When theory and biology differ: The relationship between reward prediction errors and expectancy.

PubMed

Williams, Chad C; Hassall, Cameron D; Trska, Robert; Holroyd, Clay B; Krigolson, Olave E

2017-10-01

Comparisons between expectations and outcomes are critical for learning. Termed prediction errors, the violations of expectancy that occur when outcomes differ from expectations are used to modify value and shape behaviour. In the present study, we examined how a wide range of expectancy violations impacted neural signals associated with feedback processing. Participants performed a time estimation task in which they had to guess the duration of one second while their electroencephalogram was recorded. In a key manipulation, we varied task difficulty across the experiment to create a range of different feedback expectancies - reward feedback was either very expected, expected, 50/50, unexpected, or very unexpected. As predicted, the amplitude of the reward positivity, a component of the human event-related brain potential associated with feedback processing, scaled inversely with expectancy (e.g., unexpected feedback yielded a larger reward positivity than expected feedback). Interestingly, the scaling of the reward positivity to outcome expectancy was not linear as would be predicted by some theoretical models. Specifically, we found that the amplitude of the reward positivity was about equivalent for very expected and expected feedback, and for very unexpected and unexpected feedback. As such, our results demonstrate a sigmoidal relationship between reward expectancy and the amplitude of the reward positivity, with interesting implications for theories of reinforcement learning. Copyright © 2017 Elsevier B.V. All rights reserved.

Information content versus word length in random typing

NASA Astrophysics Data System (ADS)

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

2011-12-01

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

Mediated by Self-Efficacy Status, Positive Clinician Conveyed Expectations of Treatment Effect Reduces Pain in Knee Osteoarthritis

PubMed Central

Lo, Grace Hsiao-Wei; Balasubramanyam, Ajay S.; Barbo, Andrea; Street, Richard L.; Suarez-Almazor, Maria E.

2016-01-01

Objective A prior knee osteoarthritis (OA) trial found that provider conveyed expectations for treatment success were associated with pain improvement. We hypothesized this relationship was mediated by patient self-efficacy since expectations of improvement may enhance one’s ability to control health behaviors, and therefore health. Our aim was to examine whether self-efficacy was a mediator of the relationship observed in this trial. Methods A secondary analysis of a three arm (traditional acupuncture, sham acupuncture, and wait list) trial for knee OA was conducted. Those in the acupuncture groups were equally randomized to acupuncturists trained to communicate a high or neutral expectation of treatment success (e.g. used language conveying high or unclear likelihood that acupuncture would reduce knee pain). A modified Arthritis Self-Efficacy Questionnaire and the Western Ontario McMasters (WOMAC) pain subscale were administered. Linear regression analyses were used to examine whether patient self-efficacy mediated the relationship between provider communication style and knee pain at 3 months. Results High expectation provider communication was associated with patient self-efficacy, β coefficient of 0.14 (95%CI: 0.01, 0.28). Self-efficacy was associated with WOMAC pain, β coefficient of −9.29 (95%CI: −11.11, −7.47), while controlling for the provider communication style. The indirect effect a*b of −1.36 for high versus neutral expectation, (bootstrap 95% CI: −2.80, −0.15, does not include 0), supports that patient self-efficacy mediates the relationship between provider-communicated expectations of treatment effects and knee pain. Conclusion Our findings suggest that clinician-conveyed expectations can enhance the benefit of treatments targeting knee OA symptoms, mediated by improved patient self-efficacy. PMID:26554869

Link Between Positive Clinician-Conveyed Expectations of Treatment Effect and Pain Reduction in Knee Osteoarthritis, Mediated by Patient Self-Efficacy.

PubMed

Hsiao-Wei Lo, Grace; Balasubramanyam, Ajay S; Barbo, Andrea; Street, Richard L; Suarez-Almazor, Maria E

2016-07-01

A prior knee osteoarthritis (OA) trial found that provider-conveyed expectations for treatment success were associated with pain improvement. We hypothesized this relationship was mediated by patient self-efficacy, since expectations of improvement may enhance one's ability to control health behaviors, and therefore health. Our aim was to examine whether self-efficacy was a mediator of the relationship observed in this trial. A secondary analysis of a 3-arm (traditional acupuncture, sham acupuncture, and wait list) trial for knee OA was conducted. Those in the acupuncture groups were equally randomized to acupuncturists trained to communicate a high or neutral expectation of treatment success (e.g., using language conveying high or unclear likelihood that acupuncture would reduce knee pain). A modified Arthritis Self-Efficacy Questionnaire and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale were administered. Linear regression analyses were used to examine whether patient self-efficacy mediated the relationship between provider communication style and knee pain at 3 months. High-expectation provider communication was associated with patient self-efficacy, β coefficient of 0.14 (95% confidence interval [95% CI] 0.01, 0.28). Self-efficacy was associated with WOMAC pain, β coefficient of -9.29 (95% CI -11.11, -7.47), while controlling for the provider communication style. The indirect effect a × b of -1.36 for high versus neutral expectation (bootstrap 95% CI -2.80, -0.15; does not include 0), supports the conclusion that patient self-efficacy mediates the relationship between provider-communicated expectations of treatment effects and knee pain. Our findings suggest that clinician-conveyed expectations can enhance the benefit of treatments targeting knee OA symptoms, mediated by improved patient self-efficacy. © 2016, American College of Rheumatology.

Analyzing systemic risk using non-linear marginal expected shortfall and its minimum spanning tree

NASA Astrophysics Data System (ADS)

Song, Jae Wook; Ko, Bonggyun; Chang, Woojin

2018-02-01

The aim of this paper is to propose a new theoretical framework for analyzing the systemic risk using the marginal expected shortfall (MES) and its correlation-based minimum spanning tree (MST). At first, we develop two parametric models of MES with their closed-form solutions based on the Capital Asset Pricing Model. Our models are derived from the non-symmetric quadratic form, which allows them to consolidate the non-linear relationship between the stock and market returns. Secondly, we discover the evidences related to the utility of our models and the possible association in between the non-linear relationship and the emergence of severe systemic risk by considering the US financial system as a benchmark. In this context, the evolution of MES also can be regarded as a reasonable proxy of systemic risk. Lastly, we analyze the structural properties of the systemic risk using the MST based on the computed series of MES. The topology of MST conveys the presence of sectoral clustering and strong co-movements of systemic risk leaded by few hubs during the crisis. Specifically, we discover that the Depositories are the majority sector leading the connections during the Non-Crisis period, whereas the Broker-Dealers are majority during the Crisis period.

Can we detect a nonlinear response to temperature in European plant phenology?

NASA Astrophysics Data System (ADS)

Jochner, Susanne; Sparks, Tim H.; Laube, Julia; Menzel, Annette

2016-10-01

Over a large temperature range, the statistical association between spring phenology and temperature is often regarded and treated as a linear function. There are suggestions that a sigmoidal relationship with definite upper and lower limits to leaf unfolding and flowering onset dates might be more realistic. We utilised European plant phenological records provided by the European phenology database PEP725 and gridded monthly mean temperature data for 1951-2012 calculated from the ENSEMBLES data set E-OBS (version 7.0). We analysed 568,456 observations of ten spring flowering or leafing phenophases derived from 3657 stations in 22 European countries in order to detect possible nonlinear responses to temperature. Linear response rates averaged for all stations ranged between -7.7 (flowering of hazel) and -2.7 days °C-1 (leaf unfolding of beech and oak). A lower sensitivity at the cooler end of the temperature range was detected for most phenophases. However, a similar lower sensitivity at the warmer end was not that evident. For only ˜14 % of the station time series (where a comparison between linear and nonlinear model was possible), nonlinear models described the relationship significantly better than linear models. Although in most cases simple linear models might be still sufficient to predict future changes, this linear relationship between phenology and temperature might not be appropriate when incorporating phenological data of very cold (and possibly very warm) environments. For these cases, extrapolations on the basis of linear models would introduce uncertainty in expected ecosystem changes.

"But it might be a heart attack": intolerance of uncertainty and panic disorder symptoms.

PubMed

Carleton, R Nicholas; Duranceau, Sophie; Freeston, Mark H; Boelen, Paul A; McCabe, Randi E; Antony, Martin M

2014-06-01

Panic disorder models describe interactions between feared anxiety-related physical sensations (i.e., anxiety sensitivity; AS) and catastrophic interpretations therein. Intolerance of uncertainty (IU) has been implicated as necessary for catastrophic interpretations in community samples. The current study examined relationships between IU, AS, and panic disorder symptoms in a clinical sample. Participants had a principal diagnosis of panic disorder, with or without agoraphobia (n=132; 66% women). IU was expected to account for significant variance in panic symptoms controlling for AS. AS was expected to mediate the relationship between IU and panic symptoms, whereas IU was expected to moderate the relationship between AS and panic symptoms. Hierarchical linear regressions indicated that IU accounted for significant unique variance in panic symptoms relative to AS, with comparable part correlations. Mediation and moderation models were also tested and suggested direct and indirect effects of IU on panic symptoms through AS; however, an interaction effect was not supported. The current cross-sectional evidence supports a role for IU in panic symptoms, independent of AS. Copyright © 2014 Elsevier Ltd. All rights reserved.

Consistency of the structure of Legendre transform in thermodynamics with the Kolmogorov-Nagumo average

NASA Astrophysics Data System (ADS)

Scarfone, A. M.; Matsuzoe, H.; Wada, T.

2016-09-01

We show the robustness of the structure of Legendre transform in thermodynamics against the replacement of the standard linear average with the Kolmogorov-Nagumo nonlinear average to evaluate the expectation values of the macroscopic physical observables. The consequence of this statement is twofold: 1) the relationships between the expectation values and the corresponding Lagrange multipliers still hold in the present formalism; 2) the universality of the Gibbs equation as well as other thermodynamic relations are unaffected by the structure of the average used in the theory.

Can we detect a nonlinear response to temperature in European plant phenology?

PubMed

Jochner, Susanne; Sparks, Tim H; Laube, Julia; Menzel, Annette

2016-10-01

Over a large temperature range, the statistical association between spring phenology and temperature is often regarded and treated as a linear function. There are suggestions that a sigmoidal relationship with definite upper and lower limits to leaf unfolding and flowering onset dates might be more realistic. We utilised European plant phenological records provided by the European phenology database PEP725 and gridded monthly mean temperature data for 1951-2012 calculated from the ENSEMBLES data set E-OBS (version 7.0). We analysed 568,456 observations of ten spring flowering or leafing phenophases derived from 3657 stations in 22 European countries in order to detect possible nonlinear responses to temperature. Linear response rates averaged for all stations ranged between -7.7 (flowering of hazel) and -2.7 days °C -1 (leaf unfolding of beech and oak). A lower sensitivity at the cooler end of the temperature range was detected for most phenophases. However, a similar lower sensitivity at the warmer end was not that evident. For only ∼14 % of the station time series (where a comparison between linear and nonlinear model was possible), nonlinear models described the relationship significantly better than linear models. Although in most cases simple linear models might be still sufficient to predict future changes, this linear relationship between phenology and temperature might not be appropriate when incorporating phenological data of very cold (and possibly very warm) environments. For these cases, extrapolations on the basis of linear models would introduce uncertainty in expected ecosystem changes.

Relationship between changes in vasomotor symptoms and changes in menopause-specific quality of life and sleep parameters.

PubMed

Pinkerton, JoAnn V; Abraham, Lucy; Bushmakin, Andrew G; Cappelleri, Joseph C; Komm, Barry S

2016-10-01

This study characterizes and quantifies the relationship of vasomotor symptoms (VMS) of menopause with menopause-specific quality of life (MSQOL) and sleep parameters to help predict treatment outcomes and inform treatment decision-making. Data were derived from a 12-week randomized, double-blind, placebo-controlled phase 3 trial that evaluated effects of two doses of conjugated estrogens/bazedoxifene on VMS in nonhysterectomized postmenopausal women (N = 318, mean age = 53.39) experiencing at least seven moderate to severe hot flushes (HFs) per day or at least 50 per week. Repeated measures models were used to determine relationships between HF frequency and severity and outcomes on the Menopause-Specific Quality of Life questionnaire and the Medical Outcomes Study sleep scale. Sensitivity analyses were performed to check assumptions of linearity between VMS and outcomes. Frequency and severity of HFs showed approximately linear relationships with MSQOL and sleep parameters. Sensitivity analyses supported assumptions of linearity. The largest changes associated with a reduction of five HFs and a 0.5-point decrease in severity occurred in the Menopause-Specific Quality of Life vasomotor functioning domain (0.78 for number of HFs and 0.98 for severity) and the Medical Outcomes Study sleep disturbance (7.38 and 4.86) and sleep adequacy (-5.60 and -4.66) domains and the two overall sleep problems indices (SPI: 5.17 and 3.63; SPII: 5.82 and 3.83). Frequency and severity of HFs have an approximately linear relationship with MSQOL and sleep parameters-that is, improvements in HFs are associated with improvements in MSQOL and sleep. Such relationships may enable clinicians to predict changes in sleep and MSQOL expected from various VMS treatments.

Within crown variation in the relationship between foliage biomass and sapwood area in jack pine.

PubMed

Schneider, Robert; Berninger, Frank; Ung, Chhun-Huor; Mäkelä, Annikki; Swift, D Edwin; Zhang, S Y

2011-01-01

The relationship between sapwood area and foliage biomass is the basis for a lot of research on eco-phyisology. In this paper, foliage biomass change between two consecutive whorls is studied, using different variations in the pipe model theory. Linear and non-linear mixed-effect models relating foliage differences to sapwood area increments were tested to take into account whorl location, with the best fit statistics supporting the non-linear formulation. The estimated value of the exponent is 0.5130, which is significantly different from 1, the expected value given by the pipe model theory. When applied to crown stem sapwood taper, the model indicates that foliage biomass distribution influences the foliage biomass to sapwood area at crown base ratio. This result is interpreted as being the consequence of differences in the turnover rates of sapwood and foliage. More importantly, the model explains previously reported trends in jack pine sapwood area at crown base to tree foliage biomass ratio.

Schooling, Skills, and Self-Rated Health: A Test of Conventional Wisdom on the Relationship between Educational Attainment and Health

ERIC Educational Resources Information Center

Duke, Naomi; Macmillan, Ross

2016-01-01

Education is a key sociological variable in the explanation of health and health disparities. Conventional wisdom emphasizes a life course--human capital perspective with expectations of causal effects that are quasi-linear, large in magnitude for high levels of educational attainment, and reasonably robust in the face of measured and unmeasured…

A predictive relationship between population and genetic sex ratios in clonal species

NASA Astrophysics Data System (ADS)

McLetchie, D. Nicholas; García-Ramos, Gisela

2017-04-01

Sexual reproduction depends on mate availability that is reflected by local sex ratios. In species where both sexes can clonally expand, the population sex ratio describes the proportion of males, including clonally derived individuals (ramets) in addition to sexually produced individuals (genets). In contrast to population sex ratio that accounts for the overall abundance of the sexes, the genetic sex ratio reflects the relative abundance of genetically unique mates, which is critical in predicting effective population size but is difficult to estimate in the field. While an intuitive positive relationship between population (ramet) sex ratio and genetic (genet) sex ratio is expected, an explicit relationship is unknown. In this study, we determined a mathematical expression in the form of a hyperbola that encompasses a linear to a nonlinear positive relationship between ramet and genet sex ratios. As expected when both sexes clonally have equal number of ramets per genet both sex ratios are identical, and thus ramet sex ratio becomes a linear function of genet sex ratio. Conversely, if sex differences in ramet number occur, this mathematical relationship becomes nonlinear and a discrepancy between the sex ratios amplifies from extreme sex ratios values towards intermediate values. We evaluated our predictions with empirical data that simultaneously quantified ramet and genet sex ratios in populations of several species. We found that the data support the predicted positive nonlinear relationship, indicating sex differences in ramet number across populations. However, some data may also fit the null model, which suggests that sex differences in ramet number were not extensive, or the number of populations was too small to capture the curvature of the nonlinear relationship. Data with lack of fit suggest the presence of factors capable of weakening the positive relationship between the sex ratios. Advantages of this model include predicting genet sex ratio using population sex ratios given known sex differences in ramet number, and detecting sex differences in ramet number among populations.

The Multiple Correspondence Analysis Method and Brain Functional Connectivity: Its Application to the Study of the Non-linear Relationships of Motor Cortex and Basal Ganglia.

PubMed

Rodriguez-Sabate, Clara; Morales, Ingrid; Sanchez, Alberto; Rodriguez, Manuel

2017-01-01

The complexity of basal ganglia (BG) interactions is often condensed into simple models mainly based on animal data and that present BG in closed-loop cortico-subcortical circuits of excitatory/inhibitory pathways which analyze the incoming cortical data and return the processed information to the cortex. This study was aimed at identifying functional relationships in the BG motor-loop of 24 healthy-subjects who provided written, informed consent and whose BOLD-activity was recorded by MRI methods. The analysis of the functional interaction between these centers by correlation techniques and multiple linear regression showed non-linear relationships which cannot be suitably addressed with these methods. The multiple correspondence analysis (MCA), an unsupervised multivariable procedure which can identify non-linear interactions, was used to study the functional connectivity of BG when subjects were at rest. Linear methods showed different functional interactions expected according to current BG models. MCA showed additional functional interactions which were not evident when using lineal methods. Seven functional configurations of BG were identified with MCA, two involving the primary motor and somatosensory cortex, one involving the deepest BG (external-internal globus pallidum, subthalamic nucleus and substantia nigral), one with the input-output BG centers (putamen and motor thalamus), two linking the input-output centers with other BG (external pallidum and subthalamic nucleus), and one linking the external pallidum and the substantia nigral. The results provide evidence that the non-linear MCA and linear methods are complementary and should be best used in conjunction to more fully understand the nature of functional connectivity of brain centers.

Concentration-dependent polyparameter linear free energy relationships to predict organic compound sorption on carbon nanotubes

PubMed Central

Zhao, Qing; Yang, Kun; Li, Wei; Xing, Baoshan

2014-01-01

Adsorption of organic compounds on carbon nanotubes (CNTs), governed by interactions between molecules and CNTs surfaces, is critical for their fate, transport, bioavailability and toxicity in the environment. Here, we report a promising concentration-dependent polyparameter linear free energy relationships (pp-LFERs) model to describe the compound-CNTs interactions and to predict sorption behavior of chemicals on CNTs in a wide range of concentrations (over five orders of magnitude). The developed pp-LFERs are able to capture the dependence of the ki on equilibrium concentration. The pp-LFERs indexes [r, p, a, b, v] representing different interactions are found to have a good relationship with the aqueous equilibrium concentrations of compounds. This modified model can successfully interpret the relative contribution of each interaction at a given concentration and reliably predict sorption of various chemicals on CNTs. This approach is expected to help develop a better environmental fate and risk assessment model. PMID:24463462

The relationship between posttraumatic stress disorder and smoking outcome expectancies among U.S. military veterans who served since September 11, 2001.

PubMed

Calhoun, Patrick S; Levin, Holly F; Dedert, Eric A; Johnson, Yashika; Beckham, Jean C

2011-06-01

Posttraumatic stress disorder (PTSD) is associated with increased rates of smoking although little is known regarding the mechanisms underlying this relationship. The current study examined expectations about smoking outcomes among smokers with and without PTSD. The sample included 96 veterans (mean age of 34 years) and included 17% women and 50% racial minorities. Smoking expectancies were measured with the Smoking Consequences Questionnaire-Adult (Copeland, Brandon, & Quinn, 1995). Consistent with previous work suggesting that smokers with PTSD smoke in an effort to reduce negative affect, unadjusted analyses indicated that smokers with PTSD (n = 38) had higher expectations that smoking reduces negative affect than smokers without PTSD (d = 0.61). Smokers with PTSD also had increased expectancies associated with boredom reduction (d = 0.48), stimulation (d = 0.61), taste/sensorimotor manipulation aspects of smoking (d = 0.73), and social facilitation (d = 0.61). Results of hierarchical linear regression analyses indicated that PTSD symptom severity was uniquely associated with these expectancies beyond the effects of gender and nicotine dependence. More positive beliefs about the consequences of smoking may increase risk of continued smoking among those with PTSD who smoke. Further understanding of smoking expectancies in this group may help in developing interventions tailored for this vulnerable population. Published 2011. This article is a US Government work and is in the public domain in the USA.

Modeling demand for public transit services in rural areas

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

Attaluri, P.; Seneviratne, P.N.; Javid, M.

1997-05-01

Accurate estimates of demand are critical for planning, designing, and operating public transit systems. Previous research has demonstrated that the expected demand in rural areas is a function of both demographic and transit system variables. Numerous models have been proposed to describe the relationship between the aforementioned variables. However, most of them are site specific and their validity over time and space is not reported or perhaps has not been tested. Moreover, input variables in some cases are extremely difficult to quantify. In this article, the estimation of demand using the generalized linear modeling technique is discussed. Two separate models,more » one for fixed-route and another for demand-responsive services, are presented. These models, calibrated with data from systems in nine different states, are used to demonstrate the appropriateness and validity of generalized linear models compared to the regression models. They explain over 70% of the variation in expected demand for fixed-route services and 60% of the variation in expected demand for demand-responsive services. It was found that the models are spatially transferable and that data for calibration are easily obtainable.« less

Idiosyncratic risk in the Dow Jones Eurostoxx50 Index

NASA Astrophysics Data System (ADS)

Daly, Kevin; Vo, Vinh

2008-07-01

Recent evidence by Campbell et al. [J.Y. Campbell, M. Lettau B.G. Malkiel, Y. Xu, Have individual stocks become more volatile? An empirical exploration of idiosyncratic risk, The Journal of Finance (February) (2001)] shows an increase in firm-level volatility and a decline of the correlation among stock returns in the US. In relation to the Euro-Area stock markets, we find that both aggregate firm-level volatility and average stock market correlation have trended upwards. We estimate a linear model of the market risk-return relationship nested in an EGARCH(1, 1)-M model for conditional second moments. We then show that traditional estimates of the conditional risk-return relationship, that use ex-post excess-returns as the conditioning information set, lead to joint tests of the theoretical model (usually the ICAPM) and of the Efficient Market Hypothesis in its strong form. To overcome this problem we propose alternative measures of expected market risk based on implied volatility extracted from traded option prices and we discuss the conditions under which implied volatility depends solely on expected risk. We then regress market excess-returns on lagged market implied variance computed from implied market volatility to estimate the relationship between expected market excess-returns and expected market risk.We investigate whether, as predicted by the ICAPM, the expected market risk is the main factor in explaining the market risk premium and the latter is independent of aggregate idiosyncratic risk.

Cosmic clocks: a tight radius-velocity relationship for H I-selected galaxies

NASA Astrophysics Data System (ADS)

Meurer, Gerhardt R.; Obreschkow, Danail; Wong, O. Ivy; Zheng, Zheng; Audcent-Ross, Fiona M.; Hanish, D. J.

2018-05-01

H I-selected galaxies obey a linear relationship between their maximum detected radius Rmax and rotational velocity. This result covers measurements in the optical, ultraviolet, and H I emission in galaxies spanning a factor of 30 in size and velocity, from small dwarf irregulars to the largest spirals. Hence, galaxies behave as clocks, rotating once a Gyr at the very outskirts of their discs. Observations of a large optically selected sample are consistent, implying this relationship is generic to disc galaxies in the low redshift Universe. A linear radius-velocity relationship is expected from simple models of galaxy formation and evolution. The total mass within Rmax has collapsed by a factor of 37 compared to the present mean density of the Universe. Adopting standard assumptions, we find a mean halo spin parameter λ in the range 0.020-0.035. The dispersion in λ, 0.16 dex, is smaller than expected from simulations. This may be due to the biases in our selection of disc galaxies rather than all haloes. The estimated mass densities of stars and atomic gas at Rmax are similar (˜0.5 M⊙ pc-2), indicating outer discs are highly evolved. The gas consumption and stellar population build time-scales are hundreds of Gyr, hence star formation is not driving the current evolution of outer discs. The estimated ratio between Rmax and disc scalelength is consistent with long-standing predictions from monolithic collapse models. Hence, it remains unclear whether disc extent results from continual accretion, a rapid initial collapse, secular evolution, or a combination thereof.

Conflict, social support, and relationship quality: an observational study of heterosexual, gay male, and lesbian couples' communication.

PubMed

Julien, Danielle; Chartrand, Elise; Simard, Marie-Claude; Bouthillier, Donald; Bégin, Jean

2003-09-01

Data from 42 heterosexual, 46 gay male, and 33 lesbian couples were used to assess the contribution of conflict and support discussions to relationship quality. Couples completed questionnaires, and videotaped discussions were coded for levels of negative and positive behaviors. Correlations showed that behaviors were associated with relationship quality in the expected directions. Hierarchical linear modeling analyses assessed the unique contributions of individual and dyadic behaviors to the variability of relationship quality. The findings indicated that, beyond the contribution of individual negative behaviors in the conflict task, the variables of dyadic positive behaviors in the conflict task, individual positive behaviors in the support task, and perceived help accounted for unexplained variance in relationship quality. There were no differences between types of couples on levels of behaviors or on their contributions to relationship quality.

Reducing bias and analyzing variability in the time-left procedure.

PubMed

Trujano, R Emmanuel; Orduña, Vladimir

2015-04-01

The time-left procedure was designed to evaluate the psychophysical function for time. Although previous results indicated a linear relationship, it is not clear what role the observed bias toward the time-left option plays in this procedure and there are no reports of how variability changes with predicted indifference. The purposes of this experiment were to reduce bias experimentally, and to contrast the difference limen (a measure of variability around indifference) with predictions from scalar expectancy theory (linear timing) and behavioral economic model (logarithmic timing). A control group of 6 rats performed the original time-left procedure with C=60 s and S=5, 10,…, 50, 55 s, whereas a no-bias group of 6 rats performed the same conditions in a modified time-left procedure in which only a single response per choice trial was allowed. Results showed that bias was reduced for the no-bias group, observed indifference grew linearly with predicted indifference for both groups, and difference limen and Weber ratios decreased as expected indifference increased for the control group, which is consistent with linear timing, whereas for the no-bias group they remained constant, consistent with logarithmic timing. Therefore, the time-left procedure generates results consistent with logarithmic perceived time once bias is experimentally reduced. Copyright © 2015 Elsevier B.V. All rights reserved.

Expected satiation alone does not predict actual intake of desserts.

PubMed

Guillocheau, Etienne; Davidenko, Olga; Marsset-Baglieri, Agnès; Darcel, Nicolas; Gaudichon, Claire; Tomé, Daniel; Fromentin, Gilles

2018-04-01

The degree to which consumers expect foods to satisfy hunger, referred to as expected satiation, has been reported to predict food intake. Yet this relationship has not been established precisely, at a quantitative level. We sought to explore this relationship in detail by determining whether expected satiation predicts the actual intake of semi-solid desserts. Two separate experiments were performed: the first used variations of a given food (eight apple purées), while the second involved a panel of different foods within a given category (eight desserts). Both experiments studied the consumption of two products assigned to volunteers based on their individual liking and expected satiation ratings, given ad libitum at the end of a standardised meal. A linear model was used to find predictors of food intake and included expected satiation scores, palatability scores, BMI, age, sex, TFEQ-R, TFEQ-D, water consumption during the meal, reported frequency of eating desserts, and reported frequency of consuming tested products as explanatory variables. Expected satiation was a significant predictor of actual food intake in both experiments (apple purée: F(1,97) = 18.60, P < .001; desserts: F(1,106) = 9.05, P < .01), along with other parameters such as product palatability and the volunteers' age, sex and food restriction (variation explained by the model/expected satiation in the experiments: 57%/23% and 36%/17%, respectively). However, we found a significant gap between expected and actual consumption of desserts, on group and on individual level. Our results confirm the importance of expected satiation as a predictor of subsequent food intake, but highlight the need to study individual consumption behaviour and preferences in order to fully understand the role of expected satiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Learning from Non-Linear Ecosystem Dynamics Is Vital for Achieving Land Degradation Neutrality

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

Sietz, Diana; Fleskens, Luuk; Stringer, Lindsay C.

Land Degradation Neutrality is one of the Sustainable Development Goal targets, requiring on-going degradation to be balanced by restoration and sustainable land management. However, restoration and efforts to prevent degradation have often failed to deliver expected benefits,despite enormous investments. Better acknowledging the close relationships between climate, land management and non-linear ecosystem dynamics can help restoration activities to meet their intended goals, while supporting climate change adaptation and mitigation. This paper is the first to link ecological theory of non-linear ecosystem dynamics to Land Degradation Neutrality offering essential insights into appropriate timings, climate-induced windows of opportunities and risks and the financialmore » viability of investments. These novel insights are pre-requisites for meaningful o and monitoring of progress towards Land Degradation Neutrality« less

Learning from Non-Linear Ecosystem Dynamics Is Vital for Achieving Land Degradation Neutrality

DOE PAGES

Sietz, Diana; Fleskens, Luuk; Stringer, Lindsay C.

2017-02-27

Land Degradation Neutrality is one of the Sustainable Development Goal targets, requiring on-going degradation to be balanced by restoration and sustainable land management. However, restoration and efforts to prevent degradation have often failed to deliver expected benefits,despite enormous investments. Better acknowledging the close relationships between climate, land management and non-linear ecosystem dynamics can help restoration activities to meet their intended goals, while supporting climate change adaptation and mitigation. This paper is the first to link ecological theory of non-linear ecosystem dynamics to Land Degradation Neutrality offering essential insights into appropriate timings, climate-induced windows of opportunities and risks and the financialmore » viability of investments. These novel insights are pre-requisites for meaningful o and monitoring of progress towards Land Degradation Neutrality« less

How Important Are Health Care Expenditures for Life Expectancy? A Comparative, European Analysis.

PubMed

van den Heuvel, Wim J A; Olaroiu, Marinela

2017-03-01

The relationship between health care expenditures and health care outcomes, such as life expectancy and mortality, is complex. Research outcomes show different and contradictory results on this relationship. How and why health care expenditures affect health outcomes is not clear. A causal link between the two is not proven. Without such knowledge, effects of increase/decrease in health care expenses on health outcomes may be overestimated/underestimated. This study analyzes the relationship between life expectancy at birth and expenditures on health care, taking into account expenditures of social production and education, as well as the quantity and quality of health care provisions and lifestyles. This is a cross-sectional study, analyzing national data of 31 European countries. First, the bivariate correlation between the dependent variable and independent variables are calculated and described. Next a forward linear regression analysis is applied. The data are derived from standardized, comparative data bases as available in the Organisation for Economic Co-operation and Development and Eurostat. Health care expenditures are assessed as a percentage of the Gross Domestic Product (GDP). Health care expenditures are not the main determinant of life expectancy at birth, but social protection expenditures are. The regression analysis shows that in countries that spend a high percentage of their GDP on social protection, that have fewer curative beds and low infant mortality, whose citizens report fewer unmet health care needs and drink less alcohol, citizens have a significant longer life expectancy. To realize high life expectancy of citizens, policy measures have to be directed on investment in social protection expenditures, on improving quality of care, and on promoting a healthy life style. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Geotechnical and mineralogical characteristics of marl deposits in Jordan

NASA Astrophysics Data System (ADS)

Shaqour, Fathi M.; Jarrar, Ghaleb; Hencher, Steve; Kuisi, Mostafa

2008-10-01

Marls and marly limestone deposits cover most of Northern Jordan, where Amman City and its suburbs are located. These deposits serve as foundations for most buildings and roads as well as fill material for structural back filling, especially road bases and sub-bases. The present study aims at investigating the geotechnical characteristics and mineral composition of the marl units of these deposits through field investigations and laboratory testing. Using X-ray diffraction technique along with chemical analysis, representative samples of marl horizons were tested for mineral composition, and for a set of index and geotechnical properties including: specific gravity, grain size, Atterberg limits, Proctor compaction and shear strength properties. The test results show a positive linear relationship as expected between the clay content and both liquid and plastic limits. The tests results also show an inverse linear relationship between the clay content and the maximum dry density in both standard and modified compaction. This is attributed to the adsorption of water by the clay minerals. The relationship is more prominent in the case of modified compaction test. The results also indicate a similar relationship for the angle of internal friction. No clear correlation between cohesion and clay content was apparent.

Optimal Hedging Rule for Reservoir Refill Operation

NASA Astrophysics Data System (ADS)

Wan, W.; Zhao, J.; Lund, J. R.; Zhao, T.; Lei, X.; Wang, H.

2015-12-01

This paper develops an optimal reservoir Refill Hedging Rule (RHR) for combined water supply and flood operation using mathematical analysis. A two-stage model is developed to formulate the trade-off between operations for conservation benefit and flood damage in the reservoir refill season. Based on the probability distribution of the maximum refill water availability at the end of the second stage, three zones are characterized according to the relationship among storage capacity, expected storage buffer (ESB), and maximum safety excess discharge (MSED). The Karush-Kuhn-Tucker conditions of the model show that the optimality of the refill operation involves making the expected marginal loss of conservation benefit from unfilling (i.e., ending storage of refill period less than storage capacity) as nearly equal to the expected marginal flood damage from levee overtopping downstream as possible while maintaining all constraints. This principle follows and combines the hedging rules for water supply and flood management. A RHR curve is drawn analogously to water supply hedging and flood hedging rules, showing the trade-off between the two objectives. The release decision result has a linear relationship with the current water availability, implying the linearity of RHR for a wide range of water conservation functions (linear, concave, or convex). A demonstration case shows the impacts of factors. Larger downstream flood conveyance capacity and empty reservoir capacity allow a smaller current release and more water can be conserved. Economic indicators of conservation benefit and flood damage compete with each other on release, the greater economic importance of flood damage is, the more water should be released in the current stage, and vice versa. Below a critical value, improving forecasts yields less water release, but an opposing effect occurs beyond this critical value. Finally, the Danjiangkou Reservoir case study shows that the RHR together with a rolling horizon decision approach can lead to a gradual dynamic refilling, indicating its potential for practical use.

Outcome Expectancy and Sexual Compulsivity among Men who have Sex with Men Living with HIV

PubMed Central

Brown, Monique J.; Serovich, Julianne M.; Kimberly, Judy A.

2016-01-01

Sexual compulsivity is operationalized by engaging in repetitive sexual acts, having multiple sexual partners and/or the excessive use of pornography. Outcome expectancy refers to the beliefs about the consequences of engaging in a given behavior. Research examining the relationship between outcome expectancy and sexual compulsivity is limited. The aim of this study was to assess the association between outcome expectancy and sexual compulsivity among men who have sex with men (MSM) living with HIV. Data were obtained from 338 MSM. Simple and multiple linear regression models were used to assess the association between outcome expectancy and sexual compulsivity. After adjusting for age, race/ethnicity, income, education, and employment status, for every one point increase in outcome expectancies for condom use, HIV disclosure and negotiation of safer sex practices, there was, on average, an approximate one point decrease in sexual compulsivity score. Prevention and intervention programs geared towards reducing sexual compulsivity among MSM should focus on increasing outcome expectancies for condom use, HIV disclosure and negotiation of safer sex practices. PMID:26979416

Drawing the line between constituent structure and coherence relations in visual narratives

PubMed Central

Cohn, Neil; Bender, Patrick

2016-01-01

Theories of visual narrative understanding have often focused on the changes in meaning across a sequence, like shifts in characters, spatial location, and causation, as cues for breaks in the structure of a discourse. In contrast, the theory of Visual Narrative Grammar posits that hierarchic “grammatical” structures operate at the discourse level using categorical roles for images, which may or may not co-occur with shifts in coherence. We therefore examined the relationship between narrative structure and coherence shifts in the segmentation of visual narrative sequences using a “segmentation task” where participants drew lines between images in order to divide them into sub-episodes. We used regressions to analyze the influence of the expected constituent structure boundary, narrative categories, and semantic coherence relationships on the segmentation of visual narrative sequences. Narrative categories were a stronger predictor of segmentation than linear coherence relationships between panels, though both influenced participants’ divisions. Altogether, these results support the theory that meaningful sequential images use a narrative grammar that extends above and beyond linear semantic shifts between discourse units. PMID:27709982

Drawing the line between constituent structure and coherence relations in visual narratives.

PubMed

Cohn, Neil; Bender, Patrick

2017-02-01

Theories of visual narrative understanding have often focused on the changes in meaning across a sequence, like shifts in characters, spatial location, and causation, as cues for breaks in the structure of a discourse. In contrast, the theory of visual narrative grammar posits that hierarchic "grammatical" structures operate at the discourse level using categorical roles for images, which may or may not co-occur with shifts in coherence. We therefore examined the relationship between narrative structure and coherence shifts in the segmentation of visual narrative sequences using a "segmentation task" where participants drew lines between images in order to divide them into subepisodes. We used regressions to analyze the influence of the expected constituent structure boundary, narrative categories, and semantic coherence relationships on the segmentation of visual narrative sequences. Narrative categories were a stronger predictor of segmentation than linear coherence relationships between panels, though both influenced participants' divisions. Altogether, these results support the theory that meaningful sequential images use a narrative grammar that extends above and beyond linear semantic shifts between discourse units. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Compact cosmic ray detector for unattended atmospheric ionization monitoring

NASA Astrophysics Data System (ADS)

Aplin, K. L.; Harrison, R. G.

2010-12-01

Two vertical cosmic ray telescopes for atmospheric cosmic ray ionization event detection are compared. Counter A, designed for low power remote use, was deployed in the Welsh mountains; its event rate increased with altitude as expected from atmospheric cosmic ray absorption. Independently, Counter B's event rate was found to vary with incoming particle acceptance angle. Simultaneous co-located comparison of both telescopes exposed to atmospheric ionization showed a linear relationship between their event rates.

Global non-linear effect of temperature on economic production.

PubMed

Burke, Marshall; Hsiang, Solomon M; Miguel, Edward

2015-11-12

Growing evidence demonstrates that climatic conditions can have a profound impact on the functioning of modern human societies, but effects on economic activity appear inconsistent. Fundamental productive elements of modern economies, such as workers and crops, exhibit highly non-linear responses to local temperature even in wealthy countries. In contrast, aggregate macroeconomic productivity of entire wealthy countries is reported not to respond to temperature, while poor countries respond only linearly. Resolving this conflict between micro and macro observations is critical to understanding the role of wealth in coupled human-natural systems and to anticipating the global impact of climate change. Here we unify these seemingly contradictory results by accounting for non-linearity at the macro scale. We show that overall economic productivity is non-linear in temperature for all countries, with productivity peaking at an annual average temperature of 13 °C and declining strongly at higher temperatures. The relationship is globally generalizable, unchanged since 1960, and apparent for agricultural and non-agricultural activity in both rich and poor countries. These results provide the first evidence that economic activity in all regions is coupled to the global climate and establish a new empirical foundation for modelling economic loss in response to climate change, with important implications. If future adaptation mimics past adaptation, unmitigated warming is expected to reshape the global economy by reducing average global incomes roughly 23% by 2100 and widening global income inequality, relative to scenarios without climate change. In contrast to prior estimates, expected global losses are approximately linear in global mean temperature, with median losses many times larger than leading models indicate.

Global non-linear effect of temperature on economic production

NASA Astrophysics Data System (ADS)

Burke, Marshall; Hsiang, Solomon M.; Miguel, Edward

2015-11-01

Growing evidence demonstrates that climatic conditions can have a profound impact on the functioning of modern human societies, but effects on economic activity appear inconsistent. Fundamental productive elements of modern economies, such as workers and crops, exhibit highly non-linear responses to local temperature even in wealthy countries. In contrast, aggregate macroeconomic productivity of entire wealthy countries is reported not to respond to temperature, while poor countries respond only linearly. Resolving this conflict between micro and macro observations is critical to understanding the role of wealth in coupled human-natural systems and to anticipating the global impact of climate change. Here we unify these seemingly contradictory results by accounting for non-linearity at the macro scale. We show that overall economic productivity is non-linear in temperature for all countries, with productivity peaking at an annual average temperature of 13 °C and declining strongly at higher temperatures. The relationship is globally generalizable, unchanged since 1960, and apparent for agricultural and non-agricultural activity in both rich and poor countries. These results provide the first evidence that economic activity in all regions is coupled to the global climate and establish a new empirical foundation for modelling economic loss in response to climate change, with important implications. If future adaptation mimics past adaptation, unmitigated warming is expected to reshape the global economy by reducing average global incomes roughly 23% by 2100 and widening global income inequality, relative to scenarios without climate change. In contrast to prior estimates, expected global losses are approximately linear in global mean temperature, with median losses many times larger than leading models indicate.

Changes in Bird Functional Diversity across Multiple Land Uses: Interpretations of Functional Redundancy Depend on Functional Group Identity

PubMed Central

Luck, Gary W.; Carter, Andrew; Smallbone, Lisa

2013-01-01

Examinations of the impact of land-use change on functional diversity link changes in ecological community structure driven by land modification with the consequences for ecosystem function. Yet, most studies have been small-scale, experimental analyses and primarily focussed on plants. There is a lack of research on fauna communities and at large-scales across multiple land uses. We assessed changes in the functional diversity of bird communities across 24 land uses aligned along an intensification gradient. We tested the hypothesis that functional diversity is higher in less intensively used landscapes, documented changes in diversity using four diversity metrics, and examined how functional diversity varied with species richness to identify levels of functional redundancy. Functional diversity, measured using a dendogram-based metric, increased from high to low intensity land uses, but observed values did not differ significantly from randomly-generated expected values. Values for functional evenness and functional divergence did not vary consistently with land-use intensification, although higher than expected values were mostly recorded in high intensity land uses. A total of 16 land uses had lower than expected values for functional dispersion and these were mostly low intensity native vegetation sites. Relations between functional diversity and bird species richness yielded strikingly different patterns for the entire bird community vs. particular functional groups. For all birds and insectivores, functional evenness, divergence and dispersion showed a linear decline with increasing species richness suggesting substantial functional redundancy across communities. However, for nectarivores, frugivores and carnivores, there was a significant hump-shaped or non-significant positive linear relationship between these functional measures and species richness indicating less redundancy. Hump-shaped relationships signify that the most functionally diverse communities occur at intermediate levels of species richness. Interpretations of redundancy thus vary for different functional groups and related ecosystem functions (e.g. pollination), and can be substantially different to relationships involving entire ecological communities. PMID:23696844

Characterizing Mobile/Less-Mobile Porosity and Solute Exchange in Dual-Domain Media Using Tracer Experiments and Electrical Measurements in a Hassler-Type Core Holder

NASA Astrophysics Data System (ADS)

Falzone, S.; Slater, L. D.; Day-Lewis, F. D.; Parker, B. L.; Keating, K.; Robinson, J.

2017-12-01

Mass transfer is the process by which solute is retained in less-mobile porosity domains, and later released into the mobile porosity domain. This process is often responsible for the slow arrival and gradual release of contaminants and solute tracers. Recent studies have outlined methods using dual-domain mass transfer (DDMT) models for characterizing this phenomenon. These models use the non-linear relationship of bulk (σb) and fluid (σf) conductivity, collected from electrical methods during tracer experiments, to characterize the less-mobile/mobile porosity ratio (β) and the mass-transfer rate coefficient (α). DDMT models use the hysteretic σb-σf relationship observed while solute tracers are injected and then flushed from a sample media. Due to limitations in observing the hysteretic σb-σf relationship, this method has not been used to characterize low permeability samples. We have developed an experimental method for testing porous rock cores that allows us to develop a fundamental understanding of contaminant storage and release in consolidated rock. We test the approach on cores from sedimentary rock sites where mass transfer is expected to occur between hydraulically connected fractures and the adjacent low permeability rock matrix. Our method uses a Hassler-type core holder, designed to apply confining pressure around the outside of a sample core, which hydraulically isolates the sample core, allowing water to be injected into it at increased pressures. The experimental apparatus was also designed to measure σb with spectral induced polarization (SIP) measurements, and σf from a sampling port located at the center of the core. Cores were initially saturated with a solution with high electrical conductivity ( 80000 μS/cm). DI water was then injected into the cores at elevated pressures (>60 psi) and the saturating solution was flushed from the cores, in order to generate flow rates fast enough to capture the non-linear σb-σf relationship expected when DDMT occurs. Our initial results demonstrate the existence of a non-linear σb-σf relationship indicative of DDMT for a tight sandstone core from a contaminated fractured rock site. Integrating the electrical results with known physical characteristics of the cores, we are able to quantify the mass transfer characteristics of the cores.

Using the social cognitive theory to understand physical activity among dialysis patients.

PubMed

Patterson, Megan S; Umstattd Meyer, M Renée; Beaujean, A Alexander; Bowden, Rodney G

2014-08-01

The purpose of this study was to use the social cognitive theory (SCT) constructs self-efficacy, outcome expectations, and self-regulation to better understand associations of physical activity (PA) behaviors among dialysis patients after controlling for demographic and health-related factors. This study was cross-sectional in design. Participants (N = 115; mean age = 61.51 years, SD = 14.01) completed self-report questionnaires during a regularly scheduled dialysis treatment session. Bivariate and hierarchical linear regression analyses were conducted to examine relationships among SCT constructs and PA. Significant relationships between PA and self-efficacy (r = .336), self-regulation (r = .280), and outcome expectations (r = .265) were detected among people on dialysis in bivariate analyses. Hierarchical linear regression revealed significant increases in variance explained for the addition of self-efficacy, self-regulation, and covariates (p < .01). Younger age, self-efficacy, and self-regulation were associated (p < .10) with greater participation in physical activity in the final model (R² = .272). Conclusion/Implication: This research supports the use of SCT in understanding PA among people undergoing dialysis treatment. The findings of this study can help health educators and health care practitioners better understand PA and how to promote it among this population. Future research should further investigate which activities dialysis patients participate in across the life span of their disease. Future PA programs should focus on increasing a patient's self-efficacy and self-regulation.

Predicting rates of inbreeding in populations undergoing selection.

PubMed Central

Woolliams, J A; Bijma, P

2000-01-01

Tractable forms of predicting rates of inbreeding (DeltaF) in selected populations with general indices, nonrandom mating, and overlapping generations were developed, with the principal results assuming a period of equilibrium in the selection process. An existing theorem concerning the relationship between squared long-term genetic contributions and rates of inbreeding was extended to nonrandom mating and to overlapping generations. DeltaF was shown to be approximately (1)/(4)(1 - omega) times the expected sum of squared lifetime contributions, where omega is the deviation from Hardy-Weinberg proportions. This relationship cannot be used for prediction since it is based upon observed quantities. Therefore, the relationship was further developed to express DeltaF in terms of expected long-term contributions that are conditional on a set of selective advantages that relate the selection processes in two consecutive generations and are predictable quantities. With random mating, if selected family sizes are assumed to be independent Poisson variables then the expected long-term contribution could be substituted for the observed, providing (1)/(4) (since omega = 0) was increased to (1)/(2). Established theory was used to provide a correction term to account for deviations from the Poisson assumptions. The equations were successfully applied, using simple linear models, to the problem of predicting DeltaF with sib indices in discrete generations since previously published solutions had proved complex. PMID:10747074

Preference and Expectation for Treatment Assignment in a Randomized Controlled Trial of Once- vs Twice-weekly Yoga for Chronic Low Back Pain

PubMed Central

Weinberg, Janice; Sherman, Karen J.; Saper, Robert B.

2015-01-01

Background: In studies involving nonpharmacological complementary and alternative medicine interventions, participant blinding is very difficult. Participant expectations may affect perceived benefit of therapy. In studies of yoga as treatment for chronic low back pain, little is known about the relationship between patient expectations and preferences on outcomes. This study was designed to identify baseline predictors of preference and to determine if expectations and preferences for different doses of yoga affect back-related function and low back pain intensity. Methods: This was a secondary data analysis of a 12-week randomized controlled trial comparing once-weekly vs twice-weekly yoga for treatment of chronic low back pain in 93 adults from a predominantly low-income minority population. At baseline, participants were asked about back function, back pain, treatment expectations, and treatment preferences. We created a variable “concordance” to describe the matching of participant preference to randomized treatment. Our outcome variables were change in back function and pain intensity after 12 weeks of yoga instruction. We performed logistic regression to identify predictors of preference for once- or twice-weekly yoga instruction. We created linear regression models to identify independent associations between expectations, preference, concordance, and outcomes. Results: Worse back function at baseline was associated with 20% higher odds of preferring twice-weekly yoga (OR 1.2, CI 1.1, 1.3). Individuals with higher expectation scores for twice-weekly yoga had 90% higher odds of preferring twice-weekly vs once-weekly yoga (OR 1.9, CI 1.3, 2.7). Individuals with higher expectation scores for once-weekly yoga had 40% less odds of preferring twice-weekly yoga (OR 0.6, CI 0.5, 0.9). After controlling for baseline characteristics, we found no statistically significant relationship between treatment outcomes, preference, expectation scores, or concordance. Conclusion: In a population of predominantly low-income minority participants with chronic low back pain, worse back function was associated with preference for more frequent yoga classes. Those who preferred more yoga classes had higher expectations for those classes. Twelve-week change in back pain intensity and back function were not affected by dosing preference, expectation score, or concordance. More research is needed to better measure and quantify preference, expectations, and their relationship to outcomes in yoga research. PMID:25694850

Air - water temperature relationships in the trout streams of southeastern Minnesota’s carbonate - sandstone landscape

USGS Publications Warehouse

Krider, Lori A.; Magner, Joseph A.; Perry, Jim; Vondracek, Bruce C.; Ferrington, Leonard C.

2013-01-01

Carbonate-sandstone geology in southeastern Minnesota creates a heterogeneous landscape of springs, seeps, and sinkholes that supply groundwater into streams. Air temperatures are effective predictors of water temperature in surface-water dominated streams. However, no published work investigates the relationship between air and water temperatures in groundwater-fed streams (GWFS) across watersheds. We used simple linear regressions to examine weekly air-water temperature relationships for 40 GWFS in southeastern Minnesota. A 40-stream, composite linear regression model has a slope of 0.38, an intercept of 6.63, and R2 of 0.83. The regression models for GWFS have lower slopes and higher intercepts in comparison to surface-water dominated streams. Regression models for streams with high R2 values offer promise for use as predictive tools for future climate conditions. Climate change is expected to alter the thermal regime of groundwater-fed systems, but will do so at a slower rate than surface-water dominated systems. A regression model of intercept vs. slope can be used to identify streams for which water temperatures are more meteorologically than groundwater controlled, and thus more vulnerable to climate change. Such relationships can be used to guide restoration vs. management strategies to protect trout streams.

Rare-Earth Fourth-Order Multipole Moment in Cubic ErCo2 Probed by Linear Dichroism in Core-Level Photoemission

NASA Astrophysics Data System (ADS)

Abozeed, Amina A.; Kadono, Toshiharu; Sekiyama, Akira; Fujiwara, Hidenori; Higashiya, Atsushi; Yamasaki, Atsushi; Kanai, Yuina; Yamagami, Kohei; Tamasaku, Kenji; Yabashi, Makina; Ishikawa, Tetsuya; Andreev, Alexander V.; Wada, Hirofumi; Imada, Shin

2018-03-01

We developed a method to experimentally quantify the fourth-order multipole moment of the rare-earth 4f orbital. Linear dichroism (LD) in the Er 3d5/2 core-level photoemission spectra of cubic ErCo2 was measured using bulk-sensitive hard X-ray photoemission spectroscopy. Theoretical calculation reproduced the observed LD, and the result showed that the observed result does not contradict the suggested Γ 83 ground state. Theoretical calculation further showed a linear relationship between the LD size and the size of the fourth-order multipole moment of the Er3+ ion, which is proportional to the expectation value < O40 + 5O44> , where Onm are the Stevens operators. These analyses indicate that the LD in 3d photoemission spectra can be used to quantify the average fourth-order multipole moment of rare-earth atoms in a cubic crystal electric field.

A simple theory of motor protein kinetics and energetics. II.

PubMed

Qian, H

2000-01-10

A three-state stochastic model of motor protein [Qian, Biophys. Chem. 67 (1997) pp. 263-267] is further developed to illustrate the relationship between the external load on an individual motor protein in aqueous solution with various ATP concentrations and its steady-state velocity. A wide variety of dynamic motor behavior are obtained from this simple model. For the particular case of free-load translocation being the most unfavorable step within the hydrolysis cycle, the load-velocity curve is quasi-linear, V/Vmax = (cF/Fmax-c)/(1-c), in contrast to the hyperbolic relationship proposed by A.V. Hill for macroscopic muscle. Significant deviation from the linearity is expected when the velocity is less than 10% of its maximal (free-load) value--a situation under which the processivity of motor diminishes and experimental observations are less certain. We then investigate the dependence of load-velocity curve on ATP (ADP) concentration. It is shown that the free load Vmax exhibits a Michaelis-Menten like behavior, and the isometric Fmax increases linearly with ln([ATP]/[ADP]). However, the quasi-linear region is independent of the ATP concentration, yielding an apparently ATP-independent maximal force below the true isometric force. Finally, the heat production as a function of ATP concentration and external load are calculated. In simple terms and solved with elementary algebra, the present model provides an integrated picture of biochemical kinetics and mechanical energetics of motor proteins.

The Relationship between Pedal Force and Crank Angular Velocity in Sprint Cycling.

PubMed

Bobbert, Maarten Frank; Casius, L J Richard; Van Soest, Arthur J

2016-05-01

Relationships between tangential pedal force and crank angular velocity in sprint cycling tend to be linear. We set out to understand why they are not hyperbolic, like the intrinsic force-velocity relationship of muscles. We simulated isokinetic sprint cycling at crank angular velocities ranging from 30 to 150 rpm with a forward dynamic model of the human musculoskeletal system actuated by eight lower extremity muscle groups. The input of the model was muscle stimulation over time, which we optimized to maximize average power output over a cycle. Peak tangential pedal force was found to drop more with crank angular velocity than expected based on intrinsic muscle properties. This linearizing effect was not due to segmental dynamics but rather due to active state dynamics. Maximizing average power in cycling requires muscles to bring their active state from as high as possible during shortening to as low as possible during lengthening. Reducing the active state is a relatively slow process, and hence must be initiated a certain amount of time before lengthening starts. As crank angular velocity goes up, this amount of time corresponds to a greater angular displacement, so the instant of switching off extensor muscle stimulation must occur earlier relative to the angle at which pedal force was extracted for the force-velocity relationship. Relationships between pedal force and crank angular velocity in sprint cycling do not reflect solely the intrinsic force-velocity relationship of muscles but also the consequences of activation dynamics.

Aqueous solubilities, vapor pressures, and 1-octanol-water partition coefficients for C9-C14 linear alkylbenzenes

USGS Publications Warehouse

Sherblom, P.M.; Gschwend, P.M.; Eganhouse, R.P.

1992-01-01

Measurements and estimates of aqueous solubilities, 1-octanol-water partition coefficients (Kow), and vapor pressures were made for 29 linear alkylbenzenes having alkyl chain lengths of 9-14 carbons. The ranges of values observed were vapor pressures from 0.002 to 0.418 Pa, log Kow, from 6.83 to 9.95, and aqueous solubilities from 4 to 38 nmol??L-1. Measured values exhibited a relationship to both the alkyl chain length and the position of phenyl substitution on the alkyl chain. Measurement of the aqueous concentrations resulting from equilibration of a mixture of alkylbenzenes yielded higher than expected values, indicating cosolute or other interactive effects caused enhanced aqueous concentrations of these compounds. ?? 1992 American Chemical Society.

Extant or Absent: Formation Water in New York State Drinking Water Wells

NASA Astrophysics Data System (ADS)

Christian, K.; Lautz, L. K.

2013-12-01

The current moratorium on hydraulic fracturing in New York State (NYS) provides an opportunity to collect baseline shallow groundwater quality data pre-hydraulic fracturing, which is essential for determining the natural variability of groundwater chemistry and to evaluate future claims of impaired groundwater quality if hydraulic fracturing occurs in the State. Concerns regarding the future environmental impact of shale gas extraction in NYS include potential shallow groundwater contamination due to migration of methane or formation water from shale gas extraction sites. Treatment, storage and disposal of saline flowback fluids after gas extraction could also be a source of water contamination. In this study, we combine southern NYS shallow groundwater chemistry data from Project Shale-Water Interaction Forensic Tools (SWIFT, n=60), the National Uranium Resource Evaluation program (NURE, n=684), and the USGS 305(b) Ambient Groundwater Quality Monitoring program (USGS, n=89) to examine evidence of formation water mixing with groundwater using the methodology of Warner et al. (2012). Groundwater characterized as low salinity (<20 mg/L Cl-) accounted for 72% of samples and 28% of samples had high salinity (>20 mg/L Cl-). A plot of bromide versus chloride shows high salinity groundwater samples with Br/Cl ratios >0.0001 fall on the mixing line between low salinity groundwater and Appalachian Basin formation water. Based on the observed linear relationship between bromide and chloride, it appears there is up to 1% formation water mixing with shallow groundwater in the region. The presence of formation water in shallow groundwater would indicate the existence of natural migratory pathways between deep formation wells and shallow groundwater aquifers. A plot of sodium versus chloride also illustrates a linear trend for Type D waters (R^2= 0.776), but the relationship is weaker than that for bromide versus chloride (R^2= 0.924). Similar linear relationships are not observed between other ions and chloride, including Mg, Ca, and Sr. If high salinity groundwater samples from NYS contain small percentages of formation water, we expect linear relationships between chloride and these other, generally conservative ions. The absence of these linear relationships suggests high salinity could be associated with contamination by landfill leachate, septic effluent, road salt, or other potential sources of elevated salt. Future work needs to determine if mixing of shallow groundwater with other potential sources of salinity, such as road deicers, can explain the observed linear relationships. Strontium isotopes from shallow groundwater samples will also be compared to those for NY formation water.

A first-principles core-level XPS study on the boron impurities in germanium crystal

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

Yamauchi, Jun; Yoshimoto, Yoshihide; Suwa, Yuji

2013-12-04

We systematically investigated the x-ray photoelectron spectroscopy (XPS) core-level shifts and formation energies of boron defects in germanium crystals and compared the results to those in silicon crystals. Both for XPS core-level shifts and formation energies, relationship between defects in Si and Ge is roughly linear. From the similarity in the formation energy, it is expected that the exotic clusters like icosahedral B12 exist in Ge as well as in Si.

Estimation of octanol/water partition coefficients using LSER parameters

USGS Publications Warehouse

Luehrs, Dean C.; Hickey, James P.; Godbole, Kalpana A.; Rogers, Tony N.

1998-01-01

The logarithms of octanol/water partition coefficients, logKow, were regressed against the linear solvation energy relationship (LSER) parameters for a training set of 981 diverse organic chemicals. The standard deviation for logKow was 0.49. The regression equation was then used to estimate logKow for a test of 146 chemicals which included pesticides and other diverse polyfunctional compounds. Thus the octanol/water partition coefficient may be estimated by LSER parameters without elaborate software but only moderate accuracy should be expected.

Career Preparedness and School Achievement of Portuguese Children: Longitudinal Trend Articulations

PubMed Central

Oliveira, Íris M.; Taveira, Maria do Céu; Porfeli, Erik J.

2017-01-01

Social Cognitive Career Theory suggests that students' preparedness for the school-to-work transition is a developmental process. Middle school children explore various careers, obtain feedback about their academic progress, and develop career self-efficacy and outcome expectations. These processes advance provisional educational/occupational goals. The literature has suggested articulations between career and academic development and how both vary across demographic characteristics, but longitudinal studies linking these processes are scarce. This study tested articulations between career preparedness and academic achievement during middle school years and employed gender and geographical location as potential moderators affecting the linkage between career and school domains. Participants included 429 children (47.8% girls) from northern (69.5%) and central Portugal (30.5%) followed across four occasions of measurement (MageWave1 = 10.23, SD = 0.50). Data was collected with school records, the Multidimensional Scales of Perceived Self-Efficacy, Career Exploratory Outcome Expectations Scale, Childhood Career Exploration Inventory and Childhood Career Development Scale. Average and orthnormalized linear, quadratic and cubic trends were computed. Pearson correlation coefficients suggested positive and statistically significant associations between career exploratory outcome expectations and academic achievement average trends. Career planning and self-efficacy expectations were negatively associated with academic achievement quadratic trends. Multiple linear regression models suggested that career exploratory outcome expectations and career planning were respectively statistically significant predictors of the average and quadratic trends of academic achievement. Gender moderated the association between the career variables and academic achievement linear trends as well as the relation of career planning and self-efficacy with academic achievement cubic trends. Additionally, the geographical location moderated the association between the average trend of career exploratory outcome expectations and academic achievement as well as tended to moderate the relation between the career variables and academic achievement quadratic trends. Future research could seek to explore the role of context in shaping the trajectories and linkages between career and academic progress with a more representative sample of participants from a broader array of geographical locations. This study advances extant literature by affirming the longitudinal relationship between the school and work domains in youth, which might sustain practices aimed at fostering students' career preparedness and academic achievement. PMID:28484413

Career Preparedness and School Achievement of Portuguese Children: Longitudinal Trend Articulations.

PubMed

Oliveira, Íris M; Taveira, Maria do Céu; Porfeli, Erik J

2017-01-01

Social Cognitive Career Theory suggests that students' preparedness for the school-to-work transition is a developmental process. Middle school children explore various careers, obtain feedback about their academic progress, and develop career self-efficacy and outcome expectations. These processes advance provisional educational/occupational goals. The literature has suggested articulations between career and academic development and how both vary across demographic characteristics, but longitudinal studies linking these processes are scarce. This study tested articulations between career preparedness and academic achievement during middle school years and employed gender and geographical location as potential moderators affecting the linkage between career and school domains. Participants included 429 children (47.8% girls) from northern (69.5%) and central Portugal (30.5%) followed across four occasions of measurement ( M ageWave1 = 10.23, SD = 0.50). Data was collected with school records, the Multidimensional Scales of Perceived Self-Efficacy, Career Exploratory Outcome Expectations Scale, Childhood Career Exploration Inventory and Childhood Career Development Scale. Average and orthnormalized linear, quadratic and cubic trends were computed. Pearson correlation coefficients suggested positive and statistically significant associations between career exploratory outcome expectations and academic achievement average trends. Career planning and self-efficacy expectations were negatively associated with academic achievement quadratic trends. Multiple linear regression models suggested that career exploratory outcome expectations and career planning were respectively statistically significant predictors of the average and quadratic trends of academic achievement. Gender moderated the association between the career variables and academic achievement linear trends as well as the relation of career planning and self-efficacy with academic achievement cubic trends. Additionally, the geographical location moderated the association between the average trend of career exploratory outcome expectations and academic achievement as well as tended to moderate the relation between the career variables and academic achievement quadratic trends. Future research could seek to explore the role of context in shaping the trajectories and linkages between career and academic progress with a more representative sample of participants from a broader array of geographical locations. This study advances extant literature by affirming the longitudinal relationship between the school and work domains in youth, which might sustain practices aimed at fostering students' career preparedness and academic achievement.

How did national life expectation related to school years in developing countries - an approach using panel data mining.

PubMed

Jian, Wen-Shan; Huang, Chen-Ling; Iqbal, Usman; Nguyen, Phung-Anh; Hsiao, George; Li, Hsien-Chang

2014-03-01

The purpose of the study was to probe into the changes in life expectancy associated with schooling years found by the Organization for Economic Co-operation and Development (OECD). The study was based on the OECD database from the period 2000 to 2006. The data of thirty countries were constructed to allow comparisons over time and across these countries. Panel data analysis was used to estimate the relationship of national education, as defined as school years, with life expectancy. The control factors considered were numbers of practicing physicians, practicing nurses, hospital beds, and GDP. We used fixed effects of both country and time through linear regression, the coefficient of school years in relation to life expectancy was statistically significant but negative. This finding is not in accord with the hypothesis that investing in human capital through education stimulates better health outcomes. Within developing countries, educational attainment is no longer keeping the same pace with life expectancy as before. Therefore, we suggest that an effective education policy should cover diverse topics, for example, balancing economic growth and mental hygiene, to improve national life expectancy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

WW Physics at Future e{sup +}e{sup -} Linear Colliders

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

Barklow, Timothy L

Measurements of triple gauge boson couplings and strong electroweak symmetry breaking effects at future e{sup +}e{sup -} linear colliders are reviewed. The results expected from a future e{sup +}e{sup -} linear collider are compared with LHC expectations.

New Linear Partitioning Models Based on Experimental Water: Supercritical CO2 Partitioning Data of Selected Organic Compounds.

PubMed

Burant, Aniela; Thompson, Christopher; Lowry, Gregory V; Karamalidis, Athanasios K

2016-05-17

Partitioning coefficients of organic compounds between water and supercritical CO2 (sc-CO2) are necessary to assess the risk of migration of these chemicals from subsurface CO2 storage sites. Despite the large number of potential organic contaminants, the current data set of published water-sc-CO2 partitioning coefficients is very limited. Here, the partitioning coefficients of thiophene, pyrrole, and anisole were measured in situ over a range of temperatures and pressures using a novel pressurized batch-reactor system with dual spectroscopic detectors: a near-infrared spectrometer for measuring the organic analyte in the CO2 phase and a UV detector for quantifying the analyte in the aqueous phase. Our measured partitioning coefficients followed expected trends based on volatility and aqueous solubility. The partitioning coefficients and literature data were then used to update a published poly parameter linear free-energy relationship and to develop five new linear free-energy relationships for predicting water-sc-CO2 partitioning coefficients. A total of four of the models targeted a single class of organic compounds. Unlike models that utilize Abraham solvation parameters, the new relationships use vapor pressure and aqueous solubility of the organic compound at 25 °C and CO2 density to predict partitioning coefficients over a range of temperature and pressure conditions. The compound class models provide better estimates of partitioning behavior for compounds in that class than does the model built for the entire data set.

New Linear Partitioning Models Based on Experimental Water: Supercritical CO 2 Partitioning Data of Selected Organic Compounds

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

Burant, Aniela; Thompson, Christopher; Lowry, Gregory V.

2016-05-17

Partitioning coefficients of organic compounds between water and supercritical CO2 (sc-CO2) are necessary to assess the risk of migration of these chemicals from subsurface CO2 storage sites. Despite the large number of potential organic contaminants, the current data set of published water-sc-CO2 partitioning coefficients is very limited. Here, the partitioning coefficients of thiophene, pyrrole, and anisole were measured in situ over a range of temperatures and pressures using a novel pressurized batch reactor system with dual spectroscopic detectors: a near infrared spectrometer for measuring the organic analyte in the CO2 phase, and a UV detector for quantifying the analyte inmore » the aqueous phase. Our measured partitioning coefficients followed expected trends based on volatility and aqueous solubility. The partitioning coefficients and literature data were then used to update a published poly-parameter linear free energy relationship and to develop five new linear free energy relationships for predicting water-sc-CO2 partitioning coefficients. Four of the models targeted a single class of organic compounds. Unlike models that utilize Abraham solvation parameters, the new relationships use vapor pressure and aqueous solubility of the organic compound at 25 °C and CO2 density to predict partitioning coefficients over a range of temperature and pressure conditions. The compound class models provide better estimates of partitioning behavior for compounds in that class than the model built for the entire dataset.« less

Virtual school teacher's science efficacy beliefs: The effects of community of practice on science-teaching efficacy beliefs

NASA Astrophysics Data System (ADS)

Uzoff, Phuong Pham

The purpose of this study was to examine how much K-12 science teachers working in a virtual school experience a community of practice and how that experience affects personal science-teaching efficacy and science-teaching outcome expectancy. The study was rooted in theoretical frameworks from Lave and Wenger's (1991) community of practice and Bandura's (1977) self-efficacy beliefs. The researcher used three surveys to examine schoolteachers' experiences of a community of practice and science-teaching efficacy beliefs. The instrument combined Mangieri's (2008) virtual teacher demographic survey, Riggs and Enochs (1990) Science-teaching efficacy Beliefs Instrument-A (STEBI-A), and Cadiz, Sawyer, and Griffith's (2009) Experienced Community of Practice (eCoP) instrument. The results showed a significant linear statistical relationship between the science teachers' experiences of community of practice and personal science-teaching efficacy. In addition, the study found that there was also a significant linear statistical relationship between teachers' community of practice experiences and science-teaching outcome expectancy. The results from this study were in line with numerous studies that have found teachers who are involved in a community of practice report higher science-teaching efficacy beliefs (Akerson, Cullen, & Hanson, 2009; Fazio, 2009; Lakshmanan, Heath, Perlmutter, & Elder, 2011; Liu, Lee, & Lin, 2010; Sinclair, Naizer, & Ledbetter, 2010). The researcher concluded that school leaders, policymakers, and researchers should increase professional learning opportunities that are grounded in social constructivist theoretical frameworks in order to increase teachers' science efficacy.

[Income inequality, corruption, and life expectancy at birth in Mexico].

PubMed

Idrovo, Alvaro Javier

2005-01-01

To ascertain if the effect of income inequality on life expectancy at birth in Mexico is mediated by corruption, used as a proxy of social capital. An ecological study was carried out with the 32 Mexican federative entities. Global and by sex correlations between life expectancy at birth were estimated by federative entity with the Gini coefficient, the Corruption and Good Government Index, the percentage of Catholics, and the percentage of the population speaking indigenous language. Robust linear regressions, with and without instrumental variables, were used to explore if corruption acts as intermediate variable in the studied relationship. Negative correlations with Spearman's rho near to -0.60 (p < 0.05) and greater than -0.66 (p < 0.05) between life expectancy at birth, the Gini coefficient and the population speaking indigenous language, respectively, were observed. Moreover, the Corruption and Good Government Index correlated with men's life expectancy at birth with Spearman's rho -0.3592 (p < 0.05). Regressions with instruments were more consistent than conventional ones and they show a strong negative effect (p < 0.05) of income inequality on life expectancy at birth. This effect was greater among men. The findings suggest a negative effect of income inequality on life expectancy at birth in Mexico, mediated by corruption levels and other related cultural factors.

