Does Individualism Help Explain Differences in Employers' Stigmatizing Attitudes Toward Disability Across Chinese and American Cities?

PubMed Central

Rao, Deepa; Horton, Randall A.; Tsang, Hector W.H.; Shi, Kan; Corrigan, Patrick W.

2011-01-01

Purpose Stigmatizing attitudes toward people with disabilities can jeopardize such individuals' well-being and recovery through denial of employment and community isolation. By shaping social norms that define group membership, the construct of individualism may partially explain differences in stigmatizing attitudes across cultures. Further, widespread globalization has brought intensely individualistic social practices to certain segments of non-Western cultures. This paper examines whether the construct of individualism can help to explain cross-cultural differences in stigmatizing attitudes observed between American and Chinese employers. Design Employers (N = 879) from Beijing, Hong Kong, and Chicago provided information on their attitudes toward hiring people with disabilities, and Path Analyses were conducted to examine potential mediating relationships. Results Path analyses indicated that vertical individualism, along with perceived responsibility for acquiring a condition, partially mediated the relationship between culture and employers' negative attitudes about job candidates with disabilities. Conclusion These results suggested that greater espousal of competitive and individualist values may drive stigmatizing attitudes across cultures. PMID:21171794

Mechanisms of change underlying the efficacy of cognitive behaviour therapy for chronic fatigue syndrome in a specialist clinic: a mediation analysis.

PubMed

Stahl, D; Rimes, K A; Chalder, T

2014-04-01

Several randomized controlled trials (RCTs) have shown that cognitive behavioural psychotherapy (CBT) is an efficacious treatment for chronic fatigue syndrome (CFS). However, little is known about the mechanisms by which the treatment has its effect. The aim of this study was to investigate potential mechanisms of change underlying the efficacy of CBT for CFS. We applied path analysis and introduce novel model comparison approaches to assess a theoretical CBT model that suggests that fearful cognitions will mediate the relationship between avoidance behaviour and illness outcomes (fatigue and social adjustment). Data from 389 patients with CFS who received CBT in a specialist service in the UK were collected at baseline, at discharge from treatment, and at 3-, 6- and 12-month follow-ups. Path analyses were used to assess possible mediating effects. Model selection using information criteria was used to compare support for competing mediational models. Path analyses were consistent with the hypothesized model in which fear avoidance beliefs at the 3-month follow-up partially mediate the relationship between avoidance behaviour at discharge and fatigue and social adjustment respectively at 6 months. The results strengthen the validity of a theoretical model of CBT by confirming the role of cognitive and behavioural factors in CFS.

Path analyses of cross-sectional and longitudinal data suggest that variability in natural communities of blood-associated parasites is derived from host characteristics and not interspecific interactions.

PubMed

Cohen, Carmit; Einav, Monica; Hawlena, Hadas

2015-08-19

The parasite composition of wild host individuals often impacts their behavior and physiology, and the transmission dynamics of pathogenic species thereby determines disease risk in natural communities. Yet, the determinants of parasite composition in natural communities are still obscure. In particular, three fundamental questions remain open: (1) what are the relative roles of host and environmental characteristics compared with direct interactions between parasites in determining the community composition of parasites? (2) do these determinants affect parasites belonging to the same guild and those belonging to different guilds in similar manners? and (3) can cross-sectional and longitudinal analyses work interchangeably in detecting community determinants? Our study was designed to answer these three questions in a natural community of rodents and their fleas, ticks, and two vector-borne bacteria. We sampled a natural population of Gerbillus andersoni rodents and their blood-associated parasites on two occasions. By combining path analysis and model selection approaches, we then explored multiple direct and indirect paths that connect (i) the environmental and host-related characteristics to the infection probability of a host by each of the four parasite species, and (ii) the infection probabilities of the four species by each other. Our results suggest that the majority of paths shaping the blood-associated communities are indirect, mostly determined by host characteristics and not by interspecific interactions or environmental conditions. The exact effects of host characteristics on infection probability by a given parasite depend on its life history and on the method of sampling, in which the cross-sectional and longitudinal methods are complementary. Despite the awareness of the need of ecological investigations into natural host-vector-parasite communities in light of the emergence and re-emergence of vector-borne diseases, we lack sampling methods that are both practical and reliable. Here we illustrated how comprehensive patterns can be revealed from observational data by applying path analysis and model selection approaches and combining cross-sectional and longitudinal analyses. By employing this combined approach on blood-associated parasites, we were able to distinguish between direct and indirect effects and to predict the causal relationships between host-related characteristics and the parasite composition over time and space. We concluded that direct interactions within the community play only a minor role in determining community composition relative to host characteristics and the life history of the community members.

The impact of an environmental education program on children's and parents' knowledge, attitudes, motivation and behaviors

NASA Astrophysics Data System (ADS)

Legault, Louise M. R.

1999-11-01

Developments in the Quebec educational system enabled us to evaluate the impact of a new educational environmental program (EEP) on a group of children enrolled in this program for the first time (i.e., the experimental group). This EEP comprised a formal curriculum and environmental activities. A control group of children was enrolled in schools where environmental issues were confined to the natural sciences subject. The goals of this study were threefold. The first goal was to evaluate the impact of an EEP on children's and parents' ecological knowledge, attitudes, motivation, and behaviors. The second goal was to investigate if a motivational model of ecological behaviors observed in adult populations could be replicated with children. Part of this goal also included the comparison of path analyses results across experimental conditions, independently for children and parents. The third goal was to identify more clearly what specific children's characteristics influenced parents' ecological attitudes and motivation. Included in this goal was the investigation of possible differences in the strength of associations between constructs in paths analyses conducted in the experimental and control groups of parents. Results suggested that children in the experimental group were more likely to ask teachers and parents for ecological information and presented a more self-determined motivational profile. Additional analyses revealed that children enrolled in an EEP performed ecological behaviors less for extrinsic motives. Level of knowledge, other attitudes and behavioral measures did not differ significantly between the two groups. Parents of children in the experimental group reported lower levels of satisfaction towards the environment and were more likely to get information on ecological issues and strategies from children. No other significant differences between groups of parents were found. Path analyses results suggested that parents' perceptions of children's provision of autonomy support and of ecological information, as well as, joint child/parent involvement in ecological activities favored parents' ecological attitudes and motivation. These results were consistent across the experimental and the control groups. Future studies are necessary to identify optimal intervention strategies devised to foster in people a sense of personal responsibility and self-determination that may propel them into action.

Lizard movement tracks: variation in path re-use behaviour is consistent with a scent-marking function

PubMed Central

Jackson, Grant; Roddick, John F.; Bull, C. Michael

2016-01-01

Individual movement influences the spatial and social structuring of a population. Animals regularly use the same paths to move efficiently to familiar places, or to patrol and mark home ranges. We found that Australian sleepy lizards (Tiliqua rugosa), a monogamous species with stable pair-bonds, repeatedly used the same paths within their home ranges and investigated whether path re-use functions as a scent-marking behaviour, or whether it is influenced by site familiarity. Lizards can leave scent trails on the substrate when moving through the environment and have a well-developed vomeronasal system to detect and respond to those scents. Path re-use would allow sleepy lizards to concentrate scent marks along these well-used trails, advertising their presence. Hypotheses of mate attraction and mating competition predict that sleepy lizard males, which experience greater intra-sexual competition, mark more strongly. Consistent with those hypotheses, males re-used their paths more than females, and lizards that showed pairing behaviour with individuals of the opposite sex re-used paths more than unpaired lizards, particularly among females. Hinterland marking is most economic when home ranges are large and mobility is low, as is the case in the sleepy lizard. Consistent with this strategy, re-used paths were predominantly located in the inner 50% home range areas. Together, our detailed movement analyses suggest that path re-use is a scent marking behaviour in the sleepy lizard. We also investigated but found less support for alternative explanations of path re-use behaviour, such as site familiarity and spatial knowledge. Lizards established the same number of paths, and used them as often, whether they had occupied their home ranges for one or for more years. We discuss our findings in relation to maintenance of the monogamous mating system of this species, and the spatial and social structuring of the population. PMID:27019790

Lizard movement tracks: variation in path re-use behaviour is consistent with a scent-marking function.

PubMed

Leu, Stephan T; Jackson, Grant; Roddick, John F; Bull, C Michael

2016-01-01

Individual movement influences the spatial and social structuring of a population. Animals regularly use the same paths to move efficiently to familiar places, or to patrol and mark home ranges. We found that Australian sleepy lizards (Tiliqua rugosa), a monogamous species with stable pair-bonds, repeatedly used the same paths within their home ranges and investigated whether path re-use functions as a scent-marking behaviour, or whether it is influenced by site familiarity. Lizards can leave scent trails on the substrate when moving through the environment and have a well-developed vomeronasal system to detect and respond to those scents. Path re-use would allow sleepy lizards to concentrate scent marks along these well-used trails, advertising their presence. Hypotheses of mate attraction and mating competition predict that sleepy lizard males, which experience greater intra-sexual competition, mark more strongly. Consistent with those hypotheses, males re-used their paths more than females, and lizards that showed pairing behaviour with individuals of the opposite sex re-used paths more than unpaired lizards, particularly among females. Hinterland marking is most economic when home ranges are large and mobility is low, as is the case in the sleepy lizard. Consistent with this strategy, re-used paths were predominantly located in the inner 50% home range areas. Together, our detailed movement analyses suggest that path re-use is a scent marking behaviour in the sleepy lizard. We also investigated but found less support for alternative explanations of path re-use behaviour, such as site familiarity and spatial knowledge. Lizards established the same number of paths, and used them as often, whether they had occupied their home ranges for one or for more years. We discuss our findings in relation to maintenance of the monogamous mating system of this species, and the spatial and social structuring of the population.

Implementation of the Secondary 3 Program of Project P.A.T.H.S.: observations based on the co-walker scheme.

PubMed

Shek, Daniel T L; Ma, Cecilia M S

2012-01-17

The present study was conducted to explore the implementation quality of the Secondary 3 Program of the Tier 1 Program of Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programmes) in the third year of the Full Implementation Phase. Classroom observations of 182 units in 129 schools were conducted. Results showed that the overall level of program adherence was 73.9%. Thirteen aspects concerning program delivery were significantly correlated. Multiple regression analyses revealed that overall implementation quality was significantly predicted by student participation and involvement, strategies to enhance student motivation, use of positive and supportive feedback, degree of achievement of the objectives, and lesson preparation. Success of implementation was significantly predicted by student participation and involvement, classroom control, use of positive and supportive feedback, opportunity for reflection, degree of achievement of the objectives and time management. The present findings generally suggest that the implementation quality of Project P.A.T.H.S. was high.

Adolescent-parent attachment as a mediator of relations between parenting and adolescent social behavior and wellbeing in China.

PubMed

Cai, Mengfei; Hardy, Sam A; Olsen, Joseph A; Nelson, David A; Yamawaki, Niwako

2013-01-01

The purpose of this study was to examine links between parenting dimensions (authoritative parenting, psychological control, and parental authority) and adolescent wellbeing (self-esteem, autonomy, and peer attachments) as mediated by parent-teen attachment, among Chinese families. The sample included 298 Chinese adolescents, ages 15-18 years (M(age) = 16.36, SD = .68; 60% female). The mediation model was examined using path analyses (one model with parental authority as overprotection, and one with it as perceived behavioral control). To improve model fit a direct path was added from authoritative parenting to autonomy. Authoritative parenting was positively predictive of attachment, while psychological control and overprotection (but not behavioral control) were negative predictors. In turn, adolescent-parent attachment was positively related to the three outcomes. Lastly, the model paths did not differ by adolescent gender. These findings suggest that parenting behaviors may play a crucial role in adolescent social behaviors and wellbeing via adolescent-parent attachment.

Impact of the Project P.A.T.H.S. in the junior secondary school years: objective outcome evaluation based on eight waves of longitudinal data.

PubMed

Shek, Daniel T L; Ma, Cecilia M S

2012-01-01

To assess the effectiveness of the Tier 1 Program of the Project P.A.T.H.S., a randomized group trial with eight waves of data collected was carried out. At the fifth year of data collection, 19 experimental schools (n = 2, 662 students) and 24 control schools (n = 3, 272 students) participated in the study. Analyses based on individual growth curve modeling showed that participants in the experimental schools displayed better positive youth development than did participants in the control schools in terms of different indicators derived from the Chinese Positive Youth Development Scale, including moral competence and behavioral competence and cognitive behavioral competencies. Significant results were also found when examining the trajectories of psychological development among control and experimental participants who perceived the program to be beneficial. Findings based on longitudinal objective outcome evaluation strongly suggest that the Project P.A.T.H.S. is effective in promoting positive development in Hong Kong secondary school students.

Use of chiral cell shape to ensure highly directional swimming in trypanosomes

PubMed Central

2017-01-01

Swimming cells typically move along a helical path or undergo longitudinal rotation as they swim, arising from chiral asymmetry in hydrodynamic drag or propulsion bending the swimming path into a helix. Helical paths are beneficial for some forms of chemotaxis, but why asymmetric shape is so prevalent when a symmetric shape would also allow highly directional swimming is unclear. Here, I analyse the swimming of the insect life cycle stages of two human parasites; Trypanosoma brucei and Leishmania mexicana. This showed quantitatively how chirality in T. brucei cell shape confers highly directional swimming. High speed videomicrographs showed that T. brucei, L. mexicana and a T. brucei RNAi morphology mutant have a range of shape asymmetries, from wild-type T. brucei (highly chiral) to L. mexicana (near-axial symmetry). The chiral cells underwent longitudinal rotation while swimming, with more rapid longitudinal rotation correlating with swimming path directionality. Simulation indicated hydrodynamic drag on the chiral cell shape caused rotation, and the predicted geometry of the resulting swimming path matched the directionality of the observed swimming paths. This simulation of swimming path geometry showed that highly chiral cell shape is a robust mechanism through which microscale swimmers can achieve highly directional swimming at low Reynolds number. It is insensitive to random variation in shape or propulsion (biological noise). Highly symmetric cell shape can give highly directional swimming but is at risk of giving futile circular swimming paths in the presence of biological noise. This suggests the chiral T. brucei cell shape (associated with the lateral attachment of the flagellum) may be an adaptation associated with the bloodstream-inhabiting lifestyle of this parasite for robust highly directional swimming. It also provides a plausible general explanation for why swimming cells tend to have strong asymmetries in cell shape or propulsion. PMID:28141804

Causal Mediation Analysis of Survival Outcome with Multiple Mediators.

PubMed

Huang, Yen-Tsung; Yang, Hwai-I

2017-05-01

Mediation analyses have been a popular approach to investigate the effect of an exposure on an outcome through a mediator. Mediation models with multiple mediators have been proposed for continuous and dichotomous outcomes. However, development of multimediator models for survival outcomes is still limited. We present methods for multimediator analyses using three survival models: Aalen additive hazard models, Cox proportional hazard models, and semiparametric probit models. Effects through mediators can be characterized by path-specific effects, for which definitions and identifiability assumptions are provided. We derive closed-form expressions for path-specific effects for the three models, which are intuitively interpreted using a causal diagram. Mediation analyses using Cox models under the rare-outcome assumption and Aalen additive hazard models consider effects on log hazard ratio and hazard difference, respectively; analyses using semiparametric probit models consider effects on difference in transformed survival time and survival probability. The three models were applied to a hepatitis study where we investigated effects of hepatitis C on liver cancer incidence mediated through baseline and/or follow-up hepatitis B viral load. The three methods show consistent results on respective effect scales, which suggest an adverse estimated effect of hepatitis C on liver cancer not mediated through hepatitis B, and a protective estimated effect mediated through the baseline (and possibly follow-up) of hepatitis B viral load. Causal mediation analyses of survival outcome with multiple mediators are developed for additive hazard and proportional hazard and probit models with utility demonstrated in a hepatitis study.

Non-invasive flow path characterization in a mining-impacted wetland

USGS Publications Warehouse

Bethune, James; Randell, Jackie; Runkel, Robert L.; Singha, Kamini

2015-01-01

Time-lapse electrical resistivity (ER) was used to capture the dilution of a seasonal pulse of acid mine drainage (AMD) contamination in the subsurface of a wetland downgradient of the abandoned Pennsylvania mine workings in central Colorado. Data were collected monthly from mid-July to late October of 2013, with an additional dataset collected in June of 2014. Inversion of the ER data shows the development through time of multiple resistive anomalies in the subsurface, which corroborating data suggest are driven by changes in total dissolved solids (TDS) localized in preferential flow pathways. Sensitivity analyses on a synthetic model of the site suggest that the anomalies would need to be at least several meters in diameter to be adequately resolved by the inversions. The existence of preferential flow paths would have a critical impact on the extent of attenuation mechanisms at the site, and their further characterization could be used to parameterize reactive transport models in developing quantitative predictions of remediation strategies.

Prenatal Depressive Symptoms and Toddler Behavior Problems: The Role of Maternal Sensitivity and Child Sex.

PubMed

Edwards, Renee C; Hans, Sydney L

2016-10-01

Increasing evidence suggests that maternal depression during pregnancy is associated with child behavioral outcomes even after accounting for later maternal depression. The purpose of this study was to examine various mechanisms, including maternal sensitivity, neonatal problems, and concurrent maternal depression, that might explain the association between prenatal maternal depressive symptoms and toddler behavior problems. Young, low income, African American mothers (n = 196) were interviewed during pregnancy and at 24-months postpartum, medical records were collected at the birth, and mother-child interactions were video-recorded at 24 months. Path analyses revealed that the association between prenatal depression and toddler behavior problems was mediated by maternal sensitivity and maternal depressive symptoms at 24 months. No evidence was found for a mediating effect of neonatal problems. Path models examining sex differences suggested that different mediating factors may be important for boys and girls, with boys being particularly susceptible to the effects of maternal sensitivity.

Structural abnormality of the corticospinal tract in major depressive disorder

PubMed Central

2014-01-01

Background Scientists are beginning to document abnormalities in white matter connectivity in major depressive disorder (MDD). Recent developments in diffusion-weighted image analyses, including tractography clustering methods, may yield improved characterization of these white matter abnormalities in MDD. In this study, we acquired diffusion-weighted imaging data from MDD participants and matched healthy controls. We analyzed these data using two tractography clustering methods: automated fiber quantification (AFQ) and the maximum density path (MDP) procedure. We used AFQ to compare fractional anisotropy (FA; an index of water diffusion) in these two groups across major white matter tracts. Subsequently, we used the MDP procedure to compare FA differences in fiber paths related to the abnormalities in major fiber tracts that were identified using AFQ. Results FA was higher in the bilateral corticospinal tracts (CSTs) in MDD (p’s < 0.002). Secondary analyses using the MDP procedure detected primarily increases in FA in the CST-related fiber paths of the bilateral posterior limbs of the internal capsule, right superior corona radiata, and the left external capsule. Conclusions This is the first study to implicate the CST and several related fiber pathways in MDD. These findings suggest important new hypotheses regarding the role of CST abnormalities in MDD, including in relation to explicating CST-related abnormalities to depressive symptoms and RDoC domains and constructs. PMID:25295159

An Extended Paleozoic Apparent Polar Wander Path for Baltica: new Permo-Carboniferous Paleopoles From the Donbas Region (Ukraine)

NASA Astrophysics Data System (ADS)

Hamers, M. F.; Meijers, M. J.; van Hinsbergen, D. J.; van der Meer, D. G.; Langereis, C. G.; Stephenson, R. A.

2007-12-01

An improved Paleozoic apparent polar wander (APW) path for Baltica is presented here on the basis of six new paleopoles that have been determined from samples collected in the Donbas region in the Dniepr-Donets basin in south-eastern Ukraine. Constructing APW paths allows improving paleogeographic reconstructions that reach further back in time than 200 Ma, where the use of oceanic isochrons and hotspot track has limited applicability. The absence of penetrative regional deformation and the subparallel trending bedding attitudes across the basin suggest that our sites did not suffer from local rotations and their results are interpreted as representative for Baltica. The data presented here improve the paleogeographic reconstruction of Baltica within the collage of the supercontinent Pangea. The six new paleopoles cover a time span from earliest Carboniferous (~356 Ma) to early Permian (~295 Ma). In our reconstruction, Baltica was located at a constant latitude of ~5°N during a major part of the Carboniferous, while at ~310 Ma it started to move gradually northward, reaching a paleolatitude of ~13°N at 295 Ma. From ~355 Ma to 295 Ma Baltica experienced a net ~20° clockwise rotation. Our new data differ with the APW path from Torsvik et al. (submitted) in the time span from ~320-300 Ma, wherein they propose a northward movement from more southerly latitudes. From 300 Ma onwards, our path fits the reference path from Torsvik et al. A possible Permian remagnetization of our sites is not likely, considering the rotational differences in the various time spans, and rockmagnetic analyses that have been performed. We also discuss the usage of the TK03 model (Tauxe and Kent (2004), Geoph. Mon. 145, pp 101-116) that allows for the correction of inclination error caused by compaction during burial, which is insignificant for most sites. This suggest that the NRM has been acquired after compaction.

Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

NASA Astrophysics Data System (ADS)

Wutich, A.; White, A. C.; Roberts, C. M.; White, D. D.; Larson, K. L.; Brewis, A.

2013-06-01

In this study, we examine how development status and water scarcity shape people's perceptions of "hard path" and "soft path" water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences based on development status and, to a lesser extent, water scarcity. People in less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in more developed sites. Thematically, people in less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community based solutions, while people in more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in water-rich sites. Thematically, people in water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned behavior.

PubMed

Hagger, Martin S; Chan, Derwin K C; Protogerou, Cleo; Chatzisarantis, Nikos L D

2016-08-01

Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs from social cognitive theories is important to test nomological validity, account for mediation effects, and evaluate unique effects of theory constructs independent of past behavior. We illustrate our points by conducting new analyses of two meta-analyses of a popular theory applied to health behaviors, the theory of planned behavior. We conducted meta-analytic path analyses of the theory in two behavioral contexts (alcohol and dietary behaviors) using data from the primary studies included in the original meta-analyses augmented to include intercorrelations among constructs and relations with past behavior missing from the original analysis. Findings supported the nomological validity of the theory and its hypotheses for both behaviors, confirmed important model processes through mediation analysis, demonstrated the attenuating effect of past behavior on theory relations, and provided estimates of the unique effects of theory constructs independent of past behavior. Our analysis illustrates the importance of conducting a simultaneous test of theory-stipulated effects in meta-analyses of social cognitive theories applied to health behavior. We recommend researchers adopt this analytic procedure when synthesizing evidence across primary tests of social cognitive theories in health. Copyright © 2016 Elsevier Inc. All rights reserved.

The free-flight response of Drosophila to motion of the visual environment.

PubMed

Mronz, Markus; Lehmann, Fritz-Olaf

2008-07-01

In the present study we investigated the behavioural strategies with which freely flying fruit flies (Drosophila) control their flight trajectories during active optomotor stimulation in a free-flight arena. We measured forward, turning and climbing velocities of single flies using high-speed video analysis and estimated the output of a 'Hassenstein-Reichardt' elementary motion detector (EMD) array and the fly's gaze to evaluate flight behaviour in response to a rotating visual panorama. In a stationary visual environment, flight is characterized by flight saccades during which the animals turn on average 120 degrees within 130 ms. In a rotating environment, the fly's behaviour typically changes towards distinct, concentric circular flight paths where the radius of the paths increases with increasing arena velocity. The EMD simulation suggests that this behaviour is driven by a rotation-sensitive EMD detector system that minimizes retinal slip on each compound eye, whereas an expansion-sensitive EMD system with a laterally centred visual focus potentially helps to achieve centring response on the circular flight path. We developed a numerical model based on force balance between horizontal, vertical and lateral forces that allows predictions of flight path curvature at a given locomotor capacity of the fly. The model suggests that turning flight in Drosophila is constrained by the production of centripetal forces needed to avoid side-slip movements. At maximum horizontal velocity this force may account for up to 70% of the fly's body weight during yaw turning. Altogether, our analyses are widely consistent with previous studies on Drosophila free flight and those on the optomotor response under tethered flight conditions.

Hard paths, soft paths or no paths? Cross-cultural perceptions of water solutions

NASA Astrophysics Data System (ADS)

Wutich, A.; White, A. C.; White, D. D.; Larson, K. L.; Brewis, A.; Roberts, C.

2014-01-01

In this study, we examine how development status and water scarcity shape people's perceptions of "hard path" and "soft path" water solutions. Based on ethnographic research conducted in four semi-rural/peri-urban sites (in Bolivia, Fiji, New Zealand, and the US), we use content analysis to conduct statistical and thematic comparisons of interview data. Our results indicate clear differences associated with development status and, to a lesser extent, water scarcity. People in the two less developed sites were more likely to suggest hard path solutions, less likely to suggest soft path solutions, and more likely to see no path to solutions than people in the more developed sites. Thematically, people in the two less developed sites envisioned solutions that involve small-scale water infrastructure and decentralized, community-based solutions, while people in the more developed sites envisioned solutions that involve large-scale infrastructure and centralized, regulatory water solutions. People in the two water-scarce sites were less likely to suggest soft path solutions and more likely to see no path to solutions (but no more likely to suggest hard path solutions) than people in the water-rich sites. Thematically, people in the two water-rich sites seemed to perceive a wider array of unrealized potential soft path solutions than those in the water-scarce sites. On balance, our findings are encouraging in that they indicate that people are receptive to soft path solutions in a range of sites, even those with limited financial or water resources. Our research points to the need for more studies that investigate the social feasibility of soft path water solutions, particularly in sites with significant financial and natural resource constraints.

Bullying perpetration and victimization as externalizing and internalizing pathways: A retrospective study linking parenting styles and self-esteem to depression, alcohol use, and alcohol-related problems

PubMed Central

Patock-Peckham, Julie A; Medina, Mia; Terrell, Nathan; Belton, Daniel; King, Kevin M

2016-01-01

Emerging research suggests significant positive associations between bullying and substance use behaviors. However, these studies typically focused either on the link between substance use and bullying perpetration or victimization, and few have conceptualized bullying perpetration and/or victimization as mediators. In this study, we simultaneously tested past bullying perpetration and victimization as mediational pathways from retrospective report of parenting styles and global self-esteem to current depressive symptoms, alcohol use and alcohol-related problems. Data were collected from a college sample of 419 drinkers. Mediation effects were conducted using a bias-corrected bootstrap technique in structural equation modeling. Two-path mediation analyses indicated that mother and father authoritativeness were protective against bully victimization and depression through higher self-esteem. Conversely, having a permissive or authoritarian mother was positively linked to bullying perpetration, which in turn was associated with increased alcohol use, and to a lesser degree, more alcohol-related problems. Mother authoritarianism was associated with alcohol-related problems through depressive symptoms. Three-path mediation analyses suggested a trend in which individuals with higher self-esteem were less likely to report alcohol-related problems through lower levels of bullying victimization and depression. Results suggested that bullying perpetration and victimization may respectively serve as externalizing and internalizing pathways through which parenting styles and self-esteem are linked to depression and alcohol-related outcomes. The present study identified multiple modifiable precursors of, and mediational pathways to, alcohol-related problems which could guide the development and implementation of prevention programs targeting problematic alcohol use. PMID:26757486

Bullying Perpetration and Victimization as Externalizing and Internalizing Pathways: A Retrospective Study Linking Parenting Styles and Self-Esteem to Depression, Alcohol Use, and Alcohol-Related Problems.

PubMed

Luk, Jeremy W; Patock-Peckham, Julie A; Medina, Mia; Terrell, Nathan; Belton, Daniel; King, Kevin M

2016-01-02

Emerging research suggests significant positive associations between bullying and substance use behaviors. However, these studies typically focused either on the link between substance use and bullying perpetration or victimization, and few have conceptualized bullying perpetration and/or victimization as mediators. In this study, we simultaneously tested past bullying perpetration and victimization as mediational pathways from retrospective report of parenting styles and global self-esteem to current depressive symptoms, alcohol use, and alcohol-related problems. Data were collected from a college sample of 419 drinkers. Mediation effects were conducted using a bias-corrected bootstrap technique within a structural equation modeling framework. Two-path mediation analyses indicated that mother and father authoritativeness were protective against bully victimization and depression through higher self-esteem. Conversely, having a permissive or authoritarian mother was positively linked to bullying perpetration, which in turn, was associated with increased alcohol use, and to a lesser degree, more alcohol-related problems. Mother authoritarianism was associated with alcohol-related problems through depressive symptoms. Three-path mediation analyses suggested a trend in which individuals with higher self-esteem were less likely to report alcohol-related problems through lower levels of bullying victimization and depression. Results suggested that bullying perpetration and victimization may, respectively, serve as externalizing and internalizing pathways through which parenting styles and self-esteem are linked to depression and alcohol-related outcomes. The present study identified multiple modifiable precursors of, and mediational pathways to, alcohol-related problems which could guide the development and implementation of prevention programs targeting problematic alcohol use.

Progressing from programmatic to discovery research: a case example with the overjustification effect.

PubMed

Roane, Henry S; Fisher, Wayne W; McDonough, Erin M

2003-01-01

Scientific research progresses along planned (programmatic research) and unplanned (discovery research) paths. In the current investigation, we attempted to conduct a single-case evaluation of the overjustification effect (i.e., programmatic research). Results of the initial analysis were contrary to the overjustification hypothesis in that removal of the reward contingency produced an increase in responding. Based on this unexpected finding, we conducted subsequent analyses to further evaluate the mechanisms underlying these results (i.e., discovery research). Results of the additional analyses suggested that the reward contingency functioned as punishment (because the participant preferred the task to the rewards) and that withdrawal of the contingency produced punishment contrast.

Progressing from programmatic to discovery research: a case example with the overjustification effect.

PubMed Central

Roane, Henry S; Fisher, Wayne W; McDonough, Erin M

2003-01-01

Scientific research progresses along planned (programmatic research) and unplanned (discovery research) paths. In the current investigation, we attempted to conduct a single-case evaluation of the overjustification effect (i.e., programmatic research). Results of the initial analysis were contrary to the overjustification hypothesis in that removal of the reward contingency produced an increase in responding. Based on this unexpected finding, we conducted subsequent analyses to further evaluate the mechanisms underlying these results (i.e., discovery research). Results of the additional analyses suggested that the reward contingency functioned as punishment (because the participant preferred the task to the rewards) and that withdrawal of the contingency produced punishment contrast. PMID:12723865

The Role of Sleep in the Relationship Between Victimization and Externalizing Problems in Adolescents

PubMed Central

Kliewer, Wendy; Lepore, Stephen J.

2018-01-01

Victimization is linked to externalizing outcomes in adolescents and recent theorizing suggests that sleep plays a role in this relationship; however, there is little evidence examining sleep as a mediator. This study examines associations between victimization experiences and changes in aggression, delinquency, and drug use. Data were obtained from three waves of a school-based study with middle-school youth (n = 785; 55 % female; 20 % African American; M = 12.32, SD = .51 years at T1), and path analyses were used to test the key hypotheses. Analyses controlling for major life events, demographic factors, and school site revealed that victimization indirectly affected delinquency and drug use, but not aggression, through its relationship with sleep problems. Further, the effects of sleep problems on drug use were specific to females. These data suggest that intervening to address sleep problems resulting from victimization may serve to reduce some forms of externalizing behavior. PMID:27216201

Stigma Toward Men Who Have Sex with Men Among Future Healthcare Providers in Malaysia: Would More Interpersonal Contact Reduce Prejudice?

PubMed Central

Jin, Harry; Wickersham, Jeffrey A.; Kamarulzaman, Adeeba; John, Jacob; Lim, Sin How; Altice, Frederick L.

2015-01-01

Men who have sex with men (MSM) living in countries with strong stigma toward MSM are vulnerable to HIV and experience significant barriers to HIV care. Research is needed to inform interventions to reduce stigma toward MSM in these countries, particularly among healthcare providers. A cross-sectional survey of 1158 medical and dental students was conducted at seven Malaysian universities in 2012. Multivariate analyses of variance suggest that students who had interpersonal contact with MSM were less prejudiced toward and had lower intentions to discriminate against MSM. Path analyses with bootstrapping suggest stereotypes and fear mediate associations between contact with prejudice and discrimination. Intervention strategies to reduce MSM stigma among healthcare providers in Malaysia and other countries with strong stigma toward MSM may include facilitating opportunities for direct, in-person or indirect, media-based prosocial contact between medical and dental students with MSM. PMID:26324078

Stigma Toward Men Who Have Sex with Men Among Future Healthcare Providers in Malaysia: Would More Interpersonal Contact Reduce Prejudice?

PubMed

Earnshaw, Valerie A; Jin, Harry; Wickersham, Jeffrey A; Kamarulzaman, Adeeba; John, Jacob; Lim, Sin How; Altice, Frederick L

2016-01-01

Men who have sex with men (MSM) living in countries with strong stigma toward MSM are vulnerable to HIV and experience significant barriers to HIV care. Research is needed to inform interventions to reduce stigma toward MSM in these countries, particularly among healthcare providers. A cross-sectional survey of 1158 medical and dental students was conducted at seven Malaysian universities in 2012. Multivariate analyses of variance suggest that students who had interpersonal contact with MSM were less prejudiced toward and had lower intentions to discriminate against MSM. Path analyses with bootstrapping suggest stereotypes and fear mediate associations between contact with prejudice and discrimination. Intervention strategies to reduce MSM stigma among healthcare providers in Malaysia and other countries with strong stigma toward MSM may include facilitating opportunities for direct, in-person or indirect, media-based prosocial contact between medical and dental students with MSM.

Examining the link between women's exposure to stressful life events prior to conception and infant and toddler health: the role of birth weight.

PubMed

Cheng, Erika R; Park, Hyojun; Wisk, Lauren E; Mandell, Kara C; Wakeel, Fathima; Litzelman, Kristin; Chatterjee, Debanjana; Witt, Whitney P

2016-03-01

The life course perspective suggests a pathway may exist among maternal exposure to stressful life events prior to conception (PSLEs), infant birth weight and subsequent offspring health, whereby PSLEs are part of a 'chains-of-risk' that set children on a certain health pathway. No prior study has examined the link between PSLEs and offspring health in a nationally representative sample of US mothers and their children. We used longitudinal, nationally representative data to evaluate the relation between maternal exposure to PSLEs and subsequent measures of infant and toddler health, taking both maternal and obstetric characteristics into account. We examined 6900 mother-child dyads participating in 2 waves of the nationally representative Early Childhood Longitudinal Study-Birth Cohort (n=6900). Infant and toddler health outcomes assessed at 9 and 24 months included overall health status, special healthcare needs and severe health conditions. Adjusted path analyses examined associations between PSLEs, birth weight and child health outcomes. In adjusted analyses, PSLEs increased the risk for very low birth weight (VLBW, <1500 g), which, in turn, predicted poor health at both 9 and 24 months of age. Path analyses demonstrated that PSLEs had small indirect effects on children's subsequent health that operated through VLBW. Our analysis suggests a chains-of-risk model in which women's exposure to PSLEs increases the risk for giving birth to a VLBW infant, which, in turn, adversely affects infant and toddler health. Addressing women's preconception health may have important downstream benefits for their children, although more research is needed to replicate these findings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Examining the link between women’s exposure to stressful life events prior to conception and infant and toddler health: The role of birthweight

PubMed Central

Cheng, Erika R.; Park, Hyojun; Wisk, Lauren E.; Mandell, Kara C.; Wakeel, Fathima; Litzelman, Kristin; Chatterjee, Debanjana; Witt, Whitney P.

2015-01-01

Background The lifecourse perspective suggests a pathway may exist among maternal exposure to stressful life events prior to conception (PSLEs), infant birthweight, and subsequent offspring health, whereby PLSEs are part of a “chains-of-risk” that set children on a certain health pathway. No prior study has examined the link between PSLEs and offspring health in a nationally-representative sample of US mothers and their children. We used longitudinal, nationally-representative data to evaluate the relation between maternal exposure to PSLEs and subsequent measures of infant and toddler health, taking both maternal and obstetric characteristics into account. Methods We examined 6,900 mother-child dyads participating in two waves of the nationally-representative Early Childhood Longitudinal Study-Birth Cohort (n=6,900). Infant and toddler health outcomes assessed at 9 and 24 months included overall health status, special health care needs, and severe health conditions. Adjusted path analyses examined associations between PSLEs, birthweight, and child health outcomes. Results In adjusted analyses, PSLEs increased the risk for very low birthweight (VLBW, <1,500 grams), which, in turn, predicted poor health at both 9 and 24 months of age. Path analyses demonstrated that PSLEs had small indirect effects on children’s subsequent health that operated through VLBW. Conclusion Our analysis suggests a chains-of-risk model in which women’s exposure to PSLEs increases the risk for giving birth to a VLBW infant, which, in turn, adversely affects infant and toddler health. Addressing women’s preconception health may have important downstream benefits for their children, although more research is needed to replicate these findings. PMID:26500337

Childhood neglect predicts disorganization in schizophrenia through grey matter decrease in dorsolateral prefrontal cortex.

PubMed

Cancel, A; Comte, M; Truillet, R; Boukezzi, S; Rousseau, P-F; Zendjidjian, X Y; Sage, T; Lazerges, P-E; Guedj, E; Khalfa, S; Azorin, J-M; Blin, O; Fakra, E

2015-10-01

Psychosocial trauma during childhood is associated with schizophrenia vulnerability. The pattern of grey matter decrease is similar to brain alterations seen in schizophrenia. Our objective was to explore the links between childhood trauma, brain morphology and schizophrenia symptoms. Twenty-one patients with schizophrenia stabilized with atypical antipsychotic monotherapy and 30 healthy control subjects completed the study. Anatomical MRI images were analysed using optimized voxel-based morphometry (VBM). Childhood trauma was assessed with the Childhood Trauma Questionnaire, and symptoms were rated on the Scale for the Assessment of Negative Symptoms (SANS) and Scale for the Assessment of Positive Symptoms (SAPS) (disorganization, positive and negative symptoms). In the schizophrenia group, we used structural equation modelling in a path analysis. Total grey matter volume was negatively associated with emotional neglect (EN) in patients with schizophrenia. Whole-brain VBM analyses of grey matter in the schizophrenia group revealed a specific inversed association between EN and the right dorsolateral prefrontal cortex (DLPFC). Path analyses identified a well-fitted model in which EN predicted grey matter density in DLPFC, which in turn predicted the disorganization score. Our findings suggest that EN during childhood could have an impact on psychopathology in schizophrenia, which would be mediated by developmental effects on brain regions such as the DLPFC. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The relationship between South Korean clinical nurses' attitudes toward organizations and voluntary turnover intention: A path analysis.

PubMed

Kim, Jong Kyung; Chang, Sun Ju

2015-08-01

The purpose of this study was to examine the relationship between attitudes toward their organizations and voluntary turnover intention among South Korean clinical nurses. Data from a total of 312 clinical nurses in six hospitals in South Korea were collected for the study. Both hierarchical multiple regression analysis and path analysis were used to analyse the data. The overall fit of the hypothetical model was good. Voluntary turnover intention was found to have significant direct pathways to job embeddedness and organizational commitment. Organizational commitment and satisfaction with organizational rewards had indirect pathways to voluntary turnover intention through job embeddedness. All variances explained 62.3% of the voluntary turnover intention scores. The findings suggest that greater job embeddedness, organizational commitment and satisfaction with organizational rewards lead to lower voluntary turnover intention among clinical nurses in South Korea. © 2014 Wiley Publishing Asia Pty Ltd.

Measurement of width and pressure in a propagating hydraulic fracture

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

Warpinski, N.R.

Measurements of width and pressure in a propagating hydraulic fracture have been made in tests conducted at the U.S. DOE's Nevada test site. This was accomplished by creating an ''instrumented fracture'' at a tunnel complex (at a depth of 1,400 ft (425 m)) where realistic insitu conditions prevail, particularly with respect to stress and geologic features such as natural fractures and material anisotropy. Analyses of these data show that the pressure drop along the fracture length is much larger than predicted by viscous theory, which currently is used in models. This apparently is caused by the tortuosity of the fracturemore » path, multiple fracture strands, roughness, and sharp turns (corners) in the flow path resulting from natural fractures and rock property variations. It suggests that fracture design models need to be updated to include a more realistic friction factor so that fracture lengths are not overestimated.« less

Measurement of width and pressure in a propagating hydraulic fracture

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

Warpinski, N.R.

Measurements of width and pressure in a propagating hydraulic fracture have been made in tests conducted at DOE's Nevada Test Site. This was accomplished by creating an instrumented fracture at a tunnel complex (at a depth of 1400 ft) where realistic in situ conditions prevail, particularly with respect to stress and geologic features such as natural fractures and material anisotropy. Analyses of these data show that the pressure drop along the fracture length is much larger than predicted by viscous theory and currently in use in models today. This is apparently due to the tortuosity of the fracture path, multiplemore » fracture strands, roughness and sharp turns (corners) in the flow path due to natural fractures and rock property variations. It suggests that fracture design models need to be updated to include a more realistic friction factor so that fracture lengths are not overestimated.« less

Measurement of width and pressure in a propagating hydraulic fracture

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

Warpinski, N.R.

Measurements of width and pressure in a propagating hydraulic fracture have been made in tests conducted at DOE's Nevada Test Site. This was accomplished by creating an ''instrumented fracture'' at a tunnel complex (at a depth of 1400 ft) where realistic in-situ conditions prevail, particularly with respect to stress and geologic features such as natural fractures and material anisotropy. Analyses of these data show that the pressure drop along the fracture length is much larger than predicted by viscous theory and currently in use in models today. This is apparently due to the tortuosity of the fracture path, multiple fracturemore » strands, roughness and sharp turns (corners) in the flow path due to natural fractures and rock property variations. It suggests that fracture design models need to be updated to include a more realistic friction factor so that fracture lengths are not overestimated.« less

Background radiation in inelastic X-ray scattering and X-ray emission spectroscopy. A study for Johann-type spectrometers

NASA Astrophysics Data System (ADS)

Paredes Mellone, O. A.; Bianco, L. M.; Ceppi, S. A.; Goncalves Honnicke, M.; Stutz, G. E.

2018-06-01

A study of the background radiation in inelastic X-ray scattering (IXS) and X-ray emission spectroscopy (XES) based on an analytical model is presented. The calculation model considers spurious radiation originated from elastic and inelastic scattering processes along the beam paths of a Johann-type spectrometer. The dependence of the background radiation intensity on the medium of the beam paths (air and helium), analysed energy and radius of the Rowland circle was studied. The present study shows that both for IXS and XES experiments the background radiation is dominated by spurious radiation owing to scattering processes along the sample-analyser beam path. For IXS experiments the spectral distribution of the main component of the background radiation shows a weak linear dependence on the energy for the most cases. In the case of XES, a strong non-linear behaviour of the background radiation intensity was predicted for energy analysis very close to the backdiffraction condition, with a rapid increase in intensity as the analyser Bragg angle approaches π / 2. The contribution of the analyser-detector beam path is significantly weaker and resembles the spectral distribution of the measured spectra. Present results show that for usual experimental conditions no appreciable structures are introduced by the background radiation into the measured spectra, both in IXS and XES experiments. The usefulness of properly calculating the background profile is demonstrated in a background subtraction procedure for a real experimental situation. The calculation model was able to simulate with high accuracy the energy dependence of the background radiation intensity measured in a particular XES experiment with air beam paths.

Self-Esteem as a Mediator between Personality Traits and Body Esteem: Path Analyses across Gender and Race/Ethnicity

PubMed Central

Skorek, Małgorzata; Song, Anna V.; Dunham, Yarrow

2014-01-01

Prior literature examines the direct relationship between personality traits and body esteem. This article explores the possibility that self-esteem mediates this relationship. 165 undergraduate women and 133 men (age 18–21; 42.6% Hispanic, 28.9% Asian, 28.5% Caucasian) completed items measuring personality traits (Big Five), self-esteem, and body esteem. Path analyses were used to test for mediation. The analyses confirmed that in both men and women self-esteem mediated the relationship between three personality traits and body esteem: higher levels of conscientiousness, emotional stability, and extraversion were associated with higher self-esteem and consequently higher body esteem. Once self-esteem was included in the model the relationships between personality traits and body esteem were not significant, suggesting full mediation. In addition, the analyses revealed several racial/ethnic differences. In Asian American participants, self-esteem mediated the relationship between conscientiousness and body esteem and between emotional stability and body esteem. In Hispanic Americans, self-esteem mediated the relationship between conscientiousness and body esteem and between extraversion and body esteem. And in Caucasian Americans, self-esteem mediated the relationship between emotional stability and body esteem and between extraversion and body esteem. The most important contribution of this study is evidence for an indirect relationship between personality traits and body esteem, with this relationship being mediated by self-esteem. This has important implications for the study of personality and eating disorders in young adults, most particularly implying a need for more emphasis on self-esteem as a predictor of body image problems. PMID:25375238

Between Domain Cognitive Dispersion and Functional Abilities in Older Adults

PubMed Central

Fellows, Robert P.; Schmitter-Edgecombe, Maureen

2016-01-01

Objective Within-person variability in cognitive performance is related to neurological integrity, but the association with functional abilities is less clear. The primary aim of this study was to examine the association between cognitive dispersion, or within-person variability, and everyday multitasking and the way in which these variables may influence performance on a naturalistic assessment of functional abilities. Method Participants were 156 community-dwelling adults, age 50 or older. Cognitive dispersion was calculated by measuring within-person variability in cognitive domains, established through principal components analysis. Path analysis was used to determine the independent contribution of cognitive dispersion to functional ability, mediated by multitasking. Results Results of the path analysis revealed that the number of subtasks interweaved (i.e., multitasked) mediated the association between cognitive dispersion and task sequencing and accuracy. Although increased multitasking was associated with worse task performance in the path model, secondary analyses revealed that for individuals with low cognitive dispersion, increased multitasking was associated with better task performance, whereas for those with higher levels of dispersion multitasking was negatively correlated with task performance. Conclusion These results suggest that cognitive dispersion between domains may be a useful indicator of multitasking and daily living skills among older adults. PMID:26300441

Sexual sensation seeking, co-occurring sex and alcohol use, and sexual risk behavior among adolescents in treatment for substance use problems.

PubMed

Oshri, Assaf; Tubman, Jonathan G; Morgan-Lopez, Antonio A; Saavedra, Lissette M; Csizmadia, Annamaria

2013-01-01

This study evaluated relations between sexual sensation seeking, co-occurring sex and alcohol use, and sexual risk behaviors (eg, unprotected intercourse and multiple sex partners) among adolescents receiving treatment for substance abuse problems. The ethnically diverse sample included 394 adolescents recruited from outpatient treatment (280 males; Mage  = 16.33 years, SDage  = 1.15). Structural equation modeling (SEM) was used to test direct and indirect paths between sexual sensation seeking and sexual risk behaviors via the frequency of co-occurring sex and alcohol use. Conditional indirect effects by gender were also tested. Analyses identified significant effects of sexual sensation seeking on co-occurring sex and alcohol use and sexual risk behaviors. The path from co-occurring sex and alcohol use to unprotected intercourse was significantly stronger among adolescent girls, suggesting a mediation effect moderated by gender. No gender difference was found for the indirect path from sexual sensation seeking and number of past year sexual partners via co-occurring sex and alcohol use. Selected prevention efforts are needed to promote HIV risk reduction among adolescents in substance abuse treatment. The documented conditional indirect effect for unprotected intercourse suggests that HIV prevention programs should pay special attention to gender-specific patterns of alcohol use and sexual risk behavior when tailoring program content. (Am J Addict 2013; 22:197-205). Copyright © American Academy of Addiction Psychiatry.

A cluster randomized controlled trial of the Promoting Alternative Thinking Strategies (PATHS) curriculum.

PubMed

Humphrey, Neil; Barlow, Alexandra; Wigelsworth, Michael; Lendrum, Ann; Pert, Kirsty; Joyce, Craig; Stephens, Emma; Wo, Lawrence; Squires, Garry; Woods, Kevin; Calam, Rachel; Turner, Alex

2016-10-01

This randomized controlled trial (RCT) evaluated the efficacy of the Promoting Alternative Thinking Strategies curriculum (PATHS; Kusche & Greenberg, 1994) as a means to improve children's social-emotional competence (assessed via the Social Skills Improvement System (SSIS); Gresham & Elliot, 2008) and mental health outcomes (assessed via the Strengths and Difficulties Questionnaire (SDQ); Goodman, 1997). Forty-five schools in Greater Manchester, England, were randomly assigned to treatment and control groups. Allocation was balanced by proportions of children eligible for free school meals and speaking English as an additional language via minimization. Children (N=4516) aged 7-9years at baseline in the participating schools were the target cohort. During the two-year trial period, teachers of this cohort in schools allocated to the intervention group delivered the PATHS curriculum, while their counterparts in the control group continued their usual provision. Teachers in PATHS schools received initial training and on-going support and assistance from trained coaches. Hierarchical linear modeling of outcome data was undertaken to identify both primary (e.g., for all children) and secondary (e.g., for children classified as "at-risk") intervention effects. A primary effect of the PATHS curriculum was found, demonstrating increases in teacher ratings of changes in children's social-emotional competence. Additionally, secondary effects of PATHS were identified, showing reductions in teacher ratings of emotional symptoms and increases in pro-social behavior and child ratings of engagement among children identified as at-risk at baseline. However, our analyses also identified primary effects favoring the usual provision group, showing reductions in teacher ratings of peer problems and emotional symptoms, and secondary effects demonstrating reductions in teacher ratings of conduct problems and child ratings of co-operation among at-risk children. Effect sizes were small in all cases. These mixed findings suggest that social and emotional learning interventions such as PATHS may not be as efficacious when implemented outside their country of origin and evaluated in independent trials. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Energy Optimal Path Planning: Integrating Coastal Ocean Modelling with Optimal Control

NASA Astrophysics Data System (ADS)

Subramani, D. N.; Haley, P. J., Jr.; Lermusiaux, P. F. J.

2016-02-01

A stochastic optimization methodology is formulated for computing energy-optimal paths from among time-optimal paths of autonomous vehicles navigating in a dynamic flow field. To set up the energy optimization, the relative vehicle speed and headings are considered to be stochastic, and new stochastic Dynamically Orthogonal (DO) level-set equations that govern their stochastic time-optimal reachability fronts are derived. Their solution provides the distribution of time-optimal reachability fronts and corresponding distribution of time-optimal paths. An optimization is then performed on the vehicle's energy-time joint distribution to select the energy-optimal paths for each arrival time, among all stochastic time-optimal paths for that arrival time. The accuracy and efficiency of the DO level-set equations for solving the governing stochastic level-set reachability fronts are quantitatively assessed, including comparisons with independent semi-analytical solutions. Energy-optimal missions are studied in wind-driven barotropic quasi-geostrophic double-gyre circulations, and in realistic data-assimilative re-analyses of multiscale coastal ocean flows. The latter re-analyses are obtained from multi-resolution 2-way nested primitive-equation simulations of tidal-to-mesoscale dynamics in the Middle Atlantic Bight and Shelbreak Front region. The effects of tidal currents, strong wind events, coastal jets, and shelfbreak fronts on the energy-optimal paths are illustrated and quantified. Results showcase the opportunities for longer-duration missions that intelligently utilize the ocean environment to save energy, rigorously integrating ocean forecasting with optimal control of autonomous vehicles.

Career Path Suggestion using String Matching and Decision Trees

NASA Astrophysics Data System (ADS)

Nagpal, Akshay; P. Panda, Supriya

2015-05-01

High school and college graduates seemingly are often battling for the courses they should major in order to achieve their target career. In this paper, we worked on suggesting a career path to a graduate to reach his/her dream career given the current educational status. Firstly, we collected the career data of professionals and academicians from various career fields and compiled the data set by using the necessary information from the data. Further, this was used as the basis to suggest the most appropriate career path for the person given his/her current educational status. Decision trees and string matching algorithms were employed to suggest the appropriate career path for a person. Finally, an analysis of the result has been done directing to further improvements in the model.

The path dependency theory: analytical framework to study institutional integration. The case of France.

PubMed

Trouvé, Hélène; Couturier, Yves; Etheridge, Francis; Saint-Jean, Olivier; Somme, Dominique

2010-06-30

The literature on integration indicates the need for an enhanced theorization of institutional integration. This article proposes path dependence as an analytical framework to study the systems in which integration takes place. PRISMA proposes a model for integrating health and social care services for older adults. This model was initially tested in Quebec. The PRISMA France study gave us an opportunity to analyze institutional integration in France. A qualitative approach was used. Analyses were based on semi-structured interviews with actors of all levels of decision-making, observations of advisory board meetings, and administrative documents. Our analyses revealed the complexity and fragmentation of institutional integration. The path dependency theory, which analyzes the change capacity of institutions by taking into account their historic structures, allows analysis of this situation. The path dependency to the Bismarckian system and the incomplete reforms of gerontological policies generate the coexistence and juxtaposition of institutional systems. In such a context, no institution has sufficient ability to determine gerontology policy and build institutional integration by itself. Using path dependence as an analytical framework helps to understand the reasons why institutional integration is critical to organizational and clinical integration, and the complex construction of institutional integration in France.

The Role of Sexual Communication in Couples' Sexual Outcomes: A Dyadic Path Analysis.

PubMed

Jones, Adam C; Robinson, W David; Seedall, Ryan B

2017-10-16

In a study of 142 couples, we gathered survey data to show how sexual communication influences sexual and relationship satisfaction as well as sexual and orgasm frequency. In two dyadic data path analyses, we observed the significant paths of influence that sexual communication has on sexual and relationship satisfaction, as well as sexual and orgasm frequency. Our findings revealed greater amounts of sexual communication were associated with increased orgasm frequency in women and greater relationship and sexual satisfaction in both sexes. We also observed important differences in the associations of sexual communication and general communication on satisfaction levels. With these analyses, we expand the current literature to broaden our understanding of the role that sexual communication plays in committed relationships. © 2017 American Association for Marriage and Family Therapy.

Genome Evolution and Phylogenomic Analysis of Candidatus Kinetoplastibacterium, the Betaproteobacterial Endosymbionts of Strigomonas and Angomonas

PubMed Central

Alves, João M.P.; Serrano, Myrna G.; Maia da Silva, Flávia; Voegtly, Logan J.; Matveyev, Andrey V.; Teixeira, Marta M.G.; Camargo, Erney P.; Buck, Gregory A.

2013-01-01

It has been long known that insect-infecting trypanosomatid flagellates from the genera Angomonas and Strigomonas harbor bacterial endosymbionts (Candidatus Kinetoplastibacterium or TPE [trypanosomatid proteobacterial endosymbiont]) that supplement the host metabolism. Based on previous analyses of other bacterial endosymbiont genomes from other lineages, a stereotypical path of genome evolution in such bacteria over the duration of their association with the eukaryotic host has been characterized. In this work, we sequence and analyze the genomes of five TPEs, perform their metabolic reconstruction, do an extensive phylogenomic analyses with all available Betaproteobacteria, and compare the TPEs with their nearest betaproteobacterial relatives. We also identify a number of housekeeping and central metabolism genes that seem to have undergone positive selection. Our genome structure analyses show total synteny among the five TPEs despite millions of years of divergence, and that this lineage follows the common path of genome evolution observed in other endosymbionts of diverse ancestries. As previously suggested by cell biology and biochemistry experiments, Ca. Kinetoplastibacterium spp. preferentially maintain those genes necessary for the biosynthesis of compounds needed by their hosts. We have also shown that metabolic and informational genes related to the cooperation with the host are overrepresented amongst genes shown to be under positive selection. Finally, our phylogenomic analysis shows that, while being in the Alcaligenaceae family of Betaproteobacteria, the closest relatives of these endosymbionts are not in the genus Bordetella as previously reported, but more likely in the Taylorella genus. PMID:23345457

Anger, preoccupied attachment, and domain disorganization in borderline personality disorder

PubMed Central

Morse, Jennifer Q.; Hill, Jonathan; Pilkonis, Paul A.; Yaggi, Kirsten; Broyden, Nichaela; Stepp, Stephanie; Reed, Lawrence Ian; Feske, Ulrike

2010-01-01

Emotional dysregulation and attachment insecurity have been reported in borderline personality disorder (BPD). Domain disorganization, evidenced in poor regulation of emotions and behaviors in relation to the demands of different social domains, may be a distinguishing feature of BPD. Understanding the interplay between these factors may be critical for identifying interacting processes in BPD and potential subtypes of BPD. Therefore, we examined the joint and interactive effects of anger, preoccupied attachment, and domain disorganization on BPD traits in clinical sample of 128 psychiatric patients. The results suggest that these factors contribute to BPD both independently and in interaction, even when controlling for other personality disorder traits and Axis I symptoms. In regression analyses, the interaction between anger and domain disorganization predicted BPD traits. In recursive partitioning analyses, two possible paths to BPD were identified: high anger combined with high domain disorganization and low anger combined with preoccupied attachment. These results may suggest possible subtypes of BPD or possible mechanisms by which BPD traits are established and maintained. PMID:19538080

HemoVision: An automated and virtual approach to bloodstain pattern analysis.

PubMed

Joris, Philip; Develter, Wim; Jenar, Els; Suetens, Paul; Vandermeulen, Dirk; Van de Voorde, Wim; Claes, Peter

2015-06-01

Bloodstain pattern analysis (BPA) is a subspecialty of forensic sciences, dealing with the analysis and interpretation of bloodstain patterns in crime scenes. The aim of BPA is uncovering new information about the actions that took place in a crime scene, potentially leading to a confirmation or refutation of a suspect's statement. A typical goal of BPA is to estimate the flight paths for a set of stains, followed by a directional analysis in order to estimate the area of origin for the stains. The traditional approach, referred to as stringing, consists of attaching a piece of string to each stain, and letting the string represent an approximation of the stain's flight path. Even though stringing has been used extensively, many (practical) downsides exist. We propose an automated and virtual approach, employing fiducial markers and digital images. By automatically reconstructing a single coordinate frame from several images, limited user input is required. Synthetic crime scenes were created and analysed in order to evaluate the approach. Results demonstrate the correct operation and practical advantages, suggesting that the proposed approach may become a valuable asset for practically analysing bloodstain spatter patterns. Accompanying software called HemoVision is currently provided as a demonstrator and will be further developed for practical use in forensic investigations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Spatial patterns in community response to aircraft noise associated with non-noise factors

NASA Astrophysics Data System (ADS)

Hall, F. L.; Taylor, S. M.; Birnie, S. E.

1980-08-01

Non-noise aspects of airport operations may affect individuals' responses to aircraft noise. Fear of crashes, other forms of pollution, and proximity to the flight path are three such non-noise aspects which have spatial patterns that are closely related to the pattern of noise contours around an airport. If these variables affect response to aircraft noise, they may therefore confound attempts to understand relationships between noise level and community response. Analyses based on data from 673 individuals around Toronto International Airport suggest that these factors do affect annoyance responses, but do not affect reported activity interference. Hence it may prove fruitful, in aggregate analyses of community response data, to control for these variables in order to better understand the noise-annoyance relationships.

Women and Men of the Engineering Path: A Model for Analyses of Undergraduate Careers.

ERIC Educational Resources Information Center

Adelman, Clifford

This monograph provides college academic administrators, institutional researchers, professional and learned societies, and academic advisors with information to improve understanding of the paths students take through engineering programs in higher education. The evidence used in this study comes principally from the 11-year college transcript…

Assessment of critical path analyses of the relationship between permeability and electrical conductivity of pore networks

USDA-ARS?s Scientific Manuscript database

Critical path analysis (CPA) is a method for estimating macroscopic transport coefficients of heterogeneous materials that are highly disordered at the micro-scale. Developed originally to model conduction in semiconductors, numerous researchers have noted that CPA might also have relevance to flow ...

Moderated path analysis of the relationships between masculinity and men's attitudes toward seeking psychological help.

PubMed

Levant, Ronald F; Stefanov, Dimitre G; Rankin, Thomas J; Halter, Margaret J; Mellinger, Chris; Williams, Christine M

2013-07-01

This study tested a theoretical model of one mediator and 4 moderators of the relationships between 2 masculinity variables (Traditional Masculinity Ideology and Gender Role Conflict) and Attitudes Toward Seeking Professional Psychological Services (Attitudes). Self-stigma was the hypothesized mediator, and the hypothesized moderators were (a) Depression, (b) General Self-efficacy, (c) Precontemplation, and (d) Barriers to Help-seeking. A sample of 654 men responded to an online survey of 9 questionnaires. After evaluating mediation in the absence of moderation, moderated path analyses were conducted for each moderator. The relationship between Traditional Masculinity Ideology and Attitudes was partially mediated by Self-stigma, whereas that between Gender Role Conflict and Attitudes was completely mediated. No indirect or direct paths involving Gender Role Conflict were moderated by any moderators. Both Depression and Barriers to Help-seeking demonstrated mediated moderation by moderating both Stage 1 (the path from Traditional Masculinity Ideology to Self-stigma) of the mediated relationships and the direct effects between Traditional Masculinity Ideology and Attitudes. Precontemplation moderated the direct effect between Traditional Masculinity Ideology and Attitudes. The findings suggest that the relationships between masculinity variables and men's negative help-seeking attitudes may be better understood through their relationships with other variables that serve as mediators and moderators. Findings from the present study may offer some direction in the design of interventions to remediate men's negative help-seeking attitudes. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Using wind tunnels to predict bird mortality in wind farms: the case of griffon vultures.

PubMed

de Lucas, Manuela; Ferrer, Miguel; Janss, Guyonne F E

2012-01-01

Wind farms have shown a spectacular growth during the last 15 years. Avian mortality through collision with moving rotor blades is well-known as one of the main adverse impacts of wind farms. In Spain, the griffon vulture incurs the highest mortality rates in wind farms. As far as we know, this study is the first attempt to predict flight trajectories of birds in order to foresee potentially dangerous areas for wind farm development. We analyse topography and wind flows in relation to flight paths of griffon vultures, using a scaled model of the wind farm area in an aerodynamic wind tunnel, and test the difference between the observed flight paths of griffon vultures and the predominant wind flows. Different wind currents for each wind direction in the aerodynamic model were observed. Simulations of wind flows in a wind tunnel were compared with observed flight paths of griffon vultures. No statistical differences were detected between the observed flight trajectories of griffon vultures and the wind passages observed in our wind tunnel model. A significant correlation was found between dead vultures predicted proportion of vultures crossing those cells according to the aerodynamic model. Griffon vulture flight routes matched the predominant wind flows in the area (i.e. they followed the routes where less flight effort was needed). We suggest using these kinds of simulations to predict flight paths over complex terrains can inform the location of wind turbines and thereby reduce soaring bird mortality.

Gender confirming medical interventions and eating disorder symptoms among transgender individuals.

PubMed

Testa, Rylan J; Rider, G Nicole; Haug, Nancy A; Balsam, Kimberly F

2017-10-01

Studies indicate that transgender individuals may be at risk of developing eating disorder symptoms (EDS). Elevated risk may be attributed to body dissatisfaction and/or societal reactions to nonconforming gender expression, such as nonaffirmation of a person's gender identity (e.g., using incorrect pronouns). Limited research suggests that gender-confirming medical interventions (GCMIs) may prevent or reduce EDS among transgender people. Participants included 154 transfeminine spectrum (TFS) and 288 transmasculine spectrum (TMS) individuals who completed the Trans Health Survey. Serial multiple mediation analyses controlling for age, education, and income were used to examine whether body satisfaction and nonaffirmation mediate any found relationships between various GCMIs (genital surgery, chest surgery, hormone use, hysterectomy, and hair removal) and EDS. For TFS individuals, the nonaffirmation to body satisfaction path mediated relationships between all GCMIs and EDS, although body satisfaction alone accounted for more of the indirect effects than this path for chest surgery. For TMS individuals, relationships between all GCMIs and EDS were mediated by the nonaffirmation to body satisfaction path. Findings support the hypothesis that GCMIs reduce experiences of nonaffirmation, which increases body satisfaction and thus decreases EDS. Among TFS participants, the relationship between chest surgery and lower levels of EDS was mediated most strongly by body satisfaction alone, suggesting that satisfaction with one's body may result in lower EDS even if affirmation from the external world is unchanged. Implications of these findings for intervention, policy, and legal efforts are discussed, and future research recommendations are provided. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Adolescent Support Seeking as a Path to Adult Functional Independence

ERIC Educational Resources Information Center

Szwedo, David E.; Hessel, Elenda T.; Loeb, Emily L.; Hafen, Christopher A.; Allen, Joseph P.

2017-01-01

The potential importance of depending on others during adolescence to establish independence in young adulthood was examined across adolescence to emerging adulthood. Participants included 184 teens (46% male; 42% non-White), their mothers, best friends, and romantic partners, assessed at ages 13-14, 18, 21-22, and 25. Path analyses showed that…

School-related social support and subjective well-being in school among adolescents: The role of self-system factors.

PubMed

Tian, Lili; Zhao, Jie; Huebner, E Scott

2015-12-01

This 6-week longitudinal study aimed to examine a moderated mediation model that may explain the link between school-related social support (i.e., teacher support and classmate support) and optimal subjective well-being in school among adolescents (n = 1316). Analyses confirmed the hypothesized model that scholastic competence partially mediated the relations between school-related social support and subjective well-being in school, and social acceptance moderated the mediation process in the school-related social support--> subjective well-being in school path and in the scholastic competence--> subjective well-being in school path. The findings suggested that both social contextual factors (e.g., school-related social support) and self-system factors (e.g., scholastic competence and social acceptance) are crucial for adolescents' optimal subjective well-being in school. Limitations and practical applications of the study were discussed. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Relations of mother's sense of coherence and childrearing style with child's social skills in preschoolers.

PubMed

Hosokawa, Rikuya; Katsura, Toshiki; Shizawa, Miho

2017-01-01

We examined the relationships between mothers' sense of coherence (SOC) and their child's social skills development among preschool children, and how this relationship is mediated by mother's childrearing style. Mothers of 1341 Japanese children, aged 4-5 years, completed a self-report questionnaire on their SOC and childrearing style. The children's teachers evaluated their social skills using the social skills scale (SSS), which comprises three factors: cooperation, self-control, and assertion. Path analyses revealed that the mother's childrearing mediated the positive relationship between mother's SOC and the cooperation, self-control, and assertiveness aspects of children's social skills. Additionally, there was a significant direct path from mother's SOC to the self-control component of social skills. These findings suggest that mother's SOC may directly as well as indirectly influence children's social skills development through the mediating effect of childrearing. The results offer preliminary evidence that focusing on support to improve mothers' SOC may be an efficient and effective strategy for improving children's social skills development.

Flight 20 (STS-45) polysulfide gas path investigation

NASA Technical Reports Server (NTRS)

Bjorkman, Rey C.; Bown, Charles W.; Smith, Scott D.; Walters, Jerry L.; Kulkarni, Suresh B.; Cook, Roger V.; Sebahar, David A.; Walker, Craig S.; Haddock, M. Reed; Lindstrom, Robert E.

1992-01-01

This report documents the results of the investigation into causes of gas paths on the 20A and 20B case-to-nozzle joints on STS-42. The investigation was conducted by the Investigation Board appointed by the senior vice president and general manager of Space Operations, Mr. R. E. Lindstrom, on 7 Feb. 1992. The probability of gas path occurrence in the nozzle-to-case-joint polysulfide had been identified during joint redesign. However, actual flight gas path incidence has been limited to RSRM-11 and the 20A and 20B segments. The blow-by condition on the 20A segment was a first time occurrence which was a special concern. The investigation covered all technical aspects associated with the gas path and blow-by conditions: materials and processing history, design requirements and as-built compliance to the design, thermal and structural analyses, computer modeling, and laboratory experimentation with the materials involved. The investigation was coordinated with Mr. Ken Jones at NASA Marshall in bi-weekly teleconferences. The Board also supported Dr. James C. Blair's independent NASA investigation team by providing copies of collected data, conducting requested analyses, and supporting several all-day teleconferences to provide understanding and resolve issues. The Dr. Blair support requirement was successfully concluded on 4 Mar. 1992.

