Transition of temporal scaling behavior in percolation assisted shear-branching structure during plastic deformation

DOE PAGES

Ren, Jingli; Chen, Cun; Wang, Gang; ...

2017-03-22

This study explores the temporal scaling behavior induced shear-branching structure in response to variant temperatures and strain rates during plastic deformation of Zr-based bulk metallic glass (BMG). The data analysis based on the compression tests suggests that there are two states of shear-branching structures: the fractal structure with a long-range order at an intermediate temperature of 223 K and a larger strain rate of 2.5 × 10 –2 s –1; the disordered structure dominated at other temperature and strain rate. It can be deduced from the percolation theory that the compressive ductility, ec, can reach the maximum value at themore » intermediate temperature. Furthermore, a dynamical model involving temperature is given for depicting the shear-sliding process, reflecting the plastic deformation has fractal structure at the temperature of 223 K and strain rate of 2.5 × 10 –2 s –1.« less

Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE) - A Systematic Review of Rating Scales

PubMed Central

Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

2016-01-01

Background Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students’ communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. Methods We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Results Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Discussion Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed in order to yield psychometrically sound results of the OSCEs assessing communication skills. This is especially important given that most OSCE rating scales are used for summative assessment, and thus have an impact on medical students’ academic success. PMID:27031506

Assessing Communication Skills of Medical Students in Objective Structured Clinical Examinations (OSCE)--A Systematic Review of Rating Scales.

PubMed

Cömert, Musa; Zill, Jördis Maria; Christalle, Eva; Dirmaier, Jörg; Härter, Martin; Scholl, Isabelle

2016-01-01

Teaching and assessment of communication skills have become essential in medical education. The Objective Structured Clinical Examination (OSCE) has been found as an appropriate means to assess communication skills within medical education. Studies have demonstrated the importance of a valid assessment of medical students' communication skills. Yet, the validity of the performance scores depends fundamentally on the quality of the rating scales used in an OSCE. Thus, this systematic review aimed at providing an overview of existing rating scales, describing their underlying definition of communication skills, determining the methodological quality of psychometric studies and the quality of psychometric properties of the identified rating scales. We conducted a systematic review to identify psychometrically tested rating scales, which have been applied in OSCE settings to assess communication skills of medical students. Our search strategy comprised three databases (EMBASE, PsycINFO, and PubMed), reference tracking and consultation of experts. We included studies that reported psychometric properties of communication skills assessment rating scales used in OSCEs by examiners only. The methodological quality of included studies was assessed using the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The quality of psychometric properties was evaluated using the quality criteria of Terwee and colleagues. Data of twelve studies reporting on eight rating scales on communication skills assessment in OSCEs were included. Five of eight rating scales were explicitly developed based on a specific definition of communication skills. The methodological quality of studies was mainly poor. The psychometric quality of the eight rating scales was mainly intermediate. Our results reveal that future psychometric evaluation studies focusing on improving the methodological quality are needed in order to yield psychometrically sound results of the OSCEs assessing communication skills. This is especially important given that most OSCE rating scales are used for summative assessment, and thus have an impact on medical students' academic success.

Adapting the McMaster-Ottawa scale and developing behavioral anchors for assessing performance in an interprofessional Team Observed Structured Clinical Encounter.

PubMed

Lie, Désirée; May, Win; Richter-Lagha, Regina; Forest, Christopher; Banzali, Yvonne; Lohenry, Kevin

2015-01-01

Current scales for interprofessional team performance do not provide adequate behavioral anchors for performance evaluation. The Team Observed Structured Clinical Encounter (TOSCE) provides an opportunity to adapt and develop an existing scale for this purpose. We aimed to test the feasibility of using a retooled scale to rate performance in a standardized patient encounter and to assess faculty ability to accurately rate both individual students and teams. The 9-point McMaster-Ottawa Scale developed for a TOSCE was converted to a 3-point scale with behavioral anchors. Students from four professions were trained a priori to perform in teams of four at three different levels as individuals and teams. Blinded faculty raters were trained to use the scale to evaluate individual and team performances. G-theory was used to analyze ability of faculty to accurately rate individual students and teams using the retooled scale. Sixteen faculty, in groups of four, rated four student teams, each participating in the same TOSCE station. Faculty expressed comfort rating up to four students in a team within a 35-min timeframe. Accuracy of faculty raters varied (38-81% individuals, 50-100% teams), with errors in the direction of over-rating individual, but not team performance. There was no consistent pattern of error for raters. The TOSCE can be administered as an evaluation method for interprofessional teams. However, faculty demonstrate a 'leniency error' in rating students, even with prior training using behavioral anchors. To improve consistency, we recommend two trained faculty raters per station.

Validation of Arabic and English versions of the ARSMA-II Acculturation Rating Scale.

PubMed

Jadalla, Ahlam; Lee, Jerry

2015-02-01

To translate and adapt the Acculturation Rating Scale of Mexican-Americans II (ARSMA-II) for Arab Americans. A multistage translation process followed by a pilot and a large study. The translated and adapted versions, Acculturation Rating Scale for Arabic Americans-II Arabic and English (ARSAA-IIA, ARSAA-IIE), were validated in a sample of 297 Arab Americans. Factor analyses with principal axis factoring extractions and direct oblimin rotations were used to identify the underlying structure of ARSAA-II. Factor analysis confirmed the underlying structure of ARSAA-II and produced two interpretable factors labeled as 'Attraction to American Culture' (AAmC) and 'Attraction to Arabic Culture' (AArC). The Cronbach's alphas of AAmC and AArC were .89 and .85 respectively. Findings support ARSAA-II A & E to assess acculturation among Arab Americans. The emergent factors of ARSAA-II support the theoretical structure of the original ARSMA-II tool and show high internal consistency.

Dynamic Pore-Scale Imaging of Reactive Transport in Heterogeneous Carbonates at Reservoir Conditions Across Multiple Dissolution Regimes

NASA Astrophysics Data System (ADS)

Menke, H. P.; Bijeljic, B.; Andrew, M. G.; Blunt, M. J.

2014-12-01

Sequestering carbon in deep geologic formations is one way of reducing anthropogenic CO2 emissions. When supercritical CO2 mixes with brine in a reservoir, the acid generated has the potential to dissolve the surrounding pore structure. However, the magnitude and type of dissolution are condition dependent. Understanding how small changes in the pore structure, chemistry, and flow properties affect dissolution is paramount for successful predictive modelling. Both 'Pink Beam' synchrotron radiation and a Micro-CT lab source are used in dynamic X-ray microtomography to investigate the pore structure changes during supercritical CO2 injection in carbonate rocks of varying heterogeneity at high temperatures and pressures and various flow-rates. Three carbonate rock types were studied, one with a homogeneous pore structure and two heterogeneous carbonates. All samples are practically pure calcium carbonate, but have widely varying rock structures. Flow-rate was varied in three successive experiments by over an order of magnitude whlie keeping all other experimental conditions constant. A 4-mm carbonate core was injected with CO2-saturated brine at 10 MPa and 50oC. Tomographic images were taken at 30-second to 20-minute time-resolutions during a 2 to 4-hour injection period. A pore network was extracted using a topological analysis of the pore space and pore-scale flow modelling was performed directly on the binarized images with connected pathways and used to track the altering velocity distributions. Significant differences in dissolution type and magnitude were found for each rock type and flowrate. At the highest flow-rates, the homogeneous carbonate was seen to have predominately uniform dissolution with minor dissolution rate differences between the pores and pore throats. Alternatively, the heterogeneous carbonates which formed wormholes at high flow rates. At low flow rates the homogeneous rock developed wormholes, while the heterogeneous samples showed evidence of compact dissolution. This study serves as a unique benchmark for pore-scale reactive transport modelling directly on the binarized Micro-CT images. Dynamic pore-scale imaging methods offer advantages in helping explain the dominant processes at the pore scale so that they may be up-scaled for accurate model prediction.

Clinimetric Testing of the Comprehensive Cervical Dystonia Rating Scale

PubMed Central

Comella, C. L.; Perlmutter, J.S.; Jinnah, H. A.; Waliczek, T. A.; Rosen, A. R.; Galpern, W. R.; Adler, C. H.; Barbano, R. L.; Factor, S. A.; Goetz, C.G.; Jankovic, J.; Reich, S. G.; Rodriguez, R. L.; Severt, W. L.; Zurowski, M.; Fox, S. H.; Stebbins, G.T.

2016-01-01

Objective To test the clinimetric properties of the Comprehensive Cervical Dystonia Rating Scale. Background This is a modular scale with modifications of the Toronto Western Spasmodic Torticollis Rating Scale (composed of three subscales assessing motor severity, disability and pain) now referred to as the revised Toronto Western Spasmodic Torticollis Scale-2.; a newly developed psychiatric screening instrument; and the Cervical Dystonia Impact Profile-58 as a quality of life measure. Methods Ten dystonia experts rated subjects with cervical dystonia using the comprehensive scale. Clinimetric techniques assessed each module of the scale for reliability, item correlation and factor structure. Results There were 208 cervical dystonia patients (73% women, age 59±10 years, duration 15±12 years). The internal consistency of the motor severity subscale was acceptable (Cronbach’s alpha = 0.57). Item to total correlations showed that elimination of items with low correlations (<0.20) increased alpha to 0.71. Internal consistency estimates for the subscales for disability and pain were 0.88 and 0.95 respectively. The psychiatric screening scale had a Cronbach’s alpha of 0.84 and satisfactory item to total correlations. When the subscales of the Toronto Western Spasmodic Torticollis scale -2 were combined with the psychiatric screening scale, Cronbach's alpha was 0.88, and construct validity assessment demonstrated four rational factors: motor, disability, pain and psychiatric disorders. The Cervical Dystonia Impact Profile-58 had an alpha of 0.98 and its construction was validated through a confirmatory factor analysis. Conclusions The modules of the Comprehensive Cervical Dystonia Rating Scale are internally consistent with a logical factor structure. PMID:26971359

Cross-cultural adaptation and psychometric properties of the Korean Scale for Internet Addiction (K-Scale) in Japanese high school students.

PubMed

Mak, Kwok-Kei; Nam, JeeEun Karin; Kim, Dongil; Aum, Narae; Choi, Jung-Seok; Cheng, Cecilia; Ko, Huei-Chen; Watanabe, Hiroko

2017-03-01

The Korean Scale for Internet Addiction (K-Scale) was developed in Korea for assessing addictive internet behaviors. This study aims to adopt K-Scale and examine its psychometric properties in Japanese adolescents. In 2014, 589 (36.0% boys) high school students (Grade 10-12) from Japan completed a survey, including items of Japanese versions of K-Scale and Smartphone Scale for Smartphone Addiction (S-Scale). Model fit indices of the original four-factor structure, three-factor structure obtained from exploratory factor analysis, and improved two-factor structure of K-Scale were computed using confirmatory factor analysis, with internal reliability of included items reported. The convergent validity of K-Scale was tested against self-rated internet addiction, and S-Scale using multiple regression models. The results showed that a second-order two-factor 13-item structure was the most parsimonious model (NFI=0.919, NNFI=0.935, CFI=0.949, and RMSEA=0.05) with good internal reliability (Cronbach's alpha=0.87). The two factors revealed were "Disturbance of Adaptation and Life Orientation" and "Withdrawal and Tolerance". Moreover, the correlation between internet user classifications defined by K-Scale and self-rating was significant. K-Scale total score was significantly and positively associated with S-Scale total (adjusted R 2 =0.440) and subscale scores (adjusted R 2 =0.439). In conclusion, K-Scale is a valid and reliable assessment scale of internet addiction for Japanese high school students after modifications. Copyright © 2017. Published by Elsevier B.V.

A predictive multi-linear regression model for organic micropollutants, based on a laboratory-scale column study simulating the river bank filtration process.

PubMed

Bertelkamp, C; Verliefde, A R D; Reynisson, J; Singhal, N; Cabo, A J; de Jonge, M; van der Hoek, J P

2016-03-05

This study investigated relationships between OMP biodegradation rates and the functional groups present in the chemical structure of a mixture of 31 OMPs. OMP biodegradation rates were determined from lab-scale columns filled with soil from RBF site Engelse Werk of the drinking water company Vitens in The Netherlands. A statistically significant relationship was found between OMP biodegradation rates and the functional groups of the molecular structures of OMPs in the mixture. The OMP biodegradation rate increased in the presence of carboxylic acids, hydroxyl groups, and carbonyl groups, but decreased in the presence of ethers, halogens, aliphatic ethers, methyl groups and ring structures in the chemical structure of the OMPs. The predictive model obtained from the lab-scale soil column experiment gave an accurate qualitative prediction of biodegradability for approximately 70% of the OMPs monitored in the field (80% excluding the glymes). The model was found to be less reliable for the more persistent OMPs (OMPs with predicted biodegradation rates lower or around the standard error=0.77d(-1)) and OMPs containing amide or amine groups. These OMPs should be carefully monitored in the field to determine their removal during RBF. Copyright © 2015 Elsevier B.V. All rights reserved.

PIV study of flow through porous structure using refractive index matching

NASA Astrophysics Data System (ADS)

Häfeli, Richard; Altheimer, Marco; Butscher, Denis; Rudolf von Rohr, Philipp

2014-05-01

An aqueous solution of sodium iodide and zinc iodide is proposed as a fluid that matches the refractive index of a solid manufactured by rapid prototyping. This enabled optical measurements in single-phase flow through porous structures. Experiments were also done with an organic index-matching fluid (anisole) in porous structures of different dimensions. To compare experiments with different viscosities and dimensions, we employed Reynolds similarity to deduce the scaling laws. One of the target quantities of our investigation was the dissipation rate of turbulent kinetic energy. Different models for the dissipation rate estimation were evaluated by comparing isotropy ratios. As in many other studies also, our experiments were not capable of resolving the velocity field down to the Kolmogorov length scale, and therefore, the dissipation rate has to be considered as underestimated. This is visible in experiments of different relative resolutions. However, being near the Kolmogorov scale allows estimating a reproducible, yet underestimated spatial distribution of dissipation rate inside the porous structure. Based on these results, the model was used to estimate the turbulent diffusivity. Comparing it to the dispersion coefficient obtained in the same porous structure, we conclude that even at the turbulent diffusivity makes up only a small part of mass transfer in axial direction. The main part is therefore attributed to Taylor dispersion.

The validity and internal structure of the Bipolar Depression Rating Scale: data from a clinical trial of N-acetylcysteine as adjunctive therapy in bipolar disorder.

PubMed

Berk, Michael; Dodd, Seetal; Dean, Olivia M; Kohlmann, Kristy; Berk, Lesley; Malhi, Gin S

2010-10-01

Berk M, Dodd S, Dean OM, Kohlmann K, Berk L, Malhi GS. The validity and internal structure of the Bipolar Depression Rating Scale: data from a clinical trial of N-acetylcysteine as adjunctive therapy in bipolar disorder. The phenomenology of unipolar and bipolar disorders differ in a number of ways, such as the presence of mixed states and atypical features. Conventional depression rating instruments are designed to capture the characteristics of unipolar depression and have limitations in capturing the breadth of bipolar disorder. The Bipolar Depression Rating Scale (BDRS) was administered together with the Montgomery Asberg Rating Scale (MADRS) and Young Mania Rating Scale (YMRS) in a double-blind randomised placebo-controlled clinical trial of N-acetyl cysteine for bipolar disorder (N = 75). A factor analysis showed a two-factor solution: depression and mixed symptom clusters. The BDRS has strong internal consistency (Cronbach's alpha = 0.917), the depression cluster showed robust correlation with the MADRS (r = 0.865) and the mixed subscale correlated with the YMRS (r = 0.750). The BDRS has good internal validity and inter-rater reliability and is sensitive to change in the context of a clinical trial.

Evaluation of depressive symptoms in patients with coronary artery disease using the Montgomery Åsberg Depression Rating Scale.

PubMed

Bunevicius, Adomas; Staniute, Margarita; Brozaitiene, Julija; Pommer, Antoinette M; Pop, Victor J M; Montgomery, Stuart A; Bunevicius, Robertas

2012-09-01

The aim of this study was to evaluate, in patients with coronary artery disease (CAD), factor structure and psychometric properties of the Montgomery Åsberg Depression Rating Scale (MADRS) to identify patients with current major depressive episode (MDE). The construct validity of the MADRS against self-rating scales was also evaluated. Consecutive 522 CAD patients at admission to the cardiac rehabilitation program were interviewed for the severity of depressive symptoms using the MADRS and for current MDE using the structured MINI International Neuropsychiatric Interview. Also, all patients completed the Hospital Anxiety and Depression Scale and the Beck Depression Inventory-II. The MADRS had one-factor structure and high internal consistency (Cronbach's coefficient α=0.82). Confirmative factor analysis indicated an adequate fit: comparative fit index=0.95, normed fit index=0.91, and root mean square error of approximation=0.07. At a cut-off value of 10 or higher, the MADRS had good psychometric properties for the identification of current MDE (positive predictive value=42%, with sensitivity=88% and specificity=85%). There was also a moderate to strong correlation of MADRS scores with scores on self-rating depression scales. In sum, in CAD patients undergoing rehabilitation, the MADRS is a unidimensional instrument with high internal consistency and can be used for the identification of depressed CAD patients. The association between MADRS and self-rating depression scores is moderate to strong. © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Regional processes in mangrove ecosystems: Spatial scaling relationships, biomass, and turnover rates following catastrophic disturbance

USGS Publications Warehouse

Ward, G.A.; Smith, T. J.; Whelan, K.R.T.; Doyle, T.W.

2006-01-01

Physiological processes and local-scale structural dynamics of mangroves are relatively well studied. Regional-scale processes, however, are not as well understood. Here we provide long-term data on trends in structure and forest turnover at a large scale, following hurricane damage in mangrove ecosystems of South Florida, U.S.A. Twelve mangrove vegetation plots were monitored at periodic intervals, between October 1992 and March 2005. Mangrove forests of this region are defined by a -1.5 scaling relationship between mean stem diameter and stem density, mirroring self-thinning theory for mono-specific stands. This relationship is reflected in tree size frequency scaling exponents which, through time, have exhibited trends toward a community average that is indicative of full spatial resource utilization. These trends, together with an asymptotic standing biomass accumulation, indicate that coastal mangrove ecosystems do adhere to size-structured organizing principles as described for upland tree communities. Regenerative dynamics are different between areas inside and outside of the primary wind-path of Hurricane Andrew which occurred in 1992. Forest dynamic turnover rates, however, are steady through time. This suggests that ecological, more-so than structural factors, control forest productivity. In agreement, the relative mean rate of biomass growth exhibits an inverse relationship with the seasonal range of porewater salinities. The ecosystem average in forest scaling relationships may provide a useful investigative tool of mangrove community biomass relationships, as well as offer a robust indicator of general ecosystem health for use in mangrove forest ecosystem management and restoration. ?? Springer 2006.

Examining Parents' Ratings of Middle-School Students' Academic Self-Regulation Using Principal Axis Factoring Analysis

ERIC Educational Resources Information Center

Chen, Peggy P.; Cleary, Timothy J.; Lui, Angela M.

2015-01-01

This study examined the reliability and validity of a parent rating scale, the "Self-Regulation Strategy Inventory: Parent Rating Scale" ("SRSI-PRS"), using a sample of 451 parents of sixth- and seventh-grade middle-school students. Principal axis factoring (PAF) analysis revealed a 3-factor structure for the 23-item SRSI-PRS:…

Uncertainty in age-specific harvest estimates and consequences for white-tailed deer management

USGS Publications Warehouse

Collier, B.A.; Krementz, D.G.

2007-01-01

Age structure proportions (proportion of harvested individuals within each age class) are commonly used as support for regulatory restrictions and input for deer population models. Such use requires critical evaluation when harvest regulations force hunters to selectively harvest specific age classes, due to impact on the underlying population age structure. We used a stochastic population simulation model to evaluate the impact of using harvest proportions to evaluate changes in population age structure under a selective harvest management program at two scales. Using harvest proportions to parameterize the age-specific harvest segment of the model for the local scale showed that predictions of post-harvest age structure did not vary dependent upon whether selective harvest criteria were in use or not. At the county scale, yearling frequency in the post-harvest population increased, but model predictions indicated that post-harvest population size of 2.5 years old males would decline below levels found before implementation of the antler restriction, reducing the number of individuals recruited into older age classes. Across the range of age-specific harvest rates modeled, our simulation predicted that underestimation of age-specific harvest rates has considerable influence on predictions of post-harvest population age structure. We found that the consequence of uncertainty in harvest rates corresponds to uncertainty in predictions of residual population structure, and this correspondence is proportional to scale. Our simulations also indicate that regardless of use of harvest proportions or harvest rates, at either the local or county scale the modeled SHC had a high probability (>0.60 and >0.75, respectively) of eliminating recruitment into >2.5 years old age classes. Although frequently used to increase population age structure, our modeling indicated that selective harvest criteria can decrease or eliminate the number of white-tailed deer recruited into older age classes. Thus, we suggest that using harvest proportions for management planning and evaluation should be viewed with caution. In addition, we recommend that managers focus more attention on estimation of age-specific harvest rates, and modeling approaches which combine harvest rates with information from harvested individuals to further increase their ability to effectively manage deer populations under selective harvest programs. ?? 2006 Elsevier B.V. All rights reserved.

Factor structure of the Korean version of illness intrusiveness rating scale: cross-cultural implications.

PubMed

Kim, Daeho; Kim, Kwang-iel; Lee, Haewon; Choi, Joonho; Park, Yong-Chon

2005-04-01

The Illness Intrusiveness Rating Scale (IIRS) measures illness-induced disruptions to 13 domains of lifestyles, activities, and interests. A stable three-factor structure has been well documented; however, the cross-cultural validity of this scale needs to be tested. This study investigated the factor structure of the Korean version of IIRS in 712 outpatients at a university medical center. A predominant diagnosis of the patients was rheumatoid arthritis (47%). The Center for Epidemiological Studies-Depression Scale (CES-D), and Health Assessment Questionnaire (HAQ) were also administered. Exploratory Principal Component Analysis identified a two-factor structure, "Relationships and Personal Development (RPD)" and "Instrumental", accounting for 57% of the variance. Confirmatory analyses extracted an identical factor structure. However, a goodness-of-the fit test failed to support two-factor solution (chi(2)=138.2, df=43, p<.001). Two factors had high internal consistency (RPD, alpha=.89; Instrumental, alpha=.75) and significantly correlated with scores of HAQ (RPD, r=.53, p<.001; Instrumental, .r=44, p<.001) and CES-D (RPD, .r=55, p<.001; Instrumental, .r=43, p<.001). These findings supported construct validity of the Korean version of IIRS, but did not support cross-cultural equivalence of the factor structure.

Psychometric Properties of the Revised Mathematics Anxiety Rating Scale

ERIC Educational Resources Information Center

Baloglu, Mustafa; Zelhart, Paul F.

2007-01-01

An exploratory factor analysis and several confirmatory analyses were performed to evaluate the factorial structure of the Revised Mathematics Anxiety Rating Scale (RMARS) through the responses of 805 college students. On 559 students' scores, the instrument's construct validity was tested through a confirmatory factor analysis (CFA) and was found…

Preliminary Validation of the Motor Skills Rating Scale

ERIC Educational Resources Information Center

Cameron, Claire E.; Chen, Wei-Bing; Blodgett, Julia; Cottone, Elizabeth A.; Mashburn, Andrew J.; Brock, Laura L.; Grissmer, David

2012-01-01

This study examined psychometric properties of the Motor Skills Rating Scale (MSRS), a questionnaire designed for classroom teachers of children in early elementary school. Items were developed with the guidance of two occupational therapists, and factor structure was examined with an exploratory factor analysis (EFA). The resulting model showed…

The influence of sediment transport rate on the development of structure in gravel bed rivers

NASA Astrophysics Data System (ADS)

Ockelford, Annie; Rice, Steve; Powell, Mark; Reid, Ian; Nguyen, Thao; Tate, Nick; Wood, Jo

2013-04-01

Although adjustments of surface grain size are known to be strongly influenced by sediment transport rate little work has systematically explored how different transport rates can affect the development of surface structure in gravel bed rivers. Specifically, it has been well established that the transport of mixed sized sediments leads to the development of a coarser surface or armour layer which occurs over larger areas of the gravel bed. Armour layer development is known to moderate overall sediment transport rate as well as being extremely sensitive to changes in applied shear stress. However, during this armouring process a bed is created where, smaller gain scale changes, to the bed surface are also apparent such as the development of pebble clusters and imbricate structures. Although these smaller scale changes affect the overall surface grain size distribution very little their presence has the ability to significantly increase the surface stability and hence alter overall sediment transport rates. Consequently, the interplay between the moderation of transport rate as a function of surface coarsening at a larger scale and moderation of transport rate as a function of the development of structure on the bed surface at the smaller scale is complicated and warrants further investigation. During experiments a unimodal grain size distribution (σg = 1.30, D50 = 8.8mm) was exposed to 3 different levels of constant discharge that produced sediment transport conditions ranging from marginal transport to conditions approaching full mobility of all size fractions. Sediment was re-circulated during the experiments surface grain size distribution bed load and fractional transport rates were measured at a high temporal resolution such that the time evolution of the beds could be fully described. Discussion concentrates on analysing the effects of the evolving bed condition sediment transport rate (capacity) and transported grain size (competence). The outcome of this research is pertinent to developing new methods of linking the development of bed surface organisation with near bed flow characteristics and bed load transport in gravel bed rivers. Keywords: Graded, Sediment, Structure

Defining ADHD symptom persistence in adulthood: optimizing sensitivity and specificity.

PubMed

Sibley, Margaret H; Swanson, James M; Arnold, L Eugene; Hechtman, Lily T; Owens, Elizabeth B; Stehli, Annamarie; Abikoff, Howard; Hinshaw, Stephen P; Molina, Brooke S G; Mitchell, John T; Jensen, Peter S; Howard, Andrea L; Lakes, Kimberley D; Pelham, William E

2017-06-01

Longitudinal studies of children diagnosed with ADHD report widely ranging ADHD persistence rates in adulthood (5-75%). This study documents how information source (parent vs. self-report), method (rating scale vs. interview), and symptom threshold (DSM vs. norm-based) influence reported ADHD persistence rates in adulthood. Five hundred seventy-nine children were diagnosed with DSM-IV ADHD-Combined Type at baseline (ages 7.0-9.9 years) 289 classmates served as a local normative comparison group (LNCG), 476 and 241 of whom respectively were evaluated in adulthood (Mean Age = 24.7). Parent and self-reports of symptoms and impairment on rating scales and structured interviews were used to investigate ADHD persistence in adulthood. Persistence rates were higher when using parent rather than self-reports, structured interviews rather than rating scales (for self-report but not parent report), and a norm-based (NB) threshold of 4 symptoms rather than DSM criteria. Receiver-Operating Characteristics (ROC) analyses revealed that sensitivity and specificity were optimized by combining parent and self-reports on a rating scale and applying a NB threshold. The interview format optimizes young adult self-reporting when parent reports are not available. However, the combination of parent and self-reports from rating scales, using an 'or' rule and a NB threshold optimized the balance between sensitivity and specificity. With this definition, 60% of the ADHD group demonstrated symptom persistence and 41% met both symptom and impairment criteria in adulthood. © 2016 Association for Child and Adolescent Mental Health.

Validation of the BESS TRS-P Structure with an Independent Sample of Teacher Ratings

ERIC Educational Resources Information Center

DiStefano, Christine; Greer, Fred; Liu, Jin

2016-01-01

The underlying structure of the Behavioral and Emotional Screening System, Teacher Rating Scale-Preschool was investigated with a replication sample. Ratings from more than 3,000 students were used and four alternative models were investigated. As with prior research, a bifactor model with four factors was identified. The results supported an…

Structural Equation Modeling (SEM) for Satisfaction and Dissatisfaction Ratings; Multiple Group Invariance Analysis across Scales with Different Response Format

ERIC Educational Resources Information Center

Mazaheri, Mehrdad; Theuns, Peter

2009-01-01

The current study evaluates three hypothesized models on subjective well-being, comprising life domain ratings (LDR), overall satisfaction with life (OSWL), and overall dissatisfaction with life (ODWL), using structural equation modeling (SEM). A sample of 1,310 volunteering students, randomly assigned to six conditions, rated their overall life…

Ion-Scale Structure in Mercury's Magnetopause Reconnection Diffusion Region

NASA Technical Reports Server (NTRS)

Gershman, Daniel J.; Dorelli, John C.; DiBraccio, Gina A.; Raines, Jim M.; Slavin, James A.; Poh, Gangkai; Zurbuchen, Thomas H.

2016-01-01

The strength and time dependence of the electric field in a magnetopause diffusion region relate to the rate of magnetic reconnection between the solar wind and a planetary magnetic field. Here we use approximately 150 milliseconds measurements of energetic electrons from the Mercury Surface, Space Environment, GEochemistry, and Ranging (MESSENGER) spacecraft observed over Mercury's dayside polar cap boundary (PCB) to infer such small-scale changes in magnetic topology and reconnection rates. We provide the first direct measurement of open magnetic topology in flux transfer events at Mercury, structures thought to account for a significant portion of the open magnetic flux transport throughout the magnetosphere. In addition, variations in PCB latitude likely correspond to intermittent bursts of approximately 0.3 to 3 millivolts per meter reconnection electric fields separated by approximately 5 to10 seconds, resulting in average and peak normalized dayside reconnection rates of approximately 0.02 and approximately 0.2, respectively. These data demonstrate that structure in the magnetopause diffusion region at Mercury occurs at the smallest ion scales relevant to reconnection physics.

Optimum Particle Size for Gold-Catalyzed CO Oxidation

PubMed Central

2018-01-01

The structure sensitivity of gold-catalyzed CO oxidation is presented by analyzing in detail the dependence of CO oxidation rate on particle size. Clusters with less than 14 gold atoms adopt a planar structure, whereas larger ones adopt a three-dimensional structure. The CO and O2 adsorption properties depend strongly on particle structure and size. All of the reaction barriers relevant to CO oxidation display linear scaling relationships with CO and O2 binding strengths as main reactivity descriptors. Planar and three-dimensional gold clusters exhibit different linear scaling relationship due to different surface topologies and different coordination numbers of the surface atoms. On the basis of these linear scaling relationships, first-principles microkinetics simulations were conducted to determine CO oxidation rates and possible rate-determining step of Au particles. Planar Au9 and three-dimensional Au79 clusters present the highest CO oxidation rates for planar and three-dimensional clusters, respectively. The planar Au9 cluster is much more active than the optimum Au79 cluster. A common feature of optimum CO oxidation performance is the intermediate binding strengths of CO and O2, resulting in intermediate coverages of CO, O2, and O. Both these optimum particles present lower performance than maximum Sabatier performance, indicating that there is sufficient room for improvement of gold catalysts for CO oxidation. PMID:29707098

Exploring the Interrelationship of Structure and Process in Family Child Care: The FCCERS-R and "Combined" CLASS

ERIC Educational Resources Information Center

Enns, Lionel

2012-01-01

This study examined the correlations between two prominent family child care environmental rating scales, the Family Child Care Environment Rating Scale - Revised (FCCERS-R) and the "Combined" Classroom Assessment Scoring System ("Combined" CLASS), both of which were used during the pilot study of Washington State's Quality…

Assessment of Competence in EVAR Procedures: A Novel Rating Scale Developed by the Delphi Technique.

PubMed

Strøm, M; Lönn, L; Bech, B; Schroeder, T V; Konge, L

2017-07-01

To develop a procedure specific global rating scale for assessment of operator competence in endovascular aortic repair (EVAR). A Delphi approach was used to achieve expert consensus. A panel of 32 international experts (median 300 EVAR procedures, range 200-3000) from vascular surgery (n = 21) and radiology (n = 11) was established. The first Delphi round was based on a review of endovascular skills assessment papers, stent graft instructions for use, and structured interviews. It led to a primary pool of 83 items that were formulated as global rating scale items with tentative anchors. Iterative Delphi rounds were executed. The panellists rated the importance of each item on a 5 point Likert scale. Consensus was defined as 80% of the panel rating an item 4 or 5 in the primary round and 90% in subsequent rounds. Consensus on the final assessment tool was defined as Cronbach's alpha > .8 after a minimum of three rounds. Thirty-two of 35 invited experts participated. Three rounds of surveys were completed with a completion rate of 100% in the first two rounds and 91% in round three. The 83 primary assessment items were supplemented with five items suggested by the panel and reduced to seven pivotal assessment items that reached consensus, Cronbach's alpha = 0.82. The seven item rating scale covers key elements of competence in EVAR stent placement and deployment. Each item has well defined grades with explicit anchors at unacceptable, acceptable, and superior performance on a 5 point Likert scale. The Delphi methodology allowed for international consensus on a new procedure specific global rating scale for assessment of competence in EVAR. The resulting scale, EndoVascular Aortic Repair Assessment of Technical Expertise (EVARATE), represents key elements in the procedure. EVARATE constitutes an assessment tool for providing structured feedback to endovascular operators in training. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Factor Structure of the Exercise Self-Efficacy Scale

ERIC Educational Resources Information Center

Cornick, Jessica E.

2015-01-01

The current study utilized exercise self-efficacy ratings from undergraduate students to assess the factor structure of the Self-Efficacy to Regulate Exercise Scale (Bandura, 1997, 2006). An exploratory factor analysis (n = 759) indicated a two-factor model solution and three separate confirmatory factor analyses (n = 1,798) supported this…

Visibility graph approach to exchange rate series

NASA Astrophysics Data System (ADS)

Yang, Yue; Wang, Jianbo; Yang, Huijie; Mang, Jingshi

2009-10-01

By means of a visibility graph, we investigate six important exchange rate series. It is found that the series convert into scale-free and hierarchically structured networks. The relationship between the scaling exponents of the degree distributions and the Hurst exponents obeys the analytical prediction for fractal Brownian motions. The visibility graph can be used to obtain reliable values of Hurst exponents of the series. The characteristics are explained by using the multifractal structures of the series. The exchange rate of EURO to Japanese Yen is widely used to evaluate risk and to estimate trends in speculative investments. Interestingly, the hierarchies of the visibility graphs for the exchange rate series of these two currencies are significantly weak compared with that of the other series.

[Rating scales based on the phenomenological and structural approach].

PubMed

Schiltz, L

2006-01-01

A current tendency of research in clinical psychology consists in using an integrated quantitative and qualitative methodology. This approach is especially suited to the study of the therapeutic intervention where the researcher is himself part of the situation he is investigating. As to the tools of research, the combination of the semi-structured clinical interview, of psychometric scales and projective tests has proved to be pertinent to describe the multidimensional and fluctuating reality of the therapeutic relationship and the changes induced by it in the two partners. In arts therapeutic research the investigation of the artistic production or of the free expression of people may complete the psychometric and projective tools. The concept of "expressive test" is currently being used to characterise this method. In this context, the development of rating scales, based on the phenomenological and structural or holistic approach allows us making the link between qualitative analysis and quantification, leading to the use of inferential statistics, providing that we remain at the nominal or ordinal level of measurement. We are explaining the principle of construction of these rating scales and we are illustrating our practice with some examples drawn from studies we realized in clinical psychology.

Denitrification in a large river: consideration of geomorphic controls on microbial activity and community structure.

PubMed

Tatariw, Corianne; Chapman, Elise L; Sponseller, Ryan A; Mortazavi, Behzad; Edmonds, Jennifer W

2013-10-01

Ecological theory argues that the controls over ecosystem processes are structured hierarchically, with broader-scale drivers acting as constraints over the interactions and dynamics at nested levels of organization. In river ecosystems, these interactions may arise from broadscale variation in channel form that directly shapes benthic habitat structure and indirectly constrains resource supply and biological activity within individual reaches. To evaluate these interactions, we identified sediment characteristics, water chemistry, and denitrifier community structure as factors influencing benthic denitrification rates in a sixth-order river that flows through two physiographic provinces and the transitional zone between them, each with distinct geomorphological properties. We found that denitrification rates tracked spatial changes in sediment characteristics and varied seasonally with expected trends in stream primary production. Highest rates were observed during the spring and summer seasons in the physiographic province dominated by fine-grained sediments, illustrating how large-scale changes in river structure can constrain the location of denitrification hotspots. In addition, nirS and nirK community structure each responded differently to variation in channel form, possibly due to changes in dissolved oxygen and organic matter supply. This shift in denitrifier community structure coincident with higher rates of N removal via denitrification suggests that microbial community structure may influence biogeochemical processes.

Sound production due to large-scale coherent structures

NASA Technical Reports Server (NTRS)

Gatski, T. B.

1979-01-01

The acoustic pressure fluctuations due to large-scale finite amplitude disturbances in a free turbulent shear flow are calculated. The flow is decomposed into three component scales; the mean motion, the large-scale wave-like disturbance, and the small-scale random turbulence. The effect of the large-scale structure on the flow is isolated by applying both a spatial and phase average on the governing differential equations and by initially taking the small-scale turbulence to be in energetic equilibrium with the mean flow. The subsequent temporal evolution of the flow is computed from global energetic rate equations for the different component scales. Lighthill's theory is then applied to the region with the flowfield as the source and an observer located outside the flowfield in a region of uniform velocity. Since the time history of all flow variables is known, a minimum of simplifying assumptions for the Lighthill stress tensor is required, including no far-field approximations. A phase average is used to isolate the pressure fluctuations due to the large-scale structure, and also to isolate the dynamic process responsible. Variation of mean square pressure with distance from the source is computed to determine the acoustic far-field location and decay rate, and, in addition, spectra at various acoustic field locations are computed and analyzed. Also included are the effects of varying the growth and decay of the large-scale disturbance on the sound produced.

The Impact of Spirituality Before and After Treatment of Major Depressive Disorder

PubMed Central

Peselow, Eric; Pi, Sarah; Lopez, Enrique; Besada, André; IsHak, Waguih W.

2014-01-01

Objective: The authors sought to assess spirituality in depressed patients and evaluate whether the degree of initial depressive symptoms and response to pharmacotherapy treatment has a correlation with degree of spirituality and belief in God. Methods: Our participants included 84 patients who presented to a depression/anxiety clinic for naturalistic treatment of their depressive illness over the course of two years. All patients met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria for major depression, as confirmed by structured interviews using the Structured Clinical Interview for DSM-IV, and were treated with selective serotonin reuptake inhibitors for eight weeks. Measurements: Patients were evaluated at baseline and after treatment using the Montgomery Asberg Depression Rating Scale, the Beck Hopelessness Scale, the Dysfunctional Attitude Scale, and the Spiritual Orientation to Life scale. Results: At baseline, patients reporting greater spirituality had significantly lower measures of hopelessness, dysfunctional attitudes, and depressive symptoms. Those who believed in God had a greater mean change score than those who did not on the Montgomery Asberg Depression Rating Scale, the Beck Hopelessness Scale, and the Dysfunctional Attitude Scale, with the Montgomery Asberg Depression Rating Scale showing the greatest mean change score. Significant correlations were detected between the Spiritual Orientation to Life scale score and the Montgomery Asberg Depression Rating Scale, the Beck Hopelessness Scale, and the Dysfunctional Attitude Scale pre-scores, post-scores, and change scores. Conclusion: The findings suggest that greater spirituality is associated with less severe depression. Moreover, the degree to which the measures of depressive symptom severity, hopelessness, and cognitive distortions improved over the course of eight weeks was significantly greater for those patients who were more spiritual. PMID:24800129

Factor Structure of the Korean Version of Illness Intrusiveness Rating Scale: Cross-cultural Implications

PubMed Central

Kim, Kwang-iel; Lee, Haewon; Choi, Joonho; Park, Yong-Chon

2005-01-01

The Illness Intrusiveness Rating Scale (IIRS) measures illness-induced disruptions to 13 domains of lifestyles, activities, and interests. A stable three-factor structure has been well documented; however, the cross-cultural validity of this scale needs to be tested. This study investigated the factor structure of the Korean version of IIRS in 712 outpatients at a university medical center. A predominant diagnosis of the patients was rheumatoid arthritis (47%). The Center for Epidemiological Studies-Depression Scale (CES-D), and Health Assessment Questionnaire (HAQ) were also administered. Exploratory Principal Component Analysis identified a two-factor structure, "Relationships and Personal Development (RPD)" and "Instrumental", accounting for 57% of the variance. Confirmatory analyses extracted an identical factor structure. However, a goodness-of-the fit test failed to support two-factor solution (χ2=138.2, df=43, p<.001). Two factors had high internal consistency (RPD, α=.89; Instrumental, α=.75) and significantly correlated with scores of HAQ (RPD, r=.53, p<.001; Instrumental, .r=44, p<.001) and CES-D (RPD, .r=55, p<.001; Instrumental, .r=43, p<.001). These findings supported construct validity of the Korean version of IIRS, but did not support cross-cultural equivalence of the factor structure. PMID:15832005

Leo Szilard Lectureship Award Talk - Universal Scaling Laws from Cells to Cities; A Physicist's Search for Quantitative, Unified Theories of Biological and Social Structure and Dynamics

NASA Astrophysics Data System (ADS)

West, Geoffrey

2013-04-01

Many of the most challenging, exciting and profound questions facing science and society, from the origins of life to global sustainability, fall under the banner of ``complex adaptive systems.'' This talk explores how scaling can be used to begin to develop physics-inspired quantitative, predictive, coarse-grained theories for understanding their structure, dynamics and organization based on underlying mathematisable principles. Remarkably, most physiological, organisational and life history phenomena in biology and socio-economic systems scale in a simple and ``universal'' fashion: metabolic rate scales approximately as the 3/4-power of mass over 27 orders of magnitude from complex molecules to the largest organisms. Time-scales (such as lifespans and growth-rates) and sizes (such as genome lengths and RNA densities) scale with exponents which are typically simple multiples of 1/4, suggesting that fundamental constraints underlie much of the generic structure and dynamics of living systems. These scaling laws follow from dynamical and geometrical properties of space-filling, fractal-like, hierarchical branching networks, presumed optimised by natural selection. This leads to a general framework that potentially captures essential features of diverse systems including vasculature, ontogenetic growth, cancer, aging and mortality, sleep, cell size, and DNA nucleotide substitution rates. Cities and companies also scale: wages, profits, patents, crime, disease, pollution, road lengths scale similarly across the globe, reflecting underlying universal social network dynamics which point to general principles of organization transcending their individuality. These have dramatic implications for global sustainability: innovation and wealth creation that fuel social systems, left unchecked, potentially sow the seeds for their inevitable collapse.

Behavioral and Emotional Strength-Based Assessment of Finnish Elementary Students: Psychometrics of the BERS-2

ERIC Educational Resources Information Center

Sointu, Erkko Tapio; Savolainen, Hannu; Lambert, Matthew C.; Lappalainen, Kristiina; Epstein, Michael H.

2014-01-01

When rating scales are used in different countries, thorough investigation of the psychometric properties is needed. We examined the internal structure of the Finnish translated Behavioral and Emotional Rating Scale-2 (BERS-2) using Rasch and confirmatory factor analysis approaches with a sample of youth, parents, and teachers. The results…

Confirmatory Factor Analysis of the "Preschool Behavioral and Emotional Rating Scale" (PreBERS) with Preschool Children with Disabilities

ERIC Educational Resources Information Center

Cress, Cynthia J.; Synhorst, Lori; Epstein, Michael H.; Allen, Elizabeth

2012-01-01

The "Preschool Behavioral and Emotional Rating Scale" (PreBERS) is a standardized, norm-referenced instrument that assesses emotional and behavioral strengths of preschool children. This study investigated whether the PreBERS four-factor structure (i.e., emotional regulation, school readiness, social confidence, and family involvement)…

Quality of Child Care Using the Environment Rating Scales: A Meta-Analysis of International Studies

ERIC Educational Resources Information Center

Vermeer, Harriet J.; van IJzendoorn, Marinus H.; Cárcamo, Rodrigo A.; Harrison, Linda J.

2016-01-01

The current study provides a systematic examination of child care quality around the globe, using the Environment Rating Scales (ERS). Additional goals of this study are to examine associations between ERS process quality and structural features (group size, caregiver-child ratio) that underpin quality and between ERS and more proximal aspects of…

Invariance of Parent Ratings of the ADHD Symptoms in Australian and Malaysian, and North European Australian and Malay Malaysia Children: A Mean and Covariance Structures Analysis Approach

ERIC Educational Resources Information Center

Gomez, Rapson

2009-01-01

Objective: This study used the mean and covariance structures analysis approach to examine the equality or invariance of ratings of the 18 ADHD symptoms. Method: 783 Australian and 928 Malaysian parents provided ratings for an ADHD rating scale. Invariance was tested across these groups (Comparison 1), and North European Australian (n = 623) and…

Factor Structure of Scores from the Conners’ Rating Scales–Revised Among Nepali Children

PubMed Central

Pendergast, Laura L.; Vandiver, Beverly J.; Schaefer, Barbara A.; Cole, Pamela M.; Murray-Kolb, Laura M.; Christian, Parul

2014-01-01

This study used exploratory and confirmatory factor analyses to examine the structures of scores from the Conners’ Teacher and Parent Rating Scales–Revised (CTRS-R and CPRS-R, respectively; Conners, 1997). The scales were administered to 1,835 parents and 1,387 teachers of children in Nepal's Sarlahi district – a region where no other measures of child psychopathology have been studied. With a Nepali sample, the findings indicate that reduced two factor models for the Conners’ scales are superior to the models identified in the scale development research. The hyperactivity and inattention factors were comparable to what has been identified in prior research, while other factors (e.g., social problems) differed substantially. Implications for use of the Conners’ scales in Nepal and cross cultural issues in the assessment of ADHD symptoms are discussed. PMID:25574454

Genome-scale rates of evolutionary change in bacteria

PubMed Central

Duchêne, Sebastian; Holt, Kathryn E.; Weill, François-Xavier; Le Hello, Simon; Hawkey, Jane; Edwards, David J.; Fourment, Mathieu

2016-01-01

Estimating the rates at which bacterial genomes evolve is critical to understanding major evolutionary and ecological processes such as disease emergence, long-term host–pathogen associations and short-term transmission patterns. The surge in bacterial genomic data sets provides a new opportunity to estimate these rates and reveal the factors that shape bacterial evolutionary dynamics. For many organisms estimates of evolutionary rate display an inverse association with the time-scale over which the data are sampled. However, this relationship remains unexplored in bacteria due to the difficulty in estimating genome-wide evolutionary rates, which are impacted by the extent of temporal structure in the data and the prevalence of recombination. We collected 36 whole genome sequence data sets from 16 species of bacterial pathogens to systematically estimate and compare their evolutionary rates and assess the extent of temporal structure in the absence of recombination. The majority (28/36) of data sets possessed sufficient clock-like structure to robustly estimate evolutionary rates. However, in some species reliable estimates were not possible even with ‘ancient DNA’ data sampled over many centuries, suggesting that they evolve very slowly or that they display extensive rate variation among lineages. The robustly estimated evolutionary rates spanned several orders of magnitude, from approximately 10−5 to 10−8 nucleotide substitutions per site year−1. This variation was negatively associated with sampling time, with this relationship best described by an exponential decay curve. To avoid potential estimation biases, such time-dependency should be considered when inferring evolutionary time-scales in bacteria. PMID:28348834

Physical heterogeneity control on effective mineral dissolution rates

NASA Astrophysics Data System (ADS)

Jung, Heewon; Navarre-Sitchler, Alexis

2018-04-01

Hydrologic heterogeneity may be an important factor contributing to the discrepancy in laboratory and field measured dissolution rates, but the governing factors influencing mineral dissolution rates among various representations of physical heterogeneity remain poorly understood. Here, we present multiple reactive transport simulations of anorthite dissolution in 2D latticed random permeability fields and link the information from local grid scale (1 cm or 4 m) dissolution rates to domain-scale (1m or 400 m) effective dissolution rates measured by the flux-weighted average of an ensemble of flow paths. We compare results of homogeneous models to heterogeneous models with different structure and layered permeability distributions within the model domain. Chemistry is simplified to a single dissolving primary mineral (anorthite) distributed homogeneously throughout the domain and a single secondary mineral (kaolinite) that is allowed to dissolve or precipitate. Results show that increasing size in correlation structure (i.e. long integral scales) and high variance in permeability distribution are two important factors inducing a reduction in effective mineral dissolution rates compared to homogeneous permeability domains. Larger correlation structures produce larger zones of low permeability where diffusion is an important transport mechanism. Due to the increased residence time under slow diffusive transport, the saturation state of a solute with respect to a reacting mineral approaches equilibrium and reduces the reaction rate. High variance in permeability distribution favorably develops large low permeability zones that intensifies the reduction in mixing and effective dissolution rate. However, the degree of reduction in effective dissolution rate observed in 1 m × 1 m domains is too small (<1% reduction from the corresponding homogeneous case) to explain several orders of magnitude reduction observed in many field studies. When multimodality in permeability distribution is approximated by high permeability variance in 400 m × 400 m domains, the reduction in effective dissolution rate increases due to the effect of long diffusion length scales through zones with very slow reaction rates. The observed scale dependence becomes complicated when pH dependent kinetics are compared to the results from pH independent rate constants. In small domains where the entire domain is reactive, faster anorthite dissolution rates and slower kaolinite precipitation rates relative to pH independent rates at far-from-equilibrium conditions reduce the effective dissolution rate by increasing the saturation state. However, in large domains where less- or non-reactive zones develop, higher kaolinite precipitation rates in less reactive zones increase the effective anorthite dissolution rates relative to the rates observed in pH independent cases.

Construct Validity of ADHD/ODD Rating Scales: Recommendations for the Evaluation of Forthcoming DSM-V ADHD/ODD Scales

ERIC Educational Resources Information Center

Burns, G. Leonard; Walsh, James A.; Servera, Mateu; Lorenzo-Seva, Urbano; Cardo, Esther; Rodriguez-Fornells, Antoni

2013-01-01

Exploratory structural equation modeling (SEM) was applied to a multiple indicator (26 individual symptom ratings) by multitrait (ADHD-IN, ADHD-HI and ODD factors) by multiple source (mothers, fathers and teachers) model to test the invariance, convergent and discriminant validity of the Child and Adolescent Disruptive Behavior Inventory with 872…

Comparison Analysis among Large Amount of SNS Sites

NASA Astrophysics Data System (ADS)

Toriumi, Fujio; Yamamoto, Hitoshi; Suwa, Hirohiko; Okada, Isamu; Izumi, Kiyoshi; Hashimoto, Yasuhiro

In recent years, application of Social Networking Services (SNS) and Blogs are growing as new communication tools on the Internet. Several large-scale SNS sites are prospering; meanwhile, many sites with relatively small scale are offering services. Such small-scale SNSs realize small-group isolated type of communication while neither mixi nor MySpace can do that. However, the studies on SNS are almost about particular large-scale SNSs and cannot analyze whether their results apply for general features or for special characteristics on the SNSs. From the point of view of comparison analysis on SNS, comparison with just several types of those cannot reach a statistically significant level. We analyze many SNS sites with the aim of classifying them by using some approaches. Our paper classifies 50,000 sites for small-scale SNSs and gives their features from the points of network structure, patterns of communication, and growth rate of SNS. The result of analysis for network structure shows that many SNS sites have small-world attribute with short path lengths and high coefficients of their cluster. Distribution of degrees of the SNS sites is close to power law. This result indicates the small-scale SNS sites raise the percentage of users with many friends than mixi. According to the analysis of their coefficients of assortativity, those SNS sites have negative values of assortativity, and that means users with high degree tend to connect users with small degree. Next, we analyze the patterns of user communication. A friend network of SNS is explicit while users' communication behaviors are defined as an implicit network. What kind of relationships do these networks have? To address this question, we obtain some characteristics of users' communication structure and activation patterns of users on the SNS sites. By using new indexes, friend aggregation rate and friend coverage rate, we show that SNS sites with high value of friend coverage rate activate diary postings and their comments. Besides, they become activated when hub users with high degree do not behave actively on the sites with high value of friend aggregation rate and high value of friend coverage rate. On the other hand, activation emerges when hub users behave actively on the sites with low value of friend aggregation rate and high value of friend coverage rate. Finally, we observe SNS sites which are increasing the number of users considerably, from the viewpoint of network structure, and extract characteristics of high growth SNS sites. As a result of discrimination on the basis of the decision tree analysis, we can recognize the high growth SNS sites with a high degree of accuracy. Besides, this approach suggests mixi and the other small-scale SNS sites have different character trait.

The Factor Structure of Preschool Learning Behaviors Scale Scores in Peruvian Children

ERIC Educational Resources Information Center

Hahn, Kathryn R.; Schaefer, Barbara A.; Merino, Cesar; Worrell, Frank C.

2009-01-01

The factor structure of the Escala de Conductas de Aprendizaje Preescolar (ECAP), a Spanish translation of the Preschool Learning Behaviors Scale (PLBS), was examined in this study. Children aged 2 to 6 years (N = 328) enrolled in public and private preschools in the Republic of Peru were rated by classroom teachers on the frequency of observable,…

Factor Structure and Validity of the Therapy Process Observational Coding System for Child Psychotherapy--Alliance Scale

ERIC Educational Resources Information Center

Fjermestad, Krister W.; McLeod, Bryce D.; Heiervang, Einar R.; Havik, Odd E.; Ost, Lars-Goran; Haugland, Bente S. M.

2012-01-01

The aim of this study was to examine the factor structure and psychometric properties of an observer-rated youth alliance measure, the Therapy Process Observational Coding System for Child Psychotherapy-Alliance scale (TPOCS-A). The sample was 52 youth diagnosed with anxiety disorders ("M" age = 12.43, "SD" = 2.23, range = 15;…

Pore-scale investigation on the response of heterotrophic respiration to moisture conditions in heterogeneous soils

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

Yan, Zhifeng; Liu, Chongxuan; Todd-Brown, Katherine E.

The relationship between microbial respiration rate and soil moisture content is an important property for understanding and predicting soil organic carbon degradation, CO 2 production and emission, and their subsequent effects on climate change. This paper reports a pore-scale modeling study to investigate the response of heterotrophic respiration to moisture conditions in soils and to evaluate various factors that affect this response. X-ray computed tomography was used to derive soil pore structures, which were then used for pore-scale model investigation. The pore-scale results were then averaged to calculate the effective respiration rates as a function of water content in soils.more » The calculated effective respiration rate first increases and then decreases with increasing soil water content, showing a maximum respiration rate at water saturation degree of 0.75 that is consistent with field and laboratory observations. The relationship between the respiration rate and moisture content is affected by various factors, including pore-scale organic carbon bioavailability, the rate of oxygen delivery, soil pore structure and physical heterogeneity, soil clay content, and microbial drought resistivity. Simulations also illustrates that a larger fraction of CO 2 produced from microbial respiration can be accumulated inside soil cores under higher saturation conditions, implying that CO 2 flux measured on the top of soil cores may underestimate or overestimate true soil respiration rates under dynamic moisture conditions. Overall, this study provides mechanistic insights into the soil respiration response to the change in moisture conditions, and reveals a complex relationship between heterotrophic microbial respiration rate and moisture content in soils that is affected by various hydrological, geochemical, and biophysical factors.« less

The Relationship between Symptom Relief and Psychosocial Functional Improvement during Acute Electroconvulsive Therapy for Patients with Major Depressive Disorder.

PubMed

Lin, Ching-Hua; Yang, Wei-Cheng

2017-07-01

We aimed to compare the degree of symptom relief to psychosocial functional (abbreviated as "functional") improvement and explore the relationships between symptom relief and functional improvement during acute electroconvulsive therapy for patients with major depressive disorder. Major depressive disorder inpatients (n=130) requiring electroconvulsive therapy were recruited. Electroconvulsive therapy was generally performed for a maximum of 12 treatments. Symptom severity, using the 17-item Hamilton Depression Rating Scale, and psychosocial functioning (abbreviated as "functioning"), using the Modified Work and Social Adjustment Scale, were assessed before electroconvulsive therapy, after every 3 electroconvulsive therapy treatments, and after the final electroconvulsive therapy. Both 17-item Hamilton Depression Rating Scale and Modified Work and Social Adjustment Scale scores were converted to T-score units to compare the degrees of changes between depressive symptoms and functioning after electroconvulsive therapy. Structural equation modeling was used to test the relationships between 17-item Hamilton Depression Rating Scale and Modified Work and Social Adjustment Scale during acute electroconvulsive therapy. One hundred sixteen patients who completed at least the first 3 electroconvulsive therapy treatments entered the analysis. Reduction of 17-item Hamilton Depression Rating Scale T-scores was significantly greater than that of Modified Work and Social Adjustment Scale T-scores at assessments 2, 3, 4, and 5. The model analyzed by structural equation modeling satisfied all indices of goodness-of-fit (chi-square = 32.882, P =.107, TLI = 0.92, CFI = 0.984, RMSEA = 0.057). The 17-item Hamilton Depression Rating Scale change did not predict subsequent Modified Work and Social Adjustment Scale change. Functioning improved less than depressive symptoms during acute electroconvulsive therapy. Symptom reduction did not predict subsequent functional improvement. Depressive symptoms and functional impairment are distinct domains and should be assessed independently to accurately reflect the effectiveness of electroconvulsive therapy. © The Author 2017. Published by Oxford University Press on behalf of CINP.

Effect of deposition rate on melting point of copper film catalyst substrate at atomic scale

NASA Astrophysics Data System (ADS)

Marimpul, Rinaldo; Syuhada, Ibnu; Rosikhin, Ahmad; Winata, Toto

2018-03-01

Annealing process of copper film catalyst substrate was studied by molcular dynamics simulation. This copper film catalyst substrate was produced using thermal evaporation method. The annealing process was limited in nanosecond order to observe the mechanism at atomic scale. We found that deposition rate parameter affected the melting point of catalyst substrate. The change of crystalline structure of copper atoms was observed before it had been already at melting point. The optimum annealing temperature was obtained to get the highest percentage of fcc structure on copper film catalyst substrate.

Exploring Rating Quality in Rater-Mediated Assessments Using Mokken Scale Analysis

ERIC Educational Resources Information Center

Wind, Stefanie A.; Engelhard, George, Jr.

2016-01-01

Mokken scale analysis is a probabilistic nonparametric approach that offers statistical and graphical tools for evaluating the quality of social science measurement without placing potentially inappropriate restrictions on the structure of a data set. In particular, Mokken scaling provides a useful method for evaluating important measurement…

Objective structured assessment of nontechnical skills: Reliability of a global rating scale for the in-training assessment in the operating room.

PubMed

Dedy, Nicolas J; Szasz, Peter; Louridas, Marisa; Bonrath, Esther M; Husslein, Heinrich; Grantcharov, Teodor P

2015-06-01

Nontechnical skills are critical for patient safety in the operating room (OR). As a result, regulatory bodies for accreditation and certification have mandated the integration of these competencies into postgraduate education. A generally accepted approach to the in-training assessment of nontechnical skills, however, is lacking. The goal of the present study was to develop an evidence-based and reliable tool for the in-training assessment of residents' nontechnical performance in the OR. The Objective Structured Assessment of Nontechnical Skills tool was designed as a 5-point global rating scale with descriptive anchors for each item, based on existing evidence-based frameworks of nontechnical skills, as well as resident training requirements. The tool was piloted on scripted videos and refined in an iterative process. The final version was used to rate residents' performance in recorded OR crisis simulations and during live observations in the OR. A total of 37 simulations and 10 live procedures were rated. Interrater agreement was good for total mean scores, both in simulation and in the real OR, with intraclass correlation coefficients >0.90 in all settings for average and single measures. Internal consistency of the scale was high (Cronbach's alpha = 0.80). The Objective Structured Assessment of Nontechnical Skills global rating scale was developed as an evidence-based tool for the in-training assessment of residents' nontechnical performance in the OR. Unique descriptive anchors allow for a criterion-referenced assessment of performance. Good reliability was demonstrated in different settings, supporting applications in research and education. Copyright © 2015 Elsevier Inc. All rights reserved.

Large-scale disturbance legacies and the climate sensitivity of primary Picea abies forests.

PubMed

Schurman, Jonathan S; Trotsiuk, Volodymyr; Bače, Radek; Čada, Vojtěch; Fraver, Shawn; Janda, Pavel; Kulakowski, Dominik; Labusova, Jana; Mikoláš, Martin; Nagel, Thomas A; Seidl, Rupert; Synek, Michal; Svobodová, Kristýna; Chaskovskyy, Oleh; Teodosiu, Marius; Svoboda, Miroslav

2018-05-01

Determining the drivers of shifting forest disturbance rates remains a pressing global change issue. Large-scale forest dynamics are commonly assumed to be climate driven, but appropriately scaled disturbance histories are rarely available to assess how disturbance legacies alter subsequent disturbance rates and the climate sensitivity of disturbance. We compiled multiple tree ring-based disturbance histories from primary Picea abies forest fragments distributed throughout five European landscapes spanning the Bohemian Forest and the Carpathian Mountains. The regional chronology includes 11,595 tree cores, with ring dates spanning the years 1750-2000, collected from 560 inventory plots in 37 stands distributed across a 1,000 km geographic gradient, amounting to the largest disturbance chronology yet constructed in Europe. Decadal disturbance rates varied significantly through time and declined after 1920, resulting in widespread increases in canopy tree age. Approximately 75% of current canopy area recruited prior to 1900. Long-term disturbance patterns were compared to an historical drought reconstruction, and further linked to spatial variation in stand structure and contemporary disturbance patterns derived from LANDSAT imagery. Historically, decadal Palmer drought severity index minima corresponded to higher rates of canopy removal. The severity of contemporary disturbances increased with each stand's estimated time since last major disturbance, increased with mean diameter, and declined with increasing within-stand structural variability. Reconstructed spatial patterns suggest that high small-scale structural variability has historically acted to reduce large-scale susceptibility and climate sensitivity of disturbance. Reduced disturbance rates since 1920, a potential legacy of high 19th century disturbance rates, have contributed to a recent region-wide increase in disturbance susceptibility. Increasingly common high-severity disturbances throughout primary Picea forests of Central Europe should be reinterpreted in light of both legacy effects (resulting in increased susceptibility) and climate change (resulting in increased exposure to extreme events). © 2018 John Wiley & Sons Ltd.

Validation of the Spanish version of Mackey childbirth satisfaction rating scale.

PubMed

Caballero, Pablo; Delgado-García, Beatriz E; Orts-Cortes, Isabel; Moncho, Joaquin; Pereyra-Zamora, Pamela; Nolasco, Andreu

2016-04-16

The "Mackey Childbirth Satisfaction Rating Scale" (MCSRS) is a complete non-validated scale which includes the most important factors associated with maternal satisfaction. Our primary purpose was to describe the internal structure of the scale and validate the reliability and validity of concept of its Spanish version MCSRS-E. The MCSRS was translated into Spanish, back-translated and adapted to the Spanish population. It was then administered following a pilot test with women who met the study participant requirements. The scale structure was obtained by performing an exploratory factorial analysis using a sample of 304 women. The structures obtained were tested by conducting a confirmatory factorial analysis using a sample of 159 women. To test the validity of concept, the structure factors were correlated with expectations prior to childbirth experiences. McDonald's omegas were calculated for each model to establish the reliability of each factor. The study was carried out at four University Hospitals; Alicante, Elche, Torrevieja and Vinalopo Salud of Elche. The inclusion criteria were women aged 18-45 years old who had just delivered a singleton live baby at 38-42 weeks through vaginal delivery. Women who had difficulty speaking and understanding Spanish were excluded. The process generated 5 different possible internal structures in a nested model more consistent with the theory than other internal structures of the MCSRS applied hitherto. All of them had good levels of validation and reliability. This nested model to explain internal structure of MCSRS-E can accommodate different clinical practice scenarios better than the other structures applied to date, and it is a flexible tool which can be used to identify the aspects that should be changed to improve maternal satisfaction and hence maternal health.

The Behavioural Assessment of Self-Structuring (BASS): psychometric properties in a post-acute brain injury rehabilitation programme.

PubMed

Jackson, Howard F; Tunstall, Victoria; Hague, Gemma; Daniels, Leanne; Crompton, Stacey; Taplin, Kimberly

2014-01-01

Jackson et al. (this edition) argue that structure is an important component in reducing the handicaps caused by cognitive impairments following acquired brain injury and that post-acute neuropsychological brain injury rehabilitation programmes should not only endeavour to provide structure but also aim to develop self-structuring. However, at present there is no standardized device for assessing self-structuring. To provide preliminary analysis of the psychometric properties of the Behavioural Assessment of Self-Structuring (BASS) staff rating scale (a 26 item informant five point rating scale based on the degree of support client requires to achieve self-structuring item). BASS data was utilised for clients attending residential rehabilitation. Reliability (inter-rarer and intra-rater), validity (construct, concurrent and discriminate) and sensitivity to change were investigated. Initial results indicate that the BASS has reasonably good reliability, good construct validity (via principal components analysis), good discriminant validity, and good concurrent validity correlating well with a number of other outcome measures (HoNOS; NPDS, Supervision Rating Scale, MPAI, FIM and FAM). The BASS did not correlate well with the NPCNA. Finally, the BASS was shown to demonstrate sensitivity to change. Although some caution is required in drawing firm conclusions at the present time and further exploration of the psychometric properties of the BASS is required, initial results are encouraging for the use of the BASS in assessing rehabilitation progress. These findings are discussed in terms of the value of the concept of self-structuring to the rehabilitation process for individuals with neuropsychological impairments consequent on acquired brain injury.

Structured implicit review: a new method for monitoring nursing care quality.

PubMed

Pearson, M L; Lee, J L; Chang, B L; Elliott, M; Kahn, K L; Rubenstein, L V

2000-11-01

Nurses' independent decisions about assessment, treatment, and nursing interventions for hospitalized patients are important determinants of quality of care. Physician peer implicit review of medical records has been central to Medicare quality management and is considered the gold standard for reviewing physician care, but peer implicit review of nursing processes of care has not received similar attention. The objective of this study was to develop and evaluate nurse structured implicit review (SIR) methods. We developed SIR instruments for rating the quality of inpatient nursing care for congestive heart failure (CHF) and cerebrovascular accident (CVA). Nurse reviewers used the SIR form to rate a nationally representative sample of randomly selected medical records for each disease from 297 acute care hospitals in 5 states (collected by the RAND-HCFA Prospective Payment System study). The study subjects were elderly Medicare inpatients with CHF (n = 291) or CVA (n = 283). We developed and tested scales reflecting domains of nursing process, evaluated interrater and interitem reliability, and assessed the extent to which items and scales predicted overall ratings of the quality of nursing care. Interrater reliability for 14 of 16 scales (CHF) or 10 of 16 scales (CVA) was > or = 0.40. Interitem reliability was > 0.80 for all but 1 scale (both diseases). Functional Assessment, Physical Assessment, and Medication Tracking ratings were the strongest predictors of overall nursing quality ratings (P < 0.001 for each). Nurse peer review with SIR has adequate interrater and excellent scale reliabilities and can be a valuable tool for assessing nurse performance.

Microtubule Dynamics Scale with Cell Size to Set Spindle Length and Assembly Timing.

PubMed

Lacroix, Benjamin; Letort, Gaëlle; Pitayu, Laras; Sallé, Jérémy; Stefanutti, Marine; Maton, Gilliane; Ladouceur, Anne-Marie; Canman, Julie C; Maddox, Paul S; Maddox, Amy S; Minc, Nicolas; Nédélec, François; Dumont, Julien

2018-05-21

Successive cell divisions during embryonic cleavage create increasingly smaller cells, so intracellular structures must adapt accordingly. Mitotic spindle size correlates with cell size, but the mechanisms for this scaling remain unclear. Using live cell imaging, we analyzed spindle scaling during embryo cleavage in the nematode Caenorhabditis elegans and sea urchin Paracentrotus lividus. We reveal a common scaling mechanism, where the growth rate of spindle microtubules scales with cell volume, which explains spindle shortening. Spindle assembly timing is, however, constant throughout successive divisions. Analyses in silico suggest that controlling the microtubule growth rate is sufficient to scale spindle length and maintain a constant assembly timing. We tested our in silico predictions to demonstrate that modulating cell volume or microtubule growth rate in vivo induces a proportional spindle size change. Our results suggest that scalability of the microtubule growth rate when cell size varies adapts spindle length to cell volume. Copyright © 2018 Elsevier Inc. All rights reserved.

The Modified Abbreviated Math Anxiety Scale: A Valid and Reliable Instrument for Use with Children.

PubMed

Carey, Emma; Hill, Francesca; Devine, Amy; Szűcs, Dénes

2017-01-01

Mathematics anxiety (MA) can be observed in children from primary school age into the teenage years and adulthood, but many MA rating scales are only suitable for use with adults or older adolescents. We have adapted one such rating scale, the Abbreviated Math Anxiety Scale (AMAS), to be used with British children aged 8-13. In this study, we assess the scale's reliability, factor structure, and divergent validity. The modified AMAS (mAMAS) was administered to a very large ( n = 1746) cohort of British children and adolescents. This large sample size meant that as well as conducting confirmatory factor analysis on the scale itself, we were also able to split the sample to conduct exploratory and confirmatory factor analysis of items from the mAMAS alongside items from child test anxiety and general anxiety rating scales. Factor analysis of the mAMAS confirmed that it has the same underlying factor structure as the original AMAS, with subscales measuring anxiety about Learning and Evaluation in math. Furthermore, both exploratory and confirmatory factor analysis of the mAMAS alongside scales measuring test anxiety and general anxiety showed that mAMAS items cluster onto one factor (perceived to represent MA). The mAMAS provides a valid and reliable scale for measuring MA in children and adolescents, from a younger age than is possible with the original AMAS. Results from this study also suggest that MA is truly a unique construct, separate from both test anxiety and general anxiety, even in childhood.

The Structure of the Narcissistic Personality Inventory With Binary and Rating Scale Items.

PubMed

Boldero, Jennifer M; Bell, Richard C; Davies, Richard C

2015-01-01

Narcissistic Personality Inventory (NPI) items typically have a forced-choice format, comprising a narcissistic and a nonnarcissistic statement. Recently, some have presented the narcissistic statements and asked individuals to either indicate whether they agree or disagree that the statements are self-descriptive (i.e., a binary response format) or to rate the extent to which they agree or disagree that these statements are self-descriptive on a Likert scale (i.e., a rating response format). The current research demonstrates that when NPI items have a binary or a rating response format, the scale has a bifactor structure (i.e., the items load on a general factor and on 6 specific group factors). Indexes of factor strength suggest that the data are unidimensional enough for the NPI's general factor to be considered a measure of a narcissism latent trait. However, the rating item general factor assessed more narcissism components than the binary item one. The positive correlations of the NPI's general factor, assessed when items have a rating response format, were moderate with self-esteem, strong with a measure of narcissistic grandiosity, and weak with 2 measures of narcissistic vulnerability. Together, the results suggest that using a rating format for items enhances the information provided by the NPI.

Meta-analysis of the Brief Psychiatric Rating Scale Factor Structure

ERIC Educational Resources Information Center

Shafer, Alan

2005-01-01

A meta-analysis (N=17,620; k=26) of factor analyses of the Brief Psychiatric Rating Scale (BPRS) was conducted. Analysis of the 12 items from Overall et al.'s (J. E. Overall, L. E. Hollister, & P. Pichot, 1974) 4 subscales found support for his 4 subscales. Analysis of all 18 BPRS items found 4 components similar to those of Overall et al. In a…

Structural and Practical Identifiability Issues of Immuno-Epidemiological Vector-Host Models with Application to Rift Valley Fever.

PubMed

Tuncer, Necibe; Gulbudak, Hayriye; Cannataro, Vincent L; Martcheva, Maia

2016-09-01

In this article, we discuss the structural and practical identifiability of a nested immuno-epidemiological model of arbovirus diseases, where host-vector transmission rate, host recovery, and disease-induced death rates are governed by the within-host immune system. We incorporate the newest ideas and the most up-to-date features of numerical methods to fit multi-scale models to multi-scale data. For an immunological model, we use Rift Valley Fever Virus (RVFV) time-series data obtained from livestock under laboratory experiments, and for an epidemiological model we incorporate a human compartment to the nested model and use the number of human RVFV cases reported by the CDC during the 2006-2007 Kenya outbreak. We show that the immunological model is not structurally identifiable for the measurements of time-series viremia concentrations in the host. Thus, we study the non-dimensionalized and scaled versions of the immunological model and prove that both are structurally globally identifiable. After fixing estimated parameter values for the immunological model derived from the scaled model, we develop a numerical method to fit observable RVFV epidemiological data to the nested model for the remaining parameter values of the multi-scale system. For the given (CDC) data set, Monte Carlo simulations indicate that only three parameters of the epidemiological model are practically identifiable when the immune model parameters are fixed. Alternatively, we fit the multi-scale data to the multi-scale model simultaneously. Monte Carlo simulations for the simultaneous fitting suggest that the parameters of the immunological model and the parameters of the immuno-epidemiological model are practically identifiable. We suggest that analytic approaches for studying the structural identifiability of nested models are a necessity, so that identifiable parameter combinations can be derived to reparameterize the nested model to obtain an identifiable one. This is a crucial step in developing multi-scale models which explain multi-scale data.

Spatial distribution and optimal harvesting of an age-structured population in a fluctuating environment.

PubMed

Engen, Steinar; Lee, Aline Magdalena; Sæther, Bernt-Erik

2018-02-01

We analyze a spatial age-structured model with density regulation, age specific dispersal, stochasticity in vital rates and proportional harvesting. We include two age classes, juveniles and adults, where juveniles are subject to logistic density dependence. There are environmental stochastic effects with arbitrary spatial scales on all birth and death rates, and individuals of both age classes are subject to density independent dispersal with given rates and specified distributions of dispersal distances. We show how to simulate the joint density fields of the age classes and derive results for the spatial scales of all spatial autocovariance functions for densities. A general result is that the squared scale has an additive term equal to the squared scale of the environmental noise, corresponding to the Moran effect, as well as additive terms proportional to the dispersal rate and variance of dispersal distance for the age classes and approximately inversely proportional to the strength of density regulation. We show that the optimal harvesting strategy in the deterministic case is to harvest only juveniles when their relative value (e.g. financial) is large, and otherwise only adults. With increasing environmental stochasticity there is an interval of increasing length of values of juveniles relative to adults where both age classes should be harvested. Harvesting generally tends to increase all spatial scales of the autocovariances of densities. Copyright © 2017. Published by Elsevier Inc.

Psychopathological dimensions of depression: a factor study of the 17-item Hamilton depression rating scale in unipolar depressed outpatients.

PubMed

Pancheri, P; Picardi, A; Pasquini, M; Gaetano, P; Biondi, M

2002-02-01

Agreement on the factor structure of the Hamilton Depression Rating Scale (HDRS) has not been consistent among studies, and some investigators argued that the scale's factor structure is not reliable. This study aimed at shedding more light on this debated issue. We studied 186 adults with unipolar depression (Major Depressive Disorder, n=80; Dysthymic Disorder, n=71; Depressive Disorder Not Otherwise Specified, n=25; Adjustment Disorder, n=10). They had no comorbid DSM-IV axis I or axis II disorders, and had received no treatment with antidepressant drugs in the previous 2 months. The factor structure of the scale was studied using the principal factor method, followed by oblique rotation. Factor scores were computed for each subject using the regression method. Using the scree-test criterion for factor extraction, we obtained a four-factor solution, explaining 43.8% of total variance. The four factors extracted were identified as (1) somatic anxiety/somatization factor; (2) a psychic anxiety dimension; (3) a pure depressive dimension; and (4) anorexia factor. Patients with Major Depressive Disorder scored significantly higher than patients with other diagnoses on the pure depressive dimension. These results need to be replicated in different cultures, using analogous factoring techniques. Though not exhibiting factorial invariance in the stricter sense of the term, the 17-item HDRS did exhibit a relatively reliable factor structure. Our analysis provides further evidence that the scale is multidimensional. However, as long as the multidimensional character of the scale is taken into account the scale should be able to play a useful role in clinical research.

Cooling rate effects in sodium silicate glasses: Bridging the gap between molecular dynamics simulations and experiments

NASA Astrophysics Data System (ADS)

Li, Xin; Song, Weiying; Yang, Kai; Krishnan, N. M. Anoop; Wang, Bu; Smedskjaer, Morten M.; Mauro, John C.; Sant, Gaurav; Balonis, Magdalena; Bauchy, Mathieu

2017-08-01

Although molecular dynamics (MD) simulations are commonly used to predict the structure and properties of glasses, they are intrinsically limited to short time scales, necessitating the use of fast cooling rates. It is therefore challenging to compare results from MD simulations to experimental results for glasses cooled on typical laboratory time scales. Based on MD simulations of a sodium silicate glass with varying cooling rate (from 0.01 to 100 K/ps), here we show that thermal history primarily affects the medium-range order structure, while the short-range order is largely unaffected over the range of cooling rates simulated. This results in a decoupling between the enthalpy and volume relaxation functions, where the enthalpy quickly plateaus as the cooling rate decreases, whereas density exhibits a slower relaxation. Finally, we show that, using the proper extrapolation method, the outcomes of MD simulations can be meaningfully compared to experimental values when extrapolated to slower cooling rates.