Social Cognitive Theory Predictors of Exercise Behavior in Endometrial Cancer Survivors

PubMed Central

Basen-Engquist, Karen; Carmack, Cindy L.; Li, Yisheng; Brown, Jubilee; Jhingran, Anuja; Hughes, Daniel C.; Perkins, Heidi Y.; Scruggs, Stacie; Harrison, Carol; Baum, George; Bodurka, Diane C.; Waters, Andrew

2014-01-01

Objective This study evaluated whether social cognitive theory (SCT) variables, as measured by questionnaire and ecological momentary assessment (EMA), predicted exercise in endometrial cancer survivors. Methods One hundred post-treatment endometrial cancer survivors received a 6-month home-based exercise intervention. EMAs were conducted using hand-held computers for 10- to 12-day periods every 2 months. Participants rated morning self-efficacy and positive and negative outcome expectations using the computer, recorded exercise information in real time and at night, and wore accelerometers. At the midpoint of each assessment period participants completed SCT questionnaires. Using linear mixed-effects models, we tested whether morning SCT variables predicted minutes of exercise that day (Question 1) and whether exercise minutes at time point Tj could be predicted by questionnaire measures of SCT variables from time point Tj-1 (Question 2). Results Morning self-efficacy significantly predicted that day’s exercise minutes (p<.0001). Morning positive outcome expectations was also associated with exercise minutes (p=0.0003), but the relationship was attenuated when self-efficacy was included in the model (p=0.4032). Morning negative outcome expectations was not associated with exercise minutes. Of the questionnaire measures of SCT variables, only exercise self-efficacy predicted exercise at the next time point (p=0.003). Conclusions The consistency of the relationship between self-efficacy and exercise minutes over short (same day) and longer (Tj to Tj-1) time periods provides support for a causal relationship. The strength of the relationship between morning self-efficacy and exercise minutes suggest that real-time interventions that target daily variation in self-efficacy may benefit endometrial cancer survivors’ exercise adherence. PMID:23437853

Effects of acceleration in the Gz axis on human cardiopulmonary responses to exercise.

PubMed

Bonjour, Julien; Bringard, Aurélien; Antonutto, Guglielmo; Capelli, Carlo; Linnarsson, Dag; Pendergast, David R; Ferretti, Guido

2011-12-01

The aim of this paper was to develop a model from experimental data allowing a prediction of the cardiopulmonary responses to steady-state submaximal exercise in varying gravitational environments, with acceleration in the G(z) axis (a (g)) ranging from 0 to 3 g. To this aim, we combined data from three different experiments, carried out at Buffalo, at Stockholm and inside the Mir Station. Oxygen consumption, as expected, increased linearly with a (g). In contrast, heart rate increased non-linearly with a (g), whereas stroke volume decreased non-linearly: both were described by quadratic functions. Thus, the relationship between cardiac output and a (g) was described by a fourth power regression equation. Mean arterial pressure increased with a (g) non linearly, a relation that we interpolated again with a quadratic function. Thus, total peripheral resistance varied linearly with a (g). These data led to predict that maximal oxygen consumption would decrease drastically as a (g) is increased. Maximal oxygen consumption would become equal to resting oxygen consumption when a (g) is around 4.5 g, thus indicating the practical impossibility for humans to stay and work on the biggest Planets of the Solar System.

Implementation and evaluation of PM2.5 source contribution ...

EPA Pesticide Factsheets

Source culpability assessments are useful for developing effective emissions control programs. The Integrated Source Apportionment Method (ISAM) has been implemented in the Community Multiscale Air Quality (CMAQ) model to track contributions from source groups and regions to ambient levels and deposited amounts of primary and secondary inorganic PM2.5. Confidence in this approach is established by comparing ISAM source contribution estimates to emissions zero-out simulations recognizing that these approaches are not always expected to provide the same answer. The comparisons are expected to be most similar for more linear processes such as those involving primary emissions of PM2.5 and most different for non-linear systems like ammonium nitrate formation. Primarily emitted PM2.5 (e.g. elemental carbon), sulfur dioxide, ammonia, and nitrogen oxide contribution estimates compare well to zero-out estimates for ambient concentration and deposition. PM2.5 sulfate ion relationships are strong, but nonlinearity is evident and shown to be related to aqueous phase oxidation reactions in the host model. ISAM and zero-out contribution estimates are less strongly related for PM2.5 ammonium nitrate, resulting from instances of non-linear chemistry and negative responses (increases in PM2.5 due to decreases in emissions). ISAM is demonstrated in the context of an annual simulation tracking well characterized emissions source sectors and boundary conditions shows source contri

What Can Causal Networks Tell Us about Metabolic Pathways?

PubMed Central

Blair, Rachael Hageman; Kliebenstein, Daniel J.; Churchill, Gary A.

2012-01-01

Graphical models describe the linear correlation structure of data and have been used to establish causal relationships among phenotypes in genetic mapping populations. Data are typically collected at a single point in time. Biological processes on the other hand are often non-linear and display time varying dynamics. The extent to which graphical models can recapitulate the architecture of an underlying biological processes is not well understood. We consider metabolic networks with known stoichiometry to address the fundamental question: “What can causal networks tell us about metabolic pathways?”. Using data from an Arabidopsis BaySha population and simulated data from dynamic models of pathway motifs, we assess our ability to reconstruct metabolic pathways using graphical models. Our results highlight the necessity of non-genetic residual biological variation for reliable inference. Recovery of the ordering within a pathway is possible, but should not be expected. Causal inference is sensitive to subtle patterns in the correlation structure that may be driven by a variety of factors, which may not emphasize the substrate-product relationship. We illustrate the effects of metabolic pathway architecture, epistasis and stochastic variation on correlation structure and graphical model-derived networks. We conclude that graphical models should be interpreted cautiously, especially if the implied causal relationships are to be used in the design of intervention strategies. PMID:22496633

A time series analysis of the relationship of ambient temperature and common bacterial enteric infections in two Canadian provinces

NASA Astrophysics Data System (ADS)

Fleury, Manon; Charron, Dominique F.; Holt, John D.; Allen, O. Brian; Maarouf, Abdel R.

2006-07-01

The incidence of enteric infections in the Canadian population varies seasonally, and may be expected to be change in response to global climate changes. To better understand any potential impact of warmer temperature on enteric infections in Canada, we investigated the relationship between ambient temperature and weekly reports of confirmed cases of three pathogens in Canada: Salmonella, pathogenic Escherichia coli and Campylobacter, between 1992 and 2000 in two Canadian provinces. We used generalized linear models (GLMs) and generalized additive models (GAMs) to estimate the effect of seasonal adjustments on the estimated models. We found a strong non-linear association between ambient temperature and the occurrence of all three enteric pathogens in Alberta, Canada, and of Campylobacter in Newfoundland-Labrador. Threshold models were used to quantify the relationship of disease and temperature with thresholds chosen from 0 to -10°C depending on the pathogen modeled. For Alberta, the log relative risk of Salmonella weekly case counts increased by 1.2%, Campylobacter weekly case counts increased by 2.2%, and E. coli weekly case counts increased by 6.0% for every degree increase in weekly mean temperature. For Newfoundland-Labrador the log relative risk increased by 4.5% for Campylobacter for every degree increase in weekly mean temperature.

Age differences in conservatism: evidence on the mediating effects of personality and cognitive style.

PubMed

Cornelis, Ilse; Van Hiel, Alain; Roets, Arne; Kossowska, Malgorzata

2009-02-01

The present study investigates the commonly found age-conservatism relationship by combining insights from studies on the development of personality and motivated social cognition with findings on the relationships between these factors and conservative beliefs. Based on data collected in Belgium (N=2,373) and Poland (N=939), we found the expected linear effect of age on indicators of social-cultural conservatism in Belgium and Poland and the absence of such effects for indicators of economic-hierarchical conservatism. We further demonstrated that these effects of age on indicators of cultural conservatism in both countries were (in part) mediated through the personality factor Openness to Experience and the motivated cognition variable Need for Closure. The consistency of these findings in two countries with a very dissimilar sociopolitical history attests to the importance of the developmental perspective for the study of the relationship between age and conservatism.

Linear Scaling of the Exciton Binding Energy versus the Band Gap of Two-Dimensional Materials

NASA Astrophysics Data System (ADS)

Choi, Jin-Ho; Cui, Ping; Lan, Haiping; Zhang, Zhenyu

2015-08-01

The exciton is one of the most crucial physical entities in the performance of optoelectronic and photonic devices, and widely varying exciton binding energies have been reported in different classes of materials. Using first-principles calculations within the G W -Bethe-Salpeter equation approach, here we investigate the excitonic properties of two recently discovered layered materials: phosphorene and graphene fluoride. We first confirm large exciton binding energies of, respectively, 0.85 and 2.03 eV in these systems. Next, by comparing these systems with several other representative two-dimensional materials, we discover a striking linear relationship between the exciton binding energy and the band gap and interpret the existence of the linear scaling law within a simple hydrogenic picture. The broad applicability of this novel scaling law is further demonstrated by using strained graphene fluoride. These findings are expected to stimulate related studies in higher and lower dimensions, potentially resulting in a deeper understanding of excitonic effects in materials of all dimensionalities.

Effectiveness of netilmicin and tobramycin against Pseudomonas aeruginosa in vitro and in an experimental tissue infection in mice.

PubMed

Moffie, B G; Hoogeterp, J J; Lim, T; Douwes-Idema, A E; Mattie, H

1993-03-01

The activity of netilmicin and tobramycin against Pseudomonas aeruginosa was assessed in vitro in the presence of constant and exponentially declining concentrations, and in mice in an experimental thigh infection. The activity in vitro at constant concentrations was expressed as the maximal killing rate (ER) during 3 h of exposure. On the basis of the quantitative relation between E(R) and the drug concentration, the numbers of cfu expected at consecutive times, at constant as well as at declining concentrations, were predicted. The relationship between observed numbers and predicted values of ERt were similar under both conditions for both drugs. On the same basis the numbers of cfu expected in the experimental thigh infection were predicted. There was indeed a significant linear relationship between observed numbers of cfu in homogenized muscle and the values predicted on the basis of the pharmacokinetics of the aminoglycosides, but the slope of this relationship was only 0.22. There was no difference in this respect between the two antibiotics. It is concluded that the efficacy of netilmicin and tobramycin against P. aeruginosa is considerably less in vivo than in vitro, but the relation is about the same for the two drugs; therefore the slightly higher activity of tobramycin in vitro is relevant in the in-vivo situation.

Language and hope in schizophrenia-spectrum disorders.

PubMed

Bonfils, Kelsey A; Luther, Lauren; Firmin, Ruth L; Lysaker, Paul H; Minor, Kyle S; Salyers, Michelle P

2016-11-30

Hope is integral to recovery for those with schizophrenia. Considering recent advancements in the examination of clients' lexical qualities, we were interested in how clients' words reflect hope. Using computerized lexical analysis, we examined social, emotion, and future words' relations to hope and its pathways and agency components. Forty-five clients provided detailed narratives about their life and mental illness. Transcripts were analyzed using the Linguistic Inquiry and Word Count program (LIWC), which assigns words to categories (e.g., "anxiety") based on a pre-existing dictionary. Correlations and linear multiple regression were used to examine relationships between lexical qualities and hope. Hope and its subcomponents had significant or trending bivariate correlations in expected directions with several emotion-related word categories (anger and sadness) but were not associated with expected categories such as social words, positive emotions, optimism, achievement, and future words. In linear multiple regressions, no LIWC variable significantly predicted hope agency, but anger words significantly predicted both total hope and hope pathways. Our findings indicate lexical analysis tools can be used to investigate recovery-oriented concepts such as hope, and results may inform clinical practice. Future research should aim to replicate our findings in larger samples. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Centenarian Rates and Life Expectancy Related to the Death Rates of Multiple Sclerosis, Asthma, and Rheumatoid Arthritis and the Incidence of Type 1 Diabetes in Children.

PubMed

Lens-Pechakova, Lilia S

2016-02-01

The autoimmune diseases are among the 10 leading causes of death for women and the number two cause of chronic illness in America as well as a predisposing factor for cardiovascular diseases and cancer. Patients of some autoimmune diseases have shown a shorter life span and are a model of accelerated immunosenescence. Conversely, centenarians are used as a model of successful aging and have shown several immune parameters that are better preserved and lower levels of autoantibodies. The study reported here focused on clarifying the connection between longevity and some autoimmune and allergic diseases in 29 developed Organisation for Economic Co-operation and Development (OECD) countries, because multidisciplinary analyses of the accelerated or delayed aging data could show a distinct relationship pattern, help to identify common factors, and determine new important factors that contribute to longevity and healthy aging. The relationships between the mortality rates data of multiple sclerosis (MS), rheumatoid arthritis (RA), asthma, the incidence of type 1 diabetes (T1D) from one side and centenarian rates (two sets) as well as life expectancy data from the other side were assessed using regression models and Pearson correlation coefficients. The data obtained correspond to an inverse linear correlation with different degrees of linearity. This is the first observation of a clear tendency of diminishing centenarian rates or life expectancy in countries having higher death rates of asthma, MS, and RA and a higher incidence of T1D in children. The conclusion is that most probably there are common mechanistic pathways and factors affecting the above diseases and at the same time but in the opposite direction the processes of longevity. Further study, comparing genetic data, mechanistic pathways, and other factors connected to autoimmune diseases with those of longevity could clarify the processes involved, so as to promote longevity and limit the expansion of those diseases in the younger and older population.

Increasing chloride concentration causes retention of mercury in melted Arctic snow due to changes in photoreduction kinetics.

PubMed

Mann, E A; Ziegler, S E; Steffen, A; O'Driscoll, N J

2018-06-01

Mercury (Hg) in the Arctic is a significant concern due to its bioaccumulative and neurotoxic properties, and the sensitivity of Arctic environments. Previous research has found high levels of Hg in snowpacks with high chloride (Cl - ) concentrations. We hypothesised that Cl - would increase Hg retention by decreasing Hg photoreduction to Hg(0) in melted Arctic snow. To test this, changes in Hg photoreduction kinetics in melted Alert, NU snow were quantified with changing Cl - concentration and UV intensity. Snow was collected and melted in Teflon bottles in May 2014, spiked with 0-10μg/g Cl - , and irradiated with 3.52-5.78W·m -2 UV (280-400nm) radiation in a LuzChem photoreactor. Photoreduction rate constants (k) (0.14-0.59hr - 1 ) had positive linear relationships with [Cl - ], while photoreduced Hg amounts (Hg(II) red ) had negative linear relationships with [Cl - ] (1287-64pg in 200g melted snow). Varying UV and [Cl - ] both altered Hg(II) red amounts, with more efficient Hg stabilisation by Cl - at higher UV intensity, while k can be predicted by Cl - concentration and/or UV intensity, depending on experimental parameters. Overall, with future projections for greater snowpack Cl - loading, our experimental results suggest that more Hg could be delivered to Arctic aquatic ecosystems by melted snow (smaller Hg(II) red expected), but the Hg in the melted snow that is photoreduced may do so more quickly (larger k expected). Copyright © 2018. Published by Elsevier B.V.

Impact of sociodemographic variables on executive functions.

PubMed

Campanholo, Kenia Repiso; Boa, Izadora Nogueira Fonte; Hodroj, Flávia Cristina da Silva Araujo; Guerra, Glaucia Rosana Benute; Miotto, Eliane Correa; de Lucia, Mara Cristina Souza

2017-01-01

Executive functions (EFs) regulate human behavior and allow individuals to interact and act in the world. EFs are sensitive to sociodemographic variables such as age, which promotes their decline, and to others that can exert a neuroprotective effect. To assess the predictive role of education, occupation and family income on decline in executive functions among a sample with a wide age range. A total of 925 participants aged 18-89 years with 1-28 years' education were submitted to assessment of executive functions using the Card Sorting Test (CST), Phonemic Verbal Fluency (FAS) Task and Semantic Verbal Fluency (SVF) Task. Data on income, occupation and educational level were collected for the sample. The data were analyzed using Linear Regression, as well as Pearson's and Spearman's Correlation. Age showed a significant negative correlation (p<0.001) with performance on the CST, FAS and SVF, whereas education, income and occupation were positively associated (p<0.001) with the tasks applied. After application of the multivariate linear regression model, a significant positive relationship with the FAS was maintained only for education (p<0.001) and income (p<0.001). The negative relationship of age (p<0.001) and positive relationship of both education (p<0.001) and income (p<0.001and p=0.003) were evident on the CST and SVF. Educational level and income positively influenced participants' results on executive function tests, attenuating expected decline for age. However, no relationship was found between occupation and the cognitive variables investigated.

Impact of sociodemographic variables on executive functions

PubMed Central

Campanholo, Kenia Repiso; Boa, Izadora Nogueira Fonte; Hodroj, Flávia Cristina da Silva Araujo; Guerra, Glaucia Rosana Benute; Miotto, Eliane Correa; de Lucia, Mara Cristina Souza

2017-01-01

Executive functions (EFs) regulate human behavior and allow individuals to interact and act in the world. EFs are sensitive to sociodemographic variables such as age, which promotes their decline, and to others that can exert a neuroprotective effect. Objective To assess the predictive role of education, occupation and family income on decline in executive functions among a sample with a wide age range. Methods A total of 925 participants aged 18-89 years with 1-28 years' education were submitted to assessment of executive functions using the Card Sorting Test (CST), Phonemic Verbal Fluency (FAS) Task and Semantic Verbal Fluency (SVF) Task. Data on income, occupation and educational level were collected for the sample. The data were analyzed using Linear Regression, as well as Pearson's and Spearman's Correlation. Results Age showed a significant negative correlation (p<0.001) with performance on the CST, FAS and SVF, whereas education, income and occupation were positively associated (p<0.001) with the tasks applied. After application of the multivariate linear regression model, a significant positive relationship with the FAS was maintained only for education (p<0.001) and income (p<0.001). The negative relationship of age (p<0.001) and positive relationship of both education (p<0.001) and income (p<0.001and p=0.003) were evident on the CST and SVF. Conclusion Educational level and income positively influenced participants' results on executive function tests, attenuating expected decline for age. However, no relationship was found between occupation and the cognitive variables investigated. PMID:29213495

Modeling Two-Oscillator Circadian Systems Entrained by Two Environmental Cycles

PubMed Central

Oda, Gisele A.; Friesen, W. Otto

2011-01-01

Several experimental studies have altered the phase relationship between photic and non-photic environmental, 24 h cycles (zeitgebers) in order to assess their role in the synchronization of circadian rhythms. To assist in the interpretation of the complex activity patterns that emerge from these “conflicting zeitgeber” protocols, we present computer simulations of coupled circadian oscillators forced by two independent zeitgebers. This circadian system configuration was first employed by Pittendrigh and Bruce (1959), to model their studies of the light and temperature entrainment of the eclosion oscillator in Drosophila. Whereas most of the recent experiments have restricted conflicting zeitgeber experiments to two experimental conditions, by comparing circadian oscillator phases under two distinct phase relationships between zeitgebers (usually 0 and 12 h), Pittendrigh and Bruce compared eclosion phase under 12 distinct phase relationships, spanning the 24 h interval. Our simulations using non-linear differential equations replicated complex non-linear phenomena, such as “phase jumps” and sudden switches in zeitgeber preferences, which had previously been difficult to interpret. Our simulations reveal that these phenomena generally arise when inter-oscillator coupling is high in relation to the zeitgeber strength. Manipulations in the structural symmetry of the model indicated that these results can be expected to apply to a wide range of system configurations. Finally, our studies recommend the use of the complete protocol employed by Pittendrigh and Bruce, because different system configurations can generate similar results when a “conflicting zeitgeber experiment” incorporates only two phase relationships between zeitgebers. PMID:21886835

Fuzzy bi-objective linear programming for portfolio selection problem with magnitude ranking function

NASA Astrophysics Data System (ADS)

Kusumawati, Rosita; Subekti, Retno

2017-04-01

Fuzzy bi-objective linear programming (FBOLP) model is bi-objective linear programming model in fuzzy number set where the coefficients of the equations are fuzzy number. This model is proposed to solve portfolio selection problem which generate an asset portfolio with the lowest risk and the highest expected return. FBOLP model with normal fuzzy numbers for risk and expected return of stocks is transformed into linear programming (LP) model using magnitude ranking function.

Are Successive Investments in Education Equally Worthwhile? Endogenous Schooling Decisions and Non-Linearities in the Earnings-Schooling Relationship

ERIC Educational Resources Information Center

Skalli, Ali

2007-01-01

Most of the studies that account for the endogeneity bias when estimating the returns to schooling assume that the relationship between education and earnings is linear. Studies that assume the latter relationship to be non-linear simply ignore the endogeneity bias. Moreover, they either assume an ad-hoc non-linear relationship or argue that…

Expectations for Future Relationship Satisfaction: Unique Sources and Critical Implications for Commitment

PubMed Central

Baker, Levi R.; McNulty, James K.; VanderDrift, Laura E.

2017-01-01

Contemporary perspectives on relationship commitment posit that intimates decide whether or not to maintain a relationship based on their commitment to that relationship, and that they base such commitment partially on their current satisfaction with that relationship. Nevertheless, given that ending a relationship requires knowing about both the current state of the relationship and the likely future state of the relationship, we propose that people base their commitment to a relationship more on their expected future satisfaction with the relationship than on their current satisfaction with that relationship. Six studies provided evidence for these ideas. Study 1 demonstrated that expected satisfaction is shaped by not only current satisfaction but also several unique indicators of the likelihood of future satisfaction, including anticipated life events, plans to improve the relationship, and individual differences. Then, using a combination of cross-sectional, experimental, and longitudinal methods, Studies 2–6 demonstrated that (a) expected satisfaction was a stronger predictor of relationship commitment, maintenance behaviors, and/or divorce than was current satisfaction and (b) expected satisfaction mediated the association between current satisfaction and these outcomes. These findings highlight not only the need to incorporate expected satisfaction into extent perspectives on commitment, but also the importance of expectations for decision-making processes more broadly. PMID:28368196

Earthquake hazard and risk assessment based on Unified Scaling Law for Earthquakes: Greater Caucasus and Crimea

NASA Astrophysics Data System (ADS)

Kossobokov, Vladimir G.; Nekrasova, Anastasia K.

2018-05-01

We continue applying the general concept of seismic risk analysis in a number of seismic regions worldwide by constructing regional seismic hazard maps based on morphostructural analysis, pattern recognition, and the Unified Scaling Law for Earthquakes (USLE), which generalizes the Gutenberg-Richter relationship making use of naturally fractal distribution of earthquake sources of different size in a seismic region. The USLE stands for an empirical relationship log10 N(M, L) = A + B·(5 - M) + C·log10 L, where N(M, L) is the expected annual number of earthquakes of a certain magnitude M within a seismically prone area of linear dimension L. We use parameters A, B, and C of USLE to estimate, first, the expected maximum magnitude in a time interval at seismically prone nodes of the morphostructural scheme of the region under study, then map the corresponding expected ground shaking parameters (e.g., peak ground acceleration, PGA, or macro-seismic intensity). After a rigorous verification against the available seismic evidences in the past (usually, the observed instrumental PGA or the historically reported macro-seismic intensity), such a seismic hazard map is used to generate maps of specific earthquake risks for population, cities, and infrastructures (e.g., those based on census of population, buildings inventory). The methodology of seismic hazard and risk assessment is illustrated by application to the territory of Greater Caucasus and Crimea.

Ovule positions within linear fruit are correlated with nonrandom mating in Robinia pseudoacacia

PubMed Central

Yuan, Cunquan; Sun, Yuhan; Sun, Peng; Li, Yunfei; Hu, Ruiyang; Zhao, Keqi; Wang, Jinxing; Li, Yun

2016-01-01

Post-pollination processes can lead to nonrandom mating among compatible pollen donors. Moreover, morphological patterns of ovule development within linear fruits are reportedly nonrandom and depend on ovule position. However, little is known about the relationship between nonrandom mating and ovule position within linear fruit. Here, we combined controlled pollen competition experiments and paternity analyses on R. pseudoacacia to better understand nonrandom mating and its connection with ovule position. Molecular determination of siring success showed a significant departure from the expected ratio based on each kind of pollen mixture, suggesting a nonrandom mating. Outcrossed pollen grains, which were strongly favored, produced significantly more progeny than other pollen grains. Paternity analyses further revealed that the distribution of offspring produced by one specific pollen source was also nonrandom within linear fruit. The stylar end, which has a higher probability of maturation, produced a significantly higher number of outcrossed offspring than other offspring, suggesting a correlation between pollen source and ovule position. Our results suggested that a superior ovule position exists within the linear fruit in R. pseudoacacia, and the pollen that was strongly favored often preferentially occupies the ovules that were situated in a superior position, which ensured siring success and facilitated nonrandom mating. PMID:27819357

Bark Beetles Modify the Impact of Snow Drought on Remotely Sensed Forest Productivity in the Southern Rocky Mountains, USA

NASA Astrophysics Data System (ADS)

Knowles, J. F.; Lestak, L.; Molotch, N. P.

2016-12-01

We evaluated the long term (1989-2012) relationship between the satellite-observed Normalized Difference Vegetation Index (NDVI), snowpack accumulation, and atmospheric demand throughout the Southern Rocky Mountain Ecoregion, USA. Deviations from this relationship were further explored during pre- and post-disturbance conditions associated with bark beetles and drought. Over the entire study area, both the snow water equivalent (SWE) and a snow aridity index (SAI), which used the SWE to normalize potential evapotranspiration (PET), were significant predictors of the long-term AVHRR NDVI, but the SAI was a better predictor of NDVI relative to SWE regardless of disturbance. Since these relationships were weaker in disturbed areas, we also introduced a metric of tree mortality, and subsequent multiple linear regression of SAI and cumulative mortality best predicted the NDVI from a pair of heavily impacted focus areas within the larger study area. The post-disturbance NDVI was systematically reduced per unit SAI in these areas, and the difference between the observed and predicted (from pre-disturbance regressions) post-disturbance NDVI was significantly correlated with the cumulative forest mortality. At the Ecoregion scale, these disturbance effects were not clearly evident, and we attribute this to spatial variability of both SAI and NDVI throughout the large study area as evidenced by spatial analysis of Moderate Resolution Imaging Spectroradiometer (MODIS)-derived data. These results constrain the expected reduction in forest productivity due to disturbance and demonstrate that this reduction can be particularly evident during drought conditions resultant from low snow accumulation during the winter. Hence, terrestrial carbon uptake may decrease non-linearly post disturbance. This work has implications for predicting the ecohydrological response to climate change in the southern Rocky Mountains, as reductions in SWE and increases in PET are predicted for this area in the future, and therefore changes in the terrestrial carbon, water, and energy cycles should be expected.

Characterizing driver-response relationships in marine pelagic ecosystems for improved ocean management.

PubMed

Hunsicker, Mary E; Kappel, Carrie V; Selkoe, Kimberly A; Halpern, Benjamin S; Scarborough, Courtney; Mease, Lindley; Amrhein, Alisan

2016-04-01

Scientists and resource managers often use methods and tools that assume ecosystem components respond linearly to environmental drivers and human stressors. However, a growing body of literature demonstrates that many relationships are-non-linear, where small changes in a driver prompt a disproportionately large ecological response. We aim to provide a comprehensive assessment of the relationships between drivers and ecosystem components to identify where and when non-linearities are likely to occur. We focused our analyses on one of the best-studied marine systems, pelagic ecosystems, which allowed us to apply robust statistical techniques on a large pool of previously published studies. In this synthesis, we (1) conduct a wide literature review on single driver-response relationships in pelagic systems, (2) use statistical models to identify the degree of non-linearity in these relationships, and (3) assess whether general patterns exist in the strengths and shapes of non-linear relationships across drivers. Overall we found that non-linearities are common in pelagic ecosystems, comprising at least 52% of all driver-response relation- ships. This is likely an underestimate, as papers with higher quality data and analytical approaches reported non-linear relationships at a higher frequency (on average 11% more). Consequently, in the absence of evidence for a linear relationship, it is safer to assume a relationship is non-linear. Strong non-linearities can lead to greater ecological and socioeconomic consequences if they are unknown (and/or unanticipated), but if known they may provide clear thresholds to inform management targets. In pelagic systems, strongly non-linear relationships are often driven by climate and trophodynamic variables but are also associated with local stressors, such as overfishing and pollution, that can be more easily controlled by managers. Even when marine resource managers cannot influence ecosystem change, they can use information about threshold responses to guide how other stressors are managed and to adapt to new ocean conditions. As methods to detect and reduce uncertainty around threshold values improve, managers will be able to better understand and account for ubiquitous non-linear relationships.

Development of pollution reduction strategies for Mexico City: Estimating cost and ozone reduction effectiveness

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

Thayer, G.R.; Hardie, R.W.; Barrera-Roldan, A.

1993-12-31

This reports on the collection and preparation of data (costs and air quality improvement) for the strategic evaluation portion of the Mexico City Air Quality Research Initiative (MARI). Reports written for the Mexico City government by various international organizations were used to identify proposed options along with estimates of cost and emission reductions. Information from appropriate options identified by SCAQMD for Southem California were also used in the analysis. A linear optimization method was used to select a group of options or a strategy to be evaluated by decision analysis. However, the reduction of ozone levels is not a linearmore » function of the reduction of hydrocarbon and NO{sub x} emissions. Therefore, a more detailed analysis was required for ozone. An equation for a plane on an isopleth calculated with a trajectory model was obtained using two endpoints that bracket the expected total ozone precursor reductions plus the starting concentrations for hydrocarbons and NO{sub x}. The relationship between ozone levels and the hydrocarbon and NO{sub x} concentrations was assumed to lie on this plane. This relationship was used in the linear optimization program to select the options comprising a strategy.« less

The association between workers' employability and burnout in a reorganization context: longitudinal evidence building upon the conservation of resources theory.

PubMed

De Cuyper, Nele; Raeder, Sabine; Van der Heijden, Beatrice I J M; Wittekind, Anette

2012-04-01

This longitudinal study probes the relationship between employability and burnout among employees from a company undergoing reorganization. We advanced employability as a personal resource that relates negatively to burnout. We expected that this hypothesis would hold for different operationalizations of employability, including (1) job-related and (2) transferable skills, (3) willingness to change jobs and (4) to develop competences, (5) opportunity awareness, (6) self-esteem, and (7) self-perceived employability (i.e., perceived employment opportunities). In a similar vein, we expected that the hypothesis would hold for the different dimensions of burnout; namely emotional exhaustion, depersonalization, and reduced personal accomplishment. We used longitudinal Hierarchical Linear Modeling (HLM) to test our hypotheses. Employees from a Swiss company undergoing a major reorganization were surveyed at three times with a total time lag of 19 months (Time 1: N = 287; Time 2: N = 128; Time 3: N = 107). Our results indicate that particularly self-esteem, but also job-related and transferable skills as indicators of one's employability were important predictors of burnout, with all relationships being negative. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Consequences of synergy between environmental carcinogens

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

Berenbaum, M.C.

1985-12-01

As it is generally impossible to determine dose-response relationships for carcinogens at the low concentrations in which they occur in the environment, risk-benefit considerations are by consensus based on the linear, no-threshold model, on the assumption that this represents the worst case. However, this assumption does not take into account the possibility of synergistic interactions between carcinogens. It is shown here that, as a result of such interactions, the dose-response curve for added risk due to any individual carcinogen will generally be steeper at lower doses than at higher doses, and consequently the risk at low environmental levels will bemore » higher than would be expected from a linear response. Moreover, this excess risk at low doses is shown to increase as the general level of environmental carcinogens rises and, independently of this effect, it may also increase with the number of carcinogens present.« less

Quadratic correlation filters for optical correlators

NASA Astrophysics Data System (ADS)

Mahalanobis, Abhijit; Muise, Robert R.; Vijaya Kumar, Bhagavatula V. K.

2003-08-01

Linear correlation filters have been implemented in optical correlators and successfully used for a variety of applications. The output of an optical correlator is usually sensed using a square law device (such as a CCD array) which forces the output to be the squared magnitude of the desired correlation. It is however not a traditional practice to factor the effect of the square-law detector in the design of the linear correlation filters. In fact, the input-output relationship of an optical correlator is more accurately modeled as a quadratic operation than a linear operation. Quadratic correlation filters (QCFs) operate directly on the image data without the need for feature extraction or segmentation. In this sense, the QCFs retain the main advantages of conventional linear correlation filters while offering significant improvements in other respects. Not only is more processing required to detect peaks in the outputs of multiple linear filters, but choosing a winner among them is an error prone task. In contrast, all channels in a QCF work together to optimize the same performance metric and produce a combined output that leads to considerable simplification of the post-processing. In this paper, we propose a novel approach to the design of quadratic correlation based on the Fukunaga Koontz transform. Although quadratic filters are known to be optimum when the data is Gaussian, it is expected that they will perform as well as or better than linear filters in general. Preliminary performance results are provided that show that quadratic correlation filters perform better than their linear counterparts.

Dynamic relationships between body size, species richness, abundance, and energy use in a shallow marine epibenthic faunal community

PubMed Central

Labra, Fabio A; Hernández-Miranda, Eduardo; Quiñones, Renato A

2015-01-01

We study the temporal variation in the empirical relationships among body size (S), species richness (R), and abundance (A) in a shallow marine epibenthic faunal community in Coliumo Bay, Chile. We also extend previous analyses by calculating individual energy use (E) and test whether its bivariate and trivariate relationships with S and R are in agreement with expectations derived from the energetic equivalence rule. Carnivorous and scavenger species representing over 95% of sample abundance and biomass were studied. For each individual, body size (g) was measured and E was estimated following published allometric relationships. Data for each sample were tabulated into exponential body size bins, comparing species-averaged values with individual-based estimates which allow species to potentially occupy multiple size classes. For individual-based data, both the number of individuals and species across body size classes are fit by a Weibull function rather than by a power law scaling. Species richness is also a power law of the number of individuals. Energy use shows a piecewise scaling relationship with body size, with energetic equivalence holding true only for size classes above the modal abundance class. Species-based data showed either weak linear or no significant patterns, likely due to the decrease in the number of data points across body size classes. Hence, for individual-based size spectra, the SRA relationship seems to be general despite seasonal forcing and strong disturbances in Coliumo Bay. The unimodal abundance distribution results in a piecewise energy scaling relationship, with small individuals showing a positive scaling and large individuals showing energetic equivalence. Hence, strict energetic equivalence should not be expected for unimodal abundance distributions. On the other hand, while species-based data do not show unimodal SRA relationships, energy use across body size classes did not show significant trends, supporting energetic equivalence. PMID:25691966

Psychosocial job conditions, fear avoidance beliefs and expected return to work following acute coronary syndrome: a cross-sectional study of fear-avoidance as a potential mediator.

PubMed

Söderberg, Mia; Rosengren, Annika; Gustavsson, Sara; Schiöler, Linus; Härenstam, Annika; Torén, Kjell

2015-12-21

Despite improvements in treatment, acute coronary syndrome remains a substantial cause for prolonged sick absences and premature retirement. Knowledge regarding what benefits return to work is limited, especially the effect of psychological processes and psychosocial work factors. The purposes of this cross-sectional study were two-fold: to examine associations between adverse psychosocial job conditions and fear-avoidance beliefs towards work, and to determine whether such beliefs mediated the relationship between work conditions and expected return to work in acute coronary syndrome survivors. Study inclusion criteria: acute myocardial infarction or unstable angina diagnosis, below 65 years of age, being a resident in the West county of Sweden and currently working. In all, 509 individuals (21.8 % women) accepted study participation and for whom all data of study interest were available for analysis. Psychosocial work variables; job demand-control and effort-reward imbalance, were assessed with standard questionnaire batteries. Linear regression models were used to investigate relationships between psychosocial factors and fear-avoidance, and to evaluate mediator effects for fear-avoidance. Both total sample and gender stratified analyses were calculated. Fear-avoidance beliefs about work were associated to psychosocial job environments characterized by high strain (β 1.4; CI 1.2-1.6), active and passive work and high effort-reward imbalance (β 0.6; CI 0.5-0.7). Further, such beliefs also mediated the relationship between adverse work conditions and expected time for return to work. However, these results were only observed in total sample analyses or among or male participants. For women only high strain was linked to fear-avoidance, and these relationships became non-significant when entering chosen confounders. This cross-sectional study showed that acute coronary syndrome survivors, who laboured under adverse psychosocial work conditions, held fear-avoidance beliefs towards their workplace. Furthermore, these beliefs mediated the relationships between - high strained or high effort-reward imbalanced work - and expected return to work. However, mentioned results were primarily found among men, which could results from few female study participants or gender differences in return to work mechanisms. Still, an earlier return to work might be promoted by interventions focusing on improved psychosocial work conditions and cognitive behavioural therapy targeting fear-avoidance beliefs.

In defense of commitment: The curative power of violated expectations.

PubMed

Murray, Sandra L; Lamarche, Veronica M; Gomillion, Sarah; Seery, Mark D; Kondrak, Cheryl

2017-11-01

A new model of commitment defense in romantic relationships is proposed. It assumes that relationships afford a central resource for affirming meaning and purpose in the world. Consequently, violating expectations about the world outside the relationship can precipitate commitment defense inside the relationship. A meta-analysis of 5 experiments, 2 follow-up correlational studies, and a longitudinal study of the transition to first parenthood supported the model. Experimentally violating conventional expectations about the world (e.g., "hard work pays off") motivated less satisfied people to defensively affirm their commitment. Similarly, when becoming a parent naturalistically violated culturally conditioned gendered expectations about the division of household labor, less satisfied new mothers and fathers defensively affirmed their commitment from pre-to-post baby. The findings suggest that violating expected associations in the world outside the relationship motivates vulnerable people to set relationship their relationship right, thereby affirming expected associations in the relationship in the face of an unexpected world. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Associations between health literacy and established predictors of smoking cessation.

PubMed

Stewart, Diana W; Adams, Claire E; Cano, Miguel A; Correa-Fernández, Virmarie; Li, Yisheng; Waters, Andrew J; Wetter, David W; Vidrine, Jennifer Irvin

2013-07-01

We examined associations between health literacy and predictors of smoking cessation among 402 low-socioeconomic status (SES), racially/ethnically diverse smokers. Data were collected as part of a larger study evaluating smoking health risk messages. We conducted multiple linear regression analyses to examine relations between health literacy and predictors of smoking cessation (i.e., nicotine dependence, smoking outcome expectancies, smoking risk perceptions and knowledge, self-efficacy, intentions to quit or reduce smoking). Lower health literacy was associated with higher nicotine dependence, more positive and less negative smoking outcome expectancies, less knowledge about smoking health risks, and lower risk perceptions. Associations remained significant (P < .05) after controlling for demographics and SES-related factors. These results provide the first evidence that low health literacy may serve as a critical and independent risk factor for poor cessation outcomes among low-socioeconomic status, racially/ethnically diverse smokers. Research is needed to investigate potential mechanisms underlying this relationship.

Motivation, Classroom Environment, and Learning in Introductory Geology: A Hierarchical Linear Model

NASA Astrophysics Data System (ADS)

Gilbert, L. A.; Hilpert, J. C.; Van Der Hoeven Kraft, K.; Budd, D.; Jones, M. H.; Matheney, R.; Mcconnell, D. A.; Perkins, D.; Stempien, J. A.; Wirth, K. R.

2013-12-01

Prior research has indicated that highly motivated students perform better and that learning increases in innovative, reformed classrooms, but untangling the student effects from the instructor effects is essential to understanding how to best support student learning. Using a hierarchical linear model, we examine these effects separately and jointly. We use data from nearly 2,000 undergraduate students surveyed by the NSF-funded GARNET (Geoscience Affective Research NETwork) project in 65 different introductory geology classes at research universities, public masters-granting universities, liberal arts colleges and community colleges across the US. Student level effects were measured as increases in expectancy and self-regulation using the Motivated Strategies for Learning Questionnaire (MSLQ; Pintrich et al., 1991). Instructor level effects were measured using the Reformed Teaching Observation Protocol, (RTOP; Sawada et al., 2000), with higher RTOP scores indicating a more reformed, student-centered classroom environment. Learning was measured by learning gains on a Geology Concept Inventory (GCI; Libarkin and Anderson, 2005) and normalized final course grade. The hierarchical linear model yielded significant results at several levels. At the student level, increases in expectancy and self-regulation are significantly and positively related to higher grades regardless of instructor; the higher the increase, the higher the grade. At the instructor level, RTOP scores are positively related to normalized average GCI learning gains. The higher the RTOP score, the higher the average class GCI learning gains. Across both levels, average class GCI learning gains are significantly and positively related to student grades; the higher the GCI learning gain, the higher the grade. Further, the RTOP scores are significantly and negatively related to the relationship between expectancy and course grade. The lower the RTOP score, the higher the correlation between change in expectancy and grade. As such, students with low motivation show higher grades and greater learning gains in high RTOP (student-centered) classrooms than in low RTOP ones. These results support the recommendation of student-centered practices in the classroom and consideration of student motivation in our approach to the future of geoscience education.

Modeling the effects of AADT on predicting multiple-vehicle crashes at urban and suburban signalized intersections.

PubMed

Chen, Chen; Xie, Yuanchang

2016-06-01

Annual Average Daily Traffic (AADT) is often considered as a main covariate for predicting crash frequencies at urban and suburban intersections. A linear functional form is typically assumed for the Safety Performance Function (SPF) to describe the relationship between the natural logarithm of expected crash frequency and covariates derived from AADTs. Such a linearity assumption has been questioned by many researchers. This study applies Generalized Additive Models (GAMs) and Piecewise Linear Negative Binomial (PLNB) regression models to fit intersection crash data. Various covariates derived from minor-and major-approach AADTs are considered. Three different dependent variables are modeled, which are total multiple-vehicle crashes, rear-end crashes, and angle crashes. The modeling results suggest that a nonlinear functional form may be more appropriate. Also, the results show that it is important to take into consideration the joint safety effects of multiple covariates. Additionally, it is found that the ratio of minor to major-approach AADT has a varying impact on intersection safety and deserves further investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

The too-much-talent effect: team interdependence determines when more talent is too much or not enough.

PubMed

Swaab, Roderick I; Schaerer, Michael; Anicich, Eric M; Ronay, Richard; Galinsky, Adam D

2014-08-01

Five studies examined the relationship between talent and team performance. Two survey studies found that people believe there is a linear and nearly monotonic relationship between talent and performance: Participants expected that more talent improves performance and that this relationship never turns negative. However, building off research on status conflicts, we predicted that talent facilitates performance-but only up to a point, after which the benefits of more talent decrease and eventually become detrimental as intrateam coordination suffers. We also predicted that the level of task interdependence is a key determinant of when more talent is detrimental rather than beneficial. Three archival studies revealed that the too-much-talent effect emerged when team members were interdependent (football and basketball) but not independent (baseball). Our basketball analysis also established the mediating role of team coordination. When teams need to come together, more talent can tear them apart. © The Author(s) 2014.

Comparison of Quantifiler(®) Trio and InnoQuant™ human DNA quantification kits for detection of DNA degradation in developed and aged fingerprints.

PubMed

Goecker, Zachary C; Swiontek, Stephen E; Lakhtakia, Akhlesh; Roy, Reena

2016-06-01

The development techniques employed to visualize fingerprints collected from crime scenes as well as post-development ageing may result in the degradation of the DNA present in low quantities in such evidence samples. Amplification of the DNA samples with short tandem repeat (STR) amplification kits may result in partial DNA profiles. A comparative study of two commercially available quantification kits, Quantifiler(®) Trio and InnoQuant™, was performed on latent fingerprint samples that were either (i) developed using one of three different techniques and then aged in ambient conditions or (ii) undeveloped and then aged in ambient conditions. The three fingerprint development techniques used were: cyanoacrylate fuming, dusting with black powder, and the columnar-thin-film (CTF) technique. In order to determine the differences between the expected quantities and actual quantities of DNA, manually degraded samples generated by controlled exposure of DNA standards to ultraviolet radiation were also analyzed. A total of 144 fingerprint and 42 manually degraded DNA samples were processed in this study. The results indicate that the InnoQuant™ kit is capable of producing higher degradation ratios compared to the Quantifiler(®) Trio kit. This was an expected result since the degradation ratio is a relative value specific for a kit based on the length and extent of amplification of the two amplicons that vary from one kit to the other. Additionally, samples with lower concentrations of DNA yielded non-linear relationships of degradation ratio with the duration of aging, whereas samples with higher concentrations of DNA yielded quasi-linear relationships. None of the three development techniques produced a noticeably different degradation pattern when compared to undeveloped fingerprints, and therefore do not impede downstream DNA analysis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Association between heart rate variability and manual pulse rate.

PubMed

Hart, John

2013-09-01

One model for neurological assessment in chiropractic pertains to autonomic variability, tested commonly with heart rate variability (HRV). Since HRV may not be convenient to use on all patient visits, more user-friendly methods may help fill-in the gaps. Accordingly, this study tests the association between manual pulse rate and heart rate variability. The manual rates were also compared to the heart rate derived from HRV. Forty-eight chiropractic students were examined with heart rate variability (SDNN and mean heart rate) and two manual radial pulse rate measurements. Inclusion criteria consisted of participants being chiropractic students. Exclusion criteria for 46 of the participants consisted of a body mass index being greater than 30, age greater than 35, and history of: a) dizziness upon standing, b) treatment of psychiatric disorders, and c) diabetes. No exclusion criteria were applied to the remaining two participants who were also convenience sample volunteers. Linear associations between the manual pulse rate methods and the two heart rate variability measures (SDNN and mean heart) were tested with Pearson's correlation and simple linear regression. Moderate strength inverse (expected) correlations were observed between both manual pulse rate methods and SDNN (r = -0.640, 95% CI -0.781, -0.435; r = -0.632, 95% CI -0.776, -0.425). Strong direct (expected) relationships were observed between the manual pulse rate methods and heart rate derived from HRV technology (r = 0.934, 95% CI 0.885, 0.962; r = 0.941, 95% CI 0.897, 0.966). Manual pulse rates may be a useful option for assessing autonomic variability. Furthermore, this study showed a strong relationship between manual pulse rates and heart rate derived from HRV technology.

The contribution of attenuated selection in utero to small-for-gestational-age (SGA) among term African American male infants.

PubMed

Goodman, Julia M; Karasek, Deborah; Anderson, Elizabeth; Catalano, Ralph A

2013-07-01

Natural selection conserves mechanisms allowing women to spontaneously abort gestations least likely to yield fit offspring. Small gestational size has been proposed as an indicator of fitness observable by maternal biology. Previous research suggests that exposure to ambient stress in utero results in more "culling" of small fetuses and therefore lower rates of small-for-gestational-age (SGA). However, African American women persistently have higher rates of SGA than non-Hispanic white women, despite experiencing more ambient stress. This paper tests whether attenuation of the stress response among highly stressed African American women, as suggested by the weathering hypothesis, may help to explain this apparent inconsistency. We apply time-series modeling to over 2 million African American and non-Hispanic white male term births in California over the period of January 1989 through December 2010. We test for the parabolic (i.e., "U" shaped) relationship, implied by an attenuated stress response, between unusually strong labor market contraction and the rate of SGA among African American term male infants, and a linear relationship among non-Hispanic whites. We find the hypothesized parabolic relationship among term male African American infants. As expected, we find a linear relationship between unexpected layoffs and the rate of SGA among term male non-Hispanic whites. These results are robust to sensitivity analyses. These results may help to explain the high rates of SGA among term male African American infants, despite greater maternal exposure to ambient stress during pregnancy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of the relationship between ceramic pot filter water production and turbidity in source water.

PubMed

Salvinelli, Carlo; Elmore, A Curt; Reidmeyer, Mary R; Drake, K David; Ahmad, Khaldoun I

2016-11-01

Ceramic pot filters represent a common and effective household water treatment technology in developing countries, but factors impacting water production rate are not well-known. Turbidity of source water may be principal indicator in characterizing the filter's lifetime in terms of water production capacity. A flow rate study was conducted by creating four controlled scenarios with different turbidities, and influent and effluent water samples were tested for total suspended solids and particle size distribution. A relationship between average flow rate and turbidity was identified with a negative linear trend of 50 mLh -1 /NTU. Also, a positive linear relationship was found between the initial flow rate of the filters and average flow rate calculated over the 23 day life of the experiment. Therefore, it was possible to establish a method to estimate the average flow rate given the initial flow rate and the turbidity in the influent water source, and to back calculate the maximum average turbidity that would need to be maintained in order to achieve a specific average flow rate. However, long-term investigations should be conducted to assess how these relationships change over the expected CPF lifetime. CPFs rejected fine suspended particles (below 75 μm), especially particles with diameters between 0.375 μm and 10 μm. The results confirmed that ceramic pot filters are able to effectively reduce turbidity, but pretreatment of influent water should be performed to avoid premature failure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Epidemiology, Incidence and Mortality of Bladder Cancer and their Relationship with the Development Index in the World.

PubMed

Mahdavifar, Neda; Ghoncheh, Mahshid; Pakzad, Reza; Momenimovahed, Zohre; Salehiniya, Hamid

2016-01-01

Bladder cancer is an international public health problem. It is the ninth most common cancer and the fourteenth leading cause of death due to cancer worldwide. Given aging populations, the incidence of this cancer is rising. Information on the incidence and mortality of the disease, and their relationship with level of economic development is essential for better planning. The aim of the study was to investigate bladder cancer incidence and mortality rates, and their relationship with the the Human Development Index (HDI) in the world. Data were obtained from incidence and mortality rates presented by GLOBOCAN in 2012. Data on HDI and its components were extracted from the global bank site. The number and standardized incidence and mortality rates were reported by regions and the distribution of the disease were drawn in the world. For data analysis, the relationship between incidence and death rates, and HDI and its components was measured using correlation coefficients and SPSS software. The level of significance was set at 0.05. In 2012, 429,793 bladder cancer cases and 165,084 bladder death cases occurred in the world. Five countries that had the highest age-standardized incidence were Belgium 17.5 per 100,000, Lebanon 16.6/100,000, Malta 15.8/100,000, Turkey 15.2/100,000, and Denmark 14.4/100,000. Five countries that had the highest age-standardized death rates were Turkey 6.6 per 100,000, Egypt 6.5/100,000, Iraq 6.3/100,000, Lebanon 6.3/100,000, and Mali 5.2/100,000. There was a positive linear relationship between the standardized incidence rate and HDI (r=0.653, P<0.001), so that there was a positive correlation between the standardized incidence rate with life expectancy at birth, average years of schooling, and the level of income per person of population. A positive linear relationship was also noted between the standardized mortality rate and HDI (r=0.308, P<0.001). There was a positive correlation between the standardized mortality rate with life expectancy at birth, average years of schooling, and the level of income per person of population. The incidence of bladder cancer in developed countries and parts of Africa was higher, while the highest mortality rate was observed in the countries of North Africa and the Middle East. The program for better treatment in developing countries to reduce mortality from the cancer and more detaiuled studies on the etiology of are essential.

Earthquake Hazard and Risk Assessment based on Unified Scaling Law for Earthquakes: Altai-Sayan Region

NASA Astrophysics Data System (ADS)

Kossobokov, V. G.; Nekrasova, A.

2017-12-01

We continue applying the general concept of seismic risk analysis in a number of seismic regions worldwide by constructing regional seismic hazard maps based on morphostructural analysis, pattern recognition, and the Unified Scaling Law for Earthquakes, USLE, which generalizes the Gutenberg-Richter relationship making use of naturally fractal distribution of earthquake sources of different size in a seismic region. The USLE stands for an empirical relationship log10N(M, L) = A + B·(5 - M) + C·log10L, where N(M, L) is the expected annual number of earthquakes of a certain magnitude M within an seismically prone area of linear dimension L. We use parameters A, B, and C of USLE to estimate, first, the expected maximum credible magnitude in a time interval at seismically prone nodes of the morphostructural scheme of the region under study, then map the corresponding expected ground shaking parameters (e.g. peak ground acceleration, PGA, or macro-seismic intensity etc.). After a rigorous testing against the available seismic evidences in the past (usually, the observed instrumental PGA or the historically reported macro-seismic intensity), such a seismic hazard map is used to generate maps of specific earthquake risks for population, cities, and infrastructures (e.g., those based on census of population, buildings inventory, etc.). This, USLE based, methodology of seismic hazard and risks assessment is applied to the territory of Altai-Sayan Region, of Russia. The study supported by the Russian Science Foundation Grant No. 15-17-30020.

Is More Always Better? The Curvilinear Relationships between College Student Experiences and Outcomes

ERIC Educational Resources Information Center

Bowman, Nicholas A.; Trolian, Teniell L.

2017-01-01

Many higher education studies have examined linear relationships between student experiences and outcomes, but this assumption may be questionable. In two notable examples previous research that assumed a linear relationship reached different substantive conclusions and implications than did research that explored non-linear associations among the…

Using hierarchical linear growth models to evaluate protective mechanisms that mediate science achievement

NASA Astrophysics Data System (ADS)

von Secker, Clare Elaine

The study of students at risk is a major topic of science education policy and discussion. Much research has focused on describing conditions and problems associated with the statistical risk of low science achievement among individuals who are members of groups characterized by problems such as poverty and social disadvantage. But outcomes attributed to these factors do not explain the nature and extent of mechanisms that account for differences in performance among individuals at risk. There is ample theoretical and empirical evidence that demographic differences should be conceptualized as social contexts, or collections of variables, that alter the psychological significance and social demands of life events, and affect subsequent relationships between risk and resilience. The hierarchical linear growth models used in this dissertation provide greater specification of the role of social context and the protective effects of attitude, expectations, parenting practices, peer influences, and learning opportunities on science achievement. While the individual influences of these protective factors on science achievement were small, their cumulative effect was substantial. Meta-analysis conducted on the effects associated with psychological and environmental processes that mediate risk mechanisms in sixteen social contexts revealed twenty-two significant differences between groups of students. Positive attitudes, high expectations, and more intense science course-taking had positive effects on achievement of all students, although these factors were not equally protective in all social contexts. In general, effects associated with authoritative parenting and peer influences were negative, regardless of social context. An evaluation comparing the performance and stability of hierarchical linear growth models with traditional repeated measures models is included as well.

An assessment of an F2 or N2O4 atmospheric injection from an aborted space shuttle mission

NASA Technical Reports Server (NTRS)

Watson, R. T.; Smokler, P. E.; Demore, W. B.

1978-01-01

Assuming a linear relationship between the stratosphere loading of NOx and the magnitude of the ozone perturbation, the change in ozone expected to result from space shuttle ejection of N2O4 was calculated based on the ozone change that is predicted for the (much greater) NOx input that would accompany large-scale operations of SSTs. Stratospheric fluorine reactions were critically reviewed to evaluate the magnitude of fluorine induced ozone destruction relative to the reduction that would be caused by addition of an equal amount of chlorine. The predicted effect on stratospheric ozone is vanishingly small.

Team Cohesion, Player Attitude, and Performance Expectations in Simulation.

ERIC Educational Resources Information Center

Wellington, William J.; Faria, A. J.

1996-01-01

Examines the relationship of team cohesion, participant attitude, and performance expectations to actual performance results in a simulation competition. Findings indicate a strong relationship between beginning team cohesion and performance expectations and final game performance, but little relationship between beginning participant attitudes…

The effects of own fetal growth on reported hypertension in parous women aged 33.

PubMed

Hennessy, E; Alberman, E

1997-06-01

Data from the study of the British 1958 birth cohort, National Child Development Study (NCDS), has allowed wider investigation of the relationship between retarded fetal growth and risk of adult hypertension. A history of self-reported hypertension was related to fetal growth in 3308 parous cohort members. Fetal growth, the measure used, is the difference in actual birthweight from that expected for the gestational age and subsequent adult height. The relationships were investigated both linearly and non-linearly adjusting for potential confounders. After adjustment for confounding factors, including adult weight for height, retarded fetal growth was associated with reported hypertension particularly when not confined to pregnancy. The latter was also associated with accelerated fetal growth, moderate or severe hypertension in the mother when pregnant with the cohort member, being relatively taller than your mother, and lack of educational qualifications. Hypertension confined to pregnancy was more likely among women who were themselves firstborn or older at childbirth. Neither maternal smoking during cohort's gestation nor cohort member's gestational age had a significant effect. The results are consistent with previous reports that fetal growth effects are less marked if gestation is short. The relationships between fetal growth and subsequent hypertension are extremely complex and variable, and need to be studied allowing for deviations from growth potential. Adult weight for height remains the strongest predictor of hypertension. The results suggest that losing weight is likely to have the same proportional benefit in women with and without a history of retarded fetal growth.

Abundance matters: a field experiment testing the more individuals hypothesis for richness–productivity relationships

PubMed Central

Yee, D. A.; Juliano, S. A.

2007-01-01

The more individuals hypothesis (MIH) postulates that productivity increases species richness by increasing mean equilibrium population size, thereby reducing the probability of local extinction. We tested the MIH for invertebrates colonizing microcosms that simulated tree holes by manipulating productivity through additions of leaf or animal detritus and subsequently determining the relationships among richness, total abundance, abundance per species, and measures of productivity. We quantified productivity as the rate of microorganism protein synthesis, microorganism metabolic rate, nutrient ion concentration, and type and amount of detritus. Microcosms with animal detritus attracted more species, more individuals per species, and more total individuals than did microcosms with similar amounts of leaf detritus. Relationships between richness or abundance and productivity varied with date. Richness in June increased as a linear function of productivity, whereas the power function predicted by the MIH fit best in July. Abundance in June and July was best described by a power function of productivity, but the linear function predicted by the MIH fit best in September. Abundance per species was best described by a power function of productivity in June and July. Path analysis showed that the indirect effect of productivity through abundance on richness that is predicted by MIH was important in all months, and that direct links between productivity and richness were unnecessary. Our results support many of the predictions of the MIH, but they also suggest that the effects of abundance on richness may be more complex than expected. PMID:17401581

Short communication: Genetic relationships of milk coagulation properties with body condition score and linear type traits in Holstein-Friesian cows.

PubMed

Cassandro, M; Battagin, M; Penasa, M; De Marchi, M

2015-01-01

Milk coagulation properties (MCP) are gaining popularity among dairy cattle producers and the improvement of traits associated with MCP is expected to result in a benefit for the dairy industry, especially in countries with a long tradition in cheese production. The objectives of this study were to estimate genetic correlations of MCP with body condition score (BCS) and type traits using data from first-parity Italian Holstein-Friesian cattle. The data analyzed consisted of 18,460 MCP records from 4,036 cows with information on both BCS and conformation traits. The cows were daughters of 246 sires and the pedigree file included a total of 37,559 animals. Genetic relationships of MCP with BCS and type traits were estimated using bivariate animal models. The model for MCP included fixed effects of stage of lactation, and random effects of herd-test-date, cow permanent environment, additive genetic animal, and residual. Fixed factors considered in the model for BCS and type traits were herd-date of evaluation and interaction between age at scoring and stage of lactation of the cow, and random terms were additive genetic animal, cow permanent environment, and residual. Genetic relationships between MCP and BCS, and MCP and type traits were generally low and significant only in a few cases, suggesting that MCP can be selected for without detrimental effects on BCS and linear type traits. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Establishing supervisor-students’ relationships through mutual expectation: A study from supervisors’ point of view

NASA Astrophysics Data System (ADS)

Masek, Alias

2017-08-01

The literature suggests that failure to establish a good relationship in communicating expectations of research supervision is one of the factors contributing to the slow pace of research progress. Moreover, it is not fully understood how students and a supervisor ‘pre-define’ their styles and communicate their expectations through a successful relationship. As a result, the students might lose motivation to do their research during the study period and are not able to complete their research on time. This will subsequently entail an extension of the study period. Without a good relationship between students and the supervisor, miscommunication occurs, leading to mismatched expectations from both parties. This research attempts to explore the establishment of a good supervisor-students’ relationship from supervisor point of views, so that supervision expectations can be clearly delivered and effectively communicated; guidelines will be drawn up for forging the supervisor-students’ relationship basing on mutual expectations of both parties.

Expanding the occupational health methodology: A concatenated artificial neural network approach to model the burnout process in Chinese nurses.

PubMed

Ladstätter, Felix; Garrosa, Eva; Moreno-Jiménez, Bernardo; Ponsoda, Vicente; Reales Aviles, José Manuel; Dai, Junming

2016-01-01

Artificial neural networks are sophisticated modelling and prediction tools capable of extracting complex, non-linear relationships between predictor (input) and predicted (output) variables. This study explores this capacity by modelling non-linearities in the hardiness-modulated burnout process with a neural network. Specifically, two multi-layer feed-forward artificial neural networks are concatenated in an attempt to model the composite non-linear burnout process. Sensitivity analysis, a Monte Carlo-based global simulation technique, is then utilised to examine the first-order effects of the predictor variables on the burnout sub-dimensions and consequences. Results show that (1) this concatenated artificial neural network approach is feasible to model the burnout process, (2) sensitivity analysis is a prolific method to study the relative importance of predictor variables and (3) the relationships among variables involved in the development of burnout and its consequences are to different degrees non-linear. Many relationships among variables (e.g., stressors and strains) are not linear, yet researchers use linear methods such as Pearson correlation or linear regression to analyse these relationships. Artificial neural network analysis is an innovative method to analyse non-linear relationships and in combination with sensitivity analysis superior to linear methods.

Response expectancies, treatment credibility, and hypnotic suggestibility: mediator and moderator effects in hypnotic and cognitive-behavioral pain interventions.

PubMed

Milling, Leonard S; Shores, Jessica S; Coursen, Elizabeth L; Menario, Deanna J; Farris, Catherine D

2007-04-01

Several studies have shown that response expectancies are an important mechanism of popular psychological interventions for pain. However, there has been no research on whether response expectancies and treatment credibility independently mediate hypnotic and cognitive-behavioral pain interventions and whether the pattern of mediation is affected by experience with the interventions. Also, past research has indicated that hypnotic pain interventions may be moderated by hypnotic suggestibility. However, these studies have typically failed to measure the full range of suggestibility and have assessed pain reduction and suggestibility in the same experimental context, possibly inflating the association between these variables. To clarify the mediator role of response expectancies and treatment credibility, and the moderator role of hypnotic suggestibility in the hypnotic and cognitive-behavioral reduction of pain. Approximately 300 participants were assessed for suggestibility. Then, as part of an apparently unrelated experiment, 124 of these individuals received analogue cognitive-behavioral, hypnotic, or placebo control pain interventions. Response expectancies and credibility independently mediated treatment. The extent of mediation increased as participants gained more experience with the interventions. Suggestibility moderated treatment and was associated with relief only from the hypnotic intervention. Response expectancies and treatment credibility are unique mechanisms of hypnotic and cognitive-behavioral pain interventions. Hypnotic suggestibility predicts relief from hypnotic pain interventions and this association is not simply an artifact of measuring suggestibility and pain reduction in the same experimental context. The relationship between suggestibility and hypnotic pain reduction appears to be linear in nature.

Behavioral activation: Is it the expectation or achievement, of mastery or pleasure that contributes to improvement in depression?

PubMed

Furukawa, Toshi A; Imai, Hissei; Horikoshi, Masaru; Shimodera, Shinji; Hiroe, Takahiro; Funayama, Tadashi; Akechi, Tatsuo

2018-06-06

Behavioral activation (BA) is receiving renewed interest as a stand-alone or as a component of cognitive-behavior therapy (CBT) for depression. However, few studies have examined which aspects of BA are most contributory to its efficacy. This is a secondary analysis of a 9-week randomized controlled trial of smartphone CBT for patients with major depression. Depression severity was measured at baseline and at end of treatment by the Patient Health Questionnaire-9. All aspects of behavioral activation tasks that the participants had engaged in, including their expected mastery and pleasure and obtained mastery and pleasure, were recorded in the web server. We examined their contribution to improvement in depression as simple correlations and in stepwise multivariable linear regression. Among the 78 patients who completed at least one behavioral experiment, all aspects of expected or achieved mastery or pleasure correlated with change in depression severity. Discrepancy between the expectation and achievement, representing unexpected gain in mastery or pleasure, was not correlated. In stepwise regression, expected mastery and pleasure, especially the maximum level of the latter, emerged as the strongest contributing factors. The study is observational and cannot deduce cause-effect relationships. It may be the expected and continued sense of pleasure in planning activities that are most meaningful and rewarding to individuals, and not the simple level or amount of obtained pleasure, that contributes to the efficacy of BA. Copyright © 2018. Published by Elsevier B.V.

The reciprocal relationships among parents' expectations, adolescents' expectations, and adolescents' achievement: a two-wave longitudinal analysis of the NELS data.

PubMed

Zhang, Yanyan; Haddad, Eileen; Torres, Bernadeth; Chen, Chuansheng

2011-04-01

Previous research has consistently demonstrated the importance of parents' expectations and adolescents' expectations on adolescents' academic achievement. Less is known, however, about the reciprocal relationships among these constructs. To address this issue, we analyzed two waves of data from the National Education Longitudinal Study of 1988 (NELS:88) using longitudinal cross-lagged path models. The sample consisted of 14,376 students (51.1% females; 6.5% Asian, 11.1% Hispanic, 9.2% African American, and 73.2% White). Results indicated that there was a reciprocal relationship between parents' expectations and adolescents' expectations (i.e., they had mutual influence on each other). Moreover, there was a reciprocal relationship between expectations (both parents' and adolescents') and adolescents' academic achievement. Multiple-group analyses of gender and ethnicity revealed that the effects of parents' expectations on students' expectations were stronger among males than among females. With respect to ethnic differences, the effects of adolescents' expectations were weakest on parents' expectations among African Americans as compared to the other ethnic groups (i.e., Asian, Hispanic and White). Implications of these findings are discussed.

Clinical laboratory: bigger is not always better.

PubMed

Plebani, Mario

2018-06-27

Laboratory services around the world are undergoing substantial consolidation and changes through mechanisms ranging from mergers, acquisitions and outsourcing, primarily based on expectations to improve efficiency, increasing volumes and reducing the cost per test. However, the relationship between volume and costs is not linear and numerous variables influence the end cost per test. In particular, the relationship between volumes and costs does not span the entire platter of clinical laboratories: high costs are associated with low volumes up to a threshold of 1 million test per year. Over this threshold, there is no linear association between volumes and costs, as laboratory organization rather than test volume more significantly affects the final costs. Currently, data on laboratory errors and associated diagnostic errors and risk for patient harm emphasize the need for a paradigmatic shift: from a focus on volumes and efficiency to a patient-centered vision restoring the nature of laboratory services as an integral part of the diagnostic and therapy process. Process and outcome quality indicators are effective tools to measure and improve laboratory services, by stimulating a competition based on intra- and extra-analytical performance specifications, intermediate outcomes and customer satisfaction. Rather than competing with economic value, clinical laboratories should adopt a strategy based on a set of harmonized quality indicators and performance specifications, active laboratory stewardship, and improved patient safety.

Is the Relationship Between Pornography Consumption Frequency and Lower Sexual Satisfaction Curvilinear? Results From England and Germany.

PubMed

Wright, Paul J; Steffen, Nicola J; Sun, Chyng

2017-07-28

Several studies using different methods have found that pornography consumption is associated with lower sexual satisfaction. The language used by media-effects scholars in discussions of this association implies an expectation that lowered satisfaction is primarily due to frequent-but not infrequent-consumption. Actual analyses, however, have assumed linearity. Linear analyses presuppose that for each increase in the frequency of pornography consumption there is a correspondingly equivalent decrease in sexual satisfaction. The present brief report explored the possibility that the association is curvilinear. Survey data from two studies of heterosexual adults, one conducted in England and the other in Germany, were employed. Results were parallel in each country and were not moderated by gender. Quadratic analysis indicated a curvilinear relationship, in the form of a predominantly negative, concave downward curve. Simple slope analyses suggested that when the frequency of consumption reaches once a month, sexual satisfaction begins to decrease, and that the magnitude of the decrease becomes larger with each increase in the frequency of consumption. The observational nature of the data employed precludes any causal inferences. However, if an effects perspective was adopted, these results would suggest that low rates of pornography consumption have no impact on sexual satisfaction and that adverse effects initiate only after consumption reaches a certain frequency.

Robust Nonlinear Causality Analysis of Nonstationary Multivariate Physiological Time Series.

PubMed

Schack, Tim; Muma, Michael; Feng, Mengling; Guan, Cuntai; Zoubir, Abdelhak M

2018-06-01

An important research area in biomedical signal processing is that of quantifying the relationship between simultaneously observed time series and to reveal interactions between the signals. Since biomedical signals are potentially nonstationary and the measurements may contain outliers and artifacts, we introduce a robust time-varying generalized partial directed coherence (rTV-gPDC) function. The proposed method, which is based on a robust estimator of the time-varying autoregressive (TVAR) parameters, is capable of revealing directed interactions between signals. By definition, the rTV-gPDC only displays the linear relationships between the signals. We therefore suggest to approximate the residuals of the TVAR process, which potentially carry information about the nonlinear causality by a piece-wise linear time-varying moving-average model. The performance of the proposed method is assessed via extensive simulations. To illustrate the method's applicability to real-world problems, it is applied to a neurophysiological study that involves intracranial pressure, arterial blood pressure, and brain tissue oxygenation level (PtiO2) measurements. The rTV-gPDC reveals causal patterns that are in accordance with expected cardiosudoral meachanisms and potentially provides new insights regarding traumatic brain injuries. The rTV-gPDC is not restricted to the above problem but can be useful in revealing interactions in a broad range of applications.

Determination of the anaerobic threshold by a noninvasive field test in runners.

PubMed

Conconi, F; Ferrari, M; Ziglio, P G; Droghetti, P; Codeca, L

1982-04-01

The relationship between running speed (RS) and heart rate (HR) was determined in 210 runners. On a 400-m track the athletes ran continuously from an initial velocity of 12-14 km/h to submaximal velocities varying according to the athlete's capability. The HRs were determined through ECG. In all athletes examined, a deflection from the expected linearity of the RS-HR relationship was observed at submaximal RS. The test-retest correlation for the velocities at which this deflection from linearity occurred (Vd) determined in 26 athletes was 0.99. The velocity at the anaerobic threshold (AT), established by means of blood lactate measurements, and Vd were coincident in 10 runners. The correlation between Vd and average running speed (mean RS) in competition was 0.93 in the 5,000 m (mean Vd = 19.13 +/- 1.08 km/h; mean RS = 20.25 +/- 1.15 km/h), 0.95 in the marathon (mean Vd = 18.85 +/- 1.15 km/h; mean RS = 17.40 +/- 1.14 km/h), and 0.99 in the 1-h race (mean Vd = 18.70 +/- 0.98 km/h; mean RS = 18.65 +/- 0.92 km/h), thus showing that AT is critical in determining the running pace in aerobic competitive events.

Understanding the relationship between duration of untreated psychosis and outcomes: A statistical perspective.

PubMed

Hannigan, Ailish; Bargary, Norma; Kinsella, Anthony; Clarke, Mary

2017-06-14

Although the relationships between duration of untreated psychosis (DUP) and outcomes are often assumed to be linear, few studies have explored the functional form of these relationships. The aim of this study is to demonstrate the potential of recent advances in curve fitting approaches (splines) to explore the form of the relationship between DUP and global assessment of functioning (GAF). Curve fitting approaches were used in models to predict change in GAF at long-term follow-up using DUP for a sample of 83 individuals with schizophrenia. The form of the relationship between DUP and GAF was non-linear. Accounting for non-linearity increased the percentage of variance in GAF explained by the model, resulting in better prediction and understanding of the relationship. The relationship between DUP and outcomes may be complex and model fit may be improved by accounting for the form of the relationship. This should be routinely assessed and new statistical approaches for non-linear relationships exploited, if appropriate. © 2017 John Wiley & Sons Australia, Ltd.

