthesis. Pre-dawn and midday branchlet water potential, leaf gas exchange and chlorophyll fluorescence were measured on S. sempervirens saplings exposed to increasing soil water deficit, with and without overnight canopy fog interception. Sapling fog interception increased leaf water potential and photosynthesis above the control and soil water deficit treatments despite similar dark-acclimated leaf chlorophyll fluorescence. The field observations and greenhouse experiment show that fog interception represents an overlooked flux into the soil-plant-atmosphere continuum that temporarily, but significantly, decouples leaf-level water and carbon relations from soil water availability.

The role of stable isotopes in understanding rainfall ...

EPA Pesticide Factsheets

The isotopic composition of water transmitted by the canopy as throughfall or stemflow reflects important hydrologic processes occurring in the canopy. A synthesis of the literature shows that complex spatiotemporal variations of isotopic composition are created by canopy interception. As a whole, the studies suggest a set of controlling factors including fractionation, exchange among liquid and vapor phase water, and spatiotemporal redistribution along varying canopy flowpaths. However, our limited understanding of physical processes and water routing in the canopy limits the ability to discern all details for predicting interception isotope effects. We suggest that the isotopic composition of throughfall and stemflow may be the key to improve our understanding of water storage and transport in the canopy, similar to how isotopic analysis contributed to progress in our understanding of watershed runoff processes. While interception isotope effects have largely been studied under the premise that they are a source of error, previous works also indicate a wide range of possible interactions that intercepted water may have with the canopy and airspace. We identify new research questions that may be answered by stable isotopes as a path forward in examining and generalizing small-scale interception processes that could facilitate integration of interception into watershed ecohydrological concepts. Evaporation from forest canopies (interception loss) is a prominent

The influence of visual motion on interceptive actions and perception.

PubMed

Marinovic, Welber; Plooy, Annaliese M; Arnold, Derek H

2012-05-01

Visual information is an essential guide when interacting with moving objects, yet it can also be deceiving. For instance, motion can induce illusory position shifts, such that a moving ball can seem to have bounced past its true point of contact with the ground. Some evidence suggests illusory motion-induced position shifts bias pointing tasks to a greater extent than they do perceptual judgments. This, however, appears at odds with other findings and with our success when intercepting moving objects. Here we examined the accuracy of interceptive movements and of perceptual judgments in relation to simulated bounces. Participants were asked to intercept a moving disc at its bounce location by positioning a virtual paddle, and then to report where the disc had landed. Results showed that interceptive actions were accurate whereas perceptual judgments were inaccurate, biased in the direction of motion. Successful interceptions necessitated accurate information concerning both the location and timing of the bounce, so motor planning evidently had privileged access to an accurate forward model of bounce timing and location. This would explain why people can be accurate when intercepting a moving object, but lack insight into the accurate information that had guided their actions when asked to make a perceptual judgment. Copyright © 2012 Elsevier Ltd. All rights reserved.

HEALTH CONDITIONS LINKED TO AGE-RELATED MACULAR DEGENERATION ASSOCIATED WITH DARK ADAPTATION.

PubMed

Laíns, Inês; Miller, John B; Mukai, Ryo; Mach, Steven; Vavvas, Demetrios; Kim, Ivana K; Miller, Joan W; Husain, Deeba

2018-06-01

To determine the association between dark adaption (DA) and different health conditions linked with age-related macular degeneration (AMD). Cross-sectional study, including patients with AMD and a control group. Age-related macular degeneration was graded according to the Age-Related Eye Disease Study (AREDS) classification. We obtained data on medical history, medications, and lifestyle. Dark adaption was assessed with the extended protocol (20 minutes) of AdaptDx (MacuLogix). For analyses, the right eye or the eye with more advanced AMD was selected. Multivariate linear and logistic regressions were performed, accounting for age and AMD stage. Seventy-eight subjects (75.6% AMD; 24.4% controls) were included. Multivariate assessments revealed that body mass index (BMI; β = 0.30, P = 0.045), taking AREDS vitamins (β = 5.51, P < 0.001), and family history of AMD (β = 2.68, P = 0.039) were significantly associated with worse rod intercept times. Abnormal DA (rod intercept time ≥ 6.5 minutes) was significantly associated with family history of AMD (β = 1.84, P = 0.006), taking AREDS supplements (β = 1.67, P = 0.021) and alcohol intake (β = 0.07, P = 0.017). Besides age and AMD stage, a higher body mass index, higher alcohol intake, and a family history of AMD seem to impair DA. In this cohort, the use of AREDS vitamins was also statistically linked with impaired DA, most likely because of an increased severity of disease in subjects taking them.

Time series of canopy intercepted water and dew observed in a tropical tree plantation by means of microwave radiometry

NASA Astrophysics Data System (ADS)

Schneebeli, M.; Wolf, S.; Kunert, N.; Eugster, W.; Mätzler, C.

2012-04-01

During summer and autumn 2007, a 11 GHz microwave radiometer was deployed in an experimental tree plantation in Sardinilla, Panama. With this instrument, the opacity of the tree canopy was derived from incoming brightness temperatures received on the ground. A collocated eddy-covariance flux tower measured water vapor fluxes and meteorological variables above the canopy. It was found that canopy intercepted rain and dew formation modulated the diurnal opacity cycle. With an enhanced canopy opacity model accounting for water deposited on the leaves, we quantified the influence of canopy stored water (i.e. intercepted water and dew) on the opacity. With this technique it was possible to directly monitor high resolution time series of dew formation and rain interception during a period of two weeks. In contrast to through-fall measurements, this new technique allows to determine the amount of intercepted rain more precisely and during day and night since evaporation effects do not hamper the accuracy of the method. We found that during light rainfall up to 60% of the rain amount is intercepted by the canopy whereas during periods of intense rainfall, only 4% were intercepted. On average, about 15% of the rain amount was intercepted during rainfalls of medium intensities. By comparing the interception with the water vapor flux time series it was found that intercepted water is evaporated rapidly after it is deposited on the leaves, which resulted in an enhanced water vapor flux. Our study also provides the first direct measurements and quantifications of the temporal evolution of dew formation and evaporation in a tree canopy on a diurnal base. Dew accumulated during the night and until about 2 h after sunrise, when the water vapor flux began to exceed the dew formation rate. The dew continued to evaporate for another 3.5 h until the surface of the leaves was completely dry. On average, 0.17 mm of dew was formed during the night. Dew evaporation contributed 5% to the total water vapor flux measured above the canopy.

Contrasting roles of interception and transpiration in the hydrological cycle - Part 2: Moisture recycling

NASA Astrophysics Data System (ADS)

van der Ent, R. J.; Wang-Erlandsson, L.; Keys, P. W.; Savenije, H. H. G.

2014-12-01

The contribution of land evaporation to local and remote precipitation (i.e. moisture recycling) is of significant importance to sustain water resources and ecosystems. But how important are different evaporation components in sustaining precipitation? This is the first paper to present moisture recycling metrics for partitioned evaporation. In the companion paper Wang-Erlandsson et al. (2014) (hereafter Part 1), evaporation was partitioned into vegetation interception, floor interception, soil moisture evaporation and open-water evaporation (constituting the direct, purely physical fluxes, largely dominated by interception), and transpiration (delayed, biophysical flux). Here, we track these components forward as well as backward in time. We also include age tracers to study the atmospheric residence times of these evaporation components. We present a new image of the global hydrological cycle that includes quantification of partitioned evaporation and moisture recycling as well as the atmospheric residence times of all fluxes. We demonstrate that evaporated interception is more likely to return as precipitation on land than transpired water. On average, direct evaporation (essentially interception) is found to have an atmospheric residence time of 8 days, while transpiration typically resides for 9 days in the atmosphere. The process scale over which evaporation recycles is more local for interception compared to transpiration; thus interception generally precipitates closer to its evaporative source than transpiration, which is particularly pronounced outside the tropics. We conclude that interception mainly works as an intensifier of the local hydrological cycle during wet spells and wet seasons. On the other hand, transpiration remains active during dry spells and dry seasons and is transported over much larger distances downwind, where it can act as a significant source of moisture. Thus, as various land-use types can differ considerably in their partitioning between interception and transpiration, our results stress that land-use changes (e.g. forest-to-cropland conversion) do not only affect the magnitude of moisture recycling, but could also influence the moisture recycling patterns and lead to a redistribution of water resources. As such, this research highlights that land-use changes can have complex effects on the atmospheric branch of the hydrological cycle.

Contrasting roles of interception and transpiration in the hydrological cycle - Part 2: Moisture recycling

NASA Astrophysics Data System (ADS)

van der Ent, R. J.; Wang-Erlandsson, L.; Keys, P. W.; Savenije, H. H. G.

2014-03-01

The contribution of land evaporation to local and remote precipitation (i.e., moisture recycling) is of significant importance to sustain water resources and ecosystems. But how important are different evaporation components in sustaining precipitation? This is the first paper to present moisture recycling metrics for partitioned evaporation. In the companion paper, Part 1, evaporation was partitioned into vegetation interception, floor interception, soil moisture evaporation and open water evaporation (constituting the direct, purely physical fluxes, largely dominated by interception), and transpiration (delayed, biophysical flux). Here, we track these components forward as well as backward in time. We also include age tracers to study the atmospheric residence times of these evaporation components. As the main result we present a new image of the global hydrological cycle that includes quantification of partitioned evaporation and moisture recycling as well as the atmospheric residence times of all fluxes. We demonstrate that evaporated interception is more likely to return as precipitation on land than transpired water. On average, direct evaporation (essentially interception) is found to have an atmospheric residence time of eight days, while transpiration typically resides nine days in the atmosphere. Interception recycling has a much shorter local length scale than transpiration recycling, thus interception generally precipitates closer to its evaporative source than transpiration, which is particularly pronounced outside the tropics. We conclude that interception mainly works as an intensifier of the local hydrological cycle during wet spells. On the other hand, transpiration remains active during dry spells and is transported over much larger distances downwind where it can act as a significant source of moisture. Thus, as various land-use types can differ considerably in their partitioning between interception and transpiration, our results stress that land-use changes (e.g., forest to cropland conversion) do not only affect the magnitude of moisture recycling, but could also influence the moisture recycling patterns and lead to a redistribution of water resources. As such, this research highlights that land-use changes can have complex effects on the atmospheric branch of the hydrological cycle.

Reliabilities of mental rotation tasks: limits to the assessment of individual differences.

PubMed

Hirschfeld, Gerrit; Thielsch, Meinald T; Zernikow, Boris

2013-01-01

Mental rotation tasks with objects and body parts as targets are widely used in cognitive neuropsychology. Even though these tasks are well established to study between-groups differences, the reliability on an individual level is largely unknown. We present a systematic study on the internal consistency and test-retest reliability of individual differences in mental rotation tasks comparing different target types and orders of presentations. In total n = 99 participants (n = 63 for the retest) completed the mental rotation tasks with hands, feet, faces, and cars as targets. Different target types were presented in either randomly mixed blocks or blocks of homogeneous targets. Across all target types, the consistency (split-half reliability) and stability (test-retest reliabilities) were good or acceptable both for intercepts and slopes. At the level of individual targets, only intercepts showed acceptable reliabilities. Blocked presentations resulted in significantly faster and numerically more consistent and stable responses. Mental rotation tasks-especially in blocked variants-can be used to reliably assess individual differences in global processing speed. However, the assessment of the theoretically important slope parameter for individual targets requires further adaptations to mental rotation tests.

Changes in organisation of instep kicking as a function of wearing compression and textured materials.

PubMed

Hasan, Hosni; Davids, Keith; Chow, Jia Yi; Kerr, Graham

2017-04-01

This study investigated effects of wearing compression garments and textured insoles on modes of movement organisation emerging during performance of lower limb interceptive actions in association football. Participants were six skilled (age = 15.67 ± 0.74 years) and six less-skilled (age = 15.17 ± 1.1 years) football players. All participants performed 20 instep kicks with maximum velocity in four randomly organised insoles and socks conditions, (a) Smooth Socks with Smooth Insoles (SSSI); (b) Smooth Socks with Textured Insoles (SSTI); (c) Compression Socks with Smooth Insoles (CSSI); and (d), Compression Socks with Textured Insoles (CSTI). Results showed that, when wearing textured and compression materials (CSSI condition), less-skilled participants displayed significantly greater hip extension and flexion towards the ball contact phase, indicating larger ranges of motion in the kicking limb than in other conditions. Less-skilled participants also demonstrated greater variability in knee-ankle intralimb (angle-angle plots) coordination modes in the CSTI condition. Findings suggested that use of textured and compression materials increased attunement to somatosensory information from lower limb movement, to regulate performance of dynamic interceptive actions like kicking, especially in less-skilled individuals.

How might Australian rainforest cloud interception respond to climate change?

NASA Astrophysics Data System (ADS)

Wallace, Jim; McJannet, Dave

2013-02-01

SummaryThe lower and upper montane rainforests in northern Queensland receive significant amounts of cloud interception that affect both in situ canopy wetness and downstream runoff. Cloud interception contributes 5-30% of the annual water input to the canopy and this increases to 40-70% of the monthly water input during the dry season. This occult water is therefore an important input to the canopy, sustaining the epiphytes, mosses and other species that depend on wet canopy conditions. The potential effect of climate change on cloud interception was examined using the relationship between cloud interception and cloud frequency derived from measurements made at four different rainforest locations. Any given change in cloud frequency produces a greater change in cloud interception and this 'amplification' increases from 1.1 to 1.7 as cloud frequency increases from 5% to 70%. This means that any changes in cloud frequency will have the greatest relative effects at the higher altitude sites where cloud interception is greatest. As cloud frequency is also a major factor affecting canopy wetness, any given change in cloud frequency will therefore have a greater impact on canopy wetness at the higher altitude sites. These changes in wetness duration will augment those due to changes in rainfall and may have important implications for the fauna and flora that depend on wet canopy conditions. We also found that the Australian rainforests may be more efficient (by ˜50% on average) in intercepting cloud water than American coniferous forests, which may be due to differences in canopy structure and exposure at the different sites.

Development and testing of a snow interceptometer to quantify canopy water storage and interception processes in the rain/snow transition zone of the North Cascades, Washington, USA

NASA Astrophysics Data System (ADS)

Martin, Kael A.; Van Stan, John T.; Dickerson-Lange, Susan E.; Lutz, James A.; Berman, Jeffrey W.; Gersonde, Rolf; Lundquist, Jessica D.

2013-06-01

Tree canopy snow interception is a significant hydrological process, capable of removing up to 60% of snow from the ground snowpack. Our understanding of canopy interception has been limited by our ability to measure whole canopy water storage in an undisturbed forest setting. This study presents a relatively inexpensive technique for directly measuring snow canopy water storage using an interceptometer, adapted from Friesen et al. (2008). The interceptometer is composed of four linear motion position sensors distributed evenly around the tree trunk. We incorporate a trunk laser-mapping installation method for precise sensor placement to reduce signal error due to sensor misalignment. Through calibration techniques, the amount of canopy snow required to produce the measured displacements can be calculated. We demonstrate instrument performance on a western hemlock (Tsuga heterophylla) for a snow interception event in November 2011. We find a snow capture efficiency of 83 ± 15% of accumulated ground snowfall with a maximum storage capacity of 50 ± 8 mm snow water equivalent (SWE). The observed interception event is compared to simulated interception, represented by the variable infiltration capacity (VIC) hydrologic model. The model generally underreported interception magnitude by 33% using a leaf area index (LAI) of 5 and 16% using an LAI of 10. The interceptometer captured intrastorm accumulation and melt rates up to 3 and 0.75 mm SWE h-1, respectively, which the model failed to represent. While further implementation and validation is necessary, our preliminary results indicate that forest interception magnitude may be underestimated in maritime areas.

SHIIVER (Structural Heat Intercept Insulation Vibration Evaluation Rig)

NASA Image and Video Library

2017-06-11

SHIIVER (Structural Heat Intercept Insulation Vibration Evaluation Rig) is a cryogenic test tank developed to evaluate heat intercept concepts. It arrived at Marshall Space Flight Center on August 10, 2017. The tank will receive heat sensors and spray-on foam insulation before making its way to Plum Brook station for further insulation and testing.

Gravity settling

DOEpatents

Davis, Hyman R.; Long, R. H.; Simone, A. A.

1979-01-01

Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.

Artificial night light alters nocturnal prey interception outcomes for morphologically variable spiders.

PubMed

Yuen, Suet Wai; Bonebrake, Timothy C

2017-01-01

Artificial night light has the potential to significantly alter visually-dependent species interactions. However, examples of disruptions of species interactions through changes in light remain rare and how artificial night light may alter predator-prey relationships are particularly understudied. In this study, we examined whether artificial night light could impact prey attraction and interception in Nephila pilipes orb weaver spiders, conspicuous predators who make use of yellow color patterns to mimic floral resources and attract prey to their webs. We measured moth prey attraction and interception responses to treatments where we experimentally manipulated the color/contrast of spider individuals in the field (removed yellow markings) and also set up light manipulations. We found that lit webs had lower rates of moth interception than unlit webs. Spider color, however, had no clear impact on moth interception or attraction rates in lit nor unlit webs. The results show that night light can reduce prey interception for spiders. Additionally, this study highlights how environmental and morphological variation can complicate simple predictions of ecological light pollution's disruption of species interactions.

The Impact of Biofuels on Climate Change from Marginal Land over East Asia using the RegCM4

NASA Astrophysics Data System (ADS)

Kim, S.; Lee, O.; Choi, J.

2016-12-01

In this study, the stormwater interception rate is proposed to apply in the design of LID facilities. For this purpose, EPA-SWMM is built with some areas of Noksan National Industrial Complex where long-term observed stormwater data were monitored and stormwater interception rates for various design capacities of various LID facilities are estimated. While the sensitivity of stormwater interception rate according to design specifications of bio-retention and infiltration trench facilities is not large, the sensitivity of stormwater interception rate according to local rainfall characteristics is relatively big. As a result of comparing the present rainfall interception rate estimation method which is officially operated in Korea with the one proposed in this study, it will be presented that the present method is highly likely to overestimate the performance of the bio-retention and infiltration trench facilities. Finally, a new stormwater interception rate formulas for the bio-retention and infiltration trench LID facilities will be proposed. Acknowledgement This research was supported by a grant (2016000200002) from Public Welfare Technology Development Program funded by Ministry of Environment of Korean government.

Visuo-motor coordination and internal models for object interception.

PubMed

Zago, Myrka; McIntyre, Joseph; Senot, Patrice; Lacquaniti, Francesco

2009-02-01

Intercepting and avoiding collisions with moving objects are fundamental skills in daily life. Anticipatory behavior is required because of significant delays in transforming sensory information about target and body motion into a timed motor response. The ability to predict the kinematics and kinetics of interception or avoidance hundreds of milliseconds before the event may depend on several different sources of information and on different strategies of sensory-motor coordination. What are exactly the sources of spatio-temporal information and what are the control strategies remain controversial issues. Indeed, these topics have been the battlefield of contrasting views on how the brain interprets visual information to guide movement. Here we attempt a synthetic overview of the vast literature on interception. We discuss in detail the behavioral and neurophysiological aspects of interception of targets falling under gravity, as this topic has received special attention in recent years. We show that visual cues alone are insufficient to predict the time and place of interception or avoidance, and they need to be supplemented by prior knowledge (or internal models) about several features of the dynamic interaction with the moving object.

Calibrated intercepts for solar radiometers used in remote sensor calibration

NASA Technical Reports Server (NTRS)

Gellman, David I.; Biggar, Stuart F.; Slater, Philip N.; Bruegge, Carol J.

1991-01-01

Calibrated solar radiometer intercepts allow spectral optical depths to be determined for days with intermittently clear skies. This is of particular importance on satellite sensor calibration days that are cloudy except at the time of image acquisition. This paper describes the calibration of four solar radiometers using the Langley-Bouguer technique for data collected on days with a clear, stable atmosphere. Intercepts are determined with an uncertainty of less than six percent, corresponding to a maximum uncertainty of 0.06 in optical depth. The spread of voltage intercepts calculated in this process is carried through three methods of radiometric calibration of satellite sensors to yield an uncertainty in radiance at the top of the atmosphere of less than one percent associated with the uncertainty in solar radiometer intercepts for a range of ground reflectances.

Catching What We Can't See: Manual Interception of Occluded Fly-Ball Trajectories

PubMed Central

Bosco, Gianfranco; Delle Monache, Sergio; Lacquaniti, Francesco

2012-01-01

Control of interceptive actions may involve fine interplay between feedback-based and predictive mechanisms. These processes rely heavily on target motion information available when the target is visible. However, short-term visual memory signals as well as implicit knowledge about the environment may also contribute to elaborate a predictive representation of the target trajectory, especially when visual feedback is partially unavailable because other objects occlude the visual target. To determine how different processes and information sources are integrated in the control of the interceptive action, we manipulated a computer-generated visual environment representing a baseball game. Twenty-four subjects intercepted fly-ball trajectories by moving a mouse cursor and by indicating the interception with a button press. In two separate sessions, fly-ball trajectories were either fully visible or occluded for 750, 1000 or 1250 ms before ball landing. Natural ball motion was perturbed during the descending trajectory with effects of either weightlessness (0 g) or increased gravity (2 g) at times such that, for occluded trajectories, 500 ms of perturbed motion were visible before ball disappearance. To examine the contribution of previous visual experience with the perturbed trajectories to the interception of invisible targets, the order of visible and occluded sessions was permuted among subjects. Under these experimental conditions, we showed that, with fully visible targets, subjects combined servo-control and predictive strategies. Instead, when intercepting occluded targets, subjects relied mostly on predictive mechanisms based, however, on different type of information depending on previous visual experience. In fact, subjects without prior experience of the perturbed trajectories showed interceptive errors consistent with predictive estimates of the ball trajectory based on a-priori knowledge of gravity. Conversely, the interceptive responses of subjects previously exposed to fully visible trajectories were compatible with the fact that implicit knowledge of the perturbed motion was also taken into account for the extrapolation of occluded trajectories. PMID:23166653

Catching what we can't see: manual interception of occluded fly-ball trajectories.

PubMed

Bosco, Gianfranco; Delle Monache, Sergio; Lacquaniti, Francesco

2012-01-01

Control of interceptive actions may involve fine interplay between feedback-based and predictive mechanisms. These processes rely heavily on target motion information available when the target is visible. However, short-term visual memory signals as well as implicit knowledge about the environment may also contribute to elaborate a predictive representation of the target trajectory, especially when visual feedback is partially unavailable because other objects occlude the visual target. To determine how different processes and information sources are integrated in the control of the interceptive action, we manipulated a computer-generated visual environment representing a baseball game. Twenty-four subjects intercepted fly-ball trajectories by moving a mouse cursor and by indicating the interception with a button press. In two separate sessions, fly-ball trajectories were either fully visible or occluded for 750, 1000 or 1250 ms before ball landing. Natural ball motion was perturbed during the descending trajectory with effects of either weightlessness (0 g) or increased gravity (2 g) at times such that, for occluded trajectories, 500 ms of perturbed motion were visible before ball disappearance. To examine the contribution of previous visual experience with the perturbed trajectories to the interception of invisible targets, the order of visible and occluded sessions was permuted among subjects. Under these experimental conditions, we showed that, with fully visible targets, subjects combined servo-control and predictive strategies. Instead, when intercepting occluded targets, subjects relied mostly on predictive mechanisms based, however, on different type of information depending on previous visual experience. In fact, subjects without prior experience of the perturbed trajectories showed interceptive errors consistent with predictive estimates of the ball trajectory based on a-priori knowledge of gravity. Conversely, the interceptive responses of subjects previously exposed to fully visible trajectories were compatible with the fact that implicit knowledge of the perturbed motion was also taken into account for the extrapolation of occluded trajectories.

Two zero-flow pressure intercepts exist in autoregulating isolated skeletal muscle.

PubMed

Braakman, R; Sipkema, P; Westerhof, N

1990-06-01

The autoregulating vascular bed of the isolated canine extensor digitorum longus muscle was investigated for the possible existence of two positive zero-flow pressure axis intercepts, a tone-dependent one and a tone-independent one. An isolated preparation, perfused with autologous blood, was used to exclude effects of collateral flow and nervous and humoral regulation while autoregulation was left intact [mean autoregulatory gain 0.50 +/- 0.24 (SD)]. In a first series of experiments, the steady-state (zero flow) pressure axis intercept [mean 8.9 +/- 2.6 (SD) mmHg, tone independent] and the instantaneous (zero flow) pressure axis intercept [mean 28.5 +/- 9.9 (SD) mmHg, tone dependent] were determined as a function of venous pressure (range: 0-45 mmHg) and were independent of venous pressure until the venous pressure exceeded their respective values. Beyond this point the relations between the venous pressure and the steady-state and instantaneous pressure axis intercept followed the line of identity. The findings agree with the predictions of the vascular waterfall model. In a second series it was shown by means of administration of vasoactive drugs that the instantaneous pressure axis intercept is tone dependent, whereas the steady-state pressure axis intercept is not. It is concluded that there is a (proximal) tone-dependent zero-flow pressure at the arteriolar level and a (distal) tone-independent zero-flow pressure at the venous level.

A reprogrammable receiver architecture for wireless signal interception

NASA Astrophysics Data System (ADS)

Yao, Timothy S.

2003-09-01

In this paper, a re-programmable receiver architecture, based on software-defined-radio concept, for wireless signal interception is presented. The radio-frequency (RF) signal that the receiver would like to intercept may come from a terrestrial cellular network or communication satellites, which their carrier frequency are in the range from 800 MHz (civilian mobile) to 15 GHz (Ku band). To intercept signals from such a wide range of frequency in these variant communication systems, the traditional way is to deploy multiple receivers to scan and detect the desired signal. This traditional approach is obviously unattractive due to the cost, efficiency, and accuracy. Instead, we propose a universal receiver, which is software-driven and re-configurable, to intercept signals of interest. The software-defined-radio based receiver first intercepts RF energy of wide spectrum (25MHz) through antenna, performs zero-IF down conversion (homodyne architecture) to baseband, and digital channelizes the baseband signal. The channelization module is a bank of high performance digital filters. The bandwidth of the filter bank is programmable according to the wireless communication protocol under watch. In the baseband processing, high-performance digital signal processors carry out the detection process and microprocessors handle the communication protocols. The baseband processing is also re-configurable for different wireless standards and protocol. The advantages of the software-defined-radio architecture over traditional RF receiver make it a favorable technology for the communication signal interception and surveillance.

Modelling rainfall interception by a lowland tropical rain forest in northeastern Puerto Rico

NASA Astrophysics Data System (ADS)

Schellekens, J.; Scatena, F. N.; Bruijnzeel, L. A.; Wickel, A. J.

1999-12-01

Recent surveys of tropical forest water use suggest that rainfall interception by the canopy is largest in wet maritime locations. To investigate the underlying processes at one such location—the Luquillo Experimental Forest in eastern Puerto Rico—66 days of detailed throughfall and above-canopy climatic data were collected in 1996 and analysed using the Rutter and Gash models of rainfall interception. Throughfall occurred on 80% of the days distributed over 80 rainfall events. Measured interception loss was 50% of gross precipitation. When Penman-Monteith based estimates for the wet canopy evaporation rate (0.11 mm h -1 on average) and a canopy storage of 1.15 mm were used, both models severely underestimated measured interception loss. A detailed analysis of four storms using the Rutter model showed that optimizing the model for the wet canopy evaporation component yielded much better results than increasing the canopy storage capacity. However, the Rutter model failed to properly estimate throughfall amounts during an exceptionally large event. The analytical model, on the other hand, was capable of representing interception during the extreme event, but once again optimizing wet canopy evaporation rates produced a much better fit than optimizing the canopy storage capacity. As such, the present results support the idea that it is primarily a high rate of evaporation from a wet canopy that is responsible for the observed high interception losses.

Logistic random effects regression models: a comparison of statistical packages for binary and ordinal outcomes

PubMed Central

2011-01-01

Background Logistic random effects models are a popular tool to analyze multilevel also called hierarchical data with a binary or ordinal outcome. Here, we aim to compare different statistical software implementations of these models. Methods We used individual patient data from 8509 patients in 231 centers with moderate and severe Traumatic Brain Injury (TBI) enrolled in eight Randomized Controlled Trials (RCTs) and three observational studies. We fitted logistic random effects regression models with the 5-point Glasgow Outcome Scale (GOS) as outcome, both dichotomized as well as ordinal, with center and/or trial as random effects, and as covariates age, motor score, pupil reactivity or trial. We then compared the implementations of frequentist and Bayesian methods to estimate the fixed and random effects. Frequentist approaches included R (lme4), Stata (GLLAMM), SAS (GLIMMIX and NLMIXED), MLwiN ([R]IGLS) and MIXOR, Bayesian approaches included WinBUGS, MLwiN (MCMC), R package MCMCglmm and SAS experimental procedure MCMC. Three data sets (the full data set and two sub-datasets) were analysed using basically two logistic random effects models with either one random effect for the center or two random effects for center and trial. For the ordinal outcome in the full data set also a proportional odds model with a random center effect was fitted. Results The packages gave similar parameter estimates for both the fixed and random effects and for the binary (and ordinal) models for the main study and when based on a relatively large number of level-1 (patient level) data compared to the number of level-2 (hospital level) data. However, when based on relatively sparse data set, i.e. when the numbers of level-1 and level-2 data units were about the same, the frequentist and Bayesian approaches showed somewhat different results. The software implementations differ considerably in flexibility, computation time, and usability. There are also differences in the availability of additional tools for model evaluation, such as diagnostic plots. The experimental SAS (version 9.2) procedure MCMC appeared to be inefficient. Conclusions On relatively large data sets, the different software implementations of logistic random effects regression models produced similar results. Thus, for a large data set there seems to be no explicit preference (of course if there is no preference from a philosophical point of view) for either a frequentist or Bayesian approach (if based on vague priors). The choice for a particular implementation may largely depend on the desired flexibility, and the usability of the package. For small data sets the random effects variances are difficult to estimate. In the frequentist approaches the MLE of this variance was often estimated zero with a standard error that is either zero or could not be determined, while for Bayesian methods the estimates could depend on the chosen "non-informative" prior of the variance parameter. The starting value for the variance parameter may be also critical for the convergence of the Markov chain. PMID:21605357

Random effects coefficient of determination for mixed and meta-analysis models

PubMed Central

Demidenko, Eugene; Sargent, James; Onega, Tracy

2011-01-01

The key feature of a mixed model is the presence of random effects. We have developed a coefficient, called the random effects coefficient of determination, Rr2, that estimates the proportion of the conditional variance of the dependent variable explained by random effects. This coefficient takes values from 0 to 1 and indicates how strong the random effects are. The difference from the earlier suggested fixed effects coefficient of determination is emphasized. If Rr2 is close to 0, there is weak support for random effects in the model because the reduction of the variance of the dependent variable due to random effects is small; consequently, random effects may be ignored and the model simplifies to standard linear regression. The value of Rr2 apart from 0 indicates the evidence of the variance reduction in support of the mixed model. If random effects coefficient of determination is close to 1 the variance of random effects is very large and random effects turn into free fixed effects—the model can be estimated using the dummy variable approach. We derive explicit formulas for Rr2 in three special cases: the random intercept model, the growth curve model, and meta-analysis model. Theoretical results are illustrated with three mixed model examples: (1) travel time to the nearest cancer center for women with breast cancer in the U.S., (2) cumulative time watching alcohol related scenes in movies among young U.S. teens, as a risk factor for early drinking onset, and (3) the classic example of the meta-analysis model for combination of 13 studies on tuberculosis vaccine. PMID:23750070

Gaze Behaviour during Interception in Children with Spastic Unilateral Cerebral Palsy

ERIC Educational Resources Information Center

van Kampen, P. M.; Ledebt, A.; Smorenburg, A. R. P.; Vermeulen, R. J.; Kelder, M. E.; van der Kamp, J.; Savelsbergh, G. J. P.

2012-01-01

Anticipatory gaze behaviour during interceptive movements was investigated in children with Spastic Unilateral Cerebral Palsy (SUCP), and related to the side of the intracerebral lesion. Five children with lesions of the right hemisphere (RHL) and five children with lesions of the left hemisphere (LHL) had to walk towards and intercept a ball that…

Snow catch by conifer crowns

Treesearch

Donald R. Satterlund; Harold F. Haupt

1967-01-01

Study of interception storage of snow by two species of sapling conifers in northern Idaho revealed that cumulative snow catch follows the classical law of autocatakinetic growth, or [equation - see PDF] where I, is interception storage, e is the interception storage capacity of the tree, e is the base of the natural logarithm, k is a constant expressing the rate of...

Description and Initial Evaluation of a Computer-Based Individual Trainer for the Radar Intercept Observer.

ERIC Educational Resources Information Center

Rigney, Joseph W.; And Others

An individual trainer for giving students in the radar intercept observer (RIO) schools concentrated practice in procedures for air-to-air intercepts was designed around a programmable graphics terminal with two integral minicomputers and 8k of core memory. The trainer automatically administers practice in computing values of variables in the…

WATERSHED SCALE RAINFALL INTERCEPTION ON TWO FORESTED WATERSHEDS IN THE LUQUILLO MOUNTAINS OF PUERTO RICO

Treesearch

F.N. SCATENA

1990-01-01

Interception losses were monitored for one year and related to vegetation characteristics in two forested watersheds in the Luquillo Experimental Forest of Puerto Rico. Total watershed interception was then modeled by weighting values of throughfall measured in representative areas of different vegetation types by the total watershed area of that vegetation group....

Rainfall interception by annual grass and chaparral . . . losses compared

Treesearch

Edward S. Corbett; Robert P. Crouse

1968-01-01

Loss of precipitation due to interception by annual grass and grass litter was measured during three rainy seasons on the San Dimas Experimental Forest, in southern California. Interception loss from annual grass averaged 7.9 percent; that from mature chaparral cover, 12.8 percent. If chaparral stands were converted to grass, an estimated 1.3 inches of gross...

Canopy water balance of windward and leeward Hawaiian cloud forests on Haleakalā, Maui, Hawai'i

USGS Publications Warehouse

Giambelluca, Thomas W.; DeLay, John K.; Nullet, Michael A.; Scholl, Martha A.; Gingerich, Stephen B.

2011-01-01

The contribution of intercepted cloud water to precipitation at windward and leeward cloud forest sites on the slopes of Haleakalā, Maui was assessed using two approaches. Canopy water balance estimates based on meteorological monitoring were compared with interpretations of fog screen measurements collected over a 2-year period at each location. The annual incident rainfall was 973 mm at the leeward site (Auwahi) and 2550 mm at the windward site (Waikamoi). At the leeward, dry forest site, throughfall was less than rainfall (87%), and, at the windward, wet forest site, throughfall exceeded rainfall (122%). Cloud water interception estimated from canopy water balance was 166 mm year−1 at Auwahi and 1212 mm year−1 at Waikamoi. Annual fog screen measurements of cloud water flux, corrected for wind-blown rainfall, were 132 and 3017 mm for the dry and wet sites respectively. Event totals of cloud water flux based on fog screen measurements were poorly correlated with event cloud water interception totals derived from the canopy water balance. Hence, the use of fixed planar fog screens to estimate cloud water interception is not recommended. At the wet windward site, cloud water interception made up 32% of the total precipitation, adding to the already substantial amount of rainfall. At the leeward dry site, cloud water interception was 15% of the total precipitation. Vegetation at the dry site, where trees are more exposed and isolated, was more efficient at intercepting the available cloud water than at the rainy site, but events were less frequent, shorter in duration and lower in intensity. A large proportion of intercepted cloud water, 74% and 83%, respectively for the two sites, was estimated to become throughfall, thus adding significantly to soil water at both sites

Study on Hydrological Functions of Litter Layers in North China

PubMed Central

Li, Xiang; Niu, Jianzhi; Xie, Baoyuan

2013-01-01

Canopy interception, throughfall, stemflow, and runoff have received considerable attention during the study of water balance and hydrological processes in forested ecosystems. Past research has either neglected or underestimated the role of hydrological functions of litter layers, although some studies have considered the impact of various characteristics of rainfall and litter on litter interception. Based on both simulated rainfall and litter conditions in North China, the effect of litter mass, rainfall intensity and litter type on the maximum water storage capacity of litter (S) and litter interception storage capacity (C) were investigated under five simulated rainfall intensities and four litter masses for two litter types. The results indicated: 1) the S values increased linearly with litter mass, and the S values of broadleaf litter were on average 2.65 times larger than the S values of needle leaf litter; 2) rainfall intensity rather than litter mass determined the maximum interception storage capacity (Cmax); Cmax increased linearly with increasing rainfall intensity; by contrast, the minimum interception storage capacity (Cmin) showed a linear relationship with litter mass, but a poor correlation with rainfall intensity; 3) litter type impacted Cmax and Cmin; the values of Cmax and Cmin for broadleaf litter were larger than those of needle leaf litter, which indicated that broadleaf litter could intercepte and store more water than needle leaf litter; 4) a gap existed between Cmax and Cmin, indicating that litter played a significant role by allowing rainwater to infiltrate or to produce runoff rather than intercepting it and allowing it to evaporate after the rainfall event; 5) Cmin was always less than S at the same litter mass, which should be considered in future interception predictions. Vegetation and precipitation characteristics played important roles in hydrological characteristics. PMID:23936188

Opportunities for ballistic missions to Halley's comet

NASA Technical Reports Server (NTRS)

Farquhar, R. W.; Wooden, W. H., II

1977-01-01

Alternative strategies for ballistic missions to Halley's comet in 1985-86 are described. It is shown that a large science return would be acquired from a ballistic Halley intercept in spite of the high flyby speeds of almost 60 km/sec that are associated with this mission mode. The possibility of retargeting the cometary spacecraft to additional comets after the Halley intercept also exists. In one scenario two cometary spacecraft of identical design would be used to carry out four separate cometary encounters over a three-year period. One spacecraft would intercept Halley before its perihelion passage in December 1985 and then go on to comet Borrelly witn an encounter in January 1988. The other spacecraft would be targeted for a post-perihelion Halley intercept in March 1986 before proceeding towards an encounter with comet Tempel-2 in September 1988. The flyby speeds for the Borrelly and Tempel-2 intercepts are 21 and 13 km/sec, respectively.

Logistic Regression with Multiple Random Effects: A Simulation Study of Estimation Methods and Statistical Packages.

PubMed

Kim, Yoonsang; Choi, Young-Ku; Emery, Sherry

2013-08-01

Several statistical packages are capable of estimating generalized linear mixed models and these packages provide one or more of three estimation methods: penalized quasi-likelihood, Laplace, and Gauss-Hermite. Many studies have investigated these methods' performance for the mixed-effects logistic regression model. However, the authors focused on models with one or two random effects and assumed a simple covariance structure between them, which may not be realistic. When there are multiple correlated random effects in a model, the computation becomes intensive, and often an algorithm fails to converge. Moreover, in our analysis of smoking status and exposure to anti-tobacco advertisements, we have observed that when a model included multiple random effects, parameter estimates varied considerably from one statistical package to another even when using the same estimation method. This article presents a comprehensive review of the advantages and disadvantages of each estimation method. In addition, we compare the performances of the three methods across statistical packages via simulation, which involves two- and three-level logistic regression models with at least three correlated random effects. We apply our findings to a real dataset. Our results suggest that two packages-SAS GLIMMIX Laplace and SuperMix Gaussian quadrature-perform well in terms of accuracy, precision, convergence rates, and computing speed. We also discuss the strengths and weaknesses of the two packages in regard to sample sizes.

Logistic Regression with Multiple Random Effects: A Simulation Study of Estimation Methods and Statistical Packages

PubMed Central

Kim, Yoonsang; Emery, Sherry

2013-01-01

Several statistical packages are capable of estimating generalized linear mixed models and these packages provide one or more of three estimation methods: penalized quasi-likelihood, Laplace, and Gauss-Hermite. Many studies have investigated these methods’ performance for the mixed-effects logistic regression model. However, the authors focused on models with one or two random effects and assumed a simple covariance structure between them, which may not be realistic. When there are multiple correlated random effects in a model, the computation becomes intensive, and often an algorithm fails to converge. Moreover, in our analysis of smoking status and exposure to anti-tobacco advertisements, we have observed that when a model included multiple random effects, parameter estimates varied considerably from one statistical package to another even when using the same estimation method. This article presents a comprehensive review of the advantages and disadvantages of each estimation method. In addition, we compare the performances of the three methods across statistical packages via simulation, which involves two- and three-level logistic regression models with at least three correlated random effects. We apply our findings to a real dataset. Our results suggest that two packages—SAS GLIMMIX Laplace and SuperMix Gaussian quadrature—perform well in terms of accuracy, precision, convergence rates, and computing speed. We also discuss the strengths and weaknesses of the two packages in regard to sample sizes. PMID:24288415

A Numerical Study of New Logistic Map

NASA Astrophysics Data System (ADS)

Khmou, Youssef

In this paper, we propose a new logistic map based on the relation of the information entropy, we study the bifurcation diagram comparatively to the standard logistic map. In the first part, we compare the obtained diagram, by numerical simulations, with that of the standard logistic map. It is found that the structures of both diagrams are similar where the range of the growth parameter is restricted to the interval [0,e]. In the second part, we present an application of the proposed map in traffic flow using macroscopic model. It is found that the bifurcation diagram is an exact model of the Greenberg’s model of traffic flow where the growth parameter corresponds to the optimal velocity and the random sequence corresponds to the density. In the last part, we present a second possible application of the proposed map which consists of random number generation. The results of the analysis show that the excluded initial values of the sequences are (0,1).

A New High-Resolution Direction Finding Architecture Using Photonics and Neural Network Signal Processing for Miniature Air Vehicle Applications

DTIC Science & Technology

2015-09-01

3 4. Probability of Intercept .................................................................3 5. Superresolution ...intercept. This alignment gives the shortest mean-time-to-intercept and can be less than one second. 4 5. Superresolution For single signals...at each antenna element. For multiple signals, superresolution DF techniques are often used. These techniques can be broken down into beamforming

Growth in relation to canopy light interception in a red pine (Pinus resinosa) thinning study

Treesearch

Beverly E. Law; Kurt H. Riitters; Lewis F. Ohmann

1992-01-01

Growth data from the most recent 5 years of a 40-year thinning study in an even-aged red pine (Pinus resinosa) forest in cutfoot sioux experimental forest, Minnesota, were used with intercepted photosynthetically active radiation (IPAR) data to determine the relationship between light interception and growth for a range ofstand densities. Stand basal...

Interception of precipitation by northern hardwoods

Treesearch

Raymond E. Leonard

1961-01-01

When forest watershed management research was begun at the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire in 1955, we felt certain that at least one aspect of hydrology would not require study-interception. Interception has been studied for a long time, in fact, as early as 1889 (Horton, 1919). It has been well known that a certain amount of...

Intercepted Scolytidae (Coleoptera) at U.S. ports of entry: 1985-2000.

Treesearch

Robert A. Haack

2001-01-01

Since 1985, the U.S. Department of Agriculture, Animal and Plant Health Inspection Service has maintained the 'Port Information Network' (PIN) database for plant pests intercepted at the U.S. ports of entry. As of August 2001, PIN contained 6825 records of beetles (Coleoptera) in the family Scolytidae that had been intercepted during the years 1985-2000 from...

Simplified large African carnivore density estimators from track indices.

PubMed

Winterbach, Christiaan W; Ferreira, Sam M; Funston, Paul J; Somers, Michael J

2016-01-01

The range, population size and trend of large carnivores are important parameters to assess their status globally and to plan conservation strategies. One can use linear models to assess population size and trends of large carnivores from track-based surveys on suitable substrates. The conventional approach of a linear model with intercept may not intercept at zero, but may fit the data better than linear model through the origin. We assess whether a linear regression through the origin is more appropriate than a linear regression with intercept to model large African carnivore densities and track indices. We did simple linear regression with intercept analysis and simple linear regression through the origin and used the confidence interval for ß in the linear model y  =  αx  + ß, Standard Error of Estimate, Mean Squares Residual and Akaike Information Criteria to evaluate the models. The Lion on Clay and Low Density on Sand models with intercept were not significant ( P  > 0.05). The other four models with intercept and the six models thorough origin were all significant ( P  < 0.05). The models using linear regression with intercept all included zero in the confidence interval for ß and the null hypothesis that ß = 0 could not be rejected. All models showed that the linear model through the origin provided a better fit than the linear model with intercept, as indicated by the Standard Error of Estimate and Mean Square Residuals. Akaike Information Criteria showed that linear models through the origin were better and that none of the linear models with intercept had substantial support. Our results showed that linear regression through the origin is justified over the more typical linear regression with intercept for all models we tested. A general model can be used to estimate large carnivore densities from track densities across species and study areas. The formula observed track density = 3.26 × carnivore density can be used to estimate densities of large African carnivores using track counts on sandy substrates in areas where carnivore densities are 0.27 carnivores/100 km 2 or higher. To improve the current models, we need independent data to validate the models and data to test for non-linear relationship between track indices and true density at low densities.

Mean-intercept anisotropy analysis of porous media. II. Conceptual shortcomings of the MIL tensor definition and Minkowski tensors as an alternative.