Study of Rapid-Regression Liquefying Hybrid Rocket Fuels

NASA Technical Reports Server (NTRS)

Zilliac, Greg; DeZilwa, Shane; Karabeyoglu, M. Arif; Cantwell, Brian J.; Castellucci, Paul

2004-01-01

A report describes experiments directed toward the development of paraffin-based hybrid rocket fuels that burn at regression rates greater than those of conventional hybrid rocket fuels like hydroxyl-terminated butadiene. The basic approach followed in this development is to use materials such that a hydrodynamically unstable liquid layer forms on the melting surface of a burning fuel body. Entrainment of droplets from the liquid/gas interface can substantially increase the rate of fuel mass transfer, leading to surface regression faster than can be achieved using conventional fuels. The higher regression rate eliminates the need for the complex multi-port grain structures of conventional solid rocket fuels, making it possible to obtain acceptable performance from single-port structures. The high-regression-rate fuels contain no toxic or otherwise hazardous components and can be shipped commercially as non-hazardous commodities. Among the experiments performed on these fuels were scale-up tests using gaseous oxygen. The data from these tests were found to agree with data from small-scale, low-pressure and low-mass-flux laboratory tests and to confirm the expectation that these fuels would burn at high regression rates, chamber pressures, and mass fluxes representative of full-scale rocket motors.

Pore-scale study of effects of macroscopic pores and their distributions on reactive transport in hierarchical porous media

DOE PAGES

Chen, Li; Zhang, Ruiyuan; Min, Ting; ...

2018-05-19

For applications of reactive transport in porous media, optimal porous structures should possess both high surface area for reactive sites loading and low mass transport resistance. Hierarchical porous media with a combination of pores at different scales are designed for this purpose. In this paper, using the lattice Boltzmann method, pore-scale numerical studies are conducted to investigate diffusion-reaction processes in 2D hierarchical porous media generated by self-developed reconstruction scheme. Complex interactions between porous structures and reactive transport are revealed under different conditions. Simulation results show that adding macropores can greatly enhance the mass transport, but at the same time reducemore » the reactive surface, leading to complex change trend of the total reaction rate. Effects of gradient distribution of macropores within the porous medium are also investigated. It is found that a front-loose, back-tight (FLBT) hierarchical structure is desirable for enhancing mass transport, increasing total reaction rate, and improving catalyst utilization. Finally, on the whole, from the viewpoint of reducing cost and improving material performance, hierarchical porous structures, especially gradient structures with the size of macropores gradually decreasing along the transport direction, are desirable for catalyst application.« less

Pore-scale study of effects of macroscopic pores and their distributions on reactive transport in hierarchical porous media

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

Chen, Li; Zhang, Ruiyuan; Min, Ting

For applications of reactive transport in porous media, optimal porous structures should possess both high surface area for reactive sites loading and low mass transport resistance. Hierarchical porous media with a combination of pores at different scales are designed for this purpose. In this paper, using the lattice Boltzmann method, pore-scale numerical studies are conducted to investigate diffusion-reaction processes in 2D hierarchical porous media generated by self-developed reconstruction scheme. Complex interactions between porous structures and reactive transport are revealed under different conditions. Simulation results show that adding macropores can greatly enhance the mass transport, but at the same time reducemore » the reactive surface, leading to complex change trend of the total reaction rate. Effects of gradient distribution of macropores within the porous medium are also investigated. It is found that a front-loose, back-tight (FLBT) hierarchical structure is desirable for enhancing mass transport, increasing total reaction rate, and improving catalyst utilization. Finally, on the whole, from the viewpoint of reducing cost and improving material performance, hierarchical porous structures, especially gradient structures with the size of macropores gradually decreasing along the transport direction, are desirable for catalyst application.« less

Validation of the Implementation Leadership Scale (ILS) with Supervisors' Self-Ratings.

PubMed

Torres, Elisa M; Ehrhart, Mark G; Beidas, Rinad S; Farahnak, Lauren R; Finn, Natalie K; Aarons, Gregory A

2018-01-01

Although often discussed, there is a lack of empirical research on the role of leadership in the management and delivery of health services. The implementation leadership scale (ILS) assesses the degree to which leaders are knowledgeable, proactive, perseverant, and supportive during evidence-based practice (EBP) implementation. The purpose of this study was to examine the psychometric properties of the ILS for leaders' self-ratings using a sample of mental health clinic supervisors (N = 119). Supervisors (i.e., leaders) completed surveys including self-ratings of their implementation leadership. Confirmatory factor analysis, reliability, and validity of the ILS were evaluated. The ILS factor structure was supported in the sample of supervisors. Results demonstrated internal consistency reliability and validity. Cronbach alpha's ranged from 0.92 to 0.96 for the ILS subscales and 0.95 for the ILS overall scale. The factor structure replication and reliability of the ILS in a sample of supervisors demonstrates its applicability with employees across organizational levels.

Characteristics of a gelled liquid hyprogen polyphenylene oxide (PPO) foam open-cell insulation system, phase 1

NASA Technical Reports Server (NTRS)

1973-01-01

A large scale gel production and storage facility and a small scale facility, the latter used for detailed visual examination of the gel/PPO foam interface, were developed. A subcontract was given to investigate techniques for the production of gelled liquid hydrogen, develop a process design for scale-up to a 1.89 cu m (500 gallon) gel production and storage facility, determine gel transfer characteristics, determine the solubility rate of gaseous helium in the gel, and investigate the gross gel/PPO foam interfacial phenomena. An inside-tank process for scaled-up production of gelled liquid hydrogen was selected. No detectable gel structure degradation occurred during repeated shearing. The viscosity of gelled liquid hydrogen at shear rates of 300/sec and higher is 2 to 5-fold greater than that of neat liquid hydrogen. No clogging problems were encountered during the transfer of gelled liquid hydrogen through warmed transfer lines. The solubility rate of helium in liquid hydrogen was significantly reduced by the presence of gel structure. The boil-off rates from gelled liquid hydrogen were reduced from 25 to 50 percent compared to those observed for the neat liquid hydrogen under compatible conditions. The polyphenylene oxide (PPO) foam insulation was found to be compatible with liquid ethane.

Factor structure of the Liebowitz Social Anxiety Scale for Children and Adolescents.

PubMed

Storch, Eric A; Masia-Warner, Carrie; Heidgerken, Amanda D; Fisher, Paige H; Pincus, Donna B; Liebowitz, Michael R

2006-01-01

The purpose of this study was to evaluate the factor structure of the Liebowitz Social Anxiety Scale for Children and Adolescents (LSAS-CA). The LSAS-CA was administered to 225 children and adolescents as a component of various clinical studies. In addition, other measures of psychopathology and impairment were administered to a subgroup of the sample. Confirmatory factor analyses of the social interaction and performance subscales for the anxiety and avoidance ratings yielded poor fit indices. Exploratory factor analysis supported a two-factor solution with a higher order factor for the LSAS-CA anxiety and avoidance ratings. Based on item content, factors were named Social and School Performance. The internal consistency of the factors was high and the convergent and divergent validity was supported vis-à-vis correlations with measures of depression and social anxiety, and clinician ratings of impairment and functioning. Findings suggest that the anxiety and avoidance ratings are best explained by a two-factor solution that measures social anxiety and avoidance in social and school performance interactions. This factor structure appears to be a reliable and valid framework for assessing childhood social phobia.

Effects of forcing time scale on the simulated turbulent flows and turbulent collision statistics of inertial particles

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

Rosa, B., E-mail: bogdan.rosa@imgw.pl; Parishani, H.; Department of Earth System Science, University of California, Irvine, California 92697-3100

2015-01-15

In this paper, we study systematically the effects of forcing time scale in the large-scale stochastic forcing scheme of Eswaran and Pope [“An examination of forcing in direct numerical simulations of turbulence,” Comput. Fluids 16, 257 (1988)] on the simulated flow structures and statistics of forced turbulence. Using direct numerical simulations, we find that the forcing time scale affects the flow dissipation rate and flow Reynolds number. Other flow statistics can be predicted using the altered flow dissipation rate and flow Reynolds number, except when the forcing time scale is made unrealistically large to yield a Taylor microscale flow Reynoldsmore » number of 30 and less. We then study the effects of forcing time scale on the kinematic collision statistics of inertial particles. We show that the radial distribution function and the radial relative velocity may depend on the forcing time scale when it becomes comparable to the eddy turnover time. This dependence, however, can be largely explained in terms of altered flow Reynolds number and the changing range of flow length scales present in the turbulent flow. We argue that removing this dependence is important when studying the Reynolds number dependence of the turbulent collision statistics. The results are also compared to those based on a deterministic forcing scheme to better understand the role of large-scale forcing, relative to that of the small-scale turbulence, on turbulent collision of inertial particles. To further elucidate the correlation between the altered flow structures and dynamics of inertial particles, a conditional analysis has been performed, showing that the regions of higher collision rate of inertial particles are well correlated with the regions of lower vorticity. Regions of higher concentration of pairs at contact are found to be highly correlated with the region of high energy dissipation rate.« less

Evaporation and transpiration from forests in Central Europe - relevance of patch-level studies for spatial scaling

NASA Astrophysics Data System (ADS)

Köstner, B.

Spatial scaling from patch to the landscape level requires knowledge on the effects of vegetation structure on maximum surface conductances and evaporation rates. The following paper summarizes results on atmospheric, edaphic, and structural controls on forest evaporation and transpiration observed in stands of Norway spruce (Picea abies), Scots pine (Pinus sylvestris) and European beech (Fagus sylvatica). Forest canopy transpiration (Ec) was determined by tree sapflow measurements scaled to the stand level. Estimates of understory transpiration and forest floor evaporation were derived from lysimeter and chamber measurements. Strong reduction of Ec due to soil drought was only observed at a Scots pine stand when soil water content dropped below 16% v/v. Although relative responses of Ec on atmospheric conditions were similar, daily maximum rates of could differ more than 100% between forest patches of different structure (1.5-3.0mmd-1 and 2.6-6.4mmd-1 for spruce and beech, respectively). A significant decrease of Ecmax per leaf area index with increasing stand age was found for monocultures of Norway spruce, whereas no pronounced changes in were observed for beech stands. It is concluded that structural effects on Ecmax can be specified and must be considered for spatial scaling from forest stands to landscapes. Hereby, in conjunction with LAI, age-related structural parameters are important for Norway spruce stands. Although compensating effects of tree canopy layers and understory on total evaporation of forests were observed, more information is needed to quantify structure-function relationships in forests of heterogenous structure.

Direct Numerical Simulation of a Temporally Evolving Incompressible Plane Wake: Effect of Initial Conditions on Evolution and Topology

NASA Technical Reports Server (NTRS)

Sondergaard, R.; Cantwell, B.; Mansour, N.

1997-01-01

Direct numerical simulations have been used to examine the effect of the initial disturbance field on the development of three-dimensionality and the transition to turbulence in the incompressible plane wake. The simulations were performed using a new numerical method for solving the time-dependent, three-dimensional, incompressible Navier-Stokes equations in flows with one infinite and two periodic directions. The method uses standard Fast Fourier Transforms and is applicable to cases where the vorticity field is compact in the infinite direction. Initial disturbances fields examined were combinations of two-dimensional waves and symmetric pairs of 60 deg oblique waves at the fundamental, subharmonic, and sub-subharmonic wavelengths. The results of these simulations indicate that the presence of 60 deg disturbances at the subharmonic streamwise wavelength results in the development of strong coherent three-dimensional structures. The resulting strong three-dimensional rate-of-strain triggers the growth of intense fine scale motions. Wakes initiated with 60 deg disturbances at the fundamental streamwise wavelength develop weak coherent streamwise structures, and do not develop significant fine scale motions, even at high Reynolds numbers. The wakes which develop strong three-dimensional structures exhibit growth rates on par with experimentally observed turbulent plane wakes. Wakes which develop only weak three-dimensional structures exhibit significantly lower late time growth rates. Preliminary studies of wakes initiated with an oblique fundamental and a two-dimensional subharmonic, which develop asymmetric coherent oblique structures at the subharmonic wavelength, indicate that significant fine scale motions only develop if the resulting oblique structures are above an angle of approximately 45 deg.

Implication of using different carbon sources for denitrification in wastewater treatments.

PubMed

Cherchi, Carla; Onnis-Hayden, Annalisa; El-Shawabkeh, Ibrahim; Gu, April Z

2009-08-01

Application of external carbon sources for denitrification becomes necessary for wastewater treatment plants that have to meet very stringent effluent nitrogen limits (e.g., 3 to 5 mgTN/L). In this study, we evaluated and compared three carbon sources--MicroC (Environmental Operating Solutions, Bourne, Massachusetts), methanol, and acetate-in terms of their denitrification rates and kinetics, effect on overall nitrogen removal performance, and microbial community structure of carbon-specific denitrifying enrichments. Denitrification rates and kinetics were determined with both acclimated and non-acclimated biomass, obtained from laboratory-scale sequencing batch reactor systems or full-scale plants. The results demonstrate the feasibility of the use of MicroC for denitrification processes, with maximum denitrification rates (k(dmax)) of 6.4 mgN/gVSSh and an observed yield of 0.36 mgVSS/mgCOD. Comparable maximum nitrate uptake rates were found with methanol, while acetate showed a maximum denitrification rate nearly twice as high as the others. The maximum growth rates measured at 20 degrees C for MicroC and methanol were 3.7 and 1.2 day(-1), respectively. The implications resulting from the differences in the denitrification rates and kinetics of different carbon sources on the full-scale nitrogen removal performance, under various configurations and operational conditions, were assessed using Biowin (EnviroSim Associates, Ltd., Flamborough, Ontario, Canada) simulations for both pre- and post-denitrification systems. Examination of microbial population structures using Automated Ribosomal Intergenic Spacer Analysis (ARISA) throughout the study period showed dynamic temporal changes and distinct microbial community structures of different carbon-specific denitrifying cultures. The ability of a specific carbon-acclimated denitrifying population to instantly use other carbon source also was investigated, and the chemical-structure-associated behavior patterns observed suggested that the complex biochemical pathways/enzymes involved in the denitrification process depended on the carbon sources used.

Seafloor Tectonic Fabric from Satellite Altimetry

NASA Astrophysics Data System (ADS)

Smith, Walter H. F.

Ocean floor structures with horizontal scales of 10 to a few hundred kilometers and vertical scales of 100 m or more generate sea surface gravity anomalies observable with satellite altimetry. Prior to 1990, altimeter data resolved only tectonic lineaments, some seamounts, and some aspects of mid-ocean ridge structure. New altimeter data available since mid-1995 resolve 10-km--scale structures over nearly all the world's oceans. These data are the basis of new global bathymetric maps and have been interpreted as exhibiting complexities in the sea floor spreading process including ridge jumps, propagating rifts, and variations in magma supply. This chapter reviews the satellite altimetry technique and its resolution of tectonic structures, gives examples of intriguing tectonic phenomena, and shows that structures as small as abyssal hills are partially resolved. A new result obtained here is that the amplitude of the fine-scale (10--80 km) roughness of old ocean floor is spreading-rate dependent in the same that it is at mid-ocean ridges, suggesting that fine-scale tectonic fabric is generated nearly exclusively by ridge-axis processes.

Emergence of scale-free close-knit friendship structure in online social networks.

PubMed

Cui, Ai-Xiang; Zhang, Zi-Ke; Tang, Ming; Hui, Pak Ming; Fu, Yan

2012-01-01

Although the structural properties of online social networks have attracted much attention, the properties of the close-knit friendship structures remain an important question. Here, we mainly focus on how these mesoscale structures are affected by the local and global structural properties. Analyzing the data of four large-scale online social networks reveals several common structural properties. It is found that not only the local structures given by the indegree, outdegree, and reciprocal degree distributions follow a similar scaling behavior, the mesoscale structures represented by the distributions of close-knit friendship structures also exhibit a similar scaling law. The degree correlation is very weak over a wide range of the degrees. We propose a simple directed network model that captures the observed properties. The model incorporates two mechanisms: reciprocation and preferential attachment. Through rate equation analysis of our model, the local-scale and mesoscale structural properties are derived. In the local-scale, the same scaling behavior of indegree and outdegree distributions stems from indegree and outdegree of nodes both growing as the same function of the introduction time, and the reciprocal degree distribution also shows the same power-law due to the linear relationship between the reciprocal degree and in/outdegree of nodes. In the mesoscale, the distributions of four closed triples representing close-knit friendship structures are found to exhibit identical power-laws, a behavior attributed to the negligible degree correlations. Intriguingly, all the power-law exponents of the distributions in the local-scale and mesoscale depend only on one global parameter, the mean in/outdegree, while both the mean in/outdegree and the reciprocity together determine the ratio of the reciprocal degree of a node to its in/outdegree. Structural properties of numerical simulated networks are analyzed and compared with each of the four real networks. This work helps understand the interplay between structures on different scales in online social networks.

Emergence of Scale-Free Close-Knit Friendship Structure in Online Social Networks

PubMed Central

Cui, Ai-Xiang; Zhang, Zi-Ke; Tang, Ming; Hui, Pak Ming; Fu, Yan

2012-01-01

Although the structural properties of online social networks have attracted much attention, the properties of the close-knit friendship structures remain an important question. Here, we mainly focus on how these mesoscale structures are affected by the local and global structural properties. Analyzing the data of four large-scale online social networks reveals several common structural properties. It is found that not only the local structures given by the indegree, outdegree, and reciprocal degree distributions follow a similar scaling behavior, the mesoscale structures represented by the distributions of close-knit friendship structures also exhibit a similar scaling law. The degree correlation is very weak over a wide range of the degrees. We propose a simple directed network model that captures the observed properties. The model incorporates two mechanisms: reciprocation and preferential attachment. Through rate equation analysis of our model, the local-scale and mesoscale structural properties are derived. In the local-scale, the same scaling behavior of indegree and outdegree distributions stems from indegree and outdegree of nodes both growing as the same function of the introduction time, and the reciprocal degree distribution also shows the same power-law due to the linear relationship between the reciprocal degree and in/outdegree of nodes. In the mesoscale, the distributions of four closed triples representing close-knit friendship structures are found to exhibit identical power-laws, a behavior attributed to the negligible degree correlations. Intriguingly, all the power-law exponents of the distributions in the local-scale and mesoscale depend only on one global parameter, the mean in/outdegree, while both the mean in/outdegree and the reciprocity together determine the ratio of the reciprocal degree of a node to its in/outdegree. Structural properties of numerical simulated networks are analyzed and compared with each of the four real networks. This work helps understand the interplay between structures on different scales in online social networks. PMID:23272067

Parent-rated externalizing behavior in preschoolers: the predictive utility of structured interviews, teacher reports, and classroom observations.

PubMed

Doctoroff, Greta L; Arnold, David H

2004-12-01

This study investigated multiple forms of home and school assessment as predictors of parent-rated behavior problems across a preschool year. Participants were a community sample of 79 preschool children, their parents, and their teachers. Parent ratings of behavior problems were obtained toward the beginning of the school year and approximately 6 months later. Behavior problems were also assessed early in the school year using parent structured interviews, teacher-rating scales, and classroom observations of problem and prosocial behavior. Consistent with hypotheses, each assessment method significantly predicted year-end parent ratings of behavior problems, even above initial ratings.

Scaling of number, size, and metabolic rate of cells with body size in mammals.

PubMed

Savage, Van M; Allen, Andrew P; Brown, James H; Gillooly, James F; Herman, Alexander B; Woodruff, William H; West, Geoffrey B

2007-03-13

The size and metabolic rate of cells affect processes from the molecular to the organismal level. We present a quantitative, theoretical framework for studying relationships among cell volume, cellular metabolic rate, body size, and whole-organism metabolic rate that helps reveal the feedback between these levels of organization. We use this framework to show that average cell volume and average cellular metabolic rate cannot both remain constant with changes in body size because of the well known body-size dependence of whole-organism metabolic rate. Based on empirical data compiled for 18 cell types in mammals, we find that many cell types, including erythrocytes, hepatocytes, fibroblasts, and epithelial cells, follow a strategy in which cellular metabolic rate is body size dependent and cell volume is body size invariant. We suggest that this scaling holds for all quickly dividing cells, and conversely, that slowly dividing cells are expected to follow a strategy in which cell volume is body size dependent and cellular metabolic rate is roughly invariant with body size. Data for slowly dividing neurons and adipocytes show that cell volume does indeed scale with body size. From these results, we argue that the particular strategy followed depends on the structural and functional properties of the cell type. We also discuss consequences of these two strategies for cell number and capillary densities. Our results and conceptual framework emphasize fundamental constraints that link the structure and function of cells to that of whole organisms.

Cosmological consistency tests of gravity theory and cosmic acceleration

NASA Astrophysics Data System (ADS)

Ishak-Boushaki, Mustapha B.

2017-01-01

Testing general relativity at cosmological scales and probing the cause of cosmic acceleration are among the important objectives targeted by incoming and future astronomical surveys and experiments. I present our recent results on consistency tests that can provide insights about the underlying gravity theory and cosmic acceleration using cosmological data sets. We use statistical measures, the rate of cosmic expansion, the growth rate of large scale structure, and the physical consistency of these probes with one another.

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

Zhdankin, Vladimir; Boldyrev, Stanislav; Perez, Jean Carlos

We investigate the intermittency of energy dissipation in magnetohydrodynamic (MHD) turbulence by identifying dissipative structures and measuring their characteristic scales. We find that the probability distribution of energy dissipation rates exhibits a power-law tail with an index very close to the critical value of –2.0, which indicates that structures of all intensities contribute equally to energy dissipation. We find that energy dissipation is uniformly spread among coherent structures with lengths and widths in the inertial range. At the same time, these structures have thicknesses deep within the dissipative regime. As the Reynolds number is increased, structures become thinner and moremore » numerous, while the energy dissipation continues to occur mainly in large-scale coherent structures. This implies that in the limit of high Reynolds number, energy dissipation occurs in thin, tightly packed current sheets which nevertheless span a continuum of scales up to the system size, exhibiting features of both coherent structures and nanoflares previously conjectured as a coronal heating mechanism.« less

Structural Representations in Knowledge Acquisition.

ERIC Educational Resources Information Center

Gonzalvo, Pilar; And Others

1994-01-01

Multidimensional scaling (MDS) and Pathfinder techniques for assessing changes in the structural representation of a knowledge domain were studied with relatedness ratings collected from 72 Spanish college students. Comparison of student and expert similarity measures indicate that MDS and graph theoretic approaches are valid techniques. (SLD)

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

Ren, Jingli; Chen, Cun; Wang, Gang

This study explores the temporal scaling behavior induced shear-branching structure in response to variant temperatures and strain rates during plastic deformation of Zr-based bulk metallic glass (BMG). The data analysis based on the compression tests suggests that there are two states of shear-branching structures: the fractal structure with a long-range order at an intermediate temperature of 223 K and a larger strain rate of 2.5 × 10 –2 s –1; the disordered structure dominated at other temperature and strain rate. It can be deduced from the percolation theory that the compressive ductility, ec, can reach the maximum value at themore » intermediate temperature. Furthermore, a dynamical model involving temperature is given for depicting the shear-sliding process, reflecting the plastic deformation has fractal structure at the temperature of 223 K and strain rate of 2.5 × 10 –2 s –1.« less

Design of a sensor network for structural health monitoring of a full-scale composite horizontal tail

NASA Astrophysics Data System (ADS)

Gao, Dongyue; Wang, Yishou; Wu, Zhanjun; Rahim, Gorgin; Bai, Shengbao

2014-05-01

The detection capability of a given structural health monitoring (SHM) system strongly depends on its sensor network placement. In order to minimize the number of sensors while maximizing the detection capability, optimal design of the PZT sensor network placement is necessary for structural health monitoring (SHM) of a full-scale composite horizontal tail. In this study, the sensor network optimization was simplified as a problem of determining the sensor array placement between stiffeners to achieve the desired the coverage rate. First, an analysis of the structural layout and load distribution of a composite horizontal tail was performed. The constraint conditions of the optimal design were presented. Then, the SHM algorithm of the composite horizontal tail under static load was proposed. Based on the given SHM algorithm, a sensor network was designed for the full-scale composite horizontal tail structure. Effective profiles of cross-stiffener paths (CRPs) and uncross-stiffener paths (URPs) were estimated by a Lamb wave propagation experiment in a multi-stiffener composite specimen. Based on the coverage rate and the redundancy requirements, a seven-sensor array-network was chosen as the optimal sensor network for each airfoil. Finally, a preliminary SHM experiment was performed on a typical composite aircraft structure component. The reliability of the SHM result for a composite horizontal tail structure under static load was validated. In the result, the red zone represented the delamination damage. The detection capability of the optimized sensor network was verified by SHM of a full-scale composite horizontal tail; all the diagnosis results were obtained in two minutes. The result showed that all the damage in the monitoring region was covered by the sensor network.

Extending Validity Evidence for Multidimensional Measures of Coaching Competency

ERIC Educational Resources Information Center

Myers, Nicholas D.; Wolfe, Edward W.; Maier, Kimberly S.; Feltz, Deborah L.; Reckase, Mark D.

2006-01-01

This study extended validity evidence for multidimensional measures of coaching competency derived from the Coaching Competency Scale (CCS; Myers, Feltz, Maier, Wolfe, & Reckase, 2006) by examining use of the original rating scale structure and testing how measures related to satisfaction with the head coach within teams and between teams.…

Derivation and evaluation of a labeled hedonic scale.

PubMed

Lim, Juyun; Wood, Alison; Green, Barry G

2009-11-01

The objective of this study was to develop a semantically labeled hedonic scale (LHS) that would yield ratio-level data on the magnitude of liking/disliking of sensation equivalent to that produced by magnitude estimation (ME). The LHS was constructed by having 49 subjects who were trained in ME rate the semantic magnitudes of 10 common hedonic descriptors within a broad context of imagined hedonic experiences that included tastes and flavors. The resulting bipolar scale is statistically symmetrical around neutral and has a unique semantic structure. The LHS was evaluated quantitatively by comparing it with ME and the 9-point hedonic scale. The LHS yielded nearly identical ratings to those obtained using ME, which implies that its semantic labels are valid and that it produces ratio-level data equivalent to ME. Analyses of variance conducted on the hedonic ratings from the LHS and the 9-point scale gave similar results, but the LHS showed much greater resistance to ceiling effects and yielded normally distributed data, whereas the 9-point scale did not. These results indicate that the LHS has significant semantic, quantitative, and statistical advantages over the 9-point hedonic scale.

Thermal/structural modeling of a large scale in situ overtest experiment for defense high level waste at the Waste Isolation Pilot Plant Facility

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

Morgan, H.S.; Stone, C.M.; Krieg, R.D.

Several large scale in situ experiments in bedded salt formations are currently underway at the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico, USA. In these experiments, the thermal and creep responses of salt around several different underground room configurations are being measured. Data from the tests are to be compared to thermal and structural responses predicted in pretest reference calculations. The purpose of these comparisons is to evaluate computational models developed from laboratory data prior to fielding of the in situ experiments. In this paper, the computational models used in the pretest reference calculation for one of themore » large scale tests, The Overtest for Defense High Level Waste, are described; and the pretest computed thermal and structural responses are compared to early data from the experiment. The comparisons indicate that computed and measured temperatures for the test agree to within ten percent but that measured deformation rates are between two and three times greater than corresponsing computed rates. 10 figs., 3 tabs.« less

Spanish Validation of the Care Evaluation Scale for Measuring the Quality of Structure and Process of Palliative Care From the Family Perspective.

PubMed

Benitez-Rosario, Miguel Angel; Caceres-Miranda, Raquel; Aguirre-Jaime, Armando

2016-03-01

A reliable and valid measure of the structure and process of end-of-life care is important for improving the outcomes of care. This study evaluated the validity and reliability of the Spanish adaptation of a satisfaction tool of the Care Evaluation Scale (CES), which was developed in Japan to evaluate palliative care structure and process from the perspective of family members. Standard forward-backward translation and a pilot test were conducted. A multicenter survey was conducted with the relatives of patients admitted to palliative care units for symptom control. The dimensional structure was assessed using confirmatory factor analyses. Concurrent and discriminant validity were tested by correlation with the SERQVHOS, a Spanish hospital care satisfaction scale and with an 11-point rating scale on satisfaction with care. The reliability of the CES was tested by Cronbach α and by test-retest correlation. A total of 284 primary caregivers completed the CES, with low missing response rates. The results of the factor analysis suggested a six-factor solution explaining 69% of the total variance. The CES moderately correlated with the SERQVHOS and with the overall satisfaction scale (intraclass correlation coefficients of 0.66 and 0.44, respectively; P = 0.001). Cronbach α was 0.90 overall and ranged from 0.85 to 0.89 for subdomains. Intraclass correlation coefficient was 0.88 (P = 0.001) for test-retest analysis. The Spanish CES was found to be a reliable and valid measure of the satisfaction with end-of-life care structure and process from family members' perspectives. Copyright © 2016 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Phenomenological features of dreams: Results from dream log studies using the Subjective Experiences Rating Scale (SERS).

PubMed

Kahan, Tracey L; Claudatos, Stephanie

2016-04-01

Self-ratings of dream experiences were obtained from 144 college women for 788 dreams, using the Subjective Experiences Rating Scale (SERS). Consistent with past studies, dreams were characterized by a greater prevalence of vision, audition, and movement than smell, touch, or taste, by both positive and negative emotion, and by a range of cognitive processes. A Principal Components Analysis of SERS ratings revealed ten subscales: four sensory, three affective, one cognitive, and two structural (events/actions, locations). Correlations (Pearson r) among subscale means showed a stronger relationship among the process-oriented features (sensory, cognitive, affective) than between the process-oriented and content-centered (structural) features--a pattern predicted from past research (e.g., Bulkeley & Kahan, 2008). Notably, cognition and positive emotion were associated with a greater number of other phenomenal features than was negative emotion; these findings are consistent with studies of the qualitative features of waking autobiographical memory (e.g., Fredrickson, 2001). Copyright © 2016 Elsevier Inc. All rights reserved.

Structural modeling of aircraft tires

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.; Lackey, J. I.; Nybakken, G. H.

1973-01-01

A theoretical and experimental investigation of the feasibility of determining the mechanical properties of aircraft tires from small-scale model tires was accomplished. The theoretical results indicate that the macroscopic static and dynamic mechanical properties of aircraft tires can be accurately determined from the scale model tires although the microscopic and thermal properties of aircraft tires can not. The experimental investigation was conducted on a scale model of a 40 x 12, 14 ply rated, type 7 aircraft tire with a scaling factor of 8.65. The experimental results indicate that the scale model tire exhibited the same static mechanical properties as the prototype tire when compared on a dimensionless basis. The structural modeling concept discussed in this report is believed to be exact for mechanical properties of aircraft tires under static, rolling, and transient conditions.

Identifying correlates of self-stigma in adults who stutter: Further establishing the construct validity of the Self-Stigma of Stuttering Scale (4S).

PubMed

Boyle, Michael P

2015-03-01

This study was set up to further establish the construct validity of the Self-Stigma of Stuttering Scale (4S) by demonstrating its associations with other established scales and replicating its original factor structure and reliability estimates. Web surveys were completed by 354 adults who stutter recruited from Board Certified Specialists in Fluency Disorders, and adult chapters of the National Stuttering Association. Participants completed a series of psychometrically validated scales measuring self-stigma, hope, empowerment, quality of life, social support, anxiety, depression, and self-rated speech disruption. Higher subscale and total stigma scores on the 4S were associated with significantly lower levels of hope, empowerment, quality of life, and social support, and significantly higher levels of anxiety, depression, and self-rated speech disruption. The original factor structure of the 4S was replicated, and reliability estimates of the subscales ranged from adequate to excellent. The findings of this study support the construct validity of the 4S and its use by clinicians and researchers intending to measure the construct of self-stigma in adults who stutter. Readers should be able to: (a) distinguish between the various components of self-stigma; (b) describe how the various components of the self-stigma model relate to hope, empowerment, quality of life, and social support, self-rated speech disruption, anxiety, and depression; (c) summarize the psychometric properties of the Self-Stigma of Stuttering Scale (4S) in terms of reliability, factor structure, and construct validity; (d) discuss how the 4S could be used in research and clinical practice. Copyright © 2015 Elsevier Inc. All rights reserved.

Specificity of Structural Assessment of Knowledge

ERIC Educational Resources Information Center

Trumpower, David L.; Sharara, Harold; Goldsmith, Timothy E.

2010-01-01

This study examines the specificity of information provided by structural assessment of knowledge (SAK). SAK is a technique which uses the Pathfinder scaling algorithm to transform ratings of concept relatedness into network representations (PFnets) of individuals' knowledge. Inferences about individuals' overall domain knowledge based on the…

Multi-scale, Hierarchically Nested Young Stellar Structures in LEGUS Galaxies

NASA Astrophysics Data System (ADS)

Thilker, David A.; LEGUS Team

2017-01-01

The study of star formation in galaxies has predominantly been limited to either young stellar clusters and HII regions, or much larger kpc-scale morphological features such as spiral arms. The HST Legacy ExtraGalactic UV Survey (LEGUS) provides a rare opportunity to link these scales in a diverse sample of nearby galaxies and obtain a more comprehensive understanding of their co-evolution for comparison against model predictions. We have utilized LEGUS stellar photometry to identify young, resolved stellar populations belonging to several age bins and then defined nested hierarchical structures as traced by these subsamples of stars. Analagous hierarchical structures were also defined using LEGUS catalogs of unresolved young stellar clusters. We will present our emerging results concerning the physical properties (e.g. area, star counts, stellar mass, star formation rate, ISM characteristics), occupancy statistics (e.g. clusters per substructure versus age and scale, parent/child demographics) and relation to overall galaxy morphology/mass for these building blocks of hierarchical star-forming structure.

Modelling galaxy clustering on small scales to tighten constraints on dark energy and modified gravity

NASA Astrophysics Data System (ADS)

Wang, Yun

2017-01-01

We present a new approach to measuring cosmic expansion history and growth rate of large-scale structure using the anisotropic two-dimensional galaxy correlation function (2DCF) measured from data; it makes use of the empirical modelling of small-scale galaxy clustering derived from numerical simulations by Zheng et al. We validate this method using mock catalogues, before applying it to the analysis of the CMASS sample from the Sloan Digital Sky Survey Data Release 10 of the Baryon Oscillation Spectroscopic Survey. We find that this method enables accurate and precise measurements of cosmic expansion history and growth rate of large-scale structure. Modelling the 2DCF fully including non-linear effects and redshift space distortions in the scale range of 16-144 h-1 Mpc, we find H(0.57)rs(zd)/c = 0.0459 ± 0.0006, DA(0.57)/rs(zd) = 9.011 ± 0.073, and fg(0.57)σ8(0.57) = 0.476 ± 0.050, which correspond to precisions of 1.3 per cent, 0.8 per cent, and 10.5 per cent, respectively. We have defined rs(zd) to be the sound horizon at the drag epoch computed using a simple integral, fg(z) as the growth rate at redshift z, and σ8(z) as the matter power spectrum normalization on 8 h-1 Mpc scale at z. We find that neglecting the small-scale information significantly weakens the constraints on H(z) and DA(z), and leads to a biased estimate of fg(z). Our results indicate that we can significantly tighten constraints on dark energy and modified gravity by reliably modelling small-scale galaxy clustering.

Empirically based assessment and taxonomy of psychopathology for ages 1½-90+ years: Developmental, multi-informant, and multicultural findings.

PubMed

Achenbach, Thomas M; Ivanova, Masha Y; Rescorla, Leslie A

2017-11-01

Originating in the 1960s, the Achenbach System of Empirically Based Assessment (ASEBA) comprises a family of instruments for assessing problems and strengths for ages 1½-90+ years. To provide an overview of the ASEBA, related research, and future directions for empirically based assessment and taxonomy. Standardized, multi-informant ratings of transdiagnostic dimensions of behavioral, emotional, social, and thought problems are hierarchically scored on narrow-spectrum syndrome scales, broad-spectrum internalizing and externalizing scales, and a total problems (general psychopathology) scale. DSM-oriented and strengths scales are also scored. The instruments and scales have been iteratively developed from assessments of clinical and population samples of hundreds of thousands of individuals. Items, instruments, scales, and norms are tailored to different kinds of informants for ages 1½-5, 6-18, 18-59, and 60-90+ years. To take account of differences between informants' ratings, parallel instruments are completed by parents, teachers, youths, adult probands, and adult collaterals. Syndromes and Internalizing/Externalizing scales derived from factor analyses of each instrument capture variations in patterns of problems that reflect different informants' perspectives. Confirmatory factor analyses have supported the syndrome structures in dozens of societies. Software displays scale scores in relation to user-selected multicultural norms for the age and gender of the person being assessed, according to ratings by each type of informant. Multicultural norms are derived from population samples in 57 societies on every inhabited continent. Ongoing and future research includes multicultural assessment of elders; advancing transdiagnostic progress and outcomes assessment; and testing higher order structures of psychopathology. Copyright © 2017 Elsevier Inc. All rights reserved.

Cross-cultural validation of the Child Abuse Potential Inventory in Greece: a preliminary study.

PubMed

Diareme, S; Tsiantis, J; Tsitoura, S

1997-11-01

The aim of this study was first, to provide preliminary findings on the reliability and validity of a Greek translation of the CAP Inventory (Milner, 1986), and second, to examine whether there were any differences between Greek and American scores in the CAP Inventory. A convenience sample of 320 Greek parents was recruited from the outpatient unit of a large Children's Hospital in Athens, Greece. Greek scores were compared with American scores taken from the test manual. Internal consistency reliability was high for the Abuse scale (.91), two factor scales (Distress = .93 and Rigidity = .86) and one Validity scale (Inconsistency = .80). The Greek version of the Abuse scale had a similar factorial structure with the American version. Also, 78.1% of Greek parents were classified correctly as nonabusive by the Abuse scale. This rate was increased to 88.6% when invalid questionnaires were excluded from the sample. Comparisons between Greek and American mean scale scores indicated that Greek scores were significantly higher than American scores in all but one scale. Greeks had significantly lower scores than Americans in the Problems with Child and Self scale. Current findings including the high reliability, relatively high correct classification rates and factorial structure of the Greek Abuse scale are promising and support the idea of continuation of research for the development and validation of the Greek CAP Inventory. The difference between Greek and American scores in particular indicates the need for adjustment of cut off scores in the Greek scale.

Dynamic structural disorder in supported nanoscale catalysts

NASA Astrophysics Data System (ADS)

Rehr, J. J.; Vila, F. D.

2014-04-01

We investigate the origin and physical effects of "dynamic structural disorder" (DSD) in supported nano-scale catalysts. DSD refers to the intrinsic fluctuating, inhomogeneous structure of such nano-scale systems. In contrast to bulk materials, nano-scale systems exhibit substantial fluctuations in structure, charge, temperature, and other quantities, as well as large surface effects. The DSD is driven largely by the stochastic librational motion of the center of mass and fluxional bonding at the nanoparticle surface due to thermal coupling with the substrate. Our approach for calculating and understanding DSD is based on a combination of real-time density functional theory/molecular dynamics simulations, transient coupled-oscillator models, and statistical mechanics. This approach treats thermal and dynamic effects over multiple time-scales, and includes bond-stretching and -bending vibrations, and transient tethering to the substrate at longer ps time-scales. Potential effects on the catalytic properties of these clusters are briefly explored. Model calculations of molecule-cluster interactions and molecular dissociation reaction paths are presented in which the reactant molecules are adsorbed on the surface of dynamically sampled clusters. This model suggests that DSD can affect both the prefactors and distribution of energy barriers in reaction rates, and thus can significantly affect catalytic activity at the nano-scale.

Advances in the Surface Renewal Flux Measurement Method

NASA Astrophysics Data System (ADS)

Shapland, T. M.; McElrone, A.; Paw U, K. T.; Snyder, R. L.

2011-12-01

The measurement of ecosystem-scale energy and mass fluxes between the planetary surface and the atmosphere is crucial for understanding geophysical processes. Surface renewal is a flux measurement technique based on analyzing the turbulent coherent structures that interact with the surface. It is a less expensive technique because it does not require fast-response velocity measurements, but only a fast-response scalar measurement. It is therefore also a useful tool for the study of the global cycling of trace gases. Currently, surface renewal requires calibration against another flux measurement technique, such as eddy covariance, to account for the linear bias of its measurements. We present two advances in the surface renewal theory and methodology that bring the technique closer to becoming a fully independent flux measurement method. The first advance develops the theory of turbulent coherent structure transport associated with the different scales of coherent structures. A novel method was developed for identifying the scalar change rate within structures at different scales. Our results suggest that for canopies less than one meter in height, the second smallest coherent structure scale dominates the energy and mass flux process. Using the method for resolving the scalar exchange rate of the second smallest coherent structure scale, calibration is unnecessary for surface renewal measurements over short canopies. This study forms the foundation for analysis over more complex surfaces. The second advance is a sensor frequency response correction for measuring the sensible heat flux via surface renewal. Inexpensive fine-wire thermocouples are frequently used to record high frequency temperature data in the surface renewal technique. The sensible heat flux is used in conjunction with net radiation and ground heat flux measurements to determine the latent heat flux as the energy balance residual. The robust thermocouples commonly used in field experiments underestimate the sensible heat flux, yielding results that are less than 50% of the sensible heat flux measured with finer sensors. We present the methodology for correcting the thermocouple signal to avoid underestimating the heat flux at both the smallest and the second smallest coherent structure scale.

Interpersonal Development, Stability, and Change in Early Adulthood

PubMed Central

Wright, Aidan G. C.; Pincus, Aaron L.; Lenzenweger, Mark F.

2011-01-01

Objective This goal of this research was to explore the development of the interpersonal system mapped by the interpersonal circumplex in early adulthood (Ages 18-22). Method This study uses the Longitudinal Study of Personality Disorders sample (N = 250; 53% Female). Participants completed the Revised Interpersonal Adjective Scales (Wiggins, Trapnell, & Phillips, 1988) in their freshman, sophomore, and senior years of college. Estimates of structural, rank-order, mean, individual, and ipsative stability were calculated for the broad interpersonal dimensions of Dominance and Affiliation, and also the lower-order octant scales. Additionally, the interpersonal profile parameters of differentiation and prototypicality were calculated at each wave and explored longitudinally, and also used as predictors of interpersonal stability. Results We found excellent structural and high rank-order and ipsative stability in the interpersonal scales over this time period. Mean increases on the Affiliation axis, but not on the Dominance axis, were found to mask differential rates of change among the octant scales, along with significant individual variation in the rates of change. Interpersonal differentiation and prototypicality were related to higher stability in overall interpersonal style. Conclusions Results point to evidence of both stability and nuanced change, illuminating some of the features of the structural variables that can be derived from interpersonal circumplex profiles. PMID:22224462

Development and validation of the Alcohol Myopia Scale.

PubMed

Lac, Andrew; Berger, Dale E

2013-09-01

Alcohol myopia theory conceptualizes the ability of alcohol to narrow attention and how this demand on mental resources produces the impairments of self-inflation, relief, and excess. The current research was designed to develop and validate a scale based on this framework. People who were alcohol users rated items representing myopic experiences arising from drinking episodes in the past month. In Study 1 (N = 260), the preliminary 3-factor structure was supported by exploratory factor analysis. In Study 2 (N = 289), the 3-factor structure was substantiated with confirmatory factor analysis, and it was superior in fit to an empirically indefensible 1-factor structure. The final 14-item scale was evaluated with internal consistency reliability, discriminant validity, convergent validity, criterion validity, and incremental validity. The alcohol myopia scale (AMS) illuminates conceptual underpinnings of this theory and yields insights for understanding the tunnel vision that arises from intoxication.

Flow turbulence topology in regular porous media: From macroscopic to microscopic scale with direct numerical simulation

NASA Astrophysics Data System (ADS)

Chu, Xu; Weigand, Bernhard; Vaikuntanathan, Visakh

2018-06-01

Microscopic analysis of turbulence topology in a regular porous medium is presented with a series of direct numerical simulation. The regular porous media are comprised of square cylinders in a staggered array. Triply periodic boundary conditions enable efficient investigations in a representative elementary volume. Three flow patterns—channel with sudden contraction, impinging surface, and wake—are observed and studied quantitatively in contrast to the qualitative experimental studies reported in the literature. Among these, shear layers in the channel show the highest turbulence intensity due to a favorable pressure gradient and shed due to an adverse pressure gradient downstream. The turbulent energy budget indicates a strong production rate after the flow contraction and a strong dissipation on both shear and impinging walls. Energy spectra and pre-multiplied spectra detect large scale energetic structures in the shear layer and a breakup of scales in the impinging layer. However, these large scale structures break into less energetic small structures at high Reynolds number conditions. This suggests an absence of coherent structures in densely packed porous media at high Reynolds numbers. Anisotropy analysis with a barycentric map shows that the turbulence in porous media is highly isotropic in the macro-scale, which is not the case in the micro-scale. In the end, proper orthogonal decomposition is employed to distinguish the energy-conserving structures. The results support the pore scale prevalence hypothesis. However, energetic coherent structures are observed in the case with sparsely packed porous media.

Confirmation of the Factor Structure and Measurement Invariance of the Children's Scale of Hostility and Aggression: Reactive/Proactive in Clinic-Referred Children With and Without Autism Spectrum Disorder.

PubMed

Farmer, Cristan A; Kaat, Aaron J; Mazurek, Micah O; Lainhart, Janet E; DeWitt, Mary Beth; Cook, Edwin H; Butter, Eric M; Aman, Michael G

2016-02-01

The measurement of aggression in its different forms (e.g., physical and verbal) and functions (e.g., impulsive and instrumental) is given little attention in subjects with developmental disabilities (DD). In this study, we confirm the factor structure of the Children's Scale for Hostility and Aggression: Reactive/Proactive (C-SHARP) and demonstrate measurement invariance (consistent performance across clinical groups) between clinic-referred groups with and without autism spectrum disorder (ASD). We also provide evidence of the construct validity of the C-SHARP. Caregivers provided C-SHARP, Child Behavior Checklist (CBCL), and Proactive/Reactive Rating Scale (PRRS) ratings for 644 children, adolescents, and young adults 2-21 years of age. Five types of measurement invariance were evaluated within a confirmatory factor analytic framework. Associations among the C-SHARP, CBCL, and PRRS were explored. The factor structure of the C-SHARP had a good fit to the data from both groups, and strict measurement invariance between ASD and non-ASD groups was demonstrated (i.e., equivalent structure, factor loadings, item intercepts and residuals, and latent variance/covariance between groups). The C-SHARP Problem Scale was more strongly associated with CBCL Externalizing than with CBCL Internalizing, supporting its construct validity. Subjects classified with the PRRS as both Reactive and Proactive had significantly higher C-SHARP Proactive Scores than those classified as Reactive only, who were rated significantly higher than those classified by the PRRS as Neither Reactive nor Proactive. A similar pattern was observed for the C-SHARP Reactive Score. This study provided evidence of the validity of the C-SHARP through confirmation of its factor structure and its relationship with more established scales. The demonstration of measurement invariance demonstrates that differences in C-SHARP factor scores were the result of differences in the construct rather than to error or unmeasured/nuisance variables. These data suggest that the C-SHARP is useful for quantifying subtypes of aggressive behavior in children, adolescents, and young adults with DD.

Evaluation of engineering plastic for rollover protective structure (ROPS) mounting.

PubMed

Comer, R S; Ayers, P D; Liu, J

2007-04-01

Agriculture has one of the highest fatality rates of any industry in America. Tractor rollovers are a significant contributor to the high death rate. Rollover protective structures (ROPS) have helped lower these high fatality rates on full-size tractors. However, a large number of older tractors still do not use ROPS due to the difficulty of designing and creating a mounting structure. To help reduce this difficulty, engineering plastics were evaluated for use in a ROPS mounting structure on older tractors. The use of engineering plastics around axle housings could provide a uniform mounting configuration as well as lower costs for aftermarket ROPS. Various plastics were examined through shear testing, scale model testing, and compressive strength testing. Once a material was chosen based upon strength and cost, full-scale testing of the plastic's strength on axle housings was conducted. Finally, a mounting structure was tested in static ROPS tests, and field upset tests were performed in accordance with SAE Standard J2194. Initial tests revealed that the ROPS mounting structure and axle housing combination had higher torsional strength with less twisting than the axle housing alone. An engineering plastic ROPS mounting structure was easily successful in withstanding the forces applied during the static longitudinal and lateral ROPS tests. Field upset testing revealed that the mounting structure could withstand the impact loads seen during actual upsets without a failure. During both static testing and field upset testing, no permanent twisting of the mounting structure was found. Engineering plastic could therefore be a viable option for a universal ROPS mounting structure for older tractors.

School Social Behavior Scales: an adaptation study of the Portuguese version of the social competence scale from SSBS-2.

PubMed

Raimundo, Raquel; Carapito, Elsa; Pereira, Ana Isabel; Marques Pinto, Alexandra; Lima, Maria Luísa; Ribeiro, Maria Teresa

2012-11-01

This study analyses the psychometric proprieties of a Portuguese version of the social competence scale from the School Social Behavior Scales (SSBS-2, Merrell, 2002). It is a rating instrument of children and adolescents behavior, to be used by teachers and other school personnel. This scale includes 3 subscales: self-management/compliance, peer relations and academic behavior. In our first sample, 175 teachers rated 344 students from grade 1 through 12. On the second sample 13 teachers rated 251 3rd and 4th grades students. The results from the Portuguese adaptation support the multidimensional structure of the social competence scale from the SSBS-2, although an alternative model demonstrated a better fit to the data than the model originally proposed by the author. The scale showed good internal consistency and good intercorrelations between subscales, as well as between subscales and the total scale. The final model was well replicated in the second sample. These results encourage us to pursue the SSBS-2 Portuguese adaptation, in order to provide a useful and validated instrument for the assessment of social competence and for educational interventions.

Three-Dimensional CdS/Au Butterfly Wing Scales with Hierarchical Rib Structures for Plasmon-Enhanced Photocatalytic Hydrogen Production.

PubMed

Fang, Jing; Gu, Jiajun; Liu, Qinglei; Zhang, Wang; Su, Huilan; Zhang, Di

2018-06-13

Localized surface plasmon resonance (LSPR) of plasmonic metals (e.g., Au) can help semiconductors improve their photocatalytic hydrogen (H 2 ) production performance. However, an artificial synthesis of hierarchical plasmonic structures down to nanoscales is usually difficult. Here, we adopt the butterfly wing scales from Morpho didius to fabricate three-dimensional (3D) CdS/Au butterfly wing scales for plasmonic photocatalysis. The as-prepared materials well-inherit the pristine hierarchical biostructures. The 3D CdS/Au butterfly wing scales exhibit a high H 2 production rate (221.8 μmol·h -1 within 420-780 nm), showing a 241-fold increase over the CdS butterfly wing scales. This is attributed to the effective potentiation effect of LSPR introduced by multilayer metallic rib structures and a good interface bonding state between Au and CdS nanoparticles. Thus, our study provides a relatively simple method to learn from nature and inspiration for preparing highly efficient plasmonic photocatalysts.

Advances in Structural Integrity Analysis Methods for Aging Metallic Airframe Structures with Local Damage

NASA Technical Reports Server (NTRS)

Starnes, James H., Jr.; Newman, James C., Jr.; Harris, Charles E.; Piascik, Robert S.; Young, Richard D.; Rose, Cheryl A.

2003-01-01

Analysis methodologies for predicting fatigue-crack growth from rivet holes in panels subjected to cyclic loads and for predicting the residual strength of aluminum fuselage structures with cracks and subjected to combined internal pressure and mechanical loads are described. The fatigue-crack growth analysis methodology is based on small-crack theory and a plasticity induced crack-closure model, and the effect of a corrosive environment on crack-growth rate is included. The residual strength analysis methodology is based on the critical crack-tip-opening-angle fracture criterion that characterizes the fracture behavior of a material of interest, and a geometric and material nonlinear finite element shell analysis code that performs the structural analysis of the fuselage structure of interest. The methodologies have been verified experimentally for structures ranging from laboratory coupons to full-scale structural components. Analytical and experimental results based on these methodologies are described and compared for laboratory coupons and flat panels, small-scale pressurized shells, and full-scale curved stiffened panels. The residual strength analysis methodology is sufficiently general to include the effects of multiple-site damage on structural behavior.

Protein docking by the interface structure similarity: how much structure is needed?

PubMed

Sinha, Rohita; Kundrotas, Petras J; Vakser, Ilya A

2012-01-01

The increasing availability of co-crystallized protein-protein complexes provides an opportunity to use template-based modeling for protein-protein docking. Structure alignment techniques are useful in detection of remote target-template similarities. The size of the structure involved in the alignment is important for the success in modeling. This paper describes a systematic large-scale study to find the optimal definition/size of the interfaces for the structure alignment-based docking applications. The results showed that structural areas corresponding to the cutoff values <12 Å across the interface inadequately represent structural details of the interfaces. With the increase of the cutoff beyond 12 Å, the success rate for the benchmark set of 99 protein complexes, did not increase significantly for higher accuracy models, and decreased for lower-accuracy models. The 12 Å cutoff was optimal in our interface alignment-based docking, and a likely best choice for the large-scale (e.g., on the scale of the entire genome) applications to protein interaction networks. The results provide guidelines for the docking approaches, including high-throughput applications to modeled structures.

Mississippi Scale for Combat-Related Posttraumatic Stress Disorder: Three Studies in Reliabilty and Validity.

ERIC Educational Resources Information Center

Keane, Terence M.; And Others

1988-01-01

Explored the psychometric properties of the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder to assess its internal consistency and factor structure. Administered the test to Vietnam veterans seeking help at Veteran Centers. Demonstrated high test-retest reliability, sensitivity of .93, specificity .89, and overall hit rate .90…

Brief Report: A Scale for Rating Conversational Impairment in Autism Spectrum Disorder

ERIC Educational Resources Information Center

de Villiers, Jessica; Fine, Jonathan; Ginsberg, Gary; Vaccarella, Liezanne; Szatmari, Peter

2007-01-01

There are few well-standardized measures of conversational breakdown in Autism Spectrum Disorders (ASD). The study's objective was to develop a scale for measuring pragmatic impairments in conversations of individuals with ASD. We analyzed 46 semi-structured conversations of children and adolescents with high-functioning ASD using a functional…

Elementary Pre-Service Teachers' Mathematics Anxiety and Mathematics Teaching Anxiety

ERIC Educational Resources Information Center

Haciomeroglu, Guney

2014-01-01

The present study examined the structure of elementary pre-service teachers' mathematics anxiety and mathematics teaching anxiety by asking whether the two systems of anxiety are related. The Turkish Mathematics Anxiety Rating Scale Short Version and the Mathematics Teaching Anxiety Scale were administered to 260 elementary pre-service teachers.…

Coarse-graining and hybrid methods for efficient simulation of stochastic multi-scale models of tumour growth.

PubMed

de la Cruz, Roberto; Guerrero, Pilar; Calvo, Juan; Alarcón, Tomás

2017-12-01

The development of hybrid methodologies is of current interest in both multi-scale modelling and stochastic reaction-diffusion systems regarding their applications to biology. We formulate a hybrid method for stochastic multi-scale models of cells populations that extends the remit of existing hybrid methods for reaction-diffusion systems. Such method is developed for a stochastic multi-scale model of tumour growth, i.e. population-dynamical models which account for the effects of intrinsic noise affecting both the number of cells and the intracellular dynamics. In order to formulate this method, we develop a coarse-grained approximation for both the full stochastic model and its mean-field limit. Such approximation involves averaging out the age-structure (which accounts for the multi-scale nature of the model) by assuming that the age distribution of the population settles onto equilibrium very fast. We then couple the coarse-grained mean-field model to the full stochastic multi-scale model. By doing so, within the mean-field region, we are neglecting noise in both cell numbers (population) and their birth rates (structure). This implies that, in addition to the issues that arise in stochastic-reaction diffusion systems, we need to account for the age-structure of the population when attempting to couple both descriptions. We exploit our coarse-graining model so that, within the mean-field region, the age-distribution is in equilibrium and we know its explicit form. This allows us to couple both domains consistently, as upon transference of cells from the mean-field to the stochastic region, we sample the equilibrium age distribution. Furthermore, our method allows us to investigate the effects of intracellular noise, i.e. fluctuations of the birth rate, on collective properties such as travelling wave velocity. We show that the combination of population and birth-rate noise gives rise to large fluctuations of the birth rate in the region at the leading edge of front, which cannot be accounted for by the coarse-grained model. Such fluctuations have non-trivial effects on the wave velocity. Beyond the development of a new hybrid method, we thus conclude that birth-rate fluctuations are central to a quantitatively accurate description of invasive phenomena such as tumour growth.

Coarse-graining and hybrid methods for efficient simulation of stochastic multi-scale models of tumour growth

NASA Astrophysics Data System (ADS)

de la Cruz, Roberto; Guerrero, Pilar; Calvo, Juan; Alarcón, Tomás

2017-12-01

The development of hybrid methodologies is of current interest in both multi-scale modelling and stochastic reaction-diffusion systems regarding their applications to biology. We formulate a hybrid method for stochastic multi-scale models of cells populations that extends the remit of existing hybrid methods for reaction-diffusion systems. Such method is developed for a stochastic multi-scale model of tumour growth, i.e. population-dynamical models which account for the effects of intrinsic noise affecting both the number of cells and the intracellular dynamics. In order to formulate this method, we develop a coarse-grained approximation for both the full stochastic model and its mean-field limit. Such approximation involves averaging out the age-structure (which accounts for the multi-scale nature of the model) by assuming that the age distribution of the population settles onto equilibrium very fast. We then couple the coarse-grained mean-field model to the full stochastic multi-scale model. By doing so, within the mean-field region, we are neglecting noise in both cell numbers (population) and their birth rates (structure). This implies that, in addition to the issues that arise in stochastic-reaction diffusion systems, we need to account for the age-structure of the population when attempting to couple both descriptions. We exploit our coarse-graining model so that, within the mean-field region, the age-distribution is in equilibrium and we know its explicit form. This allows us to couple both domains consistently, as upon transference of cells from the mean-field to the stochastic region, we sample the equilibrium age distribution. Furthermore, our method allows us to investigate the effects of intracellular noise, i.e. fluctuations of the birth rate, on collective properties such as travelling wave velocity. We show that the combination of population and birth-rate noise gives rise to large fluctuations of the birth rate in the region at the leading edge of front, which cannot be accounted for by the coarse-grained model. Such fluctuations have non-trivial effects on the wave velocity. Beyond the development of a new hybrid method, we thus conclude that birth-rate fluctuations are central to a quantitatively accurate description of invasive phenomena such as tumour growth.

Role of Hydrodynamic and Mineralogical Heterogeneities on Reactive Transport Processes.

NASA Astrophysics Data System (ADS)

Luquot, L.; Garcia-Rios, M.; soler Sagarra, J.; Gouze, P.; Martinez-Perez, L.; Carrera, J.

2017-12-01

Predicting reactive transport at large scale, i.e., Darcy- and field- scale, is still challenging considering the number of heterogeneities that may be present from nm- to pore-scale. It is well documented that conventional continuum-scale approaches oversimplify and/or ignore many important aspects of rock structure, chemical reactions, fluid displacement and transport, which, as a consequence, results in uncertainties when applied to field-scale operations. The changes in flow and reactive transport across the different spatial and temporal scales are of central concern in many geological applications such as groundwater systems, geo-energy, rock building heritage and geological storage... In this presentation, we will discuss some laboratory and numerical results on how local heterogeneities (structural, hydrodynamic and mineralogical) can affect the localization and the rate of the reaction processes. Different flow through laboratory experiments using various rock samples will be presented, from simple monomineral rocks such as limestone samples, and more complex rocks composed of different minerals with a large range of kinetic reactions. A new numerical approach based on multirate water mixing approach will be presented and applied to one of the laboratory experiment in order to analyze and distinguish the effect of the mineralogy distribution and the hydrodynamic heterogeneity on the total reaction rate.

Parent and teacher ratings of attention-deficit/hyperactivity disorder symptoms: Factor structure and normative data.

PubMed

DuPaul, George J; Reid, Robert; Anastopoulos, Arthur D; Lambert, Matthew C; Watkins, Marley W; Power, Thomas J

2016-02-01

Comprehensive assessment of attention-deficit/hyperactivity disorder (ADHD) symptoms includes parent and teacher questionnaires. The ADHD Rating Scale-5 was developed to incorporate changes for the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013). This study examined the fit of a correlated, 2-factor structure of ADHD (i.e., DSM-5 conceptual model) and alternative models; determined whether ADHD symptom ratings varied across teacher and child demographic characteristics; and presented normative data. Two samples were included: (a) 2,079 parents and guardians (1,131 female, 948 male) completed ADHD symptom ratings for children (N = 2,079; 1,037 males, 1,042 females) between 5 and 17 years old (M = 10.68; SD = 3.75) and (b) 1,070 teachers (766 female, 304 male) completed ADHD symptom ratings for students (N = 2,140; 1,070 males, 1,070 females) between 5 and 17 years old (M = 11.53; SD = 3.54) who attended kindergarten through 12th grade. The 2-factor structure was confirmed for both parent and teacher ratings and was invariant across child gender, age, informant, informant gender, and language. In general, boys were higher in symptom frequency than girls; older children were rated lower than younger children, especially for hyperactivity-impulsivity; and non-Hispanic children were rated higher than Hispanic children. Teachers also rated non-Hispanic African American children higher than non-Hispanic White, Asian, and Hispanic children. Non-Hispanic White teachers provided lower hyperactivity-impulsivity ratings than non-Hispanic, African American, and Hispanic teachers. Normative data are reported separately for parent and teacher ratings by child gender and age. The merits of using the ADHD Rating Scale-5 in a multimodal assessment protocol are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A Stochastic Evolutionary Model for Protein Structure Alignment and Phylogeny

PubMed Central

Challis, Christopher J.; Schmidler, Scott C.

2012-01-01

We present a stochastic process model for the joint evolution of protein primary and tertiary structure, suitable for use in alignment and estimation of phylogeny. Indels arise from a classic Links model, and mutations follow a standard substitution matrix, whereas backbone atoms diffuse in three-dimensional space according to an Ornstein–Uhlenbeck process. The model allows for simultaneous estimation of evolutionary distances, indel rates, structural drift rates, and alignments, while fully accounting for uncertainty. The inclusion of structural information enables phylogenetic inference on time scales not previously attainable with sequence evolution models. The model also provides a tool for testing evolutionary hypotheses and improving our understanding of protein structural evolution. PMID:22723302

Multi-scale structure, pasting and digestibility of heat moisture treated red adzuki bean starch.

PubMed

Wang, Hongwei; Wang, Zhaoyuan; Li, Xiaoxi; Chen, Ling; Zhang, Binjia

2017-09-01

The pasting and digestibility of a red adzuki bean starch were simultaneously modulated by heat-moisture treatment (HMT) through altering the multi-scale structure. HMT, especially at high moisture content, could disrupt the granule integrity, semicrystalline lamellae, molecular order (crystallites) and molecular chains. Also, certain rearrangement of starch molecules occurred to form ordered structures with increased thermal stability as shown by DSC. This concomitant disordering and reassembly in the multi-scale structure converted the fractions of resistant starch (RS) and rapidly digestible starch (RDS) into that of slowly digestible starch (SDS). Furthermore, the emergence of thermally-stable orders increased the pasting temperature but suppressed the swelling of granules during heating. Hence, HMT-modified red adzuki starch may serve as a potential thickener/gelling agent with slow digestion rate for various foods. Copyright © 2017. Published by Elsevier B.V.

The rotation of the sun - Observations at Stanford

NASA Technical Reports Server (NTRS)

Scherrer, P. H.; Wilcox, J. M.; Svalgaard, L.

1980-01-01

Daily observations of the photospheric rotation rate using the Doppler effect have been made at the Stanford Solar Observatory since May 1976. These observations show no daily or long-period variations in the rotation rate that exceed the observational error of about 1%. The average rotation rate is the same as that of the sunspots and the large-scale magnetic field structures.

Exploratory Factor Analysis of SRS-2 Teacher Ratings for Youth with ASD

ERIC Educational Resources Information Center

Nelson, Andrew T.; Lopata, Christopher; Volker, Martin A.; Thomeer, Marcus L.; Toomey, Jennifer A.; Dua, Elissa

2016-01-01

This study examined the factor structure and internal consistency of special education teaching staff ratings on the Social Responsiveness Scale-2 (SRS-2; Constantino and Gruber 2012), as well as the percentage of ratings falling above pre-established cut scores, for a sample of lower-functioning youth with autism spectrum disorder (ASD; n = 264).…

When less is more: validating a brief scale to rate interprofessional team competencies.

PubMed

Lie, Désirée A; Richter-Lagha, Regina; Forest, Christopher P; Walsh, Anne; Lohenry, Kevin

2017-01-01

There is a need for validated and easy-to-apply behavior-based tools for assessing interprofessional team competencies in clinical settings. The seven-item observer-based Modified McMaster-Ottawa scale was developed for the Team Objective Structured Clinical Encounter (TOSCE) to assess individual and team performance in interprofessional patient encounters. We aimed to improve scale usability for clinical settings by reducing item numbers while maintaining generalizability; and to explore the minimum number of observed cases required to achieve modest generalizability for giving feedback. We administered a two-station TOSCE in April 2016 to 63 students split into 16 newly-formed teams, each consisting of four professions. The stations were of similar difficulty. We trained sixteen faculty to rate two teams each. We examined individual and team performance scores using generalizability (G) theory and principal component analysis (PCA). The seven-item scale shows modest generalizability (.75) with individual scores. PCA revealed multicollinearity and singularity among scale items and we identified three potential items for removal. Reducing items for individual scores from seven to four (measuring Collaboration, Roles, Patient/Family-centeredness, and Conflict Management) changed scale generalizability from .75 to .73. Performance assessment with two cases is associated with reasonable generalizability (.73). Students in newly-formed interprofessional teams show a learning curve after one patient encounter. Team scores from a two-station TOSCE demonstrate low generalizability whether the scale consisted of four (.53) or seven items (.55). The four-item Modified McMaster-Ottawa scale for assessing individual performance in interprofessional teams retains the generalizability and validity of the seven-item scale. Observation of students in teams interacting with two different patients provides reasonably reliable ratings for giving feedback. The four-item scale has potential for assessing individual student skills and the impact of IPE curricula in clinical practice settings. IPE: Interprofessional education; SP: Standardized patient; TOSCE: Team objective structured clinical encounter.

A comprehensive visual rating scale of brain magnetic resonance imaging: application in elderly subjects with Alzheimer's disease, mild cognitive impairment, and normal cognition.

PubMed

Jang, Jae-Won; Park, So Young; Park, Young Ho; Baek, Min Jae; Lim, Jae-Sung; Youn, Young Chul; Kim, SangYun

2015-01-01

Brain magnetic resonance imaging (MRI) shows cerebral structural changes. However, a unified comprehensive visual rating scale (CVRS) has seldom been studied. Thus, we combined brain atrophy and small vessel disease scales and used an MRI template as a CVRS. The aims of this study were to design a simple and reliable CVRS, validate it by investigating cerebral structural changes in clinical groups, and made comparison to the volumetric measurements. Elderly subjects (n = 260) with normal cognition (NC, n = 65), mild cognitive impairment (MCI, n = 101), or Alzheimer's disease (AD, n = 94) were evaluated with brain MRI according to the CVRS of brain atrophy and small vessel disease. Validation of the CVRS with structural changes, neuropsychological tests, and volumetric analyses was performed. The CVRS revealed a high intra-rater and inter-rater agreement and it reflected the structural changes of subjects with NC, MCI, and AD better than volumetric measures (CVRS-coronal: F = 13.5, p < 0.001; CVRS-axial: F = 19.9, p < 0.001). The area under the receiver operation curve (aROC) of the CVRS showed higher accuracy than volumetric analyses. (NC versus MCI aROC: CVRS-coronal, 0.777; CVRS-axial, 0.773; MCI versus AD aROC: CVRS-coronal, 0.680; CVRS-axial, 0.681). The CVRS can be used clinically to conveniently measure structural changes of brain. It reflected cerebral structural changes of clinical groups and correlated with the age better than volumetric measures.

Pangolin armor: Overlapping, structure, and mechanical properties of the keratinous scales.

PubMed

Wang, Bin; Yang, Wen; Sherman, Vincent R; Meyers, Marc A

2016-09-01

The pangolin has a flexible dermal armor consisting of overlapping keratinous scales. Although they show potential for bioinspired flexible armor, the design principles of pangolin armor are barely known. Here we report on the overlapping organization, hierarchical structure (from the nano to the mesolevel), and mechanical response of scales from ground (Chinese) and arboreal (African tree) pangolins. Both scales exhibit the same overlapping organization, with each scale at the center of neighboring scales arranged in a hexagonal pattern. The scales have a cuticle of several layers of loosely attached flattened keratinized cells, while the interior structure exhibits three regions distinguished by the geometry and orientations of the keratinized cells, which form densely packed lamellae; each one corresponds to one layer of cells. Unlike most other keratinous materials, the scales show a crossed-lamellar structure (∼5μm) and crossed fibers (∼50μm). A nano-scale suture structure, observed for the first time, outlines cell membranes and leads to an interlocking interface between lamellae, thus enhancing the bonding and shear resistance. The tensile response of the scales shows an elastic limit followed by a short plateau prior to failure, with Young's modulus ∼1 GPa and tensile strength 60-100MPa. The mechanical response is transversely isotropic, a result of the cross lamellar structure. The strain rate sensitivity in the range of 10(-5)-10(-1)s(-1) region is found to be equal to 0.07-0.08, typical of other keratins and polymers. The mechanical response is highly dependent on the degree of hydration, a characteristic of keratins. Although many fish and reptiles have protective scales and carapaces, mammals are characteristically fast and light. The pangolin is one of the few mammal possessing a flexible dermal armor for protection from predators, such as lions. Here we study the arrangement of the scales as well as their hierarchical structure from the nano to the mesolevel and correlate it to the mechanical properties. The study reveals a unique structure consisting of crossed lamellae and interlocking sutures that provide exceptional performance and in-plane isotropy. Copyright © 2016. Published by Elsevier Ltd.

A Chinese version of the Psychotic Symptom Rating Scales: psychometric properties in recent-onset and chronic psychosis.

PubMed

Chien, Wai-Tong; Lee, Isabella Yuet-Ming; Wang, Li-Qun

2017-01-01

The purpose of this study was to test the reliability, validity, and factor structure of a Chinese version of the Psychotic Symptom Rating Scale (PSYRATS) in 198 and 202 adult patients with recent-onset and chronic psychosis, respectively. The PSYRATS has been translated into different language versions and has been validated for clinical and research use mainly in chronic psychotic patients but not in recent-onset psychosis patients or in Chinese populations. The psychometric analysis of the translated Chinese version included assessment of its content validity, semantic equivalence, interrater and test-retest reliability, reproducibility, sensitivity to changes in psychotic symptoms, internal consistency, concurrent validity (compared to a valid psychotic symptom scale), and factor structure. The Chinese version demonstrated very satisfactory content validity as rated by an expert panel, good semantic equivalence with the original version, and high interrater and test-retest (at 2-week interval) reliability. It also indicated very good reproducibility of and sensitivity to changes in psychotic symptoms in line with the symptom severity measured with the Positive and Negative Syndrome Scale (PANSS). The scale consisted of four factors for the hallucination subscale and two factors for the delusion subscale, explaining about 80% of the total variance of the construct, indicating satisfactory correlations between the hallucination and delusion factors themselves, between items, factors, subscales, and overall scale, and between factors and relevant item and subscale scores of the PANSS. The Chinese version of the PSYRATS is a reliable and valid instrument to measure symptom severity in Chinese psychotic patients complementary to other existing measures mainly in English language.

Use of the Behavior Rating Inventory of Executive Function and Child Behavior Checklist in Ugandan Children with HIV or a History of Severe Malaria.

PubMed

Familiar, Itziar; Ruisenor-Escudero, Horacio; Giordani, Bruno; Bangirana, Paul; Nakasujja, Noeline; Opoka, Robert; Boivin, Michael

2015-05-01

To assess the structural overlap between the Behavior Rating Inventory of Executive Function (BRIEF) and Achenbach Child Behavior Checklist (CBCL) among children in Uganda. Caregiver ratings for the BRIEF and CBCL were obtained for 2 independent samples of school-aged children: 106 children (5-12 years old, 50% males) with a history of severe malaria and on 144 HIV-infected children (5-12 years old, 58% males) in Uganda. Exploratory factor analysis was used to evaluate the factor structure of the 8 subscales for the BRIEF and the 8 scales of the CBCL to determine correlation. Overall, children in the severe malaria group had higher (increased symptom) BRIEF and CBCL scores than those in the HIV-infected group. Three factors that provided a reasonable fit to the data and could be characterized as 3 specific domains were identified: (1) Metacognition, which consisted of the scales in the BRIEF Metacognition domain, (2) Behavioral Adjustment, which comprised of the scales in the BRIEF Behavioral Regulation domain and the Externalizing Symptoms scales in the CBCL, and (3) Emotional Adjustment, which mainly consisted of the Internalizing Symptoms scales in the CBCL. The BRIEF Behavior Regulation and CBCL Externalizing Symptoms scales, however, did overlap in terms of assessing similar behavior symptoms. These findings were consistent across the severe malaria and HIV-infected samples of children. The BRIEF and CBCL instruments offer distinct, yet complementary, assessments of behavior in clinical pediatric populations in the Ugandan context, supporting the use of these measures for similar research settings.

Micro-computed tomography: Applications for high-resolution skeletal density determinations: An example using annually banded crustose coralline algae

NASA Astrophysics Data System (ADS)

Chan, P.; Halfar, J.; Norley, C. J. D.; Pollmann, S. I.; Adey, W.; Holdsworth, D. W.

2017-09-01

Warming and acidification of the world's oceans are expected to have widespread consequences for marine biodiversity and ecosystem functioning. However, due to the relatively short record of instrumental observations, one has to rely upon geochemical and physical proxy information stored in biomineralized shells and skeletons of calcareous marine organisms as in situ recorders of past environments. Of particular interest is the response of marine calcifiers to ocean acidification through the examination of structural growth characteristics. Here we demonstrate the application of micro-computed tomography (micro-CT) for three-dimensional visualization and analysis of growth, skeletal density, and calcification in a slow-growing, annually banded crustose coralline alga Clathromorphum nereostratum (increment width ˜380 µm). X-ray images and time series of skeletal density were generated at 20 µm resolution and rebinned to 40, 60, 80, and 100 µm for comparison in a sensitivity analysis. Calcification rates were subsequently calculated as the product of density and growth (linear extension). While both skeletal density and calcification rates do not significantly differ at varying spatial resolutions (the latter being strongly influenced by growth rates), clear visualization of micron-scale growth features and the quantification of structural changes on subannual time scales requires higher scanning resolutions. In the present study, imaging at 20 µm resolution reveals seasonal cycles in density that correspond to summer/winter variations in skeletal structure observed using scanning electron microscopy (SEM). Micro-CT is a fast, nondestructive, and high-resolution technique for structural and morphometric analyses of temporally banded paleoclimate archives, particularly those that exhibit slow or compressed growth or micron-scale structures.

A Technique for the Assessment of Flight Operability Characteristics of Human Rated Spacecraft

NASA Technical Reports Server (NTRS)

Crocker, Alan

2010-01-01

In support of new human rated spacecraft development programs, the Mission Operations Directorate at NASA Johnson Space Center has implemented a formal method for the assessment of spacecraft operability. This "Spacecraft Flight Operability Assessment Scale" defines six key themes of flight operability, with guiding principles and goals stated for each factor. A standardized rating technique provides feedback that is useful to the operations, design and program management communities. Applicability of this concept across the program structure and life cycle is addressed. Examples of operationally desirable and undesirable spacecraft design characteristics are provided, as is a sample of the assessment scale product.