Alcohol outlet density and assault: a spatial analysis.

PubMed

Livingston, Michael

2008-04-01

A large number of studies have found links between alcohol outlet densities and assault rates in local areas. This study tests a variety of specifications of this link, focusing in particular on the possibility of a non-linear relationship. Cross-sectional data on police-recorded assaults during high alcohol hours, liquor outlets and socio-demographic characteristics were obtained for 223 postcodes in Melbourne, Australia. These data were used to construct a series of models testing the nature of the relationship between alcohol outlet density and assault, while controlling for socio-demographic factors and spatial auto-correlation. Four types of relationship were examined: a normal linear relationship between outlet density and assault, a non-linear relationship with potential threshold or saturation densities, a relationship mediated by the socio-economic status of the neighbourhood and a relationship which takes into account the effect of outlets in surrounding neighbourhoods. The model positing non-linear relationships between outlet density and assaults was found to fit the data most effectively. An increasing accelerating effect for the density of hotel (pub) licences was found, suggesting a plausible upper limit for these licences in Melbourne postcodes. The study finds positive relationships between outlet density and assault rates and provides evidence that this relationship is non-linear and thus has critical values at which licensing policy-makers can impose density limits.

Future Expectations, Attitude Toward Violence, and Bullying Perpetration During Early Adolescence: A Mediation Evaluation.

PubMed

Stoddard, Sarah A; Varela, Jorge J; Zimmerman, Marc A

2015-01-01

Hopeful future expectations have been linked to positive developmental outcomes in adolescence; however, the association between future expectations and bullying perpetration has received less attention. We examined the relationship between future expectations and physical and relational bullying perpetration and tested a mediation model that linked future expectations with bullying through attitude toward violence. Structural equation modeling was used to examine the relationship between future expectations and bullying perpetration (relational and physical) and to test whether these relationships were mediated by attitude toward violence in a sample of U.S. seventh-grade students (Mage = 12.86 years, N = 196, 60% female, 46% African American). Attitude toward violence fully mediated the relationship between future expectations and physical bullying (indirect effects = -0.08, 95% CI [-0.15, -0.01], R = .17). The relationship between future expectations and relational bullying was partially mediated by attitudes toward violence (indirect effects = -0.07, 95% CI [-0.14, -0.002], R = .20). Our findings suggest that future expectations can play a role in reducing attitude toward violence and physical and relational bullying perpetration among youth. Interventions that help support the development of future goals and aspirations could play a vital role in bullying prevention efforts.

Expectancy in Real and Sham Electroacupuncture: Does Believing Make It So?

PubMed Central

Bauml, Joshua; Xie, Sharon X.; Farrar, John T.; Bowman, Marjorie A.; Li, Susan Q.; Bruner, Deborah; DeMichele, Angela

2014-01-01

Background The large placebo effect observed in prior acupuncture trials presents a substantial challenge for interpretation of the efficacy of acupuncture. We sought to evaluate the relationship between response expectancy, a key component of the placebo effect over time, and treatment outcome in real and sham electroacupuncture (EA). Methods We analyzed data from a randomized controlled trial of EA and sham acupuncture (SA) for joint pain attributable to aromatase inhibitors among women with breast cancer. Responders were identified using the Patient Global Impression of Change instrument at Week 8 (end of intervention). The Acupuncture Expectancy Scale (AES) was used to measure expectancy four times during the trial. Linear mixed-effects models were used to evaluate the association between expectancy and treatment response. Results In the wait list control group, AES remained unchanged over treatment. In the SA group, Baseline AES was significantly higher in responders than nonresponders (15.5 vs 12.1, P = .005) and AES did not change over time. In the EA group, Baseline AES scores did not differ between responders and nonresponders (14.8 vs 15.3, P = .64); however, AES increased in responders compared with nonresponders over time (P = .004 for responder and time interaction term) with significant difference at the end of trial for responders versus nonresponders (16.2 vs 11.7, P = .004). Conclusions Baseline higher response expectancy predicts treatment response in SA, but not in EA. Divergent mechanisms may exist for how SA and EA influence pain outcomes, and patients with low expectancy may do better with EA than SA. PMID:25749596

Social relationships and inflammatory markers: an analysis of Taiwan and the U.S.

PubMed

Glei, Dana A; Goldman, Noreen; Ryff, Carol D; Lin, Yu-Hsuan; Weinstein, Maxine

2012-06-01

We evaluated the association between two aspects of social relationships and six inflammatory markers in Taiwan and the U.S. These two countries share similar levels of current life expectancy, but exhibit important differences in social structure. The data comprised population based samples from Taiwan (aged 53+; n=962) and the U.S. (aged 35-86; n=990) collected between 2003 and 2009. Circulating levels of interleukin-6 (IL-6), C-reactive protein (CRP), fibrinogen, and soluble forms of intercellular adhesion molecule 1, E-selectin, and IL-6 receptor (sIL-6R) were measured in fasting blood samples. A social integration score was based on marital status, contact with family and friends, church attendance, and other social participation. A perceived social support index was based on questions regarding the availability of care and support from family and friends. Linear regression models tested the association between these two measures and each inflammatory marker controlling for sociodemographic characteristics, obesity, medication use, and baseline health status. After adjusting for potential confounders, social integration had a significant but weak inverse association with CRP in Taiwan. Perceived social support was significant in two of 12 models, and the coefficient was positive (i.e., higher support was associated with higher CRP and sIL-6R in the U.S.). We found no evidence that the coefficients for social relationship measures varied by sex or age. Our results yielded limited evidence of a weak association between two dimensions of social relationships and six inflammatory markers in Taiwan and the U.S. Given that the literature suggests a strong link between social relationships and mortality, and that inflammation plays an important role in the leading causes of death, we had expected to find consistent and moderately strong associations between social relationships and inflammatory markers. The small effect sizes and lack of robustness across markers were surprising. Copyright © 2012 Elsevier Ltd. All rights reserved.

Social Relationships and Inflammatory Markers: An Analysis of Taiwan and the U.S.

PubMed Central

Glei, Dana A.; Goldman, Noreen; Ryff, Carol D.; Lin, Yu-Hsuan; Weinstein, Maxine

2012-01-01

We evaluated the association between two aspects of social relationships and six inflammatory markers in Taiwan and the U.S. These two countries share similar levels of current life expectancy, but exhibit important differences in social structure. The data comprised population based samples from Taiwan (aged 53+; n = 962) and the U.S. (aged 35-86; n = 990) collected between 2003 and 2009. Circulating levels of interleukin-6 (IL-6), C-reactive protein (CRP), fibrinogen, and soluble forms of intercellular adhesion molecule 1, E-selectin, and IL-6 receptor (sIL-6R) were measured in fasting blood samples. A social integration score was based on marital status, contact with family and friends, church attendance, and other social participation. A perceived social support index was based on questions regarding the availability of care and support from family and friends. Linear regression models tested the association between these two measures and each inflammatory marker controlling for sociodemographic characteristics, obesity, medication use, and baseline health status. After adjusting for potential confounders, social integration had a significant but weak inverse association with CRP in Taiwan. Perceived social support was significant in two of 12 models, and the coefficient was positive (i.e., higher support was associated with higher CRP and sIL-6R in the U.S.). We found no evidence that the coefficients for social relationship measures varied by sex or age. Our results yielded limited evidence of a weak association between two dimensions of social relationships and six inflammatory markers in Taiwan and the U.S. Given that the literature suggests a strong link between social relationships and mortality, and that inflammation plays an important role in the leading causes of death, we had expected to find consistent and moderately strong associations between social relationships and inflammatory markers. The small effect sizes and lack of robustness across markers were surprising. PMID:22483707

You don't always get what you want, and you don't always want what you get: An examination of control-desire for control congruence in transactional relationships.

PubMed

Mullins, Ryan R; Bachrach, Daniel G; Rapp, Adam A; Grewal, Dhruv; Beitelspacher, Lauren Skinner

2015-07-01

In this research we develop a framework to examine the drivers of customers' desire for control over the sales relationship, and consequences of fit between perceived and desired control. Data collected in a lagged field study of 144 retailer manager (customer)-salesperson dyads were modeled using hierarchical linear modeling and response surface modeling techniques. Results from our analysis reveal that salesperson expertise drives retailers' desire for control in these relationships. In addition, while incongruence in perceived-desired control was negatively associated with both satisfaction and objective sales, retailer satisfaction was higher when both desired and perceived control were high. Further, as desired and perceived control over the sales relationship both increase, product sales initially decrease, and then increase, exhibiting a "U-shaped" effect. Implications for both theory and practice are discussed. These include adaptive sales training to identify misalignment between desired and perceived control, optimization of cocreation strategies, incorporation of interorganizational relational constructs, exploration of triadic social network configurations, examination of unmet expectations, and the implications of assimilation-contrast theory. (c) 2015 APA, all rights reserved).

Use of Statistical Analysis of Acoustic Emission Data on Carbon-Epoxy COPV Materials-of-Construction for Enhanced Felicity Ratio Onset Determination

NASA Technical Reports Server (NTRS)

Abraham, Arick Reed A.; Johnson, Kenneth L.; Nichols, Charles T.; Saulsberry, Regor L.; Waller, Jess M.

2012-01-01

Broadband modal acoustic emission (AE) data were acquired during intermittent load hold tensile test profiles on Toray T1000G carbon fiber-reinforced epoxy (C/Ep) single tow specimens. A novel trend seeking statistical method to determine the onset of significant AE was developed, resulting in more linear decreases in the Felicity ratio (FR) with load, potentially leading to more accurate failure prediction. The method developed uses an exponentially weighted moving average (EWMA) control chart. Comparison of the EWMA with previously used FR onset methods, namely the discrete (n), mean (n (raised bar)), normalized (n%) and normalized mean (n(raised bar)%) methods, revealed the EWMA method yields more consistently linear FR versus load relationships between specimens. Other findings include a correlation between AE data richness and FR linearity based on the FR methods discussed in this paper, and evidence of premature failure at lower than expected loads. Application of the EWMA method should be extended to other composite materials and, eventually, composite components such as composite overwrapped pressure vessels. Furthermore, future experiments should attempt to uncover the factors responsible for infant mortality in C/Ep strands.

Livestock and feed water productivity in the mixed crop-livestock system.

PubMed

Bekele, M; Mengistu, A; Tamir, B

2017-10-01

Recently with limited information from intensified grain-based farming systems in developed countries, livestock production is challenged as being huge consumer of freshwater. The smallholder mixed crop-livestock (MCL) system which is predominant in developing countries like Ethiopia, is maintained with considerable contributions of crop residues (CR) to livestock feeding. Inclusion of CR is expected to reduce the water requirement for feed production resulting improvement in livestock water productivity (LWP). This study was conducted to determine feed water productivity (FWP) and LWP in the MCL system. A multistage sampling procedure was followed to select farmers from different wealth status. Wealth status dictated by ownership of key farm resources such as size of cropland and livestock influenced the magnitude of livestock outputs, FWP and LWP. Significant difference in feed collected, freshwater evapotranspired, livestock outputs and water productivity (WP) were observed between wealth groups, where wealthier are relatively more advantaged. Water productivity of CR and grazing land (GL) analyzed separately showed contrasting differences where better-off gained more on CR, whereas vice versa on GL. These counterbalancing of variations may justify the non-significant difference in total FWP between wealth groups. Despite observed differences, low WP on GL indicates the need of interventions at all levels. The variation in WP of CR is attributed to availability of production factors which restrained the capacity of poor farmers most. A linear relationship between the proportion of CR in livestock feed and FWP was evident, but the relationship with LWP was not likely linear. As CR are inherently low in digestibility and nutritive values which have an effect on feed conversion into valuable livestock products and services, increasing share of CR beyond an optimum level is not a viable option to bring improvements in livestock productivity as expressed in terms of LWP. Ensuring land security, installing proper grazing management, improved forage seed supply and application of soil and water conservation are expected to enhance WP on GL. Given the relationship of production factors with crop biomass and associated WP, interventions targeted to improve provision of inputs, credit, extension and training support due emphasis to the poor would increase CR yield and reduce part of water use for feed production. Optimizing feed value of CR with treatment and supplementation, following water efficient forage production methods and maintenance of healthy productive animals are expected to amplify the benefits from livestock and eventually improve LWP.

The Effects of Traumatic Experiences on Academic Relationships and Expectations in Justice-Involved Children

ERIC Educational Resources Information Center

Johnson, Micah E.

2018-01-01

Positive school experiences are an important predictor of long-term health and well-being. Developing positive relationships with school personnel and positive academic expectations set the foundation for success. Positive relationships and expectations can be a powerful protective factor or intervention to redirect troubled children toward a more…

Investigations on colour dependent photo induced microactuation effect of FSMA and proposing suitable mechanisms to control the effect

NASA Astrophysics Data System (ADS)

Bagchi, A.; Sarkar, S.; Mukhopadhyay, P. K.

2018-02-01

Three different coloured focused laser beams were used to study the photo induced microactuation effect found in some ferromagnetic shape memory alloys. Besides trying to uncover the basic causes of this unique and as yet unexplained effect, these studies are to help find other conditions to further characterize the effect for practical use. In this study some mechanisms have been proposed to control the amplitude of actuation of the sample. Control of the actuation of the FSMA sample both linearly with the help of a continuously variable neutral density filter as well periodically with the help of a linear polarizer was achieved. Statistical analysis of the experimental data was also done by applying ANOVA studies on the data to conclusively provide evidence in support of the relationship between the actuation of the sample and the various controlling factors. This study is expected to pave the way to implement this property of the sample in fabricating and operating useful micro-mechanical systems in the near future.

Estimation of parameters in Shot-Noise-Driven Doubly Stochastic Poisson processes using the EM algorithm--modeling of pre- and postsynaptic spike trains.

PubMed

Mino, H

2007-01-01

To estimate the parameters, the impulse response (IR) functions of some linear time-invariant systems generating intensity processes, in Shot-Noise-Driven Doubly Stochastic Poisson Process (SND-DSPP) in which multivariate presynaptic spike trains and postsynaptic spike trains can be assumed to be modeled by the SND-DSPPs. An explicit formula for estimating the IR functions from observations of multivariate input processes of the linear systems and the corresponding counting process (output process) is derived utilizing the expectation maximization (EM) algorithm. The validity of the estimation formula was verified through Monte Carlo simulations in which two presynaptic spike trains and one postsynaptic spike train were assumed to be observable. The IR functions estimated on the basis of the proposed identification method were close to the true IR functions. The proposed method will play an important role in identifying the input-output relationship of pre- and postsynaptic neural spike trains in practical situations.

The f ( R ) halo mass function in the cosmic web

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

Braun-Bates, F. von; Winther, H.A.; Alonso, D.

An important indicator of modified gravity is the effect of the local environment on halo properties. This paper examines the influence of the local tidal structure on the halo mass function, the halo orientation, spin and the concentration-mass relation. We use the excursion set formalism to produce a halo mass function conditional on large-scale structure. Our simple model agrees well with simulations on large scales at which the density field is linear or weakly non-linear. Beyond this, our principal result is that f ( R ) does affect halo abundances, the halo spin parameter and the concentration-mass relationship in anmore » environment-independent way, whereas we find no appreciable deviation from \\text(ΛCDM) for the mass function with fixed environment density, nor the alignment of the orientation and spin vectors of the halo to the eigenvectors of the local cosmic web. There is a general trend for greater deviation from \\text(ΛCDM) in underdense environments and for high-mass haloes, as expected from chameleon screening.« less

Investigations on colour dependent photo induced microactuation effect of FSMA and proposing suitable mechanisms to control the effect

NASA Astrophysics Data System (ADS)

Bagchi, A.; Sarkar, S.; Mukhopadhyay, P. K.

2018-07-01

Three different coloured focused laser beams were used to study the photo induced microactuation effect found in some ferromagnetic shape memory alloys. Besides trying to uncover the basic causes of this unique and as yet unexplained effect, these studies are to help find other conditions to further characterize the effect for practical use. In this study some mechanisms have been proposed to control the amplitude of actuation of the sample. Control of the actuation of the FSMA sample both linearly with the help of a continuously variable neutral density filter as well periodically with the help of a linear polarizer was achieved. Statistical analysis of the experimental data was also done by applying ANOVA studies on the data to conclusively provide evidence in support of the relationship between the actuation of the sample and the various controlling factors. This study is expected to pave the way to implement this property of the sample in fabricating and operating useful micro-mechanical systems in the near future.

A Descriptive Study of Teenage Expectant Fathers.

ERIC Educational Resources Information Center

Barret, Robert L.; Robinson, Bryan E.

1982-01-01

Reports demographic data on 26 adolescent expectant fathers and information about their relationships with the expectant mothers and their families. Results indicated that young fathers maintained positive relationships with their girlfriend's family, maintained contact with the expectant mother, and desired to meet certain responsibilities toward…

Detection of relationships among multi-modal brain imaging meta-features via information flow.

PubMed

Miller, Robyn L; Vergara, Victor M; Calhoun, Vince D

2018-01-15

Neuroscientists and clinical researchers are awash in data from an ever-growing number of imaging and other bio-behavioral modalities. This flow of brain imaging data, taken under resting and various task conditions, combines with available cognitive measures, behavioral information, genetic data plus other potentially salient biomedical and environmental information to create a rich but diffuse data landscape. The conditions being studied with brain imaging data are often extremely complex and it is common for researchers to employ more than one imaging, behavioral or biological data modality (e.g., genetics) in their investigations. While the field has advanced significantly in its approach to multimodal data, the vast majority of studies still ignore joint information among two or more features or modalities. We propose an intuitive framework based on conditional probabilities for understanding information exchange between features in what we are calling a feature meta-space; that is, a space consisting of many individual featurae spaces. Features can have any dimension and can be drawn from any data source or modality. No a priori assumptions are made about the functional form (e.g., linear, polynomial, exponential) of captured inter-feature relationships. We demonstrate the framework's ability to identify relationships between disparate features of varying dimensionality by applying it to a large multi-site, multi-modal clinical dataset, balance between schizophrenia patients and controls. In our application it exposes both expected (previously observed) relationships, and novel relationships rarely considered investigated by clinical researchers. To the best of our knowledge there is not presently a comparably efficient way to capture relationships of indeterminate functional form between features of arbitrary dimension and type. We are introducing this method as an initial foray into a space that remains relatively underpopulated. The framework we propose is powerful, intuitive and very efficiently provides a high-level overview of a massive data space. In our application it exposes both expected relationships and relationships very rarely considered worth investigating by clinical researchers. Copyright © 2017 Elsevier B.V. All rights reserved.

Nonlinear Associations Between Co-Rumination and Both Social Support and Depression Symptoms.

PubMed

Ames-Sikora, Alyssa M; Donohue, Meghan Rose; Tully, Erin C

2017-08-18

Co-ruminating about one's problems appears to involve both beneficial self-disclosure and harmful rumination, suggesting that moderate levels may be the most adaptive. This study used nonlinear regression to determine whether moderate levels of self-reported co-rumination in relationships with a sibling, parent, friend, and romantic partner are linked to the highest levels of self-perceived social support and lowest levels of self-reported depression symptoms in 175 emerging adults (77% female; M = 19.66 years). As expected, moderate co-rumination was associated with high social support across all four relationship types, but, somewhat unexpectedly, high levels of co-rumination were also associated with high social support. As predicted, moderate levels of co-rumination with friends and siblings were associated with low levels of depression. Contrary to hypotheses, high levels of co-rumination were associated with high depression within romantic relationships. Co-rumination with a parent did not have a linear or quadratic association with depression. These findings suggest that high co-ruminating in supportive relationships and to a lesser extent low co-ruminating in unsupportive relationships are maladaptive interpersonal processes but that co-rumination's relation to depression depends on the co-ruminating partner. Psychotherapies for depression may target these maladaptive processes by supporting clients' development of balanced self-focused negative talk.

Rarity and genetic diversity in Indo–Pacific Acropora corals

PubMed Central

Richards, Zoe T; Oppen, Madeleine J H

2012-01-01

Among various potential consequences of rarity is genetic erosion. Neutral genetic theory predicts that rare species will have lower genetic diversity than common species. To examine the association between genetic diversity and rarity, variation at eight DNA microsatellite markers was documented for 14 Acropora species that display different patterns of distribution and abundance in the Indo–Pacific Ocean. Our results show that the relationship between rarity and genetic diversity is not a positive linear association because, contrary to expectations, some rare species are genetically diverse and some populations of common species are genetically depleted. Our data suggest that inbreeding is the most likely mechanism of genetic depletion in both rare and common corals, and that hybridization is the most likely explanation for higher than expected levels of genetic diversity in rare species. A significant hypothesis generated from our study with direct conservation implications is that as a group, Acropora corals have lower genetic diversity at neutral microsatellite loci than may be expected from their taxonomic diversity, and this may suggest a heightened susceptibility to environmental change. This hypothesis requires validation based on genetic diversity estimates derived from a large portion of the genome. PMID:22957189

Middle School Friendships and Academic Achievement in Early Adolescence: A Longitudinal Analysis

PubMed Central

Véronneau, Marie-Hélène; Dishion, Thomas J.

2011-01-01

Early adolescence is a critical transition period for the maintenance of academic achievement. One factor that school systems often fail to take into account is the influence of friends on academic achievement during middle school. This study investigated the influence of friends’ characteristics on change in academic achievement from Grade 6 through 8, and the role of students’ own characteristics as moderators of this relationship. The sample included 1,278 participants (698 girls). Linear regressions suggest that students with academically engaged friends may achieve to levels higher than expected in Grade 8. However, when considering the significant, negative influence of friends’ problem behavior, the role of friend's school engagement became nonsignificant. Low-achieving girls who had high-achieving friends in Grade 6 had lower academic achievement than expected by Grade 8. In contrast, high-achieving girls seemed to benefit from having high-achieving friends. Implications for theory and prevention efforts targeting young adolescents are discussed. PMID:21552353

Associations Between Health Literacy and Established Predictors of Smoking Cessation

PubMed Central

Adams, Claire E.; Cano, Miguel A.; Correa-Fernández, Virmarie; Waters, Andrew J.; Wetter, David W.; Vidrine, Jennifer Irvin

2013-01-01

Objectives. We examined associations between health literacy and predictors of smoking cessation among 402 low-socioeconomic status (SES), racially/ethnically diverse smokers. Methods. Data were collected as part of a larger study evaluating smoking health risk messages. We conducted multiple linear regression analyses to examine relations between health literacy and predictors of smoking cessation (i.e., nicotine dependence, smoking outcome expectancies, smoking risk perceptions and knowledge, self-efficacy, intentions to quit or reduce smoking). Results. Lower health literacy was associated with higher nicotine dependence, more positive and less negative smoking outcome expectancies, less knowledge about smoking health risks, and lower risk perceptions. Associations remained significant (P < .05) after controlling for demographics and SES-related factors. Conclusions. These results provide the first evidence that low health literacy may serve as a critical and independent risk factor for poor cessation outcomes among low-socioeconomic status, racially/ethnically diverse smokers. Research is needed to investigate potential mechanisms underlying this relationship. PMID:23678912

Linear relationship between water wetting behavior and microscopic interactions of super-hydrophilic surfaces.

PubMed

Liu, Jian; Wang, Chunlei; Guo, Pan; Shi, Guosheng; Fang, Haiping

2013-12-21

Using molecular dynamics simulations, we show a fine linear relationship between surface energies and microscopic Lennard-Jones parameters of super-hydrophilic surfaces. The linear slope of the super-hydrophilic surfaces is consistent with the linear slope of the super-hydrophobic, hydrophobic, and hydrophilic surfaces where stable water droplets can stand, indicating that there is a universal linear behavior of the surface energies with the water-surface van der Waals interaction that extends from the super-hydrophobic to super-hydrophilic surfaces. Moreover, we find that the linear relationship exists for various substrate types, and the linear slopes of these different types of substrates are dependent on the surface atom density, i.e., higher surface atom densities correspond to larger linear slopes. These results enrich our understanding of water behavior on solid surfaces, especially the water wetting behaviors on uncharged super-hydrophilic metal surfaces.

Self-calibrating multiplexer circuit

DOEpatents

Wahl, Chris P.

1997-01-01

A time domain multiplexer system with automatic determination of acceptable multiplexer output limits, error determination, or correction is comprised of a time domain multiplexer, a computer, a constant current source capable of at least three distinct current levels, and two series resistances employed for calibration and testing. A two point linear calibration curve defining acceptable multiplexer voltage limits may be defined by the computer by determining the voltage output of the multiplexer to very accurately known input signals developed from predetermined current levels across the series resistances. Drift in the multiplexer may be detected by the computer when the output voltage limits, expected during normal operation, are exceeded, or the relationship defined by the calibration curve is invalidated.

[Substance use and victimization in violent assaults].

PubMed

Marvelli, E; Grattagliano, I; Aventaggiato, L; Gagliano-Candela, R

2013-01-01

The aim of this work was to examine the role of substance use as factor which increase risk of assault. A review of the some of the most important international literature about drug-facilitated crimes is presented here. The whole part of the papers shows a relationship between substance use and risk increase of assault, particularly in family violence and rape. The effects of psychotropic substances use depend on the user's emotional state and on drugs use expectations. This prospective shows that we need to be cautious in interpreting processes of linear causality between abusive behaviour, processes of victimisation, abuses and abnormal sexual behaviours, which are related to the patient's desires, enhanced and validated by drugs.

Responses of the tropical gorgonian coral Eunicea fusca to ocean acidification conditions

NASA Astrophysics Data System (ADS)

Gómez, C. E.; Paul, V. J.; Ritson-Williams, R.; Muehllehner, N.; Langdon, C.; Sánchez, J. A.

2015-06-01

Ocean acidification can have negative repercussions from the organism to ecosystem levels. Octocorals deposit high-magnesium calcite in their skeletons, and according to different models, they could be more susceptible to the depletion of carbonate ions than either calcite or aragonite-depositing organisms. This study investigated the response of the gorgonian coral Eunicea fusca to a range of CO2 concentrations from 285 to 4,568 ppm (pH range 8.1-7.1) over a 4-week period. Gorgonian growth and calcification were measured at each level of CO2 as linear extension rate and percent change in buoyant weight and calcein incorporation in individual sclerites, respectively. There was a significant negative relationship for calcification and CO2 concentration that was well explained by a linear model regression analysis for both buoyant weight and calcein staining. In general, growth and calcification did not stop in any of the concentrations of pCO2; however, some of the octocoral fragments experienced negative calcification at undersaturated levels of calcium carbonate (>4,500 ppm) suggesting possible dissolution effects. These results highlight the susceptibility of the gorgonian coral E. fusca to elevated levels of carbon dioxide but suggest that E. fusca could still survive well in mid-term ocean acidification conditions expected by the end of this century, which provides important information on the effects of ocean acidification on the dynamics of coral reef communities. Gorgonian corals can be expected to diversify and thrive in the Atlantic-Eastern Pacific; as scleractinian corals decline, it is likely to expect a shift in these reef communities from scleractinian coral dominated to octocoral/soft coral dominated under a "business as usual" scenario of CO2 emissions.

Understanding differences in sexting behaviors across gender, relationship status, and sexual identity, and the role of expectancies in sexting.

PubMed

Dir, Allyson L; Coskunpinar, Ayca; Steiner, Jennifer L; Cyders, Melissa A

2013-08-01

Sexting, or the exchange of sexually explicit material via Internet social-networking site or mobile phone, is an increasingly prevalent behavior. The study sought to (1) identify expectancies regarding sexting behaviors, (2) examine how demographics (i.e., gender, sexual identity, relationship status) might be differentially related to sexting expectancies and behaviors, and (3) examine whether these concurrent relationships are consistent with a theoretical causal model in which sexting expectancies influence sexting behaviors. The sample consisted of 278 undergraduate students (mean age=21.0 years, SD=4.56; 53.8% female; 76.3% caucasian). Factor analyses supported the validity and reliability of the Sextpectancies Measure (α=0.85-0.93 across subscales) and indicated two expectancy domains each for both sending and receiving sexts: positive expectancies (sexual-related and affect-related) and negative expectancies. Males reported stronger positive expectancies (F=4.64, p=0.03) while females reported stronger negative expectancies (F=6.11, p=0.01) about receiving sexts. There were also differences across relationship status regarding negative expectancies (F=2.25, p=0.05 for sending; F=4.24, p=0.002 for receiving). There were also significant effects of positive (F=45.98, p<0.001 for sending, F=22.42, p<0.001 for receiving) and negative expectancies (F=36.65, p=0.02 sending, F=14.41, p<0.001 receiving) on sexting behaviors (η(2) from 0.04-0.13). College students reported both positive and negative sextpectancies, although sextpectancies and sexting varied significantly across gender, race, sexual identity, and relationship status. Concurrent relationships were consistent with the causal model of sextpectancies influencing sexting behaviors, and this study serves as the first test of this model, which could inform future prevention strategies to mitigate sexting risks.

Perceptions about parents' relationship and parenting quality, attachment styles, and young adults' intimate expectations: a cluster analytic approach.

PubMed

Einav, Michal

2014-01-01

This study examines the associations between young adults' perceptions of their parents' intimate relationship and the quality of their parenting as predictors of their children's expectations about intimacy in their own future relationships. A sample of 111 young adults completed questionnaires assessing their perceptions regarding their parents' intimate relationship and parenting quality, their own attachment styles, and their own expectations regarding intimate relationships. A correlational analysis revealed a positive link between the parents' relationship and parenting quality, and between parenting quality and expectations about intimacy, which supports the attachment theory. A cluster analysis identified three distinct groups of parental profiles interrelated with attachment styles that had varying effects on their children's expectations about intimacy. These findings emphasize the unique characteristics of parental relations in the family of origin relations, which have an enduring effect on the interpersonal styles of adult children, providing additional support to an integrated, intergenerational approach to family dynamics.

A Simple Piece of Apparatus to Aid the Understanding of the Relationship between Angular Velocity and Linear Velocity

ERIC Educational Resources Information Center

Unsal, Yasin

2011-01-01

One of the subjects that is confusing and difficult for students to fully comprehend is the concept of angular velocity and linear velocity. It is the relationship between linear and angular velocity that students find difficult; most students understand linear motion in isolation. In this article, we detail the design, construction and…

Acceptability of picture archiving and communication system (PACS) among hospital healthcare personnel based on a unified theory of acceptance and use of technology.

PubMed

Ahmadi, Maryam; Mehrabi, Nahid; Sheikhtaheri, Abbas; Sadeghi, Mojtaba

2017-09-01

The picture archiving and communication system (PACS) is a healthcare system technology which manages medical images and integrates equipment through a network. There are some theories about the use and acceptance of technology by people to describe the behavior and attitudes of end users towards information technologies. We investigated the influential factors on users' acceptance of PACS in the military hospitals of Tehran. In this applied analytical and cross-sectional study, 151 healthcare employees of military hospitals who had experience in using the PACS system were investigated. Participants were selected by census. The following variables were considered: performance expectancy, efforts expectancy, social influence, facilitating conditions and behavioral intention. Data were gathered using a questionnaire. Its validity and reliability were approved by a panel of experts and was piloted with 30 hospital healthcare staff (Cronbach's alpha =0.91). Spearman correlation coefficient and multiple linear regression analysis were used in analyzing the data. Expected performance, efforts expectancy, social impact and facilitating conditions had a significant relationship with behavioral intention. The multiple regression analysis indicated that only performance expectancy can predict the user's behavioral intentions to use PACS technology. Performance and effort expectancies are quite influential in accepting the use of PACS in hospitals. All healthcare personnel should become aware that using such technology is necessary in a hospital. Knowing the influencing factors that affect the acceptance of using new technology can help in improving its use, especially in a healthcare system. This can improve the offered healthcare services' quality.

Direct surface magnetometry with photoemission magnetic x-ray dichroism

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

Tobin, J.G.; Goodman, K.W.; Schumann, F.O.

1997-04-01

Element specific surface magnetometry remains a central goal of synchrotron radiation based studies of nanomagnetic structures. One appealing possibility is the combination of x-ray absorption dichroism measurements and the theoretical framework provided by the {open_quotes}sum rules.{close_quotes} Unfortunately, sum rule analysis are hampered by several limitations including delocalization of the final state, multi-electronic phenomena and the presence of surface dipoles. An alternative experiment, Magnetic X-Ray Dichroism in Photoelectron Spectroscopy, holds out promise based upon its elemental specificity, surface sensitivity and high resolution. Computational simulations by Tamura et al. demonstrated the relationship between exchange and spin orbit splittings and experimental data ofmore » linear and circular dichroisms. Now the authors have developed an analytical framework which allows for the direct extraction of core level exchange splittings from circular and linear dichroic photoemission data. By extending a model initially proposed by Venus, it is possible to show a linear relation between normalized dichroism peaks in the experimental data and the underlying exchange splitting. Since it is reasonable to expect that exchange splittings and magnetic moments track together, this measurement thus becomes a powerful new tool for direct surface magnetometry, without recourse to time consuming and difficult spectral simulations. The theoretical derivation will be supported by high resolution linear and circular dichroism data collected at the Spectromicroscopy Facility of the Advanced Light Source.« less

Non-linear Relationship between BOLD Activation and Amplitude of Beta Oscillations in the Supplementary Motor Area during Rhythmic Finger Tapping and Internal Timing.

PubMed

Gompf, Florian; Pflug, Anja; Laufs, Helmut; Kell, Christian A

2017-01-01

Functional imaging studies using BOLD contrasts have consistently reported activation of the supplementary motor area (SMA) both during motor and internal timing tasks. Opposing findings, however, have been shown for the modulation of beta oscillations in the SMA. While movement suppresses beta oscillations in the SMA, motor and non-motor tasks that rely on internal timing increase the amplitude of beta oscillations in the SMA. These independent observations suggest that the relationship between beta oscillations and BOLD activation is more complex than previously thought. Here we set out to investigate this rapport by examining beta oscillations in the SMA during movement with varying degrees of internal timing demands. In a simultaneous EEG-fMRI experiment, 20 healthy right-handed subjects performed an auditory-paced finger-tapping task. Internal timing was operationalized by including conditions with taps on every fourth auditory beat, which necessitates generation of a slow internal rhythm, while tapping to every auditory beat reflected simple auditory-motor synchronization. In the SMA, BOLD activity increased and power in both the low and the high beta band decreased expectedly during each condition compared to baseline. Internal timing was associated with a reduced desynchronization of low beta oscillations compared to conditions without internal timing demands. In parallel with this relative beta power increase, internal timing activated the SMA more strongly in terms of BOLD. This documents a task-dependent non-linear relationship between BOLD and beta-oscillations in the SMA. We discuss different roles of beta synchronization and desynchronization in active processing within the same cortical region.

Forgiveness, acceptance and the matter of expectation.

PubMed

Siassi, Shahrzad

2007-12-01

In this paper, the author argues for a dynamic conceptualization of forgiveness during psychoanalysis. The trauma of failed expectations in intimate relationships is narcissistically dislodging. When legitimate expectations in relationships are not met, forgiveness becomes a challenge for ego to restore the lost narcissistic balance through the resumption of a significant internal bond. The author argues that the ending of any successful analysis is marked by three possibilities regarding the patient's relationship to significant others and his traumas: in cases where the relationship was marked by minimal expectations, one simply learns to accept the wrongdoer without ever feeling the need for forgiveness; in cases where a relationship was marked by high expectations, the patient can learn to accept the trauma without the will or need to forgive its perpetrator. However, even with the painful frustration of high expectations in an intimate relationship, the patient can come to forgive his wrongdoer if there remains enough of a positive internal bond to be salvaged. The developmental roots of such forgiveness, as well as the addictive characteristics of 'nursing a grudge' and the conversion of the qualitative mode of seeking fulfillment into a quantitative one, are further investigated.

Smoking outcome expectancies in military veteran smokers with posttraumatic stress disorder.

PubMed

Carmody, Timothy P; McFall, Miles; Saxon, Andrew J; Malte, Carol A; Chow, Bruce; Joseph, Anne M; Beckham, Jean C; Cook, Jessica W

2012-08-01

Smoking outcome expectancies were investigated in treatment-seeking military Veteran smokers with posttraumatic stress disorder (PTSD). The investigation of smoking outcome expectancies may enhance our understanding of the relationship between PTSD and cigarette smoking. Participants were 943 military Veterans with a diagnosis of PTSD who were current smokers enrolled in a randomized multisite effectiveness trial to test whether the integration of smoking cessation treatment into mental health care (integrated care) improves prolonged abstinence rates compared with referral to specialized smoking cessation clinics (usual care). Using confirmatory factor analysis (CFA), we evaluated the conceptual model of smoking outcome expectancies measured on the Smoking Consequences Questionnaire-Adult (SCQ-A) version. The Kraemer method of mediation analysis was used to investigate the role of smoking outcome expectancies in mediating relationships between PTSD symptoms and smoking behavior, tobacco dependence, and abstinence self-efficacy. The CFA supported the 10-factor structure of the SCQ-A in smokers with PTSD. Relationships between measures of PTSD symptoms and tobacco dependence were mediated by the smoking outcome expectancy regarding negative affect reduction. This same smoking outcome expectancy mediated relationships between PTSD symptoms and smoking abstinence self-efficacy. The findings support the use of the SCQ-A as a valid measure of smoking outcome expectancies in military Veteran smokers with PTSD. Moreover, they suggest that smoking outcome expectancies may play an important role in explaining the relationship between PTSD and cigarette smoking.

Sex differences in the interacting roles of impulsivity and positive alcohol expectancy in problem drinking: A structural brain imaging study.

PubMed

Ide, Jaime S; Zhornitsky, Simon; Hu, Sien; Zhang, Sheng; Krystal, John H; Li, Chiang-Shan R

2017-01-01

Alcohol expectancy and impulsivity are implicated in alcohol misuse. However, how these two risk factors interact to determine problem drinking and whether men and women differ in these risk processes remain unclear. In 158 social drinkers (86 women) assessed for Alcohol Use Disorder Identification Test (AUDIT), positive alcohol expectancy, and Barratt impulsivity, we examined sex differences in these risk processes. Further, with structural brain imaging, we examined the neural bases underlying the relationship between these risk factors and problem drinking. The results of general linear modeling showed that alcohol expectancy best predicted problem drinking in women, whereas in men as well as in the combined group alcohol expectancy and impulsivity interacted to best predict problem drinking. Alcohol expectancy was associated with decreased gray matter volume (GMV) of the right posterior insula in women and the interaction of alcohol expectancy and impulsivity was associated with decreased GMV of the left thalamus in women and men combined and in men alone, albeit less significantly. These risk factors mediated the correlation between GMV and problem drinking. Conversely, models where GMV resulted from problem drinking were not supported. These new findings reveal distinct psychological factors that dispose men and women to problem drinking. Although mediation analyses did not determine a causal link, GMV reduction in the insula and thalamus may represent neural phenotype of these risk processes rather than the consequence of alcohol consumption in non-dependent social drinkers. The results add to the alcohol imaging literature which has largely focused on dependent individuals and help elucidate alterations in brain structures that may contribute to the transition from social to habitual drinking.

Non linear relationship between change in awareness in municipal solid waste management and domestic wastewater management - A case of the Jodipan and Ksatrian village, Malang, East Java

NASA Astrophysics Data System (ADS)

Zakiyya, Nida Maisa; Sarli, Prasanti Widyasih; Soewondo, Prayatni

2017-11-01

In developing countries the awareness on the importance of sanitation facilities, whether it is for municipal solid waste or domestic wastewater treatment, is still very low. Jodipan and Ksatrian Village, in Malang, East Java, are two slum areas that have recently been improved visually by using simple colorful paints. The visual improvement was expected to increase the resident's awareness on the importance of keeping the area clean; adjacent to the project, a new municipal waste management system was also put in place, changing the president's behaviour towards municipal solid waste. This study focuses on the relationship between community awareness in municipal solid waste management and domestic wastewater management. The result is expected to be an input for the government to enhance wastewater infrastructure program and its sustainability, related to its awareness on municipal solid waste. A descriptive model through questionnaire to 48 households of Jodipan sub district in Kampung Warna-warni and 69 households of Ksatrian sub district in Kampung 3D by random sampling, with an error of 0.1, was used to conduct this research. A nonlinear relationship between the change in awareness in municipal solid waste management (MSW) and domestic wastewater management was observed, with only 0.1312 of determination coefficient. Weak Spearman correlation coefficient number was found, ranging from 0.284 to 0.39, indicating another parameter turned into a role on affecting the awareness of wastewater. Further study about another parameter (eg. social and economic parameter) intervension on sanitation awareness could be investigated.

Expectancy after the first treatment and response to acupuncture for menopausal hot flashes.

PubMed

Ee, Carolyn C; Thuraisingam, Sharmala; Pirotta, Marie V; French, Simon D; Xue, Charlie C; Teede, Helena J

2017-01-01

Evidence on the impact of expectancy on acupuncture treatment response is conflicting. This secondary analysis of a randomized sham-controlled trial on acupuncture for menopausal hot flashes investigated whether treatment expectancy score was associated with hot flash score at end-of-treatment. Secondary analyses investigated whether there were associations between other pre-specified factors and hot flash score. Women experiencing moderately-severe hot flashes were randomized to receive 10 sessions of real or sham acupuncture over eight weeks. Hot flash score was collected using a seven-day hot flash diary, and expectancy using the modified Credibility and Expectancy Questionnaire immediately after the first treatment. Linear mixed-effects models with random intercepts were used to identify associations between expectancy score and hot flash score at end-of-treatment. Regression was also used to identify associations between pre-specified factors of interest and hot flash score. Because there was no difference between real and sham acupuncture for the primary outcome of hot flash score, both arms were combined in the analysis. 285 women returned the Credibility and Expectancy Questionnaire, and 283 women completed both expectancy measures. We found no evidence for an association between expectancy and hot flash score at end-of-treatment for individual cases in either acupuncture or sham group. Hot flash scores at end-of-treatment were 8.1 (95%CI, 3.0 to 13.2; P = 0.002) points lower in regular smokers compared to those who had never smoked, equivalent to four fewer moderate hot flashes a day. In our study of acupuncture for menopausal hot flashes, higher expectancy after the first treatment did not predict better treatment outcomes. Future research may focus on other determinants of outcomes in acupuncture such as therapist attention. The relationship between smoking and hot flashes is poorly understood and needs further exploration.

Correlation and simple linear regression.

PubMed

Zou, Kelly H; Tuncali, Kemal; Silverman, Stuart G

2003-06-01

In this tutorial article, the concepts of correlation and regression are reviewed and demonstrated. The authors review and compare two correlation coefficients, the Pearson correlation coefficient and the Spearman rho, for measuring linear and nonlinear relationships between two continuous variables. In the case of measuring the linear relationship between a predictor and an outcome variable, simple linear regression analysis is conducted. These statistical concepts are illustrated by using a data set from published literature to assess a computed tomography-guided interventional technique. These statistical methods are important for exploring the relationships between variables and can be applied to many radiologic studies.

Is Perruchet's dissociation between eyeblink conditioned responding and outcome expectancy evidence for two learning systems?

PubMed

Weidemann, Gabrielle; Tangen, Jason M; Lovibond, Peter F; Mitchell, Christopher J

2009-04-01

P. Perruchet (1985b) showed a double dissociation of conditioned responses (CRs) and expectancy for an airpuff unconditioned stimulus (US) in a 50% partial reinforcement schedule in human eyeblink conditioning. In the Perruchet effect, participants show an increase in CRs and a concurrent decrease in expectancy for the airpuff across runs of reinforced trials; conversely, participants show a decrease in CRs and a concurrent increase in expectancy for the airpuff across runs of nonreinforced trials. Three eyeblink conditioning experiments investigated whether the linear trend in eyeblink CRs in the Perruchet effect is a result of changes in associative strength of the conditioned stimulus (CS), US sensitization, or learning the precise timing of the US. Experiments 1 and 2 demonstrated that the linear trend in eyeblink CRs is not the result of US sensitization. Experiment 3 showed that the linear trend in eyeblink CRs is present with both a fixed and a variable CS-US interval and so is not the result of learning the precise timing of the US. The results are difficult to reconcile with a single learning process model of associative learning in which expectancy mediates CRs. Copyright (c) 2009 APA, all rights reserved.

Listing triangles in expected linear time on a class of power law graphs.

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

Nordman, Daniel J.; Wilson, Alyson G.; Phillips, Cynthia Ann

Enumerating triangles (3-cycles) in graphs is a kernel operation for social network analysis. For example, many community detection methods depend upon finding common neighbors of two related entities. We consider Cohen's simple and elegant solution for listing triangles: give each node a 'bucket.' Place each edge into the bucket of its endpoint of lowest degree, breaking ties consistently. Each node then checks each pair of edges in its bucket, testing for the adjacency that would complete that triangle. Cohen presents an informal argument that his algorithm should run well on real graphs. We formalize this argument by providing an analysismore » for the expected running time on a class of random graphs, including power law graphs. We consider a rigorously defined method for generating a random simple graph, the erased configuration model (ECM). In the ECM each node draws a degree independently from a marginal degree distribution, endpoints pair randomly, and we erase self loops and multiedges. If the marginal degree distribution has a finite second moment, it follows immediately that Cohen's algorithm runs in expected linear time. Furthermore, it can still run in expected linear time even when the degree distribution has such a heavy tail that the second moment is not finite. We prove that Cohen's algorithm runs in expected linear time when the marginal degree distribution has finite 4/3 moment and no vertex has degree larger than {radical}n. In fact we give the precise asymptotic value of the expected number of edge pairs per bucket. A finite 4/3 moment is required; if it is unbounded, then so is the number of pairs. The marginal degree distribution of a power law graph has bounded 4/3 moment when its exponent {alpha} is more than 7/3. Thus for this class of power law graphs, with degree at most {radical}n, Cohen's algorithm runs in expected linear time. This is precisely the value of {alpha} for which the clustering coefficient tends to zero asymptotically, and it is in the range that is relevant for the degree distribution of the World-Wide Web.« less

Solvent and substituent effects on aggregation constants of perylene bisimide π-stacks--a linear free energy relationship analysis.

PubMed

Chen, Zhijian; Fimmel, Benjamin; Würthner, Frank

2012-08-14

A series of six perylene bisimides (PBIs) with hydrophilic and hydrophobic side chains at the imide nitrogens were applied for a comparative study of the solvent and structural effects on the aggregation behaviour of this class of dyes. A comparison of the binding constants in tetrachloromethane at room temperature revealed the highest binding constant of about 10(5) M(-1) for a PBI bearing 3,4,5-tridodecyloxyphenyl substituents at the imide nitrogens, followed by 3,4,5-tridodecylphenyl and alkyl-substituted PBIs, whereas no aggregation could be observed in the accessible concentration range for PBIs equipped with bulky 2,6-diisopropylphenyl substituents at the imide nitrogens. The aggregation behaviour of three properly soluble compounds was investigated in 17 different solvents covering a broad polarity range from nonpolar n-hexane to highly polar DMSO and water. Linear free energy relationships (LFER) revealed a biphasic behaviour between Gibbs free energies of aggregation and common empirical solvent polarity scales indicating particularly strong π-π stacking interactions in nonpolar aliphatic and polar alcoholic solvents whilst the weakest binding is observed in dichloromethane and chloroform. Accordingly, PBI aggregation is dominated by electrostatic interactions in nonpolar solvents and by solvophobic interactions in protic solvents. In water, the aggregation constant is increased far beyond LFER expectations pointing at a pronounced hydrophobic effect.

Quality assurance of dynamic parameters in volumetric modulated arc therapy.

PubMed

Manikandan, A; Sarkar, B; Holla, R; Vivek, T R; Sujatha, N

2012-07-01

The purpose of this study was to demonstrate quality assurance checks for accuracy of gantry speed and position, dose rate and multileaf collimator (MLC) speed and position for a volumetric modulated arc treatment (VMAT) modality (Synergy S; Elekta, Stockholm, Sweden), and to check that all the necessary variables and parameters were synchronous. Three tests (for gantry position-dose delivery synchronisation, gantry speed-dose delivery synchronisation and MLC leaf speed and positions) were performed. The average error in gantry position was 0.5° and the average difference was 3 MU for a linear and a parabolic relationship between gantry position and delivered dose. In the third part of this test (sawtooth variation), the maximum difference was 9.3 MU, with a gantry position difference of 1.2°. In the sweeping field method test, a linear relationship was observed between recorded doses and distance from the central axis, as expected. In the open field method, errors were encountered at the beginning and at the end of the delivery arc, termed the "beginning" and "end" errors. For MLC position verification, the maximum error was -2.46 mm and the mean error was 0.0153 ±0.4668 mm, and 3.4% of leaves analysed showed errors of >±1 mm. This experiment demonstrates that the variables and parameters of the Synergy S are synchronous and that the system is suitable for delivering VMAT using a dynamic MLC.

Relationship Between Ktrans and K1 with Simultaneous Versus Separate MR/PET in Rabbits with VX2 Tumors.

PubMed

Lee, Kyung Hee; Kang, Seung Kwan; Goo, Jin Mo; Lee, Jae Sung; Cheon, Gi Jeong; Seo, Seongho; Hwang, Eui Jin

2017-03-01

To compare the relationship between K trans from DCE-MRI and K 1 from dynamic 13 N-NH 3 -PET, with simultaneous and separate MR/PET in the VX-2 rabbit carcinoma model. MR/PET was performed simultaneously and separately, 14 and 15 days after VX-2 tumor implantation at the paravertebral muscle. The K trans and K 1 values were estimated using an in-house software program. The relationships between K trans and K 1 were analyzed using Pearson's correlation coefficients and linear/non-linear regression function. Assuming a linear relationship, K trans and K 1 exhibited a moderate positive correlations with both simultaneous (r=0.54-0.57) and separate (r=0.53-0.69) imaging. However, while the K trans and K 1 from separate imaging were linearly correlated, those from simultaneous imaging exhibited a non-linear relationship. The amount of change in K 1 associated with a unit increase in K trans varied depending on K trans values. The relationship between K trans and K 1 may be mis-interpreted with separate MR and PET acquisition. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Subject-specific bone attenuation correction for brain PET/MR: can ZTE-MRI substitute CT scan accurately?

PubMed

Khalifé, Maya; Fernandez, Brice; Jaubert, Olivier; Soussan, Michael; Brulon, Vincent; Buvat, Irène; Comtat, Claude

2017-09-21

In brain PET/MR applications, accurate attenuation maps are required for accurate PET image quantification. An implemented attenuation correction (AC) method for brain imaging is the single-atlas approach that estimates an AC map from an averaged CT template. As an alternative, we propose to use a zero echo time (ZTE) pulse sequence to segment bone, air and soft tissue. A linear relationship between histogram normalized ZTE intensity and measured CT density in Hounsfield units ([Formula: see text]) in bone has been established thanks to a CT-MR database of 16 patients. Continuous AC maps were computed based on the segmented ZTE by setting a fixed linear attenuation coefficient (LAC) to air and soft tissue and by using the linear relationship to generate continuous μ values for the bone. Additionally, for the purpose of comparison, four other AC maps were generated: a ZTE derived AC map with a fixed LAC for the bone, an AC map based on the single-atlas approach as provided by the PET/MR manufacturer, a soft-tissue only AC map and, finally, the CT derived attenuation map used as the gold standard (CTAC). All these AC maps were used with different levels of smoothing for PET image reconstruction with and without time-of-flight (TOF). The subject-specific AC map generated by combining ZTE-based segmentation and linear scaling of the normalized ZTE signal into [Formula: see text] was found to be a good substitute for the measured CTAC map in brain PET/MR when used with a Gaussian smoothing kernel of [Formula: see text] corresponding to the PET scanner intrinsic resolution. As expected TOF reduces AC error regardless of the AC method. The continuous ZTE-AC performed better than the other alternative MR derived AC methods, reducing the quantification error between the MRAC corrected PET image and the reference CTAC corrected PET image.

Subject-specific bone attenuation correction for brain PET/MR: can ZTE-MRI substitute CT scan accurately?

NASA Astrophysics Data System (ADS)

Khalifé, Maya; Fernandez, Brice; Jaubert, Olivier; Soussan, Michael; Brulon, Vincent; Buvat, Irène; Comtat, Claude

2017-10-01

In brain PET/MR applications, accurate attenuation maps are required for accurate PET image quantification. An implemented attenuation correction (AC) method for brain imaging is the single-atlas approach that estimates an AC map from an averaged CT template. As an alternative, we propose to use a zero echo time (ZTE) pulse sequence to segment bone, air and soft tissue. A linear relationship between histogram normalized ZTE intensity and measured CT density in Hounsfield units (HU ) in bone has been established thanks to a CT-MR database of 16 patients. Continuous AC maps were computed based on the segmented ZTE by setting a fixed linear attenuation coefficient (LAC) to air and soft tissue and by using the linear relationship to generate continuous μ values for the bone. Additionally, for the purpose of comparison, four other AC maps were generated: a ZTE derived AC map with a fixed LAC for the bone, an AC map based on the single-atlas approach as provided by the PET/MR manufacturer, a soft-tissue only AC map and, finally, the CT derived attenuation map used as the gold standard (CTAC). All these AC maps were used with different levels of smoothing for PET image reconstruction with and without time-of-flight (TOF). The subject-specific AC map generated by combining ZTE-based segmentation and linear scaling of the normalized ZTE signal into HU was found to be a good substitute for the measured CTAC map in brain PET/MR when used with a Gaussian smoothing kernel of 4~mm corresponding to the PET scanner intrinsic resolution. As expected TOF reduces AC error regardless of the AC method. The continuous ZTE-AC performed better than the other alternative MR derived AC methods, reducing the quantification error between the MRAC corrected PET image and the reference CTAC corrected PET image.

What kind of Relationship is Between Body Mass Index and Body Fat Percentage?

PubMed

Kupusinac, Aleksandar; Stokić, Edita; Sukić, Enes; Rankov, Olivera; Katić, Andrea

2017-01-01

Although body mass index (BMI) and body fat percentage (B F %) are well known as indicators of nutritional status, there are insuficient data whether the relationship between them is linear or not. There are appropriate linear and quadratic formulas that are available to predict B F % from age, gender and BMI. On the other hand, our previous research has shown that artificial neural network (ANN) is a more accurate method for that. The aim of this study is to analyze relationship between BMI and B F % by using ANN and big dataset (3058 persons). Our results show that this relationship is rather quadratic than linear for both gender and all age groups. Comparing genders, quadratic relathionship is more pronounced in women, while linear relationship is more pronounced in men. Additionaly, our results show that quadratic relationship is more pronounced in old than in young and middle-age men and it is slightly more pronounced in young and middle-age than in old women.

Parental romantic expectations and parent-child sexuality communication in autism spectrum disorders.

PubMed

Holmes, Laura G; Himle, Michael B; Strassberg, Donald S

2016-08-01

This study examined the relationship between core symptoms of autism spectrum disorder, parental romantic expectations, and parental provision of sexuality and relationship education in an online sample of 190 parents of youth 12-18 years of age with a parent-reported diagnosis of autism spectrum disorder. Regression analyses were conducted separately for youth with autism spectrum disorder + parent-reported average or above IQ and youth with autism spectrum disorder + parent-reported below average IQ. For youth with autism spectrum disorder + parent-reported average or above IQ, autism spectrum disorder severity predicted parental romantic expectations, but not parental provision of sexuality and relationship education. For youth with autism spectrum disorder + parent-reported below average IQ, parental romantic expectations mediated the relationship between autism spectrum disorder severity and parent provision of sexuality and relationship education. This supports the importance of carefully considering intellectual functioning in autism spectrum disorder sexuality research and suggests that acknowledging and addressing parent expectations may be important for parent-focused sexuality and relationship education interventions. © The Author(s) 2015.

Shared Relationship Efficacy of Dyad Can Increase Life Satisfaction in Close Relationships: Multilevel Study

PubMed Central

Ito, Kenichi; Yoshida, Toshikazu

2016-01-01

Characteristics of relationship itself play an important role in determining well-being of individuals who participate in the relationship. We used efficacy expectations mutually shared between close friends or romantic partners as a characteristic of relationship and investigated its impact on their life satisfaction. In Study 1, we conducted a cross-sectional study among 137 pairs of close same-sex friends to test whether the efficacy expectations shared between friends are associated with levels of life satisfaction. In Study 2, we conducted a longitudinal study among 114 heterosexual romantic couples to test predictive validity of the efficacy expectations shared between couples predict levels of life satisfaction 2 month later. In both studies we found a consistent result that as degrees of the efficacy expectations shared between individuals in a relationship increased, the degree of their life satisfaction also increased. Underlying mechanisms that explain how characteristics of relationship itself increase life satisfaction are discussed. PMID:27437946

A quadratic regression modelling on paddy production in the area of Perlis

NASA Astrophysics Data System (ADS)

Goh, Aizat Hanis Annas; Ali, Zalila; Nor, Norlida Mohd; Baharum, Adam; Ahmad, Wan Muhamad Amir W.

2017-08-01

Polynomial regression models are useful in situations in which the relationship between a response variable and predictor variables is curvilinear. Polynomial regression fits the nonlinear relationship into a least squares linear regression model by decomposing the predictor variables into a kth order polynomial. The polynomial order determines the number of inflexions on the curvilinear fitted line. A second order polynomial forms a quadratic expression (parabolic curve) with either a single maximum or minimum, a third order polynomial forms a cubic expression with both a relative maximum and a minimum. This study used paddy data in the area of Perlis to model paddy production based on paddy cultivation characteristics and environmental characteristics. The results indicated that a quadratic regression model best fits the data and paddy production is affected by urea fertilizer application and the interaction between amount of average rainfall and percentage of area defected by pest and disease. Urea fertilizer application has a quadratic effect in the model which indicated that if the number of days of urea fertilizer application increased, paddy production is expected to decrease until it achieved a minimum value and paddy production is expected to increase at higher number of days of urea application. The decrease in paddy production with an increased in rainfall is greater, the higher the percentage of area defected by pest and disease.

Niche and Neutral Processes Together Determine Diversity Loss in Response to Fertilization in an Alpine Meadow Community

PubMed Central

Li, Wei; Cheng, Ji-Min; Yu, Kai-Liang; Epstein, Howard E.; Du, Guo-Zhen

2015-01-01

Fertilization via nutrient deposition and agricultural inputs is one of the most important factors driving decreases in plant diversity. However, we still do not fully understand which processes (niche process or neutral process) are more important in leading to decreases in plant diversity caused by fertilization. A hypothesis-based approach was used to test the relative importance of niche versus neutral processes along a fertilization gradient in an alpine meadow community on the eastern Tibetan plateau, China. Niche overlap values were calculated for species biomass, and the null model was used to generate the values of niche overlap expected at random. A linear regression modeling was used to evaluate the relationship between functional traits (specific leaf area, leaf dry matter content, and leaf total nitrogen concentration) and species relative abundance. Our results demonstrated that observed niche overlap for species biomass was significantly higher than expected at lower fertilization gradients. Moreover, we also found a significantly negative correlation between species relative abundance and specific leaf area and leaf dry matter content, but a significantly positive correlation between relative abundance and leaf nitrogen concentration at lower fertilization gradients. However, these relationships were not significant at higher fertilization gradients. We concluded that community assembly is dynamic progression along the environmental gradients, and niche and neutral processes may together determine species diversity loss in response to fertilization. PMID:26280919

Non-Linear Relationship between Economic Growth and CO2 Emissions in China: An Empirical Study Based on Panel Smooth Transition Regression Models

PubMed Central

Wang, Zheng-Xin; Hao, Peng; Yao, Pei-Yi

2017-01-01

The non-linear relationship between provincial economic growth and carbon emissions is investigated by using panel smooth transition regression (PSTR) models. The research indicates that, on the condition of separately taking Gross Domestic Product per capita (GDPpc), energy structure (Es), and urbanisation level (Ul) as transition variables, three models all reject the null hypothesis of a linear relationship, i.e., a non-linear relationship exists. The results show that the three models all contain only one transition function but different numbers of location parameters. The model taking GDPpc as the transition variable has two location parameters, while the other two models separately considering Es and Ul as the transition variables both contain one location parameter. The three models applied in the study all favourably describe the non-linear relationship between economic growth and CO2 emissions in China. It also can be seen that the conversion rate of the influence of Ul on per capita CO2 emissions is significantly higher than those of GDPpc and Es on per capita CO2 emissions. PMID:29236083

Non-Linear Relationship between Economic Growth and CO₂ Emissions in China: An Empirical Study Based on Panel Smooth Transition Regression Models.

PubMed

Wang, Zheng-Xin; Hao, Peng; Yao, Pei-Yi

2017-12-13

The non-linear relationship between provincial economic growth and carbon emissions is investigated by using panel smooth transition regression (PSTR) models. The research indicates that, on the condition of separately taking Gross Domestic Product per capita (GDPpc), energy structure (Es), and urbanisation level (Ul) as transition variables, three models all reject the null hypothesis of a linear relationship, i.e., a non-linear relationship exists. The results show that the three models all contain only one transition function but different numbers of location parameters. The model taking GDPpc as the transition variable has two location parameters, while the other two models separately considering Es and Ul as the transition variables both contain one location parameter. The three models applied in the study all favourably describe the non-linear relationship between economic growth and CO₂ emissions in China. It also can be seen that the conversion rate of the influence of Ul on per capita CO₂ emissions is significantly higher than those of GDPpc and Es on per capita CO₂ emissions.

Relationship between rice yield and climate variables in southwest Nigeria using multiple linear regression and support vector machine analysis

NASA Astrophysics Data System (ADS)

Oguntunde, Philip G.; Lischeid, Gunnar; Dietrich, Ottfried

2018-03-01

This study examines the variations of climate variables and rice yield and quantifies the relationships among them using multiple linear regression, principal component analysis, and support vector machine (SVM) analysis in southwest Nigeria. The climate and yield data used was for a period of 36 years between 1980 and 2015. Similar to the observed decrease ( P < 0.001) in rice yield, pan evaporation, solar radiation, and wind speed declined significantly. Eight principal components exhibited an eigenvalue > 1 and explained 83.1% of the total variance of predictor variables. The SVM regression function using the scores of the first principal component explained about 75% of the variance in rice yield data and linear regression about 64%. SVM regression between annual solar radiation values and yield explained 67% of the variance. Only the first component of the principal component analysis (PCA) exhibited a clear long-term trend and sometimes short-term variance similar to that of rice yield. Short-term fluctuations of the scores of the PC1 are closely coupled to those of rice yield during the 1986-1993 and the 2006-2013 periods thereby revealing the inter-annual sensitivity of rice production to climate variability. Solar radiation stands out as the climate variable of highest influence on rice yield, and the influence was especially strong during monsoon and post-monsoon periods, which correspond to the vegetative, booting, flowering, and grain filling stages in the study area. The outcome is expected to provide more in-depth regional-specific climate-rice linkage for screening of better cultivars that can positively respond to future climate fluctuations as well as providing information that may help optimized planting dates for improved radiation use efficiency in the study area.

Changes of Linearity in MF2 Index with R12 and Solar Activity Maximum

NASA Astrophysics Data System (ADS)

Villanueva, L.

2013-05-01

Critical frequency of F2 layer is related to the solar activity, and the sunspot number has been the standard index for ionospheric prediction programs. This layer, being considered the most important in HF radio communications due to its highest electron density, determines the maximum frequency coming back from ground base transmitter signals, and shows irregular variation in time and space. Nowadays the spatial variation, better understood due to the availability of TEC measurements, let Space Weather Centers have observations almost in real time. However, it is still the most difficult layer to predict in time. Short time variations are improved in IRI model, but long term predictions are only related to the well-known CCIR and URSI coefficients and Solar activity R12 predictions, (or ionospheric indexes in regional models). The concept of the "saturation" of the ionosphere is based on data observations around 3 solar cycles before 1970, (NBS, 1968). There is a linear relationship among MUF (0Km) and R12, for smooth Sunspot numbers R12 less than 100, but constant for higher R12, so, no rise of MUF is expected for R12 higher than 100. This recommendation has been used in most of the known Ionospheric prediction programs for HF Radio communication. In this work, observations of smoothed ionospheric index MF2 related to R12 are presented to find common features of the linear relationship, which is found to persist in different ranges of R12 depending on the specific maximum level of each solar cycle. In the analysis of individual solar cycles, the lapse of linearity is less than 100 for a low solar cycle and higher than 100 for a high solar cycle. To improve ionospheric predictions we can establish levels for solar cycle maximum sunspot numbers R12 around low 100, medium 150 and high 200 and specify the ranges of linearity of MUF(0Km) related to R12 which is not only 100 as assumed for all the solar cycles. For lower levels of solar cycle, discussions of present observations are presented.

Future road salt use in Switzerland: an example of an effective climate service

NASA Astrophysics Data System (ADS)

Zubler, Elias M.; Fischer, Andreas M.; Schlegel, Thomas H.; Liniger, Mark A.

2015-04-01

The application of salt is the predominant measure taken to enhance road safety in Switzerland by clearing the roads from snow or preventing frozen surfaces during winter. The need for road salt exhibits a strong interannual variability, according to Schweizer Salinen AG - the Swiss monopolist for production and distribution of road salt. These fluctuations are to a large extent a direct consequence of the year-to-year variability in winter climate. In the course of the 21st century, Swiss climate is projected to depart significantly from present and past conditions. By the end of the century, winter temperatures over Switzerland are expected to rise by about 2-4°C relative to the mean over the period 1980-2009, while winter precipitation may either increase or decrease based on ENSEMBLES regional climate model projections under the SRES-scenario A1B. Faced with these changes, Schweizer Salinen AG asked for an estimate of the expected future road salt use for designing their long-term business strategy. The study is based on climate change projections from the CH2011 initiative and later extensions thereof as well as monthly sales data of road salt from Schweizer Salinen AG. For the period 1997-2013, a linear relationship was derived between the average number of days with snowfall and the road salt amount sold over "saltation years" defined from October 1st to September 30th in the 26 cantons (provinces) of Switzerland. The ad-hoc linear relationship was applied to the climate change projections to obtain future salt use information in three future periods for the greenhouse gas emission scenarios A1B, A2 and RCP3PD. We find that the expected future salt use is likely to be reduced by about 50% in 2045-2074 under the scenario A1B. Currently, the countrywide mean annual road salt use corresponds to about 220'000 tons. In a particularly snow-rich year, the company sells up to 400'000 tons. At the end of the century, following a pessimistic scenario such as A1B or A2, the long-term mean salt use may even drop below today's annual minimum of 70'000 tons.

Comparing Machine Learning Classifiers and Linear/Logistic Regression to Explore the Relationship between Hand Dimensions and Demographic Characteristics

PubMed Central

2016-01-01

Understanding the relationship between physiological measurements from human subjects and their demographic data is important within both the biometric and forensic domains. In this paper we explore the relationship between measurements of the human hand and a range of demographic features. We assess the ability of linear regression and machine learning classifiers to predict demographics from hand features, thereby providing evidence on both the strength of relationship and the key features underpinning this relationship. Our results show that we are able to predict sex, height, weight and foot size accurately within various data-range bin sizes, with machine learning classification algorithms out-performing linear regression in most situations. In addition, we identify the features used to provide these relationships applicable across multiple applications. PMID:27806075

Comparing Machine Learning Classifiers and Linear/Logistic Regression to Explore the Relationship between Hand Dimensions and Demographic Characteristics.

PubMed

Miguel-Hurtado, Oscar; Guest, Richard; Stevenage, Sarah V; Neil, Greg J; Black, Sue

2016-01-01

Understanding the relationship between physiological measurements from human subjects and their demographic data is important within both the biometric and forensic domains. In this paper we explore the relationship between measurements of the human hand and a range of demographic features. We assess the ability of linear regression and machine learning classifiers to predict demographics from hand features, thereby providing evidence on both the strength of relationship and the key features underpinning this relationship. Our results show that we are able to predict sex, height, weight and foot size accurately within various data-range bin sizes, with machine learning classification algorithms out-performing linear regression in most situations. In addition, we identify the features used to provide these relationships applicable across multiple applications.

Expected performance of m-solution backtracking

NASA Technical Reports Server (NTRS)

Nicol, D. M.

1986-01-01

This paper derives upper bounds on the expected number of search tree nodes visited during an m-solution backtracking search, a search which terminates after some preselected number m problem solutions are found. The search behavior is assumed to have a general probabilistic structure. The results are stated in terms of node expansion and contraction. A visited search tree node is said to be expanding if the mean number of its children visited by the search exceeds 1 and is contracting otherwise. It is shown that if every node expands, or if every node contracts, then the number of search tree nodes visited by a search has an upper bound which is linear in the depth of the tree, in the mean number of children a node has, and in the number of solutions sought. Also derived are bounds linear in the depth of the tree in some situations where an upper portion of the tree contracts (expands), while the lower portion expands (contracts). While previous analyses of 1-solution backtracking have concluded that the expected performance is always linear in the tree depth, the model allows superlinear expected performance.

Poor medication adherence to bisphosphonates and high self-perception of aging in elderly female patients with osteoporosis.

PubMed

Wu, X; Wei, D; Sun, B; Wu, X N

2016-10-01

Non-adherence to bisphosphonates exposes the elderly female osteoporosis patients to an increased risk of fracture. This was one of the first studies to explore the relationship between medication adherence and self-perception of aging. Feelings of lacking control and expectations for negative events, beliefs of illness's chronic duration nature, and its linkage with aging were associated with of poor medication adherence. To examine the relationship between medication adherence to bisphosphonates and self-perception of aging in elderly female patients with osteoporosis. This was a cross-sectional survey. A convenience sample of 245 elderly female patients with osteoporosis prescribed regular oral bisphosphonate therapy was recruited from three tertiary hospitals in China. Sociodemographic and osteoporosis-related data, Morisky Medication Adherence Scale-8 (MMAS-8) and Aging Perceptions Questionnaire (APQ) data were collected. Mean adherence score measured by MMAS-8 was 4.46(SD = 1.91; range, 0.25-7.00). Percentages of good and poor adherence were 28.6 and 71.4 %, which showed a poor medication adherence. Six domains of APQ statistically significantly associated with medication adherence. Interestingly, with control of age, educational status, marital status, and symptoms accompanying osteoporosis as covariates in the multivariate linear regression model, the effects of three domains disappeared. Significantly, worse adherence was observed in those patients who had higher feelings of lack of control, more expectations for negative events, more beliefs of osteoporosis's chronic duration nature and its linkage with aging. We conclude that feelings of lacking control, expectations for negative events, beliefs of illness's chronic duration nature, and its linkage with aging were associated with poor medication adherence in elderly female patients with osteoporosis. Concerns about self-perception of aging need to be addressed in order to improve medication adherence.