PubMed

Klatt, Michael A; Schröder-Turk, Gerd E; Mecke, Klaus

2017-07-01

Structure-property relations, which relate the shape of the microstructure to physical properties such as transport or mechanical properties, need sensitive measures of structure. What are suitable fabric tensors to quantify the shape of anisotropic heterogeneous materials? The mean intercept length is among the most commonly used characteristics of anisotropy in porous media, e.g., of trabecular bone in medical physics. Yet, in this series of two papers we demonstrate that it has conceptual shortcomings that limit the validity of its results. We test the validity of general assumptions regarding the properties of the mean-intercept length tensor using analytical formulas for the mean-intercept lengths in anisotropic Boolean models (derived in part I of this series), augmented by numerical simulations. We discuss in detail the functional form of the mean intercept length as a function of the test line orientations. As the most prominent result, we find that, at least for the example of overlapping grains modeling porous media, the polar plot of the mean intercept length is in general not an ellipse and hence not represented by a second-rank tensor. This is in stark contrast to the common understanding that for a large collection of grains the mean intercept length figure averages to an ellipse. The standard mean intercept length tensor defined by a least-square fit of an ellipse is based on a model mismatch, which causes an intrinsic lack of accuracy. Our analysis reveals several shortcomings of the mean intercept length tensor analysis that pose conceptual problems and limitations on the information content of this commonly used analysis method. We suggest the Minkowski tensors from integral geometry as alternative sensitive measures of anisotropy. The Minkowski tensors allow for a robust, comprehensive, and systematic approach to quantify various aspects of structural anisotropy. We show the Minkowski tensors to be more sensitive, in the sense, that they can quantify the remnant anisotropy of structures not captured by the mean intercept length analysis. If applied to porous tissue and microstructures, this improved structure characterization can yield new insights into the relationships between geometry and material properties. © 2017 American Association of Physicists in Medicine.

Effects of Barbell Deadlift Training on Submaximal Motor Unit Firing Rates for the Vastus Lateralis and Rectus Femoris

PubMed Central

Stock, Matt S.; Thompson, Brennan J.

2014-01-01

Previous investigations that have studied motor unit firing rates following strength training have been limited to small muscles, isometric training, or interventions involving exercise machines. We examined the effects of ten weeks of supervised barbell deadlift training on motor unit firing rates for the vastus lateralis and rectus femoris during a 50% maximum voluntary contraction (MVC) assessment. Twenty-four previously untrained men (mean age  = 24 years) were randomly assigned to training (n = 15) or control (n = 9) groups. Before and following the intervention, the subjects performed isometric testing of the right knee extensors while bipolar surface electromyographic signals were detected from the two muscles. The signals were decomposed into their constituent motor unit action potential trains, and motor units that demonstrated accuracy levels less than 92.0% were not considered for analysis. One thousand eight hundred ninety-two and 2,013 motor units were examined for the vastus lateralis and rectus femoris, respectively. Regression analyses were used to determine the linear slope coefficients (pulses per second [pps]/% MVC) and y-intercepts (pps) of the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. Deadlift training significantly improved knee extensor MVC force (Cohen's d = .70), but did not influence force steadiness. Training had no influence on the slopes and y-intercepts for the mean firing rate and firing rate at recruitment versus recruitment threshold relationships. In agreement with previous cross-sectional comparisons and randomized control trials, our findings do not support the notion that strength training affects the submaximal control of motor units. PMID:25531294

Measuring and modelling interception loss by an isolated olive tree in a traditional olive grove - pasture system

NASA Astrophysics Data System (ADS)

Nóbrega, Cristina; Pereira, Fernando L.; Valente, Fernanda

2015-04-01

Water losses associated to the rainfall interception process by trees can be an important component of the local hydrologic balance and must be accounted for when implementing any sustainable water management programme. In many dry areas of the Mediterranean region where agro-forestry systems are common, those programmes are crucial to foster adequate water conservation measures. Recent studies have shown that the evaluation of interception loss in sparse forests or tree plantations should be made for individual trees, being the total value determined as the sum of the individual contributions. Following this approach, rainfall interception was measured and modelled over two years, in an isolated Olea europeaea L. tree, in a traditional low-density olive grove in Castelo Branco, central Portugal. Total interception loss over the experimental period was 243.5 mm, on a tree crown projected area basis, corresponding to 18.0% of gross rainfall (Pg). Modelling made for each rainfall event using the sparse version of the Gash model, slightly underestimated interception loss with a value of 240.5 mm, i.e., 17.8 % ofPg. Modelling quality, evaluated according to a number of criteria, was good, allowing the conclusion that the methodology used was adequate. Modelling was also made on a daily basis, i.e., assuming a single storm per rainday. In this case, interception loss was overestimated by 12%, mostly because 72% of all rainfall events lasted for more than a day.

The value of comparative research in major day surgery.

PubMed

Llop-Gironés, Alba; Vergara-Duarte, Montse; Sánchez, Josep Anton; Tarafa, Gemma; Benach, Joan

2017-05-19

To measure time trends in major day surgery rates according to hospital ownership and other hospital characteristics among the providers of the public healthcare network of Catalonia, Spain. Data from the Statistics of Health Establishments providing Inpatient Care. A generalized linear mixed model with Gaussian response and random intercept and random slopes. The greatest growth in the rate of major day surgery was observed among private for-profit hospitals: 42.9 (SD: 22.5) in 2009 versus 2.7 (SD: 6.7) in 1996. These hospitals exhibited a significant increase in major day surgery compared to public hospitals (coefficient 2; p-value <0.01) CONCLUSIONS: The comparative evaluation of hospital performance is a decisive tool to ensure that public resources are used as rationally and efficiently as possible. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

SHIIVER (Structural Heat Intercept Insulation Vibration Evaluation Rig)

NASA Image and Video Library

2017-06-11

SHIIVER Tank Arrives at NASA’s Marshall Center for Spray-On Foam InsulationSHIIVER (Structural Heat Intercept Insulation Vibration Evaluation Rig) is a cryogenic test tank developed to evaluate heat intercept concepts. It arrived at Marshall Space Flight Center on August 10, 2017. The tank will receive heat sensors and spray-on foam insulation before making its way to Plum Brook station for further insulation and testing.

SHIIVER (Structural Heat Intercept Insulation Vibration Evaluation Rig)

NASA Image and Video Library

2017-06-11

SHIIVER (Structural Heat Intercept Insulation Vibration Evaluation Rig) is a cryogenic test tank developed to evaluate heat intercept concepts. It arrived at Marshall Space Flight Center on August 10, 2017. The tank will receive heat sensors and spray-on foam insulation before making its way to Plum Brook station for further insulation and testing.SHIIVER Tank Arrives at NASA’s Marshall Center for Spray-On Foam Insulation

Quadrotor Intercept Trajectory Planning and Simulation

DTIC Science & Technology

2017-06-01

Figure 41. Results are grouped by geometry type and colored based on trajectory planner. Figure 41. Summary of Experimental Data Intercept Time...DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) Quadrotor drones pose a safety hazard when operated in or near controlled airspace. A hazardous...quadrotor could be intercepted and removed by another quadrotor. In this thesis, we seek to determine if optimal control methods outperform missile

Research on logistics scheduling based on PSO

NASA Astrophysics Data System (ADS)

Bao, Huifang; Zhou, Linli; Liu, Lei

2017-08-01

With the rapid development of e-commerce based on the network, the logistics distribution support of e-commerce is becoming more and more obvious. The optimization of vehicle distribution routing can improve the economic benefit and realize the scientific of logistics [1]. Therefore, the study of logistics distribution vehicle routing optimization problem is not only of great theoretical significance, but also of considerable value of value. Particle swarm optimization algorithm is a kind of evolutionary algorithm, which is based on the random solution and the optimal solution by iteration, and the quality of the solution is evaluated through fitness. In order to obtain a more ideal logistics scheduling scheme, this paper proposes a logistics model based on particle swarm optimization algorithm.

Differential contributions to the interception of occluded ballistic trajectories by the temporoparietal junction, area hMT/V5+, and the intraparietal cortex.

PubMed

Delle Monache, Sergio; Lacquaniti, Francesco; Bosco, Gianfranco

2017-09-01

The ability to catch objects when transiently occluded from view suggests their motion can be extrapolated. Intraparietal cortex (IPS) plays a major role in this process along with other brain structures, depending on the task. For example, interception of objects under Earth's gravity effects may depend on time-to-contact predictions derived from integration of visual signals processed by hMT/V5+ with a priori knowledge of gravity residing in the temporoparietal junction (TPJ). To investigate this issue further, we disrupted TPJ, hMT/V5+, and IPS activities with transcranial magnetic stimulation (TMS) while subjects intercepted computer-simulated projectile trajectories perturbed randomly with either hypo- or hypergravity effects. In experiment 1 , trajectories were occluded either 750 or 1,250 ms before landing. Three subject groups underwent triple-pulse TMS (tpTMS, 3 pulses at 10 Hz) on one target area (TPJ | hMT/V5+ | IPS) and on the vertex (control site), timed at either trajectory perturbation or occlusion. In experiment 2 , trajectories were entirely visible and participants received tpTMS on TPJ and hMT/V5+ with same timing as experiment 1 tpTMS of TPJ, hMT/V5+, and IPS affected differently the interceptive timing. TPJ stimulation affected preferentially responses to 1-g motion, hMT/V5+ all response types, and IPS stimulation induced opposite effects on 0-g and 2-g responses, being ineffective on 1-g responses. Only IPS stimulation was effective when applied after target disappearance, implying this area might elaborate memory representations of occluded target motion. Results are compatible with the idea that IPS, TPJ, and hMT/V5+ contribute to distinct aspects of visual motion extrapolation, perhaps through parallel processing. NEW & NOTEWORTHY Visual extrapolation represents a potential neural solution to afford motor interactions with the environment in the face of missing information. We investigated relative contributions by temporoparietal junction (TPJ), hMT/V5+, and intraparietal cortex (IPS), cortical areas potentially involved in these processes. Parallel organization of visual extrapolation processes emerged with respect to the target's motion causal nature: TPJ was primarily involved for visual motion congruent with gravity effects, IPS for arbitrary visual motion, whereas hMT/V5+ contributed at earlier processing stages. Copyright © 2017 the American Physiological Society.

Rainfall interception from a lowland tropical rainforest in Brunei

NASA Astrophysics Data System (ADS)

Dykes, A. P.

1997-12-01

Results from a programme of throughfall measurements in a lowland tropical rainforest in Brunei, northwest Borneo, indicate that interception losses amount to 18% of the gross incident rainfall. The high annual rainfall experienced by the study area results in annual interception losses of around 800 mm, which may result in total annual evapotranspiration losses significantly higher than in other rainforest locations. An improved version of Gash's analytical interception model is tested on the available data using assumed values for the "forest" parameters, and is found to predict interception losses extremely well. The model predictions are based on an estimated evaporation rate during rainfall of 0.71 mm h -1. This is significantly higher than has been reported in other tropical studies. It is concluded that these results are distinctive when compared with previous results from rainforests, and that further, detailed work is required to establish whether the enhanced evaporation rate is due to advective effects associated with the maritime setting of the study area.

Variations in canopy and litter interception across a forest chronosequence in the southern Appalachian Mountains

Treesearch

Steven T. Brantley; Paul V. Bolstad; Stephanie H. Laseter; A. Christopher Oishi; Kimberly A. Novick; Chelcy F. Miniat

2016-01-01

Variations in evapotranspiration (ET) have been well documented across a variety of forest types and climates in recent decades; however, most of these data have focused on mature, secondgrowth stands. Here we present data on two important fluxes of water, canopy interception (Ic) and forest floor litter interception (Iff), across a chronosequence of forest age in the...

Computer-aided mathematical analysis of probability of intercept for ground-based communication intercept system

NASA Astrophysics Data System (ADS)

Park, Sang Chul

1989-09-01

We develop a mathematical analysis model to calculate the probability of intercept (POI) for the ground-based communication intercept (COMINT) system. The POI is a measure of the effectiveness of the intercept system. We define the POI as the product of the probability of detection and the probability of coincidence. The probability of detection is a measure of the receiver's capability to detect a signal in the presence of noise. The probability of coincidence is the probability that an intercept system is available, actively listening in the proper frequency band, in the right direction and at the same time that the signal is received. We investigate the behavior of the POI with respect to the observation time, the separation distance, antenna elevations, the frequency of the signal, and the receiver bandwidths. We observe that the coincidence characteristic between the receiver scanning parameters and the signal parameters is the key factor to determine the time to obtain a given POI. This model can be used to find the optimal parameter combination to maximize the POI in a given scenario. We expand this model to a multiple system. This analysis is conducted on a personal computer to provide the portability. The model is also flexible and can be easily implemented under different situations.

An Optimal t-{Delta}v Guidance Law for Intercepting a Boosting Target

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

Ng, L.C.; Breitfeller, E.; Ledebuhr, A.G.

2002-06-30

Lawrence Livermore National Laboratory (LLNL) have developed a new missile guidance law for intercepting a missile during boost phase. Unlike other known missile guidance laws being used today, the new t-{Delta}v guidance law optimally trades an interceptor's onboard fuel capacity against time-to-go before impact. In particular, this guidance law allows a missile designer to program the interceptor to maximally impact a boosting missile before burnout or burn termination and thus negating its ability to achieve the maximum kinetic velocity. For an intercontinental range ballistic missile (ICBM), it can be shown that for every second of earlier intercept prior to burnout,more » the ICBM ground range is reduced by 350 km. Therefore, intercepting a mere 15 seconds earlier would result in amiss of 5,250 km from the intended target or approximately a distance across the continental US. This paper also shows how the t-{Delta}v guidance law can incorporate uncertainties in target burnout time, predicted intercept point (PIP) error, time-to-go error, and other track estimation errors. The authors believe that the t-{Delta}v guidance law is a step toward the development of a new and smart missile guidance law that would enhance the probability of achieving a boost phase intercept.« less

Modeling exotic highly pathogenic avian influenza virus entrance risk through air passenger violations.

PubMed

Lai, Jyh-Mirn; Hwang, Yi-Ting; Chou, Chin-Cheng

2012-06-01

The highly pathogenic avian influenza virus (HPAIV) is able to survive in poultry products and could be carried into a country by air travelers. An assessment model was constructed to estimate the probability of the exotic viable HPAIV entering Taiwan from two neighboring areas through poultry products carried illegally by air passengers at Taiwan's main airports. The entrance risk was evaluated based on HPAIV-related factors (the prevalence and the incubation period of HPAIV; the manufacturing process of poultry products; and the distribution-storage-transportation factor event) and the passenger event. Distribution functions were adopted to simulate the probabilities of each HPAIV factor. The odds of passengers being intercepted with illegal poultry products were estimated by logistic regression. The Monte Carlo simulation established that the risk caused by HPAIV-related factors from area A was lower than area B, whereas the entrance risk by the passenger event from area A was similar to area B. Sensitivity analysis showed that the incubation period of HPAIV and the interception of passenger violations were major determinants. Although the result showed viable HPAIV was unlikely to enter Taiwan through meat illegally carried by air passengers, this low probability could be caused by incomplete animal disease data and modeling uncertainties. Considering the negative socioeconomic impacts of HPAIV outbreaks, strengthening airport quarantine measures is still necessary. This assessment provides a profile of HPAIV entrance risk through air travelers arriving from endemic areas and a feasible direction for quarantine and public health measures. © 2011 Society for Risk Analysis.

Fine scale spatial and temporal variation in temperature and arrhythmia episodes in the VA Normative Aging Study

PubMed Central

Zanobetti, Antonella; Coull, Brent A.; Kloog, Itai; Sparrow, David; Vokonas, Pantel S.; Gold, Diane R.; Schwartz, Joel D.

2017-01-01

Many studies have demonstrated that cold and hot temperatures are associated with increased deaths and hospitalization rates; new findings indicate also an association with more specific cardiac risk factors. Most of these existing studies have relied on few weather stations to characterize exposures; few have used residence-specific estimates of temperature, or examined the exposure-response function. We investigated the association of arrhythmia episodes with spatial and temporal variation in temperature. We also evaluated the association between monitored ambient temperature (central) and the same outcome. This longitudinal analysis included 701 older men participating in the VA Normative Aging Study. Arrhythmia episodes were measured as ventricular ectopy (VE) (bigeminy, trigemini or couplets episodes) by 4min electrocardiogram (ECG) monitoring in repeated visits during 2000–2010. The outcome was defined as having or not VE episodes during a study visit. We applied a mixed effect logistic regression model with a random intercept for subject, controlling for seasonality, weekday, medication use, smoking, diabetes status, body mass index and age. We also examined effect modification by personal characteristics, confounding by air pollution, and the exposure-response function. For 1° C increase in the same day residence-specific temperature, the odds of having VE episodes was 1.10 (95%CI: 1.04–1.17). The odds associated with 1° C increase in central temperature was 1.05 (95%CI: 1.02–1.09). The exposure-response function was non-linear for averages of temperature, presenting a J-shaped pattern, suggesting greater risk at lower and higher temperatures. Increased warm temperature and decreased cold temperature may increase the risk of ventricular arrhythmias. PMID:28001123

Macro-level age norms for the timing of sexual initiation and adolescents' early sexual initiation in 17 European countries.

PubMed

Madkour, Aubrey Spriggs; de Looze, Margaretha; Ma, Ping; Halpern, Carolyn Tucker; Farhat, Tilda; Ter Bogt, Tom F M; Ehlinger, Virginie; Nic Gabhainn, Saoirse; Currie, Candace; Godeau, Emmanuelle

2014-07-01

To examine the relationship between country-level age norms for sexual initiation timing and early sexual initiation (ESI) among adolescent boys and girls. Nationally representative data from 17 countries that participated in the 2006/2007 European Social Survey (ESS-3, n = 33,092) and the 2005/2006 Health Behaviour in School-Aged Children Study (HBSC, n = 27,702) were analyzed. Age norms were measured as the average country-level response to an item asking the age at which ESS respondents believed someone is too young to have sexual intercourse. HBSC respondents (aged 14-16 years) self-reported age at sexual initiation, which we defined as early (<15 years) or not early (≥15 years or no initiation). Control variables included age, family affluence, perceived socioeconomic status, family living arrangement, substance use, school attachment, and country-level legal age of consent. Multivariable three-level logistic models with random intercepts were run separately by sex. In multivariable analyses, higher overall age norms were associated with reduced likelihood of ESI among girls (AOR .60, 95% CI .45-.79); associations with ESI were stronger for parent cohort (ages 31-65 years) norms (AOR .37, 95% CI .23-.58) than for peer cohort (ages 15-20 years) norms (AOR .60, 95% CI .49-.74). For boys, overall norms were also significantly negatively associated with ESI (AOR .68, 95% CI .46-.99), as were parent cohort norms (AOR .66, 95% CI .45-.96). Peer cohort norms were not significantly related to boys' ESI. Macrolevel cultural norms may impact adolescents' sexual initiation timing. Research exploring the sexual health outcomes of early initiators in countries with contrasting age norms is warranted. Copyright © 2014 Society for Adolescent Health and Medicine. All rights reserved.

Impact of implementing performance-based financing on childhood malnutrition in Rwanda.

PubMed

Binagwaho, Agnes; Condo, Jeanine; Wagner, Claire; Ngabo, Fidele; Karema, Corine; Kanters, Steve; Forrest, Jamie I; Bizimana, Jean de Dieu

2014-11-04

Malnutrition remains a serious concern in Rwanda, particularly among children under-5 years. Performance-based financing (PBF), an innovative health systems financing strategy, has been implemented at the national level since 2008. This study aimed to assess the impact of PBF and other factors associated with the prevalence of three classifications of malnutrition (stunting, wasting and underweight) in children under-5 years in Rwanda. The study is a cross-sectional study comprising of 713 children under five years old from 557 households, whose anthropometric measurements (height, weight and age) had been obtained as part of the 2008 Rwanda General Health and HIV household survey. Z-scores for height-for-age, weight-for-age, weight-for-height, and body mass index-for-age were analyzed according to the World Health Organization 2006 Child Growth Standards. Random intercept logistic regression models were used to regress each anthropometric measure (WAZ, HAZ and WHZ) against child, maternal and household characteristics. Child participants ranged in age from 0 to 60 months, 20.2% of children were under 12 months and 5.1% were HIV positive. The prevalence of wasting was 8.8%; of stunting was 58.4%; and of underweight status was 20.7%. Maternal emotional and social wellbeing was protective of wasting in children under-5 years of age. Living in districts implementing PBF was protective of wasting (Adjusted Odds Ratio: 0.43; 95% confidence interval: 0.19-0.97). Living in a district with PBF was not found to be associated with either stunting or underweight status among children under-5. PBF may have a protective association with particular forms of malnutrition among children under-5 years in Rwanda. These findings warrant further investigation in relation to the impact of implementing innovative financing schemes on health outcomes.

Risk factors for saddle-related skin lesions on elephants used in the tourism industry in Thailand.

PubMed

Magda, Scarlett; Spohn, Olivia; Angkawanish, Taweepoke; Smith, Dale A; Pearl, David L

2015-05-19

Lesions related to working conditions and improper saddle design are a concern for a variety of working animals including elephants. The objectives of the present study were to determine the prevalence of cutaneous lesions in anatomic regions (i.e., neck, girth, back, tail) in contact with saddle-related equipment among elephants in Thailand working in the tourism industry, and to identify potential risk factors associated with these lesions. Data for this cross-sectional study were collected between May 2007 and July 2007 on 194 elephants from 18 tourism camps across Thailand. There was a high prevalence (64.4 %; 95 % CI 57.3 - 71.2) of active lesions, most often located on the back region. Using multilevel multivariable logistic regression modelling containing a random intercept for camp we identified the following risk factors: increasing elephant age, the use of rice sacks as padding material in contact with the skin, and the provision of a break for the elephants. Working hours had a quadratic relationship with the log odds of an active lesion where the probability of an active lesion initially increased with the number of working hours per day and then declined possibly reflecting a "healthy worker" bias where only animals without lesions continue to be able to work these longer hours. While we recognize that the cross-sectional nature of the study posed some inferential limitations, our results offer several potential intervention points for the prevention of these lesions. Specifically, we recommend the following until longitudinal studies can be conducted: increased monitoring of older elephants and the back region of all elephants, working less than 6 hours per day, and the avoidance of rice sacks as padding material in contact with skin.

Understanding the role of violence as a social determinant of preterm birth.

PubMed

Masho, Saba W; Cha, Susan; Chapman, Derek A; Chelmow, David

2017-02-01

Preterm birth is one of the leading causes of infant morbidity and mortality. Although major strides have been made in identifying risk factors for preterm birth, the complexities between social and individual risk factors are not well understood. This study examines the association between neighborhood youth violence and preterm birth. A 10-year live birth registry data set (2004 through 2013) from Richmond, VA, a mid-sized, racially diverse city, was analyzed (N = 27,519). Data were geocoded and merged with census tract and police report data. Gestational age at birth was classified as <32 weeks, 32-36 weeks, and term ≥37 weeks. Using police report data, youth violence rates were calculated for each census tract area and categorized into quartiles. Hierarchical models were examined fitting multilevel logistic regression models incorporating randomly distributed census tract-specific intercepts assuming a binary distribution and a logit link function. Nearly a fifth of all births occurred in areas with the highest quartiles of violence. After adjusting for maternal age, race/ethnicity, education, paternal presence, parity, adequacy of prenatal care, pregnancy complications, history of preterm birth, insurance, and tobacco, alcohol, and drug use, census tracts with the highest level of violence had 38% higher odds of very preterm births (adjusted odds ratio, 1.38; 95% confidence interval, 1.06-1.80), than census tracts with the lowest level of violence. There is an association between high rate of youth violence and very preterm birth. Findings from this study may help inform future research to develop targeted interventions aimed at reducing community violence and very preterm birth in vulnerable populations. Copyright © 2016 Elsevier Inc. All rights reserved.

Predictors of Over-Reporting HIV Pre-exposure Prophylaxis (PrEP) Adherence Among Young Men Who Have Sex With Men (YMSM) in Self-Reported Versus Biomarker Data.

PubMed

Baker, Zoë; Javanbakht, Marjan; Mierzwa, Stan; Pavel, Craig; Lally, Michelle; Zimet, Gregory; Gorbach, Pamina

2018-04-01

Young men who have sex with men (YMSM) face a disproportionately high burden of HIV. Oral pre-exposure prophylaxis (PrEP) is effective in preventing HIV acquisition, but adherence to PrEP among YMSM may be inadequate. Medication adherence may be assessed via biomarkers, which are expensive and invasive, or via self-report through Audio Computer Assisted Self-Interview (ACASI), which may result in over-reporting of adherence. In this paper we assess the potential of a new method of self-report, the Interactive Questionnaire System (iQS), in validly estimating true adherence rates. PrEP adherence among 167 YMSM aged 15-23 was measured via dried blood spot (DBS), ACASI, and iQS twice over a 24-week study period. Both ACASI- and iQS-reported data revealed that over 40% of individuals self-reporting adequate PrEP adherence had DBS-estimated drug levels indicating inadequate adherence. Adjusted logistic repeated measures random intercept regression analyses indicated that younger YMSM had higher odds of over-reporting adherence than older YMSM-each 1 year increase in age was associated with 0.79 times the odds of over-reporting adherence (95% CI 0.63, 0.98; p value = 0.031), and being African American was associated with 3.22 times greater odds of over-reporting than non-African Americans (95% CI 1.51, 6.90; p-value = 0.0003). These results suggest that ACASI and iQS methods of self-report significantly overestimate true PrEP adherence rates among YMSM, and that the odds of over-reporting adherence may be affected by both age and race.

Global educational disparities in the associations between body mass index and diabetes mellitus in 49 low-income and middle-income countries.

PubMed

Wang, Aolin; Stronks, Karien; Arah, Onyebuchi A

2014-08-01

Despite the well-established link between body mass index (BMI) and diabetes mellitus (DM), it remains unclear whether this association is more pronounced at certain levels of education. This study assessed the modifying effect of educational attainment on the associations between BMI and DM-as well as the joint associations of BMI and education with DM-in low-income countries (LICs) and middle-income countries (MICs). The authors used cross-sectional data from 160 381 participants among 49 LICs and MICs in the World Health Survey. Overweight and obesity levels were defined using WHO's classification. Educational attainment was classified in four categories: 'no formal education', 'some/completed primary school', 'secondary/high school completed' and 'college and beyond'. We used random-intercept multilevel logistic regressions to investigate the modifying influence of educational attainment on the associations of different BMI levels-as well as their joint associations-with DM. We found positive associations between excessive BMI and DM at each education level in both LICs and MICs. We found that the joint associations of BMI and education with DM were larger than the product of their separate single associations among females in LICs. With joint increases in BMI and education, males and females in LICs had similar increased odds of DM, but males had higher such odds than females in MICs. BMI and education are associated with the DM, but the associations seem to differ in complex ways between LICs and MICs and by gender. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Association of nurse work environment and safety climate on patient mortality: A cross-sectional study.

PubMed

Olds, Danielle M; Aiken, Linda H; Cimiotti, Jeannie P; Lake, Eileen T

2017-09-01

There are two largely distinct research literatures on the association of the nurse work environment and the safety climate on patient outcomes. To determine whether hospital safety climate and work environment make comparable or distinct contributions to patient mortality. Cross-sectional secondary analysis of linked datasets of Registered Nurse survey responses, adult acute care discharge records, and hospital characteristics. Acute care hospitals in California, Florida, New Jersey, and Pennsylvania. The sample included 600 hospitals linked to 27,009 nurse survey respondents and 852,974 surgical patients. Nurse survey data included assessments of the nurse work environment and hospital safety climate. The outcome of interest was in-hospital mortality. Data analyses included descriptive statistics and multivariate random intercept logistic regression. In a fully adjusted model, a one standard deviation increase in work environment score was associated with an 8.1% decrease in the odds of mortality (OR 0.919, p<0.001). A one-standard deviation increase in safety climate score was similarly associated with a 7.7% decrease in the odds of mortality (OR 0.923, p<0.001). However, when work environment and safety climate were modeled together, the effect of the work environment remained significant, while safety climate became a non-significant predictor of mortality odds (OR 0.940, p=0.035 vs. OR 0.971, p=0.316). We found that safety climate perception is not predictive of patient mortality beyond the effect of the nurse work environment. To advance hospital safety and quality and improve patient outcomes, organizational interventions should be directed toward improving nurse work environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Length of Stay on Smoking among Turkish and Eastern European Immigrants in Germany—Interpretation in the Light of the Smoking Epidemic Model and the Acculturation Theory

PubMed Central

Reiss, Katharina; Schunck, Reinhard; Razum, Oliver

2015-01-01

Background: We analyzed changes in smoking by length of stay among immigrants in Germany and related them to the “smoking epidemic” model and the acculturation theory. Methods: We used data from a longitudinal survey (German Socio-economic Panel). Immigrants were identified by country of birth (Turkey: respondents n = 828, observations n = 3871; Eastern Europe: respondents n = 2009, observations n = 7202; non-immigrants: respondents n = 34,011, observations n = 140,701). Smoking status data was available for nine years between 1998 and 2012. Length of stay (LOS, in years) was used as proxy for acculturation. We calculated smoking prevalences, prevalence ratios and a random intercept multilevel logistic regression model. Results: With each year spent in Germany, smoking prevalence increases among Turkish women (OR = 1.14 (95%CI = 1.06–1.21)) and slightly decreases among men. Recently immigrated Turkish women smoke less than non-immigrant women (0–5 years: SPR = 0.25 (95%CI = 0.10–0.57)); prevalences converge with increasing LOS (31+ years: SPR = 1.25 (95%CI = 1.06–1.48)). Among Eastern European immigrants no significant changes were apparent. Conclusions: Immigrants from Turkey “import” their smoking prevalence from a country which is in the earlier stages of the “smoking epidemic”. With increasing LOS (thus, advancing acculturation), they “move” to the later stages. Anti-smoking interventions should consider different smoking attitudes in Turkey/Germany and need to discourage women from initiating smoking. Future research should also identify reasons for the possible differences between immigrant groups. PMID:26694430

The impact of training and working conditions on junior doctors’ intention to leave clinical practice

PubMed Central

2014-01-01

Background The shortage of physicians is an evolving problem throughout the world. In this study we aimed to identify to what extent junior doctors’ training and working conditions determine their intention to leave clinical practice after residency training. Methods A prospective cohort study was conducted in 557 junior doctors undergoing residency training in German hospitals. Self-reported specialty training conditions, working conditions and intention to leave clinical practice were measured over three time points. Scales covering training conditions were assessed by structured residency training, professional support, and dealing with lack of knowledge; working conditions were evaluated by work overload, job autonomy and social support, based on the Demand–Control–Support model. Multivariate ordinal logistic regression analyses with random intercept for longitudinal data were applied to determine the odds ratio of having a higher level of intention to leave clinical practice. Results In the models that considered training and working conditions separately to predict intention to leave clinical practice we found significant baseline effects and change effects. After modelling training and working conditions simultaneously, we found evidence that the change effect of job autonomy (OR 0.77, p = .005) was associated with intention to leave clinical practice, whereas for the training conditions, only the baseline effects of structured residency training (OR 0.74, p = .017) and dealing with lack of knowledge (OR 0.74, p = .026) predicted intention to leave clinical practice. Conclusions Junior doctors undergoing specialty training experience high workload in hospital practice and intense requirements in terms of specialty training. Our study indicates that simultaneously improving working conditions over time and establishing a high standard of specialty training conditions may prevent junior doctors from considering leaving clinical practice after residency training. PMID:24942360

Simple neck pain questions used in surveys, evaluated in relation to health outcomes: a cohort study

PubMed Central

2012-01-01

Background The high prevalence of pain reported in many epidemiological studies, and the degree to which this prevalence reflects severe pain is under discussion in the literature. The aim of the present study was to evaluate use of the simple neck pain questions commonly included in large epidemiological survey studies with respect to aspects of health. We investigated if and how an increase in number of days with pain is associated with reduction in health outcomes. Methods A cohort of university students (baseline age 19–25 years) were recruited in 2002 and followed annually for 4 years. The baseline response rate was 69% which resulted in 1200 respondents (627 women, 573 men). Participants were asked about present and past pain and perceptions of their general health, sleep disturbance, stress and energy levels, and general performance. The data were analyzed using a mixed model for repeated measurements and a random intercept logistic model. Results When reporting present pain, participants also reported lower prevalence of very good health, higher stress and sleep disturbance scores and lower energy score. Among those with current neck pain, additional questions characterizing the pain such as duration (categorized), additional pain sites and decreased general performance were associated with lower probability of very good health and higher amounts of sleep disturbance. Knowing about the presence or not of pain explains more of the variation in health between individuals, than within individuals. Conclusion This study of young university students has demonstrated that simple neck pain survey questions capture features of pain that affect aspects of health such as perceived general health, sleep disturbance, mood in terms of stress and energy. Simple pain questions are more useful for group descriptions than for describing or following pain in an individual. PMID:23102060

Simple neck pain questions used in surveys, evaluated in relation to health outcomes: a cohort study.

PubMed

Grimby-Ekman, Anna; Hagberg, Mats

2012-10-26

The high prevalence of pain reported in many epidemiological studies, and the degree to which this prevalence reflects severe pain is under discussion in the literature. The aim of the present study was to evaluate use of the simple neck pain questions commonly included in large epidemiological survey studies with respect to aspects of health. We investigated if and how an increase in number of days with pain is associated with reduction in health outcomes. A cohort of university students (baseline age 19-25 years) were recruited in 2002 and followed annually for 4 years. The baseline response rate was 69% which resulted in 1200 respondents (627 women, 573 men). Participants were asked about present and past pain and perceptions of their general health, sleep disturbance, stress and energy levels, and general performance. The data were analyzed using a mixed model for repeated measurements and a random intercept logistic model. When reporting present pain, participants also reported lower prevalence of very good health, higher stress and sleep disturbance scores and lower energy score. Among those with current neck pain, additional questions characterizing the pain such as duration (categorized), additional pain sites and decreased general performance were associated with lower probability of very good health and higher amounts of sleep disturbance. Knowing about the presence or not of pain explains more of the variation in health between individuals, than within individuals. This study of young university students has demonstrated that simple neck pain survey questions capture features of pain that affect aspects of health such as perceived general health, sleep disturbance, mood in terms of stress and energy. Simple pain questions are more useful for group descriptions than for describing or following pain in an individual.

Macro-level Age Norms for the Timing of Sexual Initiation and Adolescents’ Early Sexual Initiation in 17 European Countries

PubMed Central

Madkour, Aubrey Spriggs; de Looze, Margaretha; Ma, Ping; Halpern, Carolyn Tucker; Farhat, Tilda; ter Bogt, Tom F. M.; Ehlinger, Virginie; Nic Gabhainn, Saoirse; Currie, Candace; Godeau, Emmanuelle

2014-01-01

Purpose To examine the relationship between country-level age norms for sexual initiation timing and early sexual initiation (ESI) among adolescent boys and girls. Methods Nationally-representative data from 17 countries that participated in the 2006/07 European Social Survey (ESS-3, n=33,092) and the 2005/06 Health Behaviour in School-Aged Children Study (HBSC, n=27,702) were analyzed. Age norms were measured as the average country-level response to an item asking the age at which ESS respondents believed someone is too young to have sexual intercourse. HBSC respondents (aged 14-16) self-reported age at sexual initiation which we defined as early (<15 years) or not (≥15 years or no initiation). Control variables included age, family affluence, perceived socioeconomic status, family living arrangement, substance use, school attachment, and country-level legal age of consent. Multivariable three-level logistic models with random intercepts were run separately by sex. Results In multivariable analyses, higher overall age norms were associated with reduced likelihood of ESI among girls (AOR 0.60, 95% CI 0.45-0.79); associations with ESI were stronger for parent cohort (ages 31-65) norms (AOR 0.37, 95% CI 0.23-0.58) than for peer cohort (ages 15-20) norms (AOR 0.60, 95% CI 0.49-0.74). For boys, overall norms were also significantly negatively associated with ESI (AOR 0.68, 95% CI 0.46-0.99), as were parent cohort norms (AOR 0.66, 95% CI 0.45-0.96). Peer cohort norms were not significantly related to boys’ ESI. Conclusion Macro-level cultural norms may impact adolescents’ sexual initiation timing. Research exploring the sexual health outcomes of early initiators in countries with contrasting age norms is warranted. PMID:24508092

Recruit Fitness as a Predictor of Police Academy Graduation.

PubMed

Shusko, M; Benedetti, L; Korre, M; Eshleman, E J; Farioli, A; Christophi, C A; Kales, S N

2017-10-01

Suboptimal recruit fitness may be a risk factor for poor performance, injury, illness, and lost time during police academy training. To assess the probability of successful completion and graduation from a police academy as a function of recruits' baseline fitness levels at the time of academy entry. Retrospective study where all available records from recruit training courses held (2006-2012) at all Massachusetts municipal police academies were reviewed and analysed. Entry fitness levels were quantified from the following measures, as recorded at the start of each training class: body composition, push-ups, sit-ups, sit-and-reach, and 1.5-mile run-time. The primary outcome of interest was the odds of not successfully graduating from an academy. We used generalized linear mixed models in order to fit logistic regression models with random intercepts for assessing the probability of not graduating, based on entry-level fitness. The primary analyses were restricted to recruits with complete entry-level fitness data. The fitness measures most strongly associated with academy failure were lesser number of push-ups completed (odds ratio [OR] = 5.2, 95% confidence interval [CI] 2.3-11.7, for 20 versus 41-60 push-ups) and slower run times (OR = 3.8, 95% CI 1.8-7.8, [1.5 mile run time of ≥15'20″] versus [12'33″ to 10'37″]). Baseline pushups and 1.5-mile run-time showed the best ability to predict successful academy graduation, especially when considered together. Future research should include prospective validation of entry-level fitness as a predictor of subsequent police academy success. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine.

Impact of Urban Neighborhood Disadvantage on Late Stage Breast Cancer Diagnosis in Virginia.

PubMed

DeGuzman, Pam Baker; Cohn, Wendy F; Camacho, Fabian; Edwards, Brandy L; Sturz, Vanessa N; Schroen, Anneke T

2017-04-01

Research suggests that residents of inner-city urban neighborhoods have higher rates of late stage cancer diagnosis. Identifying urban neighborhoods with high rates of both concentrated disadvantage and late stage cancer diagnosis may assist health care providers to target screening interventions to reduce disparities. The purposes of this study were to (1) create an index to evaluate concentrated disadvantage (CD) using non-racial measures of poverty, (2) determine the impact of neighborhood CD on late stage breast cancer diagnosis in US cities, and (3) to understand the role of obesity on this relationship. We used census block group- (CBG) level poverty indicators from five Virginia cities to develop the index. Breast cancer cases of women aged 18-65 who lived in the five cities were identified from the 2000-2012 Virginia Cancer Registry. A logistic regression model with random intercept was used to evaluate the impact of disadvantage on late stage breast cancer diagnosis. CBG-level maps were developed to geographically identify neighborhoods with both high rates of CD and late breast cancer staging. Over 900 CBGs and 6000 breast cases were included. Global fit of the concentrated disadvantage model was acceptable. The effect of disadvantage on late stage was significant (OR = 1.0083, p = 0.032). Inner-city poverty impacts risk of late stage breast cancer diagnosis. Area-level obesity is highly correlated with neighborhood poverty (ρ = 0.74, p < 0.0001) but the mediating direct and indirect effects are non-significant. Intervening in these high poverty neighborhoods may help combat disparities in late stage diagnosis for urban poor and for minorities living in these underserved neighborhoods, but more study is needed to understanding the complex relationship between concentrated neighborhood poverty, obesity, and late stage diagnosis.

High adherence to the Western, Prudent, and Mediterranean dietary patterns and risk of gastric adenocarcinoma: MCC-Spain study.

PubMed

Castelló, Adela; Fernández de Larrea, Nerea; Martín, Vicente; Dávila-Batista, Verónica; Boldo, Elena; Guevara, Marcela; Moreno, Víctor; Castaño-Vinyals, Gemma; Gómez-Acebo, Inés; Fernández-Tardón, Guillermo; Peiró, Rosana; Olmedo-Requena, Rocío; Capelo, Rocio; Navarro, Carmen; Pacho-Valbuena, Silvino; Pérez-Gómez, Beatriz; Kogevinas, Manolis; Pollán, Marina; Aragonés, Nuria

2018-05-01

The influence of dietary habits on the development of gastric adenocarcinoma is not clear. The objective of the present study was to explore the association of three previously identified dietary patterns with gastric adenocarcinoma by sex, age, cancer site, and morphology. MCC-Spain is a multicase-control study that included 295 incident cases of gastric adenocarcinoma and 3040 controls. The association of the Western, Prudent, and Mediterranean dietary patterns-derived in another Spanish case-control study-with gastric adenocarcinoma was assessed using multivariable logistic regression models with random province-specific intercepts and considering a possible interaction with sex and age. Risk according to tumor site (cardia, non-cardia) and morphology (intestinal/diffuse) was evaluated using multinomial regression models. A high adherence to the Western pattern increased gastric adenocarcinoma risk [odds ratio fourth_vs._first_quartile (95% confidence interval), 2.09 (1.31; 3.33)] even at low levels [odds ratio second_vs._first_quartile (95% confidence interval), 1.63 (1.05; 2.52)]. High adherence to the Mediterranean dietary pattern could prevent gastric adenocarcinoma [odds ratio fourth_vs._first_quartile (95% confidence interval), 0.53 (0.34; 0.82)]. Although no significant heterogeneity of effects was observed, the harmful effect of the Western pattern was stronger among older participants and for non-cardia adenocarcinomas, whereas the protective effect of the Mediterranean pattern was only observed among younger participants and for non-cardia tumors. Decreasing the consumption of fatty and sugary products and of red and processed meat in favor of an increase in the intake of fruits, vegetables, legumes, olive oil, nuts, and fish might prevent gastric adenocarcinoma.

Random effects coefficient of determination for mixed and meta-analysis models.

PubMed

Demidenko, Eugene; Sargent, James; Onega, Tracy

2012-01-01

The key feature of a mixed model is the presence of random effects. We have developed a coefficient, called the random effects coefficient of determination, [Formula: see text], that estimates the proportion of the conditional variance of the dependent variable explained by random effects. This coefficient takes values from 0 to 1 and indicates how strong the random effects are. The difference from the earlier suggested fixed effects coefficient of determination is emphasized. If [Formula: see text] is close to 0, there is weak support for random effects in the model because the reduction of the variance of the dependent variable due to random effects is small; consequently, random effects may be ignored and the model simplifies to standard linear regression. The value of [Formula: see text] apart from 0 indicates the evidence of the variance reduction in support of the mixed model. If random effects coefficient of determination is close to 1 the variance of random effects is very large and random effects turn into free fixed effects-the model can be estimated using the dummy variable approach. We derive explicit formulas for [Formula: see text] in three special cases: the random intercept model, the growth curve model, and meta-analysis model. Theoretical results are illustrated with three mixed model examples: (1) travel time to the nearest cancer center for women with breast cancer in the U.S., (2) cumulative time watching alcohol related scenes in movies among young U.S. teens, as a risk factor for early drinking onset, and (3) the classic example of the meta-analysis model for combination of 13 studies on tuberculosis vaccine.

Suborbital Asteroid Intercept and Fragmentation for Very Short Warning Time Scenarios

NASA Technical Reports Server (NTRS)

Hupp, Ryan; Dewald, Spencer; Wie, Bong; Barbee, Brent W.

2015-01-01

Small near-Earth objects (NEOs) 50150 m in size are far more numerous (hundreds of thousands to millions yet to be discovered) than larger NEOs. Small NEOs, which are mostly asteroids rather than comets, are very faint in the night sky due to their small sizes, and are, therefore, difficult to discover far in advance of Earth impact. However, even small NEOs are capable of creating explosions with energies on the order of tens or hundreds of megatons (Mt).We are, therefore, motivated to prepare to respond effectively to short warning time, small NEO impact scenarios. In this paper we explore the lower bound on actionable warning time by investigating the performance of notional upgraded Intercontinental Ballistic Missiles (ICBMs) to carry Nuclear Explosive Device (NED) payloads to intercept and disrupt a fictitious incoming NEO at high altitudes (generally, at least 2500 km above Earth). We conduct this investigation by developing optimal NEO intercept trajectories for a range of cases and comparing their performances.Our results show that suborbital NEO intercepts using Minuteman III or SM-3 IIA launch vehicles could achieve NEO intercept a few minutes prior to when the NEOwould strike Earth. We also find that more powerful versions of the launch vehicles (e.g., total V 9.511 kms) could intercept incoming NEOs over a day prior to when the NEO would strike Earth, if launched at least several days prior to the time of NEO intercept. Finally, we discuss a number of limiting factors and practicalities that affect whether the notional systems we describe could become feasible.

A comparison of four-sample slope-intercept and single-sample 51Cr-EDTA glomerular filtration rate measurements.

PubMed

Porter, Charlotte A; Bradley, Kevin M; McGowan, Daniel R

2018-05-01

The aim of this study was to verify, with a large dataset of 1394 Cr-EDTA glomerular filtration rate (GFR) studies, the equivalence of slope-intercept and single-sample GFR. Raw data from 1394 patient studies were used to calculate four-sample slope-intercept GFR in addition to four individual single-sample GFR values (blood samples taken at 90, 150, 210 and 270 min after injection). The percentage differences between the four-sample slope-intercept and each of the single-sample GFR values were calculated, to identify the optimum single-sample time point. Having identified the optimum time point, the percentage difference between the slope-intercept and optimal single-sample GFR was calculated across a range of GFR values to investigate whether there was a GFR value below which the two methodologies cannot be considered equivalent. It was found that the lowest percentage difference between slope-intercept and single-sample GFR was for the third blood sample, taken at 210 min after injection. The median percentage difference was 2.5% and only 6.9% of patient studies had a percentage difference greater than 10%. Above a GFR value of 30 ml/min/1.73 m, the median percentage difference between the slope-intercept and optimal single-sample GFR values was below 10%, and so it was concluded that, above this value, the two techniques are sufficiently equivalent. This study supports the recommendation of performing single-sample GFR measurements for GFRs greater than 30 ml/min/1.73 m.