The path dependency theory: analytical framework to study institutional integration. The case of France

PubMed Central

Trouvé, Hélène; Couturier, Yves; Etheridge, Francis; Saint-Jean, Olivier; Somme, Dominique

2010-01-01

Background The literature on integration indicates the need for an enhanced theorization of institutional integration. This article proposes path dependence as an analytical framework to study the systems in which integration takes place. Purpose PRISMA proposes a model for integrating health and social care services for older adults. This model was initially tested in Quebec. The PRISMA France study gave us an opportunity to analyze institutional integration in France. Methods A qualitative approach was used. Analyses were based on semi-structured interviews with actors of all levels of decision-making, observations of advisory board meetings, and administrative documents. Results Our analyses revealed the complexity and fragmentation of institutional integration. The path dependency theory, which analyzes the change capacity of institutions by taking into account their historic structures, allows analysis of this situation. The path dependency to the Bismarckian system and the incomplete reforms of gerontological policies generate the coexistence and juxtaposition of institutional systems. In such a context, no institution has sufficient ability to determine gerontology policy and build institutional integration by itself. Conclusion Using path dependence as an analytical framework helps to understand the reasons why institutional integration is critical to organizational and clinical integration, and the complex construction of institutional integration in France. PMID:20689740

EuPathDB: the eukaryotic pathogen genomics database resource

PubMed Central

Aurrecoechea, Cristina; Barreto, Ana; Basenko, Evelina Y.; Brestelli, John; Brunk, Brian P.; Cade, Shon; Crouch, Kathryn; Doherty, Ryan; Falke, Dave; Fischer, Steve; Gajria, Bindu; Harb, Omar S.; Heiges, Mark; Hertz-Fowler, Christiane; Hu, Sufen; Iodice, John; Kissinger, Jessica C.; Lawrence, Cris; Li, Wei; Pinney, Deborah F.; Pulman, Jane A.; Roos, David S.; Shanmugasundram, Achchuthan; Silva-Franco, Fatima; Steinbiss, Sascha; Stoeckert, Christian J.; Spruill, Drew; Wang, Haiming; Warrenfeltz, Susanne; Zheng, Jie

2017-01-01

The Eukaryotic Pathogen Genomics Database Resource (EuPathDB, http://eupathdb.org) is a collection of databases covering 170+ eukaryotic pathogens (protists & fungi), along with relevant free-living and non-pathogenic species, and select pathogen hosts. To facilitate the discovery of meaningful biological relationships, the databases couple preconfigured searches with visualization and analysis tools for comprehensive data mining via intuitive graphical interfaces and APIs. All data are analyzed with the same workflows, including creation of gene orthology profiles, so data are easily compared across data sets, data types and organisms. EuPathDB is updated with numerous new analysis tools, features, data sets and data types. New tools include GO, metabolic pathway and word enrichment analyses plus an online workspace for analysis of personal, non-public, large-scale data. Expanded data content is mostly genomic and functional genomic data while new data types include protein microarray, metabolic pathways, compounds, quantitative proteomics, copy number variation, and polysomal transcriptomics. New features include consistent categorization of searches, data sets and genome browser tracks; redesigned gene pages; effective integration of alternative transcripts; and a EuPathDB Galaxy instance for private analyses of a user's data. Forthcoming upgrades include user workspaces for private integration of data with existing EuPathDB data and improved integration and presentation of host–pathogen interactions. PMID:27903906

Spatial and temporal analysis center of pressure displacement during adolescence: Clinical implications of developmental changes.

PubMed

Quatman-Yates, Catherine; Bonnette, Scott; Gupta, Resmi; Hugentobler, Jason A; Wade, Shari L; Glauser, Tracy A; Ittenbach, Richard F; Paterno, Mark V; Riley, Michael A

2018-04-01

This study aimed to provide insight into the development of postural control abilities in youth. A total of 276 typically developing adolescents (155 males, 121 females) with a mean age of 13.23 years (range of 7.11-18.80) were recruited for participation. Subjects performed two-minute quiet standing trials in bipedal stance on a force plate. Center of pressure (COP) trajectories were quantified using Sample Entropy (SampEn) in the anterior-posterior direction (SampEn-AP), SampEn in the medial-lateral direction (SampEn-ML), and Path Length (PL) measures. Three separate linear regression analyses were conducted to predict the relationship between age and each of the response variables after adjusting for individuals' physical characteristics. Linear regression models showed an inverse relationship between age and entropy measures after adjusting for body mass index. Results indicated that chronological age was predictive of entropy and path length patterns. Specifically, older adolescents exhibited center of pressure displacement (smaller path length) and less complex, more regular center of pressure displacement patterns (lower SampEn-AP and SampEn-ML values) compared to the younger children. These findings support prior studies suggesting that developmental changes in postural control abilities may continue throughout adolescence and into adulthood. Copyright © 2018 Elsevier B.V. All rights reserved.

Modelling cointegration and Granger causality network to detect long-term equilibrium and diffusion paths in the financial system.

PubMed

Gao, Xiangyun; Huang, Shupei; Sun, Xiaoqi; Hao, Xiaoqing; An, Feng

2018-03-01

Microscopic factors are the basis of macroscopic phenomena. We proposed a network analysis paradigm to study the macroscopic financial system from a microstructure perspective. We built the cointegration network model and the Granger causality network model based on econometrics and complex network theory and chose stock price time series of the real estate industry and its upstream and downstream industries as empirical sample data. Then, we analysed the cointegration network for understanding the steady long-term equilibrium relationships and analysed the Granger causality network for identifying the diffusion paths of the potential risks in the system. The results showed that the influence from a few key stocks can spread conveniently in the system. The cointegration network and Granger causality network are helpful to detect the diffusion path between the industries. We can also identify and intervene in the transmission medium to curb risk diffusion.

Modelling cointegration and Granger causality network to detect long-term equilibrium and diffusion paths in the financial system

PubMed Central

Huang, Shupei; Sun, Xiaoqi; Hao, Xiaoqing; An, Feng

2018-01-01

Microscopic factors are the basis of macroscopic phenomena. We proposed a network analysis paradigm to study the macroscopic financial system from a microstructure perspective. We built the cointegration network model and the Granger causality network model based on econometrics and complex network theory and chose stock price time series of the real estate industry and its upstream and downstream industries as empirical sample data. Then, we analysed the cointegration network for understanding the steady long-term equilibrium relationships and analysed the Granger causality network for identifying the diffusion paths of the potential risks in the system. The results showed that the influence from a few key stocks can spread conveniently in the system. The cointegration network and Granger causality network are helpful to detect the diffusion path between the industries. We can also identify and intervene in the transmission medium to curb risk diffusion. PMID:29657804

Which Way Is Jerusalem? Navigating on a Spheroid

ERIC Educational Resources Information Center

Schechter, Murray

2007-01-01

Given two points on a spheroidal planet, what is the direction from the first to the second? The answer depends, of course, on what path you take. This paper compares two paths which suggest themselves, namely, the loxodrome, which is the path in which the direction stays constant, and the geodesic, which is the shortest path. The geodesic does…

The "Body Pedagogics" of an Elite Footballer's Career Path--Analysing Zlatan Ibrahimovic's Biography

ERIC Educational Resources Information Center

Andersson, Joacim; Maivorsdotter, Ninitha

2017-01-01

Background: Pedagogical research on career is encouraged to not limit sport learning to athletic skills, coaching effectiveness and coach-athlete relationships, but to also focus on learning in a multidimensional sense in the context of an athlete's individual and social biography. This article examines an elite athlete's career path as a body…

Circuity analyses of HSR network and high-speed train paths in China

PubMed Central

Zhao, Shuo; Huang, Jie; Shan, Xinghua

2017-01-01

Circuity, defined as the ratio of the shortest network distance to the Euclidean distance between one origin–destination (O-D) pair, can be adopted as a helpful evaluation method of indirect degrees of train paths. In this paper, the maximum circuity of the paths of operated trains is set to be the threshold value of the circuity of high-speed train paths. For the shortest paths of any node pairs, if their circuity is not higher than the threshold value, the paths can be regarded as the reasonable paths. With the consideration of a certain relative or absolute error, we cluster the reasonable paths on the basis of their inclusion relationship and the center path of each class represents a passenger transit corridor. We take the high-speed rail (HSR) network in China at the end of 2014 as an example, and obtain 51 passenger transit corridors, which are alternative sets of train paths. Furthermore, we analyze the circuity distribution of paths of all node pairs in the network. We find that the high circuity of train paths can be decreased with the construction of a high-speed railway line, which indicates that the structure of the HSR network in China tends to be more complete and the HSR network can make the Chinese railway network more efficient. PMID:28945757

Exploiting broad-area surface emitting lasers to manifest the path-length distributions of finite-potential quantum billiards.

PubMed

Yu, Y T; Tuan, P H; Chang, K C; Hsieh, Y H; Huang, K F; Chen, Y F

2016-01-11

Broad-area vertical-cavity surface-emitting lasers (VCSELs) with different cavity sizes are experimentally exploited to manifest the influence of the finite confinement strength on the path-length distribution of quantum billiards. The subthreshold emission spectra of VCSELs are measured to obtain the path-length distributions by using the Fourier transform. It is verified that the number of the resonant peaks in the path-length distribution decreases with decreasing the confinement strength. Theoretical analyses for finite-potential quantum billiards are numerically performed to confirm that the mesoscopic phenomena of quantum billiards with finite confinement strength can be analogously revealed by using broad-area VCSELs.

Multiple paths in complex tasks

NASA Technical Reports Server (NTRS)

Galanter, Eugene; Wiegand, Thomas; Mark, Gloria

1987-01-01

The relationship between utility judgments of subtask paths and the utility of the task as a whole was examined. The convergent validation procedure is based on the assumption that measurements of the same quantity done with different methods should covary. The utility measures of the subtasks were obtained during the performance of an aircraft flight controller navigation task. Analyses helped decide among various models of subtask utility combination, whether the utility ratings of subtask paths predict the whole tasks utility rating, and indirectly, whether judgmental models need to include the equivalent of cognitive noise.

Doubly blind: a systematic review of gender in randomised controlled trials.

PubMed

Phillips, Susan P; Hamberg, Katarina

2016-01-01

Although observational data show social characteristics such as gender or socio-economic status to be strong predictors of health, their impact is seldom investigated in randomised controlled studies (RCTs). Using a random sample of recent RCTs from high-impact journals, we examined how the most often recorded social characteristic, sex/gender, is considered in design, analysis, and interpretation. Of 712 RCTs published from September 2008 to 31 December 2013 in the Annals of Internal Medicine, British Medical Journal, Lancet, Canadian Medical Association Journal, or New England Journal of Medicine, we randomly selected 57 to analyse funding, methods, number of centres, documentation of social circumstances, inclusion/exclusion criteria, proportions of women/men, and reporting about sex/gender in analyses and discussion. Participants' sex was recorded in most studies (52/57). Thirty-nine percent included men and women approximately equally. Overrepresentation of men in 43% of studies without explicit exclusions for women suggested interference in selection processes. The minority of studies that did analyse sex/gender differences (22%) did not discuss or reflect upon these, or dismissed significant findings. Two studies reinforced traditional beliefs about women's roles, finding no impact of breastfeeding on infant health but nevertheless reporting possible benefits. Questionable methods such as changing protocols mid-study, having undefined exclusion criteria, allowing local researchers to remove participants from studies, and suggesting possible benefit where none was found were evident, particularly in industry-funded research. Social characteristics like sex/gender remain hidden from analyses and interpretation in RCTs, with loss of information and embedding of error all along the path from design to interpretation, and therefore, to uptake in clinical practice. Our results suggest that to broaden external validity, in particular, more refined trial designs and analyses that account for sex/gender and other social characteristics are needed.

CMPF: class-switching minimized pathfinding in metabolic networks.

PubMed

Lim, Kevin; Wong, Limsoon

2012-01-01

The metabolic network is an aggregation of enzyme catalyzed reactions that converts one compound to another. Paths in a metabolic network are a sequence of enzymes that describe how a chemical compound of interest can be produced in a biological system. As the number of such paths is quite large, many methods have been developed to score paths so that the k-shortest paths represent the set of paths that are biologically meaningful or efficient. However, these approaches do not consider whether the sequence of enzymes can be manufactured in the same pathway/species/localization. As a result, a predicted sequence might consist of groups of enzymes that operate in distinct pathway/species/localization and may not truly reflect the events occurring within cell. We propose a path weighting method CMPF (Class-switching Minimized Pathfinder) to search for routes in a metabolic network which minimizes pathway switching. In biological terms, a pathway is a series of chemical reactions which define a specific function (e.g. glycolysis). We conjecture that routes that cross many pathways are inefficient since different pathways define different metabolic functions. In addition, native routes are also well characterized within pathways, suggesting that reasonable paths should not involve too many pathway switches. Our method can be generalized when reactions participate in a class set (e.g., pathways, species or cellular localization) so that the paths predicted have minimal class crossings. We show that our method generates k-paths that involve the least number of class switching. In addition, we also show that native paths are recoverable and alternative paths deviates less from native paths compared to other methods. This suggests that paths ranked by our method could be a way to predict paths that are likely to occur in biological systems.

Curvature singularity and film-skating during drop impact

NASA Astrophysics Data System (ADS)

Duchemin, Laurent; Josserand, Christophe

2011-09-01

We study the influence of the surrounding gas in the dynamics of drop impact on a smooth surface. We use an axisymmetric model for which both the gas and the liquid are incompressible; lubrication regime applies for the gas film dynamics and the liquid viscosity is neglected. In the absence of surface tension a finite time singularity whose properties are analysed is formed and the liquid touches the solid on a circle. When surface tension is taken into account, a thin jet emerges from the zone of impact, skating above a thin gas layer. The thickness of the air film underneath this jet is always smaller than the mean free path in the gas suggesting that the liquid film eventually wets the surface. We finally suggest an aerodynamical instability mechanism for the splash.

The future of scenarios: issues in developing new climate change scenarios

NASA Astrophysics Data System (ADS)

Pitcher, Hugh M.

2009-04-01

In September, 2007, the IPCC convened a workshop to discuss how a new set of scenarios to support climate model runs, mitigation analyses, and impact, adaptation and vulnerability research might be developed. The first phase of the suggested new approach is now approaching completion. This article discusses some of the issues raised by scenario relevant research and analysis since the last set of IPCC scenarios were created (IPCC SRES, 2000) that will need to be addressed as new scenarios are developed by the research community during the second phase. These include (1) providing a logic for how societies manage to transition from historical paths to the various future development paths foreseen in the scenarios, (2) long-term economic growth issues, (3) the appropriate GDP metric to use (purchasing power parity or market exchange rates), (4) ongoing issues with moving from the broad geographic and time scales of the emission scenarios to the finer scales needed for impacts, adaptation and vulnerability analyses and (5) some possible ways to handle the urgent request from the policy community for some guidance on scenario likelihoods. The challenges involved in addressing these issues are manifold; the reward is greater credibility and deeper understanding of an analytic tool that does much to form the context within which many issues in addition to the climate problem will need to be addressed.

Dissolution-Driven Permeability Reduction of a Fractured Carbonate Caprock

PubMed Central

Ellis, Brian R.; Fitts, Jeffrey P.; Bromhal, Grant S.; McIntyre, Dustin L.; Tappero, Ryan; Peters, Catherine A.

2013-01-01

Abstract Geochemical reactions may alter the permeability of leakage pathways in caprocks, which serve a critical role in confining CO2 in geologic carbon sequestration. A caprock specimen from a carbonate formation in the Michigan sedimentary Basin was fractured and studied in a high-pressure core flow experiment. Inflowing brine was saturated with CO2 at 40°C and 10 MPa, resulting in an initial pH of 4.6, and had a calcite saturation index of −0.8. Fracture permeability decreased during the experiment, but subsequent analyses did not reveal calcite precipitation. Instead, experimental observations indicate that calcite dissolution along the fracture pathway led to mobilization of less soluble mineral particles that clogged the flow path. Analyses of core sections via electron microscopy, synchrotron-based X-ray diffraction imaging, and the first application of microbeam Ca K-edge X-ray absorption near edge structure, provided evidence that these occlusions were fragments from the host rock rather than secondary precipitates. X-ray computed tomography showed a significant loss of rock mass within preferential flow paths, suggesting that dissolution also removed critical asperities and caused mechanical closure of the fracture. The decrease in fracture permeability despite a net removal of material along the fracture pathway demonstrates a nonintuitive, inverse relationship between dissolution and permeability evolution in a fractured carbonate caprock. PMID:23633894

Using Wind Tunnels to Predict Bird Mortality in Wind Farms: The Case of Griffon Vultures

PubMed Central

de Lucas, Manuela; Ferrer, Miguel; Janss, Guyonne F. E.

2012-01-01

Background Wind farms have shown a spectacular growth during the last 15 years. Avian mortality through collision with moving rotor blades is well-known as one of the main adverse impacts of wind farms. In Spain, the griffon vulture incurs the highest mortality rates in wind farms. Methodology/Principal Findings As far as we know, this study is the first attempt to predict flight trajectories of birds in order to foresee potentially dangerous areas for wind farm development. We analyse topography and wind flows in relation to flight paths of griffon vultures, using a scaled model of the wind farm area in an aerodynamic wind tunnel, and test the difference between the observed flight paths of griffon vultures and the predominant wind flows. Different wind currents for each wind direction in the aerodynamic model were observed. Simulations of wind flows in a wind tunnel were compared with observed flight paths of griffon vultures. No statistical differences were detected between the observed flight trajectories of griffon vultures and the wind passages observed in our wind tunnel model. A significant correlation was found between dead vultures predicted proportion of vultures crossing those cells according to the aerodynamic model. Conclusions Griffon vulture flight routes matched the predominant wind flows in the area (i.e. they followed the routes where less flight effort was needed). We suggest using these kinds of simulations to predict flight paths over complex terrains can inform the location of wind turbines and thereby reduce soaring bird mortality. PMID:23152764

The role of initial coherence and path materials in the dynamics of three rock avalanche case histories

USGS Publications Warehouse

Aaron, Jordan; McDougall, Scott; Moore, Jeffrey R.; Coe, Jeffrey A.; Hungr, Oldrich

2017-01-01

BackgroundRock avalanches are flow-like landslides that can travel at extremely rapid velocities and impact surprisingly large areas. The mechanisms that lead to the unexpected mobility of these flows are unknown and debated. Mechanisms proposed in the literature can be broadly classified into those that rely on intrinsic characteristics of the rock avalanche material, and those that rely on extrinsic factors such as path material. In this work a calibration-based numerical model is used to back-analyze three rock avalanche case histories. The results of these back-analyses are then used to infer factors that govern rock avalanche motionResultsOur study has revealed two key insights that must be considered when analyzing rock avalanches. Results from two of the case histories demonstrate the importance of accounting for the initially coherent phase of rock avalanche motion. Additionally, the back-analyzed basal resistance parameters, as well as the best-fit rheology, are different for each case history. This suggests that the governing mechanisms controlling rock avalanche motion are unlikely to be intrinsic. The back-analyzed strength parameters correspond well to those that would be expected by considering the path material that the rock avalanches overran.ConclusionOur results show that accurate simulation of rock avalanche motion must account for the initially coherent phase of movement, and that the mechanisms governing rock avalanche motion are unlikely to be intrinsic to the failed material. Interaction of rock avalanche debris with path materials is the likely mechanism that governs the motion of many rock avalanches.

High-cost, high-capacity backbone for global brain communication.

PubMed

van den Heuvel, Martijn P; Kahn, René S; Goñi, Joaquín; Sporns, Olaf

2012-07-10

Network studies of human brain structural connectivity have identified a specific set of brain regions that are both highly connected and highly central. Recent analyses have shown that these putative hub regions are mutually and densely interconnected, forming a "rich club" within the human brain. Here we show that the set of pathways linking rich club regions forms a central high-cost, high-capacity backbone for global brain communication. Diffusion tensor imaging (DTI) data of two sets of 40 healthy subjects were used to map structural brain networks. The contributions to network cost and communication capacity of global cortico-cortical connections were assessed through measures of their topology and spatial embedding. Rich club connections were found to be more costly than predicted by their density alone and accounted for 40% of the total communication cost. Furthermore, 69% of all minimally short paths between node pairs were found to travel through the rich club and a large proportion of these communication paths consisted of ordered sequences of edges ("path motifs") that first fed into, then traversed, and finally exited the rich club, while passing through nodes of increasing and then decreasing degree. The prevalence of short paths that follow such ordered degree sequences suggests that neural communication might take advantage of strategies for dynamic routing of information between brain regions, with an important role for a highly central rich club. Taken together, our results show that rich club connections make an important contribution to interregional signal traffic, forming a central high-cost, high-capacity backbone for global brain communication.

Linking Family Characteristics with Poor Peer Relations: The Mediating Role of Conduct Problems

PubMed Central

Bierman, Karen Linn; Smoot, David L.

2012-01-01

Parent, teacher, and peer ratings were collected for 75 grade school boys to test the hypothesis that certain family interaction patterns would be associated with poor peer relations. Path analyses provided support for a mediational model, in which punitive and ineffective discipline was related to child conduct problems in home and school settings which, in turn, predicted poor peer relations. Further analyses suggested that distinct subgroups of boys could be identified who exhibited conduct problems at home only, at school only, in both settings, or in neither setting. Boys who exhibited cross-situational conduct problems were more likely to experience multiple concurrent problems (e.g., in both home and school settings) and were more likely than any other group to experience poor peer relations. However, only about one-third of the boys with poor peer relations in this sample exhibited problem profiles consistent with the proposed model (e.g., experienced high rates of punitive/ineffective home discipline and exhibited conduct problems in home and school settings), suggesting that the proposed model reflects one common (but not exclusive) pathway to poor peer relations. PMID:1865049

Reflexivity and Self-Development of Competencies as Key Drivers in Individuals' Learning and Career Paths: Cases from Italy

ERIC Educational Resources Information Center

Tomassini, Massimo; Zanazzi, Silvia

2014-01-01

The article is aimed at analysing the qualitative interviews (in the form of short life stories) carried out within the Learning and Career Paths (LCP) project in Italy. Theories, such as those of reflexivity, agency, self-construction, competencies, and transformation put forward by relevant authors in the sociological and educational field, are…

Path loss variation of on-body UWB channel in the frequency bands of IEEE 802.15.6 standard.

PubMed

Goswami, Dayananda; Sarma, Kanak C; Mahanta, Anil

2016-06-01

The wireless body area network (WBAN) has gaining tremendous attention among researchers and academicians for its envisioned applications in healthcare service. Ultra wideband (UWB) radio technology is considered as excellent air interface for communication among body area network devices. Characterisation and modelling of channel parameters are utmost prerequisite for the development of reliable communication system. The path loss of on-body UWB channel for each frequency band defined in IEEE 802.15.6 standard is experimentally determined. The parameters of path loss model are statistically determined by analysing measurement data. Both the line-of-sight and non-line-of-sight channel conditions are considered in the measurement. Variations of parameter values with the size of human body are analysed along with the variation of parameter values with the surrounding environments. It is observed that the parameters of the path loss model vary with the frequency band as well as with the body size and surrounding environment. The derived parameter values are specific to the particular frequency bands of IEEE 802.15.6 standard, which will be useful for the development of efficient UWB WBAN system.

Moderating Effects of Prevention-Focus on the Paths from Two Insecure Attachment Dimensions to Depression.

PubMed

Lee, Dong-Gwi; Park, Jae Joon; Bae, Byeong Hoon; Lim, Hyun-Woo

2018-04-03

The present study investigated the moderating effects of prevention-focus on the paths from the dimensions of insecure attachment (attachment avoidance and attachment anxiety) to depression. Two hundred twenty eight Korean college students completed the Experience in Close Relationship - Revised Scale; the Regulatory Focus Strategies Scale; and the Center for Epidemiologic Studies Depression Scale. Results revealed a significant moderating effect for prevention-focus on the path from attachment avoidance to depression, but not on the path from attachment anxiety to depression. They further suggest that different interventions are needed for different combinations of persons' insecure attachment dimensions and levels of prevention-focus. Counseling implications and suggestions for future research are discussed.

Alternations in burial and exhumation along the Selimiye (Kayabükü) shear zone in the Menderes Massif from detailed garnet pressure-temperature paths

NASA Astrophysics Data System (ADS)

Kelly, E. D.; Atakturk, K. R.; Catlos, E. J.; Lizzadro-McPherson, D. J.; Cemen, I.; Lovera, O. M.

2015-12-01

Pressure-temperature (P-T) paths derived from garnet chemical zoning and supported by thermal modeling record alternating burial and exhumation during Main Menderes Metamorphism in western Turkey. We studied six rocks along the Selimiye (Kayabükü) shear zone, three from the footwall (Çine nappe) and three from the hanging wall (Selimiye nappe). The shear zone bounds the southern Menderes Massif metamorphic core complex and has been suggested to record compression followed by extension. The rocks are lower-amphibolite facies garnet-bearing metapelites with nearly identical mineral suites. Retrograde overprinting hinders classical thermobarometry; to overcome this, preserved chemical zoning in garnet combined with a G-minimization approach was used to construct detailed P-T paths (e.g., 50 points in some paths). During continuous temperature increase, the Çine nappe paths show increasing, decreasing, and then increasing pressure (an N-shaped path) ending at 7-8 kbar and ~565-590 °C. The Selimiye nappe paths show a single increase in P-T ending at ~7.3 kbar and ~580 °C. Similar bulk-rock compositions in all samples and the separation by the shear zone suggest that garnets grew during distinct events in each nappe. The timing of garnet growth, and thus the P-T paths, is currently undetermined, as monazite inclusions in garnet appear secondary and complicated by excess common Pb. The Çine nappe N-shaped path describes alternations in burial and exhumation, possibly due to thrust motion along the shear zone. To demonstrate the physical plausibility of the P-T paths, a 2-D finite difference solution to the diffusion-advection equation was applied. The results of the thermal modeling suggest that thrusting, denudation, and renewed thrusting would produce similar changes in P-T to the N-shaped path. Thus, the Çine nappe N-shaped P-T path appears to record a gap in thrust motion along the Selimiye (Kayabükü) shear zone prior to ultimate unroofing of the massif.

Two betweenness centrality measures based on Randomized Shortest Paths

PubMed Central

Kivimäki, Ilkka; Lebichot, Bertrand; Saramäki, Jari; Saerens, Marco

2016-01-01

This paper introduces two new closely related betweenness centrality measures based on the Randomized Shortest Paths (RSP) framework, which fill a gap between traditional network centrality measures based on shortest paths and more recent methods considering random walks or current flows. The framework defines Boltzmann probability distributions over paths of the network which focus on the shortest paths, but also take into account longer paths depending on an inverse temperature parameter. RSP’s have previously proven to be useful in defining distance measures on networks. In this work we study their utility in quantifying the importance of the nodes of a network. The proposed RSP betweenness centralities combine, in an optimal way, the ideas of using the shortest and purely random paths for analysing the roles of network nodes, avoiding issues involving these two paradigms. We present the derivations of these measures and how they can be computed in an efficient way. In addition, we show with real world examples the potential of the RSP betweenness centralities in identifying interesting nodes of a network that more traditional methods might fail to notice. PMID:26838176

Comparison of Kalman filter estimates of zenith atmospheric path delays using the global positioning system and very long baseline interferometry

NASA Technical Reports Server (NTRS)

Tralli, David M.; Lichten, Stephen M.; Herring, Thomas A.

1992-01-01

Kalman filter estimates of zenith nondispersive atmospheric path delays at Westford, Massachusetts, Fort Davis, Texas, and Mojave, California, were obtained from independent analyses of data collected during January and February 1988 using the GPS and VLBI. The apparent accuracy of the path delays is inferred by examining the estimates and covariances from both sets of data. The ability of the geodetic data to resolve zenith path delay fluctuations is determined by comparing further the GPS Kalman filter estimates with corresponding wet path delays derived from water vapor radiometric data available at Mojave over two 8-hour data spans within the comparison period. GPS and VLBI zenith path delay estimates agree well within one standard deviation formal uncertainties (from 10-20 mm for GPS and 3-15 mm for VLBI) in four out of the five possible comparisons, with maximum differences of 5 and 21 mm over 8- to 12-hour data spans.

A taxonomy of integral reaction path analysis

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

Grcar, Joseph F.; Day, Marcus S.; Bell, John B.

2004-12-23

W. C. Gardiner observed that achieving understanding through combustion modeling is limited by the ability to recognize the implications of what has been computed and to draw conclusions about the elementary steps underlying the reaction mechanism. This difficulty can be overcome in part by making better use of reaction path analysis in the context of multidimensional flame simulations. Following a survey of current practice, an integral reaction flux is formulated in terms of conserved scalars that can be calculated in a fully automated way. Conditional analyses are then introduced, and a taxonomy for bidirectional path analysis is explored. Many examplesmore » illustrate the resulting path analysis and uncover some new results about nonpremixed methane-air laminar jets.« less

Exploring the utility of institutional theory in analysing international health agency stasis and change.

PubMed

Gómez, Eduardo J

2013-10-01

Of recent interest is the capacity of international health agencies to adapt to changes in the global health environment and country needs. Yet, little is known about the potential benefits of using social science institutional theory, such as path dependency and institutional change theory, to explain why some international agencies, such as the WHO and the Global Fund to Fight AIDS, Tuberculosis and Malaria, fail to adapt, whereas others, such as the World Bank and UNAIDS, have. This article suggests that these institutional theories can help to better understand these differences in international agency adaptive capacity, while highlighting new areas of policy research and analysis.

Equipartition terms in transition path ensemble: Insights from molecular dynamics simulations of alanine dipeptide.

PubMed

Li, Wenjin

2018-02-28

Transition path ensemble consists of reactive trajectories and possesses all the information necessary for the understanding of the mechanism and dynamics of important condensed phase processes. However, quantitative description of the properties of the transition path ensemble is far from being established. Here, with numerical calculations on a model system, the equipartition terms defined in thermal equilibrium were for the first time estimated in the transition path ensemble. It was not surprising to observe that the energy was not equally distributed among all the coordinates. However, the energies distributed on a pair of conjugated coordinates remained equal. Higher energies were observed to be distributed on several coordinates, which are highly coupled to the reaction coordinate, while the rest were almost equally distributed. In addition, the ensemble-averaged energy on each coordinate as a function of time was also quantified. These quantitative analyses on energy distributions provided new insights into the transition path ensemble.

Efficient computation paths for the systematic analysis of sensitivities

NASA Astrophysics Data System (ADS)

Greppi, Paolo; Arato, Elisabetta

2013-01-01

A systematic sensitivity analysis requires computing the model on all points of a multi-dimensional grid covering the domain of interest, defined by the ranges of variability of the inputs. The issues to efficiently perform such analyses on algebraic models are handling solution failures within and close to the feasible region and minimizing the total iteration count. Scanning the domain in the obvious order is sub-optimal in terms of total iterations and is likely to cause many solution failures. The problem of choosing a better order can be translated geometrically into finding Hamiltonian paths on certain grid graphs. This work proposes two paths, one based on a mixed-radix Gray code and the other, a quasi-spiral path, produced by a novel heuristic algorithm. Some simple, easy-to-visualize examples are presented, followed by performance results for the quasi-spiral algorithm and the practical application of the different paths in a process simulation tool.

Iron-oxide minerals affect extracellular electron-transfer paths of Geobacter spp.

PubMed

Kato, Souichiro; Hashimoto, Kazuhito; Watanabe, Kazuya

2013-01-01

Some bacteria utilize (semi)conductive iron-oxide minerals as conduits for extracellular electron transfer (EET) to distant, insoluble electron acceptors. A previous study demonstrated that microbe/mineral conductive networks are constructed in soil ecosystems, in which Geobacter spp. share dominant populations. In order to examine how (semi)conductive iron-oxide minerals affect EET paths of Geobacter spp., the present study grew five representative Geobacter strains on electrodes as the sole electron acceptors in the absence or presence of (semi)conductive iron oxides. It was found that iron-oxide minerals enhanced current generation by three Geobacter strains, while no effect was observed in another strain. Geobacter sulfurreducens was the only strain that generated substantial amounts of currents both in the presence and absence of the iron oxides. Microscopic, electrochemical and transcriptomic analyses of G. sulfurreducens disclosed that this strain constructed two distinct types of EET path; in the absence of iron-oxide minerals, bacterial biofilms rich in extracellular polymeric substances were constructed, while composite networks made of mineral particles and microbial cells (without polymeric substances) were developed in the presence of iron oxides. It was also found that uncharacterized c-type cytochromes were up-regulated in the presence of iron oxides that were different from those found in conductive biofilms. These results suggest the possibility that natural (semi)conductive minerals confer energetic and ecological advantages on Geobacter, facilitating their growth and survival in the natural environment.

Being there is important, but getting there matters too: the role of path in the valuation process.

PubMed

Goldberg, Julie H

2006-01-01

Traditional decision-analytic models presume that utilities are invariant to context. The influence of 2 types of context on patients' utility assessments was examined here the path by which one reaches a health state and personal experience with a health state. Three groups of patients were interviewed: men older than age 49 years with prostate cancer but no diabetes (CaP), diabetes but no prostate cancer (DM), and neither disease (ND). The utility of erectile dysfunction (ED) was assessed using a standard gamble (SG). Each subject completed 2 SGs: 1) a no-context version that gave no explanation for the cause of ED and 2) a contextualized version in which prostate cancer treatment, the failure to manage diabetes, or the natural course of aging was said to be the cause. Patients with disease assigned higher utilities to ED in a matching context than in discrepant contexts. Regression models found that the valuation process was also sensitive to the match between disease path in the utility assessment and patients' personal experiences. These findings lend insight into why acontextual utility assessments typically used in decision analyses have not been able to predict patient behavior as well as expected. The valuation process appears to change systematically when context is specified, suggesting that unspecified contexts rather than random error may lead to fluctuations in the values assigned to identical health states.

Homing by path integration when a locomotion trajectory crosses itself.

PubMed

Yamamoto, Naohide; Meléndez, Jayleen A; Menzies, Derek T

2014-01-01

Path integration is a process with which navigators derive their current position and orientation by integrating self-motion signals along a locomotion trajectory. It has been suggested that path integration becomes disproportionately erroneous when the trajectory crosses itself. However, there is a possibility that this previous finding was confounded by effects of the length of a traveled path and the amount of turns experienced along the path, two factors that are known to affect path integration performance. The present study was designed to investigate whether the crossover of a locomotion trajectory truly increases errors of path integration. In an experiment, blindfolded human navigators were guided along four paths that varied in their lengths and turns, and attempted to walk directly back to the beginning of the paths. Only one of the four paths contained a crossover. Results showed that errors yielded from the path containing the crossover were not always larger than those observed in other paths, and the errors were attributed solely to the effects of longer path lengths or greater degrees of turns. These results demonstrated that path crossover does not always cause significant disruption in path integration processes. Implications of the present findings for models of path integration are discussed.

Substrate transport and anion permeation proceed through distinct pathways in glutamate transporters

PubMed Central

Cheng, Mary Hongying; Torres-Salazar, Delany; Gonzalez-Suarez, Aneysis D; Amara, Susan G; Bahar, Ivet

2017-01-01

Advances in structure-function analyses and computational biology have enabled a deeper understanding of how excitatory amino acid transporters (EAATs) mediate chloride permeation and substrate transport. However, the mechanism of structural coupling between these functions remains to be established. Using a combination of molecular modeling, substituted cysteine accessibility, electrophysiology and glutamate uptake assays, we identified a chloride-channeling conformer, iChS, transiently accessible as EAAT1 reconfigures from substrate/ion-loaded into a substrate-releasing conformer. Opening of the anion permeation path in this iChS is controlled by the elevator-like movement of the substrate-binding core, along with its wall that simultaneously lines the anion permeation path (global); and repacking of a cluster of hydrophobic residues near the extracellular vestibule (local). Moreover, our results demonstrate that stabilization of iChS by chemical modifications favors anion channeling at the expense of substrate transport, suggesting a mutually exclusive regulation mediated by the movement of the flexible wall lining the two regions. DOI: http://dx.doi.org/10.7554/eLife.25850.001 PMID:28569666

A Network Approach to Environmental Impact in Psychotic Disorder: Brief Theoretical Framework.

PubMed

Isvoranu, Adela-Maria; Borsboom, Denny; van Os, Jim; Guloksuz, Sinan

2016-07-01

The spectrum of psychotic disorder represents a multifactorial and heterogeneous condition and is thought to result from a complex interplay between genetic and environmental factors. In the current paper, we analyze this interplay using network analysis, which has been recently proposed as a novel psychometric framework for the study of mental disorders. Using general population data, we construct network models for the relation between 3 environmental risk factors (cannabis use, developmental trauma, and urban environment), dimensional measures of psychopathology (anxiety, depression, interpersonal sensitivity, obsessive-compulsive disorder, phobic anxiety, somatizations, and hostility), and a composite measure of psychosis expression. Results indicate the existence of specific paths between environmental factors and symptoms. These paths most often involve cannabis use. In addition, the analyses suggest that symptom networks are more strongly connected for people exposed to environmental risk factors, implying that environmental exposure may lead to less resilient symptom networks. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Master equations and the theory of stochastic path integrals

NASA Astrophysics Data System (ADS)

Weber, Markus F.; Frey, Erwin

2017-04-01

This review provides a pedagogic and self-contained introduction to master equations and to their representation by path integrals. Since the 1930s, master equations have served as a fundamental tool to understand the role of fluctuations in complex biological, chemical, and physical systems. Despite their simple appearance, analyses of master equations most often rely on low-noise approximations such as the Kramers-Moyal or the system size expansion, or require ad-hoc closure schemes for the derivation of low-order moment equations. We focus on numerical and analytical methods going beyond the low-noise limit and provide a unified framework for the study of master equations. After deriving the forward and backward master equations from the Chapman-Kolmogorov equation, we show how the two master equations can be cast into either of four linear partial differential equations (PDEs). Three of these PDEs are discussed in detail. The first PDE governs the time evolution of a generalized probability generating function whose basis depends on the stochastic process under consideration. Spectral methods, WKB approximations, and a variational approach have been proposed for the analysis of the PDE. The second PDE is novel and is obeyed by a distribution that is marginalized over an initial state. It proves useful for the computation of mean extinction times. The third PDE describes the time evolution of a ‘generating functional’, which generalizes the so-called Poisson representation. Subsequently, the solutions of the PDEs are expressed in terms of two path integrals: a ‘forward’ and a ‘backward’ path integral. Combined with inverse transformations, one obtains two distinct path integral representations of the conditional probability distribution solving the master equations. We exemplify both path integrals in analysing elementary chemical reactions. Moreover, we show how a well-known path integral representation of averaged observables can be recovered from them. Upon expanding the forward and the backward path integrals around stationary paths, we then discuss and extend a recent method for the computation of rare event probabilities. Besides, we also derive path integral representations for processes with continuous state spaces whose forward and backward master equations admit Kramers-Moyal expansions. A truncation of the backward expansion at the level of a diffusion approximation recovers a classic path integral representation of the (backward) Fokker-Planck equation. One can rewrite this path integral in terms of an Onsager-Machlup function and, for purely diffusive Brownian motion, it simplifies to the path integral of Wiener. To make this review accessible to a broad community, we have used the language of probability theory rather than quantum (field) theory and do not assume any knowledge of the latter. The probabilistic structures underpinning various technical concepts, such as coherent states, the Doi-shift, and normal-ordered observables, are thereby made explicit.

Master equations and the theory of stochastic path integrals.

PubMed

Weber, Markus F; Frey, Erwin

2017-04-01

This review provides a pedagogic and self-contained introduction to master equations and to their representation by path integrals. Since the 1930s, master equations have served as a fundamental tool to understand the role of fluctuations in complex biological, chemical, and physical systems. Despite their simple appearance, analyses of master equations most often rely on low-noise approximations such as the Kramers-Moyal or the system size expansion, or require ad-hoc closure schemes for the derivation of low-order moment equations. We focus on numerical and analytical methods going beyond the low-noise limit and provide a unified framework for the study of master equations. After deriving the forward and backward master equations from the Chapman-Kolmogorov equation, we show how the two master equations can be cast into either of four linear partial differential equations (PDEs). Three of these PDEs are discussed in detail. The first PDE governs the time evolution of a generalized probability generating function whose basis depends on the stochastic process under consideration. Spectral methods, WKB approximations, and a variational approach have been proposed for the analysis of the PDE. The second PDE is novel and is obeyed by a distribution that is marginalized over an initial state. It proves useful for the computation of mean extinction times. The third PDE describes the time evolution of a 'generating functional', which generalizes the so-called Poisson representation. Subsequently, the solutions of the PDEs are expressed in terms of two path integrals: a 'forward' and a 'backward' path integral. Combined with inverse transformations, one obtains two distinct path integral representations of the conditional probability distribution solving the master equations. We exemplify both path integrals in analysing elementary chemical reactions. Moreover, we show how a well-known path integral representation of averaged observables can be recovered from them. Upon expanding the forward and the backward path integrals around stationary paths, we then discuss and extend a recent method for the computation of rare event probabilities. Besides, we also derive path integral representations for processes with continuous state spaces whose forward and backward master equations admit Kramers-Moyal expansions. A truncation of the backward expansion at the level of a diffusion approximation recovers a classic path integral representation of the (backward) Fokker-Planck equation. One can rewrite this path integral in terms of an Onsager-Machlup function and, for purely diffusive Brownian motion, it simplifies to the path integral of Wiener. To make this review accessible to a broad community, we have used the language of probability theory rather than quantum (field) theory and do not assume any knowledge of the latter. The probabilistic structures underpinning various technical concepts, such as coherent states, the Doi-shift, and normal-ordered observables, are thereby made explicit.

Identifying built environmental patterns using cluster analysis and GIS: relationships with walking, cycling and body mass index in French adults.

PubMed

Charreire, Hélène; Weber, Christiane; Chaix, Basile; Salze, Paul; Casey, Romain; Banos, Arnaud; Badariotti, Dominique; Kesse-Guyot, Emmanuelle; Hercberg, Serge; Simon, Chantal; Oppert, Jean-Michel

2012-05-23

Socio-ecological models suggest that both individual and neighborhood characteristics contribute to facilitating health-enhancing behaviors such as physical activity. Few European studies have explored relationships between local built environmental characteristics, recreational walking and cycling and weight status in adults. The aim of this study was to identify built environmental patterns in a French urban context and to assess associations with recreational walking and cycling behaviors as performed by middle-aged adult residents. We used a two-step procedure based on cluster analysis to identify built environmental patterns in the region surrounding Paris, France, using measures derived from Geographic Information Systems databases on green spaces, proximity facilities (destinations) and cycle paths. Individual data were obtained from participants in the SU.VI.MAX cohort; 1,309 participants residing in the Ile-de-France in 2007 were included in this analysis. Associations between built environment patterns, leisure walking/cycling data (h/week) and measured weight status were assessed using multinomial logistic regression with adjustment for individual and neighborhood characteristics. Based on accessibility to green spaces, proximity facilities and availability of cycle paths, seven built environmental patterns were identified. The geographic distribution of built environmental patterns in the Ile-de-France showed that a pattern characterized by poor spatial accessibility to green spaces and proximity facilities and an absence of cycle paths was found only in neighborhoods in the outer suburbs, whereas patterns characterized by better spatial accessibility to green spaces, proximity facilities and cycle paths were more evenly distributed across the region. Compared to the reference pattern (poor accessibility to green areas and facilities, absence of cycle paths), subjects residing in neighborhoods characterized by high accessibility to green areas and local facilities and by a high density of cycle paths were more likely to walk/cycle, after adjustment for individual and neighborhood sociodemographic characteristics (OR = 2.5 95%CI 1.4-4.6). Body mass index did not differ across patterns. Built environmental patterns were associated with walking and cycling among French adults. These analyses may be useful in determining urban and public health policies aimed at promoting a healthy lifestyle.

Constraining Path-Dependent Processes During Basalt-CO2 Interactions with Observations From Flow-Through and Batch Experiments

NASA Astrophysics Data System (ADS)

Thomas, D.; Garing, C.; Zahasky, C.; Harrison, A. L.; Bird, D. K.; Benson, S. M.; Oelkers, E. H.; Maher, K.

2017-12-01

Predicting the timing and magnitude of CO2 storage in basaltic rocks relies partly on quantifying the dependence of reactivity on flow path and mineral distribution. Flow-through experiments that use intact cores are advantageous because the spatial heterogeneity of pore space and reactive phases is preserved. Combining aqueous geochemical analyses and petrologic characterization with non-destructive imaging techniques (e.g. micro-computed tomography) constrains the relationship between irreversible reactions, pore connectivity and accessible surface area. Our work enhances these capabilities by dynamically imaging flow through vesicular basalts with Positron Emission Tomography (PET) scanning. PET highlights the path a fluid takes by detecting photons produced during radioactive decay of an injected radiotracer (FDG). We have performed single-phase, CO2-saturated flow-through experiments with basaltic core from Iceland at CO2 sequestration conditions (50 °C; 76-90 bar Ptot). Constant flow rate and continuous pressure measurements at the inlet and outlet of the core constrain permeability. We monitor geochemical evolution through cation and anion analysis of outlet fluid sampled periodically. Before and after reaction, we perform PET scans and characterize the core using micro-CT. The PET scans indicate a discrete, localized flow path that appears to be a micro-crack connecting vesicles, suggesting that vesicle-lining minerals are immediately accessible and important reactants. Rapid increases in aqueous cation concentration, pH and HCO3- indicate that the rock reacts nearly immediately after CO2 injection. After 24 hours the solute release decreases, which may reflect a transition to reaction with phases with slower kinetic dissolution rates (e.g. zeolites and glasses to feldspar), a decrease in available reactive surface area or precipitation. We have performed batch experiments using crushed material of the same rock to elucidate the effect of flow path geometry and mineral accessibility on geochemical evolution. Interestingly, surface area-normalized dissolution rates as evinced by SiO2 release in all experiments approach similar values ( 10-15 mol/cm2/s). Our experiments show how imaging techniques are helpful in interpreting path-dependent processes in open systems.

Theoretical Study of the Mechanism of Oxoiron(IV) Formation from H2O2 and a Nonheme Iron(II) Complex: O–O Cleavage Involving Proton-Coupled Electron Transfer

PubMed Central

Hirao, Hajime; Li, Feifei; Que, Lawrence; Morokuma, Keiji

2011-01-01

It has recently been shown that the nonheme oxoiron(IV) species supported by the 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane ligand (TMC) can be generated in near-quantitative yield by reacting [FeII(TMC)(OTf)2] with a stoichiometric amount of H2O2 in CH3CN in the presence of 2,6-lutidine (Li, F.; England, J.; Que L., Jr. J. Am. Chem. Soc. 2010, 132, 2134–2135). This finding has major implications for O–O bond cleavage events in both Fenton chemistry and nonheme iron enzymes. To understand the mechanism of this process, especially the intimate details of the O–O bond cleavage step, a series of density functional theory (DFT) calculations and analyses have been carried out. Two distinct reaction paths (A and B) were identified. Path A consists of two principal steps: (1) coordination of H2O2 to Fe(II) and (2) a combination of partial homolytic O–O bond cleavage and proton-coupled electron transfer (PCET). The latter combination renders the rate-limiting O–O cleavage effectively a heterolytic process. Path B proceeds via a simultaneous homolytic O–O bond cleavage of H2O2 and Fe–O bond formation. This is followed by H-abstraction from the resultant Fe(III)–OH species by an •OH radical. Calculations suggest that path B is plausible in the absence of base. However, once 2,6-lutidine is added to the reacting system, the reaction barrier is lowered and more importantly the mechanistic path switches to path A, where 2,6-lutidine plays an essential role as an acid-base catalyst in a manner similar to how the distal histidine or glutamate residue assists in Compound I formation in heme peroxidases. The reaction was found to proceed predominantly on the quintet spin state surface, and a transition to the triplet state, the experimentally known ground state for the TMC-oxoiron(IV) species, occurs in the last stage of the oxoiron(IV) formation process. PMID:21678930

Large-scale transcriptome analysis reveals arabidopsis metabolic pathways are frequently influenced by different pathogens.

PubMed

Jiang, Zhenhong; He, Fei; Zhang, Ziding

2017-07-01

Through large-scale transcriptional data analyses, we highlighted the importance of plant metabolism in plant immunity and identified 26 metabolic pathways that were frequently influenced by the infection of 14 different pathogens. Reprogramming of plant metabolism is a common phenomenon in plant defense responses. Currently, a large number of transcriptional profiles of infected tissues in Arabidopsis (Arabidopsis thaliana) have been deposited in public databases, which provides a great opportunity to understand the expression patterns of metabolic pathways during plant defense responses at the systems level. Here, we performed a large-scale transcriptome analysis based on 135 previously published expression samples, including 14 different pathogens, to explore the expression pattern of Arabidopsis metabolic pathways. Overall, metabolic genes are significantly changed in expression during plant defense responses. Upregulated metabolic genes are enriched on defense responses, and downregulated genes are enriched on photosynthesis, fatty acid and lipid metabolic processes. Gene set enrichment analysis (GSEA) identifies 26 frequently differentially expressed metabolic pathways (FreDE_Paths) that are differentially expressed in more than 60% of infected samples. These pathways are involved in the generation of energy, fatty acid and lipid metabolism as well as secondary metabolite biosynthesis. Clustering analysis based on the expression levels of these 26 metabolic pathways clearly distinguishes infected and control samples, further suggesting the importance of these metabolic pathways in plant defense responses. By comparing with FreDE_Paths from abiotic stresses, we find that the expression patterns of 26 FreDE_Paths from biotic stresses are more consistent across different infected samples. By investigating the expression correlation between transcriptional factors (TFs) and FreDE_Paths, we identify several notable relationships. Collectively, the current study will deepen our understanding of plant metabolism in plant immunity and provide new insights into disease-resistant crop improvement.

Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna

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

Redman, R.S.; Rodriguez, R.J.; Clifton, D.R.

1999-02-01

A nonpathogenic mutant of Colletotrichum magna (path-1) was previously shown to protect watermelon (Citrullus lanatus) and cucumber (Cucumis sativus) seedlings from anthracnose disease elicited by wild-type C. magna. Disease protection was observed in stems of path-1-colonized cucurbits but not in cotyledons, indicating that path-1 conferred tissue-specific and/or localized protection. Plant biochemical indicators of a localized and systemic (peroxidase, phenylalanine ammonia-lyase, lignin, and salicylic acid) plant-defense response were investigated in anthracnose-resistant and-susceptible cultivars of cucurbit seedlings exposed to four treatments: (1) water (control), (2) path-1 conidia, (3) wild-type conidia, and (4) challenge conditions (inoculation into path-1 conidia for 48 h andmore » then exposure to wild-type conidia). Collectively, these analyses indicated that disease protection in path-1-colonized plants was correlated with the ability of these plants to mount a defense response more rapidly and to equal or greater levels than plants exposed to wild-type C. magna alone. Watermelon plants colonized with path-1 were also protected against disease caused by Colletotrichum orbiculare and Fusarium oxysporum. A model based on the kinetics of plant-defense activation is presented to explain the mechanism of path-1-conferred disease protection.« less

Biochemical analysis of plant protection afforded by a nonpathogenic endophytic mutant of Colletotrichum magna

USGS Publications Warehouse

Redman, R.S.; Freeman, S.; Clifton, D.R.; Morrel, J.; Brown, G.; Rodriguez, R.J.

1999-01-01

A nonpathogenic mutant of Colletotrichum magna (path-1) was previously shown to protect watermelon (Citrullus lanatus) and cucumber (Cucumis sativus) seedlings from anthracnose disease elicited by wild-type C. magna. Disease protection was observed in stems of path-1-colonized cucurbits but not in cotyledons, indicating that path-1 conferred tissue-specific and/or localized protection. Plant biochemical indicators of a localized and systemic (peroxidase, phenylalanine ammonia-lyase, lignin, and salicylic acid) 'plant-defense' response were investigated in anthracnose-resistant and -susceptible cultivars of cucurbit seedlings exposed to four treatments: (1) water (control), (2) path-1 conidia, (3) wild-type conidia, and (4) challenge conditions (inoculation into path-1 conidia for 48 h and then exposure to wild-type conidia). Collectively, these analyses indicated that disease protection in path-1 colonized plants was correlated with the ability of these plants to mount a defense response more rapidly and to equal or greater levels than plants exposed to wild-type C. magna alone. Watermelon plants colonized with path-1 were also protected against disease caused by Colletotrichum orbiculare and Fusarium oxysporum. A model based on the kinetics of plant-defense activation is presented to explain the mechanism of path-1-conferred disease protection.

Design of a feedback-feedforward steering controller for accurate path tracking and stability at the limits of handling

NASA Astrophysics Data System (ADS)

Kapania, Nitin R.; Gerdes, J. Christian

2015-12-01

This paper presents a feedback-feedforward steering controller that simultaneously maintains vehicle stability at the limits of handling while minimising lateral path tracking deviation. The design begins by considering the performance of a baseline controller with a lookahead feedback scheme and a feedforward algorithm based on a nonlinear vehicle handling diagram. While this initial design exhibits desirable stability properties at the limits of handling, the steady-state path deviation increases significantly at highway speeds. Results from both linear and nonlinear analyses indicate that lateral path tracking deviations are minimised when vehicle sideslip is held tangent to the desired path at all times. Analytical results show that directly incorporating this sideslip tangency condition into the steering feedback dramatically improves lateral path tracking, but at the expense of poor closed-loop stability margins. However, incorporating the desired sideslip behaviour into the feedforward loop creates a robust steering controller capable of accurate path tracking and oversteer correction at the physical limits of tyre friction. Experimental data collected from an Audi TTS test vehicle driving at the handling limits on a full length race circuit demonstrates the improved performance of the final controller design.

Root canal anatomy preservation of WaveOne reciprocating files with or without glide path.

PubMed

Berutti, Elio; Paolino, Davide Salvatore; Chiandussi, Giorgio; Alovisi, Mario; Cantatore, Giuseppe; Castellucci, Arnaldo; Pasqualini, Damiano

2012-01-01

This study evaluated the influence of glide path on canal curvature and axis modification after instrumentation with WaveOne Primary reciprocating files. Thirty ISO 15, 0.02 taper Endo Training Blocks were used. In group 1, glide path was created with PathFile 1, 2, and 3 at working length, whereas in group 2, glide path was not performed. In both groups, canals were shaped with WaveOne Primary reciprocating files at working length. Preinstrumentation and postinstrumentation digital images were superimposed and processed with Matlab r2010b software to analyze the curvature radius ratio (CRr) and the relative axis error (rAe), representing canal curvature modification. Data were analyzed with 1-way balanced analyses of variance at 2 levels (P < .05). Glide path was found to be extremely significant for both CRr parameter (F = 9.59; df = 1; P = .004) and rAe parameter (F = 13.55; df = 1; P = .001). Canal modifications seem to be significantly reduced when previous glide path is performed by using the new WaveOne nickel-titanium single-file system. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Career paths in physicians' postgraduate training - an eight-year follow-up study.

PubMed

Buddeberg-Fischer, Barbara; Stamm, Martina; Klaghofer, Richard

2010-10-06

To date, there are hardly any studies on the choice of career path in medical school graduates. The present study aimed to investigate what career paths can be identified in the course of postgraduate training of physicians; what factors have an influence on the choice of a career path; and in what way the career paths are correlated with career-related factors as well as with work-life balance aspirations. The data reported originates from five questionnaire surveys of the prospective SwissMedCareer Study, beginning in 2001 (T1, last year of medical school). The study sample consisted of 358 physicians (197 females, 55%; 161 males, 45%) participating at each assessment from T2 (2003, first year of residency) to T5 (2009, seventh year of residency), answering the question: What career do you aspire to have? Furthermore, personal characteristics, chosen specialty, career motivation, mentoring experience, work-life balance as well as workload, career success and career satisfaction were assessed. Career paths were analysed with cluster analysis, and differences between clusters analysed with multivariate methods. The cluster analysis revealed four career clusters which discriminated distinctly between each other: (1) career in practice, (2) hospital career, (3) academic career, and (4) changing career goal. From T3 (third year of residency) to T5, respondents in Cluster 1-3 were rather stable in terms of their career path aspirations, while those assigned to Cluster 4 showed a high fluctuation in their career plans. Physicians in Cluster 1 showed high values in extraprofessional concerns and often consider part-time work. Cluster 2 and 3 were characterised by high instrumentality, intrinsic and extrinsic career motivation, career orientation and high career success. No cluster differences were seen in career satisfaction. In Cluster 1 and 4, females were overrepresented. Trainees should be supported to stay on the career path that best suits his/her personal and professional profile. Attention should be paid to the subgroup of physicians in Cluster 4 switching from one to another career goal in the course of their postgraduate training.

The differential effect of the teacher-student interpersonal relationship on student outcomes for students with different ethnic backgrounds.

PubMed

den Brok, Perry; van Tartwijk, Jan; Wubbels, Theo; Veldman, Ietje

2010-06-01

The differential effectiveness of schools and teachers receives a growing interest, but few studies focused on the relevance of student ethnicity for this effectiveness and only a small number of these studies investigated teaching in terms of the teacher-student interpersonal relationship. Furthermore, the methodology employed often restricted researchers to investigating direct effects between variables across large samples of students. This study uses causal modelling to investigate associations between student background characteristics, students' perceptions of the teacher-student interpersonal relationship, and student outcomes, across and within several population subgroups in Dutch secondary multi-ethnic classes. Multi-group structural equation modelling was used to investigate causal paths between variables in four ethnic groups: Dutch (N=387), Turkish first- and second-generation immigrant students (N=267), Moroccan first and second generation (N=364), and Surinamese second-generation students (N=101). Different structural paths were necessary to explain associations between variables in the different (sub) groups. Different amounts of variance in student attitudes could be explained by these variables. The teacher-student interpersonal relationship is more important for students with a non-Dutch background than for students with a Dutch background. Results suggest that the teacher-student relationship is more important for second generation than for first-generation immigrant students. Multi-group causal model analyses can provide a better, more differentiated picture of the associations between student background variables, teacher behaviour, and student outcomes than do more traditional types of analyses.

The Intention to Discuss Advance Care Planning in the Context of Alzheimer's Disease Among Korean Americans.

PubMed

Hong, Michin; Casado, Banghwa L; Lee, Sang E

2018-01-29

Advance care planning (ACP) is crucial for quality end-of-life care for patients with Alzheimer's disease. However, limited evidence is available about ACP among ethnic minorities, particularly in the context of Alzheimer's disease. The purpose of this study was to examine intention to discuss ACP for a family member with Alzheimer's disease among Korean Americans. Guided by the theory of planned behavior and prior research, we examined the relationships between acculturation, attitudes, subjective norms, perceived control, and intention to discuss ACP for a family member with Alzheimer's disease. Path analyses were conducted on a cross-sectional convenience sample of 261 Korean Americans. Age, gender, education, and knowledge about Alzheimer's disease and ACP were included as covariates. Our descriptive findings showed positive attitudes, strong subjective norms, and a high level of perceived control toward ACP discussion among the participants. The path analyses revealed that attitudes and subjective norms were positively related to intention for ACP discussion. Perceived control was not related to intention for ACP discussion. Among the covariates, greater knowledge about Alzheimer's disease was the only factor shown to be associated with the intention for ACP discussion. To promote ACP among this population, educational interventions designed to address positives attitudes and subjective norms toward ACP are suggested. © The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of wheat-maize straw return on the fate of nitrate in groundwater in the Huaihe River Basin, China.

PubMed

Li, Rongfu; Ruan, Xiaohong; Bai, Ying; Ma, Tianhai; Liu, Congqiang

2017-08-15

Straw return is becoming a routine practice in disposing of crop residues worldwide. However, the potential effect of such operation on the chemistry of local groundwater is not well documented. Here, shallow groundwater in an area where wheat-maize straw return is practiced was analyzed, and the seasonal changes in the nitrate concentration and the isotope compositions of NO 3 - and H 2 O were determined along two flow paths. Measured δD and δ 18 O in waters indicated that the groundwater was mainly recharged by atmospheric precipitation, while measured δ 15 N and δ 18 O in nitrate suggested that the sources for groundwater NO 3 - included urea fertilizer, soil nitrogen, and sewage/manure. Reduced NO 3 - concentrations coincided with an enrichment of organic matter in the groundwater of the straw return area, revealing an environmental condition that facilitates nitrate reduction, whereas increased δ 15 N-NO 3 - and δ 18 O-NO 3 - along the flow path suggested the occurrence of denitrification. Further analyses showed that, compared to the cases in the absence of straw return, as much as 80% and 90% of groundwater nitrate was removed in low and high water seasons in the straw return area, pointing to a potential positive effect of straw return to groundwater quality. Copyright © 2017 Elsevier B.V. All rights reserved.

Methane fluxes above the Hainich forest by True Eddy Accumulation and Eddy Covariance

NASA Astrophysics Data System (ADS)

Siebicke, Lukas; Gentsch, Lydia; Knohl, Alexander

2016-04-01

Understanding the role of forests for the global methane cycle requires quantifying vegetation-atmosphere exchange of methane, however observations of turbulent methane fluxes remain scarce. Here we measured turbulent fluxes of methane (CH4) above a beech-dominated old-growth forest in the Hainich National Park, Germany, and validated three different measurement approaches: True Eddy Accumulation (TEA, closed-path laser spectroscopy), and eddy covariance (EC, open-path and closed-path laser spectroscopy, respectively). The Hainich flux tower is a long-term Fluxnet and ICOS site with turbulent fluxes and ecosystem observations spanning more than 15 years. The current study is likely the first application of True Eddy Accumulation (TEA) for the measurement of turbulent exchange of methane and one of the very few studies comparing open-path and closed-path eddy covariance (EC) setups side-by-side. We observed uptake of methane by the forest during the day (a methane sink with a maximum rate of 0.03 μmol m-2 s-1 at noon) and no or small fluxes of methane from the forest to the atmosphere at night (a methane source of typically less than 0.01 μmol m-2 s-1) based on continuous True Eddy Accumulation measurements in September 2015. First results comparing TEA to EC CO2 fluxes suggest that True Eddy Accumulation is a valid option for turbulent flux quantifications using slow response gas analysers (here CRDS laser spectroscopy, other potential techniques include mass spectroscopy). The TEA system was one order of magnitude more energy efficient compared to closed-path eddy covariance. The open-path eddy covariance setup required the least amount of user interaction but is often constrained by low signal-to-noise ratios obtained when measuring methane fluxes over forests. Closed-path eddy covariance showed good signal-to-noise ratios in the lab, however in the field it required significant amounts of user intervention in addition to a high power consumption. We conclude, based on preliminary evidence, that the Hainich forest acted as a moderate net sink for methane during the investigation. This supports earlier findings from chamber measurements at the Hainich forest site and is similar to findings from other forest sites. Our observations will be continued through 2016 and beyond to provide longer-term methane flux time series spanning entire seasons. However, the current data set already provides a basis for further consolidating methods of measurements and analysis of turbulent methane fluxes using eddy covariance and true eddy accumulation.

Cluster and Multiple Correspondence Analyses in Rheumatology: Paths to Uncovering Relationships in a Sea of Data.

PubMed

Han, Lu; Benseler, Susanne M; Tyrrell, Pascal N

2018-05-01

Rheumatic diseases encompass a wide range of conditions caused by inflammation and dysregulation of the immune system resulting in organ damage. Research in these heterogeneous diseases benefits from multivariate methods. The aim of this review was to describe and evaluate current literature in rheumatology regarding cluster analysis and correspondence analysis. A systematic review showed an increase in studies making use of these 2 methods. However, standardization in how these methods are applied and reported is needed. Researcher expertise was determined to be the main barrier to considering these approaches, whereas education and collaborating with a biostatistician were suggested ways forward. Copyright © 2018 Elsevier Inc. All rights reserved.

Where two roles intersect: spillover between parent care and employment.

PubMed

Stephens, M A; Franks, M M; Atienza, A A

1997-03-01

Spillover between the roles of parent care and employment was assessed in a sample of 105 employed adult daughter caregivers. This research examined how these 2 roles affect one another, both positively and negatively, and how such spillover was related to caregivers' psychological well-being. Path analyses indicated that negative spillover was an important mediating mechanism in the relationship between role stress and depression. In contrast, no evidence was found to suggest that positive spillover mediated the relationship between role satisfaction and positive affect. Findings extend prior research that has documented that caregiving and employment can interfere with one another by demonstrating that such spillover has implications for caregivers' emotional health.

Two ways related to performance in elite sport: the path of self-confidence and competitive anxiety and the path of group cohesion and group goal-clarity.

PubMed

Kjørmo, Odd; Halvari, Hallgeir

2002-06-01

A model tested among 136 Norwegian Olympic-level athletes yielded two paths related to performance. The first path indicated that self-confidence, modeled as an antecedent of competitive anxiety, is negatively correlated with anxiety. Competitive anxiety in turn is negatively correlated with performance. The second path indicated that group cohesion is positively correlated with group goal-clarity, which in turn is positively correlated with performance. Competitive anxiety mediates the relation between self-confidence and performance, whereas group goal-clarity mediates the relation between group cohesion and performance. Results from multiple regression analyses supported the model in the total sample and among individual sport athletes organized in training groups (n = 100). Among team sport athletes (n = 36), personality and group measures are more strongly intercorrelated than among individual sport athletes, and the relation with performance is more complex for the former group. The interaction of self-confidence and competitive anxiety is related to performance among team sport athletes.

Development of a new integrated local trajectory planning and tracking control framework for autonomous ground vehicles

NASA Astrophysics Data System (ADS)

Li, Xiaohui; Sun, Zhenping; Cao, Dongpu; Liu, Daxue; He, Hangen

2017-03-01

This study proposes a novel integrated local trajectory planning and tracking control (ILTPTC) framework for autonomous vehicles driving along a reference path with obstacles avoidance. For this ILTPTC framework, an efficient state-space sampling-based trajectory planning scheme is employed to smoothly follow the reference path. A model-based predictive path generation algorithm is applied to produce a set of smooth and kinematically-feasible paths connecting the initial state with the sampling terminal states. A velocity control law is then designed to assign a speed value at each of the points along the generated paths. An objective function considering both safety and comfort performance is carefully formulated for assessing the generated trajectories and selecting the optimal one. For accurately tracking the optimal trajectory while overcoming external disturbances and model uncertainties, a combined feedforward and feedback controller is developed. Both simulation analyses and vehicle testing are performed to verify the effectiveness of the proposed ILTPTC framework, and future research is also briefly discussed.

A Path Model of School Violence Perpetration: Introducing Online Game Addiction as a New Risk Factor.

PubMed

Kim, Jae Yop; Lee, Jeen Suk; Oh, Sehun

2015-08-10

Drawing on the cognitive information-processing model of aggression and the general aggression model, we explored why adolescents become addicted to online games and how their immersion in online games affects school violence perpetration (SVP). For this purpose, we conducted statistical analyses on 1,775 elementary and middle school students who resided in northern districts of Seoul, South Korea. The results validated the proposed structural equation model and confirmed the statistical significance of the structural paths from the variables; that is, the paths from child abuse and self-esteem to SVP were significant. The levels of self-esteem and child abuse victimization affected SVP, and this effect was mediated by online game addiction (OGA). Furthermore, a multigroup path analysis showed significant gender differences in the path coefficients of the proposed model, indicating that gender exerted differential effects on adolescents' OGA and SVP. Based on these results, prevention and intervention methods to curb violence in schools have been proposed. © The Author(s) 2015.