Dunes on Pluto

NASA Astrophysics Data System (ADS)

Telfer, Matt W.; Parteli, Eric J. R.; Radebaugh, Jani; Beyer, Ross A.; Bertrand, Tanguy; Forget, François; Nimmo, Francis; Grundy, Will M.; Moore, Jeffrey M.; Stern, S. Alan; Spencer, John; Lauer, Tod R.; Earle, Alissa M.; Binzel, Richard P.; Weaver, Hal A.; Olkin, Cathy B.; Young, Leslie A.; Ennico, Kimberly; Runyon, Kirby; aff12

2018-06-01

The surface of Pluto is more geologically diverse and dynamic than had been expected, but the role of its tenuous atmosphere in shaping the landscape remains unclear. We describe observations from the New Horizons spacecraft of regularly spaced, linear ridges whose morphology, distribution, and orientation are consistent with being transverse dunes. These are located close to mountainous regions and are orthogonal to nearby wind streaks. We demonstrate that the wavelength of the dunes (~0.4 to 1 kilometer) is best explained by the deposition of sand-sized (~200 to ~300 micrometer) particles of methane ice in moderate winds (<10 meters per second). The undisturbed morphology of the dunes, and relationships with the underlying convective glacial ice, imply that the dunes have formed in the very recent geological past.

Terahertz-induced photothermoelectric response in graphene-metal contact structures

NASA Astrophysics Data System (ADS)

Deng, Xiangquan; Wang, Yingxin; Zhao, Ziran; Chen, Zhiqiang; Sun, Jia-Lin

2016-10-01

We report on the photoresponse of a graphene-metal contact device under terahertz (THz) illumination. The device has an extremely simple structure consisting of a large-area monolayer graphene stripe contacted with two gold electrodes. A significant position-dependent photovoltage is observed across the device by THz excitation, exhibiting a linear relationship with the incident beam power. Experimental results show that the graphene channel length and the substrate thermal conductivity have obvious influence on the photovoltage amplitude and response time, which is consistent with the photothermoelectric mechanism. This compact and powerless device is expected to have a promising application in THz detection. Our work provides theoretical and experimental evidence for the development of high-performance graphene-based THz photodetectors.

Transformation of apparent ocean wave spectra observed from an aircraft sensor platform

NASA Technical Reports Server (NTRS)

Poole, L. R.

1976-01-01

The problem considered was transformation of a unidirectional apparent ocean wave spectrum observed from an aircraft sensor platform into the true spectrum that would be observed from a stationary platform. Spectral transformation equations were developed in terms of the linear wave dispersion relationship and the wave group speed. An iterative solution to the equations was outlined and used to transform reference theoretical apparent spectra for several assumed values of average water depth. Results show that changing the average water depth leads to a redistribution of energy density among the various frequency bands of the transformed spectrum. This redistribution is most severe when much of the energy density is expected, a priori, to reside at relatively low true frequencies.

Signal-to-noise ratio and spectral linewidth improvements between 1.5 and 7 Tesla in proton echo-planar spectroscopic imaging.

PubMed

Otazo, Ricardo; Mueller, Bryon; Ugurbil, Kamil; Wald, Lawrence; Posse, Stefan

2006-12-01

This study characterizes gains in sensitivity and spectral resolution of proton echo-planar spectroscopic imaging (PEPSI) with increasing magnetic field strength (B(0)). Signal-to-noise ratio (SNR) per unit volume and unit time, and intrinsic linewidth (LW) of N-acetyl-aspartate (NAA), creatine (Cr), and choline (Cho) were measured with PEPSI at 1.5, 3, 4, and 7 Tesla on scanners that shared a similar software and hardware platform, using circularly polarized (CP) and eight-channel phased-array (PA) head coils. Data were corrected for relaxation effects and processed with a time-domain matched filter (MF) adapted to each B(0). The SNR and LW measured with PEPSI were very similar to those measured with conventional point-resolved spectroscopy (PRESS) SI. Measurements with the CP coil demonstrated a nearly linear SNR gain with respect to B(0) in central brain regions. For the PA coil, the SNR-B(0) relationship was less than linear, but there was a substantial SNR increase in comparison to the CP coil. The LW in units of ppm decreased with B(0), resulting in improved spectral resolution. These studies using PEPSI demonstrated linear gains in SNR with respect to B(0), consistent with theoretical expectations, and a decrease in ppm LW with increasing B(0).

Non-Linear Concentration-Response Relationships between Ambient Ozone and Daily Mortality.

PubMed

Bae, Sanghyuk; Lim, Youn-Hee; Kashima, Saori; Yorifuji, Takashi; Honda, Yasushi; Kim, Ho; Hong, Yun-Chul

2015-01-01

Ambient ozone (O3) concentration has been reported to be significantly associated with mortality. However, linearity of the relationships and the presence of a threshold has been controversial. The aim of the present study was to examine the concentration-response relationship and threshold of the association between ambient O3 concentration and non-accidental mortality in 13 Japanese and Korean cities from 2000 to 2009. We selected Japanese and Korean cities which have population of over 1 million. We constructed Poisson regression models adjusting daily mean temperature, daily mean PM10, humidity, time trend, season, year, day of the week, holidays and yearly population. The association between O3 concentration and mortality was examined using linear, spline and linear-threshold models. The thresholds were estimated for each city, by constructing linear-threshold models. We also examined the city-combined association using a generalized additive mixed model. The mean O3 concentration did not differ greatly between Korea and Japan, which were 26.2 ppb and 24.2 ppb, respectively. Seven out of 13 cities showed better fits for the spline model compared with the linear model, supporting a non-linear relationships between O3 concentration and mortality. All of the 7 cities showed J or U shaped associations suggesting the existence of thresholds. The range of city-specific thresholds was from 11 to 34 ppb. The city-combined analysis also showed a non-linear association with a threshold around 30-40 ppb. We have observed non-linear concentration-response relationship with thresholds between daily mean ambient O3 concentration and daily number of non-accidental death in Japanese and Korean cities.

Linear Programming across the Curriculum

ERIC Educational Resources Information Center

Yoder, S. Elizabeth; Kurz, M. Elizabeth

2015-01-01

Linear programming (LP) is taught in different departments across college campuses with engineering and management curricula. Modeling an LP problem is taught in every linear programming class. As faculty teaching in Engineering and Management departments, the depth to which teachers should expect students to master this particular type of…

The Relationship between Perceived Parenting Style and Hope in College Students.

ERIC Educational Resources Information Center

Edwards, Lisa M.; Price, Gary E.

The purpose of this study was to investigate the relationship between levels of hope and perceived parental authority style in college students (N=251). It was expected that there would be a positive relationship between authoritative parenting and students' levels of hope. It was also expected that there would be a negative relationship between…

Decision making around living and deceased donor kidney transplantation: a qualitative study exploring the importance of expected relationship changes.

PubMed

de Groot, Ingrid B; Schipper, Karen; van Dijk, Sandra; van der Boog, Paul J M; Stiggelbout, Anne M; Baranski, Andrzej G; Marang-van de Mheen, Perla J

2012-09-07

Limited data exist on the impact of living kidney donation on the donor-recipient relationship. Purpose of this study was to explore motivations to donate or accept a (living donor) kidney, whether expected relationship changes influence decision making and whether relationship changes are actually experienced. We conducted 6 focus groups in 47 of 114 invited individuals (41%), asking retrospectively about motivations and decision making around transplantation. We used qualitative and quantitative methods to analyze the focus group transcripts. Most deceased donor kidney recipients had a potential living donor available which they refused or did not want. They mostly waited for a deceased donor because of concern for the donor's health (75%). They more often expected negative relationship changes than living donor kidney recipients (75% vs. 27%, p = 0.01) who also expected positive changes. Living donor kidney recipients mostly accepted the kidney to improve their own quality of life (47%). Donors mostly donated a kidney because transplantation would make the recipient less dependent (25%). After transplantation both positive and negative relationship changes are experienced. Expected relationship changes and concerns about the donor's health lead some kidney patients to wait for a deceased donor, despite having a potential living donor available. Further research is needed to assess whether this concerns a selected group.

Functions Represented as Linear Sequential Data: Relationships between Presentation and Student Responses

ERIC Educational Resources Information Center

Ayalon, Michal; Watson, Anne; Lerman, Steve

2015-01-01

This study investigates students' ways of attending to linear sequential data in two tasks, and conjectures possible relationships between those ways and elements of the task design. Drawing on the substantial literature about such situations, we focus for this paper on linear rate of change, and on covariation and correspondence approaches to…

Linear Equating for the NEAT Design: Parameter Substitution Models and Chained Linear Relationship Models

ERIC Educational Resources Information Center

Kane, Michael T.; Mroch, Andrew A.; Suh, Youngsuk; Ripkey, Douglas R.

2009-01-01

This paper analyzes five linear equating models for the "nonequivalent groups with anchor test" (NEAT) design with internal anchors (i.e., the anchor test is part of the full test). The analysis employs a two-dimensional framework. The first dimension contrasts two general approaches to developing the equating relationship. Under a "parameter…

A Comparison of Linear and Systems Thinking Approaches for Program Evaluation Illustrated Using the Indiana Interdisciplinary GK-12

ERIC Educational Resources Information Center

Dyehouse, Melissa; Bennett, Deborah; Harbor, Jon; Childress, Amy; Dark, Melissa

2009-01-01

Logic models are based on linear relationships between program resources, activities, and outcomes, and have been used widely to support both program development and evaluation. While useful in describing some programs, the linear nature of the logic model makes it difficult to capture the complex relationships within larger, multifaceted…

Building Productive Relationships: District Leaders' Advice to Researchers

ERIC Educational Resources Information Center

Harrison, Christopher; Davidson, Kristen; Farrell, Caitlin

2017-01-01

Expectations for the role of research in educational improvement are high. Meeting these expectations requires productive relationships between researchers and practitioners. Few studies, however, have systematically explored the ways researchers can build stronger, more productive relationships with practitioners. This study seeks to identify…

Friendship Expectations and the Assessment of Present Friendships.

ERIC Educational Resources Information Center

Bittle, Monnie L.; Clark, M. L.

The relationship of expectations and assessments of friendships among third and fifth graders was studied. Particular attention was given to (1) the relationships between friendship expectation (FE), the assessment of present friendships (FA), and friendship reciprocity (FR); (2) gender, racial, and grade level differences in these same three…

Acceptability of picture archiving and communication system (PACS) among hospital healthcare personnel based on a unified theory of acceptance and use of technology

PubMed Central

Ahmadi, Maryam; Mehrabi, Nahid; Sheikhtaheri, Abbas; Sadeghi, Mojtaba

2017-01-01

Background and aim The picture archiving and communication system (PACS) is a healthcare system technology which manages medical images and integrates equipment through a network. There are some theories about the use and acceptance of technology by people to describe the behavior and attitudes of end users towards information technologies. We investigated the influential factors on users’ acceptance of PACS in the military hospitals of Tehran. Methods In this applied analytical and cross-sectional study, 151 healthcare employees of military hospitals who had experience in using the PACS system were investigated. Participants were selected by census. The following variables were considered: performance expectancy, efforts expectancy, social influence, facilitating conditions and behavioral intention. Data were gathered using a questionnaire. Its validity and reliability were approved by a panel of experts and was piloted with 30 hospital healthcare staff (Cronbach’s alpha =0.91). Spearman correlation coefficient and multiple linear regression analysis were used in analyzing the data. Results Expected performance, efforts expectancy, social impact and facilitating conditions had a significant relationship with behavioral intention. The multiple regression analysis indicated that only performance expectancy can predict the user’s behavioral intentions to use PACS technology. Conclusion Performance and effort expectancies are quite influential in accepting the use of PACS in hospitals. All healthcare personnel should become aware that using such technology is necessary in a hospital. Knowing the influencing factors that affect the acceptance of using new technology can help in improving its use, especially in a healthcare system. This can improve the offered healthcare services’ quality. PMID:29038717

Using Theoretical Descriptors in Structural Activity Relationships: 4. Molecular Orbital Basicity and Electrostatic Basicity

DTIC Science & Technology

1988-11-01

rates.6 The Hammet equation , also called the Linear Free Energy Relationship (LFER) because of the relationship of the Gibb’s Free Energy to the... equations for numerous biological and physicochemical properties. Linear Solvation Enery Relationship (LSER), a sub-set of QSAR have been used by...originates from thermodynamics, where Hammet recognized the relationship of structure to the Gibb’s Free Energy, and ultimately to equilibria and reaction

Structure-to-property relationships in addition cured polymers. 4: Correlations between thermo-oxidative weight losses of norbornenyl cured polyimide resins and their composites

NASA Technical Reports Server (NTRS)

Alston, William B.

1992-01-01

Relationships are identified between the thermo-oxidative stability (TOS) at 316 C of a wide variety of PMR (polymerization of monomeric reactants) addition cured polyimide resins and their corresponding graphite fiber composites. Weight loss results at 316 C confirmed the expected relationship of increasing aliphatic endcap content with decreasing TOS. Moreover, the resin TOS study also showed an unexpected linear correlation of decreasing weight loss to increasing ratio of benzylic diamine to aliphatic endcap in the range of the stoichiometries studied. Only after long term 316 C aging does the dianhydride used with the benzylic diamines become an additional factor in influencing the amount of PMR resin and composite weight losses. Also, the benzylic systems consistently showed much lower resin and composite weight losses at 316 C than the corresponding nonbenzylic norbornenyl resins and composites, except when the nonbenzylic diamine monomer does not contain a connecting group. Instead, this diamine resulted in a 316 C resin and composite weight loss that was only competitive with benzylic type diamines. Results show excellent correlation between TOS of all graphite fiber PMR composites and resins.

Moderation of the Relationship Between Reward Expectancy and Prediction Error-Related Ventral Striatal Reactivity by Anhedonia in Unmedicated Major Depressive Disorder: Findings From the EMBARC Study

PubMed Central

Greenberg, Tsafrir; Chase, Henry W.; Almeida, Jorge R.; Stiffler, Richelle; Zevallos, Carlos R.; Aslam, Haris A.; Deckersbach, Thilo; Weyandt, Sarah; Cooper, Crystal; Toups, Marisa; Carmody, Thomas; Kurian, Benji; Peltier, Scott; Adams, Phillip; McInnis, Melvin G.; Oquendo, Maria A.; McGrath, Patrick J.; Fava, Maurizio; Weissman, Myrna; Parsey, Ramin; Trivedi, Madhukar H.; Phillips, Mary L.

2016-01-01

Objective Anhedonia, disrupted reward processing, is a core symptom of major depressive disorder. Recent findings demonstrate altered reward-related ventral striatal reactivity in depressed individuals, but the extent to which this is specific to anhedonia remains poorly understood. The authors examined the effect of anhedonia on reward expectancy (expected outcome value) and prediction error-(discrepancy between expected and actual outcome) related ventral striatal reactivity, as well as the relationship between these measures. Method A total of 148 unmedicated individuals with major depressive disorder and 31 healthy comparison individuals recruited for the multisite EMBARC (Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care) study underwent functional MRI during a well-validated reward task. Region of interest and whole-brain data were examined in the first- (N=78) and second- (N=70) recruited cohorts, as well as the total sample, of depressed individuals, and in healthy individuals. Results Healthy, but not depressed, individuals showed a significant inverse relationship between reward expectancy and prediction error-related right ventral striatal reactivity. Across all participants, and in depressed individuals only, greater anhedonia severity was associated with a reduced reward expectancy-prediction error inverse relationship, even after controlling for other symptoms. Conclusions The normal reward expectancy and prediction error-related ventral striatal reactivity inverse relationship concords with conditioning models, predicting a shift in ventral striatal responding from reward outcomes to reward cues. This study shows, for the first time, an absence of this relationship in two cohorts of unmedicated depressed individuals and a moderation of this relationship by anhedonia, suggesting reduced reward-contingency learning with greater anhedonia. These findings help elucidate neural mechanisms of anhedonia, as a step toward identifying potential biosignatures of treatment response. PMID:26183698

Moderation of the Relationship Between Reward Expectancy and Prediction Error-Related Ventral Striatal Reactivity by Anhedonia in Unmedicated Major Depressive Disorder: Findings From the EMBARC Study.

PubMed

Greenberg, Tsafrir; Chase, Henry W; Almeida, Jorge R; Stiffler, Richelle; Zevallos, Carlos R; Aslam, Haris A; Deckersbach, Thilo; Weyandt, Sarah; Cooper, Crystal; Toups, Marisa; Carmody, Thomas; Kurian, Benji; Peltier, Scott; Adams, Phillip; McInnis, Melvin G; Oquendo, Maria A; McGrath, Patrick J; Fava, Maurizio; Weissman, Myrna; Parsey, Ramin; Trivedi, Madhukar H; Phillips, Mary L

2015-09-01

Anhedonia, disrupted reward processing, is a core symptom of major depressive disorder. Recent findings demonstrate altered reward-related ventral striatal reactivity in depressed individuals, but the extent to which this is specific to anhedonia remains poorly understood. The authors examined the effect of anhedonia on reward expectancy (expected outcome value) and prediction error- (discrepancy between expected and actual outcome) related ventral striatal reactivity, as well as the relationship between these measures. A total of 148 unmedicated individuals with major depressive disorder and 31 healthy comparison individuals recruited for the multisite EMBARC (Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care) study underwent functional MRI during a well-validated reward task. Region of interest and whole-brain data were examined in the first- (N=78) and second- (N=70) recruited cohorts, as well as the total sample, of depressed individuals, and in healthy individuals. Healthy, but not depressed, individuals showed a significant inverse relationship between reward expectancy and prediction error-related right ventral striatal reactivity. Across all participants, and in depressed individuals only, greater anhedonia severity was associated with a reduced reward expectancy-prediction error inverse relationship, even after controlling for other symptoms. The normal reward expectancy and prediction error-related ventral striatal reactivity inverse relationship concords with conditioning models, predicting a shift in ventral striatal responding from reward outcomes to reward cues. This study shows, for the first time, an absence of this relationship in two cohorts of unmedicated depressed individuals and a moderation of this relationship by anhedonia, suggesting reduced reward-contingency learning with greater anhedonia. These findings help elucidate neural mechanisms of anhedonia, as a step toward identifying potential biosignatures of treatment response.

Exploratory study of factors related to educational scores of first preclinical year medical students.

PubMed

Sitticharoon, Chantacha; Srisuma, Sorachai; Kanavitoon, Sawita; Summachiwakij, Sarayut

2014-03-01

The relationships among the scores of major subjects taught in the first preclinical year of a Thai medical school, previous academic achievements, and daily life activities are rarely explored. We therefore performed an exploratory study identifying various factors possibly related to the educational scores of these medical students. Questionnaires were sent out to all first preclinical year medical students, with 79.8% being returned (245/307 questionnaires). Positive correlations were revealed between the premedical year grade point average (pre-MD GPA) and anatomy, physiology, and biochemistry scores (R = 0.664, 0.521, and 0.653, respectively, P < 0.001 for all) by Pearson's method. Using multiple linear regression analysis, anatomy scores could be predicted by pre-MD GPA, student satisfaction with anatomy, the percentage of expected reading, monthly earnings, reading after class and near exam time, and duration of sleeping periods near exam time (R = 0.773, R(2) = 0.598, P < 0.001). Physiology scores could be estimated by pre-MD GPA, the percentage of expected reading, monthly earnings, and percentage of those who fell asleep during class and near exam time (R = 0.722, R(2) = 0.521, P < 0.001). Biochemistry scores could be calculated by pre-MD GPA, the percentage of expected reading, motivation to study medicine, student satisfaction with biochemistry, and exam performance expectations (R = 0.794, R(2) = 0.630, P < 0.001). In conclusion, pre-MD GPA and the percentage of expected reading are factors involved in producing good academic results in the first preclinical year. Anatomy and biochemistry, but not physiology, scores are influenced by satisfaction.

Eutrophic water purification efficiency using a combination of hydrodynamic cavitation and ozonation on a pilot scale.

PubMed

Li, Wei-Xin; Tang, Chuan-Dong; Wu, Zhi-Lin; Wang, Wei-Min; Zhang, Yu-Feng; Zhao, Yi; Cravotto, Giancarlo

2015-04-01

This paper presents the purification of eutrophic water using a combination of hydrodynamic cavitation (HC) and ozonation (O3) at a continuous flow of 0.8 m(3) h(-1) on a pilot scale. The maximum removal rate of chlorophyll a using O3 alone and the HC/O3 combination was 62.3 and 78.8%, respectively, under optimal conditions, where the ozone utilization efficiency was 64.5 and 94.8% and total energy consumption was 8.89 and 8.25 kWh m(-3), respectively. Thus, the removal rate of chlorophyll a and the ozone utilization efficiency were improved by 26.5% and 46.9%, respectively, by using the combined technique. Meanwhile, total energy consumption was reduced by 7.2%. Turbidity linearly decreased with chlorophyll a removal rate, but no linear relationship exists between the removal of COD or UV254 and chlorophyll a. As expected, the suction-cavitation-assisted O3 exhibited higher energy efficiency than the extrusion-cavitation-assisted O3 and O3 alone methods.

Investigating Years 7 to 12 students' knowledge of linear relationships through different contexts and representations

NASA Astrophysics Data System (ADS)

Wilkie, Karina J.; Ayalon, Michal

2018-02-01

A foundational component of developing algebraic thinking for meaningful calculus learning is the idea of "function" that focuses on the relationship between varying quantities. Students have demonstrated widespread difficulties in learning calculus, particularly interpreting and modeling dynamic events, when they have a poor understanding of relationships between variables. Yet, there are differing views on how to develop students' functional thinking over time. In the Australian curriculum context, linear relationships are introduced to lower secondary students with content that reflects a hybrid of traditional and reform algebra pedagogy. This article discusses an investigation into Australian secondary students' understanding of linear functional relationships from Years 7 to 12 (approximately 12 to 18 years old; n = 215) in their approaches to three tasks (finding rate of change, pattern generalisation and interpretation of gradient) involving four different representations (table, geometric growing pattern, equation and graph). From the findings, it appears that these students' knowledge of linear functions remains context-specific rather than becoming connected over time.

Associations between individual and relationship characteristics and genital herpes disclosure.

PubMed

Myers, Jaime L; Buhi, Eric R; Marhefka, Stephanie; Daley, Ellen; Dedrick, Robert

2016-10-01

Disclosure is often a challenge for individuals living with genital herpes. This study explores determinants of genital herpes disclosure with one's most recent sexual partner using an online questionnaire (n = 93). The majority of participants reported (80.4%) disclosure. Among non-disclosers, fear of negative partner reactions was the primary reason for non-disclosure. Age, relationship commitment, time in relationship, and expectations of partner's reaction were statistically significant predictors at the bivariate level. Reaction expectations and relationship commitment remained significant in the multivariate logistic regression model. Findings indicate that future disclosure research should focus on relationship context and managing negative expectations to increase disclosure. © The Author(s) 2015.

The relationship between emotional intelligence and job stress in the faculty of medicine in Isfahan University of Medical Sciences

PubMed Central

YAMANI, NIKOO; SHAHABI, MARYAM; HAGHANI, FARIBA

2014-01-01

Introduction: health care professionals especially clinicians, undergo lots of job stress (JS). Emotional intelligence (EI) is among the variables that appear to be associated with stress. It is also included among the ways adopted by the individuals in order to resist JS in the workplace. Thus, this study aims to investigate the relationship between EI and JS in the faculty members of Isfahan University of Medical Sciences (IUMS). Methods: This was a correlational study performed on 202 faculty members of IUMS. The data was gathered through two valid and reliable questionnaires (Bradberry EI questionnaire and JS questionnaire), being analyzed by SPSS software using descriptive statistics, Pearson correlation coefficient, t-test, analysis of variance (ANOVA) and linear regression analysis (α=0.05). Results: 142 individuals (70.30%) filled out the questionnaires. 75% of the respondents were male and 98% were married. There was an inverse correlation between the total score of EI and the level of JS (r=-0.235, p=0.005). Moreover, among the factors of EI, self-awareness and self-management scores had significant inverse relationship with the level of JS. Linear regression analysis showed that the EI factors explained approximately 7% of the variance of JS levels of the teachers. Conclusions: Individuals with high EI have less JS. Since the EI can be taught, it can be expected that the JS of faculty members can be reduced through training them on emotional intelligence. Therefore, it is recommended that short-term training courses be scheduled and designed based on the concepts of EI for teachers, particularly clinicians. PMID:25512914

Non-linear Relationship between BOLD Activation and Amplitude of Beta Oscillations in the Supplementary Motor Area during Rhythmic Finger Tapping and Internal Timing

PubMed Central

Gompf, Florian; Pflug, Anja; Laufs, Helmut; Kell, Christian A.

2017-01-01

Functional imaging studies using BOLD contrasts have consistently reported activation of the supplementary motor area (SMA) both during motor and internal timing tasks. Opposing findings, however, have been shown for the modulation of beta oscillations in the SMA. While movement suppresses beta oscillations in the SMA, motor and non-motor tasks that rely on internal timing increase the amplitude of beta oscillations in the SMA. These independent observations suggest that the relationship between beta oscillations and BOLD activation is more complex than previously thought. Here we set out to investigate this rapport by examining beta oscillations in the SMA during movement with varying degrees of internal timing demands. In a simultaneous EEG-fMRI experiment, 20 healthy right-handed subjects performed an auditory-paced finger-tapping task. Internal timing was operationalized by including conditions with taps on every fourth auditory beat, which necessitates generation of a slow internal rhythm, while tapping to every auditory beat reflected simple auditory-motor synchronization. In the SMA, BOLD activity increased and power in both the low and the high beta band decreased expectedly during each condition compared to baseline. Internal timing was associated with a reduced desynchronization of low beta oscillations compared to conditions without internal timing demands. In parallel with this relative beta power increase, internal timing activated the SMA more strongly in terms of BOLD. This documents a task-dependent non-linear relationship between BOLD and beta-oscillations in the SMA. We discuss different roles of beta synchronization and desynchronization in active processing within the same cortical region. PMID:29249950

Development and validation of a competitive enzyme-linked immunosorbent assay for the measurement of total plasma immunoglobulins in healthy loggerhead sea (Caretta caretta) and green turtles (Chelonia mydas).

PubMed

Kaplan, Amy J; Stacy, Nicole I; Jacobson, Elliott; Le-Bert, Carolina R; Nollens, Hendrik H; Origgi, Francesco C; Green, Linda G; Bootorabi, Shadi; Bolten, Alan; Hernandez, Jorge A

2016-01-01

The quantification of circulating plasma immunoglobulins represents a valuable diagnostic tool in human and veterinary immunology, although its application is very limited in reptile medicine to date. The objectives of our study were the development and standardization of a competitive enzyme-linked immunosorbent assay (cELISA) for the measurement of total plasma immunoglobulins (Igs; both IgM and IgY) in loggerhead sea turtles (LST; Caretta caretta; n = 254) and green turtles (GT; Chelonia mydas; n = 111), the establishment of reference intervals for Ig for both species, and the examination of associations between Ig and total protein (TP), condition index, and water temperature. The cELISA for Ig was successfully developed and optimized. Reference intervals for Ig were 0.38-0.94 g/dL in LST (median: 0.59 g/dL; range: 0.16-2.15 g/dL) and 0.40-0.85 g/dL in GT (median: 0.58 g/dL; range: 0.18-1.80 g/dL). In LST, there were positive linear relationships of Ig with TP, and TP with Ig and condition index, and a negative relationship of Ig with condition index. The positive linear relationships of Ig with TP, and TP with Ig were also identified in GT. These positive associations of Ig and TP were expected, as Ig represents fractions of TP, and TP reportedly increases with straight carapace length and weight. The negative association of Ig with condition index may indicate potential biological variations. The cELISA and reference intervals for total Ig of LST and GT presented herein have the potential to be useful as a diagnostic and research tool for sea turtle immunology. © 2015 The Author(s).

Conformity expectations: Differential effects on IVF twins and singletons' parent-child relationships and adjustment.

PubMed

Anderson, Kayla N; Rueter, Martha A; Connor, Jennifer J; Chen, Muzi; Damario, Mark

2015-08-01

Increased utilization of in vitro fertilization (IVF) to treat infertility has resulted in a growing twin birthrate. Despite early childhood risks, twins have fewer psychosocial problems in middle childhood than singleton children. This study proposes that parents' conformity expectations for children have differential effects on parent-child relationships for twin and singleton children, which indirectly explains twins' more optimum psychosocial adjustment. Parental conformity expectations, parent-child relationship satisfaction, and children's emotional, behavioral, and attention problems were assessed in a sample of 288 6- to 12-year-old IVF-conceived twins and singletons. Overall, parents of twins had higher expectations for child conformity to parent rules than singleton parents. Path models demonstrate that twin status and parental expectations for child conformity interact to influence parent-child relationships, and this interaction indirectly accounted for differences in twins' and singletons' psychosocial adjustment. Findings suggest parenting constructs have differential influences on the association between twin status and parent-child relationships. Parenting research, predominantly conducted with singletons, should be reexamined before applying existing research to twin children and their families. (c) 2015 APA, all rights reserved).

The relationship between treatment access and spending in a managed behavioral health organization.

PubMed

Cuffel, B J; Regier, D

2001-07-01

This study replicated an earlier study that showed a linear relationship between level of treatment access and behavioral health spending. The study reported here examined whether this relationship varies by important characteristics of behavioral health plans. Access rates and total spending over a five- to seven-year period were computed for 30 behavioral health plans. Regression analysis was used to estimate the relationship between access and spending and to examine whether it varied with the characteristics of benefit plans. A linear relationship was found between level of treatment access and behavioral health spending. However, the relationship closely paralleled that found in the earlier study only for benefit plans with an employee assistance program linked to the managed behavioral health organization and for plans that do not allow the use of out-of-network providers. The results of this study replicate those of the earlier study in showing a linear relationship between access and spending, but they suggest that the magnitude of this relationship may vary according to key plan characteristics.

Associations among measures of energy balance related behaviors and psychosocial determinants in urban upper elementary school children.

PubMed

Bandelli, Lorraine N; Gray, Heewon Lee; Paul, Rachel C; Contento, Isobel R; Koch, Pamela A

2017-01-01

Childhood obesity prevention is a pressing issue. Understanding the relationships among eating and physical activity behaviors and potential psychosocial determinants of behavior will help us design more effective interventions. This study aimed to examine such relationships in a large sample of urban elementary school children. Fifth grade students in 20 recruited New York City public schools completed a validated questionnaire on six "do more" (fruits and vegetables and physical activity) and "do less" (sweetened beverages, processed packaged snacks, fast food and sedentary behavior) energy balance related behaviors (EBRBs) and psychosocial determinants of behavior from social cognitive and self-determination theories. Correlations among behaviors and hierarchical linear model analyses of the relationship between psychosocial determinants and behaviors were conducted for those with complete data (n = 952). The "do more" and the "do less" behaviors were significantly correlated within categories (p < 0.01). "Do more" food-related behaviors were correlated with physical activity but so were sports drinks, while the "do less" food-related behaviors tended to be correlated to sedentary behavior (p < 0.01). "Do more" behaviors were associated with self-efficacy and habit strength, and "do less" behaviors with outcome expectations, self-efficacy, habit strength, and behavioral intention. Interventions can address the healthy and less healthy clusters of behaviors together, focusing on strategies to enhance their self-efficacy and habit strength for the "do more" behaviors and outcome expectations to motivate intention to choose fewer "do less" behaviors, along with enhancing self-efficacy and habit. Research can examine these determinants as potential mediators of change in intervention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Expectancy Beliefs and English Language Performance of Secondary Schools Students in Maiduguri Metropolis, Borno State, Nigeria

ERIC Educational Resources Information Center

Musa, Alice K. J.; Nwachukwu, Kelechukwu I.; Ali, Domiya Geoffrey

2016-01-01

The study determined Relationship between Students' Expectancy Beliefs and English Language Performance of Students in Maiduguri Metropolis, Borno State, Nigeria. Correlation design was adopted for the study. Four hypotheses which determined the relationships between the components of expectancy beliefs: ability, tasks difficulty, and past…

Attachment Strength and Relationship Expectancies in the Prediction of Adolescent Stress and Depression

ERIC Educational Resources Information Center

Goh, Yun Lin Daphne; Wilkinson, Ross B.

2017-01-01

Interpersonal relationships are the recent focus of research identifying protective factors in adolescent psychological health. Using an attachment theory perspective, this study examines the relationship of normative attachment strength and individual differences in attachment expectancies on self-reports of depression and stress in 511…

Automatic Relationship-Harm Associations and Interpersonal Trauma Involving Close Others

ERIC Educational Resources Information Center

DePrince, Anne P.; Combs, Melody D.; Shanahan, Michelle

2009-01-01

Women exposed to violence early in life are at risk of revictimization. The interpersonal schema hypothesis of revictimization proposes that revictimized women will be more likely to hold negative expectations about intimate relationships, including expectations that relationships involve harm, relative to singly or nonvictimized women. To test…

Trust-based prayer expectancies and health among older Mexican Americans.

PubMed

Krause, Neal; Hayward, R David

2014-04-01

This study assesses the health-related effects of trust-based prayer expectancies, which reflect the belief that God answers prayers at the right time and in the best way. The following relationships are evaluated in our conceptual model: (1) older Mexican Americans who attend worship services more often tend to develop a closer relationship with God; (2) people who feel close to God will be more likely to develop trust-based prayer expectancies; (3) people who endorse trust-based prayer expectancies will have greater feelings of self-esteem; and (4) higher self-esteem is associated with better self-rated health. The data support each of these relationships.

Estimating Drivers of Autochthonous Transmission of Chikungunya Virus in its Invasion of the Americas

PubMed Central

Perkins, T. Alex; Metcalf, C. Jessica E.; Grenfell, Bryan T.; Tatem, Andrew J.

2015-01-01

Background Chikungunya is an emerging arbovirus that has caused explosive outbreaks in Africa and Asia for decades and invaded the Americas just over a year ago. During this ongoing invasion, it has spread to 45 countries where it has been transmitted autochthonously, infecting nearly 1.3 million people in total. Methods Here, we made use of weekly, country-level case reports to infer relationships between transmission and two putative climatic drivers: temperature and precipitation averaged across each country on a monthly basis. To do so, we used a TSIR model that enabled us to infer a parametric relationship between climatic drivers and transmission potential, and we applied a new method for incorporating a probabilistic description of the serial interval distribution into the TSIR framework. Results We found significant relationships between transmission and linear and quadratic terms for temperature and precipitation and a linear term for log incidence during the previous pathogen generation. The lattermost suggests that case numbers three to four weeks ago are largely predictive of current case numbers. This effect is quite nonlinear at the country level, however, due to an estimated mixing parameter of 0.74. Relationships between transmission and the climatic variables that we estimated were biologically plausible and in line with expectations. Conclusions Our analysis suggests that autochthonous transmission of Chikungunya in the Americas can be correlated successfully with putative climatic drivers, even at the coarse scale of countries and using long-term average climate data. Overall, this provides a preliminary suggestion that successfully forecasting the future trajectory of a Chikungunya outbreak and the receptivity of virgin areas may be possible. Our results also provide tentative estimates of timeframes and areas of greatest risk, and our extension of the TSIR model provides a novel tool for modeling vector-borne disease transmission. PMID:25737803

Influence of social deprivation on provision of bariatric surgery: 10-year comparative ecological study between two UK specialist centres.

PubMed

Bhanderi, Shivam; Alam, Mushfique; Matthews, Jacob Henry; Rudge, Gavin; Noble, Hamish; Mahon, David; Richardson, Martin; Welbourn, Richard; Super, Paul; Singhal, Rishi

2017-10-12

To investigate the effect of residential location and socioeconomic deprivation on the provision of bariatric surgery. Retrospective cross-sectional ecological study. Patients resident local to one of two specialist bariatric units, in different regions of the UK, who received obesity surgery between 2003 and 2013. Demographic data were collected from prospectively collected databases. Index of Multiple Deprivation (IMD 2010) was used as a measure of socioeconomic status. Obesity prevalences were obtained from Public Health England (2006). Patients were split into three IMD tertiles (high, median, low) and also tertiles of time. A generalised linear model was generated for each time period to investigate the effect of socioeconomic deprivation on the relationship between bariatric case count and prevalence of obesity. We used these to estimate surgical intervention provided in each population in each period at differing levels of deprivation. Data were included from 1163 bariatric cases (centre 1-414, centre 2-749). Incidence rate ratios (IRRs) were calculated to measure the associations between predictor and response variables. Associations were highly non-linear and changed over the 10-year study period. In general, the relationship between surgical case volume and obesity prevalence has weakened over time, with high volumes becoming less associated with prevalence of obesity. As bariatric services have matured, the associations between demand and supply factors have changed. Socioeconomic deprivation is not apparently a barrier to service provision more recently, but the positive relationships between obesity and surgical volume we would expect to find are absent. This suggests that interventions are not being taken up in the areas of need. We recommend a more detailed national analysis of the relationship between supply side and demand side factors in the provision of bariatric surgery. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Association between substandard classroom ventilation rates and students' academic achievement.

PubMed

Haverinen-Shaughnessy, U; Moschandreas, D J; Shaughnessy, R J

2011-04-01

This study focuses on the relationship between classroom ventilation rates and academic achievement. One hundred elementary schools of two school districts in the southwest United States were included in the study. Ventilation rates were estimated from fifth-grade classrooms (one per school) using CO(2) concentrations measured during occupied school days. In addition, standardized test scores and background data related to students in the classrooms studied were obtained from the districts. Of 100 classrooms, 87 had ventilation rates below recommended guidelines based on ASHRAE Standard 62 as of 2004. There is a linear association between classroom ventilation rates and students' academic achievement within the range of 0.9-7.1 l/s per person. For every unit (1 l/s per person) increase in the ventilation rate within that range, the proportion of students passing standardized test (i.e., scoring satisfactory or above) is expected to increase by 2.9% (95%CI 0.9-4.8%) for math and 2.7% (0.5-4.9%) for reading. The linear relationship observed may level off or change direction with higher ventilation rates, but given the limited number of observations, we were unable to test this hypothesis. A larger sample size is needed for estimating the effect of classroom ventilation rates higher than 7.1 l/s per person on academic achievement. The results of this study suggest that increasing the ventilation rates toward recommended guideline ventilation rates in classrooms should translate into improved academic achievement of students. More studies are needed to fully understand the relationships between ventilation rate, other indoor environmental quality parameters, and their effects on students' health and achievement. Achieving the recommended guidelines and pursuing better understanding of the underlying relationships would ultimately support both sustainable and productive school environments for students and personnel. © 2010 John Wiley & Sons A/S.

Parental Loss, Trusting Relationship with Current Caregivers and Psychosocial Adjustment among Children Affected by AIDS in China

PubMed Central

Zhao, Junfeng; Li, Xiaoming; Barnett, Douglas; Lin, Xiuyun; Fang, Xiaoyi; Zhao, Guoxiang; Naar-King, Sylvie; Stanton, Bonita

2011-01-01

Objective to examine the relationship between parental loss, trusting relationship with current caregivers, and psychosocial adjustment among children affected by AIDS in China. Methods Cross-sectional data were collected from 755 AIDS orphans (296 double orphans and 459 single orphans), 466 vulnerable children living with HIV-infected parents, and 404 comparison children in China. The trusting relationship with current caregivers was measured with a 15-item scale (Cronbach alpha=.84) modified from the Trusting Relationship Questionnaire (TRQ) developed by Mustillo and colleagues (2005). The psychosocial measures include rule compliance/acting out, anxiety/withdrawal, peer social skills, school interest, depressive symptoms, loneliness, self-esteem, future expectation, hopefulness about future, and perceived control over the future. Results Group mean comparisons using ANOVA suggested a significant association (p<.0001) between the trusting relationship with current caregivers and all the psychosocial measures except anxiety and depression. These associations remained significant in General Linear Model analysis, controlling for children's gender, age, family SES, orphan status (orphans, vulnerable children, and comparison children), and appropriate interaction terms among factor variables. Discussion The findings in the current study support the global literature on the importance of attachment relationship with caregivers in promoting children's psychosocial development. Future prevention intervention efforts to improve AIDS orphans' psychosocial well-being will need to take into consideration the quality of the child's attachment relationships with current caregivers and help their current caregivers to improve the quality of care for these children. Future study is needed to explore the possible reasons for the lack of association between a trusting relationship and some internalizing symptoms such as anxiety and depression among children affected by HIV/AIDS. PMID:21749241

Linear Relationship between Resilience, Learning Approaches, and Coping Strategies to Predict Achievement in Undergraduate Students

PubMed Central

de la Fuente, Jesús; Fernández-Cabezas, María; Cambil, Matilde; Vera, Manuel M.; González-Torres, Maria Carmen; Artuch-Garde, Raquel

2017-01-01

The aim of the present research was to analyze the linear relationship between resilience (meta-motivational variable), learning approaches (meta-cognitive variables), strategies for coping with academic stress (meta-emotional variable) and academic achievement, necessary in the context of university academic stress. A total of 656 students from a southern university in Spain completed different questionnaires: a resiliency scale, a coping strategies scale, and a study process questionnaire. Correlations and structural modeling were used for data analyses. There was a positive and significant linear association showing a relationship of association and prediction of resilience to the deep learning approach, and problem-centered coping strategies. In a complementary way, these variables positively and significantly predicted the academic achievement of university students. These results enabled a linear relationship of association and consistent and differential prediction to be established among the variables studied. Implications for future research are set out. PMID:28713298

Discrete-time Markovian-jump linear quadratic optimal control

NASA Technical Reports Server (NTRS)

Chizeck, H. J.; Willsky, A. S.; Castanon, D.

1986-01-01

This paper is concerned with the optimal control of discrete-time linear systems that possess randomly jumping parameters described by finite-state Markov processes. For problems having quadratic costs and perfect observations, the optimal control laws and expected costs-to-go can be precomputed from a set of coupled Riccati-like matrix difference equations. Necessary and sufficient conditions are derived for the existence of optimal constant control laws which stabilize the controlled system as the time horizon becomes infinite, with finite optimal expected cost.

Using CDOM optical properties for estimating DOC concentrations and pCO 2 in the Lower Amazon River

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

Valerio, Aline de Matos; Kampel, Milton; Vantrepotte, Vincent

Colored dissolved organic matter (CDOM) is largely responsible for the optical properties of freshwaters and coastal areas and can be used as a proxy to assess the non-optical carbon content as the dissolved organic carbon (DOC) and the partial pressure of carbon dioxide (pCO 2). Nevertheless, riverine studies that explores the former relationship are more challenging due to the spectral mixture caused by the high content of inorganic materials in the suspended sediment. Here we evaluate the spatial-temporal variability of CDOM, DOC and pCO 2, as well as the potential of CDOM absorption coefficient (aCDOM(412)) for estimating DOC concentration andmore » pCO 2 along the lower Amazon River. Our results revealed differences in the dissolved organic matter (DOM) quality between clear water (CW) tributaries and the Amazon River mainstem. A linear relationship between DOC and CDOM was observed when tributaries and mainstem are evaluated separately (Amazon waters: N=42, R2=0.74; CW: N= 13, R2 = 0.57). However, this linear relationship was not observed during periods of higher rainfall and river discharge, requiring a model specific to these time periods to be developed (N = 25, R2 = 0.58). A strong linear positive relation was found between aCDOM(412) and pCO 2( N=69, R2=0.65) along the lower river. pCO 2 was less affected by the optical difference between tributaries and mainstem water or by the presence of higher hygrometric conditions when compared to CDOM to DOC relationships. Including the river water temperature in the model improves our ability to estimate pCO 2 (N=69; R2 = 0.80). Our results also illustrate the complexity of DOM temporal dynamics in the lower Amazon River where the occurrence of extreme high and low discharge due to factors such as El Niño, can significantly alter the expected seasonal oscillation, as was the case during this study period. The ability to remotely assess both DOC and pCO 2 from CDOM optical properties highlight the importance of using remote sensing data for monitoring carbon dynamics in large running water systems worldwide.« less

For better and for worse: the relationship between future expectations and functioning in the second half of life.

PubMed

Shrira, Amit; Palgi, Yuval; Ben-Ezra, Menachem; Spalter, Tal; Kavé, Gitit; Shmotkin, Dov

2011-03-01

To examine age group differences in the relationship between future expectations about standards of living and physical, mental, and cognitive functioning in the second half of life. Data from the Survey of Health, Ageing, and Retirement in Europe (N=27,687, mean age=64.44). First, with increasing age, the expectation to improve (ETI) and the expectation to worsen (ETW) in standards of living became more independent of each other. Second, with increasing age, ETI was less strongly correlated with functioning whereas ETW was more strongly correlated with it. Third, with increasing age, the relationship between ETI and functioning was more strongly moderated by ETW, so that adaptive functioning was associated with expectations that no major change is to occur and with expectations for both growth and decline. Late-life positive and negative expectancies are less interdependent than they are in younger age, probably due to their stronger interaction when associating with functioning. Expectancies interact either to reflect an attempt to preserve the functional status quo (low expectancy to improve and to decline) or may signal a highly complex mental organization (high expectancy to improve and to decline).

For Better and for Worse: The Relationship between Future Expectations and Functioning in the Second Half of Life

PubMed Central

Palgi, Yuval; Ben-Ezra, Menachem; Spalter, Tal; Kavé, Gitit; Shmotkin, Dov

2011-01-01

Objectives. To examine age group differences in the relationship between future expectations about standards of living and physical, mental, and cognitive functioning in the second half of life. Method. Data from the Survey of Health, Ageing, and Retirement in Europe (N = 27,687, mean age = 64.44). Results. First, with increasing age, the expectation to improve (ETI) and the expectation to worsen (ETW) in standards of living became more independent of each other. Second, with increasing age, ETI was less strongly correlated with functioning whereas ETW was more strongly correlated with it. Third, with increasing age, the relationship between ETI and functioning was more strongly moderated by ETW, so that adaptive functioning was associated with expectations that no major change is to occur and with expectations for both growth and decline. Discussion. Late-life positive and negative expectancies are less interdependent than they are in younger age, probably due to their stronger interaction when associating with functioning. Expectancies interact either to reflect an attempt to preserve the functional status quo (low expectancy to improve and to decline) or may signal a highly complex mental organization (high expectancy to improve and to decline). PMID:21296870

I. INTRODUCTION: MOVING THROUGH ADOLESCENCE: DEVELOPMENTAL TRAJECTORIES OF AFRICAN AMERICAN AND EUROPEAN AMERICAN YOUTH.

PubMed

Gutman, Leslie Morrison; Peck, Stephen C; Malanchuk, Oksana; Sameroff, Arnold J; Eccles, Jacquelynne S

2017-12-01

In this monograph, we investigate the developmental trajectories of a predominantly middle-class, community-based sample of European American and African American adolescents growing up in urban, suburban, and rural areas in Maryland, United States. Within risk-protection and positive youth development frameworks, we selected developmental measures based on the normative tasks of adolescence and the most widely studied indicators in the three major contexts of development: families, peer groups, and schools. Using hierarchical linear growth models, we estimated adolescents' growth trajectories from ages 12 to 20 with variation accounted for by socioeconomic status (SES), gender, race/ethnicity, and the gender by race/ethnicity interaction. In general, the results indicate that: (a) periods of greatest risk and positive development depended on the time frame and outcome being examined and (b) on average, these adolescents demonstrated much stronger evidence of positive than problematic development, even at their most vulnerable times. Absolute levels of their engagement in healthy behaviors, supportive relationships with parents and friends, and positive self-perceptions and psychological well-being were much higher than their reported angry and depressive feelings, engagement in risky behaviors, and negative relationships with parents and peers. We did not find evidence to support the idea that adolescence is a time of heightened risk. Rather, on average, these adolescents experienced relatively stable and developmentally healthy trajectories for a wide range of characteristics, behaviors, and relationships, with slight increases or decreases at different points in development that varied according to domain. Developmental trajectories differed minimally by SES but in some expected ways by gender and race/ethnicity, although these latter differences were not very marked. Overall, most of the young people navigated through their adolescence and arrived at young adulthood with good mental and physical health, positive relationships with their parents and peers, and high aspirations and expectations for what their future lives might hold. © 2017 The Society for Research in Child Development, Inc.

Frequency assignments for HFDF receivers in a search and rescue network

NASA Astrophysics Data System (ADS)

Johnson, Krista E.

1990-03-01

This thesis applies a multiobjective linear programming approach to the problem of assigning frequencies to high frequency direction finding (HFDF) receivers in a search-and-rescue network in order to maximize the expected number of geolocations of vessels in distress. The problem is formulated as a multiobjective integer linear programming problem. The integrality of the solutions is guaranteed by the totally unimodularity of the A-matrix. Two approaches are taken to solve the multiobjective linear programming problem: (1) the multiobjective simplex method as implemented in ADBASE; and (2) an iterative approach. In this approach, the individual objective functions are weighted and combined in a single additive objective function. The resulting single objective problem is expressed as a network programming problem and solved using SAS NETFLOW. The process is then repeated with different weightings for the objective functions. The solutions obtained from the multiobjective linear programs are evaluated using a FORTRAN program to determine which solution provides the greatest expected number of geolocations. This solution is then compared to the sample mean and standard deviation for the expected number of geolocations resulting from 10,000 random frequency assignments for the network.

Effects of Stochastic Traffic Flow Model on Expected System Performance

DTIC Science & Technology

2012-12-01

NSWC-PCD has made considerable improvements to their pedestrian flow modeling . In addition to the linear paths, the 2011 version now includes...using stochastic paths. 2.2 Linear Paths vs. Stochastic Paths 2.2.1 Linear Paths and Direct Maximum Pd Calculation Modeling pedestrian traffic flow...as a stochastic process begins with the linear path model . Let the detec- tion area be R x C voxels. This creates C 2 total linear paths, path(Cs

Evaluating the relationship between leaf chlorophyll concentration and SPAD-502 chlorophyll meter readings.

PubMed

Uddling, J; Gelang-Alfredsson, J; Piikki, K; Pleijel, H

2007-01-01

Relationships between chlorophyll concentration ([chl]) and SPAD values were determined for birch, wheat, and potato. For all three species, the relationships were non-linear with an increasing slope with increasing SPAD. The relationships for birch and wheat were strong (r (2) approximately 0.9), while the potato relationship was comparatively weak (r (2) approximately 0.5). Birch and wheat had very similar relationships when the chlorophyll concentration was expressed per unit leaf area, but diverged when it was expressed per unit fresh weight. Furthermore, wheat showed similar SPAD-[chl] relationships for two different cultivars and during two different growing seasons. The curvilinear shape of the SPAD-[chl] relationships agreed well with the simulated effects of non-uniform chlorophyll distribution across the leaf surface and multiple scattering, causing deviations from linearity in the high and low SPAD range, respectively. The effect of non-uniformly distributed chlorophyll is likely to be more important in explaining the non-linearity in the empirical relationships, since the effect of scattering was predicted to be comparatively weak. The simulations were based on the algorithm for the calculation of SPAD-502 output values. We suggest that SPAD calibration curves should generally be parameterised as non-linear equations, and we hope that the relationships between [chl] and SPAD and the simulations of the present study can facilitate the interpretation of chlorophyll meter calibrations in relation to optical properties of leaves in future studies.

A class of stochastic optimization problems with one quadratic & several linear objective functions and extended portfolio selection model

NASA Astrophysics Data System (ADS)

Xu, Jiuping; Li, Jun

2002-09-01

In this paper a class of stochastic multiple-objective programming problems with one quadratic, several linear objective functions and linear constraints has been introduced. The former model is transformed into a deterministic multiple-objective nonlinear programming model by means of the introduction of random variables' expectation. The reference direction approach is used to deal with linear objectives and results in a linear parametric optimization formula with a single linear objective function. This objective function is combined with the quadratic function using the weighted sums. The quadratic problem is transformed into a linear (parametric) complementary problem, the basic formula for the proposed approach. The sufficient and necessary conditions for (properly, weakly) efficient solutions and some construction characteristics of (weakly) efficient solution sets are obtained. An interactive algorithm is proposed based on reference direction and weighted sums. Varying the parameter vector on the right-hand side of the model, the DM can freely search the efficient frontier with the model. An extended portfolio selection model is formed when liquidity is considered as another objective to be optimized besides expectation and risk. The interactive approach is illustrated with a practical example.

Axial calibration methods of piezoelectric load sharing dynamometer

NASA Astrophysics Data System (ADS)

Zhang, Jun; Chang, Qingbing; Ren, Zongjin; Shao, Jun; Wang, Xinlei; Tian, Yu

2018-06-01

The relationship between input and output of load sharing dynamometer is seriously non-linear in different loading points of a plane, so it's significant for accutately measuring force to precisely calibrate the non-linear relationship. In this paper, firstly, based on piezoelectric load sharing dynamometer, calibration experiments of different loading points are performed in a plane. And then load sharing testing system is respectively calibrated based on BP algorithm and ELM (Extreme Learning Machine) algorithm. Finally, the results show that the calibration result of ELM is better than BP for calibrating the non-linear relationship between input and output of loading sharing dynamometer in the different loading points of a plane, which verifies that ELM algorithm is feasible in solving force non-linear measurement problem.

Identification of Large Space Structures on Orbit

DTIC Science & Technology

1986-09-01

requires only the eigenvector corresponding to the eigenvector 93 .:. ,S --- k’.’ L derivative being calculated. However, a set of linear algebraic ...Journal of Guidance, Control and Dynamics. 204. Noble, B. and J. W. Daniel, Applied Linear Algebra , Prentice-Hall, Inc., 1977. 205. Nurre, G. S., R. S...4.2.1. Linear Relationships . . . . . . . . . . 114 4.2.2. Nonlinear Relationships . . . . . . . . . 120 4.3. Series Expansion Methods

Associations of Linear Growth and Relative Weight Gain in Early Life with Human Capital at 30 Years of Age.

PubMed

Horta, Bernardo Lessa; Victora, Cesar G; de Mola, Christian Loret; Quevedo, Luciana; Pinheiro, Ricardo Tavares; Gigante, Denise P; Motta, Janaina Vieira Dos Santos; Barros, Fernando C

2017-03-01

To assess the associations of birthweight, nutritional status and growth in childhood with IQ, years of schooling, and monthly income at 30 years of age. In 1982, the 5 maternity hospitals in Pelotas, Brazil, were visited daily and 5914 live births were identified. At 30 years of age, 3701 subjects were interviewed. IQ, years of schooling, and income were measured. On average, their IQ was 98 points, they had 11.4 years of schooling, and the mean income was 1593 reais. After controlling for several confounders, birthweight and attained weight and length/height for age at 2 and 4 years of age were associated positively with IQ, years of years of schooling, and income, except for the association between length at 2 years of age and income. Conditional growth analyses were used to disentangle linear growth from relative weight gain. Conditional length at 2 years of age ≥1 SD score above the expected value, compared with ≥1 SD below the expected, was associated with an increase in IQ (4.28 points; 95% CI, 2.66-5.90), years of schooling (1.58 years; 95% CI, 1.08-2.08), and monthly income (303 Brazilian reais; 95% CI, 44-563). Relative weight gain, above what would be expected from linear growth, was not associated with the outcomes. In a middle-income setting, promotion of linear growth in the first 1000 days of life is likely to increase adult IQ, years of schooling, and income. Weight gain in excess of what is expected from linear growth does not seem to improve human capital. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Non-Linear Interactions Determine the Impact of Sea-Level Rise on Estuarine Benthic Biodiversity and Ecosystem Processes

PubMed Central

Yamanaka, Tsuyuko; Raffaelli, David; White, Piran C. L.

2013-01-01

Sea-level rise induced by climate change may have significant impacts on the ecosystem functions and ecosystem services provided by intertidal sediment ecosystems. Accelerated sea-level rise is expected to lead to steeper beach slopes, coarser particle sizes and increased wave exposure, with consequent impacts on intertidal ecosystems. We examined the relationships between abundance, biomass, and community metabolism of benthic fauna with beach slope, particle size and exposure, using samples across a range of conditions from three different locations in the UK, to determine the significance of sediment particle size beach slope and wave exposure in affecting benthic fauna and ecosystem function in different ecological contexts. Our results show that abundance, biomass and oxygen consumption of intertidal macrofauna and meiofauna are affected significantly by interactions among sediment particle size, beach slope and wave exposure. For macrofauna on less sloping beaches, the effect of these physical constraints is mediated by the local context, although for meiofauna and for macrofauna on intermediate and steeper beaches, the effects of physical constraints dominate. Steeper beach slopes, coarser particle sizes and increased wave exposure generally result in decreases in abundance, biomass and oxygen consumption, but these relationships are complex and non-linear. Sea-level rise is likely to lead to changes in ecosystem structure with generally negative impacts on ecosystem functions and ecosystem services. However, the impacts of sea-level rise will also be affected by local ecological context, especially for less sloping beaches. PMID:23861863

Rich and Poor Cities in Europe. An Urban Scaling Approach to Mapping the European Economic Transition

PubMed Central

2016-01-01

Recent advances in the urban science make broad use of the notion of scaling. We focus here on the important scaling relationship between the gross metropolitan product (GMP) of a city and its population (pop). It has been demonstrated that GMP ∝ Y Ypopβ with β always greater than 1 and close to 1.2. This fundamental finding highlights a universal rule that holds across countries and cultures and might explain the very nature of cities. However, in an increasingly connected world, the hypothesis that the economy of a city solely depends on its population might be questionable. Using data for 248 cities in the European Union between 2005 and 2010, we found a double GMP/pop scaling regime. For West EU cities, β = 1 over the whole the period, while for post-communist cities β > 1 and increases from ∼1.2 to ∼1.4. The evolution of the scaling exponent describes the convergence of post-communist European cities to open and liberal economies. We propose a simple model of economic convergence in which, under stable political conditions, a linear GMP/pop scaling is expected for all cities. The results suggest that the GMP/pop super-linear scaling represents a phase of economic growth rather than a steady, universal urban feature. The results also suggest that relationships between cities are embedded in their political and economic context and cannot be neglected in explanations of cities, urbanization and urban economics. PMID:27551719

Non-linear interactions determine the impact of sea-level rise on estuarine benthic biodiversity and ecosystem processes.

PubMed

Yamanaka, Tsuyuko; Raffaelli, David; White, Piran C L

2013-01-01

Sea-level rise induced by climate change may have significant impacts on the ecosystem functions and ecosystem services provided by intertidal sediment ecosystems. Accelerated sea-level rise is expected to lead to steeper beach slopes, coarser particle sizes and increased wave exposure, with consequent impacts on intertidal ecosystems. We examined the relationships between abundance, biomass, and community metabolism of benthic fauna with beach slope, particle size and exposure, using samples across a range of conditions from three different locations in the UK, to determine the significance of sediment particle size beach slope and wave exposure in affecting benthic fauna and ecosystem function in different ecological contexts. Our results show that abundance, biomass and oxygen consumption of intertidal macrofauna and meiofauna are affected significantly by interactions among sediment particle size, beach slope and wave exposure. For macrofauna on less sloping beaches, the effect of these physical constraints is mediated by the local context, although for meiofauna and for macrofauna on intermediate and steeper beaches, the effects of physical constraints dominate. Steeper beach slopes, coarser particle sizes and increased wave exposure generally result in decreases in abundance, biomass and oxygen consumption, but these relationships are complex and non-linear. Sea-level rise is likely to lead to changes in ecosystem structure with generally negative impacts on ecosystem functions and ecosystem services. However, the impacts of sea-level rise will also be affected by local ecological context, especially for less sloping beaches.

Rich and Poor Cities in Europe. An Urban Scaling Approach to Mapping the European Economic Transition.

PubMed

Strano, Emanuele; Sood, Vishal

2016-01-01

Recent advances in the urban science make broad use of the notion of scaling. We focus here on the important scaling relationship between the gross metropolitan product (GMP) of a city and its population (pop). It has been demonstrated that GMP ∝ Y Ypopβ with β always greater than 1 and close to 1.2. This fundamental finding highlights a universal rule that holds across countries and cultures and might explain the very nature of cities. However, in an increasingly connected world, the hypothesis that the economy of a city solely depends on its population might be questionable. Using data for 248 cities in the European Union between 2005 and 2010, we found a double GMP/pop scaling regime. For West EU cities, β = 1 over the whole the period, while for post-communist cities β > 1 and increases from ∼1.2 to ∼1.4. The evolution of the scaling exponent describes the convergence of post-communist European cities to open and liberal economies. We propose a simple model of economic convergence in which, under stable political conditions, a linear GMP/pop scaling is expected for all cities. The results suggest that the GMP/pop super-linear scaling represents a phase of economic growth rather than a steady, universal urban feature. The results also suggest that relationships between cities are embedded in their political and economic context and cannot be neglected in explanations of cities, urbanization and urban economics.

Quality assurance of dynamic parameters in volumetric modulated arc therapy

PubMed Central

Manikandan, A; Sarkar, B; Holla, R; Vivek, T R; Sujatha, N

2012-01-01

Objectives The purpose of this study was to demonstrate quality assurance checks for accuracy of gantry speed and position, dose rate and multileaf collimator (MLC) speed and position for a volumetric modulated arc treatment (VMAT) modality (Synergy® S; Elekta, Stockholm, Sweden), and to check that all the necessary variables and parameters were synchronous. Methods Three tests (for gantry position–dose delivery synchronisation, gantry speed–dose delivery synchronisation and MLC leaf speed and positions) were performed. Results The average error in gantry position was 0.5° and the average difference was 3 MU for a linear and a parabolic relationship between gantry position and delivered dose. In the third part of this test (sawtooth variation), the maximum difference was 9.3 MU, with a gantry position difference of 1.2°. In the sweeping field method test, a linear relationship was observed between recorded doses and distance from the central axis, as expected. In the open field method, errors were encountered at the beginning and at the end of the delivery arc, termed the “beginning” and “end” errors. For MLC position verification, the maximum error was −2.46 mm and the mean error was 0.0153 ±0.4668 mm, and 3.4% of leaves analysed showed errors of >±1 mm. Conclusion This experiment demonstrates that the variables and parameters of the Synergy® S are synchronous and that the system is suitable for delivering VMAT using a dynamic MLC. PMID:22745206

Young African American Male-Male Relationships: Experiences, Expectations, and Condom Use

ERIC Educational Resources Information Center

Taggart, Tamara; Ellen, Jonathan; Arrington-Sanders, Renata

2017-01-01

HIV disproportionately impacts young African American men who have sex with men (MSM). In this study, we sought to understand how previous relationship experiences and expectations for romantic relationships influence condom use among young African American MSM. Twenty African American MSM aged 16 to 24 years completed a semi-structured interview…

The Relationship between Teacher Regard and College Attendance Expectations: Socioeconomic and Racial-Ethnic Disparities

ERIC Educational Resources Information Center

Pinchak, Nicolo P.

2018-01-01

This study uses data from wave one of the National Longitudinal Survey of Adolescent to Adult Health to analyze the relationship between middle and secondary school students' perceptions of their teachers, or "teacher regard," and students' expectations for college attendance. Variation in this relationship is further examined by…

Relationship Between the Parameters of the Linear and Nonlinear Wave Generation Stages in a Magnetospheric Cyclotron Maser in the Backward-Wave Oscillator Regime

NASA Astrophysics Data System (ADS)

Demekhov, A. G.

2017-03-01

By using numerical simulations we generalize certain relationships between the parameters of quasimonochromatic whistler-mode waves generated at the linear and nonlinear stages of the cyclotron instability in the backward-wave oscillator regime. One of these relationships is between the wave amplitude at the nonlinear stage and the linear growth rate of the cyclotron instability. It was obtained analytically by V.Yu.Trakhtengerts (1984) for a uniform medium under the assumption of constant frequency and amplitude of the generated wave. We show that a similar relationship also holds for the signals generated in a nonuniform magnetic field and having a discrete structure in the form of short wave packets (elements) with fast frequency drift inside each element. We also generalize the formula for the linear growth rate of absolute cyclotron instability in a nonuniform medium and analyze the relationship between the frequency drift rate in the discrete elements and the wave amplitude. These relationships are important for analyzing the links between the parameters of chorus emissions in the Earth's and planetary magnetospheres and the characteristics of the energetic charged particles generating these signals.

Sources of computer self-efficacy: The relationship to outcome expectations, computer anxiety, and intention to use computers

NASA Astrophysics Data System (ADS)

Antoine, Marilyn V.

2011-12-01

The purpose of this research was to extend earlier research on sources of selfefficacy (Lent, Lopez, & Biechke, 1991; Usher & Pajares, 2009) to the information technology domain. The principal investigator examined how Bandura's (1977) sources of self-efficacy information---mastery experience, vicarious experience, verbal persuasion, and physiological states---shape computer self-efficacy beliefs and influence the decision to use or not use computers. The study took place at a mid-sized Historically Black College or University in the South. A convenience sample of 105 undergraduates was drawn from students enrolled in multiple sections of two introductory computer courses. There were 67 females and 38 males. This research was a correlational study of the following variables: sources of computer self-efficacy, general computer self-efficacy, outcome expectations, computer anxiety, and intention to use computers. The principal investigator administered a survey questionnaire containing 52 Likert items to measure the major study variables. Additionally, the survey instrument collected demographic variables such as gender, age, race, intended major, classification, technology use, technology adoption category, and whether the student owns a computer. The results reveal the following: (1) Mastery experience and verbal persuasion had statistically significant relationships to general computer self-efficacy, while vicarious experience and physiological states had non-significant relationships. Mastery experience had the strongest correlation to general computer self-efficacy. (2) All of the sources of computer self-efficacy had statistically significant relationships to personal outcome expectations. Vicarious experience had the strongest correlation to personal outcome expectations. (3) All of the sources of self-efficacy had statistically significant relationships to performance outcome expectations. Vicarious experience had the strongest correlation to performance outcome expectations. (4) Mastery experience and physiological states had statistically significant relationships to computer anxiety, while vicarious experience and verbal persuasion had non-significant relationships. Physiological states had the strongest correlation to computer anxiety. (5) Mastery experience, vicarious experience, and physiological states had statistically significant relationships to intention to use computers, while verbal persuasion had a non-significant relationship. Mastery experience had the strongest correlation to intention to use computers. Gender-related findings indicate that females reported higher average mastery experience, vicarious experience, physiological states, and intention to use computers than males. Females reported lower average general computer self-efficacy, computer anxiety, verbal persuasion, personal outcome expectations, and performance outcome expectations than males. The results of this study can be used to develop strategies for increasing general computer self-efficacy, outcome expectations, and intention to use computers. The results can also be used to develop strategies for reducing computer anxiety.

Dual control and prevention of the turn-off phenomenon in a class of mimo systems

NASA Technical Reports Server (NTRS)

Mookerjee, P.; Bar-Shalom, Y.; Molusis, J. A.

1985-01-01

A recently developed methodology of adaptive dual control based upon sensitivity functions is applied here to a multivariable input-output model. The plant has constant but unknown parameters. It represents a simplified linear version of the relationship between the vibration output and the higher harmonic control input for a helicopter. The cautious and the new dual controller are examined. In many instances, the cautious controller is seen to turn off. The new dual controller modifies the cautious control design by numerator and denominator correction terms which depend upon the sensitivity functions of the expected future cost and avoids the turn-off and burst phenomena. Monte Carlo simulations and statistical tests of significance indicate the superiority of the dual controller over the cautious and the heuristic certainity equivalence controllers.

Premarital relationships and livelihoods in Ghana.

PubMed

Ankomah, A

1996-10-01

This study is based on interviews with a sample of 400 single women aged 18-25 years from the Fante ethnic group in Cape Coast, Ghana, in 1991, and on focus groups. This case study illustrates the importance of economic and living arrangement support expected from partners in premarital relationships. Support may be for living and maintenance ('chopmoney', provisions, household items, and rent); for financial security (provision of capital); and for clothing and hairdressing. Women did not always require economic support in premarital relationships. Women expect boyfriends to provide 'chopmoney' (money for food and general upkeep) and contribute some money for the rent. Only 36% of sexually active women expected their boyfriends to supply food provisions. Premarital sexual relationships are used to obtain start-up capital. The author refers to evidence that senior government officials engaged in sexual transactions with clients before loans and credit facilities were offered. 87% of sexually experienced women expected their partners to pay for at least part of clothing expenses. The study revealed that there was considerable disparity between women's expectations and actual receipt of economic support. 56% desired, but only 36% received, 'chopmoney' in full. 40% expected their partners to pay for household furnishings in full, while only 10% did so. 55% expected capital, but only 15% received it. The three most frequently received benefits in full were hair dressing, shoes, and dresses. Men provided most non-negotiable items as a means of "boosting their egos." Many young women rely on the support of men in order to improve their status. Ghanaian men control financial resources and economic power. Mothers of adolescent daughters encourage premarital sexual behavior. Prostitution is considered different from sexual exchange relationships. It is argued that gender inequalities and domestic abuse are perpetuated through sexual exchange relationships.

The Short Form Vaping Consequences Questionnaire: Psychometric Properties of a Measure of Vaping Expectancies for Use With Adult E-cigarette Users.

PubMed

Morean, Meghan E; L'Insalata, Alexa

2017-02-01

E-cigarettes are popular in the United States, but psychometrically sound measures of vaping beliefs and behaviors are lacking. We evaluated the psychometrics of the Short Form Vaping Consequences Questionnaire (S-VCQ), a modified version of the Short Form Smoking Consequences Questionnaire that assesses expectancies for negative consequences, positive reinforcement, negative reinforcement, and appetite/weight control associated with vaping. Adult, past-month e-cigarette users completed an anonymous survey in Fall 2015 (N = 522, 50.4% female; 71.5% white; 34.10 [SD = 9.66] years). Psychometric analyses included confirmatory factor analysis, internal consistency, measurement invariance, t tests, correlations, and test-criterion relationships with vaping outcomes. The S-VCQ evidenced a four-factor latent structure (Bentler's Comparative Fit Index = .95, Root Mean Square Error of Approximation = .05, Standardized Root Mean Square Residual = .06), and subscales evidenced internal consistency (mean α = 0.89). S-VCQ scores were scalar invariant for sex and smoking status; women reported stronger appetite/weight control than men and dual cigarette/e-cigarette users (n = 309) reported stronger negative vaping consequences and negative reinforcement than nonsmokers. Among dual users, vaping and smoking expectancies also were scalar invariant; dual users reported stronger positive reinforcement associated with vaping than smoking but stronger negative consequences, negative reinforcement, and appetite/weight control associated with smoking than vaping. Correlations indicated that vaping and smoking expectancies were related, yet distinct constructs. Univariate general linear models indicated that vaping frequency and dependence were associated with positive reinforcement (ηp2 = .02/.02), negative reinforcement (ηp2 = .02/.08), and appetite/weight control (ηp2 = .02/.02) from vaping. The S-VCQ evidences solid psychometrics as a measure of adult e-cigarette users' vaping expectancies. The current study provides evidence for the reliability and validity of the S-VCQ, the first measure of vaping expectancies that has been validated for use with adult e-cigarette users. Results indicated that the S-VCQ comprises four subscales that evidence internal consistency, scalar measurement invariance for important groups of interest, and test-criterion relationships with vaping outcomes. Researchers are encouraged to consider using this measure for assessing vaping expectancies in adult e-cigarette users. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Advanced statistics: linear regression, part I: simple linear regression.