The relationship between oceanic transform fault segmentation, seismicity, and thermal structure

NASA Astrophysics Data System (ADS)

Wolfson-Schwehr, Monica

Mid-ocean ridge transform faults (RTFs) are typically viewed as geometrically simple, with fault lengths readily constrained by the ridge-transform intersections. This relative simplicity, combined with well-constrained slip rates, make them an ideal environment for studying strike-slip earthquake behavior. As the resolution of available bathymetric data over oceanic transform faults continues to improve, however, it is being revealed that the geometry and structure of these faults can be complex, including such features as intra-transform pull-apart basins, intra-transform spreading centers, and cross-transform ridges. To better determine the resolution of structural complexity on RTFs, as well as the prevalence of RTF segmentation, fault structure is delineated on a global scale. Segmentation breaks the fault system up into a series of subparallel fault strands separated by an extensional basin, intra-transform spreading center, or fault step. RTF segmentation occurs across the full range of spreading rates, from faults on the ultraslow portion of the Southwest Indian Ridge to faults on the ultrafast portion of the East Pacific Rise (EPR). It is most prevalent along the EPR, which hosts the fastest spreading rates in the world and has undergone multiple changes in relative plate motion over the last couple of million years. Earthquakes on RTFs are known to be small, to scale with the area above the 600°C isotherm, and to exhibit some of the most predictable behaviors in seismology. In order to determine whether segmentation affects the global RTF scaling relations, the scalings are recomputed using an updated seismic catalog and fault database in which RTF systems are broken up according to their degree of segmentation (as delineated from available bathymetric datasets). No statistically significant differences between the new computed scaling relations and the current scaling relations were found, though a few faults were identified as outliers. Finite element analysis is used to model 3-D RTF fault geometry assuming a viscoplastic rheology in order to determine how segmentation affects the underlying thermal structure of the fault. In the models, fault segment length, length and location along fault of the intra-transform spreading center, and slip rate are varied. A new scaling relation is developed for the critical fault offset length (OC) that significantly reduces the thermal area of adjacent fault segments, such that adjacent segments are fully decoupled at ~4 OC . On moderate to fast slipping RTFs, offsets ≥ 5 km are sufficient to significantly reduce the thermal influence between two adjacent transform fault segments. The relationship between fault structure and seismic behavior was directly addressed on the Discovery transform fault, located at 4°S on the East Pacific Rise. One year of microseismicity recorded on an OBS array, and 24 years of Mw ≥ 5.4 earthquakes obtained from the Global Centroid Moment Tensor catalog, were correlated with surface fault structure delineated from high-resolution multibeam bathymetry. Each of the 15 Mw ≥ 5.4 earthquakes was relocated into one of five distinct repeating rupture patches, while microseismicity was found to be reduced within these patches. While the endpoints of these patches appeared to correlate with structural features on the western segment of Discovery, small step-overs in the primary fault trace were not observed at patch boundaries. This indicates that physical segmentation of the fault is not the primary control on the size and location of large earthquakes on Discovery, and that along-strike heterogeneity in fault zone properties must play an important role.

Validation of a Spanish-language version of the ADHD Rating Scale IV in a Spanish sample.

PubMed

Vallejo-Valdivielso, M; Soutullo, C A; de Castro-Manglano, P; Marín-Méndez, J J; Díez-Suárez, A

2017-07-14

The purpose of this study is to validate a Spanish-language version of the 18-item ADHD Rating Scale-IV (ADHD-RS-IV.es) in a Spanish sample. From a total sample of 652 children and adolescents aged 6 to 17 years (mean age was 11.14±3.27), we included 518 who met the DSM-IV-TR criteria for ADHD and 134 healthy controls. To evaluate the factorial structure, validity, and reliability of the scale, we performed a confirmatory factor analysis (CFA) using structural equation modelling on a polychoric correlation matrix and maximum likelihood estimation. The scale's discriminant validity and predictive value were estimated using ROC (receiver operating characteristics) curve analysis. Both the full scale and the subscales of the Spanish-language version of the ADHD-RS-IV showed good internal consistency. Cronbach's alpha was 0.94 for the full scale and ≥ 0.90 for the subscales, and ordinal alpha was 0.95 and ≥ 0.90, respectively. CFA showed that a two-factor model (inattention and hyperactivity/impulsivity) provided the best fit for the data. ADHD-RS-IV.es offered good discriminant ability to distinguish between patients with ADHD and controls (AUC=0.97). The two-factor structure of the Spanish-language version of the ADHD-RS-IV (ADHD-RS-IV.es) is consistent with those of the DSM-IV-TR and DSM-5 as well as with the model proposed by the author of the original scale. Furthermore, it has good discriminant ability. ADHD-RS-IV.es is therefore a valid and reliable tool for determining presence and severity of ADHD symptoms in the Spanish population. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Studies of small scale irregularities in the cusp ionosphere using sounding rockets: recent results

NASA Astrophysics Data System (ADS)

Spicher, A.; Ilyasov, A. A.; Miloch, W. J.; Chernyshov, A. A.; Moen, J.; Clausen, L. B. N.; Saito, Y.

2017-12-01

Plasma irregularities occurring over many scale sizes are common in the ionosphere. Understanding and characterizing the phenomena responsible for these irregularities is not only important from a theoretical point of view, but also in the context of space weather, as the irregularities can disturb HF communication and Global Navigation Satellite Systems signals. Overall, research about the small-scale turbulence has not progressed as fast for polar regions as for the equatorial ones, and for the high latitude ionosphere there is still no agreement nor detailed explanation regarding the formation of irregularities. To investigate plasma structuring at small scales in the cusp ionosphere, we use high resolution measurements from the Investigation of Cusp Irregularities (ICI) sounding rockets, and investigate a region associated with density enhancements and a region characterized by flow shears. Using the ICI-2 electron density data, we give further evidence of the importance of the gradient drift instability for plasma structuring inside the polar cap. In particular, using higher-order statistics, we provide new insights into the nature of the resulting plasma structures and show that they are characterized by intermittency. Using the ICI-3 data, we show that the entire region associated with a reversed flow event (RFE), with the presence of meter-scale irregularities, several flow shears and particle precipitation, is highly structured. By performing a numerical stability analysis, we show that the inhomogeneous-energy-density-driven instability (IEDDI) may be active in relation to RFEs at the rocket's altitude. In particular, we show that the presence of particle precipitation decreases the growth rates of IEDDI and, using a Local Intermittency Measure, we observe a correlation between IEDDI growth rates and electric field fluctuations over several scales. These findings support the view that large-scale inhomogeneities may provide a background for the development of micro-scale instabilities. Such interplay between macro- and micro-processes might be an important mechanism for the development of small-scale plasma gradients, and as a source for ion heating in the cusp ionosphere.

Construct validity of ADHD/ODD rating scales: recommendations for the evaluation of forthcoming DSM-V ADHD/ODD scales.

PubMed

Burns, G Leonard; Walsh, James A; Servera, Mateu; Lorenzo-Seva, Urbano; Cardo, Esther; Rodríguez-Fornells, Antoni

2013-01-01

Exploratory structural equation modeling (SEM) was applied to a multiple indicator (26 individual symptom ratings) by multitrait (ADHD-IN, ADHD-HI and ODD factors) by multiple source (mothers, fathers and teachers) model to test the invariance, convergent and discriminant validity of the Child and Adolescent Disruptive Behavior Inventory with 872 Thai adolescents and the ADHD Rating Scale-IV and ODD scale of the Disruptive Behavior Inventory with 1,749 Spanish children. Most of the individual ADHD/ODD symptoms showed convergent and discriminant validity with the loadings and thresholds being invariant over mothers, fathers and teachers in both samples (the three latent factor means were higher for parents than teachers). The ADHD-IN, ADHD-HI and ODD latent factors demonstrated convergent and discriminant validity between mothers and fathers within the two samples. Convergent and discriminant validity between parents and teachers for the three factors was either absent (Thai sample) or only partial (Spanish sample). The application of exploratory SEM to a multiple indicator by multitrait by multisource model should prove useful for the evaluation of the construct validity of the forthcoming DSM-V ADHD/ODD rating scales.

Revealing Large-Scale Asymetries in the Winds of Hot, Luminous Stars Using Spectroscopy and Polarimetry

NASA Astrophysics Data System (ADS)

St-Louis, Nicole

2015-08-01

The winds of hot, luminous stars are known to show small but also large scale density structures. Ultimately, these departures from spherical symmetry are important for the understanding of the loss of angular momentum from the star and are crucial in determining its rotation rate. There are many observational signatures of these departures from a uniform and spherically symmetric outflow. This poster will present results from spectroscopic and polarimetric observations of Wolf-Rayet stars, the descendants of massive O stars, that reveal large-scale asymmetries in their winds and discuss what can be learned about the structure of these winds and about the the physical mechanism responsible for generating them. Very little is known about the rotation rates of these small, He-burning stars which are the direct progenitors of at least some supernova explosions. If enough angular momentum is retained in the core, some may also very well be the progenitors of long gamma-ray bursts.

Ultra-Slow Dielectric Relaxation Process in Polyols

NASA Astrophysics Data System (ADS)

Yomogida, Yoshiki; Minoguchi, Ayumi; Nozaki, Ryusuke

2004-04-01

Dielectric relaxation processes with relaxation times larger than that for the structural α process are reported for glycerol, xylitol, sorbitol and their mixtures for the first time. Appearance of this ultra-slow process depends on cooling rate. More rapid cooling gives larger dielectric relaxation strength. However, relaxation time is not affected by cooling rate and shows non-Arrhenius temperature dependence with correlation to the α process. It can be considered that non-equilibrium dynamic structure causes the ultra-slow process. Scale of such structure would be much larger than that of the region for the cooperative molecular orientations for the α process.

Influence of coherent structures on the evolution of an axisymmetric turbulent jet

NASA Astrophysics Data System (ADS)

Breda, Massimiliano; Buxton, Oliver R. H.

2018-03-01

The role of initial conditions in affecting the evolution toward self-similarity of an axisymmetric turbulent jet is examined. The jet's near-field coherence was manipulated by non-circular exit geometries of identical open area, De2, including a square and a fractal exit, for comparison with a classical round orifice jet. Hot-wire anemometry and 2D-planar particle image velocimetry experiments were performed between the exit and a location 26De downstream, where the Reynolds stress profiles are self-similar. This study shows that a fractal geometry significantly changes the near-field structure of the jet, breaking up the large-scale coherent structures, thereby affecting the entrainment rate of the background fluid into the jet stream. It is found that many of the jet's turbulent characteristics scale with the number of eddy turnover times rather than simply the streamwise coordinate, with the entrainment rate (amongst others) found to be comparable across the different jets after approximately 3-4 eddies have been overturned. The study is concluded by investigating the jet's evolution toward a self-similar state. No differences are found for the large-scale spreading rate of the jets in the weakly self-similar region, so defined as the region for which some, but not all of the terms of the mean turbulent kinetic energy equation are self-similar. However, the dissipation rate of the turbulent kinetic energy was found to vary more gradually in x than predicted according to the classical equilibrium theories of Kolmogorov. Instead, the dissipation was found to vary in a non-equilibrium fashion for all three jets tested.

Fabrication of a 3D micro/nano dual-scale carbon array and its demonstration as the microelectrodes for supercapacitors

NASA Astrophysics Data System (ADS)

Jiang, Shulan; Shi, Tielin; Gao, Yang; Long, Hu; Xi, Shuang; Tang, Zirong

2014-04-01

An easily accessible method is proposed for the fabrication of a 3D micro/nano dual-scale carbon array with a large surface area. The process mainly consists of three critical steps. Firstly, a hemispherical photoresist micro-array was obtained by the cost-effective nanoimprint lithography process. Then the micro-array was transformed into hierarchical structures with longitudinal nanowires on the microstructure surface by oxygen plasma etching. Finally, the micro/nano dual-scale carbon array was fabricated by carbonizing these hierarchical photoresist structures. It has also been demonstrated that the micro/nano dual-scale carbon array can be used as the microelectrodes for supercapacitors by the electrodeposition of a manganese dioxide (MnO2) film onto the hierarchical carbon structures with greatly enhanced electrochemical performance. The specific gravimetric capacitance of the deposited micro/nano dual-scale microelectrodes is estimated to be 337 F g-1 at the scan rate of 5 mV s-1. This proposed approach of fabricating a micro/nano dual-scale carbon array provides a facile way in large-scale microstructures’ manufacturing for a wide variety of applications, including sensors and on-chip energy storage devices.

Evaluation of low-cost commercial-off-the-shelf autopilot systems for SUAS operations

NASA Astrophysics Data System (ADS)

Brown, Calvin Thomas

With this increase in unmanned aircraft system (UAS) operations, there is a need for a structured process to evaluate different commercially available systems, particularly autopilots. The Remotely Operated Aircraft Management, Interpretation, and Navigation from Ground or ROAMING scale was developed to meet this need. This scale is a modification of the widely accepted Handling Qualities Rating scale developed by George Cooper and Robert Harper Jr. The Cooper-Harper scale allows pilots to rate a vehicle's performance in completing some task. Similarly, the ROAMING scale allows UAS operators to evaluate the management and observability of UAS in completing some task. The standardized evaluative process consists of cost, size, weight, and power (SWAP) analysis, ease of implementation through procedural description of setup, ROAMING scale rating, a slightly modified NASA TLX rating, and comparison of manual operation to autonomous operation of the task. This standard for evaluation of autopilots and their software will lead to better understanding of the workload placed on UAS operators and indicate where improvements to design and operational procedures can be made. An assortment of low-cost commercial-off-the-shelf (COTS) autopilots were selected for use in the development of the evaluation and results of these tests demonstrate the commonalities and differences in these systems.

International Symposium on Palaeolimnology. Abstracts

DTIC Science & Technology

1989-09-01

Finland? 99 Siver, P. Improving palaoreconstructing efforts utilizing scaled chrysophytes: transforming scale counts to cell numbers. 100 Smol, J.P...example, to assess between core differences in diatom accumulation rates requires cross correlation or dating of individual cores; both methods have...have increased the possibilities for using such structures as paleolimnological Indicators. However, understanding of the past requires insight into the

Event management for large scale event-driven digital hardware spiking neural networks.

PubMed

Caron, Louis-Charles; D'Haene, Michiel; Mailhot, Frédéric; Schrauwen, Benjamin; Rouat, Jean

2013-09-01

The interest in brain-like computation has led to the design of a plethora of innovative neuromorphic systems. Individually, spiking neural networks (SNNs), event-driven simulation and digital hardware neuromorphic systems get a lot of attention. Despite the popularity of event-driven SNNs in software, very few digital hardware architectures are found. This is because existing hardware solutions for event management scale badly with the number of events. This paper introduces the structured heap queue, a pipelined digital hardware data structure, and demonstrates its suitability for event management. The structured heap queue scales gracefully with the number of events, allowing the efficient implementation of large scale digital hardware event-driven SNNs. The scaling is linear for memory, logarithmic for logic resources and constant for processing time. The use of the structured heap queue is demonstrated on a field-programmable gate array (FPGA) with an image segmentation experiment and a SNN of 65,536 neurons and 513,184 synapses. Events can be processed at the rate of 1 every 7 clock cycles and a 406×158 pixel image is segmented in 200 ms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cross-validation of the Student Perceptions of Team-Based Learning Scale in the United States.

PubMed

Lein, Donald H; Lowman, John D; Eidson, Christopher A; Yuen, Hon K

2017-01-01

The purpose of this study was to cross-validate the factor structure of the previously developed Student Perceptions of Team-Based Learning (TBL) Scale among students in an entry-level doctor of physical therapy (DPT) program in the United States. Toward the end of the semester in 2 patient/client management courses taught using TBL, 115 DPT students completed the Student Perceptions of TBL Scale, with a response rate of 87%. Principal component analysis (PCA) and confirmatory factor analysis (CFA) were conducted to replicate and confirm the underlying factor structure of the scale. Based on the PCA for the validation sample, the original 2-factor structure (preference for TBL and preference for teamwork) of the Student Perceptions of TBL Scale was replicated. The overall goodness-of-fit indices from the CFA suggested that the original 2-factor structure for the 15 items of the scale demonstrated a good model fit (comparative fit index, 0.95; non-normed fit index/Tucker-Lewis index, 0.93; root mean square error of approximation, 0.06; and standardized root mean square residual, 0.07). The 2 factors demonstrated high internal consistency (alpha= 0.83 and 0.88, respectively). DPT students taught using TBL viewed the factor of preference for teamwork more favorably than preference for TBL. Our findings provide evidence supporting the replicability of the internal structure of the Student Perceptions of TBL Scale when assessing perceptions of TBL among DPT students in patient/client management courses.

Rating health and stability of engineering structures via classification indexes of InSAR Persistent Scatterers

NASA Astrophysics Data System (ADS)

Pratesi, Fabio; Tapete, Deodato; Terenzi, Gloria; Del Ventisette, Chiara; Moretti, Sandro

2015-08-01

We propose a novel set of indexes to classify the information content of Persistent Scatterers (PS) and rate the health of engineering structures at urban to local scale. PS are automatically sampled and grouped via 'control areas' coinciding with the building and its surrounding environment. Density over the 'control areas' and velocity of PS are converted respectively into: Completeness of Information Index (Ici) that reflects the PS coverage grade; and Conservation Criticality Indexes (Icc) which rate the health condition of the monument separately for the object and surrounding control areas. The deformation pattern over the structure is classified as isolated (i) or diffused (d) based on the Velocity Distribution Index (Ivd). Both Ici and Icc are rated from A to E classes using a colour-coded system that intentionally emulates an energy-efficiency scale, to encourage the exploitation of PS by stakeholders and end-users in the practise of engineering surveying. Workability and reliability of the classification indexes are demonstrated over the urban heritage of Florence, Italy, using well established ERS-1/2 (1992-2000) descending, ENVISAT (2003-2010) ascending and descending PS datasets. The indexes are designed in perspective of handling outputs from InSAR processing of higher-resolution time series.

All Together Now: Measuring Staff Cohesion in Special Education Classrooms

PubMed Central

Kratz, Hilary E.; Locke, Jill; Piotrowski, Zinnia; Ouellette, Rachel R.; Xie, Ming; Stahmer, Aubyn C.; Mandell, David S.

2015-01-01

This study sought to validate a new measure, the Classroom Cohesion Survey (CCS), designed to examine the relationship between teachers and classroom assistants in autism support classrooms. Teachers, classroom assistants, and external observers showed good inter-rater agreement on the CCS and good internal consistency for all scales. Simple factor structures were found for both teacher- and classroom assistant–rated scales, with one-factor solutions for both scales. Paired t tests revealed that on average, classroom assistants rated classroom cohesion stronger than teachers. The CCS may be an effective tool for measuring cohesion between classroom staff and may have an important impact on various clinical and implementation outcomes in school settings. PMID:26213443

Validity of scale-modeling for gamma-ray attenuation. Final report

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

Verser, F.A.; Donnert, H.J.

1973-09-01

An adjoint Monte Carlo code (GADJET) was used to calculate the exposure rate in full-scale and model structures located in the center of plane fallout fields (1 Ci/square ft of cobalt-60). Problems were run for a standard detector, an open basement, a basement with two thicknesses of covers, and a blockhouse with two thicknesses of walls. For all configurations investigated, the effects of nonscaling of the ground does not cause any problem and a procedure was developed to minimize the error introduced by non-scaling of the air. If the solid angle subtended by the roof remains unchanged, scaling of roofmore » contamination offers no problems. The lip effect can be significant in structures with the detector below grade. (GRA)« less

Self-assessment differences between genders in a low-stakes objective structured clinical examination (OSCE).

PubMed

Madrazo, Lorenzo; Lee, Claire B; McConnell, Meghan; Khamisa, Karima

2018-06-15

Physicians and medical students are generally poor-self assessors. Research suggests that this inaccuracy in self-assessment differs by gender among medical students whereby females underestimate their performance compared to their male counterparts. However, whether this gender difference in self-assessment is observable in low-stakes scenarios remains unclear. Our study's objective was to determine whether self-assessment differed between male and female medical students when compared to peer-assessment in a low-stakes objective structured clinical examination. Thirty-three (15 males, 18 females) third-year students participated in a 5-station mock objective structured clinical examination. Trained fourth-year student examiners scored their performance on a 6-point Likert-type global rating scale. Examinees also scored themselves using the same scale. To examine gender differences in medical students' self-assessment abilities, mean self-assessment global rating scores were compared with peer-assessment global rating scores using an independent samples t test. Overall, female students' self-assessment scores were significantly lower compared to peer-assessment (p < 0.001), whereas no significant difference was found between self- and peer-assessment scores for male examinees (p = 0.228). This study provides further evidence that underestimation in self-assessment among females is observable even in a low-stakes formative objective structured clinical examination facilitated by fellow medical students.

The Peak Structure and Future Changes of the Relationships Between Extreme Precipitation and Temperature

NASA Technical Reports Server (NTRS)

Wang, Guiling; Wang, Dagang; Trenberth, Kevin E.; Erfanian, Amir; Yu, Miao; Bosilovich, Michael G.; Parr, Dana T.

2017-01-01

Theoretical models predict that, in the absence of moisture limitation, extreme precipitation intensity could exponentially increase with temperatures at a rate determined by the Clausius-Clapeyron (C-C) relationship. Climate models project a continuous increase of precipitation extremes for the twenty-first century over most of the globe. However, some station observations suggest a negative scaling of extreme precipitation with very high temperatures, raising doubts about future increase of precipitation extremes. Here we show for the present-day climate over most of the globe,the curve relating daily precipitation extremes with local temperatures has a peak structure, increasing as expected at the low medium range of temperature variations but decreasing at high temperatures. However, this peak-shaped relationship does not imply a potential upper limit for future precipitation extremes. Climate models project both the peak of extreme precipitation and the temperature at which it peaks (T(sub peak)) will increase with warming; the two increases generally conform to the C-C scaling rate in mid- and high-latitudes,and to a super C-C scaling in most of the tropics. Because projected increases of local mean temperature (T(sub mean)) far exceed projected increases of T(sub peak) over land, the conventional approach of relating extreme precipitation to T(sub mean) produces a misleading sub-C-C scaling rate.

Do Standard Measures of Preschool Quality Used in Statewide Policy Predict School Readiness?

ERIC Educational Resources Information Center

Sabol, Terri J.; Pianta, Robert C.

2014-01-01

In the majority of states using Quality Rating and Improvement Systems (QRIS) to improve children's school readiness, the Early Childhood Environmental Rating Scale-Revised (ECERS-R) is a core assessment of preschool program quality and is central to QRIS metrics and incentive structures. The present study utilizes nationally representative data…

The Application of Structured Job Analysis Information Based on the Position Analysis Questionnaire (PAQ).

DTIC Science & Technology

Position Analysis Questionnaire ( PAQ ). This job analysis instrument consists of 187 job elements organized into six divisions. In the analysis of a job...with the PAQ the relevance of the individual elements to the job are rated using any of several rating scales such as importance, or time.

Examining the Factorial Structure of the T-CRS 2.1

ERIC Educational Resources Information Center

Weber, Melissa R.; Lotyczewski, Bohdan S.; Montes, Guillermo; Hightower, A. Dirk; Allan, Marjorie

2017-01-01

The factor structure of the Teacher-Child Rating Scale (T-CRS 2.1) was examined using confirmatory factor analysis (CFA). A cross-sectional study was carried out on 68,497 children in prekindergarten through Grade 10. Item reduction was carried out based on modification indices, standardized residual covariance, and standardized factor loadings. A…

Factors Affecting the Development of Oxide Scales on Austenitic Stainless Steels during Hot Rolling in Steckel Mills

NASA Astrophysics Data System (ADS)

Cobo, S. J.; Rainforth, W. M.

2008-10-01

The hot rolling of austenitic stainless steels in Steckel Mills introduces particular characteristics to the development of oxides scales and surface structures. In this work, the formation of oxide structures during multipass hot rolling of 302 steel was studied under different sets of processing parameters in a laboratory system designed for the simulation of the Steckel process. The resulting surface structures were characterized by a set of complementary techniques involving scanning electron microscopy, energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and glow discharge optical spectroscopy (GDOS). The surface analysis revealed two alternative surface structures: one consisting in a thin protective oxide layer rich in Cr2O3 and the other consisting in thick complex structures containing several successive nonprotective oxide scale and metal layers resulting from a cyclic oxidation pattern involving stages of protective oxidation, chemical breakaway, and duplex oxidation. The critical condition that determined the activation of one mechanism or the other was identified associated with the parabolic rate constant for Cr2O3 growth and the diffusivity of Cr in the alloy. The effects of changes in temperature, deformation, and furnace atmosphere are discussed. Alternatives for controlling scale development are presented.

Examining the psychometric properties of the Hindi version of Family Accommodation Scale-Self-Report (FAS-SR).

PubMed

Mahapatra, Ananya; Gupta, Rishi; Patnaik, Kuppili Pooja; Pattanaik, Raman Deep; Khandelwal, Sudhir Kumar

2017-10-01

Family accommodation (FA) is the phenomenon whereby caregivers assist or facilitate rituals or behaviours related to obsessive compulsive disorder (OCD). There is a need for a self-rated instrument to assess this construct in resource-strained clinical settings of India. To explore the factor structure of Hindi version of Family Accommodation Scale-Self Rated version (FAS-SR) and compare its validity with the gold standard Family Accommodation Scale-Interviewer Rated (FAS-IR) scale. The Hindi version of FAS-SR scale and FAS-IR scale was applied on 105 caregivers of patients with OCD. The initial factor analysis yielded three-factor models with an eigenvalue of >1 and the total variance explained by these factors was 72.017%. The internal consistency of the 19-item scale was 0.93 indicating good inter-item correlation. There was a significant positive correlation between FAS-IR scale total score and all the factors of the FAS-SR Scale. The average measure ICC was 0.889 with a 95% confidence interval from 0.783 to 0.981 (F (62,84)=37.547, p<001) indicating high degree of reliability between the Hindi version of FAS-SR and the FAS-IR scale. FAS-SR is a practical alternative to FAS-IR and has the potential to be used widely in an Indian setting. Copyright © 2017 Elsevier B.V. All rights reserved.

Pore and Continuum Scale Study of the Effect of Subgrid Transport Heterogeneity on Redox Reaction Rates

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

Liu, Yuanyuan; Liu, Chongxuan; Zhang, Changyong

2015-08-01

A micromodel system with a pore structure for heterogeneous flow and transport was used to investigate the effect of subgrid transport heterogeneity on redox reaction rates. Hematite reductive dissolution by injecting a reduced form of flavin mononucleotide (FMNH2) at variable flow rates was used as an example to probe the variations of redox reaction rates in different subgrid transport domains. Experiments, pore-scale simulations, and macroscopic modeling were performed to measure and simulate in-situ hematite reduction and to evaluate the scaling behavior of the redox reaction rates from the pore to macroscopic scales. The results indicated that the measured pore-scale ratesmore » of hematite reduction were consistent with the predictions from a pore scale reactive transport model. A general trend is that hematite reduction followed reductant transport pathways, starting from the advection-dominated pores toward the interior of diffusion-dominated domains. Two types of diffusion domains were considered in the micromodel: a micropore diffusion domain, which locates inside solid grains or aggregates where reactant transport is limited by diffusion; and a macropore diffusion domain, which locates at wedged, dead-end pore spaces created by the grain-grain contacts. The rate of hematite reduction in the advection-dominated domain was faster than those in the diffusion-controlled domains, and the rate in the macropore diffusion domain was faster than that in the micropore domain. The reduction rates in the advection and macropore diffusion domains increased with increasing flow rate, but were affected by different mechanisms. The rate increase in the advection domain was controlled by the mass action effect as a faster flow supplied more reactants, and the rate increase in the macropore domain was more affected by the rate of mass exchange with the advection domain, which increased with increasing flow rate. The hematite reduction rate in the micropore domain was, however, not affected by the flow rate because molecular diffusion limits reductant supply to the micropore domain interior. Domain-based macroscopic models were evaluated to scale redox reaction rates from the pore to macroscopic scales. A single domain model, which ignores subgrid transport heterogeneity deviated significantly from the pore-scale results. Further analysis revealed that the rate expression for hematite reduction was not scalable from the pore to porous media using the single domain model. A three-domain model, which effectively considers subgrid reactive diffusion in the micropore and macropore domains, significantly improved model description. Overall this study revealed the importance of subgrid transport heterogeneity in the manifestation of redox reaction rates in porous media and in scaling reactions from the pore to porous media. The research also supported that the domain-based scaling approach can be used to directly scale redox reactions in porous media with subgrid transport heterogeneity.« less

Structure of turbulent non-premixed flames modeled with two-step chemistry

NASA Technical Reports Server (NTRS)

Chen, J. H.; Mahalingam, S.; Puri, I. K.; Vervisch, L.

1992-01-01

Direct numerical simulations of turbulent diffusion flames modeled with finite-rate, two-step chemistry, A + B yields I, A + I yields P, were carried out. A detailed analysis of the turbulent flame structure reveals the complex nature of the penetration of various reactive species across two reaction zones in mixture fraction space. Due to this two zone structure, these flames were found to be robust, resisting extinction over the parameter ranges investigated. As in single-step computations, mixture fraction dissipation rate and the mixture fraction were found to be statistically correlated. Simulations involving unequal molecular diffusivities suggest that the small scale mixing process and, hence, the turbulent flame structure is sensitive to the Schmidt number.

Extensions and evaluations of a general quantitative theory of forest structure and dynamics

PubMed Central

Enquist, Brian J.; West, Geoffrey B.; Brown, James H.

2009-01-01

Here, we present the second part of a quantitative theory for the structure and dynamics of forests under demographic and resource steady state. The theory is based on individual-level allometric scaling relations for how trees use resources, fill space, and grow. These scale up to determine emergent properties of diverse forests, including size–frequency distributions, spacing relations, canopy configurations, mortality rates, population dynamics, successional dynamics, and resource flux rates. The theory uniquely makes quantitative predictions for both stand-level scaling exponents and normalizations. We evaluate these predictions by compiling and analyzing macroecological datasets from several tropical forests. The close match between theoretical predictions and data suggests that forests are organized by a set of very general scaling rules. Our mechanistic theory is based on allometric scaling relations, is complementary to “demographic theory,” but is fundamentally different in approach. It provides a quantitative baseline for understanding deviations from predictions due to other factors, including disturbance, variation in branching architecture, asymmetric competition, resource limitation, and other sources of mortality, which are not included in the deliberately simplified theory. The theory should apply to a wide range of forests despite large differences in abiotic environment, species diversity, and taxonomic and functional composition. PMID:19363161

Convergence Rate Analysis of Distributed Gossip (Linear Parameter) Estimation: Fundamental Limits and Tradeoffs

NASA Astrophysics Data System (ADS)

Kar, Soummya; Moura, José M. F.

2011-08-01

The paper considers gossip distributed estimation of a (static) distributed random field (a.k.a., large scale unknown parameter vector) observed by sparsely interconnected sensors, each of which only observes a small fraction of the field. We consider linear distributed estimators whose structure combines the information \\emph{flow} among sensors (the \\emph{consensus} term resulting from the local gossiping exchange among sensors when they are able to communicate) and the information \\emph{gathering} measured by the sensors (the \\emph{sensing} or \\emph{innovations} term.) This leads to mixed time scale algorithms--one time scale associated with the consensus and the other with the innovations. The paper establishes a distributed observability condition (global observability plus mean connectedness) under which the distributed estimates are consistent and asymptotically normal. We introduce the distributed notion equivalent to the (centralized) Fisher information rate, which is a bound on the mean square error reduction rate of any distributed estimator; we show that under the appropriate modeling and structural network communication conditions (gossip protocol) the distributed gossip estimator attains this distributed Fisher information rate, asymptotically achieving the performance of the optimal centralized estimator. Finally, we study the behavior of the distributed gossip estimator when the measurements fade (noise variance grows) with time; in particular, we consider the maximum rate at which the noise variance can grow and still the distributed estimator being consistent, by showing that, as long as the centralized estimator is consistent, the distributed estimator remains consistent.

Synthesis of flower-like BaTiO3/Fe3O4 hierarchically structured particles and their electrorheological and magnetic properties.

PubMed

Wang, Baoxiang; Yin, Yichao; Liu, Chenjie; Yu, Shoushan; Chen, Kezheng

2013-07-21

Flower-like BaTiO3/Fe3O4 hierarchically structured particles composed of nano-scale structures on micro-scale materials were synthesized by a simple solvothermal approach and characterized by the means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), magnetic testing and rotary viscometer. The influences on the morphology and structure of solvothermal times, type and amount of surfactant, EG : H2O ratio, etc. were studied. Magnetic testing results show that the samples have strong magnetism and they exhibit superparamagnetic behavior, as evidenced by no coercivity and the remanence at room temperature, due to their very small sizes, observed on the M-H loop. The saturation magnetization (M(s)) value can achieve 18.3 emu g(-1). The electrorheological (ER) effect was investigated using a suspension of the flower-like BaTiO3/Fe3O4 hierarchically structured particles dispersed in silicone oil. We can observe a slight shear-thinning behavior of shear viscosity at a low shear rate region even at zero applied electric field and a Newtonian fluid behavior at high shear rate regions.

Meta-ecosystem dynamics and functioning on finite spatial networks

PubMed Central

Marleau, Justin N.; Guichard, Frédéric; Loreau, Michel

2014-01-01

The addition of spatial structure to ecological concepts and theories has spurred integration between sub-disciplines within ecology, including community and ecosystem ecology. However, the complexity of spatial models limits their implementation to idealized, regular landscapes. We present a model meta-ecosystem with finite and irregular spatial structure consisting of local nutrient–autotrophs–herbivores ecosystems connected through spatial flows of materials and organisms. We study the effect of spatial flows on stability and ecosystem functions, and provide simple metrics of connectivity that can predict these effects. Our results show that high rates of nutrient and herbivore movement can destabilize local ecosystem dynamics, leading to spatially heterogeneous equilibria or oscillations across the meta-ecosystem, with generally increased meta-ecosystem primary and secondary production. However, the onset and the spatial scale of these emergent dynamics depend heavily on the spatial structure of the meta-ecosystem and on the relative movement rate of the autotrophs. We show how this strong dependence on finite spatial structure eludes commonly used metrics of connectivity, but can be predicted by the eigenvalues and eigenvectors of the connectivity matrix that describe the spatial structure and scale. Our study indicates the need to consider finite-size ecosystems in meta-ecosystem theory. PMID:24403323

Pore-scale water dynamics during drying and the impacts of structure and surface wettability

NASA Astrophysics Data System (ADS)

Cruz, Brian C.; Furrer, Jessica M.; Guo, Yi-Syuan; Dougherty, Daniel; Hinestroza, Hector F.; Hernandez, Jhoan S.; Gage, Daniel J.; Cho, Yong Ku; Shor, Leslie M.

2017-07-01

Plants and microbes secrete mucilage into soil during dry conditions, which can alter soil structure and increase contact angle. Structured soils exhibit a broad pore size distribution with many small and many large pores, and strong capillary forces in narrow pores can retain moisture in soil aggregates. Meanwhile, contact angle determines the water repellency of soils, which can result in suppressed evaporation rates. Although they are often studied independently, both structure and contact angle influence water movement, distribution, and retention in soils. Here drying experiments were conducted using soil micromodels patterned to emulate different aggregation states of a sandy loam soil. Micromodels were treated to exhibit contact angles representative of those in bulk soil (8.4° ± 1.9°) and the rhizosphere (65° ± 9.2°). Drying was simulated using a lattice Boltzmann single-component, multiphase model. In our experiments, micromodels with higher contact angle surfaces took 4 times longer to completely dry versus micromodels with lower contact angle surfaces. Microstructure influenced drying rate as a function of saturation and controlled the spatial distribution of moisture within micromodels. Lattice Boltzmann simulations accurately predicted pore-scale moisture retention patterns within micromodels with different structures and contact angles.

Light propagation in the averaged universe

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

Bagheri, Samae; Schwarz, Dominik J., E-mail: s_bagheri@physik.uni-bielefeld.de, E-mail: dschwarz@physik.uni-bielefeld.de

Cosmic structures determine how light propagates through the Universe and consequently must be taken into account in the interpretation of observations. In the standard cosmological model at the largest scales, such structures are either ignored or treated as small perturbations to an isotropic and homogeneous Universe. This isotropic and homogeneous model is commonly assumed to emerge from some averaging process at the largest scales. We assume that there exists an averaging procedure that preserves the causal structure of space-time. Based on that assumption, we study the effects of averaging the geometry of space-time and derive an averaged version of themore » null geodesic equation of motion. For the averaged geometry we then assume a flat Friedmann-Lemaître (FL) model and find that light propagation in this averaged FL model is not given by null geodesics of that model, but rather by a modified light propagation equation that contains an effective Hubble expansion rate, which differs from the Hubble rate of the averaged space-time.« less

Genetic structure and seed-mediated dispersal rates of an endangered shrub in a fragmented landscape: a case study for Juniperus communis in northwestern Europe

PubMed Central

2011-01-01

Background Population extinction risk in a fragmented landscape is related to the differential ability of the species to spread its genes across the landscape. The impact of landscape fragmentation on plant population dynamics will therefore vary across different spatial scales. We quantified successful seed-mediated dispersal of the dioecious shrub Juniperus communis in a fragmented landscape across northwestern Europe by using amplified fragment length polymorphism (AFLP) markers. Furthermore we investigated the genetic diversity and structure on two spatial scales: across northwestern Europe and across Flanders (northern Belgium). We also studied whether seed viability and populations size were correlated with genetic diversity. Results Unexpectedly, estimated seed-mediated dispersal rates were quite high and ranged between 3% and 14%. No population differentiation and no spatial genetic structure were detected on the local, Flemish scale. A significant low to moderate genetic differentiation between populations was detected at the regional, northwest European scale (PhiPT = 0.10). In general, geographically nearby populations were also genetically related. High levels of within-population genetic diversity were detected but no correlation was found between any genetic diversity parameter and population size or seed viability. Conclusions In northwestern Europe, landscape fragmentation has lead to a weak isolation-by-distance pattern but not to genetic impoverishment of common juniper. Substantial rates of successful migration by seed-mediated gene flow indicate a high dispersal ability which could enable Juniperus communis to naturally colonize suitable habitats. However, it is not clear whether the observed levels of migration will suffice to counterbalance the effects of genetic drift in small populations on the long run. PMID:21859457

Genetic structure and seed-mediated dispersal rates of an endangered shrub in a fragmented landscape: a case study for Juniperus communis in northwestern Europe.

PubMed

Vanden-Broeck, An; Gruwez, Robert; Cox, Karen; Adriaenssens, Sandy; Michalczyk, Inga M; Verheyen, Kris

2011-08-22

Population extinction risk in a fragmented landscape is related to the differential ability of the species to spread its genes across the landscape. The impact of landscape fragmentation on plant population dynamics will therefore vary across different spatial scales. We quantified successful seed-mediated dispersal of the dioecious shrub Juniperus communis in a fragmented landscape across northwestern Europe by using amplified fragment length polymorphism (AFLP) markers. Furthermore we investigated the genetic diversity and structure on two spatial scales: across northwestern Europe and across Flanders (northern Belgium). We also studied whether seed viability and populations size were correlated with genetic diversity. Unexpectedly, estimated seed-mediated dispersal rates were quite high and ranged between 3% and 14%. No population differentiation and no spatial genetic structure were detected on the local, Flemish scale. A significant low to moderate genetic differentiation between populations was detected at the regional, northwest European scale (PhiPT = 0.10). In general, geographically nearby populations were also genetically related. High levels of within-population genetic diversity were detected but no correlation was found between any genetic diversity parameter and population size or seed viability. In northwestern Europe, landscape fragmentation has lead to a weak isolation-by-distance pattern but not to genetic impoverishment of common juniper. Substantial rates of successful migration by seed-mediated gene flow indicate a high dispersal ability which could enable Juniperus communis to naturally colonize suitable habitats. However, it is not clear whether the observed levels of migration will suffice to counterbalance the effects of genetic drift in small populations on the long run.

Cavitation erosion prediction based on analysis of flow dynamics and impact load spectra

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

Mihatsch, Michael S., E-mail: michael.mihatsch@aer.mw.tum.de; Schmidt, Steffen J.; Adams, Nikolaus A.

2015-10-15

Cavitation erosion is the consequence of repeated collapse-induced high pressure-loads on a material surface. The present paper assesses the prediction of impact load spectra of cavitating flows, i.e., the rate and intensity distribution of collapse events based on a detailed analysis of flow dynamics. Data are obtained from a numerical simulation which employs a density-based finite volume method, taking into account the compressibility of both phases, and resolves collapse-induced pressure waves. To determine the spectrum of collapse events in the fluid domain, we detect and quantify the collapse of isolated vapor structures. As reference configuration we consider the expansion ofmore » a liquid into a radially divergent gap which exhibits unsteady sheet and cloud cavitation. Analysis of simulation data shows that global cavitation dynamics and dominant flow events are well resolved, even though the spatial resolution is too coarse to resolve individual vapor bubbles. The inviscid flow model recovers increasingly fine-scale vapor structures and collapses with increasing resolution. We demonstrate that frequency and intensity of these collapse events scale with grid resolution. Scaling laws based on two reference lengths are introduced for this purpose. We show that upon applying these laws impact load spectra recorded on experimental and numerical pressure sensors agree with each other. Furthermore, correlation between experimental pitting rates and collapse-event rates is found. Locations of high maximum wall pressures and high densities of collapse events near walls obtained numerically agree well with areas of erosion damage in the experiment. The investigation shows that impact load spectra of cavitating flows can be inferred from flow data that captures the main vapor structures and wave dynamics without the need for resolving all flow scales.« less

A review of terrestrial, aerial and aquatic keratins: the structure and mechanical properties of pangolin scales, feather shafts and baleen plates.

PubMed

Wang, Bin; Sullivan, Tarah N

2017-12-01

Keratinous materials, omnipresent as the hard and durable epidermal appendages of animals, are among the toughest biological materials. They exhibit diverse morphologies and structures that serve a variety of amazing and inspiring mechanical functions. In this work, we provide a review of representative terrestrial, aerial and aquatic keratinous materials, pangolin scales, feather shafts and baleen plates, and correlate their hierarchical structures to respective functions of dermal armor, flight material and undersea filter. The overlapping pattern of pangolin scales provides effective body coverage, and the solid scales show transverse isotropy and strain-rate sensitivity, both important for armor function. The feather shaft displays a distinct shape factor, hierarchical fibrous structure within the cortex, and a solid shell-over-foam design, which enables synergistic stiffening and toughening with exceptional lightness to fulfill flight. Baleen plates exhibit a sandwich-tubular structure that features anisotropic flexural properties to sustain forces from water flow and remarkable fracture toughness that ensures reliable undersea functioning. The latest findings regarding the structural design principles and mechanical properties are presented in order to advance current understanding of keratinous materials and to stimulate the development of new bioinspired materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of cognitive impairment on mental healthcare costs for individuals with severe psychiatric illness.

PubMed

Mackin, R Scott; Delucchi, Kevin L; Bennett, Robert W; Areán, Patricia A

2011-02-01

This study was conducted to determine the effect of cognitive impairment (CI) on mental healthcare costs for older low-income adults with severe psychiatric illness. Data were collected from 62 ethnically diverse low-income older adults with severe psychiatric illness who were participating in day programming at a large community mental health center. CI was diagnosed by a neuropsychologist utilizing the Mattis Dementia Rating Scale-Second Edition and structured ratings of functional impairment (Clinical Dementia Rating Scale). Mental healthcare costs for 6, 12, and 24-month intervals before cognitive assessments were obtained for each participant. Substance abuse history was evaluated utilizing a structured questionnaire, depression symptom severity was assessed utilizing the Hamilton Depression Rating Scale, and psychiatric diagnoses were obtained through medical chart abstraction. CI was exhibited by 61% of participants and was associated with significantly increased mental healthcare costs during 6, 12, and 24-month intervals. Results of a regression analysis indicated that ethnicity and CI were both significant predictors of log transformed mental healthcare costs over 24 months with CI accounting for 13% of the variance in cost data. CI is a significant factor associated with increased mental healthcare costs in patients with severe psychiatric illness. Identifying targeted interventions to accommodate CI may lead to improving treatment outcomes and reducing the burden of mental healthcare costs for individuals with severe psychiatric illness.

Estimated Prevalence of Attention-Deficit/Hyperactivity Disorder in a Sample of Panamanian School-Aged Children

ERIC Educational Resources Information Center

Sanchez, Emelyn Y.; Velarde, Silvia; Britton, Gabrielle B.

2011-01-01

The present study investigated the prevalence of ADHD in a school sample of children ages 6-11 years in the city of Panama. The assessment battery included the Conners' Parent and Teacher Rating Scales, the Structured Developmental History of the Behavioral Assessment System for Children (BASC-2), and the Wechsler Intelligence Scale for Children…

Effects of eddy initial conditions on nonlinear forcing of planetary scale waves by amplifying baroclinic eddies

NASA Technical Reports Server (NTRS)

Young, Richard E.

1986-01-01

The previous study of Young and Villere concerning growth of planetary scale waves forced by wave-wave interactions of amplifying intermediate scale baroclinic eddies is extended to investigate effects of different eddy initial conditions. A global, spectral, primitive equation model is used for the calculations. For every set of eddy initial conditions considered, growth rates of planetary modes are considerably greater than growth rates computed from linear instability theory for a fixed zonally independent basic state. However, values of growth rates ranged over a factor of 3 depending on the particular set of eddy initial conditions used. Nonlinear forcing of planetary modes via wave-wave coupling becomes more important than baroclinic growth on the basic state at small values of the intermediate-scale modal amplitudes. The relative importance of direct transfer of kinetic energy from intermediate scales of motion to a planetary mode, compared to baroclinic conversion of available potential energy to kinetic energy within that planetary mode, depends on the individual case. In all cases, however, the transfer of either kinetic or available potential energy to the planetary modes was accomplished principally by wave-wave transfer from intermediate scale eddies, rather than from the zonally averaged state. The zonal wavenumber 2 planetary mode was prominent in all solutions, even in those for which eddy initial conditions were such that a different planetary mode was selectively forced at the start. General characteristics of the structural evolution of the planetary wave components of total heat and momentum flux, and modal structures themselves, were relatively insensitive to variations in eddy initial conditions, even though quantitative details varied from case to case.

Evaluation of Electronic Formats of the NASA Task Load Index

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.

2011-01-01

Paper questionnaires are being replaced by electronic questionnaires. The primary objective of this research was to determine whether electronic formats of paper questionnaires change subjects ratings and, if so, how the ratings changed. Results indicated that there were no statistically significant differences in self-assessment of workload when using the electronic replica or the paper format of the NASA-TLX scale. Variations of the electronic formats were tested to enforce structure to the TLX scale. Respondents had more consistent ratings with these alternative formats of the NASA-TLX. Non-pilots, in general, had lower workload ratings than pilots. The time to input the rating was the fastest for the electronic facsimile and random title formats. Also subjects preferred the electronic formats and thought these formats were easier to use. Therefore, moving questionnaires from paper to electronic media could change respondents' answers.

A cross-cultural comparison of climacteric symptoms, self-esteem, and perceived social support between Mosuo women and Han Chinese women.

PubMed

Zhang, Ying; Zhao, Xudong; Leonhart, Rainer; Nadig, Maya; Hasenburg, Annette; Wirsching, Michael; Fritzsche, Kurt

2016-07-01

This cross-cultural study aimed to compare climacteric symptoms, self-esteem, and perceived social support between Mosuo and Han Chinese women, and to explore the interaction between culture and climacteric symptoms. Mosuo is a Chinese minority group with a matriarchal structure, and Han Chinese is the majority ethnic group in China with a patriarchal structure. Through convenience sampling, 54 Mosuo women and 52 Han Chinese women between 40 and 60 years of age completed the sociodemographic questionnaire, the Menopause Rating Scale, the Self-Esteem Scale, and the Perceived Social Support Scale. Compared with Han Chinese women, Mosuo women scored lower on the psychological (P < 0.001) and the somato-vegetative (P = 0.047) subscales of the Menopause Rating Scale, but higher on the Self-Esteem Scale (P = 0.006) and the "support from family" subscale of the Perceived Social Support Scale (P = 0.004). Multiple linear regressions indicated that minority ethnicity (β = 0.207, P = 0.016) was one of the predictive variables of psychological symptoms severity. Referring to the severity of all symptoms, predictive variables were: perceived support from family (β = -0.210, P = 0.017); self-esteem (β = 0.320, P < 0.001); previous history of premenstrual syndrome (β = 0.293, P < 0.001); number of family members (β = -0.229, P = 0.003); and family income (β = -0.173, P = 0.028). Differences in climacteric symptoms were found between two groups. Cultural variables such as familial structure, women's self-esteem, and perceived social support were correlated with symptomatology.

Small-scale structure and turbulence observed in MAP/WINE)

NASA Technical Reports Server (NTRS)

Blix, T. A.

1989-01-01

During MAP/WINE small scale structure and turbulence in the mesosphere and lower thermosphere was studied in situ by rocket-borne instruments as well as from the ground by remote sensing techniques. The eight salvoes launched during the campaign resulted in a wealth of information on the dynamical structure of these regions. The experimental results are reviewed and their interpretation is discussed in terms of gravity waves and turbulence. It is shown that eddy diffusion coefficients and turbulent energy dissipation rates may be derived from the in situ measurements in a consistent manner. The observations are also shown to be consistent with the hypothesis that turbulence can be created by a process of gravity wave saturation.

Reynolds number scaling of straining motions in turbulence

NASA Astrophysics Data System (ADS)

Elsinga, Gerrit; Ishihara, T.; Goudar, M. V.; da Silva, C. B.; Hunt, J. C. R.

2017-11-01

Strain is an important fluid motion in turbulence as it is associated with the kinetic energy dissipation rate, vorticity stretching, and the dispersion of passive scalars. The present study investigates the scaling of the turbulent straining motions by evaluating the flow in the eigenframe of the local strain-rate tensor. The analysis is based on DNS of homogeneous isotropic turbulence covering a Reynolds number range Reλ = 34.6 - 1131. The resulting flow pattern reveals a shear layer containing tube-like vortices and a dissipation sheet, which both scale on the Kolmogorov length scale, η. The vorticity stretching motions scale on the Taylor length scale, while the flow outside the shear layer scales on the integral length scale. These scaling results are consistent with those in wall-bounded flow, which suggests a quantitative universality between the different flows. The overall coherence length of the vorticity is 120 η in all directions, which is considerably larger than the typical size of individual vortices, and reflects the importance of spatial organization at the small scales. Transitions in flow structure are identified at Reλ 45 and 250. Below these respective Reynolds numbers, the small-scale motions and the vorticity stretching motions appear underdeveloped.

The rotation of the Sun: Observations at Stanford. [using the Doppler effect

NASA Technical Reports Server (NTRS)

Scherrer, J. M.; Wilcox, J. M.; Svalgaard, L.

1980-01-01

Daily observations of the photospheric rotation rate using the Doppler effect made at the Stanford Solar Observatory since May 1976 are analyzed. Results show that these observations show no daily or long period variations in the rotation rate that exceed the observational error of about one percent. The average rotation rate is the same as that of the sunspot and the large-scale magnetic field structures.

Are trade-offs among species' ecological interactions scale dependent? A test using pitcher-plant inquiline species.

PubMed

Kneitel, Jamie M

2012-01-01

Trade-offs among species' ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species' ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species' traits in the context of coexistence at different scales can contribute to our understanding of the mechanisms underlying community structure.

Parsing the heterogeneity of depression: An exploratory factor analysis across commonly used depression rating scales.

PubMed

Ballard, Elizabeth D; Yarrington, Julia S; Farmer, Cristan A; Lener, Marc S; Kadriu, Bashkim; Lally, Níall; Williams, Deonte; Machado-Vieira, Rodrigo; Niciu, Mark J; Park, Lawrence; Zarate, Carlos A

2018-04-15

Due to the heterogeneity of depressive symptoms-which can include depressed mood, anhedonia, negative cognitive biases, and altered activity levels-researchers often use a combination of depression rating scales to assess symptoms. This study sought to identify unidimensional constructs measured across rating scales for depression and to evaluate these constructs across clinical trials of a rapid-acting antidepressant (ketamine). Exploratory factor analysis (EFA) was conducted on baseline ratings from the Beck Depression Inventory (BDI), the Hamilton Depression Rating Scale (HAM-D), the Montgomery-Asberg Depression Rating Scale (MADRS), and the Snaith-Hamilton Pleasure Rating Scale (SHAPS). Inpatients with major depressive disorder (n = 76) or bipolar depression (n = 43) were participating in clinical ketamine trials. The trajectories of the resulting unidimensional scores were evaluated in 41 subjects with bipolar depression who participated in clinical ketamine trials. The best solution, which exhibited excellent fit to the data, comprised eight factors: Depressed Mood, Tension, Negative Cognition, Impaired Sleep, Suicidal Thoughts, Reduced Appetite, Anhedonia, and Amotivation. Various response patterns were observed across the clinical trial data, both in treatment effect (ketamine versus placebo) and in degree of placebo response, suggesting that use of these unidimensional constructs may reveal patterns not observed with traditional scoring of individual instruments. Limitations include: 1) small sample (and related inability to confirm measurement invariance); 2) absence of an independent sample for confirmation of factor structure; and 3) the treatment-resistant nature of the population, which may limit generalizability. The empirical identification of unidimensional constructs creates more refined scores that may elucidate the connection between specific symptoms and underlying pathophysiology. Published by Elsevier B.V.

Evaluation of the ADHD rating scale in youth with autism

PubMed Central

Yerys, Benjamin E.; Nissley-Tsiopinis, Jenelle; de Marchena, Ashley; Watkins, Marley W.; Antezana, Ligia; Power, Thomas J.; Schultz, Robert T.

2016-01-01

Scientists and clinicians regularly use clinical screening tools for attention deficit/hyperactivity disorder (ADHD) to assess comorbidity without empirical evidence that these measures are valid in youth with autism spectrum disorder (ASD). We examined the prevalence of youth meeting ADHD criteria on the ADHD rating scale fourth edition (ADHD-RS-IV), the relationship of ADHD-RS-IV ratings with participant characteristics and behaviors, and its underlying factor structure in 386 7-17 year olds with ASD without intellectual disability. Expected parent prevalence rates, relationships with age and externalizing behaviors were observed, but confirmatory factor analyses revealed unsatisfactory fits for one-, two-, three-factor models. Exploratory analyses revealed several items cross-loading on multiple factors. Implications of screening ADHD in youth with ASD using current diagnostic criteria are discussed. PMID:27738853

Numeric rating scale: patients' perceptions of its use in postoperative pain assessments.

PubMed

Eriksson, Kerstin; Wikström, Lotta; Årestedt, Kristofer; Fridlund, Bengt; Broström, Anders

2014-02-01

The purpose of this study was to describe how patients perceive the use of the numeric rating scale in postoperative pain assessments. There are recommendations to use a pain scale to follow patients' postoperative pain. Most patients prefer the NRS but there is a discrepancy between patients and healthcare professionals how to interpret the ratings from the pain assessments. A descriptive design with a phenomenographic approach was used. Semi structured interviews were held with 25 patients. Three description categories emerged that illustrate patients' perceptions; use of the NRS facilitated communication of pain, it put demands on healthcare professionals and care routines and it contained interpretation difficulties. The NRS has a place in pain management according to the patients but there is a need for a dialogue to give the patients the opportunity to describe their pain and set a common goal. Copyright © 2014 Elsevier Inc. All rights reserved.

Measurement Invariance Between Genders on Two Measures of Borderline Personality Disorder.

PubMed

Paggeot, Amy; Huprich, Steven

2018-02-01

Gender bias in the diagnosis and assessment of borderline personality disorder (BPD) has been the subject of much controversy in the psychological research literature. Evidence regarding differential prevalence rates and diagnostic rates in clinical settings between genders has been mixed, and measurement bias is one potential explanation for these mixed findings. A total of 340 participants were recruited from a Midwestern university and four outpatient community mental health clinics. They were administered two structured clinical interviews for BPD that were then evaluated for measurement invariance. Both the SCID-II BPD scale and the PDI-IV BPD scale were found to be measurement invariant between genders. No significant differences were found on the SCID-II BPD scale in diagnosis or overall number of criteria endorsed. However, in the rates of endorsement of individual criteria, differences were found in the unstable relationships item.

Pre-Stressing Micron-Scale Aluminum Core-Shell Particles to Improve Reactivity

PubMed Central

Levitas, Valery I.; McCollum, Jena; Pantoya, Michelle

2015-01-01

The main direction in increasing reactivity of aluminum (Al) particles for energetic applications is reduction in their size down to nanoscale. However, Al nanoparticles are 30–50 times more expensive than micron scale particles and possess safety and environmental issues. Here, we improved reactivity of Al micron scale particles by synthesizing pre-stressed core-shell structures. Al particles were annealed and quenched to induce compressive stresses in the alumina passivation shell surrounding Al core. This thermal treatment was designed based on predictions of the melt-dispersion mechanism (MDM); a theory describing Al particle reaction under high heating rate. For all anneal treatment temperatures, experimental flame propagation rates for Al combined with nanoscale copper oxide (CuO) are in quantitative agreement with the theoretical predictions based on the MDM. The best treatment increases flame rate by 36% and achieves 68% of that for the best Al nanoparticles. PMID:25597747

Psychometric characteristics of the BRIEF scale for the assessment of executive functions in Spanish clinical population.

PubMed

García Fernández, Trinidad; González-Pienda, Julio Antonio; Rodríguez Pérez, Celestino; Álvarez García, David; Álvarez Pérez, Luis

2014-01-01

The Behavior Rating Inventory of Executive Functions (BRIEF) scale, completed by families, is widely known in the assessment of executive functions in children and adolescents. However, its application is limited to English-speaking population. This study analyzes the preliminary results from its application in a Spanish clinical sample, comprising 125 participants aged 5-18 years. Internal structure and reliability of the translated scale were analyzed, as well as its relationship with other behavioral measures through the analysis of their correlations with the Assessment of Attention Deficit Hyperactivity Disorder Scale (EDAH). The results were compared with those from the original validation study. The data revealed the presence of the same internal structure, as well as acceptable internal consistency and significant correlations with the Attention Deficit and Hyperactivity components of the EDAH scale. This study provides preliminary evidence of the utility of the BRIEF scale in cultural contexts different from the original, particularly in Spanish clinical population.

A correlation between the cosmic microwave background and large-scale structure in the Universe.

PubMed

Boughn, Stephen; Crittenden, Robert

2004-01-01

Observations of distant supernovae and the fluctuations in the cosmic microwave background (CMB) indicate that the expansion of the Universe may be accelerating under the action of a 'cosmological constant' or some other form of 'dark energy'. This dark energy now appears to dominate the Universe and not only alters its expansion rate, but also affects the evolution of fluctuations in the density of matter, slowing down the gravitational collapse of material (into, for example, clusters of galaxies) in recent times. Additional fluctuations in the temperature of CMB photons are induced as they pass through large-scale structures and these fluctuations are necessarily correlated with the distribution of relatively nearby matter. Here we report the detection of correlations between recent CMB data and two probes of large-scale structure: the X-ray background and the distribution of radio galaxies. These correlations are consistent with those predicted by dark energy, indicating that we are seeing the imprint of dark energy on the growth of structure in the Universe.

Parent Ratings of ADHD Symptoms: Differential Symptom Functioning across Malaysian Malay and Chinese Children

ERIC Educational Resources Information Center

Gomez, Rapson; Vance, Alasdair

2008-01-01

This study examined differential symptom functioning (DSF) in ADHD symptoms across Malay and Chinese children in Malaysia. Malay (N = 571) and Chinese (N = 254) parents completed the Disruptive Behavior Rating Scale, which lists the DSM-IV ADHD symptoms. DSF was examined using the multiple indicators multiple causes (MIMIC) structural equation…

Conversational Behaviors in Youth with High-Functioning ASD and Asperger Syndrome

ERIC Educational Resources Information Center

Paul, Rhea; Orlovski, Stephanie Miles; Marcinko, Hillary Chuba; Volkmar, Fred

2009-01-01

Twenty-nine youth with autism spectrum disorders and 26 with typical development between 12 and 18 years of age were engaged in structured interviews (ADOS). The interviews were videotaped and rated for atypical conversational behaviors by trained raters, using the Pragmatic Rating Scale (Landa et al. "Psychol Med" 22:245-254, 1992). The ASD group…

Multiphase Structural Evolution of a Continental Margin During Obduction Orogeny: Insights From the Jebel Akhdar Dome, Oman Mountains

NASA Astrophysics Data System (ADS)

Grobe, A.; Virgo, S.; von Hagke, C.; Urai, J. L.; Littke, R.

2018-03-01

The structural evolution of the carbonate platform in the footwall of the Semail ophiolite emplaced onto the passive continental margin of Arabia helps to better understand the early stages of obduction-related orogens. These early stages are rarely observable in other orogens as they are mostly overprinted by later mountain building phases. We present an extensive structural analysis of the Jebel Akhdar anticline, the largest tectonic window of the Oman Mountains, and integrate it on different scales. Outcrop observations can be linked to plate motion data, providing an absolute timeframe for structural generations consistent with radiometric dating of veins. Top-to-S overthrusting of the Semail ophiolite and Hawasina nappes onto the carbonate platform during high plate convergence rates between Arabia and Eurasia caused rapid burial and overpressure, generation and migration of hydrocarbons, and bedding-confined veins, but no major deformation in the carbonate platform. At reduced convergence rates, subsequent tectonic thinning of the ophiolite took place above a top-to-NNE, crustal-scale ductile shear zone, deforming existing veins and forming a cleavage in clay-rich layers in early Campanian times. Ongoing extension occurred along normal- to oblique-slip faults, forming horst-graben structures and a precursor of the Jebel Akhdar dome (Campanian to Maastrichtian). This was followed by NE-SW oriented ductile shortening and the formation of the Jebel Akhdar dome, deforming the earlier structures. Thereafter, exhumation was associated with low-angle normal faults on the northern flank of the anticline. We correlate the top-to-NNE crustal-scale shear zone with a similar structure in the Saih Hatat window to develop a unified model of the tectonic evolution of the Oman Mountains.

Hierarchical population monitoring of greater sage-grouse (Centrocercus urophasianus) in Nevada and California—Identifying populations for management at the appropriate spatial scale

USGS Publications Warehouse

Coates, Peter S.; Prochazka, Brian G.; Ricca, Mark A.; Wann, Gregory T.; Aldridge, Cameron L.; Hanser, Steven E.; Doherty, Kevin E.; O'Donnell, Michael S.; Edmunds, David R.; Espinosa, Shawn P.

2017-08-10

Population ecologists have long recognized the importance of ecological scale in understanding processes that guide observed demographic patterns for wildlife species. However, directly incorporating spatial and temporal scale into monitoring strategies that detect whether trajectories are driven by local or regional factors is challenging and rarely implemented. Identifying the appropriate scale is critical to the development of management actions that can attenuate or reverse population declines. We describe a novel example of a monitoring framework for estimating annual rates of population change for greater sage-grouse (Centrocercus urophasianus) within a hierarchical and spatially nested structure. Specifically, we conducted Bayesian analyses on a 17-year dataset (2000–2016) of lek counts in Nevada and northeastern California to estimate annual rates of population change, and compared trends across nested spatial scales. We identified leks and larger scale populations in immediate need of management, based on the occurrence of two criteria: (1) crossing of a destabilizing threshold designed to identify significant rates of population decline at a particular nested scale; and (2) crossing of decoupling thresholds designed to identify rates of population decline at smaller scales that decouple from rates of population change at a larger spatial scale. This approach establishes how declines affected by local disturbances can be separated from those operating at larger scales (for example, broad-scale wildfire and region-wide drought). Given the threshold output from our analysis, this adaptive management framework can be implemented readily and annually to facilitate responsive and effective actions for sage-grouse populations in the Great Basin. The rules of the framework can also be modified to identify populations responding positively to management action or demonstrating strong resilience to disturbance. Similar hierarchical approaches might be beneficial for other species occupying landscapes with heterogeneous disturbance and climatic regimes.

Reliability of a structured interview for admission to an emergency medicine residency program.

PubMed

Blouin, Danielle

2010-10-01

Interviews are most important in resident selection. Structured interviews are more reliable than unstructured ones. We sought to measure the interrater reliability of a newly designed structured interview during the selection process to an Emergency Medicine residency program. The critical incident technique was used to extract the desired dimensions of performance. The interview tool consisted of 7 clinical scenarios and 1 global rating. Three trained interviewers marked each candidate on all scenarios without discussing candidates' responses. Interitem consistency and estimates of variance were computed. Twenty-eight candidates were interviewed. The generalizability coefficient was 0.67. Removing the central tendency ratings increased the coefficient to 0.74. Coefficients of interitem consistency ranged from 0.64 to 0.74. The structured interview tool provided good although suboptimal interrater reliability. Increasing the number of scenarios improves reliability as does applying differential weights to the rating scale anchors. The latter would also facilitate the identification of those candidates with extreme ratings.

Assessing MSW Students' Integrated Behavioral Health Skills Using an Objective Structured Clinical Examination

ERIC Educational Resources Information Center

Sampson, McClain; Parrish, Danielle E.; Washburn, Micki

2018-01-01

Within the last decade, there has been a significant shift in the field of social work toward competency-based education. This article details the use of the Objective Structured Clinical Examination (OSCE) Adapted for Social Work Performance Rating Scale. We used the measure to evaluate specific practice competencies among students (n = 33)…

Music in the moment? Revisiting the effect of large scale structures.

PubMed

Lalitte, P; Bigand, E

2006-12-01

The psychological relevance of large-scale musical structures has been a matter of debate in the music community. This issue was investigated with a method that allows assessing listeners' detection of musical incoherencies in normal and scrambled versions of popular and contemporary music pieces. Musical excerpts were segmented into 28 or 29 chunks. In the scrambled version, the temporal order of these chunks was altered with the constraint that the transitions between two chunks never created local acoustical and musical disruptions. Participants were required (1) to detect on-line incoherent linking of chunks, (2) to rate aesthetic quality of pieces, and (3) to evaluate their overall coherence. The findings indicate a moderate sensitivity to large-scale musical structures for popular and contemporary music in both musically trained and untrained listeners. These data are discussed in light of current models of music cognition.

Temporal Structure of Volatility Fluctuations

NASA Astrophysics Data System (ADS)

Wang, Fengzhong; Yamasaki, Kazuko; Stanley, H. Eugene; Havlin, Shlomo

Volatility fluctuations are of great importance for the study of financial markets, and the temporal structure is an essential feature of fluctuations. To explore the temporal structure, we employ a new approach based on the return interval, which is defined as the time interval between two successive volatility values that are above a given threshold. We find that the distribution of the return intervals follows a scaling law over a wide range of thresholds, and over a broad range of sampling intervals. Moreover, this scaling law is universal for stocks of different countries, for commodities, for interest rates, and for currencies. However, further and more detailed analysis of the return intervals shows some systematic deviations from the scaling law. We also demonstrate a significant memory effect in the return intervals time organization. We find that the distribution of return intervals is strongly related to the correlations in the volatility.

Bridging scales through multiscale modeling: a case study on protein kinase A.

PubMed

Boras, Britton W; Hirakis, Sophia P; Votapka, Lane W; Malmstrom, Robert D; Amaro, Rommie E; McCulloch, Andrew D

2015-01-01

The goal of multiscale modeling in biology is to use structurally based physico-chemical models to integrate across temporal and spatial scales of biology and thereby improve mechanistic understanding of, for example, how a single mutation can alter organism-scale phenotypes. This approach may also inform therapeutic strategies or identify candidate drug targets that might otherwise have been overlooked. However, in many cases, it remains unclear how best to synthesize information obtained from various scales and analysis approaches, such as atomistic molecular models, Markov state models (MSM), subcellular network models, and whole cell models. In this paper, we use protein kinase A (PKA) activation as a case study to explore how computational methods that model different physical scales can complement each other and integrate into an improved multiscale representation of the biological mechanisms. Using measured crystal structures, we show how molecular dynamics (MD) simulations coupled with atomic-scale MSMs can provide conformations for Brownian dynamics (BD) simulations to feed transitional states and kinetic parameters into protein-scale MSMs. We discuss how milestoning can give reaction probabilities and forward-rate constants of cAMP association events by seamlessly integrating MD and BD simulation scales. These rate constants coupled with MSMs provide a robust representation of the free energy landscape, enabling access to kinetic, and thermodynamic parameters unavailable from current experimental data. These approaches have helped to illuminate the cooperative nature of PKA activation in response to distinct cAMP binding events. Collectively, this approach exemplifies a general strategy for multiscale model development that is applicable to a wide range of biological problems.

Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

NASA Technical Reports Server (NTRS)

Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

2017-01-01

This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called digital materials. We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

Robotically Assembled Aerospace Structures: Digital Material Assembly using a Gantry-Type Assembler

NASA Technical Reports Server (NTRS)

Trinh, Greenfield; Copplestone, Grace; O'Connor, Molly; Hu, Steven; Nowak, Sebastian; Cheung, Kenneth; Jenett, Benjamin; Cellucci, Daniel

2017-01-01

This paper evaluates the development of automated assembly techniques for discrete lattice structures using a multi-axis gantry type CNC machine. These lattices are made of discrete components called "digital materials." We present the development of a specialized end effector that works in conjunction with the CNC machine to assemble these lattices. With this configuration we are able to place voxels at a rate of 1.5 per minute. The scalability of digital material structures due to the incremental modular assembly is one of its key traits and an important metric of interest. We investigate the build times of a 5x5 beam structure on the scale of 1 meter (325 parts), 10 meters (3,250 parts), and 30 meters (9,750 parts). Utilizing the current configuration with a single end effector, performing serial assembly with a globally fixed feed station at the edge of the build volume, the build time increases according to a scaling law of n4, where n is the build scale. Build times can be reduced significantly by integrating feed systems into the gantry itself, resulting in a scaling law of n3. A completely serial assembly process will encounter time limitations as build scale increases. Automated assembly for digital materials can assemble high performance structures from discrete parts, and techniques such as built in feed systems, parallelization, and optimization of the fastening process will yield much higher throughput.

Multiscale properties of weighted total variation flow with applications to denoising and registration.

PubMed

Athavale, Prashant; Xu, Robert; Radau, Perry; Nachman, Adrian; Wright, Graham A

2015-07-01

Images consist of structures of varying scales: large scale structures such as flat regions, and small scale structures such as noise, textures, and rapidly oscillatory patterns. In the hierarchical (BV, L(2)) image decomposition, Tadmor, et al. (2004) start with extracting coarse scale structures from a given image, and successively extract finer structures from the residuals in each step of the iterative decomposition. We propose to begin instead by extracting the finest structures from the given image and then proceed to extract increasingly coarser structures. In most images, noise could be considered as a fine scale structure. Thus, starting the image decomposition with finer scales, rather than large scales, leads to fast denoising. We note that our approach turns out to be equivalent to the nonstationary regularization in Scherzer and Weickert (2000). The continuous limit of this procedure leads to a time-scaled version of total variation flow. Motivated by specific clinical applications, we introduce an image depending weight in the regularization functional, and study the corresponding weighted TV flow. We show that the edge-preserving property of the multiscale representation of an input image obtained with the weighted TV flow can be enhanced and localized by appropriate choice of the weight. We use this in developing an efficient and edge-preserving denoising algorithm with control on speed and localization properties. We examine analytical properties of the weighted TV flow that give precise information about the denoising speed and the rate of change of energy of the images. An additional contribution of the paper is to use the images obtained at different scales for robust multiscale registration. We show that the inherently multiscale nature of the weighted TV flow improved performance for registration of noisy cardiac MRI images, compared to other methods such as bilateral or Gaussian filtering. A clinical application of the multiscale registration algorithm is also demonstrated for aligning viability assessment magnetic resonance (MR) images from 8 patients with previous myocardial infarctions. Copyright © 2015. Published by Elsevier B.V.

Fine-scale human genetic structure in Western France.

PubMed

Karakachoff, Matilde; Duforet-Frebourg, Nicolas; Simonet, Floriane; Le Scouarnec, Solena; Pellen, Nadine; Lecointe, Simon; Charpentier, Eric; Gros, Françoise; Cauchi, Stéphane; Froguel, Philippe; Copin, Nane; Le Tourneau, Thierry; Probst, Vincent; Le Marec, Hervé; Molinaro, Sabrina; Balkau, Beverley; Redon, Richard; Schott, Jean-Jacques; Blum, Michael Gb; Dina, Christian

2015-06-01

The difficulties arising from association analysis with rare variants underline the importance of suitable reference population cohorts, which integrate detailed spatial information. We analyzed a sample of 1684 individuals from Western France, who were genotyped at genome-wide level, from two cohorts D.E.S.I.R and CavsGen. We found that fine-scale population structure occurs at the scale of Western France, with distinct admixture proportions for individuals originating from the Brittany Region and the Vendée Department. Genetic differentiation increases with distance at a high rate in these two parts of Northwestern France and linkage disequilibrium is higher in Brittany suggesting a lower effective population size. When looking for genomic regions informative about Breton origin, we found two prominent associated regions that include the lactase region and the HLA complex. For both the lactase and the HLA regions, there is a low differentiation between Bretons and Irish, and this is also found at the genome-wide level. At a more refined scale, and within the Pays de la Loire Region, we also found evidence of fine-scale population structure, although principal component analysis showed that individuals from different departments cannot be confidently discriminated. Because of the evidence for fine-scale genetic structure in Western France, we anticipate that rare and geographically localized variants will be identified in future full-sequence analyses.

An Acrobatic Substrate Metamorphosis Reveals a Requirement for Substrate Conformational Dynamics in Trypsin Proteolysis*

PubMed Central

Kayode, Olumide; Wang, Ruiying; Pendlebury, Devon F.; Cohen, Itay; Henin, Rachel D.; Hockla, Alexandra; Soares, Alexei S.; Papo, Niv; Caulfield, Thomas R.; Radisky, Evette S.

2016-01-01

The molecular basis of enzyme catalytic power and specificity derives from dynamic interactions between enzyme and substrate during catalysis. Although considerable effort has been devoted to understanding how conformational dynamics within enzymes affect catalysis, the role of conformational dynamics within protein substrates has not been addressed. Here, we examine the importance of substrate dynamics in the cleavage of Kunitz-bovine pancreatic trypsin inhibitor protease inhibitors by mesotrypsin, finding that the varied conformational dynamics of structurally similar substrates can profoundly impact the rate of catalysis. A 1.4-Å crystal structure of a mesotrypsin-product complex formed with a rapidly cleaved substrate reveals a dramatic conformational change in the substrate upon proteolysis. By using long all-atom molecular dynamics simulations of acyl-enzyme intermediates with proteolysis rates spanning 3 orders of magnitude, we identify global and local dynamic features of substrates on the nanosecond-microsecond time scale that correlate with enzymatic rates and explain differential susceptibility to proteolysis. By integrating multiple enhanced sampling methods for molecular dynamics, we model a viable conformational pathway between substrate-like and product-like states, linking substrate dynamics on the nanosecond-microsecond time scale with large collective substrate motions on the much slower time scale of catalysis. Our findings implicate substrate flexibility as a critical determinant of catalysis. PMID:27810896

Evidence of Large Fluctuations of Stock Return and Financial Crises from Turkey: Using Wavelet Coherency and Varma Modeling to Forecast Stock Return

NASA Astrophysics Data System (ADS)

Oygur, Tunc; Unal, Gazanfer

Shocks, jumps, booms and busts are typical large fluctuation markers which appear in crisis. Models and leading indicators vary according to crisis type in spite of the fact that there are a lot of different models and leading indicators in literature to determine structure of crisis. In this paper, we investigate structure of dynamic correlation of stock return, interest rate, exchange rate and trade balance differences in crisis periods in Turkey over the period between October 1990 and March 2015 by applying wavelet coherency methodologies to determine nature of crises. The time period includes the Turkeys currency and banking crises; US sub-prime mortgage crisis and the European sovereign debt crisis occurred in 1994, 2001, 2008 and 2009, respectively. Empirical results showed that stock return, interest rate, exchange rate and trade balance differences are significantly linked during the financial crises in Turkey. The cross wavelet power, the wavelet coherency, the multiple wavelet coherency and the quadruple wavelet coherency methodologies have been used to examine structure of dynamic correlation. Moreover, in consequence of quadruple and multiple wavelet coherence, strongly correlated large scales indicate linear behavior and, hence VARMA (vector autoregressive moving average) gives better fitting and forecasting performance. In addition, increasing the dimensions of the model for strongly correlated scales leads to more accurate results compared to scalar counterparts.

Multi-scale continuum modeling of biological processes: from molecular electro-diffusion to sub-cellular signaling transduction

NASA Astrophysics Data System (ADS)

Cheng, Y.; Kekenes-Huskey, P.; Hake, J. E.; Holst, M. J.; McCammon, J. A.; Michailova, A. P.

2012-01-01

This paper presents a brief review of multi-scale modeling at the molecular to cellular scale, with new results for heart muscle cells. A finite element-based simulation package (SMOL) was used to investigate the signaling transduction at molecular and sub-cellular scales (http://mccammon.ucsd.edu/smol/, http://FETK.org) by numerical solution of the time-dependent Smoluchowski equations and a reaction-diffusion system. At the molecular scale, SMOL has yielded experimentally validated estimates of the diffusion-limited association rates for the binding of acetylcholine to mouse acetylcholinesterase using crystallographic structural data. The predicted rate constants exhibit increasingly delayed steady-state times, with increasing ionic strength, and demonstrate the role of an enzyme's electrostatic potential in influencing ligand binding. At the sub-cellular scale, an extension of SMOL solves a nonlinear, reaction-diffusion system describing Ca2+ ligand buffering and diffusion in experimentally derived rodent ventricular myocyte geometries. Results reveal the important role of mobile and stationary Ca2+ buffers, including Ca2+ indicator dye. We found that alterations in Ca2+-binding and dissociation rates of troponin C (TnC) and total TnC concentration modulate sub-cellular Ca2+ signals. The model predicts that reduced off-rate in the whole troponin complex (TnC, TnI, TnT) versus reconstructed thin filaments (Tn, Tm, actin) alters cytosolic Ca2+ dynamics under control conditions or in disease-linked TnC mutations. The ultimate goal of these studies is to develop scalable methods and theories for the integration of molecular-scale information into simulations of cellular-scale systems.