Why managers should care about fairness: the effects of aggregate justice perceptions on organizational outcomes.

PubMed

Simons, Tony; Roberson, Quinetta

2003-06-01

This work examines the aggregation of justice perceptions to the departmental level and the business-unit level, the impact of these aggregate perceptions on business-unit-level outcomes, and the usefulness of the distinction between procedural and interpersonal justice at different levels of analysis. Latent variables analyses of individual-level and department-level data from 4,539 employees in 783 departments at 97 hotel properties showed that the 2 justice types exercise unique paths of impact on employees' organizational commitment and thus on turnover intentions and discretionary service behavior. Business-unit-level analyses further demonstrate paths of association between aggregate justice perceptions, aggregate commitment levels, and the business-unit-level outcomes of employee turnover rates and customer satisfaction ratings.

Trust, cooperation, and equality: a psychological analysis of the formation of social capital.

PubMed

Cozzolino, Philip J

2011-06-01

Research suggests that in modern Western culture there is a positive relationship between the equality of resources and the formation of trust and cooperation, two psychological components of social capital. Two studies elucidate the psychological processes underlying that relationship. Study 1 experimentally tested the influence of resource distributions on the formation of trust and intentions to cooperate; individuals receiving a deficit of resources and a surplus of resources evidenced lower levels of social capital (i.e., trust and cooperation) than did individuals receiving equal amounts. Analyses revealed the process was affective for deficit participants and cognitive for surplus participants. Study 2 provided suggestive support for the affective-model of equality and social capital using proxy variables in the 1996 General Social Survey data set. Results suggest support for a causal path of unequal resource distributions generating affective experiences and cognitive concerns of justice, which mediate disengagement and distrust of others. ©2010 The British Psychological Society.

Evaluation of hand hygiene compliance and associated factors with a radio-frequency-identification-based real-time continuous automated monitoring system.

PubMed

Dufour, J-C; Reynier, P; Boudjema, S; Soto Aladro, A; Giorgi, R; Brouqui, P

2017-04-01

Hand hygiene is a major means for preventing healthcare-associated infections. One critical point in understanding poor compliance is the lack of relevant markers used to monitor practices systematically. This study analysed hand hygiene compliance and associated factors with a radio-frequency-identification-based real-time continuous automated monitoring system in an infectious disease ward with 17 single bedrooms. Healthcare workers (HCWs) were tracked while performing routine care over 171 days. A multi-level multi-variate logistics model was used for data analysis. The main outcome measures were hand disinfection before entering the bedroom (outside use) and before entering the patient care zone, defined as the zone surrounding the patient's bed (inside/bedside use). Variables analysed included HCWs' characteristics and behaviour, patients, room layouts, path chains and duration of HCWs' paths. In total, 4629 paths with initial hand hygiene opportunities when entering the patient care zone were selected, of which 763 (16.5%), 285 (6.1%) and 3581 (77.4%) were associated with outside use, inside/bedside use and no use, respectively. Hand hygiene is caregiver-dependent. The shorter the duration of the HCW's path, the worse the bedside hand hygiene. Bedside hand hygiene is improved when one or two extra HCWs are present in the room. Hand hygiene compliance at the bedside, as analysed using the continuous monitoring system, depended upon the HCW's occupation and personal behaviour, number of HCWs, time spent in the room and (potentially) dispenser location. Meal tray distribution was a possible factor in the case of failure to disinfect hands. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Resident Research Experience and Career Path Association: A National Survey of Recent Otolaryngology Graduates.

PubMed

Zahtz, Gerald; Vambutas, Andrea; Hussey, Heather M; Rosen, Lisa

2014-07-01

To determine whether the research rotation experience affects the career path of otolaryngology residents. Two web-based surveys were disseminated by the AAO-HNS; one to current and former resident trainees and the other to current residency program directors. A web-based survey was disseminated to all AAO-HNS members classified as otolaryngology residents or residency graduates within the last 6 years, regarding their research rotation and its potential influence on their career path. A second web-based survey was delivered simultaneously to program directors to evaluate their perception of the need for research in a training program and their role in the rotation. Chi-square tests for independence as well as multivariate analyses were conducted to determine whether aspects of the resident research rotation related to career path. The resident survey was completed by 350 respondents (25% response rate), and 39 program directors completed the second survey (37% response rate). Multiple factors were examined, including federal funding of faculty, mentorship, publications prior to residency, success of research project measured by publication or grant submission, and type of research. Multivariate analyses revealed that factors most predictive of academic career path were intellectual satisfaction and presence of a T32 training grant within the program (P < .05). The composition and quality of the residency research rotation vary across institutions. Factors that enhance stronger intellectual satisfaction and the presence of T32 grant, which demonstrates an institution's commitment to research training, may promote pursuit of a career in academia versus private practice. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

Evaluating the performance of commonly used gas analysers for methane eddy covariance flux measurements: the InGOS inter-comparison field experiment

NASA Astrophysics Data System (ADS)

Peltola, O.; Hensen, A.; Helfter, C.; Belelli Marchesini, L.; Bosveld, F. C.; van den Bulk, W. C. M.; Elbers, J. A.; Haapanala, S.; Holst, J.; Laurila, T.; Lindroth, A.; Nemitz, E.; Röckmann, T.; Vermeulen, A. T.; Mammarella, I.

2014-01-01

The performance of eight fast-response methane (CH4) gas analysers suitable for eddy covariance flux measurements were tested at a grassland site near the Cabauw tall tower (Netherlands) during June 2012. The instruments were positioned close to each other in order to minimize the effect of varying turbulent conditions. The moderate CH4 fluxes observed at the location, of the order of 25 nmol m-2 s-1, provided a suitable signal for testing the instruments' performance. Generally, all analysers tested were able to quantify the concentration fluctuations at the frequency range relevant for turbulent exchange and were able to deliver high-quality data. The tested cavity ring-down spectrometer (CRDS) instruments from Picarro, models G2311-f and G1301-f, were superior to other CH4 analysers with respect to instrumental noise. As an open-path instrument susceptible to the effects of rain, the LI-COR LI-7700 achieved lower data coverage and also required larger density corrections; however, the system is especially useful for remote sites that are restricted in power availability. In this study the open-path LI-7700 results were compromised due to a data acquisition problem in our data-logging setup. Some of the older closed-path analysers tested do not measure H2O vapour concentrations alongside CH4 (i.e. FMA1 and DLT-100 by Los Gatos Research) and this complicates data processing since the required corrections for dilution and spectroscopic interactions have to be based on external information. To overcome this issue, we used H2O mole fractions measured by other gas analysers, adjusted them with different methods and then applied them to correct the CH4 fluxes. Following this procedure we estimated a bias on the order of 0.1 g (CH4) m-2 (8% of the measured mean flux) in the processed and corrected CH4 fluxes on a monthly scale due to missing H2O concentration measurements. Finally, cumulative CH4 fluxes over 14 days from three closed-path gas analysers, G2311-f (Picarro Inc.), FGGA (Los Gatos Research) and FMA2 (Los Gatos Research), which were measuring H2O vapour concentrations in addition to CH4, agreed within 3% (355-367 mg (CH4) m-2) and were not clearly different from each other, whereas the other instruments derived total fluxes which showed small but distinct differences (±10%, 330-399 mg (CH4) m-2).

Evaluating the performance of commonly used gas analysers for methane eddy covariance flux measurements: the InGOS inter-comparison field experiment

NASA Astrophysics Data System (ADS)

Peltola, O.; Hensen, A.; Helfter, C.; Belelli Marchesini, L.; Bosveld, F. C.; van den Bulk, W. C. M.; Elbers, J. A.; Haapanala, S.; Holst, J.; Laurila, T.; Lindroth, A.; Nemitz, E.; Röckmann, T.; Vermeulen, A. T.; Mammarella, I.

2014-06-01

The performance of eight fast-response methane (CH4) gas analysers suitable for eddy covariance flux measurements were tested at a grassland site near the Cabauw tall tower (Netherlands) during June 2012. The instruments were positioned close to each other in order to minimise the effect of varying turbulent conditions. The moderate CH4 fluxes observed at the location, of the order of 25 nmol m-2 s-1, provided a suitable signal for testing the instruments' performance. Generally, all analysers tested were able to quantify the concentration fluctuations at the frequency range relevant for turbulent exchange and were able to deliver high-quality data. The tested cavity ringdown spectrometer (CRDS) instruments from Picarro, models G2311-f and G1301-f, were superior to other CH4 analysers with respect to instrumental noise. As an open-path instrument susceptible to the effects of rain, the LI-COR LI-7700 achieved lower data coverage and also required larger density corrections; however, the system is especially useful for remote sites that are restricted in power availability. In this study the open-path LI-7700 results were compromised due to a data acquisition problem in our data-logging setup. Some of the older closed-path analysers tested do not measure H2O concentrations alongside CH4 (i.e. FMA1 and DLT-100 by Los Gatos Research) and this complicates data processing since the required corrections for dilution and spectroscopic interactions have to be based on external information. To overcome this issue, we used H2O mole fractions measured by other gas analysers, adjusted them with different methods and then applied them to correct the CH4 fluxes. Following this procedure we estimated a bias of the order of 0.1 g (CH4) m-2 (8% of the measured mean flux) in the processed and corrected CH4 fluxes on a monthly scale due to missing H2O concentration measurements. Finally, cumulative CH4 fluxes over 14 days from three closed-path gas analysers, G2311-f (Picarro Inc.), FGGA (Los Gatos Research) and FMA2 (Los Gatos Research), which were measuring H2O concentrations in addition to CH4, agreed within 3% (355-367 mg (CH4) m-2) and were not clearly different from each other, whereas the other instruments derived total fluxes which showed small but distinct differences (±10%, 330-399 mg (CH4) m-2).

Back in the USSR: Path Dependence Effects in Student Representation in Russia

ERIC Educational Resources Information Center

Chirikov, Igor; Gruzdev, Ivan

2014-01-01

This paper analyses the current state of student representation in Russia as deeply rooted in the institutional structure of the Soviet higher education system. The study traces the origins of existing institutional arrangements for student representation at the level of university governance and analyses how representation practices have been…

Overdiagnosis of ADHD in boys: Stereotype impact on neuropsychological assessment.

PubMed

Fresson, Megan; Meulemans, Thierry; Dardenne, Benoit; Geurten, Marie

2018-02-12

There is vigorous debate regarding the possibility that ADHD is overdiagnosed in boys. We investigated the impact of the gender stereotype depicting boys as inattentive and impulsive on neuropsychological assessment (observation of psychology students and child's cognitive performance). In experiment 1, after the stereotype was activated, psychology students rated a "boy," a "girl," or a "child" on a behavioral assessment scale. In experiment 2, 103 children (boys and girls) completed neuropsychological tasks under stereotype threat or neutral conditions. The gender stereotype led psychology students to assess a child's behaviors more negatively if they thought the child was a boy. Boys' performance on one cognitive score declined following stereotype threat. Regression path analyses suggested moderation by stigma consciousness. Additionally, there were mediating and suppressing (through stereotype endorsement) effects. Our results suggest that the gender stereotype might contribute to the overdiagnosis of ADHD in boys.

Ordered shotgun sequencing of a 135 kb Xq25 YAC containing ANT2 and four possible genes, including three confirmed by EST matches.

PubMed Central

Chen, C N; Su, Y; Baybayan, P; Siruno, A; Nagaraja, R; Mazzarella, R; Schlessinger, D; Chen, E

1996-01-01

Ordered shotgun sequencing (OSS) has been successfully carried out with an Xq25 YAC substrate. yWXD703 DNA was subcloned into lambda phage and sequences of insert ends of the lambda subclones were used to generate a map to select a minimum tiling path of clones to be completely sequenced. The sequence of 135 038 nt contains the entire ANT2 cDNA as well as four other candidates suggested by computer-assisted analyses. One of the putative genes is homologous to a gene implicated in Graves' disease and it, ANT2 and two others are confirmed by EST matches. The results suggest that OSS can be applied to YACs in accord with earlier simulations and further indicate that the sequence of the YAC accurately reflects the sequence of uncloned human DNA. PMID:8918809

The parallel globe: a powerful instrument to perform investigations of Earth’s illumination

NASA Astrophysics Data System (ADS)

Rossi, Sabrina; Giordano, Enrica; Lanciano, Nicoletta

2015-01-01

Many researchers have documented the difficulties for learners of different ages and preparations in understanding basic astronomical concepts. Traditional instructional strategies and communication media do not seem to be effective in producing meaningful understanding, or even induce misconceptions and misinterpretations. In line with recent proposals for pedagogical sequences and learning progressions about core concepts and basic procedures in physics and astronomy education, in this paper we suggest an intermediate, essential step in the teaching path from the local geocentric view of the Earth-Sun system to a heliocentric one. With this aim we present data collected over a day and a year from an instrument we call the ‘parallel globe’, a globe positioned locally homothetic to the Earth. Some analyses are suggested, in particular of the phenomenon of illumination of the Earth and its variations, that are consistent with the proposed instructional objectives.

Potential Underlying Mechanisms for Greater Weight Gain in Massaged Preterm Infants

PubMed Central

Field, Tiffany; Diego, Miguel; Hernandez-Reif, Maria

2010-01-01

In this paper, potential underlying mechanisms for massage therapy effects on preterm infant weight gain are reviewed. Path analyses are presented suggesting that: 1) increased vagal activity was associated with 2) increased gastric motility, which, in turn, was related to 3) greater weight gain; and 4) increased IGF-1 was related to greater weight gain. The change in vagal activity during the massage explained 49% of the variance in the change in gastric activity. And, the change in vagal activity during the massage explained 62% of the variance in the change in insulin. That the change in gastric activity was not related to the change in insulin suggests two parallel pathways via which massage therapy leads to increased weight gain: 1) insulin release via the celiac branch of the vagus; and 2) increased gastric activity via the gastric branch of the vagus. PMID:21570125

Doubly blind: a systematic review of gender in randomised controlled trials

PubMed Central

Phillips, Susan P; Hamberg, Katarina

2016-01-01

Background Although observational data show social characteristics such as gender or socio-economic status to be strong predictors of health, their impact is seldom investigated in randomised controlled studies (RCTs). Objective & design Using a random sample of recent RCTs from high-impact journals, we examined how the most often recorded social characteristic, sex/gender, is considered in design, analysis, and interpretation. Of 712 RCTs published from September 2008 to 31 December 2013 in the Annals of Internal Medicine, British Medical Journal, Lancet, Canadian Medical Association Journal, or New England Journal of Medicine, we randomly selected 57 to analyse funding, methods, number of centres, documentation of social circumstances, inclusion/exclusion criteria, proportions of women/men, and reporting about sex/gender in analyses and discussion. Results Participants’ sex was recorded in most studies (52/57). Thirty-nine percent included men and women approximately equally. Overrepresentation of men in 43% of studies without explicit exclusions for women suggested interference in selection processes. The minority of studies that did analyse sex/gender differences (22%) did not discuss or reflect upon these, or dismissed significant findings. Two studies reinforced traditional beliefs about women's roles, finding no impact of breastfeeding on infant health but nevertheless reporting possible benefits. Questionable methods such as changing protocols mid-study, having undefined exclusion criteria, allowing local researchers to remove participants from studies, and suggesting possible benefit where none was found were evident, particularly in industry-funded research. Conclusions Social characteristics like sex/gender remain hidden from analyses and interpretation in RCTs, with loss of information and embedding of error all along the path from design to interpretation, and therefore, to uptake in clinical practice. Our results suggest that to broaden external validity, in particular, more refined trial designs and analyses that account for sex/gender and other social characteristics are needed. PMID:27087576

Turbulence effects in a horizontal propagation path close to ground: implications for optics detection

NASA Astrophysics Data System (ADS)

Sjöqvist, Lars; Allard, Lars; Gustafsson, Ove; Henriksson, Markus; Pettersson, Magnus

2011-11-01

Atmospheric turbulence effects close to ground may affect the performance of laser based systems severely. The variations in the refractive index along the propagation path cause effects such as beam wander, intensity fluctuations (scintillations) and beam broadening. Typical geometries of interest for optics detection include nearly horizontal propagation paths close to the ground and up to kilometre distance to the target. The scintillations and beam wander affect the performance in terms of detection probability and false alarm rate. Of interest is to study the influence of turbulence in optics detection applications. In a field trial atmospheric turbulence effects along a 1 kilometre horizontal propagation path were studied using a diode laser with a rectangular beam profile operating at 0.8 micrometer wavelength. Single-path beam characteristics were registered and analysed using photodetectors arranged in horizontal and vertical directions. The turbulence strength along the path was determined using a scintillometer and single-point ultrasonic anemometers. Strong scintillation effects were observed as a function of the turbulence strength and amplitude characteristics were fitted to model distributions. In addition to the single-path analysis double-path measurements were carried out on different targets. Experimental results are compared with existing theoretical turbulence laser beam propagation models. The results show that influence from scintillations needs to be considered when predicting performance in optics detection applications.

Intelligence, previous convictions and interrogative suggestibility: a path analysis of alleged false-confession cases.

PubMed

Sharrock, R; Gudjonsson, G H

1993-05-01

The main purpose of this study was to investigate the relationship between interrogative suggestibility and previous convictions among 108 defendants in criminal trials, using a path analysis technique. It was hypothesized that previous convictions, which may provide defendants with interrogative experiences, would correlate negatively with 'shift' as measured by the Gudjonsson Suggestibility Scale (Gudjonsson, 1984a), after intelligence and memory had been controlled for. The hypothesis was partially confirmed and the theoretical and practical implications of the findings are discussed.

Analyses of geological and hydrodynamic controls on methane emissions experienced in a Lower Kittanning coal mine

PubMed Central

Karacan, C. Özgen; Goodman, Gerrit V.R.

2015-01-01

This paper presents a study assessing potential factors and migration paths of methane emissions experienced in a room-and-pillar mine in Lower Kittanning coal, Indiana County, Pennsylvania. Methane emissions were not excessive at idle mining areas, but significant methane was measured during coal mining and loading. Although methane concentrations in the mine did not exceed 1% limit during operation due to the presence of adequate dilution airflow, the source of methane and its migration into the mine was still a concern. In the course of this study, structural and depositional properties of the area were evaluated to assess complexity and sealing capacity of roof rocks. Composition, gas content, and permeability of Lower Kittanning coal, results of flotation tests, and geochemistry of groundwater obtained from observation boreholes were studied to understand the properties of coal and potential effects of old abandoned mines within the same area. These data were combined with the data obtained from exploration boreholes, such as depths, elevations, thicknesses, ash content, and heat value of coal. Univariate statistical and principal component analyses (PCA), as well as geostatistical simulations and co-simulations, were performed on various spatial attributes to reveal interrelationships and to establish area-wide distributions. These studies helped in analyzing groundwater quality and determining gas-in-place (GIP) of the Lower Kittanning seam. Furthermore, groundwater level and head on the Lower Kittanning coal were modeled and flow gradients within the study area were examined. Modeling results were interpreted with the structural geology of the Allegheny Group of formations above the Lower Kittanning coal to understand the potential source of gas and its migration paths. Analyses suggested that the source of methane was likely the overlying seams such as the Middle and Upper Kittanning coals and Freeport seams of the Allegheny Group. Simulated ground-water water elevations, gradients of groundwater flow, and the presence of recharge and discharge locations at very close proximity to the mine indicated that methane likely was carried with groundwater towards the mine entries. Existing fractures within the overlying strata and their orientation due to the geologic conditions of the area, and activation of slickensides between shale and sandstones due to differential compaction during mining, were interpreted as the potential flow paths. PMID:26478644

Consequences of incomplete surface energy balance closure for CO2 fluxes from open-path CO2/H2O infrared gas analyzers

Treesearch

Heping Liu; James T. Randerson; Jamie Lindfors; William J. Massman; Thomas Foken

2006-01-01

We present an approach for assessing the impact of systematic biases in measured energy fluxes on CO2 flux estimates obtained from open-path eddy-covariance systems. In our analysis, we present equations to analyse the propagation of errors through the Webb, Pearman, and Leuning (WPL) algorithm [Quart. J. Roy. Meteorol. Soc. 106, 85­100, 1980] that is widely used to...

Do Workplace Literacy Programs Promote High Skills or Low Wages? Suggestions for Future Evaluations of Workplace Literacy Programs.

ERIC Educational Resources Information Center

Sarmiento, Tony

Workplace literacy programs can support the path toward either low wages or high skills. Instead of the "high skill" path, most U.S. companies follow the "low wage" path. Depending on who is involved, which program goals are selected, and what planning process is followed, a workplace literacy program can maintain outdated workplaces or foster…

Evolutionary paths of streptococcal and staphylococcal superantigens

PubMed Central

2012-01-01

Background Streptococcus pyogenes (GAS) harbors several superantigens (SAgs) in the prophage region of its genome, although speG and smez are not located in this region. The diversity of SAgs is thought to arise during horizontal transfer, but their evolutionary pathways have not yet been determined. We recently completed sequencing the entire genome of S. dysgalactiae subsp. equisimilis (SDSE), the closest relative of GAS. Although speG is the only SAg gene of SDSE, speG was present in only 50% of clinical SDSE strains and smez in none. In this study, we analyzed the evolutionary paths of streptococcal and staphylococcal SAgs. Results We compared the sequences of the 12–60 kb speG regions of nine SDSE strains, five speG+ and four speG–. We found that the synteny of this region was highly conserved, whether or not the speG gene was present. Synteny analyses based on genome-wide comparisons of GAS and SDSE indicated that speG is the direct descendant of a common ancestor of streptococcal SAgs, whereas smez was deleted from SDSE after SDSE and GAS split from a common ancestor. Cumulative nucleotide skew analysis of SDSE genomes suggested that speG was located outside segments of steeper slopes than the stable region in the genome, whereas the region flanking smez was unstable, as expected from the results of GAS. We also detected a previously undescribed staphylococcal SAg gene, selW, and a staphylococcal SAg -like gene, ssl, in the core genomes of all Staphylococcus aureus strains sequenced. Amino acid substitution analyses, based on dN/dS window analysis of the products encoded by speG, selW and ssl suggested that all three genes have been subjected to strong positive selection. Evolutionary analysis based on the Bayesian Markov chain Monte Carlo method showed that each clade included at least one direct descendant. Conclusions Our findings reveal a plausible model for the comprehensive evolutionary pathway of streptococcal and staphylococcal SAgs. PMID:22900646

A subsystem identification method based on the path concept with coupling strength estimation

NASA Astrophysics Data System (ADS)

Magrans, Francesc Xavier; Poblet-Puig, Jordi; Rodríguez-Ferran, Antonio

2018-02-01

For complex geometries, the definition of the subsystems is not a straightforward task. We present here a subsystem identification method based on the direct transfer matrix, which represents the first-order paths. The key ingredient is a cluster analysis of the rows of the powers of the transfer matrix. These powers represent high-order paths in the system and are more affected than low-order paths by damping. Once subsystems are identified, the proposed approach also provides a quantification of the degree of coupling between subsystems. This information is relevant to decide whether a subsystem may be analysed in a computer model or measured in the laboratory independently of the rest or subsystems or not. The two features (subsystem identification and quantification of the degree of coupling) are illustrated by means of numerical examples: plates coupled by means of springs and rooms connected by means of a cavity.

Generating Performance Models for Irregular Applications

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

Friese, Ryan D.; Tallent, Nathan R.; Vishnu, Abhinav

2017-05-30

Many applications have irregular behavior --- non-uniform input data, input-dependent solvers, irregular memory accesses, unbiased branches --- that cannot be captured using today's automated performance modeling techniques. We describe new hierarchical critical path analyses for the \\Palm model generation tool. To create a model's structure, we capture tasks along representative MPI critical paths. We create a histogram of critical tasks with parameterized task arguments and instance counts. To model each task, we identify hot instruction-level sub-paths and model each sub-path based on data flow, instruction scheduling, and data locality. We describe application models that generate accurate predictions for strong scalingmore » when varying CPU speed, cache speed, memory speed, and architecture. We present results for the Sweep3D neutron transport benchmark; Page Rank on multiple graphs; Support Vector Machine with pruning; and PFLOTRAN's reactive flow/transport solver with domain-induced load imbalance.« less

Descent graphs in pedigree analysis: applications to haplotyping, location scores, and marker-sharing statistics.

PubMed Central

Sobel, E.; Lange, K.

1996-01-01

The introduction of stochastic methods in pedigree analysis has enabled geneticists to tackle computations intractable by standard deterministic methods. Until now these stochastic techniques have worked by running a Markov chain on the set of genetic descent states of a pedigree. Each descent state specifies the paths of gene flow in the pedigree and the founder alleles dropped down each path. The current paper follows up on a suggestion by Elizabeth Thompson that genetic descent graphs offer a more appropriate space for executing a Markov chain. A descent graph specifies the paths of gene flow but not the particular founder alleles traveling down the paths. This paper explores algorithms for implementing Thompson's suggestion for codominant markers in the context of automatic haplotyping, estimating location scores, and computing gene-clustering statistics for robust linkage analysis. Realistic numerical examples demonstrate the feasibility of the algorithms. PMID:8651310

Precise estimation of tropospheric path delays with GPS techniques

NASA Technical Reports Server (NTRS)

Lichten, S. M.

1990-01-01

Tropospheric path delays are a major source of error in deep space tracking. However, the tropospheric-induced delay at tracking sites can be calibrated using measurements of Global Positioning System (GPS) satellites. A series of experiments has demonstrated the high sensitivity of GPS to tropospheric delays. A variety of tests and comparisons indicates that current accuracy of the GPS zenith tropospheric delay estimates is better than 1-cm root-mean-square over many hours, sampled continuously at intervals of six minutes. These results are consistent with expectations from covariance analyses. The covariance analyses also indicate that by the mid-1990s, when the GPS constellation is complete and the Deep Space Network is equipped with advanced GPS receivers, zenith tropospheric delay accuracy with GPS will improve further to 0.5 cm or better.

Distal and proximal factors associated with aggression towards partners and non-partners among patients in substance abuse treatment.

PubMed

Epstein-Ngo, Quyen M; Walton, Maureen A; Sanborn, Michelle; Kraus, Shane; Blow, Fred; Cunningham, Rebecca; Chermack, Stephen T

2014-10-01

Studies of violence in substance use disorder (SUD) treatment settings typically focus on partner aggression (PA) although non-partner aggression (NPA) is also a common problem. This study examines potentially distinct paths of distal and proximal risk factors related to aggression towards non-partners (NPA) and partners (PA) among a SUD treatment sample. The sample included 176 adults reporting past-year violence. Bivariate analyses indicated several distal and proximal factors were associated with NPA and PA. According to multivariate, multiple mediation analyses youth aggression history was a factor for both NPA and PA. Alcohol and cocaine use and psychological distress were associated with NPA; marijuana use was associated with PA. There also was evidence of indirect effects of distal factors on NPA and PA. The results suggest that there may be substantially different dynamics associated with NPA and PA, and have implications for developing screening, assessment and treatment protocols targeting violence among individuals in SUD treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

The high-quality draft genome of peach (Prunus persica) identifies unique patterns of genetic diversity, domestication and genome evolution.

PubMed

Verde, Ignazio; Abbott, Albert G; Scalabrin, Simone; Jung, Sook; Shu, Shengqiang; Marroni, Fabio; Zhebentyayeva, Tatyana; Dettori, Maria Teresa; Grimwood, Jane; Cattonaro, Federica; Zuccolo, Andrea; Rossini, Laura; Jenkins, Jerry; Vendramin, Elisa; Meisel, Lee A; Decroocq, Veronique; Sosinski, Bryon; Prochnik, Simon; Mitros, Therese; Policriti, Alberto; Cipriani, Guido; Dondini, Luca; Ficklin, Stephen; Goodstein, David M; Xuan, Pengfei; Del Fabbro, Cristian; Aramini, Valeria; Copetti, Dario; Gonzalez, Susana; Horner, David S; Falchi, Rachele; Lucas, Susan; Mica, Erica; Maldonado, Jonathan; Lazzari, Barbara; Bielenberg, Douglas; Pirona, Raul; Miculan, Mara; Barakat, Abdelali; Testolin, Raffaele; Stella, Alessandra; Tartarini, Stefano; Tonutti, Pietro; Arús, Pere; Orellana, Ariel; Wells, Christina; Main, Dorrie; Vizzotto, Giannina; Silva, Herman; Salamini, Francesco; Schmutz, Jeremy; Morgante, Michele; Rokhsar, Daniel S

2013-05-01

Rosaceae is the most important fruit-producing clade, and its key commercially relevant genera (Fragaria, Rosa, Rubus and Prunus) show broadly diverse growth habits, fruit types and compact diploid genomes. Peach, a diploid Prunus species, is one of the best genetically characterized deciduous trees. Here we describe the high-quality genome sequence of peach obtained from a completely homozygous genotype. We obtained a complete chromosome-scale assembly using Sanger whole-genome shotgun methods. We predicted 27,852 protein-coding genes, as well as noncoding RNAs. We investigated the path of peach domestication through whole-genome resequencing of 14 Prunus accessions. The analyses suggest major genetic bottlenecks that have substantially shaped peach genome diversity. Furthermore, comparative analyses showed that peach has not undergone recent whole-genome duplication, and even though the ancestral triplicated blocks in peach are fragmentary compared to those in grape, all seven paleosets of paralogs from the putative paleoancestor are detectable.

A model of religious involvement, family processes, self-control, and juvenile delinquency in two-parent families.

PubMed

Guo, Siying

2018-02-01

Family processes, adolescent religious involvement, and self-control may serve as important mechanisms that mediate the relationship between parental religious involvement and delinquency. However, at present no study has systematically investigated the relationships among these factors and how these mediating mechanisms work. To address this gap, path analyses are conducted to test the hypothesized pathways whereby parental religious involvement operates to discourage delinquent behaviors of offspring. The study variables are taken from three waves of the study of the National Longitudinal Survey of Youth 1979 and its descendent NLSY79 Child and Young Adults at two year intervals (2000, 2002, and 2004). 1020 American adolescents who are 10-14 years old in 2002 are selected for final analyses. The findings suggest that parental religious involvement does not affect adolescent delinquency four years later directly, but indirectly through its influence on adolescent religious involvement, parenting practices, inter-parental conflict, and their interactions with adolescent self-control. Copyright © 2017. Published by Elsevier Ltd.

Cognitive capitalism: the effect of cognitive ability on wealth, as mediated through scientific achievement and economic freedom.

PubMed

Rindermann, Heiner; Thompson, James

2011-06-01

Traditional economic theories stress the relevance of political, institutional, geographic, and historical factors for economic growth. In contrast, human-capital theories suggest that peoples' competences, mediated by technological progress, are the deciding factor in a nation's wealth. Using three large-scale assessments, we calculated cognitive-competence sums for the mean and for upper- and lower-level groups for 90 countries and compared the influence of each group's intellectual ability on gross domestic product. In our cross-national analyses, we applied different statistical methods (path analyses, bootstrapping) and measures developed by different research groups to various country samples and historical periods. Our results underscore the decisive relevance of cognitive ability--particularly of an intellectual class with high cognitive ability and accomplishments in science, technology, engineering, and math--for national wealth. Furthermore, this group's cognitive ability predicts the quality of economic and political institutions, which further determines the economic affluence of the nation. Cognitive resources enable the evolution of capitalism and the rise of wealth.

Computed micro-tomographic evaluation of glide path with nickel-titanium rotary PathFile in maxillary first molars curved canals.

PubMed

Pasqualini, Damiano; Bianchi, Caterina Chiara; Paolino, Davide Salvatore; Mancini, Lucia; Cemenasco, Andrea; Cantatore, Giuseppe; Castellucci, Arnaldo; Berutti, Elio

2012-03-01

X-ray computed micro-tomography scanning allows high-resolution 3-dimensional imaging of small objects. In this study, micro-CT scanning was used to compare the ability of manual and mechanical glide path to maintain the original root canal anatomy. Eight extracted upper first permanent molars were scanned at the TOMOLAB station at ELETTRA Synchrotron Light Laboratory in Trieste, Italy, with a microfocus cone-beam geometry system. A total of 2,400 projections on 360° have been acquired at 100 kV and 80 μA, with a focal spot size of 8 μm. Buccal root canals of each specimen (n = 16) were randomly assigned to PathFile (P) or stainless-steel K-file (K) to perform glide path at the full working length. Specimens were then microscanned at the apical level (A) and at the point of the maximum curvature level (C) for post-treatment analyses. Curvatures of root canals were classified as moderate (≤35°) or severe (≥40°). The ratio of diameter ratios (RDRs) and the ratio of cross-sectional areas (RAs) were assessed. For each level of analysis (A and C), 2 balanced 2-way factorial analyses of variance (P < .05) were performed to evaluate the significance of the instrument factor and of canal curvature factor as well as the interactions of the factors both with RDRs and RAs. Specimens in the K group had a mean curvature of 35.4° ± 11.5°; those in the P group had a curvature of 38° ± 9.9°. The instrument factor (P and K) was extremely significant (P < .001) for both the RDR and RA parameters, regardless of the point of analysis. Micro-CT scanning confirmed that NiTi rotary PathFile instruments preserve the original canal anatomy and cause less canal aberrations. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Satellite Sounder-Based OLR-, Cloud- and Atmospheric Temperature Climatologies for Climate Analyses

NASA Technical Reports Server (NTRS)

Molnar, Gyula I.; Susskind, Joel

2006-01-01

Global energy balance of the Earth-atmosphere system may change due to natural and man-made climate variations. For example, changes in the outgoing longwave radiation (OLR) can be regarded as a crucial indicator of climate variations. Clouds play an important role -still insufficiently assessed in the global energy balance on all spatial and temporal scales, and satellites provide an ideal platform to measure cloud and large-scale atmospheric variables simultaneously. The TOVS series of satellites were the first to provide this type of information since 1979. OLR [Mehta and Susskind], cloud cover and cloud top pressure [Susskind et al] are among the key climatic parameters computed by the TOVS Pathfinder Path-A algorithm using mainly the retrieved temperature and moisture profiles. AIRS, regarded as the new and improved TOVS , has a much higher spectral resolution and greater S/N ratio, retrieving climatic parameters with higher accuracy. First we present encouraging agreements between MODIS and AIRS cloud top pressure (C(sub tp) and effective (A(sub eff), a product of infrared emissivity at 11 microns and physical cloud cover or A(sub c)) cloud fraction seasonal and interannual variabilities for selected months. Next we present validation efforts and preliminary trend analyses of TOVS-retrieved C(sub tp) and A(sub eff). For example, decadal global trends of the TOVS Path-A and ISCCP-D2 P(sub c), and A(sub eff)/A(sub c), values are similar. Furthermore, the TOVS Path-A and ISCCP-AVHRR [available since 19831 cloud fractions correlate even more strongly, including regional trends. We also present TOVS and AIRS OLR validation effort results and (for the longer-term TOVS Pathfinder Path-A dataset) trend analyses. OLR interannual spatial variabilities from the available state-of-the-art CERES measurements and both from the AIRS [Susskind et al] and TOVS OLR computations are in remarkably good agreement. Global monthly mean CERES and TOVS OLR time series show very good agreement in absolute values also. Finally, we will assess correlations among long-term trends of selected parameters, derived simultaneously from the TOVS Pathfinder Path-A datase

The differential impact of discrimination on health among Black and White women.

PubMed

Versey, H Shellae; Curtin, Nicola

2016-05-01

Despite a large body of research examining the impact of discrimination on health, the ways in which perceived discrimination may lead to disparate health outcomes through a sense of self and system consciousness is less understood. The current paper is concerned with both mental and physical health consequences of discrimination, as well as mediating pathways among African American and White women. Indirect effects analyses examine mediating paths from discrimination to health outcomes via structural awareness and self-esteem, using data from the Women's Life Path Study (N = 237). Our findings suggest that discrimination is both directly and indirectly associated with health outcomes for both Black and White women, mediated by individual (self-esteem) and group-level (structural awareness) processes. Evidence from this study indicates that discrimination is associated with heightened structural awareness, as well as lower self-esteem - both of which are related to poorer health. Discrimination negatively affected health across three domains, although the mechanisms varied somewhat for Black and White women. Broad implications of this research for interdisciplinary scholarship on the effects of discrimination on health and health disparities are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Facilitating energy savings with programmable thermostats: evaluation and guidelines for the thermostat user interface.

PubMed

Peffer, Therese; Perry, Daniel; Pritoni, Marco; Aragon, Cecilia; Meier, Alan

2013-01-01

Thermostats control heating and cooling in homes - representing a major part of domestic energy use - yet, poor ergonomics of these devices has thwarted efforts to reduce energy consumption. Theoretically, programmable thermostats can reduce energy by 5-15%, but in practice little to no savings compared to manual thermostats are found. Several studies have found that programmable thermostats are not installed properly, are generally misunderstood and have poor usability. After conducting a usability study of programmable thermostats, we reviewed several guidelines from ergonomics, general device usability, computer-human interfaces and building control sources. We analysed the characteristics of thermostats that enabled or hindered successfully completing tasks and in a timely manner. Subjects had higher success rates with thermostat displays with positive examples of guidelines, such as visibility of possible actions, consistency and standards, and feedback. We suggested other guidelines that seemed missing, such as navigation cues, clear hierarchy and simple decision paths. Our evaluation of a usability test of five residential programmable thermostats led to the development of a comprehensive set of specific guidelines for thermostat design including visibility of possible actions, consistency, standards, simple decision paths and clear hierarchy. Improving the usability of thermostats may facilitate energy savings.

Centre of pressure correlates with pyramid performance in acrobatic gymnastics.

PubMed

Floría, Pablo; Gómez-Landero, Luis Arturo; Harrison, Andrew J

2015-01-01

Acrobatic gymnasts need excellent balance control to execute pyramids where one gymnast is supported by another. The objectives of this study were: (1) to describe balance performance by assessing the centre of pressure displacement in a group of acrobatic gymnasts executing pyramids; (2) to determine the relationship between the parameters describing the centre of pressure oscillations and pyramid score; and (3) to examine the role of each foot in providing a solid base of support to maintain the balance of the pyramid. Sixteen acrobatic gymnasts grouped in pairs performed a Half pyramid and a Straddle pyramid held for 7 s on two force platforms. Path length, variance, range trajectory, and surface area of the centre of pressure of each foot were examined to analyse the balance of the pyramid. The path length was correlated with the pyramid score (Straddle: p = 0.692 [large]; Half: p = 0.407 [moderate]). There were differences in the functions of each leg to maintain balance, with the non-preferred leg supporting a higher weight of the pyramid while the preferred leg performed control movements to maintain balance. The results suggested that quantitative analysis of balance can provide important information on pyramid performance.

The relationship between social support and posttraumatic stress symptoms among youth exposed to a natural disaster.

PubMed

Lai, Betty S; Osborne, Melissa C; Piscitello, Jennifer; Self-Brown, Shannon; Kelley, Mary Lou

2018-01-01

Background : Children are a vulnerable population following a natural disaster, due to their age and dependence on adults. The primary presenting problem children report after disasters is posttraumatic stress symptoms (PTSS). Prior research suggests that PTSS is inversely related to social support, which is often disrupted after a disaster. Objective : This study examined the relationship between social support (from parents, teachers, and peers) and PTSS in children affected by Hurricane Katrina. The research contributes to the literature by examining the mechanisms that drive this relationship over time. Methods : In this study, 426 children were followed over four timepoints, beginning 3-7 months after Hurricane Katrina and concluding 25-27 months post-hurricane. Three path models analysed the relationship between social support (from parents, teachers, and peers, measured by the Social Support Scale for Children) and PTSS (measured by the UCLA PTSD Reaction Index). Covariates included child age, minority status, gender, perceived life threat, and actual life threat. Nonsignificant paths were trimmed from the final models. Global fit indices were examined to determine model fit. Results : In the parent and peer social support models, PTSS exhibited statistically significant effects on social support from one wave to the next. In the teacher model, this was only true between Waves 2 and 3. Social support showed a statistically significant effect on PTSS between Wave 2 and Wave 3 in the peer model (standardized estimate = -0.26, p  < .0001). No paths from social support to PTSS were significant in the parent and teacher models. Conclusion : Findings support a social selection model in which PTSS undermine social support, particularly in the first two years post-disaster. If these findings are replicated, this suggests that, in cases of limited funding, PTSS should be prioritized, given their cascading effects on social support.

Multi-path transportation futures study: Results from Phase 1

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

Patterson, Phil; Singh, Margaret; Plotkin, Steve

2007-03-09

This PowerPoint briefing provides documentation and details for Phase 1 of the Multi-Path Transportation Futures Study, which compares alternative ways to make significant reductions in oil use and carbon emissions from U.S. light vehicles to 2050. Phase I, completed in 2006, was a scoping study, aimed at identifying key analytic issues and constructing a study design. The Phase 1 analysis included an evaluation of several pathways and scenarios; however, these analyses were limited in number and scope and were designed to be preliminary.

Total MRI Small Vessel Disease Burden Correlates with Cognitive Performance, Cortical Atrophy, and Network Measures in a Memory Clinic Population.

PubMed

Banerjee, Gargi; Jang, Hyemin; Kim, Hee Jin; Kim, Sung Tae; Kim, Jae Seung; Lee, Jae Hong; Im, Kiho; Kwon, Hunki; Lee, Jong Min; Na, Duk L; Seo, Sang Won; Werring, David John

2018-01-01

Recent evidence suggests that combining individual imaging markers of cerebral small vessel disease (SVD) may more accurately reflect its overall burden and better correlate with clinical measures. We wished to establish the clinical relevance of the total SVD score in a memory clinic population by investigating the association with SVD score and cognitive performance, cortical atrophy, and structural network measures, after adjusting for amyloid-β burden. We included 243 patients with amnestic mild cognitive impairment (MCI), Alzheimer's disease dementia, subcortical vascular MCI, or subcortical vascular dementia. All underwent MR and [11C] PiB-PET scanning and had standardized cognitive testing. Multiple linear regression was used to evaluate the relationships between SVD score and cognition, cortical thickness, and structural network measures. Path analyses were performed to evaluate whether network disruption mediates the effects of SVD score on cortical thickness and cognition. Total SVD score was associated with the performance of frontal (β - 4.31, SE 2.09, p = 0.040) and visuospatial (β - 0.95, SE 0.44, p = 0.032) tasks, and with reduced cortical thickness in widespread brain regions. Total SVD score was negatively correlated with nodal efficiency, as well as changes in brain network organization, with evidence of reduced integration and increasing segregation. Path analyses showed that the associations between SVD score and frontal and visuospatial scores were partially mediated by decreases in their corresponding nodal efficiency and cortical thickness. Total SVD burden has clinical relevance in a memory clinic population and correlates with cognition, and cortical atrophy, as well as structural network disruption.

Teaching quantum physics by the sum over paths approach and GeoGebra simulations

NASA Astrophysics Data System (ADS)

Malgieri, M.; Onorato, P.; De Ambrosis, A.

2014-09-01

We present a research-based teaching sequence in introductory quantum physics using the Feynman sum over paths approach. Our reconstruction avoids the historical pathway, and starts by reconsidering optics from the standpoint of the quantum nature of light, analysing both traditional and modern experiments. The core of our educational path lies in the treatment of conceptual and epistemological themes, peculiar of quantum theory, based on evidence from quantum optics, such as the single photon Mach-Zehnder and Zhou-Wang-Mandel experiments. The sequence is supported by a collection of interactive simulations, realized in the open source GeoGebra environment, which we used to assist students in learning the basics of the method, and help them explore the proposed experimental situations as modeled in the sum over paths perspective. We tested our approach in the context of a post-graduate training course for pre-service physics teachers; according to the data we collected, student teachers displayed a greatly improved understanding of conceptual issues, and acquired significant abilities in using the sum over path method for problem solving.

Identifying built environmental patterns using cluster analysis and GIS: Relationships with walking, cycling and body mass index in French adults

PubMed Central

2012-01-01

Background Socio-ecological models suggest that both individual and neighborhood characteristics contribute to facilitating health-enhancing behaviors such as physical activity. Few European studies have explored relationships between local built environmental characteristics, recreational walking and cycling and weight status in adults. The aim of this study was to identify built environmental patterns in a French urban context and to assess associations with recreational walking and cycling behaviors as performed by middle-aged adult residents. Methods We used a two-step procedure based on cluster analysis to identify built environmental patterns in the region surrounding Paris, France, using measures derived from Geographic Information Systems databases on green spaces, proximity facilities (destinations) and cycle paths. Individual data were obtained from participants in the SU.VI.MAX cohort; 1,309 participants residing in the Ile-de-France in 2007 were included in this analysis. Associations between built environment patterns, leisure walking/cycling data (h/week) and measured weight status were assessed using multinomial logistic regression with adjustment for individual and neighborhood characteristics. Results Based on accessibility to green spaces, proximity facilities and availability of cycle paths, seven built environmental patterns were identified. The geographic distribution of built environmental patterns in the Ile-de-France showed that a pattern characterized by poor spatial accessibility to green spaces and proximity facilities and an absence of cycle paths was found only in neighborhoods in the outer suburbs, whereas patterns characterized by better spatial accessibility to green spaces, proximity facilities and cycle paths were more evenly distributed across the region. Compared to the reference pattern (poor accessibility to green areas and facilities, absence of cycle paths), subjects residing in neighborhoods characterized by high accessibility to green areas and local facilities and by a high density of cycle paths were more likely to walk/cycle, after adjustment for individual and neighborhood sociodemographic characteristics (OR = 2.5 95%CI 1.4-4.6). Body mass index did not differ across patterns. Conclusions Built environmental patterns were associated with walking and cycling among French adults. These analyses may be useful in determining urban and public health policies aimed at promoting a healthy lifestyle. PMID:22620266

Path perception during rotation: influence of instructions, depth range, and dot density

NASA Technical Reports Server (NTRS)

Li, Li; Warren, William H Jr

2004-01-01

How do observers perceive their direction of self-motion when traveling on a straight path while their eyes are rotating? Our previous findings suggest that information from retinal flow and extra-retinal information about eye movements are each sufficient to solve this problem for both perception and active control of self-motion [Vision Res. 40 (2000) 3873; Psych. Sci. 13 (2002) 485]. In this paper, using displays depicting translation with simulated eye rotation, we investigated how task variables such as instructions, depth range, and dot density influenced the visual system's reliance on retinal vs. extra-retinal information for path perception during rotation. We found that path errors were small when observers expected to travel on a straight path or with neutral instructions, but errors increased markedly when observers expected to travel on a curved path. Increasing depth range or dot density did not improve path judgments. We conclude that the expectation of the shape of an upcoming path can influence the interpretation of the ambiguous retinal flow. A large depth range and dense motion parallax are not essential for accurate path perception during rotation, but reference objects and a large field of view appear to improve path judgments.

The relation of trait and state mindfulness with satisfaction and physical activity: A cross-sectional study in 305 Dutch participants.

PubMed

Tsafou, Kalliopi-Eleni; Lacroix, Joyca Pw; van Ee, Raymond; Vinkers, Charlotte Dw; De Ridder, Denise Td

2017-09-01

Previous research has shown that satisfaction mediates the relationship of state mindfulness (i.e. during physical activity) with physical activity. This study aimed to replicate this finding and to explore the role of trait mindfulness with a cross-sectional design. In all, 305 participants completed measures on trait and state mindfulness, satisfaction with physical activity, and physical activity. Mediation analyses were used. Satisfaction mediated the effect of state mindfulness on physical activity. Trait mindfulness related to physical activity via an indirect path, namely through two consecutive mediators, first state mindfulness and then satisfaction. Our results suggest that to enhance satisfaction, both state and trait mindfulness should be considered.

What to do on spring break? The role of predicted, on-line, and remembered experience in future choice.

PubMed

Wirtz, Derrick; Kruger, Justin; Napa Scollon, Christie; Diener, Ed

2003-09-01

When individuals choose future activities on the basis of their past experiences, what guides those choices? The present study compared students' predicted, on-line, and remembered spring-break experiences, as well as the influence of these factors on students' desire to take a similar vacation in the future. Predicted and remembered experiences were both more positive-and, paradoxically, more negative-than on-line experiences. Of key importance, path analyses revealed that remembered experience, but neither on-line nor anticipated experience, directly predicted the desire to repeat the experience. These results suggest that although on-line measures may be superior to retrospective measures for approximating objective experience, retrospective measures may be superior for predicting choice.

Longitudinal Associations of Childhood Parenting and Adolescent Health: The Mediating Influence of Social Competence

PubMed Central

Boyer, Brittany P.; Nelson, Jackie A.

2014-01-01

The current study examined a process through which parenting during the primary school transition contributes to cardiovascular health in adolescence, a foundational period for adult health trajectories. Using path analyses, social competence was tested as a mediator between parental sensitivity and adolescent health among 884 families. Results indicated that mothers’ and fathers’ sensitivity was associated with increasing social competence from first grade (age 7) to sixth grade (age 12), which was associated with higher awakening cortisol in ninth grade (age 15) and decreasing blood pressure from sixth to ninth grade. Results suggest that social competence mediates associations between childhood parenting and adolescent cardiovascular risk, and may be protective to children’s health over time. PMID:25639280

Longitudinal Associations Among Religiousness, Delay Discounting, and Substance Use Initiation in Early Adolescence.

PubMed

Kim-Spoon, Jungmeen; McCullough, Michael E; Bickel, W K; Farley, Julee P; Longo, Gregory S

2015-03-01

Prior research indicates that religiousness is related negatively to adolescent health risk behaviors, yet how such protective effects operate is not well understood. This study examined the longitudinal associations among organizational and personal religiousness, delay discounting, and substance use initiation (alcohol, cigarette, and marijuana use). The sample comprised 106 early adolescents (10-13 years of age, 52% female) who were not using substances at Time 1. Path analyses suggested that high levels of personal religiousness at Time 1 were related to low levels of substance use at Time 2 (2.4 years later), mediated by low levels of delay discounting. Delay discounting appears to be an important contributor to the protective effect of religiousness on the development of substance use among adolescents.

Micro-CT evaluation of several glide path techniques and ProTaper Next shaping outcomes in maxillary first molar curved canals.

PubMed

Alovisi, M; Cemenasco, A; Mancini, L; Paolino, D; Scotti, N; Bianchi, C C; Pasqualini, D

2017-04-01

To evaluate the ability of ProGlider instruments, PathFiles and K-files to maintain canal anatomy during glide path preparation using X-ray computed micro-tomography (micro-CT). Forty-five extracted maxillary first permanent molars were selected. Mesio-buccal canals were randomly assigned (n = 15) to manual K-file, PathFile or ProGlider groups for glide path preparation. Irrigation was achieved with 5% NaOCl and 10% EDTA. After glide path preparation, each canal was shaped with ProTaper Next X1 and X2 to working length. Specimens were scanned (isotropic voxel size 9.1 μm) for matching volumes and surface areas and post-treatment analyses. Canal volume, surface area, centroid shift, canal geometry variation through ratio of diameter ratios and ratio of cross-sectional areas were assessed in the apical and coronal levels and at the point of maximum canal curvature. One-way factorial anovas were used to evaluate the significance of instrument in the various canal regions. Post-glide path analysis revealed that instrument factor was significant at the apical level for both the ratio of diameter ratios and the ratio of cross-sectional areas (P < 0.001), with an improved maintenance of root canal geometry by ProGlider and PathFile. At the coronal level and point of maximum canal curvature, ProGlider demonstrated a tendency to pre-flare the root canal compared with K-file and PathFile. PathFile and ProGlider demonstrated a significantly lower centroid shift compared with K-file at the apical level (P = 0.023). Post-shaping analysis demonstrated a more centred preparation of ProGlider, compared with PathFile and K-files, with no significant differences for other parameters. Use of ProGlider instruments led to less canal transportation than PathFiles and K-files. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

High-speed measurement of an air transect's temperature shift heated by laser beam

NASA Astrophysics Data System (ADS)

Li, WenYu; Jiang, ZongFu; Xi, Fengjie; Li, Qiang; Xie, Wenke

2005-02-01

Laser beam heat the air on the optic path, Beam-deflection optical tomography is a non-intrusive method to measure the 2-dimension temperature distribution in the transect. By means of linear Hartmann Sensor at the rate of 27kHz, the optic path was heated by a 2.7μm HF laser, continuous and high time resolution gradients of optic phase were obtained. the result of analysing and calculation showed the temperament shift in the heated beam path was not higher than 50K when the HF laser power was 9W. The experiment showed that it is a practical non-intrusive temperature shift measurement method for a small area aero-optical medium.

Proton and electron mean free paths: The Palmer consensus revisited

NASA Technical Reports Server (NTRS)

Bieber, John W.; Matthaeus, William H.; Smith, Charles W.; Wanner, Wolfgang; Kallenrode, May-Britt; Wibberenz, Gerd

1994-01-01

We present experimental and theoretical evidence suggesting that the mean free path of cosmic-ray electrons and protons may be fundamentally different at low to intermediate (less than 50 MV) rigidities. The experimental evidence is from Helios observations of solar energetic particles, which show that the mean free path of 1.4 MV electrons is often similar to that of 187 MV protons, even though proton mean free paths continue to decrease comparatively rapidly with decreasing rigidty down to the lowest channels (about 100 MV) observed. The theoretical evidence is from computations of particle scattering in dynamical magnetic turbulence, which predict that electrons will have a larger mean free path than protons of the same rigidity. In the light of these new results, 'consensus' ideas about cosmic-ray mean free paths may require drastic revision.

HF propagation factors affecting the design and operation of real time, channel evaluation, adaptive systems

NASA Astrophysics Data System (ADS)

Aarons, J.; Grossi, M. D.

1982-08-01

To develop and operate an adaptive system, propagation factors of the ionospheric medium must be given to the designer. The operation of the system must change as a function of multipath spread, Doppler spread, path losses, channel correlation functions, etc. In addition, NATO mid-latitude HF transmission and transauroral paths require varying system operation, which must fully utilize automatic path diversity across transauroral paths. Current research and literature are reviewed to estimate the extent of the available technical information. Additional investigations to allow designers to orient new systems on realistic models of these parameters are suggested.

A Bayesian model averaging approach with non-informative priors for cost-effectiveness analyses.

PubMed

Conigliani, Caterina

2010-07-20

We consider the problem of assessing new and existing technologies for their cost-effectiveness in the case where data on both costs and effects are available from a clinical trial, and we address it by means of the cost-effectiveness acceptability curve. The main difficulty in these analyses is that cost data usually exhibit highly skew and heavy-tailed distributions, so that it can be extremely difficult to produce realistic probabilistic models for the underlying population distribution. Here, in order to integrate the uncertainty about the model into the analysis of cost data and into cost-effectiveness analyses, we consider an approach based on Bayesian model averaging (BMA) in the particular case of weak prior informations about the unknown parameters of the different models involved in the procedure. The main consequence of this assumption is that the marginal densities required by BMA are undetermined. However, in accordance with the theory of partial Bayes factors and in particular of fractional Bayes factors, we suggest replacing each marginal density with a ratio of integrals that can be efficiently computed via path sampling. Copyright (c) 2010 John Wiley & Sons, Ltd.

Coping with pregnancy resolution among never-married women.

PubMed

Bracken, Michael B; Klerman, Lorraine V; Bracken, Maryann

1978-04-01

The Janis-Mann model of decision-making provides the theoretical orientation for empirical analyses of decisions to deliver or abort in matched samples of never-married women. Results focus on four variables: happiness about pregnancy; initial acceptance of delivery or abortion; ease of decision-making; and satisfaction with final choice. Path analyses summarize findings, which are discussed in terms of conflict resolution strategies.

The Large-Scale Structure of Semantic Networks: Statistical Analyses and a Model of Semantic Growth

ERIC Educational Resources Information Center

Steyvers, Mark; Tenenbaum, Joshua B.

2005-01-01

We present statistical analyses of the large-scale structure of 3 types of semantic networks: word associations, WordNet, and Roget's Thesaurus. We show that they have a small-world structure, characterized by sparse connectivity, short average path lengths between words, and strong local clustering. In addition, the distributions of the number of…

Centrality and Flow Vergence gradient based Path analysis of scientific literature: A case study of Biotechnology for Engineering

NASA Astrophysics Data System (ADS)

Lathabai, Hiran H.; Prabhakaran, Thara; Changat, Manoj

2015-07-01

Biotechnology, ever since its inception has had a huge impact on the society and its various applications have been intricately woven into the human web of life. Its evolution amidst all the other research realms vital to mankind is remarkable. In this paper, we intend to identify the radical innovations in Biotechnology for Engineering using network analyses. Centrality analysis and Path analysis are used for identifying important works. Existence of Flow Vergence effect in the scientific literature is revealed. Flow Vergence gradient, an arc metric derived from FV model, is utilised for Path analysis which detects pivotal papers of paradigm shift more accurately. A major paradigm shift has been identified in the business models of Biotechnology for Engineering - 'Capability to Connectivity' model. Evidence towards the adoption of business practices in BT firms by nanotechnology start-ups is also identified. The notion of critical divergence is introduced and the exhibition of interdisciplinary interaction in emerging fields due to critical divergence is discussed. Implications of above analyses which target: (i) Science and technology policy makers, (ii) industrialists and investors, (iii) researchers in academia as well as industry, are also discussed.

[Study on the behavioral risk of toxoplasma infection in population working in the slaughterhouse].

PubMed

Ma, Yan; Jin, Tao; Wang, Liyuan; Yang, Tingzhong; Li, Lu; Zhang, Le

2002-02-01

To explore the behavioral risk of toxoplasma infection in special population. Serum samples from workers in slaughterhouse were collected and tested for the detection of cAg, toxo-IgG, toxo-IgM antibody to toxoplasma, using ELISA. Behavioral measurements were conducted through questionnaire, which was developed according to theory of reasoned action which consists of a measurement model that specifies the relation of measured to behavioral variables and a behavioral variable model to show the influence of behavior variables on each other. Factor analysis methods were used for estimating the parameter of the former and path analyses method for the latter. With data from 302 research subjects, the responding rate was 95.87%. The overall infection rate was of 19.20% including 15.89% having cAg, 5.63% with toxo-IgG, 2.32% with toxo-IgM, 1.32% with the third of cAg, toxo-IgG and toxo-IgM, 2.65% with the both cAg and toxo-IgG, 1.99% with the both cAg and IgM respectively. There was significant association between toxoplasma infections and contact with dystocia or live pigs, body fluid or harslet. There was no relation between toxoplasma infections and abortion. from miscarriage factor analyses showed that except evaluation of behavioral outcomes and behavioral attitudes, internal consistence reliability of others behavioral variables was good (Cronbach's alpha > 0.7). These behavior variables could be explained by their measure items. Path analyses suggested that two components had provided significant independent contributions to those preventive behaviors which significantly correlated to toxoplama infections. Half of the contribution leading to toxoplasma infections had come from behavioral factors. Belief was relatively more important in predicting the preventive behavior than subjective norm. Our findings supported the application of reasoned action theory in understanding the role of behavioral factors in toxoplasma infection.

Do root hydraulic properties change during the early vegetative stage of plant development in barley (Hordeum vulgare)?

PubMed Central

Suku, Shimi; Knipfer, Thorsten; Fricke, Wieland

2014-01-01

Background and Aims As annual crops develop, transpirational water loss increases substantially. This increase has to be matched by an increase in water uptake through the root system. The aim of this study was to assess the contributions of changes in intrinsic root hydraulic conductivity (Lp, water uptake per unit root surface area, driving force and time), driving force and root surface area to developmental increases in root water uptake. Methods Hydroponically grown barley plants were analysed during four windows of their vegetative stage of development, when they were 9–13, 14–18, 19–23 and 24–28 d old. Hydraulic conductivity was determined for individual roots (Lp) and for entire root systems (Lpr). Osmotic Lp of individual seminal and adventitious roots and osmotic Lpr of the root system were determined in exudation experiments. Hydrostatic Lp of individual roots was determined by root pressure probe analyses, and hydrostatic Lpr of the root system was derived from analyses of transpiring plants. Key Results Although osmotic and hydrostatic Lp and Lpr values increased initially during development and were correlated positively with plant transpiration rate, their overall developmental increases (about 2-fold) were small compared with increases in transpirational water loss and root surface area (about 10- to 40-fold). The water potential gradient driving water uptake in transpiring plants more than doubled during development, and potentially contributed to the increases in plant water flow. Osmotic Lpr of entire root systems and hydrostatic Lpr of transpiring plants were similar, suggesting that the main radial transport path in roots was the cell-to-cell path at all developmental stages. Conclusions Increase in the surface area of root system, and not changes in intrinsic root hydraulic properties, is the main means through which barley plants grown hydroponically sustain an increase in transpirational water loss during their vegetative development. PMID:24287810

Do root hydraulic properties change during the early vegetative stage of plant development in barley (Hordeum vulgare)?

PubMed

Suku, Shimi; Knipfer, Thorsten; Fricke, Wieland

2014-02-01

As annual crops develop, transpirational water loss increases substantially. This increase has to be matched by an increase in water uptake through the root system. The aim of this study was to assess the contributions of changes in intrinsic root hydraulic conductivity (Lp, water uptake per unit root surface area, driving force and time), driving force and root surface area to developmental increases in root water uptake. Hydroponically grown barley plants were analysed during four windows of their vegetative stage of development, when they were 9-13, 14-18, 19-23 and 24-28 d old. Hydraulic conductivity was determined for individual roots (Lp) and for entire root systems (Lp(r)). Osmotic Lp of individual seminal and adventitious roots and osmotic Lp(r) of the root system were determined in exudation experiments. Hydrostatic Lp of individual roots was determined by root pressure probe analyses, and hydrostatic Lp(r) of the root system was derived from analyses of transpiring plants. Although osmotic and hydrostatic Lp and Lp(r) values increased initially during development and were correlated positively with plant transpiration rate, their overall developmental increases (about 2-fold) were small compared with increases in transpirational water loss and root surface area (about 10- to 40-fold). The water potential gradient driving water uptake in transpiring plants more than doubled during development, and potentially contributed to the increases in plant water flow. Osmotic Lp(r) of entire root systems and hydrostatic Lp(r) of transpiring plants were similar, suggesting that the main radial transport path in roots was the cell-to-cell path at all developmental stages. Increase in the surface area of root system, and not changes in intrinsic root hydraulic properties, is the main means through which barley plants grown hydroponically sustain an increase in transpirational water loss during their vegetative development.

Kinematic analyses of the golf swing hub path and its role in golfer/club kinetic transfers.

PubMed

Nesbit, Steven M; McGinnis, Ryan

2009-01-01

This study analyzed the fundamental geometric and kinematic characteristics of the swing hub path of the golf shot for four diverse subjects. In addition, the role of the hub path geometry in transferring the kinetic quantities from the golfer to the club were investigated. The hub path was found to have a complex geometry with significantly changing radii, and a constantly moving center-of-curvature during the downswing for all subjects. While the size and shape of the hub path differed considerably among the subjects, a three phase radius-based pattern was revealed that aligned with distinct stages of the downswing. Artificially controlling and optimizing the hub path of the better golfer in the group indicated that a non-circular hub path was superior to a constant radius path in minimizing the kinetic loading while generating the highest possible club head velocity. The shape and purpose of the hub path geometry appears to result from a complex combination of achieving equilibrium between the golfer and the club, and a purposeful configuring of the path to control the outward movement of the club while minimizing the kinetic loading on the golfer yet transferring the maximum kinetic quantities to the club. Describing the downswing relative to the hub path phasing is presented and was found to be informative since the phases align with significant swing, kinetic and kinematic markers. These findings challenge golf swing modeling methodologies which fix the center-of-curvature of the hub path thus constraining it to constant radius motion. Key pointsThe golf swing hub path was found to have a complex geometry with significantly changing radii, and a constantly moving center-of-curvature during the downswing.The hub path differed considerably among subjects, however a three phase radius-based pattern was revealed that aligned with distinct stages of the downswing.The shape and purpose of the hub path geometry appears to result from a complex combination of achieving equilibrium between the golfer and the club, and a purposeful configuring of the path to control the outward movement of the club while minimizing the kinetic loading on the golfer yet transferring the maximum kinetic quantities to the club.

Communication prompts donation: exploring the beliefs underlying registration and discussion of the organ donation decision.

PubMed

Hyde, Melissa K; White, Katherine M

2009-09-01

To use a theory of planned behaviour (TPB) framework to explore the beliefs underlying communication of the donation decision for people who had not previously registered their consent on a donor register or discussed their decision with significant others. Initially, a focus group study elicited the common TPB (behavioural, normative, and control) beliefs about registering and discussing the organ donation decision. The main study assessed the important TPB belief predictors of intentions to register and discuss the donation decision. University students and community members from Queensland, Australia (N=123) completed items assessing their intentions and the TPB behavioural, normative, and control beliefs for registering and discussing their donation decision. Structural equation modelling (SEM) analyses revealed significant paths between people's intentions to register their donation decisions and underlying behavioural (e.g. enabling efficient donation procedures), normative (e.g. friends, doctors/medical professionals), and control (e.g. lack of motivation, knowing details about transplant recipients) beliefs (R2=.30). There were also significant paths between people's intentions to discuss their donation decision and underlying behavioural (e.g. feeling uncomfortable talking about death related topics) and normative (e.g. partner/spouse, family members) beliefs, but not control beliefs (R2=.33). There was a significant path between intentions to register and intentions to discuss one's donation decision. Results highlight the importance of focusing on behavioural and normative beliefs about communicating the donation decision, specifically for people who have not previously communicated their decision, and suggest potential targets for interventions designed to promote decision communication.

Implementation of effective cigarette health warning labels among low and middle income countries: state capacity, path-dependency and tobacco industry activity.

PubMed

Hiilamo, Heikki; Glantz, Stanton A

2015-01-01

We investigates the effects of ratifying the WHO Framework Convention of Tobacco Control (FTCT), state capacity, path-dependency and tobacco industry activity on the implementation of effective health warning labels (HWL) on cigarette packs among low and middle income countries (LMIC). Using logistic regression in separate analyses for FCTC Article 11 compliant HWLs and graphic HWLs (GHWL), we found that the odds of FCTC compliance increased by a factor of 1.31 for each year after FCTC entered into force in the country (p < 0.01). The odds of passing GHWLs increased by a factor of 1.46 (p < 0.05) per year after FCTC entered into force. The weaker the capacity of the states were, the less likely they were to have implemented FCTC compliant HWLs (p < 0.05). The countries with voluntary HWLs in 1992 were less likely (OR = 0.19, p < 0.01) to comply with FCTC 21 years later (in 2013). The FCTC has promoted HWL policies among LMICs. Public health regulations require investments in broader state capacity. As the theory of path-dependency predicts voluntary agreements have long lasting influence on the direction of tobacco control in a country. Adopting voluntary HWL policies reduced likelihood of having FCTC compliant HWLs decades later. The fact that voluntary agreements delayed effective tobacco regulations suggests that policymakers must be careful of accepting industry efforts for voluntary agreements in other areas of public health as well, such as alcohol and junk food. Copyright © 2014 Elsevier Ltd. All rights reserved.

Direct effects of tadalafil on lower urinary tract symptoms versus indirect effects mediated through erectile dysfunction symptom improvement: integrated data analyses from 4 placebo controlled clinical studies.