Quantum-key-distribution protocol with pseudorandom bases

NASA Astrophysics Data System (ADS)

Trushechkin, A. S.; Tregubov, P. A.; Kiktenko, E. O.; Kurochkin, Y. V.; Fedorov, A. K.

2018-01-01

Quantum key distribution (QKD) offers a way for establishing information-theoretical secure communications. An important part of QKD technology is a high-quality random number generator for the quantum-state preparation and for post-processing procedures. In this work, we consider a class of prepare-and-measure QKD protocols, utilizing additional pseudorandomness in the preparation of quantum states. We study one of such protocols and analyze its security against the intercept-resend attack. We demonstrate that, for single-photon sources, the considered protocol gives better secret key rates than the BB84 and the asymmetric BB84 protocols. However, the protocol strongly requires single-photon sources.

What predicts recovery orientation in county departments of mental health? A pilot study.

PubMed

Brown, Timothy T; Mahoney, Christine B; Adams, Neal; Felton, Mistique; Pareja, Candy

2010-09-01

In this pilot study we examined the determinants of recovery orientation among employees and influential stakeholders in a sample of 12 county departments of mental health in California. A two-level hierarchical linear model with random intercepts was estimated. Analyses show that recovery orientation has a U-shaped relationship with the age of staff/influential stakeholders and is negatively related to the difference between the desired level of adhocracy and the current level of adhocracy. Recovery orientation is positively related to the education level of staff/influential stakeholders, satisfying transformational leadership outcomes, and larger mental health budgets per capita. Policy implications are discussed.

Exploring the spatial distribution of light interception and photosynthesis of canopies by means of a functional-structural plant model.

PubMed

Sarlikioti, V; de Visser, P H B; Marcelis, L F M

2011-04-01

At present most process-based models and the majority of three-dimensional models include simplifications of plant architecture that can compromise the accuracy of light interception simulations and, accordingly, canopy photosynthesis. The aim of this paper is to analyse canopy heterogeneity of an explicitly described tomato canopy in relation to temporal dynamics of horizontal and vertical light distribution and photosynthesis under direct- and diffuse-light conditions. Detailed measurements of canopy architecture, light interception and leaf photosynthesis were carried out on a tomato crop. These data were used for the development and calibration of a functional-structural tomato model. The model consisted of an architectural static virtual plant coupled with a nested radiosity model for light calculations and a leaf photosynthesis module. Different scenarios of horizontal and vertical distribution of light interception, incident light and photosynthesis were investigated under diffuse and direct light conditions. Simulated light interception showed a good correspondence to the measured values. Explicitly described leaf angles resulted in higher light interception in the middle of the plant canopy compared with fixed and ellipsoidal leaf-angle distribution models, although the total light interception remained the same. The fraction of light intercepted at a north-south orientation of rows differed from east-west orientation by 10 % on winter and 23 % on summer days. The horizontal distribution of photosynthesis differed significantly between the top, middle and lower canopy layer. Taking into account the vertical variation of leaf photosynthetic parameters in the canopy, led to approx. 8 % increase on simulated canopy photosynthesis. Leaf angles of heterogeneous canopies should be explicitly described as they have a big impact both on light distribution and photosynthesis. Especially, the vertical variation of photosynthesis in canopy is such that the experimental approach of photosynthesis measurements for model parameterization should be revised.

Exploring the spatial distribution of light interception and photosynthesis of canopies by means of a functional–structural plant model

PubMed Central

Sarlikioti, V.; de Visser, P. H. B.; Marcelis, L. F. M.

2011-01-01

Background and Aims At present most process-based models and the majority of three-dimensional models include simplifications of plant architecture that can compromise the accuracy of light interception simulations and, accordingly, canopy photosynthesis. The aim of this paper is to analyse canopy heterogeneity of an explicitly described tomato canopy in relation to temporal dynamics of horizontal and vertical light distribution and photosynthesis under direct- and diffuse-light conditions. Methods Detailed measurements of canopy architecture, light interception and leaf photosynthesis were carried out on a tomato crop. These data were used for the development and calibration of a functional–structural tomato model. The model consisted of an architectural static virtual plant coupled with a nested radiosity model for light calculations and a leaf photosynthesis module. Different scenarios of horizontal and vertical distribution of light interception, incident light and photosynthesis were investigated under diffuse and direct light conditions. Key Results Simulated light interception showed a good correspondence to the measured values. Explicitly described leaf angles resulted in higher light interception in the middle of the plant canopy compared with fixed and ellipsoidal leaf-angle distribution models, although the total light interception remained the same. The fraction of light intercepted at a north–south orientation of rows differed from east–west orientation by 10 % on winter and 23 % on summer days. The horizontal distribution of photosynthesis differed significantly between the top, middle and lower canopy layer. Taking into account the vertical variation of leaf photosynthetic parameters in the canopy, led to approx. 8 % increase on simulated canopy photosynthesis. Conclusions Leaf angles of heterogeneous canopies should be explicitly described as they have a big impact both on light distribution and photosynthesis. Especially, the vertical variation of photosynthesis in canopy is such that the experimental approach of photosynthesis measurements for model parameterization should be revised. PMID:21355008

Contrasting plant height can improve the control of rain-borne diseases in wheat cultivar mixture: modelling splash dispersal in 3-D canopies.

PubMed

Vidal, T; Gigot, C; de Vallavieille-Pope, C; Huber, L; Saint-Jean, S

2018-06-08

Growing cultivars differing by their disease resistance level together (cultivar mixtures) can reduce the propagation of diseases. Although architectural characteristics of cultivars are little considered in mixture design, they could have an effect on disease, in particular through spore dispersal by rain splash, which occurs over short distances. The objective of this work was to assess the impact of plant height of wheat cultivars in mixtures on splash dispersal of Zymoseptoria tritici, which causes septoria tritici leaf blotch. We used a modelling approach involving an explicit description of canopy architecture and splash dispersal processes. The dispersal model computed raindrop interception by a virtual canopy as well as the production, transport and interception of splash droplets carrying inoculum. We designed 3-D virtual canopies composed of susceptible and resistant plants, according to field measurements at the flowering stage. In numerical experiments, we tested different heights of virtual cultivars making up binary mixtures to assess the influence of this architectural trait on dispersal patterns of spore-carrying droplets. Inoculum interception decreased exponentially with the height relative to the main inoculum source (lower diseased leaves of susceptible plants), and little inoculum was intercepted further than 40 cm above the inoculum source. Consequently, tall plants intercepted less inoculum than smaller ones. Plants with twice the standard height intercepted 33 % less inoculum than standard height plants. In cases when the height of suscpeptible plants was doubled, inoculum interception by resistant leaves was 40 % higher. This physical barrier to spore-carrying droplet trajectories reduced inoculum interception by tall susceptible plants and was modulated by plant height differences between cultivars of a binary mixture. These results suggest that mixture effects on spore dispersal could be modulated by an adequate choice of architectural characteristics of cultivars. In particular, even small differences in plant height could reduce spore dispersal.

Blackmail propagation on small-world networks

NASA Astrophysics Data System (ADS)

Shao, Zhi-Gang; Jian-Ping Sang; Zou, Xian-Wu; Tan, Zhi-Jie; Jin, Zhun-Zhi

2005-06-01

The dynamics of the blackmail propagation model based on small-world networks is investigated. It is found that for a given transmitting probability λ the dynamical behavior of blackmail propagation transits from linear growth type to logistical growth one with the network randomness p increases. The transition takes place at the critical network randomness pc=1/N, where N is the total number of nodes in the network. For a given network randomness p the dynamical behavior of blackmail propagation transits from exponential decrease type to logistical growth one with the transmitting probability λ increases. The transition occurs at the critical transmitting probability λc=1/, where is the average number of the nearest neighbors. The present work will be useful for understanding computer virus epidemics and other spreading phenomena on communication and social networks.

Effect of folic acid on appetite in children: ordinal logistic and fuzzy logistic regressions.

PubMed

Namdari, Mahshid; Abadi, Alireza; Taheri, S Mahmoud; Rezaei, Mansour; Kalantari, Naser; Omidvar, Nasrin

2014-03-01

Reduced appetite and low food intake are often a concern in preschool children, since it can lead to malnutrition, a leading cause of impaired growth and mortality in childhood. It is occasionally considered that folic acid has a positive effect on appetite enhancement and consequently growth in children. The aim of this study was to assess the effect of folic acid on the appetite of preschool children 3 to 6 y old. The study sample included 127 children ages 3 to 6 who were randomly selected from 20 preschools in the city of Tehran in 2011. Since appetite was measured by linguistic terms, a fuzzy logistic regression was applied for modeling. The obtained results were compared with a statistical ordinal logistic model. After controlling for the potential confounders, in a statistical ordinal logistic model, serum folate showed a significantly positive effect on appetite. A small but positive effect of folate was detected by fuzzy logistic regression. Based on fuzzy regression, the risk for poor appetite in preschool children was related to the employment status of their mothers. In this study, a positive association was detected between the levels of serum folate and improved appetite. For further investigation, a randomized controlled, double-blind clinical trial could be helpful to address causality. Copyright © 2014 Elsevier Inc. All rights reserved.

Determinants of childhood immunisation coverage in urban poor settlements of Delhi, India: a cross-sectional study

PubMed Central

Devasenapathy, Niveditha; Ghosh Jerath, Suparna; Sharma, Saket; Allen, Elizabeth; Shankar, Anuraj H; Zodpey, Sanjay

2016-01-01

Objectives Aggregate data on childhood immunisation from urban settings may not reflect the coverage among the urban poor. This study provides information on complete childhood immunisation coverage among the urban poor, and explores its household and neighbourhood-level determinants. Setting Urban poor community in the Southeast district of Delhi, India. Participants We randomly sampled 1849 children aged 1–3.5 years from 13 451 households in 39 clusters (cluster defined as area covered by a community health worker) in 2 large urban poor settlements. Of these, 1343 completed the survey. We collected information regarding childhood immunisation (BCG, oral polio vaccine, diphtheria–pertussis–tetanus vaccine, hepatitis B and measles) from vaccination cards or mothers’ recall. We used random intercept logistic regression to explore the sociodemographic determinants of complete immunisation. Results Complete immunisation coverage was 46.7% and 7.5% were not immunised. The odds of complete vaccination (OR, 95% CI) were lower in female children (0.70 (0.55 to 0.89)) and Muslim households (0.65 (0.45 to 0.94)). The odds of complete vaccination were higher if the mother was literate (1.6 (1.15 to 2.16)), if the child was born within the city (2.7 (1.97 to 3.65)), in a health facility ( 1.5 (1.19 to 2.02)), belonged to the highest wealth quintile (compared with the poorest; 2.46 (1.5 to 4.02)) or possessed a birth certificate (1.40 (1.03 to 1.91)). Cluster effect due to unmeasured neighbourhood factors expressed as median OR was 1.32. Conclusions Immunisation coverage in this urban poor area was much lower than that of regional surveys reporting overall urban data. Socioeconomic status of the household, female illiteracy, health awareness and gender inequality were important determinants of coverage in this population. Hence, in addition to enhancing the infrastructure for providing mother and child services, efforts are also needed to address these issues in order to improve immunisation coverage in deprived urban communities. Trial registration number CTRI/2011/091/000095. PMID:27566644

To drain or not to drain? Predictors of tube thoracostomy insertion and outcomes associated with drainage of traumatic hemothoraces.

PubMed

Wells, Bryan J; Roberts, Derek J; Grondin, Sean; Navsaria, Pradeep H; Kirkpatrick, Andrew W; Dunham, Michael B; Ball, Chad G

2015-09-01

Historical data suggests that many traumatic hemothoraces (HTX) can be managed expectantly without tube thoracostomy (TT) drainage. The purpose of this study was to identify predictors of TT, including whether the quantity of pleural blood predicted tube placement, and to evaluate outcomes associated with TT versus expected management (EM) of traumatic HTXs. A retrospective cohort study of all trauma patients with HTXs and an Injury Severity Score (ISS) ≥12 managed at a level I trauma centre between April 1, 2005 and December 31, 2012 was completed. Mixed-effects models with a subject-specific random intercept were used to identify independent risk factors for TT. Logistic and log-linear regression were used to compute odds ratios (ORs) for mortality and empyema and percent increases in length of hospital and intensive care unit stay between patients managed with TT versus EM, respectively. A total of 635 patients with 749 HTXs were included in the study. Overall, 491 (66%) HTXs were drained while 258 (34%) were managed expectantly. Independent predictors of TT placement included concomitant ipsilateral flail chest [OR 3.03; 95% confidence interval (CI) 1.04-8.80; p=0.04] or pneumothorax (OR 6.19; 95% CI 1.79-21.5; p<0.01) and the size of the HTX (OR per 10cc increase 1.12; 95% CI 1.04-1.21; p<0.01). Although the adjusted odds of mortality were not significantly different between groups (OR 3.99; 95% CI 0.87-18.30; p=0.08), TT was associated with a 47.14% (95% CI, 25.57-69.71%; p<0.01) adjusted increase in hospital length of stay. Empyemas (n=29) only occurred among TT patients. Expectant management of traumatic HTX was associated with a shorter length of hospital stay, no empyemas, and no increase in mortality. Although EM of smaller HTXs may be safe, these findings must be confirmed by a large multi-centre cohort study and randomized controlled trials before they are used to guide practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Randomized Controlled Study of the Virginia Student Threat Assessment Guidelines in Kindergarten through Grade 12

ERIC Educational Resources Information Center

Cornell, Dewey G.; Allen, Korrie; Fan, Xitao

2012-01-01

This randomized controlled study examined disciplinary outcomes for 201 students who made threats of violence at school. The students attended 40 schools randomly assigned to use the Virginia Student Threat Assessment Guidelines or follow a business-as-usual disciplinary approach in a control group. Logistic regression analyses found, after…

Psychrometric measurement of soil water potential: Stability of calibration and test of pressure-plate samples

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

Jones, T.L.; Gee, G.W.; Heller, P.R.

1990-08-01

A commercially available thermocouple psychrometer sample changer (Decagon SC-10A) was used to measure the water potential of field soils ranging in texture from sand to silty clay loam over a range of {minus}0.5 to {minus}20.0 MPa. The standard error of prediction based on regression statistics was generally between 0.04 and 0.14 MPa at {minus}5 MPa. Replacing the measuring junction of the unit changed the calibration slightly; however, it did not significantly alter measurement accuracy. Calibration curves measured throughout a year of testing are consistent and indicate no systematic drift in calibration. Most measurement uncertainty is produced by shifts in themore » intercept in the calibration equation rather than the slope. Both the variability in intercept and the regression error seem to be random. Measurements taken with the SC-10A show that water potential in both sand and silt loam samples removed from 1.5-MPa pressure plates was often 0.5 to 1.0 MPa greater than the 1.5-MPa applied pressure. Limited data from 0.5-MPa pressure plates show close agreement between SC-10A measurements and pressure applied to these more permeable plates.« less

The Hispanic Americans Baseline Alcohol Survey (HABLAS):Predictive invariance of Demographic Characteristics on Attitudes towards Alcohol across Hispanic National Groups#

PubMed Central

Mills, Britain A.; Caetano, Raul; Bernstein, Ira H.

2011-01-01

This study compares the demographic predictors of items assessing attitudes towards drinking across Hispanic national groups. Data were from the 2006 Hispanic Americans Baseline Alcohol Survey (HABLAS), which used a multistage cluster sample design to interview 5,224 individuals randomly selected from the household population in Miami, New York, Philadelphia, Houston, and Los Angeles. Predictive invariance of demographic predictors of alcohol attitudes over four Hispanic national groups (Puerto Rican, Cuban, Mexican, and South/Central Americans) was examined using multiple-group seemingly unrelated probit regression. The analyses examined whether the influence of various demographic predictors varied across the Hispanic national groups in their regression coefficients, item intercepts, and error correlations. The hypothesis of predictive invariance was supported. Hispanic groups did not differ in how demographic predictors related to individual attitudinal items (regression slopes were invariant). In addition, the groups did not differ in attitudinal endorsement rates once demographic covariates were taken into account (item intercepts were invariant). Although Hispanic groups have different attitudes about alcohol, the influence of multiple demographic characteristics on alcohol attitudes operates similarly across Hispanic groups. Future models of drinking behavior in adult Hispanics need not posit moderating effects of group on the relation between these background characteristics and attitudes. PMID:25379120

Barriers and dispersal surfaces in minimum-time interception

NASA Technical Reports Server (NTRS)

Rajan, N.; Ardema, M. D.

1982-01-01

Minimum time interception of a target moving in a horizontal plane is analyzed as a one-player differential game. Dispersal points and points on the barrier are located for a class of pursuit evasion and interception problems. These points are determined by constructing cross sections of the isochrones and hence obtaining the barrier, dispersal, and control level surfaces. The game solution maps the controls as a function of the state within the capture region.

Internal models and prediction of visual gravitational motion.

PubMed

Zago, Myrka; McIntyre, Joseph; Senot, Patrice; Lacquaniti, Francesco

2008-06-01

Baurès et al. [Baurès, R., Benguigui, N., Amorim, M.-A., & Siegler, I. A. (2007). Intercepting free falling objects: Better use Occam's razor than internalize Newton's law. Vision Research, 47, 2982-2991] rejected the hypothesis that free-falling objects are intercepted using a predictive model of gravity. They argued instead for "a continuous guide for action timing" based on visual information updated till target capture. Here we show that their arguments are flawed, because they fail to consider the impact of sensori-motor delays on interception behaviour and the need for neural compensation of such delays. When intercepting a free-falling object, the delays can be overcome by a predictive model of the effects of gravity on target motion.

Opportunities for ballistic missions to Halley's comet

NASA Technical Reports Server (NTRS)

Farquhar, R. W.; Wooden, W. H., II

1977-01-01

Alternative strategies for ballistic missions to Halley's comet in 1985-86 are described. A large scientific return would be acquired from a ballistic Halley intercept in spite of the high flyby speeds that are associated with this mission mode. The possibility of retargeting the cometary spacecraft to additional comets after the Halley intercept also exists. Two cometary spacecraft of identical design would be used to carry out four separate cometary encounters over a 3 year period. One spacecraft would intercept Halley's comet before its perihelion passage in December 1985 and then go on to comet Borrelly with an encounter in January 1988. The other spacecraft would be targeted for a postperihelion Halley intercept in March 1986 before proceeding toward an encounter with comet Tempel 2 in September 1988.

Influence of rainfall microstructure on rainfall interception

NASA Astrophysics Data System (ADS)

Zabret, Katarina; Rakovec, Jože; Mikoš, Matjaž; Šraj, Mojca

2016-04-01

Rainfall interception is part of the hydrological cycle. Precipitation, which hits vegetation, is retained on the leaves and branches, from which it eventually evaporates into the atmosphere (interception) or reaches the ground by dripping from the canopy, falling through the gaps (throughfall) and running down the stems (stemflow). The process is influenced by various meteorological and vegetation parameters. Often neglected meteorological parameter influencing rainfall interception is also rainfall microstructure. Rain is a discrete process consisting of various numbers of individual raindrops with different sizes and velocities. This properties describe rainfall microstructure which is often neglected in hydrological analysis and replaced with rainfall intensity. Throughfall, stemflow and rainfall microstructure have been measured since the beginning of the year 2014 under two tree species (Betula pendula and Pinus nigra) on a study plot in Ljubljana, Slovenia. The preliminary analysis of the influence of rainfall microstructure on rainfall interception has been conducted using three events with different characteristics measured in May 2014. Event A is quite short with low rainfall amount and moderate rainfall intensity, whereas events B and C have similar length but low and high intensities, respectively. Event A was observed on the 1st of May 2014. It was 22 minutes long and delivered 1.2 mm of rainfall. The average rainfall intensity was equal to 3.27 mm/h. The event consisted of 1,350 rain drops with average diameter of 1.517 mm and average velocity of 5.110 m/s. Both Betula pendula and Pinus nigra intercepted similar amount of rainfall, 68 % and 69 %, respectively. Event B was observed in the night from the 7th to 8th of May 2014, it was 16 hours and 18 minutes long, and delivered 4.2 mm of rainfall with average intensity of 0.97 mm/h. There were 39,108 raindrops detected with average diameter of 0.858 mm and average velocity of 3.855 m/s. Betula pendula (23 %) has intercepted significantly less rainfall than Pinus nigra (85%). Event C was also observed in the night time between 11th and 12th of May 2014, it lasted 4 hours and 12 minutes and delivered 34.6 mm of rainfall with an average intensity equal to 8.24 mm/h. During the event 147,236 raindrops with average diameter of 1.020 mm and average velocity of 4.078 m/s were detected. Betula pendula has intercepted only 6 % of rainfall whereas Pinus nigra intercepted majority of rainfall, namely 85 %. In case of B. pendula rainfall interception is increasing with higher velocity whereas it is lower for medium diameters than for smaller or larger diameters. Rainfall interception under P. nigra is decreasing with higher velocities and behaving similar as under B. pendula for different diameters but with less obvious difference between diameter classes. We will continue with the measurements and further analysis of several rainfall events will be prepared.

Suborbital Intercept and Fragmentation of an Asteroid with Very Short Warning Time Scenario

NASA Technical Reports Server (NTRS)

Hupp, Ryan; DeWald, Spencer; Wie, Bong; Barbee, Brent W.

2015-01-01

Small near-Earth objects (NEOs) is approx. 50-150 m in size are far more numerous (hundreds of thousands to millions yet to be discovered) than larger NEOs. Small NEOs, which are mostly asteroids rather than comets, are very faint in the night sky due to their small sizes, and are, therefore, difficult to discover far in advance of Earth impact. Furthermore, even small NEOs are capable of creating explosions with energies on the order of tens or hundreds of megatons (Mt). We are, therefore, motivated to prepare to respond effectively to short warning time, small NEO impact scenarios. In this paper we explore the lower bound on actionable warning time by investigating the performance of notional upgraded Intercontinental Ballistic Missiles (ICBMs) to carry Nuclear Explosive Device (NED) payloads to intercept and disrupt a hypothetical incoming NEO at high altitudes (generally at least 2500 km above Earth). We conduct this investigation by developing optimal NEO intercept trajectories for a range of cases and comparing their performances. Our results show that suborbital NEO intercepts using Minuteman III or SM-3 IIA launch vehicles could achieve NEO intercept a few minutes prior to when the NEO would strike Earth. We also find that more powerful versions of the launch vehicles (e.g., total deltaV is approx. 9.5-11 km/s) could intercept incoming NEOs several hours prior to when the NEO would strike Earth, if launched at least several days prior to the time of intercept. Finally, we discuss a number of limiting factors and practicalities that affect whether the notional systems we describe could become feasible.

Mission Design and Analysis for Suborbital Intercept and Fragmentation of an Asteroid with Very Short Warning Time

NASA Technical Reports Server (NTRS)

Hupp, Ryan; DeWald, Spencer; Wie, Bong; Barbee, Brent W.

2014-01-01

Small near-Earth objects (NEOs) approximately 50-150 m in size are far more numerous (hundreds of thousands to millions yet to be discovered) than larger NEOs. Small NEOs, which are mostly asteroids rather than comets, are very faint in the night sky due to their small sizes, and are, therefore, difficult to discover far in advance of Earth impact. Furthermore, even small NEOs are capable of creating explosions with energies on the order of tens or hundreds of megatons (Mt). We are, therefore, motivated to prepare to respond effectively to short warning time, small NEO impact scenarios. In this paper we explore the lower bound on actionable warning time by investigating the performance of notional upgraded Intercontinental Ballistic Missiles (ICBMs) to carry Nuclear Explosive Device (NED) payloads to intercept and disrupt a hypothetical incoming NEO at high altitudes (generally at least 2500 km above Earth). We conduct this investigation by developing optimal NEO intercept trajectories for a range of cases and comparing their performances. Our results show that suborbital NEO intercepts using Minuteman III or SM-3 IIA launch vehicles could achieve NEO intercept a few minutes prior to when the NEO would strike Earth. We also find that more powerful versions of the launch vehicles (e.g., total delta V of approximately 9.5-11 km/s) could intercept incoming NEOs several hours prior to when the NEO would strike Earth, if launched at least several days prior to the time of intercept. Finally, we discuss a number of limiting factors and practicalities that affect whether the notional systems we describe could become feasible.

Satellite-based prediction of rainfall interception by tropical forest stands of a human-dominated landscape in Central Sulawesi, Indonesia

NASA Astrophysics Data System (ADS)

Nieschulze, Jens; Erasmi, Stefan; Dietz, Johannes; Hölscher, Dirk

2009-01-01

SummaryRainforest conversion to other land use types drastically alters the hydrological cycle in which changes in rainfall interception contribute significantly to the observed differences. However, little is known about the effects of more gradual changes in forest structure and at regional scales. We studied land use types ranging from natural forest over selectively-logged forest to cacao agroforest in a lower montane region in Central Sulawesi, Indonesia, and tested the suitability of high-resolution optical satellite imagery for modeling observed interception patterns. Investigated characteristics indicating canopy structure were mean and standard deviation of reflectance values, local maxima, and self-similarity measures based on the grey level co-occurrence matrix and geostatistical variogram analysis. Previously studied and published rainfall interception data comprised twelve plots and median values per land use type ranged from 30% in natural forest to 18% in cacao agroforests. A linear regression model with local maxima, mean contrast and normalized digital vegetation index (NDVI) as regressors was able to explain more than 84% ( Radj2) of the variation encountered in the data. Other investigated characteristics did not prove significant in the regression analysis. The model yielded stable results with respect to cross-validation and also produced realistic values and spatial patterns when applied at the landscape level (783.6 ha). High values of interception were rare and localized in natural forest stands distant to villages, whereas low interception characterized the intensively used sites close to settlements. We conclude that forest use intensity significantly reduced rainfall interception and satellite image analysis can successfully be applied for its regional prediction, and most forest in the study region has already been subject to human-induced structural changes.

Can Collimated Extraterrestrial Signals be Intercepted?

NASA Astrophysics Data System (ADS)

Forgan, D. H.

2014-06-01

The Optical Search for Extraterrestrial Intelligence (OSETI) attempts to detect collimated, narrow-band pulses of electromagnetic radiation. These pulses may either consist of signals intentionally directed at the Earth, or signals between two star systems with a vector that unintentionally intersects the Solar System, allowing Earth to intercept the communication. But should we expect to be able to intercept these unintentional signals? And what constraints can we place upon the frequency of intelligent civilisations if we do? We carry out Monte Carlo Realisation simulations of interstellar communications between civilisations in the Galactic Habitable Zone (GHZ) using collimated beams. We measure the frequency with which beams between two stars are intercepted by a third. The interception rate increases linearly with the fraction of communicating civilisations, and as the cube of the beam opening angle, which is somewhat stronger than theoretical expectations, which we argue is due to the geometry of the GHZ. We find that for an annular GHZ containing 10,000 civilisations, intersections are unlikely unless the beams are relatively uncollimated. These results indicate that optical SETI is more likely to find signals deliberately directed at the Earth than accidentally intercepting collimated communications. Equally, civilisations wishing to establish a network of communicating species may use weakly collimated beams to build up the network through interception, if they are willing to pay a cost penalty that is lower than that meted by fully isotropic beacons. Future SETI searches should consider the possibility that communicating civilisations will attempt to strike a balance between optimising costs and encouraging contact between civilisations, and look for weakly collimated pulses as well as narrow-beam pulses directed deliberately at the Earth.

Measurement of snow interception and canopy effects on snow accumulation and melt in a mountainous maritime climate, Oregon, United States

NASA Astrophysics Data System (ADS)

Storck, Pascal; Lettenmaier, Dennis P.; Bolton, Susan M.

2002-11-01

The results of a 3 year field study to observe the processes controlling snow interception by forest canopies and under canopy snow accumulation and ablation in mountain maritime climates are reported. The field study was further intended to provide data to develop and test models of forest canopy effects on beneath-canopy snowpack accumulation and melt and the plot and stand scales. Weighing lysimeters, cut-tree experiments, and manual snow surveys were deployed at a site in the Umpqua National Forest, Oregon (elevation 1200 m). A unique design for a weighing lysimeter was employed that allowed continuous measurements of snowpack evolution beneath a forest canopy to be taken at a scale unaffected by variability in canopy throughfall. Continuous observations of snowpack evolution in large clearings were made coincidentally with the canopy measurements. Large differences in snow accumulation and ablation were observed at sites beneath the forest canopy and in large clearings. These differences were not well described by simple relationships between the sites. Over the study period, approximately 60% of snowfall was intercepted by the canopy (up to a maximum of about 40 mm water equivalent). Instantaneous sublimation rates exceeded 0.5 mm per hour for short periods. However, apparent average sublimation from the intercepted snow was less than 1 mm per day and totaled approximately 100 mm per winter season. Approximately 72 and 28% of the remaining intercepted snow was removed as meltwater drip and large snow masses, respectively. Observed differences in snow interception rate and maximum snow interception capacity between Douglas fir (Pseudotsuga menziesii), white fir (Abies concolor), ponderosa pine (Pinus ponderosa), and lodgepole pine (Pinus contorta) were minimal.

Interoperability In Multi-Layered Active Defense:The Need For Commonality And Robustness Between Active Defense Weapon Systems

DTIC Science & Technology

2016-02-16

into areas where there is no access to maritime platforms. Sea-based interceptor platforms have the ability to intercept targets at each stage of the...argues that the most efficient concept for integrating active defense weapon systems is a multi- layered architecture with redundant intercept ...faster data transfer and will prevent data loss. The need for almost 100% interception successes is increasing as the threat becomes more

Fractional-order information in the visual control of lateral locomotor interception.

PubMed

Bootsma, Reinoud J; Ledouit, Simon; Casanova, Remy; Zaal, Frank T J M

2016-04-01

Previous work on locomotor interception of a target moving in the transverse plane has suggested that interception is achieved by maintaining the target's bearing angle (often inadvertently confused and/or confounded with the target heading angle) at a constant value. However, dynamics-based model simulations testing the veracity of the underlying control strategy of nulling the rate of change in the bearing angle have been restricted to limited conditions of target motion, and only a few alternatives have been considered. Exploring a wide range of target motion characteristics with straight and curving ball trajectories in a virtual reality setting, we examined how soccer goalkeepers moved along the goal line to intercept long-range shots on goal, a situation in which interception is naturally constrained to movement along a single dimension. Analyses of the movement patterns suggested reliance on combinations of optical position and velocity for straight trajectories and optical velocity and acceleration for curving trajectories. As an alternative to combining such standard integer-order derivatives, we demonstrate with a simple dynamical model that nulling a single informational variable of a self-tuned fractional (rather than integer) order efficiently captures the timing and patterning of the observed interception behaviors. This new perspective could fundamentally change the conception of what perceptual systems may actually provide, both in humans and in other animals. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Size-exclusion chromatography of tea tannins and intercepting potentials of peptides for the inhibition of trypsin-caseinolytic activity by tea tannins.

PubMed

Kasai, Naoya; Nakatsubo, Genki

2006-07-12

Molecular-weight distribution and characterization of tea tannin were investigated by high-performance liquid chromatography and the equivalent preparative exclusion gel chromatography using Sephadex G-25. The characteristics of the fractions were studied regarding the amounts of terminal catechin, sugar, and gallic acid, the color reaction of the Folin-Chiocalteu reagent, the UV absorbance, and the inhibition activity for the trypsin-caseinolytic activity per weight. Furthermore, we investigated the intercepting activities of the inhibition by the amino acids, peptides, their analogues, poly(ethylene glycol)s (PEGs), and histatin 5 using the inhibition of trypsin-caseinolytic activity by tea. Arg, Lys, and their peptides had strong intercepting activities for the inhibition, but only a weak activity was detected in the Pro peptides or gelatin-like peptides of (Pro-Pro-Gly)(n) (n = 5 or 10). The guanidyl group of Arg and the amino methylene group of Lys were important for the intercepting activity, but the activity was weakly dependent upon the peptide bond formation. The intercepting activity of the peptides or PEG exponentially increased with the number of polymerizations. Histatin 5 did not have a remarkably strong intercepting activity considering the peptide length. The activity of the synthetic histatin 5 in which all of the Lys and Arg were substituted by Ala was at the same level as histatin 5.

Effect of randomness in logistic maps

NASA Astrophysics Data System (ADS)

Khaleque, Abdul; Sen, Parongama

2015-01-01

We study a random logistic map xt+1 = atxt[1 - xt] where at are bounded (q1 ≤ at ≤ q2), random variables independently drawn from a distribution. xt does not show any regular behavior in time. We find that xt shows fully ergodic behavior when the maximum allowed value of at is 4. However , averaged over different realizations reaches a fixed point. For 1 ≤ at ≤ 4, the system shows nonchaotic behavior and the Lyapunov exponent is strongly dependent on the asymmetry of the distribution from which at is drawn. Chaotic behavior is seen to occur beyond a threshold value of q1(q2) when q2(q1) is varied. The most striking result is that the random map is chaotic even when q2 is less than the threshold value 3.5699⋯ at which chaos occurs in the nonrandom map. We also employ a different method in which a different set of random variables are used for the evolution of two initially identical x values, here the chaotic regime exists for all q1 ≠ q2 values.

47 CFR 0.251 - Authority delegated.

Code of Federal Regulations, 2010 CFR

2010-10-01

... interception of telephone conversations. Nothing in this paragraph, however, shall affect the authority of the Inspector General to intercept or record telephone conversations as necessary in the conduct of...

Some climatological factors of pine in the lake toba catchment area

NASA Astrophysics Data System (ADS)

Nasution, Z.

2018-02-01

The article deals with climatological factors of Pine at the Lake Toba Catchment Area also called drained basin, Pinus merkusii is a plant endemic in Sumatra. A central population of Pine in North Sumatra is located in the Tapanuli region to south of Lake Toba. Junghuhn discovered the species in the mountains range of Sipirok. He provisionally named the species as Pinus sumatrana. The article presents a detail analysis of approaches to climate factors, considers rainfall, air temperature, humidity, stemflow, throughfall and Interception following calculation of regression to determine relationship between precipitation with stemflow and interception. Stemflow, it is highly significant with significance of difference between correlation coefficients and z normal distribution. Temperature and relative humidity are the important components in the climate. These components influence the evaporation process and rainfall in the catchment. Pinus merkusii has the big crown interception. Stemflow and Interception has an opposite relation. Increasing of interception capacity will decrease stemflow. This type of Pine also has rough bark however significant channels so that, it flows water even during the wet season and caused the stemflow in Pinus merkusii relatively bigger.

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.

Temporal changes in randomness of bird communities across Central Europe.

PubMed

Renner, Swen C; Gossner, Martin M; Kahl, Tiemo; Kalko, Elisabeth K V; Weisser, Wolfgang W; Fischer, Markus; Allan, Eric

2014-01-01

Many studies have examined whether communities are structured by random or deterministic processes, and both are likely to play a role, but relatively few studies have attempted to quantify the degree of randomness in species composition. We quantified, for the first time, the degree of randomness in forest bird communities based on an analysis of spatial autocorrelation in three regions of Germany. The compositional dissimilarity between pairs of forest patches was regressed against the distance between them. We then calculated the y-intercept of the curve, i.e. the 'nugget', which represents the compositional dissimilarity at zero spatial distance. We therefore assume, following similar work on plant communities, that this represents the degree of randomness in species composition. We then analysed how the degree of randomness in community composition varied over time and with forest management intensity, which we expected to reduce the importance of random processes by increasing the strength of environmental drivers. We found that a high portion of the bird community composition could be explained by chance (overall mean of 0.63), implying that most of the variation in local bird community composition is driven by stochastic processes. Forest management intensity did not consistently affect the mean degree of randomness in community composition, perhaps because the bird communities were relatively insensitive to management intensity. We found a high temporal variation in the degree of randomness, which may indicate temporal variation in assembly processes and in the importance of key environmental drivers. We conclude that the degree of randomness in community composition should be considered in bird community studies, and the high values we find may indicate that bird community composition is relatively hard to predict at the regional scale.

Using Cluster Bootstrapping to Analyze Nested Data with a Few Clusters

ERIC Educational Resources Information Center

Huang, Francis L.

2018-01-01

Cluster randomized trials involving participants nested within intact treatment and control groups are commonly performed in various educational, psychological, and biomedical studies. However, recruiting and retaining intact groups present various practical, financial, and logistical challenges to evaluators and often, cluster randomized trials…

Development of a subway operation incident delay model using accelerated failure time approaches.

PubMed

Weng, Jinxian; Zheng, Yang; Yan, Xuedong; Meng, Qiang

2014-12-01

This study aims to develop a subway operational incident delay model using the parametric accelerated time failure (AFT) approach. Six parametric AFT models including the log-logistic, lognormal and Weibull models, with fixed and random parameters are built based on the Hong Kong subway operation incident data from 2005 to 2012, respectively. In addition, the Weibull model with gamma heterogeneity is also considered to compare the model performance. The goodness-of-fit test results show that the log-logistic AFT model with random parameters is most suitable for estimating the subway incident delay. First, the results show that a longer subway operation incident delay is highly correlated with the following factors: power cable failure, signal cable failure, turnout communication disruption and crashes involving a casualty. Vehicle failure makes the least impact on the increment of subway operation incident delay. According to these results, several possible measures, such as the use of short-distance and wireless communication technology (e.g., Wifi and Zigbee) are suggested to shorten the delay caused by subway operation incidents. Finally, the temporal transferability test results show that the developed log-logistic AFT model with random parameters is stable over time. Copyright © 2014 Elsevier Ltd. All rights reserved.

A comparison of three random effects approaches to analyze repeated bounded outcome scores with an application in a stroke revalidation study.

PubMed

Molas, Marek; Lesaffre, Emmanuel

2008-12-30

Discrete bounded outcome scores (BOS), i.e. discrete measurements that are restricted on a finite interval, often occur in practice. Examples are compliance measures, quality of life measures, etc. In this paper we examine three related random effects approaches to analyze longitudinal studies with a BOS as response: (1) a linear mixed effects (LM) model applied to a logistic transformed modified BOS; (2) a model assuming that the discrete BOS is a coarsened version of a latent random variable, which after a logistic-normal transformation, satisfies an LM model; and (3) a random effects probit model. We consider also the extension whereby the variability of the BOS is allowed to depend on covariates. The methods are contrasted using a simulation study and on a longitudinal project, which documents stroke rehabilitation in four European countries using measures of motor and functional recovery. Copyright 2008 John Wiley & Sons, Ltd.

Evaluation of two least toxic integrated pest management programs for managing bed bugs (Heteroptera: Cimicidae) with discussion of a bed bug intercepting device.

PubMed

Wang, Changlu; Gibb, Timothy; Bennett, Gary W

2009-05-01

The cost and effectiveness of two bed bug (Cimex lectularius L.) integrated pest management (IPM) programs were evaluated for 10 wk. Sixteen bed bug-infested apartments were chosen from a high-rise low-income apartment building. The apartments were randomly divided into two treatment groups: diatomaceous earth dust-based IPM (D-IPM) and chlorfenapyr spray-based IPM (S-IPM). The initial median (minimum, maximum) bed bug counts (by visual inspection) of the two treatment groups were 73.5 (10, 352) and 77 (18, 3025), respectively. A seminar and an educational brochure were delivered to residents and staff. It was followed by installing encasements on mattresses and box springs and applying hot steam to bed bug-infested areas in all 16 apartments. Diatomaceous earth dust (Mother Earth-D) was applied in the D-IPM group 2 d after steaming. In addition, bed bug-intercepting devices were installed under legs of infested beds or sofas or chairs to intercept bed bugs. The S-IPM group only received 0.5% chlorfenapyr spray (Phantom) after the nonchemical treatments. All apartments were monitored bi-weekly and retreated when necessary. After 10 wk, bed bugs were eradicated from 50% of the apartments in each group. Bed bug count reduction (mean +/- SEM) was 97.6 +/- 1.6 and 89.7 +/- 7.3% in the D-IPM and S-IPM groups, respectively. Mean treatment costs in the 10-wk period were $463 and $482 per apartment in the D-IPM and S-IPM groups, respectively. Bed bug interceptors trapped an average of 219 +/- 135 bed bugs per apartment in 10 wk. The interceptors contributed to the IPM program efficacy and were much more effective than visual inspections in estimating bed bug numbers and determining the existence of bed bug infestations.

Standardization of automated 25-hydroxyvitamin D assays: How successful is it?

PubMed

Elsenberg, E H A M; Ten Boekel, E; Huijgen, H; Heijboer, A C

2017-12-01

Multiple 25(OH)D assays have recently been aligned to improve comparibility. In this study we investigated the performance of these assays using both native single-donor sera with target values certified by a reference method as well as single donor sera from a heterogeneous patient population. 25(OH)D levels were measured in twenty reference samples (Ref!25OHD; Labquality, Finland) using five automated methods (Lumipulse, Liaison, Cobas, iSYS and Access) and one aligned ID-XLC-MS/MS method (slope: 1,00; intercept: 0,00; R=0,996). Furthermore, 25(OH)D concentrations measured in 50 pregnant women and 52 random patients using the 5 automated assays were compared to the ID-XLC-MS/MS. In addition, Vitamin D binding protein (DBP) was measured. Most automated assays showed significant differences in 25(OH)D levels measured in reference samples. Slopes varied from 1,00 to 1,33, intercepts from -5.48 to -15,81nmol/L and the R from 0,971 to 0,997. This inaccuracy was even more prominent in a heterogeneous patient population. Slopes varied from 0,75 to 1,35, intercepts from -9.02 to 11,51nmol/L and the R from 0,840 to 0,949. For most assays the deviation in 25(OH)D concentration increased with elevating DBP concentrations suggesting that DBP might be one of the factors contributing to the inaccuracy in currently used automated 25(OH)D methods. Despite the use of standardized assays, we observed significant differences in 25(OH)D concentrations in some automated methods using reference material obtained from healthy single donor sera. In sera of a patient population this inaccuracy was even worse which is highly concerning as patient samples are being investigated in clinical laboratories. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

The expression of light-related leaf functional traits depends on the location of individual leaves within the crown of isolated Olea europaea trees

PubMed Central

Escribano-Rocafort, Adrián G.; Ventre-Lespiaucq, Agustina B.; Granado-Yela, Carlos; Rubio de Casas, Rafael; Delgado, Juan A.; Balaguer, Luis

2016-01-01

Background The spatial arrangement and expression of foliar syndromes within tree crowns can reflect the coupling between crown form and function in a given environment. Isolated trees subjected to high irradiance and concomitant stress may adjust leaf phenotypes to cope with environmental gradients that are heterogeneous in space and time within the tree crown. The distinct expression of leaf phenotypes among crown positions could lead to complementary patterns in light interception at the crown scale. Methods We quantified eight light-related leaf traits across 12 crown positions of ten isolated Olea europaea trees in the field. Specifically, we investigated whether the phenotypic expression of foliar traits differed among crown sectors and layers and five periods of the day from sunrise to sunset. We investigated the consequences in terms of the exposed area of the leaves at the tree scale during a single day. Key Results All traits differed among crown positions except the length-to-width ratio of the leaves. We found a strong complementarity in the patterns of the potential exposed area of the leaves among day periods as a result of a non-random distribution of leaf angles across the crown. Leaf exposure at the outer layer was below 60 % of the displayed surface, reaching maximum interception during morning periods. Daily interception increased towards the inner layer, achieving consecutive maximization from east to west positions within the crown, matching the sun’s trajectory. Conclusions The expression of leaf traits within isolated trees of O. europaea varies continuously through the crown in a gradient of leaf morphotypes and leaf angles depending on the exposure and location of individual leaves. The distribution of light-related traits within the crown and the complementarity in the potential exposure patterns of the leaves during the day challenges the assumption of low trait variability within individuals. PMID:26944783

Comparison of the evapotranspiration and its components before and after thinning in Japanese cedar and Japanese cypress forest

NASA Astrophysics Data System (ADS)

Tateishi, Makiko; Xiang, Yang; Matsuda, Hiroki; Saito, Takami; Sun, Haotian; Otsuki, Kyoichi; Kasahara, Tamao; Onda, Yuichi

2014-05-01

Water source area of Japan is often covered by forest, and 40 % of forest cover is coniferous plantation. Thinning has become a major tool in the management of plantation in recent years, but its effects on water cycle and its components are yet to be evaluated well. In this study, we investigated the changes in evapotranspiration and its components, including stand transpiration and canopy interception loss, after thinning in 50 years old Japanese cedar and Japanese cypress plantation at Yayama experimental catchment in Fukuoka, Japan. We established study plot in each Japanese cedar and Japanese cypress stand. Sap flow measurement was conducted for evaluating stand transpiration in each plot. Through fall and stem flow were also monitored to estimate canopy interception loss. The experiments were conducted over two years. During the measurements, 50 % of trees were thinned randomly in entire catchment, which has an area of 2.98 ha. Stem density was changed from 3945 to 1977 trees per ha after thinning. The reduction of daily stand transpiration in the studied Japanese cedar and cypress stands after thinning were 31.6 % and 48.2 % under the same condition of microclimate, respectively. These values were comparable to the changes in total sapwood area, 34.2 % and 44.5 %, and sap flow density did not change after thinning. It implies that sapwood area is a primary determinant of stand transpiration. Canopy interception ratios were 27 % and 26 % for Japanese cedar and cypress before thinning, and the ratios decreased to 24 % and 21 % after thinning, respectively. Thus, we obtained the changes in annual evapotranspiration and its components at catchment scale by using observation and models. The changes in partitioning of evapotranspiration is also discussed. The evapotranspiration before and after thinning were also compared to water balance data in this study site.