Scaling Coastal Ecosystems to Oceanographic and Climatic Drivers: Making Sense of Community Variation on Rocky Shores Using the Comparative-Experimental Approach in Upwelling and Downwelling Systems

NASA Astrophysics Data System (ADS)

Menge, B. A.; Gouhier, T.; Chan, F.; Hacker, S.; Menge, D.; Nielsen, K. J.

2016-02-01

Ecology focuses increasingly on the issue of matching spatial and temporal scales responsible for ecosystem pattern and dynamics. Benthic coastal communities traditionally were studied at local scales using mostly short-term research, while environmental (oceanographic, climatic) drivers were investigated at large scales (e.g., regional to oceanic, mostly offshore) using combined snapshot and monitoring (time series) research. The comparative-experimental approach combines local-scale studies at multiple sites spanning large-scale environmental gradients in combination with monitoring of inner shelf oceanographic conditions including upwelling/downwelling wind forcing and their consequences (e.g., temperature), and inputs of subsidies (larvae, phytoplankton, detritus). Temporal scale varies depending on the questions, but can extend from years to decades. We discuss two examples of rocky intertidal ecosystem dynamics, one at a regional scale (California Current System, CCS) and one at an interhemispheric scale. In the upwelling-dominated CCS, 52% and 32% of the variance in local community structure (functional group abundances at 13 sites across 725 km) was explained by external factors (ecological subsidies, oceanographic conditions, geographic location), and species interactions, respectively. The interhemispheric study tested the intermittent upwelling hypothesis (IUH), which predicts that key ecological processes will vary unimodally along a persistent downwelling to persistent upwelling gradient. Using 14-22 sites, unimodal relationships between ecological subsidies (phytoplankton, prey recruitment), prey responses (barnacle colonization, mussel growth) and species interactions (competition rate, predation rate and effect) and the Bakun upwelling index calculated at each site accounted for 50% of the variance. Hence, external factors can account for about half of locally-expressed community structure and dynamics.

Large-scale influences in near-wall turbulence.

PubMed

Hutchins, Nicholas; Marusic, Ivan

2007-03-15

Hot-wire data acquired in a high Reynolds number facility are used to illustrate the need for adequate scale separation when considering the coherent structure in wall-bounded turbulence. It is found that a large-scale motion in the log region becomes increasingly comparable in energy to the near-wall cycle as the Reynolds number increases. Through decomposition of fluctuating velocity signals, it is shown that this large-scale motion has a distinct modulating influence on the small-scale energy (akin to amplitude modulation). Reassessment of DNS data, in light of these results, shows similar trends, with the rate and intensity of production due to the near-wall cycle subject to a modulating influence from the largest-scale motions.

Measurement invariance of the Illness Intrusiveness Ratings Scale's three-factor structure in men and women with cancer.

PubMed

Mah, Kenneth; Bezjak, Andrea; Loblaw, D Andrew; Gotowiec, Andrew; Devins, Gerald M

2011-02-01

Illness- and treatment-related disruptions to valued activities and interests (illness intrusiveness) are central to quality of life in chronic disease and are captured by three subscales of the Illness Intrusiveness Ratings Scale (IIRS): the Instrumental, Intimacy, and Relationships and Personal Development subscales. Using individual (CFA) and multisample confirmatory factor analyses (MSCFA), we evaluated measurement invariance of the IIRS's 3-factor structure in men and women with cancer. Men (n = 210) and women (n = 206) with 1 of 4 cancer diagnoses (gastrointestinal, head and neck, lymphoma, lung) recruited from outpatient clinics completed the IIRS. In the MSCFA, we applied an analysis of means and covariance structures approach to test increasingly stringent equality constraints on factor structure parameters to evaluate weak, strong, and strict measurement invariance of the 3-factor structure between men and women. Individual CFAs demonstrated fit of the hypothesized 3-factor structure for men and women, although more consistently for men. The 3-factor structure was superior to an alternative 1-factor structure. MSCFA results indicated that parameters of the 3-factor structure could be considered equivalent between the sexes up to the level of strong invariance. Strict invariance was not supported. Overall, IIRS scores can be interpreted similarly for men and women with cancer. Illness intrusiveness can be considered as important in the psychosocial adaptation of people with cancer as it is for people affected by other chronic conditions. (c) 2011 APA, all rights reserved

Ultrafast exciton fine structure relaxation dynamics in lead chalcogenide nanocrystals.

PubMed

Johnson, Justin C; Gerth, Kathrine A; Song, Qing; Murphy, James E; Nozik, Arthur J; Scholes, Gregory D

2008-05-01

The rates of fine structure relaxation in PbS, PbSe, and PbTe nanocrystals were measured on a femtosecond time scale as a function of temperature with no applied magnetic field by cross-polarized transient grating spectroscopy (CPTG) and circularly polarized pump-probe spectroscopy. The relaxation rates among exciton fine structure states follow trends with nanocrystal composition and size that are consistent with the expected influence of material dependent spin-orbit coupling, confinement enhanced electron-hole exchange interaction, and splitting between L valleys that are degenerate in the bulk. The size dependence of the fine structure relaxation rate is considerably different from what is observed for small CdSe nanocrystals, which appears to result from the unique material properties of the highly confined lead chalcogenide quantum dots. Modeling and qualitative considerations lead to conclusions about the fine structure of the lowest exciton absorption band, which has a potentially significant bearing on photophysical processes that make these materials attractive for practical purposes.

Assessment of personality-related levels of functioning: a pilot study of clinical assessment of the DSM-5 level of personality functioning based on a semi-structured interview.

PubMed

Thylstrup, Birgitte; Simonsen, Sebastian; Nemery, Caroline; Simonsen, Erik; Noll, Jane Fjernestad; Myatt, Mikkel Wanting; Hesse, Morten

2016-08-25

The personality disorder categories in the Diagnostic and Statistical Manual of Mental Disorders IV have been extensively criticized, and there is a growing consensus that personality pathology should be represented dimensionally rather than categorically. The aim of this pilot study was to test the Clinical Assessment of the Level of Personality Functioning Scale, a semi-structured clinical interview, designed to assess the Level of Personality Functioning Scale of the DSM-5 (Section III) by applying strategies similar to what characterizes assessments in clinical practice. The inter-rater reliability of the assessment of the four domains and the total impairment in the Level of Personality Functioning Scale were measured in a patient sample that varied in terms of severity and type of pathology. Ratings were done independently by the interviewer and two experts who watched a videotaped Clinical Assessment of the Level of Personality Functioning Scale interview. Inter-rater reliability coefficients varied between domains and were not sufficient for clinical practice, but may support the use of the interview to assess the dimensions of personality functioning for research purposes. While designed to measure the Level of Personality Functioning Scale with a high degree of similarity to clinical practice, the Clinical Assessment of the Level of Personality Functioning Scale had weak reliabilities and a rating based on a single interview should not be considered a stand-alone assessment of areas of functioning for a given patient.

Colorado Learning Difficulties Questionnaire:Validation of a parent-report screening measure

PubMed Central

Willcutt, Erik G.; Boada, Richard; Riddle, Margaret W.; Chhabildas, Nomita; DeFries, John C.; Pennington, Bruce F.

2011-01-01

This study evaluated the internal structure and convergent and discriminant evidence for the Colorado Learning Difficulties Questionnaire (CLDQ), a 20-item parent-report rating scale that was developed to provide a brief screening measure for learning difficulties. CLDQ ratings were obtained from parents of children in two large community samples and two samples from clinics that specialize in the assessment of learning disabilities and related disorders (total N = 8,004). Exploratory and confirmatory factor analyses revealed five correlated but separable dimensions that were labeled reading, math, social cognition, social anxiety, and spatial difficulties. Results revealed strong convergent and discriminant evidence for the CLDQ Reading scale, suggesting that this scale may provide a useful method to screen for reading difficulties in both research studies and clinical settings. Results are also promising for the other four CLDQ scales, but additional research is needed to refine each of these measures. PMID:21574721

A priori and a posteriori investigations for developing large eddy simulations of multi-species turbulent mixing under high-pressure conditions

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

Borghesi, Giulio; Bellan, Josette, E-mail: josette.bellan@jpl.nasa.gov; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109-8099

2015-03-15

A Direct Numerical Simulation (DNS) database was created representing mixing of species under high-pressure conditions. The configuration considered is that of a temporally evolving mixing layer. The database was examined and analyzed for the purpose of modeling some of the unclosed terms that appear in the Large Eddy Simulation (LES) equations. Several metrics are used to understand the LES modeling requirements. First, a statistical analysis of the DNS-database large-scale flow structures was performed to provide a metric for probing the accuracy of the proposed LES models as the flow fields obtained from accurate LESs should contain structures of morphology statisticallymore » similar to those observed in the filtered-and-coarsened DNS (FC-DNS) fields. To characterize the morphology of the large-scales structures, the Minkowski functionals of the iso-surfaces were evaluated for two different fields: the second-invariant of the rate of deformation tensor and the irreversible entropy production rate. To remove the presence of the small flow scales, both of these fields were computed using the FC-DNS solutions. It was found that the large-scale structures of the irreversible entropy production rate exhibit higher morphological complexity than those of the second invariant of the rate of deformation tensor, indicating that the burden of modeling will be on recovering the thermodynamic fields. Second, to evaluate the physical effects which must be modeled at the subfilter scale, an a priori analysis was conducted. This a priori analysis, conducted in the coarse-grid LES regime, revealed that standard closures for the filtered pressure, the filtered heat flux, and the filtered species mass fluxes, in which a filtered function of a variable is equal to the function of the filtered variable, may no longer be valid for the high-pressure flows considered in this study. The terms requiring modeling are the filtered pressure, the filtered heat flux, the filtered pressure work, and the filtered species mass fluxes. Improved models were developed based on a scale-similarity approach and were found to perform considerably better than the classical ones. These improved models were also assessed in an a posteriori study. Different combinations of the standard models and the improved ones were tested. At the relatively small Reynolds numbers achievable in DNS and at the relatively small filter widths used here, the standard models for the filtered pressure, the filtered heat flux, and the filtered species fluxes were found to yield accurate results for the morphology of the large-scale structures present in the flow. Analysis of the temporal evolution of several volume-averaged quantities representative of the mixing layer growth, and of the cross-stream variation of homogeneous-plane averages and second-order correlations, as well as of visualizations, indicated that the models performed equivalently for the conditions of the simulations. The expectation is that at the much larger Reynolds numbers and much larger filter widths used in practical applications, the improved models will have much more accurate performance than the standard one.« less

Middle School Improvement and Reform: Development and Validation of a School-Level Assessment of Climate, Cultural Pluralism, and School Safety.

ERIC Educational Resources Information Center

Brand, Stephen; Felner, Robert; Shim, Minsuk; Seitsinger, Anne; Dumas, Thaddeus

2003-01-01

Examines the structure of perceived school climate and the relationship of climate dimensions to adaptation of students who attend middle-grade-level schools. The climate scales exhibited a stable dimensional structure, high levels of internal consistency, and moderate levels of stability. Ratings of multiple climate dimensions were associated…

Resonance-modulated wavelength scaling of high-order-harmonic generation from H2+

NASA Astrophysics Data System (ADS)

Wang, Baoning; He, Lixin; Wang, Feng; Yuan, Hua; Zhu, Xiaosong; Lan, Pengfei; Lu, Peixiang

2018-01-01

Wavelength scaling of high-order harmonic generation (HHG) in a non-Born-Oppenheimer treatment of H2+ is investigated by numerical simulations of the time-dependent Schrödinger equation. The results show that the decrease in the wavelength-dependent HHG yield is reduced compared to that in the fixed-nucleus approximation. This slower wavelength scaling is related to the charge-resonance-enhanced ionization effect, which considerably increases the ionization rate at longer driving laser wavelengths due to the relatively larger nuclear separation. In addition, we find an oscillation structure in the wavelength scaling of HHG from H2+. Upon decreasing the laser intensity or increasing the nuclear mass, the oscillation structure will shift towards a longer wavelength of the laser pulse. These results permit the generation of an efficient harmonic spectrum in the midinfrared regime by manipulating the nuclear dynamics of molecules.

Analysis of small scale turbulent structures and the effect of spatial scales on gas transfer

NASA Astrophysics Data System (ADS)

Schnieders, Jana; Garbe, Christoph

2014-05-01

The exchange of gases through the air-sea interface strongly depends on environmental conditions such as wind stress and waves which in turn generate near surface turbulence. Near surface turbulence is a main driver of surface divergence which has been shown to cause highly variable transfer rates on relatively small spatial scales. Due to the cool skin of the ocean, heat can be used as a tracer to detect areas of surface convergence and thus gather information about size and intensity of a turbulent process. We use infrared imagery to visualize near surface aqueous turbulence and determine the impact of turbulent scales on exchange rates. Through the high temporal and spatial resolution of these types of measurements spatial scales as well as surface dynamics can be captured. The surface heat pattern is formed by distinct structures on two scales - small-scale short lived structures termed fish scales and larger scale cold streaks that are consistent with the footprints of Langmuir Circulations. There are two key characteristics of the observed surface heat patterns: 1. The surface heat patterns show characteristic features of scales. 2. The structure of these patterns change with increasing wind stress and surface conditions. In [2] turbulent cell sizes have been shown to systematically decrease with increasing wind speed until a saturation at u* = 0.7 cm/s is reached. Results suggest a saturation in the tangential stress. Similar behaviour has been observed by [1] for gas transfer measurements at higher wind speeds. In this contribution a new model to estimate the heat flux is applied which is based on the measured turbulent cell size und surface velocities. This approach allows the direct comparison of the net effect on heat flux of eddies of different sizes and a comparison to gas transfer measurements. Linking transport models with thermographic measurements, transfer velocities can be computed. In this contribution, we will quantify the effect of small scale processes on interfacial transport and relate it to gas transfer. References [1] T. G. Bell, W. De Bruyn, S. D. Miller, B. Ward, K. Christensen, and E. S. Saltzman. Air-sea dimethylsulfide (DMS) gas transfer in the North Atlantic: evidence for limited interfacial gas exchange at high wind speed. Atmos. Chem. Phys. , 13:11073-11087, 2013. [2] J Schnieders, C. S. Garbe, W.L. Peirson, and C. J. Zappa. Analyzing the footprints of near surface aqueous turbulence - an image processing based approach. Journal of Geophysical Research-Oceans, 2013.

GENERAL: Epidemic spreading on networks with vaccination

NASA Astrophysics Data System (ADS)

Shi, Hong-Jing; Duan, Zhi-Sheng; Chen, Guan-Rong; Li, Rong

2009-08-01

In this paper, a new susceptible-infected-susceptible (SIS) model on complex networks with imperfect vaccination is proposed. Two types of epidemic spreading patterns (the recovered individuals have or have not immunity) on scale-free networks are discussed. Both theoretical and numerical analyses are presented. The epidemic thresholds related to the vaccination rate, the vaccination-invalid rate and the vaccination success rate on scale-free networks are demonstrated, showing different results from the reported observations. This reveals that whether or not the epidemic can spread over a network under vaccination control is determined not only by the network structure but also by the medicine's effective duration. Moreover, for a given infective rate, the proportion of individuals to vaccinate can be calculated theoretically for the case that the recovered nodes have immunity. Finally, simulated results are presented to show how to control the disease prevalence.

Genetic structure of Zymoseptoria tritici in northern France at region, field, plant and leaf layer scales.

PubMed

Siah, Ali; Bomble, Myriam; Tisserant, Benoit; Cadalen, Thierry; Holvoet, Maxime; Hilbert, Jean-Louis; Halama, Patrice; Reignault, Philippe Lucien

2018-04-16

Population genetic structure of the worldwide-distributed wheat pathogen Zymoseptoria tritici has been extensively studied at large geographical scales, but to a much less extent at small or local spatial scales. A total of 627 single-conidial fungal isolates were sampled from several locations in northern France (Hauts-de-France Region) to assess fungal genetic structure at region, field, plant and leaf layer scales, using highly polymorphic microsatellite markers and mating type idiomorphs. Important and overall similar levels of both gene and genotype diversities (gene diversity values ≥ 0.44 and haplotype frequencies ≥ 94 %) were found at all the examined scales. Such rates of diversity are likely due to an active sexual recombination in the investigated areas, as revealed by equal proportions of the two mating types scored in all sampled populations. Interestingly, a rare occurrence of clones among lesions from a same leaf, as well as among leaves from different plant leaf layers (e.g. upper vs lower leaves), was highlighted, indicating that ascospores contribute much more than expected to Z. tritci epidemics, compared to pycnidiospores. Population structure and AMOVA analyses revealed significant genetic differentiation at the regional scale (GST = 0.23) and, as expected, not at the other more local scales (GST ≤ 0.01). Further analyses using Bayesian and unweighted neighbor-joining statistical methods detected six genetic clusters within the regional population, overall distributed according to the locations from which the isolates were sampled. Neither clear directional relative migration linked to the geographical distribution of the locations, nor isolation by distance, were observed. Separate evolutionary trajectories caused by selection and adaptations to habitat heterogeneity could be the main forces shaping such structuration. This study provides new insights into the epidemiology and the genetic structure of Z. tritici at small local and, for the first time, at single plant and leaf layer scales. Such findings would be helpful in implementing effective control strategies.

Use of the BRIEF and CBCL in Ugandan Children with HIV or a History of Severe Malaria

PubMed Central

Itziar, Familiar; Horacio, Ruisenor-Escudero; Bruno, Giordani; Paul, Bangirana; Noeline, Nakasujja; Robert, Opoka; Michael, Boivin

2015-01-01

Objective To assess the structural overlap between the Behavior Rating Inventory of Executive Function (BRIEF) and Achenbach Child Behavior Check List (CBCL) among children in Uganda. Methods Caregiver ratings for the BRIEF and CBCL were obtained for two independent samples of school-aged children: 106 children (5-12 years old, 50% males) with a history of severe malaria, and on 144 HIV-infected children (5-12 years old, 58% males) in Uganda. Exploratory factor analysis was used to evaluate the factor structure of the 8 sub-scales for the BRIEF and the 8 scales of the CBCL to determine correlation. Results Overall, children in the severe malaria group had higher (increased symptom) BRIEF and CBCL scores than children in the HIV-infected group. We identified 3 factors that provided a reasonable fit to the data and could be characterized as 3 specific domains: 1) Metacognition, which consisted of the scales in the BRIEF Metacognition domain; 2) Behavioral Adjustment, which was comprised of the scales in the BRIEF Behavioral Regulation domain and the Externalizing Symptoms scales in the CBCL; and 3) Emotional Adjustment, which mainly consisted of the Internalizing Symptoms scales in the CBCL. The BRIEF Behavior Regulation and CBCL Externalizing Symptoms scales, however, did overlap in terms of assessing similar behavior symptoms. These findings were consistent across the severe malaria and HIV-infected samples of children. Conclusion The BRIEF and CBCL instruments offer distinct, yet complementary, assessments of behavior in clinical pediatric populations in the Ugandan context, supporting the use of these measures for similar research settings. PMID:25738440

Multifractal scaling of the kinetic energy flux in solar wind turbulence

NASA Technical Reports Server (NTRS)

Marsch, E.; Rosenbauer, H.; Tu, C.-Y.

1995-01-01

The geometrical and scaling properties of the energy flux of the turbulent kinetic energy in the solar wind have been studied. By present experimental technology in solar wind measurements, we cannot directly measure the real volumetric dissipation rate, epsilon(t), but are constrained to represent it by surrogating the energy flux near the dissipation range at the proton gyro scales. There is evidence for the multifractal nature of the so defined dissipation field epsilon(t), a result derived from the scaling exponents of its statistical q-th order moments. The related generalized dimension D(q) has been determined and reveals that the dissipation field has a multifractal structure. which is not compatible with a scale-invariant cascade. The associated multifractal spectrum f(alpha) has been estimated for the first time for MHD turbulence in the solar wind. Its features resemble those obtained for turbulent fluids and other nonlinear multifractal systems. The generalized dimension D(q) can, for turbulence in high-speed streams, be fitted well by the functional dependence of the p-model with a comparatively large parameter, p = 0.87. indicating a strongly intermittent multifractal energy cascade. The experimental value for D(p)/3, if used in the scaling exponent s(p) of the velocity structure function, gives an exponent that can describe some of the observations. The scaling exponent mu of the auto correlation function of epsilon(t) has also been directly evaluated. It has the value of 0.37. Finally. the mean dissipation rate was determined, which could be used in solar wind heating models.

The origin of allometric scaling laws in biology from genomes to ecosystems: towards a quantitative unifying theory of biological structure and organization.

PubMed

West, Geoffrey B; Brown, James H

2005-05-01

Life is the most complex physical phenomenon in the Universe, manifesting an extraordinary diversity of form and function over an enormous scale from the largest animals and plants to the smallest microbes and subcellular units. Despite this many of its most fundamental and complex phenomena scale with size in a surprisingly simple fashion. For example, metabolic rate scales as the 3/4-power of mass over 27 orders of magnitude, from molecular and intracellular levels up to the largest organisms. Similarly, time-scales (such as lifespans and growth rates) and sizes (such as bacterial genome lengths, tree heights and mitochondrial densities) scale with exponents that are typically simple powers of 1/4. The universality and simplicity of these relationships suggest that fundamental universal principles underly much of the coarse-grained generic structure and organisation of living systems. We have proposed a set of principles based on the observation that almost all life is sustained by hierarchical branching networks, which we assume have invariant terminal units, are space-filling and are optimised by the process of natural selection. We show how these general constraints explain quarter power scaling and lead to a quantitative, predictive theory that captures many of the essential features of diverse biological systems. Examples considered include animal circulatory systems, plant vascular systems, growth, mitochondrial densities, and the concept of a universal molecular clock. Temperature considerations, dimensionality and the role of invariants are discussed. Criticisms and controversies associated with this approach are also addressed.

WindPACT Reference Wind Turbines

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

Dykes, Katherine L; Rinker, Jennifer

To fully understand how loads and turbine cost scale with turbine size, it is necessary to have identical turbine models that have been scaled to different rated powers. The report presents the WindPACT baseline models, which are a series of four baseline models that were designed to facilitate investigations into the scalings of loads and turbine cost with size. The models have four different rated powers (750 kW, 1.5 MW, 3.0 MW, and 5.0 MW), and each model was designed to its specified rated power using the same design methodology. The models were originally implemented in FAST_AD, the predecessor tomore » NREL's open-source wind turbine simulator FAST, but have yet to be implemented in FAST. This report contains the specifications for all four WindPACT baseline models - including structural, aerodynamic, and control specifications - along with the inherent assumptions and equations that were used to calculate the model parameters. It is hoped that these baseline models will serve as extremely useful resources for investigations into the scalings of costs, loads, or optimization routines.« less

The factor structure of the Buss and Plomin EAS Temperament Survey (parental ratings) in a Dutch sample of elementary school children.

PubMed

Boer, F; Westenberg, P M

1994-06-01

The psychometric properties of the Buss and Plomin (1984) EAS Temperament Survey for Children (Parental Ratings) were examined in a sample of Dutch children between 4 and 13 years of age. Ratings were obtained from 230 mothers and 172 fathers. The findings presented here provide the lacking cross-validation of the original analyses by Rowe and Plomin (1977): Emotionality, activity, and shyness were independent temperaments, regardless of age and gender. The factorial position of the yet experimental Sociability scale is more ambiguous: Sociability was significantly related to both shyness and activity but was more strongly associated with shyness in the youngest age cohort and most strongly with activity in the oldest cohort. This age trend, combined with a positive association with activity, supports the premise that sociability cannot be equated to nonshyness and justifies the inclusion of a separate Sociability scale in the EAS. All four EAS scales are reliable in terms of internal consistency and interrater agreement, but one modification of the Sociability scale is needed.

Scaling of elongation transition thickness during thin-film growth on weakly interacting substrates

NASA Astrophysics Data System (ADS)

Lü, B.; Souqui, L.; Elofsson, V.; Sarakinos, K.

2017-08-01

The elongation transition thickness ( θElong) is a central concept in the theoretical description of thin-film growth dynamics on weakly interacting substrates via scaling relations of θElong with respect to rates of key atomistic film-forming processes. To date, these scaling laws have only been confirmed quantitatively by simulations, while experimental proof has been left ambiguous as it has not been possible to measure θElong. Here, we present a method for determining experimentally θElong for Ag films growing on amorphous SiO2: an archetypical weakly interacting film/substrate system. Our results confirm the theoretically predicted θElong scaling behavior, which then allow us to calculate the rates of adatom diffusion and island coalescence completion, in good agreement with the literature. The methodology presented herein casts the foundation for studying growth dynamics and cataloging atomistic-process rates for a wide range of weakly interacting film/substrate systems. This may provide insights into directed growth of metal films with a well-controlled morphology and interfacial structure on 2D crystals—including graphene and MoS2—for catalytic and nanoelectronic applications.

Convergence and divergence in a long-term old-field succession: the importance of spatial scale and species abundance.

PubMed

Li, Shao-Peng; Cadotte, Marc W; Meiners, Scott J; Pu, Zhichao; Fukami, Tadashi; Jiang, Lin

2016-09-01

Whether plant communities in a given region converge towards a particular stable state during succession has long been debated, but rarely tested at a sufficiently long time scale. By analysing a 50-year continuous study of post-agricultural secondary succession in New Jersey, USA, we show that the extent of community convergence varies with the spatial scale and species abundance classes. At the larger field scale, abundance-based dissimilarities among communities decreased over time, indicating convergence of dominant species, whereas incidence-based dissimilarities showed little temporal tend, indicating no sign of convergence. In contrast, plots within each field diverged in both species composition and abundance. Abundance-based successional rates decreased over time, whereas rare species and herbaceous plants showed little change in temporal turnover rates. Initial abandonment conditions only influenced community structure early in succession. Overall, our findings provide strong evidence for scale and abundance dependence of stochastic and deterministic processes over old-field succession. © 2016 John Wiley & Sons Ltd/CNRS.

The trade-off between number and size of offspring in humans and other primates

PubMed Central

Walker, Robert S; Gurven, Michael; Burger, Oskar; Hamilton, Marcus J

2007-01-01

Life-history theory posits a fundamental trade-off between number and size of offspring that structures the variability in parental investment across and within species. We investigate this ‘quantity–quality’ trade-off across primates and present evidence that a similar trade-off is also found across natural-fertility human societies. Restating the classic Smith–Fretwell model in terms of allometric scaling of resource supply and offspring investment predicts an inverse scaling relation between birth rate and offspring size and a −¼ power scaling between birth rate and body size. We show that these theoretically predicted relationships, in particular the inverse scaling between number and size of offspring, tend to hold across increasingly finer scales of analyses (i.e. from mammals to primates to apes to humans). The advantage of this approach is that the quantity–quality trade-off in humans is placed into a general framework of parental investment that follows directly from first principles of energetic allocation. PMID:18077252

Scale for positive aspects of caregiving experience: development, reliability, and factor structure.

PubMed

Kate, N; Grover, S; Kulhara, P; Nehra, R

2012-06-01

OBJECTIVE. To develop an instrument (Scale for Positive Aspects of Caregiving Experience [SPACE]) that evaluates positive caregiving experience and assess its psychometric properties. METHODS. Available scales which assess some aspects of positive caregiving experience were reviewed and a 50-item questionnaire with a 5-point rating was constructed. In all, 203 primary caregivers of patients with severe mental disorders were asked to complete the questionnaire. Internal consistency, test-retest reliability, cross-language reliability, split-half reliability, and face validity were evaluated. Principal component factor analysis was run to assess the factorial validity of the scale. RESULTS. The scale developed as part of the study was found to have good internal consistency, test-retest reliability, cross-language reliability, split-half reliability, and face validity. Principal component factor analysis yielded a 4-factor structure, which also had good test-retest reliability and cross-language reliability. There was a strong correlation between the 4 factors obtained. CONCLUSION. The SPACE developed as part of this study has good psychometric properties.

A randomized-controlled trial of intensive case management emphasizing the recovery model among patients with severe and enduring mental illness.

PubMed

O'Brien, S; McFarland, J; Kealy, B; Pullela, A; Saunders, J; Cullen, W; Meagher, D

2012-09-01

There is increasing interest in the application of recovery principles in mental health services. We studied the implementation of a programme of intensive case management (ICM) emphasizing recovery principles in a community mental health service in Ireland. Eighty service attenders with severe and enduring illness characterized by significant ongoing disability were randomized into (1) a group receiving a programme of ICM and (2) a group receiving treatment as usual (TAU). Groups were compared before and after the programme for general psychopathology using the Brief Psychiatric Rating Scale (BPRS) (clinician rated) and How are You? scale (self-rated). The Functional Analysis of Care Environments (FACE) scale provided assessment of multiple functional domains. The overall group (mean age 44.5 ± 13.2 years; 60% male) had mean total Health of the Nation Outcome Scale (HoNOS) scale scores of 10.5 ± 4.6, with problems in social functioning especially prominent (mean social subscale score 5.0 ± 2.7). The ICM group were younger (p < 0.01) with higher baseline scores on the HoNOS social subscale and BPRS (p < 0.05). An analysis of covariance, controlling for these baseline differences, indicated greater improvement in BPRS scores (p = 0.001), How are You? scores (p = 0.02) and FACE domains for cognition, symptoms and interpersonal relationships (all p < 0.001) in the ICM group. The ICM group underwent greater changes in structured daily activities that were linked to improved BPRS scores (p = 0.01). A programme of ICM emphasizing recovery principles resulted in significant improvement across psychopathological and functional domains. Improvements were linked to enhanced engagement with structured daily activities. Recovery-oriented practices can be integrated into existing mental health services and provided alongside traditional models of care.

Archaeal community structure in leachate and solid waste is correlated to methane generation and volume reduction during biodegradation of municipal solid waste.

PubMed

Fei, Xunchang; Zekkos, Dimitrios; Raskin, Lutgarde

2015-02-01

Duplicate carefully-characterized municipal solid waste (MSW) specimens were reconstituted with waste constituents obtained from a MSW landfill and biodegraded in large-scale landfill simulators for about a year. Repeatability and relationships between changes in physical, chemical, and microbial characteristics taking place during the biodegradation process were evaluated. Parameters such as rate of change of soluble chemical oxygen demand in the leachate (rsCOD), rate of methane generation (rCH4), rate of specimen volume reduction (rVt), DNA concentration in the leachate, and archaeal community structures in the leachate and solid waste were monitored during operation. The DNA concentration in the leachate was correlated to rCH4 and rVt. The rCH4 was related to rsCOD and rVt when waste biodegradation was intensive. The structures of archaeal communities in the leachate and solid waste of both simulators were very similar and Methanobacteriaceae were the dominant archaeal family throughout the testing period. Monitoring the chemical and microbial characteristics of the leachate was informative of the biodegradation process and volume reduction in the simulators, suggesting that leachate monitoring could be informative of the extent of biodegradation in a full-scale landfill. Copyright © 2014 Elsevier Ltd. All rights reserved.

Compensating effect of sap velocity for stand density leads to uniform hillslope-scale forest transpiration across a steep valley cross-section

NASA Astrophysics Data System (ADS)

Renner, Maik; Hassler, Sibylle; Blume, Theresa; Weiler, Markus; Hildebrandt, Anke; Guderle, Marcus; Schymanski, Stan; Kleidon, Axel

2016-04-01

Roberts (1983) found that forest transpiration is relatively uniform across different climatic conditions and suggested that forest transpiration is a conservative process compensating for environmental heterogeneity. Here we test this hypothesis at a steep valley cross-section composed of European Beech in the Attert basin in Luxemburg. We use sapflow, soil moisture, biometric and meteorological data from 6 sites along a transect to estimate site scale transpiration rates. Despite opposing hillslope orientation, different slope angles and forest stand structures, we estimated relatively similar transpiration responses to atmospheric demand and seasonal transpiration totals. This similarity is related to a negative correlation between sap velocity and site-average sapwood area. At the south facing sites with an old, even-aged stand structure and closed canopy layer, we observe significantly lower sap velocities but similar stand-average transpiration rates compared to the north-facing sites with open canopy structure, tall dominant trees and dense understorey. This suggests that plant hydraulic co-ordination allows for flexible responses to environmental conditions leading to similar transpiration rates close to the water and energy limits despite the apparent heterogeneity in exposition, stand density and soil moisture. References Roberts, J. (1983). Forest transpiration: A conservative hydrological process? Journal of Hydrology 66, 133-141.

Control structures for high speed processors

NASA Technical Reports Server (NTRS)

Maki, G. K.; Mankin, R.; Owsley, P. A.; Kim, G. M.

1982-01-01

A special processor was designed to function as a Reed Solomon decoder with throughput data rate in the Mhz range. This data rate is significantly greater than is possible with conventional digital architectures. To achieve this rate, the processor design includes sequential, pipelined, distributed, and parallel processing. The processor was designed using a high level language register transfer language. The RTL can be used to describe how the different processes are implemented by the hardware. One problem of special interest was the development of dependent processes which are analogous to software subroutines. For greater flexibility, the RTL control structure was implemented in ROM. The special purpose hardware required approximately 1000 SSI and MSI components. The data rate throughput is 2.5 megabits/second. This data rate is achieved through the use of pipelined and distributed processing. This data rate can be compared with 800 kilobits/second in a recently proposed very large scale integration design of a Reed Solomon encoder.

Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV)

PubMed Central

Studerus, Erich; Gamma, Alex; Vollenweider, Franz X.

2010-01-01

Background The OAV questionnaire has been developed to integrate research on altered states of consciousness (ASC). It measures three primary and one secondary dimensions of ASC that are hypothesized to be invariant across ASC induction methods. The OAV rating scale has been in use for more than 20 years and applied internationally in a broad range of research fields, yet its factorial structure has never been tested by structural equation modeling techniques and its psychometric properties have never been examined in large samples of experimentally induced ASC. Methodology/Principal Findings The present study conducted a psychometric evaluation of the OAV in a sample of psilocybin (n = 327), ketamine (n = 162), and MDMA (n = 102) induced ASC that was obtained by pooling data from 43 experimental studies. The factorial structure was examined by confirmatory factor analysis, exploratory structural equation modeling, hierarchical item clustering (ICLUST), and multiple indicators multiple causes (MIMIC) modeling. The originally proposed model did not fit the data well even if zero-constraints on non-target factor loadings and residual correlations were relaxed. Furthermore, ICLUST suggested that the “oceanic boundlessness” and “visionary restructuralization” factors could be combined on a high level of the construct hierarchy. However, because these factors were multidimensional, we extracted and examined 11 new lower order factors. MIMIC modeling indicated that these factors were highly measurement invariant across drugs, settings, questionnaire versions, and sexes. The new factors were also demonstrated to have improved homogeneities, satisfactory reliabilities, discriminant and convergent validities, and to differentiate well among the three drug groups. Conclusions/Significance The original scales of the OAV were shown to be multidimensional constructs. Eleven new lower order scales were constructed and demonstrated to have desirable psychometric properties. The new lower order scales are most likely better suited to assess drug induced ASC. PMID:20824211

Semi-arid grassland bird responses to patch-burn grazing and drought

USGS Publications Warehouse

Skagen, Susan K.; Augustine, David J.; Derner, Justin D.

2018-01-01

As grassland birds of central North America experience steep population declines with changes in land use, management of remaining tracts becomes increasingly important for population viability. The integrated use of fire and grazing may enhance vegetation heterogeneity and diversity in breeding birds, but the subsequent effects on reproduction are unknown. We examined the influence of patch-burn grazing management in shortgrass steppe in eastern Colorado on habitat use and reproductive success of 3 grassland bird species, horned lark (Eremophila alpestris), lark bunting (Calamospiza melanocorys), and McCown’s longspur (Rhynchophanes mccownii), at several spatial scales during 2011 and 2012. Although no simple direct relationship to patch-burn grazing treatment existed, habitat selection depended on precipitation- and management-induced vegetation conditions and spatial scale. All species selected taller-than-expected vegetation at the nest site, whereas at the territory scale, horned larks and McCown’s longspurs selected areas with low vegetation height and sparse cover of tall plants (taller than the dominant shortgrasses). Buntings nested primarily in unburned grassland under average rainfall. Larks and longspurs shifted activity from patch burns during average precipitation (2011) to unburned pastures during drought (2012). Daily survival rate (DSR) of nests varied with time in season, species, weather, and vegetation structure. Daily survival rate of McCown’s longspur nests did not vary with foliar cover of relatively tall vegetation at the nest under average precipitation but declined with increasing cover during drought. At the 200-m scale, increasing cover of shortgrasses, rather than taller plant species, improved DSR of larks and longspurs. These birds experience tradeoffs in the selection of habitat at different spatial scales: tall structure at nests may reduce visual detection by predators and provide protection from sun, wind, and rain, yet taller structure surrounding territories may host nest predators. Patch-burn grazing management in combination with other strategies that retain taller-structured vegetation may help sustain a diversity of breeding habitats for shortgrass birds under varying weather conditions.

Aspects of turbulent-shear-layer dynamics and mixing

NASA Astrophysics Data System (ADS)

Slessor, Michael David

Experiments have been conducted in the GALCIT Supersonic Shear Layer Facility to investigate some aspects of high-Reynolds-number, turbulent, shear-layer flows in both incompressible- and compressible-flow regimes. Experiments designed to address several issues were performed; effects of inflow boundary conditions, freestream conditions (supersonic/subsonic flow), and compressibility, on both large-scale dynamics and small-scale mixing, are described. Chemically-reacting and non-reacting flows were investigated, the former relying on the (Hsb2 + NO)/Fsb2 chemical system, in the fast-kinetic regime, to infer the structure and amount of molecular-scale mixing through use of "flip" experiments. A variety of experimental techniques, including a color-schlieren visualization system developed as part of this work, were used to study the flows. Both inflow conditions and compressibility are found to have significant effects on the flow. In particular, inflow conditions are "remembered" for long distances downstream, a sensitivity similar to that observed in low-dimensionality, non-linear (chaotic) systems. The global flowfields (freestreams coupled by the shear layer) of transonic flows exhibit a sensitivity to imposed boundary conditions, a.e., local area ratios. A previously-proposed mode-selection rule for turbulent-structure convection speeds, based on the presence of a lab-frame subsonic freestream, was experimentally demonstrated to be incorrect. Compressibility, when decoupled from ail other parameters, e.g., Reynolds number, velocity and density ratios, etc., reduces large-scale entrainment and turbulent growth, but slightly enhances small-scale mixing, with an associated change in the structure of the molecularly-mixed fluid. This reduction in shear-layer growth rate is examined and a new parameter that interprets compressibility as an energy-exchange mechanism is proposed. The parameter reconciles and collapses experimentally-observed growth rates.

Lithospheric Instability beneath the Southeast Carpathians

NASA Astrophysics Data System (ADS)

Houseman, G. A.; Lorinczi, P.; Ren, Y.; Stuart, G. W.

2012-12-01

The South Carpathian Project, a major seismological experiment carried out during 2009-2011 by the University of Leeds, the National Institute of Earth Physics in Bucharest, the Eötvös Loránd Geophysical Institute in Budapest, and the Seismological Survey of Serbia in Belgrade, has resulted in the most detailed tomographic images yet obtained of the upper mantle structure beneath the Pannonian - Carpathian region (Ren et al., EPSL, 2012). These images illuminate the upper mantle over a wide region, but they specifically shed new light on the unique geological structure which is responsible for the damaging earthquakes that occur in the upper mantle beneath the Vrancea Zone of the South-east Carpathians. The earthquakes occur at the NE end of an asymmetric high velocity structure that extends upward to the SW, oblique to the southern edge of the South Carpathians. This sub-vertical high-velocity body is bounded by slow anomalies to the NW and SE, which extend down to the top of the Mantle Transition Zone. With increasing depth, the fast region becomes more circular in cross-section until about 400 km where the fast anomaly fades out. The main mass of fast (presumably dense) material is located directly beneath the seismic activity. The earthquakes are all characterised by near-vertical T-axes, which means they are caused by vertical stretching. The seismic moment release rate can be used to estimate vertical strain rates; these strain-rates imply that the mantle at 200 km is moving downward at about 20 mm/yr relative to the surface. The depth distribution of seismic-moment release rate follows a characteristic pattern that is most easily explained if this high velocity structure is produced by a Rayleigh-Taylor instability acting on an unstable stratification of mantle lithosphere above asthenosphere. Three-dimensional numerical experiments assuming viscous flow confirm that the drip-like structure that we image may be a natural consequence of a Rayleigh-Taylor instability triggered by recent convergence of Adria and Europe. One property of Rayleigh-Taylor instability is that rates of deformation increase with time during the peak development phase of the instability. The present high rate of tectonic activity in this region therefore is probably short-lived on a geological scale (< 1 Myr) but is likely to increase in energy before it is abates. These unique tomographic and seismological datasets provide clear evidence of lithospheric gravitational instability occurring on a short length-scale and fast time-scale via a mode that is best described as a form of Rayleigh-Taylor instability.

Spatially Controlled Noncovalent Functionalization of 2D Materials Based on Molecular Architecture.

PubMed

Bang, Jae Jin; Porter, Ashlin G; Davis, Tyson C; Hayes, Tyler R; Claridge, Shelley A

2018-05-15

Polymerizable amphiphiles can be assembled into lying-down phases on 2D materials such as graphite and graphene to create chemically orthogonal surface patterns at 5-10 nm scales, locally modulating functionality of the 2D basal plane. Functionalization can be carried out through Langmuir-Schaefer conversion, in which a subset of molecules is transferred out of a standing phase film on water onto the 2D substrate. Here, we leverage differences in molecular structure to spatially control transfer at both nanoscopic and microscopic scales. We compare transfer properties of five different single- and dual-chain amphiphiles, demonstrating that those with strong lateral interactions (e.g., hydrogen-bonding networks) exhibit the lowest transfer efficiencies. Since molecular structures also influence microscopic domain morphologies in Langmuir films, we show that it is possible to transfer such microscale patterns, taking advantage of variations in the local transfer rates based on the structural heterogeneity in Langmuir films. Nanoscale domain morphologies also vary in ways that are consistent with predicted relative transfer and diffusion rates. These results suggest strategies to tailor noncovalent functionalization of 2D substrates through controlled LS transfer.

Fractal mechanisms in the electrophysiology of the heart

NASA Technical Reports Server (NTRS)

Goldberger, A. L.

1992-01-01

The mathematical concept of fractals provides insights into complex anatomic branching structures that lack a characteristic (single) length scale, and certain complex physiologic processes, such as heart rate regulation, that lack a single time scale. Heart rate control is perturbed by alterations in neuro-autonomic function in a number of important clinical syndromes, including sudden cardiac death, congestive failure, cocaine intoxication, fetal distress, space sickness and physiologic aging. These conditions are associated with a loss of the normal fractal complexity of interbeat interval dynamics. Such changes, which may not be detectable using conventional statistics, can be quantified using new methods derived from "chaos theory.".

Magnetic Shear Damped Polar Convective Fluid Instabilities

NASA Astrophysics Data System (ADS)

Atul, Jyoti K.; Singh, Rameswar; Sarkar, Sanjib; Kravchenko, Oleg V.; Singh, Sushil K.; Chattopadhyaya, Prabal K.; Kaw, Predhiman K.

2018-01-01

The influence of the magnetic field shear is studied on the E × B (and/or gravitational) and the Current Convective Instabilities (CCI) occurring in the high-latitude F layer ionosphere. It is shown that magnetic shear reduces the growth rate of these instabilities. The magnetic shear-induced stabilization is more effective at the larger-scale sizes (≥ tens of kilometers) while at the scintillation causing intermediate scale sizes (˜ a few kilometers), the growth rate remains largely unaffected. The eigenmode structure gets localized about a rational surface due to finite magnetic shear and has broken reflectional symmetry due to centroid shift of the mode by equilibrium parallel flow or current.

Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces

NASA Technical Reports Server (NTRS)

Dussinger, Peter M.; Lindemuth, James E.

1997-01-01

The principal objective of this Phase 2 SBIR program was to develop and demonstrate a practically insoluble coating for nickel-based superalloys for Stirling engine heat pipe applications. Specific technical objectives of the program were: (1) Determine the solubility corrosion rates for Nickel 200, Inconel 718, and Udimet 72OLI in a simulated Stirling engine heat pipe environment, (2) Develop coating processes and techniques for capillary groove and screen wick structures, (3) Evaluate the durability and solubility corrosion rates for capillary groove and screen wick structures coated with an insoluble coating in cylindrical heat pipes operating under Stirling engine conditions, and (4) Design and fabricate a coated full-scale, partial segment of the current Stirling engine heat pipe for the Stirling Space Power Convertor program. The work effort successfully demonstrated a two-step nickel aluminide coating process for groove wick structures and interior wall surfaces in contact with liquid metals; demonstrated a one-step nickel aluminide coating process for nickel screen wick structures; and developed and demonstrated a two-step aluminum-to-nickel aluminide coating process for nickel screen wick structures. In addition, the full-scale, partial segment was fabricated and the interior surfaces and wick structures were coated. The heat pipe was charged with sodium, processed, and scheduled to be life tested for up to ten years as a Phase 3 effort.

Estimation of fine-scale recombination intensity variation in the white-echinus interval of D. melanogaster

PubMed Central

Singh, Nadia D.; Aquadro, Charles F.; Clark, Andrew G.

2009-01-01

Accurate assessment of local recombination rate variation is crucial for understanding the recombination process and for determining the impact of natural selection on linked sites. In Drosophila, local recombination intensity has been estimated primarily by statistical approaches, estimating the local slope of the relationship between the physical and genetic maps. However, these estimates are limited in resolution, and as a result, the physical scale at which recombination intensity varies in Drosophila is largely unknown. While there is some evidence suggesting as much as a 40-fold variation in crossover rate at a local scale in D. pseudoobscura, little is known about the fine-scale structure of recombination rate variation in D. melanogaster. Here, we experimentally examine the fine-scale distribution of crossover events in a 1.2 Mb region on the D. melanogaster X chromosome using a classic genetic mapping approach. Our results show that crossover frequency is significantly heterogeneous within this region, varying ~ 3.5 fold. Simulations suggest that this degree of heterogeneity is sufficient to affect levels of standing nucleotide diversity, although the magnitude of this effect is small. We recover no statistical association between empirical estimates of nucleotide diversity and recombination intensity, which is likely due to the limited number of loci sampled in our population genetic dataset. However, codon bias is significantly negatively correlated with fine-scale recombination intensity estimates, as expected. Our results shed light on the relevant physical scale to consider in evolutionary analyses relating to recombination rate, and highlight the motivations to increase the resolution of the recombination map in Drosophila. PMID:19504037

A two-scale model for dynamic damage evolution

NASA Astrophysics Data System (ADS)

Keita, Oumar; Dascalu, Cristian; François, Bertrand

2014-03-01

This paper presents a new micro-mechanical damage model accounting for inertial effect. The two-scale damage model is fully deduced from small-scale descriptions of dynamic micro-crack propagation under tensile loading (mode I). An appropriate micro-mechanical energy analysis is combined with homogenization based on asymptotic developments in order to obtain the macroscopic evolution law for damage. Numerical simulations are presented in order to illustrate the ability of the model to describe known behaviors like size effects for the structural response, strain-rate sensitivity, brittle-ductile transition and wave dispersion.

Factor structure of the Brief Negative Symptom Scale.

PubMed

Strauss, Gregory P; Hong, L Elliot; Gold, James M; Buchanan, Robert W; McMahon, Robert P; Keller, William R; Fischer, Bernard A; Catalano, Lauren T; Culbreth, Adam J; Carpenter, William T; Kirkpatrick, Brian

2012-12-01

The current study examined the factor structure of the Brief Negative Symptom Scale (BNSS), a next-generation negative symptom rating instrument developed in response to the NIMH-sponsored Consensus Development Conference on Negative Symptoms. Participants included 146 individuals with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder. Principal axis factoring indicated two distinct factors explaining 68.7% of the variance. Similar to previous findings, the factors reflected motivation and pleasure and emotional expressivity. These findings provide further support for the construct validity of the BNSS, and for the existence of these two negative symptom factors. Copyright © 2012 Elsevier B.V. All rights reserved.

Aqueous turbulence structure immediately adjacent to the air - water interface and interfacial gas exchange

NASA Astrophysics Data System (ADS)

Wang, Binbin

Air-sea interaction and the interfacial exchange of gas across the air-water interface are of great importance in coupled atmospheric-oceanic environmental systems. Aqueous turbulence structure immediately adjacent to the air-water interface is the combined result of wind, surface waves, currents and other environmental forces and plays a key role in energy budgets, gas fluxes and hence the global climate system. However, the quantification of turbulence structure sufficiently close to the air-water interface is extremely difficult. The physical relationship between interfacial gas exchange and near surface turbulence remains insufficiently investigated. This dissertation aims to measure turbulence in situ in a complex environmental forcing system on Lake Michigan and to reveal the relationship between turbulent statistics and the CO2 flux across the air-water interface. The major objective of this dissertation is to investigate the physical control of the interfacial gas exchange and to provide a universal parameterization of gas transfer velocity from environmental factors, as well as to propose a mechanistic model for the global CO2 flux that can be applied in three dimensional climate-ocean models. Firstly, this dissertation presents an advanced measurement instrument, an in situ free floating Particle Image Velocimetry (FPIV) system, designed and developed to investigate the small scale turbulence structure immediately below the air-water interface. Description of hardware components, design of the system, measurement theory, data analysis procedure and estimation of measurement error were provided. Secondly, with the FPIV system, statistics of small scale turbulence immediately below the air-water interface were investigated under a variety of environmental conditions. One dimensional wave-number spectrum and structure function sufficiently close to the water surface were examined. The vertical profiles of turbulent dissipation rate were intensively studied. Comparison between the turbulence structures measured during the wind wave initiation period and those obtained during the growing period was presented. Significant wave effects on near surface turbulence were found. A universal scaling law was proposed to parameterize turbulent dissipation rate immediately below the air-water interface with friction velocity, significant wave height and wave age. Finally, the gas transfer velocity was measured with a floating chamber (FC) system, along with simultaneously FPIV measurements. Turbulent dissipation rate both at the interface and at a short distance away from the interface (~ 10 cm) were analyzed and used to examine the small scale eddy model. The model coefficient was found to be dependent on the level of turbulence, instead of being a constant. An empirical relationship between the model coefficient and turbulent dissipation rate was provided, which improved the accuracy of the gas transfer velocity estimation by more than 100% for data acquired. Other data from the literature also supported this empirical relation. Furthermore, the relationship between model coefficient and turbulent Reynolds number was also investigated. In addition to physical control of gas exchange, the disturbance on near surface hydrodynamics by the FC was also discussed. Turbulent dissipation rates are enhanced at the short distance away from the interface, while the surface dissipation rates do not change significantly.

Evaluating Mediated Perception of Narrative Health Messages: The Perception of Narrative Performance Scale

PubMed Central

Lee, Jeong Kyu; Hecht, Michael L.; Miller-Day, Michelle; Elek, Elvira

2011-01-01

Narrative media health messages have proven effective in preventing adolescents’ substance use but as yet few measures exist to assess perceptions of them. Without such a measure it is difficult to evaluate the role these messages play in health promotion or to differentiate them from other message forms. In response to this need, a study was conducted to evaluate the Perception of Narrative Performance Scale that assesses perceptions of narrative health messages. A sample of 1185 fifth graders in public schools at Phoenix, Arizona completed a questionnaire rating of two videos presenting narrative substance use prevention messages. Confirmatory factor analyses were computed to identify the factor structure of the scale. Consistent with prior studies, results suggest a 3 factor structure for the Perception of Narrative Performance Scale: interest, realism, and identification (with characters). In addition, a path analysis was performed to test the predictive power of the scale. The analysis shows that the scale proves useful in predicting intent to use substances. Finally, practical implications and limitations are discussed. PMID:21822459

[Factor structure of the German version of the BIS/BAS Scales in a population-based sample].

PubMed

Müller, A; Smits, D; Claes, L; de Zwaan, M

2013-02-01

The Behavioural Inhibition System/Behavioural Activation System Scale (BIS/BAS-Scales) developed by Carver and White 1 is a self-rating instrument to assess the dispositional sensitivity to punishment and reward. The present work aims to examine the factor structure of the German version of the BIS/BAS-Scales. In a large German population-based sample (n = 1881) the model fit of several factor models was tested by using confirmatory factor analyses. The best model fit was found for the 5-factor model with two BIS (anxiety, fear) and three BAS (drive, reward responsiveness, fun seeking) scales, whereas the BIS-fear, the BAS-reward responsiveness, and the BAS-fun seeking subscales showed low internal consistency. The BIS/BAS scales were negatively correlated with age, and women reported higher BIS subscale scores than men. Confirmatory factor analyses suggest a 5-factor model. However, due to the low internal reliability of some of the subscales the use of this model is questionable. © Georg Thieme Verlag KG Stuttgart · New York.

A dimensional approach to measuring anxiety for DSM-5.

PubMed

Lebeau, Richard T; Glenn, Daniel E; Hanover, Lauren N; Beesdo-Baum, Katja; Wittchen, Hans-Ulrich; Craske, Michelle G

2012-12-01

In preparation for DSM-5's planned inclusion of dimensional assessments of psychopathology as a complement to traditional categorical diagnoses, we developed brief self-rated scales for anxiety disorders that are consistent in content and structure. In the present paper, we discuss the creation of the scales and examine their psychometric properties and clinical sensitivity. Phase One assessed psychometric properties of the initial versions of the scales in a large non-clinical sample (n = 702). Phase Two assessed the psychometric properties of revised versions of the scales, including test-retest reliability, in a non-clinical sample (n = 57). Phase Three examined the scales' psychometric properties and relationship with clinician ratings of disorder severity in a clinical sample (n = 48). The scales demonstrated internal consistency (α = 0.85-0.92), convergent validity (r(s)  = 0.39-0.69), and test-retest reliability in the non-clinical samples (ICC = 0.51-0.81). In the clinical sample, the scales demonstrated significantly higher total scores than in the non-clinical sample (Cohen's d = 0.72-1.50) and moderate to high correlations with clinician ratings of disorder severity (r = 0.43-0.82) Although further evaluation and refinement of the scales (particularly the specific phobia and agoraphobia scales) is needed, the results provide preliminary support for the use of these scales in DSM-5 and thus take an important step toward the integration of standardized dimensional measurement into the diagnosis of anxiety disorders. Copyright © 2012 American Psychiatric Association. All rights reserved.

Inter-rater reliability of Hamilton depression rating scale using video-recorded interviews — Focus on rater-blinding

PubMed Central

Prasad, M. Krishna; Udupa, K.; Kishore, K. R.; Thirthalli, J.; Sathyaprabha, T. N.; Gangadhar, B. N.

2009-01-01

Background: Hamilton depression rating scale (Ham-D) is the most widely used clinician rating scale for depression. There has been no Indian study that has examined the inter-rater reliability (IRR) of video-recorded interviews of the 21-item Ham-D. Aim: To study the IRR of scoring video-recorded interviews for 21-item Ham-D. Materials and Methods: Eighteen subjects with major depressive disorder involved in a larger study were interviewed using the semi-structured clinical interview of the 21-item Ham-D by a primary rater after informed consent. These interviews were video-recorded and portions edited to ensure rater blinding. Subsequently, the video-recorded interviews were rated by a “blind” rater. Both rated the different sub-domains of Ham-D according to Rhoades and Overall (1983). IRR was evaluated using intra-class correlation coefficient. Results: Excellent IRR was observed (0.9891) between the two raters. This was true for each of the primary factors and super-factors. Conclusion: Video recorded 21-item Ham-D has excellentIRR. Video-recorded interviews of Ham-D can be reliably used to blind raters in research. PMID:19881046

Forest fragmentation and bird community dynamics: inference at regional scales

USGS Publications Warehouse

Boulinier, T.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Flather, C.H.; Pollock, K.H.

2001-01-01

With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction and turnover rates, which could explain higher temporal variability in species richness. To investigate such potential landscape effects at a regional scale, we merged two independent, large-scale monitoring efforts: the North American Breeding Bird Survey (BBS) and the Land Use and Land Cover Classification data from the U.S. Geological Survey. We used methods that accounted for heterogeneity in the probability of detecting species to estimate species richness and temporal changes in the bird communities for BBS routes in three mid-Atlantic U.S. states. Forest breeding bird species were grouped prior to the analyses into area-sensitive and non-area-sensitive species according to previous studies. We tested predictions relating measures of forest structure at one point in time (1974) to species richness at that time and to parameters of forest bird community change over the following 22-yr-period (1975-1996). We used the mean size of forest patches to characterize landscape structure, as high correlations among landscape variables did not allow us to disentangle the relative roles of habitat fragmentation per se and habitat loss. As predicted, together with lower species richness for area-sensitive species on routes surrounded by landscapes with lower mean forest-patch size, we found higher mean year-to-year rates of local extinction. Moreover, the mean year-to-year rates of local turnover (proportion of locally new species) for area-sensitive species were also higher in landscapes with lower mean forest-patch size. These associations were not observed for the non-area-sensitive species group. These results suggest that landscape structure may influence forest bird communities at regional scales through its effects on the total number of species but also on the temporal rates of change in community composition. Evidence for higher rates of local extinction and turnover in more fragmented landscapes suggests that bird communities function as metapopulations at a regional scale, and points out the importance of colonizations and recolonizations from surrounding landscapes to local community dynamics. Further, our results illustrate that the methods used to estimate the community parameters can be a powerful statistical tool in addressing questions relative to the dynamics of communities.

Growth of matter perturbation in quintessence cosmology

NASA Astrophysics Data System (ADS)

Mulki, Fargiza A. M.; Wulandari, Hesti R. T.

2017-01-01

Big bang theory states that universe emerged from singularity with very high temperature and density, then expands homogeneously and isotropically. This theory gives rise standard cosmological principle which declares that universe is homogeneous and isotropic on large scales. However, universe is not perfectly homogeneous and isotropic on small scales. There exist structures starting from clusters, galaxies even to stars and planetary system scales. Cosmological perturbation theory is a fundamental theory that explains the origin of structures. According to this theory, the structures can be regarded as small perturbations in the early universe, which evolves as the universe expands. In addition to the problem of inhomogeneities of the universe, observations of supernovae Ia suggest that our universe is being accelerated. Various models of dark energy have been proposed to explain cosmic acceleration, one of them is cosmological constant. Because of several problems arise from cosmological constant, the alternative models have been proposed, one of these models is quintessence. We reconstruct growth of structure model following quintessence scenario at several epochs of the universe, which is specified by the effective equation of state parameters for each stage. Discussion begins with the dynamics of quintessence, in which exponential potential is analytically derived, which leads to various conditions of the universe. We then focus on scaling and quintessence dominated solutions. Subsequently, we review the basics of cosmological perturbation theory and derive formulas to investigate how matter perturbation evolves with time in subhorizon scales which leads to structure formation, and also analyze the influence of quintessence to the structure formation. From analytical exploration, we obtain the growth rate of matter perturbation and the existence of quintessence as a dark energy that slows down the growth of structure formation of the universe.

The limiting layer of fish scales: Structure and properties

DOE PAGES

Arola, D.; Murcia, S.; Stossel, M.; ...

2017-12-14

Fish scales serve as a flexible natural armor that have received increasing attention across the materials community. Most efforts in this area have focused on the composite structure of the predominately organic elasmodine, and limited work addresses the highly mineralized external portion known as the Limiting Layer (LL). This coating serves as the first barrier to external threats and plays an important role in resisting puncture. Here in this investigation the structure, composition and mechanical behavior of the LL were explored for three different fish, including the arapaima (Arapaima gigas), the tarpon (Megalops atlanticus) and the carp (Cyprinus carpio). Themore » scales of these three fish have received the most attention within the materials community. Features of the LL were evaluated with respect to anatomical position to distinguish site-specific functional differences. Results show that there are significant differences in the surface morphology of the LL from posterior and anterior regions in the scales, and between the three fish species. The calcium to phosphorus ratio and the mineral to collagen ratios of the LL are not equivalent among the three fish. Finally, results from nanoindentation showed that the LL of tarpon scales is the hardest, followed by the carp and the arapaima and the differences in hardness are related to the apatite structure, possibly induced by the growth rate and environment of each fish.« less

The limiting layer of fish scales: Structure and properties

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

Arola, D.; Murcia, S.; Stossel, M.

Fish scales serve as a flexible natural armor that have received increasing attention across the materials community. Most efforts in this area have focused on the composite structure of the predominately organic elasmodine, and limited work addresses the highly mineralized external portion known as the Limiting Layer (LL). This coating serves as the first barrier to external threats and plays an important role in resisting puncture. Here in this investigation the structure, composition and mechanical behavior of the LL were explored for three different fish, including the arapaima (Arapaima gigas), the tarpon (Megalops atlanticus) and the carp (Cyprinus carpio). Themore » scales of these three fish have received the most attention within the materials community. Features of the LL were evaluated with respect to anatomical position to distinguish site-specific functional differences. Results show that there are significant differences in the surface morphology of the LL from posterior and anterior regions in the scales, and between the three fish species. The calcium to phosphorus ratio and the mineral to collagen ratios of the LL are not equivalent among the three fish. Finally, results from nanoindentation showed that the LL of tarpon scales is the hardest, followed by the carp and the arapaima and the differences in hardness are related to the apatite structure, possibly induced by the growth rate and environment of each fish.« less

The Microphysical Structure of Extreme Precipitation as Inferred from Ground-Based Raindrop Spectra.

NASA Astrophysics Data System (ADS)

Uijlenhoet, Remko; Smith, James A.; Steiner, Matthias

2003-05-01

The controls on the variability of raindrop size distributions in extreme rainfall and the associated radar reflectivity-rain rate relationships are studied using a scaling-law formalism for the description of raindrop size distributions and their properties. This scaling-law formalism enables a separation of the effects of changes in the scale of the raindrop size distribution from those in its shape. Parameters controlling the scale and shape of the scaled raindrop size distribution may be related to the microphysical processes generating extreme rainfall. A global scaling analysis of raindrop size distributions corresponding to rain rates exceeding 100 mm h1, collected during the 1950s with the Illinois State Water Survey raindrop camera in Miami, Florida, reveals that extreme rain rates tend to be associated with conditions in which the variability of the raindrop size distribution is strongly number controlled (i.e., characteristic drop sizes are roughly constant). This means that changes in properties of raindrop size distributions in extreme rainfall are largely produced by varying raindrop concentrations. As a result, rainfall integral variables (such as radar reflectivity and rain rate) are roughly proportional to each other, which is consistent with the concept of the so-called equilibrium raindrop size distribution and has profound implications for radar measurement of extreme rainfall. A time series analysis for two contrasting extreme rainfall events supports the hypothesis that the variability of raindrop size distributions for extreme rain rates is strongly number controlled. However, this analysis also reveals that the actual shapes of the (measured and scaled) spectra may differ significantly from storm to storm. This implies that the exponents of power-law radar reflectivity-rain rate relationships may be similar, and close to unity, for different extreme rainfall events, but their prefactors may differ substantially. Consequently, there is no unique radar reflectivity-rain rate relationship for extreme rain rates, but the variability is essentially reduced to one free parameter (i.e., the prefactor). It is suggested that this free parameter may be estimated on the basis of differential reflectivity measurements in extreme rainfall.

A novel approach to assess clinical competence of postgraduate year 1 surgery residents

PubMed Central

Qi, Xin; Ding, Lian; Zhai, Wei; Li, Qiang; Li, Yan; Li, Haichao; Wen, Bing

2017-01-01

ABSTRACT Background: An increased demand for accountability and transparency in medicine have initiated a shift toward a more objective and standardized approach for postgraduate medical training. Objective: To develop and evaluate an objective method to assess clinical competence of postgraduate year 1 surgery residents. Design: Thirty-one postgraduate year 1 surgery residents, who had been trained in the Surgical School of Peking University First Hospital for one year, participated in an objective structured clinical examination as a final assessment of their clinical competence. A test station of irregular wound repair (debridement and suture) was specially designed to test the residents’ surgical integrative competence in a complex-trauma treatment procedure. A modified global rating scale, in combination with wound area measurement, was applied to evaluate residents’ surgical performance. The validity of the subjective global rating scale was evaluated by the objective measurement results from the software. Results: The global rating scale score had no obvious correlation with the area of the removed tissue and the residual wound area after the suture. There was significant difference in the debridement time and the residual wound area between 0–3 and >3 total stitches. There were significant differences in the area of the removed tissue between 0 and 1–2 grey stitches and 0 and 3–4 grey stitches, and in the residual wound area after suture between 0 and 3–4 grey stitches and 1–2 and 3–4 grey stitches. Conclusions: An irregular wound repair procedure could be an effective method to assess the integrative competence of surgery residents. The training for surgical thinking in the early stage of junior residents needs to be strengthened. The entire measurement process was more complex and time-consuming than expected. The possibility of measurement by simply counting the numbers of the key spots might be explored in the future. Abbreviations: ACS/APDS American College of Surgeons/Association of Program Directors in Surgery; GRS Global rating scale; LSD-T Least significant difference-test; OSATS Objective structured assessment of technical skills; OSCE Objective structured clinical examination; PBT Proficiency based training; PGY1 Postgraduate Year 1 PMID:28670976

The Effect of Verb Semantic Class and Verb Frequency (Entrenchment) on Children's and Adults' Graded Judgements of Argument-Structure Overgeneralization Errors

ERIC Educational Resources Information Center

Ambridge, Ben; Pine, Julian M.; Rowland, Caroline F.; Young, Chris R.

2008-01-01

Participants (aged 5-6 yrs, 9-10 yrs and adults) rated (using a five-point scale) grammatical (intransitive) and overgeneralized (transitive causative) uses of a high frequency, low frequency and novel intransitive verb from each of three semantic classes [Pinker, S. (1989a). "Learnability and cognition: the acquisition of argument structure."…

Nuclear Structure Aspects in Nuclear Astrophysics

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

Smith, Michael Scott

2006-12-01

Nuclear Astrophysics as a broad and diverse field of study can be viewed as a magnifier of the impact of microscopic processes on the evolution of macroscopic events. One of the primary goals in Nuclear Astrophysics is the understanding of the nucleosynthesis processes that take place in the cosmos and the simulation of the correlated stellar and explosive burning scenarios. These simulations are strongly dependent on the input from Nuclear Physics which sets the time scale for all stellar dynamic processes--from giga-years of stellar evolution to milliseconds of stellar explosions--and provides the basis for most of the signatures that wemore » have for the interpretation of these events--from stellar luminosities, elemental and isotopic abundances to neutrino flux from distant supernovae. The Nuclear Physics input comes through nuclear structure, low energy reaction rates, nuclear masses, and decay rates. There is a common perception that low energy reaction rates are the most important component of the required nuclear physics input; however, in this article we take a broader approach and present an overview of the close correlation between various nuclear structure aspects and their impact on nuclear astrophysics. We discuss the interplay between the weak and the strong forces on stellar time scales due to the limitations they provide for the evolution of slow and rapid burning processes. The effects of shell structure in nuclei on stellar burning processes as well as the impact of clustering in nuclei is outlined. Furthermore we illustrate the effects of the various nuclear structure aspects on the major nucleosynthesis processes that have been identified in the last few decades. We summarize and provide a coherent overview of the impact of all aspects of nuclear structure on nuclear astrophysics.« less

Large-Scale Flow Structure in Turbulent Nonpremixed Flames under Normal- And Low-Gravity Conditions

NASA Technical Reports Server (NTRS)

Clemens, N. T.; Idicheria, C. A.; Boxx, I. G.

2001-01-01

It is well known that buoyancy has a major influence on the flow structure of turbulent nonpremixed jet flames. Buoyancy acts by inducing baroclinic torques, which generate large-scale vortical structures that can significantly modify the flow field. Furthermore, some suggest that buoyancy can substantially influence the large-scale structure of even nominally momentum-dominated flames, since the low velocity flow outside of the flame will be more susceptible to buoyancy effects. Even subtle buoyancy effects may be important because changes in the large-scale structure affects the local entrainment and fluctuating strain rate, and hence the structure of the flame. Previous studies that have compared the structure of normal- and micro-gravity nonpremixed jet flames note that flames in microgravity are longer and wider than in normal-gravity. This trend was observed for jet flames ranging from laminar to turbulent regimes. Furthermore, imaging of the flames has shown possible evidence of helical instabilities and disturbances starting from the base of the flame in microgravity. In contrast, these characteristics were not observed in normal-gravity. The objective of the present study is to further advance our knowledge of the effects of weak levels of buoyancy on the structure of transitional and turbulent nonpremixed jet flames. In later studies we will utilize the drop tower facilities at NASA Glenn Research Center (GRC), but the preliminary work described in this paper was conducted using the 1.25-second drop tower located at the University of Texas at Austin. A more detailed description of these experiments can be found in Idicheria et al.

Gravo-Aeroelastic Scaling for Extreme-Scale Wind Turbines

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

Fingersh, Lee J; Loth, Eric; Kaminski, Meghan

2017-06-09

A scaling methodology is described in the present paper for extreme-scale wind turbines (rated at 10 MW or more) that allow their sub-scale turbines to capture their key blade dynamics and aeroelastic deflections. For extreme-scale turbines, such deflections and dynamics can be substantial and are primarily driven by centrifugal, thrust and gravity forces as well as the net torque. Each of these are in turn a function of various wind conditions, including turbulence levels that cause shear, veer, and gust loads. The 13.2 MW rated SNL100-03 rotor design, having a blade length of 100-meters, is herein scaled to the CART3more » wind turbine at NREL using 25% geometric scaling and blade mass and wind speed scaled by gravo-aeroelastic constraints. In order to mimic the ultralight structure on the advanced concept extreme-scale design the scaling results indicate that the gravo-aeroelastically scaled blades for the CART3 are be three times lighter and 25% longer than the current CART3 blades. A benefit of this scaling approach is that the scaled wind speeds needed for testing are reduced (in this case by a factor of two), allowing testing under extreme gust conditions to be much more easily achieved. Most importantly, this scaling approach can investigate extreme-scale concepts including dynamic behaviors and aeroelastic deflections (including flutter) at an extremely small fraction of the full-scale cost.« less

High-rate RTK and PPP multi-GNSS positioning for small-scale dynamic displacements monitoring

NASA Astrophysics Data System (ADS)

Paziewski, Jacek; Sieradzki, Rafał; Baryła, Radosław; Wielgosz, Pawel

2017-04-01

The monitoring of dynamic displacements and deformations of engineering structures such as buildings, towers and bridges is of great interest due to several practical and theoretical reasons. The most important is to provide information required for safe maintenance of the constructions. High temporal resolution and precision of GNSS observations predestine this technology to be applied to most demanding application in terms of accuracy, availability and reliability. GNSS technique supported by appropriate processing methodology may meet the specific demands and requirements of ground and structures monitoring. Thus, high-rate multi-GNSS signals may be used as reliable source of information on dynamic displacements of ground and engineering structures, also in real time applications. In this study we present initial results of application of precise relative GNSS positioning for detection of small scale (cm level) high temporal resolution dynamic displacements. Methodology and algorithms applied in self-developed software allowing for relative positioning using high-rate dual-frequency phase and pseudorange GPS+Galileo observations are also given. Additionally, an approach was also made to use the Precise Point Positioning technique to such application. In the experiment were used the observations obtained from high-rate (20 Hz) geodetic receivers. The dynamic displacements were simulated using specially constructed device moving GNSS antenna with dedicated amplitude and frequency. The obtained results indicate on possibility of detection of dynamic displacements of the GNSS antenna even at the level of few millimetres using both relative and Precise Point Positioning techniques after suitable signals processing.

Atomic-scale structural signature of dynamic heterogeneities in metallic liquids

NASA Astrophysics Data System (ADS)

Pasturel, Alain; Jakse, Noel

2017-08-01

With sufficiently high cooling rates, liquids will cross their equilibrium melting temperatures and can be maintained in a metastable undercooled state before solidifying. Studies of undercooled liquids reveal several intriguing dynamic phenomena and because explicit connections between liquid structure and liquids dynamics are difficult to identify, it remains a major challenge to capture the underlying structural link to these phenomena. Ab initio molecular dynamics (AIMD) simulations are yet especially powerful in providing atomic-scale details otherwise not accessible in experiments. Through the AIMD-based study of Cr additions in Al-based liquids, we evidence for the first time a close relationship between the decoupling of component diffusion and the emergence of dynamic heterogeneities in the undercooling regime. In addition, we demonstrate that the origin of both phenomena is related to a structural heterogeneity caused by a strong interplay between chemical short-range order (CSRO) and local fivefold topology (ISRO) at the short-range scale in the liquid phase that develops into an icosahedral-based medium-range order (IMRO) upon undercooling. Finally, our findings reveal that this structural signature is also captured in the temperature dependence of partial pair-distribution functions which opens up the route to more elaborated experimental studies.

Uncovering a facile large-scale synthesis of LiNi1/3Co1/3Mn1/3O2 nanoflowers for high power lithium-ion batteries

NASA Astrophysics Data System (ADS)

Hua, Wei-Bo; Guo, Xiao-Dong; Zheng, Zhuo; Wang, Yan-Jie; Zhong, Ben-He; Fang, Baizeng; Wang, Jia-Zhao; Chou, Shu-Lei; Liu, Heng

2015-02-01

Developing advanced electrode materials that deliver high energy at ultra-fast charge and discharge rates are very crucial to meet an increasing large-scale market demand for high power lithium ion batteries (LIBs). A three-dimensional (3D) nanoflower structure is successfully developed in the large-scale synthesis of LiNi1/3Co1/3Mn1/3O2 material for the first time. The fast co-precipitation is the key technique to prepare the nanoflower structure in our method. After heat treatment, the obtained LiNi1/3Co1/3Mn1/3O2 nanoflowers (NL333) pronouncedly present a pristine flower-like nano-architecture and provide fast pathways for the transport of Li-ions and electrons. As a cathode material in a LIB, the prepared NL333 electrode demonstrates an outstanding high-rate capability. Particularly, in a narrow voltage range of 2.7-4.3 V, the discharge capacity at an ultra-fast charge-discharge rate (20C) is up to 126 mAh g-1, which reaches 78% of that at 0.2C, and is much higher than that (i.e., 44.17%) of the traditional bulk LiNi1/3Co1/3Mn1/3O2.

An Acrobatic Substrate Metamorphosis Reveals a Requirement for Substrate Conformational Dynamics in Trypsin Proteolysis.

PubMed

Kayode, Olumide; Wang, Ruiying; Pendlebury, Devon F; Cohen, Itay; Henin, Rachel D; Hockla, Alexandra; Soares, Alexei S; Papo, Niv; Caulfield, Thomas R; Radisky, Evette S

2016-12-16

The molecular basis of enzyme catalytic power and specificity derives from dynamic interactions between enzyme and substrate during catalysis. Although considerable effort has been devoted to understanding how conformational dynamics within enzymes affect catalysis, the role of conformational dynamics within protein substrates has not been addressed. Here, we examine the importance of substrate dynamics in the cleavage of Kunitz-bovine pancreatic trypsin inhibitor protease inhibitors by mesotrypsin, finding that the varied conformational dynamics of structurally similar substrates can profoundly impact the rate of catalysis. A 1.4-Å crystal structure of a mesotrypsin-product complex formed with a rapidly cleaved substrate reveals a dramatic conformational change in the substrate upon proteolysis. By using long all-atom molecular dynamics simulations of acyl-enzyme intermediates with proteolysis rates spanning 3 orders of magnitude, we identify global and local dynamic features of substrates on the nanosecond-microsecond time scale that correlate with enzymatic rates and explain differential susceptibility to proteolysis. By integrating multiple enhanced sampling methods for molecular dynamics, we model a viable conformational pathway between substrate-like and product-like states, linking substrate dynamics on the nanosecond-microsecond time scale with large collective substrate motions on the much slower time scale of catalysis. Our findings implicate substrate flexibility as a critical determinant of catalysis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

High heritability of speech and language impairments in 6-year-old twins demonstrated using parent and teacher report.