PubMed

Brock, Gerald B; McVary, Kevin T; Roehrborn, Claus G; Watts, Steven; Ni, Xiao; Viktrup, Lars; Wong, David G; Donatucci, Craig

2014-02-01

Tadalafil has regulatory approval for the treatment of men with signs/symptoms of benign prostatic hyperplasia with and without erectile dysfunction. We assessed whether the effects of treatment with tadalafil for lower urinary tract symptoms/benign prostatic hyperplasia are independent of improvements in erectile dysfunction. Four separate analyses used integrated data from 4 randomized, double-blind, placebo controlled studies in men with lower urinary tract symptoms/benign prostatic hyperplasia with and without erectile dysfunction to test whether total I-PSS (International Prostate Symptom Score) improvement was due to improvement in IIEF-EF (International Index of Erectile Function-Erectile Function domain score). Unidirectional and bidirectional path analysis models determined direct and indirect treatment effects mediated by improvements in lower urinary tract symptoms/benign prostatic hyperplasia and erectile dysfunction symptoms. A total of 1,496 men, of whom 77% had erectile dysfunction, received at least 1 dose of tadalafil 5 mg once daily or placebo. The placebo adjusted treatment effect for men with erectile dysfunction was represented by a mean decrease of -2.3 (p <0.0001) in total I-PSS vs -2.2 (p = 0.0007) for men without erectile dysfunction. The correlation between change from baseline in total I-PSS and IIEF-EF was weak (r(2) = 0.08, p <0.0001). The unidirectional path analysis model suggested that the total treatment effect on total I-PSS score improvement (2.25) was derived from a direct treatment effect of 1.57 (70%, p <0.001) and an indirect treatment effect of 0.67 (30% via IIEF-EF improvement, p <0.001). Bidirectional path analysis showed that total I-PSS improvement was largely attributed to direct (92.5%, p <0.001) vs indirect (7.5%, p = 0.32) treatment effects via IIEF-EF improvement. Regardless of the analytical approach, self-reported erectile dysfunction status did not appreciably influence tadalafil treatment response in men with lower urinary tract symptoms/benign prostatic hyperplasia, supporting the dual action of tadalafil on lower urinary tract symptoms/benign prostatic hyperplasia and erectile dysfunction. Copyright © 2014. Published by Elsevier Inc.

Morphology suggests noseleaf and pinnae cooperate to enhance bat echolocation.

PubMed

Kuc, Roman

2010-11-01

A protruding noseleaf and concave pinna structures suggest that some bats may use these to enhance their echolocation capabilities. This paper considers two possible mechanisms that each exploit the combination of direct and delayed acoustic paths to achieve more complex emission or sensitivity echolocation patterns. The first is an emission mechanism, in which the protruding noseleaf vibrates to emit sound in both the forward and backward directions, and pinna structures reflect the backward emission to enhance the forward beam. The second is a reception mechanism, which has a direct echo path to the ear canal and a delayed path involving pinna structures reflecting onto the noseleaf and then into the ear canal. A model using Davis' Round-eared Bat illustrates that such direct and delayed acoustic paths provide target elevation cues. The model demonstrates the delayed pinna component can increase the on-axis emission strength, narrow the beam width, and sculpt frequency-dependent beam patterns useful for echolocation.

An international study of hospitalized cancer patients' health status, nursing care quality, perceived individuality in care and trust in nurses: A path analysis.

PubMed

Charalambous, Andreas; Radwin, Laurel; Berg, Agneta; Sjovall, Katarina; Patiraki, Elisabeth; Lemonidou, Chryssoula; Katajisto, Jouko; Suhonen, Riitta

2016-09-01

Providing high quality nursing care for patients with malignancies is complex and driven by many factors. Many of the associations between nursing care quality, trust, health status and individualized care remain obscure. To empirically test a model of association linking hospitalized cancer patients' health status, nursing care quality, perceived individuality in care and trust in nurses. A cross-sectional, exploratory and correlational study design was used. This multi-site study was conducted in cancer care clinics, in-patient wards of five tertiary care hospitals in Cyprus, Finland, Greece and Sweden. Out of 876 hospitalized patients with a confirmed histopathological diagnosis of cancer approached to participate in the study in consecutive order, 599 (response rate 68%) agreed to participate and the data from 590 were used for path analysis. Data were collected in 2012-2013 with the Individualized Care Scale-Patient (ICS-Patient), the Oncology Patients' Perceptions of Quality Nursing Care Scale (OPPQNCS), the Euro-Qol (EQ-5D-3L) and the Trust in Nurses Scale. Data were analysed statistically using descriptive and inferential statistics. Mplus version 7.11 was used to determine the best Trust model with path analysis. Although the model fit indices suggested that the hypothesized model did not perfectly to the data, a slightly modified model which includes the reciprocal path between individualized care and nursing care quality demonstrated a good fit. A model of trust in nurses was developed. Health status, individualized care, and nursing care quality were found to be associated with trust. The model highlights the complexity of caring for cancer patients. Trust in nurses is influenced by the provision of individualized care. Generating and promoting trust requires interventions, which promote nursing care quality, individuality and patients' health status. Copyright © 2016 Elsevier Ltd. All rights reserved.

Predictor laws for pictorial flight displays

NASA Technical Reports Server (NTRS)

Grunwald, A. J.

1985-01-01

Two predictor laws are formulated and analyzed: (1) a circular path law based on constant accelerations perpendicular to the path and (2) a predictor law based on state transition matrix computations. It is shown that for both methods the predictor provides the essential lead zeros for the path-following task. However, in contrast to the circular path law, the state transition matrix law furnishes the system with additional zeros that entirely cancel out the higher-frequency poles of the vehicle dynamics. On the other hand, the circular path law yields a zero steady-state error in following a curved trajectory with a constant radius. A combined predictor law is suggested that utilizes the advantages of both methods. A simple analysis shows that the optimal prediction time mainly depends on the level of precision required in the path-following task, and guidelines for determining the optimal prediction time are given.

Paths with more turns are perceived as longer: misperceptions with map-based and abstracted path stimuli.

PubMed

Brunyé, Tad T; Mahoney, Caroline R; Taylor, Holly A

2015-04-01

When navigating, people tend to overestimate distances when routes contain more turns, termed the route-angularity effect. Three experiments examined the source and generality of this effect. The first two experiments examined whether route-angularity effects occur while viewing maps and might be related to sex differences or sense of direction. The third experiment tested whether the route-angularity effect would occur with stimuli devoid of spatial context, reducing influences of environmental experience and visual complexity. In the three experiments, participants (N=1,552; M=32.2 yr.; 992 men, 560 women) viewed paths plotted on maps (Exps. 1 and 2) or against a blank background (Exp. 3). The depicted paths were always the same overall length, but varied in the number of turns (from 1 to 7) connecting an origin and destination. Participants were asked to estimate the time to traverse each path (Exp. 1) or the length of each path (Exps. 2 and 3). The Santa Barbara Sense of Direction questionnaire was administered to assess whether overall spatial sense of direction would be negatively related to the magnitude of the route-angularity effect. Repeated-measures analyses of variance (ANOVAs) indicated that paths with more turns elicited estimates of greater distance and travel times, whether they were depicted on maps or blank backgrounds. Linear regressions also indicated that these effects were significantly larger in those with a relatively low sense of direction. The results support the route-angularity effect and extend it to paths plotted on map-based stimuli. Furthermore, because the route-angularity effect was shown with paths plotted against blank backgrounds, route-angularity effects are not specific to understanding environments and may arise at the level of visual perception.

Geometric features of workspace and joint-space paths of 3D reaching movements.

PubMed

Klein Breteler, M D; Meulenbroek, R G; Gielen, S C

1998-11-01

The present study focuses on geometric features of workspace and joint-space paths of three-dimensional reaching movements. Twelve subjects repeatedly performed a three-segment, triangular-shaped movement pattern in an approximately 60 degrees tilted horizontal plane. Task variables elicited movement patterns that varied in position, rotational direction and speed. Trunk, arm, hand and finger-tip movements were recorded by means of a 3D motion-tracking system. Angular excursions of the shoulder and elbow joints were extracted from position data. Analyses of the shape of 3D workspace and joint-space paths focused on the extent to which the submovements were produced in a plane, and on the curvature of the central parts of the submovements. A systematic tendency to produce movements in a plane was found in addition to an increase of finger-tip path curvature with increasing speed. The findings are discussed in relation to the role of optimization principles in trajectory-formation models.

Research on Upgrade Path to Technology Innovation of Resource-based SMEs in China

NASA Astrophysics Data System (ADS)

Jie, Xu

2017-08-01

Complexity, diversity and coordination are features of technology innovation of resource-based SMEs in China. This paper studies on the key factors of macro-environment, cooperation among enterprises and enterprise interior, which influence the upgrading of technology innovation of resource-based SMEs in China. This paper constructs integrated system of technology innovation to analyse the upgrade path to technology innovation of resource-based SMEs in China, so that enterprises would improve their technology innovation and get a new way to accomplish sustainable innovated development.

Impulse Response Measurements Over Space-Earth Paths Using the GPS Coarse/Acquisition Codes

NASA Technical Reports Server (NTRS)

Lemmon, J. J.; Papazian, P. B.

1995-01-01

The impulse responses of radio transmission channels over space-earth paths were measured using the course/acquisition code signals from the Global Positioning System of satellites. The data acquisition system and signal processing techniques used to develop the impulse responses are described. Examples of impulse response measurements are presented. The results indicate that this measurement approach enables detection of multipath signals that are 20 dB or more below the power of the direct arrival. Channel characteristics that could be investigated with additional measurements and analyses are discussed.

Equilibrium paths analysis of materials with rheological properties by using the chaos theory

NASA Astrophysics Data System (ADS)

Bednarek, Paweł; Rządkowski, Jan

2018-01-01

The numerical equilibrium path analysis of the material with random rheological properties by using standard procedures and specialist computer programs was not successful. The proper solution for the analysed heuristic model of the material was obtained on the base of chaos theory elements and neural networks. The paper deals with mathematical reasons of used computer programs and also are elaborated the properties of the attractor used in analysis. There are presented results of conducted numerical analysis both in a numerical and in graphical form for the used procedures.

Viking navigation

NASA Technical Reports Server (NTRS)

Oneil, W. J.; Rudd, R. P.; Farless, D. L.; Hildebrand, C. E.; Mitchell, R. T.; Rourke, K. H.; Euler, E. A.

1979-01-01

A comprehensive description of the navigation of the Viking spacecraft throughout their flight from Earth launch to Mars landing is given. The flight path design, actual inflight control, and postflight reconstruction are discussed in detail. The preflight analyses upon which the operational strategies and performance predictions were based are discussed. The inflight results are then discussed and compared with the preflight predictions and, finally, the results of any postflight analyses are presented.

Formation and disruption of current paths of anodic porous alumina films by conducting atomic force microscopy

NASA Astrophysics Data System (ADS)

Oyoshi, K.; Nigo, S.; Inoue, J.; Sakai, O.; Kitazawa, H.; Kido, G.

2010-11-01

Anodic porous alumina (APA) films have a honeycomb cell structure of pores and a voltage-induced bi-stable switching effect. We have applied conducting atomic force microscopy (CAFM) as a method to form and to disrupt current paths in the APA films. A bi-polar switching operation was confirmed. We have firstly observed terminals of current paths as spots or areas typically on the center of the triangle formed by three pores. In addition, though a part of the current path showed repetitive switching, most of them were not observed again at the same position after one cycle of switching operations in the present experiments. This suggests that a part of alumina structure and/or composition along the current paths is modified during the switching operations.

Comparison of Lyman-alpha and LI-COR infrared hygrometers for airborne measurement of turbulent fluctuations of water vapour

NASA Astrophysics Data System (ADS)

Lampert, Astrid; Hartmann, Jörg; Pätzold, Falk; Lobitz, Lennart; Hecker, Peter; Kohnert, Katrin; Larmanou, Eric; Serafimovich, Andrei; Sachs, Torsten

2018-05-01

To investigate if the LI-COR humidity sensor can be used as a replacement of the Lyman-alpha sensor for airborne applications, the measurement data of the Lyman-alpha and several LI-COR sensors are analysed in direct intercomparison flights on different airborne platforms. One vibration isolated closed-path and two non-isolated open-path LI-COR sensors were installed on a Dornier 128 twin engine turbo-prop aircraft. The closed-path sensor provided absolute values and fluctuations of the water vapour mixing ratio in good agreement with the Lyman-alpha. The signals of the two open-path sensors showed considerable high-frequency noise, and the absolute value of the mixing ratio was observed to drift with time in this vibrational environment. On the helicopter-towed sensor system Helipod, with very low vibration levels, the open-path LI-COR sensor agreed very well with the Lyman-alpha sensor over the entire frequency range up to 3 Hz. The results show that the LI-COR sensors are well suited for airborne measurements of humidity fluctuations, provided that a vibrationless environment is given, and this turns out to be more important than close sensor spacing.

Marijuana Use among Students and Peers.

ERIC Educational Resources Information Center

Griffin, Brenda S.; Griffin, Charles T.

1978-01-01

A casual path model based on Sutherland's theory was developed and applied to student marijuana use as a specific delinquent act. Two types of differential association were suggested to explain the genesis of marijuana use for the individual. The data tended to lend support to the causal path model. (Author/LPG)

One Strategy for Reducing Uncertainty in Climate Change Communications

NASA Astrophysics Data System (ADS)

Romm, J.

2011-12-01

Future impacts of climate change are invariably presented with a very wide range of impacts reflecting two different sets of uncertainties. The first concerns our uncertainty about precisely how much greenhouse gas emissions humanity will emit into the atmosphere. The second concerns our uncertainty about precisely what impact those emissions will have on the climate. By failing to distinguish between these two types of uncertainties, climate scientists have not clearly explained to the public and policymakers what the scientific literature suggests is likely to happen if we don't substantially alter our current emissions path. Indeed, much of climate communications has been built around describing the range of impacts from emissions paths that are increasingly implausible given political and technological constraints, such as a stabilization at 450 or 550 parts per million atmospheric of carbon dioxide. For the past decade, human emissions of greenhouse gases have trended near the worst-case scenarios of the Intergovernmental Panel on Climate Change, emissions paths that reach 800 ppm or even 1000 ppm. The current policies of the two biggest emitters, the United States and China, coupled with the ongoing failure of international negotiations to come to an agreement on restricting emissions, suggests that recent trends will continue for the foreseeable future. This in turn suggests that greater clarity in climate change communications could be achieved by more clearly explaining to the public what the scientific literature suggests the range of impacts are for our current high emissions path. This also suggests that more focus should be given in the scientific literature to better constraining the range of impacts from the high emissions scenarios.

Chinese American immigrant parents' emotional expression in the family: Relations with parents' cultural orientations and children's emotion-related regulation.

PubMed

Chen, Stephen H; Zhou, Qing; Main, Alexandra; Lee, Erica H

2015-10-01

The present study examined 2 measures of Chinese American immigrant parents' emotional expression in the family context: self-reported emotional expressivity and observed emotional expression during a parent-child interaction task. Path analyses were conducted to examine the concurrent associations between measures of emotional expression and (a) parents' American and Chinese cultural orientations in language proficiency, media use, and social affiliation domains, and (b) parents' and teachers' ratings of children's emotion-related regulation. Results suggested that cultural orientations were primarily associated with parents' self-reported expressivity (rather than observed emotional expression), such that higher American orientations were generally associated with higher expressivity. Although parents' self-reported expressivity was only related to their own reports of children's regulation, parents' observed emotional expression was related to both parents' and teachers' reports of children's regulation. These results suggest that self-reported expressivity and observed emotional expression reflect different constructs and have differential relations to parents' cultural orientations and children's regulation. (c) 2015 APA, all rights reserved).

Revisiting Jenner's mysteries, the role of the Beaugency lymph in the evolutionary path of ancient smallpox vaccines.

PubMed

Damaso, Clarissa R

2018-02-01

In 1796, Edward Jenner developed the smallpox vaccine consisting of pustular material obtained from lesions on cows affected by so-called cow-pox. The disease, caused by cowpox virus, confers crossprotection against smallpox. However, historical evidence suggests that Jenner might have used vaccinia virus or even horsepox virus instead of cowpox virus. Mysteries surrounding the origin and nature of the smallpox vaccine persisted during the 19th century, a period of intense exchange of vaccine strains, including the Beaugency lymph. This lymph was obtained from spontaneous cases of cow-pox in France in 1866 and then distributed worldwide. A detailed Historical Review of the distribution of the Beaugency lymph supports recent genetic analyses of extant vaccine strains, suggesting the lymph was probably a vaccinia strain or a horsepox-like virus. This Review is a historical investigation that revisits the mysteries of the smallpox vaccine and reveals an intricate evolutionary relationship of extant vaccinia strains. Copyright © 2018 Elsevier Ltd. All rights reserved.

Putting the Nation on a Path for Climate Resilience and Preparedness

EPA Pesticide Factsheets

Putting current data in a historical context, NOAA publishes the monthly State of the Climate Report that includes analyses of the Nation's recent climate conditions, their unusualness, and their rank within long‐term trends.

The association between trauma and chronic medical conditions in individuals with severe mental illness.

PubMed

Raab, Phillip Andrew; Claypoole, Keith Harvey; Hayashi, Kentaro; Baker, Charlene

2012-10-01

Based on the concept of allostatic load, this study proposed and evaluated a model for the relationship between childhood trauma, chronic medical conditions, and intervening variables affecting this relationship in individuals with severe mental illness. Childhood trauma, adult trauma, major depressive disorder symptoms, posttraumatic stress disorder symptoms, health risk factors, and chronic medical conditions were retrospectively assessed using a cross-sectional survey design in a sample of 117 individuals with severe mental illness receiving public mental health services. Path analyses produced a good-fitting model, with significant pathways from childhood to adult trauma and from adult trauma to chronic medical conditions. Multisample path analyses revealed the equivalence of the model across sex. The results support a model for the relationship between childhood and adult trauma and chronic medical conditions, which highlights the pathophysiological toll of cumulative trauma experienced across the life span and the pressing need to prevent retraumatization in this population.

Childhood Predictors of Teen Dating Violence Victimization

PubMed Central

Maas, Carl D.; Fleming, Charles B.; Herrenkohl, Todd I.; Catalano, Richard F.

2009-01-01

Most research on predictors of teen dating violence (TDV) has used cross-sectional data, which weakens predictive modeling and hypothesis testing analyses. This study uses prospective and retrospective longitudinal data on a community sample to examine previously identified predictors of TDV victimization and pathways from childhood risk and protection to TDV victimization. Data are from 941 participants in the Raising Healthy Children project. Bivariate analyses found associations in the expected direction between potential predictors and TDV victimization. For girls, a multivariate path model indicated that higher levels of bonding to parents and social skills protected against TDV victimizations, partly by reducing early adolescent alcohol use. While externalizing and internalizing behaviors in early adolescence were predicted by childhood risk and protective factors for girls, neither uniquely predicted TDV victimization. For boys, there was an indirect path from childhood bonding to parents to TDV victimization through early adolescent externalizing behavior. PMID:20514813

Optimal strategies for throwing accurately

PubMed Central

2017-01-01

The accuracy of throwing in games and sports is governed by how errors in planning and initial conditions are propagated by the dynamics of the projectile. In the simplest setting, the projectile path is typically described by a deterministic parabolic trajectory which has the potential to amplify noisy launch conditions. By analysing how parabolic trajectories propagate errors, we show how to devise optimal strategies for a throwing task demanding accuracy. Our calculations explain observed speed–accuracy trade-offs, preferred throwing style of overarm versus underarm, and strategies for games such as dart throwing, despite having left out most biological complexities. As our criteria for optimal performance depend on the target location, shape and the level of uncertainty in planning, they also naturally suggest an iterative scheme to learn throwing strategies by trial and error. PMID:28484641

Shaming, Blaming, and Maiming: Functional Links Among the Moral Emotions, Externalization of Blame, and Aggression

PubMed Central

Stuewig, Jeffrey; Tangney, June P.; Heigel, Caron; Harty, Laura; McCloskey, Laura

2010-01-01

Theory suggests that shame should be positively related to aggression while guilt may serve as a protective factor. Little research has examined mediators between the moral emotions and aggression. Results using path analyses in four diverse samples were consistent with a model of no direct relationship between shame-proneness and aggression. There was, however, a significant indirect relationship through externalization of blame, but mostly when aggression was measured using self-report. Guilt-proneness, on the other hand, showed a direct negative relationship to aggression whether using self-report or other reports of aggression. Guilt was also inversely related to aggression indirectly through externalization of blame and empathy. Identifying these differing mechanisms may be useful in developing more effective interventions for aggressive individuals. PMID:20369025

Too Materialistic to Get Married and Have Children?

PubMed Central

Li, Norman P.; Lim, Amy J. Y.; Tsai, Ming-Hong; O, Jiaqing

2015-01-01

We developed new materials to induce a luxury mindset and activate materialistic values, and examined materialism’s relationship to attitudes toward marriage and having children in Singapore. Path analyses indicated that materialistic values led to more negative attitudes toward marriage, which led to more negative attitudes toward children, which in turn led to a decreased number of children desired. Results across two studies highlight, at the individual level, the tradeoff between materialistic values and attitudes toward marriage and procreation and suggest that a consideration of psychological variables such as materialistic values may allow for a better understanding of larger-scale socioeconomic issues including low fertility rates among developed countries. We discuss implications and describe how psychological factors relating to low fertility fit within evolutionary mismatch and life history theory frameworks. PMID:25955502

Optimal strategies for throwing accurately

NASA Astrophysics Data System (ADS)

Venkadesan, M.; Mahadevan, L.

2017-04-01

The accuracy of throwing in games and sports is governed by how errors in planning and initial conditions are propagated by the dynamics of the projectile. In the simplest setting, the projectile path is typically described by a deterministic parabolic trajectory which has the potential to amplify noisy launch conditions. By analysing how parabolic trajectories propagate errors, we show how to devise optimal strategies for a throwing task demanding accuracy. Our calculations explain observed speed-accuracy trade-offs, preferred throwing style of overarm versus underarm, and strategies for games such as dart throwing, despite having left out most biological complexities. As our criteria for optimal performance depend on the target location, shape and the level of uncertainty in planning, they also naturally suggest an iterative scheme to learn throwing strategies by trial and error.

Bidirectional influences between maternal parenting and children's peer problems: a longitudinal monozygotic twin difference study.

PubMed

Yamagata, Shinji; Takahashi, Yusuke; Ozaki, Koken; Fujisawa, Keiko K; Nonaka, Koichi; Ando, Juko

2013-03-01

This twin study examined the bidirectional relationship between maternal parenting behaviors and children's peer problems that were not confounded by genetic and family environmental factors. Mothers of 259 monozygotic twin pairs reported parenting behaviors and peer problems when twins were 42 and 48 months. Path analyses on monozygotic twin difference scores revealed that authoritative parenting (the presence of consistent discipline and lack of harsh parenting) and peer problems simultaneously influenced each other. Authoritative parenting reduced peer problems, and peer problems increased authoritative parenting. Neither consistent discipline nor harsh parenting alone was associated with peer problems. These results suggest that maternal authoritative parenting works protectively in regard to children's peer problems, and peer problems can evoke such effective parenting. © 2012 Blackwell Publishing Ltd.

Longitudinal Associations Among Religiousness, Delay Discounting, and Substance Use Initiation in Early Adolescence

PubMed Central

Kim-Spoon, Jungmeen; McCullough, Michael E.; Bickel, W. K.; Farley, Julee P.; Longo, Gregory S.

2014-01-01

Prior research indicates that religiousness is related negatively to adolescent health risk behaviors, yet how such protective effects operate is not well understood. This study examined the longitudinal associations among organizational and personal religiousness, delay discounting, and substance use initiation (alcohol, cigarette, and marijuana use). The sample comprised 106 early adolescents (10-13 years of age, 52% female) who were not using substances at Time 1. Path analyses suggested that high levels of personal religiousness at Time 1 were related to low levels of substance use at Time 2 (2.4 years later), mediated by low levels of delay discounting. Delay discounting appears to be an important contributor to the protective effect of religiousness on the development of substance use among adolescents. PMID:25750491

Electrical deaths in the US construction: an analysis of fatality investigations.

PubMed

Zhao, Dong; Thabet, Walid; McCoy, Andrew; Kleiner, Brian

2014-01-01

Electrocution is among the 'fatal four' in US construction according to the Occupational Safety and Health Administration. Learning from failures is believed to be an effective path to success, with deaths being the most serious system failures. This paper examined the failures in electrical safety by analysing all electrical fatality investigations (N = 132) occurring between 1989 and 2010 from the Fatality Assessment and Control Evaluation programme that is completed by the National Institute of Occupational Safety and Health. Results reveal the features of the electrical fatalities in construction and disclose the most common electrical safety challenges on construction sites. This research also suggests the sociotechnical system breakdowns and the less effectiveness of current safety training programmes may significantly contribute to worker's unsafe behaviours and electrical fatality occurrences.

Too materialistic to get married and have children?

PubMed

Li, Norman P; Lim, Amy J Y; Tsai, Ming-Hong; O, Jiaqing

2015-01-01

We developed new materials to induce a luxury mindset and activate materialistic values, and examined materialism's relationship to attitudes toward marriage and having children in Singapore. Path analyses indicated that materialistic values led to more negative attitudes toward marriage, which led to more negative attitudes toward children, which in turn led to a decreased number of children desired. Results across two studies highlight, at the individual level, the tradeoff between materialistic values and attitudes toward marriage and procreation and suggest that a consideration of psychological variables such as materialistic values may allow for a better understanding of larger-scale socioeconomic issues including low fertility rates among developed countries. We discuss implications and describe how psychological factors relating to low fertility fit within evolutionary mismatch and life history theory frameworks.

Influence of a glide path on apical extrusion of debris during canal preparation using single-file systems in curved canals.

PubMed

Topçuoğlu, H S; Düzgün, S; Akpek, F; Topçuoğlu, G; Aktı, A

2016-06-01

To evaluate the effect of a glide path on the amount of apically extruded debris during canal preparation using single-file systems in curved canals. Ninety extracted mandibular molar teeth were randomly assigned to six groups (n = 15 for each group) for canal instrumentation. Endodontic access cavities were prepared in each tooth. In three of the six groups, a glide path was not created whereas a glide path was created using PathFile instruments on the mesial canals of all teeth in the remaining three groups. The mesial canals of the teeth were then instrumented with the following single-file instrument systems: WaveOne, Reciproc and OneShape. Debris extruded apically during instrumentation was collected into pre-weighed Eppendorf tubes. The tubes were then stored in an incubator at 70 °C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. The data obtained were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests. The OneShape file was associated with less debris extrusion than the Reciproc and WaveOne files when canal instrumentation was performed without a glide path (P < 0.05). However, no significant difference was found between the Reciproc and WaveOne files (P > 0.05). There was no significant difference amongst the OneShape, Reciproc and WaveOne files when a glide path was created before canal preparation in curved root canals (P > 0.05). All systems extruded significantly less debris in groups with a glide path than in groups without a glide path (P < 0.05). All instruments were associated with apical extrusion of debris. Creating a glide path prior to canal instrumentation reduced the amount of apically extruded debris in curved canals. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Continuum beliefs in the stigma process regarding persons with schizophrenia and depression: results of path analyses

PubMed Central

Mnich, Eva E.; Angermeyer, Matthias C.; von dem Knesebeck, Olaf

2016-01-01

Background Individuals with mental illness often experience stigmatization and encounter stereotypes such as being dangerous or unpredictable. To further improve measures against psychiatric stigma, it is of importance to understand its components. In this study, we attend to the step of separation between “us” and “them” in the stigma process as conceptualized by Link and Phelan. In using the belief in continuity of mental illness symptoms as a proxy for separation, we explore its associations with stereotypes, emotional responses and desire for social distance in the stigma process. Methods Analyses are based on a representative survey in Germany. Vignettes with symptoms suggestive of schizophrenia (n = 1,338) or depression (n = 1,316) were presented to the respondents, followed by questions on continuum belief, stereotypes, emotional reactions and desire for social distance. To examine the relationship between these items, path models were computed. Results Respondents who endorsed the continuum belief tended to show greater prosocial reactions (schizophrenia: 0.07; p < 0.001, depression: 0.09; p < 0.001) and less desire for social distance (schizophrenia: −0.13; p < 0.001, depression: −0.14; p < 0.001) toward a person with mental illness. In both cases, agreement with the stereotypes of unpredictability and dangerousness was positively associated with feelings of anger and fear as well as desire for social distance. There were no statistically significant relations between stereotypes and continuum beliefs. Discussion Assumptions regarding continuum beliefs in the stigma process were only partially confirmed. However, there were associations of continuum beliefs with less stigmatizing attitudes toward persons affected by either schizophrenia or depression. Including information on continuity of symptoms, and thus oppose perceived separation, could prove helpful in future anti-stigma campaigns. PMID:27703840

Associations between forest fragmentation patterns and geneticstructure in Pfrimer’s Parakeet (Pyrrhura pfrimeri), an endangered endemic to central Brazil’s dry forests

USGS Publications Warehouse

Haig, Susan M.; Miller, Leonard F.; Bianchi, Carlos; Mullins, Thomas D.

2012-01-01

When habitat becomes fragmented, populations of species may become increasingly isolated. In the absence of habitat corridors, genetic structure may develop and populations risk reductions in genetic diversity from increased genetic drift and inbreeding. Deforestation of the Cerrado biome of Brazil, particularly of the dry forests within the Parana˜ River Basin, has incrementally occurred since the 1970s and increased forest fragmentation within the region. We performed landscape genetic analyses of Pfrimer’s parakeet (Pyrrhura pfrimeri), a globally endangered endemic to the region, to determine if forest fragmentation patterns were associated with genetic structuring in this species. We used previously generated satellite imagery that identified the locations of Parana˜ River Basin forest fragments in 1977, 1993/94, and 2008. Behavioral data quantifying the affinity of Pfrimer’s parakeet for forest habitat was used to parameterize empirically derived landscape conductance surfaces. Though genetic structure was observed among Pfrimer’s parakeet populations, no association between genetic and geographic distance was detected. Likewise, least cost path lengths, circuit theorybased resistance distances, and a new measure of least cost path length complexity could not be conclusively associated with genetic structure patterns. Instead, a new quantity that encapsulated connection redundancy from the 1977 forest fragmentation data provided the clearest associations with pairwise genetic differentiation patterns (Jost’s D: r = 0.72, P = 0.006; FST: r = 0.741, P = 0.001). Our analyses suggest a 35-year or more lag between deforestation and its effect on genetic structure. Because 66 % of the Parana˜ River Basin has been deforested since 1977, we expect that genetic structure will increase substantially among Pfrimer’s Parakeet populations in the future, especially if fragmentation continues at its current pace.

Functional connectivity in replicated urban landscapes in the land snail (Cornu aspersum).

PubMed

Balbi, Manon; Ernoult, Aude; Poli, Pedro; Madec, Luc; Guiller, Annie; Martin, Marie-Claire; Nabucet, Jean; Beaujouan, Véronique; Petit, Eric J

2018-03-01

Urban areas are highly fragmented and thereby exert strong constraints on individual dispersal. Despite this, some species manage to persist in urban areas, such as the garden snail, Cornu aspersum, which is common in cityscapes despite its low mobility. Using landscape genetic approaches, we combined study area replication and multiscale analysis to determine how landscape composition, configuration and connectivity influence snail dispersal across urban areas. At the overall landscape scale, areas with a high percentage of roads decreased genetic differentiation between populations. At the population scale, genetic differentiation was positively linked with building surface, the proportion of borders where wooded patches and roads appeared side by side and the proportion of borders combining wooded patches and other impervious areas. Analyses based on pairwise genetic distances validated the isolation-by-distance and isolation-by-resistance models for this land snail, with an equal fit to least-cost paths and circuit-theory-based models. Each of the 12 landscapes analysed separately yielded specific relations to environmental features, whereas analyses integrating all replicates highlighted general common effects. Our results suggest that urban transport infrastructures facilitate passive snail dispersal. At a local scale, corresponding to active dispersal, unfavourable habitats (wooded and impervious areas) isolate populations. This work upholds the use of replicated landscapes to increase the generalizability of landscape genetics results and shows how multiscale analyses provide insight into scale-dependent processes. © 2018 John Wiley & Sons Ltd.

Causal pathways linking environmental change with health behaviour change: Natural experimental study of new transport infrastructure and cycling to work.

PubMed

Prins, R G; Panter, J; Heinen, E; Griffin, S J; Ogilvie, D B

2016-06-01

Mechanisms linking changes to the environment with changes in physical activity are poorly understood. Insights into mechanisms of interventions can help strengthen causal attribution and improve understanding of divergent response patterns. We examined the causal pathways linking exposure to new transport infrastructure with changes in cycling to work. We used baseline (2009) and follow-up (2012) data (N=469) from the Commuting and Health in Cambridge natural experimental study (Cambridge, UK). Exposure to new infrastructure in the form of the Cambridgeshire Guided Busway was defined using residential proximity. Mediators studied were changes in perceptions of the route to work, theory of planned behaviour constructs and self-reported use of the new infrastructure. Outcomes were modelled as an increase, decrease or no change in weekly cycle commuting time. We used regression analyses to identify combinations of mediators forming potential pathways between exposure and outcome. We then tested these pathways in a path model and stratified analyses by baseline level of active commuting. We identified changes in perceptions of the route to work, and use of the cycle path, as potential mediators. Of these potential mediators, only use of the path significantly explained (85%) the effect of the infrastructure in increasing cycling. Path use also explained a decrease in cycling among more active commuters. The findings strengthen the causal argument that changing the environment led to changes in health-related behaviour via use of the new infrastructure, but also show how some commuters may have spent less time cycling as a result. Copyright © 2016. Published by Elsevier Inc.

Pathways to poor educational outcomes for HIV/AIDS-affected youth in South Africa.

PubMed

Orkin, Mark; Boyes, Mark E; Cluver, Lucie D; Zhang, Yuning

2014-01-01

A recent systematic review of studies in the developing world has critically examined linkages from familial HIV/AIDS and associated factors such as poverty and child mental health to negative child educational outcomes. In line with several recommendations in the review, the current study modelled relationships between familial HIV/AIDS, poverty, child internalising problems, gender and four educational outcomes: non-enrolment at school, non-attendance, deficits in grade progression and concentration problems. Path analyses reveal no direct associations between familial HIV/AIDS and any of the educational outcomes. Instead, HIV/AIDS-orphanhood or caregiver HIV/AIDS-sickness impacted indirectly on educational outcomes via the poverty and internalising problems that they occasioned. This has implications for evidence-based policy inferences. For instance, by addressing such intervening variables generally, rather than by seeking to target families affected by HIV/AIDS, interventions could avoid exacerbating stigmatisation, while having a more direct and stronger impact on children's educational outcomes. This analytic approach also suggests that future research should seek to identify causal paths, and may include other intervening variables related to poverty (such as child housework and caring responsibilities) or to child mental health (such as stigma and abuse), that are linked to both familial HIV/AIDS and educational outcomes.

Mediating the relation between workplace stressors and distress in ID support staff: comparison between the roles of psychological inflexibility and coping styles.

PubMed

Kurz, A Solomon; Bethay, J Scott; Ladner-Graham, Jennifer M

2014-10-01

The present study examined how different patterns of coping influence psychological distress for staff members in programs serving individuals with intellectual disabilities. With a series of path models, we examined the relative usefulness of constructs (i.e., wishful thinking and psychological inflexibility) from two distinct models of coping (i.e., the transactional model and the psychological flexibility models, respectively) as mediators to explain how workplace stressors lead to psychological distress in staff serving individuals with intellectual disabilities. Analyses involved self-report questionnaires from 128 staff members (84% female; 71% African American) from a large, state-funded residential program for individuals with intellectual and physical disabilities in the southern United States of America. Cross-sectional path models using bootstrapped standard errors and confidence intervals revealed both wishful thinking and psychological inflexibility mediated the relation between workplace stressors and psychological distress when they were included in separate models. However, when both variables were included in a multiple mediator model, only psychological inflexibility remained a significant mediator. The results suggest psychological inflexibility and the psychological flexibility model may be particularly useful for further investigation on the causes and amelioration of workplace-related stress in ID settings. Copyright © 2014 Elsevier Ltd. All rights reserved.

In situ measurements of hydraulic fracture behavior, PTE-3. Final report

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

Warpinski, N.R.

Measurements of width and pressure in a propagating hydraulic fracture have been made in tests conducted at DOE`s Nevada Test Site. This was accomplished by creating an "instrumented fracture" at a tunnel complex (at a depth of 1400 ft) where realistic in situ conditions prevail, particularly with respect to stress and geologic features such as natural fractures and material anisotropy. Analyses of these data show that the pressure drop along the fracture length is much larger than predicted by viscous theory currently in use in models today. This is apparently due to the tortuosity of the fracture path, multiple fracturemore » strands, roughness, and sharp turns (corners) in the flow path due to natural fractures and rock property variations. It suggests that fracture design models need to be updated to include a more realistic friction factor so that fracture lengths are not overestimated. The width and pressure profiles near the crack tip have been investigated in some detail, including the length of the unwetted region and the tapering of the crack tip. The overall fracture behavior has been compared with published fracture models. Mineback of the fracture provided evidence of the geometry of the fracture and details of surface features. 35 refs., 89 figs., 30 tabs.« less

Decision-making competence predicts domain-specific risk attitudes

PubMed Central

Weller, Joshua A.; Ceschi, Andrea; Randolph, Caleb

2015-01-01

Decision-making competence (DMC) reflects individual differences in rational responding across several classic behavioral decision-making tasks. Although it has been associated with real-world risk behavior, less is known about the degree to which DMC contributes to specific components of risk attitudes. Utilizing a psychological risk-return framework, we examined the associations between risk attitudes and DMC. Italian community residents (n = 804) completed an online DMC measure, using a subset of the original Adult-DMC battery. Participants also completed a self-reported risk attitude measure for three components of risk attitudes (risk-taking, risk perceptions, and expected benefits) across six risk domains. Overall, greater performance on the DMC component scales were inversely, albeit modestly, associated with risk-taking tendencies. Structural equation modeling results revealed that DMC was associated with lower perceived expected benefits for all domains. In contrast, its association with perceived risks was more domain-specific. These analyses also revealed stronger indirect effects for the DMC → expected benefits → risk-taking path than the DMC → perceived risk → risk-taking path, especially for behaviors that may be considered more maladaptive in nature. These results suggest that DMC performance differentially impacts specific components of risk attitudes, and may be more strongly related to the evaluation of expected value of a specific behavior. PMID:26029128

Gaze behaviour during space perception and spatial decision making.

PubMed

Wiener, Jan M; Hölscher, Christoph; Büchner, Simon; Konieczny, Lars

2012-11-01

A series of four experiments investigating gaze behavior and decision making in the context of wayfinding is reported. Participants were presented with screenshots of choice points taken in large virtual environments. Each screenshot depicted alternative path options. In Experiment 1, participants had to decide between them to find an object hidden in the environment. In Experiment 2, participants were first informed about which path option to take as if following a guided route. Subsequently, they were presented with the same images in random order and had to indicate which path option they chose during initial exposure. In Experiment 1, we demonstrate (1) that participants have a tendency to choose the path option that featured the longer line of sight, and (2) a robust gaze bias towards the eventually chosen path option. In Experiment 2, systematic differences in gaze behavior towards the alternative path options between encoding and decoding were observed. Based on data from Experiments 1 and 2 and two control experiments ensuring that fixation patterns were specific to the spatial tasks, we develop a tentative model of gaze behavior during wayfinding decision making suggesting that particular attention was paid to image areas depicting changes in the local geometry of the environments such as corners, openings, and occlusions. Together, the results suggest that gaze during a wayfinding tasks is directed toward, and can be predicted by, a subset of environmental features and that gaze bias effects are a general phenomenon of visual decision making.

An Anatomically Constrained Model for Path Integration in the Bee Brain.

PubMed

Stone, Thomas; Webb, Barbara; Adden, Andrea; Weddig, Nicolai Ben; Honkanen, Anna; Templin, Rachel; Wcislo, William; Scimeca, Luca; Warrant, Eric; Heinze, Stanley

2017-10-23

Path integration is a widespread navigational strategy in which directional changes and distance covered are continuously integrated on an outward journey, enabling a straight-line return to home. Bees use vision for this task-a celestial-cue-based visual compass and an optic-flow-based visual odometer-but the underlying neural integration mechanisms are unknown. Using intracellular electrophysiology, we show that polarized-light-based compass neurons and optic-flow-based speed-encoding neurons converge in the central complex of the bee brain, and through block-face electron microscopy, we identify potential integrator cells. Based on plausible output targets for these cells, we propose a complete circuit for path integration and steering in the central complex, with anatomically identified neurons suggested for each processing step. The resulting model circuit is thus fully constrained biologically and provides a functional interpretation for many previously unexplained architectural features of the central complex. Moreover, we show that the receptive fields of the newly discovered speed neurons can support path integration for the holonomic motion (i.e., a ground velocity that is not precisely aligned with body orientation) typical of bee flight, a feature not captured in any previously proposed model of path integration. In a broader context, the model circuit presented provides a general mechanism for producing steering signals by comparing current and desired headings-suggesting a more basic function for central complex connectivity, from which path integration may have evolved. Copyright © 2017 Elsevier Ltd. All rights reserved.

Advanced Launch System Multi-Path Redundant Avionics Architecture Analysis and Characterization

NASA Technical Reports Server (NTRS)

Baker, Robert L.

1993-01-01

The objective of the Multi-Path Redundant Avionics Suite (MPRAS) program is the development of a set of avionic architectural modules which will be applicable to the family of launch vehicles required to support the Advanced Launch System (ALS). To enable ALS cost/performance requirements to be met, the MPRAS must support autonomy, maintenance, and testability capabilities which exceed those present in conventional launch vehicles. The multi-path redundant or fault tolerance characteristics of the MPRAS are necessary to offset a reduction in avionics reliability due to the increased complexity needed to support these new cost reduction and performance capabilities and to meet avionics reliability requirements which will provide cost-effective reductions in overall ALS recurring costs. A complex, real-time distributed computing system is needed to meet the ALS avionics system requirements. General Dynamics, Boeing Aerospace, and C.S. Draper Laboratory have proposed system architectures as candidates for the ALS MPRAS. The purpose of this document is to report the results of independent performance and reliability characterization and assessment analyses of each proposed candidate architecture and qualitative assessments of testability, maintainability, and fault tolerance mechanisms. These independent analyses were conducted as part of the MPRAS Part 2 program and were carried under NASA Langley Research Contract NAS1-17964, Task Assignment 28.

Social-emotional competence and early adolescents' peer acceptance in school: Examining the role of afternoon cortisol.

PubMed

Oberle, Eva

2018-01-01

The present study investigated the role of afternoon cortisol in social-emotional competence and peer acceptance in early adolescence. To date, research on basal cortisol activity and social development in childhood and adolescence has predominately focused on understanding maladjustment and dysfunction in development. The degree to which basal cortisol is also involved in positive adjustment and social functioning remains largely unexplored. A total of 154 early adolescents (46% female; Mean age = 11.26; SD = .65) from diverse ethnic backgrounds provided self-reports of perspective taking, peer reports of acceptance by classmates, peer reports of prosocial behaviors, and saliva samples to assess basal cortisol. As expected and in alignment with previous research, afternoon cortisol, perspective taking, prosocial behaviors, and peer acceptance were all positively correlated. Path analyses followed by bootstrapping analyses revealed that the direct path from higher afternoon cortisol to higher levels of prosocial behavior was fully mediated by perspective taking skills. The direct path from higher afternoon cortisol to peer acceptance was fully mediated by perspective taking skills and prosocial behavior. The findings are discussed within the broader context of previous research on cortisol and social adjustment in childhood and early adolescence. The practical relevance of the findings is considered.

Relationships between stereotyped beliefs about mental illness, discrimination experiences, and distressed mood over 1 year among persons with schizophrenia enrolled in rehabilitation.

PubMed

Lysaker, Paul H; Tunze, Chloe; Yanos, Philip T; Roe, David; Ringer, Jamie; Rand, Kevin

2012-06-01

Research suggests stereotype endorsement or self-stigma serves as a barrier to functioning and well-being among persons with schizophrenia. Little is known about how stable self-stigma is and whether it is linked over time with related constructs such as discrimination experiences and psychological distress. Stereotype endorsement and discrimination experiences were assessed using the Internalized Stigma of Mental Illness Scale and psychological distress was assessed using the Emotional Discomfort component of the Positive and Negative Syndrome Scale, at three points in time across 1 year. Path analyses indicated that the constructs of stereotype endorsement and discrimination experiences are stable over periods of 5-7 months and may fluctuate over 12 months. Further, the constructs of stereotype endorsement and discrimination experiences were related to one another concurrently, but analyses failed to detect a relationship over time. Neither construct was related to psychological distress over time. Self-stigma is a stable construct in the short term, and is distinct from related constructs such as discrimination experiences and psychological distress.

Using path analysis to examine causal relationships among balanced scorecard performance indicators for general hospitals: the case of a public hospital system in Taiwan.

PubMed

Yang, Ming-Chin; Tung, Yu-Chi

2006-01-01

Examining whether the causal relationships among the performance indicators of the balanced scorecard (BSC) framework exist in hospitals is the aim of this article. Data were collected from all twenty-one general hospitals in a public hospital system and their supervising agency for the 3-year period, 2000-2002. The results of the path analyses identified significant causal relationships among four perspectives in the BSC model. We also verified the relationships among indicators within each perspective, some of which varied as time changed. We conclude that hospital administrators can use path analysis to help them identify and manage leading indicators when adopting the BSC model. However, they should also validate causal relationships between leading and lagging indicators periodically because the management environment changes constantly.

Visually based path-planning by Japanese monkeys.

PubMed

Mushiake, H; Saito, N; Sakamoto, K; Sato, Y; Tanji, J

2001-03-01

To construct an animal model of strategy formation, we designed a maze path-finding task. First, we asked monkeys to capture a goal in the maze by moving a cursor on the screen. Cursor movement was linked to movements of each wrist. When the animals learned the association between cursor movement and wrist movement, we established a start and a goal in the maze, and asked them to find a path between them. We found that the animals took the shortest pathway, rather than approaching the goal randomly. We further found that the animals adopted a strategy of selecting a fixed intermediate point in the visually presented maze to select one of the shortest pathways, suggesting a visually based path planning. To examine their capacity to use that strategy flexibly, we transformed the task by blocking pathways in the maze, providing a problem to solve. The animals then developed a strategy of solving the problem by planning a novel shortest path from the start to the goal and rerouting the path to bypass the obstacle.

Physical Therapy Intervention in the Neonatal Intensive Care Unit

ERIC Educational Resources Information Center

Byrne, Eilish; Garber, June

2013-01-01

This article presents the elements of the Intervention section of the Infant Care Path for Physical Therapy in the Neonatal Intensive Care Unit (NICU). The types of physical therapy interventions presented in this path are evidence-based and the suggested timing of these interventions is primarily based on practice knowledge from expert…

Experiential Learning: A New Research Path to the Study of Journalism Education.

ERIC Educational Resources Information Center

Brandon, Wanda

2002-01-01

Examines the learning environment of journalism education. Considers historical perspectives of journalism education before laying the groundwork for a new research area. Suggests that the experiential learning approach offers a way of assessing the quality of learning and of breaking new paths into the study of journalism education. (SG)

The Sound Path: Adding Music to a Child Care Playground.

ERIC Educational Resources Information Center

Kern, Petra; Wolery, Mark

2002-01-01

This article discusses how musical activities were added to a childcare playground and the benefits for a young child with blindness. The six-station "Sound Path" is described, and suggestions are provided for using sound pipes to develop sensorimotor skills, social and communication skills, cognitive skills, and emotional skills. (Contains…

Challenging prior evidence for a shared syntactic processor for language and music.

PubMed

Perruchet, Pierre; Poulin-Charronnat, Bénédicte

2013-04-01

A theoretical landmark in the growing literature comparing language and music is the shared syntactic integration resource hypothesis (SSIRH; e.g., Patel, 2008), which posits that the successful processing of linguistic and musical materials relies, at least partially, on the mastery of a common syntactic processor. Supporting the SSIRH, Slevc, Rosenberg, and Patel (Psychonomic Bulletin & Review 16(2):374-381, 2009) recently reported data showing enhanced syntactic garden path effects when the sentences were paired with syntactically unexpected chords, whereas the musical manipulation had no reliable effect on the processing of semantic violations. The present experiment replicated Slevc et al.'s (2009) procedure, except that syntactic garden paths were replaced with semantic garden paths. We observed the very same interactive pattern of results. These findings suggest that the element underpinning interactions is the garden path configuration, rather than the implication of an alleged syntactic module. We suggest that a different amount of attentional resources is recruited to process each type of linguistic manipulations, hence modulating the resources left available for the processing of music and, consequently, the effects of musical violations.

The Direct and Indirect Effects of Paliperidone Extended-release on Depressive Symptoms in Schizoaffective Disorder: A Path Analysis.

PubMed

Turkoz, Ibrahim; Fu, Dong-Jing; Bossie, Cynthia A; Alphs, Larry

2015-01-01

This analysis evaluates improvement in symptoms of depression in patients with schizoaffective disorder administered oral paliperidone extended-release by accounting for the magnitude of direct and indirect (changes in negative and positive symptoms and worsening of extrapyramidal symptoms) treatment effects on depressive symptoms. Data for this post hoc analysis were drawn from two six-week, randomized, placebo-controlled studies of paliperidone extended-release versus placebo in adult subjects with schizoaffective disorder (N=614; NCT00412373, NCT00397033). Subjects with baseline 17-item Hamilton Rating Scale for Depression scores of 16 or greater were included. Structural equation models (path analyses) were used to separate total effects into direct and indirect effects on depressive symptoms. Change from baseline in 17-item Hamilton Rating Scale for Depression score at the Week 6 end point was the dependent variable; changes in Positive and Negative Syndrome Scale positive and negative factors and Simpson-Angus Scale (to evaluate extrapyramidal symptoms) scores were independent variables. At baseline, 332 of 614 (54.1%) subjects had a 17-item Hamilton Rating Scale for Depression score of 16 or greater. Path analysis determined that up to 26.4 percent of the paliperidone extended-release versus placebo effect on depressive symptoms may be attributed to a direct treatment effect, and 45.8 percent and 28.4 percent were mediated indirectly through improvements on positive and negative symptoms, respectively. No effects were identified as mediated through extrapyramidal symptoms changes (-0.7%). RESULTS of this analysis suggest that paliperidone's effect on depressive symptoms in subjects with schizoaffective disorder participating in two six-week, randomized, placebo-controlled studies is mediated through indirect effects (e.g., positive and negative symptom changes) and a direct treatment effect.

Nonlinear Analysis of an Unstable Bench Press Bar Path and Muscle Activation.

PubMed

Lawrence, Michael A; Leib, Daniel J; Ostrowski, Stephanie J; Carlson, Lara A

2017-05-01

Lawrence, MA, Leib, DJ, Ostrowski, SJ, and Carlson, LA. Nonlinear analysis of an unstable bench press bar path and muscle activation. J Strength Cond Res 31(5): 1206-1211, 2017-Unstable resistance exercises are typically performed to improve the ability of stabilizing muscles to maintain joint integrity under a load. The purpose of this study was to examine the effects of an unstable load (as provided by a flexible barbell and a load suspended by elastic bands) on the bar path, the primary musculature, and stabilizing musculature while bench pressing using nonlinear analyses. Fifteen resistance-trained men (age 24.2 ± 2.7 years, mass 84.1 ± 12.0 kg, height 1.77 ± 0.05 m, 9.9 ± 3.4 years of lifting experience, and bench press 1 repetition maximum (RM) 107.5 ± 25.9 kg) volunteered for this study. Subjects pressed 2 sets of 5 repetitions in both stable (total load 75% 1RM) and unstable (total load 60% 1RM) conditions using a standard barbell and a flexible Earthquake bar, respectively. Surface electromyography was used to detect muscle activity of primary movers (pectoralis major, anterior deltoid, and triceps) and bar stabilizing musculature (latissimus dorsi, middle and posterior deltoid, biceps brachii, and upper trapezius). During the unstable condition, the bar moved in more ways and was less predictable in the mediolateral and anteroposterior directions. However, the muscle activation patterns of all muscles were more constrained with the unstable barbell. These findings suggest that the unstable condition was more challenging to control, but subjects controlled the instability by contracting their muscles in a more stable pattern or "staying tight" throughout the exercise.

A prospective examination of the path from child abuse and neglect to illicit drug use in middle adulthood: the potential mediating role of four risk factors.

PubMed

Wilson, Helen W; Widom, Cathy Spatz

2009-03-01

This study examines prostitution, homelessness, delinquency and crime, and school problems as potential mediators of the relationship between childhood abuse and neglect (CAN) and illicit drug use in middle adulthood. Children with documented cases of physical and sexual abuse and neglect (ages 0-11) during 1967-1971 were matched with non-maltreated children and followed into middle adulthood (approximate age 39). Mediators were assessed in young adulthood (approximate age 29) through in-person interviews between 1989 and 1995 and official arrest records through 1994 (N = 1,196). Drug use was assessed via self-reports of past year use of marijuana, psychedelics, cocaine, and/or heroin during 2000-2002 (N = 896). Latent variable structural equation modeling (SEM) was used to test: (1) a four-factor model with separate pathways from CAN to illicit drug use through each of the mediating risk factors and (2) a second-order model with a single mediating risk factor comprised of prostitution, homelessness, delinquency and crime, and poor school performance. Analyses were performed separately for women and men, controlling for race/ethnicity and early drug use. In the four-factor model for both men and women, CAN was significantly related to each of the mediators, but no paths from the mediators to drug use were significant. For women, the second-order risk factor mediated the relationship between CAN and illicit drug use in middle adulthood. For men, neither child abuse and neglect nor the second-order risk factor predicted drug use in middle adulthood. These results suggest that for women, the path from CAN to middle adulthood drug use is part of a general "problem behavior syndrome" evident earlier in life.

Finding False Paths in Sequential Circuits

NASA Astrophysics Data System (ADS)

Matrosova, A. Yu.; Andreeva, V. V.; Chernyshov, S. V.; Rozhkova, S. V.; Kudin, D. V.

2018-02-01

Method of finding false paths in sequential circuits is developed. In contrast with heuristic approaches currently used abroad, the precise method based on applying operations on Reduced Ordered Binary Decision Diagrams (ROBDDs) extracted from the combinational part of a sequential controlling logic circuit is suggested. The method allows finding false paths when transfer sequence length is not more than the given value and obviates the necessity of investigation of combinational circuit equivalents of the given lengths. The possibilities of using of the developed method for more complicated circuits are discussed.

Prospective associations between peer victimization and aggression.

PubMed

Ostrov, Jamie M

2010-01-01

The current study involved a short-term longitudinal study of young children (M = 44.56 months, SD = 11.88, N = 103) to test the prospective associations between peer victimization and aggression subtypes. Path analyses documented that teacher-reported physical victimization was uniquely associated with increases in observed physical aggression over time. The path model also revealed that teacher-reported relational victimization was uniquely associated with statistically significant increases in observed relational aggression over time. Ways in which these findings extend the extant developmental literature are discussed. © 2010 The Author. Child Development © 2010 Society for Research in Child Development, Inc.

Functional Organization of the Action Observation Network in Autism: A Graph Theory Approach.

PubMed

Alaerts, Kaat; Geerlings, Franca; Herremans, Lynn; Swinnen, Stephan P; Verhoeven, Judith; Sunaert, Stefan; Wenderoth, Nicole

2015-01-01

The ability to recognize, understand and interpret other's actions and emotions has been linked to the mirror system or action-observation-network (AON). Although variations in these abilities are prevalent in the neuro-typical population, persons diagnosed with autism spectrum disorders (ASD) have deficits in the social domain and exhibit alterations in this neural network. Here, we examined functional network properties of the AON using graph theory measures and region-to-region functional connectivity analyses of resting-state fMRI-data from adolescents and young adults with ASD and typical controls (TC). Overall, our graph theory analyses provided convergent evidence that the network integrity of the AON is altered in ASD, and that reductions in network efficiency relate to reductions in overall network density (i.e., decreased overall connection strength). Compared to TC, individuals with ASD showed significant reductions in network efficiency and increased shortest path lengths and centrality. Importantly, when adjusting for overall differences in network density between ASD and TC groups, participants with ASD continued to display reductions in network integrity, suggesting that also network-level organizational properties of the AON are altered in ASD. While differences in empirical connectivity contributed to reductions in network integrity, graph theoretical analyses provided indications that also changes in the high-level network organization reduced integrity of the AON.

Tornado Intensity Estimated from Damage Path Dimensions

PubMed Central

Elsner, James B.; Jagger, Thomas H.; Elsner, Ian J.

2014-01-01

The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s−1 for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93) [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width. PMID:25229242

Tornado intensity estimated from damage path dimensions.

PubMed

Elsner, James B; Jagger, Thomas H; Elsner, Ian J

2014-01-01

The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1) for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93) [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

Abnormal visual scan paths: a psychophysiological marker of delusions in schizophrenia.

PubMed

Phillips, M L; David, A S

1998-02-09

The role of the visual scan path as a psychophysiological marker of visual attention has been highlighted previously (Phillips and David, 1994). We investigated information processing in schizophrenic patients with severe delusions and again when the delusions were subsiding using visual scan path measurements. We aimed to demonstrate a specific deficit in processing human faces in deluded subjects by relating this to abnormal viewing strategies. Scan paths were measured in six deluded and five non-deluded schizophrenics (matched for medication and negative symptoms), and nine age-matched normal controls. Deluded subjects had abnormal scan paths in a recognition task, fixating non-feature areas significantly more than controls, but were equally accurate. Re-testing after improvement in delusional conviction revealed fewer group differences. The results suggest state-dependent abnormal information processing in schizophrenics when deluded, with reliance on less-salient visual information for decision-making.

Virtual hybrid test control of sinuous crack

NASA Astrophysics Data System (ADS)

Jailin, Clément; Carpiuc, Andreea; Kazymyrenko, Kyrylo; Poncelet, Martin; Leclerc, Hugo; Hild, François; Roux, Stéphane

2017-05-01

The present study aims at proposing a new generation of experimental protocol for analysing crack propagation in quasi brittle materials. The boundary conditions are controlled in real-time to conform to a predefined crack path. Servo-control is achieved through a full-field measurement technique to determine the pre-set fracture path and a simple predictor model based on linear elastic fracture mechanics to prescribe the boundary conditions on the fly so that the actual crack path follows at best the predefined trajectory. The final goal is to identify, for instance, non-local damage models involving internal lengths. The validation of this novel procedure is performed via a virtual test-case based on an enriched damage model with an internal length scale, a prior chosen sinusoidal crack path and a concrete sample. Notwithstanding the fact that the predictor model selected for monitoring the test is a highly simplified picture of the targeted constitutive law, the proposed protocol exhibits a much improved sensitivity to the sought parameters such as internal lengths as assessed from the comparison with other available experimental tests.

Path analysis of the genetic integration of traits in the sand cricket: a novel use of BLUPs.

PubMed

Roff, D A; Fairbairn, D J

2011-09-01

This study combines path analysis with quantitative genetics to analyse a key life history trade-off in the cricket, Gryllus firmus. We develop a path model connecting five traits associated with the trade-off between flight capability and reproduction and test this model using phenotypic data and estimates of breeding values (best linear unbiased predictors) from a half-sibling experiment. Strong support by both types of data validates our causal model and indicates concordance between the phenotypic and genetic expression of the trade-off. Comparisons of the trade-off between sexes and wing morphs reveal that these discrete phenotypes are not genetically independent and that the evolutionary trajectories of the two wing morphs are more tightly constrained to covary than those of the two sexes. Our results illustrate the benefits of combining a quantitative genetic analysis, which examines statistical correlations between traits, with a path model that focuses upon the causal components of variation. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

Graph theory enables drug repurposing--how a mathematical model can drive the discovery of hidden mechanisms of action.

PubMed

Gramatica, Ruggero; Di Matteo, T; Giorgetti, Stefano; Barbiani, Massimo; Bevec, Dorian; Aste, Tomaso

2014-01-01

We introduce a methodology to efficiently exploit natural-language expressed biomedical knowledge for repurposing existing drugs towards diseases for which they were not initially intended. Leveraging on developments in Computational Linguistics and Graph Theory, a methodology is defined to build a graph representation of knowledge, which is automatically analysed to discover hidden relations between any drug and any disease: these relations are specific paths among the biomedical entities of the graph, representing possible Modes of Action for any given pharmacological compound. We propose a measure for the likeliness of these paths based on a stochastic process on the graph. This measure depends on the abundance of indirect paths between a peptide and a disease, rather than solely on the strength of the shortest path connecting them. We provide real-world examples, showing how the method successfully retrieves known pathophysiological Mode of Action and finds new ones by meaningfully selecting and aggregating contributions from known bio-molecular interactions. Applications of this methodology are presented, and prove the efficacy of the method for selecting drugs as treatment options for rare diseases.

Insights into vehicle trajectories at the handling limits: analysing open data from race car drivers

NASA Astrophysics Data System (ADS)

Kegelman, John C.; Harbott, Lene K.; Gerdes, J. Christian

2017-02-01

Race car drivers can offer insights into vehicle control during extreme manoeuvres; however, little data from race teams is publicly available for analysis. The Revs Program at Stanford has built a collection of vehicle dynamics data acquired from vintage race cars during live racing events with the intent of making this database publicly available for future analysis. This paper discusses the data acquisition, post-processing, and storage methods used to generate the database. An analysis of available data quantifies the repeatability of professional race car driver performance by examining the statistical dispersion of their driven paths. Certain map features, such as sections with high path curvature, consistently corresponded to local minima in path dispersion, quantifying the qualitative concept that drivers anchor their racing lines at specific locations around the track. A case study explores how two professional drivers employ distinct driving styles to achieve similar lap times, supporting the idea that driving at the limits allows a family of solutions in terms of paths and speed that can be adapted based on specific spatial, temporal, or other constraints and objectives.

Analysis and elimination of a bias in targeted molecular dynamics simulations of conformational transitions: application to calmodulin.

PubMed

Ovchinnikov, Victor; Karplus, Martin

2012-07-26

The popular targeted molecular dynamics (TMD) method for generating transition paths in complex biomolecular systems is revisited. In a typical TMD transition path, the large-scale changes occur early and the small-scale changes tend to occur later. As a result, the order of events in the computed paths depends on the direction in which the simulations are performed. To identify the origin of this bias, and to propose a method in which the bias is absent, variants of TMD in the restraint formulation are introduced and applied to the complex open ↔ closed transition in the protein calmodulin. Due to the global best-fit rotation that is typically part of the TMD method, the simulated system is guided implicitly along the lowest-frequency normal modes, until the large spatial scales associated with these modes are near the target conformation. The remaining portion of the transition is described progressively by higher-frequency modes, which correspond to smaller-scale rearrangements. A straightforward modification of TMD that avoids the global best-fit rotation is the locally restrained TMD (LRTMD) method, in which the biasing potential is constructed from a number of TMD potentials, each acting on a small connected portion of the protein sequence. With a uniform distribution of these elements, transition paths that lack the length-scale bias are obtained. Trajectories generated by steered MD in dihedral angle space (DSMD), a method that avoids best-fit rotations altogether, also lack the length-scale bias. To examine the importance of the paths generated by TMD, LRTMD, and DSMD in the actual transition, we use the finite-temperature string method to compute the free energy profile associated with a transition tube around a path generated by each algorithm. The free energy barriers associated with the paths are comparable, suggesting that transitions can occur along each route with similar probabilities. This result indicates that a broad ensemble of paths needs to be calculated to obtain a full description of conformational changes in biomolecules. The breadth of the contributing ensemble suggests that energetic barriers for conformational transitions in proteins are offset by entropic contributions that arise from a large number of possible paths.

Inelastic and Dynamic Fracture and Stress Analyses

NASA Technical Reports Server (NTRS)

Atluri, S. N.

1984-01-01

Large deformation inelastic stress analysis and inelastic and dynamic crack propagation research work is summarized. The salient topics of interest in engine structure analysis that are discussed herein include: (1) a path-independent integral (T) in inelastic fracture mechanics, (2) analysis of dynamic crack propagation, (3) generalization of constitutive relations of inelasticity for finite deformations , (4) complementary energy approaches in inelastic analyses, and (5) objectivity of time integration schemes in inelastic stress analysis.

Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories.

PubMed

Morris, E Kathryn; Caruso, Tancredi; Buscot, François; Fischer, Markus; Hancock, Christine; Maier, Tanja S; Meiners, Torsten; Müller, Caroline; Obermaier, Elisabeth; Prati, Daniel; Socher, Stephanie A; Sonnemann, Ilja; Wäschke, Nicole; Wubet, Tesfaye; Wurst, Susanne; Rillig, Matthias C

2014-09-01

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon's diversity (H'), Simpson's diversity (D1), Simpson's dominance (D2), Simpson's evenness (E), and Berger-Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P. lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H', even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system.

Choosing and using diversity indices: insights for ecological applications from the German Biodiversity Exploratories

PubMed Central

Morris, E Kathryn; Caruso, Tancredi; Buscot, François; Fischer, Markus; Hancock, Christine; Maier, Tanja S; Meiners, Torsten; Müller, Caroline; Obermaier, Elisabeth; Prati, Daniel; Socher, Stephanie A; Sonnemann, Ilja; Wäschke, Nicole; Wubet, Tesfaye; Wurst, Susanne; Rillig, Matthias C

2014-01-01

Biodiversity, a multidimensional property of natural systems, is difficult to quantify partly because of the multitude of indices proposed for this purpose. Indices aim to describe general properties of communities that allow us to compare different regions, taxa, and trophic levels. Therefore, they are of fundamental importance for environmental monitoring and conservation, although there is no consensus about which indices are more appropriate and informative. We tested several common diversity indices in a range of simple to complex statistical analyses in order to determine whether some were better suited for certain analyses than others. We used data collected around the focal plant Plantago lanceolata on 60 temperate grassland plots embedded in an agricultural landscape to explore relationships between the common diversity indices of species richness (S), Shannon’s diversity (H’), Simpson’s diversity (D1), Simpson’s dominance (D2), Simpson’s evenness (E), and Berger–Parker dominance (BP). We calculated each of these indices for herbaceous plants, arbuscular mycorrhizal fungi, aboveground arthropods, belowground insect larvae, and P. lanceolata molecular and chemical diversity. Including these trait-based measures of diversity allowed us to test whether or not they behaved similarly to the better studied species diversity. We used path analysis to determine whether compound indices detected more relationships between diversities of different organisms and traits than more basic indices. In the path models, more paths were significant when using H’, even though all models except that with E were equally reliable. This demonstrates that while common diversity indices may appear interchangeable in simple analyses, when considering complex interactions, the choice of index can profoundly alter the interpretation of results. Data mining in order to identify the index producing the most significant results should be avoided, but simultaneously considering analyses using multiple indices can provide greater insight into the interactions in a system. PMID:25478144

Dissociable cognitive mechanisms underlying human path integration.