Visual Attention to Radar Displays

NASA Technical Reports Server (NTRS)

Moray, N.; Richards, M.; Brophy, C.

1984-01-01

A model is described which predicts the allocation of attention to the features of a radar display. It uses the growth of uncertainty and the probability of near collision to call the eye to a feature of the display. The main source of uncertainty is forgetting following a fixation, which is modelled as a two dimensional diffusion process. The model was used to predict information overload in intercept controllers, and preliminary validation obtained by recording eye movements of intercept controllers in simulated and live (practice) interception.

Apportionment of rainfall in central Himalayan forests (India)

NASA Astrophysics Data System (ADS)

Pathak, P. C.; Pandey, A. N.; Singh, J. S.

1985-02-01

The apportionment of rainfall into throughfall, stemflow and interception in certain forests of Kumaun Himalaya was assessed during the 1981 and 1982 monsoon seasons. Stemflow accounted for 0.28-0.89%, throughfall 74.7-91.5% and interception 8.1-25.0% of gross rainfall. The absolute values of throughfall, stemflow and interception were influenced by tree species. Overland flow was low for all forests, indicating that the latter are subsurface flow systems and, consequently, are specially susceptible to deforestation.

Accounting for intracell flow in models with emphasis on water table recharge and stream-aquifer interaction: 1. Problems and concepts

USGS Publications Warehouse

Jorgensen, Donald G.; Signor, Donald C.; Imes, Jeffrey L.

1989-01-01

Intracell flow is important in modeling cells that contain both sources and sinks. Special attention is needed if recharge through the water table is a source. One method of modeling multiple sources and sinks is to determine the net recharge per cell. For example, for a model cell containing both a sink and recharge through the water table, the amount of recharge should be reduced by the ratio of the area of influence of the sink within the cell to the area of the cell. The reduction is the intercepted portion of the recharge. In a multilayer model this amount is further reduced by a proportion factor, which is a function of the depth of the flow lines from the water table boundary to the internal sink. A gaining section of a stream is a typical sink. The aquifer contribution to a gaining stream can be conceptualized as having two parts; the first part is the intercepted lateral flow from the water table and the second is the flow across the streambed due to differences in head between the water level in the stream and the aquifer below. The amount intercepted is a function of the geometry of the cell, but the amount due to difference in head across the stream bed is largely independent of cell geometry. A discharging well can intercept recharge through the water table within a model cell. The net recharge to the cell would be reduced in proportion to the area of influence of the well within the cell. The area of influence generally changes with time. Thus the amount of intercepted recharge and net recharge may not be constant with time. During periods when the well is not discharging there will be no intercepted recharge even though the area of influence from previous pumping may still exist. The reduction of net recharge per cell due to internal interception of flow will result in a model-calculated mass balance less than the prototype. Additionally the “effective transmissivity” along the intercell flow paths may be altered when flow paths are occupied by intercepted recharge.

Fog interception by Ball moss (Tillandsia recurvata)

NASA Astrophysics Data System (ADS)

Guevara-Escobar, A.; Cervantes-Jiménez, M.; Suzán-Azpiri, H.; González-Sosa, E.; Hernández-Sandoval, L.; Malda-Barrera, G.; Martínez-Díaz, M.

2010-03-01

Interception losses are a major influence in the water yield of vegetated areas. For most storms, interception results in less water reaching the ground. However, fog drip or occult precipitation can result in negative interception because small drops are deposited on all plant surfaces and subsequently fall to the ground once vegetation storage capacities are exceeded. Fog drip is normally disregarded, but for some plant communities, it could be a mechanism offsetting evaporation losses. Tillandsia recurvata is a cosmopolitan epiphyte adapted to arid habitats where fog may be an important water source. Therefore, the interception storage capacity by T. recurvata was measured in controlled conditions through applying simulated rain or fog. The storage capacity was proportional to dry weight mass. Nocturnal stomatic opening in T. recurvata is not only relevant for CO2 but for water vapor, as suggested by the higher weight change of specimens wetted with fog for 1 h at dark in comparison to those wetted during daylight (543±77 vs. 325±56 mg, p=0.048). The coefficients obtained in the laboratory were used together with biomass measurements for T. recurvata in a xeric scrub to calculate the depth of water intercepted. Interception storage capacity (Cmin) was 0.19 and 0.54 mm for rainfall and fog respectively. T. recurvata contributed 20% to the rain interception of their shrub hosts: Acacia farnesiana and Prosopis laevigata. Meteorological data registered during one year at Cadereyta, México showed that radiative fog formation was possible during the dry season. The results showed the potential role of T. recurvata in capturing fog, which probably is a main source of water during the dry season that supports their reproductive and physiological activity at that time. The storage capacity of T. recurvata leaf surfaces could increase the amount of water available for evaporation, but as this species colonise montane forests, the effect could be negative on water recharge, because in the laboratory experiments it took up to 12 h to reach saturation conditions when fog was applied.

A comparison of rule-based and machine learning approaches for classifying patient portal messages.

PubMed

Cronin, Robert M; Fabbri, Daniel; Denny, Joshua C; Rosenbloom, S Trent; Jackson, Gretchen Purcell

2017-09-01

Secure messaging through patient portals is an increasingly popular way that consumers interact with healthcare providers. The increasing burden of secure messaging can affect clinic staffing and workflows. Manual management of portal messages is costly and time consuming. Automated classification of portal messages could potentially expedite message triage and delivery of care. We developed automated patient portal message classifiers with rule-based and machine learning techniques using bag of words and natural language processing (NLP) approaches. To evaluate classifier performance, we used a gold standard of 3253 portal messages manually categorized using a taxonomy of communication types (i.e., main categories of informational, medical, logistical, social, and other communications, and subcategories including prescriptions, appointments, problems, tests, follow-up, contact information, and acknowledgement). We evaluated our classifiers' accuracies in identifying individual communication types within portal messages with area under the receiver-operator curve (AUC). Portal messages often contain more than one type of communication. To predict all communication types within single messages, we used the Jaccard Index. We extracted the variables of importance for the random forest classifiers. The best performing approaches to classification for the major communication types were: logistic regression for medical communications (AUC: 0.899); basic (rule-based) for informational communications (AUC: 0.842); and random forests for social communications and logistical communications (AUCs: 0.875 and 0.925, respectively). The best performing classification approach of classifiers for individual communication subtypes was random forests for Logistical-Contact Information (AUC: 0.963). The Jaccard Indices by approach were: basic classifier, Jaccard Index: 0.674; Naïve Bayes, Jaccard Index: 0.799; random forests, Jaccard Index: 0.859; and logistic regression, Jaccard Index: 0.861. For medical communications, the most predictive variables were NLP concepts (e.g., Temporal_Concept, which maps to 'morning', 'evening' and Idea_or_Concept which maps to 'appointment' and 'refill'). For logistical communications, the most predictive variables contained similar numbers of NLP variables and words (e.g., Telephone mapping to 'phone', 'insurance'). For social and informational communications, the most predictive variables were words (e.g., social: 'thanks', 'much', informational: 'question', 'mean'). This study applies automated classification methods to the content of patient portal messages and evaluates the application of NLP techniques on consumer communications in patient portal messages. We demonstrated that random forest and logistic regression approaches accurately classified the content of portal messages, although the best approach to classification varied by communication type. Words were the most predictive variables for classification of most communication types, although NLP variables were most predictive for medical communication types. As adoption of patient portals increases, automated techniques could assist in understanding and managing growing volumes of messages. Further work is needed to improve classification performance to potentially support message triage and answering. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of the ecological water diversion project in Wenzhou City

NASA Astrophysics Data System (ADS)

Xu, Haibo; Fu, Lei; Lin, Tong

2018-02-01

As a developed city in China, Wenzhou City has been suffered from bad water quality for years. In order to improve the river network water quality, an ecological water diversion project was designed and executed by the regional government. In this study, an investigation and analysis of the regional ecological water diversion project is made for the purpose of examining the water quality improvements. A numerical model is also established, different water diversion flow rates and sewer interception levels are considered during the simulation. Simulation results reveal that higher flow rate and sewer interception level will greatly improve the river network water quality in Wenzhou City. The importance of the flow rate and interception level has been proved and future work will be focused on increasing the flow rate and upgrading the sewer interception level.

Barriers and dispersal surfaces in minimum-time interception. [for optimizing aircraft flight paths

NASA Technical Reports Server (NTRS)

Rajan, N.; Ardema, M. D.

1984-01-01

A method is proposed for mapping the barrier, dispersal, and control-level surfaces for a class of minimum-time interception and pursuit-evasion problems. Minimum-time interception of a target moving in a horizontal plane is formulated in a coordinate system whose origin is at the interceptor's terminal position and whose x-axis is along the terminal line of sight. This approach makes it possible to discuss the nature of the interceptor's extremals, using its extremal trajectory maps (ETMs), independently of target motion. The game surfaces are constructed by drawing sections of the isochrones, or constant minimum-time loci, from the interceptor and target ETMs. In this way, feedback solutions for the optimal controls are obtained. An example involving the interception of a target moving in a straight line at constant speed is presented.

The relationship between sense of community in the school and students' aggressive behavior: A multilevel analysis.

PubMed

Prati, Gabriele; Albanesi, Cinzia; Cicognani, Elvira

2018-06-18

School sense of community has been associated with lower levels of students' aggressive behaviors. The main aim of the study was to examine whether the magnitude of the influence of school sense of community on students' aggressive behavior is similar or different across schools with different levels of aggressive behaviors. Participants were 1,800 Italian students attending 44 middle and high schools. Using multilevel modeling (a random intercepts and slopes model), we found that the magnitude of the negative relationship between sense of community in the school and students' aggressive behaviors was stronger in schools with high levels of aggressive behavior. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Indirect interception actions by blind and visually impaired perceivers: echolocation for interceptive actions.

PubMed

Vernat, Jean-Philippe; Gordon, Michael S

2010-02-01

This research examined the acoustic information used to support interceptive actions by the blind. Congenitally blind and severely visually impaired participants (all wearing an opaque, black eye-mask) were asked to listen to a target ball rolling down a track. In response, participants rolled their own ball along a perpendicular path to intercept the target. To better understand what information was used the echoic conditions and rolling dynamics of the target were varied across test sessions. In addition the rolling speed of the target and the distance of the participant from the target were varied across trials. Results demonstrated that participants tended to perform most accurately at moderate speeds and distances, overestimating the target's arrival at the fastest speed, and underestimating it at the slowest speed. However, changes to the target's dynamics, that is, the amount of deceleration it underwent on approach, did not strongly influence performance. Echoic conditions were found to affect performance, as participants were slightly more accurate in conditions with faster, higher-intensity echoes. Based on these results blind individuals in this research seemed to be using spatial and temporal cues to coordinate their interceptive actions.

When up is down in 0g: how gravity sensing affects the timing of interceptive actions.

PubMed

Senot, Patrice; Zago, Myrka; Le Séac'h, Anne; Zaoui, Mohammed; Berthoz, Alain; Lacquaniti, Francesco; McIntyre, Joseph

2012-02-08

Humans are known to regulate the timing of interceptive actions by modeling, in a simplified way, Newtonian mechanics. Specifically, when intercepting an approaching ball, humans trigger their movements a bit earlier when the target arrives from above than from below. This bias occurs regardless of the ball's true kinetics, and thus appears to reflect an a priori expectation that a downward moving object will accelerate. We postulate that gravito-inertial information is used to tune visuomotor responses to match the target's most likely acceleration. Here we used the peculiar conditions of parabolic flight--where gravity's effects change every 20 s--to test this hypothesis. We found a striking reversal in the timing of interceptive responses performed in weightlessness compared with trials performed on ground, indicating a role of gravity sensing in the tuning of this response. Parallels between these observations and the properties of otolith receptors suggest that vestibular signals themselves might plausibly provide the critical input. Thus, in addition to its acknowledged importance for postural control, gaze stabilization, and spatial navigation, we propose that detecting the direction of gravity's pull plays a role in coordinating quick reactions intended to intercept a fast-moving visual target.

Large unbalanced credit scoring using Lasso-logistic regression ensemble.

PubMed

Wang, Hong; Xu, Qingsong; Zhou, Lifeng

2015-01-01

Recently, various ensemble learning methods with different base classifiers have been proposed for credit scoring problems. However, for various reasons, there has been little research using logistic regression as the base classifier. In this paper, given large unbalanced data, we consider the plausibility of ensemble learning using regularized logistic regression as the base classifier to deal with credit scoring problems. In this research, the data is first balanced and diversified by clustering and bagging algorithms. Then we apply a Lasso-logistic regression learning ensemble to evaluate the credit risks. We show that the proposed algorithm outperforms popular credit scoring models such as decision tree, Lasso-logistic regression and random forests in terms of AUC and F-measure. We also provide two importance measures for the proposed model to identify important variables in the data.

Scoring mode and age-related effects on youth soccer teams' defensive performance during small-sided games.

PubMed

Almeida, Carlos Humberto; Duarte, Ricardo; Volossovitch, Anna; Ferreira, António Paulo

2016-07-01

This study aimed to examine the scoring mode (line goal, double goal or central goal) and age-related effects on the defensive performance of youth soccer players during 4v4 small-sided games (SSGs). Altogether, 16 male players from 2 age groups (U13, n = 8, mean age: 12.61 ± 0.65 years; U15, n = 8, 14.86 ± 0.47 years) were selected as participants. In six independent sessions, participants performed the three SSGs each during 10-min periods. Teams' defensive performance was analysed at every instant ball possession was regained through the variables: ball-recovery type, ball-recovery sector, configuration of play and defence state. Multinomial logistic regression analysis used in this study revealed the following significant main effects of scoring mode and age: (1) line goal (vs. central goal) increased the odds of regaining possession through tackle and in the defensive midfield sector, and decreased the odds of successful interceptions; (2) double goal (vs. central goal) decreased the odds of regaining possession through turnover won and with elongated playing shapes; (3) the probability of regaining possession through interception significantly decreased with age. Moreover, as youth players move forward in age groups, teams tend to structurally evolve from elongated playing shapes to flattened shapes and, at a behavioural level, from defending in depth to more risky flattened configurations. Overall, by manipulating the scoring mode in SSGs, coaches can promote functional and coadaptive behaviours between teams not only in terms of configurations of play, but also on the pitch locations that teams explore to regain possession.

Predicting Brook Trout occurrence in stream reaches throughout their native range in the eastern United States

USGS Publications Warehouse

DeWeber, Jefferson Tyrell; Wagner, Tyler

2015-01-01

The Brook Trout Salvelinus fontinalis is an important species of conservation concern in the eastern USA. We developed a model to predict Brook Trout population status within individual stream reaches throughout the species’ native range in the eastern USA. We utilized hierarchical logistic regression with Bayesian estimation to predict Brook Trout occurrence probability, and we allowed slopes and intercepts to vary among ecological drainage units (EDUs). Model performance was similar for 7,327 training samples and 1,832 validation samples based on the area under the receiver operating curve (∼0.78) and Cohen's kappa statistic (0.44). Predicted water temperature had a strong negative effect on Brook Trout occurrence probability at the stream reach scale and was also negatively associated with the EDU average probability of Brook Trout occurrence (i.e., EDU-specific intercepts). The effect of soil permeability was positive but decreased as EDU mean soil permeability increased. Brook Trout were less likely to occur in stream reaches surrounded by agricultural or developed land cover, and an interaction suggested that agricultural land cover also resulted in an increased sensitivity to water temperature. Our model provides a further understanding of how Brook Trout are shaped by habitat characteristics in the region and yields maps of stream-reach-scale predictions, which together can be used to support ongoing conservation and management efforts. These decision support tools can be used to identify the extent of potentially suitable habitat, estimate historic habitat losses, and prioritize conservation efforts by selecting suitable stream reaches for a given action. Future work could extend the model to account for additional landscape or habitat characteristics, include biotic interactions, or estimate potential Brook Trout responses to climate and land use changes.

Traveler information services in rural tourism areas : appendix A, tourist intercept surveys

DOT National Transportation Integrated Search

2000-06-30

This document presents documentation regarding tourist intercept surveys for traveler information services in rural areas. It documents data collection functions and information dissemination functions, and provides an interpretive description of tra...

Color image encryption by using Yang-Gu mixture amplitude-phase retrieval algorithm in gyrator transform domain and two-dimensional Sine logistic modulation map

NASA Astrophysics Data System (ADS)

Sui, Liansheng; Liu, Benqing; Wang, Qiang; Li, Ye; Liang, Junli

2015-12-01

A color image encryption scheme is proposed based on Yang-Gu mixture amplitude-phase retrieval algorithm and two-coupled logistic map in gyrator transform domain. First, the color plaintext image is decomposed into red, green and blue components, which are scrambled individually by three random sequences generated by using the two-dimensional Sine logistic modulation map. Second, each scrambled component is encrypted into a real-valued function with stationary white noise distribution in the iterative amplitude-phase retrieval process in the gyrator transform domain, and then three obtained functions are considered as red, green and blue channels to form the color ciphertext image. Obviously, the ciphertext image is real-valued function and more convenient for storing and transmitting. In the encryption and decryption processes, the chaotic random phase mask generated based on logistic map is employed as the phase key, which means that only the initial values are used as private key and the cryptosystem has high convenience on key management. Meanwhile, the security of the cryptosystem is enhanced greatly because of high sensitivity of the private keys. Simulation results are presented to prove the security and robustness of the proposed scheme.

Dual representation of item positions in verbal short-term memory: Evidence for two access modes.

PubMed

Lange, Elke B; Verhaeghen, Paul; Cerella, John

Memory sets of N = 1~5 digits were exposed sequentially from left-to-right across the screen, followed by N recognition probes. Probes had to be compared to memory list items on identity only (Sternberg task) or conditional on list position. Positions were probed randomly or in left-to-right order. Search functions related probe response times to set size. Random probing led to ramped, "Sternbergian" functions whose intercepts were elevated by the location requirement. Sequential probing led to flat search functions-fast responses unaffected by set size. These results suggested that items in STM could be accessed either by a slow search-on-identity followed by recovery of an associated location tag, or in a single step by following item-to-item links in study order. It is argued that this dual coding of location information occurs spontaneously at study, and that either code can be utilised at retrieval depending on test demands.

Optimal feedback strategies for pursuit-evasion and interception in a plane

NASA Technical Reports Server (NTRS)

Rajan, N.; Ardema, M. D.

1983-01-01

Variable-speed pursuit-evasion and interception for two aircraft moving in a horizontal plane are analyzed in terms of a coordinate frame fixed in the plane at termination. Each participant's optimal motion can be represented by extremal trajectory maps. These maps are used to discuss sub-optimal approximations that are independent of the other participant. A method of constructing sections of the barrier, dispersal, and control-level surfaces and thus determining feedback strategies is described. Some examples are shown for pursuit-evasion and the minimum-time interception of a straight-flying target.

Proceedings of the Near-Earth-Object Interception Workshop

NASA Technical Reports Server (NTRS)

Canavan, G. J. (Editor); Solem, J. C. (Editor); Rather, John D. G. (Editor)

1993-01-01

The National Aeronautics and Space Administration Headquarters sponsored the Near-Earth-Object Interception Workshop hosted by the Los Alamos National Laboratory on 14-16 Jan. 1992 at the J. Robert Oppenheimer Study Center in Los Alamos, New Mexico. The Workshop evaluated the issues involved in intercepting celestial objects that could hit the Earth. It covered the technologies for acquiring, tracking, and homing, as well as those for sending interceptors to inspect, rendezvous with, land on, irradiate, deflect, or destroy them. This report records the presentations and technical options reviewed.

Investigation of Vapor Cooling Enhancements for Applications on Large Cryogenic Systems

NASA Technical Reports Server (NTRS)

Ameen, Lauren; Zoeckler, Joseph

2017-01-01

The need to demonstrate and evaluate the effectiveness of heat interception methods for use on a relevant cryogenic propulsion stage at a system level has been identified. Evolvable Cryogenics (eCryo) Structural Heat Intercept, Insulation and Vibration Evaluation Rig (SHIIVER) will be designed with vehicle specific geometries (SLS Exploration Upper Stage (EUS) as guidance) and will be subjected to simulated space environments. One method of reducing structure-born heat leak being investigated utilizes vapor-based heat interception. Vapor-based heat interception could potentially reduce heat leak into liquid hydrogen propulsion tanks, increasing potential mission length or payload capability. Due to the high number of unknowns associated with the heat transfer mechanism and integration of vapor-based heat interception on a realistic large-scale skirt design, a sub-scale investigation was developed. The sub-project effort is known as the Small-scale Laboratory Investigation of Cooling Enhancements (SLICE). The SLICE aims to study, design, and test sub-scale multiple attachments and flow configuration concepts for vapor-based heat interception of structural skirts. SLICE will focus on understanding the efficiency of the heat transfer mechanism to the boil-off hydrogen vapor by varying the fluid network designs and configurations. Various analyses were completed in MATLAB, Excel VBA, and COMSOL Multiphysics to understand the optimum flow pattern for heat transfer and fluid dynamics. Results from these analyses were used to design and fabricate test article subsections of a large forward skirt with vapor cooling applied. The SLICE testing is currently being performed to collect thermal mechanical performance data on multiple skirt heat removal designs while varying inlet vapor conditions necessary to intercept a specified amount of heat for a given system. Initial results suggest that applying vapor-cooling provides a 50 heat reduction in conductive heat transmission along the skirt to the tank. The information obtained by SLICE will be used by the SHIIVER engineering team to design and implement vapor-based heat removal technology into the SHIIVER forward skirt hardware design.

Plant light interception can be explained via computed tomography scanning: demonstration with pyramidal cedar (Thuja occidentalis, Fastigiata).

PubMed

Dutilleul, Pierre; Han, Liwen; Smith, Donald L

2008-01-01

Light interception by the leaf canopy is a key aspect of plant photosynthesis, which helps mitigate the greenhouse effect via atmospheric CO(2) recycling. The relationship between plant light interception and leaf area was traditionally modelled with the Beer-Lambert law, until the spatial distribution of leaves was incorporated through the fractal dimension of leafless plant structure photographed from the side allowing maximum appearance of branches and petioles. However, photographs of leafless plants are two-dimensional projections of three-dimensional structures, and sampled plants were cut at the stem base before leaf blades were detached manually, so canopy development could not be followed for individual plants. Therefore, a new measurement and modelling approach were developed to explain plant light interception more completely and precisely, based on appropriate processing of computed tomography (CT) scanning data collected for developing canopies. Three-dimensional images of canopies were constructed from CT scanning data. Leaf volumes (LV) were evaluated from complete canopy images, and fractal dimensions (FD) were estimated from skeletonized leafless images. The experimental plant species is pyramidal cedar (Thuja occidentalis, Fastigiata). The three-dimensional version of the Beer-Lambert law based on FD alone provided a much better explanation of plant light interception (R(2) = 0.858) than those using the product LV*FD (0.589) or LV alone (0.548). While values of all three regressors were found to increase over time, FD in the Beer-Lambert law followed the increase in light interception the most closely. The delayed increase of LV reflected the appearance of new leaves only after branches had lengthened and ramified. The very strong correlation obtained with FD demonstrates that CT scanning data contain fundamental information about the canopy architecture geometry. The model can be used to identify crops and plantation trees with improved light interception and productivity.

Plant Light Interception Can Be Explained via Computed Tomography Scanning: Demonstration with Pyramidal Cedar (Thuja occidentalis, Fastigiata)

PubMed Central

Dutilleul, Pierre; Han, Liwen; Smith, Donald L.

2008-01-01

Background and Aims Light interception by the leaf canopy is a key aspect of plant photosynthesis, which helps mitigate the greenhouse effect via atmospheric CO2 recycling. The relationship between plant light interception and leaf area was traditionally modelled with the Beer–Lambert law, until the spatial distribution of leaves was incorporated through the fractal dimension of leafless plant structure photographed from the side allowing maximum appearance of branches and petioles. However, photographs of leafless plants are two-dimensional projections of three-dimensional structures, and sampled plants were cut at the stem base before leaf blades were detached manually, so canopy development could not be followed for individual plants. Therefore, a new measurement and modelling approach were developed to explain plant light interception more completely and precisely, based on appropriate processing of computed tomography (CT) scanning data collected for developing canopies. Methods Three-dimensional images of canopies were constructed from CT scanning data. Leaf volumes (LV) were evaluated from complete canopy images, and fractal dimensions (FD) were estimated from skeletonized leafless images. The experimental plant species is pyramidal cedar (Thuja occidentalis, Fastigiata). Key Results The three-dimensional version of the Beer–Lambert law based on FD alone provided a much better explanation of plant light interception (R2 = 0·858) than those using the product LV*FD (0·589) or LV alone (0·548). While values of all three regressors were found to increase over time, FD in the Beer–Lambert law followed the increase in light interception the most closely. The delayed increase of LV reflected the appearance of new leaves only after branches had lengthened and ramified. Conclusions The very strong correlation obtained with FD demonstrates that CT scanning data contain fundamental information about the canopy architecture geometry. The model can be used to identify crops and plantation trees with improved light interception and productivity. PMID:17981879

Inferring microhabitat preferences of Lilium catesbaei (Liliaceae).

PubMed

Sommers, Kristen Penney; Elswick, Michael; Herrick, Gabriel I; Fox, Gordon A

2011-05-01

Microhabitat studies use varied statistical methods, some treating site occupancy as a dependent and others as an independent variable. Using the rare Lilium catesbaei as an example, we show why approaches to testing hypotheses of differences between occupied and unoccupied sites can lead to erroneous conclusions about habitat preferences. Predictive approaches like logistic regression can better lead to understanding of habitat requirements. Using 32 lily locations and 30 random locations >2 m from a lily (complete data: 31 lily and 28 random spots), we measured physical conditions--photosynthetically active radiation (PAR), canopy cover, litter depth, distance to and height of nearest shrub, and soil moisture--and number and identity of neighboring plants. Twelve lilies were used to estimate a photosynthetic assimilation curve. Analyses used logistic regression, discriminant function analysis (DFA), (multivariate) analysis of variance, and resampled Wilcoxon tests. Logistic regression and DFA found identical predictors of presence (PAR, canopy cover, distance to shrub, litter), but hypothesis tests pointed to a different set (PAR, litter, canopy cover, height of nearest shrub). Lilies are mainly in high-PAR spots, often close to light saturation. By contrast, PAR in random spots was often near the lily light compensation point. Lilies were near Serenoa repens less than at random; otherwise, neighbor identity had no significant effect. Predictive methods are more useful in this context than the hypothesis tests. Light availability plays a big role in lily presence, which may help to explain increases in flowering and emergence after fire and roller-chopping.

40 CFR 53.34 - Test procedure for methods for PM10 and Class I methods for PM2.5.

Code of Federal Regulations, 2011 CFR

2011-07-01

... linear regression parameters (slope, intercept, and correlation coefficient) describing the relationship... correlation coefficient. (2) To pass the test for comparability, the slope, intercept, and correlation...

Intercepting real and simulated falling objects: what is the difference?

PubMed

Baurès, Robin; Benguigui, Nicolas; Amorim, Michel-Ange; Hecht, Heiko

2009-10-30

The use of virtual reality is nowadays common in many studies in the field of human perception and movement control, particularly in interceptive actions. However, the ecological validity of the simulation is often taken for granted without having been formally established. If participants were to perceive the real situation and its virtual equivalent in a different fashion, the generalization of the results obtained in virtual reality to real life would be highly questionable. We tested the ecological validity of virtual reality in this context by comparing the timing of interceptive actions based upon actually falling objects and their simulated counterparts. The results show very limited differences as a function of whether participants were confronted with a real ball or a simulation thereof. And when present, such differences were limited to the first trial only. This result validates the use of virtual reality when studying interceptive actions of accelerated stimuli.

A novel guidance law using fast terminal sliding mode control with impact angle constraints.

PubMed

Sun, Lianghua; Wang, Weihong; Yi, Ran; Xiong, Shaofeng

2016-09-01

This paper is concerned with the question of, for a missile interception with impact angle constraints, how to design a guidance law. Firstly, missile interception with impact angle constraints is modeled; secondly, a novel guidance law using fast terminal sliding mode control based on extended state observer is proposed to optimize the trajectory and time of interception; finally, for stationary targets, constant velocity targets and maneuvering targets, the guidance law and the stability of the closed loop system is analyzed and the stability of the closed loop system is analyzed, respectively. Simulation results show that when missile and target are on a collision course, the novel guidance law using fast terminal sliding mode control with extended state observer has more optimized trajectory and effectively reduces the time of interception which has a great significance in modern warfare. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Spectral estimates of solar radiation intercepted by corn canopies

NASA Technical Reports Server (NTRS)

Bauer, M. E. (Principal Investigator); Daughtry, C. S. T.; Gallo, K. P.

1982-01-01

Reflectance factor data were acquired with a Landsat band radiometer throughout two growing seasons for corn (Zea mays L.) canopies differing in planting dates, populations, and soil types. Agronomic data collected included leaf area index (LAI), biomass, development stage, and final grain yields. The spectral variable, greenness, was associated with 78 percent of the variation in LAI over all treatments. Single observations of LAI or greenness have limited value in predicting corn yields. The proportions of solar radiation intercepted (SRI) by these canopies were estimated using either measured LAI or greenness. Both SRI estimates, when accumulated over the growing season, accounted for approximately 65 percent of the variation in yields. Models which simulated the daily effects of weather and intercepted solar radiation on growth had the highest correlations to grain yields. This concept of estimating intercepted solar radiation using spectral data represents a viable approach for merging spectral and meteorological data for crop yield models.

The association between levels of alcohol consumption and mental health problems and academic performance among young university students.

PubMed

Tembo, Chimwemwe; Burns, Sharyn; Kalembo, Fatch

2017-01-01

Mental health problems and harmful alcohol consumption have been found to be high among young university students compared to the general population in Australia. This research aimed to investigate the association between levels of drinking and mental health problems and academic performance among university students aged 18 to 24 years. This study used a quantitative cross-sectional design using data that were collected in 2014 as part of the Youth Alcohol Project (YAP). Participants were randomly drawn from a cross sectional sample of 6000 undergraduate students. Included in the study were only students who were within the age of 18-24, undergraduate, and internally enrolled at the main campus. A total of 2518 undergraduate students aged 18 to 24 years who were enrolled internally at Curtin University Bentley campus were randomly recruited. Data were collected through an online survey. Students were invited to participate in the study through their student email address. The email invitations coincided with the release of semester results to increase the likelihood of students accessing their emails. A further 628 students were randomly recruited through face to face intercept survey during the campus market days. Data were collected by trained research assistants. Validated instruments were used to collected data on levels of alcohol consumption, mental health, and academic performance. A considerable proportion of participants (44%) reported consuming alcohol at hazardous or harmful levels. Multiple logistic regression analysis showed that students who were consuming alcohol at hazardous levels were 1.2 times more likely to report psychological distress than those with lower levels of alcohol consumption (aOR 1.2, 95% CI: 1.1-1.5). In addition, being late for class (aOR 1.7, 95% CI:1.1-2.4), missing classes (aOR = 2.6, 95% CI: 1.9-2.6), inability to concentrate in class (aOR = 2.6, 95% CI: 1.9-3.4), and inability to complete assignments (aOR = 3.5, 95% CI 2.0-6.0) independently predicted for moderate or hazardous alcohol consumption. The study shows that a considerable proportion of undergraduate students at university consume alcohol at hazardous or harmful levels. In addition, high levels of alcohol consumption are associated with poor academic performance and mental health outcomes among students. The results of the study warrant multi-strategy interventions that focus on policy, organisational, educational, environmental and economic strategies that will help to reduce alcohol related harms among university students.

The association between levels of alcohol consumption and mental health problems and academic performance among young university students

PubMed Central

Burns, Sharyn; Kalembo, Fatch

2017-01-01

Purpose Mental health problems and harmful alcohol consumption have been found to be high among young university students compared to the general population in Australia. This research aimed to investigate the association between levels of drinking and mental health problems and academic performance among university students aged 18 to 24 years. Methods This study used a quantitative cross-sectional design using data that were collected in 2014 as part of the Youth Alcohol Project (YAP). Participants were randomly drawn from a cross sectional sample of 6000 undergraduate students. Included in the study were only students who were within the age of 18–24, undergraduate, and internally enrolled at the main campus. A total of 2518 undergraduate students aged 18 to 24 years who were enrolled internally at Curtin University Bentley campus were randomly recruited. Data were collected through an online survey. Students were invited to participate in the study through their student email address. The email invitations coincided with the release of semester results to increase the likelihood of students accessing their emails. A further 628 students were randomly recruited through face to face intercept survey during the campus market days. Data were collected by trained research assistants. Validated instruments were used to collected data on levels of alcohol consumption, mental health, and academic performance. Results A considerable proportion of participants (44%) reported consuming alcohol at hazardous or harmful levels. Multiple logistic regression analysis showed that students who were consuming alcohol at hazardous levels were 1.2 times more likely to report psychological distress than those with lower levels of alcohol consumption (aOR 1.2, 95% CI: 1.1–1.5). In addition, being late for class (aOR 1.7, 95% CI:1.1–2.4), missing classes (aOR = 2.6, 95% CI: 1.9–2.6), inability to concentrate in class (aOR = 2.6, 95% CI: 1.9–3.4), and inability to complete assignments (aOR = 3.5, 95% CI 2.0–6.0) independently predicted for moderate or hazardous alcohol consumption. Conclusion The study shows that a considerable proportion of undergraduate students at university consume alcohol at hazardous or harmful levels. In addition, high levels of alcohol consumption are associated with poor academic performance and mental health outcomes among students. The results of the study warrant multi-strategy interventions that focus on policy, organisational, educational, environmental and economic strategies that will help to reduce alcohol related harms among university students. PMID:28658300

The arcsine is asinine: the analysis of proportions in ecology.

PubMed

Warton, David I; Hui, Francis K C

2011-01-01

The arcsine square root transformation has long been standard procedure when analyzing proportional data in ecology, with applications in data sets containing binomial and non-binomial response variables. Here, we argue that the arcsine transform should not be used in either circumstance. For binomial data, logistic regression has greater interpretability and higher power than analyses of transformed data. However, it is important to check the data for additional unexplained variation, i.e., overdispersion, and to account for it via the inclusion of random effects in the model if found. For non-binomial data, the arcsine transform is undesirable on the grounds of interpretability, and because it can produce nonsensical predictions. The logit transformation is proposed as an alternative approach to address these issues. Examples are presented in both cases to illustrate these advantages, comparing various methods of analyzing proportions including untransformed, arcsine- and logit-transformed linear models and logistic regression (with or without random effects). Simulations demonstrate that logistic regression usually provides a gain in power over other methods.

[Dental alveolar bone and dental arch remodeling in children: orthodontic diagnosis and treatments based on individual child arch development].

PubMed

Xiaobing, Li

2016-12-01

The etiology of malocclusions basically involves both congenital and environmental factors. Malocclusion is the result of the abnormal development of the orofacial complex (including tooth, dental alveolar bone, upper and lower jaws). Early orthodontic interceptive treatments involve the elimination of all congenital and environmental factors that contribute to the malformation of the orofacial complex, as well as interrupt the deviated development of the orofacial complex and the occlusion. Early orthodontic interceptive treatments mainly aim to use children's growth potential to correct abnormal developments of occlusions and orthodontically treat malocclusions more efficiently. The early orthodontic interceptive treatments include correcting the child's bad oral habits, training the abnormal functioned para-oral muscles, maintaining the normal eruptions of succeeding permanent teeth, applying interceptive treatments to the mal-developed teeth, and employing functional orthopedic treatments for abnormal growths of the upper and lower jaws. In orthodontics, correcting mal-positioned teeth is called orthodontic treatment, while rectifying the abnormal relationships of the upper and lower jaws is called functional orthopedic treatment. However, no clear definition is available as regards to the early orthodontic interceptive treatment of malocclusions caused by the deviated development of the dental alveolar bone. This new theory of "early dental alveolar bone and dental arch remodeling technique" was proposed by Professor Li Xiaobing of the Department of Pediatric Dentistry, Faculty of Pediatric Dentistry and Orthodontics in West China Hospital of Stomatology through his clinical analyses and investigation of his early orthodontic interceptive treatments. He defined the early orthodontic corrections of abnormal growth of dental alveolar bone as "remodel". The "early dental alveolar bone and dental arch remodeling theory and technique" is proved useful in malocclusion diagnosis and treatment planning during early orthodontic interceptive treatment with malformed dental arch. With the development of the theory and technique, the author intended to prevent and intercept the malocclusion development more effectively and efficiently. This review presents the development and clinical usages of the theory which to provide a new vision in the analysis of malocclusions on the basis of the developmental mechanism of the alveolar bone and dental arch. With clinical case illustration, the author demonstrateshis successful orthodontic clinical practices with this theory, which may contribute to the development of contemporary orthodontic theories and techniques.

Intraoperative centration during small incision lenticule extraction (SMILE)

PubMed Central

Wong, John X.; Wong, Elizabeth P.; Htoon, Hla M.; Mehta, Jodhbir S.

2017-01-01

Abstract To evaluate intraoperative decentration from pupil center and kappa intercept during small incision lenticule extraction (SMILE) and its impact on visual outcomes. This was a retrospective noncomparative case series. A total of 164 eyes that underwent SMILE at the Singapore National Eye Center were included. Screen captures of intraoperative videos were analyzed. Preoperative and 3 month postoperative vision and refractive data were analyzed against decentration. The mean preoperative spherical equivalent (SE) was −5.84 ± 1.77. The mean decentration from the pupil center and from kappa intercept were 0.13 ± 0.06 mm and 0.47mm ± 0.25 mm, respectively. For efficacy and predictability, 69.6% and 95.0% of eyes achieved a visual acuity (VA) of 20/20 and 20/30, respectively, while 83.8% and 97.2% of eyes were within ±0.5D and ±1.0D of the targeted SE. When analyzed across 3 groups of decentration from the pupil center (<0.1 mm, 0.1–0.2 mm, and >0.2 mm), there was no statistically significant association between decentration, safety, efficacy, and predictability. When analyzed across 4 groups of decentration from kappa intercept (<0.2 mm, 0.2–<0.4 mm, 0.4–<0.6 mm, and ≥0.6 mm), there was a trend toward higher efficacy for eyes with decentration of kappa intercept between 0.4 and <0.6 mm (P = .097). A total of 85.4% of eyes in the 0.4 to <0.6 mm group had unaided distance VA of 20/20 or better, as compared to only 57.8% of eyes in ≥0.6 mm group. Decentration of 0.13 mm from the pupil center does not result in compromised visual outcomes. Decentration of greater than 0.6 mm from the kappa intercept may result in compromised visual outcomes. There was a trend toward better efficacy in eyes which had decentered treatment from 0.4 to <0.6 mm from the kappa intercept. Patients with a large kappa intercept (>0.6 mm) should have their lenticule created 0.4 to 0.6 mm from the kappa intercept and not close to the pupil. PMID:28422822

The Potential for Mindfulness-Based Intervention in Workplace Mental Health Promotion: Results of a Randomized Controlled Trial

PubMed Central

Huang, Shu-Ling; Li, Ren-Hau; Huang, Feng-Ying; Tang, Feng-Cheng

2015-01-01

Objectives This study aims to intensively evaluate the effectiveness of mindfulness-based intervention (MBI) on mental illness risks (including psychological distress, prolonged fatigue, and perceived stress) and job strain (job control and job demands) for employees with poor mental health. Methods A longitudinal research design was adopted. In total, 144 participants were randomized to the intervention group or the control group. The intervention group participated in MBI for eight weeks. Measurements were collected for both groups at five time points: at pre-intervention (T1), at mid-intervention (T2), at the completion of intervention (T3), four weeks after intervention (T4), and eight weeks after intervention (T5). Data were analyzed according to the intention-to-treat principle. A linear mixed model with two levels was employed to analyze the repeated measurement data. Results Compared with the control group, the intercepts (means at T3) for the intervention group were significantly lower on psychological distress, prolonged fatigue, and perceived stress when MBI was completed. Even with the demographic variables controlled, the positive effects remained. For growth rates of prolonged fatigue and perceived stress, participants in the intervention group showed a steeper decrease than did the participants in the control group. Regarding job strain, although the intercept (mean at T3) of job demands showed a significant decline when BMI was completed, the significance disappeared when the demographic variables were controlled. Moreover, the other results for job control and job demands did not show promising findings. Conclusion As a workplace health promotion program, the MBI seems to have potential in improving mental illness risks for employees with poor mental health. However, there was insufficient evidence to support its effect on mitigating job strain. Further research on maintaining the positive effects on mental health for the long term and on developing innovative MBI to suit job strain are recommended. Trial Registration ClinicalTrials.gov NCT02241070 PMID:26367270

Transformations of snow chemistry in the boreal forest: Accumulation and volatilization

USGS Publications Warehouse

Pomeroy, J.W.; Davies, T.D.; Jones, H.G.; Marsh, P.; Peters, N.E.; Tranter, M.

1999-01-01

This paper examines the processes and dynamics of ecologically-important inorganic chemical (primarily NO3-N) accumulation and loss in boreal forest snow during the cold winter period at a northern and southern location in the boreal forest of western Canada. Field observations from Inuvik, Northwest Territories and Waskesiu, Saskatchewan, Canada were used to link chemical transformations and physical processes in boreal forest snow. Data on the disposition and overwinter transformation of snow water equivalent, NO3-, SO42- and other major ions were examined. No evidence of enhanced dry deposition of chemical species to intercepted snow was found at either site except where high atmospheric aerosol concentrations prevailed. At Inuvik, concentrations of SO42- and Cl- were five to six times higher in intercepted snow than in surface snow away from the trees. SO4-S and Cl loads at Inuvik were correspondingly enhanced three-fold within the nearest 0.5 m to individual tree stems. Measurements of snow affected by canopy interception without rapid sublimation provided no evidence of ion volatilization from intercepted snow. Where intercepted snow sublimation rates were significant, ion loads in sub-canopy snow suggested that NO3- volatized with an efficiency of about 62% per snow mass sublimated. Extrapolating this measurement from Waskesiu to sublimation losses observed in other southern boreal environments suggests that 19-25% of snow inputs of NO3- can be lost during intercepted snow sublimation. The amount of N lost during sublimation may be large in high-snowfall, high N load southern boreal forests (Quebec) where 0.42 kg NO3-N ha-1 is estimated as a possible seasonal NO3- volatilization. The sensitivity of the N fluxes to climate and forest canopy variation and implications of the winter N losses for N budgets in the boreal forest are discussed.This paper examines the processes and dynamics of ecologically-important inorganic chemical (primarily NO3-N) accumulation and loss in boreal forest snow during the cold winter period at a northern and southern location in the boreal forest of western Canada. Field observations from Inuvik. Northwest Territories and Waskesiu, Saskatchewan, Canada were used to link chemical transformations and physical processes in boreal forest snow. Data on the disposition and overwinter transformation of snow water equivalent, NO3-, SO42- and other major ions were examined. No evidence of enhanced dry deposition of chemical species to intercepted snow was found at either site except where high atmospheric aerosol concentrations prevailed. At Inuvik, concentrations of SO42- and Cl- were five to six times higher in intercepted snow than in surface snow away from the trees. SO4-S and Cl loads at Inuvik were correspondingly enhanced three-fold within the nearest 0.5 m to individual tree stems. Measurements of snow affected by canopy interception without rapid sublimation provided no evidence of ion volatilization from intercepted snow. Where intercepted snow sublimation rates were significant, ion loads in sub-canopy snow suggested that NO3- volatized with an efficiency of about 62% per snow mass sublimated. Extrapolating this measurement from Waskesiu to sublimation losses observed in other southern boreal environments suggests that 19-25% of snow inputs of NO3- can be lost during intercepted snow sublimation. The amount of N lost during sublimation may be large in high-snowfall, high N load southern boreal forests (Quebec) where 0.42 kg NO3-N ha-1 is estimated as a possible seasonal NO3- volatilization. The sensitivity of the N fluxes to climate and forest canopy variation and implications of the winter N losses for N budgets in the boreal forest are discussed.

Comparison of Logistic Regression and Random Forests techniques for shallow landslide susceptibility assessment in Giampilieri (NE Sicily, Italy)

NASA Astrophysics Data System (ADS)

Trigila, Alessandro; Iadanza, Carla; Esposito, Carlo; Scarascia-Mugnozza, Gabriele

2015-11-01

The aim of this work is to define reliable susceptibility models for shallow landslides using Logistic Regression and Random Forests multivariate statistical techniques. The study area, located in North-East Sicily, was hit on October 1st 2009 by a severe rainstorm (225 mm of cumulative rainfall in 7 h) which caused flash floods and more than 1000 landslides. Several small villages, such as Giampilieri, were hit with 31 fatalities, 6 missing persons and damage to buildings and transportation infrastructures. Landslides, mainly types such as earth and debris translational slides evolving into debris flows, were triggered on steep slopes and involved colluvium and regolith materials which cover the underlying metamorphic bedrock. The work has been carried out with the following steps: i) realization of a detailed event landslide inventory map through field surveys coupled with observation of high resolution aerial colour orthophoto; ii) identification of landslide source areas; iii) data preparation of landslide controlling factors and descriptive statistics based on a bivariate method (Frequency Ratio) to get an initial overview on existing relationships between causative factors and shallow landslide source areas; iv) choice of criteria for the selection and sizing of the mapping unit; v) implementation of 5 multivariate statistical susceptibility models based on Logistic Regression and Random Forests techniques and focused on landslide source areas; vi) evaluation of the influence of sample size and type of sampling on results and performance of the models; vii) evaluation of the predictive capabilities of the models using ROC curve, AUC and contingency tables; viii) comparison of model results and obtained susceptibility maps; and ix) analysis of temporal variation of landslide susceptibility related to input parameter changes. Models based on Logistic Regression and Random Forests have demonstrated excellent predictive capabilities. Land use and wildfire variables were found to have a strong control on the occurrence of very rapid shallow landslides.