PubMed

Bishop, Dorothy V M; Laws, Glynis; Adams, Caroline; Norbury, Courtenay Frazier

2006-03-01

Previous twin studies have demonstrated high heritability of specific language impairment (SLI) when the diagnosis is based on psychometric testing. The current study measured the effectiveness of parent and teacher ratings of communication skills in identifying heritable language impairment. The Children's Communication Checklist was completed by parents and teachers of 6-year-old twins recruited from a general population sample. One hundred and thirty twin pairs (65 MZ) were selected because at least one twin had low language skills at 4 years of age; a further 66 pairs (37 MZ) were a low risk group with no indication of language difficulties at 4 years. Internal consistency, inter-rater reliability, and validity in identifying language impairment were assessed for all CCC scales. CCC scales, especially those assessing structural language skills, were highly effective in identifying cases of language impairment, but agreement between parent and teacher ratings was modest. Genetic analysis revealed negligible environmental influence and substantial genetic influence on most scales. A rater-specific effects model was fit to the data to assess how far parents and teachers assess a common genetic factor on the CCC. Ratings of parents and teachers were influenced to some extent by the same child characteristics, but rater-specific effects were also evident, especially on scales measuring pragmatic aspects of communication. This study shows that there are strong genetic influences on both structural and pragmatic language impairments in children, and these can be detected using a simple checklist completed by parents or teachers.

Bringing isolated dark matter out of isolation: Late-time reheating and indirect detection

NASA Astrophysics Data System (ADS)

Erickcek, Adrienne L.; Sinha, Kuver; Watson, Scott

2016-09-01

In standard cosmology, the growth of structure becomes significant following matter-radiation equality. In nonthermal histories, where an effectively matter-dominated phase occurs due to scalar oscillations prior to big bang nucleosynthesis, a new scale at smaller wavelengths appears in the matter power spectrum. Density perturbations that enter the horizon during the early matter-dominated era (EMDE) grow linearly with the scale factor prior to the onset of radiation domination, which leads to enhanced inhomogeneity on small scales if dark matter (DM) thermally and kinetically decouples during the EMDE. The microhalos that form from these enhanced perturbations significantly boost the self-annihilation rate for dark matter. This has important implications for indirect detection experiments: the larger annihilation rate may result in observable signals from dark matter candidates that are usually deemed untestable. As a proof of principle, we consider binos in heavy supersymmetry with an intermediate extended Higgs sector and all other superpartners decoupled. We find that these isolated binos, which lie under the neutrino floor, can account for the dark matter relic density and decouple from the standard model early enough to preserve the enhanced small-scale inhomogeneity generated during the EMDE. If early forming microhalos survive as subhalos within larger microhalos, the resulting boost to the annihilation rate for bino dark matter near the pseudoscalar resonance exceeds the upper limit established by Fermi-LAT's observations of dwarf spheroidal galaxies. These DM candidates motivate the N -body simulations required to eliminate uncertainties in the microhalos' internal structure by exemplifying how an EMDE can enable Fermi-LAT to probe isolated dark matter.

Are Trade-Offs Among Species’ Ecological Interactions Scale Dependent? A Test Using Pitcher-Plant Inquiline Species

PubMed Central

Kneitel, Jamie M.

2012-01-01

Trade-offs among species’ ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species’ ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species’ traits in the context of coexistence at different scales can contribute to our understanding of the mechanisms underlying community structure. PMID:22844526

Abelian Higgs cosmic strings: Small-scale structure and loops

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

Hindmarsh, Mark; Stuckey, Stephanie; Bevis, Neil

2009-06-15

Classical lattice simulations of the Abelian Higgs model are used to investigate small-scale structure and loop distributions in cosmic string networks. Use of the field theory ensures that the small-scale physics is captured correctly. The results confirm analytic predictions of Polchinski and Rocha 29 for the two-point correlation function of the string tangent vector, with a power law from length scales of order the string core width up to horizon scale. An analysis of the size distribution of string loops gives a very low number density, of order 1 per horizon volume, in contrast with Nambu-Goto simulations. Further, our loopmore » distribution function does not support the detailed analytic predictions for loop production derived by Dubath et al. 30. Better agreement to our data is found with a model based on loop fragmentation 32, coupled with a constant rate of energy loss into massive radiation. Our results show a strong energy-loss mechanism, which allows the string network to scale without gravitational radiation, but which is not due to the production of string width loops. From evidence of small-scale structure we argue a partial explanation for the scale separation problem of how energy in the very low frequency modes of the string network is transformed into the very high frequency modes of gauge and Higgs radiation. We propose a picture of string network evolution, which reconciles the apparent differences between Nambu-Goto and field theory simulations.« less

Disturbance Distance: Using a process based ecosystem model to estimate and map potential thresholds in disturbance rates that would give rise to fundamentally altered ecosystems

NASA Astrophysics Data System (ADS)

Dolan, K. A.; Hurtt, G. C.; Fisk, J.; Flanagan, S.; LePage, Y.; Sahajpal, R.

2014-12-01

Disturbance plays a critical role in shaping the structure and function of forested ecosystems as well as the ecosystem services they provide, including but not limited to: carbon storage, biodiversity habitat, water quality and flow, and land atmosphere exchanges of energy and water. As recent studies highlight novel disturbance regimes resulting from pollution, invasive pests and climate change, there is a need to include these alterations in predictions of future forest function and structure. The Ecosystem Demography (ED) model is a mechanistic model of forest ecosystem dynamics in which individual-based forest dynamics can be efficiently implemented over regional to global scales due to advanced scaling methods. We utilize ED to characterize the sensitivity of potential vegetation structure and function to changes in rates of density independent mortality. Disturbance rate within ED can either be altered directly or through the development of sub-models. Disturbance sub-models in ED currently include fire, land use and hurricanes. We use a tiered approach to understand the sensitivity of North American ecosystems to changes in background density independent mortality. Our first analyses were conducted at half-degree spatial resolution with a constant rate of disturbance in space and time, which was altered between runs. Annual climate was held constant at the site level and the land use and fire sub-models were turned off. Results showed an ~ 30% increase in non-forest area across the US when disturbance rates were changed from 0.6% a year to 1.2% a year and a more than 3.5 fold increase in non-forest area when disturbance rates doubled again from 1.2% to 2.4%. Continued runs altered natural background disturbance rates with the existing fire and hurricane sub models turned on as well as historic and future land use. By quantify differences between model outputs that characterize ecosystem structure and function related to the carbon cycle across the US, we are identifying areas and characteristics that display higher sensitivities to change in disturbance rates.

Short forms of the Schedule for Nonadaptive and Adaptive Personality (SNAP) for self- and collateral ratings: development, reliability, and validity.

PubMed

Harlan, E; Clark, L A

1999-06-01

Researchers and clinicians alike increasingly seek brief, reliable, and valid measures to obtain personality trait ratings from both selves and peers. We report the development of a paragraph-descriptor short form of a full-length personality assessment instrument, the Schedule for Nonadaptive and Adaptive Personality (SNAP) with both self- and other versions. Reliability and validity data were collected on a sample of 294 college students, from 90 of whom we also obtained parental ratings of their personality. Internal consistency reliability was good in both self- and parent data. The factorial structures of the self-report short and long forms were very similar. Convergence between parental ratings was moderately high. Self-parent convergence was variable, with lower agreement on scales assessing subjective distress than those assessing more observable behaviors; it also was stronger for higher order factors than for scales.

Measurement properties of the Patient-Rated Wrist and Hand Evaluation: Rasch analysis of responses from a traumatic hand injury population.

PubMed

Packham, Tara; MacDermid, Joy C

2013-01-01

The Patient-Rated Wrist and Hand Evaluation (PRWHE) is a self-reported assessment of pain and disability to evaluate outcome after hand injuries. Rasch analysis is an alternative strategy for examining the psychometric properties of a measurement scale based in item response theory, rather than classical test theory. This study used Rasch analysis to examine the content, scoring and measurement properties of the PRWHE. PRWHE scores (n = 264) from persons with a traumatic injury or reconstructive surgery to one hand were collected from an outpatient hand rehabilitation facility. Rasch analysis was conducted to assess how the PRWHE fit the Rasch model, confirms the scaling structure of the pain and disability subscales, and identifies any areas of bias from differential item functioning. Rasch analysis of the PRWHE supports internal consistency of the scale (α = 0.96) and reliability (as measured by the person separation index) of 0.95. While gender, age, diagnosis, and duration since injury all systematically influenced how people scored the PRWHE, hand dominance and affected side did not. Rasch analysis supported a 3 subscale structure (pain, specific activities and usual activities) rather than the current divisions of pain and disability. Initial examination of the PRWHE indicates the psychometric properties of consistency, reliability and responsiveness previously tested by classical methods are further supported by Rasch analysis. It also suggests the scale structure may be best considered as 3 subscales rather than simply pain and disability. Copyright © 2013 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Differential resistance of drinking water bacterial populations to monochloramine disinfection.

PubMed

Chiao, Tzu-Hsin; Clancy, Tara M; Pinto, Ameet; Xi, Chuanwu; Raskin, Lutgarde

2014-04-01

The impact of monochloramine disinfection on the complex bacterial community structure in drinking water systems was investigated using culture-dependent and culture-independent methods. Changes in viable bacterial diversity were monitored using culture-independent methods that distinguish between live and dead cells based on membrane integrity, providing a highly conservative measure of viability. Samples were collected from lab-scale and full-scale drinking water filters exposed to monochloramine for a range of contact times. Culture-independent detection of live cells was based on propidium monoazide (PMA) treatment to selectively remove DNA from membrane-compromised cells. Quantitative PCR (qPCR) and pyrosequencing of 16S rRNA genes was used to quantify the DNA of live bacteria and characterize the bacterial communities, respectively. The inactivation rate determined by the culture-independent PMA-qPCR method (1.5-log removal at 664 mg·min/L) was lower than the inactivation rate measured by the culture-based methods (4-log removal at 66 mg·min/L). Moreover, drastic changes in the live bacterial community structure were detected during monochloramine disinfection using PMA-pyrosequencing, while the community structure appeared to remain stable when pyrosequencing was performed on samples that were not subject to PMA treatment. Genera that increased in relative abundance during monochloramine treatment include Legionella, Escherichia, and Geobacter in the lab-scale system and Mycobacterium, Sphingomonas, and Coxiella in the full-scale system. These results demonstrate that bacterial populations in drinking water exhibit differential resistance to monochloramine, and that the disinfection process selects for resistant bacterial populations.

Design and Processing of Electret Structures

DTIC Science & Technology

2009-10-31

and width as a function of time. ( d ) Estimated current density j of dissolving copper disk as a function of time. (e) Total current I of dissolving...effect leading to a higher corrosion rate in the galvanic microreactor . Because of the small scale of our galvanic system, the dissolving copper disk is...estimated by focusing with a calibrated microscope stage.   Figure 5: Particle separation and electrolyte convection. Scale bars in ( A , D ) are 100 µm

The independence of physical attractiveness and symptoms of depression in a female twin population.

PubMed

McGovern, R J; Neale, M C; Kendler, K S

1996-03-01

The relationship between physical attractiveness and symptoms of depression was investigated in a general population simple of 1,100 female twins. Photographs were rated by 4 raters. Symptoms of depression were measured by the Depression sub-scale of the SCL-54, by a self-rating based on the DSM-III-R, and by an MD diagnosis based on a structured interview (SCID). No relationships between ratings of physical attractiveness and symptoms of depression were found.

Geometry of tracer trajectories in rotating turbulent flows

NASA Astrophysics Data System (ADS)

Alards, Kim M. J.; Rajaei, Hadi; Del Castello, Lorenzo; Kunnen, Rudie P. J.; Toschi, Federico; Clercx, Herman J. H.

2017-04-01

The geometry of passive tracer trajectories is studied in two different types of rotating turbulent flows; rotating Rayleigh-Bénard convection (RBC; experiments and direct numerical simulations) and rotating electromagnetically forced turbulence (EFT; experiments). This geometry is fully described by the curvature and torsion of trajectories, and from these geometrical quantities we can subtract information on the typical flow structures at different rotation rates. Previous studies, focusing on nonrotating homogeneous isotropic turbulence (HIT), show that the probability density functions (PDFs) of curvature and torsion reveal pronounced power laws. However, the set-ups studied here involve inhomogeneous turbulence, and in RBC the flow near the horizontal plates is definitely anisotropic. We investigate how the typical shapes of the curvature and torsion PDFs, including the pronounced scaling laws, are influenced by this level of anisotropy and inhomogeneity and how this effect changes with rotation. A first effect of rotation is observed as a shift of the curvature and torsion PDFs towards higher values in the case of RBC and towards lower values in the case of EFT. This shift is related to the length scale of typical vortical structures that decreases with rotation in RBC, but increases with rotation in EFT, explaining the opposite shifts of the curvature (and torsion) PDFs. A second remarkable observation is that in RBC the HIT scaling laws are always recovered, as long as the boundary layer (BL) is excluded. This suggests that these scaling laws are very robust and hold as long as we measure in the turbulent bulk. In the BL of the RBC cell, however, the scaling deviates from the HIT prediction for lower rotation rates. This scaling behavior is found to be consistent with the coupling between the boundary layer dynamics and the bulk flow, which changes under rotation. In particular, it is found that the active coupling of the Ekman-type boundary layer with the bulk flow suppresses anisotropy in the BL region for increasing rotation rates.

Flow visualization and acoustic consequences of the air moving through a static model of the human larynx.

PubMed

Kucinschi, Bogdan R; Scherer, Ronald C; DeWitt, Kenneth J; Ng, Terry T M

2006-06-01

Flow visualization with smoke particles illuminated by a laser sheet was used to obtain a qualitative description of the air flow structures through a dynamically similar 7.5x symmetric static scale model of the human larynx (divergence angle of 10 deg, minimal diameter of 0.04 cm real life). The acoustic level downstream of the vocal folds was measured by using a condenser microphone. False vocal folds (FVFs) were included. In general, the glottal flow was laminar and bistable. The glottal jet curvature increased with flow rate and decreased with the presence of the FVFs. The glottal exit flow for the lowest flow rate showed a curved jet which remained laminar for all geometries. For the higher flow rates, the jet flow patterns exiting the glottis showed a laminar jet core, transitioning to vortical structures, and leading spatially to turbulent dissipation. This structure was shortened and tightened with an increase in flow rate. The narrow FVF gap lengthened the flow structure and reduced jet curvature via acceleration of the flow. These results suggest that laryngeal flow resistance and the complex jet flow structure exiting the glottis are highly affected by flow rate and the presence of the false vocal folds. Acoustic consequences are discussed in terms of the quadrupole- and dipole-type sound sources due to ordered flow structures.

A novel in-plane passive microfluidic mixer with modified Tesla structures.

PubMed

Hong, Chien-Chong; Choi, Jin-Woo; Ahn, Chong H

2004-04-01

An innovative in-plane passive micromixer using modified Tesla structures, which are used as passive valves, has been designed, simulated, fabricated and successfully characterized in this paper. Simulation and experimental results of the developed novel micromixer have shown excellent mixing performance over a wide range of flow conditions in the micro scale. The micromixer realized in this work has achieved even better mixing performance at a higher flow rate, and its pressure drop is less than 10 KPa at the flow rate of 100 microl min(-1). This micromixer shows characteristics similar to Taylor dispersion, with contributions from both diffusion and convection. The mixer has a diffusion domain region at low flow rate, but it moves to a convection domain region at high flow rate. Due to the simple in-plane structure of the novel micromixer explored in this work, the mixer can be easily realized and integrated with on-chip microfluidic devices and micro total analysis systems (micro-TAS).

Structure and covariance of cloud and rain water in marine stratocumulus

NASA Astrophysics Data System (ADS)

Witte, Mikael; Morrison, Hugh; Gettelman, Andrew

2017-04-01

Many state of the art cloud microphysics parameterizations in large-scale models use assumed probability density functions (pdfs) to represent subgrid scale variability of relevant resolved scale variables such as vertical velocity and cloud liquid water content (LWC). Integration over the assumed pdfs of small scale variability results in physically consistent prediction of nonlinear microphysical process rates and obviates the need to apply arbitrary tuning parameters to the calculated rates. In such parameterizations, the covariance of cloud and rain LWC is an important quantity for parameterizing the accretion process by which rain drops grow via collection of cloud droplets. This covariance has been diagnosed by other workers from a variety of observational and model datasets (Boutle et al., 2013; Larson and Griffin, 2013; Lebsock et al., 2013), but there is poor agreement in findings across the studies. Two key assumptions that may explain some of the discrepancies among past studies are 1) LWC (both cloud and rain) distributions are statistically stationary and 2) spatial structure may be neglected. Given the highly intermittent nature of precipitation and the fact that cloud LWC has been found to be poorly represented by stationary pdfs (e.g. Marshak et al., 1997), neither of the aforementioned assumptions are valid. Therefore covariance must be evaluated as a function of spatial scale without the assumption of stationary statistics (i.e. variability cannot be expressed as a fractional standard deviation, which necessitates well-defined first and second moments of the LWC distribution). The present study presents multifractal analyses of both rain and cloud LWC using aircraft data from the VOCALS-REx field campaign to illustrate the importance of spatial structure in microphysical parameterizations and extends the results of Boutle et al. (2013) to provide a parameterization of rain-cloud water covariance as a function of spatial scale without the assumption of statistical stationarity.

Understanding how the aggregation structure of starch affects its gastrointestinal digestion rate and extent.

PubMed

Chen, Pei; Wang, Kai; Kuang, Qirong; Zhou, Sumei; Wang, Dazheng; Liu, Xingxun

2016-06-01

Regulating the starch gastrointestinal digestion rate by control of its aggregation structure is an effective way, but the mechanism is still not clear. Multi-scale structure of waxy and normal wheat starches were studied by confocal laser scanning and scanning electron microscopes, as well as wide-angle and small-angle X-ray techniques in this study. In vitro digestion kinetics of those two starches and structure-digestion relationship were also discussed. Both waxy and normal starches show A-type diffraction pattern, but waxy variety shows a slightly higher crystallinity. Small-angle X-ray scattering results show that waxy wheat starch has higher scattering peak intensity (Imax) and a larger crystallinity lamellar repeat distance (Lp) compared with the normal wheat starch. We suggested that the higher digestion rate of waxy starch at initial stage is mainly due to more small-size particles, but the higher crystallinity and the larger crystalline lamellar size limit the digestion extent. Copyright © 2016 Elsevier B.V. All rights reserved.

Physically based multiscale-viscoplastic model for metals and steel alloys: Theory and computation

NASA Astrophysics Data System (ADS)

Abed, Farid H.

The main requirement of large deformation problems such as high-speed machining, impact, and various primarily metal forming, is to develop constitutive relations which are widely applicable and capable of accounting for complex paths of deformation. Achieving such desirable goals for material like metals and steel alloys involves a comprehensive study of their microstructures and experimental observations under different loading conditions. In general, metal structures display a strong rate- and temperature-dependence when deformed non-uniformly into the inelastic range. This effect has important implications for an increasing number of applications in structural and engineering mechanics. The mechanical behavior of these applications cannot be characterized by classical (rate-independent) continuum theories because they incorporate no 'material length scales'. It is therefore necessary to develop a rate-dependent (viscoplasticity) continuum theory bridging the gap between the classical continuum theories and the microstructure simulations. Physically based vicoplasticity models for different types of metals (body centered cubic, face centered cubic and hexagonal close-packed) and steel alloys are derived in this work for this purpose. We adopt a multi-scale, hierarchical thermodynamic consistent framework to construct the material constitutive relations for the rate-dependent behavior. The concept of thermal activation energy, dislocations interactions mechanisms and the role of dislocations dynamics in crystals are used in the derivation process taking into consideration the contribution of the plastic strain evolution of dislocation density to the flow stress of polycrystalline metals. Material length scales are implicitly introduced into the governing equations through material rate-dependency (viscosity). The proposed framework is implemented into the commercially well-known finite element software ABAQUS. The finite element simulations of material instability problems converge to meaningful results upon further refinement of the finite element mesh due to the successful incorporation of the material length scale in the model formulations. It is shown that the model predicted results compare very well with different experimental data over a wide range of temperatures (77K°-1000K°) and strain rates (10-3-10 4s-1). It is also concluded from this dissertation that the width of localization zone (shear band) exhibits tremendous changes with different initial temperatures (i.e., different initial viscosities and accordingly different length scales).

Analytic study of the effect of dark energy-dark matter interaction on the growth of structures

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

Marcondes, Rafael J.F.; Landim, Ricardo C.G.; Costa, André A.

2016-12-01

Large-scale structure has been shown as a promising cosmic probe for distinguishing and constraining dark energy models. Using the growth index parametrization, we obtain an analytic formula for the growth rate of structures in a coupled dark energy model in which the exchange of energy-momentum is proportional to the dark energy density. We find that the evolution of f σ{sub 8} can be determined analytically once we know the coupling, the dark energy equation of state, the present value of the dark energy density parameter and the current mean amplitude of dark matter fluctuations. After correcting the growth function formore » the correspondence with the velocity field through the continuity equation in the interacting model, we use our analytic result to compare the model's predictions with large-scale structure observations.« less

Multi-approach quantification of denudation rates in the Gulf of Lion source-to-sink system (SE France)

NASA Astrophysics Data System (ADS)

Molliex, S.; Rabineau, M.; Leroux, E.; Bourlès, D. L.; Authemayou, C.; Aslanian, D.; Chauvet, F.; Civet, F.; Jouët, G.

2016-06-01

During the Pliocene and the Quaternary, the Gulf of Lion, the northern passive margin of the Liguro-Provençal basin in the western Mediterranean Sea, received sediments from a 120 000 km2 drainage area constituted by several structural domains. The denudation of mountainous areas, source of this sedimentary supply, results from complex interactions between tectonics, climate, morphology, and rock erodibility. In this study, denudation rates from the present-day and ranging back to the Quaternary and the Pliocene are quantified using four independent methods allowing an investigation over different time scales: 1) compilation of present-day measured sediment fluxes, 2) determination of catchment-scale cosmogenic denudation rates through measurements of in situ-produced 10Be concentrations in sands sampled at the outlet of present-day rivers, 3) estimation of eroded volumes within catchments using a DEM to quantify long-term averaged Quaternary denudation rates, and 4) quantification of sediment volumes deposited within the marine realm of the Gulf of Lion. The results obtained by these four methods are in agreement within the range of uncertainties. The internal part of the Alps exhibits significantly higher denudation rates (∼700 mm ka-1) than those estimated in the other structural domains: 150-250 mm ka-1 in the foreland Alps, ∼100 mm ka-1 in the Pyrenees, and 55-75 mm ka-1 in the Massif Central. The Alpine domain provides at least 80% of the total eroded volume supplied towards the Gulf of Lion. A quantitative geomorphological approach shows that denudation rates are controlled at the first order by catchment morphologies (slope, relief) over different time scales, suggesting glacial conditioning to be the main driver on denudation from the Quaternary to present-day. Throughout the Pliocene-Quaternary, a doubling of denudation rates related to the mid-Pleistocene Revolution (∼0.9 Ma) is highlighted.

Sacrificial bonds and hidden length in biomaterials: A kinetic constitutive description of strength and toughness in bone

NASA Astrophysics Data System (ADS)

Lieou, Charles K. C.; Elbanna, Ahmed E.; Carlson, Jean M.

2013-07-01

Sacrificial bonds and hidden length in structural molecules account for the greatly increased fracture toughness of biological materials compared to synthetic materials without such structural features by providing a molecular-scale mechanism for energy dissipation. One example is in the polymeric glue connection between collagen fibrils in animal bone. In this paper we propose a simple kinetic model that describes the breakage of sacrificial bonds and the release of hidden length, based on Bell's theory. We postulate a master equation governing the rates of bond breakage and formation. This enables us to predict the mechanical behavior of a quasi-one-dimensional ensemble of polymers at different stretching rates. We find that both the rupture peak heights and maximum stretching distance increase with the stretching rate. In addition, our theory naturally permits the possibility of self-healing in such biological structures.

Using Cognitive Pretesting in Scale Development for Parkinson’s Disease: The Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Example

PubMed Central

Tilley, Barbara C.; LaPelle, Nancy R.; Goetz, Christopher G.; Stebbins, Glenn T.

2016-01-01

Background Cognitive pretesting, a qualitative step in scale development, precedes field testing and assesses the difficulty of instrument completion for examiners and respondents. Cognitive pretesting assesses respondent interest, attention span, discomfort, and comprehension, and highlights problems with the logical structure of questions/response options that can affect understanding. In the past this approach was not consistently used in the development or revision of movement disorders scales. Methods We applied qualitative cognitive pretesting using testing guides in development of the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS). The guides were based on qualitative techniques, verbal probing and “think-aloud” interviewing, to identify problems with the scale from the patient and rater perspectives. English-speaking Parkinson’s disease patients and movement disorders specialists (raters) from multiple specialty clinics in the United States, Western Europe and Canada used the MDS-UPDRS and completed the testing guides. Results Two rounds of cognitive pretesting were necessary before proceeding to field testing of the revised scale to assess clinimetric properties. Scale revisions based on cognitive pretesting included changes in phrasing, simplification of some questions, and addition of a reassuring statement explaining that not all PD patients experience the symptoms described in the questions. Conclusions The strategy of incorporating cognitive pretesting into scale development and revision provides a model for other movement disorders scales. Cognitive pretesting is being used in translating the MDS-UPDRS into multiple languages to improve comprehension and acceptance and in the development of a new Unified Dyskinesia Rating Scale for Parkinson’s disease patients. PMID:24613868

Intraspecific variation in the metabolic scaling exponent in ectotherms: testing the effect of latitudinal cline, ontogeny and transgenerational change in the land snail Cornu aspersum.

PubMed

Gaitán-Espitia, Juan Diego; Bruning, Andrea; Mondaca, Fredy; Nespolo, Roberto F

2013-06-01

The strong dependence of metabolic rates on body mass has attracted the interest of ecological physiologists, as it has important implications to many aspects of biology including species variations in body size, the evolution of life history, and the structure and function of biological communities. The great diversity of observed scaling exponents has led some authors to conclude that there is no single universal scaling exponent, but instead it ranges from 2/3 to 1. Most of the telling evidence against the universality of power scaling exponents comes from ontogenetic changes. Nevertheless, there could be other sources of phenotypic variation that influence this allometric relationship at least at the intraspecific level. In order to explore the general concept of the metabolic scaling in terrestrial molluscs we tested the role of several biological and methodological sources of variation on the empirically estimated scaling exponent. Specifically, we measured a proxy of metabolic rate (CO(2) production) in 421 individuals, during three generations, in three different populations. Additionally, we measured this scaling relationship in 208 individuals at five developmental stages. Our results suggest that the metabolic scaling exponent at the intraspecific level does not have a single stationary value, but instead it shows some degree of variation across geographic distribution, transgenerational change and ontogenetic stages. The major differences in the metabolic scaling exponent that we found were at different developmental stages of snails, because ontogeny involves increases in size at different rates, which in turn, generate differential energy demands. Copyright © 2013 Elsevier Inc. All rights reserved.

Development of a problematic mobile phone use scale for Turkish adolescents.

PubMed

Güzeller, Cem Oktay; Coşguner, Tolga

2012-04-01

Abstract The aim of this study was to evaluate the psychometric properties of the Problematic Mobile Phone Use Scale (PMPUS) for Turkish Adolescents. The psychometric properties of PMPUS were tested in two separate sample groups that consisted of 950 Turkish high school students. The first sample group (n=309) was used to determine the factor structure of the scale. The second sample group (n=461) was used to test data conformity with the identified structure, discriminant validity and concurrent scale validity, internal consistency reliability calculations, and item statistics calculations. The results of exploratory factor analyses indicated that the scale had three factors: interference with negative effect, compulsion/persistence, and withdrawal/tolerance. The results showed that item and construct reliability values yielded satisfactory rates in general for the three-factor construct. On the other hand, the average variance extracted value remained below the scale value for three subscales. The scores for the scale significantly correlated with depression and loneliness. In addition, the discriminant validity value was above the scale in all sub-dimensions except one. Based on these data, the reliability of the PMPUS scale appears to be satisfactory and provides good internal consistency. Therefore, with limited exception, the PMPUS was found to be reliable and valid in the context of Turkish adolescents.

A novel approach to assessing technical competence of colorectal surgery residents: the development and evaluation of the Colorectal Objective Structured Assessment of Technical Skill (COSATS).

PubMed

de Montbrun, Sandra L; Roberts, Patricia L; Lowry, Ann C; Ault, Glenn T; Burnstein, Marcus J; Cataldo, Peter A; Dozois, Eric J; Dunn, Gary D; Fleshman, James; Isenberg, Gerald A; Mahmoud, Najjia N; Reznick, Richard K; Satterthwaite, Lisa; Schoetz, David; Trudel, Judith L; Weiss, Eric G; Wexner, Steven D; MacRae, Helen

2013-12-01

To develop and evaluate an objective method of technical skills assessment for graduating subspecialists in colorectal (CR) surgery-the Colorectal Objective Structured Assessment of Technical Skill (COSATS). It may be reasonable for the public to assume that surgeons certified as competent have had their technical skills assessed. However, technical skill, despite being the hallmark of a surgeon, is not directly assessed at the time of certification by surgical boards. A procedure-based, multistation technical skills examination was developed to reflect a sample of the range of skills necessary for CR surgical practice. These consisted of bench, virtual reality, and cadaveric models. Reliability and construct validity were evaluated by comparing 10 graduating CR residents with 10 graduating general surgery (GS) residents from across North America. Expert CR surgeons, blinded to level of training, evaluated performance using a task-specific checklist and a global rating scale. The mean global rating score was used as the overall examination score and a passing score was set at "borderline competent for CR practice." The global rating scale demonstrated acceptable interstation reliability (0.69) for a homogeneous group of examinees. Both the overall checklist and global rating scores effectively discriminated between CR and GS residents (P < 0.01), with 27% of the variance attributed to level of training. Nine CR residents but only 3 GS residents were deemed competent. The Colorectal Objective Structured Assessment of Technical Skill effectively discriminated between CR and GS residents. With further validation, the Colorectal Objective Structured Assessment of Technical Skill could be incorporated into the colorectal board examination where it would be the first attempt of a surgical specialty to formally assess technical skill at the time of certification.

Computational Multi-Scale Modeling of the Microstructure and Segregation of Cast Mg Alloys at Low Superheat

NASA Astrophysics Data System (ADS)

Nastac, Laurentiu; El-Kaddah, Nagy

It is well known that casting at low superheat has a strong influence on the solidification structures of the cast alloy. Recent studies on casting magnesium AZ alloys at low superheat using the Magnetic Suspension Melting (MSM) process have shown that the cast alloy exhibit a fine globular grain structure, and the grain size depend on the cooling rate. This paper describes a stochastic mesoscopic model for predicting the grain structure and segregation in cast alloys at low superheat. This model was applied to predict the globular solidification morphology and solute redistribution of Al in cast Mg AZ31B alloy at different cooling rates. The predictions were found to be in good agreement with the observed grain structure and Al segregation. This makes the model a very useful tool for optimizing the solidification structure of cast magnesium alloys.

Insights into the hierarchical structure and digestion rate of alkali-modulated starches with different amylose contents.

PubMed

Qiao, Dongling; Yu, Long; Liu, Hongsheng; Zou, Wei; Xie, Fengwei; Simon, George; Petinakis, Eustathios; Shen, Zhiqi; Chen, Ling

2016-06-25

Combined analytical techniques were used to explore the effects of alkali treatment on the multi-scale structure and digestion behavior of starches with different amylose/amylopectin ratios. Alkali treatment disrupted the amorphous matrix, and partial lamellae and crystallites, which weakened starch molecular packing and eventually enhanced the susceptibility of starch to alkali. Stronger alkali treatment (0.5% w/w) made this effect more prominent and even transformed the dual-phase digestion of starch into a triple-phase pattern. Compared with high-amylose starch, regular maize starch, which possesses some unique structure characteristics typically as pores and crystallite weak points, showed evident changes of hierarchical structure and in digestion rate. Thus, alkali treatment has been demonstrated as a simple method to modulate starch hierarchical structure and thus to realize the rational development of starch-based food products with desired digestibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

A study on phenomenology of Dhat syndrome in men in a general medical setting.

PubMed

Prakash, Sathya; Sharan, Pratap; Sood, Mamta

2016-01-01

"Dhat syndrome" is believed to be a culture-bound syndrome of the Indian subcontinent. Although many studies have been performed, many have methodological limitations and there is a lack of agreement in many areas. The aim is to study the phenomenology of "Dhat syndrome" in men and to explore the possibility of subtypes within this entity. It is a cross-sectional descriptive study conducted at a sex and marriage counseling clinic of a tertiary care teaching hospital in Northern India. An operational definition and assessment instrument for "Dhat syndrome" was developed after taking all concerned stakeholders into account and review of literature. It was applied on 100 patients along with socio-demographic profile, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Mini International Neuropsychiatric Interview, and Postgraduate Institute Neuroticism Scale. For statistical analysis, descriptive statistics, group comparisons, and Pearson's product moment correlations were carried out. Factor analysis and cluster analysis were done to determine the factor structure and subtypes of "Dhat syndrome." A diagnostic and assessment instrument for "Dhat syndrome" has been developed and the phenomenology in 100 patients has been described. Both the health beliefs scale and associated symptoms scale demonstrated a three-factor structure. The patients with "Dhat syndrome" could be categorized into three clusters based on severity. There appears to be a significant agreement among various stakeholders on the phenomenology of "Dhat syndrome" although some differences exist. "Dhat syndrome" could be subtyped into three clusters based on severity.

Geometry of tracer trajectories in turbulent rotating convection

NASA Astrophysics Data System (ADS)

Alards, Kim; Rajaei, Hadi; Kunnen, Rudie; Toschi, Federico; Clercx, Herman

2016-11-01

In Rayleigh-Bénard convection rotation is known to cause transitions in flow structures and to change the level of anisotropy close to the horizontal plates. To analyze this effect of rotation, we collect curvature and torsion statistics of passive tracer trajectories in rotating Rayleigh-Bénard convection, using both experiments and direct numerical simulations. In previous studies, focusing on homogeneous isotropic turbulence (HIT), curvature and torsion PDFs are found to reveal pronounced power laws. In the center of the convection cell, where the flow is closest to HIT, we recover these power laws, regardless of the rotation rate. However, near the top plate, where we expect the flow to be anisotropic, the scaling of the PDFs deviates from the HIT prediction for lower rotation rates. This indicates that anisotropy clearly affects the geometry of tracer trajectories. Another effect of rotation is observed as a shift of curvature and torsion PDFs towards higher values. We expect this shift to be related to the length scale of typical flow structures. Using curvature and torsion statistics, we can characterize how these typical length scales evolve under rotation and moreover analyze the effect of rotation on more complicated flow characteristics, such as anisotropy.

Dynamics of a bilayer membrane coupled to a two-dimensional cytoskeleton: Scale transfers of membrane deformations

NASA Astrophysics Data System (ADS)

Okamoto, Ryuichi; Komura, Shigeyuki; Fournier, Jean-Baptiste

2017-07-01

We theoretically investigate the dynamics of a floating lipid bilayer membrane coupled with a two-dimensional cytoskeleton network, taking into account explicitly the intermonolayer friction, the discrete lattice structure of the cytoskeleton, and its prestress. The lattice structure breaks lateral continuous translational symmetry and couples Fourier modes with different wave vectors. It is shown that within a short time interval a long-wavelength deformation excites a collection of modes with wavelengths shorter than the lattice spacing. These modes relax slowly with a common renormalized rate originating from the long-wavelength mode. As a result, and because of the prestress, the slowest relaxation is governed by the intermonolayer friction. Conversely, and most interestingly, forces applied at the scale of the cytoskeleton for a sufficiently long time can cooperatively excite large-scale modes.

“Real-Time” Cosmology with Extragalactic Proper Motions: the Secular Aberration Drift and Evolution of Large-Scale Structure

NASA Astrophysics Data System (ADS)

Truebenbach, Alexandra; Darling, Jeremy

2018-01-01

We present the VLBA Extragalactic Proper Motion Catalog, a catalog of extragalactic proper motions created using archival VLBI data and our own VLBA astrometry. The catalog contains 713 proper motions, with average uncertainties of ~ 24 microarcsec/yr, including 40 new or improved proper motion measurements using relative astrometry with the VLBA. We detect the secular aberration drift – the apparent motion of extragalactic objects caused by the solar system's acceleration around the Galactic Center – at 6.3 sigma significance with an amplitude of 1.69 +/- 0.27 microarcsec/yr and an apex consistent with the Galactic Center (275.2 +/- 10.0 deg, -29.4 +/- 8.8 deg). Our dipole model detects the aberration drift at a higher significance than some previous studies (e.g., Titov & Lambert 2013), but at a lower amplitude than expected or previously measured. We then use the correlated relative proper motions of extragalactic objects to place upper limits on the rate of large-scale structure collapse (e.g., Quercellini et al. 2009; Darling 2013). Pairs of small separation objects that are in gravitationally interacting structures such as filaments of large-scale structure will show a net decrease in angular separation (> - 15.5 microarcsec/yr) as they move towards each other, while pairs of large separation objects that are gravitationally unbound and move with the Hubble expansion will show no net change in angular separation. With our catalog, we place a 3 sigma limit on the rate of convergence of large-scale structure of -11.4 microarcsec/yr for extragalactic objects within 100 comoving Mpc of each other. We also confirm that large separation objects (> 800 comoving Mpc) move with the Hubble flow to within ~ 2.2 microarcsec/yr. In the future, we plan to incorporate the upcoming Gaia proper motions into our catalog to achieve a higher precision measurement of the average relative proper motion of gravitationally interacting extragalactic objects and to refine our measurement of the collapse of large-scale structure. This research was performed with support from the NSF grant AST-1411605.Darling, J. 2013, AJ, 777, L21; Quercellini et al. 2009. Phys. Rev. Lett., 102, 151302; Titov, O. & Lambert, S. 2013, A&A, 559, A95

The Effectiveness of Hybrid Structure in Overcoming Coastal Abration in Trimulyo, Genuk Subdistrict Semarang City

NASA Astrophysics Data System (ADS)

Kurnia, Domas; Nugroho, Denny

2018-02-01

Trimulyo is one of coastal village in Genuk Subdistrict, Semarang City which now facing serious coastal abrasion. Such a thing has been causing loss of ponds and settlements. One of solution which currently carried is hybrid structure which combining permeable structure to break up the waves and trap sediment. The hybrid structure is designed as agitation dredging, which increase suspended sediment in sea water. The goals of this research were to studying the effectiveness of hybrid structure in handling coastal abration and to counting the volume of sedimentation during 20 months as well as rate of sedimentation. To reach the goals, high resolution satellite imagery year 2015 and 2016, scaled stick and sediment trap were applied to the study. Image processing was conducted by using Arc GIS 10.3 software. The effectiveness of hybrid structured was determined by series of field survey of existing condition. Rate of sedimentation measured during before and after hybrid structure built (20 months). The results showed that hybrid structure was effective to reduce coastal abrasion, it proven by a large amount of sediment was trapped behind the structure and coastline was upward along 170 meter since it was built. The volume of sediment during 20 months is 81.500 m3. If it assumed that the rate of sedimentation constantly, monthly rate of sedimentation is 4.075 m3/month or daily rate is 135,8 m3/day. The sediment that has formed highly recommended to use as mangrove conservation area in Semarang City.

Meteorite Impact Structures as Outcrop-Scale Analogues for Mountain Building Events: Weaubleau and Decaturville, MO

NASA Astrophysics Data System (ADS)

Wu, S.; McKay, M.; Evans, K. R.

2017-12-01

Understanding the architecture of mountain belts is limited because studies are typically confined to surficial exposures with lesser amounts of subsurface data and active margins are prone to successive tectonism that obscures the rock record. In west-central Missouri, two Paleozoic meteorite impacts are exposed that contain a range of outcrop-scale structures. While the strain rate in a meteorite impact is an order of magnitude greater than that in orogeny-scale structures, the morphology and spatial relationships in these impact structures may provide insight into larger tectonic features. The entire crater could not be compared to an orogenic event because the amount of strain diffuses as distance increases from the impactor during an impacting event. The center of an impact crater could not be compared to an orogenic event because it has become too deformed. However, the crater rim and the immediate surrounding area could be used as a comparison because it has undergone the right amount of deformation to have recognizable structures. High-detail mapping and structural analyses of road cut exposures near Decaturville, MO reveals thrust fault sequences contain 1-2 m thick mixed carbonate and clastic sheets that include rollover anticlines, structural orphans, and lateral ramp features. Thrust faults dip away from the impact structure and represent gravitational collapse of the central uplift seconds after collision. Thrust sheet thickness, thrust fault spacing, ramp/flat morphology, and shortening of within these structures will be presented and assessed as an analogue for map-scale features in the Southern Appalachian fold and thrust belt. Because temperature controls rock mechanic properties, a thermal model based on thermochronology and thermobarometry for the section will also be presented and discussed in the context of orogenic thermomechanics.

Application of ERTS-1 data to the protection and management of New Jersey's coastal environment

NASA Technical Reports Server (NTRS)

Yunghans, R. S.; Feinberg, E. B.; Wobber, F. J.; Mairs, R. L. (Principal Investigator); Macomber, R. T.; Stanczuk, D.

1973-01-01

The author has identified the following significant results. Rates of erosion and accretion of the shoreline are being calculated for two test areas along the New Jersey coast. Measurements are made on aerial photographs taken over the last 20 years and processed by computer. The rates are presented in graphic form on an ERTS-1 base map at a scale of 1:125,000. These rates are being used to determine the effectiveness of various shore protection structures at preventing sand removal and encouraging sand accumulation. Information on maintenance and construction expenditures is being used to obtain a cost effectiveness ratio for various shore protection devices. The relationship of erosion rates, property value, and project cost are all criteria for selection of site type and extent of a shore protection structure. Compilation and evaluation of historical data will identify past decision making patterns. The effectiveness of these decisions with respect to erosion rates, property value, and project cost, can be used as an added criteria for future allocation of money and the selection of site and type of structure to be built.

Micro-structure and motion of two-dimensional dense short spherocylinder liquids

NASA Astrophysics Data System (ADS)

Wang, Wen; Lin, Jyun-Ting; Su, Yen-Shuo; I, Lin

2018-03-01

We numerically investigate the micro-structure and motion of 2D liquids composed of dense short spherocylinders, by reducing the shape aspect ratio from 3. It is found that reducing shape aspect ratio from 3 causes a smooth transition from heterogeneous structures composed of crystalline ordered domains with good tetratic alignment order to those with good hexagonal bond-orientational order at an aspect ratio equaling 1.35. In the intermediate regime, both structural orders are strongly deteriorated, and the translational hopping rate reaches a maximum due to the poor particle interlocking of the disordered structure. Shortening rod length allows easier rotation, induces monotonic increase of rotational hopping rates, and resumes the separation of rotational and translational hopping time scales at the small aspect ratio end, after the crossover of their rates in the intermediate regime. At the large shape aspect ratio end, the poor local tetratic order has the same positive effects on facilitating local rotational and translational hopping. In contrast, at the small shape aspect ratio end, the poor local bond orientational order has the opposite effects on facilitating local rotational and translational hopping.

Feature-Based Morphometry: Discovering Group-related Anatomical Patterns

PubMed Central

Toews, Matthew; Wells, William; Collins, D. Louis; Arbel, Tal

2015-01-01

This paper presents feature-based morphometry (FBM), a new, fully data-driven technique for discovering patterns of group-related anatomical structure in volumetric imagery. In contrast to most morphometry methods which assume one-to-one correspondence between subjects, FBM explicitly aims to identify distinctive anatomical patterns that may only be present in subsets of subjects, due to disease or anatomical variability. The image is modeled as a collage of generic, localized image features that need not be present in all subjects. Scale-space theory is applied to analyze image features at the characteristic scale of underlying anatomical structures, instead of at arbitrary scales such as global or voxel-level. A probabilistic model describes features in terms of their appearance, geometry, and relationship to subject groups, and is automatically learned from a set of subject images and group labels. Features resulting from learning correspond to group-related anatomical structures that can potentially be used as image biomarkers of disease or as a basis for computer-aided diagnosis. The relationship between features and groups is quantified by the likelihood of feature occurrence within a specific group vs. the rest of the population, and feature significance is quantified in terms of the false discovery rate. Experiments validate FBM clinically in the analysis of normal (NC) and Alzheimer's (AD) brain images using the freely available OASIS database. FBM automatically identifies known structural differences between NC and AD subjects in a fully data-driven fashion, and an equal error classification rate of 0.80 is achieved for subjects aged 60-80 years exhibiting mild AD (CDR=1). PMID:19853047

Direct electronic communication at bio-interfaces assisted by layered-metal-hydroxide slab arrays with controlled nano-micro structures.

PubMed

An, Zhe; He, Jing

2011-10-28

The electronic transfer (eT) at bio-interfaces has been achieved by orientating 2D inorganic slabs in a regular arrangement with the slab ab-planes vertical to the electrode substrate. The eT rate is effectively promoted by tuning the nano-micro scale structures of perpendicular LDH arrays. This journal is © The Royal Society of Chemistry 2011

Measuring Psychobiosocial States in Sport: Initial Validation of a Trait Measure

PubMed Central

Bertollo, Maurizio; Ruiz, Montse C.; Bortoli, Laura

2016-01-01

We examined the item characteristics, the factor structure, and the concurrent validity of a trait measure of psychobiosocial states. In Study 1, Italian athletes (N = 342, 228 men, 114 women, Mage = 23.93, SD = 6.64) rated the intensity, the frequency, and the perceived impact dimensions of a psychobiosocial states scale, trait version (PBS-ST), which is composed of 20 items (10 functional and 10 dysfunctional) referring to how they usually felt before an important competition. In Study 2, the scale was cross validated in an independent sample (N = 251, 181 men, 70 women, Mage = 24.35, SD = 7.25). The concurrent validity of the PBS-ST scale scores were also examined in comparison with two sport-specific emotion-related measures and a general measure of affect. Exploratory structural equation modeling and confirmatory factor analysis of the data of Study 1 showed that a 2-factor, 15-item solution of the PBS-ST scale (8 functional items and 7 dysfunctional items) reached satisfactory fit indices for the three dimensions (i.e., intensity, frequency, and perceived impact). Results of Study 2 provided evidence of substantial measurement and structural invariance of all dimensions across samples. The low association of the PBS-ST scale with other measures suggests that the scale taps unique constructs. Findings of the two studies offer initial validity evidence for a sport-specific tool to measure psychobiosocial states. PMID:27907111

Nonlinear temperature effects on multifractal complexity of metabolic rate of mice

PubMed Central

Bogdanovich, Jose M.; Bozinovic, Francisco

2016-01-01

Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r(VO2), in the laboratory mouse Mus musculus, assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA), finding that r(VO2) fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 102 s), either monofractal or weak multifractal dynamics are observed depending on whether Ta < 15 °C or Ta > 15 °C respectively. For larger time scales, r(VO2) fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ(q), showing that the infinite number of exponents h(q) can be described by only two independent parameters, a and b. We also show that the long-range correlation structure of r(VO2) time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system. PMID:27781179

Nonlinear temperature effects on multifractal complexity of metabolic rate of mice.

PubMed

Labra, Fabio A; Bogdanovich, Jose M; Bozinovic, Francisco

2016-01-01

Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r ( VO 2 ), in the laboratory mouse Mus musculus , assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA), finding that r(VO 2 ) fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 10 2 s), either monofractal or weak multifractal dynamics are observed depending on whether T a < 15 °C or T a > 15 °C respectively. For larger time scales, r(VO 2 ) fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ ( q ), showing that the infinite number of exponents h(q) can be described by only two independent parameters, a and b . We also show that the long-range correlation structure of r(VO 2 ) time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system.

A potential mechanism for allometric trabecular bone scaling in terrestrial mammals.

PubMed

Christen, Patrik; Ito, Keita; van Rietbergen, Bert

2015-03-01

Trabecular bone microstructural parameters, including trabecular thickness, spacing, and number, have been reported to scale with animal size with negative allometry, whereas bone volume fraction is animal size-invariant in terrestrial mammals. As for the majority of scaling patterns described in animals, its underlying mechanism is unknown. However, it has also been found that osteocyte density is inversely related to animal size, possibly adapted to metabolic rate, which shows a negative relationship as well. In addition, the signalling reach of osteocytes is limited by the extent of the lacuno-canalicular network, depending on trabecular dimensions and thus also on animal size. Here we propose animal size-dependent variations in osteocyte density and their signalling influence distance as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. Using an established and tested computational model of bone modelling and remodelling, we run simulations with different osteocyte densities and influence distances mimicking six terrestrial mammals covering a large range of body masses. Simulated trabecular structures revealed negative allometric scaling for trabecular thickness, spacing, and number, constant bone volume fraction, and bone turnover rates inversely related to animal size. These results are in agreement with previous observations supporting our proposal of osteocyte density and influence distance variation as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. The inverse relationship between bone turnover rates and animal size further indicates that trabecular bone scaling may be linked to metabolic rather than mechanical adaptations. © 2015 Anatomical Society.

The organization of verbs of knowing: evidence for cultural commonality and variation in theory of mind.

PubMed

Schwanenflugel, P J; Martin, M; Takahashi, T

1999-09-01

Cross-cultural commonality and variation in folk theories of knowing were studied by examining the organization of verbs of knowing in German and Japanese adults. German and Japanese adults performed one of two tasks: a similarity judgment task and an attribute rating task. Organizational structure was assessed for the similarity judgment task using multidimensional scaling and additive similarity tree analyses. The attribute rating task was used to describe the characteristics that organized the dimensions and clusters emerging from the scaling solutions. The folk theory of mind displayed was an information processing model with constructive components, although the constructive aspects were more salient for the Germans than for the Japanese.

Factor analysis of the catatonia rating scale and catatonic symptom distribution across four diagnostic groups.

PubMed

Krüger, Stephanie; Bagby, R Michael; Höffler, Jürgen; Bräunig, Peter

2003-01-01

Catatonia is a frequent psychomotor syndrome, which has received increasing recognition over the last decade. The assessment of the catatonic syndrome requires systematic rating scales that cover the complex spectrum of catatonic motor signs and behaviors. The Catatonia Rating Scale (CRS) is such an instrument, which has been validated and which has undergone extensive reliability testing. In the present study, to further validate the CRS, the items composing this scale were submitted to principal components factor extraction followed by a varimax rotation. An analysis of variance (ANOVA) was performed to assess group differences on the extracted factors in patients with schizophrenia, pure mania, mixed mania, and major depression (N=165). Four factors were extracted, which accounted for 71.5% of the variance. The factors corresponded to the clinical syndromes of (1) catatonic excitement, (2) abnormal involuntary movements/mannerisms, (3) disturbance of volition/catalepsy, and (4) catatonic inhibition. The ANOVA revealed that each of the groups showed a distinctive catatonic symptom pattern and that the overlap between diagnostic groups was minimal. We conclude that this four-factor symptom structure of catatonia challenges the current conceptualization, which proposes only two symptom subtypes.

Second-order structure function in high-resolution DNSs of turbulence - Where is the inertial subrange?

NASA Astrophysics Data System (ADS)

Ishihara, Takashi; Kaneda, Yukio; Morishita, Koji; Yokokawa, Mitsuo; Uno, Atsuya

2017-11-01

We report some results of a series of high resolution direct numerical simulations (DNSs) of forced incompressible isotropic turbulence with up to 122883 grid points and Taylor microscale Reynolds number Rλ 2300 . The DNSs show that there exists a scale range, approximately at 100 < r / η < 600 (η is the Kolmogorov length scale), where the second-order longitudinal velocity structure function fits well to a simple power-law scaling with respect to the distance r between the two points. However, the magnitude of the structure function depends on Rλ, i.e., the structure function normalized by the mean rate of energy dissipation and r is not independent of Rλ nor the viscosity. This implies that the range at 100 < r / η < 600 and Rλ up to 2300 is not the `inertial subrange', whose statistics are assumed to be independent from viscosity or Rλ in many turbulence theories. The measured exponents are to be not confused with those in the `inertial subrange': the constancy of the scaling exponent of a structure function in a certain range does not necessarily mean that the measured exponent is the scaling exponent in the `inertial subrange'. This yields a question, ``Where is the `inertial subrange' in experiments and DNSs?'' This study used the computational resources of the K computer provided by the RIKEN AICS through the HPCI System Research projects (ID:hp160102 and ID:hp170087). This research was partly supported by JSPS KAKENHI (S)16H06339 and (B) 15H03603.

Assessment of children's emotional adjustment: construction and validation of a new instrument.

PubMed

Thorlacius, Ö; Gudmundsson, E

2015-09-01

The present study describes the Children's Emotional Adjustment Scale (CEAS), a 47-item parent-reported scale designed to capture children's emotional functioning on four continuous dimensions. A large community sample of mothers of children (n = 606) aged 6-13 years was used to examine the psychometric properties of the CEAS. Exploratory and confirmatory factor analysis supported the hypothesized four-factor structure of the instrument: (1) temper control; (2) anxiety control; (3) mood repair; and (4) social assertiveness. Cronbach's alphas for the factors were consistently above 0.90, and convergent validity of the factors was satisfactory with maternal ratings of child psychopathology. Children rated by their mothers as having emotional problems in the clinical range on the Strengths and Difficulties Questionnaire had significantly lower scores on the CEAS scales. The CEAS is a psychometrically sound instrument, covering healthy emotional adjustment as well as maladjustment. The scale might prove to be valuable in the assessment and screening of behaviours underlying child psychopathology. © 2014 John Wiley & Sons Ltd.

Cluster Morphology-Polymer Dynamics Correlations in Sulfonated Polystyrene Melts: Computational Study

DOE PAGES

Agrawal, Anupriya; Perahia, Dvora; Grest, Gary S.

2016-04-11

Reaching exceptionally long times up to 500 ns in equilibrium and nonequilibrium molecular dynamics simulations studies, we have attained a fundamental molecular understanding of the correlation of ionomer clusters structure and multiscale dynamics, providing new insight into one critical, long-standing challenge in ionic polymer physics. The cluster structure in melts of sulfonated polystyrene with Na + and Mg 2+ counterions are resolved and correlated with the dynamics on multiple length and time scales extracted from measurements of the dynamic structure factor and shear rheology. We find that as the morphology of the ionic clusters changes from ladderlike for Na +more » to disordered structures for Mg 2+, the dynamic structure factor is affected on the length scale corresponding to the ionic clusters. Lastly, rheology studies show that the viscosity for Mg 2+ melts is higher than for Na + ones for all shear rates, which is well correlated with the larger ionic clusters’ size for the Mg 2+ melts.« less

Large-scale modeling of rain fields from a rain cell deterministic model

NASA Astrophysics Data System (ADS)

FéRal, Laurent; Sauvageot, Henri; Castanet, Laurent; Lemorton, JoëL.; Cornet, FréDéRic; Leconte, Katia

2006-04-01

A methodology to simulate two-dimensional rain rate fields at large scale (1000 × 1000 km2, the scale of a satellite telecommunication beam or a terrestrial fixed broadband wireless access network) is proposed. It relies on a rain rate field cellular decomposition. At small scale (˜20 × 20 km2), the rain field is split up into its macroscopic components, the rain cells, described by the Hybrid Cell (HYCELL) cellular model. At midscale (˜150 × 150 km2), the rain field results from the conglomeration of rain cells modeled by HYCELL. To account for the rain cell spatial distribution at midscale, the latter is modeled by a doubly aggregative isotropic random walk, the optimal parameterization of which is derived from radar observations at midscale. The extension of the simulation area from the midscale to the large scale (1000 × 1000 km2) requires the modeling of the weather frontal area. The latter is first modeled by a Gaussian field with anisotropic covariance function. The Gaussian field is then turned into a binary field, giving the large-scale locations over which it is raining. This transformation requires the definition of the rain occupation rate over large-scale areas. Its probability distribution is determined from observations by the French operational radar network ARAMIS. The coupling with the rain field modeling at midscale is immediate whenever the large-scale field is split up into midscale subareas. The rain field thus generated accounts for the local CDF at each point, defining a structure spatially correlated at small scale, midscale, and large scale. It is then suggested that this approach be used by system designers to evaluate diversity gain, terrestrial path attenuation, or slant path attenuation for different azimuth and elevation angle directions.

Effects of a group rational-emotive behavior therapy program on the Type A behavior pattern.

PubMed

Möller, A T; Botha, H C

1996-06-01

A sample of 44 male Type A insurance representatives, selected by means of the Videotaped Structured Interview, were randomly assigned to a treatment (n = 22) and a delayed treatment control group (n = 22). The treatment group participated in 9 weekly sessions of group Rational-Emotive Behavior Therapy and were followed up after 10 weeks. After the control period, the delayed treatment control group received the same treatment program. Repeated measurements were obtained by means of the Videotaped Structured Interview, Jenkins Activity Survey, Cook-Medley Hostility Scale, and Type A Cognitive Questionnaire. Self and spouse/friend ratings of Type A behavior were obtained by means of the Bortner Rating Scale. Analysis indicated that, compared to the control condition, the therapy significantly reduced the intensity of Type A behavior and its time urgency component. These improvements were maintained at follow-up and were accompanied by self-reports of significant positive changes in Type A behavior and irrational beliefs.

ProteomeVis: a web app for exploration of protein properties from structure to sequence evolution across organisms' proteomes.

PubMed

Razban, Rostam M; Gilson, Amy I; Durfee, Niamh; Strobelt, Hendrik; Dinkla, Kasper; Choi, Jeong-Mo; Pfister, Hanspeter; Shakhnovich, Eugene I

2018-05-08

Protein evolution spans time scales and its effects span the length of an organism. A web app named ProteomeVis is developed to provide a comprehensive view of protein evolution in the S. cerevisiae and E. coli proteomes. ProteomeVis interactively creates protein chain graphs, where edges between nodes represent structure and sequence similarities within user-defined ranges, to study the long time scale effects of protein structure evolution. The short time scale effects of protein sequence evolution are studied by sequence evolutionary rate (ER) correlation analyses with protein properties that span from the molecular to the organismal level. We demonstrate the utility and versatility of ProteomeVis by investigating the distribution of edges per node in organismal protein chain universe graphs (oPCUGs) and putative ER determinants. S. cerevisiae and E. coli oPCUGs are scale-free with scaling constants of 1.79 and 1.56, respectively. Both scaling constants can be explained by a previously reported theoretical model describing protein structure evolution (Dokholyan et al., 2002). Protein abundance most strongly correlates with ER among properties in ProteomeVis, with Spearman correlations of -0.49 (p-value<10-10) and -0.46 (p-value<10-10) for S. cerevisiae and E. coli, respectively. This result is consistent with previous reports that found protein expression to be the most important ER determinant (Zhang and Yang, 2015). ProteomeVis is freely accessible at http://proteomevis.chem.harvard.edu. Supplementary data are available at Bioinformatics. shakhnovich@chemistry.harvard.edu.

Bounded energy states in homogeneous turbulent shear flow - An alternative view

NASA Technical Reports Server (NTRS)

Bernard, P. S.; Speziale, C. G.

1992-01-01

The equilibrium structure of homogeneous turbulent shear flow is investigated from a theoretical standpoint. Existing turbulence models, in apparent agreement with physical and numerical experiments, predict an unbounded exponential time growth of the turbulent kinetic energy and dissipation rate; only the anisotropy tensor and turbulent time scale reach a structural equilibrium. It is shown that if a residual vortex stretching term is maintained in the dissipation rate transport equation, then there can exist equilibrium solutions, with bounded energy states, where the turbulence production is balanced by its dissipation. Illustrative calculations are presented for a k-epsilon model modified to account for net vortex stretching.

Relationship between the structure of anxiety and the self-educational ability in new pharmacists.

PubMed

Hirashima, Yutaka; Ito, Marika; Doshi, Masaru; Kunii, Midori; Ideguchi, Naoko

2009-05-01

The present study was conducted to evaluate the relationship between the structure of anxiety and the self-educational ability in new pharmacists. Ninety seven new pharmacists rated the 42 items of our anxiety scale toward working in the pharmacy in June and October, 2006 and 40 items of established self-educational ability scale in June, 2006. A factor analysis of anxiety scale indicated four factors including communication ability, professional technique of pharmacist, working condition, and self-respecting. From the evaluation of correlation between factors of anxiety scale and factors of self-educational ability scale, the anxiety concerning communication ability or the problem concerning self-respecting correlated significantly with the poorness of all four factors of self-educational ability such as the aim of self-growth and self-development, self-objectifying, practice and technique of study, and self-confidence and pride. However, working condition did not correlate all four factors. For 4 months, the anxiety of professional technique of pharmacist decreased significantly although three other factors did not indicated significant changes.

A Person-Centered Approach to Financial Capacity Assessment: Preliminary Development of a New Rating Scale

PubMed Central

Lichtenberg, Peter A.; Stoltman, Jonathan; Ficker, Lisa J.; Iris, Madelyn; Mast, Benjamin

2014-01-01

Financial exploitation and financial capacity issues often overlap when a gerontologist assesses whether an older adult’s financial decision is an autonomous, capable choice. Our goal is to describe a new conceptual model for assessing financial decisions using principles of person-centered approaches and to introduce a new instrument, the Lichtenberg Financial Decision Rating Scale (LFDRS). We created a conceptual model, convened meetings of experts from various disciplines to critique the model and provide input on content and structure, and select final items. We then videotaped administration of the LFDRS to five older adults and had 10 experts provide independent ratings. The LFDRS demonstrated good to excellent inter-rater agreement. The LFDRS is a new tool that allows gerontologists to systematically gather information about a specific financial decision and the decisional abilities in question. PMID:25866438

A Person-Centered Approach to Financial Capacity Assessment: Preliminary Development of a New Rating Scale.

PubMed

Lichtenberg, Peter A; Stoltman, Jonathan; Ficker, Lisa J; Iris, Madelyn; Mast, Benjamin

2015-01-01

Financial exploitation and financial capacity issues often overlap when a gerontologist assesses whether an older adult's financial decision is an autonomous, capable choice. Our goal is to describe a new conceptual model for assessing financial decisions using principles of person-centered approaches and to introduce a new instrument, the Lichtenberg Financial Decision Rating Scale (LFDRS). We created a conceptual model, convened meetings of experts from various disciplines to critique the model and provide input on content and structure, and select final items. We then videotaped administration of the LFDRS to five older adults and had 10 experts provide independent ratings. The LFDRS demonstrated good to excellent inter-rater agreement. The LFDRS is a new tool that allows gerontologists to systematically gather information about a specific financial decision and the decisional abilities in question.

Prey dispersal rate affects prey species composition and trait diversity in response to multiple predators in metacommunities.

PubMed

Howeth, Jennifer G; Leibold, Mathew A

2010-09-01

1. Recent studies indicate that large-scale spatial processes can alter local community structuring mechanisms to determine local and regional assemblages of predators and their prey. In metacommunities, this may occur when the functional diversity represented in the regional predator species pool interacts with the rate of prey dispersal among local communities to affect prey species diversity and trait composition at multiple scales. 2. Here, we test for effects of prey dispersal rate and spatially and temporally heterogeneous predation from functionally dissimilar predators on prey structure in pond mesocosm metacommunities. An experimental metacommunity consisted of three pond mesocosm communities supporting two differentially size-selective invertebrate predators and their zooplankton prey. In each metacommunity, two communities maintained constant predation and supported either Gyrinus sp. (Coleoptera) or Notonecta ungulata (Hemiptera) predators generating a spatial prey refuge while the third community supported alternating predation from Gyrinus sp. and N. ungulata generating a temporal prey refuge. Mesocosm metacommunities were connected at either low (0.7% day(-1)) or high (10% day(-1)) planktonic prey dispersal. The diversity, composition and body size of zooplankton prey were measured at local and regional (metacommunity) scales. 3. Metacommunities experiencing the low prey dispersal rate supported the greatest regional prey species diversity (H') and evenness (J'). Neither dispersal rate nor predation regime affected local prey diversity or evenness. The spatial prey refuge at low dispersal maintained the largest difference in species composition and body size diversity between communities under Gyrinus and Notonecta predation, suggesting that species sorting was operating at the low dispersal rate. There was no effect of dispersal rate on species diversity or body size distribution in the temporal prey refuge. 4. The frequency distribution, but not the range, of prey body sizes within communities depended upon prey dispersal rate and predator identity. Taken together, these results demonstrate that prey dispersal rate can moderate the strength of predation to influence prey species diversity and the local frequency distribution of prey traits in metacommunities supporting ecologically different predators.

Instabilities and subharmonic resonances of subsonic heated round jets, volume 2. Ph.D. Thesis Final Report

NASA Technical Reports Server (NTRS)

Ng, Lian Lai

1990-01-01

When a jet is perturbed by a periodic excitation of suitable frequency, a large-scale coherent structure develops and grows in amplitude as it propagates downstream. The structure eventually rolls up into vortices at some downstream location. The wavy flow associated with the roll-up of a coherent structure is approximated by a parallel mean flow and a small, spatially periodic, axisymmetric wave whose phase velocity and mode shape are given by classical (primary) stability theory. The periodic wave acts as a parametric excitation in the differential equations governing the secondary instability of a subharmonic disturbance. The (resonant) conditions for which the periodic flow can strongly destabilize a subharmonic disturbance are derived. When the resonant conditions are met, the periodic wave plays a catalytic role to enhance the growth rate of the subharmonic. The stability characteristics of the subharmonic disturbance, as a function of jet Mach number, jet heating, mode number and the amplitude of the periodic wave, are studied via a secondary instability analysis using two independent but complementary methods: (1) method of multiple scales, and (2) normal mode analysis. It is found that the growth rates of the subharmonic waves with azimuthal numbers beta = 0 and beta = 1 are enhanced strongly, but comparably, when the amplitude of the periodic wave is increased. Furthermore, compressibility at subsonic Mach numbers has a moderate stabilizing influence on the subharmonic instability modes. Heating suppresses moderately the subharmonic growth rate of an axisymmetric mode, and it reduces more significantly the corresponding growth rate for the first spinning mode. Calculations also indicate that while the presence of a finite-amplitude periodic wave enhances the growth rates of subharmonic instability modes, it minimally distorts the mode shapes of the subharmonic waves.

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

Fang, Ming; Albrecht, Bruce A.; Ghate, Virendra P.

This study first illustrates the utility of using the Doppler spectrum width from millimetrewavelength radar to calculate the energy dissipation rate and then to use the energy dissipation rate to study turbulence structure in a continental stratocumulus cloud. It is shown that the turbulence kinetic energy dissipation rate calculated from the radar-measured Doppler spectrum width agrees well with that calculated from the Doppler velocity power spectrum. During the 16-h stratocumulus cloud event, the small-scale turbulence contributes 40%of the total velocity variance at cloud base, 50% at normalized cloud depth=0.8 and 70% at cloud top, which suggests that small-scale turbulence playsmore » a critical role near the cloud top where the entrainment and cloud-top radiative cooling act. The 16-h mean vertical integral length scale decreases from about 160 m at cloud base to 60 m at cloud top, and this signifies that the larger scale turbulence dominates around cloud base whereas the small-scale turbulence dominates around cloud top. The energy dissipation rate, total variance and squared spectrum width exhibit diurnal variations, but unlike marine stratocumulus they are high during the day and lowest around sunset at all levels; energy dissipation rates increase at night with the intensification of the cloud-top cooling. In the normalized coordinate system, the averaged coherent structure of updrafts is characterized by low energy dissipation rates in the updraft core and higher energy dissipation rates surround the updraft core at the top and along the edges. In contrast, the energy dissipation rate is higher inside the downdraft core indicating that the downdraft core is more turbulent. The turbulence around the updraft is weaker at night and stronger during the day; the opposite is true around the downdraft. This behaviour indicates that the turbulence in the downdraft has a diurnal cycle similar to that observed in marine stratocumuluswhereas the turbulence diurnal cycle in the updraft is reversed. For both updraft and downdraft, the maximum energy dissipation rate occurs at a cloud depth=0.8 where the maximum reflectivity and air acceleration or deceleration are observed. Resolved turbulence dominates near cloud base whereas unresolved turbulence dominates near cloud top. Similar to the unresolved turbulence, the resolved turbulence described by the radial velocity variance is higher in the downdraft than in the updraft. The impact of the surface heating on the resolved turbulence in the updraft decreases with height and diminishes around the cloud top. In both updrafts and downdrafts, the resolved turbulence increases with height and reaches a maximum at cloud depth=0.4 and then decreases to the cloud top; the resolved turbulence near cloud top, just as the unresolved turbulence, is mostly due to the cloud-top radiative cooling.« less

Predicting permeability of regular tissue engineering scaffolds: scaling analysis of pore architecture, scaffold length, and fluid flow rate effects.

PubMed

Rahbari, A; Montazerian, H; Davoodi, E; Homayoonfar, S

2017-02-01

The main aim of this research is to numerically obtain the permeability coefficient in the cylindrical scaffolds. For this purpose, a mathematical analysis was performed to derive an equation for desired porosity in terms of morphological parameters. Then, the considered cylindrical geometries were modeled and the permeability coefficient was calculated according to the velocity and pressure drop values based on the Darcy's law. In order to validate the accuracy of the present numerical solution, the obtained permeability coefficient was compared with the published experimental data. It was observed that this model can predict permeability with the utmost accuracy. Then, the effect of geometrical parameters including porosity, scaffold pore structure, unit cell size, and length of the scaffolds as well as entrance mass flow rate on the permeability of porous structures was studied. Furthermore, a parametric study with scaling laws analysis of sample length and mass flow rate effects on the permeability showed good fit to the obtained data. It can be concluded that the sensitivity of permeability is more noticeable at higher porosities. The present approach can be used to characterize and optimize the scaffold microstructure due to the necessity of cell growth and transferring considerations.

A Kinetic-MHD Theory for the Self-Consistent Energy Exchange Between Energetic Particles and Active Small-scale Flux Ropes

NASA Astrophysics Data System (ADS)

le Roux, J. A.

2017-12-01

We developed previously a focused transport kinetic theory formalism with Fokker-plank coefficients (and its Parker transport limit) to model large-scale energetic particle transport and acceleration in solar wind regions with multiple contracting and merging small-scale flux ropes on MHD (inertial) scales (Zank et al. 2014; le Roux et al. 2015). The theory unifies the main acceleration mechanisms identified in particle simulations for particles temporarily trapped in such active flux rope structures, such as acceleration by the parallel electric field in reconnection regions between merging flux ropes, curvature drift acceleration in incompressible/compressible contracting and merging flux ropes, and betatron acceleration (e.g., Dahlin et al 2016). Initial analytical solutions of the Parker transport equation in the test particle limit showed that the energetic particle pressure from efficient flux-rope energization can potentially be high in turbulent solar wind regions containing active flux-rope structures. This requires taking into account the back reaction of energetic particles on flux ropes to more accurately determine the efficiency of energetic particles acceleration by small-scale flux ropes. To accomplish this goal we developed recently an extension of the kinetic theory to a kinetic-MHD level. We will present the extended theory showing the focused transport equation to be coupled to a solar wind MHD transport equation for small-scale flux-rope energy density extracted from a recently published nearly incompressible theory for solar wind MHD turbulence with a plasma beta of 1 (Zank et al. 2017). In the flux-rope transport equation appears new expressions for the damping/growth rates of flux-rope energy derived from assuming energy conservation in the interaction between energetic particles and small-scale flux ropes for all the main flux-rope acceleration mechanisms, whereas previous expressions for average particle acceleration rates have been explored in more detail. Future applications will involve exploring the relative role of diffusive shock and flux-ropes acceleration in the vicinity of traveling shocks in the supersonic solar wind near Earth where many flux-rope structures were detected recently (Hu et al 2017, this session).

New perspectives on the Popigai impact structure

NASA Technical Reports Server (NTRS)

Garvin, J. B.; Deino, A. L.

1992-01-01

The record of large-scale cratering on Earth is scant, and the only currently 'proven' 100-km-class impact structure known to have formed within the Cenozoic is Popigai, located in the Siberian Arctic at 71.5 deg N, 111 deg E. Popigai is clearly a multiringed impact basin formed within the crystalline shield rocks (Anabar) and platform sediments of the Siberian taiga, and estimates of the volume of preserved impact melt typically exceed 1700 cu km, which is within a factor of 2-3 of what would be predicted using scaling relationships. We present the preliminary results of an analysis of the present-day topography of the Popigai structure, together with refined absolute age estimates, in order to reconstruct the pre-erosional morphology of the basin, as well as to quantify the erosion or sediment infill rates in the Popigai region.

An experimental study of combustion: The turbulent structure of a reacting shear layer formed at a rearward-facing step. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Pitz, R. W.

1981-01-01

A premixed propane-air flame is stabilized in a turbulent free shear layer formed at a rearward-facing step. The mean and rms averages of the turbulent velocity flow field were determined by LDV for both reacting and non-reacting flows. The reaching flow was visualized by high speed schlieren photography. Large scale structures dominate the reacting shear layer. The growth of the large scale structures is tied to the propagation of the flame. The linear growth rate of the reacting shear layer defined by the mean velocity profiles is unchanged by combustion but the virtual origin is shifted downstream. The reacting shear layer based on the mean velocity profiles is shifted toward the recirculation zone and the reattachments lengths are shortened by 30%.

Acoustic structure of the five perceptual dimensions of timbre in orchestral instrument tones

PubMed Central

Elliott, Taffeta M.; Hamilton, Liberty S.; Theunissen, Frédéric E.

2013-01-01

Attempts to relate the perceptual dimensions of timbre to quantitative acoustical dimensions have been tenuous, leading to claims that timbre is an emergent property, if measurable at all. Here, a three-pronged analysis shows that the timbre space of sustained instrument tones occupies 5 dimensions and that a specific combination of acoustic properties uniquely determines gestalt perception of timbre. Firstly, multidimensional scaling (MDS) of dissimilarity judgments generated a perceptual timbre space in which 5 dimensions were cross-validated and selected by traditional model comparisons. Secondly, subjects rated tones on semantic scales. A discriminant function analysis (DFA) accounting for variance of these semantic ratings across instruments and between subjects also yielded 5 significant dimensions with similar stimulus ordination. The dimensions of timbre space were then interpreted semantically by rotational and reflectional projection of the MDS solution into two DFA dimensions. Thirdly, to relate this final space to acoustical structure, the perceptual MDS coordinates of each sound were regressed with its joint spectrotemporal modulation power spectrum. Sound structures correlated significantly with distances in perceptual timbre space. Contrary to previous studies, most perceptual timbre dimensions are not the result of purely temporal or spectral features but instead depend on signature spectrotemporal patterns. PMID:23297911

Factorial Validity of the ADHD Adult Symptom Rating Scale in a French Community Sample: Results From the ChiP-ARD Study.

PubMed

Morin, Alexandre J S; Tran, Antoine; Caci, Hervé

2016-06-01

Recent publications reported that a bifactor model better represented the underlying structure of ADHD than classical models, at least in youth. The Adult ADHD Symptoms Rating Scale (ASRS) has been translated into many languages, but a single study compared its structure in adults across Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) and International Classification of Diseases (ICD-10) classifications. We investigated the factor structure, reliability, and measurement invariance of the ASRS among a community sample of 1,171 adults. Results support a bifactor model, including one general ADHD factor and three specific Inattention, Hyperactivity, and Impulsivity factors corresponding to ICD-10, albeit the Impulsivity specific factor was weakly defined. Results also support the complete measurement invariance of this model across gender and age groups, and that men have higher scores than women on the ADHD G-factor but lower scores on all three S-factors. Results suggest that a total ASRS-ADHD score is meaningful, reliable, and valid in adults. (J. of Att. Dis. 2016; 20(6) 530-541). © The Author(s) 2013.

Factor structure and clinical correlates of the 61-item Wender Utah Rating Scale (WURS).

PubMed

Calamia, Matthew; Hill, Benjamin D; Musso, Mandi W; Pella, Russell D; Gouvier, Wm Drew

2018-02-09

The objective of this study was to assess the factor structure and clinical correlates of a 61-item version of the Wender Utah Rating Scale (WURS), a self-report retrospective measure of childhood problems, experiences, and behavior used in ADHD assessment. Given the currently mostly widely used form of the WURS was derived via a criterion-keyed approach, the study aimed to use latent variable modeling of the 61-item WURS to potentially identify more and more homogeneous set of items reflecting current conceptualizations of ADHD symptoms. Exploratory structural equation modeling was used to generate factor scores which were then correlated with neuropsychological measures of intelligence and executive attention as well as a broad measure of personality and emotional functioning. Support for a modified five-factor model was found: ADHD, disruptive mood and behavior, negative affectivity, social confidence, and academic problems. The ADHD factor differed somewhat from the traditional 25-item WURS short form largely through weaker associations with several measures of personality and psychopathology. This study identified a factor more aligned with DSM-5 conceptualization of ADHD as well as measures of other types of childhood characteristics and symptoms which may prove useful for both research and clinical practice.

Body mass scaling of passive oxygen diffusion in endotherms and ectotherms

PubMed Central

Gillooly, James F.; Gomez, Juan Pablo; Mavrodiev, Evgeny V.; Rong, Yue; McLamore, Eric S.