PubMed

Wiener, Jan M; Berthoz, Alain; Wolbers, Thomas

2011-01-01

Path integration is a fundamental mechanism of spatial navigation. In non-human species, it is assumed to be an online process in which a homing vector is updated continuously during an outward journey. In contrast, human path integration has been conceptualized as a configural process in which travelers store working memory representations of path segments, with the computation of a homing vector only occurring when required. To resolve this apparent discrepancy, we tested whether humans can employ different path integration strategies in the same task. Using a triangle completion paradigm, participants were instructed either to continuously update the start position during locomotion (continuous strategy) or to remember the shape of the outbound path and to calculate home vectors on basis of this representation (configural strategy). While overall homing accuracy was superior in the configural condition, participants were quicker to respond during continuous updating, strongly suggesting that homing vectors were computed online. Corroborating these findings, we observed reliable differences in head orientation during the outbound path: when participants applied the continuous updating strategy, the head deviated significantly from straight ahead in direction of the start place, which can be interpreted as a continuous motor expression of the homing vector. Head orientation-a novel online measure for path integration-can thus inform about the underlying updating mechanism already during locomotion. In addition to demonstrating that humans can employ different cognitive strategies during path integration, our two-systems view helps to resolve recent controversies regarding the role of the medial temporal lobe in human path integration.

Mg Isotope Evolution During Water-Rock Interaction in a Carbonate Aquifer

NASA Astrophysics Data System (ADS)

Zhang, Z.; Jacobson, A. D.; Lundstrom, C. C.; Huang, F.

2008-12-01

To better understand how Mg isotopes behave during weathering and aqueous transport, we used a Nu Plasma MC-ICP-MS to measure δ26Mg values (relative to DSM-3) in water samples along a 236 km flow path in the Madison aquifer of South Dakota, a confined carbonate aquifer recharging in the igneous Black Hills. We also analyzed local granite and dolomite samples to characterize the Mg isotope composition of source rocks constituting the recharge zone and aquifer, respectively. Repeated analyses of Mg standard solutions yielded external precisions (2σ) better than 0.1 permil for δ26Mg(CAM-1, - 2.584±0.071, n=13; UIMg-1, -2.217±0.087, n=9.). The Madison aquifer provides a unique opportunity to quantify Mg isotope effects during water-rock interaction because (1) fluids and rock have chemically equilibrated over a much longer timescale (up to ~15 kyr) than can be simulated in laboratory experiments and (2) previous studies have determined the rates and mass-balances of de- dolomitization and other geochemical reactions controlling solute evolution along the flow path. Reactions important for changing the concentration and isotope composition of Mg include dolomite dissolution, Mg-for- Na ion exchange, calcite precipitation, and isotope exchange. δ26Mg values within the recharge region (0-17 km along flow path) vary between -1.08 and -1.63 permil, and then remain essentially constant at -1.408±0.010 permil(1σ, 5 samples) from 17 to 189 km. A final sample at 236 km shows an increase to -1.09 permil. Either mixing between different recharge waters or rapid isotope exchange between infiltrating waters and dolomite could control δ26Mg variability between 0 and 17 km. Likewise, reactive transport modeling suggests that preferential uptake of 24Mg during Mg-for-Na ion exchange might cause an increase in δ26Mg between 189 and 236 km. However, unchanging δ26Mg values observed throughout most of the aquifer clearly demonstrate that Mg isotopes are not fractionated during reactive transport. This suggests that Mg isotopes can conservatively trace weathering inputs and groundwater flow in dolomite-rich aquifers.

Using Paleomagnetic, Geochemical and Structural Data to Recognize Post-metamorphic Tectonic Events in the Caledonide Terranes of Western Svalbard.

NASA Astrophysics Data System (ADS)

Michalski, K.; Manby, G.; Nejbert, K.; Domańska Siuda, J.; Burzyński, M.

2015-12-01

A total of 170 oriented palaeomagnetic samples of Proterozoic-Lower Palaeozoic metacarbonates and metabasites from 28 sites in Hornsund and Oscar II Land, Western Spitsbergen (Fig. 1A) were investigated at the Polish Academy of Sciences Institute of Geophysics . Petrographic and rock-magnetic analyses revealed that the ferromagnetic carriers are dominated by metamorphic pyrrhotite and Low-Ti magnetite. Simultaneous in situ laser ablation 40Ar/39Ar age determination of the samples indicate that a 426-380 Ma Caledonian sensu lato thermal overprint was followed by younger events in the 377-326 Ma and ca. 300 Ma intervals (Fig. 1B). The latter two ages appear to coincide with recently published seismic data indicating that Late Devonian - Carboniferous rifting was followed by similar crustal extension in the SW Barents shelf area in Late Carboniferous time. Published in situ palaeomagnetic directions from Hornsund area in SW Svalbard fit the Silurian sector of the Baltica reference path suggesting that the geometry of the sampled Caledonian Sofekammen Syncline was not modified during following Svalbardian or Eurekan deformation events (Fig. 1C). In contrast, palaeomagnetic directions obtained from Oscar II Land are distant from Caledonian sector of Baltica reference path (Fig. 1C). It is suggested here, that the most significant mechanism responsible for the rotation of the palaeomagnetic directions and modification of geometry of Caledonian tectonic structures of Oscar II Land was listric normal faulting related to the opening of the North Atlantic -Arctic Ocean Basins. Late Cretaceous- Early Tertiary Eurekan folding and thrust faulting appear to have had minor influence on the palaeomagnetic directions obtained. This study is part of the Polish National Science Centre - DEC 2011/03/D/ST10/05193 PALMAG 2012-2016 funded project . Fig. 1. A. Geological sketch map of Western Spitsbergen. B. Probability diagrams derived from insitu 40Ar/39Ar laser ablation age determinations for Oscar II/Haakon VII Land. C. The most stable palaeomagnetic components from Hornsund (squares) and Oscar II Land (ovals) against the reference path for the Batica paleomagnetic directions recalculated for the area of Western Spitsbergen; equal area; open/ full symbols -upper/lower hemisphere.

Metabolic PathFinding: inferring relevant pathways in biochemical networks.

PubMed

Croes, Didier; Couche, Fabian; Wodak, Shoshana J; van Helden, Jacques

2005-07-01

Our knowledge of metabolism can be represented as a network comprising several thousands of nodes (compounds and reactions). Several groups applied graph theory to analyse the topological properties of this network and to infer metabolic pathways by path finding. This is, however, not straightforward, with a major problem caused by traversing irrelevant shortcuts through highly connected nodes, which correspond to pool metabolites and co-factors (e.g. H2O, NADP and H+). In this study, we present a web server implementing two simple approaches, which circumvent this problem, thereby improving the relevance of the inferred pathways. In the simplest approach, the shortest path is computed, while filtering out the selection of highly connected compounds. In the second approach, the shortest path is computed on the weighted metabolic graph where each compound is assigned a weight equal to its connectivity in the network. This approach significantly increases the accuracy of the inferred pathways, enabling the correct inference of relatively long pathways (e.g. with as many as eight intermediate reactions). Available options include the calculation of the k-shortest paths between two specified seed nodes (either compounds or reactions). Multiple requests can be submitted in a queue. Results are returned by email, in textual as well as graphical formats (available in http://www.scmbb.ulb.ac.be/pathfinding/).

Energetically optimal travel across terrain: visualizations and a new metric of geographic distance with anthropological applications

NASA Astrophysics Data System (ADS)

Wood, Brian M.; Wood, Zoë J.

2006-01-01

We present a visualization and computation tool for modeling the caloric cost of pedestrian travel across three dimensional terrains. This tool is being used in ongoing archaeological research that analyzes how costs of locomotion affect the spatial distribution of trails and artifacts across archaeological landscapes. Throughout human history, traveling by foot has been the most common form of transportation, and therefore analyses of pedestrian travel costs are important for understanding prehistoric patterns of resource acquisition, migration, trade, and political interaction. Traditionally, archaeologists have measured geographic proximity based on "as the crow flies" distance. We propose new methods for terrain visualization and analysis based on measuring paths of least caloric expense, calculated using well established metabolic equations. Our approach provides a human centered metric of geographic closeness, and overcomes significant limitations of available Geographic Information System (GIS) software. We demonstrate such path computations and visualizations applied to archaeological research questions. Our system includes tools to visualize: energetic cost surfaces, comparisons of the elevation profiles of shortest paths versus least cost paths, and the display of paths of least caloric effort on Digital Elevation Models (DEMs). These analysis tools can be applied to calculate and visualize 1) likely locations of prehistoric trails and 2) expected ratios of raw material types to be recovered at archaeological sites.

Quantifying selective elbow movements during an exergame in children with neurological disorders: a pilot study.

PubMed

van Hedel, Hubertus J A; Häfliger, Nadine; Gerber, Corinna N

2016-10-21

It is difficult to distinguish between restorative and compensatory mechanisms underlying (pediatric) neurorehabilitation, as objective measures assessing selective voluntary motor control (SVMC) are scarce. We aimed to quantify SVMC of elbow movements in children with brain lesions. Children played an airplane game with the glove-based YouGrabber system. Participants were instructed to steer an airplane on a screen through a cloud-free path by correctly applying bilateral elbow flexion and extension movements. Game performance measures were (i) % time on the correct path and (ii) similarity between the ideal flight path and the actually flown path. SVMC was quantified by calculating a correlation coefficient between the derivative of the ideal path and elbow movements. A therapist scored whether the child had used compensatory movements. Thirty-three children with brain lesions (11 girls; 12.6 ± 3.6 years) participated. Clinical motor and cognitive scores correlated moderately with SVMC (0.50-0.74). Receiver Operating Characteristics analyses showed that SVMC could differentiate well and better than clinical and game performance measures between compensatory and physiological movements. We conclude that a simple measure assessed while playing a game appears promising in quantifying SVMC. We propose how to improve the methodology, and how this approach can be easily extended to other joints.

Some tests of wet tropospheric calibration for the CASA Uno Global Positioning System experiment

NASA Technical Reports Server (NTRS)

Dixon, T. H.; Wolf, S. Kornreich

1990-01-01

Wet tropospheric path delay can be a major error source for Global Positioning System (GPS) geodetic experiments. Strategies for minimizing this error are investigted using data from CASA Uno, the first major GPS experiment in Central and South America, where wet path delays may be both high and variable. Wet path delay calibration using water vapor radiometers (WVRs) and residual delay estimation is compared with strategies where the entire wet path delay is estimated stochastically without prior calibration, using data from a 270-km test baseline in Costa Rica. Both approaches yield centimeter-level baseline repeatability and similar tropospheric estimates, suggesting that WVR calibration is not critical for obtaining high precision results with GPS in the CASA region.

Spatial Updating Strategy Affects the Reference Frame in Path Integration.

PubMed

He, Qiliang; McNamara, Timothy P

2018-06-01

This study investigated how spatial updating strategies affected the selection of reference frames in path integration. Participants walked an outbound path consisting of three successive waypoints in a featureless environment and then pointed to the first waypoint. We manipulated the alignment of participants' final heading at the end of the outbound path with their initial heading to examine the adopted reference frame. We assumed that the initial heading defined the principal reference direction in an allocentric reference frame. In Experiment 1, participants were instructed to use a configural updating strategy and to monitor the shape of the outbound path while they walked it. Pointing performance was best when the final heading was aligned with the initial heading, indicating the use of an allocentric reference frame. In Experiment 2, participants were instructed to use a continuous updating strategy and to keep track of the location of the first waypoint while walking the outbound path. Pointing performance was equivalent regardless of the alignment between the final and the initial headings, indicating the use of an egocentric reference frame. These results confirmed that people could employ different spatial updating strategies in path integration (Wiener, Berthoz, & Wolbers Experimental Brain Research 208(1) 61-71, 2011), and suggested that these strategies could affect the selection of the reference frame for path integration.

Physical Therapy Observation and Assessment in the Neonatal Intensive Care Unit

ERIC Educational Resources Information Center

Byrne, Eilish; Campbell, Suzann K.

2013-01-01

This article presents the elements of the Observation and Assessment section of the Infant Care Path for Physical Therapy in the Neonatal Intensive Care Unit (NICU). The types of physical therapy assessments presented in this path are evidence-based and the suggested timing of these assessments is primarily based on practice knowledge from expert…

A Re-evaluation of the Dominant Paradigm of Communication and Development.

ERIC Educational Resources Information Center

Ghorpade, Shailendra; And Others

The D. Lerner and W. Schramm model of the role of mass media in national development has influenced most media oriented studies of development for almost two decades. Briefly, the model suggests that the evolution from traditional to modern societies follows a causal path that leads to increased mass media use. The path ends with increased…

Linking Organisational Training and Development Practices with New Forms of Career Structure: A Cross-National Exploration.

ERIC Educational Resources Information Center

Kelly, Aidan; Brannick, Teresa; Hulpke, John; Levine, Jacqueline; To, Michelle

2003-01-01

Human resource management data were collected from 149 Irish, 201 Hong Kong, 92 Singaporean, and 144 Chinese organizations. Career patterns and training practices showed distinct differences. Irish organizations were more likely to have lower levels of career paths; their training practices suggested more new forms of careers. Fewer paths indicate…

Fraction of young water as an indicator of aquifer vulnerability along two regional flow paths in the Mississippi embayment aquifer system, southeastern USA

USGS Publications Warehouse

Kingsbury, James A.; Barlow, Jeannie R.; Jurgens, Bryant; McMahon, Peter B.; Carmichael, John K.

2017-01-01

Wells along two regional flow paths were sampled to characterize changes in water quality and the vulnerability to contamination of the Memphis aquifer across a range of hydrologic and land-use conditions in the southeastern United States. The flow paths begin in the aquifer outcrop area and end at public supply wells in the confined parts of the aquifer at Memphis, Tennessee. Age-date tracer (e.g. SF6, 3H, 14C) data indicate that a component of young water is present in the aquifer at most locations along both flow paths, which is consistent with previous studies at Memphis that documented leakage of shallow water into the Memphis aquifer locally where the overlying confining unit is thin or absent. Mixtures of young and old water were most prevalent where long-term pumping for public supply has lowered groundwater levels and induced downward movement of young water. The occurrence of nitrate, chloride and synthetic organic compounds was correlated to the fraction of young water along the flow paths. Oxic conditions persisted for 10 km or more down dip of the confining unit, and the presence of young water in confined parts of the aquifer suggest that contaminants such as nitrate-N have the potential for transport. Long-term monitoring data for one of the flow-path wells screened in the confined part of the aquifer suggest that the vulnerability of the aquifer as indicated by the fraction of young water is increasing over time.

Fraction of young water as an indicator of aquifer vulnerability along two regional flow paths in the Mississippi embayment aquifer system, southeastern USA

NASA Astrophysics Data System (ADS)

Kingsbury, James A.; Barlow, Jeannie R. B.; Jurgens, Bryant C.; McMahon, Peter B.; Carmichael, John K.

2017-09-01

Wells along two regional flow paths were sampled to characterize changes in water quality and the vulnerability to contamination of the Memphis aquifer across a range of hydrologic and land-use conditions in the southeastern United States. The flow paths begin in the aquifer outcrop area and end at public supply wells in the confined parts of the aquifer at Memphis, Tennessee. Age-date tracer (e.g. SF6, 3H, 14C) data indicate that a component of young water is present in the aquifer at most locations along both flow paths, which is consistent with previous studies at Memphis that documented leakage of shallow water into the Memphis aquifer locally where the overlying confining unit is thin or absent. Mixtures of young and old water were most prevalent where long-term pumping for public supply has lowered groundwater levels and induced downward movement of young water. The occurrence of nitrate, chloride and synthetic organic compounds was correlated to the fraction of young water along the flow paths. Oxic conditions persisted for 10 km or more down dip of the confining unit, and the presence of young water in confined parts of the aquifer suggest that contaminants such as nitrate-N have the potential for transport. Long-term monitoring data for one of the flow-path wells screened in the confined part of the aquifer suggest that the vulnerability of the aquifer as indicated by the fraction of young water is increasing over time.

Computational fluid dynamics analysis in support of the simplex turbopump design

NASA Technical Reports Server (NTRS)

Garcia, Roberto; Griffin, Lisa W.; Benjamin, Theodore G.; Cornelison, Joni W.; Ruf, Joseph H.; Williams, Robert W.

1994-01-01

Simplex is a turbopump that is being developed at NASA/Marshall Space Flight Center (MSFC) by an in-house team. The turbopump consists of a single-stage centrifugal impeller, vaned-diffuser pump powered by a single-stage, axial, supersonic, partial admission turbine. The turbine is driven by warm gaseous oxygen tapped off of the hybrid motor to which it will be coupled. Rolling element bearings are cooled by the pumping fluid. Details of the configuration and operating conditions are given by Marsh. CFD has been used extensively to verify one-dimensional (1D) predictions, assess aerodynamic and hydrodynamic designs, and to provide flow environments. The complete primary flow path of the pump-end and the hot gas path of the turbine, excluding the inlet torus, have been analyzed. All CFD analyses conducted for the Simplex turbopump employed the pressure based Finite Difference Navier-Stokes (FDNS) code using a standard kappa-epsilon turbulence model with wall functions. More detailed results are presented by Garcia et. al. To support the team, loading and temperature results for the turbine rotor were provided as inputs to structural and thermal analyses, and blade loadings from the inducer were provided for structural analyses.

Transfer path analysis: Current practice, trade-offs and consideration of damping

NASA Astrophysics Data System (ADS)

Oktav, Akın; Yılmaz, Çetin; Anlaş, Günay

2017-02-01

Current practice of experimental transfer path analysis is discussed in the context of trade-offs between accuracy and time cost. An overview of methods, which propose solutions for structure borne noise, is given, where assumptions, drawbacks and advantages of methods are stated theoretically. Applicability of methods is also investigated, where an engine induced structure borne noise of an automobile is taken as a reference problem. Depending on this particular problem, sources of measurement errors, processing operations that affect results and physical obstacles faced in the application are analysed. While an operational measurement is common in all stated methods, when it comes to removal of source, or the need for an external excitation, discrepancies are present. Depending on the chosen method, promised outcomes like independent characterisation of the source, or getting information about mounts also differ. Although many aspects of the problem are reported in the literature, damping and its effects are not considered. Damping effect is embedded in the measured complex frequency response functions, and it is needed to be analysed in the post processing step. Effects of damping, reasons and methods to analyse them are discussed in detail. In this regard, a new procedure, which increases the accuracy of results, is also proposed.

Optical reset modulation in the SiO2/Cu conductive-bridge resistive memory stack

NASA Astrophysics Data System (ADS)

Kawashima, T.; Zhou, Y.; Yew, K. S.; Ang, D. S.

2017-09-01

We show that the negative photoconductivity property of the nanoscale filamentary breakdown path in the SiO2 electrolyte of the SiO2/Cu conductive bridge resistive random access memory (CBRAM) stack is affected by the number of positive-voltage sweeps applied to the Cu electrode (with respect to a non-metal counter electrode). The path's photo-response to white light, of a given intensity, is suppressed with an increasing number of applied positive-voltage sweeps. When this occurs, the path may only be disrupted by the light of a higher intensity. It is further shown that the loss of the path's photosensitivity to the light of a given intensity can be recovered using a negative-voltage sweep (which eliminates the path), followed by the reformation of the path by a positive-voltage sweep. The above behavior is, however, not seen in the SiO2/Si stack (which involves a non-metal Si electrode), suggesting that the photo-response modulation effect is related to the Cu electrode. The demonstrated reversible electrical modulation of the path's photo-response may afford greater flexibility in the electro-optical control of the CBRAM device.

An integrated experimental and theoretical reaction path search: analyses of the multistage reaction of an ionized diethylether dimer involving isomerization, proton transfer, and dissociation.

PubMed

Matsuda, Yoshiyuki; Xie, Min; Fujii, Asuka

2018-05-30

An ionization-induced multistage reaction of an ionized diethylether (DEE) dimer involving isomerization, proton transfer, and dissociation is investigated by combining infrared (IR) spectroscopy, tandem mass spectrometry, and a theoretical reaction path search. The vertically-ionized DEE dimer isomerizes to a hydrogen-bonded cluster of protonated DEE and the [DEE-H] radical through barrierless intermolecular proton transfer from the CH bond of the ionized moiety. This isomerization process is confirmed by IR spectroscopy and the theoretical reaction path search. The multiple dissociation pathways following the isomerization are analyzed by tandem mass spectrometry. The isomerized cluster dissociates stepwise into a [protonated DEE-acetaldehyde (AA)] cluster, protonated DEE, and protonated AA. The structure of the fragment ion is also analyzed by IR spectroscopy. The reaction map of the multistage processes is revealed through a harmony of these experimental and theoretical methods.

Evaluation of programs for adolescents with greater psychosocial needs: community-based Project P.A.T.H.S. in Hong Kong.

PubMed

Shek, Daniel T L; Law, Moon Y M

2017-02-01

This study examined the perceptions of the Tier 2 Program of the Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social programmes) among Chinese secondary school students displaying greater psychosocial needs. Results showed that participants held positive views of program qualities, implementer qualities, as well as the perceived effectiveness of the program. Significant grade differences in terms of various indicators of satisfaction related to program qualities, implementer qualities, and program effectiveness were found. Correlation analyses showed that there were significant inter-relationships amongst program qualities, implementer qualities and program effectiveness. In line with the predictions, both program qualities and implementer qualities were significant predictors of perceived program effectiveness. The present study provides support for the perceived effectiveness of the Tier 2 Program of the Project P.A.T.H.S. in the community-based project context.

Understanding Associations Between Neighborhood Socioeconomic Status and Negative Consequences of Drinking: a Moderated Mediation Analysis.

PubMed

Karriker-Jaffe, Katherine J; Liu, HuiGuo; Kaplan, Lauren M

2016-05-01

We explored how neighborhood socioeconomic status (SES) is related to negative consequences of drinking to explain why racial/ethnic minority group members are more at risk than Whites for adverse alcohol outcomes. We tested direct and indirect effects of neighborhood SES on alcohol problems and examined differences by gender and race. We used data from the 2000 and 2005 National Alcohol Surveys (N = 7912 drinkers aged 18 and older; 49 % female) linked with data from the 2000 Decennial Census in multivariate path models adjusting for individual demographics. In the full sample, neighborhood disadvantage had a significant direct path to increased negative consequences, with no indirect paths through depression, positive affect or pro-drinking attitudes. Neighborhood affluence had significant indirect paths to increased negative consequences through greater pro-drinking attitudes and increased heavy drinking. Subgroup analyses showed the indirect path from affluence to consequences held for White men, with no effects of neighborhood disadvantage. For racial/ethnic minority men, significant indirect paths emerged from both neighborhood disadvantage and affluence to increased consequences through greater pro-drinking attitudes and more heavy drinking. For minority women, there was an indirect effect of neighborhood affluence through reduced depression to fewer drinking consequences. There were limited neighborhood effects on alcohol outcomes for White women. Interventions targeting pro-drinking attitudes in both affluent and disadvantaged areas may help reduce alcohol-related problems among men. Initiatives to improve neighborhood conditions could enhance mental health of minority women and reduce alcohol-related health disparities.

Spanking and Child Development during the First Five Years of Life

PubMed Central

Maguire-Jack, Kathryn; Gromoske, Andrea N.; Berger, Lawrence M.

2012-01-01

The authors used data from the Fragile Families and Child Wellbeing Study to examine whether spanking at ages 1 and 3 is adversely associated with child cognitive skills and behavior problems at ages 3 and 5. Results from cross-lagged path analyses revealed spanking at age 1 to be associated with a higher level of both spanking and externalizing behavior problems at age 3, and spanking at age 3 to be associated with a higher level of both internalizing and externalizing behavior problems at age 5. Additionally, the longer-term associations between spanking at age 1 and behavioral problems at age 5 appeared to predominantly operate through ongoing spanking at age 3. Results for cognitive skills, though less consistent, suggested no association between spanking at age 1 with poorer receptive vocabulary at age 3 or age 5. PMID:22860622

Life stress, social support, and problem-solving skills predictive of depressive symptoms, hopelessness, and suicide ideation in an Asian student population: a test of a model.

PubMed

Yang, B; Clum, G A

1994-01-01

The present study tested both a stress-problem-solving model and a stress-social support model in the etiology of depressive symptoms, hopelessness, and suicide ideation for a group of Asian international students in the United States. Problem-solving skills and social support were hypothesized as two mediators between life stress and depressive symptoms, hopelessness, and suicide ideation. The results from a series of stepwise regression analyses and a path analysis support the hypotheses, indicating that these models generalized to a sample of Asian international students. The roles of social support and problem-solving skills in depressive symptoms and hopelessness are discussed. The results also suggest that hopelessness may serve as a cognitive factor directly affecting depressive symptoms and indirectly affecting suicide ideation.

Antecedents of eating disorders and muscle dysmorphia in a non-clinical sample.

PubMed

Lamanna, J; Grieve, F G; Derryberry, W Pitt; Hakman, M; McClure, A

2010-01-01

Muscle Dysmorphia (MD) has recently been conceptualized as the male form of Eating Disorders (ED); although, it is not currently classified as an ED. The current study compares etiological models of MD symptomatology and ED symptomatology. It was hypothesized that sociocultural influences on appearance (SIA) would predict body dissatisfaction (BD), and that this relationship would be mediated by self-esteem (SE) and perfectionism (P); that BD would predict negative affect (NA); and that NA would predict MD and ED symptomatology. Two-hundred-forty-seven female and 101 male college students at a midsouth university completed the study. All participants completed measures assessing each of the constructs, and multiple regression analyses were conducted to test each model's fit. In both models, most predictor paths were significant. These results suggest similarity in symptomatology and etiological models between ED and MD.

Gender Differences in Patterns of Association Between Prosocial Behavior, Personality, and Externalizing Problems

PubMed Central

Pursell, Gwen R.; Laursen, Brett; Rubin, Kenneth H.; Booth-LaForce, Cathryn; Rose-Krasnor, Linda

2008-01-01

This study examines whether prosocial behavior and personality have independent or overlapping associations with adolescent externalizing problems. A total of 128 female and 103 male early adolescents (M = 13.6 years old) completed personality inventories. Prosocial behavior was assessed by peer nominations (N = 663). Composite aggression and delinquency scores were derived from maternal and self-reports. Path analyses indicated gender differences in patterns of association. For girls, links between prosocial behavior and both aggression and delinquency were fully mediated by agreeableness and partially mediated by conscientiousness. For boys, prosocial behavior, agreeableness, and conscientiousness were independently and negatively associated with aggression and delinquency. The findings suggest that personality and prosocial behavior are uniquely related to boys’ behavior problems but cannot be readily disentangled when it comes to girls’ behavior problems. PMID:18836524

The drive for muscularity in men: media influences and objectification theory.

PubMed

Daniel, Samantha; Bridges, Sara K

2010-01-01

Presently, objectification theory has yielded mixed results when utilized to explain body image concerns in men. An online survey assessing internalization of media ideals, self-objectification, body surveillance, body shame, the drive for muscularity, and body mass index (BMI) was completed by 244 predominantly college-aged males. Path analyses were used to investigate relationships among these variables where it was hypothesized that objectification variables would mediate the relationship between internalization of media ideals and the drive for muscularity. Internalization of media ideals was the strongest predictor of the drive for muscularity, followed by BMI, though variables of objectification theory had no impact on the drive for muscularity contrary to hypotheses. The results suggest that objectification theory may not be applicable to men as it is currently measured. Copyright 2009 Elsevier Ltd. All rights reserved.

Predicting Filipino Mothers' and Fathers' Reported Use of Corporal Punishment From Education, Authoritarian Attitudes, and Endorsement of Corporal Punishment.

PubMed

Jocson, Rosanne M; Alampay, Liane Peña; Lansford, Jennifer E

2012-03-09

The relations of education, authoritarian childrearing attitudes, and endorsement of corporal punishment to Filipino parents' reported use of corporal punishment were examined using two waves of data. Structured interviews using self-report questionnaires were conducted with 117 mothers and 98 fathers from 120 families when their children were 8 years old, and when their children were 9 years old. Path analyses showed that, among mothers, higher education predicted lower authoritarian attitudes, which in turn predicted lower reports of corporal punishment use. Among fathers, higher education predicted lower endorsement of corporal punishment, which in turn predicted lower reports of its use. Results suggest that education has an indirect relation to use of corporal punishment through parenting cognitions, and highlight distinctions in Filipino mothers' and fathers' parenting roles.

Predicting Filipino Mothers' and Fathers' Reported Use of Corporal Punishment From Education, Authoritarian Attitudes, and Endorsement of Corporal Punishment

PubMed Central

Jocson, Rosanne M.; Alampay, Liane Peña; Lansford, Jennifer E.

2013-01-01

The relations of education, authoritarian childrearing attitudes, and endorsement of corporal punishment to Filipino parents' reported use of corporal punishment were examined using two waves of data. Structured interviews using self-report questionnaires were conducted with 117 mothers and 98 fathers from 120 families when their children were 8 years old, and when their children were 9 years old. Path analyses showed that, among mothers, higher education predicted lower authoritarian attitudes, which in turn predicted lower reports of corporal punishment use. Among fathers, higher education predicted lower endorsement of corporal punishment, which in turn predicted lower reports of its use. Results suggest that education has an indirect relation to use of corporal punishment through parenting cognitions, and highlight distinctions in Filipino mothers' and fathers' parenting roles. PMID:24357887

An empirical study of rape in the context of multiple murder.

PubMed

DeLisi, Matt

2014-03-01

In recent years, multiple homicide offending has received increased research attention from criminologists; however, there is mixed evidence about the role of rape toward the perpetration of multiple murder. Drawing on criminal career data from a nonprobability sample of 618 confined male homicide offenders selected from eight U.S. states, the current study examines the role of rape as a predictor of multiple homicide offending. Bivariate analyses indicated a significant association between rape and murder charges. Multivariate path regression models indicated that rape had a significant and robust association with multiple murder. This relationship withstood the confounding effects of kidnapping, prior prison confinement, and prior murder, rape, and kidnapping. These results provide evidence that rape potentially serves as a gateway to multiple murder for some serious offenders. Suggestions for future research are proffered.

Effect of Psychiatric Illness on Acute Care Utilization at End of Life From Serious Medical Illness.

PubMed

Lavin, Kyle; Davydow, Dimitry S; Downey, Lois; Engelberg, Ruth A; Dunlap, Ben; Sibley, James; Lober, William B; Okimoto, Kelson; Khandelwal, Nita; Loggers, Elizabeth T; Teno, Joan M; Curtis, J Randall

2017-08-01

Little is known about psychiatric illness and utilization of end-of-life care. We hypothesized that preexisting psychiatric illness would increase hospital utilization at end of life among patients with chronic medical illness due to increased severity of illness and care fragmentation. We reviewed electronic health records to identify decedents with one or more of eight chronic medical conditions based on International Classification of Diseases-9 codes. We used International Classification of Diseases-9 codes and prescription information to identify preexisting psychiatric illness. Regression models compared hospital utilization among patients with and without psychiatric illness. Path analyses examined the effect of severity of illness and care fragmentation. Eleven percent of 16,214 patients with medical illness had preexisting psychiatric illness, which was associated with increased risk of death in nursing homes (P = 0.002) and decreased risk of death in hospitals (P < 0.001). In the last 30 days of life, psychiatric illness was associated with reduced inpatient and intensive care unit utilization but increased emergency department utilization. Path analyses confirmed an association between psychiatric illness and increased hospital utilization mediated by severity of illness and care fragmentation, but a stronger direct effect of psychiatric illness decreasing hospitalizations. Our findings differ from the increased hospital utilization for patients with psychiatric illness in circumstances other than end-of-life care. Path analyses confirmed hypothesized associations between psychiatric illness and increased utilization mediated by severity of illness and care fragmentation but identified more powerful direct effects decreasing hospital use. Further investigation should examine whether this effect represents a disparity in access to preferred care. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Applications of graph theory to landscape genetics

PubMed Central

Garroway, Colin J; Bowman, Jeff; Carr, Denis; Wilson, Paul J

2008-01-01

We investigated the relationships among landscape quality, gene flow, and population genetic structure of fishers (Martes pennanti) in ON, Canada. We used graph theory as an analytical framework considering each landscape as a network node. The 34 nodes were connected by 93 edges. Network structure was characterized by a higher level of clustering than expected by chance, a short mean path length connecting all pairs of nodes, and a resiliency to the loss of highly connected nodes. This suggests that alleles can be efficiently spread through the system and that extirpations and conservative harvest are not likely to affect their spread. Two measures of node centrality were negatively related to both the proportion of immigrants in a node and node snow depth. This suggests that central nodes are producers of emigrants, contain high-quality habitat (i.e., deep snow can make locomotion energetically costly) and that fishers were migrating from high to low quality habitat. A method of community detection on networks delineated five genetic clusters of nodes suggesting cryptic population structure. Our analyses showed that network models can provide system-level insight into the process of gene flow with implications for understanding how landscape alterations might affect population fitness and evolutionary potential. PMID:25567802

Quadcopter Path Following Control Design Using Output Feedback with Command Generator Tracker LOS Based At Square Path

NASA Astrophysics Data System (ADS)

Nugraha, A. T.; Agustinah, T.

2018-01-01

Quadcopter an unstable system, underactuated and nonlinear in quadcopter control research developments become an important focus of attention. In this study, following the path control method for position on the X and Y axis, used structure-Generator Tracker Command (CGT) is tested. Attitude control and position feedback quadcopter is compared using the optimal output. The addition of the H∞ performance optimal output feedback control is used to maintain the stability and robustness of quadcopter. Iterative numerical techniques Linear Matrix Inequality (LMI) is used to find the gain controller. The following path control problems is solved using the method of LQ regulators with output feedback. Simulations show that the control system can follow the paths that have been defined in the form of a reference signal square shape. The result of the simulation suggest that the method which used can bring the yaw angle at the expected value algorithm. Quadcopter can do automatically following path with cross track error mean X=0.5 m and Y=0.2 m.

Tortuous Pore Path Through the Glaucomatous Lamina Cribrosa.

PubMed

Wang, Bo; Lucy, Katie A; Schuman, Joel S; Sigal, Ian A; Bilonick, Richard A; Lu, Chen; Liu, Jonathan; Grulkowski, Ireneusz; Nadler, Zachary; Ishikawa, Hiroshi; Kagemann, Larry; Fujimoto, James G; Wollstein, Gadi

2018-05-08

The lamina cribrosa is a primary site of damage in glaucoma. While mechanical distortion is hypothesized to cause reduction of axoplasmic flow, little is known about how the pores, which contains the retinal ganglion cell axons, traverse the lamina cribrosa. We investigated lamina cribrosa pore paths in vivo to quantify differences in tortuosity of pore paths between healthy and glaucomatous eyes. We imaged 16 healthy, 23 glaucoma suspect and 48 glaucomatous eyes from 70 subjects using a swept source optical coherence tomography system. The lamina cribrosa pores were automatically segmented using a previously described segmentation algorithm. Individual pore paths were automatically tracked through the depth of the lamina cribrosa using custom software. Pore path convergence to the optic nerve center and tortuosity was quantified for each eye. We found that lamina cribrosa pore pathways traverse the lamina cribrosa closer to the optic nerve center along the depth of the lamina cribrosa regardless of disease severity or diagnostic category. In addition, pores of glaucoma eyes take a more tortuous path through the lamina cribrosa compared to those of healthy eyes, suggesting a potential mechanism for reduction of axoplasmic flow in glaucoma.

Reality versus fantasy: reply to Lynn et al. (2014).

PubMed

Dalenberg, Constance J; Brand, Bethany L; Loewenstein, Richard J; Gleaves, David H; Dorahy, Martin J; Cardeña, Etzel; Frewen, Paul A; Carlson, Eve B; Spiegel, David

2014-05-01

We respond to Lynn et al.'s (2014) comments on our review (Dalenberg et al., 2012) demonstrating the superiority of the trauma model (TM) over the fantasy model (FM) in explaining the trauma-dissociation relationship. Lynn et al. conceded that our meta-analytic results support the TM hypothesis that trauma exposure is a causal risk factor for the development of dissociation. Although Lynn et al. suggested that our meta-analyses were selective, we respond that each omitted study failed to meet inclusion criteria; our meta-analyses thus reflect a balanced view of the predominant trauma-dissociation findings. In contrast, Lynn et al. were hypercritical of studies that supported the TM while ignoring methodological problems in studies presented as supportive of the FM. We clarify Lynn et al.'s misunderstandings of the TM and demonstrate consistent superiority in prediction of time course of dissociative symptoms, response to psychotherapy of dissociative patients, and pattern of relationships of trauma to dissociation. We defend our decision not to include studies using the Dissociative Experiences Scale-Comparison, a rarely used revision of the Dissociative Experiences Scale that shares less than 10% of the variance with the original scale. We highlight several areas of agreement: (a) Trauma plays a complex role in dissociation, involving indirect and direct paths; (b) dissociation-suggestibility relationships are small; and (c) controls and measurement issues should be addressed in future suggestibility and dissociation research. Considering the lack of evidence that dissociative individuals simply fantasize trauma, future researchers should examine more complex models of trauma and valid measures of dissociation.

Aerosol optical properties inferred from in-situ and path-averaged measurements

NASA Astrophysics Data System (ADS)

van Binsbergen, Sven A.; Grossmann, Peter; Cohen, Leo H.; van Eijk, Alexander M. J.; Stein, Karin U.

2017-09-01

This paper compares in-situ and path-averaged measurements of the electro-optical transmission, with emphasis on aerosol effects. The in-situ sensors consisted of optical particle counters (OPC) and a visibility meter, the path-averaged data was provided by a 7-wavelength transmissometer (MSRT) and a scintillometer (BLS). Data was collected at a test site in Northern Germany. A retrieval algorithm was developed to infer characteristics of the aerosol size distribution (Junge approximation) from the MSRT data. A comparison of the various sensors suggests that the optical particle counters are over-optimistic in their estimate of the transmission.

Moderating effect of gender on the prospective relation of physical activity with psychosocial outcomes and asthma control in adolescents: a longitudinal study.

PubMed

Tiggelman, Dana; van de Ven, Monique O M; van Schayck, Onno C P; Engels, Rutger C M E

2014-12-01

Adolescents with asthma experience more psychosocial and physiological problems compared to their healthy peers. Physical activity (PA) might decrease these problems. This study was the first observational longitudinal study to examine whether habitual PA could predict changes in psychosocial outcomes (i.e., symptoms of anxiety and depression, quality of life [QOL] and stress) and asthma control over time in adolescents with asthma and whether gender moderated these relationships. Adolescents with asthma (N = 253; aged 10-14 years at baseline) were visited at home in the spring/summer of 2012 and 2013. They completed questionnaires assessing their habitual PA, symptoms of anxiety and depression, QOL, perceived stress and asthma control. Path analyses using Mplus were conducted to examine longitudinal relationships among habitual PA, psychosocial outcomes and asthma control (controlled for body mass index, age and gender). Using multi-group analyses, we examined whether gender moderated these relationships. Path analyses in the total group showed that habitual PA did not predict changes in psychosocial outcomes or asthma control over time. Multi-group analyses showed that gender moderated the relation of habitual PA with anxiety and depression. Habitual PA only significantly predicted a decrease in anxiety and depression over time for girls but not for boys. Increasing habitual PA in girls with asthma might decrease their symptoms of anxiety and depression.

Quality assessment of static aggregation compared to the temporal approach based on a pig trade network in Northern Germany.

PubMed

Büttner, Kathrin; Salau, Jennifer; Krieter, Joachim

2016-07-01

Recent analyses of animal movement networks focused on the static aggregation of trade contacts over different time windows, which neglects the system's temporal variation. In terms of disease spread, ignoring the temporal dynamics can lead to an over- or underestimation of an outbreak's speed and extent. This becomes particularly evident, if the static aggregation allows for the existence of more paths compared to the number of time-respecting paths (i.e. paths in the right chronological order). Therefore, the aim of this study was to reveal differences between static and temporal representations of an animal trade network and to assess the quality of the static aggregation in comparison to the temporal counterpart. Contact data from a pig trade network (2006-2009) of a producer community in Northern Germany were analysed. The results show that a median value of 8.7 % (4.6-14.1%) of the nodes and 3.1% (1.6-5.5%) of the edges were active on a weekly resolution. No fluctuations in the activity patterns were obvious. Furthermore, 50% of the nodes already had one trade contact after approximately six months. For an accumulation window with increasing size (one day each), the accumulation rate, i.e. the relative increase in the number of nodes or edges, stayed relatively constant below 0.07% for the nodes and 0.12 % for the edges. The temporal distances had a much wider distribution than the topological distances. 84% of the temporal distances were smaller than 90 days. The maximum temporal distance was 1000 days, which corresponds to the temporal diameter of the present network. The median temporal correlation coefficient, which measures the probability for an edge to persist across two consecutive time steps, was 0.47, with a maximum value of 0.63 at the accumulation window of 88 days. The causal fidelity measures the fraction of the number of static paths which can also be taken in the temporal network. For the whole observation period relatively high values indicate that 67% of the time-respecting paths existed in both network representations. An increase to 0.87 (0.82-0.88) and 0.92 (0.80-0.98), respectively, could be observed for yearly and monthly aggregation windows. The results show that the investigated pig trade network in its static aggregation represents the temporal dynamics of the system sufficiently well. Therefore, the methodology for analysing static instead of dynamic networks can be used without losing too much information. Copyright © 2016 Elsevier B.V. All rights reserved.

5-HT1a Receptor Antagonists Block Perforant Path-Dentate LTP Induced in Novel, but Not Familiar, Environments

ERIC Educational Resources Information Center

Sanberg, Cyndy Davis; Jones, Floretta L.; Do, Viet H.; Dieguez, Dario, Jr.; Derrick, Brian E.

2006-01-01

Numerous studies suggest roles for monoamines in modulating long-term potentiation (LTP). Previously, we reported that both induction and maintenance of perforant path-dentate gyrus LTP is enhanced when induced while animals explore novel environments. Here we investigate the contribution of serotonin and 5-HT1a receptors to the novelty-mediated…

The Development of Close Relationships in Japan and the United States: Paths of Symbiotic Harmony and Generative Tension.

ERIC Educational Resources Information Center

Rothbaum, Fred; Pott, Martha; Azuma, Hiroshi; Miyake, Kazuo; Weisz, John

2000-01-01

Compares paths of development in Japan (symbiotic harmony) and the United States (generative tension) of parent-child and adult mate relationships, challenging assumptions that certain processes are central in all relationships or that U.S. relationships are less valued or weaker than Japan's. Suggests need to investigate processes underlying, and…

Oceanic geoid and tides derived from GEOS 3 satellite data in the Northwestern Atlantic Ocean

NASA Technical Reports Server (NTRS)

Won, I. J.; Miller, L. S.

1979-01-01

Two sets of GEOS 3 altimeter data which fall within about a 2.5-deg width are analyzed for ocean geoid and tides. One set covers a path from Newfoundland to Cuba, and the other a path from Puerto Rico to the North Carolina coast. Forty different analyses using various parameters are performed in order to investigate convergence. Profiles of the geoid and four tides, M2, O1, S2, and K1, are derived along the two strips. While the analyses produced convergent solutions for all 40 cases, the uncertainty caused by the linear orbital bias error of the satellite is too large to claim that the solutions represent the true ocean tides in the area. A spot check of the result with the Mode deep-sea tide gauge data shows poor agreement. A positive conclusion of this study is that despite the uncertain orbital error the oceanic geoid obtained through this analysis can improve significantly the short-wavelength structure over existing spherical harmonic geoid models.

Changes at work and employee reactions: organizational elements, job insecurity, and short-term stress as predictors for employee health and safety.

PubMed

Størseth, Fred

2006-12-01

The objective was to identify focus areas for possible reduction of job insecurity and its outcomes. A model was specified and tested as a prediction model for health and safety. First, a parsimonious model was specified. The model consisted of perceived job insecurity (as a stressor), organizational factors (information quality, leadership style, work task administration), and short-term stress reactions (job dissatisfaction, reduced work motivation). Second, the model was tested as a prediction model in three separate path analyses, in order to examine the model's contribution in explaining (1) physical health complaints, (2) mental health complaints, and (3) risk taking behavior. A quota sample of Norwegian employees (N= 1,002) was obtained by means of a self-completion questionnaire survey. The results of the structural equation modeling (path analyses) supported the hypothesized model. Mental health complaints and employee risk taking behavior were significantly predicted (not physical health complaints).

Can cycling safety be improved by opening all unidirectional cycle paths for cycle traffic in both directions? A theoretical examination of available literature and data.

PubMed

Methorst, Rob; Schepers, Paul; Kamminga, Jaap; Zeegers, Theo; Fishman, Elliot

2017-08-01

Many studies have found bicycle-motor vehicle crashes to be more likely on bidirectional cycle paths than on unidirectional cycle paths because drivers do not expect cyclists riding at the right side of the road. In this paper we discuss the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions prevent this lack of expectancy and accordingly improves cycling safety. A new national standard requires careful consideration because a reversal is difficult once cyclists are used to their new freedom of route choice. We therefore explored the hypothesis using available data, research, and theories. The results show that of the length of cycle paths along distributor roads in the Netherlands, 72% is bidirectional. If drivers would become used to cyclists riding at the left side of the road, this result raises the question of why bidirectional cycle paths in the Netherlands still have a poor safety record compared to unidirectional cycle paths. Moreover, our exploration suggested that bidirectional cycle paths have additional safety problems. It increases the complexity of unsignalized intersections because drivers have to scan more directions in a short period of time. Moreover, there are some indications that the likelihood of frontal crashes between cyclists increases. We reject the hypothesis that opening all unidirectional cycle paths for cycle traffic in both directions will improve cycle safety. We recommend more attention for mitigating measures given the widespread application of bidirectional cycle paths in the Netherlands. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mindfully Green and Healthy: An Indirect Path from Mindfulness to Ecological Behavior

PubMed Central

Geiger, Sonja M.; Otto, Siegmar; Schrader, Ulf

2018-01-01

This paper examines the nature of the link between mindfulness and ecological behavior. Based on the notion that mindfulness incorporates heightened awareness of bodily sensations, we suggest an indirect path from mindfulness to ecological behavior that is mediated through individual health behavior, such as improved nutrition and increased exercise. This indirect path is corroborated with two online studies (n = 147/n = 239) where mindfulness, personal health behavior and ecological behavior were assessed. We conclude that increased mindful awareness of momentary experience indeed favors more healthy lifestyles, which in turn relate to increased ecological behavior beyond personal health benefits. The findings support an agreeableness of personal and planetary health behavior and open up a path for environmental educational interventions based on mindfulness practices and personal health gains. PMID:29403406

Vector navigation in desert ants, Cataglyphis fortis: celestial compass cues are essential for the proper use of distance information.

PubMed

Sommer, Stefan; Wehner, Rüdiger

2005-10-01

Foraging desert ants navigate primarily by path integration. They continually update homing direction and distance by employing a celestial compass and an odometer. Here we address the question of whether information about travel distance is correctly used in the absence of directional information. By using linear channels that were partly covered to exclude celestial compass cues, we were able to test the distance component of the path-integration process while suppressing the directional information. Our results suggest that the path integrator cannot process the distance information accumulated by the odometer while ants are deprived of celestial compass information. Hence, during path integration directional cues are a prerequisite for the proper use of travel-distance information by ants.

Does the Theory of Planned Behaviour Explain Condom Use Behaviour Among Men Who have Sex with Men? A Meta-analytic Review of the Literature.

PubMed

Andrew, Benjamin J; Mullan, Barbara A; de Wit, John B F; Monds, Lauren A; Todd, Jemma; Kothe, Emily J

2016-12-01

The aim of this meta-analysis was to explore whether the constructs in the theory of planned behaviour (TPB; i.e., attitude, subjective norm, perceived behavioural control, intention) explain condom use behaviour among men who have sex with men (MSM). Electronic databases were searched for studies that measured TPB variables and MSM condom use. Correlations were meta-analysed using a random effects model and path analyses. Moderation analyses were conducted for the time frame of the behavioural measure used (retrospective versus prospective). Attitude, subjective norm and perceived behavioural control accounted for 24.0 % of the variance in condom use intention and were all significant correlates. Intention and PBC accounted for 12.4 % of the variance in condom use behaviour. However, after taking intention into account, PBC was no longer significantly associated with condom use. The strength of construct relationships did not differ between retrospective and prospective behavioural assessments. The medium to large effect sizes of the relationships between the constructs in the TPB, which are consistent with previous meta-analyses with different behaviours or target groups, suggest that the TPB is also a useful model for explaining condom use behaviour among MSM. However, the research in this area is rather small, and greater clarity over moderating factors can only be achieved when the literature expands.

Memory for the search path: evidence for a high-capacity representation of search history.

PubMed

Dickinson, Christopher A; Zelinsky, Gregory J

2007-06-01

Using a gaze-contingent paradigm, we directly measured observers' memory capacity for fixated distractor locations during search. After approximately half of the search objects had been fixated, they were masked and a spatial probe appeared at either a previously fixated location or a non-fixated location; observers then rated their confidence that the target had appeared at the probed location. Observers were able to differentiate the 12 most recently fixated distractor locations from non-fixated locations, but analyses revealed that these locations were represented fairly coarsely. We conclude that there exists a high-capacity, but low-resolution, memory for a search path.

Biodamage via shock waves initiated by irradiation with ions.

PubMed

Surdutovich, Eugene; Yakubovich, Alexander V; Solov'yov, Andrey V

2013-01-01

Radiation damage following the ionising radiation of tissue has different scenarios and mechanisms depending on the projectiles or radiation modality. We investigate the radiation damage effects due to shock waves produced by ions. We analyse the strength of the shock wave capable of directly producing DNA strand breaks and, depending on the ion's linear energy transfer, estimate the radius from the ion's path, within which DNA damage by the shock wave mechanism is dominant. At much smaller values of linear energy transfer, the shock waves turn out to be instrumental in propagating reactive species formed close to the ion's path to large distances, successfully competing with diffusion.

The mediating role of interpersonal cognition on the relationships between personality and adolescent ego development.

PubMed

Liu, Yih-Lan

2013-01-01

The author investigated whether interpersonal cognition mediated the relationships between defense, social sensitivity, and ego development. Participants (N = 616; M age = 15.66 years, SD = .52 year; 276 boys) from northwestern Taiwan completed a battery of questionnaires. Structural equation modeling and mediation analyses supported the hypothesis that interpersonal cognition would mediate the path between defense and ego development, and the path between social sensitivity and ego development. Defense and social sensitivity were found to have direct effects on ego development. The study provides evidence of the mediating effect of interpersonal cognition on the association between personality and ego development.

Predator effects on a detritus-based food web are primarily mediated by non-trophic interactions.

PubMed

Majdi, Nabil; Boiché, Anatole; Traunspurger, Walter; Lecerf, Antoine

2014-07-01

Predator effects on ecosystems can extend far beyond their prey and are often not solely lethally transmitted. Change in prey traits in response to predation risk can have important repercussions on community assembly and key ecosystem processes (i.e. trait-mediated indirect effects). In addition, some predators themselves alter habitat structure or nutrient cycling through ecological engineering effects. Tracking these non-trophic pathways is thus an important, yet challenging task to gain a better grasp of the functional role of predators. Multiple lines of evidence suggest that, in detritus-based food webs, non-trophic interactions may prevail over purely trophic interactions in determining predator effects on plant litter decomposition. This hypothesis was tested in a headwater stream by modulating the density of a flatworm predator (Polycelis felina) in enclosures containing oak (Quercus robur) leaf litter exposed to natural colonization by small invertebrates and microbial decomposers. Causal path modelling was used to infer how predator effects propagated through the food web. Flatworms accelerated litter decomposition through positive effects on microbial decomposers. The biomass of prey and non-prey invertebrates was not negatively affected by flatworms, suggesting that net predator effect on litter decomposition was primarily determined by non-trophic interactions. Flatworms enhanced the deposition and retention of fine sediments on leaf surface, thereby improving leaf colonization by invertebrates - most of which having strong affinities with interstitial habitats. This predator-induced improvement of habitat availability was attributed to the sticky nature of the mucus that flatworms secrete in copious amount while foraging. Results of path analyses further indicated that this bottom-up ecological engineering effect was as powerful as the top-down effect on invertebrate prey. Our findings suggest that predators have the potential to affect substantially carbon flow and nutrient cycling in detritus-based ecosystems and that this impact cannot be fully appreciated without considering non-trophic effects. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Geologic, hydrologic, and geochemical identification of flow paths in the Edwards Aquifer, northeastern Bexar and southern Comal Counties, Texas

USGS Publications Warehouse

Otero, Cassi L.

2007-01-01

The U.S. Geological Survey, in cooperation with the San Antonio Water System, conducted a 4-year study during 2002?06 to identify major flow paths in the Edwards aquifer in northeastern Bexar and southern Comal Counties (study area). In the study area, faulting directs ground water into three hypothesized flow paths that move water, generally, from the southwest to the northeast. These flow paths are identified as the southern Comal flow path, the central Comal flow path, and the northern Comal flow path. Statistical correlations between water levels for six observation wells and between the water levels and discharges from Comal Springs and Hueco Springs yielded evidence for the hypothesized flow paths. Strong linear correlations were evident between the datasets from wells and springs within the same flow path and the datasets from wells in areas where flow between flow paths was suspected. Geochemical data (major ions, stable isotopes, sulfur hexafluoride, and tritium and helium) were used in graphical analyses to obtain evidence of the flow path from which wells or springs derive water. Major-ion geochemistry in samples from selected wells and springs showed relatively little variation. Samples from the southern Comal flow path were characterized by relatively high sulfate and chloride concentrations, possibly indicating that the water in the flow path was mixing with small amounts of saline water from the freshwater/saline-water transition zone. Samples from the central Comal flow path yielded the most varied major-ion geochemistry of the three hypothesized flow paths. Central Comal flow path samples were characterized, in general, by high calcium concentrations and low magnesium concentrations. Samples from the northern Comal flow path were characterized by relatively low sulfate and chloride concentrations and high magnesium concentrations. The high magnesium concentrations characteristic of northern Comal flow path samples from the recharge zone in Comal County might indicate that water from the Trinity aquifer is entering the Edwards aquifer in the subsurface. A graph of the relation between the stable isotopes deuterium and delta-18 oxygen showed that, except for samples collected following an unusually intense rain storm, there was not much variation in stable isotope values among the flow paths. In the study area deuterium ranged from -36.00 to -20.89 per mil and delta-18 oxygen ranged from -6.03 to -3.70 per mil. Excluding samples collected following the intense rain storm, the deuterium range in the study area was -33.00 to -20.89 per mil and the delta-18 oxygen range was -4.60 to -3.70 per mil. Two ground-water age-dating techniques, sulfur hexafluoride concentrations and tritium/helium-3 isotope ratios, were used to compute apparent ages (time since recharge occurred) of water samples collected in the study area. In general, the apparent ages computed by the two methods do not seem to indicate direction of flow. Apparent ages computed for water samples in northeastern Bexar and southern Comal Counties do not vary greatly except for some very young water in the recharge zone in central Comal County.

Arena geometry and path shape: when rats travel in straight or in circuitous paths?

PubMed

Yaski, Osnat; Portugali, Juval; Eilam, David

2011-12-01

We show here that the global geometry of the environment affects the shape of the paths of travel in rats. To examine this, individual rats were introduced into an unfamiliar arena. One group of rats (n=8) was tested in a square arena (2 m × 2 m), and the other group (n=8) in a round arena (2 m diameter). Testing was in a total darkness, since in the absence of visual information the geometry is not perceived immediately and the extraction of environment shape is slower. We found that while the level of the rats' activity did not seem to differ between both arenas, path shape differed significantly. When traveling along the perimeter, path shape basically followed the arena walls, with perimeter paths curving along the walls of the round arena, while being straight along the walls of the square arena. A similar impact of arena geometry was observed for travel away from the arena walls. Indeed, when the rats abandoned the arena walls to crosscut through the center of the arena, their center paths were circuitous in the round arena and relatively straight in the square arena. We suggest that the shapes of these paths are exploited for the same spatial task: returning back to a familiar location in the unsighted environment. Copyright © 2011 Elsevier B.V. All rights reserved.

Curvature and torsion in growing actin networks

NASA Astrophysics Data System (ADS)

Shaevitz, Joshua W.; Fletcher, Daniel A.

2008-06-01

Intracellular pathogens such as Listeria monocytogenes and Rickettsia rickettsii move within a host cell by polymerizing a comet-tail of actin fibers that ultimately pushes the cell forward. This dense network of cross-linked actin polymers typically exhibits a striking curvature that causes bacteria to move in gently looping paths. Theoretically, tail curvature has been linked to details of motility by considering force and torque balances from a finite number of polymerizing filaments. Here we track beads coated with a prokaryotic activator of actin polymerization in three dimensions to directly quantify the curvature and torsion of bead motility paths. We find that bead paths are more likely to have low rather than high curvature at any given time. Furthermore, path curvature changes very slowly in time, with an autocorrelation decay time of 200 s. Paths with a small radius of curvature, therefore, remain so for an extended period resulting in loops when confined to two dimensions. When allowed to explore a three-dimensional (3D) space, path loops are less evident. Finally, we quantify the torsion in the bead paths and show that beads do not exhibit a significant left- or right-handed bias to their motion in 3D. These results suggest that paths of actin-propelled objects may be attributed to slow changes in curvature, possibly associated with filament debranching, rather than a fixed torque.

Path Complexity in Virtual Water Maze Navigation: Differential Associations with Age, Sex, and Regional Brain Volume.

PubMed

Daugherty, Ana M; Yuan, Peng; Dahle, Cheryl L; Bender, Andrew R; Yang, Yiqin; Raz, Naftali

2015-09-01

Studies of human navigation in virtual maze environments have consistently linked advanced age with greater distance traveled between the start and the goal and longer duration of the search. Observations of search path geometry suggest that routes taken by older adults may be unnecessarily complex and that excessive path complexity may be an indicator of cognitive difficulties experienced by older navigators. In a sample of healthy adults, we quantify search path complexity in a virtual Morris water maze with a novel method based on fractal dimensionality. In a two-level hierarchical linear model, we estimated improvement in navigation performance across trials by a decline in route length, shortening of search time, and reduction in fractal dimensionality of the path. While replicating commonly reported age and sex differences in time and distance indices, a reduction in fractal dimension of the path accounted for improvement across trials, independent of age or sex. The volumes of brain regions associated with the establishment of cognitive maps (parahippocampal gyrus and hippocampus) were related to path dimensionality, but not to the total distance and time. Thus, fractal dimensionality of a navigational path may present a useful complementary method of quantifying performance in navigation. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Defining conditions of garnet growth across the central and southern Menderes Massif, western Turkey

NASA Astrophysics Data System (ADS)

Etzel, T. M.; Catlos, E. J.; Kelly, E. D.; Cemen, I.; Ozerdem, C.; Atakturk, K. R.

2017-12-01

Here we apply thermodynamic modeling using Theriak-Domino to garnet-bearing rocks from the central and southern portions of the Menderes Massif to gain insight into the dynamics of western Turkey as the region experienced a transition from collisional to extensional tectonics. To this end, we report new pressure-temperature (P-T) paths from garnet-bearing rocks collected along the Alasehir detachment fault, a prominent exhumation structure in the central portion of the Menderes Massif in western Turkey, constituting the southern margin of the Alasehir Graben. These paths are compared to those from the Selimiye shear zone in the Southern (Cine) Massif. Two Alasehir garnets collected from the same outcrop record two P-T paths: 1) a prograde path beginning at 565oC and 6.4 kbar increasing to 592 oC and 7.5 kbar; and 2) near isobaric growth initiating at 531oC and 7.1 kbar and terminating at 571oC and 7.3 kbar. High-resolution P-T paths could not be modeled for the majority of Alasehir samples due to diffusional modification of garnet. However, conditions were estimated by garnet isopleth thermobarometry at the point of highest spessartine content for each crystal. Calculated P-T values for this subset of samples range between 566-651oC and 6.2-6.8 kbar. Despite this broad range, these P-T conditions are consistent with what is observed in the modeled paths. Th-Pb ages of matrix monazite range from 35.8±3.0 to 20.6±2.4 Ma, suggesting metamorphism in the central Menderes Massif occurred over a 15 m.y. period. Selimiye shear zone rocks show distinct N-shaped P-T paths, suggesting garnets in the central and southern portion of the Menderes Massif record distinctly different tectonic histories.

Simulated impacts of artificial groundwater recharge and discharge of the source area and source volume of an Atlantic Coastal Plain Stream, Delaware, USA

USGS Publications Warehouse

Kasper, Joshua W.; Denver, Judish M.; McKenna, Thomas E.; Ullman, William J.

2010-01-01

A numerical groundwater-flow model was used to characterize the source area and volume of Phillips Branch, a baseflow-dominated stream incising a highly permeable unconfined aquifer on the low relief Delmarva Peninsula, USA. Particle-tracking analyses indicate that the source area (5.51 km2) is ~20% smaller than the topographically defined watershed (6.85 km2), and recharge entering ~37% of the surface watershed does not discharge to Phillips Branch. Groundwater residence time within the source volume ranges from a few days to almost 100 years, with 95% of the volume "flushing" within 50 years. Artificial discharge from groundwater pumping alters the shape of the source area and reduces baseflow due to the interception of stream flow paths, but has limited impacts on the residence time of groundwater discharged as baseflow. In contrast, artificial recharge from land-based wastewater disposal substantially reduces the source area, lowers the range in residence time due to the elimination of older flow paths to the stream, and leads to increased discharge to adjacent surface-water bodies. This research suggests that, in this and similar hydrogeologic settings, the "watershed" approach to water-resource management may be limited, particularly where anthropogenic stresses alter the transport of soluble contaminants through highly permeable unconfined aquifers.

Quantifying Spatial Misclassification in Exposure to Noise Complaints Among Low-Income Housing Residents Across New York City Neighborhoods: A Global Positioning System (GPS) Study

PubMed Central

Duncan, Dustin T.; Tamura, Kosuke; Regan, Seann D.; Athens, Jessica; Elbel, Brian; Meline, Julie; Al-Ajlouni, Yazan A.; Chaix, Basile

2016-01-01

Purpose To examine if there was spatial misclassification in exposure to neighborhood noise complaints among a sample of low-income housing residents in New York City, comparing home-based spatial buffers and Global Positioning Systems (GPS) daily path buffers. Methods Data came from the community-based NYC Low-Income Housing, Neighborhoods and Health Study, where GPS tracking of the sample was conducted for a week (analytic n=102). We created a GPS daily path buffer (a buffering zone drawn around GPS tracks) of 200-meters and 400-meters. We also used home-based buffers of 200-meters and 400-meters. Using these “neighborhoods” (or exposure areas) we calculated neighborhood exposure to noisy events from 311 complaints data (analytic n=143,967). Friedman tests (to compare overall differences in neighborhood definitions) were applied. Results There were differences in neighborhood noise complaints according to the selected neighborhood definitions (p<0.05). For example, the mean neighborhood noise complaint count was 1196 per square kilometer for the 400-meter home-based and 812 per square kilometer for the 400-meter activity space buffer, illustrating how neighborhood definition influences the estimates of exposure to neighborhood noise complaints. Conclusions These analyses suggest that, whenever appropriate, GPS neighborhood definitions can be used in spatial epidemiology research in spatially mobile populations to understand people's lived experience. PMID:28063754

The effects of perceived torture controllability on symptom severity of posttraumatic stress, depression and anger in refugees and asylum seekers: A path analysis.

PubMed

Le, Lillian; Morina, Naser; Schnyder, Ulrich; Schick, Matthis; Bryant, Richard A; Nickerson, Angela

2018-06-01

Torture is associated with greater psychopathology, however, the specific mechanisms underlying the effects of torture remain unclear. Research suggests that the perceived uncontrollable nature of, rather than the exposure to, torture, influences the development of psychological disorders. Perceived distress during torture has also been shown to influence psychological outcomes. This cross-sectional study explored the relationship between perceived torture controllability, emotions (i.e., anger and fear) during torture, and current posttraumatic stress (PTS), depression and anger symptoms, controlling for the effects of post-migration living difficulties. Data were collected from 108 refugees and asylum seekers in treatment at two psychiatric clinics in Zurich, Switzerland. Path analyses revealed negative correlations between PTS, depression and anger symptoms, and perceived torture controllability, and positive correlations with anger and fear during torture. Furthermore, the effects of perceived torture controllability on PTS and depression symptoms were mediated by fear during torture, and on anger symptoms via anger during torture. This was over and above the effects of post-migration living difficulties on psychological symptoms. The study provides preliminary evidence that perceived uncontrollability and distress during torture might be significant risk factors for current mental health of torture survivors. These findings may have implications for informing interventions for torture survivors. Copyright © 2018 Elsevier B.V. All rights reserved.

Hope-inspiring therapeutic relationships, professional expectations and social inclusion for young people with psychosis.

PubMed

Berry, Clio; Greenwood, Kathryn

2015-10-01

Personal recovery accounts suggest that a positive therapeutic relationship with an optimistic mental health professional may facilitate social inclusion. However, little empirical research has investigated the role of the therapeutic relationship in social outcomes or explored potential mechanisms of change within community psychosis care. This study investigated the direct predictive associations of the therapeutic relationship and professional expectancies for social inclusion and vocational activity for young people with psychosis, and indirect associations through hopefulness. Young people with psychosis and their main mental health professional (n=51 dyads) participated across two time points. Measures of therapeutic relationships, professional expectancies, and vocational activity were obtained at baseline. Measures of hopefulness, social inclusion and vocational activity were obtained at follow-up. Direct and indirect associations between variables were analysed using path modelling. Directed path models were consistent with a positive therapeutic relationship and positive professional expectancies predicting social inclusion and vocational activity through mediation by increased patient domain-specific hopefulness. The professional-rated therapeutic relationship more directly predicts change in vocational activity status. Change in vocational activity status predicts increased patient hopefulness. The therapeutic relationship between professionals and young people with psychosis appears hope-inspiring and important to patients' social inclusion and vocational outcomes. Vocational activity may produce reciprocal gains in hopefulness. Copyright © 2015 Elsevier B.V. All rights reserved.

A theory-based dual-focus alcohol intervention for preadolescents: the Strong African American Families Program.

PubMed

Gerrard, Meg; Gibbons, Frederick X; Brody, Gene H; Murry, Velma McBride; Cleveland, Michael J; Wills, Thomas A

2006-06-01

This study examined mediators of the Strong African American Families Program, a randomized, dual-focus prevention trial intended to delay the onset of alcohol use and reduce alcohol consumption among rural African American youths. More specifically, it demonstrated that changes in consumption 2 yrs after the intervention were mediated through 2 different paths, a social reaction path and a reasoned/intention path. The social reaction path provided evidence that relative to the control condition, the intervention decreased children's willingness to drink by making their images of drinkers less favorable. The reasoned/intention path provided evidence that the intervention influenced the children's intentions to drink by increasing targeted parenting behaviors related to alcohol. Furthermore, the data demonstrate that these changes in willingness and intentions were independently associated with alcohol consumption at the follow-up, and they suggest that a dual-process model approach that targets both intentions and willingness can be more successful than either approach alone.

A Dynamic Bayesian Observer Model Reveals Origins of Bias in Visual Path Integration.

PubMed

Lakshminarasimhan, Kaushik J; Petsalis, Marina; Park, Hyeshin; DeAngelis, Gregory C; Pitkow, Xaq; Angelaki, Dora E

2018-06-20

Path integration is a strategy by which animals track their position by integrating their self-motion velocity. To identify the computational origins of bias in visual path integration, we asked human subjects to navigate in a virtual environment using optic flow and found that they generally traveled beyond the goal location. Such a behavior could stem from leaky integration of unbiased self-motion velocity estimates or from a prior expectation favoring slower speeds that causes velocity underestimation. Testing both alternatives using a probabilistic framework that maximizes expected reward, we found that subjects' biases were better explained by a slow-speed prior than imperfect integration. When subjects integrate paths over long periods, this framework intriguingly predicts a distance-dependent bias reversal due to buildup of uncertainty, which we also confirmed experimentally. These results suggest that visual path integration in noisy environments is limited largely by biases in processing optic flow rather than by leaky integration. Copyright © 2018 Elsevier Inc. All rights reserved.