Logistic regression of family data from retrospective study designs.

PubMed

Whittemore, Alice S; Halpern, Jerry

2003-11-01

We wish to study the effects of genetic and environmental factors on disease risk, using data from families ascertained because they contain multiple cases of the disease. To do so, we must account for the way participants were ascertained, and for within-family correlations in both disease occurrences and covariates. We model the joint probability distribution of the covariates of ascertained family members, given family disease occurrence and pedigree structure. We describe two such covariate models: the random effects model and the marginal model. Both models assume a logistic form for the distribution of one person's covariates that involves a vector beta of regression parameters. The components of beta in the two models have different interpretations, and they differ in magnitude when the covariates are correlated within families. We describe ascertainment assumptions needed to estimate consistently the parameters beta(RE) in the random effects model and the parameters beta(M) in the marginal model. Under the ascertainment assumptions for the random effects model, we show that conditional logistic regression (CLR) of matched family data gives a consistent estimate beta(RE) for beta(RE) and a consistent estimate for the covariance matrix of beta(RE). Under the ascertainment assumptions for the marginal model, we show that unconditional logistic regression (ULR) gives a consistent estimate for beta(M), and we give a consistent estimator for its covariance matrix. The random effects/CLR approach is simple to use and to interpret, but it can use data only from families containing both affected and unaffected members. The marginal/ULR approach uses data from all individuals, but its variance estimates require special computations. A C program to compute these variance estimates is available at http://www.stanford.edu/dept/HRP/epidemiology. We illustrate these pros and cons by application to data on the effects of parity on ovarian cancer risk in mother/daughter pairs, and use simulations to study the performance of the estimates. Copyright 2003 Wiley-Liss, Inc.

Large Unbalanced Credit Scoring Using Lasso-Logistic Regression Ensemble

PubMed Central

Wang, Hong; Xu, Qingsong; Zhou, Lifeng

2015-01-01

Recently, various ensemble learning methods with different base classifiers have been proposed for credit scoring problems. However, for various reasons, there has been little research using logistic regression as the base classifier. In this paper, given large unbalanced data, we consider the plausibility of ensemble learning using regularized logistic regression as the base classifier to deal with credit scoring problems. In this research, the data is first balanced and diversified by clustering and bagging algorithms. Then we apply a Lasso-logistic regression learning ensemble to evaluate the credit risks. We show that the proposed algorithm outperforms popular credit scoring models such as decision tree, Lasso-logistic regression and random forests in terms of AUC and F-measure. We also provide two importance measures for the proposed model to identify important variables in the data. PMID:25706988

The pattern of the discovery of medication errors in a tertiary hospital in Hong Kong.

PubMed

Samaranayake, N R; Cheung, S T D; Chui, W C M; Cheung, B M Y

2013-06-01

The primary goal of reducing medication errors is to eliminate those that reach the patient. We aimed to study the pattern of interceptions to tackle medication errors along the medication use processes. Tertiary care hospital in Hong Kong. The 'Swiss Cheese Model' was used to explain the interceptions targeting medication error reporting over 5 years (2006-2010). Proportions of prescribing, dispensing and drug administration errors intercepted by pharmacists and nurses; proportions of prescribing, dispensing and drug administration errors that reached the patient. Our analysis included 1,268 in-patient medication errors, of which 53.4% were related to prescribing, 29.0% to administration and 17.6% to dispensing. 34.1% of all medication errors (4.9% prescribing, 26.8% drug administration and 2.4% dispensing) were not intercepted. Pharmacy staff intercepted 85.4% of the prescribing errors. Nurses detected 83.0% of dispensing and 5.0% of prescribing errors. However, 92.4% of all drug administration errors reached the patient. Having a preventive measure at each stage of the medication use process helps to prevent most errors. Most drug administration errors reach the patient as there is no defense against these. Therefore, more interventions to prevent drug administration errors are warranted.

A new terminal guidance sensor system for asteroid intercept or rendezvous missions

NASA Astrophysics Data System (ADS)

Lyzhoft, Joshua; Basart, John; Wie, Bong

2016-02-01

This paper presents the initial conceptual study results of a new terminal guidance sensor system for asteroid intercept or rendezvous missions, which explores the use of visual, infrared, and radar devices. As was demonstrated by NASA's Deep Impact mission, visual cameras can be effectively utilized for hypervelocity intercept terminal guidance for a 5 kilometer target. Other systems such as Raytheon's EKV (Exoatmospheric Kill Vehicle) employ a different scheme that utilizes infrared target information to intercept ballistic missiles. Another example that uses infrared information is the NEOWISE telescope, which is used for asteroid detection and tracking. This paper describes the signal-to-noise ratio estimation problem for infrared sensors, minimum and maximum range of detection, and computational validation using GPU accelerated simulations. Small targets (50-100 m in diameter) are considered, and scaled polyhedron models of known objects, such as the Rosetta mission's Comet 67P/Churyumov-Gerasimenko, 101,955 Bennu, target of the OSIRIS-REx mission, and asteroid 433 Eros, are utilized. A parallelized ray tracing algorithm to simulate realistic surface-to-surface shadowing of a given celestial body is developed. By using the simulated models and parameters given from the formulation of the different sensors, impact mission scenarios are used to verify the feasibility for intercepting a small target.

The perceptual control of goal-directed locomotion: a common control architecture for interception and navigation?

PubMed

Chardenon, A; Montagne, G; Laurent, M; Bootsma, R J

2004-09-01

Intercepting a moving object while locomoting is a highly complex and demanding ability. Notwithstanding the identification of several informational candidates, the role of perceptual variables in the control process underlying such skills remains an open question. In this study we used a virtual reality set-up for studying locomotor interception of a moving ball. The subject had to walk along a straight path and could freely modify forward velocity, if necessary, in order to intercept-with the head-a ball moving along a straight path that led it to cross the agent's displacement axis. In a series of experiments we manipulated a local (ball size) and a global (focus of expansion) component of the visual flow but also the egocentric orientation of the ball. The experimental observations are well captured by a dynamic model linking the locomotor acceleration to properties of both global flow and egocentric direction. More precisely the changes in locomotor velocity depend on a linear combination of the change in bearing angle and the change in egocentric orientation, allowing the emergence of adaptive behavior under a variety of circumstances. We conclude that the mechanisms underlying the control of different goal-directed locomotion tasks (i.e. steering and interceptive tasks) could share a common architecture.

Testing self-regulation interventions to increase walking using factorial randomized N-of-1 trials.

PubMed

Sniehotta, Falko F; Presseau, Justin; Hobbs, Nicola; Araújo-Soares, Vera

2012-11-01

To investigate the suitability of N-of-1 randomized controlled trials (RCTs) as a means of testing the effectiveness of behavior change techniques based on self-regulation theory (goal setting and self-monitoring) for promoting walking in healthy adult volunteers. A series of N-of-1 RCTs in 10 normal and overweight adults ages 19-67 (M = 36.9 years). We randomly allocated 60 days within each individual to text message-prompted daily goal-setting and/or self-monitoring interventions in accordance with a 2 (step-count goal prompt vs. alternative goal prompt) × 2 (self-monitoring: open vs. blinded Omron-HJ-113-E pedometer) factorial design. Aggregated data were analyzed using random intercept multilevel models. Single cases were analyzed individually. The primary outcome was daily pedometer step counts over 60 days. Single-case analyses showed that 4 participants significantly increased walking: 2 on self-monitoring days and 2 on goal-setting days, compared with control days. Six participants did not benefit from the interventions. In aggregated analyses, mean step counts were higher on goal-setting days (8,499.9 vs. 7,956.3) and on self-monitoring days (8,630.3 vs. 7,825.9). Multilevel analyses showed a significant effect of the self-monitoring condition (p = .01), the goal-setting condition approached significance (p = .08), and there was a small linear increase in walking over time (p = .03). N-of-1 randomized trials are a suitable means to test behavioral interventions in individual participants.

A study on crown interception with four dominant tree species: a direct measurement

Treesearch

Xiang Li; Jianzhi Niu; Linus Zhang; Qingfu Xiao; Gregory E. McPherson; Natalie van Doorn; Xinxiao Yu; Baoyuan Xie; Salli Dymond; Jiao Li; Chen Meng; Ziteng Luo

2016-01-01

An experiment was conducted to concentrate on the rainfall interception process of individual trees for four common species in Beijing, China, which included needle species (Platycladus orientalis and Pinus tabulaeformis) and broadleaf species (Quercus variabilis and Acer truncatum)....

The dynamics of rainfall interception by a seasonal temperate rainforest.

Treesearch

Timothy E. Link; Mike Unsworth; Danny Marks

2004-01-01

Net canopy interception (Inet) during rainfall in an old-growth Douglas-fir-western hemlock ecosystem was 22.8 and 25.0% of the gross rainfall (PG) for 1999 and 2000, respectively. The average direct throughfall proportion (p) and canopy storage capacity (

How Funding Instability Affects Army Programs

DTIC Science & Technology

2007-01-01

rocket motor, aerodynamic vane controls, and inertial guidance to navigate to an intercept point. Shortly before arrival at the intercept point, the...responsiveness. Significant features of the C-17 include: super-critical wing design and winglets to reduce drag and increase fuel efficiency and

Digital Sound Encryption with Logistic Map and Number Theoretic Transform

NASA Astrophysics Data System (ADS)

Satria, Yudi; Gabe Rizky, P. H.; Suryadi, MT

2018-03-01

Digital sound security has limits on encrypting in Frequency Domain. Number Theoretic Transform based on field (GF 2521 – 1) improve and solve that problem. The algorithm for this sound encryption is based on combination of Chaos function and Number Theoretic Transform. The Chaos function that used in this paper is Logistic Map. The trials and the simulations are conducted by using 5 different digital sound files data tester in Wave File Extension Format and simulated at least 100 times each. The key stream resulted is random with verified by 15 NIST’s randomness test. The key space formed is very big which more than 10469. The processing speed of algorithm for encryption is slightly affected by Number Theoretic Transform.

Effects of forest structure on hydrological processes in China

NASA Astrophysics Data System (ADS)

Sun, Jiamei; Yu, Xinxiao; Wang, Henian; Jia, Guodong; Zhao, Yang; Tu, Zhihua; Deng, Wenping; Jia, Jianbo; Chen, Jungang

2018-06-01

There are serious concerns between forest and water quantity, Chinese extensive land area makes the relationship more complicated, thus, the effects of forest structure on hydrological processes in China were not fully comprehended. In this research, forest's hydrological functions, including rainfall partitioning, litter interception, evapotranspiration (ET), were analyzed in China. The results showed that throughfall was the largest proportion of gross precipitation with fraction between 69.3 ± 8.8% and 84.4 ± 5.6%. Then was canopy interception which varied from 14.6 ± 1.4% to 29.1 ± 3.3%. Throughfall was correlated with gross precipitation, canopy thickness and canopy density. Canopy interception was correlated with gross precipitation, LAI, canopy density, biomass, mixed degree, uniform angle index, aggregation index. Stemflow accounted for only 1.2 ± 0.32% of gross precipitation, with the greatest fraction of 2.1 ± 0.2% in XBH site and the least fraction of 0.3 ± 0.1% in DB site. Gross precipitation was the main factor in determining stemflow. DB site had the greatest litter interception (7.7 ± 0.8 mm) and HB site had the least (0.9 ± 0.3 mm). Litter interception had closer correlation with undecomposed litter mass (0.66) than total litter mass (0.46). Path-coefficient analysis showed that stand density, Shannon-Wiener index, litter mass, size ratio had greater impact on litter interception than other factors. ET was mainly influenced by precipitation, and it also correlated with LAI, canopy density and biomass. In north China, ET percentage (the ratio of ET and precipitation) was 82.7-109.5%, while it decreased to 63.1-88.5% in south China, ET demand in XBS site was larger than precipitation. ET percentage increased with increasing latitude and elevation, decreased with increasing temperature.

Corner store purchases made by adults, adolescents and children: items, nutritional characteristics and amount spent.

PubMed

Lent, Michelle R; Vander Veur, Stephanie; Mallya, Giridhar; McCoy, Tara A; Sanders, Timothy A; Colby, Lisa; Rauchut Tewksbury, Colleen; Lawman, Hannah G; Sandoval, Brianna; Sherman, Sandy; Wylie-Rosett, Judith; Foster, Gary D

2015-06-01

Corner stores, also known as bodegas, are prevalent in low-income urban areas and primarily stock high-energy foods and beverages. Little is known about individual-level purchases in these locations. The purpose of the present study was to assess corner store purchases (items, nutritional characteristics and amount spent) made by children, adolescents and adults in a low-income urban environment. Evaluation staff used 9238 intercept surveys to directly examine food and beverage purchases. Intercepts were collected at 192 corner stores in Philadelphia, PA, USA. Participants were adult, adolescent and child corner store shoppers. Among the 9238 intercept surveys, there were 20 244 items. On average, at each corner store visit, consumers purchased 2.2 (sd 2.1) items (1.3 (sd 2.0) foods and 0.9 (sd 0.9) beverages) that cost $US 2.74 (sd $US 3.52) and contained 2786.5 (sd 4454.2) kJ (666.0 (sd 1064.6) kcal). Whether the data were examined as a percentage of total items purchased or as a percentage of intercepts, the most common corner store purchases were beverages, chips, prepared food items, pastries and candy. Beverage purchases occurred during 65.9% of intercepts and accounted for 39.2% of all items. Regular soda was the most popular beverage purchase. Corner store purchases averaged 66.2 g of sugar, 921.1 mg of sodium and 2.5 g of fibre per intercept. Compared with children and adolescents, adults spent the most money and purchased the most energy. Urban corner store shoppers spent almost $US 3.00 for over 2700 kJ (650 kcal) per store visit. Obesity prevention efforts may benefit from including interventions aimed at changing corner store food environments in low-income, urban areas.

Challenges in Estimating Evapotranspiration of Young Sparse Stands in a Boreal Forest of Eastern-Canada

NASA Astrophysics Data System (ADS)

Hadiwijaya, B.; Nadeau, D.; Pépin, S.

2017-12-01

Forest evapotranspiration is the sum of transpiration, evaporation from intercepted rainfall by the canopy and soil evaporation, each component being governed by distinct time scales and mechanisms. Therefore, to develop a simple, yet realistic, model to estimate evapotranspiration over forested areas, field measurements must capture the full chronological sequence of events taking place following rainfall. This becomes a challenge in the case of young sparse forest stands due to large diversity in canopy covers and leaf area indices, which leads to strong spatial variation in intercepted rainfall by the canopy. Unfortunately, very few studies have focused on transition between the dry and wet canopy conditions. The objectives of this study are to investigate each element of rain interception and intercepted water loss, to characterize water loss partitioning processes based on precipitation rate, elapsed time and time-sequence events. To do this, we conducted a summer field campaign at Forêt Montmorency (47°N, 71°W), in southern Québec, Canada, started from early May until late October. The site is characterized by a humid continental climate, with a mean annual precipitation of 1500 mm. The site is located at the boreal forest region, in the balsam for-white birch ecosystem, whose growing season typically extends from May until October. Six measurement plots were established around two micrometeorological towers located in juvenile and sapling forest stands. Five sap flow probes to measure transpiration and a set of rainfall interception instruments (measuring throughfall, free throughfall and stemflow separately) have been deployed on each plot. Initial results presented will include the estimated evapotranspiration rate and soil evaporation measured using eddy covariance method, transpiration rate and high resolution analysis of rainfall interception.

Use and interpretation of logistic regression in habitat-selection studies

USGS Publications Warehouse

Keating, Kim A.; Cherry, Steve

2004-01-01

 Logistic regression is an important tool for wildlife habitat-selection studies, but the method frequently has been misapplied due to an inadequate understanding of the logistic model, its interpretation, and the influence of sampling design. To promote better use of this method, we review its application and interpretation under 3 sampling designs: random, case-control, and use-availability. Logistic regression is appropriate for habitat use-nonuse studies employing random sampling and can be used to directly model the conditional probability of use in such cases. Logistic regression also is appropriate for studies employing case-control sampling designs, but careful attention is required to interpret results correctly. Unless bias can be estimated or probability of use is small for all habitats, results of case-control studies should be interpreted as odds ratios, rather than probability of use or relative probability of use. When data are gathered under a use-availability design, logistic regression can be used to estimate approximate odds ratios if probability of use is small, at least on average. More generally, however, logistic regression is inappropriate for modeling habitat selection in use-availability studies. In particular, using logistic regression to fit the exponential model of Manly et al. (2002:100) does not guarantee maximum-likelihood estimates, valid probabilities, or valid likelihoods. We show that the resource selection function (RSF) commonly used for the exponential model is proportional to a logistic discriminant function. Thus, it may be used to rank habitats with respect to probability of use and to identify important habitat characteristics or their surrogates, but it is not guaranteed to be proportional to probability of use. Other problems associated with the exponential model also are discussed. We describe an alternative model based on Lancaster and Imbens (1996) that offers a method for estimating conditional probability of use in use-availability studies. Although promising, this model fails to converge to a unique solution in some important situations. Further work is needed to obtain a robust method that is broadly applicable to use-availability studies.

Logistic quantile regression provides improved estimates for bounded avian counts: a case study of California Spotted Owl fledgling production

Treesearch

Brian S. Cade; Barry R. Noon; Rick D. Scherer; John J. Keane

2017-01-01

Counts of avian fledglings, nestlings, or clutch size that are bounded below by zero and above by some small integer form a discrete random variable distribution that is not approximated well by conventional parametric count distributions such as the Poisson or negative binomial. We developed a logistic quantile regression model to provide estimates of the empirical...

17 CFR 200.113 - Opportunity to respond; interception.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Opportunity to respond; interception. 200.113 Section 200.113 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Code of Behavior Governing Ex Parte...

17 CFR 200.113 - Opportunity to respond; interception.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 17 Commodity and Securities Exchanges 2 2013-04-01 2013-04-01 false Opportunity to respond; interception. 200.113 Section 200.113 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Code of Behavior Governing Ex Parte...

17 CFR 200.113 - Opportunity to respond; interception.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Opportunity to respond; interception. 200.113 Section 200.113 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Code of Behavior Governing Ex Parte...

17 CFR 200.113 - Opportunity to respond; interception.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 17 Commodity and Securities Exchanges 3 2014-04-01 2014-04-01 false Opportunity to respond; interception. 200.113 Section 200.113 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Code of Behavior Governing Ex Parte...

17 CFR 200.113 - Opportunity to respond; interception.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Opportunity to respond; interception. 200.113 Section 200.113 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Code of Behavior Governing Ex Parte...

Separation of Intercepted Multi-Radar Signals Based on Parameterized Time-Frequency Analysis

NASA Astrophysics Data System (ADS)

Lu, W. L.; Xie, J. W.; Wang, H. M.; Sheng, C.

2016-09-01

Modern radars use complex waveforms to obtain high detection performance and low probabilities of interception and identification. Signals intercepted from multiple radars overlap considerably in both the time and frequency domains and are difficult to separate with primary time parameters. Time-frequency analysis (TFA), as a key signal-processing tool, can provide better insight into the signal than conventional methods. In particular, among the various types of TFA, parameterized time-frequency analysis (PTFA) has shown great potential to investigate the time-frequency features of such non-stationary signals. In this paper, we propose a procedure for PTFA to separate overlapped radar signals; it includes five steps: initiation, parameterized time-frequency analysis, demodulating the signal of interest, adaptive filtering and recovering the signal. The effectiveness of the method was verified with simulated data and an intercepted radar signal received in a microwave laboratory. The results show that the proposed method has good performance and has potential in electronic reconnaissance applications, such as electronic intelligence, electronic warfare support measures, and radar warning.

Motion patterns and phase-transition of a defender-intruder problem and optimal interception strategy of the defender

NASA Astrophysics Data System (ADS)

Wang, Jiangliu; Li, Wei

2015-10-01

In this paper, we consider a defense-intrusion interaction, in which an intruder is attracted by a protected stationary target but repulsed by a defender; while the defender tries to move towards an appropriate interception position (IP) between the intruder and the target in order to intercept the intruder and expel the intruder away from the target as maximum as possible. Intuitionally, to keep the intruder further away, one may wonder that: is it a better strategy for the defender trying to approach the intruder as near as possible? Unexpectedly and interestingly enough, this is not always the case. We first introduce the flexibility for IP selection, then investigate the system dynamics and the stable motion patterns, and characterize the phase-transition surface for the motion patterns. We show that, the phase-transition surface just defines the optimal interception strategy of the defender for IP selection; and from the perspective of mobility of agents, the optimal strategy just depends on relative mobility of the two agents.

Rapid design and optimization of low-thrust rendezvous/interception trajectory for asteroid deflection missions

NASA Astrophysics Data System (ADS)

Li, Shuang; Zhu, Yongsheng; Wang, Yukai

2014-02-01

Asteroid deflection techniques are essential in order to protect the Earth from catastrophic impacts by hazardous asteroids. Rapid design and optimization of low-thrust rendezvous/interception trajectories is considered as one of the key technologies to successfully deflect potentially hazardous asteroids. In this paper, we address a general framework for the rapid design and optimization of low-thrust rendezvous/interception trajectories for future asteroid deflection missions. The design and optimization process includes three closely associated steps. Firstly, shape-based approaches and genetic algorithm (GA) are adopted to perform preliminary design, which provides a reasonable initial guess for subsequent accurate optimization. Secondly, Radau pseudospectral method is utilized to transcribe the low-thrust trajectory optimization problem into a discrete nonlinear programming (NLP) problem. Finally, sequential quadratic programming (SQP) is used to efficiently solve the nonlinear programming problem and obtain the optimal low-thrust rendezvous/interception trajectories. The rapid design and optimization algorithms developed in this paper are validated by three simulation cases with different performance indexes and boundary constraints.

Genome-wide association study on legendre random regression coefficients for the growth and feed intake trajectory on Duroc Boars.

PubMed

Howard, Jeremy T; Jiao, Shihui; Tiezzi, Francesco; Huang, Yijian; Gray, Kent A; Maltecca, Christian

2015-05-30

Feed intake and growth are economically important traits in swine production. Previous genome wide association studies (GWAS) have utilized average daily gain or daily feed intake to identify regions that impact growth and feed intake across time. The use of longitudinal models in GWAS studies, such as random regression, allows for SNPs having a heterogeneous effect across the trajectory to be characterized. The objective of this study is therefore to conduct a single step GWAS (ssGWAS) on the animal polynomial coefficients for feed intake and growth. Corrected daily feed intake (DFI Adj) and average daily weight measurements (DBW Avg) on 8981 (n=525,240 observations) and 5643 (n=283,607 observations) animals were utilized in a random regression model using Legendre polynomials (order=2) and a relationship matrix that included genotyped and un-genotyped animals. A ssGWAS was conducted on the animal polynomials coefficients (intercept, linear and quadratic) for animals with genotypes (DFIAdj: n=855; DBWAvg: n=590). Regions were characterized based on the variance of 10-SNP sliding windows GEBV (WGEBV). A bootstrap analysis (n=1000) was conducted to declare significance. Heritability estimates for the traits trajectory ranged from 0.34-0.52 to 0.07-0.23 for DBWAvg and DFIAdj, respectively. Genetic correlations across age classes were large and positive for both DBWAvg and DFIAdj, albeit age classes at the beginning had a small to moderate genetic correlation with age classes towards the end of the trajectory for both traits. The WGEBV variance explained by significant regions (P<0.001) for each polynomial coefficient ranged from 0.2-0.9 to 0.3-1.01% for DBWAvg and DFIAdj, respectively. The WGEBV variance explained by significant regions for the trajectory was 1.54 and 1.95% for DBWAvg and DFIAdj. Both traits identified candidate genes with functions related to metabolite and energy homeostasis, glucose and insulin signaling and behavior. We have identified regions of the genome that have an impact on the intercept, linear and quadratic terms for DBWAvg and DFIAdj. These results provide preliminary evidence that individual growth and feed intake trajectories are impacted by different regions of the genome at different times.

Quantifying dominance of intra-storm phase of interception process by small isolated canopies

NASA Astrophysics Data System (ADS)

Yerk, Walter; Montalto, Franco

2014-05-01

Precipitation interception by vegetation canopies has long been recognized as a major component of the hydrologic cycle; however, historically most research has been dedicated to closed or sparse canopy forests. The goal of our research was to quantify rainfall partitioning by small isolated canopies in an urban setting. The field experiment involved small forms of four shrub species (Prunus laurocerasus, Cornus sericea, Itea virginica and Hydrangea quercifolia) with crown heights 40 - 80 cm and diameters 35 - 60 cm. Each plant had ten rain gauges to measure throughfall with a sampling frequency of 5 seconds. An on-site automated weather station provided meteorological data. Leaf area index (LAI) was measured by manual counting. We estimated the canopy storage capacities of all four species to be less than 0.5 mm. The obtained data showed statistically significant differences in interception properties among all four species, except between Cornus and Itea. Cumulative interception loss for the period of August-December 2013 was 10% for Cornus, 16% for Itea, 29% for Hydrangea, and 49% for Prunus. The observations revealed a weak relationship between interception abilities and LAI for all four species. Throughfall and precipitation intensities (mm/hr) expressed very strong linear relationship (adjusted coefficients of determination were from 0.80 to 0.95) for the entire range of observed rainfall intensities. For Cornus the ratio of throughfall to precipitation intensity was close to 0.93:1, for Itea it was 0.82:1. The ratios were lesser for Hydrangea (0.65:1), and especially for Prunus (0.48:1). Therefore we show that reduced by the canopy, throughfall intensity results in the bulk of precipitation depth intercepted during the rain events. In contrast, the amount of water stored on the canopy and evaporated between and after rain events contributes minimally to interception. Simulations of potential evaporation based on the Penman-Monteith method showed a large underestimation of evaporation from the wet canopies during the rain events. Approaches other than energy balance models of potential evaporation from a still water surface are being discussed in order to explain large evaporation from within a wet isolated canopy.

A New TS Algorithm for Solving Low-Carbon Logistics Vehicle Routing Problem with Split Deliveries by Backpack-From a Green Operation Perspective.

PubMed

Xia, Yangkun; Fu, Zhuo; Tsai, Sang-Bing; Wang, Jiangtao

2018-05-10

In order to promote the development of low-carbon logistics and economize logistics distribution costs, the vehicle routing problem with split deliveries by backpack is studied. With the help of the model of classical capacitated vehicle routing problem, in this study, a form of discrete split deliveries was designed in which the customer demand can be split only by backpack. A double-objective mathematical model and the corresponding adaptive tabu search (TS) algorithm were constructed for solving this problem. By embedding the adaptive penalty mechanism, and adopting the random neighborhood selection strategy and reinitialization principle, the global optimization ability of the new algorithm was enhanced. Comparisons with the results in the literature show the effectiveness of the proposed algorithm. The proposed method can save the costs of low-carbon logistics and reduce carbon emissions, which is conducive to the sustainable development of low-carbon logistics.

On the Simulation-Based Reliability of Complex Emergency Logistics Networks in Post-Accident Rescues.

PubMed

Wang, Wei; Huang, Li; Liang, Xuedong

2018-01-06

This paper investigates the reliability of complex emergency logistics networks, as reliability is crucial to reducing environmental and public health losses in post-accident emergency rescues. Such networks' statistical characteristics are analyzed first. After the connected reliability and evaluation indices for complex emergency logistics networks are effectively defined, simulation analyses of network reliability are conducted under two different attack modes using a particular emergency logistics network as an example. The simulation analyses obtain the varying trends in emergency supply times and the ratio of effective nodes and validates the effects of network characteristics and different types of attacks on network reliability. The results demonstrate that this emergency logistics network is both a small-world and a scale-free network. When facing random attacks, the emergency logistics network steadily changes, whereas it is very fragile when facing selective attacks. Therefore, special attention should be paid to the protection of supply nodes and nodes with high connectivity. The simulation method provides a new tool for studying emergency logistics networks and a reference for similar studies.

On the Simulation-Based Reliability of Complex Emergency Logistics Networks in Post-Accident Rescues

PubMed Central

Wang, Wei; Huang, Li; Liang, Xuedong

2018-01-01

This paper investigates the reliability of complex emergency logistics networks, as reliability is crucial to reducing environmental and public health losses in post-accident emergency rescues. Such networks’ statistical characteristics are analyzed first. After the connected reliability and evaluation indices for complex emergency logistics networks are effectively defined, simulation analyses of network reliability are conducted under two different attack modes using a particular emergency logistics network as an example. The simulation analyses obtain the varying trends in emergency supply times and the ratio of effective nodes and validates the effects of network characteristics and different types of attacks on network reliability. The results demonstrate that this emergency logistics network is both a small-world and a scale-free network. When facing random attacks, the emergency logistics network steadily changes, whereas it is very fragile when facing selective attacks. Therefore, special attention should be paid to the protection of supply nodes and nodes with high connectivity. The simulation method provides a new tool for studying emergency logistics networks and a reference for similar studies. PMID:29316614

Functional Data Analysis Applied to Modeling of Severe Acute Mucositis and Dysphagia Resulting From Head and Neck Radiation Therapy

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

Dean, Jamie A., E-mail: jamie.dean@icr.ac.uk; Wong, Kee H.; Gay, Hiram

Purpose: Current normal tissue complication probability modeling using logistic regression suffers from bias and high uncertainty in the presence of highly correlated radiation therapy (RT) dose data. This hinders robust estimates of dose-response associations and, hence, optimal normal tissue–sparing strategies from being elucidated. Using functional data analysis (FDA) to reduce the dimensionality of the dose data could overcome this limitation. Methods and Materials: FDA was applied to modeling of severe acute mucositis and dysphagia resulting from head and neck RT. Functional partial least squares regression (FPLS) and functional principal component analysis were used for dimensionality reduction of the dose-volume histogrammore » data. The reduced dose data were input into functional logistic regression models (functional partial least squares–logistic regression [FPLS-LR] and functional principal component–logistic regression [FPC-LR]) along with clinical data. This approach was compared with penalized logistic regression (PLR) in terms of predictive performance and the significance of treatment covariate–response associations, assessed using bootstrapping. Results: The area under the receiver operating characteristic curve for the PLR, FPC-LR, and FPLS-LR models was 0.65, 0.69, and 0.67, respectively, for mucositis (internal validation) and 0.81, 0.83, and 0.83, respectively, for dysphagia (external validation). The calibration slopes/intercepts for the PLR, FPC-LR, and FPLS-LR models were 1.6/−0.67, 0.45/0.47, and 0.40/0.49, respectively, for mucositis (internal validation) and 2.5/−0.96, 0.79/−0.04, and 0.79/0.00, respectively, for dysphagia (external validation). The bootstrapped odds ratios indicated significant associations between RT dose and severe toxicity in the mucositis and dysphagia FDA models. Cisplatin was significantly associated with severe dysphagia in the FDA models. None of the covariates was significantly associated with severe toxicity in the PLR models. Dose levels greater than approximately 1.0 Gy/fraction were most strongly associated with severe acute mucositis and dysphagia in the FDA models. Conclusions: FPLS and functional principal component analysis marginally improved predictive performance compared with PLR and provided robust dose-response associations. FDA is recommended for use in normal tissue complication probability modeling.« less

Functional Data Analysis Applied to Modeling of Severe Acute Mucositis and Dysphagia Resulting From Head and Neck Radiation Therapy.

PubMed

Dean, Jamie A; Wong, Kee H; Gay, Hiram; Welsh, Liam C; Jones, Ann-Britt; Schick, Ulrike; Oh, Jung Hun; Apte, Aditya; Newbold, Kate L; Bhide, Shreerang A; Harrington, Kevin J; Deasy, Joseph O; Nutting, Christopher M; Gulliford, Sarah L

2016-11-15

Current normal tissue complication probability modeling using logistic regression suffers from bias and high uncertainty in the presence of highly correlated radiation therapy (RT) dose data. This hinders robust estimates of dose-response associations and, hence, optimal normal tissue-sparing strategies from being elucidated. Using functional data analysis (FDA) to reduce the dimensionality of the dose data could overcome this limitation. FDA was applied to modeling of severe acute mucositis and dysphagia resulting from head and neck RT. Functional partial least squares regression (FPLS) and functional principal component analysis were used for dimensionality reduction of the dose-volume histogram data. The reduced dose data were input into functional logistic regression models (functional partial least squares-logistic regression [FPLS-LR] and functional principal component-logistic regression [FPC-LR]) along with clinical data. This approach was compared with penalized logistic regression (PLR) in terms of predictive performance and the significance of treatment covariate-response associations, assessed using bootstrapping. The area under the receiver operating characteristic curve for the PLR, FPC-LR, and FPLS-LR models was 0.65, 0.69, and 0.67, respectively, for mucositis (internal validation) and 0.81, 0.83, and 0.83, respectively, for dysphagia (external validation). The calibration slopes/intercepts for the PLR, FPC-LR, and FPLS-LR models were 1.6/-0.67, 0.45/0.47, and 0.40/0.49, respectively, for mucositis (internal validation) and 2.5/-0.96, 0.79/-0.04, and 0.79/0.00, respectively, for dysphagia (external validation). The bootstrapped odds ratios indicated significant associations between RT dose and severe toxicity in the mucositis and dysphagia FDA models. Cisplatin was significantly associated with severe dysphagia in the FDA models. None of the covariates was significantly associated with severe toxicity in the PLR models. Dose levels greater than approximately 1.0 Gy/fraction were most strongly associated with severe acute mucositis and dysphagia in the FDA models. FPLS and functional principal component analysis marginally improved predictive performance compared with PLR and provided robust dose-response associations. FDA is recommended for use in normal tissue complication probability modeling. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Ni-Catalyzed Regioselective 1,2-Dicarbofunctionalization of Olefins by Intercepting Heck Intermediates as Imine-Stabilized Transient Metallacycles

DOE PAGES

Shrestha, Bijay; Basnet, Prakash; Dhungana, Roshan K.; ...

2017-07-24

We disclose a strategy for Ni-catalyzed regioselective dicarbofunctionalization of olefins in styrene derivatives by intercepting Heck C(sp 3)-NiX intermediates with arylzinc reagents. This approach utilizes a readily removable imine as a coordinating group that plays a dual role of intercepting oxidative addition species derived from aryl halides and triflates to promote Heck carbometallation, and stabilizing the Heck C(sp 3)-NiX intermediates as transient metallacycles to suppress β-hydride elimination and facilitate transmetalation/reductive elimination steps. This method affords diversely-substituted 1,1,2-riarylethyl products that occur as structural motifs in various natural products.

A new logistic dynamic particle swarm optimization algorithm based on random topology.

PubMed

Ni, Qingjian; Deng, Jianming

2013-01-01

Population topology of particle swarm optimization (PSO) will directly affect the dissemination of optimal information during the evolutionary process and will have a significant impact on the performance of PSO. Classic static population topologies are usually used in PSO, such as fully connected topology, ring topology, star topology, and square topology. In this paper, the performance of PSO with the proposed random topologies is analyzed, and the relationship between population topology and the performance of PSO is also explored from the perspective of graph theory characteristics in population topologies. Further, in a relatively new PSO variant which named logistic dynamic particle optimization, an extensive simulation study is presented to discuss the effectiveness of the random topology and the design strategies of population topology. Finally, the experimental data are analyzed and discussed. And about the design and use of population topology on PSO, some useful conclusions are proposed which can provide a basis for further discussion and research.

77 FR 18707 - USPS Package Intercept-New Product Offerings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-28

... service that replaced the former recall of mail process. Plans were announced to implement new features.... Additionally, customers using the electronic process will have the option of adding selected extra services to... POSTAL SERVICE 39 CFR Part 111 USPS Package Intercept--New Product Offerings AGENCY: Postal...

High-throughput estimation of incident light, light interception and radiation-use efficiency of thousands of plants in a phenotyping platform.

PubMed

Cabrera-Bosquet, Llorenç; Fournier, Christian; Brichet, Nicolas; Welcker, Claude; Suard, Benoît; Tardieu, François

2016-10-01

Light interception and radiation-use efficiency (RUE) are essential components of plant performance. Their genetic dissections require novel high-throughput phenotyping methods. We have developed a suite of methods to evaluate the spatial distribution of incident light, as experienced by hundreds of plants in a glasshouse, by simulating sunbeam trajectories through glasshouse structures every day of the year; the amount of light intercepted by maize (Zea mays) plants via a functional-structural model using three-dimensional (3D) reconstructions of each plant placed in a virtual scene reproducing the canopy in the glasshouse; and RUE, as the ratio of plant biomass to intercepted light. The spatial variation of direct and diffuse incident light in the glasshouse (up to 24%) was correctly predicted at the single-plant scale. Light interception largely varied between maize lines that differed in leaf angles (nearly stable between experiments) and area (highly variable between experiments). Estimated RUEs varied between maize lines, but were similar in two experiments with contrasting incident light. They closely correlated with measured gas exchanges. The methods proposed here identified reproducible traits that might be used in further field studies, thereby opening up the way for large-scale genetic analyses of the components of plant performance. © 2016 INRA New Phytologist © 2016 New Phytologist Trust.

Classification of Snowfall Events and Their Effect on Canopy Interception Efficiency in a Temperate Montane Forest.

NASA Astrophysics Data System (ADS)

Roth, T. R.; Nolin, A. W.

2015-12-01

Forest canopies intercept as much as 60% of snowfall in maritime environments, while processes of sublimation and melt can reduce the amount of snow transferred from the canopy to the ground. This research examines canopy interception efficiency (CIE) as a function of forest and event-scale snowfall characteristics. We use a 4-year dataset of continuous meteorological measurements and monthly snow surveys from the Forest Elevation Snow Transect (ForEST) network that has forested and open sites at three elevations spanning the rain-snow transition zone to the upper seasonal snow zone. Over 150 individual storms were classified by forest and storm type characteristics (e.g. forest density, vegetation type, air temperature, snowfall amount, storm duration, wind speed, and storm direction). The between-site comparisons showed that, as expected, CIE was highest for the lower elevation (warmer) sites with higher forest density compared with the higher elevation sites where storm temperatures were colder, trees were smaller and forests were less dense. Within-site comparisons based on storm type show that this classification system can be used to predict CIE.Our results suggest that the coupling of forest type and storm type information can improve estimates of canopy interception. Understanding the effects of temperature and storm type in temperate montane forests is also valuable for future estimates of canopy interception under a warming climate.

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.

Determinants of childhood immunisation coverage in urban poor settlements of Delhi, India: a cross-sectional study.

PubMed

Devasenapathy, Niveditha; Ghosh Jerath, Suparna; Sharma, Saket; Allen, Elizabeth; Shankar, Anuraj H; Zodpey, Sanjay

2016-08-26

Aggregate data on childhood immunisation from urban settings may not reflect the coverage among the urban poor. This study provides information on complete childhood immunisation coverage among the urban poor, and explores its household and neighbourhood-level determinants. Urban poor community in the Southeast district of Delhi, India. We randomly sampled 1849 children aged 1-3.5 years from 13 451 households in 39 clusters (cluster defined as area covered by a community health worker) in 2 large urban poor settlements. Of these, 1343 completed the survey. We collected information regarding childhood immunisation (BCG, oral polio vaccine, diphtheria-pertussis-tetanus vaccine, hepatitis B and measles) from vaccination cards or mothers' recall. We used random intercept logistic regression to explore the sociodemographic determinants of complete immunisation. Complete immunisation coverage was 46.7% and 7.5% were not immunised. The odds of complete vaccination (OR, 95% CI) were lower in female children (0.70 (0.55 to 0.89)) and Muslim households (0.65 (0.45 to 0.94)). The odds of complete vaccination were higher if the mother was literate (1.6 (1.15 to 2.16)), if the child was born within the city (2.7 (1.97 to 3.65)), in a health facility ( 1.5 (1.19 to 2.02)), belonged to the highest wealth quintile (compared with the poorest; 2.46 (1.5 to 4.02)) or possessed a birth certificate (1.40 (1.03 to 1.91)). Cluster effect due to unmeasured neighbourhood factors expressed as median OR was 1.32. Immunisation coverage in this urban poor area was much lower than that of regional surveys reporting overall urban data. Socioeconomic status of the household, female illiteracy, health awareness and gender inequality were important determinants of coverage in this population. Hence, in addition to enhancing the infrastructure for providing mother and child services, efforts are also needed to address these issues in order to improve immunisation coverage in deprived urban communities. CTRI/2011/091/000095. 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/

Exploring the characteristics and dynamics of Ontario dairy herds experiencing increases in bulk milk somatic cell count during the summer.

PubMed

Shock, D A; LeBlanc, S J; Leslie, K E; Hand, K; Godkin, M A; Coe, J B; Kelton, D F

2015-06-01

Regionally aggregated bulk milk somatic cell count (BMSCC) data from around the world shows a repeatable cyclicity, with the highest levels experienced during warm, humid seasons. No studies have evaluated this seasonal phenomenon at the herd level. The objectives of this study were to define summer seasonality in BMSCC on an individual herd basis, and subsequently to describe the characteristics and dynamics of herds with increased BMSCC in the summer. The data used for this analysis were from all dairy farms in Ontario, Canada, between January 2000 and December 2011 (n≈4,000 to 6,000 herds/yr). Bulk milk data were obtained from the milk marketing board and consisted of bulk milk production, components (fat, protein, lactose, other solids), and quality (BMSCC, bacterial count, inhibitor presence, freezing point), total milk quota of the farm, and milk quota and incentive fill percentage. A time-series linear mixed model, with random slopes and intercepts, was constructed using sine and cosine terms as predictors to describe seasonality, with herd as a random effect. For each herd, seasonality was described with reference to 1 cosine function of variable amplitude and phase shift. The predicted months of maximal and minimal BMSCC were then calculated. Herds were assigned as low, medium, and high summer increase (LSI, MSI, and HSI, respectively) based on percentiles of amplitude in BMSCC change for each of the 4 seasons. Using these seasonality classifications, 2 transitional repeated measures logistic regression models were built to assess the characteristics of MSI and HSI herds, using LSI herds as controls. Based on the analyses performed, a history of summer BMSCC increases increased the odds of experiencing a subsequent increase. As herd size decreased, the odds of experiencing HSI to MSI in BMSCC increased. Herds with more variability in daily BMSCC were at higher odds of experiencing MSI and HSI in BMSCC, as were herds with lower annual mean BMSCC. Finally, a negative association was noted between filling herd production targets and experiencing MSI to HSI in BMSCC. These findings provide farm advisors direction for predicting herds likely to experience increases in SCC over the summer, allowing them to proactively focus udder health prevention strategies before the high-risk summer period. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The role of neighborhood characteristics in racial/ethnic disparities in type 2 diabetes: Results from the Boston Area Community Health (BACH) Survey

PubMed Central

Piccolo, Rebecca S.; Duncan, Dustin T.; Pearce, Neil; McKinlay, John B.

2015-01-01

Racial/ethnic disparities in the prevalence of type 2 diabetes mellitus (T2DM) are well documented and until recently, research has focused almost exclusively on individual-based determinants as potential contributors to these disparities (health behaviors, biological/genetic factors, and individual-level sociodemographics). Research on the role of neighborhood characteristics in relation to racial/ethnic disparities in T2DM is very limited. Therefore, the aim of this research is to identify and estimate the contribution of specific aspects of neighborhoods that may be associated with racial/ethnic disparities in T2DM. Data from the Boston Area Community Health III Survey (N = 2,764) was used in this study, which is a community-based random-sample survey of adults in Boston, Massachusetts from three racial/ethnic groups (Black, Hispanic, and White). We applied two-level random intercepts logistic regression to assess the associations between race/ethnicity, neighborhood characteristics (census tract socioeconomic status, racial composition, property and violent crime, open space, geographic proximity to grocery stores, convenience stores, and fast food, and neighborhood disorder) and prevalent T2DM (fasting glucose > 125 mg/dL, HbA1c ≥ 6.5%, or self-report of a T2DM diagnosis). Black and Hispanic participants had 2.89 times and 1.48 times the odds of T2DM as White participants, respectively. Multilevel models indicated a significant between-neighborhood variance estimate of 0.943, providing evidence of neighborhood variation. Individual demographics (race/ethnicity, age and gender) explained 22.3% of the neighborhood variability in T2DM. The addition of neighborhood-level variables to the model had very little effect on the magnitude of the racial/ethnic disparities and on the between-neighborhood variability. For example, census tract poverty explained less than 1% and 6% of the excess odds of T2DM among Blacks and Hispanics and only 1.8% of the neighborhood variance in T2DM. While the findings of this study overall suggest that neighborhood factors are not a major contributor to racial/ethnic disparities in T2DM, further research is needed including data from other geographic locations. PMID:25687243

The expression of light-related leaf functional traits depends on the location of individual leaves within the crown of isolated Olea europaea trees.