2016-01-01

The area and thickness of respiratory surfaces, and the constraints they impose on passive oxygen diffusion, have been linked to differences in oxygen consumption rates and/or aerobic activity levels in vertebrates. However, it remains unclear how respiratory surfaces and associated diffusion rates vary with body mass across vertebrates, particularly in relation to the body mass scaling of oxygen consumption rates. Here we address these issues by first quantifying the body mass dependence of respiratory surface area and respiratory barrier thickness for a diversity of endotherms (birds and mammals) and ectotherms (fishes, amphibians, and reptiles). Based on these findings, we then use Fick’s law to predict the body mass scaling of oxygen diffusion for each group. Finally, we compare the predicted body mass dependence of oxygen diffusion to that of oxygen consumption in endotherms and ectotherms. We find that the slopes and intercepts of the relationships describing the body mass dependence of passive oxygen diffusion in these two groups are statistically indistinguishable from those describing the body mass dependence of oxygen consumption. Thus, the area and thickness of respiratory surfaces combine to match oxygen diffusion capacity to oxygen consumption rates in both air- and water-breathing vertebrates. In particular, the substantially lower oxygen consumption rates of ectotherms of a given body mass relative to those of endotherms correspond to differences in oxygen diffusion capacity. These results provide insights into the long-standing effort to understand the structural attributes of organisms that underlie the body mass scaling of oxygen consumption. PMID:27118837

Body mass scaling of passive oxygen diffusion in endotherms and ectotherms.

PubMed

Gillooly, James F; Gomez, Juan Pablo; Mavrodiev, Evgeny V; Rong, Yue; McLamore, Eric S

2016-05-10

The area and thickness of respiratory surfaces, and the constraints they impose on passive oxygen diffusion, have been linked to differences in oxygen consumption rates and/or aerobic activity levels in vertebrates. However, it remains unclear how respiratory surfaces and associated diffusion rates vary with body mass across vertebrates, particularly in relation to the body mass scaling of oxygen consumption rates. Here we address these issues by first quantifying the body mass dependence of respiratory surface area and respiratory barrier thickness for a diversity of endotherms (birds and mammals) and ectotherms (fishes, amphibians, and reptiles). Based on these findings, we then use Fick's law to predict the body mass scaling of oxygen diffusion for each group. Finally, we compare the predicted body mass dependence of oxygen diffusion to that of oxygen consumption in endotherms and ectotherms. We find that the slopes and intercepts of the relationships describing the body mass dependence of passive oxygen diffusion in these two groups are statistically indistinguishable from those describing the body mass dependence of oxygen consumption. Thus, the area and thickness of respiratory surfaces combine to match oxygen diffusion capacity to oxygen consumption rates in both air- and water-breathing vertebrates. In particular, the substantially lower oxygen consumption rates of ectotherms of a given body mass relative to those of endotherms correspond to differences in oxygen diffusion capacity. These results provide insights into the long-standing effort to understand the structural attributes of organisms that underlie the body mass scaling of oxygen consumption.

Characterizing regional-scale temporal evolution of air dose rates after the Fukushima Daiichi Nuclear Power Plant accident.

PubMed

Wainwright, Haruko M; Seki, Akiyuki; Mikami, Satoshi; Saito, Kimiaki

2018-09-01

In this study, we quantify the temporal changes of air dose rates in the regional scale around the Fukushima Dai-ichi Nuclear Power Plant in Japan, and predict the spatial distribution of air dose rates in the future. We first apply the Bayesian geostatistical method developed by Wainwright et al. (2017) to integrate multiscale datasets including ground-based walk and car surveys, and airborne surveys, all of which have different scales, resolutions, spatial coverage, and accuracy. This method is based on geostatistics to represent spatial heterogeneous structures, and also on Bayesian hierarchical models to integrate multiscale, multi-type datasets in a consistent manner. We apply this method to the datasets from three years: 2014 to 2016. The temporal changes among the three integrated maps enables us to characterize the spatiotemporal dynamics of radiation air dose rates. The data-driven ecological decay model is then coupled with the integrated map to predict future dose rates. Results show that the air dose rates are decreasing consistently across the region. While slower in the forested region, the decrease is particularly significant in the town area. The decontamination has contributed to significant reduction of air dose rates. By 2026, the air dose rates will continue to decrease, and the area above 3.8 μSv/h will be almost fully contained within the non-residential forested zone. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evidence of a forward energy cascade and Kolmogorov self-similarity in submesoscale ocean surface drifter observations

NASA Astrophysics Data System (ADS)

Poje, Andrew C.; Ã-zgökmen, Tamay M.; Bogucki, Darek J.; Kirwan, A. D.

2017-02-01

Using two-point velocity and position data from the near-simultaneous release of O(100) GPS-tracked surface drifters in the northern Gulf of Mexico, we examine the applicability of classical turbulent scaling laws to upper ocean velocity fields. The dataset allows direct estimates of both velocity structure functions and the temporal evolution of the distribution of particle pair separations. On 100 m-10 km spatial scales, and time scales of order 1-10 days, all metrics of the observed surface fluctuations are consistent with standard Kolmogorov turbulence theory in an energy cascade inertial-range regime. The sign of the third-order structure function is negative and proportional to the separation distance for scales ≲10 km where local, fluctuating Rossby numbers are found to be larger than 0.1. The scale-independent energy dissipation rate, or downscale spectral flux, estimated from Kolmogorov's 4/5th law in this regime closely matches nearby microscale dissipation measurements in the near-surface. In contrast, similar statistics derived from a like-sized set of synthetic drifters advected by purely geostrophic altimetric AVISO data agree well with Kolmogorov-Kraichnan scaling for 2D turbulence in the forward enstrophy cascade range.

The scaling of contact rates with population density for the infectious disease models.

PubMed

Hu, Hao; Nigmatulina, Karima; Eckhoff, Philip

2013-08-01

Contact rates and patterns among individuals in a geographic area drive transmission of directly-transmitted pathogens, making it essential to understand and estimate contacts for simulation of disease dynamics. Under the uniform mixing assumption, one of two mechanisms is typically used to describe the relation between contact rate and population density: density-dependent or frequency-dependent. Based on existing evidence of population threshold and human mobility patterns, we formulated a spatial contact model to describe the appropriate form of transmission with initial growth at low density and saturation at higher density. We show that the two mechanisms are extreme cases that do not capture real population movement across all scales. Empirical data of human and wildlife diseases indicate that a nonlinear function may work better when looking at the full spectrum of densities. This estimation can be applied to large areas with population mixing in general activities. For crowds with unusually large densities (e.g., transportation terminals, stadiums, or mass gatherings), the lack of organized social contact structure deviates the physical contacts towards a special case of the spatial contact model - the dynamics of kinetic gas molecule collision. In this case, an ideal gas model with van der Waals correction fits well; existing movement observation data and the contact rate between individuals is estimated using kinetic theory. A complete picture of contact rate scaling with population density may help clarify the definition of transmission rates in heterogeneous, large-scale spatial systems. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Reliability and validity of the work and social adjustment scale in phobic disorders.

PubMed

Mataix-Cols, David; Cowley, Amy J; Hankins, Matthew; Schneider, Andreas; Bachofen, Martin; Kenwright, Mark; Gega, Lina; Cameron, Rachel; Marks, Isaac M

2005-01-01

The Work and Social Adjustment Scale (WSAS) is a simple widely used 5-item measure of disability whose psychometric properties need more analysis in phobic disorders. The reliability, factor structure, validity, and sensitivity to change of the WSAS were studied in 205 phobic patients (73 agoraphobia, 62 social phobia, and 70 specific phobia) who participated in various open and randomized trials of self-exposure therapy. Internal consistency of the WSAS was excellent in all phobics pooled and in agoraphobics and social phobics separately. Principal components analysis extracted a single general factor of disability. Specific phobics gave less consistent ratings across WSAS items, suggesting that some items were less relevant to their problem. Internal consistency was marginally higher for self-ratings than clinician ratings of the WSAS. Self-ratings and clinician ratings correlated highly though patients tended to rate themselves as more disabled than clinicians did. WSAS total scores reflected differences in phobic severity and improvement with treatment. The WSAS is a valid, reliable, and change-sensitive measure of work/social and other adjustment in phobic disorders, especially in agoraphobia and social phobia.

Exploring tectonomagmatic controls on mid-ocean ridge faulting and morphology with 3-D numerical models

NASA Astrophysics Data System (ADS)

Howell, S. M.; Ito, G.; Behn, M. D.; Olive, J. A. L.; Kaus, B.; Popov, A.; Mittelstaedt, E. L.; Morrow, T. A.

2016-12-01

Previous two-dimensional (2-D) modeling studies of abyssal-hill scale fault generation and evolution at mid-ocean ridges have predicted that M, the ratio of magmatic to total extension, strongly influences the total slip, spacing, and rotation of large faults, as well as the morphology of the ridge axis. Scaling relations derived from these 2-D models broadly explain the globally observed decrease in abyssal hill spacing with increasing ridge spreading rate, as well as the formation of large-offset faults close to the ends of slow-spreading ridge segments. However, these scaling relations do not explain some higher resolution observations of segment-scale variability in fault spacing along the Chile Ridge and the Mid-Atlantic Ridge, where fault spacing shows no obvious correlation with M. This discrepancy between observations and 2-D model predictions illuminates the need for three-dimensional (3-D) numerical models that incorporate the effects of along-axis variations in lithospheric structure and magmatic accretion. To this end, we use the geodynamic modeling software LaMEM to simulate 3-D tectono-magmatic interactions in a visco-elasto-plastic lithosphere under extension. We model a single ridge segment subjected to an along-axis gradient in the rate of magma injection, which is simulated by imposing a mass source in a plane of model finite volumes beneath the ridge axis. Outputs of interest include characteristic fault offset, spacing, and along-axis gradients in seafloor morphology. We also examine the effects of along-axis variations in lithospheric thickness and off-axis thickening rate. The main objectives of this study are to quantify the relative importance of the amount of magmatic extension and the local lithospheric structure at a given along-axis location, versus the importance of along-axis communication of lithospheric stresses on the 3-D fault evolution and morphology of intermediate-spreading-rate ridges.

The Classroom Environment Questionnaire (CEQ): Development and preliminary structural validity.

PubMed

Lyons, Carissa; Brown, Ted; Bourke-Taylor, Helen

2018-04-16

Occupational therapists offer a unique perspective regarding the contribution of the environment to occupational performance. Therefore, a scale that measures the unique characteristics of the primary school classroom environment where children complete their daily schoolwork occupations is needed. The aim of this study was to develop and psychometrically evaluate a new teacher-report questionnaire that measures a number of environmental characteristics of primary school classrooms. Participants (N = 117) completed the Classroom Environment Questionnaire (CEQ), which utilises a 4-point Likert scale where teachers rate 51 environmental characteristics of their classroom. Teachers also rate the extent to which they believe the physical, social, temporal, institutional and cultural classroom environmental domains contribute to students' schoolwork performance using a 10-point scale. The structural validity of the CEQ was examined using principal component analysis (PCA). Inter-item correlations were examined using Pearson r correlations, while the internal consistency of the CEQ was assessed using Cronbach's alpha. PCA revealed the CEQ to be multidimensional, with 31 items loading onto nine viable factors, representing the unique nature of classroom environments. Based on the PCA results, 20 items were removed from the CEQ. Cronbach's alpha and correlation analysis indicated that most CEQ subsections had acceptable internal consistency (alpha range 0.70-0.82), with four subsections demonstrating a lower level of internal consistency (alpha range 0.55-0.69). Preliminary structural validity and internal consistency analysis findings confirm that the CEQ has potential to be a useful scale for professionals wishing to examine the unique characteristics of primary school classrooms that influence the occupational performance of students. Ongoing analyses will be undertaken to further explore the CEQ's validity and reliability. © 2018 Occupational Therapy Australia.

Aspects of turbulent-shear-layer dynamics and mixing

NASA Astrophysics Data System (ADS)

Slessor, Michael David

Experiments have been conducted in the GALCIT Supersonic Shear Layer Facility to investigate some aspects of high-Reynolds-number, turbulent, shearlayer flows in both incompressible- and compressible-flow regimes. Experiments designed to address several issues were performed; effects of inflow boundary conditions, freestream conditions (supersonic/subsonic flow), and compressibility, on both large-scale dynamics and small-scale mixing, are described. Chemically-reacting and non-reacting flows were investigated, the former relying on the (H2 + NO/F2) chemical system, in the fast-kinetic regime, to infer the structure and amount of molecular-scale mixing through use of "flip" experiments. A variety of experimental techniques, including a color-schlieren visualization system developed as part of this work, were used to study the flows. Both inflow conditions and compressibility are found to have significant effects on the flow. In particular, inflow conditions are "remembered" for long distances downstream, a sensitivity similar to that observed in low-dimensionality, non-linear (chaotic) systems. The global flowfields (freestreams coupled by the shear layer) of transonic flows exhibit a sensitivity to imposed boundary conditions, i. e., local area ratios. A previously-proposed mode-selection rule for turbulent-structure convection speeds, based on the presence of a lab-frame subsonic freestream, was experimentally demonstrated to be incorrect. Compressibility, when decoupled from all other parameters, e.g., Reynolds number, velocity and density ratios, etc., reduces laxge-scale entrainment and turbulent growth, but slightly enhances smallscale mixing, with an associated change in the structure of the molecularly-mixed fluid. This reduction in shear-layer growth rate is examined and a new parameter that interprets compressibility as an energy-exchange mechanism is proposed. The parameter reconciles and collapses experimentally-observed growth rates.

The validity and structure of culture-level personality scores: data from ratings of young adolescents.

PubMed

McCrae, Robert R; Terracciano, Antonio; De Fruyt, Filip; De Bolle, Marleen; Gelfand, Michele J; Costa, Paul T

2010-06-01

We examined properties of culture-level personality traits in ratings of targets (N=5,109) ages 12 to 17 in 24 cultures. Aggregate scores were generalizable across gender, age, and relationship groups and showed convergence with culture-level scores from previous studies of self-reports and observer ratings of adults, but they were unrelated to national character stereotypes. Trait profiles also showed cross-study agreement within most cultures, 8 of which had not previously been studied. Multidimensional scaling showed that Western and non-Western cultures clustered along a dimension related to Extraversion. A culture-level factor analysis replicated earlier findings of a broad Extraversion factor but generally resembled the factor structure found in individuals. Continued analysis of aggregate personality scores is warranted.

The Validity and Structure of Culture-Level Personality Scores: Data From Ratings of Young Adolescents

PubMed Central

McCrae, Robert R.; Terracciano, Antonio; De Fruyt, Filip; De Bolle, Marleen; Gelfand, Michele J.; Costa, Paul T.; Aguilar-Vafaie, Maria E.; Ahn, Chang-kyu; Ahn, Hyun-nie; Alcalay, Lidia; Allik, Jüri; Avdeyeva, Tatyana V.; Blatný, Marek; Bratko, Denis; Brunner-Sciarra, Marina; Cain, Thomas R.; Chittcharat, Niyada; Crawford, Jarret T.; de Lima, Margarida P.; Fehr, Ryan; Ficková, Emília; Gülgöz, Sami; Hřebíčková, Martina; Jussim, Lee; Klinkosz, Waldemar; Knežević, Goran; de Figueroa, Nora Leibovich; Löckenhoff, Corinna E.; Martin, Thomas A.; Marušić, Iris; Mastor, Khairul Anwar; Nakazato, Katsuharu; Nansubuga, Florence; Porrata, Jose; Purić, Danka; Realo, Anu; Reátegui, Norma; Rolland, Jean-Pierre; Schmidt, Vanina; Sekowski, Andrzej; Shakespeare-Finch, Jane; Shimonaka, Yoshiko; Simonetti, Franco; Siuta, Jerzy; Szmigielska, Barbara; Vanno, Vitanya; Wang, Lei; Yik, Michelle

2010-01-01

We examined properties of culture-level personality traits in ratings of targets (N = 5,109) aged 12 to 17 in 24 cultures. Aggregate scores were generalizable across gender, age, and relationship groups and showed convergence with culture-level scores from previous studies of self-reports and observer ratings of adults, but they were unrelated to national character stereotypes. Trait profiles also showed cross-study agreement within most cultures, eight of which had not previously been studied. Multidimensional scaling showed that Western and non-Western cultures clustered along a dimension related to Extraversion. A culture-level factor analysis replicated earlier findings of a broad Extraversion factor, but generally resembled the factor structure found in individuals. Continued analysis of aggregate personality scores is warranted. PMID:20573127

Re-Structuring of Marine Communities Exposed to Environmental Change: A Global Study on the Interactive Effects of Species and Functional Richness

PubMed Central

Wahl, Martin; Link, Heike; Alexandridis, Nicolaos; Thomason, Jeremy C.; Cifuentes, Mauricio; Costello, Mark J.; da Gama, Bernardo A. P.; Hillock, Kristina; Hobday, Alistair J.; Kaufmann, Manfred J.; Keller, Stefanie; Kraufvelin, Patrik; Krüger, Ina; Lauterbach, Lars; Antunes, Bruno L.; Molis, Markus; Nakaoka, Masahiro; Nyström, Julia; bin Radzi, Zulkamal; Stockhausen, Björn; Thiel, Martin; Vance, Thomas; Weseloh, Annika; Whittle, Mark; Wiesmann, Lisa; Wunderer, Laura; Yamakita, Takehisa; Lenz, Mark

2011-01-01

Species richness is the most commonly used but controversial biodiversity metric in studies on aspects of community stability such as structural composition or productivity. The apparent ambiguity of theoretical and experimental findings may in part be due to experimental shortcomings and/or heterogeneity of scales and methods in earlier studies. This has led to an urgent call for improved and more realistic experiments. In a series of experiments replicated at a global scale we translocated several hundred marine hard bottom communities to new environments simulating a rapid but moderate environmental change. Subsequently, we measured their rate of compositional change (re-structuring) which in the great majority of cases represented a compositional convergence towards local communities. Re-structuring is driven by mortality of community components (original species) and establishment of new species in the changed environmental context. The rate of this re-structuring was then related to various system properties. We show that availability of free substratum relates negatively while taxon richness relates positively to structural persistence (i.e., no or slow re-structuring). Thus, when faced with environmental change, taxon-rich communities retain their original composition longer than taxon-poor communities. The effect of taxon richness, however, interacts with another aspect of diversity, functional richness. Indeed, taxon richness relates positively to persistence in functionally depauperate communities, but not in functionally diverse communities. The interaction between taxonomic and functional diversity with regard to the behaviour of communities exposed to environmental stress may help understand some of the seemingly contrasting findings of past research. PMID:21611170

A novel approach to gravitation from fluid theory: Titius-Bode structures, flat rotation rate of galaxies, and other predictions

NASA Astrophysics Data System (ADS)

Munera, Hector A.

Following the discovery of quantum phenomena at laboratory scale (Couder & Fort 2006), de Broglie pilot wave theory (De Broglie 1962) has been revived under a hydrodynamic guise (Bush 2015). Theoretically, it boils down to solving the transport equations for the energy and linear momentum densities of a postulated fundamental fluid in terms of classical wave equations, which inherently are Lorentz-invariant and scale-invariant. Instead of the conventional harmonic solutions, for astronomical and gravitational problems the novel solutions for the homogeneous wave equation in spherical coordinates are more suitable (Munera et al. 1995, Munera & Guzman 1997, and Munera 2000). Two groups of solutions are particularly relevant: (a) The inherently-quantized helicoidal solutions that may be applicable to describe spiral galaxies, and (b) The non-harmonic solutions with time (t) and distance (r) entangled in the single variable q = Ct/r (C is the two-way local electromagnetic speed). When these functions are plotted against 1/q they manifestly depict quantum effects in the near field, and Newtonian-like gravity in the far-field. The near-field predicts quantized effects similar to ring structures and to Titius-Bode structures, both in our own solar system and in exoplanets, the correlation between predicted and observed structures being typically larger than 99 per cent. In the far-field, some non-harmonic functions have a rate of decrement with distance slower than inverse-square thus explaining the flat rotation rate of galaxies. Additional implications for Trojan orbits, and quantized effects in photon deflection were also noted.

Latent constructs of the autobiographical memory questionnaire: a recollection-belief model of autobiographical experience.

PubMed

Fitzgerald, Joseph M; Broadbridge, Carissa L

2013-01-01

Many researchers employ single-item scales of subjective experiences such as imagery and confidence to assess autobiographical memory. We tested the hypothesis that four latent constructs, recollection, belief, impact, and rehearsal, account for the variance in commonly used scales across four different types of autobiographical memory: earliest childhood memory, cue word memory of personal experience, highly vivid memory, and most stressful memory. Participants rated each memory on scales hypothesised to be indicators of one of four latent constructs. Multi-group confirmatory factor analyses and structural analyses confirmed the similarity of the latent constructs of recollection, belief, impact, and rehearsal, as well as the similarity of the structural relationships among those constructs across memory type. The observed pattern of mean differences between the varieties of autobiographical experiences was consistent with prior research and theory in the study of autobiographical memory.

A short generic measure of work stress in the era of globalization: effort-reward imbalance.

PubMed

Siegrist, Johannes; Wege, Natalia; Pühlhofer, Frank; Wahrendorf, Morten

2009-08-01

We evaluate psychometric properties of a short version of the original effort-reward imbalance (ERI) questionnaire. This measure is of interest in the context of assessing stressful work conditions in the era of economic globalization. In a representative sample of 10,698 employed men and women participating in the longitudinal Socio-Economic Panel (SOEP) in Germany, a short version of the ERI questionnaire was included in the 2006 panel wave. Structural equation modeling and logistic regression analysis were applied. In addition to satisfactory internal consistency of scales, a model representing the theoretical structure of the scales provided the best data fit in a competitive test (RMSEA = 0.059, CAIC = 4124.19). Scoring high on the ERI scales was associated with elevated risks of poor self-rated health. This short version of the ERI questionnaire reveals satisfactory psychometric properties, and can be recommended for further use in research and practice.

Time scale defined by the fractal structure of the price fluctuations in foreign exchange markets

NASA Astrophysics Data System (ADS)

Kumagai, Yoshiaki

2010-04-01

In this contribution, a new time scale named C-fluctuation time is defined by price fluctuations observed at a given resolution. The intraday fractal structures and the relations of the three time scales: real time (physical time), tick time and C-fluctuation time, in foreign exchange markets are analyzed. The data set used is trading prices of foreign exchange rates; US dollar (USD)/Japanese yen (JPY), USD/Euro (EUR), and EUR/JPY. The accuracy of the data is one minute and data within a minute are recorded in order of transaction. The series of instantaneous velocity of C-fluctuation time flowing are exponentially distributed for small C when they are measured by real time and for tiny C when they are measured by tick time. When the market is volatile, for larger C, the series of instantaneous velocity are exponentially distributed.

Development and Evaluation of the Telephone Crisis Support Skills Scale.

PubMed

Kitchingman, Taneile A; Wilson, Coralie J; Caputi, Peter; Woodward, Alan; Hunt, Tara

2015-01-01

Although telephone services continue to play an important role in the delivery of front-line crisis support, published evidence of the standardized assessment of such services does not exist to date. To describe the development of the Telephone Crisis Support Skills Scale (TCSSS), an instrument to assess workers' intentions to use recommended skills with callers, and to evaluate its factor structure and reliability. TCSSS items were mapped to a national telephone crisis support practice model. A national sample of workers (n = 210) completed the TCSSS as part of a larger online survey. Principal axis factoring was used to evaluate the structure of the instrument. Internal consistency was assessed by Cronbach's α values. A single factor accounted for more than 40% of the variance within TCSSS ratings, indicating unidimensional structure. Cronbach's α coefficients suggested adequate internal consistency. Results indicate that the TCSSS is an internally consistent, unidimensional scale, sufficiently sensitive to detect workers' skill priorities for different caller problem types. Further study is required to confirm the factor structure and reliability of the TCSSS using workers from different organizations. Following further evaluation, the TCSSS may be applied to assessing readiness for and quality of service delivery.

Core-shell-structured nanothermites synthesized by atomic layer deposition

NASA Astrophysics Data System (ADS)

Qin, Lijun; Gong, Ting; Hao, Haixia; Wang, Keyong; Feng, Hao

2013-12-01

Thermite materials feature very exothermic solid-state redox reactions. However, the energy release rates of traditional thermite mixtures are limited by the reactant diffusion velocities. In this work, atomic layer deposition (ALD) is utilized to synthesize thermite materials with greatly enhanced reaction rates. By depositing certain types of metal oxides (oxidizers) onto a commercial Al nanopowder, core-shell-structured nanothermites can be produced. The average film deposition rate on the Al nanopowder is 0.17 nm/cycle for ZnO and 0.031 nm/cycle for SnO2. The thickness of the oxidizer layer can be precisely controlled by adjusting the ALD cycle number. The compositions, morphologies, and structures of the ALD nanothermites are characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. The characterization results reveal nearly perfect coverage of the Al nanoparticles by uniform ALD oxidizer layers and confirm the formation of core-shell nanoparticles. Combustion properties of the nanothermites are probed by laser ignition technique. Reactions of the core-shell-structured nanothermites are several times faster than the mixture of nanopowders. The promoted reaction rate is mostly attributed to the uniform distribution of reactants on the nanometer scale. These core-shell-structured nanothermites provide a potential pathway to control and enhance thermite reactions.

The hierarchical structure of self-reported impulsivity

PubMed Central

Kirby, Kris N.; Finch, Julia C.

2010-01-01

The hierarchical structure of 95 self-reported impulsivity items, along with delay-discount rates for money, was examined. A large sample of college students participated in the study (N = 407). Items represented every previously proposed dimension of self-reported impulsivity. Exploratory PCA yielded at least 7 interpretable components: Prepared/Careful, Impetuous, Divertible, Thrill and Risk Seeking, Happy-Go-Lucky, Impatiently Pleasure Seeking, and Reserved. Discount rates loaded on Impatiently Pleasure Seeking, and correlated with the impulsiveness and venturesomeness scales from the I7 (Eysenck, Pearson, Easting, & Allsopp, 1985). The hierarchical emergence of the components was explored, and we show how this hierarchical structure may help organize conflicting dimensions found in previous analyses. Finally, we argue that the discounting model (Ainslie, 1975) provides a qualitative framework for understanding the dimensions of impulsivity. PMID:20224803

Influence factors and forecast of carbon emission in China: structure adjustment for emission peak

NASA Astrophysics Data System (ADS)

Wang, B.; Cui, C. Q.; Li, Z. P.

2018-02-01

This paper introduced Principal Component Analysis and Multivariate Linear Regression Model to verify long-term balance relationships between Carbon Emissions and the impact factors. The integrated model of improved PCA and multivariate regression analysis model is attainable to figure out the pattern of carbon emission sources. Main empirical results indicate that among all selected variables, the role of energy consumption scale was largest. GDP and Population follow and also have significant impacts on carbon emission. Industrialization rate and fossil fuel proportion, which is the indicator of reflecting the economic structure and energy structure, have a higher importance than the factor of urbanization rate and the dweller consumption level of urban areas. In this way, some suggestions are put forward for government to achieve the peak of carbon emissions.

Energy Dissipation in Earthquake Soil Structure Interaction: The September 3rd, 2016 M5.8 Pawnee Oklahoma Earthquake

NASA Astrophysics Data System (ADS)

Yang, H.; Sinha, S. K.; Feng, Y.; Jeremic, B.

2016-12-01

The M5.8 earthquake occurred in Pawnee, Oklahoma on September 3rd 2016 is the strongest seismic event recorded in Oklahoma. Soil structure interaction (SSI) played an important role in this tragic event. As a major aspect of SSI analysis, the propagation and dissipation of seismic energy will be studied in depth, with particular focus on the ground motion recorded in this earthquake. Seismic energy propagates from seismic source to the SSI system and is dissipated within and around the SSI system. Energy dissipation with the SSI system is related to inelastic behavior of soil, rock, contact zone (foundation-soil/rock), structural components and energy dissipators. Accurate evaluation of seismic energy can be used to optimize SSI system for safety and economy. The SSI system can be designed so that majority of seismic energy is dissipated within soil and soil-foundation contact zone, away from the structure.Accurate and theoretically sound modeling of propagation and dissipation is essential to use of seismic energy for design and assessment. The rate of plastic work is defined as the product of stress and the rate of plastic strain. On the other hand, plastic dissipation is defined as a form of heat transfer. The difference between these two quantities, which has been neglected in many studies, is a plastic part of the free energy. By considering energy storage and dissipation at both micro (particle) scale and macro (continuum) scale, it can be shown that the plastic free energy is an intrinsic attribute at the continuum scale due to particle rearrangement. Proper application of thermodynamics to finite element simulations, plastic dissipation can be correctly modeled. Examples will be used to illustrate above point on both constitutive, single element and SSI model scales. In addition, propagation of seismic energy, its dissipation (timing and location) will be used to illustrate use in design and assessment.

Multi-scale simulations of black hole accretion in barred galaxies. Self-gravitating disk models

NASA Astrophysics Data System (ADS)

Jung, M.; Illenseer, T. F.; Duschl, W. J.

2018-06-01

Due to the non-axisymmetric potential of the central bar, in addition to their characteristic arms and bar, barred spiral galaxies form a variety of structures within the thin gas disk, such as nuclear rings, inner spirals, and dust lanes. These structures in the inner kiloparsec are extremely important in order to explain and understand the rate of black hole feeding. The aim of this work is to investigate the influence of stellar bars in spiral galaxies on the thin self-gravitating gas disk. We focus on the accretion of gas onto the central supermassive black hole and its time-dependent evolution. We conducted multi-scale simulations simultaneously resolving the galactic disk and the accretion disk around the central black hole. In all the simulations we varied the initial gas disk mass. As an additional parameter we chose either the gas temperature for isothermal simulations or the cooling timescale for non-isothermal simulations. Accretion was either driven by a gravitationally unstable or clumpy accretion disk or by energy dissipation in strong shocks. Most of the simulations show a strong dependence of the accretion rate at the outer boundary of the central accretion disk (r < 300 pc) on the gas flow at kiloparsec scales. The final black hole masses reach up to 109 M⊙ after 1.6 Gyr. Our models show the expected influence of the Eddington limit and a decline in growth rate at the corresponding sub-Eddington limit.

Iogenic Plasma and its Rotation-Driven Transport in Jupiter's Magnetosphere

NASA Technical Reports Server (NTRS)

Smyth, William H.

2001-01-01

Model calculations are reported for the Iogenic plasma source created by atomic oxygen and sulfur above Io's exobase in the corona and extended clouds (Outer Region). On a circumplanetary scale, two-dimensional distributions produced by integrating the proper three dimensional rate information for electron impact and charge exchange processes along the magnetic field lines are presented for the pickup ion rates, the net-mass and total-mass loading rates, the mass per unit magnetic flux rate, the pickup conductivity, the radial pickup current, and the net-energy loading rate for the plasma torus. All of the two-dimensional distributions are highly peaked at Io's location and hence highly asymmetric about Jupiter. The Iogenic plasma source is also calculated on a much smaller near-Io scale to investigate the structure of the highly peak rates centered about lo's instantaneous location. The Iogenic plasma source for the Inner Region (pickup rates produced below Io's exobase) is, however, expected to be the dominant source near lo for the formation of the plasma torus ribbon and to be a comparable source, if not a larger contributor, to the energy budget of the plasma torus, so as to provide the necessary power to sustain the plasma torus radiative loss rate.

Porous materials for thermal management under extreme conditions.

PubMed

Clyne, T W; Golosnoy, I O; Tan, J C; Markaki, A E

2006-01-15

A brief analysis is presented of how heat transfer takes place in porous materials of various types. The emphasis is on materials able to withstand extremes of temperature, gas pressure, irradiation, etc. i.e. metals and ceramics, rather than polymers. A primary aim is commonly to maximize either the thermal resistance (i.e. provide insulation) or the rate of thermal equilibration between the material and a fluid passing through it (i.e. to facilitate heat exchange). The main structural characteristics concern porosity (void content), anisotropy, pore connectivity and scale. The effect of scale is complex, since the permeability decreases as the structure is refined, but the interfacial area for fluid-solid heat exchange is, thereby, raised. The durability of the pore structure may also be an issue, with a possible disadvantage of finer scale structures being poor microstructural stability under service conditions. Finally, good mechanical properties may be required, since the development of thermal gradients, high fluid fluxes, etc. can generate substantial levels of stress. There are, thus, some complex interplays between service conditions, pore architecture/scale, fluid permeation characteristics, convective heat flow, thermal conduction and radiative heat transfer. Such interplays are illustrated with reference to three examples: (i) a thermal barrier coating in a gas turbine engine; (ii) a Space Shuttle tile; and (iii) a Stirling engine heat exchanger. Highly porous, permeable materials are often made by bonding fibres together into a network structure and much of the analysis presented here is oriented towards such materials.

Intrinsic Origins of Crack Generation in Ni-rich LiNi0.8Co0.1Mn0.1O2 Layered Oxide Cathode Material.

PubMed

Lim, Jin-Myoung; Hwang, Taesoon; Kim, Duho; Park, Min-Sik; Cho, Kyeongjae; Cho, Maenghyo

2017-01-03

Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 layered oxide cathodes have been highlighted for large-scale energy applications due to their high energy density. Although its specific capacity is enhanced at higher voltages as Ni ratio increases, its structural degradation due to phase transformations and lattice distortions during cycling becomes severe. For these reasons, we focused on the origins of crack generation from phase transformations and structural distortions in Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 using multiscale approaches, from first-principles to meso-scale phase-field model. Atomic-scale structure analysis demonstrated that opposite changes in the lattice parameters are observed until the inverse Li content x = 0.75; then, structure collapses due to complete extraction of Li from between transition metal layers. Combined-phase investigations represent the highest phase barrier and steepest chemical potential after x = 0.75, leading to phase transformations to highly Li-deficient phases with an inactive character. Abrupt phase transformations with heterogeneous structural collapse after x = 0.81 (~220 mAh g -1 ) were identified in the nanodomain. Further, meso-scale strain distributions show around 5% of anisotropic contraction with lower critical energy release rates, which cause not only micro-crack generations of secondary particles on the interfaces between the contracted primary particles, but also mechanical instability of primary particles from heterogeneous strain changes.

Quantifying the scale- and process- dependent reorganization of landscape under climatic change: inferences from an experimental landscape

NASA Astrophysics Data System (ADS)

Singh, A.; Tejedor, A.; Grimaud, J. L.; Zaliapin, I. V.; Foufoula-Georgiou, E.

2016-12-01

Knowledge of the dynamics of evolving landscapes in terms of their geomorphic and topologic re-organization in response to changing climatic or tectonic forcing is of scientific and practical interest. Although several studies have addressed the large-scale response (e.g., change in mean relief), studies on the smaller-scale drainage pattern re-organization and quantification of landscape vulnerability to the timing, magnitude, and frequency of changing forcing are lacking. The reason is the absence of data for such an analysis. To that goal, a series of controlled laboratory experiments were conducted at the St. Anthony Falls laboratory of the University of Minnesota to study the effect of changing precipitation patterns on landscape evolution at the short and long-time scales. High resolution digital elevation (DEM) both in space and time were measured for a range of rainfall patterns and uplift rates. Results from our study show a distinct signature of the precipitation increase on the probabilistic and geometrical structure of landscape features, evident in widening and deepening of channels and valleys, change in drainage patterns within sub-basins and change in the space-time structure of erosional and depositional events. A spatially explicit analysis of the locus of these erosional and depositional events suggests a regime shift, during the onset of the transient state, from supply-limited to transport-limited fluvial channels. We document a characteristic scale-dependent signature of erosion at steady state (which we term the "E50-area curve") and show that during reorganization, its evolving shape reflects process and scales of geomorphic change. Finally, we document changes in the longitudinal river profiles, in response to increased precipitation rate, with the formation of abrupt gradient (knickpoints) that migrate upstream as time proceeds.

Direct evidence of atomic-scale structural fluctuations in catalyst nanoparticles.

PubMed

Lin, Pin Ann; Gomez-Ballesteros, Jose L; Burgos, Juan C; Balbuena, Perla B; Natarajan, Bharath; Sharma, Renu

2017-05-01

Rational catalyst design requires an atomic scale mechanistic understanding of the chemical pathways involved in the catalytic process. A heterogeneous catalyst typically works by adsorbing reactants onto its surface, where the energies for specific bonds to dissociate and/or combine with other species (to form desired intermediate or final products) are lower. Here, using the catalytic growth of single-walled carbon nanotubes (SWCNTs) as a prototype reaction, we show that the chemical pathway may in-fact involve the entire catalyst particle, and can proceed via the fluctuations in the formation and decomposition of metastable phases in the particle interior. We record in situ and at atomic resolution, the dynamic phase transformations occurring in a Cobalt catalyst nanoparticle during SWCNT growth, using a state-of-the-art environmental transmission electron microscope (ETEM). The fluctuations in catalyst carbon content are quantified by the automated, atomic-scale structural analysis of the time-resolved ETEM images and correlated with the SWCNT growth rate. We find the fluctuations in the carbon concentration in the catalyst nanoparticle and the fluctuations in nanotube growth rates to be of complementary character. These findings are successfully explained by reactive molecular dynamics (RMD) simulations that track the spatial and temporal evolution of the distribution of carbon atoms within and on the surface of the catalyst particle. We anticipate that our approach combining real-time, atomic-resolution image analysis and molecular dynamics simulations will facilitate catalyst design, improving reaction efficiencies and selectivity towards the growth of desired structure.

Fabrication of 3D surface structures using grayscale lithography

NASA Astrophysics Data System (ADS)

Stilson, Christopher; Pal, Rajan; Coutu, Ronald A.

2014-03-01

The ability to design and develop 3D microstructures is important for microelectromechanical systems (MEMS) fabrication. Previous techniques used to create 3D devices included tedious steps in direct writing and aligning patterns onto a substrate followed by multiple photolithography steps using expensive, customized equipment. Additionally, these techniques restricted batch processing and placed limits on achievable shapes. Gray-scale lithography enables the fabrication of a variety of shapes using a single photolithography step followed by reactive ion etching (RIE). Micromachining 3D silicon structures for MEMS can be accomplished using gray-scale lithography along with dry anisotropic etching. In this study, we investigated: using MATLAB for mask designs; feasibility of using 1 μm Heidelberg mask maker to direct write patterns onto photoresist; using RIE processing to etch patterns into a silicon substrate; and the ability to tailor etch selectivity for precise fabrication. To determine etch rates and to obtain desired etch selectivity, parameters such as gas mixture, gas flow, and electrode power were studied. This process successfully demonstrates the ability to use gray-scale lithography and RIE for use in the study of micro-contacts. These results were used to produce a known engineered non-planer surface for testing micro-contacts. Surface structures are between 5 μm and 20 μm wide with varying depths and slopes based on mask design and etch rate selectivity. The engineered surfaces will provide more insight into contact geometries and failure modes of fixed-fixed micro-contacts.

Meter scale variation in shrub dominance and soil moisture structure Arctic arthropod communities

PubMed Central

Hansen, Oskar Liset Pryds; Bowden, Joseph J.; Treier, Urs A.; Normand, Signe; Høye, Toke

2016-01-01

The Arctic is warming at twice the rate of the rest of the world. This impacts Arctic species both directly, through increased temperatures, and indirectly, through structural changes in their habitats. Species are expected to exhibit idiosyncratic responses to structural change, which calls for detailed investigations at the species and community level. Here, we investigate how arthropod assemblages of spiders and beetles respond to variation in habitat structure at small spatial scales. We sampled transitions in shrub dominance and soil moisture between three different habitats (fen, dwarf shrub heath, and tall shrub tundra) at three different sites along a fjord gradient in southwest Greenland, using yellow pitfall cups. We identified 2,547 individuals belonging to 47 species. We used species richness estimation, indicator species analysis and latent variable modeling to examine differences in arthropod community structure in response to habitat variation at local (within site) and regional scales (between sites). We estimated species responses to the environment by fitting species-specific generalized linear models with environmental covariates. Species assemblages were segregated at the habitat and site level. Each habitat hosted significant indicator species, and species richness and diversity were significantly lower in fen habitats. Assemblage patterns were significantly linked to changes in soil moisture and vegetation height, as well as geographic location. We show that meter-scale variation among habitats affects arthropod community structure, supporting the notion that the Arctic tundra is a heterogeneous environment. To gain sufficient insight into temporal biodiversity change, we require studies of species distributions detailing species habitat preferences. PMID:27478709

Landscape structure control on soil CO2 efflux variability in complex terrain: Scaling from point observations to watershed scale fluxes

Treesearch

Diego A. Riveros-Iregui; Brian L. McGlynn

2009-01-01

We investigated the spatial and temporal variability of soil CO2 efflux across 62 sites of a 393-ha complex watershed of the northern Rocky Mountains. Growing season (83 day) cumulative soil CO2 efflux varied from ~300 to ~2000 g CO2 m-2, depending upon landscape position, with a median of 879.8 g CO2 m-2. Our findings revealed that highest soil CO2 efflux rates were...

Role of thermal history in atomic dynamics of chalcogenide glass: A case study on Ge{sub 20}Te{sub 80} glass

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

Sharma, Yashika; Kalra, Geetanjali; Murugavel, Sevi, E-mail: murug@physics.du.ac.in

The non-existence of thermodynamic equilibrium in glasses, their thermal history plays a very crucial role in explaining the relaxation behavior in various time scales and its configurational states. More importantly, the associated relaxation behavior is related mainly to the structural phenomenon of the glasses. Here, we report the dependence of quenching rate on the variation of structural units. The local structures of these glasses are monitored by recording the Raman spectroscopy and related to the different configurational states. The observed variations in structural differences are reflected in the measured density of the corresponding glasses. The quenching rate dependent of themore » relative fractions of edge-shared and corner-shared GeTe{sub 4} tetrahedral units are shown to be consistent with the corresponding variations in the measured density values.« less

A situation-specific approach to measure attention in adults with ADHD: The everyday life attention scale (ELAS).

PubMed

Groen, Yvonne; Fuermaier, Anselm B M; Tucha, Lara; Weisbrod, Matthias; Aschenbrenner, Steffen; Tucha, Oliver

2018-03-14

This study describes the development and utility of a new self-report measure of attentional capacities of adults with Attention Deficit Hyperactivity Disorder (ADHD): the Everyday Life Attention Scale (ELAS). Different from previous attention scales, attentional capacities are rated for nine everyday situations. Study 1 investigated the factor structure, validity, and reliability of the ELAS in 1206 healthy participants. Confirmatory factor analysis supported a situation-specific approach which categorizes everyday attention into nine situation scales: Reading, Movie, Activity, Lecture, Conversation, Assignment, Cooking, Cleaning up, and Driving. Each scale was composed of ratings for sustained, focused, selective, and divided attention as well as motivation, and had good internal consistency. Most scales showed weak correlations with ADHD Symptoms, Executive Functioning, and Memory Efficacy. Study 2 further investigated the sensitivity of the ELAS in 80 adults with ADHD compared to matched healthy controls and a mixed clinical group of 56 patients diagnosed with other psychiatric disorders. Compared to healthy controls, patients with ADHD reported reduced attentional capacities with large effect sizes on all situation scales and had a substantially higher number of situations with impaired attention scores. The ELAS may become useful in the clinical evaluation of ADHD and related psychiatric disorders in adults.

[Study of functional rating scale for amyotrophic lateral sclerosis: revised ALSFRS(ALSFRS-R) Japanese version].

PubMed

Ohashi, Y; Tashiro, K; Itoyama, Y; Nakano, I; Sobue, G; Nakamura, S; Sumino, S; Yanagisawa, N

2001-04-01

Amyotrophic lateral sclerosis(ALS) is progressive, degenerative, fatal disease of the motor neuron. No efficacious therapy is available to slow the progressive loss of function, but several new approaches including neurotrophic factors, antioxidants and glutamate antagonists, are currently being evaluated as potential therapies. Mortality, and/or time to tracheostomy, muscle strength and pulmonary function are used as primary endpoints in clinical trials for treatment of ALS. The effect of new therapies on the quality of patients' lives are also important, so we sought to develop a rating scale to measure it. The revised ALS Functional Rating Scale(ALSFRS-R), which has addition of items to ALSFRS to enhance the ability to assess respiratory symptoms, is an assessment determining the degree of impairment in ALS patients' abilities to function independently in activities of daily living. It consists of 12 items to evaluate bulbar function, motor function and respiratory function and each item is scored from 0(unable) to 4(normal). We translated the English score into Japanese one with minor modification considering the inter cultural difference. And we examined reliability of the translated scale. As a measure of reliability, the intraclass correlation coefficient(ICC) was evaluated for total score and the Kappa coefficient proposed by Cohen and Kraemer was calculated for each item. Moreover, we examined sensitivity to clinical change over time and carried out the factor analysis to analyze the factorial structure. The subjects were 27 ALS patients and each was scored twice for reliability or three times for sensitivity by 2 to 5 neurologists and if possible, nurses. The ICC for total score was 0.97(95% C. I.; 0.94-0.98). Extension of the Kappa coefficients were 0.48 to 1.00 for inter-rater reliability and the averaged Kappa coefficients were 0.63 to 1.00 for intra rater reliability, respectively. Concerning the factorial structure, the contribution of the first factor(the first principal component) were 53.5% principal factor solution. The factor loadings of items were 0.52-0.91 except "salivation" and this factor almost equal to the simple sum of all items was interpreted as the general degree of deterioration. The promax votation revealed the riginally supposed factor structure with 3 factors(groups of items): neuromuscuclar function, respiratory function and bulbar function. The rating scale correlated with Global clinical impression of change(GCIC) scored by neurologists and declined with time, indicating its sensitivity to change. On the bases of these results, ALSFRS-R(Japanese version) is considered to be highly reliable enough for clinical use.

Factor solutions of the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) in a Swedish population.

PubMed

Mörtberg, Ewa; Reuterskiöld, Lena; Tillfors, Maria; Furmark, Tomas; Öst, Lars-Göran

2017-06-01

Culturally validated rating scales for social anxiety disorder (SAD) are of significant importance when screening for the disorder, as well as for evaluating treatment efficacy. This study examined construct validity and additional psychometric properties of two commonly used scales, the Social Phobia Scale and the Social Interaction Anxiety Scale, in a clinical SAD population (n = 180) and in a normal population (n = 614) in Sweden. Confirmatory factor analyses of previously reported factor solutions were tested but did not reveal acceptable fit. Exploratory factor analyses (EFA) of the joint structure of the scales in the total population yielded a two-factor model (performance anxiety and social interaction anxiety), whereas EFA in the clinical sample revealed a three-factor solution, a social interaction anxiety factor and two performance anxiety factors. The SPS and SIAS showed good to excellent internal consistency, and discriminated well between patients with SAD and a normal population sample. Both scales showed good convergent validity with an established measure of SAD, whereas the discriminant validity of symptoms of social anxiety and depression could not be confirmed. The optimal cut-off score for SPS and SIAS were 18 and 22 points, respectively. It is concluded that the factor structure and the additional psychometric properties of SPS and SIAS support the use of the scales for assessment in a Swedish population.

Meso-scopic Densification in Brittle Granular Materials

NASA Astrophysics Data System (ADS)

Neal, William; Appleby-Thomas, Gareth; Collins, Gareth

2013-06-01

Particulate materials are ideally suited to shock absorbing applications due to the large amounts of energy required to deform their inherently complex meso-structure. Significant effort is being made to improve macro-scale material models to represent these atypical materials. On the long road towards achieving this capability, an important milestone would be to understand how particle densification mechanisms are affected by loading rate. In brittle particulate materials, the majority of densification is caused by particle fracture. Macro-scale quasi-static and dynamic compaction curves have been measured that show good qualitative agreement. There are, however, some differences that appear to be dependent on the loading rate that require further investigation. This study aims to investigate the difference in grain-fracture behavior between the quasi-static and shock loading response of brittle glass microsphere beds using a combination of quasi-static and dynamic loading techniques. Results from pressure-density measurements, sample recovery, and meso-scale hydrocode models (iSALE, an in-house simulation package) are discussed to explain the differences in particle densification mechanisms between the two loading rate regimes. Gratefully funded by AWE.plc.

MAGNETIC BRAIDING AND PARALLEL ELECTRIC FIELDS

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

Wilmot-Smith, A. L.; Hornig, G.; Pontin, D. I.

2009-05-10

The braiding of the solar coronal magnetic field via photospheric motions-with subsequent relaxation and magnetic reconnection-is one of the most widely debated ideas of solar physics. We readdress the theory in light of developments in three-dimensional magnetic reconnection theory. It is known that the integrated parallel electric field along field lines is the key quantity determining the rate of reconnection, in contrast with the two-dimensional case where the electric field itself is the important quantity. We demonstrate that this difference becomes crucial for sufficiently complex magnetic field structures. A numerical method is used to relax a braided magnetic field towardmore » an ideal force-free equilibrium; the field is found to remain smooth throughout the relaxation, with only large-scale current structures. However, a highly filamentary integrated parallel current structure with extremely short length-scales is found in the field, with the associated gradients intensifying during the relaxation process. An analytical model is developed to show that, in a coronal situation, the length scales associated with the integrated parallel current structures will rapidly decrease with increasing complexity, or degree of braiding, of the magnetic field. Analysis shows the decrease in these length scales will, for any finite resistivity, eventually become inconsistent with the stability of the coronal field. Thus the inevitable consequence of the magnetic braiding process is a loss of equilibrium of the magnetic field, probably via magnetic reconnection events.« less

A similarity hypothesis for the two-point correlation tensor in a temporally evolving plane wake

NASA Technical Reports Server (NTRS)

Ewing, D. W.; George, W. K.; Moser, R. D.; Rogers, M. M.

1995-01-01

The analysis demonstrated that the governing equations for the two-point velocity correlation tensor in the temporally evolving wake admit similarity solutions, which include the similarity solutions for the single-point moment as a special case. The resulting equations for the similarity solutions include two constants, beta and Re(sub sigma), that are ratios of three characteristic time scales of processes in the flow: a viscous time scale, a time scale characteristic of the spread rate of the flow, and a characteristic time scale of the mean strain rate. The values of these ratios depend on the initial conditions of the flow and are most likely measures of the coherent structures in the initial conditions. The occurrences of these constants in the governing equations for the similarity solutions indicates that these solutions, in general, will only be the same for two flows if these two constants are equal (and hence the coherent structures in the flows are related). The comparisons between the predictions of the similarity hypothesis and the data presented here and elsewhere indicate that the similarity solutions for the two-point correlation tensors provide a good approximation of the measures of those motions that are not significantly affected by the boundary conditions caused by the finite extent of real flows. Thus, the two-point similarity hypothesis provides a useful tool for both numerical and physical experimentalist that can be used to examine how the finite extent of real flows affect the evolution of the different scales of motion in the flow.

A study on phenomenology of Dhat syndrome in men in a general medical setting

PubMed Central

Prakash, Sathya; Sharan, Pratap; Sood, Mamta

2016-01-01

Background: “Dhat syndrome” is believed to be a culture-bound syndrome of the Indian subcontinent. Although many studies have been performed, many have methodological limitations and there is a lack of agreement in many areas. Aims: The aim is to study the phenomenology of “Dhat syndrome” in men and to explore the possibility of subtypes within this entity. Settings and Design: It is a cross-sectional descriptive study conducted at a sex and marriage counseling clinic of a tertiary care teaching hospital in Northern India. Materials and Methods: An operational definition and assessment instrument for “Dhat syndrome” was developed after taking all concerned stakeholders into account and review of literature. It was applied on 100 patients along with socio-demographic profile, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Mini International Neuropsychiatric Interview, and Postgraduate Institute Neuroticism Scale. Statistical Analysis: For statistical analysis, descriptive statistics, group comparisons, and Pearson's product moment correlations were carried out. Factor analysis and cluster analysis were done to determine the factor structure and subtypes of “Dhat syndrome.” Results: A diagnostic and assessment instrument for “Dhat syndrome” has been developed and the phenomenology in 100 patients has been described. Both the health beliefs scale and associated symptoms scale demonstrated a three-factor structure. The patients with “Dhat syndrome” could be categorized into three clusters based on severity. Conclusions: There appears to be a significant agreement among various stakeholders on the phenomenology of “Dhat syndrome” although some differences exist. “Dhat syndrome” could be subtyped into three clusters based on severity. PMID:27385844

Economics of Utility Scale Photovoltaics at Purdue University

NASA Astrophysics Data System (ADS)

Arnett, William

The research for this case study shows that utility scale solar photovoltaics has become a competitive energy investment option, even when a campus operates a power plant at low electricity rates. To evaluate this an economic model called SEEMS (Solar Economic Evaluation Modelling Spreadsheets) was developed to evaluate a number of financial scenarios in Real Time Pricing for universities. The three main financing structures considered are 1) land leasing, 2) university direct purchase, and 3) third party purchase. Unlike other commercially available models SEEMS specifically accounts for real time pricing, where the local utility provides electricity at an hourly rate that changes with the expected demand. In addition, SEEMS also includes a random simulation that allows the model to predict the likelihood of success for a given solar installation strategy. The research showed that there are several options for utility scale solar that are financially attractive. The most practical financing structure is with a third party partnership because of the opportunity to take advantage of tax incentives. Other options could become more attractive if non-financial benefits are considered. The case study for this research, Purdue University, has a unique opportunity to integrate utility-scale solar electricity into its strategic planning. Currently Purdue is updating its master plan which will define how land is developed. Purdue is also developing a sustainability plan that will define long term environmental goals. In addition, the university is developing over 500 acres of land west of campus as part of its Aerospace Innovation District. This research helps make the case for including utility-scale solar electricity as part of the university's strategic planning.

The relation between magnetic and material arms in models for spiral galaxies

NASA Astrophysics Data System (ADS)

Moss, D.; Beck, R.; Sokoloff, D.; Stepanov, R.; Krause, M.; Arshakian, T. G.

2013-08-01

Context. Observations of polarized radio emission show that large-scale (regular) magnetic fields in spiral galaxies are not fully axisymmetric, but generally stronger in interarm regions. In some nearby galaxies such as NGC 6946 they are organized in narrow magnetic arms situated between the material spiral arms. Aims: The phenomenon of magnetic arms and their relation to the optical spiral arms (the material arms) calls for an explanation in the framework of galactic dynamo theory. Several possibilities have been suggested but are not completely satisfactory; here we attempt a consistent investigation. Methods: We use a 2D mean-field dynamo model in the no-z approximation and add injections of small-scale magnetic field, taken to result from supernova explosions, to represent the effects of dynamo action on smaller scales. This injection of small scale field is situated along the spiral arms, where star-formation mostly occurs. Results: A straightforward explanation of magnetic arms as a result of modulation of the dynamo mechanism by material arms struggles to produce pronounced magnetic arms, at least with realistic parameters, without introducing new effects such as a time lag between Coriolis force and α-effect. In contrast, by taking into account explicitly the small-scale magnetic field that is injected into the arms by the action of the star forming regions that are concentrated there, we can obtain dynamo models with magnetic structures of various forms that can be compared with magnetic arms. These are rather variable entities and their shape changes significantly on timescales of a few 100 Myr. Properties of magnetic arms can be controlled by changing the model parameters. In particular, a lower injection rate of small-scale field makes the magnetic configuration smoother and eliminates distinct magnetic arms. Conclusions: We conclude that magnetic arms can be considered as coherent magnetic structures generated by large-scale dynamo action, and associated with spatially modulated small-scale magnetic fluctuations, caused by enhanced star formation rates within the material arms.

3D-Stereoscopic Analysis of Solar Active Region Loops. 2; SoHo/EIT Observations at Temperatures of 1.5-2.5 MK

NASA Technical Reports Server (NTRS)

Aschwanden, Markus J.; Alexander, David; Hurlburt, Neal; Newmark, Jeffrey S.; Neupert, Werner M.; Klimchuk, J. A.; Gary, G. Allen

1999-01-01

In this paper we study the three-dimensional (3D) structure of hot (T(sub e) approximately equals 1.5 - 2.5 MK) loops in solar active region NOAA 7986, observed on 1996 August 30 with the Extreme-ultraviolet Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory (SoHO). This complements a first study on cooler (T(sub e) approximately equals 1.0 - 1.5 MK) loops of the same active region, using the same method of Dynamic Stereoscopy to reconstruct the 3D geometry. We reconstruct the 3D-coordinates x(s), y(s), z(s), the density n(sub e)(s), and temperature profile T(sub e)(s) of 35 individual loop segments (as function of the loop coordinate s) using EIT 195 A and 284 A images. The major findings are: (1) All loops are found to be in hydrostatic equilibrium, in the entire temperature regime of T(sub e) = 1.0 - 2.5 MK; (2) The analyzed loops have a height of 2-3 scale heights, and thus only segments extending over about one vertical scale height have sufficient emission measure contrast for detection; (3) The temperature gradient over the lowest scale height is of order dT/ds is approximately 1 - 4 K/km; (4) The radiative loss rate is found to exceed the conductive loss rate by about two orders or magnitude, making thermal conduction negligible to explain the temperature structure of the loops; (5) A steady-state can only be achieved when the heating rate E(sub H) matches the radiative loss rate in hydrostatic equilibrium, requiring a heat deposition length lambda(sub H) of the half density scale height lambda, predicting a scaling law with the loop base pressure, EH varies as p(sub 0 exp 2). This favors coronal heating mechanisms that operate near the loop footpoints; (6) We find a reciprocal correlation between the loop pressure p(sub 0) and loop length L, i.e. p(sub 0) varies as 1/L, implying a scaling law of the steady-state requirement with loop length, i.e. E(sub H ) varies as 1/L(exp 2). The heating rate shows no correlation with the loop-aligned magnetic field component B(sub z) at the footpoints, but is correlated with the azimuthal field B(sub phi) = Bz(RDelta Phi/L) of a twisted loop, and is thus consistent with heating mechanisms based on field-aligned currents.

Do more hospital beds lead to higher hospitalization rates? a spatial examination of Roemer's Law.

PubMed

Delamater, Paul L; Messina, Joseph P; Grady, Sue C; WinklerPrins, Vince; Shortridge, Ashton M

2013-01-01

Roemer's Law, a widely cited principle in health care policy, states that hospital beds that are built tend to be used. This simple but powerful expression has been invoked to justify Certificate of Need regulation of hospital beds in an effort to contain health care costs. Despite its influence, a surprisingly small body of empirical evidence supports its content. Furthermore, known geographic factors influencing health services use and the spatial structure of the relationship between hospital bed availability and hospitalization rates have not been sufficiently explored in past examinations of Roemer's Law. We pose the question, "Accounting for space in health care access and use, is there an observable association between the availability of hospital beds and hospital utilization?" We employ an ecological research design based upon the Anderson behavioral model of health care utilization. This conceptual model is implemented in an explicitly spatial context. The effect of hospital bed availability on the utilization of hospital services is evaluated, accounting for spatial structure and controlling for other known determinants of hospital utilization. The stability of this relationship is explored by testing across numerous geographic scales of analysis. The case study comprises an entire state system of hospitals and population, evaluating over one million inpatient admissions. We find compelling evidence that a positive, statistically significant relationship exists between hospital bed availability and inpatient hospitalization rates. Additionally, the observed relationship is invariant with changes in the geographic scale of analysis. This study provides evidence for the effects of Roemer's Law, thus suggesting that variations in hospitalization rates have origins in the availability of hospital beds. This relationship is found to be robust across geographic scales of analysis. These findings suggest continued regulation of hospital bed supply to assist in controlling hospital utilization is justified.

76 FR 43983 - Request for Information on How To Structure Proposed New Program: Advanced Manufacturing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-22

... agenda most likely to achieve high rates of technological innovation. The goals of AMTech include...; Collapsing the time scale of technological innovation; Fostering a robust U.S. innovation system through... key players across the entire innovation lifecycle, AMTech consortia will work toward eliminating...

A scale for measuring hygiene behavior: development, reliability and validity.

PubMed

Stevenson, Richard J; Case, Trevor I; Hodgson, Deborah; Porzig-Drummond, Renata; Barouei, Javad; Oaten, Megan J

2009-09-01

There is currently no general self-report measure for assessing hygiene behavior. This article details the development and testing of such a measure. In studies 1 to 4, a total of 855 participants were used for scale and subscale development and for reliability and validity testing. The latter involved establishing the relationships between self-reported hygiene behavior and existing measures, hand hygiene behavior, illness rates, and a physiological marker of immune function. In study 5, a total of 507 participants were used to assess the psychometric properties of the final revised version of the scale. The final 23-item scale comprised 5 subscales: general, household, food-related, handwashing technique, and personal hygiene. Studies 1 to 4 confirmed the scale's reliability and validity, and study 5 confirmed the scale's 5-factor structure. The scale is potentially suitable for multiple uses, in various settings, and for experimental and correlational approaches.

[Late-onset depression and a new psychometric scale for its clinical evaluation].

PubMed

Ivanets, N N; Kinkul'kina, M A; Avdeeva, T I

2012-01-01

The most of existed psychometric scales for depression have some shortcomings hampering their use in old patients. The authors worked out the original scale for clinical evaluation of symptoms of late-onset depression. The list of symptoms was made up basing on literature data. The most significant symptoms that characterized the structure and severity of depression in old patients were singled out. According to results of factor analyses they were combined in the groups forming the corresponding items of the scale. In addition, some symptoms with particular clinical significance for late-onset depression (suicidal thoughts, senesto-hypochondriac symptoms, insight) were singled out. The scale comprises 13 items with scores from -6 to +6. It can be implemented for symptom screening, clinical diagnosis and rating, including dynamics of depression in elderly patients.

Research on the fractal structure in the Chinese stock market

NASA Astrophysics Data System (ADS)

Zhuang, Xin-tian; Huang, Xiao-yuan; Sha, Yan-li

2004-02-01

Applying fractal theory, this paper probes and discusses self-similarity and scale invariance of the Chinese stock market. It analyses three kinds of scale indexes, i.e., autocorrelation index, Hurst index and the scale index on the basis of detrended fluctuation analysis (DFA) algorithm and promotes DFA into a recursive algorithm. Using the three kinds of scale indexes, we conduct empirical research on the Chinese Shanghai and Shenzhen stock markets. The results indicate that the rate of returns of the two stock markets does not obey the normal distribution. A correlation exists between the stock price indexes over time scales. The stock price indexes exhibit fractal time series. It indicates that the policy guide hidden at the back influences the characteristic of the Chinese stock market.

Tetrahedron deformation and alignment of perceived vorticity and strain in a turbulent flow

NASA Astrophysics Data System (ADS)

Pumir, Alain; Bodenschatz, Eberhard; Xu, Haitao

2013-03-01

We describe the structure and dynamics of turbulence by the scale-dependent perceived velocity gradient tensor as supported by following four tracers, i.e., fluid particles, that initially form a regular tetrahedron. We report results from experiments in a von Kármán swirling water flow and from numerical simulations of the incompressible Navier-Stokes equation. We analyze the statistics and the dynamics of the perceived rate of strain tensor and vorticity for initially regular tetrahedron of size r0 from the dissipative to the integral scale. Just as for the true velocity gradient, at any instant, the perceived vorticity is also preferentially aligned with the intermediate eigenvector of the perceived rate of strain. However, in the perceived rate of strain eigenframe fixed at a given time t = 0, the perceived vorticity evolves in time such as to align with the strongest eigendirection at t = 0. This also applies to the true velocity gradient. The experimental data at the higher Reynolds number suggests the existence of a self-similar regime in the inertial range. In particular, the dynamics of alignment of the perceived vorticity and strain can be rescaled by t0, the turbulence time scale of the flow when the scale r0 is in the inertial range. For smaller Reynolds numbers we found the dynamics to be scale dependent.

A small-scale turbulence model

NASA Technical Reports Server (NTRS)

Lundgren, T. S.

1993-01-01

A previously derived analytical model for the small-scale structure of turbulence is reformulated in such a way that the energy spectrum may be computed. The model is an ensemble of two-dimensional (2D) vortices with internal spiral structure, each stretched by an axially symmetric strain flow. Stretching and differential rotation produce an energy cascade to smaller scales in which the stretching represents the effect of instabilities and the spiral structure is the source of dissipation at the end of the cascade. The energy spectrum of the resulting flow may be expressed as a time integration involving only the enstrophy spectrum of the time evolving 2D cross section flow, which may be obtained numerically. Examples are given in which a k exp -5/3 spectrum is obtained by this method. The k exp -5/3 inertial range spectrum is shown to be related to the existence of a self-similar enstrophy preserving range in the 2D enstrophy spectrum. The results are found to be insensitive to time dependence of the strain rate, including even intermittent on-or-off strains.

One-Step Sub-micrometer-Scale Electrohydrodynamic Inkjet Three-Dimensional Printing Technique with Spontaneous Nanoscale Joule Heating.

PubMed

Zhang, Bin; Seong, Baekhoon; Lee, Jaehyun; Nguyen, VuDat; Cho, Daehyun; Byun, Doyoung

2017-09-06

A one-step sub-micrometer-scale electrohydrodynamic (EHD) inkjet three-dimensional (3D)-printing technique that is based on the drop-on-demand (DOD) operation for which an additional postsintering process is not required is proposed. Both the numerical simulation and the experimental observations proved that nanoscale Joule heating occurs at the interface between the charged silver nanoparticles (Ag-NPs) because of the high electrical contact resistance during the printing process; this is the reason why an additional postsintering process is not required. Sub-micrometer-scale 3D structures were printed with an above-35 aspect ratio via the use of the proposed printing technique; furthermore, it is evident that the designed 3D structures such as a bridge-like shape can be printed with the use of the proposed printing technique, allowing for the cost-effective fabrication of a 3D touch sensor and an ultrasensitive air flow-rate sensor. It is believed that the proposed one-step printing technique may replace the conventional 3D conductive-structure printing techniques for which a postsintering process is used because of its economic efficiency.

The Multi-Needle Langmuir Probe System on Board NorSat-1

NASA Astrophysics Data System (ADS)

Hoang, H.; Clausen, L. B. N.; Røed, K.; Bekkeng, T. A.; Trondsen, E.; Lybekk, B.; Strøm, H.; Bang-Hauge, D. M.; Pedersen, A.; Spicher, A.; Moen, J. I.

2018-06-01

On July 14th, 2017, the first Norwegian scientific satellite NorSat-1 was launched into a high-inclination (98∘), low-Earth orbit (600 km altitude) from Baikonur, Kazakhstan. As part of the payload package, NorSat-1 carries the multi-needle Langmuir probe (m-NLP) instrument which is capable of sampling the electron density at a rate up to 1 kHz, thus offering an unprecedented opportunity to continuously resolve ionospheric plasma density structures down to a few meters. Over the coming years, NorSat-1 will cross the equatorial and polar regions twice every 90 minutes, providing a wealth of data that will help to better understand the mechanisms that dissipate energy input from larger spatial scales by creating small-scale plasma density structures within the ionosphere. In this paper we describe the m-NLP system on board NorSat-1 and present some first results from the instrument commissioning phase. We show that the m-NLP instrument performs as expected and highlight its unique capabilities at resolving small-scale ionospheric plasma density structures.

Multidisciplinary Delphi Development of a Scale to Evaluate Team Function in Obstetric Emergencies: The PETRA Scale.

PubMed

Balki, Mrinalini; Hoppe, David; Monks, David; Cooke, Mary Ellen; Sharples, Lynn; Windrim, Rory

2017-06-01

The objective of this study was to develop a new interdisciplinary teamwork scale, the Perinatal Emergency: Team Response Assessment (PETRA), for the management of obstetric crises, through consensus agreement of obstetric caregivers. This prospective study was performed using expert consensus, based on a Delphi method. The study investigators developed a new PETRA tool, specifically related to obstetric crisis management, based on the existing literature and discussions among themselves. The scale was distributed to a selected panel of experts in the field for the Delphi process. After each round of Delphi, every component of the scale was analyzed quantitatively by the percentage of agreement ratings and each comment reviewed by the blinded investigators. The assessment scale was then modified, with components of less than 80% agreement removed from the scale. The process was repeated on three occasions to reach a consensus and final PETRA scale. Fourteen of 24 invited experts participated in the Delphi process. The original PETRA scale included six categories and 48 items, one global scale item, and a 3-point rubric for rating. The overall percentage agreement by experts in the first, second, and third rounds was 95.0%, 93.2%, and 98.5%, respectively. The final scale after the third round of Delphi consisted of the following seven categories: shared mental model, communication, situational awareness, leadership, followership, workload management, and positive/effective behaviours and attitudes. There were 34 individual items within these categories, each with a 5-point rating rubric (1 = unacceptable to 5 = perfect). Using a structured Delphi method, we established the face and content validity of this assessment scale that focuses on important aspects of interdisciplinary teamwork in the management of obstetric crises. Copyright © 2017 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

Examining parents' ratings of middle-school students' academic self-regulation using principal axis factoring analysis.

PubMed

Chen, Peggy P; Cleary, Timothy J; Lui, Angela M

2015-09-01

This study examined the reliability and validity of a parent rating scale, the Self-Regulation Strategy Inventory: Parent Rating Scale (SRSI-PRS), using a sample of 451 parents of sixth- and seventh-grade middle-school students. Principal axis factoring (PAF) analysis revealed a 3-factor structure for the 23-item SRSI-PRS: (a) Managing Behavior and Learning (α = .92), (b) Maladaptive Regulatory Behaviors (α = .76), and (c) Managing Environment (α = .84). The majority of the observed relations between these 3 subscales, and the SRSI-SR, student motivation beliefs, and student mathematics grades were statistically significant and in the small to medium range. After controlling for various student variables and motivation indices of parental involvement, 2 SRSI-PRS factors (Managing Behavior and Learning, Maladaptive Regulatory Behaviors) reliably predicted students' achievement in their mathematics course. This study provides initial support for the validity and reliability of the SRSI-PRS and underscores the advantages of obtaining parental ratings of students' SRL behaviors. (c) 2015 APA, all rights reserved).

Validation of the Hebrew version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale.

PubMed

Zitser, Jennifer; Peretz, Chava; Ber David, Aya; Shabtai, Herzl; Ezra, Adi; Kestenbaum, Meir; Brozgol, Marina; Rosenberg, Alina; Herman, Talia; Balash, Yakov; Gadoth, Avi; Thaler, Avner; Stebbins, Glenn T; Goetz, Christopher G; Tilley, Barbara C; Luo, Sheng T; Liu, Yuanyuan; Giladi, Nir; Gurevich, Tanya

2017-12-01

The Movement Disorders Society (MDS) published the English new Unified Parkinson's Disease Rating Scale (MDS-UPDRS) as the official benchmark scale for Parkinson's disease (PD) in 2008. We aimed to validate the Hebrew version of the MDS-UPDRS, explore its dimensionality and compare it to the original English one. The MDS-UPDRS questionnaire was translated to Hebrew and was tested on 389 patients with PD, treated at the Movement Disorders Unit at Tel-Aviv Medical Center. The MDS-UPDRS is made up of four sections. The higher the score, the worst the clinical situation of the patient is. Confirmatory and explanatory factor analysis were applied to determine if the factor structure of the English version could be confirmed in the Hebrew version. The Hebrew version of the MDS-UPDRS showed satisfactory clinimetric properties. The internal consistency of the Hebrew-version was satisfactory, with Cronbach's alpha values 0.79, 0.90, 0.93, 0.80, for parts 1 to 4 respectively. In the confirmatory factor analysis, all four parts had high (greater than 0.90) comparative fit index (CFI) in comparison to the original English MDS-UPDRS with high factor structure (0.96, 0.99, 0.94, 1.00, respectively), thus confirming the pre-specified English factor structure. Explanatory factor analysis yielded that the Hebrew responses differed from the English one within an acceptable range: in isolated item differences in factor structure and in the findings of few items having cross loading on multiple factors. The Hebrew version of the MDS-UPDRS meets the requirements to be designated as the Official Hebrew Version of the MDS-UPDRS. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heart rate complexity in sinoaortic-denervated mice.

PubMed

Silva, Luiz Eduardo V; Rodrigues, Fernanda Luciano; de Oliveira, Mauro; Salgado, Hélio Cesar; Fazan, Rubens

2015-02-01

What is the central question of this study? New measurements for cardiovascular complexity, such as detrended fluctuation analysis (DFA) and multiscale entropy (MSE), have been shown to predict cardiovascular outcomes. Given that cardiovascular diseases are accompanied by autonomic imbalance and decreased baroreflex sensitivity, the central question is: do baroreceptors contribute to cardiovascular complexity? What is the main finding and its importance? Sinoaortic denervation altered both DFA scaling exponents and MSE, indicating that both short- and long-term mechanisms of complexity are altered in sinoaortic denervated mice, resulting in a loss of physiological complexity. These results suggest that the baroreflex is a key element in the complex structures involved in heart rate variability regulation. Recently, heart rate (HR) oscillations have been recognized as complex behaviours derived from non-linear processes. Physiological complexity theory is based on the idea that healthy systems present high complexity, i.e. non-linear, fractal variability at multiple scales, with long-range correlations. The loss of complexity in heart rate variability (HRV) has been shown to predict adverse cardiovascular outcomes. Based on the idea that most cardiovascular diseases are accompanied by autonomic imbalance and a decrease in baroreflex sensitivity, we hypothesize that the baroreflex plays an important role in complex cardiovascular behaviour. Mice that had been subjected to sinoaortic denervation (SAD) were implanted with catheters in the femoral artery and jugular vein 5 days prior to the experiment. After recording the baseline arterial pressure (AP), pulse interval time series were generated from the intervals between consecutive values of diastolic pressure. The complexity of the HRV was determined using detrended fluctuation analysis and multiscale entropy. The detrended fluctuation analysis α1 scaling exponent (a short-term index) was remarkably decreased in the SAD mice (0.79 ± 0.06 versus 1.13 ± 0.04 for the control mice), whereas SAD slightly increased the α2 scaling exponent (a long-term index; 1.12 ± 0.03 versus 1.04 ± 0.02 for control mice). In the SAD mice, the total multiscale entropy was decreased (13.2 ± 1.3) compared with the control mice (18.9 ± 1.4). In conclusion, fractal and regularity structures of HRV are altered in SAD mice, affecting both short- and long-term mechanisms of complexity, suggesting that the baroreceptors play a considerable role in the complex structure of HRV. © 2014 The Authors. Experimental Physiology © 2014 The Physiological Society.

Anthropogenic disturbance and environmental associations with fish assemblage structure in two nonwadeable rivers

USGS Publications Warehouse

Parks, T. P.; Quist, Michael C.; Pierce, C.L.

2016-01-01

Nonwadeable rivers are unique ecosystems that support high levels of aquatic biodiversity, yet they have been greatly altered by human activities. Although riverine fish assemblages have been studied in the past, we still have an incomplete understanding of how fish assemblages respond to both natural and anthropogenic influences in large rivers. The purpose of this study was to evaluate associations between fish assemblage structure and reach-scale habitat, dam, and watershed land use characteristics. In the summers of 2011 and 2012, comprehensive fish and environmental data were collected from 33 reaches in the Iowa and Cedar rivers of eastern-central Iowa. Canonical correspondence analysis (CCA) was used to evaluate environmental relationships with species relative abundance, functional trait abundance (e.g. catch rate of tolerant species), and functional trait composition (e.g. percentage of tolerant species). On the basis of partial CCAs, reach-scale habitat, dam characteristics, and watershed land use features explained 25.0–81.1%, 6.2–25.1%, and 5.8–47.2% of fish assemblage variation, respectively. Although reach-scale, dam, and land use factors contributed to overall assemblage structure, the majority of fish assemblage variation was constrained by reach-scale habitat factors. Specifically, mean annual discharge was consistently selected in nine of the 11 CCA models and accounted for the majority of explained fish assemblage variance by reach-scale habitat. This study provides important insight on the influence of anthropogenic disturbances across multiple spatial scales on fish assemblages in large river systems.

Observations of the birth of a small coronal hole

NASA Technical Reports Server (NTRS)

Solodyna, C. V.; Krieger, A. S.; Nolte, J. T.

1977-01-01

Using soft X-ray data from the S-054 X-ray spectrographic telescope aboard Skylab, we observed temporal changes in the emission structure of the X-ray corona associated with the birth of a small coronal hole. Designated as CH6, this coronal hole was born near the equator in a time interval less than 9-1/2 hr. By constructing a light curve for a point near the center of CH6, we observed a sudden 40% decrease in X-ray emission associated with the birth of this coronal hole. On a time scale of hours, the growth of CH6 in area proceeded faster than the average rate predicted by the diffusion of solar fields. The short term decay of CH6 followed the diffusive rate to within experimental uncertainty. On a time scale of one rotation, the subsequent development of CH6 was not consistent with steady growth at the average rate predicted by diffusion.

Stochastic thermodynamics across scales: Emergent inter-attractoral discrete Markov jump process and its underlying continuous diffusion

NASA Astrophysics Data System (ADS)

Santillán, Moisés; Qian, Hong

2013-01-01

We investigate the internal consistency of a recently developed mathematical thermodynamic structure across scales, between a continuous stochastic nonlinear dynamical system, i.e., a diffusion process with Langevin and Fokker-Planck equations, and its emergent discrete, inter-attractoral Markov jump process. We analyze how the system’s thermodynamic state functions, e.g. free energy F, entropy S, entropy production ep, free energy dissipation Ḟ, etc., are related when the continuous system is described with coarse-grained discrete variables. It is shown that the thermodynamics derived from the underlying, detailed continuous dynamics gives rise to exactly the free-energy representation of Gibbs and Helmholtz. That is, the system’s thermodynamic structure is the same as if one only takes a middle road and starts with the natural discrete description, with the corresponding transition rates empirically determined. By natural we mean in the thermodynamic limit of a large system, with an inherent separation of time scales between inter- and intra-attractoral dynamics. This result generalizes a fundamental idea from chemistry, and the theory of Kramers, by incorporating thermodynamics: while a mechanical description of a molecule is in terms of continuous bond lengths and angles, chemical reactions are phenomenologically described by a discrete representation, in terms of exponential rate laws and a stochastic thermodynamics.