PubMed

Marill, Keith A

2004-01-01

Simple linear regression is a mathematical technique used to model the relationship between a single independent predictor variable and a single dependent outcome variable. In this, the first of a two-part series exploring concepts in linear regression analysis, the four fundamental assumptions and the mechanics of simple linear regression are reviewed. The most common technique used to derive the regression line, the method of least squares, is described. The reader will be acquainted with other important concepts in simple linear regression, including: variable transformations, dummy variables, relationship to inference testing, and leverage. Simplified clinical examples with small datasets and graphic models are used to illustrate the points. This will provide a foundation for the second article in this series: a discussion of multiple linear regression, in which there are multiple predictor variables.

Interpreting the sub-linear Kennicutt-Schmidt relationship: the case for diffuse molecular gas

NASA Astrophysics Data System (ADS)

Shetty, Rahul; Clark, Paul C.; Klessen, Ralf S.

2014-08-01

Recent statistical analysis of two extragalactic observational surveys strongly indicate a sub-linear Kennicutt-Schmidt (KS) relationship between the star formation rate (ΣSFR) and molecular gas surface density (Σmol). Here, we consider the consequences of these results in the context of common assumptions, as well as observational support for a linear relationship between ΣSFR and the surface density of dense gas. If the CO traced gas depletion time (τ_dep^CO) is constant, and if CO only traces star-forming giant molecular clouds (GMCs), then the physical properties of each GMC must vary, such as the volume densities or star formation rates. Another possibility is that the conversion between CO luminosity and Σmol, the XCO factor, differs from cloud-to-cloud. A more straightforward explanation is that CO permeates the hierarchical interstellar medium, including the filaments and lower density regions within which GMCs are embedded. A number of independent observational results support this description, with the diffuse gas comprising at least 30 per cent of the total molecular content. The CO bright diffuse gas can explain the sub-linear KS relationship, and consequently leads to an increasing τ_dep^CO with Σmol. If ΣSFR linearly correlates with the dense gas surface density, a sub-linear KS relationship indicates that the fraction of diffuse gas fdiff grows with Σmol. In galaxies where Σmol falls towards the outer disc, this description suggests that fdiff also decreases radially.

First-time parents' expectations about the division of childcare and play.

PubMed

Biehle, Susanne N; Mickelson, Kristin D

2012-02-01

The current study examines violated expectations regarding the division of childcare and play in first-time parents during the initial transition to parenthood. The study's goal was threefold: (a) to compare prenatal expectations with the reported postpartum division of childcare and play, (b) to compare the influence of the reported division versus violated expectations on postpartum relationship satisfaction and depression, and (c) to examine the role of persistent violations of expectations on these outcomes. Couples expecting their first child were interviewed during the third trimester of pregnancy and at 1 and 4 months postpartum. Results indicated both mothers and fathers have unrealistic expectations during pregnancy; interestingly, the direction violation was opposite but converging for mothers and fathers. As found in prior research, mothers experienced unmet expectations with fathers doing less than mothers expected. Fathers, on the other hand, experienced overmet expectations with mothers doing more than fathers expected. Violated expectations were also a stronger predictor of depression and relationship satisfaction than the reported division, although again in opposite directions for mothers and fathers. Unmet expectations were negative for mothers, while overmet expectations with regard to childcare tasks were beneficial for fathers. The one caveat was for fathers' overmet expectations with play; in this case, a mother playing with the baby more than a father expected was related to less relationship satisfaction. A similar pattern of results was found for mothers and fathers with persistent violations. This study highlights the importance of understanding violated expectations in both mothers and fathers, as well as examining play separately from childcare.

Bias due to two-stage residual-outcome regression analysis in genetic association studies.

PubMed

Demissie, Serkalem; Cupples, L Adrienne

2011-11-01

Association studies of risk factors and complex diseases require careful assessment of potential confounding factors. Two-stage regression analysis, sometimes referred to as residual- or adjusted-outcome analysis, has been increasingly used in association studies of single nucleotide polymorphisms (SNPs) and quantitative traits. In this analysis, first, a residual-outcome is calculated from a regression of the outcome variable on covariates and then the relationship between the adjusted-outcome and the SNP is evaluated by a simple linear regression of the adjusted-outcome on the SNP. In this article, we examine the performance of this two-stage analysis as compared with multiple linear regression (MLR) analysis. Our findings show that when a SNP and a covariate are correlated, the two-stage approach results in biased genotypic effect and loss of power. Bias is always toward the null and increases with the squared-correlation between the SNP and the covariate (). For example, for , 0.1, and 0.5, two-stage analysis results in, respectively, 0, 10, and 50% attenuation in the SNP effect. As expected, MLR was always unbiased. Since individual SNPs often show little or no correlation with covariates, a two-stage analysis is expected to perform as well as MLR in many genetic studies; however, it produces considerably different results from MLR and may lead to incorrect conclusions when independent variables are highly correlated. While a useful alternative to MLR under , the two -stage approach has serious limitations. Its use as a simple substitute for MLR should be avoided. © 2011 Wiley Periodicals, Inc.

First Observations of Laser-Driven Acceleration of Relativistic Electrons in a Semi-Infinite Vacuum Space

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

Plettner, T.; Byer, R.L.; Smith, T.I.

2006-02-17

We have observed acceleration of relativistic electrons in vacuum driven by a linearly polarized visible laser beam incident on a thin gold-coated reflective boundary. The observed energy modulation effect follows all the characteristics expected for linear acceleration caused by a longitudinal electric field. As predicted by the Lawson-Woodward theorem the laser driven modulation only appears in the presence of the boundary. It shows a linear dependence with the strength of the electric field of the laser beam and also it is critically dependent on the laser polarization. Finally, it appears to follow the expected angular dependence of the inverse transitionmore » radiation process. experiment as the Laser Electron Accelerator Project (LEAP).« less

Dilations and the Equation of a Line

ERIC Educational Resources Information Center

Yopp, David A.

2016-01-01

Students engage in proportional reasoning when they use covariance and multiple comparisons. Without rich connections to proportional reasoning, students may develop inadequate understandings of linear relationships and the equations that model them. Teachers can improve students' understanding of linear relationships by focusing on realistic…

On the Period-Amplitude and Amplitude-Period Relationships

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.

2008-01-01

Examined are Period-Amplitude and Amplitude-Period relationships based on the cyclic behavior of the 12-month moving averages of monthly mean sunspot numbers for cycles 0.23, both in terms of Fisher's exact tests for 2x2 contingency tables and linear regression analyses. Concerning the Period-Amplitude relationship (same cycle), because cycle 23's maximum amplitude is known to be 120.8, the inferred regressions (90-percent prediction intervals) suggest that its period will be 131 +/- 24 months (using all cycles) or 131 +/- 18 months (ignoring cycles 2 and 4, which have the extremes of period, 108 and 164 months, respectively). Because cycle 23 has already persisted for 142 months (May 1996 through February 2008), based on the latter prediction, it should end before September 2008. Concerning the Amplitude-Period relationship (following cycle maximum amplitude versus preceding cycle period), because cycle 23's period is known to be at least 142 months, the inferred regressions (90-percent prediction intervals) suggest that cycle 24's maximum amplitude will be about less than or equal to 96.1 +/- 55.0 (using all cycle pairs) or less than or equal to 91.0 +/- 36.7 (ignoring statistical outlier cycle pairs). Hence, cycle 24's maximum amplitude is expected to be less than 151, perhaps even less than 128, unless cycle pair 23/24 proves to be a statistical outlier.

Multivariate Relationships of Specific Impression Cues with Teacher Expectations and Dyadic Interactions in Elementary Physical Education Classes.

ERIC Educational Resources Information Center

Martinek, Thomas J.; Karper, William B.

1984-01-01

This study determined multivariate relationships of the impression cues of attractiveness and effort with teacher expectations and dyadic interaction in two groups of elementary school children. (Author/JMK)

Restoring Low Sidelobe Antenna Patterns with Failed Elements in a Phased Array Antenna

DTIC Science & Technology

2016-02-01

optimum low sidelobes are demonstrated in several examples. Index Terms — Array signal processing, beams, linear algebra , phased arrays, shaped...represented by a linear combination of low sidelobe beamformers with no failed elements, ’s, in a neighborhood around under the constraint that the linear ...would expect that linear combinations of them in a neighborhood around would also have low sidelobes. The algorithms in this paper exploit this

Optimization of detectors for the ILC

NASA Astrophysics Data System (ADS)

Suehara, Taikan; ILD Group; SID Group

2016-04-01

International Linear Collider (ILC) is a next-generation e+e- linear collider to explore Higgs, Beyond-Standard-Models, top and electroweak particles with great precision. We are optimizing our two detectors, International Large Detector (ILD) and Silicon Detector (SiD) to maximize the physics reach expected in ILC with reasonable detector cost and good reliability. The optimization study on vertex detectors, main trackers and calorimeters is underway. We aim to conclude the optimization to establish final designs in a few years, to finish detector TDR and proposal in reply to expected ;green sign; of the ILC project.

Students' motivational beliefs in science learning, school motivational contexts, and science achievement in Taiwan

NASA Astrophysics Data System (ADS)

Wang, Cheng-Lung; Liou, Pey-Yan

2017-05-01

Taiwanese students are featured as having high academic achievement but low motivational beliefs according to the serial results of the Trends in Mathematics and Science Study (TIMSS). Moreover, given that the role of context has become more important in the development of academic motivation theory, this study aimed to examine the relationship between motivational beliefs and science achievement at both the student and school levels. Based on the Expectancy-Value Theory, the three motivational beliefs, namely self-concept, intrinsic value, and utility value, were the focuses of this study. The two-level hierarchical linear model was used to analyse the Taiwanese TIMSS 2011 eighth-grade student data. The results indicated that each motivational belief had a positive predictive effect on science achievement. Additionally, a positive school contextual effect of self-concept on science achievement was identified. Furthermore, school-mean utility value had a negative moderating effect on the relationship between utility value and science achievement. In conclusion, this study sheds light on the functioning of motivational beliefs in science learning among Taiwanese adolescents with consideration of the school motivational contexts.

Perceptions about Dormitory Wing-Mates and Alcohol-Related Secondhand Effects Among College Freshmen

PubMed Central

Bush, Elizabeth N.; Novik, Melinda G.

2009-01-01

Objective This study examined secondhand effects college students experienced from others’ alcohol use and their relationship with student characteristics and alcohol-related perceptions about wing-mates. Participants Incoming freshmen (n=509) residing in predominantly freshmen dormitories. Methods A web-based survey was administered two months into the 2006 fall academic semester. Linear Mixed Modeling was utilized to examine the independent relationships of secondhand effects with student characteristics and perceptions. Results Most (80%) students experienced at least one secondhand effect. Perceiving wing-mate acceptance and expectation of alcohol use, and inability to protect against wing-mate secondhand effects as well as being female and a drinker were related to experiencing secondhand effects. Conclusions Incoming college freshmen frequently experienced secondhand effects. Involving dormitory wings in norms-based interventions aimed at reducing secondhand effects warrant evaluation. Further research is also warranted on skill-building among college students to resist and intervene into others’ drinking and on Resident Advisor negotiation of their roles as both engenderers of trust/cooperation and enforcers of alcohol rules. PMID:19433400

Loneliness and life satisfaction of boys with developmental coordination disorder: the impact of leisure participation and perceived freedom in leisure.

PubMed

Poulsen, Anne A; Ziviani, Jenny M; Johnson, Helen; Cuskelly, Monica

2008-04-01

A theoretical model linking motor ability with perceived freedom in leisure, participation in team sports, loneliness, and global life satisfaction was tested using linear confirmatory path analysis. Participants were 173 boys aged 10-13 years who filled in self-report questionnaires about perceived freedom in leisure, loneliness, and global life satisfaction. Parents of boys completed 7-day diaries and 12-month retrospective recall questionnaires about their son's leisure-time activity participation. Results of path analyses confirmed that the fit of the hypothetical model was consistent with predictions. The inferred direct pathways of influence between both total loneliness and global life satisfaction on motor ability were in the expected directions (i.e., inverse and positive relationships, respectively). Perceived Freedom in Leisure (PFL) and participation in team sports were two intermediate variables indirectly influencing these relationships. Although PFL was identified as a motivational process influencing participation levels in team sports it was noted that other psychological and environmental factors must also be considered when evaluating child-activity-environment fit for boys with developmental coordination disorder.

Linear scaling relationships and volcano plots in homogeneous catalysis – revisiting the Suzuki reaction† †Electronic supplementary information (ESI) available: Detailed derivation of the linear scaling relationships and construction of the volcano plots as well as comparisons of computed values using PBE0-dDsC and M06 functionals is included. See DOI: 10.1039/c5sc02910d Click here for additional data file.

PubMed Central

Busch, Michael; Wodrich, Matthew D.

2015-01-01

Linear free energy scaling relationships and volcano plots are common tools used to identify potential heterogeneous catalysts for myriad applications. Despite the striking simplicity and predictive power of volcano plots, they remain unknown in homogeneous catalysis. Here, we construct volcano plots to analyze a prototypical reaction from homogeneous catalysis, the Suzuki cross-coupling of olefins. Volcano plots succeed both in discriminating amongst different catalysts and reproducing experimentally known trends, which serves as validation of the model for this proof-of-principle example. These findings indicate that the combination of linear scaling relationships and volcano plots could serve as a valuable methodology for identifying homogeneous catalysts possessing a desired activity through a priori computational screening. PMID:28757966

The Mediating Effect of Listening Metacognitive Awareness between Test-Taking Motivation and Listening Test Score: An Expectancy-Value Theory Approach

PubMed Central

Xu, Jian

2017-01-01

The present study investigated test-taking motivation in L2 listening testing context by applying Expectancy-Value Theory as the framework. Specifically, this study was intended to examine the complex relationships among expectancy, importance, interest, listening anxiety, listening metacognitive awareness, and listening test score using data from a large-scale and high-stakes language test among Chinese first-year undergraduates. Structural equation modeling was used to examine the mediating effect of listening metacognitive awareness on the relationship between expectancy, importance, interest, listening anxiety, and listening test score. According to the results, test takers’ listening scores can be predicted by expectancy, interest, and listening anxiety significantly. The relationship between expectancy, interest, listening anxiety, and listening test score was mediated by listening metacognitive awareness. The findings have implications for test takers to improve their test taking motivation and listening metacognitive awareness, as well as for L2 teachers to intervene in L2 listening classrooms. PMID:29312063

The Mediating Effect of Listening Metacognitive Awareness between Test-Taking Motivation and Listening Test Score: An Expectancy-Value Theory Approach.

PubMed

Xu, Jian

2017-01-01

The present study investigated test-taking motivation in L2 listening testing context by applying Expectancy-Value Theory as the framework. Specifically, this study was intended to examine the complex relationships among expectancy, importance, interest, listening anxiety, listening metacognitive awareness, and listening test score using data from a large-scale and high-stakes language test among Chinese first-year undergraduates. Structural equation modeling was used to examine the mediating effect of listening metacognitive awareness on the relationship between expectancy, importance, interest, listening anxiety, and listening test score. According to the results, test takers' listening scores can be predicted by expectancy, interest, and listening anxiety significantly. The relationship between expectancy, interest, listening anxiety, and listening test score was mediated by listening metacognitive awareness. The findings have implications for test takers to improve their test taking motivation and listening metacognitive awareness, as well as for L2 teachers to intervene in L2 listening classrooms.

Relationships between the Active Aging Index and Disability-Free Life Expectancy: A Case Study in the Rajshahi District of Bangladesh.

PubMed

Tareque, Md Ismail; Hoque, Nazrul; Islam, Towfiqua Mahfuza; Kawahara, Kazuo; Sugawa, Makiko

2013-12-01

Life expectancy has increased considerably throughout the world. In Bangladesh, life expectancy has increased from about 53 years in 1975 to 69 years in 2010. However, it is unknown whether the increase in life expectancy is simultaneously accompanied by an increase in disability-free life expectancy (DFLE). The purpose of the study described in this article was to explore the relationship between life expectancy and DFLE in the Rajshahi District of Bangladesh by examining the relationships between the Active Aging Index (AAI) and DFLE. The study fi ndings suggest that urban, more-educated, elderly males are more active in all aspects of life and have longer DFLE. Females are found to outlive males but are more likely to live a greater part of their remaining life with disability. Positive correlations between the AAI and DFLE suggest that older adults could enjoy more DFLE by involving themselves in active aging activities.

Applying Quality Function Deployment Model in Burn Unit Service Improvement.

PubMed

Keshtkaran, Ali; Hashemi, Neda; Kharazmi, Erfan; Abbasi, Mehdi

2016-01-01

Quality function deployment (QFD) is one of the most effective quality design tools. This study applies QFD technique to improve the quality of the burn unit services in Ghotbedin Hospital in Shiraz, Iran. First, the patients' expectations of burn unit services and their priorities were determined through Delphi method. Thereafter, burn unit service specifications were determined through Delphi method. Further, the relationships between the patients' expectations and service specifications and also the relationships between service specifications were determined through an expert group's opinion. Last, the final importance scores of service specifications were calculated through simple additive weighting method. The findings show that burn unit patients have 40 expectations in six different areas. These expectations are in 16 priority levels. Burn units also have 45 service specifications in six different areas. There are four-level relationships between the patients' expectations and service specifications and four-level relationships between service specifications. The most important burn unit service specifications have been identified in this study. The QFD model developed in the study can be a general guideline for QFD planners and executives.

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

Liu, Jian; Guo, Pan; University of Chinese Academy of Sciences, Beijing 100049

Using molecular dynamics simulations, we show a fine linear relationship between surface energies and microscopic Lennard-Jones parameters of super-hydrophilic surfaces. The linear slope of the super-hydrophilic surfaces is consistent with the linear slope of the super-hydrophobic, hydrophobic, and hydrophilic surfaces where stable water droplets can stand, indicating that there is a universal linear behavior of the surface energies with the water-surface van der Waals interaction that extends from the super-hydrophobic to super-hydrophilic surfaces. Moreover, we find that the linear relationship exists for various substrate types, and the linear slopes of these different types of substrates are dependent on the surfacemore » atom density, i.e., higher surface atom densities correspond to larger linear slopes. These results enrich our understanding of water behavior on solid surfaces, especially the water wetting behaviors on uncharged super-hydrophilic metal surfaces.« less

Testing the dose-response specification in epidemiology: public health and policy consequences for lead.

PubMed

Rothenberg, Stephen J; Rothenberg, Jesse C

2005-09-01

Statistical evaluation of the dose-response function in lead epidemiology is rarely attempted. Economic evaluation of health benefits of lead reduction usually assumes a linear dose-response function, regardless of the outcome measure used. We reanalyzed a previously published study, an international pooled data set combining data from seven prospective lead studies examining contemporaneous blood lead effect on IQ (intelligence quotient) of 7-year-old children (n = 1,333). We constructed alternative linear multiple regression models with linear blood lead terms (linear-linear dose response) and natural-log-transformed blood lead terms (log-linear dose response). We tested the two lead specifications for nonlinearity in the models, compared the two lead specifications for significantly better fit to the data, and examined the effects of possible residual confounding on the functional form of the dose-response relationship. We found that a log-linear lead-IQ relationship was a significantly better fit than was a linear-linear relationship for IQ (p = 0.009), with little evidence of residual confounding of included model variables. We substituted the log-linear lead-IQ effect in a previously published health benefits model and found that the economic savings due to U.S. population lead decrease between 1976 and 1999 (from 17.1 microg/dL to 2.0 microg/dL) was 2.2 times (319 billion dollars) that calculated using a linear-linear dose-response function (149 billion dollars). The Centers for Disease Control and Prevention action limit of 10 microg/dL for children fails to protect against most damage and economic cost attributable to lead exposure.

Effects of Remedial Sport Hunting on Cougar Complaints and Livestock Depredations

PubMed Central

Peebles, Kaylie A.; Wielgus, Robert B.; Maletzke, Benjamin T.; Swanson, Mark E.

2013-01-01

Remedial sport hunting of predators is often used to reduce predator populations and associated complaints and livestock depredations. We assessed the effects of remedial sport hunting on reducing cougar complaints and livestock depredations in Washington from 2005 to 2010 (6 years). The number of complaints, livestock depredations, cougars harvested, estimated cougar populations, human population and livestock populations were calculated for all 39 counties and 136 GMUs (game management units) in Washington. The data was then analyzed using a negative binomial generalized linear model to test for the expected negative relationship between the number of complaints and depredations in the current year with the number of cougars harvested the previous year. As expected, we found that complaints and depredations were positively associated with human population, livestock population, and cougar population. However, contrary to expectations we found that complaints and depredations were most strongly associated with cougars harvested the previous year. The odds of increased complaints and livestock depredations increased dramatically (36 to 240%) with increased cougar harvest. We suggest that increased young male immigration, social disruption of cougar populations, and associated changes in space use by cougars - caused by increased hunting resulted in the increased complaints and livestock depredations. Widespread indiscriminate hunting does not appear to be an effective preventative and remedial method for reducing predator complaints and livestock depredations. PMID:24260291

The First Few Times: Similarities and Differences in Sexual Behaviors and Attitudes of West German Male and Female Adolescents.

ERIC Educational Resources Information Center

Oswald, Hans; von Salisch, Maria

The study reported in this paper examined: (1) how the expectations of sexual relationships relate to the sexual experiences which male and female adolescents gather in their relationships with the opposite sex; and (2) whether male and female adolescents differ in their sexual behavior, their expectations for sexual relationships, their…

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 distributed lag approach to fitting non-linear dose-response models in particulate matter air pollution time series investigations.

PubMed

Roberts, Steven; Martin, Michael A

2007-06-01

The majority of studies that have investigated the relationship between particulate matter (PM) air pollution and mortality have assumed a linear dose-response relationship and have used either a single-day's PM or a 2- or 3-day moving average of PM as the measure of PM exposure. Both of these modeling choices have come under scrutiny in the literature, the linear assumption because it does not allow for non-linearities in the dose-response relationship, and the use of the single- or multi-day moving average PM measure because it does not allow for differential PM-mortality effects spread over time. These two problems have been dealt with on a piecemeal basis with non-linear dose-response models used in some studies and distributed lag models (DLMs) used in others. In this paper, we propose a method for investigating the shape of the PM-mortality dose-response relationship that combines a non-linear dose-response model with a DLM. This combined model will be shown to produce satisfactory estimates of the PM-mortality dose-response relationship in situations where non-linear dose response models and DLMs alone do not; that is, the combined model did not systemically underestimate or overestimate the effect of PM on mortality. The combined model is applied to ten cities in the US and a pooled dose-response model formed. When fitted with a change-point value of 60 microg/m(3), the pooled model provides evidence for a positive association between PM and mortality. The combined model produced larger estimates for the effect of PM on mortality than when using a non-linear dose-response model or a DLM in isolation. For the combined model, the estimated percentage increase in mortality for PM concentrations of 25 and 75 microg/m(3) were 3.3% and 5.4%, respectively. In contrast, the corresponding values from a DLM used in isolation were 1.2% and 3.5%, respectively.

Moderated mediation of the relationships between masculinity ideology, outcome expectations, and energy drink use.

PubMed

Levant, Ronald F; Parent, Mike C; McCurdy, Eric R; Bradstreet, Tyler C

2015-11-01

The consumption of energy drinks is a growing health-risk behavior for young men in the United States. The present study investigated the relationship between masculinity ideology, outcome expectations, energy drink use, and sleep disturbances. The authors recruited 467 adult males from universities and the Internet who provided data on their endorsement of traditional masculinity ideology, outcome expectations for use of energy drinks, use of energy drinks, and sleep disturbances. A theoretical model positing moderated mediation was tested using structural equation modeling and conditional process modeling. The results supported the hypothesized model in which endorsement of traditional masculinity ideology was linked with increased outcome expectations for benefits of energy drinks, which in turn was linked with increased energy drink consumption, and which finally was linked with greater sleep disturbance symptoms. The relationship between masculinity ideology and energy drink outcome expectations was moderated by age (significant for younger men but not for older men), and the relationship between energy drink outcome expectations and energy drink use was moderated by race (significant for White men but not for racial minority men). The present study adds to the literature on potential negative health implications of the endorsement of traditional masculinity ideology by offering a link between predictors of energy drink use (masculinity ideology, outcome expectations) and health outcomes of energy drink use (e.g., sleep disturbance). (c) 2015 APA, all rights reserved).

White matter changes and word finding failures with increasing age.

PubMed

Stamatakis, Emmanuel A; Shafto, Meredith A; Williams, Guy; Tam, Phyllis; Tyler, Lorraine K

2011-01-07

Increasing life expectancy necessitates the better understanding of the neurophysiological underpinnings of age-related cognitive changes. The majority of research examining structural-cognitive relationships in aging focuses on the role of age-related changes to grey matter integrity. In the current study, we examined the relationship between age-related changes in white matter and language production. More specifically, we concentrated on word-finding failures, which increase with age. We used Diffusion tensor MRI (a technique used to image, in vivo, the diffusion of water molecules in brain tissue) to relate white matter integrity to measures of successful and unsuccessful picture naming. Diffusion tensor images were used to calculate Fractional Anisotropy (FA) images. FA is considered to be a measure of white matter organization/integrity. FA images were related to measures of successful picture naming and to word finding failures using voxel-based linear regression analyses. Successful naming rates correlated positively with white matter integrity across a broad range of regions implicated in language production. However, word finding failure rates correlated negatively with a more restricted region in the posterior aspect of superior longitudinal fasciculus. The use of DTI-MRI provides evidence for the relationship between age-related white matter changes in specific language regions and word finding failures in old age.

Hydrogen Ion Buffering During Complete Brain Ischemia

PubMed Central

KRAIG, RICHARD P.; PULSINELLI, WILLIAM A.; PLUM, FRED

2011-01-01

As a first step to quantify [H+] changes in brain during ischemia we used H+-selective microelectrodes and enzyme fluorometric techniques to describe the relationship between interstitial [H+] ([H+]o) and peak tissue lactate after cardiac arrest. We found a step function relationship between [H+]o and tissue lactate rather than the linear titration expected in a homogeneous protein solution. Within a blood glucose range from 3–7 mM, brain lactate rose from 8–13 mmol/kg along with a rise in [H+]o of 99 ± 6 nM (0.44 ± 0.02 pH). At higher blood glucose levels (17–80 mM), brain lactate accumulated to levels of 16–31 mmol/kg; concurrently [H+]o rose by 608 ± 16 nM (1.07 ± 0.02 pH). The unchanging level of [H+]o between 8–13 and 16–31 mmol/kg lactate implies that [H+]o is at a steady-state, but not equilibrium with respect to [H+] in other brain compartments. We propose that ion-transport characteristics of astroglia account for the observed relationship of [H+]o to tissue lactate during complete ischemia and suggest that brain infarction develops after plasma membranes in brain cells can no longer transport ions to regulate [H+]. PMID:4041829

Evidence for a nonmonotonic relationship between ecosystem-scale peatland methane emissions and water table depth

NASA Astrophysics Data System (ADS)

Brown, Mathew G.; Humphreys, Elyn R.; Moore, Tim R.; Roulet, Nigel T.; Lafleur, Peter M.

2014-05-01

Although temporal and spatial variations in peatland methane (CH4) emissions at broad scales are often related to water table (WT) using a linear relationship, a potentially complex relationship exists between these variables locally and over shorter time scales. To explore this issue, CH4 fluxes were measured using eddy covariance at the Mer Bleue bog over two summer seasons. Peak CH4 emissions (30 to 50 mg CH4-C m-2 d-1) occurred not when the WT was closest to the surface but instead, when it dropped to 40 to 55 cm below the surface. When the WT was below or above this zone, average fluxes were 14 mg CH4-C m-2 d-1. We speculate this critical zone coincides with the necessary redox potentials and sources of fresh organic material that lead to maximum production of CH4 and/or with conditions that lead to degassing of stored CH4. However, as expected, total summer CH4 emissions were 47% lower during the drier year. This occurred in part because the WT was within the critical zone for fewer days in the drier year but also because after an extended midsummer dry period there was little recovery of CH4 emissions, even a month after rewetting.

Generalized Dissimilarity Modeling of Late-Quaternary Variations in Pollen-Based Compositional Dissimilarity

NASA Astrophysics Data System (ADS)

Williams, J. W.; Blois, J.; Ferrier, S.; Manion, G.; Fitzpatrick, M.; Veloz, S.; He, F.; Liu, Z.; Otto-Bliesner, B. L.

2011-12-01

In Quaternary paleoecology and paleoclimatology, compositionally dissimilar fossil assemblages usually indicate dissimilar environments; this relationship underpins assemblage-level techniques for paleoenvironmental reconstruction such as mutual climatic ranges or the modern analog technique. However, there has been relatively little investigation into the form of the relationship between compositional dissimilarity and climatic dissimilarity. Here we apply generalized dissimilarity modeling (GDM; Ferrier et al. 2007) as a tool for modeling the expected non-linear relationships between compositional and climatic dissimilarity. We use the CCSM3.0 transient paleoclimatic simulations from the SynTrace working group (Liu et al. 2009) and a new generation of fossil pollen maps from eastern North America (Blois et al. 2011) to 1) assess the spatial relationships between compositional dissimilarity and climatic dissimilarity and 2) whether these spatial relationships change over time. We used a taxonomic list of 106 genus-level pollen types, six climatic variables (winter precipitation and mean temperature, summer precipitation and temperature, seasonality of precipitation, and seasonality of temperature) that were chosen to minimize collinearity, and a cross-referenced pollen and climate dataset mapped for time slices spaced 1000 years apart. When GDM was trained for one time slice, the correlation between predicted and observed spatial patterns of community dissimilarity for other times ranged between 0.3 and 0.73. The selection of climatic predictor variables changed over time, as did the form of the relationship between compositional turnover and climatic predictors. Summer temperature was the only variable selected for all time periods. These results thus suggest that the relationship between compositional dissimilarity in pollen assemblages (and, by implication, beta diversity in plant communities) and climatic dissimilarity can change over time, for reasons to be further studied.

Parental loss, trusting relationship with current caregivers, and psychosocial adjustment among children affected by AIDS in China.

PubMed

Zhao, Junfeng; Li, Xiaoming; Barnett, Douglas; Lin, Xiuyun; Fang, Xiaoyi; Zhao, Guoxiang; Naar-King, Sylvie; Stanton, Bonita

2011-08-01

The objective of this study was to examine the relationship between parental loss, trusting relationship with current caregivers, and psychosocial adjustment among children affected by AIDS in China. In this study, cross-sectional data were collected from 755 AIDS orphans (296 double orphans and 459 single orphans), 466 vulnerable children living with HIV-infected parents, and 404 comparison children in China. The trusting relationship with current caregivers was measured with a 15-item scale (Cronbach's α = 0.84) modified from the Trusting Relationship Questionnaire developed by Mustillo et al. in 2005 (Quality of relationships between youth and community service providers: Reliability and validity of the trusting relationship questionnaire. Journal of Child and Family Studies, 14, 577-590). The psychosocial measures include rule compliance/acting out, anxiety/withdrawal, peer social skills, school interest, depressive symptoms, loneliness, self-esteem, future expectation, hopefulness about future, and perceived control over the future. Group mean comparisons using analysis of variance suggested a significant association (p < 0.0001) between the trusting relationship with current caregivers and all the psychosocial measures, except anxiety and depression. These associations remained significant in General Linear Model analysis, controlling for children's gender, age, family socioeconomic status, orphan status (orphans, vulnerable children, and comparison children), and appropriate interaction terms among factor variables. The findings in the current study support the global literature on the importance of attachment relationship with caregivers in promoting children's psychosocial development. Future prevention intervention efforts to improve AIDS orphans' psychosocial well-being will need to take into consideration the quality of the child's attachment relationships with current caregivers and help their current caregivers to improve the quality of care for these children. Future study is needed to explore the possible reasons for the lack of association between a trusting relationship and some internalizing symptoms such as anxiety and depression among children affected by HIV/AIDS.

Evaluation of force-velocity and power-velocity relationship of arm muscles.

PubMed

Sreckovic, Sreten; Cuk, Ivan; Djuric, Sasa; Nedeljkovic, Aleksandar; Mirkov, Dragan; Jaric, Slobodan

2015-08-01

A number of recent studies have revealed an approximately linear force-velocity (F-V) and, consequently, a parabolic power-velocity (P-V) relationship of multi-joint tasks. However, the measurement characteristics of their parameters have been neglected, particularly those regarding arm muscles, which could be a problem for using the linear F-V model in both research and routine testing. Therefore, the aims of the present study were to evaluate the strength, shape, reliability, and concurrent validity of the F-V relationship of arm muscles. Twelve healthy participants performed maximum bench press throws against loads ranging from 20 to 70 % of their maximum strength, and linear regression model was applied on the obtained range of F and V data. One-repetition maximum bench press and medicine ball throw tests were also conducted. The observed individual F-V relationships were exceptionally strong (r = 0.96-0.99; all P < 0.05) and fairly linear, although it remains unresolved whether a polynomial fit could provide even stronger relationships. The reliability of parameters obtained from the linear F-V regressions proved to be mainly high (ICC > 0.80), while their concurrent validity regarding directly measured F, P, and V ranged from high (for maximum F) to medium-to-low (for maximum P and V). The findings add to the evidence that the linear F-V and, consequently, parabolic P-V models could be used to study the mechanical properties of muscular systems, as well as to design a relatively simple, reliable, and ecologically valid routine test of the muscle ability of force, power, and velocity production.

Reconsidering the Relationship between Air Pollution and Deprivation

PubMed Central

Bailey, Nick; Dong, Guanpeng; Minton, Jon; Pryce, Gwilym

2018-01-01

This paper critically examines the relationship between air pollution and deprivation. We argue that focusing on a particular economic or social model of urban development might lead one to erroneously expect all cities to converge towards a particular universal norm. A naive market sorting model, for example, would predict that poor households will eventually be sorted into high pollution areas, leading to a positive relationship between air pollution and deprivation. If, however, one considers a wider set of theoretical perspectives, the anticipated relationship between air pollution and deprivation becomes more complex and idiosyncratic. Specifically, we argue the relationship between pollution and deprivation can only be made sense of by considering processes of risk perception, path dependency, gentrification and urbanization. Rather than expecting all areas to eventually converge to some universal norm, we should expect the differences in the relationship between air pollution and deprivation across localities to persist. Mindful of these insights, we propose an approach to modeling which does not impose a geographically fixed relationship. Results for Scotland reveal substantial variations in the observed relationships over space and time, supporting our argument. PMID:29596380

Reconsidering the Relationship between Air Pollution and Deprivation.

PubMed

Bailey, Nick; Dong, Guanpeng; Minton, Jon; Pryce, Gwilym

2018-03-29

This paper critically examines the relationship between air pollution and deprivation. We argue that focusing on a particular economic or social model of urban development might lead one to erroneously expect all cities to converge towards a particular universal norm. A naive market sorting model, for example, would predict that poor households will eventually be sorted into high pollution areas, leading to a positive relationship between air pollution and deprivation. If, however, one considers a wider set of theoretical perspectives, the anticipated relationship between air pollution and deprivation becomes more complex and idiosyncratic. Specifically, we argue the relationship between pollution and deprivation can only be made sense of by considering processes of risk perception, path dependency, gentrification and urbanization. Rather than expecting all areas to eventually converge to some universal norm, we should expect the differences in the relationship between air pollution and deprivation across localities to persist. Mindful of these insights, we propose an approach to modeling which does not impose a geographically fixed relationship. Results for Scotland reveal substantial variations in the observed relationships over space and time, supporting our argument.

NSFC Health Research Funding and Burden of Disease in China

PubMed Central

Xu, Gelin; Zhang, Zhizhong; Lv, Qiushi; Li, Yun; Ye, Ruidong; Xiong, Yunyun; Jiang, Yongjun; Liu, Xinfeng

2014-01-01

Background Allocation of health research funds among diseases has never been evaluated in China. This study aimed to examine the relationship between disease-specific funding levels of National Nature Science Foundation of China (NSFC), the main governmental resource for health research in China, and burden of disease. Methods Funding magnitudes for 53 diseases or conditions were obtained from the website of NSFC. Measures of disease burden, mortality, years of life lost (YLLs) and disability-adjusted life years (DALYs), were derived from the Global Burden of Disease Study 2010. The relationship between NSFC funding and disease burden was analyzed with univariate linear regression. For each measure associated with funding, regression-derived estimates were used to calculate the expected funds for each disease. The actual and expected funds were then compared. We also evaluated the impacts of changes of disease burden metrics since 1990, and differences from the world averages on NSFC funding. Results NSFC health research funding was associated with disease burden measured in mortality (R = 0.33, P = 0.02), YLLs (R = 0.39, P = 0.004), and DALYs (R = 0.40, P = 0.003). But none of the changes of mortality (R = 0.22, P = 0.12), YLLs (R = −0.04, P = 0.79) and DALYs (R = −0.003, P = 0.98) since 1990 was associated with the funding magnitudes. None of the differences of mortality (R = −0.11, P = 0.45), YLLs (R = −0.11, P = 0.43) and DALYs (R = −0.12, P = 0.38) from that of the concurrent world averages were associated with the funding magnitudes. Measured by DALY, stroke and COPD received the least funding compared to expected; while leukemia and diabetes received the most funding compared to expected. Conclusion Although NSFC funding were roughly associated with disease burden as measured in mortality, YLLs and DALYs. Some major diseases such as stroke were underfunded; while others such as leukaemia were overfunded. Change of disease burden during the last 20 years and country-specialized disease burden were not reflected in current allocation of NSFC funds. PMID:25369330

NSFC health research funding and burden of disease in China.

PubMed

Xu, Gelin; Zhang, Zhizhong; Lv, Qiushi; Li, Yun; Ye, Ruidong; Xiong, Yunyun; Jiang, Yongjun; Liu, Xinfeng

2014-01-01

Allocation of health research funds among diseases has never been evaluated in China. This study aimed to examine the relationship between disease-specific funding levels of National Nature Science Foundation of China (NSFC), the main governmental resource for health research in China, and burden of disease. Funding magnitudes for 53 diseases or conditions were obtained from the website of NSFC. Measures of disease burden, mortality, years of life lost (YLLs) and disability-adjusted life years (DALYs), were derived from the Global Burden of Disease Study 2010. The relationship between NSFC funding and disease burden was analyzed with univariate linear regression. For each measure associated with funding, regression-derived estimates were used to calculate the expected funds for each disease. The actual and expected funds were then compared. We also evaluated the impacts of changes of disease burden metrics since 1990, and differences from the world averages on NSFC funding. NSFC health research funding was associated with disease burden measured in mortality (R = 0.33, P = 0.02), YLLs (R = 0.39, P = 0.004), and DALYs (R  = 0.40, P = 0.003). But none of the changes of mortality (R = 0.22, P = 0.12), YLLs (R =  -0.04, P = 0.79) and DALYs (R =  -0.003, P = 0.98) since 1990 was associated with the funding magnitudes. None of the differences of mortality (R =  -0.11, P = 0.45), YLLs (R =  -0.11, P = 0.43) and DALYs (R =  -0.12, P = 0.38) from that of the concurrent world averages were associated with the funding magnitudes. Measured by DALY, stroke and COPD received the least funding compared to expected; while leukemia and diabetes received the most funding compared to expected. Although NSFC funding were roughly associated with disease burden as measured in mortality, YLLs and DALYs. Some major diseases such as stroke were underfunded; while others such as leukaemia were overfunded. Change of disease burden during the last 20 years and country-specialized disease burden were not reflected in current allocation of NSFC funds.

Patient Expectations and Patient-Reported Outcomes in Surgery: A Systematic Review

PubMed Central

Waljee, Jennifer; McGlinn, Evan P.; Sears, Erika Davis; Chung, Kevin C.

2014-01-01

Background Recent events in healthcare reform have brought national attention to integrating patient experiences and expectations into quality metrics. Few studies have comprehensively evaluated the effect of patient expectations on patient-reported outcomes (PROs) following surgery. The purpose of this study is to systematically review the available literature describing the relationship between patient expectations and postoperative PROs. Methods We performed a search of the literature published prior to November 1, 2012. Articles were included in the review if 1) primary data were presented 2) patient expectations regarding a surgical procedure were measured 3) PROs were measured, and 4) the relationship between patient expectations and PROs was specifically examined. PROs were categorized into five subgroups: satisfaction, quality of life (QOL), disability, mood disorder, and pain. We examined each study to determine the relationship between patient expectations and PROs as well as study quality. Results From the initial literature search yielding 1,708 studies, 60 articles were included. Fulfillment of expectations was associated with improved PROs among 24 studies. Positive expectations were correlated with improved PROs for 28 (47%) studies, and poorer PROs for 9 (15%) studies. Eighteen studies reported that fulfillment of expectations was correlated with improved patient satisfaction, and 10 studies identified that positive expectations were correlated with improved postoperative QOL. Finally, patients with positive preoperative expectations reported less pain (8 studies) and disability (15 studies) compared with patients with negative preoperative expectations. Conclusions Patient expectations are inconsistently correlated with PROs following surgery, and there is no accepted method to capture perioperative expectations. Future efforts to rigorously measure expectations and explore their influence on postoperative outcomes can inform clinicians and policy-makers seeking to integrate PROs into measures of surgical quality. PMID:24787107

In-law Relationships Before and After Marriage

PubMed Central

Fingerman, Karen L.; Gilligan, Megan; VanderDrift, Laura; Pitzer, Lindsay

2013-01-01

Relationships with in-laws play an important role in individuals’ lives, but we do not know how these ties are formed. We considered two pathways through which early relationships with mothers-in-laws may affect subsequent in-law relationship qualities: a) dimensions of the early relationship and, b) beliefs and expectations of the future relationship. Sixty men and women engaged to be married and their mothers (N = 240) completed interviews prior to, and 6 to 8 months following the wedding. Measures at Time 1 assessed three dimensions of the in-law relationship: a) behavioral (contact by phone, in person), b) emotional (positive and negative relationship qualities), and c) cognitive (knowledge about the other person). Participants also described positive and negative expectations of their future tie. Multilevel models revealed that dimensions of the tie prior to the marriage were associated with post-wedding in-law relationship qualities. When the parties had individual contact with one another and positive feelings before the wedding, ties were stronger following the wedding. Data from open-ended descriptions of negative expectations obtained before the wedding predicted negative relationship qualities after the wedding. Husbands, wives, and mothers-in-law showed similar patterns with regard to relationship qualities. Discussion focuses on the role of early emotional qualities of the in-law tie for subsequent in-law relationships. PMID:23794954

Comparing Childhood Meal Frequency to Current Meal Frequency, Routines and Expectations Among Parents

PubMed Central

Friend, Sarah; Fulkerson, Jayne A.; Neumark-Sztainer, Dianne; Garwick, Ann; Flattum, Colleen Freech; Draxten, Michelle

2015-01-01

Little is known about the continuation of family meals from childhood to parenthood. This study aims to examine associations between parents’ report of eating family meals while growing up and their current family meal frequency, routines, and expectations. Baseline data were used from the Healthy Home Offerings via the Mealtime Environment (HOME) Plus study, a randomized controlled trial with a program to promote healthful behaviors and family meals at home. Participants (160 parent/child dyads) completed data collection in 2011–2012 in the Minneapolis/St. Paul, MN metropolitan area. Parents were predominately female (95%) and white (77%) with a mean age of 41.3 years. General linear modeling examined relationships between parents’ report of how often they ate family meals while growing up and their current family meal frequency, routines and expectations as parents, controlling for parent age, education level and race. Parental report of eating frequent family meals while growing up was positively and significantly associated with age, education and self-identification as white (all p<0.05). Compared to those who ate family meals less than three times/week or four to five times/week, parents who ate six to seven family meals/week while growing up reported significantly more frequent family meals with their current family (4.0, 4.2 vs 5.3 family meals/week, p=.001). Eating frequent family meals while growing up was also significantly and positively associated with having current regular meal routines and meal expectations about family members eating together (both p<.05). Promoting family meals with children may have long-term benefits over generations. PMID:25485670

Physical Attractiveness, Year of University, and the Expectations of Student-Teachers

ERIC Educational Resources Information Center

Clifton, Rodney A.; Baksh, Ismael J.

1978-01-01

Extends previous research (Clifford & Walster, 1973) on the relationship between pupils' physical attractiveness and teacher expectations. Examines the extent to which the length of time that a student-teacher has been in university mediates this relationship. (Author/R K)

Understanding Change in Romantic Relationship Expectations of International Female Students from Turkey

PubMed Central

Bugay, Aslı

2010-01-01

In the light of grounded theory, the authors explored change in romantic relationship expectations of international students. Twelve female graduate students from Turkey were interviewed and several themes were identified explaining the presence and absence of change in participants’ attitudes toward romantic relationships. The findings are discussed in relation to acculturation and direction for future research is presented. PMID:20835294

Use of a tracing task to assess visuomotor performance for evidence of concussion and recuperation.

PubMed

Kelty-Stephen, Damian G; Qureshi Ahmad, Mona; Stirling, Leia

2015-12-01

The likelihood of suffering a concussion while playing a contact sport ranges from 15-45% per year of play. These rates are highly variable as athletes seldom report concussive symptoms, or do not recognize their symptoms. We performed a prospective cohort study (n = 206, aged 10-17) to examine visuomotor tracing to determine the sensitivity for detecting neuromotor components of concussion. Tracing variability measures were investigated for a mean shift with presentation of concussion-related symptoms and a linear return toward baseline over subsequent return visits. Furthermore, previous research relating brain injury to the dissociation of smooth movements into "submovements" led to the expectation that cumulative micropause duration, a measure of motion continuity, might detect likelihood of injury. Separate linear mixed effects regressions of tracing measures indicated that 4 of the 5 tracing measures captured both short-term effects of injury and longer-term effects of recovery with subsequent visits. Cumulative micropause duration has a positive relationship with likelihood of participants having had a concussion. The present results suggest that future research should evaluate how well the coefficients for the tracing parameter in the logistic regression help to detect concussion in novel cases. (c) 2015 APA, all rights reserved).

The brain adjusts grip forces differently according to gravity and inertia: a parabolic flight experiment

PubMed Central

White, Olivier

2015-01-01

In everyday life, one of the most frequent activities involves accelerating and decelerating an object held in precision grip. In many contexts, humans scale and synchronize their grip force (GF), normal to the finger/object contact, in anticipation of the expected tangential load force (LF), resulting from the combination of the gravitational and the inertial forces. In many contexts, GF and LF are linearly coupled. A few studies have examined how we adjust the parameters–gain and offset–of this linear relationship. However, the question remains open as to how the brain adjusts GF regardless of whether LF is generated by different combinations of weight and inertia. Here, we designed conditions to generate equivalent magnitudes of LF by independently varying mass and movement frequency. In a control experiment, we directly manipulated gravity in parabolic flights, while other factors remained constant. We show with a simple computational approach that, to adjust GF, the brain is sensitive to how LFs are produced at the fingertips. This provides clear evidence that the analysis of the origin of LF is performed centrally, and not only at the periphery. PMID:25717293

Revisiting shape selectivity in liquid chromatography for polycyclic aromatic hydrocarbons (PAHs) - six-ring and seven-ring Cata-condensed PAH isomers of molecular mass 328 Da and 378 Da.

PubMed

Oña-Ruales, Jorge O; Sander, Lane C; Wilson, Walter B; Wise, Stephen A

2018-01-01

The relationship of reversed-phase liquid chromatography (RPLC) retention on a polymeric C 18 stationary phase and the shape of polycyclic aromatic hydrocarbons (PAHs) was investigated for three-ring to seven-ring cata-condensed isomers. We report the first RPLC separation for six-ring and seven-ring cata-condensed PAH isomers. Correlations of LC retention and shape parameters (length-to-breath ratio, L/B and thickness, T) were investigated for 2 three-ring isomers (molecular mass 178 Da), 5 four-ring isomers (molecular mass 228 Da), 11 five-ring isomers (molecular mass 278 Da), 17 six-ring isomers (molecular mass 328 Da), and 20 seven-ring isomers (molecular mass 378 Da). Significant linear correlations were found for all isomer groups (r = 0.71 to 0.94). Nonplanarity of the PAH isomers was found to influence retention (i.e., nonplanar isomers eluting earlier than expected based on L/B) and linear correlations of retention vs. T for isomer groups containing nonplanar isomers were significant (r = 0.71 to 0.86). Graphical abstract.

Bayesian Inference for Generalized Linear Models for Spiking Neurons

PubMed Central

Gerwinn, Sebastian; Macke, Jakob H.; Bethge, Matthias

2010-01-01

Generalized Linear Models (GLMs) are commonly used statistical methods for modelling the relationship between neural population activity and presented stimuli. When the dimension of the parameter space is large, strong regularization has to be used in order to fit GLMs to datasets of realistic size without overfitting. By imposing properly chosen priors over parameters, Bayesian inference provides an effective and principled approach for achieving regularization. Here we show how the posterior distribution over model parameters of GLMs can be approximated by a Gaussian using the Expectation Propagation algorithm. In this way, we obtain an estimate of the posterior mean and posterior covariance, allowing us to calculate Bayesian confidence intervals that characterize the uncertainty about the optimal solution. From the posterior we also obtain a different point estimate, namely the posterior mean as opposed to the commonly used maximum a posteriori estimate. We systematically compare the different inference techniques on simulated as well as on multi-electrode recordings of retinal ganglion cells, and explore the effects of the chosen prior and the performance measure used. We find that good performance can be achieved by choosing an Laplace prior together with the posterior mean estimate. PMID:20577627

On the stability of the relationship between reference evapotranspiration and single tree transpiration: test and validation over several irrigated tree orchards

NASA Astrophysics Data System (ADS)

Ayyoub, Abdellatif; Er-Raki, Salah; Khabba, Saïd; Merlin, Olivier; César Rodriguez, Julio; Ezzahar, Jamal; Bahlaoui, Ahmed; Chehbouni, Abdelghani

2016-04-01

The present work aims to develop a simple approach relating normalized daily sap flow (per unit of leaf area) and daily ET0 (mm/day) calculated by two methods: FAO-Penman-Monteith (FAO-PM) and Hargreaves-Samani (HARG). The data sets used for developing this approach are taken from three experimental sites (olive trees, cv. "Oleaeuropaea L.", olive trees, cv. "Arbequino" and citrus trees cv. "Clementine Afourar") conducted in the Tensift region around Marrakech, Morocco and one experimental site (pecan orchard, cv. "Caryaillinoinensis, Wangenh. K. Koch") conducted in the Yaqui Valley, northwest of Mexico). The results showed that the normalized daily sap flow (volume of transpired water per unit of leaf area) was linearly correlated with ET0 (mm per day) calculated by FAO-PM method. The coefficient of determination (R2) and the slope of this linear regression varied between 0.71 and 0.97 and between 0.30 and 0.35, respectively, depending on the type of orchards. For HARG method, the relationship between both terms is also linear but with less accuracy (R2 =0.7) as expected due to the underestimation of ET0 by this method. Afterward, the validation of the developed linear relationship was performed over an olive orchard ("Oleaeuropaea L.") where the measurements of sap flow were available for another (2004) cropping season. The scatter plot between the normalized measured and estimated sap flow based on FAO-PM method reveals a very good agreement (slope = 1, with R2 = 0.83 and RMSE=0.14 L/m2 leaf area). However, for the estimation of normalized sap flow based on HARG method, the correlation is more scattered with some underestimation (5%). A further validation wasperformed using the measurements of evapotranspiration (ET) by eddy correlation system and the results showed that the correlation between normalized measured ET and estimated normalized sap flow is best when using FAO-PM method (RMSE=0.33 L/m2 leaf area) for estimating ET0 than when using HARG method (RMSE= 0.51 L/m2 leaf area). Finally, the performance of the developed approach was compared to the traditional dual crop coefficient scheme for estimating plant transpiration. Cross-comparison of these two approaches with the measurements data gave satisfactory results with an average value of RMSE equal to about 0.37 mm/day for both approaches.

Caribou distribution during the post-calving period in relation to infrastructure in the Prudhoe Bay oil field, Alaska

USGS Publications Warehouse

Cronin, Matthew A.; Amstrup, Steven C.; Durner, George M.; Noel, Lynn E.; McDonald, Trent L.; Ballard, Warren B.

1998-01-01

There is concern that caribou (Rangifer tarandus) may avoid roads and facilities (i.e., infrastructure) in the Prudhoe Bay oil field (PBOF) in northern Alaska, and that this avoidance can have negative effects on the animals. We quantified the relationship between caribou distribution and PBOF infrastructure during the post-calving period (mid-June to mid-August) with aerial surveys from 1990 to 1995. We conducted four to eight surveys per year with complete coverage of the PBOF. We identified active oil field infrastructure and used a geographic information system (GIS) to construct ten 1 km wide concentric intervals surrounding the infrastructure. We tested whether caribou distribution is related to distance from infrastructure with a chi-squared habitat utilization-availability analysis and log-linear regression. We considered bulls, calves, and total caribou of all sex/age classes separately. The habitat utilization-availability analysis indicated there was no consistent trend of attraction to or avoidance of infrastructure. Caribou frequently were more abundant than expected in the intervals close to infrastructure, and this trend was more pronounced for bulls and for total caribou of all sex/age classes than for calves. Log-linear regression (with Poisson error structure) of numbers of caribou and distance from infrastructure were also done, with and without combining data into the 1 km distance intervals. The analysis without intervals revealed no relationship between caribou distribution and distance from oil field infrastructure, or between caribou distribution and Julian date, year, or distance from the Beaufort Sea coast. The log-linear regression with caribou combined into distance intervals showed the density of bulls and total caribou of all sex/age classes declined with distance from infrastructure. Our results indicate that during the post-calving period: 1) caribou distribution is largely unrelated to distance from infrastructure; 2) caribou regularly use habitats in the PBOF; 3) caribou often occur close to infrastructure; and 4) caribou do not appear to avoid oil field infrastructure.

Associations between extreme precipitation and acute gastro-intestinal illness due to cryptosporidiosis and giardiasis in an urban Canadian drinking water system (1997-2009).

PubMed

Chhetri, Bimal K; Takaro, Tim K; Balshaw, Robert; Otterstatter, Michael; Mak, Sunny; Lem, Marcus; Zubel, Marc; Lysyshyn, Mark; Clarkson, Len; Edwards, Joanne; Fleury, Manon D; Henderson, Sarah B; Galanis, Eleni

2017-10-01

Drinking water related infections are expected to increase in the future due to climate change. Understanding the current links between these infections and environmental factors is vital to understand and reduce the future burden of illness. We investigated the relationship between weekly reported cryptosporidiosis and giardiasis (n = 7,422), extreme precipitation (>90th percentile), drinking water turbidity, and preceding dry periods in a drinking water system located in greater Vancouver, British Columbia, Canada (1997-2009) using distributed lag non-linear Poisson regression models adjusted for seasonality, secular trend, and the effect of holidays on reporting. We found a significant increase in cryptosporidiosis and giardiasis 4-6 weeks after extreme precipitation. The effect was greater following a dry period. Similarly, extreme precipitation led to significantly increased turbidity only after prolonged dry periods. Our results suggest that the risk of cryptosporidiosis and giardiasis increases with extreme precipitation, and that the effects are more pronounced after a prolonged dry period. Given that extreme precipitation events are expected to increase with climate change, it is important to further understand the risks from these events, develop planning tools, and build resilience to these future risks.

Zero-Determinant Strategies in Iterated Public Goods Game

PubMed Central

Pan, Liming; Hao, Dong; Rong, Zhihai; Zhou, Tao

2015-01-01

Recently, Press and Dyson have proposed a new class of probabilistic and conditional strategies for the two-player iterated Prisoner’s Dilemma, so-called zero-determinant strategies. A player adopting zero-determinant strategies is able to pin the expected payoff of the opponents or to enforce a linear relationship between his own payoff and the opponents’ payoff, in a unilateral way. This paper considers zero-determinant strategies in the iterated public goods game, a representative multi-player game where in each round each player will choose whether or not to put his tokens into a public pot, and the tokens in this pot are multiplied by a factor larger than one and then evenly divided among all players. The analytical and numerical results exhibit a similar yet different scenario to the case of two-player games: (i) with small number of players or a small multiplication factor, a player is able to unilaterally pin the expected total payoff of all other players; (ii) a player is able to set the ratio between his payoff and the total payoff of all other players, but this ratio is limited by an upper bound if the multiplication factor exceeds a threshold that depends on the number of players. PMID:26293589

Relationship of gas hydrate concentration to porosity and reflection amplitude in a research well, Mackenzie Delta, Canada

USGS Publications Warehouse

Jin, Y.K.; Lee, M.W.; Collett, T.S.

2002-01-01

Well logs acquired at the Mallik 2L-38 gas hydrate research well. Mackenzie Delta, Canada, reveal a distinct trend showing that the resistivity of gas-hydrate-bearing sediments increases with increases in density porosities. This trend, opposite to the general trend of decrease in resistivity with porosity, implies that gas hydrates are more concentrated in the higher porosity. Using the Mallik 2L-38 well data, a proportional gas hydrate concentration (PGHC) model, which states that the gas hydrate concentration in the sediment's pore space is linearly proportional to porosity, is proposed for the general habitat of gas hydrate in sediments. Anomalous data (less than 6% of the total data) outside the dominant observed trend can be explained by local geological characteristics. The anomalous data analysis indicates that highly concentrated gas-hydrate-bearing layers would be expected where sediments have high proportions of gravel and coarse sand. Using the parameters in the PGHC model determined from resistivity-porosity logs, it is possible to qualitatively predict the degree of reflection amplitude variations in seismic profiles. Moderate-to-strong reflections are expected for the Mallik 2L-38 well. ?? 2002 Elsevier Science Ltd. All rights reserved.

A re-evaluation of thermal expansion measurements of metallic liquids and glasses from x-ray scattering experiments

NASA Astrophysics Data System (ADS)

Gangopadhyay, A. K.; Kelton, K. F.

2018-05-01

Previous studies reported a number of anomalies when estimates of linear thermal expansion coefficients of metallic liquids and glasses from x-ray scattering experiments were compared with direct measurements of volume/length changes with temperature. In most cases, the first peak of the pair correlation function showed a contraction, while the structure factor showed an expansion, but both at rates much different from those expected from the direct volume measurements. In addition, the relationship between atomic volume and the characteristic lengths obtained from the structure factor from scattering experiments was found to have a fractional exponent instead of one equal to three, as expected from the Ehrenfest relation. This has led to the speculation that the atomic packing in liquids and glasses follow a fractal behavior. These issues are revisited in this study using more in-depth analysis of recent higher resolution data and some new ideas suggested in the literature. The main conclusion is that for metallic alloys, at least to a large extent, most of these anomalies arise from complicated interplays of the temperature dependences of the various partial structure factors, which contribute to the total intensities of the scattering peaks.

Knot probabilities in random diagrams

NASA Astrophysics Data System (ADS)

Cantarella, Jason; Chapman, Harrison; Mastin, Matt

2016-10-01

We consider a natural model of random knotting—choose a knot diagram at random from the finite set of diagrams with n crossings. We tabulate diagrams with 10 and fewer crossings and classify the diagrams by knot type, allowing us to compute exact probabilities for knots in this model. As expected, most diagrams with 10 and fewer crossings are unknots (about 78% of the roughly 1.6 billion 10 crossing diagrams). For these crossing numbers, the unknot fraction is mostly explained by the prevalence of ‘tree-like’ diagrams which are unknots for any assignment of over/under information at crossings. The data shows a roughly linear relationship between the log of knot type probability and the log of the frequency rank of the knot type, analogous to Zipf’s law for word frequency. The complete tabulation and all knot frequencies are included as supplementary data.

A CORRELATION BETWEEN RADIATION TOLERANCE AND NUCLEAR SURFACE AREA

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

Iversen, S.

1962-09-22

Sparrow and Miksche (Science, 134:282) determined the dose (r/day) required to produce severe growth inhibition in 23 species of plants and found a linear relationship between log nuclear volume and log dose. The following equations hold for 6 species: log nuclear volume - 4.42 -0.82 log dose and log nuclear volume = 1.66 + 0.66 log (DNA content). If all the nuclear DNA is distributed in two peripheral zones, the equations also hold: 2(log nuclear surface area) - 1.33(log nuclear volume) - 2.21 + 0.88 log(DNA content) and 5.88-- 1.09 log dose. For the 23 species, the equation was obtained:more » 2(log nuclear surface area) = 5.41 -- 0.97 log dose. All the slopes are close to the expected value of 1.00. (D.L.C.)« less

Evaluation of aerodynamic derivatives from a magnetic balance system

NASA Technical Reports Server (NTRS)

Raghunath, B. S.; Parker, H. M.

1972-01-01

The dynamic testing of a model in the University of Virginia cold magnetic balance wind-tunnel facility is expected to consist of measurements of the balance forces and moments, and the observation of the essentially six degree of freedom motion of the model. The aerodynamic derivatives of the model are to be evaluated from these observations. The basic feasibility of extracting aerodynamic information from the observation of a model which is executing transient, complex, multi-degree of freedom motion is demonstrated. It is considered significant that, though the problem treated here involves only linear aerodynamics, the methods used are capable of handling a very large class of aerodynamic nonlinearities. The basic considerations include the effect of noise in the data on the accuracy of the extracted information. Relationships between noise level and the accuracy of the evaluated aerodynamic derivatives are presented.

Relationships among Professionals' Knowledge, Experience, and Expectations Regarding Cochlear Implants

ERIC Educational Resources Information Center

Ben-Itzhak, D.; Most, T.; Weisel, A.

2005-01-01

The present study examined the relationships between teachers' and communication clinicians' self-reported knowledge on cochlear implants and their expectations of CIs. The authors also explored these professionals' views regarding the child's communication mode, educational setting, and social options following cochlear implantation. The…

Threat Appeals: The Fear-Persuasion Relationship is Linear and Curvilinear.

PubMed

Dillard, James Price; Li, Ruobing; Huang, Yan

2017-11-01

Drive theory may be seen as the first scientific theory of health and risk communication. However, its prediction of a curvilinear association between fear and persuasion is generally held to be incorrect. A close rereading of Hovland et al. reveals that within- and between-persons processes were conflated. Using a message that advocated obtaining a screening for colonoscopy, this study (N = 259) tested both forms of the inverted-U hypothesis. In the between-persons data, analyses revealed a linear effect that was consistent with earlier investigations. However, the data showed an inverted-U relationship in within-persons data. Hence, the relationship between fear and persuasion is linear or curvilinear depending on the level of analysis.

Linear scaling relationships and volcano plots in homogeneous catalysis - revisiting the Suzuki reaction.

PubMed

Busch, Michael; Wodrich, Matthew D; Corminboeuf, Clémence

2015-12-01

Linear free energy scaling relationships and volcano plots are common tools used to identify potential heterogeneous catalysts for myriad applications. Despite the striking simplicity and predictive power of volcano plots, they remain unknown in homogeneous catalysis. Here, we construct volcano plots to analyze a prototypical reaction from homogeneous catalysis, the Suzuki cross-coupling of olefins. Volcano plots succeed both in discriminating amongst different catalysts and reproducing experimentally known trends, which serves as validation of the model for this proof-of-principle example. These findings indicate that the combination of linear scaling relationships and volcano plots could serve as a valuable methodology for identifying homogeneous catalysts possessing a desired activity through a priori computational screening.

A Preliminary Application of Social Cognitive Theory to Nonsuicidal Self-Injury.

PubMed

Hasking, Penelope; Rose, Alyssa

2016-08-01

Researchers have established a relationship between exposure to nonsuicidal self-injury (NSSI), and increased probability of engaging in the behavior, but few have endeavored to explain the mechanisms underlying the relationship. We drew on Social Cognitive Theory to argue that core cognitions, including NSSI outcome expectancies and self-efficacy expectancies, moderate this relationship. We also explored whether knowledge about NSSI and attitudes toward the behavior played a role in this relationship. A sample of 389 university students (73.1 % female, M age = 20.90, SD = 2.36), completed online questionnaires assessing the constructs of interest. Our findings support the application of Social Cognitive Theory to better understanding NSSI, with clear links between expectancies, self-efficacy and NSSI. Further, these cognitions moderated a number of exposure-NSSI relationships. Implications of these findings for theory, research and intervention are discussed.

Adhesion of Streptococcus sanguis CH3 to polymers with different surface free energies.

PubMed Central

van Pelt, A W; Weerkamp, A H; Uyen, M H; Busscher, H J; de Jong, H P; Arends, J

1985-01-01

The adhesion of the oral bacterium Streptococcus sanguis CH3 to various polymeric surfaces with surface free energies (gamma s) ranging from 22 to 141 erg cm-2 was investigated. Suspensions containing nine different bacterial concentrations (2.5 X 10(7) to 2.5 X 10(9) cells per ml) were used. After adhesion for 1 h at 21 degrees C and a standardized rinsing procedure, the number of attached bacteria per square centimeter (nb) was determined by scanning electron microscopy. The highest number of bacteria was consistently found on polytetrafluorethylene (gamma s = 22 erg cm-2), and the lowest number was found on glass (gamma s = 141 erg cm-2) at all bacterial concentrations tested. The overall negative correlation between nb and gamma s was weak. However, the slope of the line showing this decrease, calculated from an assumed linear relationship between nb and gamma s, appeared to depend strongly on the bacterial concentration and increased with increasing numbers of bacteria in the suspension. Analysis of the data for each separate polymer showed that the numbers of attached cells on polyvinyl chloride and polypropylene were higher but that those on polycarbonate were lower than would be expected on basis of a linear relationship between nb and gamma s. Desorption experiments were performed by first allowing the bacteria to attach to substrata for 1 h, after which the substrata and attached bacteria were removed to bacterial suspensions containing 10-fold lower bacterial concentrations.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:4004241

Assessment of the relationship between chlorophyll fluorescence and photosynthesis across scales from measurements and simulations

NASA Astrophysics Data System (ADS)

Zhang, Y.; Guanter, L.; Berry, J. A.; Tol, C. V. D.

2016-12-01

Solar-induced chlorophyll fluorescence (SIF) is a novel optical tool for assessment of terrestrial photosynthesis (GPP). Recent work have shown the strong link between GPP and satellite retrievals of SIF at broad scales. However, critical gaps remain between short term small-scale mechanistic understanding and seasonal global observations. In this presentation, we provide a model-based analysis of the relationship between SIF and GPP across scales for diverse vegetation types and a range of meteorological conditions, with the ultimate focus on reproducing the environmental conditions during remote sensing measurements. The coupled fluorescence-photosynthesis model SCOPE is used to simulate GPP and SIF at the both leaf and canopy levels for 13 flux sites. Analyses were conducted to investigate the effects of temporal scaling, canopy structure, overpass time, and spectral domain on the relationship between SIF and GPP. The simulated SIF is highly non-linear with GPP at the leaf level and instantaneous time scale and tends to linearize when scaling to the canopy level and daily to seasonal scales. These relationships are consistent across a wide range of vegetation types. The relationship between SIF and GPP is primarily driven by absorbed photosynthetically active radiation (APAR), especially at the seasonal scale, although the photosynthetic efficiency also contributes to strengthen the link between them. The linearization of their relationship from leaf to canopy and averaging over time is because the overall conditions of the canopy fall within the range of the linear responses of GPP and SIF to light and the photosynthetic capacity. Our results further show that the top-of-canopy relationships between simulated SIF and GPP have similar linearity regardless of whether we used the morning or midday satellite overpass times. These findings are confirmed by field measurements. In addition, the simulated red SIF at 685 nm has a similar relationship with GPP as that of far-red SIF at 740 nm at the canopy level.

On the expected relationships among apparent stress, static stress drop, effective shear fracture energy, and efficiency

USGS Publications Warehouse

Beeler, N.M.; Wong, T.-F.; Hickman, S.H.

2003-01-01

We consider expected relationships between apparent stress ??a and static stress drop ????s using a standard energy balance and find ??a = ????s (0.5 - ??), where ?? is stress overshoot. A simple implementation of this balance is to assume overshoot is constant; then apparent stress should vary linearly with stress drop, consistent with spectral theories (Brune, 1970) and dynamic crack models (Madariaga, 1976). Normalizing this expression by the static stress drop defines an efficiency ??sw = ??sa/????s as follows from Savage and Wood (1971). We use this measure of efficiency to analyze data from one of a number of observational studies that find apparent stress to increase with seismic moment, namely earthquakes recorded in the Cajon Pass borehole by Abercrombie (1995). Increases in apparent stress with event size could reflect an increase in seismic efficiency; however, ??sw for the Cajon earthquakes shows no such increase and is approximately constant over the entire moment range. Thus, apparent stress and stress drop co-vary, as expected from the energy balance at constant overshoot. The median value of ??sw for the Cajon earthquakes is four times lower than ??sw for laboratory events. Thus, these Cajon-recorded earthquakes have relatively low and approximately constant efficiency. As the energy balance requires ??sw = 0.5 - ??, overshoot can be estimated directly from the Savage-Wood efficiency; overshoot is positive for Cajon Pass earthquakes. Variations in apparent stress with seismic moment for these earthquakes result primarily from systematic variations in static stress drop with seismic moment and do not require a relative decrease in sliding resistance with increasing event size (dynamic weakening). Based on the comparison of field and lab determinations of the Savage-Wood efficiency, we suggest the criterion ??sw > 0.3 as a test for dynamic weakening in excess of that seen in the lab.

Competition Experiments as a Means of Evaluating Linear Free Energy Relationships

ERIC Educational Resources Information Center

Mullins, Richard J.; Vedernikov, Andrei; Viswanathan, Rajesh

2004-01-01

The use of competition experiments as a means of evaluating linear free energy relationship in the undergraduate teaching laboratory is reported. The use of competition experiments proved to be a reliable method for the construction of Hammett plots with good correlation providing great flexibility with regard to the compounds and reactions that…

Looking for Connections between Linear and Exponential Functions

ERIC Educational Resources Information Center

Lo, Jane-Jane; Kratky, James L.

