167 research outputs found
Informational Support And Online Information Seeking: Examining The Association Between Factors Contributing To Healthy Eating Behavior.
This study explores the nature of the relationship between informational social support and components of online health information seeking and how this process influences college students’ healthy eating intentions. Results showed that social support was positively associated with online information seeking and more favorable impressions of nutrition/healthy diet information on the web. In addition, although socialsupport was not associated with healthy eating intentions, all three information-seeking measures significantly predicted this outcome – even after controlling for numerous health-related factors. Additional mediation tests showed that social support had an indirect impact on healthy eating intentions through use as well as through a multi-step process involving perceptions of online resources. Overall, these results suggest that by raising health consciousness, informational support may trigger online health information seeking leading to healthier lifestyle intentions
Microfluidic rheometry
The development and growth of microfluidics has stimulated interest in the behaviour of complex liquids in micro-scale geometries and provided a rich platform for rheometric investigations of non-Newtonian phenomena at small scales. Microfluidic techniques present the rheologist with new opportunities for material property measurement and this review discusses the use of microfluidic devices to measure bulk rheology in both shear and extensional flows. Capillary, stagnation and contraction flows are presented in this context and developments, limitations and future perspectives are examined
A comprehensive constitutive law for waxy crude oil: a thixotropic yield stress fluid
Guided by a series of discriminating rheometric tests, we develop a new constitutive model that can quantitatively predict the key rheological features of waxy crude oils. We first develop a series of model crude oils, which are characterized by a complex thixotropic and yielding behavior that strongly depends on the shear history of the sample. We then outline the development of an appropriate preparation protocol for carrying out rheological measurements, to ensure consistent and reproducible initial conditions. We use RheoPIV measurements of the local kinematics within the fluid under imposed deformations in order to validate the selection of a particular protocol. Velocimetric measurements are also used to document the presence of material instabilities within the model crude oil under conditions of imposed steady shearing. These instabilities are a result of the underlying non-monotonic steady flow curve of the material. Three distinct deformation histories are then used to probe the material's constitutive response. These deformations are steady shear, transient response to startup of steady shear with different aging times, and large amplitude oscillatory shear (LAOS). The material response to these three different flows is used to motivate the development of an appropriate constitutive model. This model (termed the IKH model) is based on a framework adopted from plasticity theory and implements an additive strain decomposition into characteristic reversible (elastic) and irreversible (plastic) contributions, coupled with the physical processes of isotropic and kinematic hardening. Comparisons of experimental to simulated response for all three flows show good quantitative agreement, validating the chosen approach for developing constitutive models for this class of materials.Chevron Corporatio
Exploring How Perceived Threat And Self-Efficacy Contribute To College Students’ Use And Perceptions Of Online Mental Health Resources
Drawing from prior fear-appeal and information seeking research, this study explored how perceived threat and self-efficacy predicted college students’ use and perceptions of online mental health resources. Results showed that perceived vulnerability was a modest, yet robust predictor of visiting any Internet website and joining an online support group, while self-efficacy modestly predicted greater perceived usefulness and trust for online support groups. Although numerous interactions emerged between self-efficacy and perceived threat, the impact of these relationships on use and perceptions of these services varied significantly. In particular, at higher levels of self-efficacy, perceived severity negatively predict use of online services yet also positively predicted trust in these resources. Furthermore, results showed that vulnerability was only associated with favorable judgments of web services at lower levels of efficacy. Overall, the findings suggest that self-efficacy and perceived threat play a small, yet significant role in explaining online mental health information seeking outcomes; however, the exact nature by which these factors operate together to influence one’s use and larger impressions such resources remains unclear
Social Identity Theory as a Framework for Understanding the Effects of Exposure to Positive Media Images of Self and Other on Intergroup Outcomes
Based on the tenets of social identity theory, a two-study experimental design was conducted which examined the influence of exposure to positive Latino media exemplars on ingroup (Latino) and outgroup (white) consumers. Specifically, the impact of exposure on interethnic evaluations as well as perceptions of self and other was evaluated. Results from Study 1 and Study 2 suggest that although exposure to positive media depictions of Latinos can prompt more favorable evaluations of ingroup and self among Latinos, the same cannot necessarily be said for the effects of exposure to affirmative messages on judgments about Latinos among outgroup members (i.e., whites). Instead, these data indicate that for whites, ingroup (racial/ethnic) identification is a potent factor in media-related interethnic evaluations. [ABSTRACT FROM AUTHOR
The Influence of Statistical versus Exemplar Appeals on Indian Adults’ Health Intentions: An Investigation of Direct Effects and Intervening Persuasion Processes
In two separate investigations, we examined the persuasive effectiveness of statistical versus exemplar appeals on Indian adults’ smoking cessation and mammography screening intentions. To more comprehensively address persuasion processes, we explored whether message response and perceived message effectiveness functioned as antecedents to persuasive effects. Results showed that statistical appeals led to higher levels of health intentions than exemplar appeals. In addition, findings from both studies indicated that statistical appeals stimulated more attention and were perceived as more effective than anecdotal accounts. Among male smokers, statistical appeals also generated greater cognitive processing than exemplar appeals. Subsequent mediation analyses revealed that message response and perceived message effectiveness fully carried the influence of appeal format on health intentions. Given these findings, future public health initiatives conducted among similar populations should design messages that include substantive factual information while ensuring that this content is perceived as credible and valuable. [ABSTRACT FROM PUBLISHER