The combustion behavior of large scale lithium titanate battery

PubMed Central

Huang, Peifeng; Wang, Qingsong; Li, Ke; Ping, Ping; Sun, Jinhua

2015-01-01

Safety problem is always a big obstacle for lithium battery marching to large scale application. However, the knowledge on the battery combustion behavior is limited. To investigate the combustion behavior of large scale lithium battery, three 50 Ah Li(NixCoyMnz)O2/Li4Ti5O12 batteries under different state of charge (SOC) were heated to fire. The flame size variation is depicted to analyze the combustion behavior directly. The mass loss rate, temperature and heat release rate are used to analyze the combustion behavior in reaction way deeply. Based on the phenomenon, the combustion process is divided into three basic stages, even more complicated at higher SOC with sudden smoke flow ejected. The reason is that a phase change occurs in Li(NixCoyMnz)O2 material from layer structure to spinel structure. The critical temperatures of ignition are at 112–121°C on anode tab and 139 to 147°C on upper surface for all cells. But the heating time and combustion time become shorter with the ascending of SOC. The results indicate that the battery fire hazard increases with the SOC. It is analyzed that the internal short and the Li+ distribution are the main causes that lead to the difference. PMID:25586064

Concordance cosmology without dark energy

NASA Astrophysics Data System (ADS)

Rácz, Gábor; Dobos, László; Beck, Róbert; Szapudi, István; Csabai, István

2017-07-01

According to the separate universe conjecture, spherically symmetric sub-regions in an isotropic universe behave like mini-universes with their own cosmological parameters. This is an excellent approximation in both Newtonian and general relativistic theories. We estimate local expansion rates for a large number of such regions, and use a scale parameter calculated from the volume-averaged increments of local scale parameters at each time step in an otherwise standard cosmological N-body simulation. The particle mass, corresponding to a coarse graining scale, is an adjustable parameter. This mean field approximation neglects tidal forces and boundary effects, but it is the first step towards a non-perturbative statistical estimation of the effect of non-linear evolution of structure on the expansion rate. Using our algorithm, a simulation with an initial Ωm = 1 Einstein-de Sitter setting closely tracks the expansion and structure growth history of the Λ cold dark matter (ΛCDM) cosmology. Due to small but characteristic differences, our model can be distinguished from the ΛCDM model by future precision observations. Moreover, our model can resolve the emerging tension between local Hubble constant measurements and the Planck best-fitting cosmology. Further improvements to the simulation are necessary to investigate light propagation and confirm full consistency with cosmic microwave background observations.

Small-scale variability in tropical tropopause layer humidity

NASA Astrophysics Data System (ADS)

Jensen, E. J.; Ueyama, R.; Pfister, L.; Karcher, B.; Podglajen, A.; Diskin, G. S.; DiGangi, J. P.; Thornberry, T. D.; Rollins, A. W.; Bui, T. V.; Woods, S.; Lawson, P.

2016-12-01

Recent advances in statistical parameterizations of cirrus cloud processes for use in global models are highlighting the need for information about small-scale fluctuations in upper tropospheric humidity and the physical processes that control the humidity variability. To address these issues, we have analyzed high-resolution airborne water vapor measurements obtained in the Airborne Tropical TRopopause EXperiment over the tropical Pacific between 14 and 20 km. Using accurate and precise 1-Hz water vapor measurements along approximately-level aircraft flight legs, we calculate structure functions spanning horizontal scales ranging from about 0.2 to 50 km, and we compare the water vapor variability in the lower (about 14 km) and upper (16-19 km) Tropical Tropopause Layer (TTL). We also compare the magnitudes and scales of variability inside TTL cirrus versus in clear-sky regions. The measurements show that in the upper TTL, water vapor concentration variance is stronger inside cirrus than in clear-sky regions. Using simulations of TTL cirrus formation, we show that small variability in clear-sky humidity is amplified by the strong sensitivity of ice nucleation rate to supersaturation, which results in highly-structured clouds that subsequently drive variability in the water vapor field. In the lower TTL, humidity variability is correlated with recent detrainment from deep convection. The structure functions indicate approximately power-law scaling with spectral slopes ranging from about -5/3 to -2.

Development of social capital scale from a national longitudinal survey and examination of its validity and reliability.

PubMed

Aiba, Miyuki; Tachikawa, Hirokazu; Nakamine, Shin; Takahashi, Sho; Noguchi, Haruko; Takahashi, Hideto; Tamiya, Nanako

2017-01-01

Objectives　Social capital consists of two subordinate concepts; first one is structural formal, structural informal, or cognitive and second one is bonding or bridging. This study was designed to develop a social capital scale using samples from a national longitudinal survey and evaluate the validity and test-retest reliability of the scale.Methods　Data were collected from a nationwide panel survey, the "Longitudinal Survey of Middle-aged and Elderly Persons." Individuals aged 50-59 years living in Japan were selected by stratified random sampling in the first wave conducted in 2005. The first (n=34,240) and second (n=32,285) sets of data were used for Phase 1, and the sixth (n=26,220) and seventh (n=25,321) sets of data were used for Phase 2. In regard to first subordinate concept, the occurrence of six selected social activities with "neighborhood association" and "NPOs, or Public Interest Corporations" were calculated as the structural formal index, and the occurrence of six selected social activities with "families or friends" and "colleagues" were calculated as the structural informal index. Moreover, satisfaction with social activities (community activities, support for the elderly, and others) was used as the cognitive index. In regard to second subordinate concept, the bonding index was calculated using "families or friends," "colleagues," and "neighborhood association;" the bridging index was calculated using "NPOs or Public Interest Corporations." The diagnoses of heart disease, stroke, and cancer (yes=1, no=0) and self-rated health (1 item, 6-point scale) were used as variables for determining validity.Results　We categorized social capital indices into subordinate concepts based on the construct of social capital defined by professional agreement to assess content validity. The results showed that this survey questionnaire was constructed using items that assessed all the subordinate concepts. Hierarchical Linear Modeling examined the relationship between social capital and health as assessed by diagnoses of physical disease and self-rated health to examine convergent validity, which indicated that all social capital indices had significant positive effects on self-rated health at an individual or group level. However, the diagnosis of a stroke was negatively influenced by cognitive and formal social capital indices at a group level, whereas heart disease and cancer were not significantly affected.　Multilevel correlation analyses of Phase 1 (the first and second) and Phase 2 (sixth and seventh) were conducted to assess test-retest reliability, which indicated correlation coefficients of 0.392 to 0.999.Conclusion　The findings of this study indicated the content validity of the scale that was developed from the national longitudinal survey. Moreover, results of Hierarchical Linear Modeling confirmed the partial convergent validity of the scale. Furthermore, multilevel correlation analyses demonstrated the adequate test-retest reliability of the scale at the group level.

Invariance of parent ratings of the ADHD symptoms in Australian and Malaysian, and north European Australian and Malay Malaysia children: a mean and covariance structures analysis approach.

PubMed

Gomez, Rapson

2009-03-01

This study used the mean and covariance structures analysis approach to examine the equality or invariance of ratings of the 18 ADHD symptoms. 783 Australian and 928 Malaysian parents provided ratings for an ADHD rating scale. Invariance was tested across these groups (Comparison 1), and North European Australian (n = 623) and Malay Malaysian (n = 571, Comparison 2) groups. Results indicate support for form and item factor loading invariance; more than half the total number of symptoms showed item intercept invariance, and 14 symptoms showed invariance for error variances. There was invariance for both the factor variances and the covariance, and the latent mean scores for hyperactivity/impulsivity. For inattention latent scores, the Malaysian (Comparison 1) and Malay Malaysian (Comparison 2) groups had higher scores. These results indicate fairly good support for invariance for parent ratings of the ADHD symptoms across the groups compared.

A review of the performance and structural considerations of paraffin wax hybrid rocket fuels with additives

NASA Astrophysics Data System (ADS)

Veale, Kirsty; Adali, Sarp; Pitot, Jean; Brooks, Michael

2017-12-01

Paraffin wax as a hybrid rocket fuel has not been comprehensively characterised, especially regarding the structural feasibility of the material in launch applications. Preliminary structural testing has shown paraffin wax to be a brittle, low strength material, and at risk of failure under launch loading conditions. Structural enhancing additives have been identified, but their effect on motor performance has not always been considered, nor has any standard method of testing been identified between research institutes. A review of existing regression rate measurement techniques on paraffin wax based fuels and the results obtained with various additives are collated and discussed in this paper. The review includes 2D slab motors that enable visualisation of liquefying fuel droplet entrainment and the effect of an increased viscosity on the droplet entrainment mechanism, which can occur with the addition of structural enhancing polymers. An increased viscosity has been shown to reduce the regression rate of liquefying fuels. Viscosity increasing additives that have been tested include EVA and LDPE. Both these additives increase the structural properties of paraffin wax, where the elongation and UTS are improved. Other additives, such as metal hydrides, aluminium and boron generally offer improvements on the regression rate. However, very little consideration has been given to the structural effects these additives have on the wax grain. A 40% aluminised grain, for example, offers a slight increase in the UTS but reduces the elongation of paraffin wax. Geometrically accurate lab-scale motors have also been used to determine the regression rate properties of various additives in paraffin wax. A concise review of all available regression rate testing techniques and results on paraffin wax based hybrid propellants, as well as existing structural testing data, is presented in this paper.

Coupled hydrological and geochemical process evolution at the Landscape Evolution Observatory

NASA Astrophysics Data System (ADS)

Troch, P. A. A.

2015-12-01

Predictions of hydrologic and biogeochemical responses to natural and anthropogenic forcing at the landscape scale are highly uncertain due to the effects of heterogeneity on the scaling of reaction, flow and transport phenomena. The physical, chemical and biological structures and processes controlling reaction, flow and transport in natural landscapes interact at multiple space and time scales and are difficult to quantify. The current paradigm of hydrological and geochemical theory is that process descriptions derived from observations at small scales in controlled systems can be applied to predict system response at much larger scales, as long as some 'equivalent' or 'effective' values of the scale-dependent parameters can be identified. Furthermore, natural systems evolve in time in a way that is hard to observe in short-run laboratory experiments or in natural landscapes with unknown initial conditions and time-variant forcing. The spatial structure of flow pathways along hillslopes determines the rate, extent and distribution of geochemical reactions (and biological colonization) that drive weathering, the transport and precipitation of solutes and sediments, and the further evolution of soil structure. The resulting evolution of structures and processes, in turn, produces spatiotemporal variability of hydrological states and flow pathways. There is thus a need for experimental research to improve our understanding of hydrology-biogeochemistry interactions and feedbacks at appropriate spatial scales larger than laboratory soil column experiments. Such research is complicated in real-world settings because of poorly constrained impacts of initial conditions, climate variability, ecosystems dynamics, and geomorphic evolution. The Landscape Evolution Observatory (LEO) at Biosphere 2 offers a unique research facility that allows real-time observations of incipient hydrologic and biogeochemical response under well-constrained initial conditions and climate forcing. The LEO allows to close the water, carbon and energy budgets at hillslope scales, thereby enabling elucidation of the tight coupling between the time water spends along subsurface flow paths and geochemical weathering reactions, including the feedbacks between flow and pedogenesis.

Lake Erie Yellow perch age estimation based on three structures: Precision, processing times, and management implications

USGS Publications Warehouse

Vandergoot, C.S.; Bur, M.T.; Powell, K.A.

2008-01-01

Yellow perch Perca flavescens support economically important recreational and commercial fisheries in Lake Erie and are intensively managed. Age estimation represents an integral component in the management of Lake Erie yellow perch stocks, as age-structured population models are used to set safe harvest levels on an annual basis. We compared the precision associated with yellow perch (N = 251) age estimates from scales, sagittal otoliths, and anal spine sections and evaluated the time required to process and estimate age from each structure. Three readers of varying experience estimated ages. The precision (mean coefficient of variation) of estimates among readers was 1% for sagittal otoliths, 5-6% for anal spines, and 11-13% for scales. Agreement rates among readers were 94-95% for otoliths, 71-76% for anal spines, and 45-50% for scales. Systematic age estimation differences were evident among scale and anal spine readers; less-experienced readers tended to underestimate ages of yellow perch older than age 4 relative to estimates made by an experienced reader. Mean scale age tended to underestimate ages of age-6 and older fish relative to otolith ages estimated by an experienced reader. Total annual mortality estimates based on scale ages were 20% higher than those based on otolith ages; mortality estimates based on anal spine ages were 4% higher than those based on otolith ages. Otoliths required more removal and preparation time than scales and anal spines, but age estimation time was substantially lower for otoliths than for the other two structures. We suggest the use of otoliths or anal spines for age estimation in yellow perch (regardless of length) from Lake Erie and other systems where precise age estimates are necessary, because age estimation errors resulting from the use of scales could generate incorrect management decisions. ?? Copyright by the American Fisheries Society 2008.

Detecting the Reconnection Electron Diffusion Regions in Magnetospheric MultiScale mission high resolution data

NASA Astrophysics Data System (ADS)

Shimoda, E.; Eriksson, S.; Ahmadi, N.; Ergun, R.; Wilder, F. D.; Goodrich, K.

2017-12-01

The Magnetospheric Multi-Scale (MMS) mission resolves the small-scale structure of the Reconnection Electron Diffusion Regions (EDRs) using four spacecraft. We have surveyed two years of MMS data to find the candidates for the EDRs. We searched all the high-resolution segments when Fast Plasma Investigation (FPI) instrument was on. The search criteria are based on measuring the dissipation rate, agyrotropy, a reversal in jet velocity and magnetic field. Once these events were found for MMS1 data, the burst period for the other spacecraft was analyzed. We present our results of the best possible EDR candidates.

The growth of radiative filamentation modes in sheared magnetic fields

NASA Technical Reports Server (NTRS)

Vanhoven, Gerard

1986-01-01

Observations of prominences show them to require well-developed magnetic shear and to have complex small-scale structure. Researchers show here that these features are reflected in the results of the theory of radiative condensation. Researchers studied, in particular, the influence of the nominally negligible contributions of perpendicular (to B) thermal conduction. They find a large number of unstable modes, with closely spaced growth rates. Their scale widths across B show a wide range of longitudinal and transverse sizes, ranging from much larger than to much smaller than the magnetic shear scale, the latter characterization applying particularly in the direction of shear variation.

The Development and Validation of the Memory Support Rating Scale (MSRS)

PubMed Central

Lee, Jason Y.; Worrell, Frank C.; Harvey, Allison G.

2015-01-01

Patient memory for treatment information is poor, and worse memory for treatment information is associated with poorer clinical outcomes. Memory support techniques have been harnessed to improve patient memory for treatment. However, a measure of memory support used by treatment providers during sessions has yet to be established. The present study reports on the development and psychometric properties of the Memory Support Rating Scale (MSRS) – an observer-rated scale designed to measure memory support. Forty-two adults with major depressive disorder (MDD) were randomized to either cognitive therapy plus memory support (CS+MS; n = 22) or cognitive therapy as-usual (CT-as-usual; n = 20). At post-treatment, patients freely recalled treatment points via the Patient Recall Task. Sessions (n = 171) were coded for memory support using the MSRS, 65% of which were also assessed for the quality of cognitive therapy via the Cognitive Therapy Rating Scale (CTRS). A unidimensional scale composed of 8 items was developed using exploratory factor analysis, though a larger sample is needed to further assess the factor structure of MSRS scores. High inter-rater and test-retest reliabilities of MSRS scores were observed across seven MSRS coders. MSRS scores were higher in the CT+MS condition compared to CT-as-usual, demonstrating group differentiation ability. MSRS scores were positively associated with Patient Recall Task scores but not associated with CTRS scores, demonstrating convergent and discriminant validity, respectively. Results indicate that the MSRS yields reliable and valid scores for measuring treatment providers’ use of memory support while delivering cognitive therapy. PMID:26389597

The development and validation of the Memory Support Rating Scale.

PubMed

Lee, Jason Y; Worrell, Frank C; Harvey, Allison G

2016-06-01

Patient memory for treatment information is poor, and worse memory for treatment information is associated with poorer clinical outcomes. Memory support techniques have been harnessed to improve patient memory for treatment. However, a measure of memory support used by treatment providers during sessions has yet to be established. The present study reports on the development and psychometric properties of the Memory Support Rating Scale (MSRS)-an observer-rated scale designed to measure memory support. Adults with major depressive disorder (MDD; N = 42) were randomized to either cognitive therapy plus memory support (CT + MS; n = 22) or cognitive therapy as-usual (CT-as-usual; n = 20). At posttreatment, patients freely recalled treatment points via the patient recall task. Sessions (n = 171) were coded for memory support using the MSRS, 65% of which were also assessed for the quality of cognitive therapy via the Cognitive Therapy Rating Scale (CTRS). A unidimensional scale composed of 8 items was developed using exploratory factor analysis, though a larger sample is needed to further assess the factor structure of MSRS scores. High interrater and test-retest reliabilities of MSRS scores were observed across 7 MSRS coders. MSRS scores were higher in the CT + MS condition compared with CT-as-usual, demonstrating group differentiation ability. MSRS scores were positively associated with patient recall task scores but not associated with CTRS scores, demonstrating convergent and discriminant validity, respectively. Results indicate that the MSRS yields reliable and valid scores for measuring treatment providers' use of memory support while delivering cognitive therapy. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Factor structure and correlates of the Mandarin version of the Managing the Emotions of Others (MEOS) scale.

PubMed

Saklofske, Donald H; Austin, Elizabeth J; Yan, Gonggu; Smith, Martin M

2016-02-01

The English-language version of the Managing the Emotions of Others (MEOS) scale has been found to have a six-factor structure. This includes two pairs (Enhance, Divert and Worsen, Inauthentic) that respectively describe prosocial and non-prosocial interpersonal emotion management, together with an emotional concealment factor (Conceal) and a factor assessing poor self-rated emotional skills. A Mandarin translation of the MEOS was completed by 277 Chinese student participants. Factor analysis indicated a four-factor structure comprising a merged Enhance/Divert factor, together with Worsen, Inauthentic and Conceal factors. The emergence of a different factor structure compared to Western samples may be related to culture-dependent attitudes to emotional expression. The associations of the MEOS factors with Five-Factor model personality, the Dark Triad and trait emotional intelligence (EI) were examined; these were similar to but generally weaker than those found for the English-language version. © 2015 International Union of Psychological Science.

Covariant Evolutionary Event Analysis for Base Interaction Prediction Using a Relational Database Management System for RNA.

PubMed

Xu, Weijia; Ozer, Stuart; Gutell, Robin R

2009-01-01

With an increasingly large amount of sequences properly aligned, comparative sequence analysis can accurately identify not only common structures formed by standard base pairing but also new types of structural elements and constraints. However, traditional methods are too computationally expensive to perform well on large scale alignment and less effective with the sequences from diversified phylogenetic classifications. We propose a new approach that utilizes coevolutional rates among pairs of nucleotide positions using phylogenetic and evolutionary relationships of the organisms of aligned sequences. With a novel data schema to manage relevant information within a relational database, our method, implemented with a Microsoft SQL Server 2005, showed 90% sensitivity in identifying base pair interactions among 16S ribosomal RNA sequences from Bacteria, at a scale 40 times bigger and 50% better sensitivity than a previous study. The results also indicated covariation signals for a few sets of cross-strand base stacking pairs in secondary structure helices, and other subtle constraints in the RNA structure.

Covariant Evolutionary Event Analysis for Base Interaction Prediction Using a Relational Database Management System for RNA

PubMed Central

Xu, Weijia; Ozer, Stuart; Gutell, Robin R.

2010-01-01

With an increasingly large amount of sequences properly aligned, comparative sequence analysis can accurately identify not only common structures formed by standard base pairing but also new types of structural elements and constraints. However, traditional methods are too computationally expensive to perform well on large scale alignment and less effective with the sequences from diversified phylogenetic classifications. We propose a new approach that utilizes coevolutional rates among pairs of nucleotide positions using phylogenetic and evolutionary relationships of the organisms of aligned sequences. With a novel data schema to manage relevant information within a relational database, our method, implemented with a Microsoft SQL Server 2005, showed 90% sensitivity in identifying base pair interactions among 16S ribosomal RNA sequences from Bacteria, at a scale 40 times bigger and 50% better sensitivity than a previous study. The results also indicated covariation signals for a few sets of cross-strand base stacking pairs in secondary structure helices, and other subtle constraints in the RNA structure. PMID:20502534

Assessing the Universal Structure of Personality in Early Adolescence: The NEO-PI-R and NEO-PI-3 in 24 Cultures

PubMed Central

De Fruyt, Filip; De Bolle, Marleen; McCrae, Robert R.; Terracciano, Antonio; Costa, Paul T.

2010-01-01

The structure and psychometric characteristics of the NEO-PI-3, a more readable version of the NEO-PI-R, are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 from 24 cultures. Replacement items in the PI-3 showed on average stronger item/total correlations and slightly improved facet reliabilities compared with the NEO-PI-R in both English- and non-English-speaking samples. NEO-PI-3 replacement items did not substantially affect scale means compared with the original scales. Analyses across and within cultures confirmed the intended factor structure of both versions when used to describe young adolescents. We discuss implications of these cross-cultural findings for the advancement of studies in adolescence and personality development across the lifespan. PMID:19419953

Multiple energetic injections in a strong spike-like solar burst

NASA Technical Reports Server (NTRS)

Kaufmann, P.; Correia, E.; Costa, J. E. R.; Dennis, B. R.; Hurford, G. H.; Brown, J. C.

1983-01-01

An intense and fast spike-like solar burst was built up of short time scale structures superimposed on an underlying gradual emission, the time evolution of which shows remarkable proportionality between hard X-ray and microwave fluxes. The finer time structure were best defined at mm-microwaves. At the peak of the event, the finer structures repeat every 30x60ms. The more slowly varying component with a time scale of about 1 second was identified in microwave hard X-rays throughout the burst duration. It is suggested that X-ray fluxes might also be proportional to the repetition rate of basic units of energy injection (quasi-quantized). The relevant parameters of one primary energy release site are estimated both in the case where hard X-rays are produced primarily by thick-target bremsstrahlung, and when they are purely thermal. The relation of this figure to global energy considerations is discussed.

Assessing the universal structure of personality in early adolescence: The NEO-PI-R and NEO-PI-3 in 24 cultures.

PubMed

De Fruyt, Filip; De Bolle, Marleen; McCrae, Robert R; Terracciano, Antonio; Costa, Paul T

2009-09-01

The structure and psychometric characteristics of the NEO Personality Inventory-3 (NEO-PI-3), a more readable version of the Revised NEO Personality Inventory (NEO-PI-R), are examined and compared with NEO-PI-R characteristics using data from college student observer ratings of 5,109 adolescents aged 12 to 17 years from 24 cultures. Replacement items in the PI-3 showed on average stronger item-total correlations and slightly improved facet reliabilities compared with the NEO-PI-R in both English- and non-English-speaking samples. NEO-PI-3 replacement items did not substantially affect scale means compared with the original scales. Analyses across and within cultures confirmed the intended factor structure of both versions when used to describe young adolescents. The authors discuss implications of these cross-cultural findings for the advancement of studies in adolescence and personality development across the lifespan.

Epidemic spreading in time-varying community networks.

PubMed

Ren, Guangming; Wang, Xingyuan

2014-06-01

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold qc. The epidemic will survive when q > qc and die when q < qc. These results can help understanding the impacts of human travel on the epidemic spreading in complex networks with community structure.

Outbreak statistics and scaling laws for externally driven epidemics.

PubMed

Singh, Sarabjeet; Myers, Christopher R

2014-04-01

Power-law scalings are ubiquitous to physical phenomena undergoing a continuous phase transition. The classic susceptible-infectious-recovered (SIR) model of epidemics is one such example where the scaling behavior near a critical point has been studied extensively. In this system the distribution of outbreak sizes scales as P(n)∼n-3/2 at the critical point as the system size N becomes infinite. The finite-size scaling laws for the outbreak size and duration are also well understood and characterized. In this work, we report scaling laws for a model with SIR structure coupled with a constant force of infection per susceptible, akin to a "reservoir forcing". We find that the statistics of outbreaks in this system fundamentally differ from those in a simple SIR model. Instead of fixed exponents, all scaling laws exhibit tunable exponents parameterized by the dimensionless rate of external forcing. As the external driving rate approaches a critical value, the scale of the average outbreak size converges to that of the maximal size, and above the critical point, the scaling laws bifurcate into two regimes. Whereas a simple SIR process can only exhibit outbreaks of size O(N1/3) and O(N) depending on whether the system is at or above the epidemic threshold, a driven SIR process can exhibit a richer spectrum of outbreak sizes that scale as O(Nξ), where ξ∈(0,1]∖{2/3} and O((N/lnN)2/3) at the multicritical point.

Obsessive-compulsive symptoms in a normative Chinese sample of youth: prevalence, symptom dimensions, and factor structure of the Leyton Obsessional Inventory--Child Version.

PubMed

Sun, Jing; Boschen, Mark J; Farrell, Lara J; Buys, Nicholas; Li, Zhan-Jiang

2014-08-01

Chinese adolescents face life stresses from multiple sources, with higher levels of stress predictive of adolescent mental health outcomes, including in the area of obsessive-compulsive disorders (OCD). Valid assessment of OCD among this age group is therefore a critical need in China. This study aims to standardise the Chinese version of the Leyton short version scale for adolescents of secondary schools in order to assess this condition. Stratified randomly selected adolescents were selected from four high schools located in Beijing, China. The Chinese version of the Leyton scale was administered to 3221 secondary school students aged between 12 and 18 years. A high response rate was achieved, with 3185 adolescents responding to the survey (98.5 percent). Exploratory factor analysis (EFA) extracted four factors from the scale: compulsive thoughts, concerns of cleanliness, lucky number, repetitiveness and repeated checking. The four-factor structures were confirmed using Confirmatory Factor Analysis (CFA). Overall the four-factor structure had a good model fit and high levels of reliability for each individual dimension and reasonable content validity. Invariance analyses in unconstrained, factor loading, and error variance models demonstrated that the Leyton scale is invariant in relation to the presence or absence OCD, age and gender. Discriminant validity analysis demonstrated that the four-factor structure scale also had excellent ability to differentiate between OCD and non-OCD students, male and female students, and age groups. The dataset was a non-clinical sample of high school students, rather than a sample of individuals with OCD. Future research may examine symptom structure in clinical populations to assess whether this structure fits into both clinical and community population. The structure derived from the Leyton short version scale in a non-clinical secondary school sample of adolescents, suggests that a four-factor solution can be utilised as a screening tool to assess adolescents׳ psychopathological symptoms in the area of OCD in mainland Chinese non-clinical secondary school students. Copyright © 2014 Elsevier B.V. All rights reserved.

Validity and reliability of the International Cooperative Ataxia Rating Scale (ICARS) and the Scale for the Assessment and Rating of Ataxia (SARA) in multiple sclerosis patients with ataxia.

PubMed

Salcı, Yeliz; Fil, Ayla; Keklicek, Hilal; Çetin, Barış; Armutlu, Kadriye; Dolgun, Anıl; Tuncer, Aslı; Karabudak, Rana

2017-11-01

Ataxia is an extremely common problem in multiple sclerosis (MS) patients. Thus, appropriate scales are required for detailed assessment of this issue. The aim of our study was to investigate the reliability and validity of the Turkish version of the International Cooperative Ataxia Rating Scale (ICARS) and Scale for the Assessment and Rating of Ataxia (SARA), which are widely used in ataxia evaluation in the context of other cerebellar diseases. This cross-sectional study included 80 MS patients with Kurtzke cerebellar functional system score (C-FSS) greater than zero and slight pyramidal involvement. The Expanded Disability Status Scale (EDSS), C-FSS, and Berg Balance Scale (BBS) were administered. SARA and ICARS were assessed on first admission by two physical therapists. Seven days later, second assessments were repeated in same way for reliability. Intra-rater and inter-rater reliability were found to be high for both ICARS and SARA (p< 0.001) The Cronbach's α coefficients were 0.922 and 0.921 for SARA (reviewer 1 and reviewer 2 respectively) and 0.952 and 0.952 for ICARS (reviewer 1 and reviewer 2, respectively). There were no floor or ceiling effects determined for either scale except for item 17 of ICARS (p= 0.055). The EDSS total score had significant correlations with both SARA and ICARS (rho: 0.557 and 0.707, respectively). C-FSS had moderate correlation with SARA and high correlation with ICARS (rho: 0.469 and 0.653, respectively). BBS had no significant correlation with SARA and ICARS. (rho: -0.048 and -0.008 respectively). According to the area under the curve (AUC) value, ICARS is the best scale to discriminate mild and moderate ataxia. (AUC: 0.875). Factor analyses of ICARS showed that the rating results were determined by five different factors that did not coincide with the ICARS sub-scales. Our study demonstrated that ICARS and SARA are both reliable in MS patients with ataxia. Although ICARS has some structural problems, it seems to be more valid given its high correlations with EDSS and C-FSS. SARA also can be preferred as a brief assessment. Copyright © 2017 Elsevier B.V. All rights reserved.

Significant demographic and fine-scale genetic structure in expanding and senescing populations of the terrestrial orchid Cymbidium goeringii (Orchidaceae).

PubMed

Chung, Mi Yoon; Nason, John D; Chung, Myong Gi

2011-12-01

Fine-scale genetic structure (FSGS) in plants is influenced by variation in spatial and temporal demographic processes. To determine how demographic structure and FSGS change with stages of population succession, we studied replicate expanding and senescing populations of the Asian terrestrial orchid Cymbidium goeringii. We used spatial autocorrelation methods (O-ring and kinship statistics) to quantify spatial demographic structure and FSGS in two expanding and two senescing populations, also measuring genetic diversity and inbreeding in each. All populations exhibited significant aggregation of individuals and FSGS at short spatial scales. In expanding populations, this finding was associated with high recruitment rates, suggesting restricted seed dispersal. In senescing populations, recruitment was minimal, suggesting alternative mechanisms of aggregation, perhaps including spatial associations with mycorrhizal fungi. All populations had significant evidence of genetic bottlenecks, and inbreeding levels were consistently high. Our results indicate that different successional stages can generate similar patterns of spatial demographic and genetic structure, but as a consequence of different processes. These results contrast with the only other study of senescence effects on population genetic structure in an herbaceous perennial, which found little to no FSGS in senescing populations. With the exception of populations subject to mass collection by orchid sellers, significant FSGS is characteristic of the 16 terrestrial orchid species examined to date. From a conservation perspective, this result suggests that inference of orchid population history will benefit from analyses of both FSGS and demographic structure in combination with other ecological field data.

Observations on the oxidation of Mn-modified Ni-base Haynes 230 alloy under SOFC exposure conditions

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

Yang, Z Gary; Xia, Gordon; Stevenson, Jeffry W.

2005-07-01

The commercial Ni-base Haynes 230 alloy (Ni-Cr-Mo-W-Mn) was modified with two increased levels of Mn (1 and 2 wt per cent) and evaluated for its oxidation resistance under simulated SOFC interconnect exposure conditions. Oxidation rate, oxide morphology, oxide conductivity and thermal expansion were measured and compared with commercial Haynes 230. It was observed that additions of higher levels of Mn to the bulk alloy facilitated the formation of a bi-layered oxide scale that was comprised of an outer M3O4 (M=Mn, Cr, Ni) spinel-rich layer at the oxide – gas interface over a Cr2O3-rich sub-layer at the metal – oxide interface.more » The modified alloys showed higher oxidation rates and the formation of thicker oxide scales compared to the base alloy. The formation of a spinel-rich top layer improved the scale conductivity, especially during the early stages of the oxidation, but the higher scale growth rate resulted in an increase in the area-specific electrical resistance over time. Due to their face-centered cubic crystal structure, both commercial and modified alloys demonstrated a coefficient of thermal expansion that was higher than that of typical anode-supported and electrolyte-supported SOFCs.« less

Dynamic three-dimensional pore-scale imaging of reaction in a carbonate at reservoir conditions.

PubMed

Menke, Hannah P; Bijeljic, Branko; Andrew, Matthew G; Blunt, Martin J

2015-04-07

Quantifying CO2 transport and average effective reaction rates in the subsurface is essential to assess the risks associated with underground carbon capture and storage. We use X-ray microtomography to investigate dynamic pore structure evolution in situ at temperatures and pressures representative of underground reservoirs and aquifers. A 4 mm diameter Ketton carbonate core is injected with CO2-saturated brine at 50 °C and 10 MPa while tomographic images are taken at 15 min intervals with a 3.8 μm spatial resolution over a period of 2(1/2) h. An approximate doubling of porosity with only a 3.6% increase in surface area to volume ratio is measured from the images. Pore-scale direct simulation and network modeling on the images quantify an order of magnitude increase in permeability and an appreciable alteration of the velocity field. We study the uniform reaction regime, with dissolution throughout the core. However, at the pore scale, we see variations in the degree of dissolution with an overall reaction rate which is approximately 14 times lower than estimated from batch measurements. This work implies that in heterogeneous rocks, pore-scale transport of reactants limits dissolution and can reduce the average effective reaction rate by an order of magnitude.

The structure of temperament and personality in Russian children.

PubMed

Digman, J M; Shmelyov, A G

1996-08-01

Russian schoolchildren (N = 480) 8-10 years old were rated by their teachers on 60 scales drawn from 3 sources: the temperament literature, studies of child personality, and Russian educators. Analysis of 21 temperament scales produced 4 meaningful components: sociability, anger, impulsivity, and fear. Component scores formed from these scales were then analyzed in the context of the remaining scales, leading to a solution that demonstrated the usefulness of the Big Five for the organization of personality characteristics in the Russian language and culture. The high degree of relation between the temperament dimensions and 4 of the 5 personality dimensions supports the view of many developmentalists that temperament not only is a major component of personality but may be the foundation of personality.

Optical Response of Sr2RuO4 Reveals Universal Fermi-Liquid Scaling and Quasiparticles Beyond Landau Theory

NASA Astrophysics Data System (ADS)

Stricker, D.; Mravlje, J.; Berthod, C.; Fittipaldi, R.; Vecchione, A.; Georges, A.; van der Marel, D.

2014-08-01

We report optical measurements demonstrating that the low-energy relaxation rate (1/τ) of the conduction electrons in Sr2RuO4 obeys scaling relations for its frequency (ω) and temperature (T) dependence in accordance with Fermi-liquid theory. In the thermal relaxation regime, 1/τ∝(ℏω)2+(pπkBT)2 with p=2, and ω/T scaling applies. Many-body electronic structure calculations using dynamical mean-field theory confirm the low-energy Fermi-liquid scaling and provide quantitative understanding of the deviations from Fermi-liquid behavior at higher energy and temperature. The excess optical spectral weight in this regime provides evidence for strongly dispersing "resilient" quasiparticle excitations above the Fermi energy.

Metabolic principles of river basin organization.

PubMed

Rodriguez-Iturbe, Ignacio; Caylor, Kelly K; Rinaldo, Andrea

2011-07-19

The metabolism of a river basin is defined as the set of processes through which the basin maintains its structure and responds to its environment. Green (or biotic) metabolism is measured via transpiration and blue (or abiotic) metabolism through runoff. A principle of equal metabolic rate per unit area throughout the basin structure is developed and tested in a river basin characterized by large heterogeneities in precipitation, vegetation, soil, and geomorphology. This principle is suggested to have profound implications for the spatial organization of river basin hydrologic dynamics, including the minimization of energy expenditure known to control the scale-invariant characteristics of river networks over several orders of magnitude. Empirically derived, remarkably constant rates of average transpiration per unit area through the basin structure lead to a power law for the probability distribution of transpiration from a randomly chosen subbasin. The average runoff per unit area, evaluated for subbasins of a wide range of topological magnitudes, is also shown to be remarkably constant independently of size. A similar result is found for the rainfall after accounting for canopy interception. Allometric scaling of metabolic rates with size, variously addressed in the biological literature and network theory under the label of Kleiber's law, is similarly derived. The empirical evidence suggests that river basin metabolic activity is linked with the spatial organization that takes place around the drainage network and therefore with the mechanisms responsible for the fractal geometry of the network, suggesting a new coevolutionary framework for biological, geomorphological, and hydrologic dynamics.

Factor analysis of the Hamilton Depression Rating Scale in Parkinson's disease.

PubMed

Broen, M P G; Moonen, A J H; Kuijf, M L; Dujardin, K; Marsh, L; Richard, I H; Starkstein, S E; Martinez-Martin, P; Leentjens, A F G

2015-02-01

Several studies have validated the Hamilton Depression Rating Scale (HAMD) in patients with Parkinson's disease (PD), and reported adequate reliability and construct validity. However, the factorial validity of the HAMD has not yet been investigated. The aim of our analysis was to explore the factor structure of the HAMD in a large sample of PD patients. A principal component analysis of the 17-item HAMD was performed on data of 341 PD patients, available from a previous cross sectional study on anxiety. An eigenvalue ≥1 was used to determine the number of factors. Factor loadings ≥0.4 in combination with oblique rotations were used to identify which variables made up the factors. Kaiser-Meyer-Olkin measure (KMO), Cronbach's alpha, Bartlett's test, communality, percentage of non-redundant residuals and the component correlation matrix were computed to assess factor validity. KMO verified the sample's adequacy for factor analysis and Cronbach's alpha indicated a good internal consistency of the total scale. Six factors had eigenvalues ≥1 and together explained 59.19% of the variance. The number of items per factor varied from 1 to 6. Inter-item correlations within each component were low. There was a high percentage of non-redundant residuals and low communality. This analysis demonstrates that the factorial validity of the HAMD in PD is unsatisfactory. This implies that the scale is not appropriate for studying specific symptom domains of depression based on factorial structure in a PD population. Copyright © 2014 Elsevier Ltd. All rights reserved.

Reliability of a novel, semi-quantitative scale for classification of structural brain magnetic resonance imaging in children with cerebral palsy.

PubMed

Fiori, Simona; Cioni, Giovanni; Klingels, Katrjin; Ortibus, Els; Van Gestel, Leen; Rose, Stephen; Boyd, Roslyn N; Feys, Hilde; Guzzetta, Andrea

2014-09-01

To describe the development of a novel rating scale for classification of brain structural magnetic resonance imaging (MRI) in children with cerebral palsy (CP) and to assess its interrater and intrarater reliability. The scale consists of three sections. Section 1 contains descriptive information about the patient and MRI. Section 2 contains the graphical template of brain hemispheres onto which the lesion is transposed. Section 3 contains the scoring system for the quantitative analysis of the lesion characteristics, grouped into different global scores and subscores that assess separately side, regions, and depth. A larger interrater and intrarater reliability study was performed in 34 children with CP (22 males, 12 females; mean age at scan of 9 y 5 mo [SD 3 y 3 mo], range 4 y-16 y 11 mo; Gross Motor Function Classification System level I, [n=22], II [n=10], and level III [n=2]). Very high interrater and intrarater reliability of the total score was found with indices above 0.87. Reliability coefficients of the lobar and hemispheric subscores ranged between 0.53 and 0.95. Global scores for hemispheres, basal ganglia, brain stem, and corpus callosum showed reliability coefficients above 0.65. This study presents the first visual, semi-quantitative scale for classification of brain structural MRI in children with CP. The high degree of reliability of the scale supports its potential application for investigating the relationship between brain structure and function and examining treatment response according to brain lesion severity in children with CP. © 2014 Mac Keith Press.

Intermittency and Alignment in Strong RMHD Turbulence

NASA Astrophysics Data System (ADS)

Chandran, B. D. G.; Schekochihin, A. A.; Mallet, A.

2015-12-01

Intermittency is one of the critical unsolved problems in solar-wind turbulence. Intermittency is important not just because it affects the observable properties of turbulence in the inertial range, but also because it modifies the nature of turbulent dissipation at small scales. In this talk, I will present recent work by colleagues A. Schekochihin, A. Mallet, and myself that focuses on the development of intermittency within the inertial range of solar-wind turbulence. We restrict our analysis to the transverse, non-compressive component of the turbulence. Previous work has shown that this component of the turbulence is anisotropic, varying most rapidly in directions perpendicular to the magnetic field. We argue that, deep within the inertial range, this component of the turbulence is well modeled by the equations of reduced magnetohydrodynamics (RMHD). We then develop an analytic model of intermittent, three-dimensional, strong, reduced magnetohydrodynamic turbulence with zero cross helicity. We take the fluctuation amplitudes to have a log-Poisson distribution and incorporate into the model a new phenomenology of scale-dependent dynamic alignment. The log-Poisson distribution in our model is characterized by two parameters. To calculate these parameters, we make use of two assumptions: that the energy cascade rate is independent of scale within the inertial range and that the most intense coherent structures at scale lambda are sheet-like with a volume filling factor proportional to lambda. We then compute the scalings of the power spectrum, the kurtosis, higher-order structure functions, and three different average alignment angles. We also carry out a direct numerical simulation of RMHD turbulence. The scalings in our model are similar to the scalings in this simulation as well as the structure-function scalings observed in the slow solar wind.

Genus age, provincial area and the taxonomic structure of marine faunas.

PubMed

Harnik, Paul G; Jablonski, David; Krug, Andrew Z; Valentine, James W

2010-11-22

Species are unevenly distributed among genera within clades and regions, with most genera species-poor and few species-rich. At regional scales, this structure to taxonomic diversity is generated via speciation, extinction and geographical range dynamics. Here, we use a global database of extant marine bivalves to characterize the taxonomic structure of climate zones and provinces. Our analyses reveal a general, Zipf-Mandelbrot form to the distribution of species among genera, with faunas from similar climate zones exhibiting similar taxonomic structure. Provinces that contain older taxa and/or encompass larger areas are expected to be more species-rich. Although both median genus age and provincial area correlate with measures of taxonomic structure, these relationships are interdependent, nonlinear and driven primarily by contrasts between tropical and extra-tropical faunas. Provincial area and taxonomic structure are largely decoupled within climate zones. Counter to the expectation that genus age and species richness should positively covary, diverse and highly structured provincial faunas are dominated by young genera. The marked differences between tropical and temperate faunas suggest strong spatial variation in evolutionary rates and invasion frequencies. Such variation contradicts biogeographic models that scale taxonomic diversity to geographical area.

Genus age, provincial area and the taxonomic structure of marine faunas

PubMed Central

Harnik, Paul G.; Jablonski, David; Krug, Andrew Z.; Valentine, James W.

2010-01-01

Species are unevenly distributed among genera within clades and regions, with most genera species-poor and few species-rich. At regional scales, this structure to taxonomic diversity is generated via speciation, extinction and geographical range dynamics. Here, we use a global database of extant marine bivalves to characterize the taxonomic structure of climate zones and provinces. Our analyses reveal a general, Zipf–Mandelbrot form to the distribution of species among genera, with faunas from similar climate zones exhibiting similar taxonomic structure. Provinces that contain older taxa and/or encompass larger areas are expected to be more species-rich. Although both median genus age and provincial area correlate with measures of taxonomic structure, these relationships are interdependent, nonlinear and driven primarily by contrasts between tropical and extra-tropical faunas. Provincial area and taxonomic structure are largely decoupled within climate zones. Counter to the expectation that genus age and species richness should positively covary, diverse and highly structured provincial faunas are dominated by young genera. The marked differences between tropical and temperate faunas suggest strong spatial variation in evolutionary rates and invasion frequencies. Such variation contradicts biogeographic models that scale taxonomic diversity to geographical area. PMID:20534619

Primary intervention for memory structuring and meaning acquisition (PIMSMA): study of a mental health first-aid intervention in the ED with injured survivors of suicide bombing attacks.

PubMed

Schreiber, Shaul; Dolberg, Ornah T; Barkai, Gabriel; Peles, Einat; Leor, Agnes; Rapoport, Elena; Heinik, Jeremia; Bloch, Miki

2007-01-01

To assess the impact of a structured intervention, the "primary intervention for memory structuring and meaning acquisition" (PIMSMA) performed randomly in the emergency department with survivors of suicide bombing attacks, on their medium-term mental health outcome. Follow up and assessment 3-9 months postinjury, and 24 months thereafter. A tertiary referral general hospital in Tel Aviv, Israel. Injured survivors of 9 suicide bombing and suicide shooting, men and women aged 16-72 at the time of the incident. Diagnosis of posttraumatic stress disorder (PTSD) was made using the Hebrew validated version of the DSM-IV SCID-PTSD rating scale. Other psychiatric symptoms were assessed using the following rating scales: impact of event scale (IES), Hamilton rating scale for depression (HAM-D) and for anxiety (HAM-A), and the Pittsburgh sleep quality index (PSQI). Effects of PIMSMA and PTSD level of psychological distress were analyzed using ANOVA and for change over time for continuous variables repeated measured multivariate analyses was performed, and for categorical variables nonparametric-related sample McNemar. Logistic regression for variable associated with PTSD was performed. Out of 213 eligible injured survivors evacuated to our ER, 129 were retrieved 3-9 months after the incident, and 53 were available for assessment 2 years later. Multivariate analyses for being PTSD vs non-PTSD at the first evaluation, being hospitalized OR = 5.6 (95 percent CI 1.1-27.6) and treated OR = 24.5 (95 percent CI 2.8-200) were the only predictors, with no effect (p = 0.9) for PIMSMA vs other supportive intervention. Predictor for PTSD at the second evaluation were IES severity score at first evaluation OR = 1.1 (95 percent CI 1.04-1.2). The PIMSMA approach is as good as the nonspecific supportive treatment performed routinely in the ED with all survivors of traumatic events of any origin. Further studies are needed to establish valid, evidence-based treatment approaches for the acute aftermath of exposure to severe potentially traumatic events.

Suicidal behavior in obsessive-compulsive disorder.

PubMed

Kamath, Prakash; Reddy, Y C Janardhan; Kandavel, Thennarasu

2007-11-01

There are limited data on suicidal behavior in obsessive-compulsive disorder (OCD). This study examines suicidal behavior and its clinical correlates in OCD subjects. One hundred consecutive DSM-IV OCD subjects attending the specialty OCD clinic and the inpatient services of a major psychiatric hospital in India from November 1, 2003, to October 31, 2004, formed the sample of this study. Subjects were assessed systematically by using structured interviews and various rating scales. The Scale for Suicide Ideation-worst ever (lifetime) and -current measured suicidal ideation. The 24-item Hamilton Rating Scale for Depression (HAM-D) measured severity of depression, and the Beck Hopelessness Scale (BHS) measured hopelessness. We performed assessments at study entry. We employed binary logistic regression (Wald) forward stepwise analysis for prediction of suicidal ideation and suicide attempt, and we used structural equation modeling for identifying the potential factors contributing to suicidal ideation. The rates of suicidal ideation, worst ever and current, were 59% and 28%, respectively. History of suicide attempt was reported in 27% of the subjects. For past suicide attempt, worst ever suicidal ideation (p < .001) was the only significant predictor, with an overall prediction of 89%, and accounted for 60% of the variance. For worst ever suicidal ideation, major depression (p = .043), HAM-D score (p = .013), BHS score (p = .011), and history of attempt (p = .009) were significant predictors, with an overall prediction of 82% and variance of 56%. Somewhat similar predictors emerged as significant for current suicidal ideators, with an overall prediction of 85% and variance of 50%. In the structural equation model, too, presence of depression and high BHS score contributed to suicidal ideation. OCD is associated with a high risk for suicidal behavior. Depression and hopelessness are the major correlates of suicidal behavior. It is vital that patients with OCD undergo detailed assessment for suicide risk and associated depression. Aggressive treatment of depression may be warranted to modify the risk for suicide. Future studies should examine suicidal behavior in a prospective design in larger samples to examine if severity of OCD and treatment nonresponse contribute to suicide risk.

Experimental evidence of chaotic mixing at pore scale in 3D porous media

NASA Astrophysics Data System (ADS)

Heyman, J.; Turuban, R.; Jimenez Martinez, J.; Lester, D. R.; Meheust, Y.; Le Borgne, T.

2017-12-01

Mixing of dissolved chemical species in porous media plays a central role in many natural and industrial processes, such as contaminant transport and degradation in soils, oxygen and nitrates delivery in river beds, clogging in geothermal systems, CO2 sequestration. In particular, incomplete mixing at the pore scale may strongly affect the spatio-temporal distribution of reaction rates in soils and rocks, questioning the validity of diffusion-reaction models at the Darcy scale. Recent theoretical [1] and numerical [2] studies of flow in idealized porous media have suggested that fluid mixing may be chaotic at pore scale, hence pointing to a whole new set of models for mixing and reaction in porous media. However, so far this remained to be confirmed experimentally. Here we present experimental evidence of the chaotic nature of transverse mixing at the pore scale in three-dimensional porous media. We designed a novel experimental setup allowing high resolution pore scale imaging of the structure of a tracer plume in porous media columns consisting of 7, 10 and 20 mm glass bead packings. We conjointly used refractive index matching techniques, laser induced fluorescence and a moving laser-sheet to reconstruct the shape of a steady tracer plume as it gets deformed by the porous media flow. In this talk, we focus on the transverse behavior of mixing, that is, on the plane orthogonal to the main flow direction, in the limit of high Péclet numbers (diffusion is negligible). Moving away from the injection point, the plume cross-section turns quickly into complex, interlaced, lamellar structures. These structures elongated at an exponential rate, characteristic of a chaotic system, that can be characterized by an average Lyapunov exponent. We finally discuss the origin of this chaotic behavior and its most significant consequences for upscaling mixing and reactive transport in porous media. Reference:[1] D. R. Lester, G. Metcafle, M. G. Trefry, Physical Review Letters, 111, 174101 (2013) [2] R. Turuban, D. R. Lester, T. Le Borgne, and Y. Méheust (2017), under review.

Mapping Structure-Composition-Property Relationships in V- and Fe-Doped LiMnPO4 Cathodes for Lithium-Ion Batteries.

PubMed

Johnson, Ian D; Loveridge, Melanie; Bhagat, Rohit; Darr, Jawwad A

2016-11-14

A series of LiMn 1-x-y Fe x V y PO 4 (LMFVP) nanomaterials have been synthesized using a pilot-scale continuous hydrothermal synthesis process (CHFS) and evaluated as high voltage cathodes in Li-ion batteries at a production rate of 0.25 kg h -1 . The rapid synthesis and screening approach has allowed the specific capacity of the high Mn content olivines to be optimized, particularly at high discharge rates. Consistent and gradual changes in the structure and performance are observed across the compositional region under investigation; the doping of Fe at 20 at% (with respect to Mn) into lithium manganese phosphate, rather than V or indeed codoping of Fe and V, gives the best balance of high capacity and high rate performance.

Culmination of the inverse cascade - mean flow and fluctuations

NASA Astrophysics Data System (ADS)

Frishman, Anna; Herbert, Corentin

2017-11-01

An inverse cascade-energy transfer to progressively larger scales - is a salient feature of two-dimensional turbulence. If the cascade reaches the system scale, it terminates in the self organization of the turbulence into a large scale coherent structure, on top of small scale fluctuations. A recent theoretical framework in which this coherent mean flow can be obtained will be discussed. Assuming that the quasi-linear approximation applies, the forcing acts at small scales, and a strong shear, the theory gives an inverse relation between the average momentum flux and the mean shear rate. It will be argued that this relation is quite general, being independent of the dissipation mechanism and largely insensitive to the type of forcing. Furthermore, in the special case of a homogeneous forcing, the relation between the momentum flux and mean shear rate is completely determined by dimensional analysis and symmetry arguments. The subject of the average energy of the fluctuations will also be touched upon, focusing on a vortex mean flow. In contrast to the momentum flux, we find that the energy of the fluctuations is determined by zero modes of the mean-flow advection operator. Using an analytic derivation for the zero mo.

Analysis of BJ493 diesel engine lubrication system properties

NASA Astrophysics Data System (ADS)

Liu, F.

2017-12-01

The BJ493ZLQ4A diesel engine design is based on the primary model of BJ493ZLQ3, of which exhaust level is upgraded to the National GB5 standard due to the improved design of combustion and injection systems. Given the above changes in the diesel lubrication system, its improved properties are analyzed in this paper. According to the structures, technical parameters and indices of the lubrication system, the lubrication system model of BJ493ZLQ4A diesel engine was constructed using the Flowmaster flow simulation software. The properties of the diesel engine lubrication system, such as the oil flow rate and pressure at different rotational speeds were analyzed for the schemes involving large- and small-scale oil filters. The calculated values of the main oil channel pressure are in good agreement with the experimental results, which verifies the proposed model feasibility. The calculation results show that the main oil channel pressure and maximum oil flow rate values for the large-scale oil filter scheme satisfy the design requirements, while the small-scale scheme yields too low main oil channel’s pressure and too high. Therefore, application of small-scale oil filters is hazardous, and the large-scale scheme is recommended.

Genetic co-structuring in host-parasite systems: Empirical data from raccoons and raccoon ticks

DOE PAGES

Dharmarajan, Guha; Beasley, James C.; Beatty, William S.; ...

2016-03-31

Many aspects of parasite biology critically depend on their hosts, and understanding how host-parasite populations are co-structured can help improve our understanding of the ecology of parasites, their hosts, and host-parasite interactions. Here, this study utilized genetic data collected from raccoons (Procyon lotor), and a specialist parasite, the raccoon tick (Ixodes texanus), to test for genetic co-structuring of host-parasite populations at both landscape and host scales. At the landscape scale, our analyses revealed a significant correlation between genetic and geographic distance matrices (i.e., isolation by distance) in ticks, but not their hosts. While there are several mechanisms that could leadmore » to a stronger pattern of isolation by distance in tick vs. raccoon datasets, our analyses suggest that at least one reason for the above pattern is the substantial increase in statistical power (due to the ≈8-fold increase in sample size) afforded by sampling parasites. Host-scale analyses indicated higher relatedness between ticks sampled from related vs. unrelated raccoons trapped within the same habitat patch, a pattern likely driven by increased contact rates between related hosts. Lastly, by utilizing fine-scale genetic data from both parasites and hosts, our analyses help improve our understanding of epidemiology and host ecology.« less

Evaluating Abstract Art: Relation between Term Usage, Subjective Ratings, Image Properties and Personality Traits.

PubMed

Lyssenko, Nathalie; Redies, Christoph; Hayn-Leichsenring, Gregor U

2016-01-01

One of the major challenges in experimental aesthetics is the uncertainty of the terminology used in experiments. In this study, we recorded terms that are spontaneously used by participants to describe abstract artworks and studied their relation to the second-order statistical image properties of the same artworks (Experiment 1). We found that the usage frequency of some structure-describing terms correlates with statistical image properties, such as PHOG Self-Similarity, Anisotropy and Complexity. Additionally, emotion-associated terms correlate with measured color values. Next, based on the most frequently used terms, we created five different rating scales (Experiment 2) and obtained ratings of participants for the abstract paintings on these scales. We found significant correlations between descriptive score ratings (e.g., between structure and subjective complexity), between evaluative and descriptive score ratings (e.g., between preference and subjective complexity/interest) and between descriptive score ratings and statistical image properties (e.g., between interest and PHOG Self-Similarity, Complexity and Anisotropy). Additionally, we determined the participants' personality traits as described in the 'Big Five Inventory' (Goldberg, 1990; Rammstedt and John, 2005) and correlated them with the ratings and preferences of individual participants. Participants with higher scores for Neuroticism showed preferences for objectively more complex images, as well as a different notion of the term complex when compared with participants with lower scores for Neuroticism. In conclusion, this study demonstrates an association between objectively measured image properties and the subjective terms that participants use to describe or evaluate abstract artworks. Moreover, our results suggest that the description of abstract artworks, their evaluation and the preference of participants for their low-level statistical properties are linked to personality traits.

Evaluating Abstract Art: Relation between Term Usage, Subjective Ratings, Image Properties and Personality Traits

PubMed Central

Lyssenko, Nathalie; Redies, Christoph; Hayn-Leichsenring, Gregor U.

2016-01-01

One of the major challenges in experimental aesthetics is the uncertainty of the terminology used in experiments. In this study, we recorded terms that are spontaneously used by participants to describe abstract artworks and studied their relation to the second-order statistical image properties of the same artworks (Experiment 1). We found that the usage frequency of some structure-describing terms correlates with statistical image properties, such as PHOG Self-Similarity, Anisotropy and Complexity. Additionally, emotion-associated terms correlate with measured color values. Next, based on the most frequently used terms, we created five different rating scales (Experiment 2) and obtained ratings of participants for the abstract paintings on these scales. We found significant correlations between descriptive score ratings (e.g., between structure and subjective complexity), between evaluative and descriptive score ratings (e.g., between preference and subjective complexity/interest) and between descriptive score ratings and statistical image properties (e.g., between interest and PHOG Self-Similarity, Complexity and Anisotropy). Additionally, we determined the participants’ personality traits as described in the ‘Big Five Inventory’ (Goldberg, 1990; Rammstedt and John, 2005) and correlated them with the ratings and preferences of individual participants. Participants with higher scores for Neuroticism showed preferences for objectively more complex images, as well as a different notion of the term complex when compared with participants with lower scores for Neuroticism. In conclusion, this study demonstrates an association between objectively measured image properties and the subjective terms that participants use to describe or evaluate abstract artworks. Moreover, our results suggest that the description of abstract artworks, their evaluation and the preference of participants for their low-level statistical properties are linked to personality traits. PMID:27445933

Scale Invariance in Landscape Evolution Models Using Stream Power Laws

NASA Astrophysics Data System (ADS)

Kwang, J. S.; Parker, G.

2014-12-01

Landscape evolution models (LEM) commonly utilize stream power laws to simulate river incision with formulations such as E = KAmSn, where E is a vertical incision rate [L/T], K is an erodibility constant [L1-2m/T], A is an upstream drainage area [L2], S is a local channel gradient [-], and m and n are positive exponents that describe the basin hydrology. In our reduced complexity model, the landscape approached equilibrium by balancing an incision rate with a constant, uniform, vertical rock uplift rate at every location in the landscape. From our simulations, for a combination of m and n, the landscape exhibited scale invariance. That is, regardless of the size and scale of the basin, the relief and vertical structure of the landscape remained constant. Therefore, the relief and elevation profile of the landscape at equilibrium were only dependent on the coefficients for erodibility and uplift and an equation that described how upstream area, A, increased as the length of a stream increased. In our analytical 1D models, we utilized two equations that described upslope area, (a) A = Bl, where B is the profile width [L], and l is the stream length from the ridge [L] and (b) A = Clh, Hack's Law, where C is a constant [L2-h] and h is a positive exponent. With these equations, (a) m = n and (b) hm = n resulted in scale invariance. In our numerical 2D models, the relationship between A and l was inherent in the actual structure of the drainage network. From our numerical 2D results, scale invariance occurred when 2m = n. Additionally, using reasonable values from the literature for exponents, n, m and h, resulted in singularities at the ridges in the landscape, which caused truncation error. In consequence, the elevation of the ridge increased as the number of grid cells in the domain increased in the numerical model, and the model was unable to converge. These singularities at the ridges appeared when (a) m ≥ n and (b) hm ≥ n in the analytical model and 2m ≥ n in the numerical model. Here we present (1) 1D analytical solutions and (2) 2D numerical solutions that demonstrate scale invariance in LEMs and (3) the consequences of the singularity in 2D LEM numerical simulations. These results will help provide insight about the structure and dynamics of landscapes and drainage networks and shed light on geomorphological empirical relationships.

Classification of epilepsy types through global network analysis of scalp electroencephalograms

NASA Astrophysics Data System (ADS)

Lee, Uncheol; Kim, Seunghwan; Jung, Ki-Young

2006-04-01

Epilepsy is a dynamic disease in which self-organization and emergent structures occur dynamically at multiple levels of neuronal integration. Therefore, the transient relationship within multichannel electroencephalograms (EEGs) is crucial for understanding epileptic processes. In this paper, we show that the global relationship within multichannel EEGs provides us with more useful information in classifying two different epilepsy types than pairwise relationships such as cross correlation. To demonstrate this, we determine the global network structure within channels of the scalp EEG based on the minimum spanning tree method. The topological dissimilarity of the network structures from different types of temporal lobe epilepsy is described in the form of the divergence rate and is computed for 11 patients with left (LTLE) and right temporal lobe epilepsy (RTLE). We find that patients with LTLE and RTLE exhibit different large scale network structures, which emerge at the epoch immediately before the seizure onset, not in the preceding epochs. Our results suggest that patients with the two different epilepsy types display distinct large scale dynamical networks with characteristic epileptic network structures.

Preparation of zein nanoparticles by using solution-enhanced dispersion with supercritical CO2 and elucidation with computational fluid dynamics.

PubMed

Li, Sining; Zhao, Yaping

2017-01-01

Nanoparticles have attracted more and more attention in the medicinal field. Zein is a biomacromolecule and can be used as a carrier for delivering active ingredients to prepare controlled release drugs. In this article, we presented the preparation of zein nanoparticles by solution-enhanced dispersion by supercritical CO 2 (SEDS) approach. Scanning electron microscopy and transmission electron microscopy were applied to characterize the size and morphology of the obtained particles. The nozzle structure and the CO 2 flow rate greatly affected the morphology and the size of the particles. The size of zein was able to be reduced to 50-350 nm according to the different conditions. The morphologies of the resultant zein were either sphere or the filament network consisted of nanoparticles. The influence of the nozzle structure and the CO 2 flow rate on the velocity field was elucidated by using computational fluid dynamics. The nozzle structure and the CO 2 flow rate greatly affected the distribution of the velocity field. However, a similar velocity field could also be obtained when the nozzle structure or the CO 2 flow rate, or both were different. Therefore, the influence of the nozzle structure and the CO 2 flow rate on the size and morphology of the particles, can boil down to the velocity field. The results demonstrated that the velocity field can be a potential criterion for producing nanoparticles with controllable morphology and size, which is useful to scale-up the SEDS process.

Canonical Nonlinear Viscous Core Solution in pipe and elliptical geometry

NASA Astrophysics Data System (ADS)

Ozcakir, Ozge

2016-11-01

In an earlier paper (Ozcakir et al. (2016)), two new nonlinear traveling wave solutions were found with collapsing structure towards the center of the pipe as Reynolds number R -> ∞ , which were called Nonlinear Viscous Core (NVC) states. Asymptotic scaling arguments suggested that the NVC state collapse rate scales as R - 1 / 4 where axial, radial and azimuthal velocity perturbations from Hagen-Poiseuille flow scale as R - 1 / 2, R - 3 / 4 and R - 3 / 4 respectively, while (1 - c) = O (R - 1 / 2) where c is the traveling wave speed. The theoretical scaling results were roughly consistent with full Navier-Stokes numerical computations in the range 105 < R <106 . In the present paper, through numerical solutions, we show that the scaled parameter free canonical differential equations derived in Ozcakir et al. (2016) indeed has solution that satisfies requisite far-field conditions. We also show that these are in good agreement with full Navier-Stokes calculations in a larger R range than previously calculated (R upto 106). Further, we extend our study to NVC states for pipes with elliptical cross-section and identify similar canonical structure in these cases. National Science Foundation NSF-DMS-1515755, EPSRC Grant EP/1037948/1.

The delineation and interpretation of the earth's gravity field

NASA Technical Reports Server (NTRS)

Marsh, Bruce D.

1988-01-01

A series of fluid dynamical experiments in variable viscosity fluid have been made and are in progress to study: (1) the onset of small scale convection relative to lithosphere growth rate; (2) the influence of paired fracture zones in modulating the horizontal scale of small scale convection; (3) the influence of the mantle vertical viscosity structure on determing the mode of small scale convection; and (4) the 3-D and temporal evolution of flows beneath a high viscosity lid. These experiments extend and amplify the present experimental work that has produced small scale convection beneath a downward-moving solidification front. Rapid growth of a high viscosity lid stifles the early onset of convection such that convection only begins once the lithosphere is older than a certain minimum age. The interplay of this convection with both the structure of the lithosphere and mantle provide a fertile field of investigation into the origin of geoid, gravity, and topographic anomalies in the central Pacific. These highly correlated fields of intermediate wavelength (approximately 200 to 2000 km), but not the larger wavelengths. It is the ultimate, dynamic origin of this class of anomalies that is sought in this investigation.

Genomic correlates of recombination rate and its variability across eight recombination maps in the western honey bee (Apis mellifera L.).

PubMed

Ross, Caitlin R; DeFelice, Dominick S; Hunt, Greg J; Ihle, Kate E; Amdam, Gro V; Rueppell, Olav

2015-02-21

Meiotic recombination has traditionally been explained based on the structural requirement to stabilize homologous chromosome pairs to ensure their proper meiotic segregation. Competing hypotheses seek to explain the emerging findings of significant heterogeneity in recombination rates within and between genomes, but intraspecific comparisons of genome-wide recombination patterns are rare. The honey bee (Apis mellifera) exhibits the highest rate of genomic recombination among multicellular animals with about five cross-over events per chromatid. Here, we present a comparative analysis of recombination rates across eight genetic linkage maps of the honey bee genome to investigate which genomic sequence features are correlated with recombination rate and with its variation across the eight data sets, ranging in average marker spacing ranging from 1 Mbp to 120 kbp. Overall, we found that GC content explained best the variation in local recombination rate along chromosomes at the analyzed 100 kbp scale. In contrast, variation among the different maps was correlated to the abundance of microsatellites and several specific tri- and tetra-nucleotides. The combined evidence from eight medium-scale recombination maps of the honey bee genome suggests that recombination rate variation in this highly recombining genome might be due to the DNA configuration instead of distinct sequence motifs. However, more fine-scale analyses are needed. The empirical basis of eight differing genetic maps allowed for robust conclusions about the correlates of the local recombination rates and enabled the study of the relation between DNA features and variability in local recombination rates, which is particularly relevant in the honey bee genome with its exceptionally high recombination rate.

Correspondence between Psychometric and Clinical High Risk for Psychosis in an Undergraduate Population

PubMed Central

Cicero, David C.; Martin, Elizabeth A.; Becker, Theresa M.; Docherty, Anna; Kerns, John G.

2014-01-01

Despite the common use of either psychometric or clinical methods for identifying individuals at risk for psychosis, previous research has not examined the correspondence and extent of convergence of these two approaches. Undergraduates (n = 160), selected from a larger pool, completed three self-report schizotypy scales, the Magical Ideation Scale, the Perceptual Aberration Scale, and the Revised Social Anhedonia Scale, and were administered the Structured Interview for Prodromal Syndromes (SIPS). First, high correlations were observed for self-report and interview-rated psychotic like experiences (rs between .48 and .61, p < .001). Second, 77 percent of individuals identified as having a risk for psychosis with the self-report measures reported at least one clinically meaningful psychotic-like experience on the SIPS. Third, receiver operating characteristic curve analyses showed that the self-report scales can be used to identify which participants report clinically meaningful positive symptoms. These results suggest that mostly white undergraduate participants identified as at risk with the psychometric schizotypy approach report clinically meaningful psychotic-like experiences in an interview format and that the schizotypy scales are moderately to strongly correlated with interview-rated psychotic-like experiences. The results of the current research provide a baseline for comparing research between these two approaches. PMID:24708081

Direct and inverse energy cascades in a forced rotating turbulence experiment

NASA Astrophysics Data System (ADS)

Campagne, Antoine; Gallet, Basile; Moisy, Frédéric; Cortet, Pierre-Philippe

2014-12-01

We present experimental evidence for a double cascade of kinetic energy in a statistically stationary rotating turbulence experiment. Turbulence is generated by a set of vertical flaps, which continuously injects velocity fluctuations towards the center of a rotating water tank. The energy transfers are evaluated from two-point third-order three-component velocity structure functions, which we measure using stereoscopic particle image velocimetry in the rotating frame. Without global rotation, the energy is transferred from large to small scales, as in classical three-dimensional turbulence. For nonzero rotation rates, the horizontal kinetic energy presents a double cascade: a direct cascade at small horizontal scales and an inverse cascade at large horizontal scales. By contrast, the vertical kinetic energy is always transferred from large to small horizontal scales, a behavior reminiscent of the dynamics of a passive scalar in two-dimensional turbulence. At the largest rotation rate, the flow is nearly two-dimensional, and a pure inverse energy cascade is found for the horizontal energy. To describe the scale-by-scale energy budget, we consider a generalization of the Kármán-Howarth-Monin equation to inhomogeneous turbulent flows, in which the energy input is explicitly described as the advection of turbulent energy from the flaps through the surface of the control volume where the measurements are performed.

Small-Scale Dynamical Structures Using OH Airglow From Astronomical Observations

NASA Astrophysics Data System (ADS)

Franzen, C.; Espy, P. J.; Hibbins, R. E.; Djupvik, A. A.

2017-12-01

Remote sensing of perturbations in the hydroxyl (OH) Meinel airglow has often been used to observe gravity, tidal and planetary waves travelling through the 80-90 km region. While large scale (>1 km) gravity waves and the winds caused by their breaking are widely documented, information on the highest frequency waves and instabilities occurring during the breaking process is often limited by the temporal and spatial resolution of the available observations. In an effort to better quantify the full range of wave scales present near the mesopause, we present a series of observations of the OH Meinel (9,7) transition that were executed with the Nordic Optical Telescope on La Palma (18°W, 29°N). These measurements have a 24 s repetition rate and horizontal spatial resolutions at 87 km as small as 10 cm, allowing us to quantify the transition in the mesospheric wave domains as the gravity waves break. Temporal scales from hours to minutes, as well as sub-100 m coherent structures in the OH airglow have been observed and will be presented.

Psychometric properties of the Spanish version of the UPPS-P Impulsive Behavior Scale: A Rasch rating scale analysis and confirmatory factor analysis.

PubMed

Pilatti, Angelina; Lozano, Oscar M; Cyders, Melissa A

2015-12-01

The present study was aimed at determining the psychometric properties of the Spanish version of the UPPS-P Impulsive Behavior Scale in a sample of college students. Participants were 318 college students (36.2% men; mean age = 20.9 years, SD = 6.4 years). The psychometric properties of this Spanish version were analyzed using the Rasch model, and the factor structure was examined using confirmatory factor analysis. The verification of the global fit of the data showed adequate indexes for persons and items. The reliability estimates were high for both items and persons. Differential item functioning across gender was found for 23 items, which likely reflects known differences in impulsivity levels between men and women. The factor structure of the Spanish version of the UPPS-P replicates previous work with the original UPPS-P Scale. Overall, results suggest that test scores from the Spanish version of the UPPS-P show adequate psychometric properties to accurately assess the multidimensional model of impulsivity, which represents the most exhaustive measure of this construct. (c) 2015 APA, all rights reserved).

Small-scale behavior in distorted turbulent boundary layers at low Reynolds number

NASA Technical Reports Server (NTRS)

Saddoughi, Seyed G.

1994-01-01

During the last three years we have conducted high- and low-Reynolds-number experiments, including hot-wire measurements of the velocity fluctuations, in the test-section-ceiling boundary layer of the 80- by 120-foot Full-Scale Aerodynamics Facility at NASA Ames Research Center, to test the local-isotropy predictions of Kolmogorov's universal equilibrium theory. This hypothesis, which states that at sufficiently high Reynolds numbers the small-scale structures of turbulent motions are independent of large-scale structures and mean deformations, has been used in theoretical studies of turbulence and computational methods such as large-eddy simulation; however, its range of validity in shear flows has been a subject of controversy. The present experiments were planned to enhance our understanding of the local-isotropy hypothesis. Our experiments were divided into two sets. First, measurements were taken at different Reynolds numbers in a plane boundary layer, which is a 'simple' shear flow. Second, experiments were designed to address this question: will our criteria for the existence of local isotropy hold for 'complex' nonequilibrium flows in which extra rates of mean strain are added to the basic mean shear?

Transverse electron-scale instability in relativistic shear flows.

PubMed

Alves, E P; Grismayer, T; Fonseca, R A; Silva, L O

2015-08-01

Electron-scale surface waves are shown to be unstable in the transverse plane of a sheared flow in an initially unmagnetized collisionless plasma, not captured by (magneto)hydrodynamics. It is found that these unstable modes have a higher growth rate than the closely related electron-scale Kelvin-Helmholtz instability in relativistic shears. Multidimensional particle-in-cell simulations verify the analytic results and further reveal the emergence of mushroomlike electron density structures in the nonlinear phase of the instability, similar to those observed in the Rayleigh Taylor instability despite the great disparity in scales and different underlying physics. This transverse electron-scale instability may play an important role in relativistic and supersonic sheared flow scenarios, which are stable at the (magneto)hydrodynamic level. Macroscopic (≫c/ωpe) fields are shown to be generated by this microscopic shear instability, which are relevant for particle acceleration, radiation emission, and to seed magnetohydrodynamic processes at long time scales.

A Feedback Model of Attention Explains the Diverse Effects of Attention on Neural Firing Rates and Receptive Field Structure.

PubMed

Miconi, Thomas; VanRullen, Rufin

2016-02-01

Visual attention has many effects on neural responses, producing complex changes in firing rates, as well as modifying the structure and size of receptive fields, both in topological and feature space. Several existing models of attention suggest that these effects arise from selective modulation of neural inputs. However, anatomical and physiological observations suggest that attentional modulation targets higher levels of the visual system (such as V4 or MT) rather than input areas (such as V1). Here we propose a simple mechanism that explains how a top-down attentional modulation, falling on higher visual areas, can produce the observed effects of attention on neural responses. Our model requires only the existence of modulatory feedback connections between areas, and short-range lateral inhibition within each area. Feedback connections redistribute the top-down modulation to lower areas, which in turn alters the inputs of other higher-area cells, including those that did not receive the initial modulation. This produces firing rate modulations and receptive field shifts. Simultaneously, short-range lateral inhibition between neighboring cells produce competitive effects that are automatically scaled to receptive field size in any given area. Our model reproduces the observed attentional effects on response rates (response gain, input gain, biased competition automatically scaled to receptive field size) and receptive field structure (shifts and resizing of receptive fields both spatially and in complex feature space), without modifying model parameters. Our model also makes the novel prediction that attentional effects on response curves should shift from response gain to contrast gain as the spatial focus of attention drifts away from the studied cell.

Ecomorphodynamic Response of Foreshore Saltmarsh to the Implementation of Flood and Erosion Mitigation and Adaptation Structures in a Hypertidal Estuary: Minas Basin, Bay of Fundy, Canada.

NASA Astrophysics Data System (ADS)

Matheson, G.; van Proosdij, D.; Ross, C.

2017-12-01

Flood and erosion mitigations and adaptation structures are often implemented in anthropogenically modified coastal regions, such as dykelands, to protect against coastal hazards. If saltmarshes are to be incorporated into a coastal management plan as a source of coastal defence, it is paramount to understand how ecomorphodynamic feedbacks triggered by implementing these structures can impact saltmarshes. This study examines how these structures, in combination with natural drivers, have precipitated changes in foreshore saltmarsh erosion and progradation rates over varying spatial scales in the hypertidal Minas Basin, located in the upper Bay of Fundy, during the past 80 years. Foreshore change rates (in 25m segments) are obtained using empirical field measurements, geomatics techniques in a geographical information system (GIS), as well as imagery and digital surface models (DSMs) derived from an unmanned aerial vehicle (UAV). Furthermore, UAV DSMs were used to determine infill rates and short-term sediment budgets in saltmarsh borrow pits. Natural cyclical foreshore change rates are observed in the Minas Basin, but are often augmented by the presence of anthropogenic structures. Erosion and progradation rates in individual transects have been observed to be as much as -14.9m/yr and 20.1m/yr, respectively. In individual saltmarsh communities, average change rates have been observed to be as much -3.4m/yr and 2.1m/yr across the entire foreshore. Furthermore, results suggest that under specific environmental conditions some structures (e.g. kickers) work in tandem with saltmarshes to protect the upland by precipitating ecomorphodynamic feedbacks that promote saltmarsh progradation. Conversely, other structures (e.g. foreshore rocking) can exacerbate natural cycles of erosion, locally. Borrow pit studies reveal that although local suspended sediment concentrations, which can vary from 50mg/l to 50000mg/l, play an integral role in pit sedimentation, channel geometry design may play an equally important role in governing infill rates.