2012-01-01

Students frequently have difficulty determining whether a given real-life situation is best modeled as a linear relationship or as an exponential relationship. One root of such difficulty is the lack of deep understanding of the very concept of "rate of change." The authors will provide a lesson that allows students to reveal their misconceptions…

Learned helplessness or expectancy-value? A psychological model for describing the experiences of different categories of unemployed people.

PubMed

García Rodríguez, Y

1997-06-01

Various studies have explored the relationships between unemployment and expectation of success, commitment to work, motivation, causal attributions, self-esteem and depression. A model is proposed that assumes the relationships between these variables are moderated by (a) whether or not the unemployed individual is seeking a first job and (b) age. It is proposed that for the unemployed who are seeking their first job (seekers) the relationships among these variables will be consistent with expectancy-value theory, but for those who have had a previous job (losers), the relationships will be more consistent with learned helplessness theory. It is further assumed that within this latter group the young losers will experience "universal helplessness" whereas the adult losers will experience "personal helplessness".

Self-Efficacy, Satisfaction, and Academic Achievement: The Mediator Role of Students' Expectancy-Value Beliefs

PubMed Central

Doménech-Betoret, Fernando; Abellán-Roselló, Laura; Gómez-Artiga, Amparo

2017-01-01

Although there is considerable evidence to support the direct effects of self-efficacy beliefs on academic achievement, very few studies have explored the motivational mechanism that mediates the self-efficacy–achievement relationship, and they are necessary to understand how and why self-efficacy affects students' academic achievement. Based on a socio-cognitive perspective of motivation, this study examines the relationships among academic self-efficacy, students' expectancy-value beliefs, teaching process satisfaction, and academic achievement. Its main aim is to identify some motivational-underlying processes through which students' academic self-efficacy affects student achievement and satisfaction. Student achievement and satisfaction are two of the most important learning outcomes, and are considered key indicators of education quality. The sample comprises 797 Spanish secondary education students from 36 educational settings and three schools. The scales that referred to self-efficacy and expectancy-value beliefs were administered at the beginning of the course, while student satisfaction and achievement were measured at the end of the course. The data analysis was conducted by structural equation modeling (SEM). The results revealed that students' expectancy-value beliefs (Subject value, Process expectancy, Achievement expectancy, Cost expectancy) played a mediator role between academic self-efficacy and the achievement/satisfaction relationship. These results provided empirical evidence to better understand the mechanism that mediates self-efficacy–achievement and efficacy–course satisfaction relationships. The implications of these findings for teaching and learning in secondary education are discussed. PMID:28769839

Self-Efficacy, Satisfaction, and Academic Achievement: The Mediator Role of Students' Expectancy-Value Beliefs.

PubMed

Doménech-Betoret, Fernando; Abellán-Roselló, Laura; Gómez-Artiga, Amparo

2017-01-01

Although there is considerable evidence to support the direct effects of self-efficacy beliefs on academic achievement, very few studies have explored the motivational mechanism that mediates the self-efficacy-achievement relationship, and they are necessary to understand how and why self-efficacy affects students' academic achievement. Based on a socio-cognitive perspective of motivation, this study examines the relationships among academic self-efficacy, students' expectancy-value beliefs, teaching process satisfaction, and academic achievement. Its main aim is to identify some motivational-underlying processes through which students' academic self-efficacy affects student achievement and satisfaction. Student achievement and satisfaction are two of the most important learning outcomes, and are considered key indicators of education quality. The sample comprises 797 Spanish secondary education students from 36 educational settings and three schools. The scales that referred to self-efficacy and expectancy-value beliefs were administered at the beginning of the course, while student satisfaction and achievement were measured at the end of the course. The data analysis was conducted by structural equation modeling (SEM). The results revealed that students' expectancy-value beliefs (Subject value, Process expectancy, Achievement expectancy, Cost expectancy) played a mediator role between academic self-efficacy and the achievement/satisfaction relationship. These results provided empirical evidence to better understand the mechanism that mediates self-efficacy-achievement and efficacy-course satisfaction relationships. The implications of these findings for teaching and learning in secondary education are discussed.

Global versus local linear beat-to-beat analysis of the relationship between arterial pressure and pulse transit time during dynamic exercise.

PubMed

Porta, A; Gasperi, C; Nollo, G; Lucini, D; Pizzinelli, P; Antolini, R; Pagani, M

2006-04-01

Global linear analysis has been traditionally performed to verify the relationship between pulse transit time (PTT) and systolic arterial pressure (SAP) at the level of their spontaneous beat-to-beat variabilities: PTT and SAP have been plotted in the plane (PTT,SAP) and a significant linear correlation has been found. However, this relationship is weak and in specific individuals cannot be found. This result prevents the utilization of the SAP-PTT relationship to derive arterial pressure changes from PTT measures on an individual basis. We propose a local linear approach to study the SAP-PTT relationship. This approach is based on the definition of short SAP-PTT sequences characterized by SAP increase (decrease) and PTT decrease (increase) and on their search in the SAP and PTT beat-to-beat series. This local approach was applied to PTT and SAP series derived from 13 healthy humans during incremental supine dynamic exercise (at 10, 20 and 30% of the nominal individual maximum effort) and compared to the global approach. While global approach failed in some subjects, local analysis allowed the extraction of the gain of the SAP-PTT relationship in all subjects both at rest and during exercise. When both local and global analyses were successful, the local SAP-PTT gain is more negative than the global one as a likely result of noise reduction.

The Relationship between Expectancy and Academic Achievement--How Can It Be Explained?

ERIC Educational Resources Information Center

Vollmer, Fred

1986-01-01

Describes a study conducted with undergraduate psychology students to determine if the relationship between expectancy measured shortly before an examination and subsequent achievement can be accounted for by the possible common antecedents of previous achievement, past effort expenditure, and perceived ability. (MBR)

The Non-Linear Relationship between BMI and Health Care Costs and the Resulting Cost Fraction Attributable to Obesity.

PubMed

Laxy, Michael; Stark, Renée; Peters, Annette; Hauner, Hans; Holle, Rolf; Teuner, Christina M

2017-08-30

This study aims to analyse the non-linear relationship between Body Mass Index (BMI) and direct health care costs, and to quantify the resulting cost fraction attributable to obesity in Germany. Five cross-sectional surveys of cohort studies in southern Germany were pooled, resulting in data of 6757 individuals (31-96 years old). Self-reported information on health care utilisation was used to estimate direct health care costs for the year 2011. The relationship between measured BMI and annual costs was analysed using generalised additive models, and the cost fraction attributable to obesity was calculated. We found a non-linear association of BMI and health care costs with a continuously increasing slope for increasing BMI without any clear threshold. Under the consideration of the non-linear BMI-cost relationship, a shift in the BMI distribution so that the BMI of each individual is lowered by one point is associated with a 2.1% reduction of mean direct costs in the population. If obesity was eliminated, and the BMI of all obese individuals were lowered to 29.9 kg/m², this would reduce the mean direct costs by 4.0% in the population. Results show a non-linear relationship between BMI and health care costs, with very high costs for a few individuals with high BMI. This indicates that population-based interventions in combination with selective measures for very obese individuals might be the preferred strategy.

Smoking Outcome Expectancies among College Students.

ERIC Educational Resources Information Center

Brandon, Thomas H.; Baker, Timothy B.

Alcohol expectancies have been found to predict later onset of drinking among adolescents. This study examined whether the relationship between level of alcohol use and expectancies is paralleled with cigarette smoking, and attempted to identify the content of smoking expectancies. An instrument to measure the subjective expected utility of…

Expectancies, working alliance, and outcome in transdiagnostic and single diagnosis treatment for anxiety disorders: An investigation of mediation.

PubMed

Sauer-Zavala, Shannon; Boswell, James F; Bentley, Kate H; Thompson-Hollands, Johanna; Farchione, Todd J; Barlow, David H

2018-04-01

Patients' outcome expectancies and the working alliance are two psychotherapy process variables that researchers have found to be associated with treatment outcome, irrespective of treatment approach and problem area. Despite this, little is known about the mechanisms accounting for this association, and whether contextual factors (e.g., psychotherapy type) impact the strength of these relationships. The primary aim of this study was to examine whether patient-rated working alliance quality mediates the relationship between outcome expectancies and pre- to post-treatment change in anxiety symptoms using data from a recent randomized clinical trial comparing a transdiagnostic treatment (the Unified Protocol [UP]; Barlow et al., 2011a; Barlow, Sauer-Zavala, et al., in press) to single diagnosis protocols (SDPs) for patients with a principal heterogeneous anxiety disorder ( n = 179). The second aim was to explore whether cognitive-behavioral treatment condition (UP versus SDP) moderated this indirect relationship. Results from mediation and moderated mediation models indicated that, when collapsing across the two treatment conditions, the relationship between expectancies and outcome was partially mediated by the working alliance ( B = .037, SE = .05, 95% CI [.005, .096]). Interestingly, within-condition analyses showed that this conditional indirect effect was only present for SDP patients, whereas in the UP condition, working alliance did not account for the association between expectancies and outcome. These findings suggest that outcome expectancies and working alliance quality may interact to influence treatment outcomes, and that the nature and strength of the relationships among these constructs may differ as a function of the specific cognitive-behavioral treatment approach utilized.

Detector noise statistics in the non-linear regime

NASA Technical Reports Server (NTRS)

Shopbell, P. L.; Bland-Hawthorn, J.

1992-01-01

The statistical behavior of an idealized linear detector in the presence of threshold and saturation levels is examined. It is assumed that the noise is governed by the statistical fluctuations in the number of photons emitted by the source during an exposure. Since physical detectors cannot have infinite dynamic range, our model illustrates that all devices have non-linear regimes, particularly at high count rates. The primary effect is a decrease in the statistical variance about the mean signal due to a portion of the expected noise distribution being removed via clipping. Higher order statistical moments are also examined, in particular, skewness and kurtosis. In principle, the expected distortion in the detector noise characteristics can be calibrated using flatfield observations with count rates matched to the observations. For this purpose, some basic statistical methods that utilize Fourier analysis techniques are described.

Incorporating nonlinearity into mediation analyses.

PubMed

Knafl, George J; Knafl, Kathleen A; Grey, Margaret; Dixon, Jane; Deatrick, Janet A; Gallo, Agatha M

2017-03-21

Mediation is an important issue considered in the behavioral, medical, and social sciences. It addresses situations where the effect of a predictor variable X on an outcome variable Y is explained to some extent by an intervening, mediator variable M. Methods for addressing mediation have been available for some time. While these methods continue to undergo refinement, the relationships underlying mediation are commonly treated as linear in the outcome Y, the predictor X, and the mediator M. These relationships, however, can be nonlinear. Methods are needed for assessing when mediation relationships can be treated as linear and for estimating them when they are nonlinear. Existing adaptive regression methods based on fractional polynomials are extended here to address nonlinearity in mediation relationships, but assuming those relationships are monotonic as would be consistent with theories about directionality of such relationships. Example monotonic mediation analyses are provided assessing linear and monotonic mediation of the effect of family functioning (X) on a child's adaptation (Y) to a chronic condition by the difficulty (M) for the family in managing the child's condition. Example moderated monotonic mediation and simulation analyses are also presented. Adaptive methods provide an effective way to incorporate possibly nonlinear monotonicity into mediation relationships.

Profile of High School Students’ Propositional Network Representation when Interpreting Convention Diagrams

NASA Astrophysics Data System (ADS)

Fatiha, M.; Rahmat, A.; Solihat, R.

2017-09-01

The delivery of concepts in studying Biology often represented through a diagram to easily makes student understand about Biology material. One way to knowing the students’ understanding about diagram can be seen from causal relationship that is constructed by student in the propositional network representation form. This research reveal the trend of students’ propositional network representation patterns when confronted with convention diagram. This descriptive research involved 32 students at one of senior high school in Bandung. The research data was acquired by worksheet that was filled by diagram and it was developed according on information processing standards. The result of this research revealed three propositional network representation patterns are linear relationship, simple reciprocal relationship, and complex reciprocal relationship. The dominating pattern is linear form that is simply connect some information components in diagram by 59,4% students, the reciprocal relationship form with medium level by 28,1% students while the complex reciprocal relationship by only 3,1% and the rest was students who failed to connect information components by 9,4%. Based on results, most of student only able to connect information components on the picture in linear form and a few student constructing reciprocal relationship between information components on convention diagram.

Relationship Between Timing of Multiple Retention Bonuses and the Quality of Officers Retained on the Cost Savings for the Navy

DTIC Science & Technology

2016-12-01

more years. At YOS 12, you expect to be an O- 4 . In 2016 dollars, you expect a monthly base pay of $7,081.50, meaning the minimum continuation pay...active duty for four more years. At YOS 12, you expect to be an O- 4 . In 2016 dollars, you expect a monthly base pay of $7,081.50, meaning the...blank) 2. REPORT DATE December 2016 3. REPORT TYPE AND DATES COVERED Master’s thesis 4 . TITLE AND SUBTITLE RELATIONSHIP BETWEEN TIMING OF MULTIPLE

The Effects of Impurities on Protein Crystal Growth and Nucleation: A Preliminary Study

NASA Technical Reports Server (NTRS)

Schall, Constance A.

1998-01-01

Kubota and Mullin (1995) devised a simple model to account for the effects of impurities on crystal growth of small inorganic and organic molecules in aqueous solutions. Experimentally, the relative step velocity and crystal growth of these molecules asymptotically approach zero or non-zero values with increasing concentrations of impurities. Alternatively, the step velocity and crystal growth can linearly approach zero as the impurity concentration increases. The Kubota-Mullin model assumes that the impurity exhibits Langmuirian adsorption onto the crystal surface. Decreases in step velocities and subsequent growth rates are related to the fractional coverage (theta) of the crystal surface by adsorbed impurities; theta = Kx / (I +Kx), x = mole fraction of impurity in solution. In the presence of impurities, the relative step velocity, V/Vo, and the relative growth rate of a crystal face, G/Go, are proposed to conform to the following equations: V/Vo approx. = G/Go = 1 - (alpha)(theta). The adsorption of impurity is assumed to be rapid and in quasi-equilibrium with the crystal surface sites available. When the value of alpha, an effectiveness factor, is one the growth will asymptotically approach zero with increasing concentrations of impurity. At values less than one, growth approaches a non-zero value asymptotically. When alpha is much greater than one, there will be a linear relationship between impurity concentration and growth rates. Kubota and Mullin expect alpha to decrease with increasing supersaturation and shrinking size of a two dimensional nucleus. It is expected that impurity effects on protein crystal growth will exhibit behavior similar to that of impurities in small molecule growth. A number of proteins were added to purified chicken egg white lysozyme, the effect on crystal nucleation and growth assessed.

Incorporating Psychological Predictors of Treatment Response into Health Economic Simulation Models: A Case Study in Type 1 Diabetes.

PubMed

Kruger, Jen; Pollard, Daniel; Basarir, Hasan; Thokala, Praveen; Cooke, Debbie; Clark, Marie; Bond, Rod; Heller, Simon; Brennan, Alan

2015-10-01

. Health economic modeling has paid limited attention to the effects that patients' psychological characteristics have on the effectiveness of treatments. This case study tests 1) the feasibility of incorporating psychological prediction models of treatment response within an economic model of type 1 diabetes, 2) the potential value of providing treatment to a subgroup of patients, and 3) the cost-effectiveness of providing treatment to a subgroup of responders defined using 5 different algorithms. . Multiple linear regressions were used to investigate relationships between patients' psychological characteristics and treatment effectiveness. Two psychological prediction models were integrated with a patient-level simulation model of type 1 diabetes. Expected value of individualized care analysis was undertaken. Five different algorithms were used to provide treatment to a subgroup of predicted responders. A cost-effectiveness analysis compared using the algorithms to providing treatment to all patients. . The psychological prediction models had low predictive power for treatment effectiveness. Expected value of individualized care results suggested that targeting education at responders could be of value. The cost-effectiveness analysis suggested, for all 5 algorithms, that providing structured education to a subgroup of predicted responders would not be cost-effective. . The psychological prediction models tested did not have sufficient predictive power to make targeting treatment cost-effective. The psychological prediction models are simple linear models of psychological behavior. Collection of data on additional covariates could potentially increase statistical power. . By collecting data on psychological variables before an intervention, we can construct predictive models of treatment response to interventions. These predictive models can be incorporated into health economic models to investigate more complex service delivery and reimbursement strategies. © The Author(s) 2015.

Mediating Effects of Global Negative Effect Expectancies on the Association between Problematic Cannabis Use and Social Anxiety.

PubMed

Di Blasi, Maria; Cavani, Paola; Pavia, Laura; Tosto, Crispino; La Grutta, Sabina; Lo Baido, Rosa; Giordano, Cecilia; Schimmenti, Adriano

2017-01-01

The relationship between social anxiety (SA) and cannabis use among adolescents and young adults is a highly debated topic. In this cross-sectional study, we tested whether cannabis use expectancies mediated the association between SA and cannabis use severity in a sample of 343 young adults (74.3% male) who used cannabis. They completed self-report measures for the screening of problematic cannabis use (Cannabis Use Problems Identification Test) and SA symptoms (Social Interaction Anxiety Scale and Social Phobia Scale). A multiple mediation analysis was used to test whether marijuana effect expectancies mediate SA effect on problematic cannabis use. SA was negatively associated with cannabis use severity in this sample, and we found evidence that cannabis use expectancies fully mediated this relationship. Specifically, global negative effect expectancies influence the relationship between SA and problematic cannabis use. These findings may inform current prevention strategies and clinical intervention for young adults who use cannabis.

Mediating Effects of Global Negative Effect Expectancies on the Association between Problematic Cannabis Use and Social Anxiety

PubMed Central

Di Blasi, Maria; Cavani, Paola; Pavia, Laura; Tosto, Crispino; La Grutta, Sabina; Lo Baido, Rosa; Giordano, Cecilia; Schimmenti, Adriano

2017-01-01

The relationship between social anxiety (SA) and cannabis use among adolescents and young adults is a highly debated topic. In this cross-sectional study, we tested whether cannabis use expectancies mediated the association between SA and cannabis use severity in a sample of 343 young adults (74.3% male) who used cannabis. They completed self-report measures for the screening of problematic cannabis use (Cannabis Use Problems Identification Test) and SA symptoms (Social Interaction Anxiety Scale and Social Phobia Scale). A multiple mediation analysis was used to test whether marijuana effect expectancies mediate SA effect on problematic cannabis use. SA was negatively associated with cannabis use severity in this sample, and we found evidence that cannabis use expectancies fully mediated this relationship. Specifically, global negative effect expectancies influence the relationship between SA and problematic cannabis use. These findings may inform current prevention strategies and clinical intervention for young adults who use cannabis. PMID:29213247

Reinvestigation of the relationship between the amplitude of the first heart sound to cardiac dynamics.

PubMed

Tang, Hong; Ruan, Chengjie; Qiu, Tianshuang; Park, Yongwan; Xiao, Shouzhong

2013-08-01

The relationships between the amplitude of the first heart sound (S1) and the rising rate of left ventricular pressure (LVP) concluded in previous studies were not consistent. Some researchers believed the relationship was positively linear; others stated the relationship was only positively correlated. To further investigate this relationship, this study simultaneously sampled the external phonocardiogram, electrocardiogram, and intracardiac pressure in the left ventricle in three anesthetized dogs, while invoking wide hemodynamic changes using various doses of epinephrine. The relationship between the maximum amplitude of S1 and the maximum rising rate of LVP and the relationship between the amplitude of dominant peaks/valleys and the corresponding rising rate of LVP were examined by linear, quadratic, cubic, and exponential models. The results showed that the relationships are best fit by nonlinear exponential models.

Predicting gambling problems from gambling outcome expectancies in college student-athletes.

PubMed

St-Pierre, Renée A; Temcheff, Caroline E; Gupta, Rina; Derevensky, Jeffrey; Paskus, Thomas S

2014-03-01

While previous research has suggested the potential importance of gambling outcome expectancies in determining gambling behaviour among adolescents, the predictive ability of gambling outcome expectancies has not yet been clearly delineated for college-aged youth. The current study aims to explore the relationships between gender and outcome expectancies in the prediction of gambling severity among college student-athletes. Data from the National Collegiate Athletic Association (NCAA) study assessing gambling behaviours and problems among U.S. college student-athletes were utilized. Complete data was available for 7,517 student-athletes. As expected, male college student-athletes reported more gambling participation as well as greater gambling problems than their female counterparts. Findings showed positive relationships between the outcome expectancies of financial gain, and negative emotional impacts and gambling problems. That is, those who endorsed more items on the outcome expectancy scales for financial gain and negative emotional impacts also tended to endorse more gambling-related problems. Findings also showed a negative relationship between outcome expectancies of fun and enjoyment, and gambling problems over and above the variance accounted for by gender. Those with gambling problems were less likely to have the expectation that gambling would be fun than those without gambling problems. Despite NCAA efforts to curb gambling activity, the results suggest that college student-athletes are at risk for over-involvement in gambling. Therefore, it is important to explore gambling outcome expectancies within this group since the motivations and reasons for gambling might be able to inform treatment initiatives.

An Investigation of the Relationship between Teachers' Expectations and Teachers' Perceptions of Student Attributes

ERIC Educational Resources Information Center

Timmermans, Anneke C.; de Boer, Hester; van der Werf, Margaretha P. C.

2016-01-01

Little is known about factors other than students' abilities and background variables that shape teachers' achievement expectations. This study was aimed at investigating the role of teachers' perceptions of students attributes (working habits, popularity, self-confidence, student--teacher relationships, and classroom behavior) in shaping…

Parental Educational Expectations and Their Impact on Student Outcomes. Project LONGSTEP Memorandum Report.

ERIC Educational Resources Information Center

Chalupsky, Albert B.; Coles, Gary J.

This report summarizes the results of an exploratory study of the relationship between parents' educational expectations for their children, the children's perceptions of these expectations, and student outcomes. Of particular interest were the congruence between parental expectations and the children's perceptions of these expectations and the…

Alexithymia and Mood: Recognition of Emotion in Self and Others.

PubMed

Lyvers, Michael; Kohlsdorf, Susan M; Edwards, Mark S; Thorberg, Fred Arne

2017-01-01

The present study explored relationships between alexithymia-a trait characterized by difficulties identifying and describing feelings and an external thinking style-and negative moods, negative mood regulation expectancies, facial recognition of emotions, emotional empathy, and alcohol consumption. The sample consisted of 102 university (primarily psychology) students (13 men, 89 women) aged 18 to 50 years (M = 22.18 years). Participants completed the Toronto Alexithymia Scale (TAS-20), Negative Mood Regulation Scale (NMRS), Depression Anxiety Stress Scales (DASS-21), Reading the Mind in the Eyes Test (RMET), Interpersonal Reactivity Index (IRI), and Alcohol Use Disorders Identification Test (AUDIT). Results were consistent with previous findings of positive relationships of TAS-20 alexithymia scores with both alcohol use (AUDIT) and negative moods (DASS-21) and a negative relationship with emotional self-regulation as indexed by NMRS. Predicted negative associations of both overall TAS-20 alexithymia scores and the externally oriented thinking (EOT) subscale of the TAS-20 with both RMET facial recognition of emotions and the empathic concern (EC) subscale of the IRI were supported. The mood self-regulation index NMRS fully mediated the relationship between alexithymia and negative moods. Hierarchical linear regressions revealed that, after other relevant variables were controlled for, the EOT subscale of the TAS-20 predicted RMET and EC. The concrete thinking or EDT facet of alexithymia thus appears to be associated with diminished facial recognition of emotions and reduced emotional empathy. The negative moods associated with alexithymia appear to be linked to subjective difficulties in self-regulation of emotions.

A morphometric comparison of the Namib and southwest Kalahari dunefields using ASTER GDEM data

NASA Astrophysics Data System (ADS)

White, Kevin; Bullard, Joanna; Livingstone, Ian; Moran, Lisa

2015-12-01

The increased availability of digital elevation models and satellite image data enable testing of morphometric relationships between sand dune variables (dune height, spacing and equivalent sand thickness), which were originally established using limited field survey data. These long-established geomorphological hypotheses can now be tested against very much larger samples than were possible when available data were limited to what could be collected by field surveys alone. This project uses ASTER global digital elevation model (GDEM) data to compare morphometric relationships between sand dune variables in the southwest Kalahari dunefield to those of the Namib sand sea, to test whether the relationships found in an active sand sea (Namib) also hold for the fixed dune system of the nearby southwest Kalahari. The data show significant morphometric differences between the simple linear dunes of the Namib sand sea and the southwest Kalahari; the latter do not show the expected positive relationship between dune height and spacing. The southwest Kalahari dunes show a similar range of dune spacings, but they are less tall, on average, than the Namib sand sea dunes. There is a clear spatial pattern to these morphometric data; the tallest and most closely spaced dunes are towards the southeast of the Kalahari dunefield; and this is where the highest values of equivalent sand thickness result. We consider the possible reasons for the observed differences and highlight the need for more studies comparing sand seas and dunefields from different environmental settings.

Duck gait: Relationship to hip angle, bone ash, bone density, and morphology.

PubMed

Robison, Cara I; Rice, Meredith; Makagon, Maja M; Karcher, Darrin M

2015-05-01

The rapid growth meat birds, including ducks, undergo requires skeletal integrity; however, fast growth may not be conducive to adequate bone structure. A relationship likely exists between skeletal changes and duck mobility. Reduced mobility in meat ducks may have impacts on welfare and production. This study examined the relationships among gait score, bone parameters, and hip angle. Commercial Pekin ducks, ages 14 d (n = 100), 21 d (n = 100), and 32 d (n = 100) were weighed and gait scored with a 3-point gait score system by an observer as they walked over a Tekscan gait analysis system. Gait was scored as GS0, GS1, or GS2 with a score of GS0 defined as good walking ability and a score of GS2 as poorest walking ability. Ducks were humanely euthanized, full body scanned using quantitative computed tomography (QCT), and the right femur and tibia were extracted. Leg bones were cleaned, measured, fat extracted, and ashed. QCT scans were rendered to create computerized 3D models where pelvic hip angles and bone density were measured. Statistical analysis was conducted using PROC MIXED with age and gait score in the model. Body weight increased with age, but within an age, body weight decreased as walking ability became worse (P < 0.01). As expected, linear increases in tibia and femur bone width and length were observed as the ducks aged (P < 0.01). Right and left hip angle increased with duck age (P < 0.01). Additionally, ducks with a GS2 had wider hip angles opposed to ducks with a GS0 (P < 0.01). Bone density increased linearly with both age and gait score (P < 0.05). Femur ash content was lowest in 32-day-old ducks and ducks with GS1 and GS2 (P < 0.0001). Tibia ash content increased with age, but decreased as gait score increased (P < 0.001). The observation that right hip angle changed with gait scores merits further investigation into the relationship between duck mobility and skeletal changes during growth. © 2015 Poultry Science Association Inc.

USE OF LINEAR FREE ENERGY RELATIONSHIPS AND AN EVALUATIVE MODEL TO ASSESS THE FATE AND TRANSPORT OF PHTHALATE ESTERS IN THE AQUATIC ENVIRONMENT

EPA Science Inventory

Linear free energy relationships for selected phthalate esters were used to estimate the rate constants for hydrolysis, biolysis, sediment-water partition coefficients, and biosorption required for modeling. The fate and transport behavior of dimethyl, diethyl, di-n-butyl, di-n-o...

The Effects of Multiple Linked Representations on Students' Learning of Linear Relationships

ERIC Educational Resources Information Center

Ozgun-Koca, S. Asli

2004-01-01

The focus of this study was on comparing three groups of Algebra I 9th-year students: one group using linked representation software, the second group using similar software but with semi-linked representations, and the control group in order to examine the effects on students' understanding of linear relationships. Data collection methods…

Relationships among Instructional Practices, Students' Motivational Beliefs and Science Achievement in Taiwan Using Hierarchical Linear Modelling

ERIC Educational Resources Information Center

Liou, Pey-Yan; Ho, Hsin-Ning Jessie

2018-01-01

The purpose of this study is to examine students' perceptions of instructional practices in the classroom, and to further investigate the relationships among instructional practices, motivational beliefs and science achievement. Hierarchical linear modelling was utilised to examine the Trends in International Mathematics and Science Study 2007…

The relationship between compressive strength and flexural strength of pavement geopolymer grouting material

NASA Astrophysics Data System (ADS)

Zhang, L.; Han, X. X.; Ge, J.; Wang, C. H.

2018-01-01

To determine the relationship between compressive strength and flexural strength of pavement geopolymer grouting material, 20 groups of geopolymer grouting materials were prepared, the compressive strength and flexural strength were determined by mechanical properties test. On the basis of excluding the abnormal values through boxplot, the results show that, the compressive strength test results were normal, but there were two mild outliers in 7days flexural strength test. The compressive strength and flexural strength were linearly fitted by SPSS, six regression models were obtained by linear fitting of compressive strength and flexural strength. The linear relationship between compressive strength and flexural strength can be better expressed by the cubic curve model, and the correlation coefficient was 0.842.

Accounting for the relationship between per diem cost and LOS when estimating hospitalization costs.

PubMed

Ishak, K Jack; Stolar, Marilyn; Hu, Ming-yi; Alvarez, Piedad; Wang, Yamei; Getsios, Denis; Williams, Gregory C

2012-12-01

Hospitalization costs in clinical trials are typically derived by multiplying the length of stay (LOS) by an average per-diem (PD) cost from external sources. This assumes that PD costs are independent of LOS. Resource utilization in early days of the stay is usually more intense, however, and thus, the PD cost for a short hospitalization may be higher than for longer stays. The shape of this relationship is unlikely to be linear, as PD costs would be expected to gradually plateau. This paper describes how to model the relationship between PD cost and LOS using flexible statistical modelling techniques. An example based on a clinical study of clevidipine for the treatment of peri-operative hypertension during hospitalizations for cardiac surgery is used to illustrate how inferences about cost-savings associated with good blood pressure (BP) control during the stay can be affected by the approach used to derive hospitalization costs.Data on the cost and LOS of hospitalizations for coronary artery bypass grafting (CABG) from the Massachusetts Acute Hospital Case Mix Database (the MA Case Mix Database) were analyzed to link LOS to PD cost, factoring in complications that may have occurred during the hospitalization or post-discharge. The shape of the relationship between LOS and PD costs in the MA Case Mix was explored graphically in a regression framework. A series of statistical models including those based on simple logarithmic transformation of LOS to more flexible models using LOcally wEighted Scatterplot Smoothing (LOESS) techniques were considered. A final model was selected, using simplicity and parsimony as guiding principles in addition traditional fit statistics (like Akaike's Information Criterion, or AIC). This mapping was applied in ECLIPSE to predict an LOS-specific PD cost, and then a total cost of hospitalization. These were then compared for patients who had good vs. poor peri-operative blood-pressure control. The MA Case Mix dataset included data from over 10,000 patients. Visual inspection of PD vs. LOS revealed a non-linear relationship. A logarithmic model and a series of LOESS and piecewise-linear models with varying connection points were tested. The logarithmic model was ultimately favoured for its fit and simplicity. Using this mapping in the ECLIPSE trials, we found that good peri-operative BP control was associated with a cost savings of $5,366 when costs were derived using the mapping, compared with savings of $7,666 obtained using the traditional approach of calculating the cost. PD costs vary systematically with LOS, with short stays being associated with high PD costs that drop gradually and level off. The shape of the relationship may differ in other settings. It is important to assess this and model the observed pattern, as this may have an impact on conclusions based on derived hospitalization costs.

Accounting for the relationship between per diem cost and LOS when estimating hospitalization costs

PubMed Central

2012-01-01

Background Hospitalization costs in clinical trials are typically derived by multiplying the length of stay (LOS) by an average per-diem (PD) cost from external sources. This assumes that PD costs are independent of LOS. Resource utilization in early days of the stay is usually more intense, however, and thus, the PD cost for a short hospitalization may be higher than for longer stays. The shape of this relationship is unlikely to be linear, as PD costs would be expected to gradually plateau. This paper describes how to model the relationship between PD cost and LOS using flexible statistical modelling techniques. Methods An example based on a clinical study of clevidipine for the treatment of peri-operative hypertension during hospitalizations for cardiac surgery is used to illustrate how inferences about cost-savings associated with good blood pressure (BP) control during the stay can be affected by the approach used to derive hospitalization costs. Data on the cost and LOS of hospitalizations for coronary artery bypass grafting (CABG) from the Massachusetts Acute Hospital Case Mix Database (the MA Case Mix Database) were analyzed to link LOS to PD cost, factoring in complications that may have occurred during the hospitalization or post-discharge. The shape of the relationship between LOS and PD costs in the MA Case Mix was explored graphically in a regression framework. A series of statistical models including those based on simple logarithmic transformation of LOS to more flexible models using LOcally wEighted Scatterplot Smoothing (LOESS) techniques were considered. A final model was selected, using simplicity and parsimony as guiding principles in addition traditional fit statistics (like Akaike’s Information Criterion, or AIC). This mapping was applied in ECLIPSE to predict an LOS-specific PD cost, and then a total cost of hospitalization. These were then compared for patients who had good vs. poor peri-operative blood-pressure control. Results The MA Case Mix dataset included data from over 10,000 patients. Visual inspection of PD vs. LOS revealed a non-linear relationship. A logarithmic model and a series of LOESS and piecewise-linear models with varying connection points were tested. The logarithmic model was ultimately favoured for its fit and simplicity. Using this mapping in the ECLIPSE trials, we found that good peri-operative BP control was associated with a cost savings of $5,366 when costs were derived using the mapping, compared with savings of $7,666 obtained using the traditional approach of calculating the cost. Conclusions PD costs vary systematically with LOS, with short stays being associated with high PD costs that drop gradually and level off. The shape of the relationship may differ in other settings. It is important to assess this and model the observed pattern, as this may have an impact on conclusions based on derived hospitalization costs. PMID:23198908

Low quality of life and depressive symptoms are connected with an unhealthy lifestyle.

PubMed

Savolainen, Jorma; Kautiainen, Hannu; Miettola, Juhani; Niskanen, Leo; Mäntyselkä, Pekka

2014-03-01

The Lapinlahti 2005 study was carried out to explore cardiovascular disease risk factors, lifestyle and quality of life in Lapinlahti residents in eastern Finland. Our aim was to study the association between lifestyle and health-related quality of life (HRQoL) in the community. The present study is based on the baseline data of the followed up (2005-2010) population-based cohort (N = 376, n of males = 184). A trained research nurse measured weight, height, waist circumference and blood pressure. Self-reported HRQoL was measured using a 15D questionnaire. A BDI-21 inventory was used to assess the presence of self-reported depressive symptoms. Lifestyle factors (nutrition, exercise, smoking and alcohol use) were examined with a structured questionnaire. Each lifestyle item was valued as -1, 0 or 1, depending on how well it corresponded to the recommendations. Based on the index the participants were divided into three lifestyle sum tertiles: I = unhealthy, II = neutral and III = healthy. The age- and sex-adjusted linear trend between the tertiles was tested. The 15D score had a positive linear relationship with the lifestyle tertiles (P = .0048 for linearity, age- and sex-adjusted). Respectively, self-reported depressive symptoms were less frequent among subjects with a healthier lifestyle (P = .038). People who are expected to strive most to change their lifestyle have the lowest quality of life and psychological welfare, which should be taken into account in both clinical work and health promotion.

Romantic Relationship Dynamics of Urban African American Adolescents: Patterns of Monogamy, Commitment, and Trust.

PubMed

Towner, Senna L; Dolcini, M Margaret; Harper, Gary W

2015-05-01

Relationship dynamics develop early in life and are influenced by social environments. STI/HIV prevention programs need to consider romantic relationship dynamics that contribute to sexual health. The aim of this study was to examine monogamous patterns, commitment, and trust in African American adolescent romantic relationships. The authors also focused on the differences in these dynamics between and within gender. The way that such dynamics interplay in romantic relationships has the potential to influence STI/HIV acquisition risk. In-depth interviews were conducted with 28 African American adolescents aged 14 to 21 living in San Francisco. Our results discuss data related to monogamous behaviors, expectations, and values; trust and respect in romantic relationships; commitment to romantic relationships; and outcomes of mismatched relationship expectations. Incorporating gender-specific romantic relationships dynamics can enhance the effectiveness of prevention programs.

Determination of soil–water sorption coefficients of volatile methylsiloxanes

PubMed Central

Kozerski, Gary E; Xu, Shihe; Miller, Julie; Durham, Jeremy

2014-01-01

The sorption behaviors of 4 cyclic and linear volatile methyl siloxane (VMS) compounds between water and organic matter in 3 United Kingdom soils were studied by a batch equilibrium method using13C-enriched sorbates. Sorption and desorption kinetics and isotherms were determined for octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), octamethyltrisiloxane (L3), and decamethyltetrasiloxane (L4). Concentrations of [13C]-VMS in the soil and aqueous phases were measured directly by extraction and gas chromatography–mass spectrometry techniques. All VMS compounds were sorbed rapidly, reaching constant distributions in all soils by 24 h. Desorption kinetics were very rapid, with reattainment of equilibrium within 1 h. In the main, linear isotherms were observed for aqueous concentrations at or below 4% of the solubility limits. The average sorption organic carbon partition coefficient (log KOC) values across soils were 4.23 for D4, 5.17 for D5, 4.32 for L3, and 5.13 for L4, with standard deviations of 0.09 to 0.34. Desorption KOC values were systematically greater by 0.1 log units to 0.3 log units. The linear isotherms and low variation in KOC values across soils suggested partitioning-dominated sorption of the VMS. Compared with traditional hydrophobic organic compounds, KOC values for the VMS compounds were significantly lower than expected on the basis of their octanol–water partition coefficients. A linear free energy relationship analysis showed that these differences could be rationalized quantitatively in terms of the inherent characteristics of the VMS compounds, combined with the differences in solvation properties of organic matter and octanol. Environ Toxicol Chem 2014; 33:1937–1945. PMID:24862578

The risk equivalent of an exposure to-, versus a dose of radiation

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

Bond, V.P.

The long-term potential carcinogenic effects of low-level exposure (LLE) are addressed. The principal point discussed is linear, no-threshold dose-response curve. That the linear no-threshold, or proportional relationship is widely used is seen in the way in which the values for cancer risk coefficients are expressed - in terms of new cases, per million persons exposed, per year, per unit exposure or dose. This implies that the underlying relationship is proportional, i.e., ''linear, without threshold''. 12 refs., 9 figs., 1 tab.

Optimistic expectations in early marriage: a resource or vulnerability for adaptive relationship functioning?

PubMed

Neff, Lisa A; Geers, Andrew L

2013-07-01

Do optimistic expectations facilitate or hinder adaptive responses to relationship challenges? Traditionally, optimism has been characterized as a resource that encourages positive coping efforts within relationships. Yet, some work suggests optimism can be a liability, as expecting the best may prevent individuals from taking proactive steps when confronted with difficulties. To reconcile these perspectives, the current article argues that greater attention must be given to the way in which optimistic expectancies are conceptualized. Whereas generalized dispositional optimism may predict constructive responses to relationship difficulties, more focused relationship-specific forms of optimism may predict poor coping responses. A multi-method, longitudinal study of newly married couples confirmed that spouses higher in dispositional optimism (a) reported engaging in more positive problem-solving behaviors on days in which they experienced greater relationship conflict, (b) were observed to display more constructive problem-solving behaviors when discussing important marital issues with their partner in the lab, and (c) experienced fewer declines in marital well-being over the 1st year of marriage. Conversely, spouses higher in relationship-specific optimism (a) reported engaging in fewer constructive problem-solving behaviors on high conflict days, (b) were observed to exhibit worse problem-solving behaviors in the lab-particularly when discussing marital issues of greater importance-and (c) experienced steeper declines in marital well-being over time. All findings held controlling for self-esteem and neuroticism. Together, results suggest that whereas global forms of optimism may represent a relationship asset, specific forms of optimism can place couples at risk for marital deterioration. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear?

PubMed

Ye, Jian-Sheng; Pei, Jiu-Ying; Fang, Chao

2018-03-01

Understanding under which climate and soil conditions the plant productivity-precipitation relationship is linear or nonlinear is useful for accurately predicting the response of ecosystem function to global environmental change. Using long-term (2000-2016) net primary productivity (NPP)-precipitation datasets derived from satellite observations, we identify >5600pixels in the North Hemisphere landmass that fit either linear or nonlinear temporal NPP-precipitation relationships. Differences in climate (precipitation, radiation, ratio of actual to potential evapotranspiration, temperature) and soil factors (nitrogen, phosphorous, organic carbon, field capacity) between the linear and nonlinear types are evaluated. Our analysis shows that both linear and nonlinear types exhibit similar interannual precipitation variabilities and occurrences of extreme precipitation. Permutational multivariate analysis of variance suggests that linear and nonlinear types differ significantly regarding to radiation, ratio of actual to potential evapotranspiration, and soil factors. The nonlinear type possesses lower radiation and/or less soil nutrients than the linear type, thereby suggesting that nonlinear type features higher degree of limitation from resources other than precipitation. This study suggests several factors limiting the responses of plant productivity to changes in precipitation, thus causing nonlinear NPP-precipitation pattern. Precipitation manipulation and modeling experiments should combine with changes in other climate and soil factors to better predict the response of plant productivity under future climate. Copyright © 2017 Elsevier B.V. All rights reserved.

Inferring frail life expectancies in Chicago from daily fluctuations in elderly mortality.

PubMed

Murray, Christian J; Lipfert, Frederick W

2013-07-01

Susceptible sub-populations with existing disease have exhibited stronger relationships between air quality and mortality in time-series studies, but their associated life expectancies have largely been overlooked. Murray and Nelson developed a new time-series model that estimated a small unobserved (frail) sub-population and their resulting life expectancies in Philadelphia, including environment relationships. As a further example in a different geographic area, we used this model with 1987-2000 daily mortality data in Chicago and found a stable frail population at risk of ∼900 persons with a mean life expectancy of ∼11 days; fewer than two daily deaths were associated with air pollution. We considered daily concentrations of CO, NO₂, O₃, PM₁₀ and SO₂, and found PM₁₀ and O₃ to have stronger associations with frail mortality. Our estimates of life expectancy and air pollution and temperature relationships are similar to those found in other studies that used different methods. Temperature was more important than air pollution during the 1995 heat wave, when mortality risks increased dramatically after 2 d exposure and life expectancies decreased to 3-5 d. Modeling this event separately had substantial effects on lagged mortality--air pollution relationships and the population at risk. The premises of the Murray-Nelson model were supported by simultaneously considering an additional subgroup of non-frail individuals; they contributed only ∼1% of total elderly deaths. We conclude that frail life expectancies estimated by the Murray-Nelson model are robust, and that under these conditions non-frail persons have little risk of acute mortality, with or without contributions from air pollution.

Relationships between Treatment Expectations and Treatment Outcomes among Outpatients with Substance Use Problems

ERIC Educational Resources Information Center

Raylu, Namrata; Kaur, Inderjit

2012-01-01

Currently, studies exploring the relationship between treatment expectations (TE) and outcome among individuals with substance use problems are significantly lacking. This is important as relapse and attrition rates among this group are greater than those with other psychological problems. Understanding how TE impact treatment outcomes among this…

Parental Romantic Expectations and Parent-Child Sexuality Communication in Autism Spectrum Disorders

ERIC Educational Resources Information Center

Holmes, Laura G.; Himle, Michael B.; Strassberg, Donald S.

2016-01-01

This study examined the relationship between core symptoms of autism spectrum disorder, parental romantic expectations, and parental provision of sexuality and relationship education in an online sample of 190 parents of youth 12-18 years of age with a parent-reported diagnosis of autism spectrum disorder. Regression analyses were conducted…

Community College Vice Presidents for Institutional Advancement: Role Expectations, Fundraising Responsibilities, Professional Relationships, and Commitment to the Institution

ERIC Educational Resources Information Center

Ciampa, Donna Lynn

2009-01-01

This study examined how the role expectations, responsibilities toward fundraising, and professional relationships by the vice president of institutional advancement influenced commitment to the institution. A qualitative analysis was conducted across the mid-Atlantic region by interviewing community college vice presidents of institutional…

Testing the Relationship of Gender and Business Major to Professional Development Behaviors and Expected Employment

ERIC Educational Resources Information Center

Blau, Gary; Hill, Theodore L.; Snell, Corinne; Atwater, Craig; Halbert, Terry; Zuckerman, M. Michael

2016-01-01

This study's results, with 664 surveyed graduating business students, demonstrated that creating four groups, using gender and quantitative or nonquantitative major, was useful for testing their relationships to professional development behaviors and expected employment. Results showed that male-nonquantitative majors (n = 144) reported the lowest…

Developmental Differences in Recall and Recognition: The Relationship between Rehearsal and Memory as Test Expectation Changes

ERIC Educational Resources Information Center

Naus, Mary J.; And Others

1977-01-01

An overt rehearsal procedure was used to study the relationship between 48 third- and 48 sixth-grade children's rehearsal strategies and their memory performance under difficult conditions of test expectation. This study addressed the question of why active rehearsal content results in superior recall performances. (MS)

Emerging adults' expectations for pornography use in the context of future committed romantic relationships: a qualitative study.

PubMed

Olmstead, Spencer B; Negash, Sesen; Pasley, Kay; Fincham, Frank D

2013-05-01

Using qualitative content analysis from the written comments of 404 primarily heterosexual college students, we examined (1) their expectations for pornography use while married or in a committed long-term relationship and (2) variations by gender. Four prominent groups emerged. A majority of men (70.8 %) and almost half of women (45.5 %) reported circumstances (alone or with their partners) wherein pornography use was acceptable in a relationship and several conditions for, and consequences associated with, such use also emerged. Another group (22.3 % men; 26.2 % women) viewed pornography use as unacceptable because of being in a committed relationship whereas a third group (5.4 % men; 12.9 % women) reported that pornography use was unacceptable in any context or circumstance. A final group emerged of a few women (10.4 %) who stated that a partner's use of pornography was acceptable, but they did not expect to use it personally. Implications for relationship education among emerging adults and future research on pornography use within the context of romantic relationships are discussed.

Change-related expectations and commitment to change of nurses: the role of leadership and communication.

PubMed

Portoghese, Igor; Galletta, Maura; Battistelli, Adalgisa; Saiani, Luisa; Penna, Maria Pietronilla; Allegrini, Elisabetta

2012-07-01

The purpose of this study was to test a theoretical model linking the impact of expectations on commitment to change and to explore whether change-related communication is a mediating variable between leader-member exchange and expectations. Expectations for change outcomes are an important condition to increase nurses' commitment to change. To understand the role of leadership and communication in expectations development is crucial to promote commitment to change. A predictive, non-experimental design was used in a random sample of 395 nurses. Structural equation modelling was used to analyse the hypothesized model. Positive expectations had a direct effect on affective commitment to change, whereas negative expectation had a direct effect on continuance commitment to change. Leader-member exchange and communication influenced nurse's expectations about change. Communication partially mediated the relationship between Leader-member exchange and expectations. These findings suggested that nurses' expectation about change were strongly linked to commitment to change. Furthermore, the enhancement of communication and relationship with leader contributed to the development of positive and negative expectations. Strategies to promote commitment to change include developing positive expectations about change outcomes and building high-quality leadership style oriented to the communication. © 2011 Blackwell Publishing Ltd.

Reliability of the Load-Velocity Relationship Obtained Through Linear and Polynomial Regression Models to Predict the One-Repetition Maximum Load.

PubMed

Pestaña-Melero, Francisco Luis; Haff, G Gregory; Rojas, Francisco Javier; Pérez-Castilla, Alejandro; García-Ramos, Amador

2017-12-18

This study aimed to compare the between-session reliability of the load-velocity relationship between (1) linear vs. polynomial regression models, (2) concentric-only vs. eccentric-concentric bench press variants, as well as (3) the within-participants vs. the between-participants variability of the velocity attained at each percentage of the one-repetition maximum (%1RM). The load-velocity relationship of 30 men (age: 21.2±3.8 y; height: 1.78±0.07 m, body mass: 72.3±7.3 kg; bench press 1RM: 78.8±13.2 kg) were evaluated by means of linear and polynomial regression models in the concentric-only and eccentric-concentric bench press variants in a Smith Machine. Two sessions were performed with each bench press variant. The main findings were: (1) first-order-polynomials (CV: 4.39%-4.70%) provided the load-velocity relationship with higher reliability than second-order-polynomials (CV: 4.68%-5.04%); (2) the reliability of the load-velocity relationship did not differ between the concentric-only and eccentric-concentric bench press variants; (3) the within-participants variability of the velocity attained at each %1RM was markedly lower than the between-participants variability. Taken together, these results highlight that, regardless of the bench press variant considered, the individual determination of the load-velocity relationship by a linear regression model could be recommended to monitor and prescribe the relative load in the Smith machine bench press exercise.

The relationship between health and GDP in OECD countries in the very long run.

PubMed

Swift, Robyn

2011-03-01

This paper uses Johansen multivariate cointegration analysis to examine the relationship between health and GDP for 13 OECD countries over the last two centuries, for periods ranging from 1820-2001 to 1921-2001. A similar, long run, cointegrating relationship between life expectancy and both total GDP and GDP per capita was found for all the countries estimated. The relationships have a significant influence on both total GDP and GPD per capita in most of the countries estimated, with 1% increase in life expectancy resulting in an average 6% increase in total GDP in the long run, and 5% increase in GDP per capita. Total GDP and GDP per capita also have a significant influence on life expectancy for most countries. There is no evidence of changes in the relationships for any country over the periods estimated, indicating that shifts in the major causes of illness and death over time do not appear to have influenced the link between health and economic growth. Copyright © 2010 John Wiley & Sons, Ltd.

Friendship Expectations and Children's Friendship-Related Behavior and Adjustment

ERIC Educational Resources Information Center

MacEvoy, Julie Paquette; Papadakis, Alison A.; Fedigan, Shea K.; Ash, Sarah E.

2016-01-01

Although relationship expectations are thought to influence all social interactions, little is known about the function of children's friendship expectations. This study examined the associations among children's friendship expectations and their behavior within their friendships, their friendship adjustment, and their socioemotional functioning.…

Quantifying the influence of ambient temperature on dairy and beef cattle mortality in France from a time-series analysis.

PubMed

Morignat, Eric; Gay, Emilie; Vinard, Jean-Luc; Calavas, Didier; Hénaux, Viviane

2015-07-01

In the context of climate change, the frequency and severity of extreme weather events are expected to increase in temperate regions, and potentially have a severe impact on farmed cattle through production losses or deaths. In this study, we used distributed lag non-linear models to describe and quantify the relationship between a temperature-humidity index (THI) and cattle mortality in 12 areas in France. THI incorporates the effects of both temperature and relative humidity and was already used to quantify the degree of heat stress on dairy cattle because it does reflect physical stress deriving from extreme conditions better than air temperature alone. Relationships between daily THI and mortality were modeled separately for dairy and beef cattle during the 2003-2006 period. Our general approach was to first determine the shape of the THI-mortality relationship in each area by modeling THI with natural cubic splines. We then modeled each relationship assuming a three-piecewise linear function, to estimate the critical cold and heat THI thresholds, for each area, delimiting the thermoneutral zone (i.e. where the risk of death is at its minimum), and the cold and heat effects below and above these thresholds, respectively. Area-specific estimates of the cold or heat effects were then combined in a hierarchical Bayesian model to compute the pooled effects of THI increase or decrease on dairy and beef cattle mortality. A U-shaped relationship, indicating a mortality increase below the cold threshold and above the heat threshold was found in most of the study areas for dairy and beef cattle. The pooled estimate of the mortality risk associated with a 1°C decrease in THI below the cold threshold was 5.0% for dairy cattle [95% posterior interval: 4.4, 5.5] and 4.4% for beef cattle [2.0, 6.5]. The pooled mortality risk associated with a 1°C increase above the hot threshold was estimated to be 5.6% [5.0, 6.2] for dairy and 4.6% [0.9, 8.7] for beef cattle. Knowing the thermoneutral zone and temperature effects outside this zone is of primary interest for farmers because it can help determine when to implement appropriate preventive and mitigation measures. Copyright © 2015 Elsevier Inc. All rights reserved.

Relationships between trait urgency, smoking reinforcement expectancies, and nicotine dependence

PubMed Central

Pang, Raina D.; Hom, Marianne S.; Geary, Bree A.; Doran, Neal; Spillane, Nichea S.; Guillot, Casey R.; Leventhal, Adam M.

2014-01-01

Urgency (i.e. the tendency to act rashly during negative/positive affect) may increase vulnerability to a variety of risky behaviors. This cross-sectional study of non-treatment-seeking smokers examined the relationship between urgency, level of nicotine dependence, and smoking reinforcement expectancies. Both positive and negative urgency were associated with nicotine dependence. Mediational analyses illustrated that smoking reinforcement expectancies significantly accounted for urgency-dependence relations, with negative reinforcement expectancies displaying incremental mediational effects. If replicated and extended, these findings may support the use of treatments that modify beliefs regarding smoking reinforcement outcomes as a means of buffering the risk of nicotine dependence carried by urgency. PMID:24784229

Identifying and Aligning Expectations in a Mentoring Relationship

PubMed Central

Huskins, W. Charles; Silet, Karin; Weber‐Main, Anne Marie; Begg, Melissa D.; Fowler, Jr, Vance G.; Hamilton, John; Fleming, Michael

2011-01-01

Abstract The mentoring relationship between a scholar and their primary mentor is a core feature of research training. Anecdotal evidence suggests this relationship is adversely affected when scholar and mentor expectations are not aligned. We examined three questions: (1) What is the value in assuring that the expectations of scholars and mentors are mutually identified and aligned? (2) What types of programmatic interventions facilitate this process? (3) What types of expectations are important to identify and align? We addressed these questions through a systematic literature review, focus group interviews of mentors and scholars, a survey of Clinical and Translational Science Award (CTSA) KL2 program directors, and review of formal programmatic mechanisms used by KL2 programs. We found broad support for the importance of identifying and aligning the expectations of scholars and mentors and evidence that mentoring contracts, agreements, and training programs facilitate this process. These tools focus on aligning expectations with respect to the scholar’s research, education, professional development and career advancement as well as support, communication, and personal conduct and interpersonal relations. Research is needed to assess test the efficacy of formal alignment activities. Clin Trans Sci 2011; Volume 4: 439–447 PMID:22212226

State-variable analysis of non-linear circuits with a desk computer

NASA Technical Reports Server (NTRS)

Cohen, E.

1981-01-01

State variable analysis was used to analyze the transient performance of non-linear circuits on a desk top computer. The non-linearities considered were not restricted to any circuit element. All that is required for analysis is the relationship defining each non-linearity be known in terms of points on a curve.

Using nonlinear quantile regression to estimate the self-thinning boundary curve

Treesearch

Quang V. Cao; Thomas J. Dean

2015-01-01

The relationship between tree size (quadratic mean diameter) and tree density (number of trees per unit area) has been a topic of research and discussion for many decades. Starting with Reineke in 1933, the maximum size-density relationship, on a log-log scale, has been assumed to be linear. Several techniques, including linear quantile regression, have been employed...

Comparing Linear Relationships between E-Book Usage and University Student and Faculty Populations: The Differences between E-Reference and E-Monograph Collections

ERIC Educational Resources Information Center

Lamothe, Alain R.

2013-01-01

This paper reports the results from a quantitative study examining the strength of linear relationships between Laurentian University students and faculty members and the J. N. Desmarais Library's reference and monograph e-book collections. The number of full-text items accessed, searches performed, and undergraduate, graduate, and faculty…

Comparing childhood meal frequency to current meal frequency, routines, and expectations among parents.

PubMed

Friend, Sarah; Fulkerson, Jayne A; Neumark-Sztainer, Dianne; Garwick, Ann; Flattum, Colleen Freeh; Draxten, Michelle

2015-02-01

Little is known about the continuation of family meals from childhood to parenthood. This study aims to examine associations between parents' report of eating family meals while growing up and their current family meal frequency, routines, and expectations. Baseline data were used from the Healthy Home Offerings via the Mealtime Environment (HOME) Plus study, a randomized controlled trial with a program to promote healthful behaviors and family meals at home. Participants (160 parent/child dyads) completed data collection in 2011-2012 in the Minneapolis/St. Paul, MN metropolitan area. Parents were predominately female (95%) and white (77%) with a mean age of 41.3 years. General linear modeling examined relationships between parents' report of how often they ate family meals while growing up and their current family meal frequency, routines, and expectations as parents, controlling for parent age, education level, and race. Parental report of eating frequent family meals while growing up was positively and significantly associated with age, education, and self-identification as white (all p < .05). Compared to those who ate family meals less than three times/week or four to five times/week, parents who ate six to seven family meals/week while growing up reported significantly more frequent family meals with their current family (4.0, 4.2 vs. 5.3 family meals/week, p = .001). Eating frequent family meals while growing up was also significantly and positively associated with having current regular meal routines and meal expectations about family members eating together (both p < .05). Promoting family meals with children may have long-term benefits over generations. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Positive Outcome Expectancy Mediates the Relationship Between Peer Influence and Internet Gaming Addiction Among Adolescents in Taiwan.

PubMed

Wu, Jo Yung Wei; Ko, Huei-Chen; Wong, Tsui-Yin; Wu, Li-An; Oei, Tian Po

2016-01-01

The present study examined the role of positive outcome expectancy in the relationship between peer/parental influence and Internet gaming addiction (IGA) among adolescents in Taiwan. Two thousand, one hundred and four junior high students completed the Chen Internet Addiction Scale for IGA, Parental Influence for IGA, peer influence for IGA, and Positive Outcome Expectancy of Internet Gaming Questionnaire. Results showed that the three types of peer influences (positive attitudes toward Internet gaming, frequency of Internet game use, and invitation to play) and positive outcome expectancy were significantly and positively correlated with IGA. Moreover, peer influence was also positively correlated with positive outcome expectancy. On the other hand, positive outcome expectancy and parental influences had a low correlation. Structural equation modeling analysis revealed that positive outcome expectancy did not mediate the relationship between either type of parental influences and IGA, and only the parent's invitation to play Internet games directly predicted IGA severity. However, peers' positive attitude or the frequency of peers' Internet game use positively predicted IGA and was fully mediated through positive outcome expectancy of Internet gaming. In addition, the frequency of peers' invitation to play Internet games directly and indirectly predicted IGA severity through a partial mediation of positive outcome expectancy of Internet gaming. The overall fit of the model was adequate and was able to explain 25.0 percent of the variance. The findings provide evidence in illuminating the role of peer influences and positive outcome expectancy of Internet gaming in the process of why adolescents may develop IGA.

Met expectations and the wellbeing of diaspora immigrants: a longitudinal study.

PubMed

Mähönen, Tuuli Anna; Leinonen, Elina; Jasinskaja-Lahti, Inga

2013-01-01

Previous research has pointed to the importance of expectations for the adaptation of immigrants. However, most studies have been methodologically retrospective with only limited possibilities to show the optimal relationship between migrants' expectations and actual acculturation experiences for their wellbeing and other aspects of psychological adaptation. Moreover, previous research has been conducted mostly among sojourners and students. This longitudinal study focused on the relationship between premigration expectations and postmigration experiences of diaspora immigrants from Russia to Finland (N = 153). We examined how the fulfillment of premigration expectations in social (i.e., family relations, friendships, and free time) and economic (i.e., occupational position, working conditions, and economic and career situation) domains affects immigrants' wellbeing (i.e., satisfaction with life and general mood) after migration. Three alternative models of expectation confirmation (i.e., disconfirmation model, ideal point model, and the importance of experiences only) derived from previous organizational psychological research were tested with polynomial regression and response surface analysis. In the economic domain, immigrants' expectations, experiences, and their interrelationship did not affect wellbeing in the postmigration stage. However, in the social domain, the more expectations were exceeded by actual experiences, the better were life satisfaction and the general mood of immigrants. The results underline the importance of social relationships and the context-dependent nature of immigrants' wellbeing. Interventions in the preacculturation stage should create positive but realistic expectations for diaspora immigrants and other groups of voluntary (re)migrants. Furthermore, policies concerning the postmigration stage should facilitate the fulfillment of these expectations and support the social adaptation of immigrants.

Expectancies mediate the relationship between perceived injustice and return to work following whiplash injury: A 1-year prospective study.

PubMed

Carriere, J S; Thibault, P; Adams, H; Milioto, M; Ditto, B; Sullivan, M J L

2017-08-01

Emerging evidence suggests that perceived injustice is a risk factor for work disability in individuals with whiplash injury. At present, however, little is known about the processes by which perceived injustice impacts on return to work. The purpose of this study was to examine whether expectancies mediated the relationship between perceived injustice and return to work in patients with whiplash injury. One hundred and fifty-two individuals (81 men, 71 women) with a primary diagnosis of whiplash injury completed self-report measures of pain intensity, perceived injustice and return-to-work expectancies following admission to a rehabilitation programme. Work status was assessed 1 year after discharge. Consistent with previous research, high scores on a measure of perceived injustice were associated with prolonged work disability. Results indicated that high perceptions of injustice were associated with low return-to-work expectancies. Causal mediation analyses revealed that expectancies fully mediated the relationship between perceived injustice and return to work. The findings suggest that intervention techniques designed to target expectancies could improve return-to-work outcomes in patients with whiplash injury. Discussion addresses the processes by which expectancies might impact on return-to-work outcomes and the manner in which negative return-to-work expectancies might be modified through intervention. The study confirms that expectancies are the mechanism through which perceived injustice impacts return to work following whiplash injury. The findings suggest that interventions designed to specifically target return-to-work expectancies might improve rehabilitation outcomes in patients with whiplash injury. © 2017 European Pain Federation - EFIC®.

An investigation to improve the Menhaden fishery prediction and detection model through the application of ERTS-A data

NASA Technical Reports Server (NTRS)

Maughan, P. M. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Linear regression of secchi disc visibility against number of sets yielded significant results in a number of instances. The variability seen in the slope of the regression lines is due to the nonuniformity of sample size. The longer the period sampled, the larger the total number of attempts. Further, there is no reason to expect either the influence of transparency or of other variables to remain constant throughout the season. However, the fact that the data for the entire season, variable as it is, was significant at the 5% level, suggests its potential utility for predictive modeling. Thus, this regression equation will be considered representative and will be utilized for the first numerical model. Secchi disc visibility was also regressed against number of sets for the three day period September 27-September 29, 1972 to determine if surface truth data supported the intense relationship between ERTS-1 identified turbidity and fishing effort previously discussed. A very negative correlation was found. These relationship lend additional credence to the hypothesis that ERTS imagery, when utilized as a source of visibility (turbidity) data, may be useful as a predictive tool.

Patient-Reported Disease-Modifying Therapy Adherence in the Clinic: A Reliable Metric?

PubMed

Conway, Devon S; Cecilia Vieira, Maria; Thompson, Nicolas R; Parker, Kaila N; Meng, Xiangyi; Fox, Robert J

2018-01-01

Adherence to multiple sclerosis (MS) disease-modifying therapy (DMT) is commonly assessed through patient reporting, but patient-reported adherence is rarely studied. To determine rates of DMT adherence reported from patient to clinician, reasons for nonadherence, and relationships between adherence and outcomes. We identified relapsing-remitting MS patients on DMT for ≥3 months. DMT adherence was defined as taking ≥80% of doses. Linear and logistic regression models were created used to determine the association of baseline adherence with several patient reported outcomes and the timed 25-foot walk at 6 months, 1 year, 2 years, and 3 years after the index visit. The analysis included 1148 patients, of whom 501 had data at 6 months, 544 at 1 year, 331 at 2 years, and 247 at 3 years. Baseline adherence was 94.9% and overall adherence was 93.1%. Forgetting was the most common reason for missed doses. In the adjusted models, adherence was not associated with the outcomes. Higher than expected adherence and a lack of association between adherence and outcomes suggests patient reported adherence may not be reliable. Further research is needed to clarify the relationship between patient-reported adherence and relapses or new lesion formation.

Maximizing phylogenetic diversity in biodiversity conservation: Greedy solutions to the Noah's Ark problem.

PubMed

Hartmann, Klaas; Steel, Mike

2006-08-01

The Noah's Ark Problem (NAP) is a comprehensive cost-effectiveness methodology for biodiversity conservation that was introduced by Weitzman (1998) and utilizes the phylogenetic tree containing the taxa of interest to assess biodiversity. Given a set of taxa, each of which has a particular survival probability that can be increased at some cost, the NAP seeks to allocate limited funds to conserving these taxa so that the future expected biodiversity is maximized. Finding optimal solutions using this framework is a computationally difficult problem to which a simple and efficient "greedy" algorithm has been proposed in the literature and applied to conservation problems. We show that, although algorithms of this type cannot produce optimal solutions for the general NAP, there are two restricted scenarios of the NAP for which a greedy algorithm is guaranteed to produce optimal solutions. The first scenario requires the taxa to have equal conservation cost; the second scenario requires an ultrametric tree. The NAP assumes a linear relationship between the funding allocated to conservation of a taxon and the increased survival probability of that taxon. This relationship is briefly investigated and one variation is suggested that can also be solved using a greedy algorithm.

Does neighborhood social capital buffer the effects of maternal depression on adolescent behavior problems?

PubMed

Delany-Brumsey, Ayesha; Mays, Vickie M; Cochran, Susan D

2014-06-01

Neighborhood characteristics have been shown to impact child well-being. However, it remains unclear how these factors combine with family characteristics to influence child development. The current study helps develop that understanding by investigating how neighborhoods directly impact child and adolescent behavior problems as well as moderate the influence of family characteristics on behavior. Using multilevel linear models, we examined the relationship among neighborhood conditions (poverty and social capital) and maternal depression on child and adolescent behavior problems. The sample included 741 children, age 5–11, and 564 adolescents, age 12–17. Outcomes were internalizing (e.g. anxious/depressed) and externalizing (e.g. aggressive/hyperactive) behavior problems. Neighborhood poverty and maternal depression were both positively associated with behavior problems for children and adolescents. However, while neighborhood social capital was not directly associated with behavior problems, the interaction of social capital and maternal depression was significantly related to behavior problems for adolescents. This interaction showed that living in neighborhoods with higher levels of social capital attenuated the relationship between maternal depression and adolescent behavior problems and confirmed the expectation that raising healthy well-adjusted children depends not only on the family, but also the context in which the family lives.

Linear Mode HgCdTe Avalanche Photodiodes for Photon Counting Applications

NASA Technical Reports Server (NTRS)

Sullivan, William, III; Beck, Jeffrey; Scritchfield, Richard; Skokan, Mark; Mitra, Pradip; Sun, Xiaoli; Abshire, James; Carpenter, Darren; Lane, Barry

2015-01-01

An overview of recent improvements in the understanding and maturity of linear mode photon counting with HgCdTe electron-initiated avalanche photodiodes is presented. The first HgCdTe LMPC 2x8 format array fabricated in 2011 with 64 micron pitch was a remarkable success in terms of demonstrating a high single photon signal to noise ratio of 13.7 with an excess noise factor of 1.3-1.4, a 7 ns minimum time between events, and a broad spectral response extending from 0.4 micron to 4.2 micron. The main limitations were a greater than 10x higher false event rate than expected of greater than 1 MHz, a 5-7x lower than expected APD gain, and a photon detection efficiency of only 50% when greater than 60% was expected. This paper discusses the reasons behind these limitations and the implementation of their mitigations with new results.

Farmers' knowledge and expectations of antimicrobial use and resistance are strongly related to usage in Dutch livestock sectors.

PubMed

Kramer, Tineke; Jansen, Leonie E; Lipman, Len J A; Smit, Lidwien A M; Heederik, Dick J J; Dorado-García, Alejandro

2017-11-01

Comprehensive strategies to improve on-farm antimicrobial use (AMU) are needed to contain antimicrobial resistance (AMR). Little is known about farmers' motivating and enabling factors, and about their influence on AMU. In a cross-sectional online survey, Dutch dairy, veal and pig farmers (n=457) reported their on-farm AMU as "Defined Daily Dose Animal" per year (DDDA F ) and completed a detailed questionnaire on their view, knowledge and behavior towards AMU and AMR. Exploratory factor analysis (EFA) on the questionnaire items identified four psychological factors labeled as 'referent beliefs', 'perceived risk', 'knowledge', and 'undesired attitude to regulations'. Linear regression was done to explore the relationship between the obtained factors and on-farm AMU across the three animal sectors. Dairy farmers showed the highest factor scores for 'knowledge' and the lowest for 'perceived risk'. 'Knowledge' scores were significantly and inversely related to AMU (P=0.0004). Borderline significant associations with AMU were found for 'perceived risk' and 'undesired attitude to regulations' (negative and positive relationships respectively). There were no apparent differences for these relationships between the three livestock sectors. Behavioral interventions in farmers such as educational campaigns or increased support by veterinarians could empower farmers with more prudent and rational practices, eventually reducing AMU in food animals. Copyright © 2017 Elsevier B.V. All rights reserved.

Integrating Nonadditive Genomic Relationship Matrices into the Study of Genetic Architecture of Complex Traits.

PubMed

Nazarian, Alireza; Gezan, Salvador A

2016-03-01

The study of genetic architecture of complex traits has been dramatically influenced by implementing genome-wide analytical approaches during recent years. Of particular interest are genomic prediction strategies which make use of genomic information for predicting phenotypic responses instead of detecting trait-associated loci. In this work, we present the results of a simulation study to improve our understanding of the statistical properties of estimation of genetic variance components of complex traits, and of additive, dominance, and genetic effects through best linear unbiased prediction methodology. Simulated dense marker information was used to construct genomic additive and dominance matrices, and multiple alternative pedigree- and marker-based models were compared to determine if including a dominance term into the analysis may improve the genetic analysis of complex traits. Our results showed that a model containing a pedigree- or marker-based additive relationship matrix along with a pedigree-based dominance matrix provided the best partitioning of genetic variance into its components, especially when some degree of true dominance effects was expected to exist. Also, we noted that the use of a marker-based additive relationship matrix along with a pedigree-based dominance matrix had the best performance in terms of accuracy of correlations between true and estimated additive, dominance, and genetic effects. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Response of selected binomial coefficients to varying degrees of matrix sparseness and to matrices with known data interrelationships

USGS Publications Warehouse

Archer, A.W.; Maples, C.G.