Re-examining LGBT Resources on College Counseling Center Websites: An Over-time and Cross-country Analysis
Lesbian, gay, bisexual, and transgender (LGBT) students continue to perceive a hostile climate on college campuses. For students facing these challenges, the university college counseling center website (CCW) may serve as a critical resource. This study provides an updated content analysis of the prevalence of LGBT communication on CCWs. Results showed that there remains a lack of LGBT-specific information about services provided on US CCWs. Furthermore, over-time analyses of 2008 and 2013 data showed that there have been no significant increases in any LGBT communication, and CCWs from religious schools continue to provide significantly less LGBT-related communication than nonreligious institutions. Separate analyses of UK CCWs showed that these websites were more likely than US CCWs to make any mention of LGBT issues but less likely to note group counseling services, links to LGBT-specific pamphlets, and educational outreach services offered. Overall, given attractive features of online health information, as well as the extent that students value CCWs, institutions must pursue stronger efforts to promote LGBT-related web counseling information. [ABSTRACT FROM AUTHOR
Spatiotemporal dynamics of multiple shear-banding events for viscoelastic micellar fluids in cone-plate shearing flows
We characterize the transient response of semi-dilute wormlike micellar solutions under an imposed steady shear flow in a cone-plate geometry. By combining conventional rheometry with 2-D Particle Image Velocimetry (PIV), we can simultaneously correlate the temporal stress response with time-resolved velocimetric measurements. By imposing a well defined shear history protocol, consisting of a stepped shear flow sweep, we explore both the linear and nonlinear responses of two surfactant solutions: cetylpiridinium chloride (CPyCl) and sodium salicylate (NaSal) mixtures at concentrations of [66:40] mM and [100:60] mM, respectively. The transient stress signal of the more dilute solution relaxes to its equilibrium value very fast and the corresponding velocity profiles remain linear, even in the strongly shear-thinning regime. The more concentrated solution also exhibits linear velocity profiles at small shear rates. At large enough shear rates, typically larger than the inverse of the relaxation time of the fluid, the flow field reorganizes giving rise to strongly shear-banded velocity profiles. These are composed of an odd number of shear bands with low-shear-rate bands adjacent to both gap boundaries. In the non-linear regime long transients (much longer than the relaxation time of the fluid) are observed in the transient stress response before the fluid reaches a final, fully-developed state. The temporal evolution in the shear stress can be correlated with the spatiotemporal dynamics of the multiple shear-banded structure measured using RheoPIV. In particular our experiments show the onset of elastic instabilities in the flow which are characterized by the presence of multiple shear bands that evolve and rearrange in time resulting in a slow increase in the average torque acting on the rotating fixture
Microfluidic extensional rheometry using a hyperbolic contraction geometry
Microfluidic devices are ideally suited for the study of complex fluids undergoing large deformation rates in the absence of inertial complications. In particular, a microfluidic contraction geometry can be utilized to characterize the material response of complex fluids in an extensionally-dominated flow, but the mixed nature of the flow kinematics makes quantitative measurements of material functions such as the true extensional viscosity challenging. In this paper, we introduce the ‘extensional viscometer-rheometer-on-a-chip’ (EVROC), which is a hyperbolically-shaped contraction-expansion geometry fabricated using microfluidic technology for characterizing the importance of viscoelastic effects in an extensionally-dominated flow at large extension rates (λ[. over ε][subscript a] ≫ 1, where λ is the characteristic relaxation time, or for many industrial processes . over ε][subscript a] ≫ 1 s[superscript −1]). We combine measurements of the flow kinematics, the mechanical pressure drop across the contraction and spatially-resolved flow-induced birefringence to study a number of model rheological fluids, as well as several representative liquid consumer products, in order to assess the utility of EVROC as an extensional viscosity indexer.National Science Foundation (U.S.). Graduate Research FellowshipUnited States. National Aeronautics and Space Administration (Microgravity Fluid Sciences Grant NNX09AV99G)European Commission. Marie Curie Actions (FP7-PEOPLE-2011-IIF Grant 298220
Nutrition Knowledge, Personal Motivation, And Food Label Use Among Indian Adults With Multiple Chronic Conditions: A Moderated Mediation Model.
Background: There has been little research conducted within developing nations examining the link between knowledge and diet-related perceptions and behaviors. In addition, prior investigations have rarely examined interrelationships between knowledge and other nutrition-related factors. Purpose: This study explored the relationship between nutrition knowledge, social/informational factors, and diet-related outcomes among Indian adults with multiple chronic conditions. Methods: A snowball sampling technique was employed to recruit individuals. Hierarchical regression analysis was employed to examine mediating and moderating relationships. Results: Results from a cross-sectional survey indicated that knowledge only predicted use among those reporting greater pressure/concern from close others. Furthermore, social support and social trust were found to moderate the relationship between knowledge and diet-related perceptions and behaviors. Discussion: Results suggest that social factors may play a critical role in moderating the impact of nutritionknowledge on diet-related perceptions and behaviors. Translation to Health Education Practice: Public Health Education interventions targeting developing nations should aim to maximize consumers\u27 nutritionknowledge while identifying valued close others who can help encourage positive health action. Furthermore, Health Educators as well as government and local communities must engage in outreach efforts to reinforce or, if necessary, change public perceptions regarding the food industry
- …