Architectural constraints are a major factor reducing path integration accuracy in the rat head direction cell system.

PubMed

Page, Hector J I; Walters, Daniel; Stringer, Simon M

2015-01-01

Head direction cells fire to signal the direction in which an animal's head is pointing. They are able to track head direction using only internally-derived information (path integration)In this simulation study we investigate the factors that affect path integration accuracy. Specifically, two major limiting factors are identified: rise time, the time after stimulation it takes for a neuron to start firing, and the presence of symmetric non-offset within-layer recurrent collateral connectivity. On the basis of the latter, the important prediction is made that head direction cell regions directly involved in path integration will not contain this type of connectivity; giving a theoretical explanation for architectural observations. Increased neuronal rise time is found to slow path integration, and the slowing effect for a given rise time is found to be more severe in the context of short conduction delays. Further work is suggested on the basis of our findings, which represent a valuable contribution to understanding of the head direction cell system.

Near-common-path interferometer for imaging Fourier-transform spectroscopy in wide-field microscopy

PubMed Central

Wadduwage, Dushan N.; Singh, Vijay Raj; Choi, Heejin; Yaqoob, Zahid; Heemskerk, Hans; Matsudaira, Paul; So, Peter T. C.

2017-01-01

Imaging Fourier-transform spectroscopy (IFTS) is a powerful method for biological hyperspectral analysis based on various imaging modalities, such as fluorescence or Raman. Since the measurements are taken in the Fourier space of the spectrum, it can also take advantage of compressed sensing strategies. IFTS has been readily implemented in high-throughput, high-content microscope systems based on wide-field imaging modalities. However, there are limitations in existing wide-field IFTS designs. Non-common-path approaches are less phase-stable. Alternatively, designs based on the common-path Sagnac interferometer are stable, but incompatible with high-throughput imaging. They require exhaustive sequential scanning over large interferometric path delays, making compressive strategic data acquisition impossible. In this paper, we present a novel phase-stable, near-common-path interferometer enabling high-throughput hyperspectral imaging based on strategic data acquisition. Our results suggest that this approach can improve throughput over those of many other wide-field spectral techniques by more than an order of magnitude without compromising phase stability. PMID:29392168

Neural basis of the cognitive map: path integration does not require hippocampus or entorhinal cortex.

PubMed

Shrager, Yael; Kirwan, C Brock; Squire, Larry R

2008-08-19

The hippocampus and entorhinal cortex have been linked to both memory functions and to spatial cognition, but it has been unclear how these ideas relate to each other. An important part of spatial cognition is the ability to keep track of a reference location using self-motion cues (sometimes referred to as path integration), and it has been suggested that the hippocampus or entorhinal cortex is essential for this ability. Patients with hippocampal lesions or larger lesions that also included entorhinal cortex were led on paths while blindfolded (up to 15 m in length) and were asked to actively maintain the path in mind. Patients pointed to and estimated their distance from the start location as accurately as controls. A rotation condition confirmed that performance was based on self-motion cues. When demands on long-term memory were increased, patients were impaired. Thus, in humans, the hippocampus and entorhinal cortex are not essential for path integration.

Landscape genetics of leaf-toed geckos in the tropical dry forest of northern Mexico.

PubMed

Blair, Christopher; Jiménez Arcos, Victor H; Mendez de la Cruz, Fausto R; Murphy, Robert W

2013-01-01

Habitat fragmentation due to both natural and anthropogenic forces continues to threaten the evolution and maintenance of biological diversity. This is of particular concern in tropical regions that are experiencing elevated rates of habitat loss. Although less well-studied than tropical rain forests, tropical dry forests (TDF) contain an enormous diversity of species and continue to be threatened by anthropogenic activities including grazing and agriculture. However, little is known about the processes that shape genetic connectivity in species inhabiting TDF ecosystems. We adopt a landscape genetic approach to understanding functional connectivity for leaf-toed geckos (Phyllodactylus tuberculosus) at multiple sites near the northernmost limit of this ecosystem at Alamos, Sonora, Mexico. Traditional analyses of population genetics are combined with multivariate GIS-based landscape analyses to test hypotheses on the potential drivers of spatial genetic variation. Moderate levels of within-population diversity and substantial levels of population differentiation are revealed by FST and Dest. Analyses using structure suggest the occurrence of from 2 to 9 genetic clusters depending on the model used. Landscape genetic analysis suggests that forest cover, stream connectivity, undisturbed habitat, slope, and minimum temperature of the coldest period explain more genetic variation than do simple Euclidean distances. Additional landscape genetic studies throughout TDF habitat are required to understand species-specific responses to landscape and climate change and to identify common drivers. We urge researchers interested in using multivariate distance methods to test for, and report, significant correlations among predictor matrices that can impact results, particularly when adopting least-cost path approaches. Further investigation into the use of information theoretic approaches for model selection is also warranted.

Experimental characterization of seasonal variations in infrasonic traveltimes on the Korean Peninsula with implications for infrasound event location

NASA Astrophysics Data System (ADS)

Che, Il-Young; Stump, Brian W.; Lee, Hee-Il

2011-04-01

The dependence of infrasound propagation on the season and path environment was quantified by the analysis of more than 1000 repetitive infrasonic ground-truth events at an active, open-pit mine over two years. Blast-associated infrasonic signals were analysed from two infrasound arrays (CHNAR and ULDAR) located at similar distances of 181 and 169 km, respectively, from the source but in different azimuthal directions and with different path environments. The CHNAR array is located to the NW of the source area with primarily a continental path, whereas the ULDAR is located East of the source with a path dominated by open ocean. As a result, CHNAR observations were dominated by stratospheric phases with characteristic celerities of 260-289 m s-1 and large seasonal variations in the traveltime, whereas data from ULDAR consisted primarily of tropospheric phases with larger celerities from 322 to 361 m s-1 and larger daily than seasonal variation in the traveltime. The interpretation of these observations is verified by ray tracing using atmospheric models incorporating daily weather balloon data that characterizes the shallow atmosphere for the two years of the study. Finally, experimental celerity models that included seasonal path effects were constructed from the long-term data set. These experimental celerity models were used to constrain traveltime variations in infrasonic location algorithms providing improved location estimates as illustrated with the empirical data set.

[Not Available].

PubMed

Yanashima, Ryoji; Kitagawa, Noriyuki; Matsubara, Yoshiya; Weatheritt, Robert; Oka, Kotaro; Kikuchi, Shinichi; Tomita, Masaru; Ishizaki, Shun

2009-01-01

The scale-free and small-world network models reflect the functional units of networks. However, when we investigated the network properties of a signaling pathway using these models, no significant differences were found between the original undirected graphs and the graphs in which inactive proteins were eliminated from the gene expression data. We analyzed signaling networks by focusing on those pathways that best reflected cellular function. Therefore, our analysis of pathways started from the ligands and progressed to transcription factors and cytoskeletal proteins. We employed the Python module to assess the target network. This involved comparing the original and restricted signaling cascades as a directed graph using microarray gene expression profiles of late onset Alzheimer's disease. The most commonly used method of shortest-path analysis neglects to consider the influences of alternative pathways that can affect the activation of transcription factors or cytoskeletal proteins. We therefore introduced included k-shortest paths and k-cycles in our network analysis using the Python modules, which allowed us to attain a reasonable computational time and identify k-shortest paths. This technique reflected results found in vivo and identified pathways not found when shortest path or degree analysis was applied. Our module enabled us to comprehensively analyse the characteristics of biomolecular networks and also enabled analysis of the effects of diseases considering the feedback loop and feedforward loop control structures as an alternative path.

Spatiotemporal evolution of the chlorophyll a trend in the North Atlantic Ocean.

PubMed

Zhang, Min; Zhang, Yuanling; Shu, Qi; Zhao, Chang; Wang, Gang; Wu, Zhaohua; Qiao, Fangli

2018-01-15

Analyses of the chlorophyll a concentration (chla) from satellite ocean color products have suggested the decadal-scale variability of chla linked to the climate change. The decadal-scale variability in chla is both spatially and temporally non-uniform. We need to understand the spatiotemporal evolution of chla in decadal or multi-decadal timescales to better evaluate its linkage to climate variability. Here, the spatiotemporal evolution of the chla trend in the North Atlantic Ocean for the period 1997-2016 is analyzed using the multidimensional ensemble empirical mode decomposition method. We find that this variable trend signal of chla shows a dipole pattern between the subpolar gyre and along the Gulf Stream path, and propagation along the opposite direction of the North Atlantic Current. This propagation signal has an overlapping variability of approximately twenty years. Our findings suggest that the spatiotemporal evolution of chla during the two most recent decades is part of the multidecadal variations and possibly regulated by the changes of Atlantic Meridional Overturning Circulation, whereas the mechanisms of such evolution patterns still need to be explored. Copyright © 2017 Elsevier B.V. All rights reserved.

Psychological distress and student engagement as mediators of the relationship between peer victimization and achievement in middle school youth.

PubMed

Totura, Christine M Wienke; Karver, Marc S; Gesten, Ellis L

2014-01-01

Peer victimization is a well-known national and international problem, contributing to a range of emotional, social, and behavioral consequences. Using structural equation modeling, the authors tested a theoretical model suggesting that psychological distress and student engagement mediate the association between the experience of victimization and concurrent academic achievement. Participants were 469 (46.4 % male, 53.6 % female) 6th to 8th grade students, from randomly selected classrooms in 11 middle schools in a southeastern school district. Structural equation models of the hypothesized effects demonstrated adequate fit to the data, with both symptoms of psychological distress and engagement mediating the relationship between victimization and academic achievement. In general, the results suggest that victimization predicts diminished academic achievement by way of psychological distress and poorer engagement in classroom and academic tasks. However, the direct relationship between victimization and measures of achievement lacked significance across many correlational and path analyses conducted. These findings have implications for researchers and practitioners in understanding how psychological distress and student engagement are associated with the academic performance of students who experience peer victimization.

The relationship between self-efficacy and reductions in smoking in a contingency management procedure.

PubMed

Romanowich, Paul; Mintz, Jim; Lamb, R J

2009-06-01

Social--cognitive and behavioral theories of change disagree on what the relevant controlling variables for initiating behavior change are. Correlations between baseline smoking cessation self-efficacy and the changes in breath carbon monoxide (CO) and the reduction in breath CO and increases in smoking cessation self-efficacy from baseline were obtained from a contingency management smoking cessation procedure. A test of the difference between the cross-lag correlations suggested a nonspurious causal relationship between smoking cessation self-efficacy and changes in breath CO. Path analyses showed that decreases in breath CO (reductions in smoking) predicted later increases in smoking cessation self-efficacy. Baseline self-reports of smoking cessation self-efficacy were not significantly correlated with subsequent changes in breath CO. Rather, significant correlations were found between reductions in breath CO and later increases in smoking cessation self-efficacy. These results suggest that self-efficacy may be a cognitive response to one's own behavior, and are inconsistent with a social--cognitive view of self-efficacy's role in behavior change. Implications for the development of smoking cessation programs and health-promoting behavior changes in general are discussed.

A New Path Forward: Four Approaches to Quality Teaching and Better Schools

ERIC Educational Resources Information Center

Weingarten, Randi

2010-01-01

In a global knowledge economy, filling in the bubbles on a standardized test isn't going to prepare children to succeed in life. This is the time to shed the old conflicts and come together. In this article, the author suggests a new path forward--toward a 21st-century education system, a serious and comprehensive reform plan to transform U.S.…

Integrative Families and Systems Treatment: A Middle Path toward Integrating Common and Specific Factors in Evidence-Based Family Therapy

ERIC Educational Resources Information Center

Fraser, J. Scott; Solovey, Andrew D.; Grove, David; Lee, Mo Yee; Greene, Gilbert J.

2012-01-01

A moderate common factors approach is proposed as a synthesis or middle path to integrate common and specific factors in evidence-based approaches to high-risk youth and families. The debate in family therapy between common and specific factors camps is reviewed and followed by suggestions from the literature for synthesis and creative flexibility…

Roles of Impulsivity, Motivation, and Emotion Regulation in Procrastination - Path Analysis and Comparison Between Students and Non-students.

PubMed

Wypych, Marek; Matuszewski, Jacek; Dragan, Wojciech Ł

2018-01-01

Procrastination - an irrational delay of intended actions despite expecting to be worse off - is a complex and non-homogenous phenomenon. Previous studies have found a number of correlates of procrastination, some of which seem to be particularly important. Impulsivity is closely connected to procrastination on behavioral, genetic, and neuronal levels. Difficulties in emotion regulation have also been shown to be strongly related to procrastination. Procrastination can also be considered as a motivation-based problem. To try to disentangle the connections of impulsivity, emotion regulation, and motivation to procrastination we collected data from over 600 subjects using multiple questionnaires (PPS - Pure Procrastination Scale; UPPSP - Impulsive Behavior Scale, ERQ - Emotion Regulation Questionnaire and MDT - Motivational Diagnostic Test). Structural equation modeling was performed to test several possible relationships between the measured variables. The effects of student status and age have also been investigated. The final path model was a directional model based on six explanatory variables and accounted for 70% of the variance in procrastination. Path analysis revealed that the strongest contributions to procrastination came from lack of value, delay discounting, and lack of perseverance, suggesting the involvement of motivation and impulsivity. The model also revealed the moderating role of expressive suppression between several aspects of impulsivity and procrastination. Close inspection of the paths' weights suggests that there may be two partly competing strategies for dealing with impulsivity and negative emotions: either to suppress emotions and impulsive reactions or to react impulsively, discarding previous plans, and to procrastinate. Path invariance analysis showed the significant moderating roles of student status and age. Both in non-students and high-age groups, the path leading from suppression to procrastination was insignificant. This suggests that caution should be used in generalizing the results of studies carried out on students. These results support previous findings that procrastination may serve as a short-term mood regulation strategy. However, as the spectrum of the emotion regulation strategies included in the study was very limited, we conclude that future studies should seek more insight into the relationship between emotion regulation, self-control, and procrastination.

Vertical Scales of Turbulence at the Mount Wilson Observatory

NASA Technical Reports Server (NTRS)

Treuhaft, Robert N.; Lowe, Stephen T.; Bester, Manfred; Danchi, William C.; Townes, Charles H.

1995-01-01

The vertical scales of turbulence at the Mount Wilson Observatory are inferred from data from the University of California at Berkeley Infrared Spatial Interferometer (ISI), by modeling path length fluctuations observed in the interferometric paths to celestial objects and those in instrumental ground-based paths. The correlations between the stellar and ground-based path length fluctuations and the temporal statistics of those fluctuations are modeled on various timescales to constrain the vertical scales. A Kolmogorov-Taylor turbulence model with a finite outer scale was used to simulate ISI data. The simulation also included the white instrumental noise of the interferometer, aperture-filtering effects, and the data analysis algorithms. The simulations suggest that the path delay fluctuations observed in the 1992-1993 ISI data are largely consistent with being generated by refractivity fluctuations at two characteristic vertical scales: one extending to a height of 45 m above the ground, with a wind speed of about 1 m/ s, and another at a much higher altitude, with a wind speed of about 10 m/ s. The height of the lower layer is of the order of the dimensions of trees and other structures near the interferometer, which suggests that these objects, including elements of the interferometer, may play a role in generating the lower layer of turbulence. The modeling indicates that the high- attitude component contributes primarily to short-period (less than 10 s) fluctuations, while the lower component dominates the long-period (up to a few minutes) fluctuations. The lower component turbulent height, along with outer scales of the order of 10 m, suggest that the baseline dependence of long-term interferometric, atmospheric fluctuations should weaken for baselines greater than a few tens of meters. Simulations further show that there is the potential for improving the seeing or astrometric accuracy by about 30%-50% on average, if the path length fluctuations in the lower component are directly calibrated. Statistical and systematic effects induce an error of about 15 m in the estimate of the lower component turbulent altitude.

The Gravitational Process Path (GPP) model (v1.0) - a GIS-based simulation framework for gravitational processes

NASA Astrophysics Data System (ADS)

Wichmann, Volker

2017-09-01

The Gravitational Process Path (GPP) model can be used to simulate the process path and run-out area of gravitational processes based on a digital terrain model (DTM). The conceptual model combines several components (process path, run-out length, sink filling and material deposition) to simulate the movement of a mass point from an initiation site to the deposition area. For each component several modeling approaches are provided, which makes the tool configurable for different processes such as rockfall, debris flows or snow avalanches. The tool can be applied to regional-scale studies such as natural hazard susceptibility mapping but also contains components for scenario-based modeling of single events. Both the modeling approaches and precursor implementations of the tool have proven their applicability in numerous studies, also including geomorphological research questions such as the delineation of sediment cascades or the study of process connectivity. This is the first open-source implementation, completely re-written, extended and improved in many ways. The tool has been committed to the main repository of the System for Automated Geoscientific Analyses (SAGA) and thus will be available with every SAGA release.

Morphological awareness and reading comprehension: Examining mediating factors.

PubMed

Levesque, Kyle C; Kieffer, Michael J; Deacon, S Hélène

2017-08-01

The relation between morphological awareness-defined as the awareness of and ability to manipulate the smallest units of meaning in language-and reading comprehension remains in need of specification. In this study, we evaluated four potential intervening variables through which morphological awareness may contribute indirectly to reading comprehension. We assessed word reading and vocabulary as well as children's ability to read and analyze the meaning of morphologically complex words (morphological decoding and morphological analysis, respectively). Controls of phonological awareness and nonverbal ability were included in the model. Participants were 221 English-speaking children in Grade 3. Multivariate path analyses revealed evidence of two indirect relations and one direct relation between morphological awareness and reading comprehension. In the first indirect path, morphological awareness contributed to morphological decoding, which then influenced word reading and finally reading comprehension. In a second indirect path, morphological awareness contributed to morphological analysis, which contributed to reading comprehension. Finally, in a direct path, morphological awareness contributed to reading comprehension beyond all other variables. These findings inform as to the potential mechanisms underlying the relation between morphological awareness and reading comprehension in children. Copyright © 2017 Elsevier Inc. All rights reserved.

[Factors Influencing Physical Activity among Community-dwelling Older Adults with Type 2 Diabetes: A Path Analysis].

PubMed

Jang, Sun Joo; Park, Hyunju; Kim, Hyunjung; Chang, Sun Ju

2015-06-01

The purpose of the study was to identify factors influencing physical activity among community-dwelling older adults with type 2 diabetes. The study design was based on the Theory of Triadic Influence. A total of 242 older adults with type 2 diabetes participated in this study. Six variables related to physical activity in older adults, including self-efficacy, social normative belief, attitudes, intention, experience, and level of physical activity, were measured using reliable instruments. Data were analyzed using descriptive statistics, Pearson's correlation analyses, and a path analysis. The mean physical activity score was 104.2, range from zero to 381.21. The path analysis showed that self-efficacy had the greatest total effect on physical activity. Also, experience had direct and total effects on physical activity as well as mediated the paths of social normative beliefs to attitudes and intention to physical activity. These factors accounted for 10% of the total variance, and the fit indices of the model satisfied the criteria of fitness. The findings of the study reveal the important role of self-efficacy and past experience in physical activity in older adults with type 2 diabetes.

Understanding Associations between Neighborhood Socioeconomic Status and Negative Consequences of Drinking: A Moderated Mediation Analysis

PubMed Central

Karriker-Jaffe, Katherine J.; Liu, HuiGuo; Kaplan, Lauren M.

2016-01-01

Aims We explored how neighborhood socioeconomic status (SES) is related to negative consequences of drinking to explain why racial/ethnic minority group members are more at risk than Whites for adverse alcohol outcomes. We tested direct and indirect effects of neighborhood SES on alcohol problems and examined differences by gender and race. Methods We used data from the 2000 and 2005 National Alcohol Surveys (N=7,912 drinkers aged 18 and older; 49% female) linked with data from the 2000 Decennial Census in multivariate path models adjusting for individual demographics. Results In the full sample, neighborhood disadvantage had a significant direct path to increased negative consequences, with no indirect paths through depression, positive affect or pro-drinking attitudes. Neighborhood affluence had significant indirect paths to increased negative consequences through greater pro-drinking attitudes and increased heavy drinking. Sub-group analyses showed the indirect path from affluence to consequences held for White men, with no effects of neighborhood disadvantage. For racial/ethnic minority men, significant indirect paths emerged from both neighborhood disadvantage and affluence to increased consequences through greater pro-drinking attitudes and more heavy drinking. For minority women, there was an indirect effect of neighborhood affluence through reduced depression to fewer drinking consequences. There were limited neighborhood effects on alcohol outcomes for White women. Conclusions Interventions targeting pro-drinking attitudes in both affluent and disadvantaged areas may help reduce alcohol-related problems among men. Initiatives to improve neighborhood conditions could enhance mental health of minority women and reduce alcohol-related health disparities. PMID:26898509

Characterization and Comparison of Vibration Transfer Paths in a Helicopter Gearbox and a Fixture Mounted Gearbox

NASA Technical Reports Server (NTRS)

Islam, Akm Anwarul; Dempsey, Paula J.; Feldman, Jason; Larsen, Chris

2014-01-01

Health monitoring of rotorcraft components, currently being performed by Health and Usage Monitoring Systems through analyses of vibration signatures of dynamic mechanical components, is very important for their safe and economic operation. HUMS analyze vibration signatures associated with faults and quantify them as condition indicators to predict component behavior. Vibration transfer paths are characterized by frequency response functions derived from the input/output relationship between applied force and dynamic response through a structure as a function of frequency. With an objective to investigate the differences in transfer paths, transfer path measurements were recorded under similar conditions in the left and right nose gearboxes of an AH-64 helicopter and in an isolated left nose gearbox in a test fixture at NASA Glenn Research Center. The test fixture enabled the application of measured torques-common during an actual operation. An impact hammer as well as commercial and lab piezo shakers, were used in conjunction with two types of commercially available accelerometers to collect the vibration response under various test conditions. The frequency response functions measured under comparable conditions of both systems were found to be consistent. Measurements made on the fixture indicated certain real-world installation and maintenance issues, such as sensor alignments, accelerometer locations and installation torques, had minimal effect. However, gear vibration transfer path dynamics appeared to be somewhat dependent on the presence of oil, and the transfer path dynamics were notably different if the force input was on the internal ring gear rather than on the external gearbox case.

Two-condition within-participant statistical mediation analysis: A path-analytic framework.

PubMed

Montoya, Amanda K; Hayes, Andrew F

2017-03-01

Researchers interested in testing mediation often use designs where participants are measured on a dependent variable Y and a mediator M in both of 2 different circumstances. The dominant approach to assessing mediation in such a design, proposed by Judd, Kenny, and McClelland (2001), relies on a series of hypothesis tests about components of the mediation model and is not based on an estimate of or formal inference about the indirect effect. In this article we recast Judd et al.'s approach in the path-analytic framework that is now commonly used in between-participant mediation analysis. By so doing, it is apparent how to estimate the indirect effect of a within-participant manipulation on some outcome through a mediator as the product of paths of influence. This path-analytic approach eliminates the need for discrete hypothesis tests about components of the model to support a claim of mediation, as Judd et al.'s method requires, because it relies only on an inference about the product of paths-the indirect effect. We generalize methods of inference for the indirect effect widely used in between-participant designs to this within-participant version of mediation analysis, including bootstrap confidence intervals and Monte Carlo confidence intervals. Using this path-analytic approach, we extend the method to models with multiple mediators operating in parallel and serially and discuss the comparison of indirect effects in these more complex models. We offer macros and code for SPSS, SAS, and Mplus that conduct these analyses. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Longitudinal data analyses using linear mixed models in SPSS: concepts, procedures and illustrations.

PubMed

Shek, Daniel T L; Ma, Cecilia M S

2011-01-05

Although different methods are available for the analyses of longitudinal data, analyses based on generalized linear models (GLM) are criticized as violating the assumption of independence of observations. Alternatively, linear mixed models (LMM) are commonly used to understand changes in human behavior over time. In this paper, the basic concepts surrounding LMM (or hierarchical linear models) are outlined. Although SPSS is a statistical analyses package commonly used by researchers, documentation on LMM procedures in SPSS is not thorough or user friendly. With reference to this limitation, the related procedures for performing analyses based on LMM in SPSS are described. To demonstrate the application of LMM analyses in SPSS, findings based on six waves of data collected in the Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programmes) in Hong Kong are presented.

Longitudinal Data Analyses Using Linear Mixed Models in SPSS: Concepts, Procedures and Illustrations

PubMed Central

Shek, Daniel T. L.; Ma, Cecilia M. S.

2011-01-01

Although different methods are available for the analyses of longitudinal data, analyses based on generalized linear models (GLM) are criticized as violating the assumption of independence of observations. Alternatively, linear mixed models (LMM) are commonly used to understand changes in human behavior over time. In this paper, the basic concepts surrounding LMM (or hierarchical linear models) are outlined. Although SPSS is a statistical analyses package commonly used by researchers, documentation on LMM procedures in SPSS is not thorough or user friendly. With reference to this limitation, the related procedures for performing analyses based on LMM in SPSS are described. To demonstrate the application of LMM analyses in SPSS, findings based on six waves of data collected in the Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programmes) in Hong Kong are presented. PMID:21218263

Which physical and social environmental factors are most important for adolescents' cycling for transport? An experimental study using manipulated photographs.

PubMed

Verhoeven, Hannah; Ghekiere, Ariane; Van Cauwenberg, Jelle; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Clarys, Peter; Deforche, Benedicte

2017-08-17

Ecological models emphasize that cycling for transport is determined by an interplay between individual, physical and social environmental factors. The current study investigated (a) which physical and social environmental factors determine adolescents' preferences towards cycling for transport and (b) which individual, physical and social environmental factors are associated with their intention to actually cycle for transport. An online questionnaire consisting of questions on individual and social environmental variables, and 15 choice-based conjoint tasks with manipulated photographs was completed by 882 adolescents (55.3% male; 13.9 ± 1.6 years). Within the choice tasks, participants were asked to indicate which of two situations they would prefer to cycle to a friend's house. The manipulated photographs were all modified versions of one semi-urban street which differed in the following physical micro-environmental attributes (separation of cycle path, evenness of cycle path, speed limit, speed bump, traffic density, amount of vegetation and maintenance). In addition, each photograph was accompanied by two sentences which described varying cycling distances and co-participation in cycling (i.e. cycling alone or with a friend). After each choice task participants were also asked if they would actually cycle in that situation in real life (i.e. intention). Hierarchical Bayes analyses were performed to calculate relative importances and part-worth utilities of environmental attributes. Logistic regression analyses were performed to investigate which individual, physical and social environmental factors were associated with adolescents' intention to actually cycle for transport. Adolescents' preference to cycle for transport was predominantly determined by separation of cycle path, followed by shorter cycling distance and co-participation in cycling. Higher preferences were observed for a separation between the cycle path and motorized traffic by means of a hedge versus a curb, versus a marked line. Similar findings were observed for intention to cycle. Furthermore, evenness of the cycle path and general maintenance of the street were also of considerable importance among adolescents, but to a lesser extent. Results of this experimental study justify investment by local governments in well-separated cycling infrastructure, which seemed to be more important than cycling distance and the social environment.

Manninotriose is a major carbohydrate in red deadnettle (Lamium purpureum, Lamiaceae)

PubMed Central

dos Santos, Raquel; Vergauwen, Rudy; Pacolet, Pieter; Lescrinier, Eveline; Van den Ende, Wim

2013-01-01

Background and Aims There is a great need to search for natural compounds with superior prebiotic, antioxidant and immunostimulatory properties for use in (food) applications. Raffinose family oligosaccharides (RFOs) show such properties. Moreover, they contribute to stress tolerance in plants, acting as putative membrane stabilizers, antioxidants and signalling agents. Methods A large-scale soluble carbohydrate screening was performed within the plant kingdom. An unknown compound accumulated to a high extent in early-spring red deadnettle (Lamium purpureum) but not in other RFO plants. The compound was purified and its structure was unravelled with NMR. Organs and organ parts of red deadnettle were carefully dissected and analysed for soluble sugars. Phloem sap content was analysed by a common EDTA-based method. Key Results Early-spring red deadnettle stems and roots accumulate high concentrations of the reducing trisaccharide manninotriose (Galα1,6Galα1,6Glc), a derivative of the non-reducing RFO stachyose (Galα1,6Galα1,6Glcα1,2βFru). Detailed soluble carbohydrate analyses on dissected stem and leaf sections, together with phloem sap analyses, strongly suggest that stachyose is the main transport compound, but extensive hydrolysis of stachyose to manninotriose seems to occur along the transport path. Based on the specificities of the observed carbohydrate dynamics, the putative physiological roles of manninotriose in red deadnettle are discussed. Conclusions It is demonstrated for the first time that manninotriose is a novel and important player in the RFO metabolism of red dead deadnettle. It is proposed that manninotriose represents a temporary storage carbohydrate in early-spring deadnettle, at the same time perhaps functioning as a membrane protector and/or as an antioxidant in the vicinity of membranes, as recently suggested for other RFOs and fructans. This novel finding urges further research on this peculiar carbohydrate on a broader array of RFO accumulators. PMID:23264235

Total Solar Eclipse of 1997 March 9

NASA Technical Reports Server (NTRS)

Espenak, Fred; Anderson, Jay

1995-01-01

A total eclipse of the Sun will be visible from Asia and the Pacific Ocean on 1997 March 9. The path of the Moon's umbral shadow begins in eastern Kazakhstan and travels through Mongolia and eastern Siberia, where it swings northward to end at sunset in the Arctic Ocean. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes eastern Asia, the northern Pacific, and the northwest corner of North America. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 280 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

Forward- and reverse-bias tunneling effects in n/+/p silicon solar cells

NASA Technical Reports Server (NTRS)

Garlick, G. F. J.; Kachare, A. H.

1980-01-01

Excess currents due to field-assisted tunneling in both forward and reverse bias directions have been observed in n(+)-p silicon solar cells. These currents arise from the effect of conducting paths produced in the depletion layer by n(+) diffusion and cell processing. Forward-bias data indicate a small potential barrier with height of 0.04 eV at the n(+) end of conducting paths. Under reverse bias, excess tunneling currents involve a potential barrier at the p end of the conducting paths, the longer paths being associated with smaller barrier heights and dominating at the lower temperatures. Low-reverse-bias data give energy levels of 0.11 eV for lower temperatures (253-293 K) and 0.35 eV for higher temperatures (293-380 K). A model is suggested to explain the results.

Total Solar Eclipse of 2001 June 21

NASA Technical Reports Server (NTRS)

Espenak, Fred; Anderson, Jay

1999-01-01

On 2001 June 21, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Southern Hemisphere. The path of the Moon's umbral shadow begins in the South Atlantic, crosses southern Africa and Madagascar, and ends at sunset in the Indian Ocean. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes eastern South America and the southern two thirds of Africa. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 350 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

The impact of environmental factors on cycling speed on shared paths.

PubMed

Boufous, Soufiane; Hatfield, Julie; Grzebieta, Raphael

2018-01-01

Despite the importance of cycling speed on shared paths to the amenity and safety of users, few studies have systematically measured it, nor examined circumstances surrounding it. Speed was measured for 5421 riders who were observed cycling on shared paths across 12 metropolitan and regional locations in Sydney, Australia. Multivariate regression analysis was carried out to examine rider and environmental factors that contribute to riders cycling above the median speed. The study found that observed riders travelled at a median speed of 16km/h (mean 18.4km/h). Nearly 80% of riders travelled at 20km/h or less and 7.8% at speeds of more than 30km/h. Riders were significantly less likely to cycle above the median speed on shared paths that had an average volume of over 20 pedestrians/hour. Riders were significantly more likely to travel above the median speed on paths that had a centreline (OR: 1.71, 95% CI: 1.41-2.07), on wider paths (over 3.5m) (OR: 1.34, 95% CI: 1.12-1.59) and on paths with visual segregation between cyclists and pedestrians. Visual segregation, where cycling and walking areas are differentiated by the type of material or by paint colour used, was the strongest predictor of travelling above median speed on shared paths (OR: 3.9, 95% CI: 3.1-4.8). The findings suggest that riders adjust their speeds to accommodate pedestrians and path conditions. Path characteristics that support separation from pedestrians may allow relatively higher speeds, and associated amenity, without substantial loss of safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

Generation of Path-Encoded Greenberger-Horne-Zeilinger States

NASA Astrophysics Data System (ADS)

Bergamasco, N.; Menotti, M.; Sipe, J. E.; Liscidini, M.

2017-11-01

We study the generation of Greenberger-Horne-Zeilinger (GHZ) states of three path-encoded photons. Inspired by the seminal work of Bouwmeester et al. [Phys. Rev. Lett. 82, 1345 (1999), 10.1103/PhysRevLett.82.1345] on polarization-entangled GHZ states, we find a corresponding path representation for the photon states of an optical circuit, identify the elements required for the state generation, and propose a possible implementation of our strategy. Besides the practical advantage of employing an integrated system that can be fabricated with proven lithographic techniques, our example suggests that it is possible to enhance the generation efficiency by using microring resonators.

Prospective Association of Childhood Receptive Vocabulary and Conduct Problems with Self-Reported Adolescent Delinquency: Tests of Mediation and Moderation in Sibling-Comparison Analyses

PubMed Central

Lahey, Benjamin B.; D'Onofrio, Brian M.; Van Hulle, Carol A.; Rathouz, Paul J.

2014-01-01

Associations among receptive vocabulary measured at 4–9 years, mother-reported childhood conduct problems at 4–9 years, and self-reported adolescent delinquency at 14–17 years were assessed using data from a prospective study of the offspring of a large U.S. nationally representative sample of women. A novel quasi-experimental strategy was used to rule out family-level confounding by estimating path-analytic associations within families in a sibling comparison design. This allowed simultaneous tests of the direct and indirect effects of receptive vocabulary and childhood conduct problems, and of their joint moderation, on adolescent delinquency without family-level environmental confounding. The significant association of receptive vocabulary with later adolescent delinquency was indirect, mediated by childhood conduct problems. Furthermore, a significant interaction between receptive vocabulary and childhood conduct problems reflected a steeper slope for the predictive association between childhood conduct problems and adolescent delinquency when receptive vocabulary scores were higher. These findings of significant indirect association were qualitatively identical in both population-level and within-family analyses, suggesting that they are not the result of family-level confounds. PMID:24736982

Prospective association of childhood receptive vocabulary and conduct problems with self-reported adolescent delinquency: tests of mediation and moderation in sibling-comparison analyses.

PubMed

Lahey, Benjamin B; D'Onofrio, Brian M; Van Hulle, Carol A; Rathouz, Paul J

2014-11-01

Associations among receptive vocabulary measured at 4-9 years, mother-reported childhood conduct problems at 4-9 years, and self-reported adolescent delinquency at 14-17 years were assessed using data from a prospective study of the offspring of a large U.S. nationally representative sample of women. A novel quasi-experimental strategy was used to rule out family-level confounding by estimating path-analytic associations within families in a sibling comparison design. This allowed simultaneous tests of the direct and indirect effects of receptive vocabulary and childhood conduct problems, and of their joint moderation, on adolescent delinquency without family-level environmental confounding. The significant association of receptive vocabulary with later adolescent delinquency was indirect, mediated by childhood conduct problems. Furthermore, a significant interaction between receptive vocabulary and childhood conduct problems reflected a steeper slope for the predictive association between childhood conduct problems and adolescent delinquency when receptive vocabulary scores were higher. These findings of significant indirect association were qualitatively identical in both population-level and within-family analyses, suggesting that they are not the result of family-level confounds.

Scientific Inquiry Self-Efficacy and Computer Game Self-Efficacy as Predictors and Outcomes of Middle School Boys' and Girls' Performance in a Science Assessment in a Virtual Environment

NASA Astrophysics Data System (ADS)

Bergey, Bradley W.; Ketelhut, Diane Jass; Liang, Senfeng; Natarajan, Uma; Karakus, Melissa

2015-10-01

The primary aim of the study was to examine whether performance on a science assessment in an immersive virtual environment was associated with changes in scientific inquiry self-efficacy. A secondary aim of the study was to examine whether performance on the science assessment was equitable for students with different levels of computer game self-efficacy, including whether gender differences were observed. We examined 407 middle school students' scientific inquiry self-efficacy and computer game self-efficacy before and after completing a computer game-like assessment about a science mystery. Results from path analyses indicated that prior scientific inquiry self-efficacy predicted achievement on end-of-module questions, which in turn predicted change in scientific inquiry self-efficacy. By contrast, computer game self-efficacy was neither predictive of nor predicted by performance on the science assessment. While boys had higher computer game self-efficacy compared to girls, multi-group analyses suggested only minor gender differences in how efficacy beliefs related to performance. Implications for assessments with virtual environments and future design and research are discussed.

Do ethnicity and gender matter when using the theory of planned behavior to understand fruit and vegetable consumption?

PubMed

Blanchard, Chris M; Kupperman, Janet; Sparling, Phillip B; Nehl, Eric; Rhodes, Ryan E; Courneya, Kerry S; Baker, Frank

2009-02-01

A majority of Americans do not meet the recommendation to eat five servings of fruits and vegetables per day (5-A-Day). The purpose of the present study was to examine the utility of the theory of planned behavior (TPB) for understanding 5-A-Day intentions and behavior and to determine whether any of the TPB relationships were moderated by ethnicity or gender. A total of 413 participants completed a baseline TPB questionnaire and a fruit and vegetable consumption measure 2 weeks later. Path analyses showed that affective attitude and perceived behavioral control significantly predicted intention for blacks, whites, males and females (R(2) ranged from .32 to .40), whereas subjective norm was a significant predictor for blacks, males, and females only. Intention significantly predicted 5-A-Day (R(2) ranged from .17 to .22) for all groups. Follow-up invariance analyses showed that the subjective norm/intention relationship was significantly stronger for black compared to white students. Finally, several key beliefs were identified for all four demographic groups. Therefore, the current results suggest that the TPB may be a useful framework to utilize when developing 5-A-Day interventions.

Toward a Model of Social Influence that Explains Minority Student Integration into the Scientific Community

PubMed Central

Estrada, Mica; Woodcock, Anna; Hernandez, Paul R.; Schultz, P. Wesley

2010-01-01

Students from several ethnic minority groups are underrepresented in the sciences, such that minority students more frequently drop out of the scientific career path than non-minority students. Viewed from a perspective of social influence, this pattern suggests that minority students do not integrate into the scientific community at the same rate as non-minority students. Kelman (1958, 2006) describes a tripartite integration model of social influence (TIMSI) by which a person orients to a social system. To test if this model predicts integration into the scientific community, we conducted analyses of data from a national panel of minority science students. A structural equation model framework showed that self-efficacy (operationalized consistent with Kelman’s ‘rule-orientation’) predicted student intentions to pursue a scientific career. However, when identification as a scientist and internalization of values are added to the model, self-efficacy becomes a poorer predictor of intention. Additional mediation analyses support the conclusion that while having scientific self-efficacy is important, identifying with and endorsing the values of the social system reflect a deeper integration and more durable motivation to persist as a scientist. PMID:21552374

The Development of the Obligation System in Mexican Spanish: A Variationist Sociolinguistic Perspective

ERIC Educational Resources Information Center

Honea, Katherine

2012-01-01

Research that examines diachronic change and modality posit that modal verbs follow certain universal paths of development (e.g. Cornillie, 2007; Bybee & Fleischman, 1995; Bybee, Perkins & Pagliuca, 1994). The present study examines the development of Spanish modality in Mexico through the use of multivariate analyses, relative…

The Effects of Attention Problems on Depression: Developmental, Academic, and Cognitive Pathways

ERIC Educational Resources Information Center

Herman, Keith C.; Ostrander, Rick

2007-01-01

The present study investigated developmental pathways between inattention and depression, particularly the roles of school maladjustment and child cognitions. Additionally, a measure of conduct problems was included in all analyses to test competing theories about the emergence of depressive symptoms. Results supported the hypothesized path models…

Gendered Divisions on Classed Routes to Vocational Education

ERIC Educational Resources Information Center

Lappalainen, Sirpa; Mietola, Reetta; Lahelma, Elina

2013-01-01

In this article our focus is on the persistent gendered divisions in educational routes of young people who choose a vocational path after compulsory education in Finland. We analyse how gendered subjectivities are constructed within the practices of educational and vocational guidance and within student cultures in the comprehensive school, as…

Linkages over Time between Adolescents' Relationships with Parents and Friends

ERIC Educational Resources Information Center

De Goede, Irene H. A.; Branje, Susan J. T.; Delsing, Marc J. M. H.; Meeus, Wim H. J.

2009-01-01

This 5-wave longitudinal study examines linkages over time between adolescents' perceptions of relationships with parents and friends with respect to support, negative interaction, and power. A total of 575 early adolescents (54.1% boys) and 337 middle adolescents (43.3% boys) participated. Path analyses mainly showed bidirectional associations…

Some Psychometric and Design Implications of Game-Based Learning Analytics

ERIC Educational Resources Information Center

Gibson, David; Clarke-Midura, Jody

2013-01-01

The rise of digital game and simulation-based learning applications has led to new approaches in educational measurement that take account of patterns in time, high resolution paths of action, and clusters of virtual performance artifacts. The new approaches, which depart from traditional statistical analyses, include data mining, machine…

The Role of Teachers in Facilitating Situational Interest in an Active-Learning Classroom

ERIC Educational Resources Information Center

Rotgans, Jerome I.; Schmidt, Henk G.

2011-01-01

The study sought to explore whether interactional teacher characteristics such as social congruence, subject-matter expertise, and cognitive congruence increase situational interest in students. Correlational and path analyses were conducted on a sample of 498 polytechnic students to assess potential differences in situational interest based on…

Family Racial Socialization and Ecological Competence: Longitudinal Assessments of African-American Transracial Adoptees.

ERIC Educational Resources Information Center

DeBerry, Kimberly M.; And Others

1996-01-01

Examined family racial socialization and ecological competence during childhood and adolescence in a sample of 88 African-American transracial adoptees and their families. Longitudinal path analyses indicated that Eurocentric reference group orientation (RGO) increased over time while Africentric RGO declined for the adoptees, and maladjustment…

Marital Satisfaction, Family Emotional Expressiveness, Home Learning Environments, and Children's Emergent Literacy

ERIC Educational Resources Information Center

Froyen, Laura C.; Skibbe, Lori E.; Bowles, Ryan P.; Blow, Adrian J.; Gerde, Hope K.

2013-01-01

The current study investigates associations among marital satisfaction, family emotional expressiveness, the home learning environment, and preschool-aged children's emergent literacy skills among 385 Midwestern mothers and their children. Path analyses examined how marital satisfaction related to emotional expressiveness in the home and whether…

Pathways to Suicidal Behaviors in Childhood

ERIC Educational Resources Information Center

Greening, Leilani; Stoppelbein, Laura; Fite, Paula; Dhossche, Dirk; Erath, Stephen; Brown, Jacqueline; Cramer, Robert; Young, Laura

2008-01-01

Path analyses were applied to test a model that includes internalizing and externalizing behavior problems as predictors of suicidal behaviors in children. Parents of an inpatient sample of boys (N = 87; M age = 9.81 years) rated the frequency of suicidal ideation and completed standardized measures of behavior problems. Blind raters rated the…

Factors Associated with Technology Integration to Improve Instructional Abilities: A Path Model

ERIC Educational Resources Information Center

Uslu, Öner

2018-01-01

Today, students are expected to access, analyse and synthesise information, and work cooperatively. Their learning environment, therefore, should be equipped with appropriate tools and materials, and teachers should have instructional abilities to use them effectively. This study aims to propose a model to improve teachers' instructional abilities…

Cross Cultural Perspectives of Gender and Management in Universities

ERIC Educational Resources Information Center

White, K.; Riordan, S.; Ozkanli, O.; Neale, J.

2010-01-01

Aim: This article presents preliminary results of a cross cultural study of gender and management in universities. Methodology: Qualitative interviews with senior managers in each country were analysed in relation to key concepts of career paths, support, gate keeping, management skills, disciplinary factors, gendered leadership styles and…

Goal-Orientation and Teacher Motivation among Teacher Applicants and Student Teachers

ERIC Educational Resources Information Center

Malmberg, Lars-Erik

2006-01-01

The relationship between goal-orientation, intrinsic/extrinsic motivation for the teaching profession, previous achievement and entrance scores was investigated among teacher applicants (Study 1; N=230), and student teachers (Study 2; N=114). Utilizing path-analyses the following relationships were found in both studies, between: (a) mastery goals…

Self-Perceived Competence as a Mediator between Maternal Feedback and Depressive Symptoms in Adolescents

ERIC Educational Resources Information Center

Jacquez, Farrah; Cole, David A.; Searle, Barbara

2004-01-01

Self-report, other-report, clinical interview, and behavioral observations of evaluative maternal feedback (e.g., positive feedback, criticism), adolescent depressive symptoms, and self-perceived competence were obtained from 72 adolescents and their mothers. Most path analyses supported the hypothesis that adolescent self-perceived competence…

Career Paths, Images and Anchors: A Study with Brazilian Professionals

ERIC Educational Resources Information Center

Kilimnik, Zelia Miranda; de Oliveira, Luiz Claudio Vieira; Sant'anna, Anderson De Souza; Barros, Delba Teixeira Rodrigues

2011-01-01

This article analyses career anchors changes associated to images and professionals trajectories. Its main question: Do anchors careers change through time? We conducted twelve interviews involving professionals from the Administration Area, applying Schein's Career Anchors Inventory (1993). We did the same two years later. In both of them, the…

Functional Organization of the Action Observation Network in Autism: A Graph Theory Approach

PubMed Central

Alaerts, Kaat; Geerlings, Franca; Herremans, Lynn; Swinnen, Stephan P.; Verhoeven, Judith; Sunaert, Stefan; Wenderoth, Nicole

2015-01-01

Background The ability to recognize, understand and interpret other’s actions and emotions has been linked to the mirror system or action-observation-network (AON). Although variations in these abilities are prevalent in the neuro-typical population, persons diagnosed with autism spectrum disorders (ASD) have deficits in the social domain and exhibit alterations in this neural network. Method Here, we examined functional network properties of the AON using graph theory measures and region-to-region functional connectivity analyses of resting-state fMRI-data from adolescents and young adults with ASD and typical controls (TC). Results Overall, our graph theory analyses provided convergent evidence that the network integrity of the AON is altered in ASD, and that reductions in network efficiency relate to reductions in overall network density (i.e., decreased overall connection strength). Compared to TC, individuals with ASD showed significant reductions in network efficiency and increased shortest path lengths and centrality. Importantly, when adjusting for overall differences in network density between ASD and TC groups, participants with ASD continued to display reductions in network integrity, suggesting that also network-level organizational properties of the AON are altered in ASD. Conclusion While differences in empirical connectivity contributed to reductions in network integrity, graph theoretical analyses provided indications that also changes in the high-level network organization reduced integrity of the AON. PMID:26317222

Satellite-Based Assessment of Possible Dust Aerosols Semi-Direct Effect on Cloud Water Path over East Asia

NASA Technical Reports Server (NTRS)

Huang, Jianping; Lin, Bing; Minnis, Patrick; Wang, Tainhe; Wang, Xin; Hu, Yongxiang; Yi, Yuhong; Ayers, J. Kirk

2006-01-01

The semi-direct effects of dust aerosols are analyzed over eastern Asia using 2 years (June 2002 to June 2004) of data from the Clouds and the Earth s Radiant Energy System (CERES) scanning radiometer and MODerate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite, and 18 years (1984 to 2001) of International Satellite Cloud Climatology Project (ISCCP) data. The results show that the water path of dust-contaminated clouds is considerably smaller than that of dust-free clouds. The mean ice water path (IWP) and liquid water path (LWP) of dusty clouds are less than their dust-free counterparts by 23.7% and 49.8%, respectively. The long-term statistical relationship derived from ISCCP also confirms that there is significant negative correlation between dust storm index and ISCCP cloud water path. These results suggest that dust aerosols warm clouds, increase the evaporation of cloud droplets and further reduce cloud water path, the so-called semi-direct effect. The semi-direct effect may play a role in cloud development over arid and semi-arid areas of East Asia and contribute to the reduction of precipitation.

Role strain in couples with and without a child with a chronic illness: associations with marital satisfaction, intimacy, and daily mood.

PubMed

Quittner, A L; Opipari, L C; Espelage, D L; Carter, B; Eid, N; Eigen, H

1998-03-01

This study examined marital role strain in 33 couples caring for a child with cystic fibrosis (CF) and 33 couples with a healthy child. The relationship between role strain, marital satisfaction, and psychological distress was tested. Couples completed a structured interview, questionnaires, a card sort procedure, and 4 daily diaries assessing activities and mood. Couples in the CF versus comparison group reported greater role strain on measures of role conflict, child-care tasks, and exchanges of affection. They also spent less time in recreational activities, but no reliable group differences were found in marital satisfaction or depression. Regression analyses indicated that role strain was related to marital satisfaction and depression and that recreation time accounted for additional variance. Path analysis suggested that recreation mediated the negative relationship between role strain and distress. The importance of using a contextual, process-oriented approach is discussed.

Endorsement of formal leaders: an integrative model.

PubMed

Michener, H A; Lawler, E J

1975-02-01

This experiment develops an integrative, path-analytic model for the endorsement accorded formal leaders. The model contains four independent variables reflecting aspects of group structure (i.e., group success-failure, the payoff distribution, the degree of support by others members for the leader, and the vulnerability of the leader). Also included are two intervening variables reflecting perceptual processes (attributed competence and attributed fairness), and one dependent variable endorsement). The results indicate that endorsement is greater when the group's success is high, when the payoff distribution is flat rather than hierarchial, and when the leader is not vulnerable to removal from office. Other support had no significant impact on endorsement. Analyses further demonstrate that the effect of success-failure on endorsement is mediated by attributed competence, while the effect of the payoff distributed is mediated by attributed fairness. These results suggest that moral and task evaluations are distinct bases of endorsement.

The gender role motivation model of women's sexually submissive behavior and satisfaction in heterosexual couples.

PubMed

Sanchez, Diana T; Phelan, Julie E; Moss-Racusin, Corinne A; Good, Jessica J

2012-04-01

Previous findings suggest that women are more likely than men to take on the submissive role during sexual activities (e.g., waiting for their partner to initiate and orchestrate sexual activities), often to the detriment of their sexual satisfaction. Extending previous research on gender role motivation, the authors recruited 181 heterosexual couples to examine scripted sexual behavior, motivation for such behavior, and relationship outcomes (sexual satisfaction, perceptions of closeness, and relationship satisfaction) for both women and their partners. Using the actor-partner interdependence model, path analyses revealed that women's submissive behavior had negative links to personal sexual satisfaction and their partner's sexual satisfaction but only when their submission was inconsistent with their sexual preferences. Moreover, the authors show there are negative downstream consequences of diminished sexual satisfaction on perceptions of closeness and overall relationship satisfaction for both partners in the relationship.

Overcoming barriers to exercise among parents: A social cognitive theory perspective

PubMed Central

Mailey, Emily L.; Phillips, Siobhan M.; Dlugonski, Deirdre; Conroy, David E.

2017-01-01

Parents face numerous barriers to exercise and exhibit high levels of inactivity. Examining theory-based determinants of exercise among parents may inform interventions for this population. The purpose of this study was to test a social-cognitive model of parental exercise participation over a 12-month period. Mothers (n=226) and fathers (n=70) of children <16 completed measures of exercise, barriers self-efficacy, perceived barriers, and exercise planning at baseline and one year later. Panel analyses were used to test the hypothesized relationships. Barriers self-efficacy was related to exercise directly and indirectly through perceived barriers and prioritization/planning. Prioritization and planning also mediated the relationship between perceived barriers and exercise. These paths remained significant at 12 months. These results suggest efforts to increase exercise in parents should focus on improving confidence to overcome exercise barriers, reducing perceptions of barriers, and helping parents make specific plans for prioritizing and engaging in exercise. PMID:27108160

Cumulative Childhood Trauma and Adult Sexual Satisfaction: Mediation by Affect Dysregulation and Sexual Anxiety in Men and Women.

PubMed

Bigras, Noémie; Daspe, Marie-Ève; Godbout, Natacha; Briere, John; Sabourin, Stéphane

2017-05-19

Childhood cumulative trauma (CCT) refers to an amalgam of childhood maltreatment experiences that can lead to a range of symptoms and problems in adulthood. The current study examined an integrative model of CCT for its relevance to psychosexual adjustment in adult survivors. A total of 620 participants aged 18 years and over completed a questionnaire assessing early life experiences, affect dysregulation, sexual anxiety, and sexual satisfaction. Path analyses confirmed the hypothesis that CCT is associated with affect dysregulation and sexual anxiety that, in turn, predict lower levels of sexual satisfaction. The validity of this mediational model was demonstrated for different operationalizations of CCT. The results suggested that sex therapists, who are likely to encounter CCT survivors in their practice, should consider targeting affect dysregulation in their efforts to decrease sexual anxiety and increase sexual satisfaction.

Predictors of Disordered Eating in Young Males.

PubMed

Doumit, R; Abi Kharma, J; Sanchez-Ruiz, M J; Zeeni, N

2018-02-01

Recent findings suggest that disordered eating (DE) symptomatology may be underestimated in the male population. The present study examined depressive symptomatology as a potential mediator of the relationships between body image dissatisfaction, strategies to change body weight and muscles, media pressure, and DE (emotional, restrained and emotional eating) in 260 male undergraduates who completed a self-reported questionnaire. Path analyses indicated that media influence and strategies to decrease body weight had direct positive effects on depressive symptomatology, which in turn predicted emotional eating. Media influence had a direct positive effect on emotional eating, whereas strategies to decrease body weight did not exhibit a direct effect on emotional eating. Therefore, the latter pathway was removed from the model. The link between media pressure, strategies to decrease body weight and emotional eating was partially mediated by depressive symptomatology. The present findings can inform the development and implementation of prevention and education programs for DE in schools and universities.

Small-scale ionospheric troughs detected over a range of mid-latitude locations

NASA Astrophysics Data System (ADS)

Bowman, G. G.

1991-07-01

Spread-F structures at three spaced midlatitude stations (Canberra, 45 deg CGlat; Bribie Island, 36 deg CGlat; Townsville, 28 deg CGlat) obtained by N(h) analyses reveal modulated ionospheric height rises, electron-density depletions with spread-F recorded during the recovery stage of these ionospheric structure changes. At Bribie Island, fixed-frequency phase-path measurements (at 1.98 MHz) reveal a traveling ionospheric disturbance wavetrain of several cycles (periodicity 25 m) before and during the height rise associated with the spread-F event. When these midlatitude spread-F characteristics (including speeds of movement) are compared with those related to the daytime trough in high-latitude regions, the two phenomena are found to be similar. However, the magnitudes of the high-latitude changes are much greater than for the midlatitude spread-F events. It is suggested that both phenomena may result from the breaking of atmospheric gravity waves.

The role of emotional dysregulation in concurrent eating disorders and substance use disorders.

PubMed

Spence, Sarah; Courbasson, Christine

2012-12-01

This study explored the role of emotional dysregulation in 178 participants with concurrent EDs and SUDs. We ran two path analyses: Model 1 predicted negative mood regulation from alexithymia, and Model 2 predicted emotional eating from negative mood regulation. For Model 1, difficulty identifying and describing feelings was related to poor coping expectancies, while externally-oriented thinking was related to greater coping expectancies. For Model 2, poor coping expectancies in general were related to emotional eating, while greater coping expectancies in relation to behavior (i.e., the belief that some behavior or action can alleviate one's negative affect) also resulted in increased emotional eating. This finding suggests that there may be differences in the purpose of emotional eating; some people may believe that emotional eating can be used as an effective coping strategy to deal with negative affect. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cryo-Scanning Electron Microscopy of Captured Cirrus Ice Particles

NASA Astrophysics Data System (ADS)

Magee, N. B.; Boaggio, K.; Bandamede, M.; Bancroft, L.; Hurler, K.

2016-12-01

We present the latest collection of high-resolution cryo-scanning electron microscopy images and microanalysis of cirrus ice particles captured by high-altitude balloon (ICE-Ball, see abstracts by K. Boaggio and M. Bandamede). Ice particle images and sublimation-residues are derived from particles captured during approximately 15 balloon flights conducted in Pennsylvania and New Jersey over the past 12 months. Measurements include 3D digital elevation model reconstructions of ice particles, and associated statistical analyses of entire particles and particle sub-facets and surfaces. This 3D analysis reveals that morphologies of most ice particles captured deviate significantly from ideal habits, and display geometric complexity and surface roughness at multiple measureable scales, ranging from 100's nanometers to 100's of microns. The presentation suggests potential a path forward for representing scattering from a realistically complex array of ice particle shapes and surfaces.

The path of helpseeking: perceptions of law enforcement among American Indian victims of sexual assault.

PubMed

Hamby, Sherry

2008-01-01

The longstanding history of violence and oppression toward American Indians (AI) by the United States has created numerous problems for native communities, including high crime rates. AI women are sexually victimized more than other U.S. racial groups, but often receive very limited services. Secondary analyses of National Violence Against Women Survey data indicate that AI women's reasons for not reporting rape suggest ongoing suspicion of law enforcement. AI women, compared to others, more often said law enforcement would not believe or would blame them, and more often reported that they or their family dealt with the perpetrator. Many other barriers to helpseeking persist, including prejudice, conflict between Western and native values, language barriers, and poverty. AI communities also possess numerous resources that are specific to their cultures and their sovereign relationships with the U.S. government. More needs to be done to minimize barriers and make full use of community assets.

Participation in clubs and groups from childhood to adolescence and its effects on attachment and self-esteem.

PubMed

McGee, Rob; Williams, Sheila; Howden-Chapman, Philippa; Martin, Jennifer; Kawachi, Ichiro

2006-02-01

We examined social participation in organized clubs and groups from childhood to adolescence in a sample of young people from Dunedin, New Zealand. Groups were broadly categorized as "sports" and "cultural/youth" groups. While the results indicated high levels of participation in childhood with a decline over the ensuing adolescent years, path analyses suggested strong continuities in participation over time. Both family "active-recreational" orientation (ARO) and "intellectual-cultural" orientation (ICO) predicted participation, and mediated the effects of disadvantage on participation. Participation was significantly related to adolescent attachment to parents, friends and school/workplace, as well as self-perceived strengths, after controlling for early family disadvantage and social support, peer attachment and literacy. The effect of participation in adolescence is to widen the "social convoy" to which young people are exposed as well as strengthening relationships within that convoy.

Are Negative Peer Influences Domain Specific? Examining the Influence of Peers and Parents on Externalizing and Drug Use Behaviors.

PubMed

Cox, Ronald B; Criss, Michael M; Harrist, Amanda W; Zapata-Roblyer, Martha

2017-10-01

Most studies tend to characterize peer influences as either positive or negative. In a sample of 1815 youth from 14 different schools in Caracas, Venezuela, we explored how two types of peer affiliations (i.e., deviant and drug-using peers) differentially mediated the paths from positive parenting to youth's externalizing behavior and licit and illicit drug use. We used Zero Inflated Poisson models to test the probability of use and the extent of use during the past 12 months. Results suggested that peer influences are domain specific among Venezuelan youth. That is, deviant peer affiliations mediated the path from positive parenting to youth externalizing behaviors, and peer drug-using affiliations mediated the paths to the drug use outcomes. Mediation effects were partial, suggesting that parenting explained unique variance in the outcomes after accounting for both peer variables, gender, and age. We discuss implications for the development of screening tools and for prevention interventions targeting adolescents from different cultures.

Going the distance: spatial scale of athletic experience affects the accuracy of path integration.

PubMed

Smith, Alastair D; Howard, Christina J; Alcock, Niall; Cater, Kirsten

2010-09-01

Evidence suggests that athletically trained individuals are more accurate than untrained individuals in updating their spatial position through idiothetic cues. We assessed whether training at different spatial scales affects the accuracy of path integration. Groups of rugby players (large-scale training) and martial artists (small-scale training) participated in a triangle-completion task: they were led (blindfolded) along two sides of a right-angled triangle and were required to complete the hypotenuse by returning to the origin. The groups did not differ in their assessment of the distance to the origin, but rugby players were more accurate than martial artists in assessing the correct angle to turn (heading), and landed significantly closer to the origin. These data support evidence that distance and heading components can be dissociated. Furthermore, they suggest that the spatial scale at which an individual is trained may affect the accuracy of one component of path integration but not the other.

Migration mechanisms and diffusion barriers of vacancies in Ga2O3

NASA Astrophysics Data System (ADS)

Kyrtsos, Alexandros; Matsubara, Masahiko; Bellotti, Enrico

2017-06-01

We employ the nudged elastic band and the dimer methods within the standard density functional theory (DFT) formalism to study the migration of the oxygen and gallium vacancies in the monoclinic structure of β -Ga2O3 . We identify all the first nearest neighbor paths and calculate the migration barriers for the diffusion of the oxygen and gallium vacancies. We also identify the metastable sites of the gallium vacancies which are critical for the diffusion of the gallium atoms. The migration barriers for the diffusion of the gallium vacancies are lower than the migration barriers for oxygen vacancies by 1 eV on average, suggesting that the gallium vacancies are mobile at lower temperatures. Using the calculated migration barriers we estimate the annealing temperature of these defects within the harmonic transition state theory formalism, finding excellent agreement with the observed experimental annealing temperatures. Finally, we suggest the existence of percolation paths which enable the migration of the species without utilizing all the migration paths of the crystal.

Memory for the search path: Evidence for a high-capacity representation of search history

PubMed Central

Dickinson, Christopher A.; Zelinsky, Gregory J.

2007-01-01

Using a gaze-contingent paradigm, we directly measured observers’ memory capacity for fixated distractor locations during search. After approximately half of the search objects had been fixated, they were masked and a spatial probe appeared at either a previously fixated location (varied n-back) or a non-fixated location; observers then rated their confidence that the target had appeared at the probed location. Observers were able to differentiate the 12 most recently fixated distractor locations from non-fixated locations, but analyses revealed that these locations were represented fairly coarsely. We conclude that there exists a high-capacity, but low-resolution, memory for a search path. PMID:17482657

Dehydroxyl effect of Sn-doped silicon oxide resistance random access memory with supercritical CO2 fluid treatment

NASA Astrophysics Data System (ADS)

Tsai, Tsung-Ming; Chang, Kuan-Chang; Chang, Ting-Chang; Syu, Yong-En; Liao, Kuo-Hsiao; Tseng, Bae-Heng; Sze, Simon M.

2012-09-01

The tin-doped can supply conduction path to induce resistance switching behavior. However, the defect of tin-doped silicon oxide (Sn:SiOx) increased the extra leakage path lead to power consumption and joule heating degradation. In the study, supercritical CO2 fluids treatment was used to improve resistive switching property. The current conduction of high resistant state in post-treated Sn:SiOx film was transferred to Schottky emission from Frenkel-Poole due to the passivation effect. The molecular reaction model is proposed that the defect was passivated through dehydroxyl effect of supercritical fluid technology, verified by material analyses of x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.

Resolving Risks in Individual Astronauts: A New Paradigm for Critical Path Exposures

NASA Technical Reports Server (NTRS)

Richmond, Robert C.

2005-01-01

The limited number of astronauts available for risk-assessment prevents classic epidemiologic study, and thereby requires alternative approach to assessing risks within individual astronauts exposed to toxic agents identified within the Bioastronautics Critical Path Roadmap (BCPR). Developing a system of noninvasive real-time biodosimetry that provides large datasets for analyses before, during, and after missions for simultaneously determining 1) the kinds of toxic insult, 2) the degree of that insult, both within tissues absorbing that insult, would be usehl for resolving statistically significant risk-assessment in individual astronauts. Therefore, a currently achievable multiparametric paradigm is presented for use in analyzing gene-expression and protein-expression so as to establish predictive outcomes.

Crew procedures and workload of retrofit concepts for microwave landing system

NASA Technical Reports Server (NTRS)

Summers, Leland G.; Jonsson, Jon E.

1989-01-01

Crew procedures and workload for Microwave Landing Systems (MLS) that could be retrofitted into existing transport aircraft were evaluated. Two MLS receiver concepts were developed. One is capable of capturing a runway centerline and the other is capable of capturing a segmented approach path. Crew procedures were identified and crew task analyses were performed using each concept. Crew workload comparisons were made between the MLS concepts and an ILS baseline using a task-timeline workload model. Workload indexes were obtained for each scenario. The results showed that workload was comparable to the ILS baseline for the MLS centerline capture concept, but significantly higher for the segmented path capture concept.

Sorority Affiliation and Sexual Assault Victimization: Assessing Vulnerability Using Path Analysis.

PubMed

Franklin, Cortney A

2016-07-01

The current research used survey data from 282 college women to investigate the relationship between female Greek membership and sexual assault victimization. Drawing from routine activity theory, low self-control, and social learning theory, this study tested a theoretical model that identified pertinent factors present among sorority environments to determine the relationships between Greek affiliation and sexual assault. Path analyses revealed that sorority women reported consuming more alcohol and with greater frequency, increased risk-taking behavior, delayed assessments of threat and responses to risk, and increased contact with fraternity men-all of which significantly predicted sexual assault. Future theory, research, and policy directions are proposed. © The Author(s) 2015.

Geospatial analysis based on GIS integrated with LADAR.

PubMed

Fetterman, Matt R; Freking, Robert; Fernandez-Cull, Christy; Hinkle, Christopher W; Myne, Anu; Relyea, Steven; Winslow, Jim

2013-10-07

In this work, we describe multi-layered analyses of a high-resolution broad-area LADAR data set in support of expeditionary activities. High-level features are extracted from the LADAR data, such as the presence and location of buildings and cars, and then these features are used to populate a GIS (geographic information system) tool. We also apply line-of-sight (LOS) analysis to develop a path-planning module. Finally, visualization is addressed and enhanced with a gesture-based control system that allows the user to navigate through the enhanced data set in a virtual immersive experience. This work has operational applications including military, security, disaster relief, and task-based robotic path planning.

VLF Trimpi modelling on the path NWC-Dunedin using both finite element and 3D Born modelling

NASA Astrophysics Data System (ADS)

Nunn, D.; Hayakawa, K. B. M.

1998-10-01

This paper investigates the numerical modelling of VLF Trimpis, produced by a D region inhomogeneity on the great circle path. Two different codes are used to model Trimpis on the path NWC-Dunedin. The first is a 2D Finite Element Method Code (FEM), whose solutions are rigorous and valid in the strong scattering or non-Born limit. The second code is a 3D model that invokes the Born approximation. The predicted Trimpis from these codes compare very closely, thus confirming the validity of both models. The modal scattering matrices for both codes are analysed in some detail and are found to have a comparable structure. They indicate strong scattering between the dominant TM modes. Analysis of the scattering matrix from the FEM code shows that departure from linear Born behaviour occurs when the inhomogeneity has a horizontal scale size of about 100 km and a maximum electron density enhancement at 75 km altitude of about 6 electrons.

Neutron capture studies with a short flight path

NASA Astrophysics Data System (ADS)

Walter, Stephan; Heil, Michael; Käppeler, Franz; Plag, Ralf; Reifarth, René

The time of flight (TOF) method is an important tool for the experimental determination of neu- tron capture cross sections which are needed for s-process nucleosynthesis in general, and for analyses of branchings in the s-process reaction path in particular. So far, sample masses of at least several milligrams are required to compensate limitations in the currently available neutron fluxes. This constraint leads to unacceptable backgrounds for most of the relevant unstable branch point nuclei, due to the decay activity of the sample. A possible solution has been proposed by the NCAP project at the University of Frankfurt. A first step in this direction is reported here, which aims at enhancing the sensitivity of the Karlsruhe TOF array by reducing the neutron flight path to only a few centimeters. Though sample masses in the microgram regime can be used by this approach, the increase in neutron flux has to be paid by a higher background from the prompt flash related to neutron production. Test measurements with Au samples are reported.

