Clusters of midlife women by physical activity and their racial/ethnic differences.

PubMed

Im, Eun-Ok; Ko, Young; Chee, Eunice; Chee, Wonshik; Mao, Jun James

2017-04-01

The purpose of this study was to identify clusters of midlife women by physical activity and to determine racial/ethnic differences in physical activities in each cluster. This was a secondary analysis of the data from 542 women (157 non-Hispanic [NH] Whites, 127 Hispanics, 135 NH African Americans, and 123 NH Asian) in a larger Internet study on midlife women's attitudes toward physical activity. The instruments included the Barriers to Health Activities Scale, the Physical Activity Assessment Inventory, the Questions on Attitudes toward Physical Activity, Subjective Norm, Perceived Behavioral Control, and Behavioral Intention, and the Kaiser Physical Activity Survey. The data were analyzed using hierarchical cluster analyses, analysis of variance, and multinominal logistic analyses. A three-cluster solution was adopted: cluster 1 (high active living and sports/exercise activity group; 48%), cluster 2 (high household/caregiving and occupational activity group; 27%), and cluster 3 (low active living and sports/exercise activity group; 26%). There were significant racial/ethnic differences in occupational activities of clusters 1 and 3 (all P < 0.01). Compared with cluster 1, cluster 2 tended to have lower family income, less access to health care, higher unemployment, higher perceived barriers scores, and lower social influences scores (all P < 0.01). Compared with cluster 1, cluster 3 tended to have greater obesity, less access to health care, higher perceived barriers scores, more negative attitudes toward physical activity, and lower self-efficacy scores (all P < 0.01). Midlife women's unique patterns of physical activity and their associated factors need to be considered in future intervention development.

Clusters of Midlife Women by Physical Activity and Their Racial/Ethnic Differences

PubMed Central

Im, Eun-Ok; Ko, Young; Chee, Eunice; Chee, Wonshik; Mao, Jun James

2016-01-01

Objective The purpose of this study was to identify clusters of midlife women by physical activity and to determine racial/ethnic differences in physical activities in each cluster. Methods This was a secondary analysis of the data from 542 women (157 Non-Hispanic [NH] Whites, 127 Hispanics, 135 NH African Americans, and 123 NH Asian) in a larger Internet study on midlife women’s attitudes toward physical activity. The instruments included the Barriers to Health Activities Scale, the Physical Activity Assessment Inventory, the Questions on Attitudes toward Physical Activity, Subjective Norm, Perceived Behavioral Control, and Behavioral Intention, and the Kaiser Physical Activity Survey. The data were analyzed using hierarchical cluster analyses, ANOVA, and multinominal logistic analyses. Results A three cluster solution was adopted: Cluster 1 (high active living and sports/exercise activity group; 48%), Cluster 2 (high household/caregiving and occupational activity group; 27%), and Cluster 3 (low active living and sports/exercise activity group; 26%). There were significant racial/ethnic differences in occupational activities of Clusters 1 and 3 (all p<.01). Compared with Cluster 1, Cluster 2 tended to have lower family income, less access to health care, higher unemployment, higher perceived barriers scores, and lower social influences scores (all p<.01). Compared with Cluster 1, Cluster 3 tended to have greater obesity, less access to health care, higher perceived barriers scores, more negative attutides toward physical activity, and lower self-efficacy scores (all p<.01). Conclusions Midlife women’s unique patterns of physical activity and their associated factors need to be considered in future intervention development. PMID:27846052

Barriers to involvement in physical activities of persons with mental illness.

PubMed

Shor, Ron; Shalev, Anat

2016-03-01

Participating in physical activities could be essential for reducing the multiple risk factors for health problems that persons with severe mental illness (SMI) may suffer. However, people with SMI are significantly less active than the general population. To develop knowledge about factors related to the perceived barriers hindering this population's participation in physical activities and the benefits this participation would have, a study was conducted in Israel with 86 people with mental illness living in community mental health facilities prior to their participation in a health promotion program. A mixed method was implemented and included: a scale designed to measure participants' perceptions of the barriers to and benefits of involvement in physical activities; instruments focusing on bio-psycho-social factors that may affect the level of barriers experienced; and personal interviews. The findings revealed high ranking for accessibility barriers hindering the participation in physical activities. Bio-psycho-social factors stemming from the participants' mental health, such as level of depression, were correlated with higher ranking of accessibility barriers. Bio-psycho-social factors reflecting positive mental health and health, such as positive appraisal of body weight, were correlated with lower ranking of accessibility barriers. Other barriers may include organizational and broader systemic barriers in the mental health facilities where the participants reside. These findings illuminate the need to consider the unique challenges that persons with mental illness may face in any attempt to advance their involvement in physical activity. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Active cooling-based surface confinement system for thermal soil treatment

DOEpatents

Aines, R.D.; Newmark, R.L.