Nanoscale heterogeneity as remnant hexagonal-type local structures in shocked Cu-Pb and Zr

NASA Astrophysics Data System (ADS)

Tayal, Akhil; Conradson, Steven D.; Batuk, Olga N.; Fensin, Saryu; Cerreta, Ellen; Gray, George T.; Saxena, Avadh

2017-09-01

Extended X-ray absorption fine structure spectroscopy was used to determine the local structure in: (1) Zr that had undergone quasistatic elongation; (2) Zr that had undergone plastic deformation by shock at pressures above and below the ω-phase transformation; and (3) shocked Cu that contained a few percent of insoluble Pb. Below the transition pressure, Zr samples showed only general disorder as increases in the widths of the Zr-Zr pair distributions. Above this pressure, Zr that was a mixture of the original hcp and the high pressure ω-phase when measured by diffraction showed two sets of peaks in its distribution corresponding to these two phases. Some of the ones from the ω-phase were at distances substantially different from those calculated from the diffraction pattern, although they are still consistent with small domains exhibiting stacking faults associated with hexagonal-type structural components exhibiting variability in the [0001] basal plane spacing. A similar result, new pairs at just over 3 and 4 Å consistent with hexagonal-type stacking faults in addition to the original fcc structure, is found in shocked Cu despite the absence of a second diffraction pattern and peak pressures being far below those expected to induce an fcc to hcp transition. This result, therefore, demonstrates that the correlation between high strain rates and reduced stacking fault energy continues down to the length scale of atom pairs. These findings are significant as: (1) a microscopic description of the behavior of systems far from equilibrium; (2) a demonstration of the importance of strain rate at short length scales; and (3) a bridge between the abruptness of macroscopic pressure-induced phase transitions and the continuity of martensitic ones over their fluctuation region in terms of the inverse relationship between the length scale of the martensitic texture, manifested here as ordered lattice distortions and the lower pressure at which such texture first appears relative to the bulk transition pressure.

SeqRate: sequence-based protein folding type classification and rates prediction

PubMed Central

2010-01-01

Background Protein folding rate is an important property of a protein. Predicting protein folding rate is useful for understanding protein folding process and guiding protein design. Most previous methods of predicting protein folding rate require the tertiary structure of a protein as an input. And most methods do not distinguish the different kinetic nature (two-state folding or multi-state folding) of the proteins. Here we developed a method, SeqRate, to predict both protein folding kinetic type (two-state versus multi-state) and real-value folding rate using sequence length, amino acid composition, contact order, contact number, and secondary structure information predicted from only protein sequence with support vector machines. Results We systematically studied the contributions of individual features to folding rate prediction. On a standard benchmark dataset, the accuracy of folding kinetic type classification is 80%. The Pearson correlation coefficient and the mean absolute difference between predicted and experimental folding rates (sec-1) in the base-10 logarithmic scale are 0.81 and 0.79 for two-state protein folders, and 0.80 and 0.68 for three-state protein folders. SeqRate is the first sequence-based method for protein folding type classification and its accuracy of fold rate prediction is improved over previous sequence-based methods. Its performance can be further enhanced with additional information, such as structure-based geometric contacts, as inputs. Conclusions Both the web server and software of predicting folding rate are publicly available at http://casp.rnet.missouri.edu/fold_rate/index.html. PMID:20438647

Rating the raters: assessing the quality of Hamilton rating scale for depression clinical interviews in two industry-sponsored clinical drug trials.

PubMed

Engelhardt, Nina; Feiger, Alan D; Cogger, Kenneth O; Sikich, Dawn; DeBrota, David J; Lipsitz, Joshua D; Kobak, Kenneth A; Evans, Kenneth R; Potter, William Z

2006-02-01

The quality of clinical interviews conducted in industry-sponsored clinical drug trials is an important but frequently overlooked variable that may influence the outcome of a study. We evaluated the quality of Hamilton Rating Scale for Depression (HAM-D) clinical interviews performed at baseline in 2 similar multicenter, randomized, placebo-controlled depression trials sponsored by 2 pharmaceutical companies. A total of 104 audiotaped HAM-D clinical interviews were evaluated by a blinded expert reviewer for interview quality using the Rater Applied Performance Scale (RAPS). The RAPS assesses adherence to a structured interview guide, clarification of and follow-up to patient responses, neutrality, rapport, and adequacy of information obtained. HAM-D interviews were brief and cursory and the quality of interviews was below what would be expected in a clinical drug trial. Thirty-nine percent of the interviews were conducted in 10 minutes or less, and most interviews were rated fair or unsatisfactory on most RAPS dimensions. Results from our small sample illustrate that the clinical interview skills of raters who administered the HAM-D were below what many would consider acceptable. Evaluation and training of clinical interview skills should be considered as part of a rater training program.

Intrinsic Origins of Crack Generation in Ni-rich LiNi0.8Co0.1Mn0.1O2 Layered Oxide Cathode Material

PubMed Central

Lim, Jin-Myoung; Hwang, Taesoon; Kim, Duho; Park, Min-Sik; Cho, Kyeongjae; Cho, Maenghyo

2017-01-01

Ni-rich LiNi0.8Co0.1Mn0.1O2 layered oxide cathodes have been highlighted for large-scale energy applications due to their high energy density. Although its specific capacity is enhanced at higher voltages as Ni ratio increases, its structural degradation due to phase transformations and lattice distortions during cycling becomes severe. For these reasons, we focused on the origins of crack generation from phase transformations and structural distortions in Ni-rich LiNi0.8Co0.1Mn0.1O2 using multiscale approaches, from first-principles to meso-scale phase-field model. Atomic-scale structure analysis demonstrated that opposite changes in the lattice parameters are observed until the inverse Li content x = 0.75; then, structure collapses due to complete extraction of Li from between transition metal layers. Combined-phase investigations represent the highest phase barrier and steepest chemical potential after x = 0.75, leading to phase transformations to highly Li-deficient phases with an inactive character. Abrupt phase transformations with heterogeneous structural collapse after x = 0.81 (~220 mAh g−1) were identified in the nanodomain. Further, meso-scale strain distributions show around 5% of anisotropic contraction with lower critical energy release rates, which cause not only micro-crack generations of secondary particles on the interfaces between the contracted primary particles, but also mechanical instability of primary particles from heterogeneous strain changes. PMID:28045118

The Psychometric Properties of the Invitational School Survey (ISS): An Australian Study

ERIC Educational Resources Information Center

Smith, Kenneth H.; Barnard, John

2004-01-01

This study provides psychometric data on the Inviting School Survey (Purkey & Fuller, 1995) using a rating scale analysis within the framework of the Rasch measurement philosophy (Bond & Fox, 2001; Rasch, 1980). The Inviting School Survey's factor structure and internal consistency are examined and compared with the Invitational Education…

Development of a Questionnaire Assessing School Physical Activity Environment

ERIC Educational Resources Information Center

Robertson-Wilson, Jennifer; Levesque, Lucie; Holden, Ronald R.

2007-01-01

This study was designed to develop the Questionnaire Assessing School Physical Activity Environment (Q--SPACE) based on student perceptions. Twenty-eight items rated on 4-point Likert scales were administered to 244 middle school students in 9 schools. Exploratory factor analysis was used to evaluate the underlying structure of the items and 2…

The Architecture, Dynamics, and Development of Mental Processing: Greek, Chinese, or Universal?

ERIC Educational Resources Information Center

Demetriou, A.; Kui, Z.X.; Spanoudis, G.; Christou, C.; Kyriakides, L.; Platsidou, M.

2005-01-01

This study compared Greeks with Chinese, from 8 to 14 years of age, on measures of processing efficiency, working memory, and reasoning. All processes were addressed through three domains of relations: verbal/propositional, quantitative, and visuo/spatial. Structural equations modelling and rating scale analysis showed that the architecture and…

Design Your Own Home. Courseware Evaluation for Vocational and Technical Education.

ERIC Educational Resources Information Center

Turner, Gordon; And Others

This courseware evaluation rates the Design Your Own Home program developed by Avant-Garde Publishing Company. (The program--not contained in this document--uses standard architectural scales and 126 shapes to allow creation of structural floorplans and sideviews.) Part A describes the program in terms of subject area and hardware requirements…

Confirmatory Factor Analysis on the Professional Suitability Scale for Social Work Practice

ERIC Educational Resources Information Center

Tam, Dora M. Y.; Twigg, Robert C.; Boey, Kam-Wing; Kwok, Siu-Ming

2013-01-01

Objective: This article presents a validation study to examine the factor structure of an instrument designed to measure professional suitability for social work practice. Method: Data were collected from registered social workers in a provincial mailed survey. The response rate was 23.2%. After eliminating five cases with multivariate outliers,…

The Process of Identifying Gifted Children in Elementary Education: Teachers' Evaluations of Creativity

ERIC Educational Resources Information Center

Garcia-Ros, Rafael; Talaya, Isabel; Perez-Gonzalez, Francisco

2012-01-01

This study describes the importance of creativity in the identification of gifted elementary-aged children and presents the process of validating a scale for rating the creativity of the students through the teachers' responses. The results show the instrument's unifactorial structure, satisfactory levels of internal consistency, as well as…

A Model-Based Approach for Visualizing the Dimensional Structure of Ordered Successive Categories Preference Data

ERIC Educational Resources Information Center

DeSarbo, Wayne S.; Park, Joonwook; Scott, Crystal J.

2008-01-01

A cyclical conditional maximum likelihood estimation procedure is developed for the multidimensional unfolding of two- or three-way dominance data (e.g., preference, choice, consideration) measured on ordered successive category rating scales. The technical description of the proposed model and estimation procedure are discussed, as well as the…

The Home Situations Questionnaire-PDD Version: Factor Structure and Psychometric Properties

ERIC Educational Resources Information Center

Chowdhury, M.; Aman, M. G.; Scahill, L.; Swiezy, N.; Arnold, L. E.; Lecavalier, L.; Johnson, C.; Handen, B.; Stigler, K.; Bearss, K.; Sukhodolsky, D.; McDougle, C. J.

2010-01-01

Background: The Home Situations Questionnaire (HSQ) is a caregiver-rated scale designed to assess behavioural non-compliance in everyday settings that has been used in several studies in typically developing children. Currently there is no accepted measure of behavioural non-compliance in children with pervasive developmental disorders (PDDs).…

Factors affecting length of stay in forensic hospital setting: need for therapeutic security and course of admission.

PubMed

Davoren, Mary; Byrne, Orla; O'Connell, Paul; O'Neill, Helen; O'Reilly, Ken; Kennedy, Harry G

2015-11-23

Patients admitted to a secure forensic hospital are at risk of a long hospital stay. Forensic hospital beds are a scarce and expensive resource and ability to identify the factors predicting length of stay at time of admission would be beneficial. The DUNDRUM-1 triage security scale and DUNDRUM-2 triage urgency scale are designed to assess need for therapeutic security and urgency of that need while the HCR-20 predicts risk of violence. We hypothesized that items on the DUNDRUM-1 and DUNDRUM-2 scales, rated at the time of pre-admission assessment, would predict length of stay in a medium secure forensic hospital setting. This is a prospective study. All admissions to a medium secure forensic hospital setting were collated over a 54 month period (n = 279) and followed up for a total of 66 months. Each patient was rated using the DUNDRUM-1 triage security scale and DUNDRUM-2 triage urgency scale as part of a pre-admission assessment (n = 279) and HCR-20 within 2 weeks of admission (n = 187). Episodes of harm to self, harm to others and episodes of seclusion whilst an in-patient were collated. Date of discharge was noted for each individual. Diagnosis at the time of pre-admission assessment (adjustment disorder v other diagnosis), predicted legal status (sentenced v mental health order) and items on the DUNDRUM-1 triage security scale and the DUNDRUM-2 triage urgency scale, also rated at the time of pre-admission assessment, predicted length of stay in the forensic hospital setting. Need for seclusion following admission also predicted length of stay. These findings may form the basis for a structured professional judgment instrument, rated prior to or at time of admission, to assist in estimating length of stay for forensic patients. Such a tool would be useful to clinicians, service planners and commissioners given the high cost of secure psychiatric care.

Effects of geometry and composition of soft polymer films embedded with nanoparticles on rates for optothermal heat dissipation.

PubMed

Roper, D Keith; Berry, Keith R; Dunklin, Jeremy R; Chambers, Caitlyn; Bejugam, Vinith; Forcherio, Gregory T; Lanier, Megan

2018-06-12

Embedding soft matter with nanoparticles (NPs) can provide electromagnetic tunability at sub-micron scales for a growing number of applications in healthcare, sustainable energy, and chemical processing. However, the use of NP-embedded soft material in temperature-sensitive applications has been constrained by difficulties in validating the prediction of rates for energy dissipation from thermally insulating to conducting behavior. This work improved the embedment of monodisperse NPs to stably decrease the inter-NP spacings in polydimethylsiloxane (PDMS) to nano-scale distances. Lumped-parameter and finite element analyses were refined to apportion the effects of the structure and composition of the NP-embedded soft polymer on the rates for conductive, convective, and radiative heat dissipation. These advances allowed for the rational selection of PDMS size and NP composition to optimize measured rates of internal (conductive) and external (convective and radiative) heat dissipation. Stably reducing the distance between monodisperse NPs to nano-scale intervals increased the overall heat dissipation rate by up to 29%. Refined fabrication of NP-embedded polymer enabled the tunability of the dynamic thermal response (the ratio of internal to external dissipation rate) by a factor of 3.1 to achieve a value of 0.091, the largest reported to date. Heat dissipation rates simulated a priori were consistent with 130 μm resolution thermal images across 2- to 15-fold changes in the geometry and composition of NP-PDMS. The Nusselt number was observed to increase with the fourth root of the Rayleigh number across thermally insulative and conductive regimes, further validating the approach. These developments support the model-informed design of soft media embedded with nano-scale-spaced NPs to optimize the heat dissipation rates for evolving temperature-sensitive diagnostic and therapeutic modalities, as well as emerging uses in flexible bioelectronics, cell and tissue culture, and solar-thermal heating.

Development of a novel carbon-coating strategy for producing core-shell structured carbon coated LiFePO4 for an improved Li-ion battery performance.

PubMed

Pratheeksha, Parakandy Muzhikara; Mohan, Erabhoina Hari; Sarada, Bulusu Venkata; Ramakrishna, Mantripragada; Hembram, Kalyan; Srinivas, Pulakhandam Veera Venkata; Daniel, Paul Joseph; Rao, Tata Narasinga; Anandan, Srinivasan

2016-12-21

In the present study, LiFePO 4 (LFP) has been synthesized using a flame spray pyrolysis unit followed by carbon coating on LFP using a novel strategy of dehydration assisted polymerization process (DAP) in order to improve its electronic conductivity. Characterization studies revealed the presence of a pure LFP structure and the formation of a thin, uniform and graphitic carbon layer with a thickness of 6-8 nm on the surface of the LFP. A carbon coated LFP with 3 wt% of carbon, using a DAP process, delivered a specific capacity of 167 mA h g -1 at a 0.1C rate, whereas LFP carbon coated by a carbothermal process (CLFP-C) delivered a capacity of 145 mA h g -1 at 0.1C. Further carbon coated LFP by the DAP exhibited a good rate capability and cyclic stability. The enhanced electrochemical performance of C-LFP by DAP is attributed to the presence of a uniform, thin and ordered graphitic carbon layer with a core-shell structure, which greatly increased the electronic conductivity of LFP and thereby showed an improved electro-chemical performance. Interestingly, the developed carbon coating process has been extended to synthesize a bulk quantity (0.5 kg) of carbon coated LFP under optimized experimental conditions as a part of up-scaling and the resulting material electro-chemical performance has been evaluated and compared with commercial electrode materials. Bulk C-LFP showed a capacity of 131 mA h g -1 and 87 mA h g -1 at a rate of 1C and at 10C, respectively, illustrating that the developed DAP process greatly improved the electrochemical performance of LFP in terms of rate capability and cyclic stability, not only during the lab scale synthesis but also during the large scale synthesis. Benchmark studies concluded that the electro-chemical performance of C-LFP by DAP is comparable with that of TODA LFP and better than that of UNTPL LFP. The DAP process developed in the present study can be extended to other electrode materials as well.

Molecular quenching and relaxation in a plasmonic tunable system

NASA Astrophysics Data System (ADS)

Baffou, Guillaume; Girard, Christian; Dujardin, Erik; Colas Des Francs, Gérard; Martin, Olivier J. F.

2008-03-01

Molecular fluorescence decay is significantly modified when the emitting molecule is located near a plasmonic structure. When the lateral sizes of such structures are reduced to nanometer-scale cross sections, they can be used to accurately control and amplify the emission rate. In this Rapid Communication, we extend Green’s dyadic method to quantitatively investigate both radiative and nonradiative decay channels experienced by a single fluorescent molecule confined in an adjustable dielectric-metal nanogap. The technique produces data in excellent agreement with current experimental work.

Partial validation of a French version of the ADHD-rating scale IV on a French population of children with ADHD and epilepsy. Factorial structure, reliability, and responsiveness.

PubMed

Mercier, Catherine; Roche, Sylvain; Gaillard, Ségolène; Kassai, Behrouz; Arzimanoglou, Alexis; Herbillon, Vania; Roy, Pascal; Rheims, Sylvain

2016-05-01

Attention deficit hyperactivity disorder (ADHD) is a well-known comorbidity in children with epilepsy. In English-speaking countries, the scores of the original ADHD-rating scale IV are currently used as main outcomes in various clinical trials in children with epilepsy. In French-speaking countries, several French versions are in use though none has been fully validated yet. We sought here for a partial validation of a French version of the ADHD-RS IV regarding construct validity, internal consistency (i.e., scale reliability), item reliability, and responsiveness in a group of French children with ADHD and epilepsy. The study involved 167 children aged 6-15years in 10 French neuropediatric units. The factorial structure and item reliability were assessed with a confirmatory factorial analysis for ordered categorical variables. The dimensions' internal consistency was assessed with Guttman's lambda 6 coefficient. The responsiveness was assessed by the change in score under methylphenidate and in comparison with a control group. The results confirmed the original two-dimensional factorial structure (inattention, hyperactivity/impulsivity) and showed a satisfactory reliability of most items, a good dimension internal consistency, and a good responsiveness of the total score and the two subscores. The studied French version of the ADHD-RS IV is thus validated regarding construct validity, reliability, and responsiveness. It can now be used in French-speaking countries in clinical trials of treatments involving children with ADHD and epilepsy. The full validation requires further investigations. Copyright © 2016 Elsevier Inc. All rights reserved.

Imprints of the large-scale structure on AGN formation and evolution

NASA Astrophysics Data System (ADS)

Porqueres, Natàlia; Jasche, Jens; Enßlin, Torsten A.; Lavaux, Guilhem

2018-04-01

Black hole masses are found to correlate with several global properties of their host galaxies, suggesting that black holes and galaxies have an intertwined evolution and that active galactic nuclei (AGN) have a significant impact on galaxy evolution. Since the large-scale environment can also affect AGN, this work studies how their formation and properties depend on the environment. We have used a reconstructed three-dimensional high-resolution density field obtained from a Bayesian large-scale structure reconstruction method applied to the 2M++ galaxy sample. A web-type classification relying on the shear tensor is used to identify different structures on the cosmic web, defining voids, sheets, filaments, and clusters. We confirm that the environmental density affects the AGN formation and their properties. We found that the AGN abundance is equivalent to the galaxy abundance, indicating that active and inactive galaxies reside in similar dark matter halos. However, occurrence rates are different for each spectral type and accretion rate. These differences are consistent with the AGN evolutionary sequence suggested by previous authors, Seyferts and Transition objects transforming into low-ionization nuclear emission line regions (LINERs), the weaker counterpart of Seyferts. We conclude that AGN properties depend on the environmental density more than on the web-type. More powerful starbursts and younger stellar populations are found in high densities, where interactions and mergers are more likely. AGN hosts show smaller masses in clusters for Seyferts and Transition objects, which might be due to gas stripping. In voids, the AGN population is dominated by the most massive galaxy hosts.

High throughput platforms for structural genomics of integral membrane proteins.

PubMed

Mancia, Filippo; Love, James

2011-08-01

Structural genomics approaches on integral membrane proteins have been postulated for over a decade, yet specific efforts are lagging years behind their soluble counterparts. Indeed, high throughput methodologies for production and characterization of prokaryotic integral membrane proteins are only now emerging, while large-scale efforts for eukaryotic ones are still in their infancy. Presented here is a review of recent literature on actively ongoing structural genomics of membrane protein initiatives, with a focus on those aimed at implementing interesting techniques aimed at increasing our rate of success for this class of macromolecules. Copyright © 2011 Elsevier Ltd. All rights reserved.

Shockwave dynamics: a comparison between stochastic and periodic porous architectures

NASA Astrophysics Data System (ADS)

Branch, Brittany; Ionite, Axinte; Clements, Bradford; Montgomery, David; Schmalzer, Andrew; Patterson, Brian; Mueller, Alexander; Jensen, Brian; Dattelbaum, Dana

Polymeric foams are used extensively as structural supports and load mitigating materials in which they are subjected to compressive loading at a range of strain rates, up to the high strain rates encountered in blast and shockwave loading. To date, there have been few insights into compaction phenomena in porous structures at the mesoscale, and the influence of structure on shockwave localization. Of particular interest is when the properties of the inherent mesoscopic, periodic structure begin to emerge, versus the discrete behavior of the individual cell. Here, we illustrate, for the first time, modulation of shockwave dynamics controlled at micron-length scales in additively manufactured periodic porous structures measured using in situ, time-resolved x-ray phase contrast imaging at the Advanced Photon Source. Further, we demonstrate how the shockwave dynamics in periodic structures differ from stochastic foams of similar density and we conclude that microstructural control in elastomer foams has a dramatic effect on shockwave dynamics and can be tailored towards a variety of applications. Laboratory Directed Research and Development (LDRD) program at Los Alamos National Laboratory (project# 20160103DR) and DOE/NNSA Campaign 2.

Predictors and Effects of Knowledge Management in U.S. Colleges and Schools of Pharmacy

NASA Astrophysics Data System (ADS)

Watcharadamrongkun, Suntaree

Public demands for accountability in higher education have placed increasing pressure on institutions to document their achievement of critical outcomes. These demands also have had wide-reaching implications for the development and enforcement of accreditation standards, including those governing pharmacy education. The knowledge management (KM) framework provides perspective for understanding how organizations evaluate themselves and guidance for how to improve their performance. In this study, we explore knowledge management processes, how these processes are affected by organizational structure and by information technology resources, and how these processes affect organizational performance. This is done in the context of Accreditation Standards and Guidelines for the Professional Program in Pharmacy Leading to the Doctor of Pharmacy Degree (Standards 2007). Data were collected using an online census survey of 121 U.S. Colleges and Schools of Pharmacy and supplemented with archival data. A key informant method was used with CEO Deans and Assessment leaders serving as respondents. The survey yielded a 76.0% (92/121) response rate. Exploratory factor analysis was used to construct scales (and scales) describing core KM processes: Knowledge Acquisition, Knowledge Integration, and Institutionalization; all scale reliabilities were found to be acceptable. Analysis showed that, as expected, greater Knowledge Acquisition predicts greater Knowledge Integration and greater Knowledge Integration predicts greater Institutionalization. Predictive models were constructed using hierarchical multiple regression and path analysis. Overall, information technology resources had stronger effects on KM processes than did characteristics of organizational structure. Greater Institutionalization predicted better outcomes related to direct measures of performance (i.e., NAPLEX pass rates, Accreditation actions) but Institutionalization was unrelated to an indirect measure of performance (i.e., USNWR ratings). Several organizational structure characteristics (i.e., size, age, and being part of an academic health center) were significant predictors of organizational performance; in contrast, IT resources had no direct effects on performance. Findings suggest that knowledge management processes, organizational structures and IT resources are related to better performance for Colleges and Schools of Pharmacy. Further research is needed to understand mechanisms through which specific knowledge management processes translate into better performance and, relatedly, to establish how enhancing KM processes can be used to improve institutional quality.

[Acceptance and understandability of various methods of health valuations for the chronically ill: willingness to pay, visual analogue scale and rating scale].

PubMed

Meder, M; Farin, E

2009-11-01

Health valuations are one way of measuring patient preferences with respect to the results of their treatment. The study examines three different methods of health valuations--willingness to pay (WTP), visual analogue scale (VAS), and a rating question for evaluating the subjective significance. The goal is to test the understandability and acceptance of these methods for implementation in questionnaires. In various rehabilitation centres, a total of six focus groups were conducted with 5-9 patients each with a mean age of 57.1 years. The illnesses considered were chronic-ischaemic heart disease, chronic back pain, and breast cancer. Patients filled out a questionnaire that was then discussed in the group. In addition to the quantitative evaluation of the data in the questionnaire, a qualitative analysis of the contents of the group discussion protocols was made. We have results from a total of 42 patients. 14.6% of the patients had "great difficulties" understanding the WTP or rated it as "completely incomprehensible"; this value was 7.3% for VAS and 0% for the rating scale. With respect to acceptance, 31.0% of the patients indicated that they were "not really" or "not at all" willing to answer such a WTP question in a questionnaire; this was 6.6% for the VAS, and again 0% for the rating scale. The qualitative analysis provided an indication as to why some patients view the WTP question in particular in a negative light. Many difficulties in understanding it were related to the formulation of the question and the structure of the questionnaire. However, the patients' statements also made it apparent that the hypothetical nature of the WTP questionnaire was not always recognised. The most frequent reason for the lack of acceptance of the WTP was the patients' fear of negative financial consequences of their responses. With respect to understandability and acceptance, VAS questions appear to be better suited for reflecting patient preferences than WTP questions. The rating scale for assessing the personally estimated importance was understandable, but had poor distribution properties and was considered by patients to be superfluous.

Up-Scaling Geochemical Reaction Rates for Carbon Dioxide (CO2) in Deep Saline Aquifers

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

Peters, Catherine A

2013-02-28

Geochemical reactions in deep subsurface environments are complicated by the consolidated nature and mineralogical complexity of sedimentary rocks. Understanding the kinetics of these reactions is critical to our ability to make long-term predictions about subsurface processes such as pH buffering, alteration in rock structure, permeability changes, and formation of secondary precipitates. In this project, we used a combination of experiments and numerical simulation to bridge the gap between our knowledge of these reactions at the lab scale and rates that are meaningful for modeling reactive transport at core scales. The focus is on acid-driven mineral dissolution, which is specifically relevantmore » in the context of CO2-water-rock interactions in geological sequestration of carbon dioxide. The project led to major findings in three areas. First, we modeled reactive transport in pore-network systems to investigate scaling effects in geochemical reaction rates. We found significant scaling effects when CO2 concentrations are high and reaction rates are fast. These findings indicate that the increased acidity associated with geological sequestration can generate conditions for which proper scaling tools are yet to be developed. Second, we used mathematical modeling to investigate the extent to which SO2, if co-injected with CO2, would acidify formation brines. We found that there exist realistic conditions in which the impact on brine acidity will be limited due to diffusion rate-limited SO2 dissolution from the CO2 phase, and the subsequent pH shift may also be limited by the lack of availability of oxidants to produce sulfuric acid. Third, for three Viking sandstones (Alberta sedimentary basin, Canada), we employed backscattered electron microscopy and energy dispersive X-ray spectroscopy to statistically characterize mineral contact with pore space. We determined that for reactive minerals in sedimentary consolidated rocks, abundance alone is not a good predictor of mineral accessible surface area, and should not be used in reactive transport modeling. Our work showed that reaction rates would be overestimated by three to five times.« less

Not Fully Developed Turbulence in the Dow Jones Index

NASA Astrophysics Data System (ADS)

Trincado, Estrella; Vindel, Jose María

2013-08-01

The shape of the curves relating the scaling exponents of the structure functions to the order of these functions is shown to distinguish the Dow Jones index from other stock market indices. We conclude from the shape differences that the information-loss rate for the Dow Jones index is reduced at smaller time scales, while it grows for other indices. This anomaly is due to the construction of the index, in particular to its dependence on a single market parameter: price. Prices are subject to turbulence bursts, which act against full development of turbulence.

Detecting structural variances of Co 3O 4 catalysts by controlling beam-induced sample alterations in the vacuum of a transmission electron microscope

DOE PAGES

Kisielowski, C.; Frei, H.; Specht, P.; ...

2016-11-02

This article summarizes core aspects of beam-sample interactions in research that aims at exploiting the ability to detect single atoms at atomic resolution by mid-voltage transmission electron microscopy. Investigating the atomic structure of catalytic Co 3O 4 nanocrystals underscores how indispensable it is to rigorously control electron dose rates and total doses to understand native material properties on this scale. We apply in-line holography with variable dose rates to achieve this goal. Genuine object structures can be maintained if dose rates below ~100 e/Å 2s are used and the contrast required for detection of single atoms is generated by capturing largemore » image series. Threshold doses for the detection of single atoms are estimated. An increase of electron dose rates and total doses to common values for high resolution imaging of solids stimulates object excitations that restructure surfaces, interfaces, and defects and cause grain reorientation or growth. We observe a variety of previously unknown atom configurations in surface proximity of the Co 3O 4 spinel structure. These are hidden behind broadened diffraction patterns in reciprocal space but become visible in real space by solving the phase problem. Finallly, an exposure of the Co 3O 4 spinel structure to water vapor or other gases induces drastic structure alterations that can be captured in this manner.« less

Developing strong concurrent multiphysics multiscale coupling to understand the impact of microstructural mechanisms on the structural scale

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

Foulk, James W.; Alleman, Coleman N.; Mota, Alejandro

The heterogeneity in mechanical fields introduced by microstructure plays a critical role in the localization of deformation. To resolve this incipient stage of failure, it is therefore necessary to incorporate microstructure with sufficient resolution. On the other hand, computational limitations make it infeasible to represent the microstructure in the entire domain at the component scale. In this study, the authors demonstrate the use of concurrent multi- scale modeling to incorporate explicit, finely resolved microstructure in a critical region while resolving the smoother mechanical fields outside this region with a coarser discretization to limit computational cost. The microstructural physics is modeledmore » with a high-fidelity model that incorporates anisotropic crystal elasticity and rate-dependent crystal plasticity to simulate the behavior of a stainless steel alloy. The component-scale material behavior is treated with a lower fidelity model incorporating isotropic linear elasticity and rate-independent J 2 plas- ticity. The microstructural and component scale subdomains are modeled concurrently, with coupling via the Schwarz alternating method, which solves boundary-value problems in each subdomain separately and transfers solution information between subdomains via Dirichlet boundary conditions. Beyond cases studies in concurrent multiscale, we explore progress in crystal plastic- ity through modular designs, solution methodologies, model verification, and extensions to Sierra/SM and manycore applications. Advances in conformal microstructures having both hexahedral and tetrahedral workflows in Sculpt and Cubit are highlighted. A structure-property case study in two-phase metallic composites applies the Materials Knowledge System to local metrics for void evolution. Discussion includes lessons learned, future work, and a summary of funded efforts and proposed work. Finally, an appendix illustrates the need for two-way coupling through a single degree of freedom.« less

The influence of surface roughness on volatile transport on the Moon

NASA Astrophysics Data System (ADS)

Prem, P.; Goldstein, D. B.; Varghese, P. L.; Trafton, L. M.

2018-01-01

The Moon and other virtually airless bodies provide distinctive environments for the transport and sequestration of water and other volatiles delivered to their surfaces by various sources. In this work, we conduct Monte Carlo simulations of water vapor transport on the Moon to investigate the role of small-scale roughness (unresolved by orbital measurements) in the migration and cold-trapping of volatiles. Observations indicate that surface roughness, combined with the insulating nature of lunar regolith and the absence of significant exospheric heat flow, can cause large variations in temperature over very small scales. Surface temperature has a strong influence on the residence time of migrating water molecules on the lunar surface, which in turn affects the rate and magnitude of volatile transport to permanently shadowed craters (cold traps) near the lunar poles, as well as exospheric structure and the susceptibility of migrating molecules to photodestruction. Here, we develop a stochastic rough surface temperature model suitable for simulations of volatile transport on a global scale, and compare the results of Monte Carlo simulations of volatile transport with and without the surface roughness model. We find that including small-scale temperature variations and shadowing leads to a slight increase in cold-trapping at the lunar poles, accompanied by a slight decrease in photodestruction. Exospheric structure is altered only slightly, primarily at the dawn terminator. We also examine the sensitivity of our results to the temperature of small-scale shadows, and the energetics of water molecule desorption from the lunar regolith - two factors that remain to be definitively constrained by other methods - and find that both these factors affect the rate at which cold trap capture and photodissociation occur, as well as exospheric density and longevity.

Validity of personality measurement in adults with anxiety disorders: psychometric properties of the Spanish NEO-FFI-R using Rasch analyses

PubMed Central

Inchausti, Felix; Mole, Joe; Fonseca-Pedrero, Eduardo; Ortuño-Sierra, Javier

2015-01-01

The aim of this study was to analyse the psychometric properties of the Spanish NEO Five Factor Inventory–Revised (NEO-FFI-R) using Rasch analyses, in order to test its rating scale functioning, the reliability of scores, internal structure, and differential item functioning (DIF) by gender in a psychiatric sample. The NEO-FFI-R responses of 433 Spanish adults (154 males) with an anxiety disorder as primary diagnosis were analysed using the Rasch model for rating scales. Two intermediate categories of response (‘neutral’ and ‘agree’) malfunctioned in the Neuroticism and Conscientiousness scales. In addition, model reliabilities were lower than expected in Agreeableness and Neuroticism, and the item fit values indicated each scale had items that did not achieve moderate to high discrimination on its dimension, particularly in the Agreeableness scale. Concerning unidimensionality, the five NEO-FFI-R scales showed large first components of unexplained variance. Finally, DIF by gender was detected in many items. The results suggest that the scores of the Spanish NEO-FFI-R are unreliable in psychiatric samples and cannot be generalized between males and females, especially in the Openness, Conscientiousness, and Agreeableness scales. Future directions for testing and refinement should be developed before the NEO-FFI-R can be used reliably in clinical samples. PMID:25954224

Psychometrics of the preschool behavioral and emotional rating scale with children from early childhood special education settings.

PubMed

Lambert, Matthew C; Cress, Cynthia J; Epstein, Michael H

2015-01-01

In a previous study with a nationally representative sample, researchers found that the items of the Preschool Behavioral and Emotional Rating Scale can best be described by a four-factor structure model (Emotional Regulation, School Readiness, Social Confidence, and Family Involvement). The findings of this investigation replicate and extend these previous results with a national sample of children (N = 1,075) with disabilities enrolled in early childhood special education programs. Data were analyzed using classical tests theory, Rasch modeling, and confirmatory factor analysis. Results confirmed that for the most part, individual items were internally consistent within a four-factor model and showed consistent item difficulty, discrimination, and fit relative to their respective subscale scores. © 2015 Michigan Association for Infant Mental Health.

The evolutionary origin of feathers.

PubMed

Regal, P J

1975-03-01

Previous theories relating the origin of feathers to flight or to heat conservation are considered to be inadequate. There is need for a model of feather evolution that gives attention to the function and adaptive advantage of intermediate structures. The present model attempts to reveal and to deal with, the spectrum of complex questions that must be considered. In several genera of modern lizards, scales are elongated in warm climates. It is argued that these scales act as small shields to solar radiation. Experiments are reported that tend to confirm this. Using lizards as a conceptual model, it is argued that feathers likewise arose as adaptations to intense solar radiation. Elongated scales are assumed to have subdivided into finely branched structures that produced a heat-shield, flexible as well as long and broad. Associated muscles had the function of allowing the organism fine control over rates of heat gain and loss: the specialized scales or early feathers could be moved to allow basking in cool weather or protection in hot weather. Subdivision of the scales also allowed a close fit between the elements of the insulative integument. There would have been mechanical and thermal advantages to having branches that interlocked into a pennaceous structure early in evolution, so the first feathers may have been pennaceous. A versatile insulation of movable, branched scales would have been a preadaptation for endothermy. As birds took to the air they faced cooling problems despite their insulative covering because of high convective heat loss. Short glides may have initially been advantageous in cooling an animal under heat stress, but at some point the problem may have shifted from one of heat exclusion to one of heat retention. Endothermy probably evolved in conjunction with flight. If so, it is an unnecessary assumption to postulate that the climate cooled and made endothermy advantageous. The development of feathers is complex and a model is proposed that gives attention to the fundamental problems of deriving a branched structure with a cylindrical base from an elongated scale.

Sensitivity and specificity of the Geriatric Anxiety Inventory and the Hospital Anxiety and Depression Scale in the detection of anxiety disorders in older people with chronic obstructive pulmonary disease.

PubMed

Cheung, Gary; Patrick, Colin; Sullivan, Glenda; Cooray, Manisha; Chang, Catherina L

2012-01-01

Anxiety and depression are prevalent in patients with chronic obstructive pulmonary disease (COPD). This study evaluates the sensitivity and specificity of two self-administered anxiety rating scales in older people with COPD. The Geriatric Anxiety Inventory (GAI) and the Hospital Anxiety and Depression Scale (HADS) are established useful screening tools but they have not been previously validated in this population. Older people with COPD completed the GAI and the HADS along with a structured diagnostic psychiatric interview, the Mini International Neuropsychiatric Interview (MINI). The outcomes of both rating scales were compared against the diagnosis of anxiety disorders based on the MINI. Receiver operating characteristic (ROC) curves were used to identify the optimal diagnostic cut points for each scale. Fourteen (25.5%) of the 55 participants, were diagnosed with an anxiety disorder. Mean GAI and HADS-anxiety subscale scores were significantly higher in subjects with an anxiety disorder than those without the diagnosis (p = 0.002 and 0.005 respectively). Both scales demonstrated moderate diagnostic value (area under the ROC curve was 0.83 for GAI and 0.79 for HADS). Optimal cut points were ≥3 (GAI) and ≥4 (HADS-anxiety subscale). At these cut-points, the GAI had a sensitivity of 85.7%, specificity of 78.0% and the HADS had a sensitivity of 78.6%, specificity 70.7%. Our results support the use of the GAI and HADS as screening instruments for anxiety disorders in older people with COPD. The optimal cut points in this population were lower than previously recommended for both rating scales. The results of this study should be replicated before these cut points can be recommended for general use in older people with COPD.

Developing a short measure of organizational justice: a multisample health professionals study.

PubMed

Elovainio, Marko; Heponiemi, Tarja; Kuusio, Hannamaria; Sinervo, Timo; Hintsa, Taina; Aalto, Anna-Mari

2010-11-01

To develop and test the validity of a short version of the original questionnaire measuring organizational justice. The study samples comprised working physicians (N = 2792) and registered nurses (n = 2137) from the Finnish Health Professionals study. Structural equation modelling was applied to test structural validity, using the justice scales. Furthermore, criterion validity was explored with well-being (sleeping problems) and health indicators (psychological distress/self-rated health). The short version of the organizational justice questionnaire (eight items) provides satisfactory psychometric properties (internal consistency, a good model fit of the data). All scales were associated with an increased risk of sleeping problems and psychological distress, indicating satisfactory criterion validity. This short version of the organizational justice questionnaire provides a useful tool for epidemiological studies focused on health-adverse effects of work environment.

A new respirometric endpoint-based biosensor to assess the relative toxicity of chemicals on immobilized human cells.

PubMed

Dragone, Roberto; Frazzoli, Chiara; Grappelli, Claudio; Campanella, Luigi

2009-01-01

Several functional and biochemical parameters have been proposed as biomarkers of effect of environmental pollutants. A rapid biosensor working with immobilized human U-937 cells was developed and applied to environmentally relevant chemicals with different structures and toxicological pathways, i.e. benzalkonium chloride, clofibric acid, diclofenac, mercury nitrate, ofloxacin, and sodium dodecyl sulphate. Respiration of cells was relied upon as a comprehensive biochemical effect for screening purposes. Analytical parameter (DeltappmO(2)) and toxicological index (respiratory inhibition, delta%) measured after 1h of exposure were utilized for dose-response relationship study. Results (toxicity rating scales based on delta(50)% and steepness) were compared with those obtained by the same approach previously optimized on Saccharomyces cerevisiae. The toxicity rating scale obtained by the biomarker based on human mitochondrial and cell metabolic activities compared well with previous scale obtained on yeast cells and with available in-vivo acute toxicity indexes; respiration was confirmed as toxicological endpoint reliably measurable by the biosensor.

Introduction: demography and cultural macroevolution.

PubMed

Steele, James; Shennan, Stephen

2009-04-01

The papers in this special issue of Human Biology, which derive from a conference sponsored by the Arts and Humanities Research Council (AHRC) Center for the Evolution of Cultural Diversity, lay some of the foundations for an empirical macroevolutionary analysis of cultural dynamics. Our premise here is that cultural dynamics-including the stability of traditions and the rate of origination of new variants-are influenced by independently occurring demographic processes (population size, structure, and distribution as these vary over time as a result of changes in rates of fertility, mortality, and migration). The contributors focus on three sets of problems relevant to empirical studies of cultural macroevolution: large-scale reconstruction of past population dynamics from archaeological and genetic data; juxtaposition of models and evidence of cultural dynamics using large-scale archaeological and historical data sets; and juxtaposition of models and evidence of cultural dynamics from large-scale linguistic data sets. In this introduction we outline some of the theoretical and methodological issues and briefly summarize the individual contributions.

Resolving the fine-scale structure in turbulent Rayleigh-Benard convection

NASA Astrophysics Data System (ADS)

Scheel, Janet; Emran, Mohammad; Schumacher, Joerg

2013-11-01

Results from high-resolution direct numerical simulations of turbulent Rayleigh-Benard convection in a cylindrical cell with an aspect ratio of one will be presented. We focus on the finest scales of convective turbulence, in particular the statistics of the kinetic energy and thermal dissipation rates in the bulk and the whole cell. These dissipation rates as well as the local dissipation scales are compared for different Rayleigh and Prandtl numbers. We also have investigated the convergence properties of our spectral element method and have found that both dissipation fields are very sensitive to insufficient resolution. We also demonstrate that global transport properties, such as the Nusselt number and the energy balances, are partly insensitive to insufficient resolution and yield consistent results even when the dissipation fields are under-resolved. Our present numerical framework is also compared with high-resolution simulations which use a finite difference method. For most of the compared quantities the agreement is found to be satisfactory.

Preliminary Validation of a New Measure of Negative Response Bias: The Temporal Memory Sequence Test.

PubMed

Hegedish, Omer; Kivilis, Naama; Hoofien, Dan

2015-01-01

The Temporal Memory Sequence Test (TMST) is a new measure of negative response bias (NRB) that was developed to enrich the forced-choice paradigm. The TMST does not resemble the common structure of forced-choice tests and is presented as a temporal recall memory test. The validation sample consisted of 81 participants: 21 healthy control participants, 20 coached simulators, and 40 patients with acquired brain injury (ABI). The TMST had high reliability and significantly high positive correlations with the Test of Memory Malingering and Word Memory Test effort scales. Moreover, the TMST effort scales exhibited high negative correlations with the Glasgow Coma Scale, thus validating the previously reported association between probable malingering and mild traumatic brain injury. A suggested cutoff score yielded acceptable classification rates in the ABI group as well as in the simulator and control groups. The TMST appears to be a promising measure of NRB detection, with respectable rates of reliability and construct and criterion validity.

Reusable Launch Vehicle Control in Multiple Time Scale Sliding Modes

NASA Technical Reports Server (NTRS)

Shtessel, Yuri

1999-01-01

A reusable launch vehicle control problem during ascent is addressed via multiple-time scaled continuous sliding mode control. The proposed sliding mode controller utilizes a two-loop structure and provides robust, de-coupled tracking of both orientation angle command profiles and angular rate command profiles in the presence of bounded external disturbances and plant uncertainties. Sliding mode control causes the angular rate and orientation angle tracking error dynamics to be constrained to linear, de-coupled, homogeneous, and vector valued differential equations with desired eigenvalues placement. The dual-time scale sliding mode controller was designed for the X-33 technology demonstration sub-orbital launch vehicle in the launch mode. 6DOF simulation results show that the designed controller provides robust, accurate, de-coupled tracking of the orientation angle command profiles in presence of external disturbances and vehicle inertia uncertainties. It creates possibility to operate the X-33 vehicle in an aircraft-like mode with reduced pre-launch adjustment of the control system.

Hyperviscosity for unstructured ALE meshes

NASA Astrophysics Data System (ADS)

Cook, Andrew W.; Ulitsky, Mark S.; Miller, Douglas S.

2013-01-01

An artificial viscosity, originally designed for Eulerian schemes, is adapted for use in arbitrary Lagrangian-Eulerian simulations. Changes to the Eulerian model (dubbed 'hyperviscosity') are discussed, which enable it to work within a Lagrangian framework. New features include a velocity-weighted grid scale and a generalised filtering procedure, applicable to either structured or unstructured grids. The model employs an artificial shear viscosity for treating small-scale vorticity and an artificial bulk viscosity for shock capturing. The model is based on the Navier-Stokes form of the viscous stress tensor, including the diagonal rate-of-expansion tensor. A second-order version of the model is presented, in which Laplacian operators act on the velocity divergence and the grid-weighted strain-rate magnitude to ensure that the velocity field remains smooth at the grid scale. Unlike sound-speed-based artificial viscosities, the hyperviscosity model is compatible with the low Mach number limit. The new model outperforms a commonly used Lagrangian artificial viscosity on a variety of test problems.

Self-esteem mediates the effect of the parent-adolescent relationship on depression.

PubMed

Hu, Junmin; Ai, Hongshan

2016-06-01

There is a trend of rapid growth in both the level and occurrence of depression when people reach adolescence. The present study aimed to investigate the impact of the parent-adolescent relationship on depression in adolescents, and mainly focused on the confirmation of the mediator role of self-esteem. A total of 364 senior middle school students accomplished the Parent-Adolescent Relationship Scale, Rosenberg Self-Esteem Scale, and Zung Self-Rating Depression Scale. The results suggested that both parent-adolescent relationship and self-esteem were significantly correlated with depression. Structural equation modeling indicated that self-esteem partially mediated the relationship between parent-adolescent relationship and depression. © The Author(s) 2014.

Dispersal and population structure at different spatial scales in the subterranean rodent Ctenomys australis

PubMed Central

2010-01-01

Background The population genetic structure of subterranean rodent species is strongly affected by demographic (e.g. rates of dispersal and social structure) and stochastic factors (e.g. random genetic drift among subpopulations and habitat fragmentation). In particular, gene flow estimates at different spatial scales are essential to understand genetic differentiation among populations of a species living in a highly fragmented landscape. Ctenomys australis (the sand dune tuco-tuco) is a territorial subterranean rodent that inhabits a relatively secure, permanently sealed burrow system, occurring in sand dune habitats on the coastal landscape in the south-east of Buenos Aires province, Argentina. Currently, this habitat is threatened by urban development and forestry and, therefore, the survival of this endemic species is at risk. Here, we assess population genetic structure and patterns of dispersal among individuals of this species at different spatial scales using 8 polymorphic microsatellite loci. Furthermore, we evaluate the relative importance of sex and habitat configuration in modulating the dispersal patterns at these geographical scales. Results Our results show that dispersal in C. australis is not restricted at regional spatial scales (~ 4 km). Assignment tests revealed significant population substructure within the study area, providing support for the presence of two subpopulations from three original sampling sites. Finally, male-biased dispersal was found in the Western side of our study area, but in the Eastern side no apparent philopatric pattern was found, suggesting that in a more continuous habitat males might move longer distances than females. Conclusions Overall, the assignment-based approaches were able to detect population substructure at fine geographical scales. Additionally, the maintenance of a significant genetic structure at regional (~ 4 km) and small (less than 1 km) spatial scales despite apparently moderate to high levels of gene flow between local sampling sites could not be explained simply by the linear distance among them. On the whole, our results support the hypothesis that males disperse more frequently than females; however they do not provide support for strict philopatry within females. PMID:20109219

Vaccination intervention on epidemic dynamics in networks

NASA Astrophysics Data System (ADS)

Peng, Xiao-Long; Xu, Xin-Jian; Fu, Xinchu; Zhou, Tao

2013-02-01

Vaccination is an important measure available for preventing or reducing the spread of infectious diseases. In this paper, an epidemic model including susceptible, infected, and imperfectly vaccinated compartments is studied on Watts-Strogatz small-world, Barabási-Albert scale-free, and random scale-free networks. The epidemic threshold and prevalence are analyzed. For small-world networks, the effective vaccination intervention is suggested and its influence on the threshold and prevalence is analyzed. For scale-free networks, the threshold is found to be strongly dependent both on the effective vaccination rate and on the connectivity distribution. Moreover, so long as vaccination is effective, it can linearly decrease the epidemic prevalence in small-world networks, whereas for scale-free networks it acts exponentially. These results can help in adopting pragmatic treatment upon diseases in structured populations.

Scaling behavior of nonisothermal phase separation.

PubMed

Rüllmann, Max; Alig, Ingo

2004-04-22

The phase separation process in a critical mixture of polydimethylsiloxane and polyethylmethylsiloxane (PDMS/PEMS, a system with an upper critical solution temperature) was investigated by time-resolved light scattering during continuous quenches from the one-phase into the two-phase region. Continuous quenches were realized by cooling ramps with different cooling rates kappa. Phase separation kinetics is studied by means of the temporal evolution of the scattering vector qm and the intensity Im at the scattering peak. The curves qm(t) for different cooling rates can be shifted onto a single mastercurve. The curves Im(t) show similar behavior. As shift factors, a characteristic length Lc and a characteristic time tc are introduced. Both characteristic quantities depend on the cooling rate through power laws: Lc approximately kappa(-delta) and tc approximately kappa(-rho). Scaling behavior in isothermal critical demixing is well known. There the temporal evolutions of qm and Im for different quench depths DeltaT can be scaled with the correlation length xi and the interdiffusion coefficient D, both depending on DeltaT through critical power laws. We show in this paper that the cooling rate scaling in nonisothermal demixing is a consequence of the quench depth scaling in the isothermal case. The exponents delta and rho are related to the critical exponents nu and nu* of xi and D, respectively. The structure growth during nonisothermal demixing can be described with a semiempirical model based on the hydrodynamic coarsening mechanism well known in the isothermal case. In very late stages of nonisothermal phase separation a secondary scattering maximum appears. This is due to secondary demixing. We explain the onset of secondary demixing by a competition between interdiffusion and coarsening. (c) 2004 American Institute of Physics

Development of a clinician-administered National Institutes of Health-Brief Fatigue Inventory: A measure of fatigue in the context of depressive disorders.

PubMed

Saligan, Leorey N; Luckenbaugh, David A; Slonena, Elizabeth E; Machado-Vieira, Rodrigo; Zarate, Carlos A

2015-09-01

Fatigue is a complex, multidimensional condition. Although it is often associated with depression, it is not known whether it has a distinct network from depression or whether it can be clinically evaluated, separately. This study describes preliminary findings in the development of a brief, clinician-administered instrument to measure fatigue in the context of depressive disorders using items from existing clinician-administered depression and mania scales. Based on items from prior fatigue measurements, items were selected from the Hamilton Depression Rating Scale (HDRS), Montgomery-Asberg Depression Rating Scale (MADRS), Young Mania Rating Scale, and Structured Interview Guide for HDRS with Atypical Depression. The final items composed the NIH-Brief Fatigue Inventory (NIH-BFI). Responses from 89 depressed adults collected pre- and post-antidepressant therapy (ADT) determined the reliability and consistency of the NIH-BFI using Cronbach's alpha and principal components analysis (PCA). Correlations of the NIH-BFI and fatigue items from other scales before and after ADT explored validity. The 7-item NIH-BFI had Cronbach alphas ranging from 0.81 to 0.88 and PCA indicating a single dimension. The NIH-BFI score was strongly correlated (r = 0.73, p < 0.001) with fatigue items from Beck Depression Index, with MADRS without fatigue items (r = 0.77, p < 0.001), and HDRS without fatigue items (pre: r = 0.69, p < 0.001). Preliminary findings show support for internal consistency reliability and validity of the NIH-BFI, a clinician-administered measure of fatigue. Further testing in other clinical populations is recommended to obtain additional information on reliability and validity. The NIH-BFI provides a method for clinician-rated fatigue that may be a separate from depression. Published by Elsevier Ltd.

Structures of microbial communities found in anaerobic batch runs that produce methane from propionic acid--Seeded from full-scale anaerobic digesters above a certain threshold.

PubMed

Kim, Woong; Shin, Seung Gu; Han, Gyuseong; Cho, Kyungjin; Hwang, Seokhwan

2015-11-20

The volatile fatty acid propionate inhibits anaerobic digestion during organic waste treatments. To examine potential microbial interactions that accelerate propionate oxidation, anaerobic digestion systems seeded with various types of anaerobic sludge were analyzed. Seed samples were collected from 10 different full-scale anaerobic reactors in South Korea. Propionate oxidation was estimated as the methane production rate per gram of propionate used per day. Two domestic sewage sludge showed the highest methane production rate values, 109.1 ± 4.2 and 74.5 ± 8.6 mL CH4/(g propionate ∙ d). A food waste recycling wastewater source exhibited the lowest methane production rate, 33.2 ± 2.6 mL CH4/(g propionate ∙ d). To investigate how the microbial community structure affected propionate oxidation, qualitative molecular analyses were carried out using denaturing gradient gel electrophoresis. Methanosaeta concilii, an aceticlastic methanogen, was detected in most batch runs. Smithella propionica, a unique propionate oxidizer and simultaneous producer of acetate, was found in domestic sewage sludge sources showing the highest methane production rate; in contrast, Desulfobulbus rhabdoformis, a sulfate reducer coupled with the consumption of acetate to be used as a precursor of methane, was observed in food waste recycling wastewater sludge source showing the lowest methane production rate. Thus, we propose that S. propionica, a syntrophic acetate producer using propionate, might cooperate with aceticlastic methanogens for high methane production during anaerobic digestion that included propionate. Copyright © 2015 Elsevier B.V. All rights reserved.

Structured reports of videofluoroscopic swallowing studies have the potential to improve overall report quality compared to free text reports.

PubMed

Schoeppe, Franziska; Sommer, Wieland H; Haack, Mareike; Havel, Miriam; Rheinwald, Marika; Wechtenbruch, Juliane; Fischer, Martin R; Meinel, Felix G; Sabel, Bastian O; Sommer, Nora N

2018-01-01

To compare free text (FTR) and structured reports (SR) of videofluoroscopic swallowing studies (VFSS) and evaluate satisfaction of referring otolaryngologists and speech therapists. Both standard FTR and SR of 26 patients with VFSS were acquired. A dedicated template focusing on oropharyngeal phases was created for SR using online software with clickable decision-trees and concomitant generation of semantically structured reports. All reports were evaluated regarding overall quality and content, information extraction and clinical decision support (10-point Likert scale (0 = I completely disagree, 10 = I completely agree)). Two otorhinolaryngologists and two speech therapists evaluated FTR and SR. SR received better ratings than FTR in all items. SR were perceived to contain more details on the swallowing phases (median rating: 10 vs. 5; P < 0.001), penetration and aspiration (10 vs. 5; P < 0.001) and facilitated information extraction compared to FTR (10 vs. 4; P < 0.001). Overall quality was rated significantly higher in SR than FTR (P < 0.001). SR of VFSS provide more detailed information and facilitate information extraction. SR better assist in clinical decision-making, might enhance the quality of the report and, thus, are recommended for the evaluation of VFSS. • Structured reports on videofluoroscopic exams of deglutition lead to improved report quality. • Information extraction is facilitated when using structured reports based on decision trees. • Template-based reports add more value to clinical decision-making than free text reports. • Structured reports receive better ratings by speech therapists and otolaryngologists. • Structured reports on videofluoroscopic exams may improve the comparability between exams.

Linking Surface Topography Variations To Subsurface Mixing And Reaction Patterns

NASA Astrophysics Data System (ADS)

Le Borgne, T.; Bandopadhyay, A.; Davy, P.

2017-12-01

Fluctuations in surface topography generate nested streamline patterns in the subsurface over scales ranging from millimeters to kilometers. Because solute residence times can be very different for each streamlines, these patterns exert a strong control on biogeochemical reactions. While this effect has been quantified in reactive transport models, solute transfer across streamlines has been generally neglected. Yet, this process can lead to significant solute dilution and may trigger reactions by mixing water with different chemical compositions. Considering topography-driven subsurface flow cells of different sizes, we show that the resulting streamline structures act as shear flows, with shear rates that can vary over orders of magnitude depending on scale, permeability and hydraulic head gradient. This leads to the formation of localized layers of enhanced dilution and reaction, where mixing rates can be orders of magnitude larger than diffusion limited rates (Bandopadhyay et al. under review). We develop a theoretical model that predicts the depth and magnitude of these mixing hotspots and quantifies the resulting exports of conservative and reactive chemical species at discharge locations. We discuss consequences of these findings by applying this model at hyporheic zone, hillslope, and catchment scales.

Item-Level Psychometrics of the Glasgow Outcome Scale: Extended Structured Interviews.

PubMed

Hong, Ickpyo; Li, Chih-Ying; Velozo, Craig A

2016-04-01

The Glasgow Outcome Scale-Extended (GOSE) structured interview captures critical components of activities and participation, including home, shopping, work, leisure, and family/friend relationships. Eighty-nine community dwelling adults with mild-moderate traumatic brain injury (TBI) were recruited (average = 2.7 year post injury). Nine items of the 19 items were used for the psychometrics analysis purpose. Factor analysis and item-level psychometrics were investigated using the Rasch partial-credit model. Although the principal components analysis of residuals suggests that a single measurement factor dominates the measure, the instrument did not meet the factor analysis criteria. Five items met the rating scale criteria. Eight items fit the Rasch model. The instrument demonstrated low person reliability (0.63), low person strata (2.07), and a slight ceiling effect. The GOSE demonstrated limitations in precisely measuring activities/participation for individuals after TBI. Future studies should examine the impact of the low precision of the GOSE on effect size. © The Author(s) 2016.

Image classification using multiscale information fusion based on saliency driven nonlinear diffusion filtering.

PubMed

Hu, Weiming; Hu, Ruiguang; Xie, Nianhua; Ling, Haibin; Maybank, Stephen

2014-04-01

In this paper, we propose saliency driven image multiscale nonlinear diffusion filtering. The resulting scale space in general preserves or even enhances semantically important structures such as edges, lines, or flow-like structures in the foreground, and inhibits and smoothes clutter in the background. The image is classified using multiscale information fusion based on the original image, the image at the final scale at which the diffusion process converges, and the image at a midscale. Our algorithm emphasizes the foreground features, which are important for image classification. The background image regions, whether considered as contexts of the foreground or noise to the foreground, can be globally handled by fusing information from different scales. Experimental tests of the effectiveness of the multiscale space for the image classification are conducted on the following publicly available datasets: 1) the PASCAL 2005 dataset; 2) the Oxford 102 flowers dataset; and 3) the Oxford 17 flowers dataset, with high classification rates.

Fate of Large-Scale Structure in Modified Gravity After GW170817 and GRB170817A

NASA Astrophysics Data System (ADS)

Amendola, Luca; Kunz, Martin; Saltas, Ippocratis D.; Sawicki, Ignacy

2018-03-01

The coincident detection of gravitational waves (GW) and a gamma-ray burst from a merger of neutron stars has placed an extremely stringent bound on the speed of GWs. We showed previously that the presence of gravitational slip (η ) in cosmology is intimately tied to modifications of GW propagation. This new constraint implies that the only remaining viable source of gravitational slip is a conformal coupling to gravity in scalar-tensor theories, while viable vector-tensor theories cannot now generate gravitational slip at all. We discuss structure formation in the remaining viable models, demonstrating that (i) the dark-matter growth rate must now be at least as fast as in general relativity (GR), with the possible exception of that beyond the Horndeski model, and (ii) if there is any scale dependence at all in the slip parameter, it is such that it takes the GR value at large scales. We show a consistency relation that must be violated if gravity is modified.

Epidemic spreading in time-varying community networks

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

Ren, Guangming, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com; Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116024; Wang, Xingyuan, E-mail: wangxy@dlut.edu.cn, E-mail: ren-guang-ming@163.com

2014-06-15

The spreading processes of many infectious diseases have comparable time scale as the network evolution. Here, we present a simple networks model with time-varying community structure, and investigate susceptible-infected-susceptible epidemic spreading processes in this model. By both theoretic analysis and numerical simulations, we show that the efficiency of epidemic spreading in this model depends intensively on the mobility rate q of the individuals among communities. We also find that there exists a mobility rate threshold q{sub c}. The epidemic will survive when q > q{sub c} and die when q < q{sub c}. These results can help understanding the impacts of human travel onmore » the epidemic spreading in complex networks with community structure.« less

Factors affecting commercial application of embryo technologies in dairy cattle in Europe--a modelling approach.

PubMed

van Arendonk, Johan A M; Bijma, Piter

2003-01-15

Reproductive techniques have a major impact on the structure of breeding programmes, the rate of genetic gain and dissemination of genetic gain in populations. This manuscript reviews the impact of reproductive technologies on the underlying components of genetic gain and inbreeding with special reference to the role of female reproductive technology. Evaluation of alternative breeding schemes should be based on genetic gain while constraining inbreeding. Optimum breeding schemes can be characterised by: decreased importance of sib information; increased accuracy at the expense of intensity; and a factorial mating strategy. If large-scale embryo cloning becomes feasible, this will have a small impact on the rate of genetic gain but will have a large impact on the structure of breeding programmes.

Fractal And Multi-fractal Analysis Of The Hydraulic Property Variations Of Karst Aquifers

NASA Astrophysics Data System (ADS)

Majone, B.; Bellin, A.; Borsato, A.

Karst aquifers are very heterogeneous systems with hydraulic property variations acting at several continuous and discrete scales, as a result of the fact that macro- structural elements, such as faults and karst channels, and fractures are intertwined in a complex, and largely unknown, manner. Many experimental studies on karst springs showed that the recession limb of the typical storm hydrograph can be divided into several regions with different decreasing rate, suggesting that the discharge is com- posed of contributions experiencing different travel times. Despite the importance of karst aquifers as a source of fresh water for most Mediterranean countries fostered the attention of scientists and practitioners, the mechanisms controlling runoff production in such a complex subsurface environment need to be further explored. A detailed sur- vey, lasting for one year and conducted by the Museo Tridentino di Scienze Naturali of Trento, represents a unique opportunity to analyze the imprint of hydraulic prop- erty variations on the hydrological signal recorded at the spring of Prese Val, located in the Dolomiti group near Trento. Data include water discharge (Q), temperature (T) and electric conductivity of water (E). Analysis of the data revealed that the power spectrum of E scales as 1/f, with slightly, but significantly, smaller than 1. The scaling nature of the E-signal has been confirmed by rescaled range analysis of the time series. Since the electric conductivity is proportional to the concentration of ions in the spring water, which increases with the residence time, one may conclude that the fractal structure of the E signal is the consequence of a similar structure in the hydraulic property variations. This finding confirms previous results of Kirchner et al. (2000), who reported a similar behavior for chloride concentration in the streamflow of three small Welsh catchments. A more detailed analysis revealed that E and T are both multifractal signals suggesting that transport is controlled by hydraulic property variations interesting several scales of variability. However, the travel time distribution is also shaped by the spatial variability of the dissolution rate and of the rainfall, as well as by the occurrence of rate limited dissolution processes. These phenomena may conspire to hide the imprint of the hydraulic property variations on the observed signal, complicating the inference of the geostatistical model of hydraulic property variations from the E signal. The discharge at Prese Val shows a multiscale power spectrum with convexity directed upward, such that the low frequency, long range, contributions to discharge are characterized by a much smaller slope than the high frequency contri- butions, which are characterized by much shorter travel times. This interpretation is consistent with the overall structure of the karst aquifers which is composed of the intertwined arrangement of macro-structures, such as faults and karstic channels, and small-scale diffused fractures, the latter showing a fractal dimension much smaller than that of the former.

Study on Collapse Mechanism of Steel Frame Structure under High Temperature and Blast Loading

NASA Astrophysics Data System (ADS)

Baoxin, Qi; Yan, Shi; Bi, Jialiang

2018-03-01

Numerical simulation analysis for collapsing process and mechanism of steel frame structures under the combined effects of fire and explosion is performed in this paper. First of all, a new steel constitutive model considering fire (high temperature softening effect) and blast (strain rate effect) is established. On the basis of the traditional Johnson-Cook model and the Perzyna model, the relationship between strain and scaled distance as well as the EOUROCODE3 standard heating curve taking into account the temperature effect parameters is introduced, and a modified Johnson-Cook constitutive model is established. Then, the influence of considering the scaled distance is introduced in order to more effectively describe the destruction and collapse phenomena of steel frame structures. Some conclusions are obtained based on the numerical analysis that the destruction will be serious and even progressively collapse with decreasing of the temperature of the steel column for the same scaled distance under the combined effects of fire and blast; the damage will be serious with decreasing of the scaled distance of the steel column under the same temperature under the combined effects of fire and blast; in the case of the combined effects of fire and blast happening in the side-spans, the partial progressive collapse occurs as the scaled distance is less than or equal to 1.28; six kinds of damages which are no damage, minor damage, moderate damage, severe damage, critical collapse, and progressive collapse.

Cross-correlation patterns in social opinion formation with sequential data

NASA Astrophysics Data System (ADS)

Chakrabarti, Anindya S.

2016-11-01

Recent research on large-scale internet data suggests existence of patterns in the collective behavior of billions of people even though each of them may pursue own activities. In this paper, we interpret online rating activity as a process of forming social opinion about individual items, where people sequentially choose a rating based on the current information set comprising all previous ratings and own preferences. We construct an opinion index from the sequence of ratings and we show that (1) movie-specific opinion converges much slower than an independent and identically distributed (i.i.d.) sequence of ratings, (2) rating sequence for individual movies shows lesser variation compared to an i.i.d. sequence of ratings, (3) the probability density function of the asymptotic opinions has more spread than that defined over opinion arising from i.i.d. sequence of ratings, (4) opinion sequences across movies are correlated with significantly higher and lower correlation compared to opinion constructed from i.i.d. sequence of ratings, creating a bimodal cross-correlation structure. By decomposing the temporal correlation structures from panel data of movie ratings, we show that the social effects are very prominent whereas group effects cannot be differentiated from those of surrogate data and individual effects are quite small. The former explains a large part of extreme positive or negative correlations between sequences of opinions. In general, this method can be applied to any rating data to extract social or group-specific effects in correlation structures. We conclude that in this particular case, social effects are important in opinion formation process.

Fine-structure resolved rotational transitions and database for CN+H2 collisions

NASA Astrophysics Data System (ADS)

Burton, Hannah; Mysliwiec, Ryan; Forrey, Robert C.; Yang, B. H.; Stancil, P. C.; Balakrishnan, N.

2018-06-01

Cross sections and rate coefficients for CN+H2 collisions are calculated using the coupled states (CS) approximation. The calculations are benchmarked against more accurate close-coupling (CC) calculations for transitions between low-lying rotational states. Comparisons are made between the two formulations for collision energies greater than 10 cm-1. The CS approximation is used to construct a database which includes highly excited rotational states that are beyond the practical limitations of the CC method. The database includes fine-structure resolved rotational quenching transitions for v = 0 and j ≤ 40, where v and j are the vibrational and rotational quantum numbers of the initial state of the CN molecule. Rate coefficients are computed for both para-H2 and ortho-H2 colliders. The results are shown to be in good agreement with previous calculations, however, the rates are substantially different from mass-scaled CN+He rates that are often used in astrophysical models.

Please Touch: Object Properties that Invite Touch.

PubMed

Klatzky, R L; Peck, J

2012-01-01

Touch has received increasing interest in marketing, given research indicating that contact with products influences evaluation and the tendency to purchase. However, little is known from the marketing or psychophysical literature about visible attributes of objects that elicit touch for hedonic purposes. In these studies, participants rated the tendency of pictured objects to invite touch, or "touch-ability." Rated touch-ability varied reliably with structural attributes of objects, and the structural influences were distinct from those on other ratings such as attractiveness and apparent expense. Although the trends varied across object sets, touch-ability generally declined as surface textures became markedly rough and shape complexity became extreme. Holding stimulus factors constant, touch-ability also varied with the specific hand movements that were anticipated. Finally, mean touch-ability ratings were correlated across participants with the "Need for Touch" scale, which measures an individual's tendency to touch products. The studies point to touch-ability as a potential factor that might be incorporated into product design.

Measuring self-rated productivity: factor structure and variance component analysis of the Health and Work Questionnaire.

PubMed

von Thiele Schwarz, Ulrica; Sjöberg, Anders; Hasson, Henna; Tafvelin, Susanne

2014-12-01

To test the factor structure and variance components of the productivity subscales of the Health and Work Questionnaire (HWQ). A total of 272 individuals from one company answered the HWQ scale, including three dimensions (efficiency, quality, and quantity) that the respondent rated from three perspectives: their own, their supervisor's, and their coworkers'. A confirmatory factor analysis was performed, and common and unique variance components evaluated. A common factor explained 81% of the variance (reliability 0.95). All dimensions and rater perspectives contributed with unique variance. The final model provided a perfect fit to the data. Efficiency, quality, and quantity and three rater perspectives are valid parts of the self-rated productivity measurement model, but with a large common factor. Thus, the HWQ can be analyzed either as one factor or by extracting the unique variance for each subdimension.

Resolving Microzooplankton Functional Groups In A Size-Structured Planktonic Model

NASA Astrophysics Data System (ADS)

Taniguchi, D.; Dutkiewicz, S.; Follows, M. J.; Jahn, O.; Menden-Deuer, S.

2016-02-01

Microzooplankton are important marine grazers, often consuming a large fraction of primary productivity. They consist of a great diversity of organisms with different behaviors, characteristics, and rates. This functional diversity, and its consequences, are not currently reflected in large-scale ocean ecological simulations. How should these organisms be represented, and what are the implications for their biogeography? We develop a size-structured, trait-based model to characterize a diversity of microzooplankton functional groups. We compile and examine size-based laboratory data on the traits, revealing some patterns with size and functional group that we interpret with mechanistic theory. Fitting the model to the data provides parameterizations of key rates and properties, which we employ in a numerical ocean model. The diversity of grazing preference, rates, and trophic strategies enables the coexistence of different functional groups of micro-grazers under various environmental conditions, and the model produces testable predictions of the biogeography.

Multigroup confirmatory factor analysis and structural invariance with age of the Behavior Rating Inventory of Executive Function (BRIEF)--French version.

PubMed

Fournet, Nathalie; Roulin, Jean-Luc; Monnier, Catherine; Atzeni, Thierry; Cosnefroy, Olivier; Le Gall, Didier; Roy, Arnaud

2015-01-01

The parent and teacher forms of the French version of the Behavioral Rating Inventory of Executive Function (BRIEF) were used to evaluate executive function in everyday life in a large sample of healthy children (N = 951) aged between 5 and 18. Several psychometric methods were applied, with a view to providing clinicians with tools for score interpretation. The parent and teacher forms of the BRIEF were acceptably reliable. Demographic variables (such as age and gender) were found to influence the BRIEF scores. Confirmatory factor analysis was then used to test five competing models of the BRIEF's latent structure. Two of these models (a three-factor model and a two-factor model, both based on a nine-scale structure) had a good fit. However, structural invariance with age was only obtained with the two-factor model. The French version of the BRIEF provides a useful measure of everyday executive function and can be recommended for use in clinical research and practice.

Modeling the Internal Structure of Mars Using Normal Mode Relaxation Theory

NASA Astrophysics Data System (ADS)

Pithawala, T. M.; Ghent, R. R.; Bills, B. G.

2010-12-01

We seek to resolve an apparent paradox between two sets of observations, which seem to suggest quite different thermal structures for the deep interior of Mars. The orbit of Phobos is observed to be accelerating along-track at a rate of (273.4 ± 1.2) 10^(-5) deg/yr^(2), which implies that the orbit is shrinking at (4.03 ± 0.03) cm/yr, and losing energy at a rate of 3.4 MW. The most likely sink for that energy is tidal dissipation within Mars, seemingly requiring a warm interior. However, static support of the gravity and topography of Mars requires a thick elastic lithosphere, indicating a relatively cool (and therefore stiff) mantle. Using normal mode relaxation theory we model the internal viscosity structure of Mars by analyzing its response to tidal forcing from Phobos. We investigate spherical axisymmetric layered viscoelastic models, seeking to satisfy what is known about planetary differentiation, to support large-scale topography via a thick elastic lithosphere, and to yield the observed tidal dissipation rate. We present a family of 4-layer models (core, mantle, lithosphere, and thin weak layer) that satisfy these constraints, and discuss the implications for Mars’ internal structure.

Quality of life in Essential Tremor Questionnaire (QUEST): development and initial validation.

PubMed

Tröster, Alexander I; Pahwa, Rajesh; Fields, Julie A; Tanner, Caroline M; Lyons, Kelly E

2005-09-01

Essential tremor (ET) can diminish functioning and quality of life (QOL) but generic QOL measures may be relatively insensitive to ET and its therapies. We sought to develop an ET-specific measure that might be more sensitive, acceptable to patients, relatively brief, and easily used. A sample of 200 patients (average age 70 years, range 30-91; average disease duration 15 years) rated the extent to which tremor impacts a function or state, tremor severity in various body parts, perceived health, and overall QOL. Responses to this initial questionnaire were subjected to principal components analysis (PCA). Inspection of factor coordinates, Eigenvalues, variance accounted for, and correlation matrices were used to select items for confirmatory PCA. Final scale reliability was assessed using Cronbach's alpha. Validity was evaluated by correlations between QOL scales and self-rated tremor severity. PCA of 65 initial items yielded 11 factors accounting for 71% of variance. Six factors were discarded. Two items were eliminated for not loading on a factor and 33 for perceived redundancy. Confirmatory PCA of the retained 30 items yielded an almost identical factor structure (six factors, 70% of variance accounted for, and similar item loadings). Because two factors had very few items loading on them, these two factors were combined into one scale. The final measure has five scales: Physical, Psychosocial, Communication, Hobbies/Leisure, and Work/Finance. Reliability was excellent for the whole instrument and four scales (> or =0.89), and good for the Work/Finance scale (0.79). Severity of voice and head tremor were the best correlates of Communication (0.70 and 0.35), while the Physical scale was related to right and left upper extremity tremor (0.59 and 0.56). Scales correlated more highly with patients' rating of their overall QOL than their health perception. A brief, 30-item, ET-specific QOL scale with excellent reliability was developed. Preliminary validity data are encouraging. The Quality of Life in Essential Tremor Questionnaire (QUEST) promises to facilitate QOL measurement in ET.

Development of Ultra-Fine Multigroup Cross Section Library of the AMPX/SCALE Code Packages

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

Jeon, Byoung Kyu; Sik Yang, Won; Kim, Kang Seog

The Consortium for Advanced Simulation of Light Water Reactors Virtual Environment for Reactor Applications (VERA) neutronic simulator MPACT is being developed by Oak Ridge National Laboratory and the University of Michigan for various reactor applications. The MPACT and simplified MPACT 51- and 252-group cross section libraries have been developed for the MPACT neutron transport calculations by using the AMPX and Standardized Computer Analyses for Licensing Evaluations (SCALE) code packages developed at Oak Ridge National Laboratory. It has been noted that the conventional AMPX/SCALE procedure has limited applications for fast-spectrum systems such as boiling water reactor (BWR) fuels with very highmore » void fractions and fast reactor fuels because of its poor accuracy in unresolved and fast energy regions. This lack of accuracy can introduce additional error sources to MPACT calculations, which is already limited by the Bondarenko approach for resolved resonance self-shielding calculation. To enhance the prediction accuracy of MPACT for fast-spectrum reactor analyses, the accuracy of the AMPX/SCALE code packages should be improved first. The purpose of this study is to identify the major problems of the AMPX/SCALE procedure in generating fast-spectrum cross sections and to devise ways to improve the accuracy. For this, various benchmark problems including a typical pressurized water reactor fuel, BWR fuels with various void fractions, and several fast reactor fuels were analyzed using the AMPX 252-group libraries. Isotopic reaction rates were determined by SCALE multigroup (MG) calculations and compared with continuous energy (CE) Monte Carlo calculation results. This reaction rate analysis revealed three main contributors to the observed differences in reactivity and reaction rates: (1) the limitation of the Bondarenko approach in coarse energy group structure, (2) the normalization issue of probability tables, and (3) neglect of the self-shielding effect of resonance-like cross sections at high energy range such as (n,p) cross section of Cl35. The first error source can be eliminated by an ultra-fine group (UFG) structure in which the broad scattering resonances of intermediate-weight nuclides can be represented accurately by a piecewise constant function. A UFG AMPX library was generated with modified probability tables and tested against various benchmark problems. The reactivity and reaction rates determined with the new UFG AMPX library agreed very well with respect to Monte Carlo Neutral Particle (MCNP) results. To enhance the lattice calculation accuracy without significantly increasing the computational time, performing the UFG lattice calculation in two steps was proposed. In the first step, a UFG slowing-down calculation is performed for the corresponding homogenized composition, and UFG cross sections are collapsed into an intermediate group structure. In the second step, the lattice calculation is performed for the intermediate group level using the condensed group cross sections. A preliminary test showed that the condensed library reproduces the results obtained with the UFG cross section library. This result suggests that the proposed two-step lattice calculation approach is a promising option to enhance the applicability of the AMPX/SCALE system to fast system analysis.« less