1989-01-01

Numerous departures from ideal relationships are revealed by Monte Carlo simulations of widely accepted binomial coefficients. For example, simulations incorporating varying levels of matrix sparseness (presence of zeros indicating lack of data) and computation of expected values reveal that not only are all common coefficients influenced by zero data, but also that some coefficients do not discriminate between sparse or dense matrices (few zero data). Such coefficients computationally merge mutually shared and mutually absent information and do not exploit all the information incorporated within the standard 2 ?? 2 contingency table; therefore, the commonly used formulae for such coefficients are more complicated than the actual range of values produced. Other coefficients do differentiate between mutual presences and absences; however, a number of these coefficients do not demonstrate a linear relationship to matrix sparseness. Finally, simulations using nonrandom matrices with known degrees of row-by-row similarities signify that several coefficients either do not display a reasonable range of values or are nonlinear with respect to known relationships within the data. Analyses with nonrandom matrices yield clues as to the utility of certain coefficients for specific applications. For example, coefficients such as Jaccard, Dice, and Baroni-Urbani and Buser are useful if correction of sparseness is desired, whereas the Russell-Rao coefficient is useful when sparseness correction is not desired. ?? 1989 International Association for Mathematical Geology.

Longitudinal analyses of adoptive parents' expectations and depressive symptoms.

PubMed

Foli, Karen J; Lim, Eunjung; South, Susan C

2017-12-01

Grounded in a theoretical model specific to adoptive parents, we examined the relationship between parental expectations and depressive symptoms across time. Assessments of 129 adoptive parents of 64 children were performed at three time points before and after placement of an adopted child with the family: 4-6 weeks pre-placement and 4-6 weeks and 5-6 months post-placement. Expectations were assessed in four dimensions: expectations of self as parents, of the child, of family and friends, and of society. Depressive symptoms were assessed with the Center for Epidemiologic Studies-Depression scale. Associations between parental expectations and depressive symptoms were analyzed, and longitudinal multilevel modeling was conducted to explore influences on expectations over time. Parental expectations changed from pre- to post-placement. With the exception of expectations of self as parent, adoptive parents' pre-adoption expectations were affirmed in the post-adoption time periods. In each expectation dimension, higher affirmation of expectations was correlated with decreased depressive symptoms before and after placement of a child. While parental expectations are not unique to adoptive parents, the essence and characteristics of certain expectations are unique to these parents. When working with adoptive parents, nurses who care for families should assess expectations both pre- and post-placement with awareness of their relationship to depressive symptoms. © 2017 Wiley Periodicals, Inc.

Romantic Relationship Dynamics of Urban African American Adolescents: Patterns of Monogamy, Commitment, and Trust

PubMed Central

Towner, Senna L.; Dolcini, M. Margaret; Harper, Gary W.

2013-01-01

Relationship dynamics develop early in life and are influenced by social environments. STI/HIV prevention programs need to consider romantic relationship dynamics that contribute to sexual health. The aim of this study was to examine monogamous patterns, commitment, and trust in African American adolescent romantic relationships. The authors also focused on the differences in these dynamics between and within gender. The way that such dynamics interplay in romantic relationships has the potential to influence STI/HIV acquisition risk. In-depth interviews were conducted with 28 African American adolescents aged 14 to 21 living in San Francisco. Our results discuss data related to monogamous behaviors, expectations, and values; trust and respect in romantic relationships; commitment to romantic relationships; and outcomes of mismatched relationship expectations. Incorporating gender-specific romantic relationships dynamics can enhance the effectiveness of prevention programs. PMID:26691404

Ultra-sensitive and selective detection of mercury ion (Hg2+) using free-standing silicon nanowire sensors

NASA Astrophysics Data System (ADS)

Jin, Yan; Gao, Anran; Jin, Qinghui; Li, Tie; Wang, Yuelin; Zhao, Jianlong

2018-04-01

In this paper, ultra-sensitive and highly selective Hg2+ detection in aqueous solutions was studied by free-standing silicon nanowire (SiNW) sensors. The all-around surface of SiNW arrays was functionalized with (3-Mercaptopropyl)trimethoxysilane serving as Hg2+ sensitive layer. Due to effective electrostatic control provided by the free-standing structure, a detection limit as low as 1 ppt was obtained. A linear relationship (R 2 = 0.9838) between log(CHg2+ ) and a device current change from 1 ppt to 5 ppm was observed. Furthermore, the developed SiNW sensor exhibited great selectivity for Hg2+ over other heavy metal ions, including Cd2+. Given the extraordinary ability for real-time Hg2+ detection, the small size and low cost of the SiNW device, it is expected to be a potential candidate in field detection of environmentally toxic mercury.

[Age structure and dynamics of Quercus wutaishanica population in Lingkong Mountain of Shanxi Province, China].

PubMed

Zhang, Jie; Shangguan, Tie-Liang; Duan, Yi-Hao; Guo, Wei; Liu, Wei-Hua; Guo, Dong-Gang

2014-11-01

Using the plant survivorship theory, the age structure, and the relationship between tree height and diameter (DBH) of Quercus wutaishanica population in Lingkong Mountain were analyzed, and the static life table was compiled and the survival curve plotted. The shuttle shape in age structure of Q. wutaishanica population suggested its temporal stability. The linear regression significantly fitted the positive correlation between tree height and DBH. The maximal life expectancy was observed among the trees beyond the age of the highest mortality and coincided with the lowest point of mortality density, suggesting the strong vitality of the seedlings and young trees that survived in the natural selection and intraspecific competition. The population stability of the Q. wutaishanica population was characterized by the Deevey-II of the survival curve. The dynamic pattern was characterized by the recession in the early phase, growth in the intermediate phase, and stability in the latter phase.

Optimization of Sinter Plant Operating Conditions Using Advanced Multivariate Statistics: Intelligent Data Processing

NASA Astrophysics Data System (ADS)

Fernández-González, Daniel; Martín-Duarte, Ramón; Ruiz-Bustinza, Íñigo; Mochón, Javier; González-Gasca, Carmen; Verdeja, Luis Felipe

2016-08-01

Blast furnace operators expect to get sinter with homogenous and regular properties (chemical and mechanical), necessary to ensure regular blast furnace operation. Blends for sintering also include several iron by-products and other wastes that are obtained in different processes inside the steelworks. Due to their source, the availability of such materials is not always consistent, but their total production should be consumed in the sintering process, to both save money and recycle wastes. The main scope of this paper is to obtain the least expensive iron ore blend for the sintering process, which will provide suitable chemical and mechanical features for the homogeneous and regular operation of the blast furnace. The systematic use of statistical tools was employed to analyze historical data, including linear and partial correlations applied to the data and fuzzy clustering based on the Sugeno Fuzzy Inference System to establish relationships among the available variables.

Dunes on Pluto.

PubMed

Telfer, Matt W; Parteli, Eric J R; Radebaugh, Jani; Beyer, Ross A; Bertrand, Tanguy; Forget, François; Nimmo, Francis; Grundy, Will M; Moore, Jeffrey M; Stern, S Alan; Spencer, John; Lauer, Tod R; Earle, Alissa M; Binzel, Richard P; Weaver, Hal A; Olkin, Cathy B; Young, Leslie A; Ennico, Kimberly; Runyon, Kirby; Buie, Marc; Buratti, Bonnie; Cheng, Andy; Kavelaars, J J; Linscott, Ivan; McKinnon, William B; Reitsema, Harold; Reuter, Dennis; Schenk, Paul; Showalter, Mark; Tyler, Len

2018-06-01

The surface of Pluto is more geologically diverse and dynamic than had been expected, but the role of its tenuous atmosphere in shaping the landscape remains unclear. We describe observations from the New Horizons spacecraft of regularly spaced, linear ridges whose morphology, distribution, and orientation are consistent with being transverse dunes. These are located close to mountainous regions and are orthogonal to nearby wind streaks. We demonstrate that the wavelength of the dunes (~0.4 to 1 kilometer) is best explained by the deposition of sand-sized (~200 to ~300 micrometer) particles of methane ice in moderate winds (<10 meters per second). The undisturbed morphology of the dunes, and relationships with the underlying convective glacial ice, imply that the dunes have formed in the very recent geological past. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

An introduction to using Bayesian linear regression with clinical data.

PubMed

Baldwin, Scott A; Larson, Michael J

2017-11-01

Statistical training psychology focuses on frequentist methods. Bayesian methods are an alternative to standard frequentist methods. This article provides researchers with an introduction to fundamental ideas in Bayesian modeling. We use data from an electroencephalogram (EEG) and anxiety study to illustrate Bayesian models. Specifically, the models examine the relationship between error-related negativity (ERN), a particular event-related potential, and trait anxiety. Methodological topics covered include: how to set up a regression model in a Bayesian framework, specifying priors, examining convergence of the model, visualizing and interpreting posterior distributions, interval estimates, expected and predicted values, and model comparison tools. We also discuss situations where Bayesian methods can outperform frequentist methods as well has how to specify more complicated regression models. Finally, we conclude with recommendations about reporting guidelines for those using Bayesian methods in their own research. We provide data and R code for replicating our analyses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Modified Regression Correlation Coefficient for Poisson Regression Model

NASA Astrophysics Data System (ADS)

Kaengthong, Nattacha; Domthong, Uthumporn

2017-09-01

This study gives attention to indicators in predictive power of the Generalized Linear Model (GLM) which are widely used; however, often having some restrictions. We are interested in regression correlation coefficient for a Poisson regression model. This is a measure of predictive power, and defined by the relationship between the dependent variable (Y) and the expected value of the dependent variable given the independent variables [E(Y|X)] for the Poisson regression model. The dependent variable is distributed as Poisson. The purpose of this research was modifying regression correlation coefficient for Poisson regression model. We also compare the proposed modified regression correlation coefficient with the traditional regression correlation coefficient in the case of two or more independent variables, and having multicollinearity in independent variables. The result shows that the proposed regression correlation coefficient is better than the traditional regression correlation coefficient based on Bias and the Root Mean Square Error (RMSE).

Development of urine glucose meter based on micro-planer amperometric biosensor and its clinical application for self-monitoring of urine glucose.

PubMed

Miyashita, Mariko; Ito, Narushi; Ikeda, Satoshi; Murayama, Tatsuro; Oguma, Koji; Kimura, Jun

2009-01-01

The highly sensitive urine glucose meter based on amperometric glucose sensor was developed and commercialized. It shows remarkable performances of wide measurement range in 0-2000 mgdl(-1), rapid response time as 6s and robustness against influence by interferents like ascorbic acid or acetaminophen. Correlation between the developed urine glucose meter and commercialized clinical-use urine glucose analyzer showed excellent linear relationship. The monitoring of postmeal blood glucose levels by assess of urine glucose of actual subjects was performed with the developed urine glucose meter. The experimental results suggest the urine glucose level 120 min following the meal should be the appropriate index for diabetes or impaired glucose tolerance to control blood glucose level. The new portable meter was developed, and is expected for flexible use at places other than home or office.

Concentration, physical state, and purity of bacterial endotoxin affect its detoxification by ionizing radiation

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

Csako, G.; Tsai, C.M.; Hochstein, H.D.

Increasing concentrations of a highly purified bacterial lipopolysaccharide preparation, the U.S. Reference Standard Endotoxin, were exposed to increasing doses of ionizing radiation from a 60Co source. At identical radiation doses both the structural change and Limulus amebocyte lysate (LAL) reactivity were progressively smaller with increasing concentrations of the lipopolysaccharide in an aqueous medium. Under the experimental conditions used, there was a linear relationship between the endotoxin concentration and radiation dose for the structural changes. In contrast to endotoxin in aqueous medium, endotoxin irradiated in its dry state showed no decrease in LAL reactivity and rabbit pyrogenicity. Endotoxin exposed to radiationmore » in water in the presence of albumin showed a much smaller decrease in LAL and pyrogenic activities than expected. The results show that the concentration, physical state, and purity of endotoxin influence its structural and functional alteration by ionizing radiation.« less

Gradient shadow pattern reveals refractive index of liquid

PubMed Central

Kim, Wonkyoung; Kim, Dong Sung

2016-01-01

We propose a simple method that uses a gradient shadow pattern (GSP) to measure the refractive index nL of liquids. A light source generates a “dark-bright-dark” GSP when it is projected through through the back of a transparent, rectangular block with a cylindrical chamber that is filled with a liquid sample. We found that there is a linear relationship between nL and the proportion of the bright region in a GSP, which provides the basic principle of the proposed method. A wide range 1.33 ≤ nL ≤ 1.46 of liquids was measured in the single measurement setup with error <0.01. The proposed method is simple but robust to illuminating conditions, and does not require for any expensive or precise optical components, so we expect that it will be useful in many portable measurement systems that use nL to estimate attributes of liquid samples. PMID:27302603

Gradient shadow pattern reveals refractive index of liquid.

PubMed

Kim, Wonkyoung; Kim, Dong Sung

2016-06-15

We propose a simple method that uses a gradient shadow pattern (GSP) to measure the refractive index nL of liquids. A light source generates a "dark-bright-dark" GSP when it is projected through through the back of a transparent, rectangular block with a cylindrical chamber that is filled with a liquid sample. We found that there is a linear relationship between nL and the proportion of the bright region in a GSP, which provides the basic principle of the proposed method. A wide range 1.33 ≤ nL ≤ 1.46 of liquids was measured in the single measurement setup with error <0.01. The proposed method is simple but robust to illuminating conditions, and does not require for any expensive or precise optical components, so we expect that it will be useful in many portable measurement systems that use nL to estimate attributes of liquid samples.

Quantum error correction of continuous-variable states against Gaussian noise

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

Ralph, T. C.

2011-08-15

We describe a continuous-variable error correction protocol that can correct the Gaussian noise induced by linear loss on Gaussian states. The protocol can be implemented using linear optics and photon counting. We explore the theoretical bounds of the protocol as well as the expected performance given current knowledge and technology.

EVALUATING PREDICTIVE ERRORS OF A COMPLEX ENVIRONMENTAL MODEL USING A GENERAL LINEAR MODEL AND LEAST SQUARE MEANS

EPA Science Inventory

A General Linear Model (GLM) was used to evaluate the deviation of predicted values from expected values for a complex environmental model. For this demonstration, we used the default level interface of the Regional Mercury Cycling Model (R-MCM) to simulate epilimnetic total mer...

On Spectral Invariance of Single Scattering Albedo for Weakly Absorbing Wavelengths

NASA Technical Reports Server (NTRS)

Marshak, Alexander; Knyazikhin, Yuri; Chiu, J. Christine; Wiscombe, Warren J.

2011-01-01

This note shows that for water droplets at weakly absorbing wavelengths, the ratio omega(sub O lambda(r))/omega(sub O lambda(r(sub O)) of two single scattering albedo spectra, omega(sub O lambda(r) and omega(sub O lambda(r (sub O)), is a linear function of omega(sub O lambda(r). The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo omega(sub O lambda(r) via one known spectrum omega(sub O lambda(r(sub O)). The note provides a simple physical explanation of the discovered relationship. In addition to water droplets, similar linear relationships were found for the single scattering albedo of non-spherical ice crystals.

Normative Beliefs, Expectancies, and Alcohol-Related Problems among College Students; Implications for Theory and Practice.

ERIC Educational Resources Information Center

Fearnow-Kenny, Melodie D.; Wyrick, David L.; Hansen, William B.; Dyreg, Doug; Beau, Dan B.

2001-01-01

Investigation (1) examined interrelations among normative beliefs, alcohol expectancies, and alcohol-related problems, and (2) investigated whether alcohol-related expectancies mediate associations between normative beliefs and alcohol-related problems. Analyses revealed that alcohol expectancies mediate the relationship between normative beliefs…

Bats in a Farming Landscape Benefit from Linear Remnants and Unimproved Pastures

PubMed Central

Lentini, Pia E.; Gibbons, Philip; Fischer, Joern; Law, Brad; Hanspach, Jan; Martin, Tara G.

2012-01-01

Schemes designed to make farming landscapes less hostile to wildlife have been questioned because target taxa do not always respond in the expected manner. Microbats are often overlooked in this process, yet persist in agricultural landscapes and exert top-down control of crop pests. We investigated the relationship between microbats and measures commonly incorporated into agri-environment schemes, to derive management recommendations for their ongoing conservation. We used acoustic detectors to quantify bat species richness, activity, and feeding in 32 linear remnants and adjacent fields across an agricultural region of New South Wales, Australia. Nocturnal arthropods were simultaneously trapped using black-light traps. We recorded 91,969 bat calls, 17,277 of which could be attributed to one of the 13 taxa recorded, and 491 calls contained feeding buzzes. The linear remnants supported higher bat activity than the fields, but species richness and feeding activity did not significantly differ. We trapped a mean 87.6 g (±17.6 g SE) of arthropods per night, but found no differences in biomass between land uses. Wider linear remnants with intact native vegetation supported more bat species, as did those adjacent to unsealed, as opposed to sealed roads. Fields of unimproved native pastures, with more retained scattered trees and associated hollows and logs, supported the greatest bat species richness and activity. We conclude that the juxtaposition of linear remnants of intact vegetation and scattered trees in fields, coupled with less-intensive land uses such as unimproved pastures will benefit bat communities in agricultural landscapes, and should be incorporated into agri-environment schemes. In contrast, sealed roads may act as a deterrent. The “wildlife friendly farming” vs “land sparing” debate has so far primarily focussed on birds, but here we have found evidence that the integration of both approaches could particularly benefit bats. PMID:23155378

Predicting trace organic compound breakthrough in granular activated carbon using fluorescence and UV absorbance as surrogates.

PubMed

Anumol, Tarun; Sgroi, Massimiliano; Park, Minkyu; Roccaro, Paolo; Snyder, Shane A

2015-06-01

This study investigated the applicability of bulk organic parameters like dissolved organic carbon (DOC), UV absorbance at 254 nm (UV254), and total fluorescence (TF) to act as surrogates in predicting trace organic compound (TOrC) removal by granular activated carbon in water reuse applications. Using rapid small-scale column testing, empirical linear correlations for thirteen TOrCs were determined with DOC, UV254, and TF in four wastewater effluents. Linear correlations (R(2) > 0.7) were obtained for eight TOrCs in each water quality in the UV254 model, while ten TOrCs had R(2) > 0.7 in the TF model. Conversely, DOC was shown to be a poor surrogate for TOrC breakthrough prediction. When the data from all four water qualities was combined, good linear correlations were still obtained with TF having higher R(2) than UV254 especially for TOrCs with log Dow>1. Excellent linear relationship (R(2) > 0.9) between log Dow and the removal of TOrC at 0% surrogate removal (y-intercept) were obtained for the five neutral TOrCs tested in this study. Positively charged TOrCs had enhanced removals due to electrostatic interactions with negatively charged GAC that caused them to deviate from removals that would be expected with their log Dow. Application of the empirical linear correlation models to full-scale samples provided good results for six of seven TOrCs (except meprobamate) tested when comparing predicted TOrC removal by UV254 and TF with actual removals for GAC in all the five samples tested. Surrogate predictions using UV254 and TF provide valuable tools for rapid or on-line monitoring of GAC performance and can result in cost savings by extended GAC run times as compared to using DOC breakthrough to trigger regeneration or replacement. Copyright © 2015 Elsevier Ltd. All rights reserved.

An improved null model for assessing the net effects of multiple stressors on communities.

PubMed

Thompson, Patrick L; MacLennan, Megan M; Vinebrooke, Rolf D

2018-01-01

Ecological stressors (i.e., environmental factors outside their normal range of variation) can mediate each other through their interactions, leading to unexpected combined effects on communities. Determining whether the net effect of stressors is ecologically surprising requires comparing their cumulative impact to a null model that represents the linear combination of their individual effects (i.e., an additive expectation). However, we show that standard additive and multiplicative null models that base their predictions on the effects of single stressors on community properties (e.g., species richness or biomass) do not provide this linear expectation, leading to incorrect interpretations of antagonistic and synergistic responses by communities. We present an alternative, the compositional null model, which instead bases its predictions on the effects of stressors on individual species, and then aggregates them to the community level. Simulations demonstrate the improved ability of the compositional null model to accurately provide a linear expectation of the net effect of stressors. We simulate the response of communities to paired stressors that affect species in a purely additive fashion and compare the relative abilities of the compositional null model and two standard community property null models (additive and multiplicative) to predict these linear changes in species richness and community biomass across different combinations (both positive, negative, or opposite) and intensities of stressors. The compositional model predicts the linear effects of multiple stressors under almost all scenarios, allowing for proper classification of net effects, whereas the standard null models do not. Our findings suggest that current estimates of the prevalence of ecological surprises on communities based on community property null models are unreliable, and should be improved by integrating the responses of individual species to the community level as does our compositional null model. © 2017 John Wiley & Sons Ltd.

An MCMC method for the evaluation of the Fisher information matrix for non-linear mixed effect models.

PubMed

Riviere, Marie-Karelle; Ueckert, Sebastian; Mentré, France

2016-10-01

Non-linear mixed effect models (NLMEMs) are widely used for the analysis of longitudinal data. To design these studies, optimal design based on the expected Fisher information matrix (FIM) can be used instead of performing time-consuming clinical trial simulations. In recent years, estimation algorithms for NLMEMs have transitioned from linearization toward more exact higher-order methods. Optimal design, on the other hand, has mainly relied on first-order (FO) linearization to calculate the FIM. Although efficient in general, FO cannot be applied to complex non-linear models and with difficulty in studies with discrete data. We propose an approach to evaluate the expected FIM in NLMEMs for both discrete and continuous outcomes. We used Markov Chain Monte Carlo (MCMC) to integrate the derivatives of the log-likelihood over the random effects, and Monte Carlo to evaluate its expectation w.r.t. the observations. Our method was implemented in R using Stan, which efficiently draws MCMC samples and calculates partial derivatives of the log-likelihood. Evaluated on several examples, our approach showed good performance with relative standard errors (RSEs) close to those obtained by simulations. We studied the influence of the number of MC and MCMC samples and computed the uncertainty of the FIM evaluation. We also compared our approach to Adaptive Gaussian Quadrature, Laplace approximation, and FO. Our method is available in R-package MIXFIM and can be used to evaluate the FIM, its determinant with confidence intervals (CIs), and RSEs with CIs. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

An analysis of the relationship between teachers' acquisition of physics content knowledge and their level of science teaching efficacy

NASA Astrophysics Data System (ADS)

Marion, Virginia Frances

1998-12-01

The goal of Project Inquiry, a two-year long multiphase study, was to transform the delivery of science instruction from a traditional, textbook driven delivery approach to a hands-on, minds-on, constructivist approach. Teachers from a midwestern urban school district were trained in constructivism while learning physics concepts and content through guided inquiry instruction in collaborative groups. The objectives aimed to increase teachers' content expertise and science teaching efficacy, as well as to have teachers become better facilitators of learning. Phase two of the three phases of Project Inquiry was the focus of this study. Fifty-seven teachers participated in Phase two, which began with an intense two week summer institute in 1995. A longitudinal time-series (OxOO), quasi-experimental research design was used to investigate the relationship between science teaching efficacy scores and gains in physics content knowledge. The data consisted of: (a) six sets of pre and post physics content knowledge test scores (electricity, magnetism, matter and balance); (b) three sets of STEBI-A (inservice), Science Teaching Efficacy Belief Instrument scores, a pre to post, pre to follow-up, and post to follow-up; and (c) demographic variables that were used as covariates, grade taught, years of experience, and postbaccalaureate training. Using the general linear model with an Alpha level of.05, and testing the hypothesized relationships, results indicated that although there were significant positive gains in content knowledge (p =.000) and science teaching efficacy (p =.000), the overall average gains in physics content knowledge were not predictive of gains in either Personal Science Teaching Efficacy or Science Outcome Expectancy. Post hoc analysis used individual content gain scores, in regression models that included the three covariates: grade taught, years of experience, and post baccalaureate training, to test the relationship between knowledge gains and efficacy gains. A series of interactions between significant content areas and the covariates was also run. Science Teaching Outcome Expectancy and Personal Science Teaching Efficacy showed different relationships with the predictor variables. Though gains in specific content areas were related to gains in Science Teaching Outcome Expectancy and Personal Science Teaching Efficacy, gains in Personal Science Teaching Efficacy were further modified by the covariates. These results may reflect not only a more complex relationship between content knowledge gain and Personal Science Teaching Efficacy but also the complex nature of the construct. Evaluation of the physics content knowledge tests revealed that the tests were not valid for evaluating 35 of the 37 identified learning objectives. Although the data did not render valid results, it does give insights into possible relationships that may exist given a more stringent investigation with a valid instrument to measure content knowledge gains. In addition, this study demonstrated the importance of considering the likelihood of interactions among a given set of variables and the covariates. The findings also suggest the possible value of considering the psychological factors associated with the change process when planning professional development programs.

Values and depressive symptoms in American Indian youth of the Northern Plains: examining the potential moderating roles of outcome expectancies and perceived community values.

PubMed

Mousseau, Alicia C; Scott, Walter D; Estes, David

2014-03-01

Very little is known about processes contributing to depressive experiences in American Indian youth. We explored the relationship between value priorities and depressive symptoms among 183 (65% female) American Indian youth in grades 9-12. In addition, two potential moderators of this relationship were examined: value outcome expectations (i.e., whether one expects that values will be realized or not) and perceived community values. We found that American Indian youth who endorsed higher levels of tradition/benevolence values reported fewer depressive symptoms. However, the relationship between endorsing power/materialism values and depressive symptoms depended on the extent to which youth perceived their communities as valuing power/materialism. Finally, value outcome expectancies appeared to relate more strongly to depressive symptoms than did value priorities. Overall, these findings support tribal community efforts to impart tradition/benevolence values to American Indian youth but also emphasize the importance of attending to value outcome expectations and the perceived values of the community in understanding American Indian youth's depressive experiences.

Relationships between otolith size and fish length in some mesopelagic teleosts (Myctophidae, Paralepididae, Phosichthyidae and Stomiidae).

PubMed

Battaglia, P; Malara, D; Ammendolia, G; Romeo, T; Andaloro, F

2015-09-01

Length-mass relationships and linear regressions are given for otolith size (length and height) and standard length (LS ) of certain mesopelagic fishes (Myctophidae, Paralepididae, Phosichthyidae and Stomiidae) living in the central Mediterranean Sea. The length-mass relationship showed isometric growth in six species, whereas linear regressions of LS and otolith size fit the data well for all species. These equations represent a useful tool for dietary studies on Mediterranean marine predators. © 2015 The Fisheries Society of the British Isles.

Expectations of millennial nurse graduates transitioning into practice.

PubMed

Andrews, Diane Randall

2013-01-01

Identified as Millennials, nurses born after 1980 are anticipated to redefine the employer-employee relationship as one based on the employee's wants and needs. The purpose of this study is to portray the expectations of Millennial student nurses immediately before graduation. Understanding these expectations may provide insight for leaders who are responsible for crafting a successful transition experience. Successful transition and decreased turnover are important elements of cost management for the nursing enterprise. A qualitative descriptive design was used to collect data from 14 students enrolled in a traditional BSN academic nursing program approximately 2 months prior to graduation. Upon completion of private, confidential semistructured interviews, data were transcribed, coded, and analyzed. Demographic data were compiled and interview data summarized according to identified themes. Three overarching themes emerged: the expectation that transition would be stressful, the expectation that there would be a safety net of support, and the expectation to be valued and respected as a professional. Revealing was the expectation of supportive relationships and a collaborative approach to patient care. Failure to meet those expectations may result in turnover as Millennials seek opportunities that meet their expectations.

Doctoral Student Persistence in Non-Traditional Cohort Programs: Examining Educationally-Related Peer Relationships, Students' Understanding of Faculty Expectations, and Student Characteristics

ERIC Educational Resources Information Center

Fitzpatrick, Julie A.

2013-01-01

The purpose of this study is to examine the influence of educationally-related peer relationships, students' understanding of faculty expectations, and student characteristics on the persistence of doctoral students in non-traditional, residential, cohort programs in educational leadership. Drawing on the concepts of academic and social…

The Effect Social Information Processing in Six-Year-Old Children Has on Their Social Competence and Peer Relationships

ERIC Educational Resources Information Center

Ogelman, Hulya Gulay; Seven, Serdal

2012-01-01

The purpose of this study was to investigate the effect social information processing levels has on the social competence (entering a peer group, response towards provocation, response to failure, response to success, social expectations, teacher expectations, reactive aggression, proactive aggression) and peer relationship (prosocial behaviour,…

The Relationship Between Black Mothers' Attitudes Toward Sex Roles and Their Educational Aspirations and Expectations for Their Daughters.

ERIC Educational Resources Information Center

Sell, Jane Ann

Conducted during the summers of 1970 and 1971, this study examined the relationship between the maternal attitudes of Negro mothers towards women's role and their educational aspirations and expectations for their daughters. A random sample of 294 metropolitan and 259 nonmetropolitan black Texas homemakers was used. These homemakers were…

Physiological Arousal in the Context of a Specified Anticipatory Period and Experimentally Induced Expectancy for Shock

ERIC Educational Resources Information Center

Mead, John D.; Dengerink, Harold A.

1977-01-01

The major intent of this research was to provide a further test of the relationships between physiological arousal and event probability by experimentally generating subjective expectancies for shock. The relationship of event probability to stress was discussed with respect to length of the anticipatory periods and methods used to establish…

The Moderating Effects of Internet Parenting Styles on the Relationship between Internet Parenting Behavior, Internet Expectancy, and Internet Addiction Tendency

ERIC Educational Resources Information Center

Chou, Chien; Lee, Yuan-Hsuan

2017-01-01

This study investigated the moderating effect of children's perceived Internet parenting styles (IPS) on the relationship among their perceived Internet parenting behaviors (operationalized as warmth and control on Internet use from their parents), Internet expectancy (IE), and Internet addiction tendency (IAT). Participants were 3169 Taiwanese…

Commitment to Change: Its Role in the Relationship between Expectation of Change Outcome and Emotional Exhaustion

ERIC Educational Resources Information Center

Ning, Jing; Jing, Runtian

2012-01-01

Successful implementation of organizational changes greatly depends on committed employees. It is crucial for managers, leaders, and HRD professionals to understand the antecedents and outcomes of commitment to change. The purpose of this study is to investigate the relationships among expectation of change outcome at the individual level,…

Relationships among Middle School Students' Expectancy Beliefs, Task Values, and Health-Related Fitness Performance

ERIC Educational Resources Information Center

Chen, Han; Sun, Haichun; Dai, Jun; Griffin, Michael

2017-01-01

Purpose: The purpose of the study was to identify gender and body weight differences in Chinese adolescents' perceived expectancy value (EV) motivation in their physical education (PE) class. The study also explored the relationship between EV and adolescents' health-related fitness performances. Method: A group of seventh and eighth graders (N =…

Effect of Four Aspects of Rational Statements on Expected Satisfaction with a Close Relationship

ERIC Educational Resources Information Center

Cramer, Duncan

2005-01-01

This study tested whether each of the four main aspects of rational thinking decreased expected relationship dissatisfaction when imagining having a serious disagreement with either a romantic partner or closest friend. The four features, common to cognitive theories of therapy, were the tendency not to exaggerate negative effects, not to demand…

Non-susceptible landslide areas in Italy and in the Mediterranean region

NASA Astrophysics Data System (ADS)

Marchesini, I.; Ardizzone, F.; Alvioli, M.; Rossi, M.; Guzzetti, F.

2014-04-01

We used landslide information for 13 study areas in Italy and morphometric information obtained from the 3 arc-second SRTM DEM to determine areas where landslide susceptibility is expected to be null or negligible in Italy, and in the landmasses surrounding the Mediterranean Sea. The morphometric information consisted in the local terrain slope computed in a square 3 × 3 cell moving window, and in the regional relative relief computed in a circular 15 × 15 cell moving window. We tested three different models to determine the non-susceptible landslide areas, including a linear model (LR), a quantile linear model (QLR), and a quantile non-linear model (QNL). We tested the performance of the three models using independent landslide information represented by the Italian Landslide Inventory (Inventario Fenomeni Franosi in Italia - IFFI). Best results were obtained using the QNL model. The corresponding zonation of non-susceptible landslide areas was intersected in a GIS with geographical census data for Italy. The result allowed determining that 57.5% of the population of Italy (in 2001) was located in areas where landslide susceptibility is expected to be null or negligible, and that the remaining 42.5% was located in areas where some landslide susceptibility is expected. We applied the QNL model to the landmasses surrounding the Mediterranean Sea, and we tested the synoptic non-susceptibility zonation using independent landslide information for three study areas in Spain. Results proved that the QNL model was capable of determining where landslide susceptibility is expected to be negligible in the Mediterranean area. We expect our results to be applicable in similar study areas, facilitating the identification of non-susceptible and susceptible landslide areas, at the synoptic scale.

Can change in high-density lipoprotein cholesterol levels reduce cardiovascular risk?

PubMed

Dean, Bonnie B; Borenstein, Jeff E; Henning, James M; Knight, Kevin; Merz, C Noel Bairey

2004-06-01

The cardiovascular risk reduction observed in many trials of lipid-lowering agents is greater than expected on the basis of observed low-density lipoprotein cholesterol (LDL-C) level reductions. Our objective was to explore the degree to which high-density lipoprotein cholesterol (HDL-C) level changes explain cardiovascular risk reduction. A systematic review identified trials of lipid-lowering agents reporting changes in HDL-C and LDL-C levels and the incidence of coronary heart disease (CHD). The observed relative risk reduction (RRR) in CHD morbidity and mortality rates was calculated. The expected RRR, given the treatment effect on total cholesterol level, was calculated for each trial with logistic regression coefficients from observational studies. The difference between observed and expected RRR was plotted against the change in HDL-C level, and a least-squares regression line was calculated. Fifty-one trials were identified. Nineteen statin trials addressed the association of HDL-C with CHD. Limited numbers of trials of other therapies precluded additional analyses. Among statin trials, therapy reduced total cholesterol levels as much as 32% and LDL-C levels as much as 45%. HDL-C level increases were <10%. Treatment effect on HDL-C levels was not a significant linear predictor of the difference in observed and expected CHD mortality rates, although we observed a trend in this direction (P =.08). Similarly, HDL-C effect was not a significant linear predictor of the difference between observed and expected RRRs for CHD morbidity (P =.20). Although a linear trend toward greater risk reduction was observed with greater effects on HDL-C, differences were not statistically significant. The narrow range of HDL-C level increases in the statin trials likely reduced our ability to detect a beneficial HDL-C effect, if present.

[A cross-level analysis of the links between service quality and disconfirmation of expectations and customer satisfaction].

PubMed

Sánchez-Hernández, Rosa M; Martínez-Tur, Vicente; González-Morales, M Gloria; Ramos, José; Peiró, José M

2009-08-01

This article examines links between disconfirmation of expectations and functional and relational service quality perceived by employees and customer satisfaction. A total of 156 employees, who were working in 52 work units, participated in the research study. In addition, 517 customers who were assisted by these work units were surveyed. Using a cross-level approach, we used a random coefficient model to test the aforementioned relationships. A strong relationship between disconfirmation of expectations and customer satisfaction was observed. Also, the results confirmed that functional service quality maintains an additional and significant association with customer satisfaction. In contrast, there were no significant relationships between relational service quality and customer satisfaction. The article concludes with a discussion of these results.

Linearly chirped fiber Bragg grating response to thermal gradient: from bench tests to the real-time assessment during in vivo laser ablations of biological tissue.

PubMed

Saccomandi, Paola; Varalda, Ambra; Gassino, Riccardo; Tosi, Daniele; Massaroni, Carlo; Caponero, Michele A; Pop, Raoul; Korganbayev, Sanzhar; Perrone, Guido; Diana, Michele; Vallan, Alberto; Costamagna, Guido; Marescaux, Jacques; Schena, Emiliano

2017-09-01

The response of a fiber optic sensor [linearly chirped fiber Bragg grating (LCFBG)] to a linear thermal gradient applied on its sensing length (i.e., 1.5 cm) has been investigated. After these bench tests, we assessed their feasibility for temperature monitoring during thermal tumor treatment. In particular, we performed experiments during ex vivo laser ablation (LA) in pig liver and in vivo thermal ablation in animal models (pigs). We investigated the following: (i) the relationship between the full width at half maximum of the LCFBG spectrum and the temperature difference among the extremities of the LCFBG and (ii) the relationship between the mean spectrum wavelength and the mean temperature acting on the LCFBG sensing area. These relationships showed a linear trend during both bench tests and LA in animal models. Thermal sensitivity was significant although different values were found with regards to bench tests and animal experiments. The linear trend and significant sensitivity allow hypothesizing a future use of this kind of sensor to monitor both temperature gradient and mean temperature within a tissue undergoing thermal treatment. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

Formation of linear dominance relationship in captive jungle crows (Corvus macrorhynchos): implications for individual recognition.

PubMed

Izawa, Ei-Ichi; Watanabe, Shigeru

2008-05-01

Jungle crows (Corvus macrorhynchos) flexibly change their social forms depending on their age, time of the day, and the season. In the daytime, paired adults behave territorially and unpaired subadults form small flocks of ten birds, whereas at night hundreds of birds roost together. In the breeding season, pairings remain in their nest all day. This fission-fusion raises questions about the underlying social structure and the cognitive capability of jungle crows. In this study, dyadic encounters were used to investigate dominance relationships (linear or non-linear) and the underlying mechanisms in captive jungle crows. Fourteen crows were tested in 455 encounters (i.e., 5 encounters per dyad), and a stable linear dominance relationship emerged. Sex and aggressiveness were determinants as individual characteristics for dominance formation. Males dominated females, and more aggressive individuals dominated less aggressive ones. Aggressive interactions in dyads occurred primarily during the first encounter and drastically declined during subsequent encounters without any signs of a confidence effect. These results suggest that, in captive jungle crow, a linear form of dominance is intrinsically determined by sex and aggressiveness and maintained extrinsically by memories of past outcomes associated with specific individuals, implying individual recognition.

Development of the Social Efficacy and Social Outcome Expectations Scale

ERIC Educational Resources Information Center

Wright, Stephen L.; Wright, Dorothy A.; Jenkins-Guarnieri, Michael A.

2013-01-01

The current study developed an 18-item scale measuring individuals' social expectations in relationships related to their efficacy expectations (Subscale 1) and outcome expectations (Subscale 2) based on Bandura's self-efficacy theory. Results from exploratory and confirmatory factor analyses, using an undergraduate sample ("N" = 486),…

Testing the Dose–Response Specification in Epidemiology: Public Health and Policy Consequences for Lead

PubMed Central

Rothenberg, Stephen J.; Rothenberg, Jesse C.

2005-01-01

Statistical evaluation of the dose–response function in lead epidemiology is rarely attempted. Economic evaluation of health benefits of lead reduction usually assumes a linear dose–response function, regardless of the outcome measure used. We reanalyzed a previously published study, an international pooled data set combining data from seven prospective lead studies examining contemporaneous blood lead effect on IQ (intelligence quotient) of 7-year-old children (n = 1,333). We constructed alternative linear multiple regression models with linear blood lead terms (linear–linear dose response) and natural-log–transformed blood lead terms (log-linear dose response). We tested the two lead specifications for nonlinearity in the models, compared the two lead specifications for significantly better fit to the data, and examined the effects of possible residual confounding on the functional form of the dose–response relationship. We found that a log-linear lead–IQ relationship was a significantly better fit than was a linear–linear relationship for IQ (p = 0.009), with little evidence of residual confounding of included model variables. We substituted the log-linear lead–IQ effect in a previously published health benefits model and found that the economic savings due to U.S. population lead decrease between 1976 and 1999 (from 17.1 μg/dL to 2.0 μg/dL) was 2.2 times ($319 billion) that calculated using a linear–linear dose–response function ($149 billion). The Centers for Disease Control and Prevention action limit of 10 μg/dL for children fails to protect against most damage and economic cost attributable to lead exposure. PMID:16140626

Hypnotherapy to Reduce Hot Flashes: Examination of Response Expectancies as a Mediator of Outcomes

PubMed Central

Sliwinski, Jim R.; Elkins, Gary R.

2017-01-01

The mechanism of action responsible for hypnotherapy’s effect in reducing hot flashes is not yet known. The purpose of this study was to examine the role of response expectancies as a potential mediator. Hypnotizability was also tested as an effect moderator. Data were collected from a sample of 172 postmenopausal women, who had been randomized to receive either a 5-week hypnosis intervention or structured attention counseling. Measures of response expectancies were analyzed to determine if the relationship between group assignment and hot flashes frequency was mediated by expectancies for treatment efficacy. A series of simple mediation and conditional process analyses did not support mediation of the relationship between treatment condition and hot flash frequency through response expectancy. The effect of hypnotherapy in reducing hot flashes does not appear to be due to placebo effects as determined by response expectancies. Implications for clinical practice and future research are discussed. PMID:28528570

The importance of vegetation density for tourists' wildlife viewing experience and satisfaction in African savannah ecosystems.

PubMed

Arbieu, Ugo; Grünewald, Claudia; Schleuning, Matthias; Böhning-Gaese, Katrin

2017-01-01

Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists' wildlife viewing experience and satisfaction. In this study, we collected data on vegetation structure and perceived mammal densities along 196 road transects (each 5 km long) and conducted a social survey with 651 questionnaires across four PAs in three Southern African countries. Our objectives were 1) to assess visitors' attitude towards vegetation, 2) to test the influence of perceived mammal density and vegetation structure on the easiness to spot animals, and 3) on visitors' satisfaction during their visit to PAs. Using a Boosted Regression Tree procedure, we found mostly negative non-linear relationships between vegetation density and wildlife tourists' experience, and positive relationships between perceived mammal densities and wildlife tourists' experience. In particular, wildlife tourists disliked road transects with high estimates of vegetation density. Similarly, the easiness to spot animals dropped at thresholds of high vegetation density and at perceived mammal densities lower than 46 individuals per road transect. Finally, tourists' satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. Our results suggest that vegetation density has important impacts on tourists' wildlife viewing experience and satisfaction. Hence, the management of PAs in savannah landscapes should consider how tourists perceive these landscapes and their mammal diversity in order to maintain and develop a sustainable wildlife tourism.

Polar ice magnetization: Comparison of results from NorthGRIP (Greenland) and Vostok (Antarctica) ice cores

NASA Astrophysics Data System (ADS)

Lanci, L.; Kent, D. V.

2007-12-01

Low temperature measurements of isothermal remanent magnetization (IRM) in Greenland ice spanning the last glacial and Holocene have shown that ice samples contain a measurable concentration of magnetic minerals which are part of the atmospheric aerosol. Assuming that the source materials do not change much with time, the concentration of magnetic minerals should be proportional to the measured concentration of dust in ice. We have indeed found a consistent linear relationship with the contents of dust. However, the linear relationship between low temperature ice magnetization vs. dust concentration has an offset, which when extrapolated to zero dust concentration would seemingly indicate that a significantly large magnetization corresponds to a null amount of dust in ice. Thermal relaxation experiments have shown that magnetic grains of nanometric size carry virtually all the uncorrelated magnetization. Magnetic measurements in Antarctic ice cores confirm the existence of a similar nanometric-size magnetic fraction, which also appear uncorrelated with measured aerosol concentration. The magnitude of the uncorrelated magnetization from Vostok is similar to that measured in NorthGRIP ice. Measurements of IRM at 250K suggest that the SP magnetic particles are in the size range of about 7-17 nm, which is compatible with the expected size of particles produced by ablation and subsequent condensation of meteorites in the atmosphere. The concentration of extraterrestrial material in NorthGRIP ice was estimated from the magnetic relaxation data based on a crude estimate of chondritic Ms. The resulting concentration of 0.78±0.22 ppb for Greenland is in good agreement with the outcome based on published iridium concentrations; a virtually identical concentration of 0.53±0.18 ppb has been measured in Vostok ice core.

Intracultural Differences in Local Botanical Knowledge and Knowledge Loss among the Mexican Isthmus Zapotecs.

PubMed

Saynes-Vásquez, Alfredo; Vibrans, Heike; Vergara-Silva, Francisco; Caballero, Javier

2016-01-01

This study reports on the socio-demographic and locality factors that influence ethnobiological knowledge in three communities of Zapotec indigenous people of the Isthmus of Tehuantepec, Mexico. It uses local botanical nomenclature as a proxy for general ethnobiological knowledge. In each of these communities (one urban and two rural), 100 adult men were interviewed aided with a field herbarium. Fifty had a background in farming, and 50 worked in the secondary or tertiary sector as their main economic activity, totaling 300 interviews. Using a field herbarium with samples of 30 common and rare wild regional species, we documented visual recognition, knowledge of the local life form, generic and specific names and uses (five knowledge levels measuring knowledge depth). The relationship between sociodemographic variables and knowledge was analyzed with simple correlations. Differences between the three communities and the five knowledge levels were then evaluated with a discriminant analysis. A general linear analysis identified factors and covariables that influenced the observed differences. Differences between the groups with different economic activities were estimated with a t-test for independent samples. Most of the relationships found between sociodemographic variables and plant knowledge were expected: age and rurality were positively related with knowledge and years of formal schooling was negatively related. However, the somewhat less rural site had more traditional knowledge due to local circumstances. The general linear model explained 70-77% of the variation, a high value. It showed that economic activity was by far the most important factor influencing knowledge, by a factor of five. The interaction of locality and economic activity followed. The discriminant analysis assigned interviewees correctly to their localities in 94% of the cases, strengthening the evidence for intracultural variation. Both sociodemographic and historic intracultural differences heavily influence local knowledge.

The importance of vegetation density for tourists’ wildlife viewing experience and satisfaction in African savannah ecosystems

PubMed Central

Grünewald, Claudia; Schleuning, Matthias; Böhning-Gaese, Katrin

2017-01-01

Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists’ wildlife viewing experience and satisfaction. In this study, we collected data on vegetation structure and perceived mammal densities along 196 road transects (each 5 km long) and conducted a social survey with 651 questionnaires across four PAs in three Southern African countries. Our objectives were 1) to assess visitors’ attitude towards vegetation, 2) to test the influence of perceived mammal density and vegetation structure on the easiness to spot animals, and 3) on visitors’ satisfaction during their visit to PAs. Using a Boosted Regression Tree procedure, we found mostly negative non-linear relationships between vegetation density and wildlife tourists’ experience, and positive relationships between perceived mammal densities and wildlife tourists’ experience. In particular, wildlife tourists disliked road transects with high estimates of vegetation density. Similarly, the easiness to spot animals dropped at thresholds of high vegetation density and at perceived mammal densities lower than 46 individuals per road transect. Finally, tourists’ satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. Our results suggest that vegetation density has important impacts on tourists’ wildlife viewing experience and satisfaction. Hence, the management of PAs in savannah landscapes should consider how tourists perceive these landscapes and their mammal diversity in order to maintain and develop a sustainable wildlife tourism. PMID:28957420

Association between Serum Uric Acid Level and Carotid Atherosclerosis in Chinese Individuals Aged 75 Years or Older: A Hospital-Based Case-Control Study.

PubMed

Feng, L; Hua, C; Sun, H; Qin, L-Y; Niu, P-P; Guo, Z-N; Yang, Y

2018-01-01

To investigate the association between serum uric acid level and the presence and progression of carotid atherosclerosis in Chinese individuals aged 75 years or older. Case-control study. In a teaching hospital. Five hundred and sixty-four elderlies (75 years or above) who underwent general health screening in our hospital were enrolled. The detailed carotid ultrasound results, physical examination information, medical history, and laboratory test results including serum uric acid level were recorded, these data were used to analyze the relationship between serum uric acid level and carotid atherosclerosis. Then, subjects who underwent the second carotid ultrasound 1.5-2 years later were further identified to analyzed the relationship between serum uric acid and the progression of carotid atherosclerosis. A total of 564 subjects were included, carotid plaque was found in 482 (85.5%) individuals. Logistic regression showed that subjects with elevated serum uric acid (expressed per 1 standard deviation change) had significantly higher incidence of carotid plaque (odds ratio, 1.37; 95% confidence interval, 1.07-1.75; P= 0.012) after controlling for other factors. A total of 236 subjects underwent the follow-up carotid ultrasound. Linear regression showed that serum uric acid level (expressed per 1 standard deviation change; 1 standard deviation = 95.5 μmol/L) was significantly associated with percentage of change of plaque score (P = 0.008). Multivariable linear regression showed that 1 standard deviation increase in serum uric acid levels was expected to increase 0.448% of plaque score (P = 0.023). The elevated serum uric acid level may be independently and significantly associated with the presence and progression of carotid atherosclerosis in Chinese individuals aged 75 years or older.

In vitro validation of a Pitot-based flow meter for the measurement of respiratory volume and flow in large animal anaesthesia.

PubMed

Moens, Yves P S; Gootjes, Peter; Ionita, Jean-Claude; Heinonen, Erkki; Schatzmann, Urs

2009-05-01

To remodel and validate commercially available monitors and their Pitot tube-based flow sensors for use in large animals, using in vitro techniques. Prospective, in vitro experiment. Both the original and the remodelled sensor were studied with a reference flow generator. Measurements were taken of the static flow-pressure relationship and linearity of the flow signal. Sensor airway resistance was calculated. Following recalibration of the host monitor, volumes ranging from 1 to 7 L were generated by a calibration syringe, and bias and precision of spirometric volume was determined. Where manual recalibration was not available, a conversion factor for volume measurement was determined. The influence of gas composition mixture and peak flow on the conversion factor was studied. Both the original and the remodelled sensor showed similar static flow-pressure relationships and linearity of the flow signal. Mean bias (%) of displayed values compared with the reference volume of 3, 5 and 7 L varied between -0.4% and +2.4%, and this was significantly smaller than that for 1 L (4.8% to +5.0%). Conversion factors for 3, 5 and 7 L were very similar (mean 6.00 +/- 0.2, range 5.91-6.06) and were not significantly influenced by the gas mixture used. Increasing peak flow caused a small decrease in the conversion factor. Volume measurement error and conversion factors for inspiration and expiration were close to identity. The combination of the host monitor with the remodelled flow sensor allowed accurate in vitro measurement of flows and volumes in a range expected during large animal anaesthesia. This combination has potential as a reliable spirometric monitor for use during large animal anaesthesia.

Inconsistent Correlation Between Carotid Artery Intima-Media Thickness and Peripheral Arterial Tonometry

PubMed Central

Lemos, Sara P.; Passos, Valéria Maria A.; Brant, Luisa C.C.; Bensenor, Isabela J.M.; Ribeiro, Antônio Luiz P.; Barreto, Sandhi Maria

2015-01-01

Abstract To estimate the association between 2 markers for atherosclerosis, measurements of carotid artery intima-media thickness (IMT) and of peripheral arterial tonometry (PAT), and to evaluate the role of traditional cardiovascular risk factors in this association. We applied the 2 diagnostic tests to 588 participants from the ELSA-Brazil longitudinal study cohort. The PAT measurements, obtained with the EndoPAT2000, were the reactive hyperemia index (RHI), the Framingham RHI (F-RHI), and the mean basal pulse amplitude (BPA). We used the mean of the mean scores of carotid IMT of the distal layers of the left and right common carotids obtained by ultrasonography after 3 cardiac cycles. We used linear regression and the Spearman correlation coefficient to test the relationship between the 2 markers, and multiple linear regressions to exam the relationship between the RHI/F-RHI scores and the mean BPA and IMT scores after adjusting for cardiovascular risk factors. In the multivariate analysis, RHI (but not F-RHI) was positively correlated with the mean of the means of the IMT values after adjusting for sex and risk factors connected with both measures (β = 0.05, P = 0.02). Mean BPA did not remain significantly associated with IMT after adjusting for common risk factors. We found that the higher the IMT (or the worse the IMT), the higher the RHI (or the better the endothelial function). F-RHI was not associated with IMT. These 2 results are against the direction that one would expect and may imply that digital endothelial function (RHI and F-RHI) and IMT correspond to distinct and independent stages of the complex atherosclerosis process and represent different pathways in the disease's progression. Therefore, IMT and PAT measures may be considered complementary and not interchangeable. PMID:26287431

Application of global sensitivity analysis methods to Takagi-Sugeno-Kang rainfall-runoff fuzzy models

NASA Astrophysics Data System (ADS)

Jacquin, A. P.; Shamseldin, A. Y.

2009-04-01

This study analyses the sensitivity of the parameters of Takagi-Sugeno-Kang rainfall-runoff fuzzy models previously developed by the authors. These models can be classified in two types, where the first type is intended to account for the effect of changes in catchment wetness and the second type incorporates seasonality as a source of non-linearity in the rainfall-runoff relationship. The sensitivity analysis is performed using two global sensitivity analysis methods, namely Regional Sensitivity Analysis (RSA) and Sobol's Variance Decomposition (SVD). In general, the RSA method has the disadvantage of not being able to detect sensitivities arising from parameter interactions. By contrast, the SVD method is suitable for analysing models where the model response surface is expected to be affected by interactions at a local scale and/or local optima, such as the case of the rainfall-runoff fuzzy models analysed in this study. The data of six catchments from different geographical locations and sizes are used in the sensitivity analysis. The sensitivity of the model parameters is analysed in terms of two measures of goodness of fit, assessing the model performance from different points of view. These measures are the Nash-Sutcliffe criterion and the index of volumetric fit. The results of the study show that the sensitivity of the model parameters depends on both the type of non-linear effects (i.e. changes in catchment wetness or seasonality) that dominates the catchment's rainfall-runoff relationship and the measure used to assess the model performance. Acknowledgements: This research was supported by FONDECYT, Research Grant 11070130. We would also like to express our gratitude to Prof. Kieran M. O'Connor from the National University of Ireland, Galway, for providing the data used in this study.

Intracultural Differences in Local Botanical Knowledge and Knowledge Loss among the Mexican Isthmus Zapotecs

PubMed Central

Saynes-Vásquez, Alfredo; Vibrans, Heike; Vergara-Silva, Francisco; Caballero, Javier

2016-01-01

This study reports on the socio-demographic and locality factors that influence ethnobiological knowledge in three communities of Zapotec indigenous people of the Isthmus of Tehuantepec, Mexico. It uses local botanical nomenclature as a proxy for general ethnobiological knowledge. In each of these communities (one urban and two rural), 100 adult men were interviewed aided with a field herbarium. Fifty had a background in farming, and 50 worked in the secondary or tertiary sector as their main economic activity, totaling 300 interviews. Using a field herbarium with samples of 30 common and rare wild regional species, we documented visual recognition, knowledge of the local life form, generic and specific names and uses (five knowledge levels measuring knowledge depth). The relationship between sociodemographic variables and knowledge was analyzed with simple correlations. Differences between the three communities and the five knowledge levels were then evaluated with a discriminant analysis. A general linear analysis identified factors and covariables that influenced the observed differences. Differences between the groups with different economic activities were estimated with a t-test for independent samples. Most of the relationships found between sociodemographic variables and plant knowledge were expected: age and rurality were positively related with knowledge and years of formal schooling was negatively related. However, the somewhat less rural site had more traditional knowledge due to local circumstances. The general linear model explained 70–77% of the variation, a high value. It showed that economic activity was by far the most important factor influencing knowledge, by a factor of five. The interaction of locality and economic activity followed. The discriminant analysis assigned interviewees correctly to their localities in 94% of the cases, strengthening the evidence for intracultural variation. Both sociodemographic and historic intracultural differences heavily influence local knowledge. PMID:26986077

A new method to approximate load-displacement relationships of spinal motion segments for patient-specific multi-body models of scoliotic spine.

PubMed

Jalalian, Athena; Tay, Francis E H; Arastehfar, Soheil; Liu, Gabriel

2017-06-01

Load-displacement relationships of spinal motion segments are crucial factors in characterizing the stiffness of scoliotic spine models to mimic the spine responses to loads. Although nonlinear approach to approximation of the relationships can be superior to linear ones, little mention has been made to deriving personalized nonlinear load-displacement relationships in previous studies. A method is developed for nonlinear approximation of load-displacement relationships of spinal motion segments to assist characterizing in vivo the stiffness of spine models. We propose approximation by tangent functions and focus on rotational displacements in lateral direction. The tangent functions are characterized using lateral bending test. A multi-body model was characterized to 18 patients and utilized to simulate four spine positions; right bending, left bending, neutral, and traction. The same was done using linear functions to assess the performance of the proposed tangent function in comparison with the linear function. Root-mean-square error (RMSE) of the displacements estimated by the tangent functions was 44 % smaller than the linear functions. This shows the ability of our tangent function in approximation of the relationships for a range of infinitesimal to large displacements involved in the spine movement to the four positions. In addition, the models based on the tangent functions yielded 67, 55, and 39 % smaller RMSEs of Ferguson angles, locations of vertebrae, and orientations of vertebrae, respectively, implying better estimates of spine responses to loads. Overall, it can be concluded that our method for approximating load-displacement relationships of spinal motion segments can offer good estimates of scoliotic spine stiffness.

Political conservatism, rigidity, and dogmatism in American foreign policy officials: the 1966 Mennis data.

PubMed

Kemmelmeier, Markus

2007-01-01

Researchers have established a relationship between political orientation and cognitive styles (A. Chirumbolo, 2002; J. T. Jost, J. Glaser, A. W. Kruglanski, & F. Sulloway, 2003a, 2003b; M. Kemmelmeier, 1997). In this article, the author examined whether this finding is true in the political elite, whether the relationship is linear or curvilinear, and whether interest in politics moderates the relationship between political orientation and cognitive styles. He used a 1966 sample of American foreign policy officials (N = 95) to examine the relationship between self-described conservatism and party identification and individual differences in rigidity and dogmatism. Rigidity was related to self-described conservatism, but this relationship was only significant among participants high in political interest, whereas dogmatism was unconditionally related to party identification. All relationships were linear and did not contain a curvilinear component.

Shifts in water availability mediate plant-pollinator interactions.

PubMed

Gallagher, M Kate; Campbell, Diane R

2017-07-01

Altered precipitation patterns associated with anthropogenic climate change are expected to have many effects on plants and insect pollinators, but it is unknown if effects on pollination are mediated by changes in water availability. We tested the hypothesis that impacts of climate on plant-pollinator interactions operate through changes in water availability, and specifically that such effects occur through alteration of floral attractants. We manipulated water availability in two naturally occurring Mertensia ciliata (Boraginaceae) populations using water addition, water reduction and control plots and measured effects on vegetative and floral traits, pollinator visitation and seed set. While most floral trait values, including corolla size and nectar, increased linearly with increasing water availability, in this bumblebee-pollinated species, pollinator visitation peaked at intermediate water levels. Visitation also peaked at an intermediate corolla length, while its relationship to corolla width varied across sites. Seed set, however, increased linearly with water. These results demonstrate the potential for changes in water availability to impact plant-pollinator interactions through pollinator responses to differences in floral attractants, and that the effects of water on pollinator visitation can be nonlinear. Plant responses to changes in resource availability may be an important mechanism by which climate change will affect species interactions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Measurements of Infrared and Acoustic Source Distributions in Jet Plumes

NASA Technical Reports Server (NTRS)

Agboola, Femi A.; Bridges, James; Saiyed, Naseem

2004-01-01

The aim of this investigation was to use the linear phased array (LPA) microphones and infrared (IR) imaging to study the effects of advanced nozzle-mixing techniques on jet noise reduction. Several full-scale engine nozzles were tested at varying power cycles with the linear phased array setup parallel to the jet axis. The array consisted of 16 sparsely distributed microphones. The phased array microphone measurements were taken at a distance of 51.0 ft (15.5 m) from the jet axis, and the results were used to obtain relative overall sound pressure levels from one nozzle design to the other. The IR imaging system was used to acquire real-time dynamic thermal patterns of the exhaust jet from the nozzles tested. The IR camera measured the IR radiation from the nozzle exit to a distance of six fan diameters (X/D(sub FAN) = 6), along the jet plume axis. The images confirmed the expected jet plume mixing intensity, and the phased array results showed the differences in sound pressure level with respect to nozzle configurations. The results show the effects of changes in configurations to the exit nozzles on both the flows mixing patterns and radiant energy dissipation patterns. By comparing the results from these two measurements, a relationship between noise reduction and core/bypass flow mixing is demonstrated.

Predicting the math/science career goals of low-income prospective first-generation college students.

PubMed

Garriott, Patton O; Flores, Lisa Y; Martens, Matthew P

2013-04-01

The present study used social cognitive career theory (SCCT; Lent, Brown, & Hackett, 1994) to predict the math/science goal intentions of a sample of low-income prospective first-generation college students (N = 305). Structural equation modeling was used to test a model depicting relationships between contextual (i.e., social class, learning experiences, proximal supports and barriers) and person-cognitive (i.e., self-efficacy, outcome expectations, interests, goals) variables as hypothesized in SCCT and based on previous literature on low-income first-generation college students. Results indicated that the hypothesized model provided the best representation of the data. All paths in the model were statistically significant, with the exceptions of paths from self-efficacy to goals, outcome expectations to interests, and perceived barriers to self-efficacy. Bootstrapping procedures revealed that the relationships between social class, self-efficacy, and outcome expectations were mediated through learning experiences. Furthermore, the relationship between social supports and goals was mediated by self-efficacy and interests and the relationships between self-efficacy, outcome expectations, and goals were mediated by interests. Contrary to hypotheses, the relationship between barriers and goals was not mediated by self-efficacy and interests. The hypothesis that proximal contextual supports and barriers would moderate the relationship between interests and goals was not supported. The final model explained 66% and 55% of the variance in math/science interests and goals, respectively. Implications for future research and practice are discussed.

Differences between genomic-based and pedigree-based relationships in a chicken population, as a function of quality control and pedigree links among individuals.

PubMed

Wang, H; Misztal, I; Legarra, A

2014-12-01

This work studied differences between expected (calculated from pedigree) and realized (genomic, from markers) relationships in a real population, the influence of quality control on these differences, and their fit to current theory. Data included 4940 pure line chickens across five generations genotyped for 57,636 SNP. Pedigrees (5762 animals) were available for the five generations, pedigree starting on the first one. Three levels of quality control were used. With no quality control, mean difference between realized and expected relationships for different type of relationships was ≤ 0.04 with standard deviation ≤ 0.10. With strong quality control (call rate ≥ 0.9, parent-progeny conflicts, minor allele frequency and use of only autosomal chromosomes), these numbers reduced to ≤ 0.02 and ≤ 0.04, respectively. While the maximum difference was 1.02 with the complete data, it was only 0.18 with the latest three generations of genotypes (but including all pedigrees). Variation of expected minus realized relationships agreed with theoretical developments and suggests an effective number of loci of 70 for this population. When the pedigree is complete and as deep as the genotypes, the standard deviation of difference between the expected and realized relationships is around 0.04, all categories confounded. Standard deviation of differences larger than 0.10 suggests bad quality control, mistakes in pedigree recording or genotype labelling, or insufficient depth of pedigree. © 2014 Blackwell Verlag GmbH.

Smoking abstinence-related expectancies among American Indians, African Americans, and women: potential mechanisms of tobacco-related disparities.

PubMed

Hendricks, Peter S; Westmaas, J Lee; Ta Park, Van M; Thorne, Christopher B; Wood, Sabrina B; Baker, Majel R; Lawler, R Marsh; Webb Hooper, Monica; Delucchi, Kevin L; Hall, Sharon M

2014-03-01

Research has documented tobacco-related health disparities by race and gender. Prior research, however, has not examined expectancies about the smoking cessation process (i.e., abstinence-related expectancies) as potential contributors to tobacco-related disparities in special populations. This cross-sectional study compared abstinence-related expectancies between American Indian (n = 87), African American (n = 151), and White (n = 185) smokers, and between women (n = 231) and men (n = 270) smokers. Abstinence-related expectancies also were examined as mediators of race and gender relationships with motivation to quit and abstinence self efficacy. Results indicated that American Indians and African Americans were less likely than Whites to expect withdrawal effects, and more likely to expect that quitting would be unproblematic. African Americans also were less likely than Whites to expect smoking cessation interventions to be effective. Compared with men, women were more likely to expect withdrawal effects and weight gain. These expectancy differences mediated race and gender relationships with motivation to quit and abstinence self-efficacy. Findings emphasize potential mechanisms underlying tobacco-related health disparities among American Indians, African Americans, and women and suggest a number of specific approaches for targeting tobacco dependence interventions to these populations.

Smoking Abstinence-related Expectancies among American Indians, African Americans, and Women: Potential Mechanisms of Tobacco-related Disparities

PubMed Central

Hendricks, Peter S.; Westmaas, J. Lee; Park, Van M. Ta; Thorne, Christopher B.; Wood, Sabrina B.; Baker, Majel R.; Lawler, R. Marsh; Hooper, Monica Webb; Delucchi, Kevin L.; Hall, Sharon M.

2014-01-01

Research has documented tobacco-related health disparities by race and gender. Prior research, however, has not examined expectancies about the smoking cessation process (i.e., abstinence-related expectancies) as potential contributors to tobacco-related disparities in special populations. This cross-sectional study compared abstinence-related expectancies between American Indian (n = 87), African American (n = 151), and White (n = 185) smokers, and between women (n = 231) and men (n = 270) smokers. Abstinence-related expectancies also were examined as mediators of race and gender relationships with motivation to quit and abstinence self-efficacy. Results indicated that American Indians and African Americans were less likely than Whites to expect withdrawal effects, and more likely to expect that quitting would be unproblematic. African Americans also were less likely than Whites to expect smoking cessation interventions to be effective. Compared to men, women were more likely to expect withdrawal effects and weight gain.These expectancy differences mediated race and gender relationships with motivation to quit and abstinence self-efficacy. Findings emphasize potential mechanisms underlying tobacco-related health disparities among American Indians, African Americans, and women, and suggest a number of specific approaches for targeting tobacco dependence interventions to these populations. PMID:23528192

On the pth moment estimates of solutions to stochastic functional differential equations in the G-framework.

PubMed

Faizullah, Faiz

2016-01-01

The aim of the current paper is to present the path-wise and moment estimates for solutions to stochastic functional differential equations with non-linear growth condition in the framework of G-expectation and G-Brownian motion. Under the nonlinear growth condition, the pth moment estimates for solutions to SFDEs driven by G-Brownian motion are proved. The properties of G-expectations, Hölder's inequality, Bihari's inequality, Gronwall's inequality and Burkholder-Davis-Gundy inequalities are used to develop the above mentioned theory. In addition, the path-wise asymptotic estimates and continuity of pth moment for the solutions to SFDEs in the G-framework, with non-linear growth condition are shown.

Aberration measurement technique based on an analytical linear model of a through-focus aerial image.

PubMed

Yan, Guanyong; Wang, Xiangzhao; Li, Sikun; Yang, Jishuo; Xu, Dongbo; Erdmann, Andreas

2014-03-10

We propose an in situ aberration measurement technique based on an analytical linear model of through-focus aerial images. The aberrations are retrieved from aerial images of six isolated space patterns, which have the same width but different orientations. The imaging formulas of the space patterns are investigated and simplified, and then an analytical linear relationship between the aerial image intensity distributions and the Zernike coefficients is established. The linear relationship is composed of linear fitting matrices and rotation matrices, which can be calculated numerically in advance and utilized to retrieve Zernike coefficients. Numerical simulations using the lithography simulators PROLITH and Dr.LiTHO demonstrate that the proposed method can measure wavefront aberrations up to Z(37). Experiments on a real lithography tool confirm that our method can monitor lens aberration offset with an accuracy of 0.7 nm.

Relationship Churning, Physical Violence, and Verbal Abuse in Young Adult Relationships

ERIC Educational Resources Information Center

Halpern-Meekin, Sarah; Manning, Wendy D.; Giordano, Peggy C.; Longmore, Monica A.

2013-01-01

Young adults' romantic relationships are often unstable, commonly including breakup--reconcile patterns. From the developmental perspective of emerging adulthood exploration, such relationship "churning" is expected; however, minor conflicts are more common in churning relationships. Using data from the Toledo Adolescent Relationships…

The Impact of Repeat HIV Testing on Risky Sexual Behavior: Evidence from a Randomized Controlled Trial in Malawi

PubMed Central

Delavande, Adeline; Wagner, Zachary; Sood, Neeraj

2016-01-01

A significant proportion of HIV-positive adults in sub-Saharan Africa are in serodiscordant relationships. Identification of such serodiscordant couples through couple HIV testing and counseling (HTC) is thought to promote safe sexual behavior and reduce the probability of within couple seroconversion. However, it is possible HTC benefits are not sustained over time and therefore repeated HTC may be more effective at preventing seroconversion than one time HTC. We tested this theory in Zomba, Malawi by randomly assigning 170 serodiscordant couples to receive repeated HTC and 167 serodiscordant couples to receive one time HTC upon study enrollment (control group). We used linear probability models and probit model with couple fixed effects to assess the impact of the intervention on risky sexual behavior. At one-year follow-up, we found that couples that received repeated HTC reported significantly more condom use. However, we found no difference in rate of seroconversion between groups, nor did we find differences in subjective expectations about seroconversion or false beliefs about HIV, two expected pathways of behavior change. We conclude that repeated HTC may promote safe sexual behavior, but this result should be interpreted with caution, as it is inconsistent with the result from biological and subjective outcomes. PMID:27158553

The Impact of Repeat HIV Testing on Risky Sexual Behavior: Evidence from a Randomized Controlled Trial in Malawi.

PubMed

Delavande, Adeline; Wagner, Zachary; Sood, Neeraj

2016-03-01

A significant proportion of HIV-positive adults in sub-Saharan Africa are in serodiscordant relationships. Identification of such serodiscordant couples through couple HIV testing and counseling (HTC) is thought to promote safe sexual behavior and reduce the probability of within couple seroconversion. However, it is possible HTC benefits are not sustained over time and therefore repeated HTC may be more effective at preventing seroconversion than one time HTC. We tested this theory in Zomba, Malawi by randomly assigning 170 serodiscordant couples to receive repeated HTC and 167 serodiscordant couples to receive one time HTC upon study enrollment (control group). We used linear probability models and probit model with couple fixed effects to assess the impact of the intervention on risky sexual behavior. At one-year follow-up, we found that couples that received repeated HTC reported significantly more condom use. However, we found no difference in rate of seroconversion between groups, nor did we find differences in subjective expectations about seroconversion or false beliefs about HIV, two expected pathways of behavior change. We conclude that repeated HTC may promote safe sexual behavior, but this result should be interpreted with caution, as it is inconsistent with the result from biological and subjective outcomes.

Why you cannot transform your way out of trouble for small counts.