PubMed

Escribano-Rocafort, Adrián G; Ventre-Lespiaucq, Agustina B; Granado-Yela, Carlos; Rubio de Casas, Rafael; Delgado, Juan A; Balaguer, Luis

2016-04-01

The spatial arrangement and expression of foliar syndromes within tree crowns can reflect the coupling between crown form and function in a given environment. Isolated trees subjected to high irradiance and concomitant stress may adjust leaf phenotypes to cope with environmental gradients that are heterogeneous in space and time within the tree crown. The distinct expression of leaf phenotypes among crown positions could lead to complementary patterns in light interception at the crown scale. We quantified eight light-related leaf traits across 12 crown positions of ten isolated Olea europaea trees in the field. Specifically, we investigated whether the phenotypic expression of foliar traits differed among crown sectors and layers and five periods of the day from sunrise to sunset. We investigated the consequences in terms of the exposed area of the leaves at the tree scale during a single day. All traits differed among crown positions except the length-to-width ratio of the leaves. We found a strong complementarity in the patterns of the potential exposed area of the leaves among day periods as a result of a non-random distribution of leaf angles across the crown. Leaf exposure at the outer layer was below 60 % of the displayed surface, reaching maximum interception during morning periods. Daily interception increased towards the inner layer, achieving consecutive maximization from east to west positions within the crown, matching the sun's trajectory. The expression of leaf traits within isolated trees of O. europaea varies continuously through the crown in a gradient of leaf morphotypes and leaf angles depending on the exposure and location of individual leaves. The distribution of light-related traits within the crown and the complementarity in the potential exposure patterns of the leaves during the day challenges the assumption of low trait variability within individuals. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Monitoring post-fire vegetation rehabilitation projects: A common approach for non-forested ecosystems

USGS Publications Warehouse

Wirth, Troy A.; Pyke, David A.

2007-01-01

Emergency Stabilization and Rehabilitation (ES&R) and Burned Area Emergency Response (BAER) treatments are short-term, high-intensity treatments designed to mitigate the adverse effects of wildfire on public lands. The federal government expends significant resources implementing ES&R and BAER treatments after wildfires; however, recent reviews have found that existing data from monitoring and research are insufficient to evaluate the effects of these activities. The purpose of this report is to: (1) document what monitoring methods are generally used by personnel in the field; (2) describe approaches and methods for post-fire vegetation and soil monitoring documented in agency manuals; (3) determine the common elements of monitoring programs recommended in these manuals; and (4) describe a common monitoring approach to determine the effectiveness of future ES&R and BAER treatments in non-forested regions. Both qualitative and quantitative methods to measure effectiveness of ES&R treatments are used by federal land management agencies. Quantitative methods are used in the field depending on factors such as funding, personnel, and time constraints. There are seven vegetation monitoring manuals produced by the federal government that address monitoring methods for (primarily) vegetation and soil attributes. These methods vary in their objectivity and repeatability. The most repeatable methods are point-intercept, quadrat-based density measurements, gap intercepts, and direct measurement of soil erosion. Additionally, these manuals recommend approaches for designing monitoring programs for the state of ecosystems or the effect of management actions. The elements of a defensible monitoring program applicable to ES&R and BAER projects that most of these manuals have in common are objectives, stratification, control areas, random sampling, data quality, and statistical analysis. The effectiveness of treatments can be determined more accurately if data are gathered using an approach that incorporates these six monitoring program design elements and objectives, as well as repeatable procedures to measure cover, density, gap intercept, and soil erosion within each ecoregion and plant community. Additionally, using a common monitoring program design with comparable methods, consistently documenting results, and creating and maintaining a central database for query and reporting, will ultimately allow a determination of the effectiveness of post-fire rehabilitation activities region-wide.

Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses

NASA Astrophysics Data System (ADS)

Cambra-López, María; Winkel, Albert; Mosquera, Julio; Ogink, Nico W. M.; Aarnink, André J. A.

2015-06-01

The objective of this study was to compare co-located real-time light scattering devices and equivalent gravimetric samplers in poultry and pig houses for PM10 mass concentration, and to develop animal-specific calibration factors for light scattering samplers. These results will contribute to evaluate the comparability of different sampling instruments for PM10 concentrations. Paired DustTrak light scattering device (DustTrak aerosol monitor, TSI, U.S.) and PM10 gravimetric cyclone sampler were used for measuring PM10 mass concentrations during 24 h periods (from noon to noon) inside animal houses. Sampling was conducted in 32 animal houses in the Netherlands, including broilers, broiler breeders, layers in floor and in aviary system, turkeys, piglets, growing-finishing pigs in traditional and low emission housing with dry and liquid feed, and sows in individual and group housing. A total of 119 pairs of 24 h measurements (55 for poultry and 64 for pigs) were recorded and analyzed using linear regression analysis. Deviations between samplers were calculated and discussed. In poultry, cyclone sampler and DustTrak data fitted well to a linear regression, with a regression coefficient equal to 0.41, an intercept of 0.16 mg m-3 and a correlation coefficient of 0.91 (excluding turkeys). Results in turkeys showed a regression coefficient equal to 1.1 (P = 0.49), an intercept of 0.06 mg m-3 (P < 0.0001) and a correlation coefficient of 0.98. In pigs, we found a regression coefficient equal to 0.61, an intercept of 0.05 mg m-3 and a correlation coefficient of 0.84. Measured PM10 concentrations using DustTraks were clearly underestimated (approx. by a factor 2) in both poultry and pig housing systems compared with cyclone pre-separators. Absolute, relative, and random deviations increased with concentration. DustTrak light scattering devices should be self-calibrated to investigate PM10 mass concentrations accurately in animal houses. We recommend linear regression equations as animal-specific calibration factors for DustTraks instead of manufacturer calibration factors, especially in heavily dusty environments such as animal houses.

Expected scientific results on ballistic spacecraft missions to comet Encke during the 1980 apparition

NASA Technical Reports Server (NTRS)

Mumma, M. J.

1976-01-01

Summarized are three proposed ballistic spacecraft missions to intercept P/Encke during the 1980 apparition. A baseline physical activity model for P/Encke is established and the performances of the neutral mass spectrometer and of the imaging experiment on each intercept mission are assessed.

42 CFR 410.40 - Coverage of ambulance services.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., level 2 (ALS2). (4) Paramedic ALS intercept (PI). (5) Specialty care transport (SCT). (6) Fixed wing transport (FW). (7) Rotary wing transport (RW). (c) Paramedic ALS intercept services. Paramedic ALS...) Be prohibited by State law from billing for any service. (3) Be furnished by a paramedic ALS...

42 CFR 410.40 - Coverage of ambulance services.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., level 2 (ALS2). (4) Paramedic ALS intercept (PI). (5) Specialty care transport (SCT). (6) Fixed wing transport (FW). (7) Rotary wing transport (RW). (c) Paramedic ALS intercept services. Paramedic ALS...) Be prohibited by State law from billing for any service. (3) Be furnished by a paramedic ALS...

42 CFR 410.40 - Coverage of ambulance services.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., level 2 (ALS2). (4) Paramedic ALS intercept (PI). (5) Specialty care transport (SCT). (6) Fixed wing transport (FW). (7) Rotary wing transport (RW). (c) Paramedic ALS intercept services. Paramedic ALS...) Be prohibited by State law from billing for any service. (3) Be furnished by a paramedic ALS...

42 CFR 410.40 - Coverage of ambulance services.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., level 2 (ALS2). (4) Paramedic ALS intercept (PI). (5) Specialty care transport (SCT). (6) Fixed wing transport (FW). (7) Rotary wing transport (RW). (c) Paramedic ALS intercept services. Paramedic ALS...) Be prohibited by State law from billing for any service. (3) Be furnished by a paramedic ALS...

42 CFR 410.40 - Coverage of ambulance services.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., level 2 (ALS2). (4) Paramedic ALS intercept (PI). (5) Specialty care transport (SCT). (6) Fixed wing transport (FW). (7) Rotary wing transport (RW). (c) Paramedic ALS intercept services. Paramedic ALS...) Be prohibited by State law from billing for any service. (3) Be furnished by a paramedic ALS...

Placement of riparian forest buffers to improve water quality

Treesearch

Mark D. Tomer; Michael G. Dosskey; Michael R. Burkart; David E. James; Matthew J. Helmers; Dean E. Eisenhauer

2005-01-01

Riparian forest buffers can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, hydrology, and surficial geology detemine the capability of forest buffers to intercept and treat these flows. This paper describes landscape analysis techniques for identifying and mapping...

15 CFR 742.13 - Communications intercepting devices.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... 742.13 Section 742.13 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade... POLICY-CCL BASED CONTROLS § 742.13 Communications intercepting devices. (a) License requirement. (1) In... Canada, for ECCNs having an “SL” under the “Reason for Control” paragraph. These items include any...

The Nomad Explorer assembly assist vehicle: An architecture for rapid global extraterrestrial base infrastructure establishment

NASA Technical Reports Server (NTRS)

Thangavelu, Madhu

1994-01-01

Traditional concepts of lunar bases describe scenarios where components of the bases are landed on the lunar surface, one at a time, and then put together to form a complete stationary lunar habitat. Recently, some concepts have described the advantages of operating a mobile or 'roving' lunar base. Such a base vastly improves the exploration range from a primary lunar base. Roving bases would also allow the crew to first deploy, test, operationally certify, and then regularly maintain, service, and evolve long life-cycle facilities like observatories or other science payload platforms that are operated far apart from each other across the extraterrestrial surface. The Nomad Explorer is such a mobile lunar base. This paper describes the architectural program of the Nomad Explorer, its advantages over a stationary lunar base, and some of the embedded system concepts which help the roving base to speedily establish a global extraterrestrial infrastructure. A number of modular autonomous logistics landers will carry deployable or erectable payloads, service, and logistically resupply the Nomad Explorer at regular intercepts along the traverse. Starting with the deployment of science experiments and telecommunication networks, and the manned emplacement of a variety of remote outposts using a unique EVA Bell system that enhances manned EVA, the Nomad Explorer architecture suggests the capability for a rapid global development of the extraterrestrial body. The Moon and Mars are candidates for this 'mission oriented' strategy. The lunar case is emphasized in this paper.

Traditional beliefs about the cause of AIDS and AIDS-related stigma in South Africa.

PubMed

Kalichman, S C; Simbayi, L

2004-07-01

AIDS-related stigmas are pervasive in some segments of South African society and stigmas can impede efforts to promote voluntary counselling and testing and other HIV-AIDS prevention efforts. The current study examined associations among the belief that AIDS is caused by spirits and supernatural forces, AIDS-related knowledge and AIDS-related stigmas. A street intercept survey with 487 men and women living in a Black township in Cape Town, South Africa showed that 11% (n=54) believed that AIDS is caused by spirits and supernatural forces, 21% (n=105) were unsure if AIDS is caused by spirits and the supernatural, and 68% (n=355) did not believe that AIDS is caused by spirits and supernatural forces. Multiple logistic regression analyses controlling for participant age, gender, years of education and survey venue showed that people who believed HIV-AIDS is caused by spirits and the supernatural demonstrated significantly more misinformation about AIDS and were significantly more likely to endorse repulsion and social sanction stigmatizing beliefs against people living with HIV-AIDS. However, nearly all associations between beliefs that AIDS is caused by spirits and AIDS stigmas were non-significant when logistic regressions were repeated with AIDS-related knowledge included as a control variable. This finding suggests that relationships between traditional beliefs about the cause of HIV-AIDS and AIDS stigmas are mediated by AIDS-related knowledge. AIDS education efforts are urgently needed to reach people who hold traditional beliefs about AIDS to remedy AIDS stigmas.

Pedestrians' perceptions of walkability and safety in relation to the built environment in Cali, Colombia, 2009-10.

PubMed

Villaveces, Andrés; Nieto, Luis Alfonso; Ortega, Delia; Ríos, José Fernando; Medina, John Jairo; Gutiérrez, María Isabel; Rodríguez, Daniel

2012-10-01

To assess pedestrians' perceptions of the walkability of the urban environment and pedestrian safety in Cali, Colombia. Standardised intercept interviews were conducted of 400 pedestrians walking in 20 randomly selected urban zones to ascertain frequency of walking, and perceptions of safety, the built environment and security. Four focus group meetings were held with community members and students addressing these issues in an open-ended forum. The study analysed quantitative data collected in street interviews and qualitative information from focus groups addressing respondents' views on problems for pedestrians, how the built environment affects walking and ideal walking conditions. Access to public transportation was deemed the most positive characteristic of the built environment and 61% of respondents liked walking in the street. When disaggregating street conditions, the majority of pedestrians were dissatisfied with their walking experiences. Pedestrians cited lack of respect for norms, personal safety and built environment characteristics as their main concerns. Among frequent walkers, residents tended to rate their neighbourhoods more negatively compared with non-residents. Through qualitative interviews it became apparent that narrow sidewalks that are frequently obstructed by motor vehicles are a key reason for pedestrian dissatisfaction. A perception of overall insecurity further determines how pedestrians assess or modulate their walking in this city. Overall, walking in Cali was perceived negatively by pedestrians because of built environment characteristics and perceptions of insecurity. Qualitative information used to complement intercept surveys can provide a better way to identify pedestrian-specific transport-related problems.

Fast adaptation of the internal model of gravity for manual interceptions: evidence for event-dependent learning.

PubMed

Zago, Myrka; Bosco, Gianfranco; Maffei, Vincenzo; Iosa, Marco; Ivanenko, Yuri P; Lacquaniti, Francesco

2005-02-01

We studied how subjects learn to deal with two conflicting sensory environments as a function of the probability of each environment and the temporal distance between repeated events. Subjects were asked to intercept a visual target moving downward on a screen with randomized laws of motion. We compared five protocols that differed in the probability of constant speed (0g) targets and accelerated (1g) targets. Probability ranged from 9 to 100%, and the time interval between consecutive repetitions of the same target ranged from about 1 to 20 min. We found that subjects systematically timed their responses consistent with the assumption of gravity effects, for both 1 and 0g trials. With training, subjects rapidly adapted to 0g targets by shifting the time of motor activation. Surprisingly, the adaptation rate was independent of both the probability of 0g targets and their temporal distance. Very few 0g trials sporadically interspersed as catch trials during immersive practice with 1g trials were sufficient for learning and consolidation in long-term memory, as verified by retesting after 24 h. We argue that the memory store for adapted states of the internal gravity model is triggered by individual events and can be sustained for prolonged periods of time separating sporadic repetitions. This form of event-related learning could depend on multiple-stage memory, with exponential rise and decay in the initial stages followed by a sample-and-hold module.

Accounting for center in the Early External Cephalic Version trials: an empirical comparison of statistical methods to adjust for center in a multicenter trial with binary outcomes.

PubMed

Reitsma, Angela; Chu, Rong; Thorpe, Julia; McDonald, Sarah; Thabane, Lehana; Hutton, Eileen

2014-09-26

Clustering of outcomes at centers involved in multicenter trials is a type of center effect. The Consolidated Standards of Reporting Trials Statement recommends that multicenter randomized controlled trials (RCTs) should account for center effects in their analysis, however most do not. The Early External Cephalic Version (EECV) trials published in 2003 and 2011 stratified by center at randomization, but did not account for center in the analyses, and due to the nature of the intervention and number of centers, may have been prone to center effects. Using data from the EECV trials, we undertook an empirical study to compare various statistical approaches to account for center effect while estimating the impact of external cephalic version timing (early or delayed) on the outcomes of cesarean section, preterm birth, and non-cephalic presentation at the time of birth. The data from the EECV pilot trial and the EECV2 trial were merged into one dataset. Fisher's exact method was used to test the overall effect of external cephalic version timing unadjusted for center effects. Seven statistical models that accounted for center effects were applied to the data. The models included: i) the Mantel-Haenszel test, ii) logistic regression with fixed center effect and fixed treatment effect, iii) center-size weighted and iv) un-weighted logistic regression with fixed center effect and fixed treatment-by-center interaction, iv) logistic regression with random center effect and fixed treatment effect, v) logistic regression with random center effect and random treatment-by-center interaction, and vi) generalized estimating equations. For each of the three outcomes of interest approaches to account for center effect did not alter the overall findings of the trial. The results were similar for the majority of the methods used to adjust for center, illustrating the robustness of the findings. Despite literature that suggests center effect can change the estimate of effect in multicenter trials, this empirical study does not show a difference in the outcomes of the EECV trials when accounting for center effect. The EECV2 trial was registered on 30 July 30 2005 with Current Controlled Trials: ISRCTN 56498577.

Impact of a social-emotional and character development program on school-level indicators of academic achievement, absenteeism, and disciplinary outcomes: A matched-pair, cluster randomized, controlled trial.

PubMed

Snyder, Frank; Flay, Brian; Vuchinich, Samuel; Acock, Alan; Washburn, Isaac; Beets, Michael; Li, Kin-Kit

2010-01-01

This paper reports the effects of a comprehensive elementary school-based social-emotional and character education program on school-level achievement, absenteeism, and disciplinary outcomes utilizing a matched-pair, cluster randomized, controlled design. The Positive Action Hawai'i trial included 20 racially/ethnically diverse schools (mean enrollment = 544) and was conducted from the 2002-03 through the 2005-06 academic years. Using school-level archival data, analyses comparing change from baseline (2002) to one-year post trial (2007) revealed that intervention schools scored 9.8% better on the TerraNova (2 nd ed.) test for reading and 8.8% on math; 20.7% better in Hawai'i Content and Performance Standards scores for reading and 51.4% better in math; and that intervention schools reported 15.2% lower absenteeism and fewer suspensions (72.6%) and retentions (72.7%). Overall, effect sizes were moderate to large (range 0.5-1.1) for all of the examined outcomes. Sensitivity analyses using permutation models and random-intercept growth curve models substantiated results. The results provide evidence that a comprehensive school-based program, specifically developed to target student behavior and character, can positively influence school-level achievement, attendance, and disciplinary outcomes concurrently.

Methods for obtaining true particle size distributions from cross section measurements

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

Lord, Kristina Alyse

2013-01-01

Sectioning methods are frequently used to measure grain sizes in materials. These methods do not provide accurate grain sizes for two reasons. First, the sizes of features observed on random sections are always smaller than the true sizes of solid spherical shaped objects, as noted by Wicksell [1]. This is the case because the section very rarely passes through the center of solid spherical shaped objects randomly dispersed throughout a material. The sizes of features observed on random sections are inversely related to the distance of the center of the solid object from the section [1]. Second, on a planemore » section through the solid material, larger sized features are more frequently observed than smaller ones due to the larger probability for a section to come into contact with the larger sized portion of the spheres than the smaller sized portion. As a result, it is necessary to find a method that takes into account these reasons for inaccurate particle size measurements, while providing a correction factor for accurately determining true particle size measurements. I present a method for deducing true grain size distributions from those determined from specimen cross sections, either by measurement of equivalent grain diameters or linear intercepts.« less

Efficient Thermally Conductive Strap Design for Cryogenic Propellant Tank Supports and Plumbing

NASA Technical Reports Server (NTRS)

Elchert, J. P.; Christie, R.; Kashani, A.; Opalach, C.

2012-01-01

After evaluating NASA space architecture goals, the Office of Chief Technologist identified the need for developing enabling technology for long term loiters in space with cryogenic fluids. One such technology is structural heat interception. In this prototype, heat interception at the tank support strut was accomplished using a thermally conductive link to the broad area cooled shield. The design methodology for both locating the heat intercept and predicting the reduction in boil-off heat leak is discussed in detail. Results from the chosen design are presented. It was found that contact resistance resulting from different mechanical attachment techniques played a significant role in the form and functionality of a successful design.

The chemical composition of fogs and intercepted clouds in the United States

NASA Astrophysics Data System (ADS)

Collett, Jeffrey L.; Bator, Aaron; Sherman, D. Eli; Moore, Katharine F.; Hoag, Katherine J.; Demoz, Belay B.; Rao, Xin; Reilly, Jill E.

Over the past decade, the chemical compositions of fogs and intercepted clouds have been investigated at more than a dozen locations across the United States. Sampling sites have been located in the northeast, southeast, Rocky Mountain, and west coast regions of the US. They include both pristine and heavily polluted locations. Frontal/orographic clouds (warm and supercooled), intercepted coastal stratiform clouds, and radiation fogs have all been examined. Sample pH values range from below 3 to above 7. Major ions also exhibit a wide concentration range, with clouds at some locations exhibiting high sea salt concentrations, while composition at other locations is dominated by ammonium and sulfate or nitrate.

Efficient Thermally Conductive Strap Design for Cryogenic Propellant Tank Supports and Plumbing

NASA Technical Reports Server (NTRS)

Elchert, J. P.; Christie, R.; Gebby, P.; Kashani, A.

2012-01-01

After evalu1ating NASA space architecture goals, the Office of Chief Technologist identified the need for developing enabling technology for long term loiters in space with cryogenic fluids. One such technology is structural heat interception. In this prototype, heat interception at the tank support strut was accomplished using a thermally conductive link to the broad area cooled shield. The design methodology for both locating the heat intercept and predicting the reduction in boil-off heat leak is discussed in detail. Results from the chosen design are presented. It was found that contact resistance resulting from different mechanical attachment techniques played a significant role in the form and functionality of a successful design.

Intercept-Resend-Measure Attack Towards Quantum Private Comparison Protocol Using Genuine Four-Particle Entangled States and its Improvement

NASA Astrophysics Data System (ADS)

Pan, Hong-Ming

2018-03-01

Recently, Jia et al. proposed the quantum private comparison protocol with the genuine four-particle entangled states (Jia et al., Int. J. Theor. Phys. 51(4), 1187-1194 (2012)). Jia et al. claimed that in this protocol, TP cannot obtain Alice and Bob's secrets and only knows their comparison result. However, in this paper, we demonstrate that if TP is a genuine semi-honest third party, he can totally obtain Alice and Bob's secrets by launching a particular intercept-resend-measure attack. After suggesting the intercept-resend-measure attack strategy from TP first, we put forward one corresponding improvement to prevent this attack.

Range-azimuth decouple beamforming for frequency diverse array with Costas-sequence modulated frequency offsets

NASA Astrophysics Data System (ADS)

Wang, Zhe; Wang, Wen-Qin; Shao, Huaizong

2016-12-01

Different from the phased-array using the same carrier frequency for each transmit element, the frequency diverse array (FDA) uses a small frequency offset across the array elements to produce range-angle-dependent transmit beampattern. FDA radar provides new application capabilities and potentials due to its range-dependent transmit array beampattern, but the FDA using linearly increasing frequency offsets will produce a range and angle coupled transmit beampattern. In order to decouple the range-azimuth beampattern for FDA radar, this paper proposes a uniform linear array (ULA) FDA using Costas-sequence modulated frequency offsets to produce random-like energy distribution in the transmit beampattern and thumbtack transmit-receive beampattern. In doing so, the range and angle of targets can be unambiguously estimated through matched filtering and subspace decomposition algorithms in the receiver signal processor. Moreover, random-like energy distributed beampattern can also be utilized for low probability of intercept (LPI) radar applications. Numerical results show that the proposed scheme outperforms the standard FDA in focusing the transmit energy, especially in the range dimension.

Interception of rainfall and surface runoff in the Brazilian Cerrado

NASA Astrophysics Data System (ADS)

Tarso Oliveira, Paulo; Wendland, Edson; Nearing, Mark; Perea Martins, João

2014-05-01

The Brazilian Cerrado plays a fundamental role in water resources dynamics because it distributes fresh water to the largest basins in Brazil and South America. In recent decades, the native Cerrado vegetation has increasingly been replaced by agricultural crops and pasture. These land cover and land use changes have altered the hydrological processes. Meanwhile, little is known about the components of the water balance in the Brazilian Cerrado, mainly because the experimental field studies in this region are scarce or nonexistent. The objective of this study was to evaluate two hydrological processes under native Cerrado vegetation, the canopy interception (CI) and the surface runoff (R). The Cerrado physiognomy was classified as "cerrado sensu stricto denso" with an absolute density of 15,278 trees ha-1, and a basal area of 11.44 m2 ha-1. We measured the gross rainfall (P) from an automated tipping bucket rain gauge (model TB4) located in a tower with 11 m of height on the Cerrado. Throughfall (TF) was obtained from 15 automated tipping bucket rain gauges (model Davis) spread below the Cerrado vegetation and randomly relocated every month during the wet season. Stemflow (SF) was measured on 12 trees using a plastic hose wrapped around the trees trunks, sealed with neutral silicone sealant, and a bucket to store the water. The canopy interception was computed by the difference between P and the sum of TF and SF. Surface runoff under undisturbed Cerrado was collected in three plots of 100 m2(5 x 20 m) in size and slope steepness of approximately 0.09 m m-1. The experimental study was conducted between January 2012 and November 2013. We found TF of 81.0% of P and SF of 1.6% of P, i.e. the canopy interception was calculated at 17.4% of P. There was a statistically significant correlation (p < 0.05) between gross rainfall and TF, SF, and CI with correlation coefficients r > 0.8. Our results suggest that the rainfall intensity, the characteristics of the trees trunks (crooked and twisted) and stand structure are the main factors that have influenced CI. The average surface runoff under undisturbed Cerrado was less than 1% of the P, and did not have significant correlation (p > 0.05) with P, but had a significant correlation with maximum 30 minute rainfall intensity (I30). This low value for surface runoff indicates that the forest ?oor has a strong influence over surface runoff generation under undisturbed Cerrado. This process is poorly studied; however, we believe this can be a key to understanding the surface runoff generation under undisturbed Cerrado, and in other tropical vegetation, such as the Amazon rainforest.

Who was concerned about radiation, food safety, and natural disasters after the great East Japan earthquake and Fukushima catastrophe? A nationwide cross-sectional survey in 2012.

PubMed

Sugimoto, Takashi; Shinozaki, Tomohiro; Naruse, Takashi; Miyamoto, Yuki

2014-01-01

Disaster-related concerns by sub-populations have not been clarified after the great East Japan earthquake and the Fukushima nuclear power plant incidents. This paper assesses who was concerned about radiation, food safety, and natural disasters among the general population in order to buffer such concerns effectively. The hypothesis that women, parents, and family caregivers were most concerned about radiation, food safety, and natural disaster was tested using a varying-intercept multivariable logistic regression with 5809 responses from a nationwide cross-sectional survey random-sampled in March 2012. Many people were at least occasionally concerned about radiation (53.5%), food safety (47.3%), and about natural disaster (69.5%). Women were more concerned than men about radiation (OR = 1.67; 95% CI = 1.35-2.06), food safety (1.70; 1.38-2.10), and natural disasters (1.74; 1.39-2.19). Parents and family care needs were not significant. Married couples were more concerned about radiation (1.53; 1.33-1.77), food safety (1.38; 1.20-1.59), and natural disasters (1.30; 1.12-1.52). Age, child-cohabitation, college-completion, retirement status, homemaker status, and the house-damage certificate of the last disaster were also associated with at least one concern. Participants from the Kanto region were more concerned about radiation (2.08; 1.58-2.74) and food safety (1.30; 1.07-1.59), which demonstrate similar positive associations to participants from Tohoku where a disaster relief act was invoked (3.36; 2.25-5.01 about radiation, 1.49; 1.08-2.06 about food safety). Sectioning the populations by gender and other demographics will clarify prospective targets for interventions, allow for a better understanding of post-disaster concerns, and help communicate relevant information effectively.

Steps Towards Alcohol Misuse Prevention Programme (STAMPP): a school-based and community-based cluster randomised controlled trial

PubMed Central

McKay, Michael; Agus, Ashley; Cole, Jonathan; Doherty, Paul; Foxcroft, David; Harvey, Séamus; Murphy, Lynn; Percy, Andrew; Sumnall, Harry

2018-01-01

Objectives To assess the effectiveness of a combined classroom curriculum and parental intervention (the Steps Towards Alcohol Misuse Prevention Programme (STAMPP)), compared with alcohol education as normal (EAN), in reducing self-reported heavy episodic drinking (HED) and alcohol-related harms (ARHs) in adolescents. Setting 105 high schools in Northern Ireland (NI) and in Scotland. Participants Schools were stratified by free school meal provision. Schools in NI were also stratified by school type (male/female/coeducational). Eligible students were in school year 8/S1 (aged 11–12 years) at baseline (June 2012). Intervention A classroom-based alcohol education intervention, coupled with a brief alcohol intervention for parents/carers. Primary outcomes (1) The prevalence of self-reported HED in the previous 30 days and (2) the number of self-reported ARHs in the previous 6 months. Outcomes were assessed using two-level random intercepts models (logistic regression for HED and negative binomial for number of ARHs). Results At 33 months, data were available for 5160 intervention and 5073 control students (HED outcome), and 5234 and 5146 students (ARH outcome), respectively. Of those who completed a questionnaire at either baseline or 12 months (n=12 738), 10 405 also completed the questionnaire at 33 months (81.7%). Fewer students in the intervention group reported HED compared with EAN (17%vs26%; OR=0.60, 95% CI 0.49 to 0.73), with no significant difference in the number of self-reported ARHs (incident rate ratio=0.92, 95% CI 0.78 to 1.05). Although the classroom component was largely delivered as intended, there was low uptake of the parental component. There were no reported adverse effects. Conclusions Results suggest that STAMPP could be an effective programme to reduce HED prevalence. While there was no significant reduction in ARH, it is plausible that effects on harms would manifest later. Trial registration number ISRCTN47028486; Post-results. PMID:29525770

Application of the Beers Criteria to Alternate Level of Care Patients in Hospital Inpatient Units

PubMed Central

Slaney, Heather; MacAulay, Stacey; Irvine-Meek, Janice; Murray, Joshua

2015-01-01

Background: The Beers criteria were developed to help in identifying potentially inappropriate medications (PIMs) for elderly patients. These medications are often associated with adverse events and limited effectiveness in older adults. Patients awaiting an alternate level of care (ALC patients) are those who no longer require acute care hospital services and are waiting for placement elsewhere. They are often elderly, have complex medication regimens, and are at high risk of adverse events. At the time of this study no studies had applied the Beers criteria to ALC patients in Canadian hospitals. Objectives: To determine the proportion of ALC patients receiving PIMs and the proportion experiencing selected PIM-related adverse events. Methods: A retrospective chart review of ALC patients 65 years of age or older was performed to identify PIMs and the occurrence of selected adverse events (specifically central nervous system [CNS] events, falls, bradycardia, hypoglycemia, seizures, insomnia, gastrointestinal bleeding, and urinary tract infections). A logistic regression model with a random intercept for each patient was constructed to estimate odds ratios and probabilities of adverse events. Results: Fifty-two ALC patients were included in the study. Of these, 48 (92%) were taking a PIM. Of the 922 adverse events evaluated, 407 (44.1%) were associated with a regularly scheduled PIM. Among patients who were taking regularly scheduled PIMs, there was a significantly increased probability of an adverse CNS event and of a fall (p < 0.001 for both). The most common PIM medication classes were first-generation antihistamines (24 [46%] of the 52 patients), antipsychotics (21 patients [40%]), short-acting benzodiazepines (15 patients [29%]), and nonbenzodiazepine hypnotics (14 patients [27%]). Conclusions: A high proportion of ALC patients were taking PIMs and experienced an adverse event that may have been related to these drugs. These findings suggest that the ALC population might benefit from regular medication review and monitoring to prevent or detect adverse events. PMID:26157183

Using Satellite-Based Spatiotemporal Resolved Air Temperature Exposure to Study the Association between Ambient Air Temperature and Birth Outcomes in Massachusetts

PubMed Central

Melly, Steven J.; Coull, Brent A.; Nordio, Francesco; Schwartz, Joel D.

2015-01-01

Background Studies looking at air temperature (Ta) and birth outcomes are rare. Objectives We investigated the association between birth outcomes and daily Ta during various prenatal exposure periods in Massachusetts (USA) using both traditional Ta stations and modeled addresses. Methods We evaluated birth outcomes and average daily Ta during various prenatal exposure periods in Massachusetts (USA) using both traditional Ta stations and modeled address Ta. We used linear and logistic mixed models and accelerated failure time models to estimate associations between Ta and the following outcomes among live births > 22 weeks: term birth weight (≥ 37 weeks), low birth weight (LBW; < 2,500 g at term), gestational age, and preterm delivery (PT; < 37 weeks). Models were adjusted for individual-level socioeconomic status, traffic density, particulate matter ≤ 2.5 μm (PM2.5), random intercept for census tract, and mother’s health. Results Predicted Ta during multiple time windows before birth was negatively associated with birth weight: Average birth weight was 16.7 g lower (95% CI: –29.7, –3.7) in association with an interquartile range increase (8.4°C) in Ta during the last trimester. Ta over the entire pregnancy was positively associated with PT [odds ratio (OR) = 1.02; 95% CI: 1.00, 1.05] and LBW (OR = 1.04; 95% CI: 0.96, 1.13). Conclusions Ta during pregnancy was associated with lower birth weight and shorter gestational age in our study population. Citation Kloog I, Melly SJ, Coull BA, Nordio F, Schwartz JD. 2015. Using satellite-based spatiotemporal resolved air temperature exposure to study the association between ambient air temperature and birth outcomes in Massachusetts. Environ Health Perspect 123:1053–1058; http://dx.doi.org/10.1289/ehp.1308075 PMID:25850104

Psychological and Social Work Factors as Predictors of Mental Distress: A Prospective Study

PubMed Central

Finne, Live Bakke; Christensen, Jan Olav; Knardahl, Stein

2014-01-01

Studies exploring psychological and social work factors in relation to mental health problems (anxiety and depression) have mainly focused on a limited set of exposures. The current study investigated prospectively a broad set of specific psychological and social work factors as predictors of potentially clinically relevant mental distress (anxiety and depression), i.e. “caseness” level of distress. Employees were recruited from 48 Norwegian organizations, representing a wide variety of job types. A total of 3644 employees responded at both baseline and at follow-up two years later. Respondents were distributed across 832 departments within the 48 organizations. Nineteen work factors were measured. Two prospective designs were tested: (i) with baseline predictors and (ii) with average exposure over time ([T1+T2]/2) as predictors. Random intercept logistic regressions were conducted to account for clustering of the data. Baseline “cases” were excluded (n = 432). Age, sex, skill level, and mental distress as a continuous variable at T1 were adjusted for. Fourteen of 19 factors showed some prospective association with mental distress. The most consistent risk factor was role conflict (highest odds ratio [OR] 2.08, 99% confidence interval [CI]: 1.45–3.00). The most consistent protective factors were support from immediate superior (lowest OR 0.56, 99% CI: 0.43–0.72), fair leadership (lowest OR 0.52, 99% CI: 0.40–0.68), and positive challenge (lowest OR 0.60, 99% CI: 0.41–0.86). The present study demonstrated that a broad set of psychological and social work factors predicted mental distress of potential clinical relevance. Some of the most consistent predictors were different from those traditionally studied. This highlights the importance of expanding the range of factors beyond commonly studied concepts like the demand-control model and the effort-reward imbalance model. PMID:25048033

Area-level income inequality and oral health among Australian adults—A population-based multilevel study

PubMed Central

2018-01-01

Background A lack of evidence exists on the association between area-level income inequality and oral health within Australia. This study examined associations between area-level income inequality and oral health outcomes (inadequate dentition (<21 teeth) and poor self-rated oral health) among Australian adults. Variations in the association between area-level income inequality and oral health outcomes according to area-level mean income were also assessed. Finally, household-income gradients in oral health outcomes according to area-level income inequality were compared. Methods For the analyses, data on Australian dentate adults (n = 5,165 nested in 435 Local Government Areas (LGAs)) was obtained from the National Dental Telephone Interview Survey-2013. Multilevel multivariable logistic regression models with random intercept and fixed slopes were fitted to test associations between area-level income inequality and oral health outcomes, examine variations in associations according to area-level mean income, and examine variations in household-income gradients in outcomes according to area-level income inequality. Covariates included age, sex, LGA-level mean weekly household income, geographic remoteness and household income. Results LGA-level income inequality was not associated with poor self-rated oral health and inversely associated with inadequate dentition (OR: 0.64; 95% CI: 0.48, 0.87) after adjusting for covariates. Inverse association between income inequality and inadequate dentition at the individual level was limited to LGAs within the highest tertile of mean weekly household income. Household income gradients in both outcomes showed poorer oral health at lower levels of household income. The household income gradients for inadequate dentition varied according to the LGA-level income inequality. Conclusion Findings suggest that income inequality at the LGA-level in Australia is not positively associated with poorer oral health outcomes. Inverse association between income inequality and inadequate dentition is likely due to the contextual differences between Australia and other high-income countries. PMID:29364943

A longitudinal study of feed contamination by European starling excreta in Ohio dairy farms (2007-2008).

PubMed

Medhanie, G A; Pearl, D L; McEwen, S A; Guerin, M T; Jardine, C M; Schrock, J; LeJeune, J T

2014-01-01

The objectives of this study were to understand the temporal pattern of contamination of cattle feed by starling excrement on dairy farms and to evaluate the temporal pattern in recovering Escherichia coli O157:H7 or Salmonella in relation to the absolute mass of excrement recovered. A longitudinal study was conducted on 15 dairy farms in Ohio from July 2007 to October 2008. One open-topped tray filled with bird feed was placed near a cattle feeding site; bird excrement from the tray was weighed monthly for 12 consecutive months. Linear regression models with a random intercept for farm were computed to examine the association between the absolute weight of excrement recovered each month or the farm-specific standard score for weight of excrement, and month or season. Exact logistic regression was used to determine whether an association between recovering E. coli O157:H7 or Salmonella was present and the amount of excrement recovered and season. A spatial scan statistic was used to test for evidence of space-time clustering of excrement, based on the standard score for the weight of the excrement, among our study farms. A total of 5 of 179 excrement samples (2.79%) were positive for E. coli O157:H7 and 2 (1.12%) were positive for Salmonella. A significantly higher level of contamination with excrement was observed during the winter. The odds of recovering a pathogen increased with the amount of excrement recovered and decreased if the excrement was collected in the winter. A spatio-temporal cluster of contamination with excrement was detected. These findings provide basic information for future quantitative microbial risk assessments concerning the role of starlings in spreading enteric pathogens on dairy farms. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Association between plasma concentrations of vitamin D metabolites and depressive symptoms throughout pregnancy in a prospective cohort of Brazilian women.

PubMed

Cunha Figueiredo, Amanda C; Trujillo, Janet; Freitas-Vilela, Ana Amélia; Franco-Sena, Ana Beatriz; Rebelo, Fernanda; Cunha, Geraldo Marcelo; de Castro, Maria Beatriz Trindade; Farnum, Amanda; Mokhtar, Rana R; Holick, Michael F; Kac, Gilberto

2017-12-01

Plasma concentrations of vitamin D metabolites can be inversely associated with depressive symptoms. However, few longitudinal studies have investigated this association, especially during pregnancy. The aim of this study was to investigate the association between concentrations of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxivitamin D [1,25(OH) 2 D] with the occurrence of depressive symptoms throughout pregnancy. A prospective cohort of 179 women was followed at 5th-13th, 20th-26th and 30th-36th gestational weeks. At each trimester of pregnancy, the plasma concentrations of 25(OH)D and 1,25(OH) 2 D were analyzed by liquid chromatography tandem mass spectroscopy. Vitamin D status was categorized according to the Endocrine Society Practice Guidelines and the Institute of Medicine. Depressive symptoms were measured at each trimester using the Edinburgh Postnatal Depressive Scale (cutoff ≥13). Statistical analyses included random intercept logistic regression models for longitudinal analyses. In the first trimester, the prevalence of 25(OH)D <75, <50 and <30 nmol/L were 69.3%, 14.0% and 1.7%, respectively. Prevalence of depressive symptoms were 20.1%, 14.7% and 7.8% for the first, second and third trimesters, respectively. The probability of occurrence of depressive symptoms decreased throughout pregnancy (p-value = 0.005). Women with higher concentrations of 25(OH)D in the first trimester presented a lower odds ratio (OR) for the development of depressive symptoms during pregnancy (OR = 0.98; 95%CI: 0.96 to 0.99, p-value = 0.047) in the adjusted model. In conclusion, there was a higher prevalence of vitamin D inadequacy and depressive symptoms during the first trimester. Higher 25(OH)D concentrations in the first trimester were associated with a decrease of 2% in the odds for presenting depressive symptoms throughout pregnancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Area-level income inequality and oral health among Australian adults-A population-based multilevel study.

PubMed

Singh, Ankur; Harford, Jane; Antunes, José Leopoldo Ferreira; Peres, Marco A

2018-01-01

A lack of evidence exists on the association between area-level income inequality and oral health within Australia. This study examined associations between area-level income inequality and oral health outcomes (inadequate dentition (<21 teeth) and poor self-rated oral health) among Australian adults. Variations in the association between area-level income inequality and oral health outcomes according to area-level mean income were also assessed. Finally, household-income gradients in oral health outcomes according to area-level income inequality were compared. For the analyses, data on Australian dentate adults (n = 5,165 nested in 435 Local Government Areas (LGAs)) was obtained from the National Dental Telephone Interview Survey-2013. Multilevel multivariable logistic regression models with random intercept and fixed slopes were fitted to test associations between area-level income inequality and oral health outcomes, examine variations in associations according to area-level mean income, and examine variations in household-income gradients in outcomes according to area-level income inequality. Covariates included age, sex, LGA-level mean weekly household income, geographic remoteness and household income. LGA-level income inequality was not associated with poor self-rated oral health and inversely associated with inadequate dentition (OR: 0.64; 95% CI: 0.48, 0.87) after adjusting for covariates. Inverse association between income inequality and inadequate dentition at the individual level was limited to LGAs within the highest tertile of mean weekly household income. Household income gradients in both outcomes showed poorer oral health at lower levels of household income. The household income gradients for inadequate dentition varied according to the LGA-level income inequality. Findings suggest that income inequality at the LGA-level in Australia is not positively associated with poorer oral health outcomes. Inverse association between income inequality and inadequate dentition is likely due to the contextual differences between Australia and other high-income countries.

Sexual Behaviors and Partner-Specific Correlates of Heterosexual Anal Intercourse Among Truck Drivers and Their Wives in South India

PubMed Central

Bhatnagar, Tarun; Saravanamurthy, P. Sakthivel; Detels, Roger

2015-01-01

It is important to know about patterns of sexual behaviors among married couples in order to develop effective HIV prevention strategies for them. Herein we describe the sexual behaviors, estimate prevalence of anal intercourse (AI) among truck drivers (‘‘truckers’’) and their wives, and determine partner-specific demographic and behavioral correlates of AI. We carried out a cluster-sampled cross-sectional survey among 18–49 year-old wives and their trucker husbands in a south Indian district. Data were collected by same-gender research team members with color-coded computer-assisted interviews. We used random intercept logistic regression to identify the independent correlates of AI. Thirteen percent of 475 wives and 467 truckers reported ever having AI with their spouse. Of those who responded, 55 % of 40 wives and 47 % of 36 truckers never used condoms during AI. Of those who responded, 22 of 32 wives and 24 of 32 husbands felt that condoms were unnecessary during AI. Reporting ever having AI was associated with younger age and higher education of both husband and wife. AI reported by wives was associated with having sexual partner(s) other than husband (adjusted OR 8.8 [95 % CI 3.2–24.0]), correctly answering all HIV knowledge items (adjusted OR 4.9 [95 % CI 1.9–12.5]), husband’s sexual debut occurring before marriage (adjusted OR 1.9 [95 % CI 1.0–3.5]), and husband’s high HIV risk perception (adjusted OR 2.5 [95 % CI 1.2–5.4]). AI reported by truckers was associated with having sex with a male or transgender (adjusted OR 4.0 [95 % CI 1.2–13.3]). Reported prevalence of AI was high considering that in India anal sex is non-normative, heavily stigmatized and, criminal. Indian heterosexual mobile populations need to be informed about the greater risk of HIV infection consequent to unprotected AI. PMID:25252610

Who Was Concerned about Radiation, Food Safety, and Natural Disasters after the Great East Japan Earthquake and Fukushima Catastrophe? A Nationwide Cross-Sectional Survey in 2012

PubMed Central

Sugimoto, Takashi; Shinozaki, Tomohiro; Naruse, Takashi; Miyamoto, Yuki

2014-01-01

Background Disaster-related concerns by sub-populations have not been clarified after the great East Japan earthquake and the Fukushima nuclear power plant incidents. This paper assesses who was concerned about radiation, food safety, and natural disasters among the general population in order to buffer such concerns effectively. Methods The hypothesis that women, parents, and family caregivers were most concerned about radiation, food safety, and natural disaster was tested using a varying-intercept multivariable logistic regression with 5809 responses from a nationwide cross-sectional survey random-sampled in March 2012. Results Many people were at least occasionally concerned about radiation (53.5%), food safety (47.3%), and about natural disaster (69.5%). Women were more concerned than men about radiation (OR = 1.67; 95% CI = 1.35–2.06), food safety (1.70; 1.38–2.10), and natural disasters (1.74; 1.39–2.19). Parents and family care needs were not significant. Married couples were more concerned about radiation (1.53; 1.33–1.77), food safety (1.38; 1.20–1.59), and natural disasters (1.30; 1.12–1.52). Age, child-cohabitation, college-completion, retirement status, homemaker status, and the house-damage certificate of the last disaster were also associated with at least one concern. Participants from the Kanto region were more concerned about radiation (2.08; 1.58–2.74) and food safety (1.30; 1.07–1.59), which demonstrate similar positive associations to participants from Tohoku where a disaster relief act was invoked (3.36; 2.25–5.01 about radiation, 1.49; 1.08–2.06 about food safety). Conclusions Sectioning the populations by gender and other demographics will clarify prospective targets for interventions, allow for a better understanding of post-disaster concerns, and help communicate relevant information effectively. PMID:25181292

Impact of geographic accessibility on utilization of the annual health check-ups by income level in Japan: A multilevel analysis.