Topological analysis of polymeric melts: chain-length effects and fast-converging estimators for entanglement length.

PubMed

Hoy, Robert S; Foteinopoulou, Katerina; Kröger, Martin

2009-09-01

Primitive path analyses of entanglements are performed over a wide range of chain lengths for both bead spring and atomistic polyethylene polymer melts. Estimators for the entanglement length N_{e} which operate on results for a single chain length N are shown to produce systematic O(1/N) errors. The mathematical roots of these errors are identified as (a) treating chain ends as entanglements and (b) neglecting non-Gaussian corrections to chain and primitive path dimensions. The prefactors for the O(1/N) errors may be large; in general their magnitude depends both on the polymer model and the method used to obtain primitive paths. We propose, derive, and test new estimators which eliminate these systematic errors using information obtainable from the variation in entanglement characteristics with chain length. The new estimators produce accurate results for N_{e} from marginally entangled systems. Formulas based on direct enumeration of entanglements appear to converge faster and are simpler to apply.

Predictors of science, technology, engineering, and mathematics choice options: A meta-analytic path analysis of the social-cognitive choice model by gender and race/ethnicity.

PubMed

Lent, Robert W; Sheu, Hung-Bin; Miller, Matthew J; Cusick, Megan E; Penn, Lee T; Truong, Nancy N

2018-01-01

We tested the interest and choice portion of social-cognitive career theory (SCCT; Lent, Brown, & Hackett, 1994) in the context of science, technology, engineering, and mathematics (STEM) domains. Data from 143 studies (including 196 independent samples) conducted over a 30-year period (1983 through 2013) were subjected to meta-analytic path analyses. The interest/choice model was found to fit the data well over all samples as well as within samples composed primarily of women and men and racial/ethnic minority and majority persons. The model also accounted for large portions of the variance in interests and choice goals within each path analysis. Despite the general predictive utility of SCCT across gender and racial/ethnic groups, we did find that several parameter estimates differed by group. We present both the group similarities and differences and consider their implications for future research, intervention, and theory refinement. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Delayed memory effects after intense stress in Special Forces candidates: exploring path processes between cortisol secretion and memory recall.

PubMed

Taverniers, John; Taylor, Marcus K; Smeets, Tom

2013-05-01

The aim of this paper is twofold. First, it explores delayed effects of high endogenously evoked cortisol concentrations on visuo-spatial declarative memory. Subsequently, it applies multiple mediation (MM) analyses to reveal path processes between stress and cognitive performance in a sample of 24 male Special Forces (SF) candidates (mean age = 27.0 years, SD = 4.1). The SF candidates were randomly assigned to a control (n = 12) or an intense stress group (n = 12), and cortisol secretion for the intense stress condition was triggered by a brusque 60 min prisoner of war exercise. Stress exposure provoked robust increases in cortisol concentrations and a significant decline in immediate recall performance, measured with the Rey-Osterrieth Complex Figure (ROCF). The relative retrieval differences in regard to the ROCF persisted even after a recovery period of 24 h, as both groups showed similar levels of memory decline over 24 h. Next, the study applied a MM design that involved distribution-independent asymptotic and resampling strategies to extend traditional bivariate analyses. MM results showed that ROCF performance was mediated by increases in cortisol concentrations. Considering the studied variables, the current analysis was the first to provide statistical support for the generally accepted thesis that cortisol secretion in itself, rather than subjective strain or the experimental treatment, affects cognitive performance. The revelation of such path processes is important because it establishes process identification and may refine existing paradigms.

WAIS-IV subtest covariance structure: conceptual and statistical considerations.

PubMed

Ward, L Charles; Bergman, Maria A; Hebert, Katina R

2012-06-01

D. Wechsler (2008b) reported confirmatory factor analyses (CFAs) with standardization data (ages 16-69 years) for 10 core and 5 supplemental subtests from the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV). Analyses of the 15 subtests supported 4 hypothesized oblique factors (Verbal Comprehension, Working Memory, Perceptual Reasoning, and Processing Speed) but also revealed unexplained covariance between Block Design and Visual Puzzles (Perceptual Reasoning subtests). That covariance was not included in the final models. Instead, a path was added from Working Memory to Figure Weights (Perceptual Reasoning subtest) to improve fit and achieve a desired factor pattern. The present research with the same data (N = 1,800) showed that the path from Working Memory to Figure Weights increases the association between Working Memory and Matrix Reasoning. Specifying both paths improves model fit and largely eliminates unexplained covariance between Block Design and Visual Puzzles but with the undesirable consequence that Figure Weights and Matrix Reasoning are equally determined by Perceptual Reasoning and Working Memory. An alternative 4-factor model was proposed that explained theory-implied covariance between Block Design and Visual Puzzles and between Arithmetic and Figure Weights while maintaining compatibility with WAIS-IV Index structure. The proposed model compared favorably with a 5-factor model based on Cattell-Horn-Carroll theory. The present findings emphasize that covariance model comparisons should involve considerations of conceptual coherence and theoretical adherence in addition to statistical fit. (c) 2012 APA, all rights reserved

A path analysis of gender differences in adolescent onset of alcohol, tobacco and other drug use (ATOD), reported ATOD use and adverse consequences of ATOD use.

PubMed

Thomas, B S

1996-01-01

Gender differences in the ways a risk factor approach explains onset of using alcohol, tobacco and other drugs (ATOD), reported use of ATOD and adverse consequences from ATOD use were investigated by means of separate path analyses for male and female adolescents. A fully recursive model was specified in which alienation, trait anger, interaction anxiety and cognitive motivation for ATOD use comprised the first column variables which were used to predict earliness of onset. For the second step, column one variables plus onset were used to predict ATOD use. In the final step, column one variables plus onset and ATOD use were used to predict adverse consequences of ATOD use. An ex post facto design was used in surveying 796 high school students in a single Midwestern community. The data from this sample supported the predictive validity of the theoretical model. In addition to the expected indirect or mediated effects of the risk factors via onset of ATOD use on ATOD use and via onset and ATOD use on adverse consequences of ATOD use, there were direct effects of column on risk factors on both ATOD use and on adverse consequences of ATOD use for both males and females, lending support to the concept of multiple pathway risk factors. The three gender differences that emerged in the separate path analyses were entirely consistent with the gendered deviance model.

The effect of the pore-fluid factor on strength and failure mechanism of Wilkeson sandstone

NASA Astrophysics Data System (ADS)

Kätker, A. K.; Rempe, M.; Renner, J.

2016-12-01

The effective stress law, σn,eff = σn - αpf, is a central tool in analysing phenomena related to hydromechanical coupling, such as fluid-induced seismicity or aftershock activity. The effective-stress coefficient α assumes different values for specific physical properties and may deviate from 1. The limited number of studies suggest that brittle compressive strength obeys an effective-stress law when effective drainage is achieved. Yet, open questions remain regarding, e.g., the role of the loading path. We performed suites of triaxial compression tests on samples of Wilkeson sandstone at a range of pore-fluid pressures but identical effective confining pressure (60, 100, and 120 MPa) maintaining the pore-fluid factor λ = pf / pc constant (0.05, 0.2, 0.4, 0.55) during the isostatic loading stage to ensure uniform loading paths. Samples were shortened with a strain rate of 4×10-7 s-1 yielding drained conditions. All tests were terminated at a total axial strain of 4.5% for comparability of microstructures. The tests also included continuous permeability determination and ultrasonic p-wave-velocity measurements to monitor microstructural evolution. Results from experiments conducted at peff = 100 MPa show that dry samples exhibit a higher peak strength and brittle failure while water-saturated samples tend to deform at lower stress by cataclastic flow indicating physico-chemical weakening. Regardless of pore-fluid factor, the saturated experiments exhibit similar peak and residual strength. Differences in failure mechanism (degree of macroscopic localization) and volumetric strain evolution are however noticed, albeit without systematic relation to pore-fluid factor. Microstructure analyses by optical and scanning electron microscopy revealed an evolution from localized shear zones in dry experiments and experiments with a low pore-fluid factor to rather distributed cataclastic flow for experiments with high pore fluid factors. Yet, mechanical and structural differences observed so far may result from sample-to-sample variability and the proximity of the experimental conditions to the brittle-ductile transition.

Effect of Carcass Traits on Carcass Prices of Holstein Steers in Korea

PubMed Central

Alam, M.; Cho, K. H.; Lee, S. S.; Choy, Y. H.; Kim, H. S.; Cho, C. I.; Choi, T. J.

2013-01-01

The present study investigated the contribution of carcass traits on carcass prices of Holstein steers in Korea. Phenotypic data consisted of 76,814 slaughtered Holsteins (1 to 6 yrs) from all over Korea. The means for live body weight at slaughter (BWT), chilled carcass weight (CWT), dressing percentage (DP), quantity grade index (QGI), eye muscle area (EMA), backfat thickness (BF) and marbling score (MS), carcass unit price (CUP), and carcass sell prices (CSP) were 729.0 kg, 414.2 kg, 56.79%, 64.42, 75.26 cm2, 5.77 mm, 1.98, 8,952.80 Korean won/kg and 3,722.80 Thousand Korean won/head. Least squares means were significantly different by various age groups, season of slaughter, marbling scores and yield grades. Pearson’s correlation coefficients of CUP with carcass traits ranged from 0.12 to 0.62. Besides, the relationships of carcass traits with CSP were relatively stronger than those with CUP. The multiple regression models for CUP and CSP with carcass traits accounted 39 to 63% of the total variation, respectively. Marbling score had maximum economic effects (partial coefficients) on both prices. In addition, the highest standardized partial coefficients (relative economic weights) for CUP and CSP were calculated to be on MS and CWT by 0.608 and 0.520, respectively. Path analyses showed that MS (0.376) and CWT (0.336) had maximum total effects on CUP and CSP, respectively; whereas BF contributed negatively. Further sub-group (age and season of slaughter) analyses also confirmed the overall outcomes. However, the relative economic weights and total path contributions also varied among the animal sub-groups. This study suggested the significant influences of carcass traits on carcass prices; especially MS and CWT were found to govern the carcass prices of Holstein steers in Korea. PMID:25049722

Simulation and validation of concentrated subsurface lateral flow paths in an agricultural landscape

NASA Astrophysics Data System (ADS)

Zhu, Q.; Lin, H. S.

2009-08-01

The importance of soil water flow paths to the transport of nutrients and contaminants has long been recognized. However, effective means of detecting concentrated subsurface flow paths in a large landscape are still lacking. The flow direction and accumulation algorithm based on single-direction flow algorithm (D8) in GIS hydrologic modeling is a cost-effective way to simulate potential concentrated flow paths over a large area once relevant data are collected. This study tested the D8 algorithm for simulating concentrated lateral flow paths at three interfaces in soil profiles in a 19.5-ha agricultural landscape in central Pennsylvania, USA. These interfaces were (1) the interface between surface plowed layers of Ap1 and Ap2 horizons, (2) the interface with subsoil water-restricting clay layer where clay content increased to over 40%, and (3) the soil-bedrock interface. The simulated flow paths were validated through soil hydrologic monitoring, geophysical surveys, and observable soil morphological features. The results confirmed that concentrated subsurface lateral flow occurred at the interfaces with the clay layer and the underlying bedrock. At these two interfaces, the soils on the simulated flow paths were closer to saturation and showed more temporally unstable moisture dynamics than those off the simulated flow paths. Apparent electrical conductivity in the soil on the simulated flow paths was elevated and temporally unstable as compared to those outside the simulated paths. The soil cores collected from the simulated flow paths showed significantly higher Mn content at these interfaces than those away from the simulated paths. These results suggest that (1) the D8 algorithm is useful in simulating possible concentrated subsurface lateral flow paths if used with appropriate threshold value of contributing area and sufficiently detailed digital elevation model (DEM); (2) repeated electromagnetic surveys can reflect the temporal change of soil water storage and thus is a useful indicator of possible subsurface flow path over a large area; and (3) observable Mn distribution in soil profiles can be used as a simple indicator of water flow paths in soils and over the landscape; however, it does require sufficient soil sampling (by excavation or augering) to possibly infer landscape-scale subsurface flow paths. In areas where subsurface interface topography varies similarly with surface topography, surface DEM can be used to simulate potential subsurface lateral flow path reasonably so the cost associated with obtaining depth to subsurface water-restricting layer can be minimized.

Total Solar Eclipse of 1999 August 11

NASA Technical Reports Server (NTRS)

Espenak, Fred; Anderson, Jay

1997-01-01

On 1999 August 11, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Eastern Hemisphere. The path of the Moon's umbral shadow begins in the Atlantic and crosses central Europe, the Middle East, and India, where it ends at sunset in the Bay of Bengal. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, all of Europe, northern Africa, and the western half of Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 1400 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

Amplitude and Phase Characteristics of Signals at the Output of Spatially Separated Antennas for Paths with Scattering

NASA Astrophysics Data System (ADS)

Anikin, A. S.

2018-06-01

Conditional statistical characteristics of the phase difference are considered depending on the ratio of instantaneous output signal amplitudes of spatially separated weakly directional antennas for the normal field model for paths with radio-wave scattering. The dependences obtained are related to the physical processes on the radio-wave propagation path. The normal model parameters are established at which the statistical characteristics of the phase difference depend on the ratio of the instantaneous amplitudes and hence can be used to measure the phase difference. Using Shannon's formula, the amount of information on the phase difference of signals contained in the ratio of their amplitudes is calculated depending on the parameters of the normal field model. Approaches are suggested to reduce the shift of phase difference measured for paths with radio-wave scattering. A comparison with results of computer simulation by the Monte Carlo method is performed.

Six paths for the future of social epidemiology.

PubMed

Galea, Sandro; Link, Bruce G

2013-09-15

Social epidemiology is now an accepted part of the academic intellectual landscape. However, in many ways, social epidemiology also runs the risk of losing the identity that distinguished it as a field during its emergence. In the present article, we scan the strengths of social epidemiology to imagine paths forward that will make the field distinct and useful to the understanding of population health in future. We suggest 6 paths to such a future, each emerging from promising research trends in the field in which social epidemiologists can, and should, lead in coming years. Each of these paths contributes to the formation of distinct capacities that social epidemiologists can claim and use to elaborate or fill in gaps in the already strong history of social epidemiology. They present an opportunity for the field to build on its strengths and move forward while leading in new and critical areas in population health.

Six Paths for the Future of Social Epidemiology

PubMed Central

Galea, Sandro; Link, Bruce G.

2013-01-01

Social epidemiology is now an accepted part of the academic intellectual landscape. However, in many ways, social epidemiology also runs the risk of losing the identity that distinguished it as a field during its emergence. In the present article, we scan the strengths of social epidemiology to imagine paths forward that will make the field distinct and useful to the understanding of population health in future. We suggest 6 paths to such a future, each emerging from promising research trends in the field in which social epidemiologists can, and should, lead in coming years. Each of these paths contributes to the formation of distinct capacities that social epidemiologists can claim and use to elaborate or fill in gaps in the already strong history of social epidemiology. They present an opportunity for the field to build on its strengths and move forward while leading in new and critical areas in population health. PMID:24008899

In-situ and path-averaged measurements of aerosol optical properties

NASA Astrophysics Data System (ADS)

van Binsbergen, Sven A.; Grossmann, Peter; February, Faith J.; Cohen, Leo H.; van Eijk, Alexander M. J.; Stein, Karin U.

2017-09-01

This paper compares in-situ and path-averaged measurements of the electro-optical transmission, with emphasis on aerosol effects. The in-situ sensors consisted of optical particle counters (OPC), the path-averaged data was provided by a 7-wavelength transmissometer (MSRT) and scintillometers (BLS). Data were collected at two sites: a homogeneous test site in Northern Germany, and over the inhomogeneous False Bay near Cape Town, South Africa. A retrieval algorithm was developed to infer characteristics of the aerosol size distribution (Junge approximation) from the MSRT data. A comparison of the various sensors suggests that the optical particle counters are over optimistic in their estimate of the transmission. For the homogeneous test site, in-situ and path-averaged sensors yield similar results. For the inhomogeneous test site, sensors may react differently or temporally separated to meteorological events such as a change in wind speed and/or direction.

Comparative Genomics Reveals High Genomic Diversity in the Genus Photobacterium

PubMed Central

Machado, Henrique; Gram, Lone

2017-01-01

Vibrionaceae is a large marine bacterial family, which can constitute up to 50% of the prokaryotic population in marine waters. Photobacterium is the second largest genus in the family and we used comparative genomics on 35 strains representing 16 of the 28 species described so far, to understand the genomic diversity present in the Photobacterium genus. Such understanding is important for ecophysiology studies of the genus. We used whole genome sequences to evaluate phylogenetic relationships using several analyses (16S rRNA, MLSA, fur, amino-acid usage, ANI), which allowed us to identify two misidentified strains. Genome analyses also revealed occurrence of higher and lower GC content clades, correlating with phylogenetic clusters. Pan- and core-genome analysis revealed the conservation of 25% of the genome throughout the genus, with a large and open pan-genome. The major source of genomic diversity could be traced to the smaller chromosome and plasmids. Several of the physiological traits studied in the genus did not correlate with phylogenetic data. Since horizontal gene transfer (HGT) is often suggested as a source of genetic diversity and a potential driver of genomic evolution in bacterial species, we looked into evidence of such in Photobacterium genomes. Genomic islands were the source of genomic differences between strains of the same species. Also, we found transposase genes and CRISPR arrays that suggest multiple encounters with foreign DNA. Presence of genomic exchange traits was widespread and abundant in the genus, suggesting a role in genomic evolution. The high genetic variability and indications of genetic exchange make it difficult to elucidate genome evolutionary paths and raise the awareness of the roles of foreign DNA in the genomic evolution of environmental organisms. PMID:28706512

Comparative Genomics Reveals High Genomic Diversity in the Genus Photobacterium.

PubMed

Machado, Henrique; Gram, Lone

2017-01-01

Vibrionaceae is a large marine bacterial family, which can constitute up to 50% of the prokaryotic population in marine waters. Photobacterium is the second largest genus in the family and we used comparative genomics on 35 strains representing 16 of the 28 species described so far, to understand the genomic diversity present in the Photobacterium genus. Such understanding is important for ecophysiology studies of the genus. We used whole genome sequences to evaluate phylogenetic relationships using several analyses (16S rRNA, MLSA, fur , amino-acid usage, ANI), which allowed us to identify two misidentified strains. Genome analyses also revealed occurrence of higher and lower GC content clades, correlating with phylogenetic clusters. Pan- and core-genome analysis revealed the conservation of 25% of the genome throughout the genus, with a large and open pan-genome. The major source of genomic diversity could be traced to the smaller chromosome and plasmids. Several of the physiological traits studied in the genus did not correlate with phylogenetic data. Since horizontal gene transfer (HGT) is often suggested as a source of genetic diversity and a potential driver of genomic evolution in bacterial species, we looked into evidence of such in Photobacterium genomes. Genomic islands were the source of genomic differences between strains of the same species. Also, we found transposase genes and CRISPR arrays that suggest multiple encounters with foreign DNA. Presence of genomic exchange traits was widespread and abundant in the genus, suggesting a role in genomic evolution. The high genetic variability and indications of genetic exchange make it difficult to elucidate genome evolutionary paths and raise the awareness of the roles of foreign DNA in the genomic evolution of environmental organisms.

Applications and development of new algorithms for displacement analysis using InSAR time series

NASA Astrophysics Data System (ADS)

Osmanoglu, Batuhan

Time series analysis of Synthetic Aperture Radar Interferometry (InSAR) data has become an important scientific tool for monitoring and measuring the displacement of Earth's surface due to a wide range of phenomena, including earthquakes, volcanoes, landslides, changes in ground water levels, and wetlands. Time series analysis is a product of interferometric phase measurements, which become ambiguous when the observed motion is larger than half of the radar wavelength. Thus, phase observations must first be unwrapped in order to obtain physically meaningful results. Persistent Scatterer Interferometry (PSI), Stanford Method for Persistent Scatterers (StaMPS), Short Baselines Interferometry (SBAS) and Small Temporal Baseline Subset (STBAS) algorithms solve for this ambiguity using a series of spatio-temporal unwrapping algorithms and filters. In this dissertation, I improve upon current phase unwrapping algorithms, and apply the PSI method to study subsidence in Mexico City. PSI was used to obtain unwrapped deformation rates in Mexico City (Chapter 3),where ground water withdrawal in excess of natural recharge causes subsurface, clay-rich sediments to compact. This study is based on 23 satellite SAR scenes acquired between January 2004 and July 2006. Time series analysis of the data reveals a maximum line-of-sight subsidence rate of 300mm/yr at a high enough resolution that individual subsidence rates for large buildings can be determined. Differential motion and related structural damage along an elevated metro rail was evident from the results. Comparison of PSI subsidence rates with data from permanent GPS stations indicate root mean square (RMS) agreement of 6.9 mm/yr, about the level expected based on joint data uncertainty. The Mexico City results suggest negligible recharge, implying continuing degradation and loss of the aquifer in the third largest metropolitan area in the world. Chapters 4 and 5 illustrate the link between time series analysis and three-dimensional (3-D) phase unwrapping. Chapter 4 focuses on the unwrapping path. Unwrapping algorithms can be divided into two groups, path-dependent and path-independent algorithms. Path-dependent algorithms use local unwrapping functions applied pixel-by-pixel to the dataset. In contrast, path-independent algorithms use global optimization methods such as least squares, and return a unique solution. However, when aliasing and noise are present, path-independent algorithms can underestimate the signal in some areas due to global fitting criteria. Path-dependent algorithms do not underestimate the signal, but, as the name implies, the unwrapping path can affect the result. Comparison between existing path algorithms and a newly developed algorithm based on Fisher information theory was conducted. Results indicate that Fisher information theory does indeed produce lower misfit results for most tested cases. Chapter 5 presents a new time series analysis method based on 3-D unwrapping of SAR data using extended Kalman filters. Existing methods for time series generation using InSAR data employ special filters to combine two-dimensional (2-D) spatial unwrapping with one-dimensional (1-D) temporal unwrapping results. The new method, however, combines observations in azimuth, range and time for repeat pass interferometry. Due to the pixel-by-pixel characteristic of the filter, the unwrapping path is selected based on a quality map. This unwrapping algorithm is the first application of extended Kalman filters to the 3-D unwrapping problem. Time series analyses of InSAR data are used in a variety of applications with different characteristics. Consequently, it is difficult to develop a single algorithm that can provide optimal results in all cases, given that different algorithms possess a unique set of strengths and weaknesses. Nonetheless, filter-based unwrapping algorithms such as the one presented in this dissertation have the capability of joining multiple observations into a uniform solution, which is becoming an important feature with continuously growing datasets.

Education and dementia in the context of the cognitive reserve hypothesis: a systematic review with meta-analyses and qualitative analyses.

PubMed

Meng, Xiangfei; D'Arcy, Carl

2012-01-01

Cognitive reserve (CR) or brain reserve capacity explains why individuals with higher IQ, education, or occupational attainment have lower risks of developing dementia, Alzheimer's disease (AD) or vascular dementia (VaD). The CR hypothesis postulates that CR reduces the prevalence and incidence of AD or VaD. It also hypothesizes that among those who have greater initial cognitive reserve (in contrast to those with less reserve) greater brain pathology occurs before the clinical symptoms of disease becomes manifest. Thus clinical disease onset triggers a faster decline in cognition and function, and increased mortality among those with initial greater cognitive reserve. Disease progression follows distinctly separate pathological and clinical paths. With education as a proxy we use meta-analyses and qualitative analyses to review the evidence for the CR hypothesis. We searched PubMed, PsycoINFO, EMBASE, HealthStar, and Scopus databases from January 1980 to June 2011 for observational studies with clear criteria for dementia, AD or VaD and education. One hundred and thirty-three articles with a variety of study designs met the inclusion criteria. Prevalence and incidence studies with odds ratios (ORs), relative risks or original data were included in the meta-analyses. Other studies were reviewed qualitatively. The studies covered 437,477 subjects. Prevalence and incidence studies with pooled ORs of 2.61 (95%CI 2.21-3.07) and 1.88 (95%CI 1.51-2.34) respectively, showed low education increased the risk of dementia. Heterogeneity and sensitivity tests confirmed the evidence. Generally, study characteristics had no effect on conclusions. Qualitative analyses also showed the protective effects of higher education on developing dementia and with clinical disease onset hastening a decline in cognition and function, and greater brain pathology. This systematic review and meta-analyses covering a wide range of observational studies and diverse settings provides robust support for the CR hypothesis. The CR hypothesis suggests several avenues for dementia prevention.

Are Tornadoes Getting Stronger?

NASA Astrophysics Data System (ADS)

Elsner, J.; Jagger, T.

2013-12-01

A cumulative logistic model for tornado damage category is developed and examined. Damage path length and width are significantly correlated to the odds of a tornado receiving the next highest damage category. Given values for the cube root of path length and square root of path width, the model predicts a probability for each category. The length and width coefficients are insensitive to the switch to the Enhanced Fujita (EF) scale and to distance from nearest city although these variables are statistically significant in the model. The width coefficient is sensitive to whether or not the tornado caused at least one fatality. This is likely due to the fact that the dimensions and characteristics of the damage path for such events are always based on ground surveys. The model predicted probabilities across the categories are then multiplied by the center wind speed from the categorical EF scale to obtain an estimate of the highest tornado wind speed on a continuous scale in units of meters per second. The estimated wind speeds correlate at a level of .82 (.46, .95) [95% confidence interval] to wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. More work needs to be done to understand the upward trends in path length and width. The increases lead to an apparent increase in tornado intensity across all EF categories.

Positive and negative social exchanges and cognitive aging in young-old adults: differential associations across family, friend, and spouse domains.

PubMed

Windsor, Tim D; Gerstorf, Denis; Pearson, Elissa; Ryan, Lindsay H; Anstey, Kaarin J

2014-03-01

We examined how positive and negative social exchanges with friends, family, and spouses were related to cognitive aging in episodic and working memory, and perceptual speed. To do so, we used a large sample of cognitively intact young-old participants from the PATH Through Life Study (PATH; aged 60 to 64 years at baseline, n = 1,618) who were assessed on 3 occasions over 8 years. Additional replication analyses were conducted using the Health and Retirement Study (HRS), which provided data on episodic memory. The main analysis of PATH Through Life showed that positive exchanges with friends and family were associated with less decline in perceptual speed, with these associations attenuated by adjustment for physical functioning and depressive symptoms. Negative exchanges with spouses were associated with poorer working memory performance. Positive exchanges with friends were associated with better initial episodic memory in both PATH and HRS. More frequent negative exchanges with friends and family were associated with better episodic memory in the PATH sample. However, these findings were not replicated in HRS. Our findings provide indirect support for the role of social exchange quality in contributing to cognitive enrichment. However, the inconsistent pattern of results across cognitive and social exchange domains points to possibilities of reverse causality, and may also indicate that social exchange quality plays a less important role for cognitive enrichment than other psychosocial characteristics. (c) 2014 APA, all rights reserved.

Path attenuation statistics influenced by orientation of rain cells

NASA Technical Reports Server (NTRS)

Goldhirsh, J.

1976-01-01

The influence of path azimuth on fade and space diversity statistics associated with propagation along earth-satellite paths at a frequency of 18 GHz is examined. A radar rain reflectivity data base obtained during the summer of 1973 is injected into a modeling program and the attenuation along parallel earth-satellite paths are obtained for a conglomeration of azimuths. Statistics are separated into two groupings: one pertaining to earth-satellite paths oriented in the northwest-southeast and the other in the northeast-southwest quadrants using a fixed elevation angle of 45 deg. The latter case shows fading to be greater with a degraded space diversity suggesting rain cells to be elongated along this direction. Cell dimensions are analyzed for both sets of quadrants and are found to have average values larger by 2 km in the northeast-southwest quadrants; a result consistent with the fade and space diversity results. Examination of the wind direction for the 14 rain days of data analyzed shows good correlation of the average or median wind directions with the directions of maximum fading and degraded space diversity.

Elevation effects in volcano applications of the COSPEC

USGS Publications Warehouse

Gerlach, T.M.

2003-01-01

Volcano applications commonly involve sizeable departures from the reference pressure and temperature of COSPEC calibration cells. Analysis shows that COSPEC SO2 column abundances and derived mass emission rates are independent of pressure and temperature, and thus unaffected by elevation effects related to deviations from calibration cell reference state. However, path-length concentrations are pressure and temperature dependent. Since COSPEC path-length concentration data assume the reference pressure and temperature of calibration cells, they can lead to large errors when used to calculate SO2 mixing ratios of volcanic plumes. Correction factors for COSPEC path-length concentrations become significant (c.10%) at elevations of about 1 km (e.g. Kilauea volcano) and rise rapidly to c.80% at 6 km (e.g. Cotopaxi volcano). Calculating SO2 mixing ratios for volcanic plumes directly from COSPEC path-length concentrations always gives low results. Corrections can substantially increase mixing ratios; for example, corrections increase SO2 ppm concentrations reported for the Mount St Helens, Colima, and Erebus plumes by 25-50%. Several arguments suggest it would be advantageous to calibrate COSPEC measurements in column abundance units rather than path-length concentration units.

Comparison of path visualizations and cognitive measures relative to travel technique in a virtual environment.

PubMed

Zanbaka, Catherine A; Lok, Benjamin C; Babu, Sabarish V; Ulinski, Amy C; Hodges, Larry F

2005-01-01

We describe a between-subjects experiment that compared four different methods of travel and their effect on cognition and paths taken in an immersive virtual environment (IVE). Participants answered a set of questions based on Crook's condensation of Bloom's taxonomy that assessed their cognition of the IVE with respect to knowledge, understanding and application, and higher mental processes. Participants also drew a sketch map of the IVE and the objects within it. The users' sense of presence was measured using the Steed-Usoh-Slater Presence Questionnaire. The participants' position and head orientation were automatically logged during their exposure to the virtual environment. These logs were later used to create visualizations of the paths taken. Path analysis, such as exploring the overlaid path visualizations and dwell data information, revealed further differences among the travel techniques. Our results suggest that, for applications where problem solving and evaluation of information is important or where opportunity to train is minimal, then having a large tracked space so that the participant can walk around the virtual environment provides benefits over common virtual travel techniques.

Longitudinal impact of the project PATHS on adolescent risk behavior: what happened after five years?

PubMed

Shek, Daniel T L; Yu, Lu

2012-01-01

The present study investigated the longitudinal impact of the Project PATHS, a large-scale curriculum-based positive youth development program in Hong Kong, on the development of adolescents' risk behavior over a period of five years. Using a longitudinal randomized controlled design, eight waves of data were collected from 19 experimental schools in which students participated in the Project PATHS (N = 2,850 at Wave 8) and 24 control schools without joining the Project PATHS (N = 3,640 at Wave 8). At each wave, students responded to measures assessing their current risk behaviors, including delinquency, use of different types of drug, and their intentions of participating in risk behaviors in the future. Results demonstrated that adolescents receiving the program exhibited significantly slower increases in delinquent behaviors and substance use as compared to the control participants. During two years after the completion of the program, differences in youth risk behaviors in the two groups still existed. These results suggest that the Project PATHS has long-term effect in preventing adolescent problem behavior through promoting positive youth development.

Volcanic eruption induced WWVB transmission path interruption

NASA Astrophysics Data System (ADS)

Buckmaster, H. A.; Hansen, C. H.

1985-07-01

It is reported that the 60 kHz transmission of WWVB from Fort Collins, Colorado, was not received in Calgary, Alberta, Canada, for about 11 h from 1109 UT to 2153 UT on July 23, 1980. It is suggested that this transmission path interruption is correlated with the 15 km height ash cloud due to the July 22, 1980 volcanic eruption of Mount St. Helens as it drifted eastward interrupting both the ground- and first hop sky-wave paths and that this ash cloud is the source of the conductivity and/or ionization necessary to produce this interruption. Small phase retardations are also reported which could be correlated with other Mount St. Helens volcanic events during May-July 1980.

Dry paths effectively reduce road mortality of small and medium-sized terrestrial vertebrates.

PubMed

Niemi, Milla; Jääskeläinen, Niina C; Nummi, Petri; Mäkelä, Tiina; Norrdahl, Kai

2014-11-01

Wildlife passages are widely used mitigation measures designed to reduce the adverse impacts of roads on animals. We investigated whether road kills of small and medium-sized terrestrial vertebrates can be reduced by constructing dry paths adjacent to streams that pass under road bridges. The study was carried out in southern Finland during the summer of 2008. We selected ten road bridges with dry paths and ten bridges without them, and an individual dry land reference site for each study bridge on the basis of landscape and traffic features. A total of 307 dead terrestrial vertebrates were identified during the ten-week study period. The presence of dry paths decreased the amount of road-killed terrestrial vertebrates (Poisson GLMM; p < 0.001). That was true also when considering amphibians alone (p < 0.001). The evidence on road-kills on mammals was not such clear. In the mammal model, a lack of dry paths increased the amount of carcasses (p = 0.001) whereas the number of casualties at dry path bridges was comparable with dry land reference sites. A direct comparison of the dead ratios suggests an average efficiency of 79% for the dry paths. When considering amphibians and mammals alone, the computed effectiveness was 88 and 70%, respectively. Our results demonstrate that dry paths under road bridges can effectively reduce road-kills of small and medium-sized terrestrial vertebrates, even without guiding fences. Dry paths seemed to especially benefit amphibians which are a threatened species group worldwide and known to suffer high traffic mortality. Copyright © 2014 Elsevier Ltd. All rights reserved.

Which way and how far? Tracking of translation and rotation information for human path integration.

PubMed

Chrastil, Elizabeth R; Sherrill, Katherine R; Hasselmo, Michael E; Stern, Chantal E

2016-10-01

Path integration, the constant updating of the navigator's knowledge of position and orientation during movement, requires both visuospatial knowledge and memory. This study aimed to develop a systems-level understanding of human path integration by examining the basic building blocks of path integration in humans. To achieve this goal, we used functional imaging to examine the neural mechanisms that support the tracking and memory of translational and rotational components of human path integration. Critically, and in contrast to previous studies, we examined movement in translation and rotation tasks with no defined end-point or goal. Navigators accumulated translational and rotational information during virtual self-motion. Activity in hippocampus, retrosplenial cortex (RSC), and parahippocampal cortex (PHC) increased during both translation and rotation encoding, suggesting that these regions track self-motion information during path integration. These results address current questions regarding distance coding in the human brain. By implementing a modified delayed match to sample paradigm, we also examined the encoding and maintenance of path integration signals in working memory. Hippocampus, PHC, and RSC were recruited during successful encoding and maintenance of path integration information, with RSC selective for tasks that required processing heading rotation changes. These data indicate distinct working memory mechanisms for translation and rotation, which are essential for updating neural representations of current location. The results provide evidence that hippocampus, PHC, and RSC flexibly track task-relevant translation and rotation signals for path integration and could form the hub of a more distributed network supporting spatial navigation. Hum Brain Mapp 37:3636-3655, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Organizational Predictors of Staff Stress, Satisfaction, and Intended Turnover in a Service for People with Multiple Disabilities.

ERIC Educational Resources Information Center

Hatton, Chris; Emerson, Eric

1993-01-01

Questionnaire data were collected from 64 direct-care staff members in a residential facility for people with multiple disabilities. Path analyses identified factors predicting levels of perceived stress, overall job satisfaction, overall life satisfaction, and perceived likelihood of leaving the organization. Factors included staff support, job…

Modernization of Russian Higher Education: Exploring Paths of Influence

ERIC Educational Resources Information Center

Gounko, Tatiana; Smale, William

2007-01-01

This article discusses the changes in Russian higher education policies and the role of international organizations--the World Bank and OECD--in promoting education reforms in this country. General and specific recommendations offered by the World Bank and the OECD expert teams to improve Russian higher education are analysed to determine if any…

Teaching as a Political Act: Critical Pedagogy in Library Instruction

ERIC Educational Resources Information Center

Fritch, Melia Erin

2018-01-01

This article establishes a theoretical framework for critical library instruction (and thereby critical information literacy) that is built upon critical feminist theory, critical race theory, and engaged pedagogy, among others. Using the ideas and work of theorists to create a path linking the ideas of critical analyses together, the author…

Autonomy-Mastery, Supportive or Performance Focused? Different Teacher Behaviours and Pupils' Outcomes in Physical Education

ERIC Educational Resources Information Center

Ommundsen, Yngvar; Kvalo, Silje Eikanger

2007-01-01

We investigated the role of motivational climates, teacher autonomy support, perceived competence and autonomy on pupils' self-regulated motivation in physical education (PE) classes of Norwegian 10th-graders. Path analyses revealed that a mastery climate and teacher autonomy support both (a) positively influenced intrinsically regulated…

Exploration of Individual Study Paths of Successful First-Year Students: An Interview Study

ERIC Educational Resources Information Center

Lindblom-Ylänne, Sari; Haarala-Muhonen, Anne; Postareff, Liisa; Hailikari, Telle

2017-01-01

The aim of the present study was to explore the individual profiles of successful, rapidly progressing first-year university students. The participants numbered 38 humanities and law students, who volunteered to be interviewed. The interview data were analysed using abductive content analysis. Two student profiles were distinguished:…

Differential Validation of a Path Analytic Model of University Dropout.

ERIC Educational Resources Information Center

Winteler, Adolf

Tinto's conceptual schema of college dropout forms the theoretical framework for the development of a model of university student dropout intention. This study validated Tinto's model in two different departments within a single university. Analyses were conducted on a sample of 684 college freshmen in the Education and Economics Department. A…

A State Level Investigation of the Associations among Intellectual Capital, Religiosity and Reproductive Health

ERIC Educational Resources Information Center

Reeve, Charlie L.; Basalik, Debra

2011-01-01

The current study examines the degree to which state intellectual capital, state religiosity and reproductive health form a meaningful nexus of ecological relations. Though the specific magnitude of effects vary across outcomes, results from hierarchical regression analyses were consistent with the hypothesized path model indicating that a state's…

Career Patterns: A Twenty-Year Panel Study

ERIC Educational Resources Information Center

Biemann, Torsten; Zacher, Hannes; Feldman, Daniel C.

2012-01-01

Using 20years of employment and job mobility data from a representative German sample (N = 1259), we employ optimal matching analysis (OMA) to identify six career patterns which deviate from the traditional career path of long-term, full-time employment in one organization. Then, in further analyses, we examine which socio-demographic predictors…

Mobley et al. Turnover Model Reanalysis and Review of Existing Data.

ERIC Educational Resources Information Center

Dalessio, Anthony; And Others

Job satisfaction has been identified as one of the most important antecedents of turnover, although it rarely accounts for more than 16% of the variance in employee withdrawal. Several data sets collected on the Mobley, Horner, and Hollingsworth (1978) model of turnover were reanalyzed with path analytic techniques. Data analyses revealed support…

Quality Assurance Policies and Practices in Scandinavian Higher Education Systems: Convergence or Different Paths?

ERIC Educational Resources Information Center

Kalpazidou Schmidt, Evanthia

2017-01-01

Because there is close cooperation on quality assurance in the Scandinavian countries, one would expect there to be convergence of quality assurance policies and practices in Scandinavian higher education. Few studies have analysed these quality assurance policies and practices from a comparative viewpoint. Based on empirical evidence produced in…

Effortful Control and Academic Achievement in Rural China

ERIC Educational Resources Information Center

Zhang, Li; Rao, Nirmala

2017-01-01

Research Findings: This study investigated the relationships between effortful control and early literacy and mathematics achievement. A total of 181 children (85 girls and 96 boys) from rural China were assessed when they were in Grades 1 and 2. Path analyses controlling for maternal education indicated that effortful control at the beginning of…

Students' Perspectives on University Experiences; The Role of Protective Factors in Students' Lives

ERIC Educational Resources Information Center

Jdaitawi, Malek; Maya-Panorama; Nawafleh, Ahmad; Nabrawi, Ismaeel; Talafha, Feras; Mohd, Amani

2013-01-01

This study examined the relationship between protective factors and students' university experiences among 289 first year university students. The study made use of exploratory and confirmatory factor analyses to reveal initial support for the research variables. In addition, path analysis was utilized to investigate the relationship among the…

Family Background and Educational Path of Italian Graduates

ERIC Educational Resources Information Center

Vergolini, Loris; Vlach, Eleonora

2017-01-01

In this paper, we analyse social inequalities along the horizontal dimension of education in Italy. More precisely, we focus on the role of family background in completing specific fields of study at both secondary and tertiary levels of education. To mitigate the limitations of the traditional sequential model, we construct a typology of…

Moderators of Youth Exercise Intention and Behavior

ERIC Educational Resources Information Center

Ellis, Rebecca; Kosma, Maria; Symons Downs, Danielle

2013-01-01

This study tested moderators of the theory of planned behavior (TPB) based on geographical region, gender, race, and income among adolescents in an exercise context using multigroup path analyses. Participants were eighth- and ninth-grade students from Louisiana (LA; N = 448, M[subscript age] = 14.37 years) and Pennsylvania (PA; N = 681,…

Factors of Role Conflict among Livestock Extension Professionals in Andhra Pradesh, India

ERIC Educational Resources Information Center

Sasidhar, P. V. K.; Rao, B. Sudhakar; Sreeramulu, Piedy

2008-01-01

To know the factors of role conflict among livestock extension professionals in Andhra Pradesh, India. Study was conducted following ex-post facto research design. Data were collected from 180 respondents through survey questionnaires. The data were subjected to multiple regression and path analyses to know the factors of role conflict.…

Path analyses of grain P, Zn, Cu, Fe, and Ni in a biosolids-amended dryland wheat agroecosystem

USDA-ARS?s Scientific Manuscript database

Biosolids land application is an effective means of recycling plant nutrients and is the preferred method of biosolids reuse by the US Environmental Protection Agency. One issue concerning biosolids application is the extent of the contribution of biosolids-borne plant nutrients to the overall crop...

The Utilization of Community Mental Health Services by the Hispanic Elderly.

ERIC Educational Resources Information Center

Starrett,Richard A.; And Others

Multiple regression and path analyses of 29 demographic, social, and psychological variables were carried out to determine those variables that influenced the use of community-based mental health services by the Hispanic elderly. The variables were classified using the Andersen and Newman framework which conceptualizes the individual's demand for…

Understanding Chinese American Adolescents' Developmental Outcomes: Insights from the Family Stress Model

ERIC Educational Resources Information Center

Benner, Aprile D.; Kim, Su Yeong

2010-01-01

In this brief report, we investigated whether the Family Stress Model could be replicated with a sample of Chinese American families. Path analyses with 444 adolescents and their parents provided support for the model's generalizability. Specifically, mothers' and fathers' reports of economic status (i.e., income, financial, and job instability)…

Intergenerational Relationship Quality, Gender, and Grandparent Involvement

ERIC Educational Resources Information Center

Barnett, Melissa A.; Scaramella, Laura V.; Neppl, Tricia K.; Ontai, Lenna; Conger, Rand D.

2010-01-01

This prospective, intergenerational study (N = 181) considered how parent (G1, Generation 1) and child (G2, Generation 2) relationship quality during adolescence and adulthood is associated with G1's level of involvement with their 3- to 4-year-old grandchildren (G3, Generation 3). Path model analyses indicated different patterns of results for…

Displaying the results of three-dimensional analysis using GRAPE. Part one: vector graphics. [In FORTRAN for CDC 7600

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

Brown, B.E.

1979-10-01

GRAPE is a display program for three-dimensional polygon and polyhedral models. It can produce line-drawing and continuous-tone black and white or color images in still frame or movie mode. The code was written specifically to be a post-processor for finite element and finite difference analyses. It runs on the CDC 7600 computer, and is compiled with the LLL FTN system. The allocation of storage is dynamic. There are presently three data paths into the code. The first is the binary inerface from the analyses codes and this with the other databases is described. The second data path is the SAMPPmore » format, and the last is the MOVIE format. The code structure is described first; then the commands are discussed in general terms to try to give the user some feel for what they do. The next section deals with the exact format of the commands by overlay. Then examples are given and discussed. Next, the various output options are covered. 57 figures. (RWR)« less

The Relationships Between Fatigue, Quality of Life, and Family Impact Among Children With Special Health Care Needs

PubMed Central

Anderson, Mary; Gandhi, Pranav; Tuli, Sanjeev; Krull, Kevin; Lai, Jin-Shei; Nackashi, John; Shenkman, Elizabeth

2013-01-01

Objective To examine the relationships among pediatric fatigue, health-related quality of life (HRQOL), and family impact among children with special health care needs (CSHCNs), specifically whether HRQOL mediates the influence of fatigue on family impact. Methods 266 caregivers of CSHCNs were studied. The Pediatric Quality of Life Inventory Multidimensional Fatigue Scale, Pediatric Quality of Life Inventory Generic Scale, and Impact on Family Scale were used to measure fatigue, HRQOL, and family impact, respectively. Linear regressions were used to analyze the designated relationships; path analyses were performed to quantify the mediating effects of HRQOL on fatigue–family impact relationship. Results Although greater fatigue was associated with family impact (p < .05), the association was not significant after accounting for HRQOL. Path analyses indicated the direct effect of fatigue on family impact was not significant (p > .05), whereas physical and emotional functioning significantly mediated the fatigue–family impact relationship (p < .001). Conclusion Fatigue is related to family impact among CSHCNs, acting through the impairment in HRQOL. PMID:23584707

A study of partial coherence for identifying interior noise sources and paths on general aviation aircraft

NASA Technical Reports Server (NTRS)

Howlett, J. T.

1979-01-01

The partial coherence analysis method for noise source/path determination is summarized and the application to a two input, single output system with coherence between the inputs is illustrated. The augmentation of the calculations on a digital computer interfaced with a two channel, real time analyzer is also discussed. The results indicate possible sources of error in the computations and suggest procedures for avoiding these errors.

Transitioning DARPA Technology

DTIC Science & Technology

2001-05-01

logo suggests, the Institute’s work reflects the summation of technology’s effects on business and government. With a reputation for fierce objectivity... effective for "customerpull" strategies. b. Products moved along the DIS path 30 percent of the time. This path was particularlysuccessful for small...must often be "waited out." But DARPA ha s few effective mechanisms for continuing to "market" its products after the prog ram is over- particularly

Mariner 9 navigation

NASA Technical Reports Server (NTRS)

Neil, W. J.; Jordan, J. F.; Zielenbach, J. W.; Wong, S. K.; Mitchell, R. T.; Webb, W. A.; Koskela, P. E.

1973-01-01

A final, comprehensive description of the navigation of Mariner 9-the first U.S. spacecraft to orbit another planet is provided. The Mariner 9 navigation function included not only precision flight path control but also pointing of the spacecraft's scientific instruments mounted on a two degree of freedom scan platform. To the extent appropriate, each section describes the perflight analyses on which the operational strategies and performance predictions were based. Inflight results are then discussed and compared with the preflight predictions. Postflight analyses, which were primarily concerned with developing a thorough understanding of unexpected in-flight results, are also presented.

Analyses of shuttle orbiter approach and landing conditions

NASA Technical Reports Server (NTRS)

Teper, G. L.; Dimarco, R. J.; Ashkenas, I. L.; Hoh, R. H.

1981-01-01

A study of one shuttle orbiter approach and landing conditions are summarized. Causes of observed PIO like flight deficiencies are identified and potential cures are examined. Closed loop pilot/vehicle analyses are described and path/attitude stability boundaries defined. The latter novel technique proved of great value in delineating and illustrating the basic causes of this multiloop pilot control problem. The analytical results are shown to be consistent with flight test and fixed base simulation. Conclusions are drawn relating to possible improvements of the shuttle orbiter/digital flight control system.

Effects of affective picture viewing on postural control.

PubMed

Stins, John F; Beek, Peter J

2007-10-04

Emotion theory holds that unpleasant events prime withdrawal actions, whereas pleasant events prime approach actions. Recent studies have suggested that passive viewing of emotion eliciting images results in postural adjustments, which become manifest as changes in body center of pressure (COP) trajectories. From those studies it appears that posture is modulated most when viewing pictures with negative valence. The present experiment was conducted to test the hypothesis that pictures with negative valence have a greater impact on postural control than neutral or positive ones. Thirty-four healthy subjects passively viewed a series of emotion eliciting images, while standing either in a bipedal or unipedal stance on a force plate. The images were adopted from the International Affective Picture System (IAPS). We analysed mean and variability of the COP and the length of the associated sway path as a function of emotion. The mean position of the COP was unaffected by emotion, but unipedal stance resulted in overall greater body sway than bipedal stance. We found a modest effect of emotion on COP: viewing pictures of mutilation resulted in a smaller sway path, but only in unipedal stance. We obtained valence and arousal ratings of the images with an independent sample of viewers. These subjects rated the unpleasant images as significantly less pleasant than neutral images, and the pleasant images as significantly more pleasant than neutral images. However, the subjects rated the images as overall less pleasant and less arousing than viewers in a closely comparable American study, pointing to unknown differences in viewer characteristics. Overall, viewing emotion eliciting images had little effect on body sway. Our finding of a reduction in sway path length when viewing pictures of mutilation was indicative of a freezing strategy, i.e. fear bradycardia. The results are consistent with current knowledge about the neuroanatomical organization of the emotion system and the neural control of behavior.

Effects of affective picture viewing on postural control

PubMed Central

Stins, John F; Beek, Peter J

2007-01-01

Background Emotion theory holds that unpleasant events prime withdrawal actions, whereas pleasant events prime approach actions. Recent studies have suggested that passive viewing of emotion eliciting images results in postural adjustments, which become manifest as changes in body center of pressure (COP) trajectories. From those studies it appears that posture is modulated most when viewing pictures with negative valence. The present experiment was conducted to test the hypothesis that pictures with negative valence have a greater impact on postural control than neutral or positive ones. Thirty-four healthy subjects passively viewed a series of emotion eliciting images, while standing either in a bipedal or unipedal stance on a force plate. The images were adopted from the International Affective Picture System (IAPS). We analysed mean and variability of the COP and the length of the associated sway path as a function of emotion. Results The mean position of the COP was unaffected by emotion, but unipedal stance resulted in overall greater body sway than bipedal stance. We found a modest effect of emotion on COP: viewing pictures of mutilation resulted in a smaller sway path, but only in unipedal stance. We obtained valence and arousal ratings of the images with an independent sample of viewers. These subjects rated the unpleasant images as significantly less pleasant than neutral images, and the pleasant images as significantly more pleasant than neutral images. However, the subjects rated the images as overall less pleasant and less arousing than viewers in a closely comparable American study, pointing to unknown differences in viewer characteristics. Conclusion Overall, viewing emotion eliciting images had little effect on body sway. Our finding of a reduction in sway path length when viewing pictures of mutilation was indicative of a freezing strategy, i.e. fear bradycardia. The results are consistent with current knowledge about the neuroanatomical organization of the emotion system and the neural control of behavior. PMID:17916245

Exploring the path of Mediterranean diet on 10-year incidence of cardiovascular disease: the ATTICA study (2002-2012).

PubMed

Panagiotakos, D B; Georgousopoulou, E N; Pitsavos, C; Chrysohoou, C; Skoumas, I; Pitaraki, E; Georgiopoulos, G A; Ntertimani, M; Christou, A; Stefanadis, C

2015-03-01

A Mediterranean diet has been associated with lower all-cause and cardiovascular disease (CVD) morbidity and mortality, but the clinical and behavioral pathway has not been well understood and appreciated. The aim of this work was to explore the path between adherence to a Mediterranean-type diet, lifestyle behaviors, clinical status, and a 10-year incidence of CVD. The ATTICA study was carried out in the Athens area during 2001-2002 and included 3042 participants free of CVD at baseline (49.8% men, aged 18-89). Adherence to a Mediterranean diet was assessed using the MedDietScore (range 0-55). During 2011-2012, 2583 out of the 3042 participants were found during the 10-year follow-up (15% lost to follow-up). Adherence to a Mediterranean diet decreased CVD risk (relative Risk (RR) per 1/55 unit = 0.96, 95% confidence interval (CI): 0.93, 1.00), independently of various sociodemographic, lifestyle, and clinical factors. Subgroup analyses revealed that participants with an unhealthy lifestyle (i.e., smokers, and obese and sedentary persons) remained protected from CVD through a greater adherence to a Mediterranean diet (RR for smokers = 0.92, 95%CI: 0.88, 0.97; RR for obese participants = 0.90, 95%CI: 0.82, 0.979; and RR for sedentary participants = 0.95, 95%CI: 0.90, 0.99). Path analysis revealed that adherence to a Mediterranean diet not only decreases the levels of C-reactive protein and interleukin-6 but also has an independent protective role against CVD risk per se (total effect of the MedDietScore on CVD = -0.003, 95%CI: -0.005 to 0.000). Adherence to a Mediterranean diet confers a considerable reduction on CVD risk, independent of various factors. Therefore, even subjects with unhealthy lifestyle behaviors may benefit from adherence to this diet, suggesting another dimension to prevention strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

Spatio-Temporal Structure, Path Characteristics, and Perceptual Grouping in Immediate Serial Spatial Recall

PubMed Central

De Lillo, Carlo; Kirby, Melissa; Poole, Daniel

2016-01-01

Immediate serial spatial recall measures the ability to retain sequences of locations in short-term memory and is considered the spatial equivalent of digit span. It is tested by requiring participants to reproduce sequences of movements performed by an experimenter or displayed on a monitor. Different organizational factors dramatically affect serial spatial recall but they are often confounded or underspecified. Untangling them is crucial for the characterization of working-memory models and for establishing the contribution of structure and memory capacity to spatial span. We report five experiments assessing the relative role and independence of factors that have been reported in the literature. Experiment 1 disentangled the effects of spatial clustering and path-length by manipulating the distance of items displayed on a touchscreen monitor. Long-path sequences segregated by spatial clusters were compared with short-path sequences not segregated by clusters. Recall was more accurate for sequences segregated by clusters independently from path-length. Experiment 2 featured conditions where temporal pauses were introduced between or within cluster boundaries during the presentation of sequences with the same paths. Thus, the temporal structure of the sequences was either consistent or inconsistent with a hierarchical representation based on segmentation by spatial clusters but the effect of structure could not be confounded with effects of path-characteristics. Pauses at cluster boundaries yielded more accurate recall, as predicted by a hierarchical model. In Experiment 3, the systematic manipulation of sequence structure, path-length, and presence of path-crossings of sequences showed that structure explained most of the variance, followed by the presence/absence of path-crossings, and path-length. Experiments 4 and 5 replicated the results of the previous experiments in immersive virtual reality navigation tasks where the viewpoint of the observer changed dynamically during encoding and recall. This suggested that the effects of structure in spatial span are not dependent on perceptual grouping processes induced by the aerial view of the stimulus array typically afforded by spatial recall tasks. These results demonstrate the independence of coding strategies based on structure from effects of path characteristics and perceptual grouping in immediate serial spatial recall. PMID:27891101

Electronic excited state paths of Stone-Wales rearrangement in pyrene: roles of conical intersections.

PubMed

Yamazaki, Kaoru; Niitsu, Naoyuki; Nakamura, Kosuke; Kanno, Manabu; Kono, Hirohiko

2012-11-26

We investigated the reaction paths of Stone-Wales rearrangement (SWR), i.e., π/2 rotation of two carbon atoms with respect to the midpoint of the bond, in graphene and carbon nanotube quantum chemically. Our particular attention is focused on the roles of electronic excitations and conical intersections (CIs) in the reaction mechanism. We used pyrene as a model system. The reaction paths were determined by constructing potential energy surfaces at the MS-CASPT2//SA-CASSCF level of theory. We found that there are no CIs involved in SWR when both of C-C bond cleavage and formation occur simultaneously (concerted mechanism). In contrast, for the reaction path with stepwise cleavage and formation of C-C bonds, C-C bond breaking and making processes proceed through two CIs. When SWR starts from the ground (S(0)) state, the concerted and stepwise paths have an equivalent reaction barrier ΔE(‡) (9.5-9.6 eV). For the reaction path starting from excited states, only the stepwise mechanism is energetically preferable. This path contains a nonadabatic transition between the S(1) and S(0) states via a CI associated with the first stage of C-C bond cleavage and has ΔE(‡) as large as in the S(0) paths. We confirmed that the main active molecular orbitals and electron configurations for the low-lying electronic states of larger nanocarbons are the same as those in pyrene. This result suggests the importance of the nonadiabatic transitions through CIs in the photochemical reactions in large nanocarbons.

Siblings versus parents and friends: longitudinal linkages to adolescent externalizing problems.

PubMed

Defoe, Ivy N; Keijsers, Loes; Hawk, Skyler T; Branje, Susan; Dubas, Judith Semon; Buist, Kirsten; Frijns, Tom; van Aken, Marcel A G; Koot, Hans M; van Lier, Pol A C; Meeus, Wim

2013-08-01

It is well documented that friends' externalizing problems and negative parent-child interactions predict externalizing problems in adolescence, but relatively little is known about the role of siblings. This four-wave, multi-informant study investigated linkages of siblings' externalizing problems and sibling-adolescent negative interactions on adolescents' externalizing problems, while examining and controlling for similar linkages with friends and parents. Questionnaire data on externalizing problems and negative interactions were annually collected from 497 Dutch adolescents (M = 13.03 years, SD = 0.52, at baseline), as well as their siblings, mothers, fathers, and friends. Cross-lagged panel analyses revealed modest unique longitudinal paths from sibling externalizing problems to adolescent externalizing problems, for male and female adolescents, and for same-sex and mixed-sex sibling dyads, but only from older to younger siblings. Moreover, these paths were above and beyond significant paths from mother-adolescent negative interaction and friend externalizing problems to adolescent externalizing problems, 1 year later. No cross-lagged paths existed between sibling-adolescent negative interaction and adolescent externalizing problems. Taken together, it appears that especially older sibling externalizing problems may be a unique social risk factor for adolescent externalizing problems, equal in strength to significant parents' and friends' risk factors. © 2013 The Authors. Journal of Child Psychology and Psychiatry © 2013 Association for Child and Adolescent Mental Health.

Siblings versus parents and friends: longitudinal linkages to adolescent externalizing problems

PubMed Central

Defoe, Ivy N; Keijsers, Loes; Hawk, Skyler T; Branje, Susan; Dubas, Judith Semon; Buist, Kirsten; Frijns, Tom; van Aken, Marcel AG; Koot, Hans M; van Lier, Pol AC; Meeus, Wim

2013-01-01

Background: It is well documented that friends’ externalizing problems and negative parent–child interactions predict externalizing problems in adolescence, but relatively little is known about the role of siblings. This four-wave, multi-informant study investigated linkages of siblings’ externalizing problems and sibling–adolescent negative interactions on adolescents’ externalizing problems, while examining and controlling for similar linkages with friends and parents. Methods: Questionnaire data on externalizing problems and negative interactions were annually collected from 497 Dutch adolescents (M = 13.03 years, SD = 0.52, at baseline), as well as their siblings, mothers, fathers, and friends. Results: Cross-lagged panel analyses revealed modest unique longitudinal paths from sibling externalizing problems to adolescent externalizing problems, for male and female adolescents, and for same-sex and mixed-sex sibling dyads, but only from older to younger siblings. Moreover, these paths were above and beyond significant paths from mother–adolescent negative interaction and friend externalizing problems to adolescent externalizing problems, 1 year later. No cross-lagged paths existed between sibling–adolescent negative interaction and adolescent externalizing problems. Conclusions: Taken together, it appears that especially older sibling externalizing problems may be a unique social risk factor for adolescent externalizing problems, equal in strength to significant parents’ and friends’ risk factors. PMID:23398022

Pre- and post-displacement stressors and time of migration as related to self-rated health among Iraqi immigrants and refugees in Southeast Michigan.

PubMed

Jamil, Hikmet; Nassar-McMillanb, Sylvia; Lambert, Richard; Wangd, Yun; Ager, Joel; Arnetz, Bengt

2010-01-01

The objective of this study was to determine whether perceived health status of Iraqi immigrants and refugees residing in the United States was related to pre-migration environmental stress, current unemployment, and if they had emigrated before or after the 1991 Gulf War. A random sample of Iraqis residing in Southeast Michigan, US, was interviewed using an Arab language structured survey. The main outcome measure was self-rated health (SRH). Major predictors included socioeconomics, employment status, pre-migration environmental stress, and health disorders. Path analysis was used to look at mediating effects between predictors and SRH. We found that SRH was significantly worse among participants that had left Iraq after the 1991 Gulf War. Unemployment and environmental stress exposure were inversely related to SRH. There was a direct path between Gulf War exposure and poor health. In addition, there were indirect paths mediated through psychosomatic and psychiatric disorders to SRH. Another path went from Gulf War exposure, via environmental stress and somatic health to poor health. Unemployment had a direct path, as well as indirect paths mediated through psychiatric and psychosomatic disorders, to poor self-rated health. In conclusion, these results suggest that pre- as well as post-migration factors, and period of migration, affect health.

The processing of spatial information in short-term memory: insights from eye tracking the path length effect.

PubMed

Guérard, Katherine; Tremblay, Sébastien; Saint-Aubin, Jean

2009-10-01

Serial memory for spatial locations increases as the distance between successive stimuli locations decreases. This effect, known as the path length effect [Parmentier, F. B. R., Elford, G., & Maybery, M. T. (2005). Transitional information in spatial serial memory: Path characteristics affect recall performance. Journal of Experimental Psychology: Learning, Memory & Cognition, 31, 412-427], was investigated in a systematic manner using eye tracking and interference procedures to explore the mechanisms responsible for the processing of spatial information. In Experiment 1, eye movements were monitored during a spatial serial recall task--in which the participants have to remember the location of spatially and temporally separated dots on the screen. In the experimental conditions, eye movements were suppressed by requiring participants to incessantly move their eyes between irrelevant locations. Ocular suppression abolished the path length effect whether eye movements were prevented during item presentation or during a 7s retention interval. In Experiment 2, articulatory suppression was combined with a spatial serial recall task. Although articulatory suppression impaired performance, it did not alter the path length effect. Our results suggest that rehearsal plays a key role in serial memory for spatial information, though the effect of path length seems to involve other processes located at encoding, such as the time spent fixating each location and perceptual organization.

Requirements for Next Generation Comprehensive Analysis of Rotorcraft

NASA Technical Reports Server (NTRS)

Johnson, Wayne; Data, Anubhav

2008-01-01

The unique demands of rotorcraft aeromechanics analysis have led to the development of software tools that are described as comprehensive analyses. The next generation of rotorcraft comprehensive analyses will be driven and enabled by the tremendous capabilities of high performance computing, particularly modular and scaleable software executed on multiple cores. Development of a comprehensive analysis based on high performance computing both demands and permits a new analysis architecture. This paper describes a vision of the requirements for this next generation of comprehensive analyses of rotorcraft. The requirements are described and substantiated for what must be included and justification provided for what should be excluded. With this guide, a path to the next generation code can be found.

Does the Effect of Micro-Environmental Factors on a Street's Appeal for Adults' Bicycle Transport Vary across Different Macro-Environments? An Experimental Study.

PubMed

Mertens, Lieze; Van Cauwenberg, Jelle; Ghekiere, Ariane; Van Holle, Veerle; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Nasar, Jack; Van de Weghe, Nico; Van Dyck, Delfien

2015-01-01

Characteristics of the physical environment can be classified into two broad categories: macro- ("raw" urban planning features influenced on a regional level) and micro- (features specifically within a streetscape influenced on a neighborhood level) environmental factors. In urban planning applications, it is more feasible to modify conditions at the neighborhood level than at the regional level. Yet for the promotion of bicycle transport we need to know whether relationships between micro-environmental factors and bicycle transport depend on different types of macro-environments. This study aimed to identify whether the effect of three micro-environmental factors (i.e., evenness of the cycle path surface, speed limits and type of separation between cycle path and motorized traffic) on the street's appeal for adults' bicycle transport varied across three different macro-environments (i.e., low, medium and high residential density street). In total, 389 middle-aged adults completed a web-based questionnaire consisting of socio-demographic characteristics and a series of choice tasks with manipulated photographs, depicting two possible routes to cycle along. Conjoint analysis was used to analyze the data. Although the magnitude of the overall effects differed, in each macro-environment (i.e., low, medium and high residential density), middle-aged adults preferred a speed limit of 30 km/h, an even cycle path surface and a hedge as separation between motorized traffic and the cycle path compared to a speed limit of 50 or 70 km/h, a slightly uneven or uneven cycle path surface and a curb as separation or no separation between motorized traffic and the cycle path. Our results suggest that irrespective of the macro-environment, the same micro-environmental factors are preferred in middle-aged adults concerning the street's appeal for bicycle transport. The controlled environment simulations in the experimental choice task have the potential to inform real life environmental interventions and suggest that micro-environmental changes can have similar results in different macro-environments.

Interactive multi-objective path planning through a palette-based user interface

NASA Astrophysics Data System (ADS)

Shaikh, Meher T.; Goodrich, Michael A.; Yi, Daqing; Hoehne, Joseph

2016-05-01

n a problem where a human uses supervisory control to manage robot path-planning, there are times when human does the path planning, and if satisfied commits those paths to be executed by the robot, and the robot executes that plan. In planning a path, the robot often uses an optimization algorithm that maximizes or minimizes an objective. When a human is assigned the task of path planning for robot, the human may care about multiple objectives. This work proposes a graphical user interface (GUI) designed for interactive robot path-planning when an operator may prefer one objective over others or care about how multiple objectives are traded off. The GUI represents multiple objectives using the metaphor of an artist's palette. A distinct color is used to represent each objective, and tradeoffs among objectives are balanced in a manner that an artist mixes colors to get the desired shade of color. Thus, human intent is analogous to the artist's shade of color. We call the GUI an "Adverb Palette" where the word "Adverb" represents a specific type of objective for the path, such as the adverbs "quickly" and "safely" in the commands: "travel the path quickly", "make the journey safely". The novel interactive interface provides the user an opportunity to evaluate various alternatives (that tradeoff between different objectives) by allowing her to visualize the instantaneous outcomes that result from her actions on the interface. In addition to assisting analysis of various solutions given by an optimization algorithm, the palette has additional feature of allowing the user to define and visualize her own paths, by means of waypoints (guiding locations) thereby spanning variety for planning. The goal of the Adverb Palette is thus to provide a way for the user and robot to find an acceptable solution even though they use very different representations of the problem. Subjective evaluations suggest that even non-experts in robotics can carry out the planning tasks with a great deal of flexibility using the adverb palette.

Quantifying spatial misclassification in exposure to noise complaints among low-income housing residents across New York City neighborhoods: a Global Positioning System (GPS) study.