PubMed

Warton, David I

2018-03-01

While data transformation is a common strategy to satisfy linear modeling assumptions, a theoretical result is used to show that transformation cannot reasonably be expected to stabilize variances for small counts. Under broad assumptions, as counts get smaller, it is shown that the variance becomes proportional to the mean under monotonic transformations g(·) that satisfy g(0)=0, excepting a few pathological cases. A suggested rule-of-thumb is that if many predicted counts are less than one then data transformation cannot reasonably be expected to stabilize variances, even for a well-chosen transformation. This result has clear implications for the analysis of counts as often implemented in the applied sciences, but particularly for multivariate analysis in ecology. Multivariate discrete data are often collected in ecology, typically with a large proportion of zeros, and it is currently widespread to use methods of analysis that do not account for differences in variance across observations nor across responses. Simulations demonstrate that failure to account for the mean-variance relationship can have particularly severe consequences in this context, and also in the univariate context if the sampling design is unbalanced. © 2017 The Authors. Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

Exponential increase in postprandial blood-glucose exposure with increasing carbohydrate loads using a linear carbohydrate-to-insulin ratio.

PubMed

Marran, K J; Davey, B; Lang, A; Segal, D G

2013-04-10

Postprandial glucose excursions contribute significantly to average blood glucose, glycaemic variability and cardiovascular risk. Carbohydrate counting is a method of insulin dosing that balances carbohydrate load to insulin dose using a fixed ratio. Many patients and current insulin pumps calculate insulin delivery for meals based on a linear carbohydrate-to-insulin relationship. It is our hypothesis that a non-linear relationship exists between the amounts of carbohydrate consumed and the insulin required to cover it. To document blood glucose exposure in response to increasing carbohydrate loads on fixed carbohydrate-to-insulin ratios. Five type 1 diabetic subjects receiving insulin pump therapy with good control were recruited. Morning basal rates and carbohydrate- to-insulin ratios were optimised. A Medtronic glucose sensor was used for 5 days to collect data for area-under-the-curve (AUC) analysis, during which standardised meals of increasing carbohydrate loads were consumed. Increasing carbohydrate loads using a fixed carbohydrate-to-insulin ratio resulted in increasing glucose AUC. The relationship was found to be exponential rather than linear. Late postprandial hypoglycaemia followed carbohydrate loads of >60 g and this was often followed by rebound hyperglycaemia that lasted >6 hours. A non-linear relationship exists between carbohydrates consumed and the insulin required to cover them. This has implications for control of postprandial blood sugars, especially when consuming large carbohydrate loads. Further studies are required to look at the optimal ratios, duration and type of insulin boluses required to cover increasing carbohydrate loads.

Relationship Between Motor Variability, Accuracy, and Ball Speed in the Tennis Serve

PubMed Central

Antúnez, Ruperto Menayo; Hernández, Francisco Javier Moreno; García, Juan Pedro Fuentes; Vaíllo, Raúl Reina; Arroyo, Jesús Sebastián Damas

2012-01-01

The main objective of this study was to analyze the motor variability in the performance of the tennis serve and its relationship to performance outcome. Seventeen male tennis players took part in the research, and they performed 20 serves. Linear and non-linear variability during the hand movement was measured by 3D Motion Tracking. Ball speed was recorded with a sports radar gun and the ball bounces were video recorded to calculate accuracy. The results showed a relationship between the amount of variability and its non-linear structure found in performance of movement and the outcome of the serve. The study also found that movement predictability correlates with performance. An increase in the amount of movement variability could affect the tennis serve performance in a negative way by reducing speed and accuracy of the ball. PMID:23486998

Protégés' Personality Traits, Expectations, the Quality of the Mentoring Relationship and Adjustment: A Big Five Analysis

ERIC Educational Resources Information Center

Goldner, Limor

2016-01-01

Background: Community-based mentoring interventions can benefit high-risk youth. However, meta-analyses suggest that these benefits may be conditioned by protégés' personality. Objectives: Associations between protégés' personality traits and mentoring expectations, the quality of the mentoring relationship, the perceived mentoring contribution,…

Using the Expectancy Value Model of Motivation to Understand the Relationship between Student Attitudes and Achievement in Statistics

ERIC Educational Resources Information Center

Hood, Michelle; Creed, Peter A.; Neumann, David L.

2012-01-01

We tested a model of the relationship between attitudes toward statistics and achievement based on Eccles' Expectancy Value Model (1983). Participants (n = 149; 83% female) were second-year Australian university students in a psychology statistics course (mean age = 23.36 years, SD = 7.94 years). We obtained demographic details, past performance,…

Three Validity Studies of the Daily Progress Report in Relationship to the Check, Connect, and Expect Intervention

ERIC Educational Resources Information Center

Stage, Scott A.; Cheney, Doug; Lynass, Lori; Mielenz, Christine; Flower, Andrea

2012-01-01

Elementary students (N = 104) at risk for severe behavior problems or with special education eligibility participated in three validity studies of the daily progress report (DPR) used in a Tier 2 behavioral intervention known as "Check, Connect, and Expect" (CCE). In Study 1, the relationship between teachers' ratings of students'…

The Relationship Between Psychological Distress, Negative Cognitions, and Expectancies on Problem Drinking: Exploring a Growing Problem Among University Students.

PubMed

Obasi, Ezemenari M; Brooks, Jessica J; Cavanagh, Lucia

2016-01-01

Few studies have sought to understand the concurrent relationship between cognitive and affective processes on alcohol use and negative alcohol-related consequences, despite both being identified as predictive risk factors in the college population. More research is needed to understand the relationships between identified factors of problem drinking among this at-risk population. The purpose of this study was to test if the relationship between psychological distress and problem drinking among university students (N = 284; M-age = 19.77) was mediated by negative affect regulation strategies and positive alcohol-related expectancies. Two latent mediation models of problem drinking were tested using structural equation modeling (SEM). The parsimonious three-path mediated latent model was supported by the data, as evidenced by several model fit indices. Furthermore, the alternate saturated model provided similar fit to the data, but contained several direct relationships that were not statistically significant. The relationship between psychological distress and problem drinking was mediated by an extended contributory chain, including negative affect regulation and positive alcohol-related expectancies. Implications for prevention and treatment, as well as future directions, are discussed. © The Author(s) 2015.

Portfolio optimization using fuzzy linear programming

NASA Astrophysics Data System (ADS)

Pandit, Purnima K.

2013-09-01

Portfolio Optimization (PO) is a problem in Finance, in which investor tries to maximize return and minimize risk by carefully choosing different assets. Expected return and risk are the most important parameters with regard to optimal portfolios. In the simple form PO can be modeled as quadratic programming problem which can be put into equivalent linear form. PO problems with the fuzzy parameters can be solved as multi-objective fuzzy linear programming problem. In this paper we give the solution to such problems with an illustrative example.

Parent and teen agreement on driving expectations prior to teen licensure.

PubMed

Hamann, Cara J; Ramirez, Marizen; Yang, Jingzhen; Chande, Vidya; Peek-Asa, Corinne

2014-01-01

To examine pre-licensure agreement on driving expectations and predictors of teen driving expectations among parent-teen dyads. Cross-sectional survey of 163 parent-teen dyads. Descriptive statistics, weighted Kappa coefficients, and linear regression were used to examine expectations about post-licensure teen driving. Teens reported high pre-licensure unsupervised driving (N = 79, 48.5%) and regular access to a car (N = 130, 81.8%). Parents and teens had low agreement on teen driving expectations (eg, after dark, κw = 0.23). Each time teens currently drove to/from school, their expectation of driving in risky conditions post-licensure increased (β = 0.21, p = .02). Pre-licensure improvement of parent-teen agreement on driving expectations are needed to have the greatest impact on preventing teens from driving in high risk conditions.

Disturbances of automatic gait control mechanisms in higher level gait disorder.

PubMed

Danoudis, Mary; Ganesvaran, Ganga; Iansek, Robert

2016-07-01

The underlying mechanisms responsible for the gait changes in frontal gait disorder (FGD), a form of higher level gait disorders, are poorly understood. We investigated the relationship between stride length and cadence (SLCrel) in people with FGD (n=15) in comparison to healthy older adults (n=21) to improve our understanding of the changes to gait in FGD. Gait data was captured using an electronic walkway system as participants walked at five self-selected speed conditions: preferred, very slow, slow, fast and very fast. Linear regression was used to determine the strength of the relationship (R(2)), slope and intercept. In the FGD group 9 participants had a strong SLCrel (linear group) (R(2)>0.8) and 6 a weak relationship (R(2)<0.8) (nonlinear group). The linear FGD group did not differ to healthy control for slope (p>0.05) but did have a lower intercept (p<0.001). The linear FGD group modulated gait speed by adjusting stride length and cadence similar to controls whereas the nonlinear FGD participants adjusted stride length but not cadence similar to controls. The non-linear FGD group had greater disturbance to their gait, poorer postural control and greater fear of falling compared to the linear FGD group. Investigation of the SLCrel resulted in new insights into the underlying mechanisms responsible for the gait changes found in FGD. The findings suggest stride length regulation was disrupted in milder FGD but as the disorder worsened, cadence control also became disordered resulting in a break down in the relationship between stride length and cadence. Copyright © 2016 Elsevier B.V. All rights reserved.

The lead-lag relationships between spot and futures prices of natural gas

NASA Astrophysics Data System (ADS)

Zhang, Yahui; Liu, Li

2018-01-01

The lead-lag relationships between spot and futures markets are of great interest for academics. Previous studies neglect the possibility of nonlinear behaviors which may be caused by asymmetry or persistence. To fill this gap, this paper uses the MF-DCCA method and the linear and nonlinear causality tests to explore the causal relationships between natural gas spot and futures prices in the New York Mercantile Exchange. We find that spot and futures prices are positive cross-correlated, the natural gas futures can linearly Granger cause spot price, and there are bidirectional nonlinear causality relationships between natural gas spot and futures prices. Further, we explore the sources of nonlinear causality relationships, and find that the volatility spillover can partly explain the nonlinear causality and affect their cross-correlations.

Linear proportional relationship between N(OH) and N(CH) in the diffuse interstellar medium

NASA Astrophysics Data System (ADS)

Hong, Seung Yeong; Kwak, Kyujin

2018-04-01

It has been known that there is a linearly proportional relationship between the column densities of CH and OH measured toward bright UV-emitting stars, although there are four outliers in this relationship among the total 24 measured targets. By using the Simbad database, we investigate reasonable configurations of diffuse interstellar medium (ISM) which could explain the observed relationship. We first identify the locations of 24 targets on the celestial sphere getting the distances to them and then count the number of molecular clouds, nebulae, and peculiar stars toward the targets which could contribute to the production of OH and CH. We present the results of our search by testing three hypothetical configurations of diffuse ISM which may explain the observed relationship.

The Relationship between Parent Expectations and Postschool Outcomes of Adolescents with Disabilities

ERIC Educational Resources Information Center

Doren, Bonnie; Gau, Jeff M.; Lindstrom, Lauren E.

2012-01-01

A secondary analysis was conducted of the National Longitudinal Transition Study-2 to examine (a) main effects of parents' school and postschool outcome expectations on the actual outcomes achieved, (b) demographic moderators, and (c) adolescent autonomy as a mediator of parent expectations and outcomes. Parent expectations were found to…

Taking Student Expectations Seriously: A Guide for Campus Applications. NASPA-050

ERIC Educational Resources Information Center

Miller, Thomas; Kuh, George D.; Paine, Dorie

2006-01-01

Students' expectations for college form the foundation for the nature of the relationship they have with their college or university. "Taking Expectations Seriously: A Guide for Campus Applications" is the companion guide to "Promoting Reasonable Expectations: Aligning Student and Institutional Views of the College Experience" (Jossey-Bass, 2005).…

Immigrant Students' Educational Expectations: The Role of Religious Affiliation and Practice

ERIC Educational Resources Information Center

Hemmerechts, Kenneth; Kavadias, Dimokritos; Agirdag, Orhan

2018-01-01

A body of scholarly work has emerged on educational expectations. More recently, the relationship between educational expectations and immigrant background in Western Europe has been investigated. Although the results of this type of inquiry show that students with an immigrant background tend to have higher educational expectations, potential…

Multiple Intelligence Scores of Science Stream Students and Their Relation with Reading Competency in Malaysian University English Test (MUET)

ERIC Educational Resources Information Center

Razak, Norizan Abdul; Zaini, Nuramirah

2014-01-01

Many researches have shown that different approach needed in analysing linear and non-linear reading comprehension texts and different cognitive skills are required. This research attempts to discover the relationship between Science Stream students' reading competency on linear and non-linear texts in Malaysian University English Test (MUET) with…

LINEARIZATION OF EMPIRICAL RHEOLOGICAL DATA FOR USE IN COMPOSITION CONTROL OF MULTICOMPONENT FOODSTUFFS.

PubMed

Drake, Birger; Nádai, Béla

1970-03-01

An empirical measure of viscosity, which is often far from being a linear function of composition, was used together with refractive index to build up a function which bears a linear relationship to the composition of tomato paste-water-sucrose mixtures. The new function can be used directly for rapid composition control by linear vector-vector transformation.

'If I buy the Kellogg's then he should [buy] the milk': young women's perspectives on relationship dynamics, gender power and HIV risk in Johannesburg, South Africa.

PubMed

Pettifor, Audrey; Macphail, Catherine; Anderson, Althea D; Maman, Suzanne

2012-01-01

Ideals of masculinity and femininity may limit South African women's decision making power in relationships and increase their risk of HIV infection. We conducted 30 in-depth interviews with 18-24-year-old women in inner-city Johannesburg with the aim of understanding young women's expectations of intimate relationships with men, their perceptions of gender and power and how this influences HIV risk. We found that the majority of young women reported expectations of power in relationships that conform to a model of femininity marked by financial independence, freedom to make decisions, including over sexuality, and equality (resistant femininity). The majority of young women, however, were in relationships marked by intimate partner violence, infidelity or lack of condom use. In spite of this, more young women who subscribed to a resistant model of femininity were in less risky relationships than young women who subscribed to acquiescent models, in which power was vested in their male partners. Further, young women who subscribed to resistant femininity had more education than women who subscribed to an acquiescent model. The disconnect between expectations of relationships and young women's lived realities emphasises the need for structural changes that afford women greater economic and thus decision making power.

The National Emergency Access Target (NEAT) and the 4-hour rule: time to review the target.

PubMed

Sullivan, Clair; Staib, Andrew; Khanna, Sankalp; Good, Norm M; Boyle, Justin; Cattell, Rohan; Heiniger, Liam; Griffin, Bronwyn R; Bell, Anthony Jr; Lind, James; Scott, Ian A

2016-05-16

We explored the relationship between the National Emergency Access Target (NEAT) compliance rate, defined as the proportion of patients admitted or discharged from emergency departments (EDs) within 4 hours of presentation, and the risk-adjusted in-hospital mortality of patients admitted to hospital acutely from EDs. Retrospective observational study of all de-identified episodes of care involving patients who presented acutely to the EDs of 59 Australian hospitals between 1 July 2010 and 30 June 2014. The relationship between the risk-adjusted mortality of inpatients admitted acutely from EDs (the emergency hospital standardised mortality ratio [eHSMR]: the ratio of the numbers of observed to expected deaths) and NEAT compliance rates for all presenting patients (total NEAT) and admitted patients (admitted NEAT). ED and inpatient data were aggregated for 12.5 million ED episodes of care and 11.6 million inpatient episodes of care. A highly significant (P < 0.001) linear, inverse relationship between eHSMR and each of total and admitted NEAT compliance rates was found; eHSMR declined to a nadir of 73 as total and admitted NEAT compliance rates rose to about 83% and 65% respectively. Sensitivity analyses found no confounding by the inclusion of palliative care and/or short-stay patients. As NEAT compliance rates increased, in-hospital mortality of emergency admissions declined, although this direct inverse relationship is lost once total and admitted NEAT compliance rates exceed certain levels. This inverse association between NEAT compliance rates and in-hospital mortality should be considered when formulating targets for access to emergency care.

Epidemiology, incidence and mortality of lung cancer and their relationship with the development index in the world

PubMed Central

Rafiemanesh, Hosein; Mehtarpour, Mojtaba; Khani, Farah; Hesami, Sayed Mohammadali; Shamlou, Reza; Towhidi, Farhad; Makhsosi, Behnam Reza; Moini, Ali

2016-01-01

Background The highest incidence of lung cancer is seen in North America and the lowest incidence in central Africa. Socioeconomic factors of inequality reflect regional disparities in human development. Due to the importance of awareness about incidence and mortality of lung cancer in health programming and the possible role of the human development index (HDI), this study was done with the aim to investigate the epidemiology of lung cancer in the world and its relationship with HDI. Methods The study was conducted based on data from the world data of cancer and the World Bank (including the HDI and its components). Data about the age-specific incidence and mortality rate (ASR) for every country in 2012 were getting from the global cancer project. To analyze data, correlation tests between incidence and death rates, and HDI and its components were employed with a significance level of 0.05 using SPSS software. Results Lung cancer with standardized incidence rate (ASIR) and standardized mortality rate (ASMR), equal to 23.1 and 19.7 (in 100,000 people), respectively. The highest and lowest values of mortality incidence ratio (MIR) for lung cancer due to continents division were 0.93 and 0.71 for Eastern Africa and Australia/New Zealand, respectively. Univariate analysis showed significant relationship (P<0.0001) between ASIR and ASMR with life expectancy at birth and mean years of schooling. Conclusions The highest MIR for lung cancer was for medium human development countries. Linear regression analysis showed a reverse significant relationship between MIR and HDI. PMID:27293825

Epidemiology, incidence and mortality of lung cancer and their relationship with the development index in the world.

PubMed

Rafiemanesh, Hosein; Mehtarpour, Mojtaba; Khani, Farah; Hesami, Sayed Mohammadali; Shamlou, Reza; Towhidi, Farhad; Salehiniya, Hamid; Makhsosi, Behnam Reza; Moini, Ali

2016-06-01

The highest incidence of lung cancer is seen in North America and the lowest incidence in central Africa. Socioeconomic factors of inequality reflect regional disparities in human development. Due to the importance of awareness about incidence and mortality of lung cancer in health programming and the possible role of the human development index (HDI), this study was done with the aim to investigate the epidemiology of lung cancer in the world and its relationship with HDI. The study was conducted based on data from the world data of cancer and the World Bank (including the HDI and its components). Data about the age-specific incidence and mortality rate (ASR) for every country in 2012 were getting from the global cancer project. To analyze data, correlation tests between incidence and death rates, and HDI and its components were employed with a significance level of 0.05 using SPSS software. Lung cancer with standardized incidence rate (ASIR) and standardized mortality rate (ASMR), equal to 23.1 and 19.7 (in 100,000 people), respectively. The highest and lowest values of mortality incidence ratio (MIR) for lung cancer due to continents division were 0.93 and 0.71 for Eastern Africa and Australia/New Zealand, respectively. Univariate analysis showed significant relationship (P<0.0001) between ASIR and ASMR with life expectancy at birth and mean years of schooling. The highest MIR for lung cancer was for medium human development countries. Linear regression analysis showed a reverse significant relationship between MIR and HDI.

What explains violated expectations of parent-child relationship in transition to parenthood?

PubMed

Flykt, Marjo; Palosaari, Esa; Lindblom, Jallu; Vänskä, Mervi; Poikkeus, Piia; Repokari, Leena; Tiitinen, Aila; Tulppala, Maija; Punamäki, Raija-Leena

2014-04-01

Parent-child relationship is created already in prenatal fantasies and expectations of the child-to-be. Negative violation of these expectations after the child is born is known to be harmful for the parent-child relationship. Yet, research is scarce about the medical and psychological factors contributing to violated expectations (VE). This study models the role of parent-, delivery- and infant-related underlying mechanisms for VE. It further compares parents with assisted reproductive treatment (ART) and spontaneous conception (SC), and primi- and multiparous couples. The couples (n = 743) separately filled in questionnaires concerning their prenatal expectations (T1) and 2 months postnatal representations (T2) of intimacy and autonomy in the relationship with their child, measured with Subjective Family Picture Test. A negative or positive discrepancy indicated violated expectations. The parent-related (mental health and marital quality), delivery-related (maternal and paternal birth experience, unplanned Caesarean, and amount of analgesia) and infant-related (infant health problems, difficult infant characteristics, and parental worry) factors were assessed at T2. Results show that among mothers, the associations were mostly indirect and mediated via mental health problems. Among fathers, the associations were direct, marital problems most crucially predicting VE. ART fathers were less susceptible to VE resulting from infant-related problems than SC fathers, but more susceptible to VE resulting from delivery problems. Delivery- and infant-related factors also predicted VE differently among primi- and multiparous mothers. Considering factors that contribute to VE is important when working with couples in transition to parenthood. PsycINFO Database Record (c) 2014 APA, all rights reserved.

[Quantitative relationship between gas chromatographic retention time and structural parameters of alkylphenols].

PubMed

Ruan, Xiaofang; Zhang, Ruisheng; Yao, Xiaojun; Liu, Mancang; Fan, Botao

2007-03-01

Alkylphenols are a group of permanent pollutants in the environment and could adversely disturb the human endocrine system. It is therefore important to effectively separate and measure the alkylphenols. To guide the chromatographic analysis of these compounds in practice, the development of quantitative relationship between the molecular structure and the retention time of alkylphenols becomes necessary. In this study, topological, constitutional, geometrical, electrostatic and quantum-chemical descriptors of 44 alkylphenols were calculated using a software, CODESSA, and these descriptors were pre-selected using the heuristic method. As a result, three-descriptor linear model (LM) was developed to describe the relationship between the molecular structure and the retention time of alkylphenols. Meanwhile, the non-linear regression model was also developed based on support vector machine (SVM) using the same three descriptors. The correlation coefficient (R(2)) for the LM and SVM was 0.98 and 0. 92, and the corresponding root-mean-square error was 0. 99 and 2. 77, respectively. By comparing the stability and prediction ability of the two models, it was found that the linear model was a better method for describing the quantitative relationship between the retention time of alkylphenols and the molecular structure. The results obtained suggested that the linear model could be applied for the chromatographic analysis of alkylphenols with known molecular structural parameters.

Measuring functional service quality using SERVQUAL in a high-dependence health service relationship.

PubMed

Clark, W Randy; Clark, Leigh Anne

2007-01-01

Although there is a growing concern about health care quality, little research has focused on how to measure quality in long-term care settings. In this article, we make the following observations: (1) most users of the SERVQUAL instrument reassess customers' expectations each time they measure quality perceptions; (2) long-term care relationships are likely to be ongoing, dependent relationships; (3) because of this dependence, customers in the long-term care setting are likely to reduce their expectations when faced with poor service quality; (4) by using this "settled" expectations level, service providers may make biased conclusions of quality improvements. We recommend various methods for overcoming or minimizing this "settling" effect and propose modifications to the SERVQUAL gap 5 measure to assess quality in a long-term care setting.

Reinforcement expectations explain the relationship between depressive history and smoking status in college students.

PubMed

McChargue, Dennis E; Spring, Bonnie; Cook, Jessica W; Neumann, Christopher A

2004-07-01

Little is understood about biobehavioral mechanisms that mediate the comorbidity between cigarette smoking and depression. We hypothesized that expectancies about nicotine's reinforcing effects are associated with vulnerability to depression, and may partially explain the relationship between history of depression and smoking. Young adult smokers and never smokers (N=175, mean age=19.9 years, S.D.=3.2) were assessed for history of depression and expectations about the negative (e.g., dispels bad moods) and positive (e.g., increases pleasure) reinforcing effects of smoking. Results are inconsistent with the premise that negative reinforcement expectancies mediate the comorbidity between depression and nicotine dependence. Instead, findings suggest that young adults with a prior history of major depression hold exaggerated expectations about nicotine's positive effects, which could enhance their likelihood of initiating smoking. Copyright 2004 Elsevier Ltd.

Emotional Dependency and Dysfunctional Relationship Beliefs as Predictors of Married Turkish Individuals' Relationship Satisfaction.

PubMed

Kemer, Gülşah; Çetinkaya Yıldız, Evrim; Bulgan, Gökçe

2016-11-02

In this study, we examined married individuals' relationship satisfaction in relation to their emotional dependency and dysfunctional relationship beliefs. Our participants consisted of 203 female and 181 male, a total of 384 married individuals from urban cities of Turkey. Controlling the effects of gender and length of marriage, we performed a hierarchical regression analysis. Results revealed that married Turkish individuals' relationship satisfaction was significantly explained by their emotional dependency (sr 2 = .300, p < .001), and perceptions of interpersonal rejection (sr 2 = .075, p < .001) and unrealistic relationship expectations (sr 2 = .028, p .05). When compared to perceptions of interpersonal rejection and unrealistic relationship expectations, emotional dependency had the largest role in explaining participants' satisfaction with their marriages. We discuss the results in light of current literature as well as cultural relevance. We also provide implications for future research and mental health practices.

The Intergenerational Family Relationships of Grandparents and GLBQ Grandchildren

PubMed Central

Scherrer, Kristin S.

2010-01-01

This paper describes the intergenerational family relationships of grandparents and GLBQ grandchildren. Reviewing empirical research on GLBQ family of origin relationships that include materials on grandparent-GLBQ grandchild relationships, this paper examines, 1) disclosure patterns with grandparents, 2) social expectations that exist about “coming out” to grandparents, 3) social expectations of GLBQ grandchildren when “coming out” to grandparents, 4) the mediating role of parents and other extended family in grandparent-GLBQ grandchild relationships, and 5) theorizing differences amongst grandparent-GLBQ grandchild relationships. This review indicates that grandparents have been overlooked in existing empirical research in research on GLBQ family relationships. Grandparents may be a unique source of support for younger GLBQ individuals and their parents. Future research may usefully incorporate grandparents, as well as other extended family members, to better understand the experience of “coming out” in families. PMID:20865130

The Relationship Between X-Ray Radiance and Magnetic Flux

NASA Astrophysics Data System (ADS)

Pevtsov, Alexei A.; Fisher, George H.; Acton, Loren W.; Longcope, Dana W.; Johns-Krull, Christopher M.; Kankelborg, Charles C.; Metcalf, Thomas R.

2003-12-01

We use soft X-ray and magnetic field observations of the Sun (quiet Sun, X-ray bright points, active regions, and integrated solar disk) and active stars (dwarf and pre-main-sequence) to study the relationship between total unsigned magnetic flux, Φ, and X-ray spectral radiance, LX. We find that Φ and LX exhibit a very nearly linear relationship over 12 orders of magnitude, albeit with significant levels of scatter. This suggests a universal relationship between magnetic flux and the power dissipated through coronal heating. If the relationship can be assumed linear, it is consistent with an average volumetric heating rate Q~B/L, where B is the average field strength along a closed field line and L is its length between footpoints. The Φ-LX relationship also indicates that X-rays provide a useful proxy for the magnetic flux on stars when magnetic measurements are unavailable.

Curvilinear relationships between resource allocation and life domain-specific interference.

PubMed

Waldrop, Jessica S; Erb, Kaitlyn R; Grawitch, Matthew J

2017-10-01

This study investigated the inherent complexities of the work-life interface (WLI) by examining the relationship between resource allocation (i.e., time and energy dedicated to a particular domain) and perceived interference of individual life domains. Much of the research on the WLI is based on the assumption that a linear pattern best describes the relationship between resource allocation and the interference caused by various life domains; however, this study examined the possibility that curvilinear relationships may be a more appropriate representation. Results indicated that resource allocation is a meaningful predictor of interference, and for many life domains a curvilinear relationship accounts for more variance than a linear one; a breakdown of the sample also revealed this relationship varies by gender. Overall, findings suggest that the nature of the WLI is more individualized and complex than is currently conceptualized in the field. Copyright © 2016 John Wiley & Sons, Ltd.

Utility of Higher Harmonics in Electrospray Ionization Fourier Transform Electrostatic Linear Ion Trap Mass Spectrometry.

PubMed

Dziekonski, Eric T; Johnson, Joshua T; McLuckey, Scott A

2017-04-18

Mass resolution (M/ΔM fwhm) is observed to linearly increase with harmonic order in a Fourier transform electrostatic linear ion trap (ELIT) mass spectrometer. This behavior was predicted by Grosshans and Marshall for frequency-multiple detection in a Fourier transform ion cyclotron resonance mass spectrometer only for situations when the prominent mechanism for signal decay is ion ejection from the trap. As the analyzer pressure in our ELIT chamber is relatively high, such that collisional scattering and collision-induced dissociation are expected to underlie much of the ion loss, we sought to explore the relationship between harmonic order and mass resolution. Mass resolutions of 36 900 (fundamental), 75 850 (2nd harmonic), and 108 200 (3rd harmonic) were obtained for GdO + (avg. m/z 173.919) with a transient length of 300 ms. To demonstrate that the mass resolution was truly increasing with harmonic order, the unresolved isotopes at the fundamental distribution of cytochrome c +8 (m/z ∼ 1549) were nearly baseline, resolved at the third harmonic (mass resolution ≈ 23 000) with a transient length of only 200 ms. This experiment demonstrates that, when the ion density is sufficiently low, ions with frequency differences of less than 4 Hz remain uncoalesced. Higher harmonics can be used to increase the effective mass resolution for a fixed transient length and thereby may enable the resolution of closely spaced masses, determination of a protein ion's charge state, and study of the onset of peak coalescence when the resolution at the fundamental frequency is insufficient.

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

Otake, M.; Schull, W.J.

The occurrence of lenticular opacities among atomic bomb survivors in Hiroshima and Nagasaki detected in 1963-1964 has been examined in reference to their ..gamma.. and neutron doses. A lenticular opacity in this context implies an ophthalmoscopic and slit lamp biomicroscopic defect in the axial posterior aspect of the lens which may or may not interfere measureably with visual acuity. Several different dose-response models were fitted to the data after the effects of age at time of bombing (ATB) were examined. Some postulate the existence of a threshold(s), others do not. All models assume a ''background'' exists, that is, that somemore » number of posterior lenticular opacities are ascribable to events other than radiation exposure. Among these alternatives we can show that a simple linear ..gamma..-neutron relationship which assumes no threshold does not fit the data adequately under the T65 dosimetry, but does fit the recent Oak Ridge and Lawrence Livermore estimates. Other models which envisage quadratic terms in gamma and which may or may not assume a threshold are compatible with the data. The ''best'' fit, that is, the one with the smallest X/sup 2/ and largest tail probability, is with a ''linear gamma:linear neutron'' model which postulates a ..gamma.. threshold but no threshold for neutrons. It should be noted that the greatest difference in the dose-response models associated with the three different sets of doses involves the neutron component, as is, of course, to be expected. No effect of neutrons on the occurrence of lenticular opacities is demonstrable with either the Lawrence Livermore or Oak Ridge estimates.« less

Relationships between nonlinear normal modes and response to random inputs

NASA Astrophysics Data System (ADS)

Schoneman, Joseph D.; Allen, Matthew S.; Kuether, Robert J.

2017-02-01

The ability to model nonlinear structures subject to random excitation is of key importance in designing hypersonic aircraft and other advanced aerospace vehicles. When a structure is linear, superposition can be used to construct its response to a known spectrum in terms of its linear modes. Superposition does not hold for a nonlinear system, but several works have shown that a system's dynamics can still be understood qualitatively in terms of its nonlinear normal modes (NNMs). This work investigates the connection between a structure's undamped nonlinear normal modes and the spectrum of its response to high amplitude random forcing. Two examples are investigated: a spring-mass system and a clamped-clamped beam modeled within a geometrically nonlinear finite element package. In both cases, an intimate connection is observed between the smeared peaks in the response spectrum and the frequency-energy dependence of the nonlinear normal modes. In order to understand the role of coupling between the underlying linear modes, reduced order models with and without modal coupling terms are used to separate the effect of each NNM's backbone from the nonlinear couplings that give rise to internal resonances. In the cases shown here, uncoupled, single-degree-of-freedom nonlinear models are found to predict major features in the response with reasonable accuracy; a highly inexpensive approximation such as this could be useful in design and optimization studies. More importantly, the results show that a reduced order model can be expected to give accurate results only if it is also capable of accurately predicting the frequency-energy dependence of the nonlinear modes that are excited.

Diagnosis of Enzyme Inhibition Using Excel Solver: A Combined Dry and Wet Laboratory Exercise

ERIC Educational Resources Information Center

Dias, Albino A.; Pinto, Paula A.; Fraga, Irene; Bezerra, Rui M. F.

2014-01-01

In enzyme kinetic studies, linear transformations of the Michaelis-Menten equation, such as the Lineweaver-Burk double-reciprocal transformation, present some constraints. The linear transformation distorts the experimental error and the relationship between "x" and "y" axes; consequently, linear regression of transformed data…

Relationships between depression, anxiety, and pain in a group of university music students.

PubMed

Wristen, Brenda W; Fountain, Sarah E

2013-09-01

There is emerging interest in studying the incidence of music-related injuries and problems among students. The current study drew on a data set collected from 287 music majors and minors at a large US midwestern university school of music in order to determine if correlations existed between anxiety and/or depression and the reported presence of physical pain, and to understand the nature of any such relationships. Physical pain symptoms were scored on a scale of 0 (none) to 10 (excruciating) and summed across 21 body regions. Depression and anxiety symptoms were scored as none (0), mild (1), moderate (2), or severe (3), and each summed across either 13 symptoms for depression or 8 symptoms for anxiety. The potential linear relationship among these variables was evaluated using F-tests (as part of ANOVAs) and linear regression parameter estimation techniques. The explanatory value of these relationships was evaluated using R² values. Results indicate a clear positive linear relationship between both depression and pain, and anxiety and pain. However, the presence of depression and/or anxiety symptoms was insufficient to explain variability in pain scores of these participants.

Dynamic linkages among the gold market, US dollar and crude oil market

NASA Astrophysics Data System (ADS)

Mo, Bin; Nie, He; Jiang, Yonghong

2018-02-01

This paper aims to examine the dynamic linkages among the gold market, US dollar and crude oil market. The analysis also delves more deeply into the effect of the global financial crisis on the short-term relationship. We use fractional cointegration to analyze the long-term memory feature of these volatility processes to investigate whether they are tied through a common long-term equilibrium. The DCC-MGARCH model is employed to investigate the time-varying long-term linkages among these markets. The Krystou-Labys non-linear asymmetric Granger causality method is used to examine the effect of the financial crisis. We find that (i) there is clearly a long-term dependence among these markets; (ii) the dynamic gold-oil relationship is always positive and the oil-dollar relationship is always negative; and (iii) after the crisis, we can observe evidence of a positive non-linear causal relationship from gold to US dollar and US dollar to crude oil, and a negative non-linear causal relationship from US dollar to gold. Investors who want to construct their optimal portfolios and policymakers who aim to make effective macroeconomic policies should take these findings into account.

Deriving Hounsfield units using grey levels in cone beam computed tomography

PubMed Central

Mah, P; Reeves, T E; McDavid, W D

2010-01-01

Objectives An in vitro study was performed to investigate the relationship between grey levels in dental cone beam CT (CBCT) and Hounsfield units (HU) in CBCT scanners. Methods A phantom containing 8 different materials of known composition and density was imaged with 11 different dental CBCT scanners and 2 medical CT scanners. The phantom was scanned under three conditions: phantom alone and phantom in a small and large water container. The reconstructed data were exported as Digital Imaging and Communications in Medicine (DICOM) and analysed with On Demand 3D® by Cybermed, Seoul, Korea. The relationship between grey levels and linear attenuation coefficients was investigated. Results It was demonstrated that a linear relationship between the grey levels and the attenuation coefficients of each of the materials exists at some “effective” energy. From the linear regression equation of the reference materials, attenuation coefficients were obtained for each of the materials and CT numbers in HU were derived using the standard equation. Conclusions HU can be derived from the grey levels in dental CBCT scanners using linear attenuation coefficients as an intermediate step. PMID:20729181

A meta-analysis of cambium phenology and growth: linear and non-linear patterns in conifers of the northern hemisphere.

PubMed

Rossi, Sergio; Anfodillo, Tommaso; Cufar, Katarina; Cuny, Henri E; Deslauriers, Annie; Fonti, Patrick; Frank, David; Gricar, Jozica; Gruber, Andreas; King, Gregory M; Krause, Cornelia; Morin, Hubert; Oberhuber, Walter; Prislan, Peter; Rathgeber, Cyrille B K

2013-12-01

Ongoing global warming has been implicated in shifting phenological patterns such as the timing and duration of the growing season across a wide variety of ecosystems. Linear models are routinely used to extrapolate these observed shifts in phenology into the future and to estimate changes in associated ecosystem properties such as net primary productivity. Yet, in nature, linear relationships may be special cases. Biological processes frequently follow more complex, non-linear patterns according to limiting factors that generate shifts and discontinuities, or contain thresholds beyond which responses change abruptly. This study investigates to what extent cambium phenology is associated with xylem growth and differentiation across conifer species of the northern hemisphere. Xylem cell production is compared with the periods of cambial activity and cell differentiation assessed on a weekly time scale on histological sections of cambium and wood tissue collected from the stems of nine species in Canada and Europe over 1-9 years per site from 1998 to 2011. The dynamics of xylogenesis were surprisingly homogeneous among conifer species, although dispersions from the average were obviously observed. Within the range analysed, the relationships between the phenological timings were linear, with several slopes showing values close to or not statistically different from 1. The relationships between the phenological timings and cell production were distinctly non-linear, and involved an exponential pattern. The trees adjust their phenological timings according to linear patterns. Thus, shifts of one phenological phase are associated with synchronous and comparable shifts of the successive phases. However, small increases in the duration of xylogenesis could correspond to a substantial increase in cell production. The findings suggest that the length of the growing season and the resulting amount of growth could respond differently to changes in environmental conditions.

Bidirectional Associations between Sibling Relationships and Parental Support during Adolescence

ERIC Educational Resources Information Center

Derkman, Marleen M. S.; Engels, Rutger C. M. E.; Kuntsche, Emmanuel; van der Vorst, Haske; Scholte, Ron H. J.

2011-01-01

Sibling relationships and parental support are important for adolescents' development and well-being, yet both are likely to change during adolescence. Since adolescents participate in both the sibling relationship and the parent-child relationship, we can expect sibling relationships and parental support to be associated with each other.…

[Heath and political regimes: presidential or parliamentary government for Colombia?].

PubMed

Idrovo, Alvaro J

2007-01-01

Changing the presidential regime for a parliamentarian one is currently be-ing discussed in Colombia. This preliminary study explores the potential effects on health of both presidential and parliamentary regimes by using world-wide data. An ecological study was undertaken using countries from which comparable information concerning life-expectancy at birth, political regime, economic development, inequality in income, social capital (as measured by general-ised trust or Corruption Perceptions Index), political rights, civil freedom and cultural diversity could be obtained. Life-expectancy at birth and macro-determinants were compared between both political regimes. The co-relationship between these macro-determinants was estimated and the relationship between political regimen and life-expectancy at birth was estimated using robust regression. Crude analysis revealed that parliamentary countries have greater life-expectancy at birth than countries having a presidential regime. Significant co-relationships between all macro-determinants were observed. No differential effects were observed between both political regimes regarding life-expectancy at birth in multiple robust regressions. There is no evidence that presidential or parliamentary regimes provide greater levels of health for the population. It is suggested that public health policies be focused on other macro-determinants having more known effects on health, such as income inequality.

A Qualitative Study of Three Urban Catholic High Schools: Investigating Parent and Principal Expectations and Realizations of Parental Involvement and the Parent-School Relationship

ERIC Educational Resources Information Center

Holyk-Casey, Karen

2012-01-01

This qualitative study investigated parents' and principals' expectations of their roles in the parent-school relationship and how they defined, encouraged, and realized parental involvement within an urban Catholic high school setting. Through pattern analysis and axial coding of the data collected from parents and principal interviews,…

Relationships between High School Chemistry Students' Perceptions of a Constructivist Learning Environment and their STEM Career Expectations

NASA Astrophysics Data System (ADS)

Wild, Andrew

2015-09-01

Considerable attention has been devoted to factors affecting the persistence of women and historically underrepresented ethnic groups in their science education trajectories. The literature has focused more on structural factors that affect longitudinal outcomes rather than classroom experiences. This exploratory survey study described relationships among high school chemistry students' perceptions of a constructivist learning environment (CLE) and STEM career expectations. The sample included 693 students from 7 public high schools within the San Francisco Bay Area. Students' perceptions of a CLE predicted their expectations of entering a science career, but not engineering, computer, health, or mathematics-related careers. When all groups of students perceived the learning environment as more constructivist, they were more likely to expect science careers.

Implementation of software-based sensor linearization algorithms on low-cost microcontrollers.

PubMed

Erdem, Hamit

2010-10-01

Nonlinear sensors and microcontrollers are used in many embedded system designs. As the input-output characteristic of most sensors is nonlinear in nature, obtaining data from a nonlinear sensor by using an integer microcontroller has always been a design challenge. This paper discusses the implementation of six software-based sensor linearization algorithms for low-cost microcontrollers. The comparative study of the linearization algorithms is performed by using a nonlinear optical distance-measuring sensor. The performance of the algorithms is examined with respect to memory space usage, linearization accuracy and algorithm execution time. The implementation and comparison results can be used for selection of a linearization algorithm based on the sensor transfer function, expected linearization accuracy and microcontroller capacity. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

Regional variability among nonlinear chlorophyll-phosphorus relationships in lakes

USGS Publications Warehouse

Filstrup, Christopher T.; Wagner, Tyler; Soranno, Patricia A.; Stanley, Emily H.; Stow, Craig A.; Webster, Katherine E.; Downing, John A.

2014-01-01

The relationship between chlorophyll a (Chl a) and total phosphorus (TP) is a fundamental relationship in lakes that reflects multiple aspects of ecosystem function and is also used in the regulation and management of inland waters. The exact form of this relationship has substantial implications on its meaning and its use. We assembled a spatially extensive data set to examine whether nonlinear models are a better fit for Chl a—TP relationships than traditional log-linear models, whether there were regional differences in the form of the relationships, and, if so, which regional factors were related to these differences. We analyzed a data set from 2105 temperate lakes across 35 ecoregions by fitting and comparing two different nonlinear models and one log-linear model. The two nonlinear models fit the data better than the log-linear model. In addition, the parameters for the best-fitting model varied among regions: the maximum and lower Chl aasymptotes were positively and negatively related to percent regional pasture land use, respectively, and the rate at which chlorophyll increased with TP was negatively related to percent regional wetland cover. Lakes in regions with more pasture fields had higher maximum chlorophyll concentrations at high TP concentrations but lower minimum chlorophyll concentrations at low TP concentrations. Lakes in regions with less wetland cover showed a steeper Chl a—TP relationship than wetland-rich regions. Interpretation of Chl a—TP relationships depends on regional differences, and theory and management based on a monolithic relationship may be inaccurate.

A phenomenological biological dose model for proton therapy based on linear energy transfer spectra.

PubMed

Rørvik, Eivind; Thörnqvist, Sara; Stokkevåg, Camilla H; Dahle, Tordis J; Fjaera, Lars Fredrik; Ytre-Hauge, Kristian S

2017-06-01

The relative biological effectiveness (RBE) of protons varies with the radiation quality, quantified by the linear energy transfer (LET). Most phenomenological models employ a linear dependency of the dose-averaged LET (LET d ) to calculate the biological dose. However, several experiments have indicated a possible non-linear trend. Our aim was to investigate if biological dose models including non-linear LET dependencies should be considered, by introducing a LET spectrum based dose model. The RBE-LET relationship was investigated by fitting of polynomials from 1st to 5th degree to a database of 85 data points from aerobic in vitro experiments. We included both unweighted and weighted regression, the latter taking into account experimental uncertainties. Statistical testing was performed to decide whether higher degree polynomials provided better fits to the data as compared to lower degrees. The newly developed models were compared to three published LET d based models for a simulated spread out Bragg peak (SOBP) scenario. The statistical analysis of the weighted regression analysis favored a non-linear RBE-LET relationship, with the quartic polynomial found to best represent the experimental data (P = 0.010). The results of the unweighted regression analysis were on the borderline of statistical significance for non-linear functions (P = 0.053), and with the current database a linear dependency could not be rejected. For the SOBP scenario, the weighted non-linear model estimated a similar mean RBE value (1.14) compared to the three established models (1.13-1.17). The unweighted model calculated a considerably higher RBE value (1.22). The analysis indicated that non-linear models could give a better representation of the RBE-LET relationship. However, this is not decisive, as inclusion of the experimental uncertainties in the regression analysis had a significant impact on the determination and ranking of the models. As differences between the models were observed for the SOBP scenario, both non-linear LET spectrum- and linear LET d based models should be further evaluated in clinically realistic scenarios. © 2017 American Association of Physicists in Medicine.

Age at menarche, total mortality and mortality from ischaemic heart disease and stroke: the Adventist Health Study, 1976–88

PubMed Central

Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E

2009-01-01

Background Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. Methods A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. Results An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16–18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3–6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2–10.6)] and stroke [8.6% (95% CI 1.6–15.1)] mortality. Conclusions The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality. PMID:19188208

Age at menarche, total mortality and mortality from ischaemic heart disease and stroke: the Adventist Health Study, 1976-88.

PubMed

Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E

2009-02-01

Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16-18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3-6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2-10.6)] and stroke [8.6% (95% CI 1.6-15.1)] mortality. The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality.

Expectancy Theory as a Predictor of Faculty Motivation to Use a Course Management System

ERIC Educational Resources Information Center

Turcan, Marian

2010-01-01

The aim of this study was to explore the relationships between the elements of the Expectancy theory and faculty motivation to use a course management system. Specifically it analyzed if the elements of the Expectancy theory (Valence, Instrumentality and Expectancy) were useful in predicting faculty motivation when using Blackboard tools in…

Network diffusion accurately models the relationship between structural and functional brain connectivity networks

PubMed Central

Abdelnour, Farras; Voss, Henning U.; Raj, Ashish

2014-01-01

The relationship between anatomic connectivity of large-scale brain networks and their functional connectivity is of immense importance and an area of active research. Previous attempts have required complex simulations which model the dynamics of each cortical region, and explore the coupling between regions as derived by anatomic connections. While much insight is gained from these non-linear simulations, they can be computationally taxing tools for predicting functional from anatomic connectivities. Little attention has been paid to linear models. Here we show that a properly designed linear model appears to be superior to previous non-linear approaches in capturing the brain’s long-range second order correlation structure that governs the relationship between anatomic and functional connectivities. We derive a linear network of brain dynamics based on graph diffusion, whereby the diffusing quantity undergoes a random walk on a graph. We test our model using subjects who underwent diffusion MRI and resting state fMRI. The network diffusion model applied to the structural networks largely predicts the correlation structures derived from their fMRI data, to a greater extent than other approaches. The utility of the proposed approach is that it can routinely be used to infer functional correlation from anatomic connectivity. And since it is linear, anatomic connectivity can also be inferred from functional data. The success of our model confirms the linearity of ensemble average signals in the brain, and implies that their long-range correlation structure may percolate within the brain via purely mechanistic processes enacted on its structural connectivity pathways. PMID:24384152

Evaluating and Improving the SAMA (Segmentation Analysis and Market Assessment) Recruiting Model

DTIC Science & Technology

2015-06-01

and rewarding me with your love every day. xx THIS PAGE INTENTIONALLY LEFT BLANK 1 I. INTRODUCTION A. THE UNITED STATES ARMY RECRUITING...the relationship between the calculated SAMA potential and the actual 2014 performance. The scatterplot in Figure 8 shows a strong linear... relationship between the SAMA calculated potential and the contracting achievement for 2014, with an R-squared value of 0.871. Simple Linear Regression of

Prediction of trivalent actinide amino(poly)carboxylate complex stability constants using linear free energy relationships with the lanthanide series

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

Uhnak, Nic E.

Prediction of Trivalent Actinide Amino(poly)carboxylate Complex Stability Constants Using Linear Free Energy Relationships with the Lanthanide Series Alternative title: LFER Based Prediction of An(III) APC Stability Constants There is a gap in the literature regarding the complexation of amino(poly)carboxylate (APC) ligands with trivalent actinides (An(III))). The chemistry of the An(III) is nearly identical to that of the trivalent lanthanides Lns, but the An(III) express a slight enhancement when binding APC ligands. Presented in this report is a simple method of predicting the stability constants of the An(III), Pu, Am, Cm, Bk and Cf by using linear free energy relationships (LFER)more » of the An and the lanthanide (Ln) series for 91 APCs. This method produced An stability constants within uncertainty to available literature values for most ligands.« less

Adjusting head circumference for covariates in autism: clinical correlates of a highly heritable continuous trait.

PubMed

Chaste, Pauline; Klei, Lambertus; Sanders, Stephan J; Murtha, Michael T; Hus, Vanessa; Lowe, Jennifer K; Willsey, A Jeremy; Moreno-De-Luca, Daniel; Yu, Timothy W; Fombonne, Eric; Geschwind, Daniel; Grice, Dorothy E; Ledbetter, David H; Lord, Catherine; Mane, Shrikant M; Lese Martin, Christa; Martin, Donna M; Morrow, Eric M; Walsh, Christopher A; Sutcliffe, James S; State, Matthew W; Devlin, Bernie; Cook, Edwin H; Kim, Soo-Jeong

2013-10-15

Brain development follows a different trajectory in children with autism spectrum disorders (ASD) than in typically developing children. A proxy for neurodevelopment could be head circumference (HC), but studies assessing HC and its clinical correlates in ASD have been inconsistent. This study investigates HC and clinical correlates in the Simons Simplex Collection cohort. We used a mixed linear model to estimate effects of covariates and the deviation from the expected HC given parental HC (genetic deviation). After excluding individuals with incomplete data, 7225 individuals in 1891 families remained for analysis. We examined the relationship between HC/genetic deviation of HC and clinical parameters. Gender, age, height, weight, genetic ancestry, and ASD status were significant predictors of HC (estimate of the ASD effect = .2 cm). HC was approximately normally distributed in probands and unaffected relatives, with only a few outliers. Genetic deviation of HC was also normally distributed, consistent with a random sampling of parental genes. Whereas larger HC than expected was associated with ASD symptom severity and regression, IQ decreased with the absolute value of the genetic deviation of HC. Measured against expected values derived from covariates of ASD subjects, statistical outliers for HC were uncommon. HC is a strongly heritable trait, and population norms for HC would be far more accurate if covariates including genetic ancestry, height, and age were taken into account. The association of diminishing IQ with absolute deviation from predicted HC values suggests HC could reflect subtle underlying brain development and warrants further investigation. © 2013 Society of Biological Psychiatry.

Immunocytometric quantitation of foeto-maternal haemorrhage with the Abbott Cell-Dyn CD4000 haematology analyser.

PubMed

Little, B H; Robson, R; Roemer, B; Scott, C S

2005-02-01

This study evaluated the extended use of a haematology analyser (Abbott Cell-Dyn CD4000) for the immunofluorescent enumeration of foeto-maternal haemorrhage (FMH) with fluorescein isothiocyanate-labelled monoclonal anti-RhD. Method performance was assessed with artificial FMH standards, and a series of 44 clinical samples. Within run precision was <15% (coefficient of variation, CV) for FMH volumes of 3 ml and above, 18.8% at an FMH volume of 2 ml and 31.7% at an FMH volume of 1 ml. Linearity analysis showed excellent agreement (observed FMH% = 0.98x expected FMH% + 0.02), and a close relationship (R(2) = 0.99) between observed and expected FMH percentages. The lower limit of quantification of the CD4000 (SRP-Ret) method with a maximum CV of 15% was 1.6 ml, and the limit of detection was <1 ml. Parallel Kleihauer-Betke test (KBT) assessments of FMH standards showed an overall trend for higher KBT values (observed = 1.25x expected - 0.38). At an FMH level of 4 ml, KBT observer estimates ranged from 0.57 to 11.94 ml with a mean inter-observer CV of 63%. For 44 clinical samples, there was decision point agreement between KBT and SRP-Ret results for 42 samples with an FMH of <2 ml. Analysis in the low FMH range (<1 ml) showed that small volume foetal leaks could be detected with the SRP-Ret method in most of 23 samples with negative KBT results. CD4000 SRP-Ret method performance for FMH determination was similar to that reported for flow cytometry.

Clinician perceptions of an electronic medical record during the first year of implementaton in emergency services.

PubMed

Chisolm, Deena J; Purnell, Tanjala S; Cohen, Daniel M; McAlearney, Ann Scheck

2010-02-01

The objectives of this study were to measure clinician perceptions of the recently implemented electronic medical record (EMR) system in a pediatric emergency department and off-site urgent care centers and to determine how user perceptions changed over time. Physicians and nurses from the emergency department/urgent care center were recruited to complete an online survey at 3 points in time: 30 to 89 days (wave 1), 90 to 179 days (wave 2), and 180 to 270 days after implementation (wave 3). Potential predictors of initial satisfaction studied included effort expectancy, performance expectancy, social support, and facilitating conditions, along with user demographics and general attitudes toward technology. Bivariate relationships with satisfaction were assessed using the Wilcoxon rank sum test and correlation analysis. A final multivariate linear regression model was calculated. Change in satisfaction over time was tested using a Wilcoxon signed rank test. A total of 71 clinicians completed the surveys. Initial satisfaction was strongly associated with perceptions of training and support (facilitating conditions) and with perceived usefulness (performance expectancy). Satisfaction was not associated with user sex, age, or role (physician vs nurse). No significant change was found in any satisfaction measure at wave 2 or 3; however, satisfaction with functionality trended higher and satisfaction with reliability trended lower over the course of use. Satisfaction with an EMR at its launch generally persisted through the first year of use. Implementation plans must maximize the likelihood of achieving positive early impressions of training, support, and performance to engender high user satisfaction with the EMR.

Adjusting head circumference for covariates in autism: clinical correlates of a highly heritable continuous trait

PubMed Central

Chaste, Pauline; Klei, Lambertus; Sanders, Stephan J.; Murtha, Michael T.; Hus, Vanessa; Lowe, Jennifer K.; Willsey, A. Jeremy; Moreno-De-Luca, Daniel; Yu, Timothy W.; Fombonne, Eric; Geschwind, Daniel; Grice, Dorothy E.; Ledbetter, David H.; Lord, Catherine; Mane, Shrikant M.; Martin, Christa Lese; Martin, Donna M.; Morrow, Eric M.; Walsh, Christopher A.; Sutcliffe, James S.; State, Matthew W.; Devlin, Bernie; Cook, Edwin H.; Kim, Soo-Jeong

2013-01-01

BACKGROUND Brain development follows a different trajectory in children with Autism Spectrum Disorders (ASD) than in typically developing children. A proxy for neurodevelopment could be head circumference (HC), but studies assessing HC and its clinical correlates in ASD have been inconsistent. This study investigates HC and clinical correlates in the Simons Simplex Collection cohort. METHODS We used a mixed linear model to estimate effects of covariates and the deviation from the expected HC given parental HC (genetic deviation). After excluding individuals with incomplete data, 7225 individuals in 1891 families remained for analysis. We examined the relationship between HC/genetic deviation of HC and clinical parameters. RESULTS Gender, age, height, weight, genetic ancestry and ASD status were significant predictors of HC (estimate of the ASD effect=0.2cm). HC was approximately normally distributed in probands and unaffected relatives, with only a few outliers. Genetic deviation of HC was also normally distributed, consistent with a random sampling of parental genes. Whereas larger HC than expected was associated with ASD symptom severity and regression, IQ decreased with the absolute value of the genetic deviation of HC. CONCLUSIONS Measured against expected values derived from covariates of ASD subjects, statistical outliers for HC were uncommon. HC is a strongly heritable trait and population norms for HC would be far more accurate if covariates including genetic ancestry, height and age were taken into account. The association of diminishing IQ with absolute deviation from predicted HC values suggests HC could reflect subtle underlying brain development and warrants further investigation. PMID:23746936

The influence of prior experience and expected timing on vibrotactile discrimination

PubMed Central

Karim, Muhsin; Harris, Justin A.; Langdon, Angela; Breakspear, Michael

2013-01-01

Vibrotactile discrimination tasks involve perceptual judgements on stimulus pairs separated by a brief interstimulus interval (ISI). Despite their apparent simplicity, decision making during these tasks is biased by prior experience in a manner that is not well understood. A striking example is when participants perform well on trials where the first stimulus is closer to the mean of the stimulus-set than the second stimulus, and perform comparatively poorly when the first stimulus is further from the stimulus mean. This “time-order effect” suggests that participants implicitly encode the mean of the stimulus-set and use this internal standard to bias decisions on any given trial. For relatively short ISIs, the magnitude of the time-order effect typically increases with the distance of the first stimulus from the global mean. Working from the premise that the time-order effect reflects the loss of precision in working memory representations, we predicted that the influence of the time-order effect, and this superimposed “distance” effect, would monotonically increase for trials with longer ISIs. However, by varying the ISI across four intervals (300, 600, 1200, and 2400 ms) we instead found a complex, non-linear dependence of the time-order effect on both the ISI and the distance, with the time-order effect being paradoxically stronger at short ISIs. We also found that this relationship depended strongly on participants' prior experience of the ISI (from previous task titration). The time-order effect not only depends on participants' expectations concerning the distribution of stimuli, but also on the expected timing of the trials. PMID:24399927

The intergenerational transmission of problem gambling: The mediating role of offspring gambling expectancies and motives.

PubMed

Dowling, N A; Oldenhof, E; Shandley, K; Youssef, G J; Vasiliadis, S; Thomas, S A; Frydenberg, E; Jackson, A C

2018-02-01

The risk for developing a gambling problem is greater among offspring who have a problem gambling parent, yet little research has directly examined the mechanisms by which this transmission of problem gambling occurs. For this reason, the present study sought to examine the degree to which children's expectancies and motives relating to gambling explain, at least in part, the intergenerational transmission of problem gambling. Participants (N=524; 56.5% male) were recruited from educational institutions, and retrospectively reported on parental problem gambling. Problem gambling was measured using the Problem Gambling Severity Index and a range of positive and negative expectancies and gambling motives were explored as potential mediators of the relationship between parent-and-participant problem gambling. The relationship between parent-and-participant problem gambling was significant, and remained so after controlling for sociodemographic factors and administration method. Significant mediators of this relationship included self-enhancement expectancies (feeling in control), money expectancies (financial gain), over-involvement (preoccupation with gambling) and emotional impact expectancies (guilt, shame, and loss), as well as enhancement motives (gambling to increase positive feelings) and coping motives (gambling to reduce or avoid negative emotions). All mediators remained significant when entered into the same model. The findings highlight that gambling expectancies and motives present unique pathways to the development of problem gambling in the offspring of problem gambling parents, and suggest that gambling cognitions may be potential candidates for targeted interventions for the offspring of problem gamblers. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Opinions about Relationship between Students and Teachers in the Class of Hands-on

NASA Astrophysics Data System (ADS)

Pigultong, M.

2018-02-01

This research has the purpose to study on 1) Relationship between Students and Teachers in the Class of Hands - on and 2) Class Management at Rajamangala University of Technology Thanyaburi. The research consists of collecting information from 400 students who have valid student status in 2016 at Rajamangala University of Technology Thanyaburi. This research uses content analysis technique, Average (-X) and Standard Deviation to interpret the information. The results of the research focus on 2 topics 1) The Human relationship between Students and Teachers. The samples group had high expectations of human relationship (x=3.87). 2) Class Management. The samples group had high expectations of Class Management (x=3.88).

Examining the relationships between posttraumatic stress disorder symptoms, positive smoking outcome expectancies, and cigarette smoking in people with substance use disorders: a multiple mediator model.

PubMed

Hruska, Bryce; Bernier, Jennifer; Kenner, Frank; Kenne, Deric R; Boros, Alec P; Richardson, Christopher J; Delahanty, Douglas L

2014-01-01

Cigarette smoking is highly prevalent in people with substance use disorders (SUDs) and is associated with significant physical health problems. Posttraumatic stress disorder (PTSD) is also highly associated with both SUDs and cigarette smoking and may serve as a barrier to smoking cessation efforts. In addition, people with PTSD are more likely to hold positive smoking outcome expectancies (i.e., beliefs that smoking cigarettes results in positive outcomes); these beliefs may contribute to cigarette smoking in people with SUDs experiencing PTSD symptoms. The present study examined the relationship between PTSD symptoms and typical daily cigarette smoking/cigarette dependence symptoms in a sample of 227 trauma-exposed current smokers with SUDs (59.9% male, 89.4% Caucasian) seeking detoxification treatment services. Additionally, the indirect effects of multiple types of positive smoking outcome expectancies on these relationships were examined. Participants completed questionnaires assessing PTSD symptoms, positive smoking outcome expectancies, cigarette consumption, and cigarette dependence symptoms. Results indicated that PTSD symptoms were not directly related to cigarette consumption or cigarette dependence symptoms. However, negative affect reduction outcome expectancies were shown to have a significant indirect effect between PTSD symptoms and cigarette consumption, while negative affect reduction, boredom reduction, and taste-sensorimotor manipulation outcome expectancies were all found to have significant indirect effects between PTSD symptoms and cigarette dependence symptoms. The indirect effect involving negative affect reduction outcome expectancies was statistically larger than that of taste sensorimotor manipulation outcome expectancies, while negative affect reduction and boredom reduction outcome expectancies were comparable in magnitude. These results suggest that expectancies that smoking can manage negative affective experiences are related to cigarette smoking in people with SUDs experiencing PTSD symptoms and suggest that effective smoking cessation treatments should take into account these expectancies. © 2013.

Longitudinal Change in Happiness during Aging: The Predictive Role of Positive Expectancies

ERIC Educational Resources Information Center

Holahan, Carole K.; Holahan, Charles J.; Velasquez, Katherine E.; North, Rebecca J.

2008-01-01

This study employed hierarchical linear modeling to document the time course of happiness across 20 years from average ages of 66 to 86 among 717 members of the Terman Study of the Gifted. In addition, the study examined the role of positive expectancies about aging, assessed at an average age of 61, in enhancing happiness in aging. The results…

Girls (and Boys) Just Want to Have Fun: A Mixed-Methods Examination of the Role of Gender in Youth Mentoring Relationship Duration and Quality.

PubMed

Spencer, Renée; Drew, Alison L; Walsh, Jill; Kanchewa, Stella S

2018-02-01

This prospective, mixed-methods study examined the role of gender in youth mentoring relationship duration and quality. Participants were 67 gender-matched pairs of adult mentors and youth participating in community-based mentoring programs as well as the youths' guardians. Mentors and youth completed surveys and qualitative interviews at multiple time points. At baseline, male youth reported stronger relationships with their guardians. Analysis of the survey data from the 3-month follow-up revealed that male mentors and youth reported stronger mentoring relationship quality. Male matches were more likely to last at least 1 year. Further, male youth whose matches lasted at least 1 year reported better relationships with their guardians at baseline and reported stronger mentoring relationships after 3 months, compared to both females whose matches lasted greater than a year, and females whose matches lasted less than 1 year. Examinations of the qualitative interviews from a sub-sample of matched pairs (n = 29) showed that male and female youth and male mentors held similar expectations for the relationship, mainly to engage in fun activities, while female mentors were more often looking for a close relationship to develop quickly, which resulted in a disconnect between female mentees' and female mentors' expectations. Findings highlight the importance of developmentally appropriate relationships for youth and suggest that mentoring programs may be able facilitate longer, more effective matches for girls by tempering female mentors' expectations for how close and quickly those relationships will develop.

Understanding the relationship between religiousness, spirituality, and underage drinking: the role of positive alcohol expectancies.

PubMed

Sauer-Zavala, Shannon; Burris, Jessica L; Carlson, Charles R

2014-02-01

Research has consistently found that religiousness and spirituality are negatively associated with underage drinking. However, there is a paucity of research exploring the mechanisms by which these variables influence this important outcome. With 344 underage young adults (ages 18-20; 61 % women), we investigated positive alcohol expectancies as a mediator between religiousness and spirituality (measured separately) and underage alcohol use. Participants completed the Religious Commitment Inventory-10, Daily Spiritual Experiences Scale, Alcohol Expectancies Questionnaire, and Drinking Styles Questionnaire. Results indicate less positive alcohol expectancies partially mediate the relationship between both religiousness and spirituality and underage alcohol use. This suggests religiousness and spirituality's protective influence on underage drinking is partly due to their influence on expectations about alcohol's positive effects. Since underage drinking predicts problem drinking later in life and places one at risk for serious physical and mental health problems, it is important to identify specific points of intervention, including expectations about alcohol that rise from religious and spiritual factors.

The predictive utility of drinking refusal self-efficacy and alcohol expectancy: a diary-based study of tension reduction.

PubMed

Young, R M; Oei, T P

2000-01-01

The potential tension reduction effects of alcohol may be most appropriately tested by examining the role of alcohol related beliefs regarding alcohol's anxiolytic properties. The relationship between affective change drinking refusal self-efficacy, tension reduction alcohol expectancies, and ongoing drinking behavior was examined amongst 57 regular drinkers. Alcohol consumption, antecedent, and consequent mood states were monitored prospectively by diary, Social learning theory hypothesizes that low drinking refusal self-efficacy when experiencing a negative mood state should be associated with more frequent drinking when tense. Strong alcohol expectancies of tension reduction were hypothesized to predict subsequent tension reduction. Contrary to this hypothesis, the present study found that alcohol expectancies were more strongly related to antecedent mood states. Only a weak relationship between drinking refusal self-efficacy and predrinking tension, and between alcohol expectancy and subsequent tension reduction, was evident.

The Relationships of Expectancies With E-cigarette Use Among Hospitalized Smokers: A Prospective Longitudinal Study.

PubMed

Hendricks, Peter S; Thorne, Christopher B; Lappan, Sara N; Sweat, Noah W; Cheong, JeeWon; Ramachandran, Rekha; Kohler, Connie L; Bailey, William C; Harrington, Kathleen F

2018-01-05

Expectancies demonstrate cross-sectional associations with e-cigarette use, but the prospective relationships between expectancies and e-cigarette use are unknown. This study examined the longitudinal associations of expectancies with e-cigarette use among hospitalized tobacco cigarette smokers. E-cigarette expectancies (e-cigarette-specific Brief Smoking Consequences Questionnaire-Adult [BSCQ-A]), tobacco cigarette expectancies (tobacco-specific BSCQ-A), and number of days used e-cigarettes in the past 30 days were assessed at baseline hospitalization, 6-months post-hospitalization, and 12-months post-hospitalization among 978 hospitalized tobacco cigarette smokers. Expectancy difference scores (e-cigarette-specific expectancies minus tobacco-specific expectancies) were computed for each of the 10 BSCQ-A scales. Cross-lagged panel models tested the relationships between expectancy difference scores and number of days used e-cigarettes in the past 30 days for each of the 10 BSCQ-A scales. Though some models revealed partial associations between expectancies and e-cigarette use, only one yielded results consistent with hypotheses. Greater e-cigarette use at baseline predicted greater expectancies that e-cigarettes taste pleasant as compared to tobacco cigarettes at 6 months, which then predicted greater e-cigarette use at 12 months. To a lesser degree greater expectancies that e-cigarettes taste pleasant as compared to tobacco cigarettes at baseline predicted greater e-cigarette use at 6 months, which then predicted greater expectancies that e-cigarettes taste pleasant as compared to tobacco cigarettes at 12 months. Expectancies that e-cigarettes provide similar or more pleasant taste sensations as compared to tobacco cigarettes may be both a cause and consequence of e-cigarette use. Focusing on the taste experience may prove most effective in modifying e-cigarette use behavior. The current study offers the first longitudinal examination of expectancies and e-cigarette use. Results suggest expectancies that e-cigarettes provide similar or more pleasant taste sensations relative to tobacco cigarettes are both a cause and consequence of e-cigarette use. Efforts that focus on the e-cigarette taste experience may prove most effective in modifying e-cigarette use behavior. © The Author 2017. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Physics and control of wall turbulence for drag reduction.

PubMed

Kim, John

2011-04-13

Turbulence physics responsible for high skin-friction drag in turbulent boundary layers is first reviewed. A self-sustaining process of near-wall turbulence structures is then discussed from the perspective of controlling this process for the purpose of skin-friction drag reduction. After recognizing that key parts of this self-sustaining process are linear, a linear systems approach to boundary-layer control is discussed. It is shown that singular-value decomposition analysis of the linear system allows us to examine different approaches to boundary-layer control without carrying out the expensive nonlinear simulations. Results from the linear analysis are consistent with those observed in full nonlinear simulations, thus demonstrating the validity of the linear analysis. Finally, fundamental performance limit expected of optimal control input is discussed.

A Novel Nonlinear Piezoelectric Energy Harvesting System Based on Linear-Element Coupling: Design, Modeling and Dynamic Analysis.

PubMed

Zhou, Shengxi; Yan, Bo; Inman, Daniel J

2018-05-09

This paper presents a novel nonlinear piezoelectric energy harvesting system which consists of linear piezoelectric energy harvesters connected by linear springs. In principle, the presented nonlinear system can improve broadband energy harvesting efficiency where magnets are forbidden. The linear spring inevitably produces the nonlinear spring force on the connected harvesters, because of the geometrical relationship and the time-varying relative displacement between two adjacent harvesters. Therefore, the presented nonlinear system has strong nonlinear characteristics. A theoretical model of the presented nonlinear system is deduced, based on Euler-Bernoulli beam theory, Kirchhoff’s law, piezoelectric theory and the relevant geometrical relationship. The energy harvesting enhancement of the presented nonlinear system (when n = 2, 3) is numerically verified by comparing with its linear counterparts. In the case study, the output power area of the presented nonlinear system with two and three energy harvesters is 268.8% and 339.8% of their linear counterparts, respectively. In addition, the nonlinear dynamic response characteristics are analyzed via bifurcation diagrams, Poincare maps of the phase trajectory, and the spectrum of the output voltage.

Transmission of linear regression patterns between time series: From relationship in time series to complex networks

NASA Astrophysics Data System (ADS)

Gao, Xiangyun; An, Haizhong; Fang, Wei; Huang, Xuan; Li, Huajiao; Zhong, Weiqiong; Ding, Yinghui

2014-07-01

The linear regression parameters between two time series can be different under different lengths of observation period. If we study the whole period by the sliding window of a short period, the change of the linear regression parameters is a process of dynamic transmission over time. We tackle fundamental research that presents a simple and efficient computational scheme: a linear regression patterns transmission algorithm, which transforms linear regression patterns into directed and weighted networks. The linear regression patterns (nodes) are defined by the combination of intervals of the linear regression parameters and the results of the significance testing under different sizes of the sliding window. The transmissions between adjacent patterns are defined as edges, and the weights of the edges are the frequency of the transmissions. The major patterns, the distance, and the medium in the process of the transmission can be captured. The statistical results of weighted out-degree and betweenness centrality are mapped on timelines, which shows the features of the distribution of the results. Many measurements in different areas that involve two related time series variables could take advantage of this algorithm to characterize the dynamic relationships between the time series from a new perspective.