PubMed

Fujita, Misuzu; Sato, Yasunori; Nagashima, Kengo; Takahashi, Sho; Hata, Akira

2017-01-01

Although both geographic accessibility and socioeconomic status have been indicated as being important factors for the utilization of health care services, their combined effect has not been evaluated. The aim of this study was to reveal whether an income-dependent difference in the impact of geographic accessibility on the utilization of government-led annual health check-ups exists. Existing data collected and provided by Chiba City Hall were employed and analyzed as a retrospective cohort study. The subjects were 166,966 beneficiaries of National Health Insurance in Chiba City, Japan, aged 40 to 74 years. Of all subjects, 54,748 (32.8%) had an annual health check-up in fiscal year 2012. As an optimal index of geographic accessibility has not been established, five measures were calculated: travel time to the nearest health care facility, density of health care facilities (number facilities within a 30-min walking distance from the district of residence), and three indices based on the two-step floating catchment area method. Three-level logistic regression modeling with random intercepts for household and district of residence was performed. Of the five measures, density of health care facilities was the most compatible according to Akaike's information criterion. Both low density and low income were associated with decreased utilization of the health check-ups. Furthermore, a linear relationship was observed between the density of facilities and utilization of the health check-ups in all income groups and its slope was significantly steeper among subjects with an equivalent income of 0.00 yen than among those with equivalent income of 1.01-2.00 million yen (p = 0.028) or 2.01 million yen or more (p = 0.040). This result indicated that subjects with lower incomes were more susceptible to the effects of geographic accessibility than were those with higher incomes. Thus, better geographic accessibility could increase the health check-up utilization and also decrease the income-related disparity of utilization.

Meaningful use of health information technology and declines in in-hospital adverse drug events.

PubMed

Furukawa, Michael F; Spector, William D; Rhona Limcangco, M; Encinosa, William E

2017-07-01

Nationwide initiatives have promoted greater adoption of health information technology as a means to reduce adverse drug events (ADEs). Hospital adoption of electronic health records with Meaningful Use (MU) capabilities expected to improve medication safety has grown rapidly. However, evidence that MU capabilities are associated with declines in in-hospital ADEs is lacking. Data came from the 2010-2013 Medicare Patient Safety Monitoring System and the 2008-2013 Healthcare Information and Management Systems Society (HIMSS) Analytics Database. Two-level random intercept logistic regression was used to estimate the association of MU capabilities and occurrence of ADEs, adjusting for patient characteristics, hospital characteristics, and year of observation. Rates of in-hospital ADEs declined by 19% from 2010 to 2013. Adoption of MU capabilities was associated with 11% lower odds of an ADE (95% confidence interval [CI], 0.84-0.96). Interoperability capability was associated with 19% lower odds of an ADE (95% CI, 0.67- 0.98). Adoption of MU capabilities explained 22% of the observed reduction in ADEs, or 67,000 fewer ADEs averted by MU. Concurrent with the rapid uptake of MU and interoperability, occurrence of in-hospital ADEs declined significantly from 2010 to 2013. MU capabilities and interoperability were associated with lower occurrence of ADEs, but the effects did not vary by experience with MU. About one-fifth of the decline in ADEs from 2010 to 2013 was attributable to MU capabilities. Findings support the contention that adoption of MU capabilities and interoperability spurred by the Health Information Technology for Economic and Clinical Health Act contributed in part to the recent decline in ADEs. Published by Oxford University Press on behalf of the American Medical Informatics Association 2017. This work is written by US Government employees and is in the public domain in the United States.

The incidence and health burden of earaches attributable to recreational swimming in natural waters: a prospective cohort study.

PubMed

Wade, Timothy J; Sams, Elizabeth A; Beach, Michael J; Collier, Sarah A; Dufour, Alfred P

2013-08-21

Earaches and outer ear infections are commonly associated with swimming. In this study, we estimated the excess risk and health burden of earaches due to swimming in natural fresh and marine waters using results from a survey of over 50,000 beachgoers at nine beaches across the United States. Prospective cohort studies were conducted at four freshwater and five marine sites in the United States and Puerto Rico. Beach visitors were enrolled on summer weekends and holidays. Ten to twelve days after the beach visit, respondents answered questions about health symptoms, including earaches or ear infections experienced since the beach visit. Economic and physical burdens were also obtained. Fixed slope, random intercept (beach site) multivariate logistic regression models were used to estimate the relationship between head immersion swimming exposure and earaches. Model results were used to calculate excess risk for earaches attributable to swimming. The overall incidence of self-reported earache was 1.6% in the 10-12 days after the beach visit. Earaches were more frequent in head immersion swimmers compared to non-swimmers for all beach sites and age groups. Earaches were unassociated with water sample measures of fecal contamination and turbidity. After adjustment for covariates, we calculated 7.12 excess earaches among head immersion swimmers per 1,000 swimming events. Twenty-four percent of those with earache reported missing their regular activities; 28% visited a doctor; 4% visited the emergency room; and 31% and 40% used prescription and non-prescription medications, respectively. There are at least 128 million swimming events in natural waters annually. Such frequent exposures could result in 900,000 excess earaches, 260,000 visits to the doctor, 39,900 visits to the emergency room, nearly $4 million dollars in out-of-pocket expenditures on prescription and over-the-counter medications, and close to 75,000 hours of clinician time. More accurate estimates of swimming exposure are needed to improve population burden and associated cost estimates.

Association Between State Medical Malpractice Environment and Postoperative Outcomes in the United States.

PubMed

Minami, Christina A; Sheils, Catherine R; Pavey, Emily; Chung, Jeanette W; Stulberg, Jonah J; Odell, David D; Yang, Anthony D; Bentrem, David J; Bilimoria, Karl Y

2017-03-01

The US medical malpractice system assumes that the threat of liability should deter negligence, but it is unclear whether malpractice environment affects health care quality. We sought to explore the association between state malpractice environment and postoperative complication rates. This observational study included Medicare fee-for-service beneficiaries undergoing one of the following operations in 2010: colorectal, lung, esophageal, or pancreatic resection, total knee arthroplasty, craniotomy, gastric bypass, abdominal aortic aneurysm repair, coronary artery bypass grafting, or cystectomy. The state-specific malpractice environment was measured by 2010 medical malpractice insurance premiums, state average award size, paid malpractice claims/100 physicians, and a composite malpractice measure. Outcomes of interest included 30-day readmission, mortality, and postoperative complications (eg sepsis, myocardial infarction [MI], pneumonia). Using Medicare administrative claims data, associations between malpractice environment and postoperative outcomes were estimated using hierarchical logistic regression models with hospital random-intercepts. Measures of malpractice environment did not have significant, consistent associations with postoperative outcomes. No individual tort reform law was consistently associated with improved postoperative outcomes. Higher-risk state malpractice environment, based on the composite measure, was associated with higher likelihood of sepsis (odds ratio [OR] 1.22; 95% CI 1.07 to 1.39), MI (OR 1.14; 95% CI 1.06 to 1.23), pneumonia (OR 1.09; 95% CI 1.03 to 1.16), acute renal failure (OR 1.15; 95% CI 1.08 to 1.22), deep vein thrombosis/pulmonary embolism (OR 1.22; 95% CI 1.13 to 1.32), and gastrointestinal bleed (OR 1.18; 95% CI 1.08 to 1.30). Higher risk malpractice environments were not consistently associated with a lower likelihood of surgical postoperative complications, bringing into question the ability of malpractice lawsuits to promote health care quality. Copyright © 2017 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

High Prevalence of Inappropriate Benzodiazepine and Sedative Hypnotic Prescriptions among Hospitalized Older Adults.

PubMed

Pek, Elisabeth Anna; Remfry, Andrew; Pendrith, Ciara; Fan-Lun, Chris; Bhatia, R Sacha; Soong, Christine

2017-05-01

Benzodiazepines and sedative hypnotics are commonly used to treat insomnia and agitation in older adults despite significant risk. A clear understanding of the extent of the problem and its contributors is required to implement effective interventions. To determine the proportion of hospitalized older adults who are inappropriately prescribed benzodiazepines or sedative hypnotics, and to identify patient and prescriber factors associated with increased prescriptions. Single-center retrospective observational study. Urban academic medical center. Medical-surgical inpatients aged 65 or older who were newly prescribed a benzodiazepine or zopiclone. Our primary outcome was the proportion of patients who were prescribed a potentially inappropriate benzodiazepine or sedative hypnotic. Potentially inappropriate indications included new prescriptions for insomnia or agitation/anxiety. We used a multivariable random-intercept logistic regression model to identify patient- and prescriber-level variables that were associated with potentially inappropriate prescriptions. Of 1308 patients, 208 (15.9%) received a potentially inappropriate prescription. The majority of prescriptions, 254 (77.4%), were potentially inappropriate. Of these, most were prescribed for insomnia (222; 87.4%) and during overnight hours (159; 62.3%). Admission to a surgical or specialty service was associated with significantly increased odds of potentially inappropriate prescription compared to the general internal medicine service (odds ratio [OR], 6.61; 95% confidence interval [CI], 2.70-16.17). Prescription by an attending physician or fellow was associated with significantly fewer prescriptions compared to first-year trainees (OR, 0.28; 95% CI, 0.08-0.93). Nighttime prescriptions did not reach significance in initial bivariate analyses but were associated with increased odds of potentially inappropriate prescription in our regression model (OR, 4.48; 95% CI, 2.21-9.06). The majority of newly prescribed benzodiazepines and sedative hypnotics were potentially inappropriate and were primarily prescribed as sleep aids. Future interventions should focus on the development of safe sleep protocols and education targeted at first-year trainees.Journal of Hospital Medicine 2017;12:310-316.

Managing competing demands through task-switching and multitasking: a multi-setting observational study of 200 clinicians over 1000 hours.

PubMed

Walter, Scott R; Li, Ling; Dunsmuir, William T M; Westbrook, Johanna I

2014-03-01

To provide a detailed characterisation of clinicians' work management strategies. 1002.3 h of observational data were derived from three previous studies conducted in a teaching hospital in Sydney, Australia, among emergency department (ED) doctors (n=40), ward doctors (n=57) and ward nurses (n=104). The rates of task-switching (pausing a task to handle an incoming task) and multitasking (adding a task in parallel to an existing task) were compared in each group. Random intercepts logistic regression was used to determine factors significantly associated with clinicians' use of task-switching over multitasking and to quantify variation between individual clinicians. Task-switching rates were higher among ED doctors (6.0 per hour) than ward staff (2.2 and 1.8 per hour for doctors and nurses, respectively) and vice versa for multitasking rates (9.2 vs 17.3 and 14.1 per hour). Clinicians' strategy use was significantly related to the nature and complexity of work and to the person they were working with. In some settings, time of day, day of the week or previous chosen strategy affected a clinician's strategy. Independent of these factors, there was significant variation between individual clinicians in their use of strategies in a given situation (ED doctors p=0.04, ward staff p=0.03). Despite differences in factors associated with work management strategy use among ED doctors, ward doctors and ward nurses, clinicians in all settings appeared to prioritise certain types of tasks over others. Documentation was generally given low priority in all groups, while the arrival of direct care tasks tended to be treated with high priority. These findings suggest that considerations of safety may be implicit in task-switching and multitasking decisions. Although these strategies have been cast in a negative light, future research should consider their role in optimising competing quality and efficiency demands.

Factors related to the level of occurrence of bovine abortion in Chilean dairy herds.

PubMed

Gädicke, Paula; Monti, Gustavo

2013-06-01

The objectives of this study were (1) to estimate the frequency and dynamics of bovine abortion syndrome; (2) to identify groups of cows affected by abortion; and (3) to assess the characteristics of herd management and lactation associated with abortion rates. The study was performed using farmers' historical records for 77 dairy herds in the south of Chile (Bio-Bio, Los Lagos and Los Ríos Regions) collected between 2001 and 2005. These records included 44,959 lactations from 20,977 cows. In addition, farm management practices were assessed through a questionnaire involving 127 herds. The herds were selected according to the farmers' willingness to participate and the existence of high-quality electronic records assessed by the practitioners advising the farms. The frequency distribution of observed, inferred and general abortions was estimated by the incidence rate (IR). A hierarchical logistic regression analysis with random intercept was performed to assess the association between herd management and lactation characteristics and the occurrence of abortion. An IR of 1.74 per 100 cow-months at risk was estimated. General abortions were highest in first-parity cows (IR: 1.85 per 100 cow-months at risk). Abortion cases inferred from individual records were most frequent in the first trimester of gestation and decreased over time, whereas observed abortions increased in accordance with gestation time. The period of highest risk for abortion was around 82 days of gestation. Management practices such as a tap drinking system for cows, a closed herd, vaccination against leptospirosis, exclusive use of pasture for cows, animal density, the time that a calf stays with its dam and breed type were associated with the risk of abortion. The results of this study demonstrate that there is a large underestimation of abortion rates when only farmers' abortion records are analysed, and there are several factors associated with the risk of abortion. Copyright © 2012 Elsevier B.V. All rights reserved.

Grade Retention in Primary Education Is Associated with Quarter of Birth and Socioeconomic Status.

PubMed

González-Betancor, Sara M; López-Puig, Alexis J

2016-01-01

Grade retention is still common practice in some countries though longstanding experience tells us that it is a highly criticised practice for its unclear benefits, its important costs for the educational systems and its relation with school dropout. Therefore, the aim of the present study is to analyse which variables increase the probability of being retained in primary education differentiating between being retained in second or in fourth grade, and paying special attention to the role of the socioeconomic status of the families. By knowing which analysed variables are related to grade retention, and how, we may offer some suggestions to reduce it. We use a national dataset with more observations for Spain than any other international ones, called 'Evaluación General de Diagnóstico', conducted in Spain in 2009 with the participation of 28708 students of fourth grade of primary education from 874 schools, considered to be representative for every Spanish autonomous region. This assessment focused on four competences and includes information about the learning context collected through questionnaires for students, families, school management and teachers. Estimating different multilevel random-intercept logistic regressions we obtain the following three main findings: 1) the existence of a 'quarter of birth' effect, that nearly doubles the probability of grade retention in second grade of primary -compared to the probability of grade retention in fourth grade-, for the youngest students of their same age cohort (OR = 1.93 vs. OR = 1.53, both p<0.001); 2) that the mothers' education level influences more than the fathers' one -especially in second grade (OR = 0.20 vs. OR = 0.45, both p<0.001)-; and 3) that having an unemployed father increases the probability of grade retention much more than having an unemployed mother -especially in second grade (OR = 1.48, p<0.005 vs. OR = 1.18, p>0.05)-.

Health information exchange in the wild: the association between organizational capability and perceived utility of clinical event notifications in ambulatory and community care.

PubMed

Vest, Joshua R; Ancker, Jessica S

2017-01-01

Event notifications are real-time, electronic, automatic alerts to providers of their patients' health care encounters at other facilities. Our objective was to examine the effects of organizational capability and related social/organizational issues upon users' perceptions of the impact of event notifications on quality, efficiency, and satisfaction. We surveyed representatives (n = 49) of 10 organizations subscribing to the Bronx Regional Health Information Organization's event notification services about organizational capabilities, notification information quality, perceived usage, perceived impact, and organizational and respondent characteristics. The response rate was 89%. Average item scores were used to create an individual domain summary score. The association between the impact of event notifications and organizational characteristics was modeled using random-intercept logistic regression models. Respondents estimated that organizations followed up on the majority (83%) of event notifications. Supportive organizational policies were associated with the perception that event notifications improved quality of care (odds ratio [OR] = 2.12; 95% CI, = 1.05, 4.45), efficiency (OR = 2.06; 95% CI = 1.00, 4.21), and patient satisfaction (OR = 2.56; 95% CI = 1.13, 5.81). Higher quality of event notification information was also associated with a perceived positive impact on quality of care (OR = 2.84; 95% CI = 1.31, 6.12), efficiency (OR = 3.04; 95% CI = 1.38, 6.69), and patient satisfaction (OR = 2.96; 95% CI = 1.25, 7.03). Health care organizations with appropriate processes, workflows, and staff may be better positioned to use event notifications. Additionally, information quality remains critical in users' assessments and perceptions. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hospital evaluation of health literacy and associated outcomes in patients after acute myocardial infarction.

PubMed

Rymer, Jennifer A; Kaltenbach, Lisa A; Anstrom, Kevin J; Fonarow, Gregg C; Erskine, Nathaniel; Peterson, Eric D; Wang, Tracy Y

2018-04-01

Low health literacy is common in the United States and may affect outcomes after myocardial infarction (MI). How often hospitals screen for low health literacy is unknown. We surveyed 122 hospitals in the TRANSLATE-ACS study and divided them into those that reported routinely (>75% of patients), selectively (1%-75%), or never (0%) screening MI patients for low health literacy prior to discharge. We performed logistic regression with random intercepts to compare 6-week and 6-month patient-reported medication adherence and multivariable Cox regression to compare 1-year major adverse cardiovascular events and all-cause readmission risks between hospital groups. Overall, 25 (20.5%), 47 (38.5%), and 50 (41.0%) hospitals reported routinely, selectively, or never screening patients for low health literacy, respectively. Patients discharged from hospitals that routinely screened were more likely to report 6-week medication adherence [routinely: adjusted odds ratio (OR) 1.26, 95% CI 1.01-1.57; selectively: adjusted OR 1.19, 95% CI 1.00-1.43, both referenced to those discharged from hospitals that never screened]. Compared with hospitals that never screened health literacy, 1-year major adverse cardiovascular events were similar for hospitals that reported routinely screening (adjusted HR 0.92, 95% CI 0.75-1.14) or selectively screening (adjusted HR 1.01, 95% CI 0.84-1.21). Hospitals that reported selectively screening health literacy were associated with a lower adjusted risk of 1-year all-cause readmission (adjusted HR 0.89, 95% CI 0.79-1.00, P=.041). Only a minority of US hospitals routinely screen MI patients for low health literacy. Hospital screening was associated with higher medication adherence and lower readmission risk. Further investigation is needed to understand how inpatient screening can be implemented to improve longitudinal post-MI care. Copyright © 2017 Elsevier Inc. All rights reserved.

Positive and negative affectivity as risk factors for heavy drinking in the second half of life: a prospective cohort study.

PubMed

Brunborg, Geir Scott

2017-05-01

To estimate the prospective relations between levels of propensity to experience positive affect (PA) and propensity to experience negative affect (NA) and risk of heavy drinking in a cohort of Norwegians aged 40-80 years. Clustered sampling was used to draw Norwegians aged 40-79 years in 2002/03 (t1). The relationship between PA and NA measured at t1 and heavy drinking measured in 2007/08 (t2) was estimated with random-intercept logistic regression. Norway. A total of 2142 (44.0% men) who consumed mean = 3.07 [standard deviation (SD) = 3.15] UK units of alcohol on average per week and were intoxicated less than once per week at t1. The Brief Measure of Positive and Negative Affect, quantity-frequency measure of alcohol use and frequency of drinking to intoxication. Heavy drinking at t2 (> 14 units per week and/or intoxication ≥ once per week) was regressed on PA and NA at t1. Controlling for alcohol consumption, gender, age, income and level of education (at t1) and change in PA and NA, there was little evidence for an association between level of PA and heavy drinking [odds ratio (OR) = 0.96, 95% confidence interval (CI) = 0.71, 1.29, Bayes factor = 0.15]. The level of NA at t1 was associated with greater risk of heavy drinking at t2 (OR = 1.40, 95% CI = 1.02, 1.93). There is little evidence for an association between the propensity to experience positive affect and heavy drinking among Norwegians aged 40-80 years. Norwegian adults in the second half of life with a high propensity to experience negative affect are at greater risk of heavy drinking approximately 5 years later than those with a low propensity to experience negative affect. © 2016 Society for the Study of Addiction.

On-farm starling populations and other environmental and management factors associated with the presence of cefotaxime and ciprofloxacin resistant E. coli among dairy cattle in Ohio.

PubMed

Medhanie, Genet A; Pearl, David L; McEwen, Scott A; Guerin, Michele T; Jardine, Claire M; Schrock, Jennifer; LeJeune, Jeffrey T

2016-11-01

Wild birds that forage around livestock facilities have been implicated as vectors of antimicrobial resistant organisms. Although antimicrobial resistant bacteria have been isolated from European starlings (Sturnus vulgaris), their role in the dissemination of antimicrobial resistant elements in livestock facilities needs further investigation. To determine whether on-farm starling density and other factors were associated with the presence of cefotaxime and ciprofloxacin resistant E. coli among dairy cows in Ohio, bovine fecal pats from 150 farms were tested for the presence of cefotaxime and ciprofloxacin resistant E. coli. Each farm was visited twice (during the summer and fall of 2007-2009). Multi-level logistic regression models with a random intercept to account for fecal pats collected within a specific visit to a farm were used to assess the associations. The percentage of samples with cefotaxime and ciprofloxacin resistant E. coli was 13.4% and 13.6%, respectively. The percentage of farms having at least one sample testing positive for cefotaxime and ciprofloxacin resistant E. coli was 56.7% and 48.7%, respectively. The odds of detecting cefotaxime and ciprofloxacin resistant E. coli in the samples was significantly higher in 2007 compared to 2008 and 2009, in fall compared to summer, and from farms closer than 60km to starling night roost sites compared to the farms further than 60km. The presence of starlings during the day had a negative association with the likelihood of detecting cefotaxime resistant E. coli. Presence of calves also had a negative association with the likelihood of detecting both cefotaxime and ciprofloxacin resistant E. coli. European starlings might play a role in the dissemination of antimicrobial resistant agents in livestock facilities related to their daily population movements rather than the specific density of birds on farm during the day. Copyright © 2016 Elsevier B.V. All rights reserved.

Grade Retention in Primary Education Is Associated with Quarter of Birth and Socioeconomic Status

PubMed Central

2016-01-01

Grade retention is still common practice in some countries though longstanding experience tells us that it is a highly criticised practice for its unclear benefits, its important costs for the educational systems and its relation with school dropout. Therefore, the aim of the present study is to analyse which variables increase the probability of being retained in primary education differentiating between being retained in second or in fourth grade, and paying special attention to the role of the socioeconomic status of the families. By knowing which analysed variables are related to grade retention, and how, we may offer some suggestions to reduce it. We use a national dataset with more observations for Spain than any other international ones, called ‘Evaluación General de Diagnóstico’, conducted in Spain in 2009 with the participation of 28708 students of fourth grade of primary education from 874 schools, considered to be representative for every Spanish autonomous region. This assessment focused on four competences and includes information about the learning context collected through questionnaires for students, families, school management and teachers. Estimating different multilevel random-intercept logistic regressions we obtain the following three main findings: 1) the existence of a ‘quarter of birth’ effect, that nearly doubles the probability of grade retention in second grade of primary –compared to the probability of grade retention in fourth grade–, for the youngest students of their same age cohort (OR = 1.93 vs. OR = 1.53, both p<0.001); 2) that the mothers’ education level influences more than the fathers’ one –especially in second grade (OR = 0.20 vs. OR = 0.45, both p<0.001)–; and 3) that having an unemployed father increases the probability of grade retention much more than having an unemployed mother –especially in second grade (OR = 1.48, p<0.005 vs. OR = 1.18, p>0.05)–. PMID:27851779

From policy to practice: strategies to meet physical activity standards in YMCA afterschool programs.

PubMed

Beets, Michael W; Weaver, Robert G; Moore, Justin B; Turner-McGrievy, Gabriel; Pate, Russell R; Webster, Collin; Beighle, Aaron

2014-03-01

In 2011, the U.S. Young Men's Christian Association (YMCA) adopted activity standards recommending that afterschool programs (ASPs) ensure all children engage in a minimum of 30 minutes of moderate to vigorous physical activity (MVPA) daily during the ASP. ASPs decide how to accomplish this standard, for which few effective strategies exist. To evaluate strategies designed to help ASPs meet the MVPA standard. Single group intervention with pretest and three follow-up measures repeated-cross-sectional design with a subsample cohort. Four large-scale YMCA ASPs, serving approximately 500 children each day. Community-based participatory development of strategies focused on modification of program schedules, professional development training, and weekly checklists to evaluate activity opportunities. Accelerometry-derived MVPA classified as meet or fail-to-meet the 30 minutes' MVPA/day standard collected over a minimum of 4 nonconsecutive days at baseline (fall 2011) and three follow-up assessments (spring 2012, fall 2012, spring 2013). Random intercept logistic regression models evaluated the probability of meeting the standard for boys and girls, separately (analyzed summer 2013). A total of 895 children (aged 5-12 years, 48.4% girls) representing 3654 daily measures were collected across the four assessments. The percentage of girls and boys meeting the MVPA standard at baseline was 13.3% and 28.0%, respectively. By spring 2013, this increased to 29.3% and 49.6%. These changes represented an increase in the odds of meeting the 30 minutes' MVPA/day standard by 1.5 (95% CI=1.1, 2.0) and 2.4 (95% CI=1.2, 4.8) for girls and boys, respectively. The strategies developed herein represent an effective approach to enhancing current practice within YMCA ASPs to achieve existing MVPA standards. Additional work is necessary to evaluate the scalability of the strategies in a larger sample of ASPs. © 2014 American Journal of Preventive Medicine Published by American Journal of Preventive Medicine All rights reserved.

Real-World Contexts, Multiple Representations, Student-Invented Terminology, and Y-Intercept

ERIC Educational Resources Information Center

Davis, Jon D.

2007-01-01

One classroom using two units from a "Standards"-based curriculum was the focus of a study designed to examine the effects of real-world contexts, delays in the introduction of formal mathematics terminology, and multiple function representations on student understanding. Students developed their own terminology for y-intercept, which was tightly…

46 CFR 174.255 - Restricted service.

Code of Federal Regulations, 2014 CFR

2014-10-01

... wind heeling moment, either to the angle of the second intercept of those curves or to the angle of heel at which downflooding would occur, whichever angle is less. (iii) A residual righting energy of at... righting moment and wind heeling moment, either to the angle of the second intercept of those curves or to...

46 CFR 174.255 - Restricted service.

Code of Federal Regulations, 2013 CFR

2013-10-01

... wind heeling moment, either to the angle of the second intercept of those curves or to the angle of heel at which downflooding would occur, whichever angle is less. (iii) A residual righting energy of at... righting moment and wind heeling moment, either to the angle of the second intercept of those curves or to...

46 CFR 174.255 - Restricted service.

Code of Federal Regulations, 2012 CFR

2012-10-01

... wind heeling moment, either to the angle of the second intercept of those curves or to the angle of heel at which downflooding would occur, whichever angle is less. (iii) A residual righting energy of at... righting moment and wind heeling moment, either to the angle of the second intercept of those curves or to...

Point Intercept (PO)

Treesearch

John F. Caratti

2006-01-01

The FIREMON Point Intercept (PO) method is used to assess changes in plant species cover or ground cover for a macroplot. This method uses a narrow diameter sampling pole or sampling pins, placed at systematic intervals along line transects to sample within plot variation and quantify statistically valid changes in plant species cover and height over time. Plant...

Do sampling methods differ in their utility for ecological monitoring? Comparison of line-point intercept, grid-point intercept, and ocular estimate methods

USDA-ARS?s Scientific Manuscript database

This study compared the utility of three sampling methods for ecological monitoring based on: interchangeability of data (rank correlations), precision (coefficient of variation), cost (minutes/transect), and potential of each method to generate multiple indicators. Species richness and foliar cover...

Establishing conservation buffers using precision information

Treesearch

Mike G. Dosskey; Dean E. Eisenhauer; Matthew J. Helmers

2005-01-01

Conservation buffers, such as filter strips and riparian forest buffers, are widely prescribed to improve and protect water quality in agricultural landscapes. These buffers intercept field runoff and retain some of its pollutant load before it reaches a waterway. A buffer typically is designed to have uniform width along a field margin and to intercept runoff that...

Human Factors Evaluation of the Hidalgo Equivital EQ-02 Physiological Status Monitoring System

DTIC Science & Technology

2013-10-11

Destruction – Civil Support Team (WMD-CST) responding (11), and ricin letters that were intercepted en route to a member of Congress and the President...positive for ricin at Washington mail facility. CNN U.S., April 17, 2013. (http://www.cnn.com/2013/04/16/us/tainted-letter- intercepted accessed

An Experimental System for Research on Dynamic Skills Training.

DTIC Science & Technology

1981-09-01

Bogey to be intercepted. The student enters B1 . The system then displays a recommended intercept heading, say 270 degrees. The student must now send this...DRIVE LRDC OTTAWA, CANADA K1A 0K2 UNIVERSITY OF PITTSBURGH 3939 O’HARA STREET ERIC Facility-Acquisitions PITTSBURGH, PA 15213 4833 Rugby Avenue Bethesda

Methods to prioritize placement of riparian buffers for improved water quality

Treesearch

Mark D. Tomer; Michael G. Dosskey; Michael R. Burkart; David E. James; Matthew J. Helmers; Dean E. Eisenhauer

2008-01-01

Agroforestry buffers in riparian zones can improve stream water quality, provided they intercept and remove contaminants from surface runoff and/or shallow groundwater. Soils, topography, surficial geology, and hydrology determine the capability of forest buffers to intercept and treat these flows. This paper describes two landscape analysis techniques for identifying...

Statistical Power for a Simultaneous Test of Factorial and Predictive Invariance

ERIC Educational Resources Information Center

Olivera-Aguilar, Margarita; Millsap, Roger E.

2013-01-01

A common finding in studies of differential prediction across groups is that although regression slopes are the same or similar across groups, group differences exist in regression intercepts. Building on earlier work by Birnbaum (1979), Millsap (1998) presented an invariant factor model that would explain such intercept differences as arising due…

An analysis of arthropod interceptions by APHIS-PPQ and Customs and Border Patrol in Puerto Rico

USDA-ARS?s Scientific Manuscript database

USDA Animal Plant Health Inspection Service Plant Protection and Quarantine (APHIS-PPQ) and Customs and Border Patrol (CBP) inspect traffic entering the United States for arthropods that pose a threat to national agriculture and/or ecosystems. We analyzed interceptions made by these agencies in Puer...

Line Intercept (LI)

Treesearch

John F. Caratti

2006-01-01

The FIREMON Line Intercept (LI) method is used to assess changes in plant species cover for a macroplot. This method uses multiple line transects to sample within plot variation and quantify statistically valid changes in plant species cover and height over time. This method is suited for most forest and rangeland communities, but is especially useful for sampling...

Surface water storage capacity of twenty tree species in Davis, California

Treesearch

Qingfu Xiao; E. Gregory McPherson

2016-01-01

Urban forestry is an important green infrastructure strategy because healthy trees can intercept rainfall, reducing stormwater runoff and pollutant loading. Surface saturation storage capacity, defined as the thin film of water that must wet tree surfaces before flow begins, is the most important variable influencing rainfall interception processes. Surface storage...

HOWARD FORK ACID ROCK DRAINAGE SOURCE INTERCEPTION STUDY; HOWARD FORK OF THE SAN MIGUEL RIVER NEAR OPHIR, COLORADO

EPA Science Inventory

This project proposes to analyze regional hydrogeology as it relates to mine workings which discharge significant heavy metals into the Howard Fork of the San Miguel River and recommend strategies to intercept and divert water away from mineralized zones. The study also includes...

Canopy Light Interception of a Conventional and an Erect Leaf Mutant Sorghum

USDA-ARS?s Scientific Manuscript database

Two sorghum lines, an erect leafed mutant sorghum and the wild type from which the mutant was generated, were field grown in rectilinear arrays at low (23 plants per square meter) and high (10 plants per square meter) population densities. Canopy light interception, biomass accretion and yield were ...

A comparison of cover calculation techniques for relating point-intercept vegetation sampling to remote sensing imagery

USDA-ARS?s Scientific Manuscript database

Accurate and timely spatial predictions of vegetation cover from remote imagery are an important data source for natural resource management. High-quality in situ data are needed to develop and validate these products. Point-intercept sampling techniques are a common method for obtaining quantitativ...

Interception processes during snowstorms

Treesearch

David H. Miller

1964-01-01

Four processes are identified as determining the initial interception of falling snow by forest during storms: delivery of snow particles from the airstream to the forest; true throughfall of particles to the forest floor; impaction and adhesion of particles to foliage and branches; and cohesion of particles into masses of snow. Delivery and impaction processes seem...

Expert Anticipatory Skill in Striking Sports: A Review and a Model

ERIC Educational Resources Information Center

Muller, Sean; Abernethy, Bruce

2012-01-01

Expert performers in striking sports can hit objects moving at high speed with incredible precision. Exceptionally well developed anticipation skills are necessary to cope with the severe constraints on interception. In this paper, we provide a review of the empirical evidence regarding expert interception in striking sports and propose a…

Cometary exploration in the shuttle era

NASA Technical Reports Server (NTRS)

Farquhar, R. W.; Wooden, W. H., II

1978-01-01

A comprehensive program plan for cometary exploration in the 1980-2000 time frame is proposed. Plans for ground-based observations, a Spacelab cometary observatory, and the Space Telescope are included in the observational program. The cometary mission sequence begins with a dual-spacecraft flyby of Halley's comet. The nominal mission strategy calls for a simultaneous launch of two spacecraft towards an intercept with Halley in March 1986. After the Halley encounter, the spacecraft are retargeted: one to intercept comet Borrelly in January 1988 and the other to intercept comet Tempel-2 in September 1988. The additional cometary intercepts are accomplished by utilizing a novel Earth-swingby technique. The next mission in the cometary program plan, a rendezvous with Encke's comet, is scheduled for launch in early 1990. It is planned to rendezvous with Encke in September 1992 at a heliocentric distance of 4 AU. Following this near-aphelion rendezvous, the spacecraft will remain with with Encke through the next two perihelion passages in February 1994 and May 1997. The rendezvous mission will be terminated about seven months after the second perihelion passage.

A parameter estimation algorithm for LFM/BPSK hybrid modulated signal intercepted by Nyquist folding receiver

NASA Astrophysics Data System (ADS)

Qiu, Zhaoyang; Wang, Pei; Zhu, Jun; Tang, Bin

2016-12-01

Nyquist folding receiver (NYFR) is a novel ultra-wideband receiver architecture which can realize wideband receiving with a small amount of equipment. Linear frequency modulated/binary phase shift keying (LFM/BPSK) hybrid modulated signal is a novel kind of low probability interception signal with wide bandwidth. The NYFR is an effective architecture to intercept the LFM/BPSK signal and the LFM/BPSK signal intercepted by the NYFR will add the local oscillator modulation. A parameter estimation algorithm for the NYFR output signal is proposed. According to the NYFR prior information, the chirp singular value ratio spectrum is proposed to estimate the chirp rate. Then, based on the output self-characteristic, matching component function is designed to estimate Nyquist zone (NZ) index. Finally, matching code and subspace method are employed to estimate the phase change points and code length. Compared with the existing methods, the proposed algorithm has a better performance. It also has no need to construct a multi-channel structure, which means the computational complexity for the NZ index estimation is small. The simulation results demonstrate the efficacy of the proposed algorithm.

Constrained orbital intercept-evasion

NASA Astrophysics Data System (ADS)

Zatezalo, Aleksandar; Stipanovic, Dusan M.; Mehra, Raman K.; Pham, Khanh

2014-06-01

An effective characterization of intercept-evasion confrontations in various space environments and a derivation of corresponding solutions considering a variety of real-world constraints are daunting theoretical and practical challenges. Current and future space-based platforms have to simultaneously operate as components of satellite formations and/or systems and at the same time, have a capability to evade potential collisions with other maneuver constrained space objects. In this article, we formulate and numerically approximate solutions of a Low Earth Orbit (LEO) intercept-maneuver problem in terms of game-theoretic capture-evasion guaranteed strategies. The space intercept-evasion approach is based on Liapunov methodology that has been successfully implemented in a number of air and ground based multi-player multi-goal game/control applications. The corresponding numerical algorithms are derived using computationally efficient and orbital propagator independent methods that are previously developed for Space Situational Awareness (SSA). This game theoretical but at the same time robust and practical approach is demonstrated on a realistic LEO scenario using existing Two Line Element (TLE) sets and Simplified General Perturbation-4 (SGP-4) propagator.

Interception of LPI radar signals

NASA Astrophysics Data System (ADS)

Lee, Jim P.

1991-11-01

Most current radars are designed to transmit short duration pulses with relatively high peak power. These radars can be detected easily by the use of relatively modest EW intercept receivers. Three radar functions (search, anti-ship missile (ASM) seeker, and navigation) are examined to evaluate the effectiveness of potential low probability of intercept (LPI) techniques, such as waveform coding, antenna profile control, and power management that a radar may employ against current Electronic Warfare (EW) receivers. The general conclusion is that it is possible to design a LPI radar which is effective against current intercept EW receivers. LPI operation is most easily achieved at close ranges and against a target with a large radar cross section. The general system sensitivity requirement for the detection of current and projected LPI radars is found to be on the order of -100 dBmi which cannot be met by current EW receivers. Finally, three potential LPI receiver architectures, using channelized, superhet, and acousto-optic receivers with narrow RF and video bandwidths are discussed. They have shown some potential in terms of providing the sensitivity and capability in an environment where both conventional and LPI signals are present.

Logistic quantile regression provides improved estimates for bounded avian counts: A case study of California Spotted Owl fledgling production

USGS Publications Warehouse

Cade, Brian S.; Noon, Barry R.; Scherer, Rick D.; Keane, John J.

2017-01-01

Counts of avian fledglings, nestlings, or clutch size that are bounded below by zero and above by some small integer form a discrete random variable distribution that is not approximated well by conventional parametric count distributions such as the Poisson or negative binomial. We developed a logistic quantile regression model to provide estimates of the empirical conditional distribution of a bounded discrete random variable. The logistic quantile regression model requires that counts are randomly jittered to a continuous random variable, logit transformed to bound them between specified lower and upper values, then estimated in conventional linear quantile regression, repeating the 3 steps and averaging estimates. Back-transformation to the original discrete scale relies on the fact that quantiles are equivariant to monotonic transformations. We demonstrate this statistical procedure by modeling 20 years of California Spotted Owl fledgling production (0−3 per territory) on the Lassen National Forest, California, USA, as related to climate, demographic, and landscape habitat characteristics at territories. Spotted Owl fledgling counts increased nonlinearly with decreasing precipitation in the early nesting period, in the winter prior to nesting, and in the prior growing season; with increasing minimum temperatures in the early nesting period; with adult compared to subadult parents; when there was no fledgling production in the prior year; and when percentage of the landscape surrounding nesting sites (202 ha) with trees ≥25 m height increased. Changes in production were primarily driven by changes in the proportion of territories with 2 or 3 fledglings. Average variances of the discrete cumulative distributions of the estimated fledgling counts indicated that temporal changes in climate and parent age class explained 18% of the annual variance in owl fledgling production, which was 34% of the total variance. Prior fledgling production explained as much of the variance in the fledgling counts as climate, parent age class, and landscape habitat predictors. Our logistic quantile regression model can be used for any discrete response variables with fixed upper and lower bounds.

Predictive saccade in the absence of smooth pursuit: interception of moving targets in the archer fish.

PubMed

Ben-Simon, Avi; Ben-Shahar, Ohad; Vasserman, Genadiy; Segev, Ronen

2012-12-15

Interception of fast-moving targets is a demanding task many animals solve. To handle it successfully, mammals employ both saccadic and smooth pursuit eye movements in order to confine the target to their area centralis. But how can non-mammalian vertebrates, which lack smooth pursuit, intercept moving targets? We studied this question by exploring eye movement strategies employed by archer fish, an animal that possesses an area centralis, lacks smooth pursuit eye movements, but can intercept moving targets by shooting jets of water at them. We tracked the gaze direction of fish during interception of moving targets and found that they employ saccadic eye movements based on prediction of target position when it is hit. The fish fixates on the target's initial position for ∼0.2 s from the onset of its motion, a time period used to predict whether a shot can be made before the projection of the target exits the area centralis. If the prediction indicates otherwise, the fish performs a saccade that overshoots the center of gaze beyond the present target projection on the retina, such that after the saccade the moving target remains inside the area centralis long enough to prepare and perform a shot. These results add to the growing body of knowledge on biological target tracking and may shed light on the mechanism underlying this behavior in other animals with no neural system for the generation of smooth pursuit eye movements.

Anticipating the effects of gravity when intercepting moving objects: differentiating up and down based on nonvisual cues.

PubMed

Senot, Patrice; Zago, Myrka; Lacquaniti, Francesco; McIntyre, Joseph

2005-12-01

Intercepting an object requires a precise estimate of its time of arrival at the interception point (time to contact or "TTC"). It has been proposed that knowledge about gravitational acceleration can be combined with first-order, visual-field information to provide a better estimate of TTC when catching falling objects. In this experiment, we investigated the relative role of visual and nonvisual information on motor-response timing in an interceptive task. Subjects were immersed in a stereoscopic virtual environment and asked to intercept with a virtual racket a ball falling from above or rising from below. The ball moved with different initial velocities and could accelerate, decelerate, or move at a constant speed. Depending on the direction of motion, the acceleration or deceleration of the ball could therefore be congruent or not with the acceleration that would be expected due to the force of gravity acting on the ball. Although the best success rate was observed for balls moving at a constant velocity, we systematically found a cross-effect of ball direction and acceleration on success rate and response timing. Racket motion was triggered on average 25 ms earlier when the ball fell from above than when it rose from below, whatever the ball's true acceleration. As visual-flow information was the same in both cases, this shift indicates an influence of the ball's direction relative to gravity on response timing, consistent with the anticipation of the effects of gravity on the flight of the ball.

Nonlinear isochrones in murine left ventricular pressure-volume loops: how well does the time-varying elastance concept hold?

PubMed

Claessens, T E; Georgakopoulos, D; Afanasyeva, M; Vermeersch, S J; Millar, H D; Stergiopulos, N; Westerhof, N; Verdonck, P R; Segers, P

2006-04-01

The linear time-varying elastance theory is frequently used to describe the change in ventricular stiffness during the cardiac cycle. The concept assumes that all isochrones (i.e., curves that connect pressure-volume data occurring at the same time) are linear and have a common volume intercept. Of specific interest is the steepest isochrone, the end-systolic pressure-volume relationship (ESPVR), of which the slope serves as an index for cardiac contractile function. Pressure-volume measurements, achieved with a combined pressure-conductance catheter in the left ventricle of 13 open-chest anesthetized mice, showed a marked curvilinearity of the isochrones. We therefore analyzed the shape of the isochrones by using six regression algorithms (two linear, two quadratic, and two logarithmic, each with a fixed or time-varying intercept) and discussed the consequences for the elastance concept. Our main observations were 1) the volume intercept varies considerably with time; 2) isochrones are equally well described by using quadratic or logarithmic regression; 3) linear regression with a fixed intercept shows poor correlation (R(2) < 0.75) during isovolumic relaxation and early filling; and 4) logarithmic regression is superior in estimating the fixed volume intercept of the ESPVR. In conclusion, the linear time-varying elastance fails to provide a sufficiently robust model to account for changes in pressure and volume during the cardiac cycle in the mouse ventricle. A new framework accounting for the nonlinear shape of the isochrones needs to be developed.

Estimation of air-to-grass mass interception factors for iodine.

PubMed

Karunakara, N; Ujwal, P; Yashodhara, I; Sudeep Kumara, K; Mohan, M P; Bhaskar Shenoy, K; Geetha, P V; Dileep, B N; James, Joshi P; Ravi, P M

2018-06-01

Air-to-grass mass interception factors for radionuclide are important basic input parameter for the estimation of radiation dose to the public around a nuclear power plant. In this paper, we present the determination of air-to- grass mass interception factors for iodine using a 2 m × 2 m × 2 m (l × b × h) size environmental chamber. The temperature, humidity, and rainfall inside the environmental chamber was controlled to required values to simulate different environmental conditions. Grass (Pennisetum purpureum, Schum), grown in pots, was kept inside the environmental chamber and stable iodine in elemental form was sublimed quickly inside the chamber to simulate an accidental release of iodine to the environment. The concentration of iodine in the air was measured periodically by drawing air through a bubbling setup, containing 1% sodium carbonate solution. The mass interception factor for dry deposition varied in the range of 0.25-7.7 m 2  kg -1 with mean value of 2.2 m 2  kg -1 with respect to fresh weight of grass, and that due to wet deposition varied in the range of 0.6-4.8 m 2  kg -1 with mean value of 2.3 m 2  kg -1 . The mass interception factor was inversely correlated with the total iodine deposited through dry deposition as well as with the rainfall. Copyright © 2017. Published by Elsevier Ltd.

Is perception of self-motion speed a necessary condition for intercepting a moving target while walking?