PubMed

Duncan, Dustin T; Tamura, Kosuke; Regan, Seann D; Athens, Jessica; Elbel, Brian; Meline, Julie; Al-Ajlouni, Yazan A; Chaix, Basile

2017-01-01

To examine if there was spatial misclassification in exposure to neighborhood noise complaints among a sample of low-income housing residents in New York City, comparing home-based spatial buffers and Global Positioning System (GPS) daily path buffers. Data came from the community-based NYC Low-Income Housing, Neighborhoods and Health Study, where GPS tracking of the sample was conducted for a week (analytic n = 102). We created a GPS daily path buffer (a buffering zone drawn around GPS tracks) of 200 m and 400 m. We also used home-based buffers of 200 m and 400 m. Using these "neighborhoods" (or exposure areas), we calculated neighborhood exposure to noisy events from 311 complaints data (analytic n = 143,967). Friedman tests (to compare overall differences in neighborhood definitions) were applied. There were differences in neighborhood noise complaints according to the selected neighborhood definitions (P < .05). For example, the mean neighborhood noise complaint count was 1196 per square kilometer for the 400-m home-based and 812 per square kilometer for the 400-m activity space buffer, illustrating how neighborhood definition influences the estimates of exposure to neighborhood noise complaints. These analyses suggest that, whenever appropriate, GPS neighborhood definitions can be used in spatial epidemiology research in spatially mobile populations to understand people's lived experience. Copyright © 2016 Elsevier Inc. All rights reserved.

Acculturation, Social Self-Control, and Substance Use Among Hispanic Adolescents

PubMed Central

Pokhrel, Pallav; Herzog, Thaddeus A.; Sun, Ping; Rohrbach, Louise A.; Sussman, Steve

2014-01-01

It is unclear how acculturation is related to self-control characteristics and whether part of the effect of acculturation on Hispanic adolescents’ substance use behavior is mediated through lower self-control. We tested social self-control, peer substance use, and baseline substance use as mediators of the effect of Hispanic (predominantly Mexican or Mexican American) adolescents’ level of U.S. acculturation on their substance use behavior 1 year later. In addition, we tested gender as a possible moderator of the pathways involved in the mediation model. Participants included 1,040 self-identified Hispanic/Latino adolescents (M = 14.7; SD = 0.90; 89% Mexican/Mexican American) recruited from nine public high schools. Acculturation was measured in terms of adolescents’ extent of English language use in general, at home, with friends, and their use of the English-language entertainment media. Analyses were conducted using structural equation modeling and controlled for potential confounders such as age and parental education. Results indicated a statistically significant three-path mediation in which poor social self-control and peer substance use mediated the effects of acculturation on prospective substance use. Paths in the mediation model were not found to differ by gender. Our findings suggest that acculturation may influence adolescents’ self-control characteristics related to interpersonal functioning, which may in turn influence their affiliation with substance-using friends and substance use behavior. Implications of the findings are discussed in terms of future research and prevention programming. PMID:23772765

Using GPS telemetry to determine roadways most susceptible to deer-vehicle collisions

USGS Publications Warehouse

Kramer, David W.; Prebyl, Thomas J.; Stickles, James H.; Osborn, David A.; Irwin, Brian J.; Nibbelink, Nathan P.; Warren, Robert J.; Miller, Karl V.

2016-01-01

More than 1 million wildlife-vehicle collisions occur annually in the United States. The majority of these accidents involve white-tailed deer (Odocoileus virginianus) and result in >US $4.6 billion in damage and >200 human fatalities. Prior research has used collision locations to assess sitespecific as well as landscape features that contribute to risk of deer-vehicle collisions. As an alternative approach, we calculated road-crossing locations from 25 GPS-instrumented white-tailed deer near Madison, Georgia (n=154,131 hourly locations). We identified crossing locations by creating movement paths between subsequent GPS points and then intersecting the paths with road locations. Using AIC model selection, we determined whether 10 local and landscape variables were successful at identifying areas where higher frequencies of deer crossings were likely to occur. Our findings indicate that traffic volume, distance to riparian areas, and the amount of forested area influenced the frequency of road crossings. Roadways that were predominately located in wooded landscapes and 200–300 m from riparian areas were crossed frequently. Additionally, we found that areas of low traffic volume (e.g., county roads) had the highest frequencies of deer crossings. Analyses utilizing only records of deer-vehicle collision locations cannot separate the relative contribution of deer crossing rates and traffic volume. Increased frequency of road crossings by deer in low-traffic, forested areas may lead to a greater risk of deer-vehicle collision than suggested by evaluations of deer-vehicle collision frequency alone.

Mediation of an efficacious HIV risk reduction intervention for South African men.

PubMed

O'Leary, Ann; Jemmott, John B; Jemmott, Loretta S; Bellamy, Scarlett; Icard, Larry D; Ngwane, Zolani

2015-10-01

"Men, Together Making a Difference!" is an HIV/STD risk-reduction intervention that significantly increased self-reported consistent condom use during vaginal intercourse compared with a health-promotion attention-control intervention among men (N = 1181) in Eastern Cape Province, South Africa. The present analyses were designed to identify mediators of the intervention's efficacy. The potential mediators were Social Cognitive Theory (SCT) constructs that the intervention targeted, including several aspects of condom-use self-efficacy, outcome expectancies, and knowledge. Mediation was assessed using a product-of-coefficients approach where an α path (the intervention's effect on the potential mediator) and a β path (the potential mediator's effect on the outcome of interest, adjusting for intervention) were estimated independently in a generalized estimating equations framework. Condom-use negotiation self-efficacy, technical-skill self-efficacy, and impulse-control self-efficacy were significant mediators. Although not mediators, descriptive norm and expected friends' approval of condom use predicted subsequent self-reported condom use, whereas the expected approval of sexual partner did not. The present results suggest that HIV/STD risk-reduction interventions that draw upon SCT and that address self-efficacy to negotiate condom use, to apply condoms correctly, and to exercise sufficient control when sexually aroused to use condoms may contribute to efforts to reduce sexual risk behavior among South African men. Future research must examine whether approaches that build normative support for condom use among men's friends are also efficacious.

Gender differences in caregiver-child relationship mediation of the association between violence exposure severity and adolescent behavior problems.

PubMed

Yoon, Susan; Kobulsky, Julia M; Voith, Laura A; Steigerwald, Stacey; Holmes, Megan R

2015-12-01

The main objectives of this study were to investigate (1) the relationship between mild, moderate, and severe violence exposure in the home and behavior problems in adolescents; (2) the caregiver-child relationship as a potential mediator in this relationship; and (3) gender differences. A series of path analyses were conducted using a sample drawn from the National Survey of Child and Adolescent Well-Being (NCSAW-I) of 848 adolescents (ages 11-15) who had been reported to Child Protective Services for maltreatment and who remained in their homes. Exposure to violence and the caregiver-child relationship were reported by adolescents. Both caregiver ratings and adolescent self-reports were used to assess adolescents' behavior problems. Path analysis indicated that exposure to mild and severe violence was directly associated with higher levels of child-reported behavior problems. However, exposure to violence was not directly associated with caregiver ratings of adolescent behavior problems. The caregiver-child relationship mediated the relationship between mild and moderate violence on both caregiver and child-reported adolescent behavior problems. Gender differences also emerged; for girls, the caregiver-child relationship mediated the effects of mild and moderate violence, whereas for boys, it mediated the effects of severe violence on behavior problems. Study findings suggest caregiver-child relationships as a critical underlying mechanism in the association between violence exposure and adolescent behavior problems, highlighting the importance of adding the caregiver-child relationship factor to intervention efforts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of fears of compassion on body image shame and disordered eating.

PubMed

Dias, Bernardo Santos; Ferreira, Cláudia; Trindade, Inês A

2018-06-07

The current study tested a path model examining the impact of fears of compassion in the adoption of disordered eating and whether social safeness and body shame would mediate this relationship. Participants were 645 women (aged between 18 and 55) from the general community, who completed an online survey. Results indicated that fears of compassion were negatively associated with one's ability to feel secure and safe within close relationships, and positively linked with higher levels of body shame and disordered eating. The tested model accounted for 62% of the variance of disordered eating. Path analyses results revealed that the three dimensions of fears of compassion impacted on disordered eating. Particularly, fear of expressing compassion for others presented a direct impact on disordered eating. Moreover, fears of self-compassion and fears of receiving compassion from others partially impacted on disordered eating attitudes and behaviours, through the mechanisms of social safeness and body image-focused shame. These findings suggested that women who present higher levels of fear of self-compassion and of receiving signs of affection and compassion from others tend to feel more insecure in their social group, which seem explain body shame and the engagement in disordered eating behaviours. This study highlights the pathogenic impact of fears of compassion on body image and eating attitudes and behaviours. The current data seem to offer relevant insights for research and clinical practice, by supporting the relevance of developing compassionate abilities and attitudes to target body image and eating-related difficulties.

Elevated temperature crack growth

NASA Technical Reports Server (NTRS)

Kim, K. S.; Vanstone, R. H.

1992-01-01

The purpose of this program was to extend the work performed in the base program (CR 182247) into the regime of time-dependent crack growth under isothermal and thermal mechanical fatigue (TMF) loading, where creep deformation also influences the crack growth behavior. The investigation was performed in a two-year, six-task, combined experimental and analytical program. The path-independent integrals for application to time-dependent crack growth were critically reviewed. The crack growth was simulated using a finite element method. The path-independent integrals were computed from the results of finite-element analyses. The ability of these integrals to correlate experimental crack growth data were evaluated under various loading and temperature conditions. The results indicate that some of these integrals are viable parameters for crack growth prediction at elevated temperatures.

Effect of equilibration on primitive path analyses of entangled polymers.

PubMed

Hoy, Robert S; Robbins, Mark O

2005-12-01

We use recently developed primitive path analysis (PPA) methods to study the effect of equilibration on entanglement density in model polymeric systems. Values of Ne for two commonly used equilibration methods differ by a factor of 2-4 even though the methods produce similar large-scale chain statistics. We find that local chain stretching in poorly equilibrated samples increases entanglement density. The evolution of Ne with time shows that many entanglements are lost through fast processes such as chain retraction as the local stretching relaxes. Quenching a melt state into a glass has little effect on Ne. Equilibration-dependent differences in short-scale structure affect the craze extension ratio much less than expected from the differences in PPA values of Ne.

The link between employee attitudes and employee effectiveness: Data matrix of meta-analytic estimates based on 1161 unique correlations.

PubMed

Mackay, Michael M

2016-09-01

This article offers a correlation matrix of meta-analytic estimates between various employee job attitudes (i.e., Employee engagement, job satisfaction, job involvement, and organizational commitment) and indicators of employee effectiveness (i.e., Focal performance, contextual performance, turnover intention, and absenteeism). The meta-analytic correlations in the matrix are based on over 1100 individual studies representing over 340,000 employees. Data was collected worldwide via employee self-report surveys. Structural path analyses based on the matrix, and the interpretation of the data, can be found in "Investigating the incremental validity of employee engagement in the prediction of employee effectiveness: a meta-analytic path analysis" (Mackay et al., 2016) [1].

A human factors framework and study of the effect of nursing workload on patient safety and employee quality of working life

PubMed Central

Holden, Richard J.; Scanlon, Matthew C.; Patel, Neal R.; Kaushal, Rainu; Escoto, Kamisha Hamilton; Brown, Roger L.; Alper, Samuel J.; Arnold, Judi M.; Shalaby, Theresa M.; Murkowski, Kathleen; Karsh, Ben-Tzion

2010-01-01

Backgrounds Nursing workload is increasingly thought to contribute to both nurses’ quality of working life and quality/safety of care. Prior studies lack a coherent model for conceptualizing and measuring the effects of workload in health care. In contrast, we conceptualized a human factors model for workload specifying workload at three distinct levels of analysis and having multiple nurse and patient outcomes. Methods To test this model, we analyzed results from a cross-sectional survey of a volunteer sample of nurses in six units of two academic tertiary care pediatric hospitals. Results Workload measures were generally correlated with outcomes of interest. A multivariate structural model revealed that: the unit-level measure of staffing adequacy was significantly related to job dissatisfaction (path loading = .31) and burnout (path loading = .45); the task-level measure of mental workload related to interruptions, divided attention, and being rushed was associated with burnout (path loading = .25) and medication error likelihood (path loading = 1.04). Job-level workload was not uniquely and significantly associated with any outcomes. Discussion The human factors engineering model of nursing workload was supported by data from two pediatric hospitals. The findings provided a novel insight into specific ways that different types of workload could affect nurse and patient outcomes. These findings suggest further research and yield a number of human factors design suggestions. PMID:21228071

Drone based structural mapping at Holuhraun indicates fault reactivation and complexity

NASA Astrophysics Data System (ADS)

Mueller, Daniel; Walter, Thomas R.; Steinke, Bastian; Witt, Tanja; Schoepa, Anne; Duerig, Tobi; Gudmundsson, Magnus T.

2016-04-01

Accompanied by an intense seismic swarm in August 2014, a dike laterally formed, starting under Icelands Vatnajökull glacier, propagating over a distance of more than 45 km within only two weeks, leading to the largest eruption by volume since the 1783-84 Laki eruption. Along its propagation path, the dike caused intense surface displacements up to meters. Based on seismicity, GPS and InSAR, the propagation has already been analysed and described as segmented lateral dike growth. We now focus on few smaller regions of the dike. We consider the Terrasar-X tandem digital elevation map and aerial photos and find localized zones where structural fissures formed and curved. At these localized, regions we performed a field campaign in summer 2015, applying the close range remote sensing techniques Structure from Motion (SfM) and Terrestrial Laser Scanning (TLS). Over 4 TLS scan were collected, along with over 5,000 aerial images. Point clouds from SfM and TLS are merged and compared, and local structural lineaments analysed. As a result, we obtained an unprecedentedly high-resolution digital elevation map. With this map, we analyse the structural expression of the fissure eruption at the surface and improve understanding on the conditions that influenced the magma propagation path. We elaborate scenarios that lead to complexities of the surface structures and the link to the underlying dike intrusion.

Efficacy-mediated effects of spirituality and physical activity on quality of life: A path analysis

PubMed Central

2012-01-01

Background Physical activity has been established as an important determinant of quality of life, particularly among older adults. Previous research has suggested that physical activity’s influence on quality of life perceptions is mediated by changes in self-efficacy and health status. In the same vein, spirituality may be a salient quality of life determinant for many individuals. Methods In the current study, we used path analysis to test a model in which physical activity, spirituality, and social support were hypothesized to influence global quality of life in paths mediated by self-efficacy and health status. Cross-sectional data were collected from a sample of 215 adults (male, n = 51; female, n = 164) over the age of 50 (M age = 66.55 years). Results The analysis resulted in a model that provided acceptable fit to the data (χ2 = 33.10, df = 16, p < .01; RMSEA = .07; SRMR = .05; CFI = .94). Conclusions These results support previous findings of an efficacy-mediated relationship between physical activity and quality of life, with the exception that self-efficacy in the current study was moderately associated with physical health status (.38) but not mental health status. Our results further suggest that spirituality may influence health and well-being via a similar, efficacy-mediated path, with strongest effects on mental health status. These results suggest that those who are more spiritual and physically active report greater quality of life, and the effects of these factors on quality of life may be partially mediated by perceptions of self-efficacy. PMID:22642832

An expansion of glider observation strategies to systematically transmit and analyze preferred waypoints of underwater gliders

NASA Astrophysics Data System (ADS)

Smedstad, Lucy F.; Barron, Charlie N.; Bourg, Rachel N.; Brooking, Michael W.; Bryant, Danielle A.; Carr, Robert J.; Heaney, Kevin D.; Holmberg, Edward A.; Mask, Andrea C.; Mensi, Bryan L.

2015-05-01

The Glider Observation STrategies (GOST) system provides real-time assistance to ocean glider pilots by suggesting preferred ocean glider waypoints based on ocean forecasts and their uncertainties. Restrictions on waterspace, preferred operational areas, and other glider trajectories are also taken into account. Using existing operational regional Navy Coastal Ocean Model (RNCOM) output, demonstrations of glider waypoint calculation are ongoing in Navy operational areas. After the ocean forecast models and GOST components run at the Navy DoD Supercomputing Resource Center (Navy DSRC), GOST-suggested glider paths are transferred to the Glider Operations Center (GOC). The glider pilots at the GOC import this information into their Unmanned Systems Interface (USI), developed at the University of Washington, Applied Physics Laboratory (APL-UW) to evaluate the suggested glider paths, make adjustments, and update waypoints for the gliders. The waypoints being sent are visualized and analyzed using graphic capabilities to convey guidance uncertainty developed under a grant to the University of New Orleans (UNO) and added under the Environmental Measurements Path Planner (EMPath) system within GOST. USI forwards automatic messages from the gliders with recent glider location, speed, and depth to GOST for the next cycle. Over the course of these demonstrations, capabilities were added or modified including use of initial glider bearing, preferred path, refinement of glider turn frequency, correction of glider speed, and introduction of glider rendezvous locations. Automation has been added with help from the modeling group at the Naval Oceanographic Office (NAVOCEANO). GOST supports NAVOCEANO's ongoing efforts to direct and recover gliders, to safely navigate in changing ocean conditions, and to provide feedback to improve ocean model prediction.

Cirrus cloud retrieval with MSG/SEVIRI using artificial neural networks

NASA Astrophysics Data System (ADS)

Strandgren, Johan; Bugliaro, Luca; Sehnke, Frank; Schröder, Leon

2017-09-01

Cirrus clouds play an important role in climate as they tend to warm the Earth-atmosphere system. Nevertheless their physical properties remain one of the largest sources of uncertainty in atmospheric research. To better understand the physical processes of cirrus clouds and their climate impact, enhanced satellite observations are necessary. In this paper we present a new algorithm, CiPS (Cirrus Properties from SEVIRI), that detects cirrus clouds and retrieves the corresponding cloud top height, ice optical thickness and ice water path using the SEVIRI imager aboard the geostationary Meteosat Second Generation satellites. CiPS utilises a set of artificial neural networks trained with SEVIRI thermal observations, CALIOP backscatter products, the ECMWF surface temperature and auxiliary data. CiPS detects 71 and 95 % of all cirrus clouds with an optical thickness of 0.1 and 1.0, respectively, that are retrieved by CALIOP. Among the cirrus-free pixels, CiPS classifies 96 % correctly. With respect to CALIOP, the cloud top height retrieved by CiPS has a mean absolute percentage error of 10 % or less for cirrus clouds with a top height greater than 8 km. For the ice optical thickness, CiPS has a mean absolute percentage error of 50 % or less for cirrus clouds with an optical thickness between 0.35 and 1.8 and of 100 % or less for cirrus clouds with an optical thickness down to 0.07 with respect to the optical thickness retrieved by CALIOP. The ice water path retrieved by CiPS shows a similar performance, with mean absolute percentage errors of 100 % or less for cirrus clouds with an ice water path down to 1.7 g m-2. Since the training reference data from CALIOP only include ice water path and optical thickness for comparably thin clouds, CiPS also retrieves an opacity flag, which tells us whether a retrieved cirrus is likely to be too thick for CiPS to accurately derive the ice water path and optical thickness. By retrieving CALIOP-like cirrus properties with the large spatial coverage and high temporal resolution of SEVIRI during both day and night, CiPS is a powerful tool for analysing the temporal evolution of cirrus clouds including their optical and physical properties. To demonstrate this, the life cycle of a thin cirrus cloud is analysed.

Self-Regulation, Language Skills, and Emotion Knowledge in Young Children from Northern Germany

ERIC Educational Resources Information Center

von Salisch, Maria; Haenel, Martha; Denham, Susanne Ayers

2015-01-01

Research Findings: In order to examine the explanatory power of behavioral self-regulation in the domain of emotion knowledge, especially in a non-U.S. culture, 365 German 4- and 5-year-olds were individually tested on these constructs. Path analyses revealed that children's behavioral self-regulation explained their emotion knowledge in the…

Re-Thinking Dewey's Democracy: Shifting from a Process of Participation to an Institution of Association

ERIC Educational Resources Information Center

Stone, Lynda

2016-01-01

Dewey's definition of democracy from "Democracy and Education" (1916) is analysed and rethought through a path exploring a shift from a conception of participation as a process to one of association as an institution. Contributions to this pathway among others come from political philosophy and educational philosophy. The rationale for…

Education, Industry and the Knowing-Doing Gap: A Knowledge Management Perspective of Business Education

ERIC Educational Resources Information Center

Nicolaidis, Christos S.; Michalopoulos, George

2004-01-01

This paper examines the evolutionary path of the university and its impact on the quality of education it provides to people, industry and society. The authors first analyse the (Kantian) paradigm of reason, the (German Idealists') paradigm of culture and the current dominant techno-bureaucratic paradigm of excellence. They then argue that the…

Analysing the Role of Business Intelligence, Knowledge Sharing and Organisational Innovation on Gaining Competitive Advantage

ERIC Educational Resources Information Center

Eidizadeh, Rosa; Salehzadeh, Reza; Chitsaz Esfahani, Ali

2017-01-01

Purpose: This paper aims to study the role of business intelligence, knowledge sharing and organisational innovation on gaining competitive advantage. Design/Methodology/Approach: The statistical population of the study was the managers and the specialists of some export companies of which 213 persons participated in this research. Path analysis…

Bidirectional Influences between Maternal Parenting and Children's Peer Problems: A Longitudinal Monozygotic Twin Difference Study

ERIC Educational Resources Information Center

Yamagata, Shinji; Takahashi, Yusuke; Ozaki, Koken; Fujisawa, Keiko K.; Nonaka, Koichi; Ando, Juko

2013-01-01

This twin study examined the bidirectional relationship between maternal parenting behaviors and children's peer problems that were not confounded by genetic and family environmental factors. Mothers of 259 monozygotic twin pairs reported parenting behaviors and peer problems when twins were 42 and 48 months. Path analyses on monozygotic twin…

Linking Socioeconomic Status to Social Cognitive Career Theory Factors: A Partial Least Squares Path Modeling Analysis

ERIC Educational Resources Information Center

Huang, Jie-Tsuen; Hsieh, Hui-Hsien

2011-01-01

The purpose of this study was to investigate the contributions of socioeconomic status (SES) in predicting social cognitive career theory (SCCT) factors. Data were collected from 738 college students in Taiwan. The results of the partial least squares (PLS) analyses indicated that SES significantly predicted career decision self-efficacy (CDSE);…

The Chicano Movement: Paths to Power

ERIC Educational Resources Information Center

Gutierrez, Jose Angel

2011-01-01

This article is a quick overview of the Chicano Movement (CM) with specific analyses of the five major strategies employed by its adherents to effect social change. The CM was a social movement that occurred in the United States with increased activity in the southwest and midwest during a time frame: 1950s to 1980s. Persons of Mexican ancestry…

Reading Development in European Portuguese: Relationships between Oral Reading Fluency, Vocabulary and Reading Comprehension

ERIC Educational Resources Information Center

Fernandes, Sandra; Querido, Luís; Verhaeghe, Arlette; Marques, Catarina; Araújo, Luísa

2017-01-01

This study investigated direct and indirect effects between oral reading fluency, vocabulary and reading comprehension across reading development in European Portuguese. Participants were 329 children attending basic education, from grade 1 to grade 6. The results of path analyses showed that text reading fluency is much more dependent on the…

Stochastic and deterministic models for agricultural production networks.

PubMed

Bai, P; Banks, H T; Dediu, S; Govan, A Y; Last, M; Lloyd, A L; Nguyen, H K; Olufsen, M S; Rempala, G; Slenning, B D

2007-07-01

An approach to modeling the impact of disturbances in an agricultural production network is presented. A stochastic model and its approximate deterministic model for averages over sample paths of the stochastic system are developed. Simulations, sensitivity and generalized sensitivity analyses are given. Finally, it is shown how diseases may be introduced into the network and corresponding simulations are discussed.

Trends and sensitivities of low streamflow extremes to discharge timing and magnitude in Pacific Northwest mountain streams

Treesearch

Patrick R. Kormos; Charlie Luce; Seth J. Wenger; Wouter R. Berghuijs

2016-01-01

Path analyses of historical streamflow data from the Pacific Northwest indicate that the precipitation amount has been the dominant control on the magnitude of low streamflow extremes compared to the air temperature-affected timing of snowmelt runoff. The relative sensitivities of low streamflow to precipitation and temperature changes have important...

Rethinking Models of Professional Learning as Tools: A Conceptual Analysis to Inform Research and Practice

ERIC Educational Resources Information Center

Boylan, Mark; Coldwell, Mike; Maxwell, Bronwen; Jordan, Julie

2018-01-01

One approach to designing, researching or evaluating professional learning experiences is to use models of learning processes. Here we analyse and critique five significant contemporary analytical models: three variations on path models, proposed by Guskey, by Desimone and by Clarke and Hollingsworth; a model using a systemic conceptualisation of…

An examination of the path between recent sexual violence and sexually transmitted infections.

PubMed

von Sternberg, Kirk; Cardoso, Jodi Berger; Jun, Jina; Learman, Joy; Velasquez, Mary M

2012-01-01

Sexually transmitted infections (STIs) are among the most common infections in the United States and are particularly prevalent in survivors of sexual violence. The purpose of this study is to examine co-occurring risk factors for sexual violence and STIs including mental health, alcohol use, drug use, and multiple partners as intersecting pathways to STIs for women who experienced sexual abuse in the past year. Secondary analyses were conducted on cross-sectional data from women originally recruited as respondents for an epidemiologic survey funded by the Centers for Disease Control and Prevention (CDC): Project CHOICES. The survey was administered to 2,672 women in six settings: A large, urban jail and residential alcohol and drug treatment facilities (Texas); a gynecology clinic (Virginia); two primary care clinics (Virginia and Florida); and media solicitation (Florida). Women were included in the current study if they were fertile, sexually active, and not pregnant or trying to get pregnant (n = 1,183). Structural equation modeling (SEM) was used to test the conceptual path model between sexual violence and STI occurrence. In the SEM, there were no significant paths from mental health, alcohol severity, or drug use to STI occurrence contrary to the results of the initial bivariate analyses. Multiple sexual partners significantly mediated the relationship between sexual violence and STIs and between mental health and drug use and STIs. This study highlights the importance of providing effective treatment to survivors of sexual violence, which includes addressing risky sexual behaviors to reduce STI occurrence. Copyright © 2012 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

White matter microstructural alterations in clinically isolated syndrome and multiple sclerosis.

PubMed

Huang, Jing; Liu, Yaou; Zhao, Tengda; Shu, Ni; Duan, Yunyun; Ren, Zhuoqiong; Sun, Zheng; Liu, Zheng; Chen, Hai; Dong, Huiqing; Li, Kuncheng

2018-07-01

This study aims to determine whether and how diffusion alteration occurs in the earliest stage of multiple sclerosis (MS) and the differences in diffusion metrics between CIS and MS by using the tract-based spatial statistics (TBSS) method based on diffusion tensor imaging (DTI). Thirty-six CIS patients (mean age ± SD: 34.0 years ± 12.6), 36 relapsing-remitting multiple sclerosis (RRMS) patients (mean age ± SD: 35.0 years ± 9.4) and 36 age- and gender-matched normal controls (NCs) were included in this study. Voxel-wise analyses were performed with TBSS using multiple diffusion metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ 1 ) and radial diffusivity (λ 23 ). In the CIS patients, TBSS analyses revealed diffusion alterations in a few white matter (WM) regions including the anterior thalamic radiation, corticospinal tract, inferior fronto-occipital fasciculus, superior longitudinal fasciculus, body and splenium of the corpus callosum, internal capsule, external capsule, and cerebral peduncle. MS patients showed more widespread diffusion changes (decreased FA, increased λ 1 , λ 23 and MD) than CIS. Exploratory analyses also revealed the possible associations between WM diffusion metrics and clinical variables (Expanded Disability Status Scale and disease duration) in the patients. This study provided imaging evidence for DTI abnormalities in CIS and MS and suggested that DTI can improve our knowledge of the path physiology of CIS and MS and clinical progression. Copyright © 2018 Elsevier Ltd. All rights reserved.

Field swimming performance of bluegill sunfish, Lepomis macrochirus: implications for field activity cost estimates and laboratory measures of swimming performance.

PubMed

Cathcart, Kelsey; Shin, Seo Yim; Milton, Joanna; Ellerby, David

2017-10-01

Mobility is essential to the fitness of many animals, and the costs of locomotion can dominate daily energy budgets. Locomotor costs are determined by the physiological demands of sustaining mechanical performance, yet performance is poorly understood for most animals in the field, particularly aquatic organisms. We have used 3-D underwater videography to quantify the swimming trajectories and propulsive modes of bluegills sunfish ( Lepomis macrochirus , Rafinesque) in the field with high spatial (1-3 mm per pixel) and temporal (60 Hz frame rate) resolution. Although field swimming trajectories were variable and nonlinear in comparison to quasi steady-state swimming in recirculating flumes, they were much less unsteady than the volitional swimming behaviors that underlie existing predictive models of field swimming cost. Performance analyses suggested that speed and path curvature data could be used to derive reasonable estimates of locomotor cost that fit within measured capacities for sustainable activity. The distinct differences between field swimming behavior and performance measures obtained under steady-state laboratory conditions suggest that field observations are essential for informing approaches to quantifying locomotor performance in the laboratory.

Transactional Associations Between Youths’ Responses to Peer Stress and Depression: The Moderating Roles of Sex and Stress Exposure

PubMed Central

Agoston, Anna Monica; Rudolph, Karen D.

2011-01-01

This study examined transactional associations between responses to peer stress and depression in youth. Specifically, it tested the hypotheses that (a) depression would predict fewer effortful responses and more involuntary, dysregulated responses to peer stress over time; and (b) fewer adaptive and more maladaptive responses would predict subsequent depression. Youth (M age = 12.41; SD = 1.19; 86 girls, 81 boys) and their maternal caregivers completed semi-structured interviews and questionnaires at three annual waves. Multi-group comparison path analyses were conducted to examine sex and stress-level differences in the proposed reciprocal-influence model. In girls and in youth exposed to high levels of peer stress, maladaptive stress responses predicted more depressive symptoms and adaptive stress responses predicted fewer depressive symptoms at each wave. These findings suggest the utility of preventive interventions for depression designed to enhance the quality of girls’ stress responses. In boys, depression predicted less adaptive and more maladaptive stress responses, but only at the second wave. These findings suggest that interventions designed to reduce boys’ depressive symptoms may help them develop more adaptive stress responses. PMID:20852929

Self-esteem and fear of negative evaluation as mediators between family socioeconomic status and social anxiety in Chinese emerging adults.

PubMed

Cheng, Gang; Zhang, Dajun; Ding, Fangyuan

2015-09-01

The social causation hypothesis suggests that the stress in connection with a depressing social position results in the development of mental disorders. This study examines the psychological mechanisms underlying the link between family socioeconomic status (SES) and social anxiety in Chinese emerging adults. A self-administered questionnaire was given to a representative sample (N = 717) of undergraduate students (17-23 years old) at three universities in China. Correlational and structural equation modeling analyses were employed to test the hypothesized three-path effect of self-esteem and fear of negative evaluation (FNE) as mediators between family SES and social anxiety. Findings suggest the following: (1) the emerging adults belonging to families with low SES are at an increased risk of social anxiety, and (2) lower family SES caused lower self-esteem, which, in turn, serves to enhance the levels of FNE, thereby increasing social anxiety. In addressing the prevention and treatment of social anxiety, we conclude that preventive efforts toward improving self-esteem may help reduce social anxiety in individuals with low family SES. © The Author(s) 2014.

Uric acid, lung function, physical capacity and exacerbation frequency in patients with COPD: a multi-dimensional approach.

PubMed

Kahnert, Kathrin; Alter, Peter; Welte, Tobias; Huber, Rudolf M; Behr, Jürgen; Biertz, Frank; Watz, Henrik; Bals, Robert; Vogelmeier, Claus F; Jörres, Rudolf A

2018-06-04

Recent investigations showed single associations between uric acid levels, functional parameters, exacerbations and mortality in COPD patients. The aim of this study was to describe the role of uric acid within the network of multiple relationships between function, exacerbation and comorbidities. We used baseline data from the German COPD cohort COSYCONET which were evaluated by standard multiple regression analyses as well as path analysis to quantify the network of relations between parameters, particularly uric acid. Data from 1966 patients were analyzed. Uric acid was significantly associated with reduced FEV 1 , reduced 6-MWD, higher burden of exacerbations (GOLD criteria) and cardiovascular comorbidities, in addition to risk factors such as BMI and packyears. These associations remained significant after taking into account their multiple interdependences. Compared to uric acid levels the diagnosis of hyperuricemia and its medication played a minor role. Within the limits of a cross-sectional approach, our results strongly suggest that uric acid is a biomarker of high impact in COPD and plays a genuine role for relevant outcomes such as physical capacity and exacerbations. These findings suggest that more attention should be paid to uric acid in the evaluation of COPD disease status.

A Hybrid Analytical/Numerical Model for the Characterization of Preferential Flow Path with Non-Darcy Flow

PubMed Central

Wang, Sen; Feng, Qihong; Han, Xiaodong

2013-01-01

Due to the long-term fluid-solid interactions in waterflooding, the tremendous variation of oil reservoir formation parameters will lead to the widespread evolution of preferential flow paths, thereby preventing the further enhancement of recovery efficiency because of unstable fingering and premature breakthrough. To improve oil recovery, the characterization of preferential flow paths is essential and imperative. In efforts that have been previously documented, fluid flow characteristics within preferential paths are assumed to obey Darcy's equation. However, the occurrence of non-Darcy flow behavior has been increasingly suggested. To examine this conjecture, the Forchheimer number with the inertial coefficient estimated from different empirical formulas is applied as the criterion. Considering a 10% non-Darcy effect, the fluid flow in a preferential path may do experience non-Darcy behavior. With the objective of characterizing the preferential path with non-Darcy flow, a hybrid analytical/numerical model has been developed to investigate the pressure transient response, which dynamically couples a numerical model describing the non-Darcy effect of a preferential flow path with an analytical reservoir model. The characteristics of the pressure transient behavior and the sensitivities of corresponding parameters have also been discussed. In addition, an interpretation approach for pressure transient testing is also proposed, in which the Gravitational Search Algorithm is employed as a non-linear regression technology to match measured pressure with this hybrid model. Examples of applications from different oilfields are also presented to illustrate this method. This cost-effective approach provides more accurate characterization of a preferential flow path with non-Darcy flow, which will lay a solid foundation for the design and operation of conformance control treatments, as well as several other Enhanced Oil Recovery projects. PMID:24386224

Integration across Time Determines Path Deviation Discrimination for Moving Objects

PubMed Central

Whitaker, David; Levi, Dennis M.; Kennedy, Graeme J.

2008-01-01

Background Human vision is vital in determining our interaction with the outside world. In this study we characterize our ability to judge changes in the direction of motion of objects–a common task which can allow us either to intercept moving objects, or else avoid them if they pose a threat. Methodology/Principal Findings Observers were presented with objects which moved across a computer monitor on a linear path until the midline, at which point they changed their direction of motion, and observers were required to judge the direction of change. In keeping with the variety of objects we encounter in the real world, we varied characteristics of the moving stimuli such as velocity, extent of motion path and the object size. Furthermore, we compared performance for moving objects with the ability of observers to detect a deviation in a line which formed the static trace of the motion path, since it has been suggested that a form of static memory trace may form the basis for these types of judgment. The static line judgments were well described by a ‘scale invariant’ model in which any two stimuli which possess the same two-dimensional geometry (length/width) result in the same level of performance. Performance for the moving objects was entirely different. Irrespective of the path length, object size or velocity of motion, path deviation thresholds depended simply upon the duration of the motion path in seconds. Conclusions/Significance Human vision has long been known to integrate information across space in order to solve spatial tasks such as judgment of orientation or position. Here we demonstrate an intriguing mechanism which integrates direction information across time in order to optimize the judgment of path deviation for moving objects. PMID:18414653

Theoretical investigation on the mechanism and dynamics of oxo exchange of neptunyl(VI) hydroxide in aqueous solution.

PubMed

Yang, Xia; Chai, Zhifang; Wang, Dongqi

2015-03-21

Four types of reaction mechanisms for the oxo ligand exchange of monomeric and dimeric neptunyl(VI) hydroxide in aqueous solution were explored computationally using density functional theory (DFT) and ab initio classical molecular dynamics. The obtained results were compared with previous studies on the oxo exchange of uranyl hydroxide, as well as with experiments. It is found that the stable T-shaped [NpO3(OH)3](3-) intermediate is a key species for oxo exchange in the proton transfer in mononuclear Path I and binuclear Path IV, similar to the case of uranyl(VI) hydroxide. Path I is thought to be the preferred oxo exchange mechanism for neptunyl(VI) hydroxide in our calculations, due to the lower activation energy (22.7 and 13.1 kcal mol(-1) for ΔG(‡) and ΔH(‡), respectively) of the overall reaction. Path II via a cis-neptunyl structure assisted by a water molecule might be a competitive channel against Path I with a mononuclear mechanism, owing to a rapid dynamical process occurring in Path II. In Path IV with the binuclear mechanism, oxo exchange is accomplished via the interaction between [NpO2(OH)4](2-) and T-shaped [NpO3(OH)3](3-) with a low activation energy for the rate-determining step, however, the overall energy required to fulfill the reaction is slightly higher than that in mononuclear Path I, suggesting a possible binuclear process in the higher energy region. The chemical bonding evolution along the reaction pathways was discussed by using topological methodologies of the electron localization function (ELF).

The Effect of Sharrows, Painted Bicycle Lanes and Physically Protected Paths on the Severity of Bicycle Injuries Caused by Motor Vehicles.

PubMed

Wall, Stephen P; Lee, David C; Frangos, Spiros G; Sethi, Monica; Heyer, Jessica H; Ayoung-Chee, Patricia; DiMaggio, Charles J

2016-01-01

We conducted individual and ecologic analyses of prospectively collected data from 839 injured bicyclists who collided with motorized vehicles and presented to Bellevue Hospital, an urban Level-1 trauma center in New York City, from December 2008 to August 2014. Variables included demographics, scene information, rider behaviors, bicycle route availability, and whether the collision occurred before the road segment was converted to a bicycle route. We used negative binomial modeling to assess the risk of injury occurrence following bicycle path or lane implementation. We dichotomized U.S. National Trauma Data Bank Injury Severity Scores (ISS) into none/mild (0-8) versus moderate, severe, or critical (>8) and used adjusted multivariable logistic regression to model the association of ISS with collision proximity to sharrows (i.e., bicycle lanes designated for sharing with cars), painted bicycle lanes, or physically protected paths. Negative binomial modeling of monthly counts, while adjusting for pedestrian activity, revealed that physically protected paths were associated with 23% fewer injuries. Painted bicycle lanes reduced injury risk by nearly 90% (IDR 0.09, 95% CI 0.02-0.33). Holding all else equal, compared to no bicycle route, a bicycle injury nearby sharrows was nearly twice as likely to be moderate, severe, or critical (adjusted odds ratio 1.94; 95% confidence interval (CI) 0.91-4.15). Painted bicycle lanes and physically protected paths were 1.52 (95% CI 0.85-2.71) and 1.66 (95% CI 0.85-3.22) times as likely to be associated with more than mild injury respectively.

Star-Paths, Stones and Horizon Astronomy

NASA Astrophysics Data System (ADS)

Brady, Bernadette

2015-05-01

Archaeoastronomers tend to approach ancient monuments focusing on the landscape and the horizon calendar events of sun and moon and, due to problems with precession, generally ignore the movement of the stars. However, locating the position of solar calendar points on the horizon can have other uses apart from calendar and/or cosmological purposes. This paper firstly suggests that the stars do not need to be ignored. By considering the evidence of the Phaenomena, a sky poem by Aratus of Soli, a third century BC Greek poet, and his use of second millennium BC star lore fragments, this paper argues that the stars were a part of the knowledge of horizon astronomy. Aratus' poem implied that the horizon astronomy of the late Neolithic and Bronze Age periods included knowledge of star-paths or 'linear constellations' that were defined by particular horizon calendar events and other azimuths. Knowledge of such star-paths would have enabled navigation and orientation, and by using permanent markers, constructed or natural, to define these paths, they were immune to precession as the stones could redefine a star-path for a future generation. Finally the paper presents other possible intentions behind the diverse orientation of passage tombs and some megalithic sites.

Seasonal and Interannual Variations of Top-of-Atmosphere Irradiance and Cloud Cover over Polar Regions Derived from the CERES Data Set

NASA Technical Reports Server (NTRS)

Kato, Seiji; Loeb, Norman G.; Minnis, Patrick; Francis, Jennifer A.; Charlock, Thomas P.; Rutan, David A.; Clothiaux, Eugene E.; Sun-Mack, Szedung

2006-01-01

The semi-direct effects of dust aerosols are analyzed over eastern Asia using 2 years (June 2002 to June 2004) of data from the Clouds and the Earth s Radiant Energy System (CERES) scanning radiometer and MODerate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite, and 18 years (1984 to 2001) of International Satellite Cloud Climatology Project (ISCCP) data. The results show that the water path of dust-contaminated clouds is considerably smaller than that of dust-free clouds. The mean ice water path (IWP) and liquid water path (LWP) of dusty clouds are less than their dust-free counterparts by 23.7% and 49.8%, respectively. The long-term statistical relationship derived from ISCCP also confirms that there is significant negative correlation between dust storm index and ISCCP cloud water path. These results suggest that dust aerosols warm clouds, increase the evaporation of cloud droplets and further reduce cloud water path, the so-called semi-direct effect. The semi-direct effect may play a role in cloud development over arid and semi-arid areas of East Asia and contribute to the reduction of precipitation.

Improving young children's social and emotional competence: a randomized trial of the preschool "PATHS" curriculum.

PubMed

Domitrovich, Celene E; Cortes, Rebecca C; Greenberg, Mark T

2007-03-01

This paper reports the results from a randomized clinical trial evaluating an adaptation of the Promoting Alternative Thinking Strategies curriculum (PATHS) for preschool-age children in Head Start. PATHS is a universal, teacher-taught social-emotional curriculum that is designed to improve children's social competence and reduce problem behavior. Twenty classrooms in two Pennsylvania communities participated in the study. Teachers in the 10 intervention classrooms implemented weekly lessons and extension activities across a 9-month period. Child assessments and teacher and parent reports of child behavior assessments were collected at the beginning and end of the school year. Analysis of covariance was used to control for baseline differences between the groups and pretest scores on each of the outcome measures. The results suggest that after exposure to PATHS, intervention children had higher emotion knowledge skills and were rated by parents and teachers as more socially competent compared to peers. Further, teachers rated intervention children as less socially withdrawn at the end of the school year compared to controls.

Development of Thin-Walled Magnesium Alloy Extrusions for Improved Crash Performance Based Upon Texture Control

NASA Astrophysics Data System (ADS)

Williams, Bruce W.; Agnew, Sean R.; Klein, Robert W.; McKinley, Jonathan

Recent investigations suggest that it is possible to achieve dramatic modifications to both strength and ductility of magnesium alloys through a combination of alloying, grain refinement, and texture control. The current work explores the possibility of altering the texture in extruded thin-walled magnesium alloy tubes for improved ductility during axial crush in which energy is absorbed through progressive buckling. The texture evolution was predicted using the viscoplastic self-consistent (VPSC) crystal plasticity model, with strain path input from continuum-based finite element simulations of extrusion. A limited diversity of textures can be induced by altering the strain path through the extrusion die design. In some cases, such as for simple bar extrusion, the textures predicted can be connected with simple shape change. In other cases, a subtle influence of strain path involving shear-reverse-shear is predicted. The most promising textures predicted for a variety of strain paths are selected for subsequent experimental study.

Adaptation in protein fitness landscapes is facilitated by indirect paths

PubMed Central

Wu, Nicholas C; Dai, Lei; Olson, C Anders; Lloyd-Smith, James O; Sun, Ren

2016-01-01

The structure of fitness landscapes is critical for understanding adaptive protein evolution. Previous empirical studies on fitness landscapes were confined to either the neighborhood around the wild type sequence, involving mostly single and double mutants, or a combinatorially complete subgraph involving only two amino acids at each site. In reality, the dimensionality of protein sequence space is higher (20L) and there may be higher-order interactions among more than two sites. Here we experimentally characterized the fitness landscape of four sites in protein GB1, containing 204 = 160,000 variants. We found that while reciprocal sign epistasis blocked many direct paths of adaptation, such evolutionary traps could be circumvented by indirect paths through genotype space involving gain and subsequent loss of mutations. These indirect paths alleviate the constraint on adaptive protein evolution, suggesting that the heretofore neglected dimensions of sequence space may change our views on how proteins evolve. DOI: http://dx.doi.org/10.7554/eLife.16965.001 PMID:27391790

Quantum correlation in degenerate optical parametric oscillators with mutual injections

NASA Astrophysics Data System (ADS)

Takata, Kenta; Marandi, Alireza; Yamamoto, Yoshihisa

2015-10-01

We theoretically and numerically study the quantum dynamics of two degenerate optical parametric oscillators with mutual injections. The cavity mode in the optical coupling path between the two oscillator facets is explicitly considered. Stochastic equations for the oscillators and mutual injection path based on the positive P representation are derived. The system of two gradually pumped oscillators with out-of-phase mutual injections is simulated, and its quantum state is investigated. When the incoherent loss of the oscillators other than the mutual injections is small, the squeezed quadratic amplitudes p ̂ in the oscillators are positively correlated near the oscillation threshold. It indicates finite quantum correlation, estimated via Gaussian quantum discord, and the entanglement between the intracavity subharmonic fields. When the loss in the injection path is low, each oscillator around the phase transition point forms macroscopic superposition even under a small pump noise. It suggests that the squeezed field stored in the low-loss injection path weakens the decoherence in the oscillators.

U.S. Policy in the Israeli-Palestinian Dispute

DTIC Science & Technology

2017-09-01

historical path dependency and the power of spoilers in the peace process. Also important has been the nature of U.S. support for Israel, the lack of a...results of the thesis suggest a historical path dependency and the power of spoilers in the peace process. Also important has been the nature of U.S...and others have argued that Israel has lost any real interest in peace with the Palestinians, and is instead attempting to play the long game with

Correlations between the Hand Test Pathology score and Personality Assessment Inventory scales for pain clinic patients.

PubMed

George, J M; Wagner, E E

1995-06-01

Pearson correlations between the Hand Test Pathology (PATH) score and Personality Assessment Inventory scales produced a cluster of relationships characteristic of an antisocial orientation. Likewise, PATH significantly differentiated between a "P" (Pathology) group flagged by a high Negative Impression score on the inventory, and an "N" (Normal) group of 100 pain patients. It was suggested that the interpretive simplicity of Hand Test scores renders the scores amenable to further correlational studies involving the inventory.

Physics thematic paths: laboratorial activities and historical scientific instruments

NASA Astrophysics Data System (ADS)

Pantano, O.; Talas, S.

2010-03-01

The Physics Department of Padua University keeps an important collection of historical physics instruments which alludes to the fruitful scientific activity of Padua through the centuries. This heritage led to the suggestion of setting up laboratory activities connected to the Museum collection for secondary school students. This article shows how different thematic paths have been developed, reflecting on the importance of historical perspectives in science teaching. We also show how a scientific historical museum can play a central role in improving the learning of physics concepts.

Spectral correlation and interference in non-degenerate photon pairs at telecom wavelengths.

PubMed

Kuo, Paulina S; Gerrits, Thomas; Verma, Varun B; Nam, Sae Woo

2016-11-01

We characterize an entangled-photon-pair source that produces signal and idler photons at 1533 nm and 1567 nm using fiber-assisted signal-photon spectroscopy. By erasing the polarization distinguishability, we observe interference between the two down-conversion paths. The observed interference signature is closely related to the spectral correlations between photons in a Hong-Ou-Mandel interferometer. These measurements suggest good indistinguishability between the two down-conversion paths, which is required for high entanglement visibility.

Status Report on Ex-Vessel Coolability and Water Management

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

Farmer, M. T.; Robb, K. R.

Specific to BWR plants, current accident management guidance calls for flooding the drywell to a level of approximately 1.2 m (4 feet) above the drywell floor once vessel breach has been determined. While this action can help to submerge ex-vessel core debris, it can also result in flooding the wetwell and thereby rendering the wetwell vent path unavailable. An alternate strategy is being developed in the industry guidance for responding to the severe accident capable vent Order, EA-13-109. The alternate strategy being proposed would throttle the flooding rate to achieve a stable wetwell water level while preserving the wetwell ventmore » path. The overall objective of this work is to upgrade existing analytical tools (i.e. MELTSPREAD and CORQUENCH - which have been used as part of the DOE-sponsored Fukushima accident analyses) in order to provide flexible, analytically capable, and validated models to support the development of water throttling strategies for BWRs that are aimed at keeping ex-vessel core debris covered with water while preserving the wetwell vent path.« less

Perceptual Training in Beach Volleyball Defence: Different Effects of Gaze-Path Cueing on Gaze and Decision-Making

PubMed Central

Klostermann, André; Vater, Christian; Kredel, Ralf; Hossner, Ernst-Joachim

2015-01-01

For perceptual-cognitive skill training, a variety of intervention methods has been proposed, including the so-called “color-cueing method” which aims on superior gaze-path learning by applying visual markers. However, recent findings challenge this method, especially, with regards to its actual effects on gaze behavior. Consequently, after a preparatory study on the identification of appropriate visual cues for life-size displays, a perceptual-training experiment on decision-making in beach volleyball was conducted, contrasting two cueing interventions (functional vs. dysfunctional gaze path) with a conservative control condition (anticipation-related instructions). Gaze analyses revealed learning effects for the dysfunctional group only. Regarding decision-making, all groups showed enhanced performance with largest improvements for the control group followed by the functional and the dysfunctional group. Hence, the results confirm cueing effects on gaze behavior, but they also question its benefit for enhancing decision-making. However, before completely denying the method’s value, optimisations should be checked regarding, for instance, cueing-pattern characteristics and gaze-related feedback. PMID:26648894

Cascading effects of predator activity on tick-borne disease risk.

PubMed

Hofmeester, Tim R; Jansen, Patrick A; Wijnen, Hendrikus J; Coipan, Elena C; Fonville, Manoj; Prins, Herbert H T; Sprong, Hein; van Wieren, Sipke E

2017-07-26

Predators and competitors of vertebrates can in theory reduce the density of infected nymphs (DIN)-an often-used measure of tick-borne disease risk-by lowering the density of reservoir-competent hosts and/or the tick burden on reservoir-competent hosts. We investigated this possible indirect effect of predators by comparing data from 20 forest plots across the Netherlands that varied in predator abundance. In each plot, we measured the density of questing Ixodes ricinus nymphs (DON), DIN for three pathogens, rodent density, the tick burden on rodents and the activity of mammalian predators. We analysed whether rodent density and tick burden on rodents were correlated with predator activity, and how rodent density and tick burden predicted DON and DIN for the three pathogens. We found that larval burden on two rodent species decreased with activity of two predator species, while DON and DIN for all three pathogens increased with larval burden on rodents, as predicted. Path analyses supported an indirect negative correlation of activity of both predator species with DON and DIN. Our results suggest that predators can indeed lower the number of ticks feeding on reservoir-competent hosts, which implies that changes in predator abundance may have cascading effects on tick-borne disease risk. © 2017 The Authors.

Atopic Dermatitis and Comorbidities: Added Value of Comprehensive Dermatoepidemiology.

PubMed

Nijsten, Tamar

2017-05-01

Atopic dermatitis is common and in its severe form is devastating. This chronic inflammatory dermatosis is part of the atopic syndrome, which includes asthma, food allergies, and hay fever and is known to be associated with mental health disorders. In line with psoriasis, several recent observational studies using national survey and linkage data have suggested a link between atopic dermatitis and cardiovascular disease. The atopic dermatitis field can benefit from the past experiences in psoriasis research and should not follow the same path, but, rather, aim for a more comprehensive approach from the beginning. A recent German consortium studying links between atopic dermatitis and cardiovascular disease first screened a large claims database, followed by analyses of more deeply phenotyped (birth) cohorts with longitudinal data. In addition, genetic and metabolic analyses assessing the predisposition of patients with atopic dermatitis for cardiovascular disease were performed. Overall, the association between atopic dermatitis and cardiovascular disease was at most modest, but in more refined cohorts the cardiovascular risk profile and genetic architecture was comparable. A more integrated approach could create clarity about the clinical relevance of cardiovascular disease in individuals with atopic dermatitis sooner, avoid speculation that affects patient care, and save scientific resources. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Have we left some behind? Trends in socio-economic inequalities in breastfeeding initiation: a population-based epidemiological surveillance study.

PubMed

Nickel, Nathan C; Martens, Patricia J; Chateau, Dan; Brownell, Marni D; Sarkar, Joykrishna; Goh, Chun Yan; Burland, Elaine; Taylor, Carole; Katz, Alan

2014-07-31

Breastfeeding is associated with improved health. Surveillance data show that breastfeeding initiation rates have increased; however, limited work has examined trends in socio-economic inequalities in initiation. The study's research question was whether socio-economic inequalities in breastfeeding initiation have changed over the past 20 years. This population-based study is a project within PATHS Equity for Children. Analyses used hospital discharge data for Manitoba mother-infant dyads with live births, 1988-2011 (n=316,027). Income quintiles were created, each with ~20% of dyads. Three-year, overall and by-quintile breastfeeding initiation rates were estimated for Manitoba and two hospitals. Age-adjusted rates were estimated for Manitoba. Rates were modelled using generalized linear models. Three measures, rate ratios (RRs), rate differences (RDs) and concentration indices, assessed inequality at each time point. We also compared concentration indices with Gini coefficients to assess breastfeeding inequality vis-à-vis income inequality. Trend analyses tested for changes over time. Manitoba and Hospital A initiation rates increased; Hospital B rates did not change. Significant inequalities existed in nearly every period, across all three measures: RRs, RDs and concentration indices. RRs and concentration indices suggested little to no change in inequality from 1988 to 2011. RDs for Manitoba (comparing initiation in the highest to lowest income quintiles) did not change significantly over time. RDs decreased for Hospital A, suggesting decreasing socio-economic inequalities in breastfeeding; RDs increased for Hospital B. Income inequality increased significantly in Manitoba during the study period. Overall breastfeeding initiation rates can improve while inequality persists or worsens.

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

Akagi, Sheryl; Burling, Ian R.; Mendoza, Albert

We report trace-gas emission factors from three pine-understory prescribed fires in South Carolina, U.S. measured during the fall of 2011. The fires were an attempt to simulate high-intensity burns and the fuels included mature pine stands not frequently subjected to prescribed fire that were lit following a sustained period of drought. In this work we focus on the emission factor measurements made using a fixed open-path gas analyzer Fourier transform infrared (FTIR) system. We compare these emission factors with those measured using a roving, point sampling, land-based FTIR and an airborne FTIR that were deployed on the same fires. Wemore » also compare to emission factors measured by a similar open-path FTIR system deployed on savanna fires in Africa. The data suggest that the method in which the smoke is sampled can strongly influence the relative abundance of the emissions that are observed. The airborne FTIR probed the bulk of the emissions, which were lofted in the convection column and the downwind chemistry while the roving ground-based point sampling FTIR measured the contribution of individual residual smoldering combustion fuel elements scattered throughout the burn site. The open-path FTIR provided a fixed path-integrated sample of emissions produced directly upwind mixed with emissions that were redirected by wind gusts, or right after ignition and before the adjacent plume achieved significant vertical development. It typically probed two distinct combustion regimes, “flaming-like” (immediately after adjacent ignition) and “smoldering-like”, denoted “early” and “late”, respectively. The calculated emission factors from open-path measurements were closer to the airborne than to the point measurements, but this could vary depending on the calculation method or from fire to fire given the changing MCE and dynamics over the duration of a typical burn. The emission factors for species whose emissions are not highly fuel dependent (e.g. CH4 and CH3OH) from all three systems can be plotted versus modified combustion efficiency and fit to a single consistent trend suggesting that differences between the systems for these species may be mainly due to the unique mix of flaming and smoldering that each system sampled. For other more fuel dependent species, the different fuels sampled also likely contributed to platform differences in emission factors. The path-integrated sample of the ground-level smoke layer adjacent to the fire provided by the open-path measurements is important for estimating fire-line exposure to smoke for wildland fire personnel. We provide a table of estimated fire-line exposures for numerous known air toxics based on synthesizing results from several studies. Our data suggest that peak exposures are more likely to challenge permissible exposure limits for wildland fire personnel than shift-average exposures.« less

Roles of Impulsivity, Motivation, and Emotion Regulation in Procrastination – Path Analysis and Comparison Between Students and Non-students

PubMed Central

Wypych, Marek; Matuszewski, Jacek; Dragan, Wojciech Ł.

2018-01-01

Procrastination – an irrational delay of intended actions despite expecting to be worse off – is a complex and non-homogenous phenomenon. Previous studies have found a number of correlates of procrastination, some of which seem to be particularly important. Impulsivity is closely connected to procrastination on behavioral, genetic, and neuronal levels. Difficulties in emotion regulation have also been shown to be strongly related to procrastination. Procrastination can also be considered as a motivation-based problem. To try to disentangle the connections of impulsivity, emotion regulation, and motivation to procrastination we collected data from over 600 subjects using multiple questionnaires (PPS – Pure Procrastination Scale; UPPSP – Impulsive Behavior Scale, ERQ – Emotion Regulation Questionnaire and MDT – Motivational Diagnostic Test). Structural equation modeling was performed to test several possible relationships between the measured variables. The effects of student status and age have also been investigated. The final path model was a directional model based on six explanatory variables and accounted for 70% of the variance in procrastination. Path analysis revealed that the strongest contributions to procrastination came from lack of value, delay discounting, and lack of perseverance, suggesting the involvement of motivation and impulsivity. The model also revealed the moderating role of expressive suppression between several aspects of impulsivity and procrastination. Close inspection of the paths’ weights suggests that there may be two partly competing strategies for dealing with impulsivity and negative emotions: either to suppress emotions and impulsive reactions or to react impulsively, discarding previous plans, and to procrastinate. Path invariance analysis showed the significant moderating roles of student status and age. Both in non-students and high-age groups, the path leading from suppression to procrastination was insignificant. This suggests that caution should be used in generalizing the results of studies carried out on students. These results support previous findings that procrastination may serve as a short-term mood regulation strategy. However, as the spectrum of the emotion regulation strategies included in the study was very limited, we conclude that future studies should seek more insight into the relationship between emotion regulation, self-control, and procrastination. PMID:29922205

Modeling heading and path perception from optic flow in the case of independently moving objects

PubMed Central

Raudies, Florian; Neumann, Heiko

2013-01-01

Humans are usually accurate when estimating heading or path from optic flow, even in the presence of independently moving objects (IMOs) in an otherwise rigid scene. To invoke significant biases in perceived heading, IMOs have to be large and obscure the focus of expansion (FOE) in the image plane, which is the point of approach. For the estimation of path during curvilinear self-motion no significant biases were found in the presence of IMOs. What makes humans robust in their estimation of heading or path using optic flow? We derive analytical models of optic flow for linear and curvilinear self-motion using geometric scene models. Heading biases of a linear least squares method, which builds upon these analytical models, are large, larger than those reported for humans. This motivated us to study segmentation cues that are available from optic flow. We derive models of accretion/deletion, expansion/contraction, acceleration/deceleration, local spatial curvature, and local temporal curvature, to be used as cues to segment an IMO from the background. Integrating these segmentation cues into our method of estimating heading or path now explains human psychophysical data and extends, as well as unifies, previous investigations. Our analysis suggests that various cues available from optic flow help to segment IMOs and, thus, make humans' heading and path perception robust in the presence of such IMOs. PMID:23554589

Pre- and post-displacement stressors and time of migration as related to self-rated health among Iraqi immigrants and refugees in Southeast Michigan

PubMed Central

Jamil, Hikraei; Nassar-McMillan, Sylvia; Lambert, Richard; Wang, Yun; Ager, Joel; Arnetz, Bengt

2011-01-01

The objective of this study was to determine whether perceived health status of Iraqi immigrants and refugees residing in the United States was related to pre-migration environmental stress, current unemployment, and if they had emigrated before or after the 1991 Gulf War. A random sample of Iraqis residing in Southeast Michigan, US, was interviewed using an Arab language structured survey. The main outcome measure was self-rated health (SRH). Major predictors included socioeconomics, employment status, pre-migration environmental stress, and health disorders. Path analysis was used to look: at mediating effects between predictors and SRH. We found that SRH was significantly worse among participants that had left Iraq after the 1991 Gulf War. Unemployment and environmental stress exposure were inversely related to SRH. There was a direct path between Gulf War exposure and poor health. In addition, there were indirect paths mediated through psychosomatic and psychiatric disorders to SRH. Another path went from Gulf War exposure, via environmen tal stress and somatic health to poor health. Unemployment had a direct path, as well as an indirect paths mediated through psychiatric and psychosomatic disorders, to poor self-rated health. In conclusion, these results suggest that pre- as well as post-migration factors, and period of migration, affect health. PMID:21291168

Analyses of Shuttle Orbiter approach and landing

NASA Technical Reports Server (NTRS)

Ashkenas, I. L.; Hoh, R. H.; Teper, G. L.

1982-01-01

A study of the Shuttle Orbiter approach and landing conditions is summarized. The causes of observed PIO-like flight deficiencies are listed, and possible corrective measures are examined. Closed-loop pilot/vehicle analyses are described, and a description is given of path-attitude stability boundaries. The latter novel approach is found to be of great value in delineating and illustrating the basic causes of this multiloop pilot control problem. It is shown that the analytical results are consistent with flight test and fixed-base simulation. Conclusions are drawn concerning possible improvements in the Shuttle Orbiter/Digital Flight Control System.

Infiltration and hydraulic connections from the Niagara River to a fractured-dolomite aquifer in Niagara Falls, New York

USGS Publications Warehouse

Yager, R.M.; Kappel, W.M.

1998-01-01

The spatial distribution of hydrogen and oxygen stable-isotope values in groundwater can be used to distinguish different sources of recharge and to trace groundwater flow directions from recharge boundaries. This method can be particularly useful in fractured-rock settings where multiple lines of evidence are required to delineate preferential flow paths that result from heterogeneity within fracture zones. Flow paths delineated with stable isotopes can be combined with hydraulic data to form a more complete picture of the groundwater flow system. In this study values of ??D and ??18O were used to delineate paths of river-water infiltration into the Lockport Group, a fractured dolomite aquifer, and to compute the percentage of fiver water in groundwater samples from shallow bedrock wells. Flow paths were correlated with areas of high hydraulic diffusivity in the shallow bedrock that were delineated from water-level fluctuations induced by diurnal stage fluctuations in man-made hydraulic structures. Flow paths delineated with the stable-isotope and hydraulic data suggest that fiver infiltration reaches an unlined storm sewer in the bedrock through a drainage system that surrounds aqueducts carrying river water to hydroelectric power plants. This finding is significant because the storm sewer is the discharge point for contaminated groundwater from several chemical waste-disposal sites and the cost of treating the storm sewer's discharge could be reduced if the volume of infiltration from the river were decreased.The spatial distribution of hydrogen and oxygen stable-isotope values in groundwater can be used to distinguish different sources of recharge and to trace groundwater flow directions from recharge boundaries. This method can be particularly useful in fractured-rock settings where multiple lines of evidence are required to delineate preferential flow paths that result from heterogeneity within fracture zones. Flow paths delineated with stable isotopes can be combined with hydraulic data to form a more complete picture of the groundwater flow system. In this study values of ??D and ??18O were used to delineate paths of river-water infiltration into the Lockport Group, a fractured dolomite aquifer, and to compute the percentage of river water in groundwater samples from shallow bedrock wells. Flow paths were correlated with areas of high hydraulic diffusivity in the shallow bedrock that were delineated from water-level fluctuations induced by diurnal stage fluctuations in man-made hydraulic structures. Flow paths delineated with the stable-isotope and hydraulic data suggest that river infiltration reaches an unlined storm sewer in the bedrock through a drainage system that surrounds aqueducts carrying river water to hydroelectric power plants. This finding is significant because the storm sewer is the discharge point for contaminated groundwater from several chemical waste-disposal sites and the cost of treating the storm sewer's discharge could be reduced if the volume of infiltration from the river were decreased.

HCN and chromophore formation on Jupiter

NASA Technical Reports Server (NTRS)

Ferris, James P.; Ishikawa, Yoji

1987-01-01

Reaction paths for the formation of HCN and chromophores on Jupiter are suggested. The reactions involve photolysis of ammonia/acetylene mixtures. Experimental data supporting these pathways are reported.

Molecular cloning and biochemical characterization of two cation chloride cotransporter subfamily members of Hydra vulgaris.

PubMed

Hartmann, Anna-Maria; Pisella, Lucie I; Medina, Igor; Nothwang, Hans Gerd

2017-01-01

Cation Chloride Cotransporters (CCCs) comprise secondary active membrane proteins mainly mediating the symport of cations (Na+, K+) coupled with chloride (Cl-). They are divided into K+-Cl- outward transporters (KCCs), the Na+-K+-Cl- (NKCCs) and Na+-Cl- (NCCs) inward transporters, the cation chloride cotransporter interacting protein CIP1, and the polyamine transporter CCC9. KCCs and N(K)CCs are established in the genome since eukaryotes and metazoans, respectively. Most of the physiological and functional data were obtained from vertebrate species. To get insights into the basal functional properties of KCCs and N(K)CCs in the metazoan lineage, we cloned and characterized KCC and N(K)CC from the cnidarian Hydra vulgaris. HvKCC is composed of 1,032 amino-acid residues. Functional analyses revealed that hvKCC mediates a Na+-independent, Cl- and K+ (Tl+)-dependent cotransport. The classification of hvKCC as a functional K-Cl cotransporter is furthermore supported by phylogenetic analyses and a similar structural organization. Interestingly, recently obtained physiological analyses indicate a role of cnidarian KCCs in hyposmotic volume regulation of nematocytes. HvN(K)CC is composed of 965 amino-acid residues. Phylogenetic analyses and structural organization suggest that hvN(K)CC is a member of the N(K)CC subfamily. However, no inorganic ion cotransport function could be detected using different buffer conditions. Thus, hvN(K)CC is a N(K)CC subfamily member without a detectable inorganic ion cotransporter function. Taken together, the data identify two non-bilaterian solute carrier 12 (SLC12) gene family members, thereby paving the way for a better understanding of the evolutionary paths of this important cotransporter family.

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies

PubMed Central

Grob, Robin; Fleischmann, Pauline N.; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance—presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system. PMID:29184487

The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies.

PubMed

Grob, Robin; Fleischmann, Pauline N; Grübel, Kornelia; Wehner, Rüdiger; Rössler, Wolfgang

2017-01-01

Central place foragers are faced with the challenge to learn the position of their nest entrance in its surroundings, in order to find their way back home every time they go out to search for food. To acquire navigational information at the beginning of their foraging career, Cataglyphis noda performs learning walks during the transition from interior worker to forager. These small loops around the nest entrance are repeatedly interrupted by strikingly accurate back turns during which the ants stop and precisely gaze back to the nest entrance-presumably to learn the landmark panorama of the nest surroundings. However, as at this point the complete navigational toolkit is not yet available, the ants are in need of a reference system for the compass component of the path integrator to align their nest entrance-directed gazes. In order to find this directional reference system, we systematically manipulated the skylight information received by ants during learning walks in their natural habitat, as it has been previously suggested that the celestial compass, as part of the path integrator, might provide such a reference system. High-speed video analyses of distinct learning walk elements revealed that even exclusion from the skylight polarization pattern, UV-light spectrum and the position of the sun did not alter the accuracy of the look back to the nest behavior. We therefore conclude that C. noda uses a different reference system to initially align their gaze directions. However, a comparison of neuroanatomical changes in the central complex and the mushroom bodies before and after learning walks revealed that exposure to UV light together with a naturally changing polarization pattern was essential to induce neuroplasticity in these high-order sensory integration centers of the ant brain. This suggests a crucial role of celestial information, in particular a changing polarization pattern, in initially calibrating the celestial compass system.