PubMed

Morice, Antoine H P; Wallet, Grégory; Montagne, Gilles

2014-04-30

While it has been shown that the Global Optic Flow Rate (GOFR) is used in the control of self-motion speed, this study examined its relevance in the control of interceptive actions while walking. We asked participants to intercept approaching targets by adjusting their walking speed in a virtual environment, and predicted that the influence of the GOFR depended on their interception strategy. Indeed, unlike the Constant Bearing Angle (CBA), the Modified Required Velocity (MRV) strategy relies on the perception of self-displacement speed. On the other hand, the CBA strategy involves specific speed adjustments depending on the curvature of the target's trajectory, whereas the MRV does not. We hypothesized that one strategy is selected among the two depending on the informational content of the environment. We thus manipulated the curvature and display of the target's trajectory, and the relationship between physical walking speed and the GOFR (through eye height manipulations). Our results showed that when the target trajectory was not displayed, walking speed profiles were affected by curvature manipulations. Otherwise, walking speed profiles were less affected by curvature manipulations and were affected by the GOFR manipulations. Taken together, these results show that the use of the GOFR for intercepting a moving target while walking depends on the informational content of the environment. Finally we discuss the complementary roles of these two perceptual-motor strategies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Implication of Intrastorm Rainfall-Canopy Interaction on Interception Performance of Broadleaf Evergreen Shrubs in Urban Setting

NASA Astrophysics Data System (ADS)

Yerk, W.; Montalto, F. A.

2014-12-01

Because of its ability to intercept a portion of rainfall, vegetated canopy has a significant influence on the urban hydrological cycle. In turn, urban watersheds, characterized by large impervious areas, have an enormous and often adverse impact on receiving waters. However, most historical interception research has been dedicated to forest canopies. The goal of our research was to quantify rainfall partitioning by isolated evergreen canopies in an urban setting. Two years of the field experiment involved three exemplars of Cherry Laurel (Prunus laurocerasus'Otto Luyken'.) Each plant had ten rain gauges to measure throughfall with a five second sampling frequency. A number of preventive techniques were introduced to minimize the gauges' errors (e.g., splash-in, splash-out and excessive wetting.) Leaf area index was measured manually. We estimated the canopy storage capacity to be less than 0.5 mm. An on-site automated weather station provided meteorological data. Cumulative interception loss for the periods of August-December 2013 and April-July 2014 was 51%. Phenological change did not show a stable pattern of influence on throughfall depths. Measurements in May and July 2014 showed a high variability of stemflow (2-16%) between rain events. Throughfall and precipitation intensities (mm/hr) expressed strong linear relationships (adjusted coefficient of determination R20.79) for the entire range of observed rainfall intensities. The ratio of throughfall to precipitation intensity was 0.49:1. The observations suggest that reduction of throughfall intensity by the canopy during a rainstorm determines the bulk of interception depth. In contrast, the amount of water stored on the canopy and evaporated between and after rain events contributes minimally to interception. Simulations of potential evaporation based on the Penman-Monteith method revealed a serious underestimation of evaporation from the wet canopy surfaces during the rain events. Mechanisms other than heat balance models of potential evaporation from a still water surface are being discussed in order to explain large intrastorm evaporation from within an isolated canopy.

An Efficient Ray-Tracing Method for Determining Terrain Intercepts in EDL Simulations

NASA Technical Reports Server (NTRS)

Shidner, Jeremy D.

2016-01-01

The calculation of a ray's intercept from an arbitrary point in space to a prescribed surface is a common task in computer simulations. The arbitrary point often represents an object that is moving according to the simulation, while the prescribed surface is fixed in a defined frame. For detailed simulations, this surface becomes complex, taking the form of real-world objects such as mountains, craters or valleys which require more advanced methods to accurately calculate a ray's intercept location. Incorporation of these complex surfaces has commonly been implemented in graphics systems that utilize highly optimized graphics processing units to analyze such features. This paper proposes a simplified method that does not require computationally intensive graphics solutions, but rather an optimized ray-tracing method for an assumed terrain dataset. This approach was developed for the Mars Science Laboratory mission which landed on the complex terrain of Gale Crater. First, this paper begins with a discussion of the simulation used to implement the model and the applicability of finding surface intercepts with respect to atmosphere modeling, altitude determination, radar modeling, and contact forces influencing vehicle dynamics. Next, the derivation and assumptions of the intercept finding method are presented. Key assumptions are noted making the routines specific to only certain types of surface data sets that are equidistantly spaced in longitude and latitude. The derivation of the method relies on ray-tracing, requiring discussion on the formulation of the ray with respect to the terrain datasets. Further discussion includes techniques for ray initialization in order to optimize the intercept search. Then, the model implementation for various new applications in the simulation are demonstrated. Finally, a validation of the accuracy is presented along with the corresponding data sets used in the validation. A performance summary of the method will be shown using the analysis from the Mars Science Laboratory's terminal descent sensing model. Alternate uses will also be shown for determining horizon maps and orbiter set times.

Pathogen inactivation efficacy of Mirasol PRT System and Intercept Blood System for non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma.

PubMed

Kwon, S Y; Kim, I S; Bae, J E; Kang, J W; Cho, Y J; Cho, N S; Lee, S W

2014-10-01

This study was conducted to evaluate the efficacy of pathogen inactivation (PI) in non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma using the Mirasol PRT System and the Intercept Blood System. Platelets were pooled using the Acrodose PL system and separated into two aliquots for Mirasol and Intercept treatment. Four replicates of each viral strain were used for the evaluation. For bacteria, both low-titre (45-152 CFU/unit) inoculation and high-titre (7·34-10·18 log CFU/unit) inoculation with two replicates for each bacterial strain were used. Platelets with non-detectable bacterial growth and platelets inoculated with a low titre were stored for 5 days, and culture was performed with the BacT/ALERT system. The inactivation efficacy expressed as log reduction for Mirasol and Intercept systems for viruses was as follows: human immunodeficiency virus 1, ≥4·19 vs. ≥4·23; bovine viral diarrhoea virus, 1·83 vs. ≥6·03; pseudorabies virus, 2·73 vs. ≥5·20; hepatitis A virus, 0·62 vs. 0·76; and porcine parvovirus, 0·28 vs. 0·38. The inactivation efficacy for bacteria was as follows: Escherichia coli, 5·45 vs. ≥9·22; Staphylococcus aureus, 4·26 vs. ≥10·11; and Bacillus subtilis, 5·09 vs. ≥7·74. Postinactivation bacterial growth in platelets inoculated with a low titre of S. aureus or B. subtilis was detected only with Mirasol. Pathogen inactivation efficacy of Intercept for enveloped viruses was found to be satisfactory. Mirasol showed satisfactory inactivation efficacy for HIV-1 only. The two selected non-enveloped viruses were not inactivated by both systems. Inactivation efficacy of Intercept was more robust for all bacteria tested at high or low titres. © 2014 International Society of Blood Transfusion.

A pragmatic approach for mortality prediction after surgery in infective endocarditis: optimizing and refining EuroSCORE.

PubMed

Fernández-Hidalgo, N; Ferreria-González, I; Marsal, J R; Ribera, A; Aznar, M L; de Alarcón, A; García-Cabrera, E; Gálvez-Acebal, J; Sánchez-Espín, G; Reguera-Iglesias, J M; De La Torre-Lima, J; Lomas, J M; Hidalgo-Tenorio, C; Vallejo, N; Miranda, B; Santos-Ortega, A; Castro, M A; Tornos, P; García-Dorado, D; Almirante, B

2018-03-03

To simplify and optimize the ability of EuroSCORE I and II to predict early mortality after surgery for infective endocarditis (IE). Multicentre retrospective study (n = 775). Simplified scores, eliminating irrelevant variables, and new specific scores, adding specific IE variables, were created. The performance of the original, recalibrated and specific EuroSCOREs was assessed by Brier score, C-statistic and calibration plot in bootstrap samples. The Net Reclassification Index was quantified. Recalibrated scores including age, previous cardiac surgery, critical preoperative state, New York Heart Association >I, and emergent surgery (EuroSCORE I and II); renal failure and pulmonary hypertension (EuroSCORE I); and urgent surgery (EuroSCORE II) performed better than the original EuroSCOREs (Brier original and recalibrated: EuroSCORE I: 0.1770 and 0.1667; EuroSCORE II: 0.2307 and 0.1680). Performance improved with the addition of fistula, staphylococci and mitral location (EuroSCORE I and II) (Brier specific: EuroSCORE I 0.1587, EuroSCORE II 0.1592). Discrimination improved in specific models (C-statistic original, recalibrated and specific: EuroSCORE I: 0.7340, 0.7471 and 0.7728; EuroSCORE II: 0.7442, 0.7423 and 0.7700). Calibration improved in both EuroSCORE I models (intercept 0.295, slope 0.829 (original); intercept -0.094, slope 0.888 (recalibrated); intercept -0.059, slope 0.925 (specific)) but only in specific EuroSCORE II model (intercept 2.554, slope 1.114 (original); intercept -0.260, slope 0.703 (recalibrated); intercept -0.053, slope 0.930 (specific)). Net Reclassification Index was 5.1% and 20.3% for the specific EuroSCORE I and II CONCLUSIONS: The use of simplified EuroSCORE I and EuroSCORE II models in IE with the addition of specific variables may lead to simpler and more accurate models. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Development of Botanical Composition in Maribaya Pasture, Brebes, Central Java

NASA Astrophysics Data System (ADS)

Umami, N.; Ngadiyono, N.; Panjono; Agus, F. N.; Shirothul, H. M.; Budisatria, I. G. S.; Hendrawati, Y.; Subroto, I.

2018-02-01

The research was aimed to observe the development of botanical composition in Maribaya pastures. The sampling method was cluster random sampling. The observed variables were the type of forages and the botanical composition in the pasture. Botanical composition was measured by using Line Intercept method and the production was measured by the estimation of botany production for each square meter using its dry matter measurement. The botani sampling was performed using square with size of 1×1 m2. The observation was performed before the pasture made (at 2015) and after the pasture made (at 2017). Based on the research result, it was found that there was significant difference between the forage type in the pasture at 2015 and at 2017. It happens due to the adjustment for the Jabres cattle feed.

Using a generalized linear mixed model approach to explore the role of age, motor proficiency, and cognitive styles in children's reach estimation accuracy.

PubMed

Caçola, Priscila M; Pant, Mohan D

2014-10-01

The purpose was to use a multi-level statistical technique to analyze how children's age, motor proficiency, and cognitive styles interact to affect accuracy on reach estimation tasks via Motor Imagery and Visual Imagery. Results from the Generalized Linear Mixed Model analysis (GLMM) indicated that only the 7-year-old age group had significant random intercepts for both tasks. Motor proficiency predicted accuracy in reach tasks, and cognitive styles (object scale) predicted accuracy in the motor imagery task. GLMM analysis is suitable to explore age and other parameters of development. In this case, it allowed an assessment of motor proficiency interacting with age to shape how children represent, plan, and act on the environment.

Heterogeneous Suppression of Sequential Effects in Random Sequence Generation, but Not in Operant Learning.

PubMed

Shteingart, Hanan; Loewenstein, Yonatan

2016-01-01

There is a long history of experiments in which participants are instructed to generate a long sequence of binary random numbers. The scope of this line of research has shifted over the years from identifying the basic psychological principles and/or the heuristics that lead to deviations from randomness, to one of predicting future choices. In this paper, we used generalized linear regression and the framework of Reinforcement Learning in order to address both points. In particular, we used logistic regression analysis in order to characterize the temporal sequence of participants' choices. Surprisingly, a population analysis indicated that the contribution of the most recent trial has only a weak effect on behavior, compared to more preceding trials, a result that seems irreconcilable with standard sequential effects that decay monotonously with the delay. However, when considering each participant separately, we found that the magnitudes of the sequential effect are a monotonous decreasing function of the delay, yet these individual sequential effects are largely averaged out in a population analysis because of heterogeneity. The substantial behavioral heterogeneity in this task is further demonstrated quantitatively by considering the predictive power of the model. We show that a heterogeneous model of sequential dependencies captures the structure available in random sequence generation. Finally, we show that the results of the logistic regression analysis can be interpreted in the framework of reinforcement learning, allowing us to compare the sequential effects in the random sequence generation task to those in an operant learning task. We show that in contrast to the random sequence generation task, sequential effects in operant learning are far more homogenous across the population. These results suggest that in the random sequence generation task, different participants adopt different cognitive strategies to suppress sequential dependencies when generating the "random" sequences.

A New TS Algorithm for Solving Low-Carbon Logistics Vehicle Routing Problem with Split Deliveries by Backpack—From a Green Operation Perspective

PubMed Central

Fu, Zhuo; Wang, Jiangtao

2018-01-01

In order to promote the development of low-carbon logistics and economize logistics distribution costs, the vehicle routing problem with split deliveries by backpack is studied. With the help of the model of classical capacitated vehicle routing problem, in this study, a form of discrete split deliveries was designed in which the customer demand can be split only by backpack. A double-objective mathematical model and the corresponding adaptive tabu search (TS) algorithm were constructed for solving this problem. By embedding the adaptive penalty mechanism, and adopting the random neighborhood selection strategy and reinitialization principle, the global optimization ability of the new algorithm was enhanced. Comparisons with the results in the literature show the effectiveness of the proposed algorithm. The proposed method can save the costs of low-carbon logistics and reduce carbon emissions, which is conducive to the sustainable development of low-carbon logistics. PMID:29747469

Constructing Graphical Representations: Middle Schoolers' Intuitions and Developing Knowledge about Slope and Y-Intercept

ERIC Educational Resources Information Center

Hattikudur, Shanta; Prather, Richard W.; Asquith, Pamela; Alibali, Martha W.; Knuth, Eric J.; Nathan, Mitchell

2012-01-01

Middle-school students are expected to understand key components of graphs, such as slope and y-intercept. However, constructing graphs is a skill that has received relatively little research attention. This study examined students' construction of graphs of linear functions, focusing specifically on the relative difficulties of graphing slope and…

Beetle fauna captured in traps baited with Tomicus piniperda pheromone blends in a pine stand in Central Croatia

Treesearch

Milan Pernek; Boris Hrasovec; Miljenko Zupanic

2003-01-01

During field evaluations of pheromone blends used for monitoring Tomicus piniperda beetles, many non-target beetles were captured and identified. Five pheromone blends, plus commercially available TOMODOR were used in two different traps: the IPM Tech Intercept PTBB and the THEYSOHN intercept barrier trap. In addition to Tomicus...

Interception in three dimensions - An energy formulation

NASA Technical Reports Server (NTRS)

Rajan, N.; Ardema, M. D.

1983-01-01

The problem of minimum-time interception of a target flying in three dimensional space is analyzed with the interceptor aircraft modeled through energy-state approximation. A coordinate transformation that uncouples the interceptor's extremals from the target motion in an open-loop sense is introduced, and the necessary conditions for optimality and the optimal controls are derived. Example extremals are shown.

Muscular Proprioception Contributes to the Control of Interceptive Actions

ERIC Educational Resources Information Center

Bastin, Julien; Calvin, Sarah; Montagne, Gilles

2006-01-01

The authors proposed a model of the control of interceptive action over a ground plane (Chardenon, Montagne, Laurent, & Bootsma, 2004). This model is based on the cancellation of the rate of change of the angle between the current position of the target and the direction of displacement (i.e., the bearing angle). While several sources of visual…

The Calculus of Elasticity

ERIC Educational Resources Information Center

Gordon, Warren B.

2006-01-01

This paper examines the elasticity of demand, and shows that geometrically, it may be interpreted as the ratio of two simple distances along the tangent line: the distance from the point on the curve to the x-intercept to the distance from the point on the curve to the y-intercept. It also shows that total revenue is maximized at the transition…

Children's Age-Related Speed--Accuracy Strategies in Intercepting Moving Targets in Two Dimensions

ERIC Educational Resources Information Center

Rothenberg-Cunningham, Alek; Newell, Karl M.

2013-01-01

Purpose: This study investigated the age-related speed--accuracy strategies of children, adolescents, and adults in performing a rapid striking task that allowed the self-selection of the interception position in a virtual, two-dimensional environment. Method: The moving target had curvilinear trajectories that were determined by combinations of…

Anti-Smoking Practice in Hospitals: An Intercept Survey among Patients in Hubei Province, China

ERIC Educational Resources Information Center

Zhou, Dunjin; Yan, Yaqiong; Yu, Huihong; Xia, Qinghua; Yang, Niannian; Zhang, Zhifeng; Zhu, Zhaoyang; Li, Fang; Gong, Jie

2012-01-01

Purpose: This study aims to examine whether, in the opinion of patients selected in 13 hospitals of Hubei province, China, hospitals are smoke free. Patients were also asked whether their physicians had inquired about their smoking status. Design/methodology/approach: Patients were recruited through an intercept method (i.e. stopped by the…

The densiometer for measurement of crown intercept above a line transect.

Treesearch

J. Edward Dealy

1960-01-01

An adaptation in the use of Lemmon's spherical densiometer, has been developed to measure low overstory crown foliage as intercept above a line transect. This adaptation provides added information for the evaluation of ecological relationships within and among plant communities where some species are too low for overstory density estimates and too high for direct...

Comparing Food Label Experiments Using Samples from Web Panels versus Mall Intercepts

ERIC Educational Resources Information Center

Chang, LinChiat; Lin, Chung-Tung Jordan

2015-01-01

To regulate health messages on food labels, the U.S. Food and Drug Administration (FDA) traditionally relied on mall intercepts to collect consumer data. In recent years, web surveys have presented a viable alternative for presenting visual stimuli with more control and efficiency in data collection. However, there is a paucity of empirical data…

Rainfall Interception by Hardwood Forest Litter in the Southern Appalachians

Treesearch

J.D. Helvey

1964-01-01

The portion of rainfall over forest cover which does not reach mineral soil can be separated into the parts evaporated from the canopy and from the litter. Canopy interception loss is usually estimated by subtracting the sum of throughfall (water falling through tree crowns) and stemflow (water running down stems) from rainfall measured in forest openings (Hamilton...

Action-perception dissociation in response to target acceleration.

PubMed

Dubrowski, Adam; Carnahan, Heather

2002-05-01

The purpose of this study was to investigate whether information about the acceleration characteristics of a moving target can be used for both action and perception. Also of interest was whether prior movement experience altered perceptual judgements. Participants manually intercepted targets moving with various acceleration, velocity and movement time characteristics. They also made perceptual judgements about the acceleration characteristics of these targets either with or without prior manual interception experience. Results showed that while aiming kinematics were sensitive to the acceleration characteristics of the target, participants were only able to perceptually discriminate the velocity characteristics of target motion, even after performing interceptive actions to the same targets. These results are discussed in terms of a two channel (action-perception) model of visuomotor control.

Conceptual Design of a Hypervelocity Asteroid Intercept Vehicle (HAIV) Flight Validation Mission

NASA Technical Reports Server (NTRS)

Barbee, Brent W.; Wie, Bong; Steiner, Mark; Getzandanner, Kenneth

2013-01-01

In this paper we present a detailed overview of the MDL study results and subsequent advances in the design of GNC algorithms for accurate terminal guidance during hypervelocity NEO intercept. The MDL study produced a conceptual con guration of the two-body HAIV and its subsystems; a mission scenario and trajectory design for a notional flight validation mission to a selected candidate target NEO; GNC results regarding the ability of the HAIV to reliably intercept small (50 m) NEOs at hypervelocity (typically greater than 10 km/s); candidate launch vehicle selection; a notional operations concept and cost estimate for the flight validation mission; and a list of topics to address during the remainder of our NIAC Phase II study.

Analysis of a range estimator which uses MLS angle measurements

NASA Technical Reports Server (NTRS)

Downing, David R.; Linse, Dennis

1987-01-01

A concept that uses the azimuth signal from a microwave landing system (MLS) combined with onboard airspeed and heading data to estimate the horizontal range to the runway threshold is investigated. The absolute range error is evaluated for trajectories typical of General Aviation (GA) and commercial airline operations (CAO). These include constant intercept angles for GA and CAO, and complex curved trajectories for CAO. It is found that range errors of 4000 to 6000 feet at the entry of MLS coverage which then reduce to 1000-foot errors at runway centerline intercept are possible for GA operations. For CAO, errors at entry into MLS coverage of 2000 feet which reduce to 300 feet at runway centerline interception are possible.

Estimating correlation between multivariate longitudinal data in the presence of heterogeneity.

PubMed

Gao, Feng; Philip Miller, J; Xiong, Chengjie; Luo, Jingqin; Beiser, Julia A; Chen, Ling; Gordon, Mae O

2017-08-17

Estimating correlation coefficients among outcomes is one of the most important analytical tasks in epidemiological and clinical research. Availability of multivariate longitudinal data presents a unique opportunity to assess joint evolution of outcomes over time. Bivariate linear mixed model (BLMM) provides a versatile tool with regard to assessing correlation. However, BLMMs often assume that all individuals are drawn from a single homogenous population where the individual trajectories are distributed smoothly around population average. Using longitudinal mean deviation (MD) and visual acuity (VA) from the Ocular Hypertension Treatment Study (OHTS), we demonstrated strategies to better understand the correlation between multivariate longitudinal data in the presence of potential heterogeneity. Conditional correlation (i.e., marginal correlation given random effects) was calculated to describe how the association between longitudinal outcomes evolved over time within specific subpopulation. The impact of heterogeneity on correlation was also assessed by simulated data. There was a significant positive correlation in both random intercepts (ρ = 0.278, 95% CI: 0.121-0.420) and random slopes (ρ = 0.579, 95% CI: 0.349-0.810) between longitudinal MD and VA, and the strength of correlation constantly increased over time. However, conditional correlation and simulation studies revealed that the correlation was induced primarily by participants with rapid deteriorating MD who only accounted for a small fraction of total samples. Conditional correlation given random effects provides a robust estimate to describe the correlation between multivariate longitudinal data in the presence of unobserved heterogeneity (NCT00000125).

Comparing the efficiency of digital and conventional soil mapping to predict soil types in a semi-arid region in Iran

NASA Astrophysics Data System (ADS)

Zeraatpisheh, Mojtaba; Ayoubi, Shamsollah; Jafari, Azam; Finke, Peter

2017-05-01

The efficiency of different digital and conventional soil mapping approaches to produce categorical maps of soil types is determined by cost, sample size, accuracy and the selected taxonomic level. The efficiency of digital and conventional soil mapping approaches was examined in the semi-arid region of Borujen, central Iran. This research aimed to (i) compare two digital soil mapping approaches including Multinomial logistic regression and random forest, with the conventional soil mapping approach at four soil taxonomic levels (order, suborder, great group and subgroup levels), (ii) validate the predicted soil maps by the same validation data set to determine the best method for producing the soil maps, and (iii) select the best soil taxonomic level by different approaches at three sample sizes (100, 80, and 60 point observations), in two scenarios with and without a geomorphology map as a spatial covariate. In most predicted maps, using both digital soil mapping approaches, the best results were obtained using the combination of terrain attributes and the geomorphology map, although differences between the scenarios with and without the geomorphology map were not significant. Employing the geomorphology map increased map purity and the Kappa index, and led to a decrease in the 'noisiness' of soil maps. Multinomial logistic regression had better performance at higher taxonomic levels (order and suborder levels); however, random forest showed better performance at lower taxonomic levels (great group and subgroup levels). Multinomial logistic regression was less sensitive than random forest to a decrease in the number of training observations. The conventional soil mapping method produced a map with larger minimum polygon size because of traditional cartographic criteria used to make the geological map 1:100,000 (on which the conventional soil mapping map was largely based). Likewise, conventional soil mapping map had also a larger average polygon size that resulted in a lower level of detail. Multinomial logistic regression at the order level (map purity of 0.80), random forest at the suborder (map purity of 0.72) and great group level (map purity of 0.60), and conventional soil mapping at the subgroup level (map purity of 0.48) produced the most accurate maps in the study area. The multinomial logistic regression method was identified as the most effective approach based on a combined index of map purity, map information content, and map production cost. The combined index also showed that smaller sample size led to a preference for the order level, while a larger sample size led to a preference for the great group level.

Landscape-scale spatial abundance distributions discriminate core from random components of boreal lake bacterioplankton.

PubMed

Niño-García, Juan Pablo; Ruiz-González, Clara; Del Giorgio, Paul A

2016-12-01

Aquatic bacterial communities harbour thousands of coexisting taxa. To meet the challenge of discriminating between a 'core' and a sporadically occurring 'random' component of these communities, we explored the spatial abundance distribution of individual bacterioplankton taxa across 198 boreal lakes and their associated fluvial networks (188 rivers). We found that all taxa could be grouped into four distinct categories based on model statistical distributions (normal like, bimodal, logistic and lognormal). The distribution patterns across lakes and their associated river networks showed that lake communities are composed of a core of taxa whose distribution appears to be linked to in-lake environmental sorting (normal-like and bimodal categories), and a large fraction of mostly rare bacteria (94% of all taxa) whose presence appears to be largely random and linked to downstream transport in aquatic networks (logistic and lognormal categories). These rare taxa are thus likely to reflect species sorting at upstream locations, providing a perspective of the conditions prevailing in entire aquatic networks rather than only in lakes. © 2016 John Wiley & Sons Ltd/CNRS.

Encrypted data stream identification using randomness sparse representation and fuzzy Gaussian mixture model

NASA Astrophysics Data System (ADS)

Zhang, Hong; Hou, Rui; Yi, Lei; Meng, Juan; Pan, Zhisong; Zhou, Yuhuan

2016-07-01

The accurate identification of encrypted data stream helps to regulate illegal data, detect network attacks and protect users' information. In this paper, a novel encrypted data stream identification algorithm is introduced. The proposed method is based on randomness characteristics of encrypted data stream. We use a l1-norm regularized logistic regression to improve sparse representation of randomness features and Fuzzy Gaussian Mixture Model (FGMM) to improve identification accuracy. Experimental results demonstrate that the method can be adopted as an effective technique for encrypted data stream identification.

Improving Risk Adjustment for Mortality After Pediatric Cardiac Surgery: The UK PRAiS2 Model.

PubMed

Rogers, Libby; Brown, Katherine L; Franklin, Rodney C; Ambler, Gareth; Anderson, David; Barron, David J; Crowe, Sonya; English, Kate; Stickley, John; Tibby, Shane; Tsang, Victor; Utley, Martin; Witter, Thomas; Pagel, Christina

2017-07-01

Partial Risk Adjustment in Surgery (PRAiS), a risk model for 30-day mortality after children's heart surgery, has been used by the UK National Congenital Heart Disease Audit to report expected risk-adjusted survival since 2013. This study aimed to improve the model by incorporating additional comorbidity and diagnostic information. The model development dataset was all procedures performed between 2009 and 2014 in all UK and Ireland congenital cardiac centers. The outcome measure was death within each 30-day surgical episode. Model development followed an iterative process of clinical discussion and development and assessment of models using logistic regression under 25 × 5 cross-validation. Performance was measured using Akaike information criterion, the area under the receiver-operating characteristic curve (AUC), and calibration. The final model was assessed in an external 2014 to 2015 validation dataset. The development dataset comprised 21,838 30-day surgical episodes, with 539 deaths (mortality, 2.5%). The validation dataset comprised 4,207 episodes, with 97 deaths (mortality, 2.3%). The updated risk model included 15 procedural, 11 diagnostic, and 4 comorbidity groupings, and nonlinear functions of age and weight. Performance under cross-validation was: median AUC of 0.83 (range, 0.82 to 0.83), median calibration slope and intercept of 0.92 (range, 0.64 to 1.25) and -0.23 (range, -1.08 to 0.85) respectively. In the validation dataset, the AUC was 0.86 (95% confidence interval [CI], 0.82 to 0.89), and the calibration slope and intercept were 1.01 (95% CI, 0.83 to 1.18) and 0.11 (95% CI, -0.45 to 0.67), respectively, showing excellent performance. A more sophisticated PRAiS2 risk model for UK use was developed with additional comorbidity and diagnostic information, alongside age and weight as nonlinear variables. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Risk factors for highly pathogenic avian influenza in commercial layer chicken farms in bangladesh during 2011.

PubMed

Osmani, M G; Thornton, R N; Dhand, N K; Hoque, M A; Milon, Sk M A; Kalam, M A; Hossain, M; Yamage, M

2014-12-01

A case-control study conducted during 2011 involved 90 randomly selected commercial layer farms infected with highly pathogenic avian influenza type A subtype H5N1 (HPAI) and 175 control farms randomly selected from within 5 km of infected farms. A questionnaire was designed to obtain information about potential risk factors for contracting HPAI and was administered to farm owners or managers. Logistic regression analyses were conducted to identify significant risk factors. A total of 20 of 43 risk factors for contracting HPAI were identified after univariable logistic regression analysis. A multivariable logistic regression model was derived by forward stepwise selection. Both unmatched and matched analyses were performed. The key risk factors identified were numbers of staff, frequency of veterinary visits, presence of village chickens roaming on the farm and staff trading birds. Aggregating these findings with those from other studies resulted in a list of 16 key risk factors identified in Bangladesh. Most of these related to biosecurity. It is considered feasible for Bangladesh to achieve a very low incidence of HPAI. Using the cumulative list of risk factors to enhance biosecurity pertaining to commercial farms would facilitate this objective. © 2013 Blackwell Verlag GmbH.

Risk Reduction and Soil Ecosystem Restoration in an Active Oil Producing Area in an Ecologically Sensitive Setting

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

Kerry L. Sublette; Greg Thoma; Kathleen Duncan

2006-01-01

The empowerment of small independent oil and gas producers to solve their own remediation problems will result in greater environmental compliance and more effective protection of the environment as well as making small producers more self-reliant. In Chapter 1 we report on the effectiveness of a low-cost method of remediation of a combined spill of crude oil and brine in the Tallgrass Prairie Preserve in Osage County, OK. Specifically, we have used hay and fertilizer as amendments for remediation of both the oil and the brine. No gypsum was used. Three spills of crude oil plus produced water brine weremore » treated with combinations of ripping, fertilizers and hay, and a downslope interception trench in an effort to demonstrate an inexpensive, easily implemented, and effective remediation plan. There was no statistically significant effect of treatment on the biodegradation of crude oil. However, TPH reduction clearly proceeded in the presence of brine contamination. The average TPH half-life considering all impacted sites was 267 days. The combination of hay addition, ripping, and a downslope interception trench was superior to hay addition with ripping, or ripping plus an interception trench in terms of rates of sodium and chloride leaching from the impacted sites. Reductions in salt inventories (36 months) were 73% in the site with hay addition, ripping and an interception trench, 40% in the site with hay addition and ripping only, and < 3% in the site with ripping and an interception trench.« less

Quantifying interception associated with new urban vegetation canopies

NASA Astrophysics Data System (ADS)

Yerk, W.; Montalto, F. A.

2013-12-01

Interception of precipitation by vegetation canopies has long been recognized as an important component of the hydrologic cycle, though most research has been in closed or sparse canopy forests. Much less work has been published on interception by urban vegetation, and especially associated with the low growing shrubs commonly installed in green infrastructure program. To inform urban watershed model with vegetation-specific interception data, a field experiment was designed to directly measure canopy throughfall associated with two shrub species commonly included in urban greening programs. Data was collected at a high (e.g. five second) sampling frequency. A non-parametric Kruskal-Wallis test performed on data collected between August and October of 2012 demonstrated statistically significant (p= 0.0011) differences in recorded throughfall between two species (94% for Itea virginica, 86% for Cornus sericea). Additionally, the results suggested that the relationship of throughfall to rainfall intensity varied by species. For Itea, the ratio of throughfall to precipitation intensity was close to 1:1. However, for Cornus, the throughfall rate was on average slower (or 0.85 of the precipitation intensity). An improved and expanded set-up installed in 2013 added two additional species (Prunus laurocerasus and Hydrangea quercifolia). The 2013 results confirm interspecies differences in both throughfall amount, and in the relationship of throughfall rate to precipitation intensity. The results are discussed with respect to droplet splashing and enhanced evaporation within the canopy. Both years' findings suggest that the quantity of water intercepted by vegetation canopies exceeds the canopy storage capacity, as assumed in many conventional hydrologic models.

Metastability and emergent performance of dynamic interceptive actions.

PubMed

Pinder, Ross A; Davids, Keith; Renshaw, Ian

2012-09-01

Adaptive patterning of human movement is context specific and dependent on interacting constraints of the performer-environment relationship. Flexibility of skilled behaviour is predicated on the capacity of performers to move between different states of movement organisation to satisfy dynamic task constraints, previously demonstrated in studies of visual perception, bimanual coordination, and an interceptive combat task. Metastability is a movement system property that helps performers to remain in a state of relative coordination with their performance environments, poised between multiple co-existing states (stable and distinct movement patterns or responses). The aim of this study was to examine whether metastability could be exploited in externally paced interceptive actions in fast ball sports, such as cricket. Here we report data on metastability in performance of multi-articular hitting actions by skilled junior cricket batters (n=5). Participants' batting actions (key movement timings and performance outcomes) were analysed in four distinct performance regions varied by ball pitching (bounce) location. Results demonstrated that, at a pre-determined distance to the ball, participants were forced into a meta-stable region of performance where rich and varied patterns of functional movement behaviours emerged. Participants adapted the organisation of responses, resulting in higher levels of variability in movement timing in this performance region, without detrimental effects on the quality of interceptive performance outcomes. Findings provide evidence for the emergence of metastability in a dynamic interceptive action in cricket batting. Flexibility and diversity of movement responses were optimised using experiential knowledge and careful manipulation of key task constraints of the specific sport context. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Test study on the performance of shielding configuration with stuffed layer under hypervelocity impact

NASA Astrophysics Data System (ADS)

Ke, Fa-wei; Huang, Jie; Wen, Xue-zhong; Ma, Zhao-xia; Liu, Sen

2016-10-01

In order to study the cracking and intercepting mechanism of stuffed layer configuration on the debris cloud and to develop stuffed layer configuration with better performance, the hypervelocity impact tests on shielding configurations with stuffed layer were carried out. Firstly, the hypervelocity impact tests on the shielding configuration with stuffed layer of 3 layer ceramic fibre and 3 layer aramid fibre were finished, the study results showed that the debris cloud generated by the aluminum sphere impacting bumper at the velocity of about 6.2 km/s would be racked and intercepted by the stuffed layer configuration efficiently when the ceramic fibre layers and aramid fibre layers were jointed together, however, the shielding performance would be declined when the ceramic fibre layers and aramid fibre layers were divided by some distance. The mechanism of stuffed layer racking and intercepting the debris cloud was analyzed according to the above test results. Secondly, based on the mechanism of the stuffed layer cracking and intercepint debirs cloud the hypervelocity impact tests on the following three stuffed layer structures with the equivalent areal density to the 1 mm-thick aluminum plate were also carried out to compare their performance of cracking and intercepting debris cloud. The mechanisms of stuffed layer racking and intercepting the debris cloud were validated by the test result. Thirdly, the influence of the stuffed layer position on the shielding performance was studied by the test, too. The test results would provide reference for the design of better performance shielding configuration with stuffed layer.

Quantification of the effects of architectural traits on dry mass production and light interception of tomato canopy under different temperature regimes using a dynamic functional–structural plant model

PubMed Central

Chen, Tsu-Wei; Nguyen, Thi My Nguyet; Kahlen, Katrin; Stützel, Hartmut

2014-01-01

There is increasing interest in evaluating the environmental effects on crop architectural traits and yield improvement. However, crop models describing the dynamic changes in canopy structure with environmental conditions and the complex interactions between canopy structure, light interception, and dry mass production are only gradually emerging. Using tomato (Solanum lycopersicum L.) as a model crop, a dynamic functional–structural plant model (FSPM) was constructed, parameterized, and evaluated to analyse the effects of temperature on architectural traits, which strongly influence canopy light interception and shoot dry mass. The FSPM predicted the organ growth, organ size, and shoot dry mass over time with high accuracy (>85%). Analyses of this FSPM showed that, in comparison with the reference canopy, shoot dry mass may be affected by leaf angle by as much as 20%, leaf curvature by up to 7%, the leaf length:width ratio by up to 5%, internode length by up to 9%, and curvature ratios and leaf arrangement by up to 6%. Tomato canopies at low temperature had higher canopy density and were more clumped due to higher leaf area and shorter internodes. Interestingly, dry mass production and light interception of the clumped canopy were more sensitive to changes in architectural traits. The complex interactions between architectural traits, canopy light interception, dry mass production, and environmental conditions can be studied by the dynamic FSPM, which may serve as a tool for designing a canopy structure which is ‘ideal’ in a given environment. PMID:25183746

A 3-level Bayesian mixed effects location scale model with an application to ecological momentary assessment data.

PubMed

Lin, Xiaolei; Mermelstein, Robin J; Hedeker, Donald

2018-06-15

Ecological momentary assessment studies usually produce intensively measured longitudinal data with large numbers of observations per unit, and research interest is often centered around understanding the changes in variation of people's thoughts, emotions and behaviors. Hedeker et al developed a 2-level mixed effects location scale model that allows observed covariates as well as unobserved variables to influence both the mean and the within-subjects variance, for a 2-level data structure where observations are nested within subjects. In some ecological momentary assessment studies, subjects are measured at multiple waves, and within each wave, subjects are measured over time. Li and Hedeker extended the original 2-level model to a 3-level data structure where observations are nested within days and days are then nested within subjects, by including a random location and scale intercept at the intermediate wave level. However, the 3-level random intercept model assumes constant response change rate for both the mean and variance. To account for changes in variance across waves, as well as clustering attributable to waves, we propose a more comprehensive location scale model that allows subject heterogeneity at baseline as well as across different waves, for a 3-level data structure where observations are nested within waves and waves are then further nested within subjects. The model parameters are estimated using Markov chain Monte Carlo methods. We provide details on the Bayesian estimation approach and demonstrate how the Stan statistical software can be used to sample from the desired distributions and achieve consistent estimates. The proposed model is validated via a series of simulation studies. Data from an adolescent smoking study are analyzed to demonstrate this approach. The analyses clearly favor the proposed model and show significant subject heterogeneity at baseline as well as change over time, for both mood mean and variance. The proposed 3-level location scale model can be widely applied to areas of research where the interest lies in the consistency in addition to the mean level of the responses. Copyright © 2018 John Wiley & Sons, Ltd.

Synchronizing Self and Object Movement: How Child and Adult Cyclists Intercept Moving Gaps in a Virtual Environment

ERIC Educational Resources Information Center

Chihak, Benjamin J.; Plumert, Jodie M.; Ziemer, Christine J.; Babu, Sabarish; Grechkin, Timofey; Cremer, James F.; Kearney, Joseph K.

2010-01-01

Two experiments examined how 10- and 12-year-old children and adults intercept moving gaps while bicycling in an immersive virtual environment. Participants rode an actual bicycle along a virtual roadway. At 12 test intersections, participants attempted to pass through a gap between 2 moving, car-sized blocks without stopping. The blocks were…

Height intercept for estimating site index in young ponderosa pine plantations and natural stands

Treesearch

William W. Oliver

1972-01-01

Site index is difficult to estimate with any reliability in ponderosa pine (Pinus ponderosa Laws.) stands below 20 yeas old. A method of estimating site index based on 4-year height intercepts (total length of the first four internodes above breast height) is described. Equations based on two sets of published site-index curves were developed. They...

Recurrent bridgehead effects accelerate global alien ant spread

Treesearch

Cleo Bertelsmeier; Sébastien Ollier; Andrew M. Liebhold; Eckehard G. Brockerhoff; Darren Ward; Laurent Keller

2018-01-01

Biological invasions are a major threat to biological diversity, agriculture, and human health. To predict and prevent new invasions, it is crucial to develop a better understanding of the drivers of the invasion process. The analysis of 4,533 border interception events revealed that at least 51 different alien ant species were intercepted at US ports over a period of...

Top-Level Players' Visual Control of Interceptive Actions: Bootsma and Van Wieringen (1990) 20 Years Later

ERIC Educational Resources Information Center

Bootsma, Reinoud J.; Fernandez, Laure; Morice, Antoine H. P.; Montagne, Gilles

2010-01-01

Using a two-step approach, Van Soest et al. (2010) recently questioned the pertinence of the conclusions drawn by Bootsma and Van Wieringen (1990) with respect to the visual regulation of an exemplary rapid interceptive action: the attacking forehand drive in table tennis. In the first step, they experimentally compared the movement behaviors of…

An improved growth intercept method for estimating site index of red pine.

Treesearch

David H. Alban

1972-01-01

Equations for predicting red pine (Pinus resinosa Ait.) site index from various internode lengths were developed from ring counts on sectioned trees form 69 natural stands in Minnesota. The precision of estimating site index was much improved by measuring the 5-year growth intercept beginning at 7 feet above the ground rather than at the conventional breast height....

Test of Slope and Intercept Bias in College Admissions: A Response to Aguinis, Culpepper, and Pierce (2010)

ERIC Educational Resources Information Center

Mattern, Krista D.; Patterson, Brian F.

2013-01-01

Research on the predictive bias of cognitive tests has generally shown (a) no slope effects and (b) small intercept effects, typically favoring the minority group. Aguinis, Culpepper, and Pierce (2010) simulated data and demonstrated that statistical artifacts may have led to a lack of power to detect slope differences and an overestimate of the…

Intercept™ Panel Trap (INT PT) effective in management of forest Coleoptera

Treesearch

D. Czokajlo; J. McLaughlin; L. I. Abu Ayyash; S. Teale; J. Wickham; J. Warren; R. Hoffman; B. Aukema; K. Raffa; P. Kirsch

2003-01-01

Trap efficacy in capturing economically important forest Coleoptera was measured in field trials comparing the Intercept Panel Trap (INT PT) with the Multi-Funnel Trap. The INT PT was designed to provide a better option for the monitoring of forest Coleoptera. The trap is made of corrugated plastic and is very robust under rigorous field conditions, but still...

Dilution of Fluon Before Trap Surface Treatment Has No Effect on Longhorned Beetle (Coleoptera: Cerambycidae) Captures

Treesearch

Jeremy D. Allison; Elizabeth E. Graham; Therese M. Poland; Brian L. Strom

2016-01-01

Several studies have observed that trap captures of longhorned beetles (Coleoptera: Cerambycidae) can be increased by treating the surface of intercept traps with a lubricant. In addition to being expensive, these treatments can alter the spectral properties of intercept traps when applied neat. These surface treatments, particularly Fluon, are commonly used diluted as...

Average Annual Rainfall over the Globe

ERIC Educational Resources Information Center

Agrawal, D. C.

2013-01-01

The atmospheric recycling of water is a very important phenomenon on the globe because it not only refreshes the water but it also redistributes it over land and oceans/rivers/lakes throughout the globe. This is made possible by the solar energy intercepted by the Earth. The half of the globe facing the Sun, on the average, intercepts 1.74 ×…

A method to study response of large trees to different amounts of available soil water

Treesearch

D.H. Marx; Shi-Jean S. Sung; J.S. Cunningham; M.D. Thompson; L.M. White

1995-01-01

A method was developed to manipulate available soil water on large trees by intercepting thrufall with gutters placed under tree canopies and irrigating the intercepted thrufall onto other trees. With this design, trees were exposed for 2 years to either 25% less thrufall, normal thrufall, or 25% additional thrufall.Undercanopy construction in these plots moderately...

A Method to Study Response of Large Trees to Different Amounts of Available Soil Water

Treesearch

Donald H. Marx; Shi-jean S. Sung; James S. Cunningham; Michael D. Thompson; Linda M. White

1995-01-01

A method was developed to manipulate available soil water on large trees by intercepting thrufall with gutters placed under tree canopies and irrigating the intercepted thrufall onto other trees. With this design, trees were exposed for 2 years to either 25 percent less thrufall, normal tbrufall,or 25 percent additional thrufall. Undercanopy construction in these plots...

Sensorless battery temperature measurements based on electrochemical impedance spectroscopy

NASA Astrophysics Data System (ADS)

Raijmakers, L. H. J.; Danilov, D. L.; van Lammeren, J. P. M.; Lammers, M. J. G.; Notten, P. H. L.

2014-02-01

A new method is proposed to measure the internal temperature of (Li-ion) batteries. Based on electrochemical impedance spectroscopy measurements, an intercept frequency (f0) can be determined which is exclusively related to the internal battery temperature. The intercept frequency is defined as the frequency at which the imaginary part of the impedance is zero (Zim = 0), i.e. where the phase shift between the battery current and voltage is absent. The advantage of the proposed method is twofold: (i) no hardware temperature sensors are required anymore to monitor the battery temperature and (ii) the method does not suffer from heat transfer delays. Mathematical analysis of the equivalent electrical-circuit, representing the battery performance, confirms that the intercept frequency decreases with rising temperatures. Impedance measurements on rechargeable Li-ion cells of various chemistries were conducted to verify the proposed method. These experiments reveal that the intercept frequency is clearly dependent on the temperature and does not depend on State-of-Charge (SoC) and aging. These impedance-based sensorless temperature measurements are therefore simple and convenient for application in a wide range of stationary, mobile and high-power devices, such as hybrid- and full electric vehicles.

Trajectories of teacher-student warmth and conflict at the transition to middle school: Effects on academic engagement and achievement.

PubMed

Hughes, Jan N; Cao, Qian

2018-04-01

Using piece-wise longitudinal trajectory analysis, this study investigated trajectories of teacher-reported warmth and conflict in their relationships with students 4years prior to and 3years following the transition to middle school in a sample of 550 academically at-risk and ethnically diverse adolescents. At the transition to middle school, teacher reports of warmth showed a significant drop (shift in intercept), above age-related declines. Both warmth and conflict declined across the middle school years. Structural equation modeling (SEM) tested effects of the shifts in intercept and the post-transition slopes on reading and math achievement, teacher-rated engagement, and student-reported school belonging 3years post-transition, above pre-transition levels of the outcome. For warmth, a drop in intercept predicted lower math scores and engagement, and a more positive slope predicted higher engagement. For conflict, an increase in intercept and a negative slope predicted lower engagement. Implications of findings for reducing normative declines in academic engagement in middle school are discussed. Copyright © 2017 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.