1997-10-28

A thermal barrier is disclosed for surface confinement with active cooling to control subsurface pressures during thermal remediation of shallow (5-20 feet) underground contaminants. If steam injection is used for underground heating, the actively cooled thermal barrier allows the steam to be injected into soil at pressures much higher (20-60 psi) than the confining strength of the soil, while preventing steam breakthrough. The rising steam is condensed to liquid water at the thermal barrier-ground surface interface. The rapid temperature drop forced by the thermal barrier drops the subsurface pressure to below atmospheric pressure. The steam and contaminant vapors are contained by the thermal blanket, which can be made of a variety of materials such as steel plates, concrete slabs, membranes, fabric bags, or rubber bladders. 1 fig.

Active cooling-based surface confinement system for thermal soil treatment

DOEpatents

Aines, Roger D.; Newmark, Robin L.

1997-01-01

A thermal barrier is disclosed for surface confinement with active cooling to control subsurface pressures during thermal remediation of shallow (5-20 feet) underground contaminants. If steam injection is used for underground heating, the actively cooled thermal barrier allows the steam to be injected into soil at pressures much higher (20-60 psi) than the confining strength of the soil, while preventing steam breakthrough. The rising steam is condensed to liquid water at the thermal barrier-ground surface interface. The rapid temperature drop forced by the thermal barrier drops the subsurface pressure to below atmospheric pressure. The steam and contaminant vapors are contained by the thermal blanket, which can be made of a variety of materials such as steel plates, concrete slabs, membranes, fabric bags, or rubber bladders.

Understanding exercise self-efficacy and barriers to leisure-time physical activity among postnatal women.

PubMed

Cramp, Anita G; Bray, Steven R

2011-07-01

Studies have demonstrated that postnatal women are at high risk for physical inactivity and generally show lower levels of leisure-time physical activity (LTPA) compared to prepregnancy. The overall purpose of the current study was to investigate social cognitive correlates of LTPA among postnatal women during a 6-month period following childbirth. A total of 230 women (mean age = 30.9) provided descriptive data regarding barriers to LTPA and completed measures of LTPA and self-efficacy (exercise and barrier) for at least one of the study data collection periods. A total of 1,520 barriers were content analyzed. Both exercise and barrier self-efficacy were positively associated with subsequent LTPA. Exercise self-efficacy at postnatal week 12 predicted LTPA from postnatal weeks 12 to 18 (β = .40, R (2) = .18) and exercise self-efficacy at postnatal week 24 predicted LTPA during weeks 24-30 (β = .49, R (2) = .30). Barrier self-efficacy at week 18 predicted LTPA from weeks 18 to 24 (β = .33, R (2) = .13). The results of the study identify a number of barriers to LTPA at multiple time points closely following childbirth which may hinder initiation, resumption or maintenance of LTPA. The results also suggest that higher levels of exercise and barrier self-efficacy are prospectively associated with higher levels of LTPA in the early postnatal period. Future interventions should be designed to investigate causal effects of developing participants' exercise and barrier self-efficacy for promoting and maintaining LTPA during the postnatal period.

Sports participation after rehabilitation: Barriers and facilitators.

PubMed

Jaarsma, Eva A; Dekker, Rienk; Geertzen, Jan H B; Dijkstra, Pieter U

2016-01-01

To analyse barriers to, and facilitators of, sports participation among people with physical disabilities after rehabilitation and to compare differences between inactive and active participants regarding these experienced barriers and facilitators. Participants were 1,223 adults (mean age 51.6 years, standard deviation 15.1 years) treated in the Rehabilitation Centre of the University Medical Center Groningen, who completed a questionnaire. The questionnaire consisted of a self-constructed questionnaire regarding barriers and facilitators. Fifty-eight percent of the participants were active in sports after their rehabilitation. Younger age and a higher level of education were positively associated with sports participation, whereas using assistive devices and experiencing environmental barriers were negatively associated. Facilitators of sports participation were health, fun and increasing physical strength, and advice from rehabilitation professionals. Rehabilitation professionals should emphasize the health benefits of, and enjoyment from, sports participation for people with physical disabilities. They should repeatedly remind people with physical disabilities to stay/become active after completing their rehabilitation programme. Rehabilitation professionals should also provide information about strategies to reduce environmental barriers to sports participation, which could help people using assistive devices to overcome these barriers.

Identifying barriers to remaining physically active after rehabilitation: differences in perception between physical therapists and older adult patients.

PubMed

Zalewski, Kathryn; Alt, Carlynn; Arvinen-Barrow, Monna

2014-06-01

Cross-sectional study. To describe readiness for change and barriers to physical activity in older adults and to contrast perceptions of physical therapists and patients using the Barriers to Being Active Quiz. Regular physical activity is vital to recovery after discharge from physical therapy. Physical therapists are positioned to support change in physical activity habits for those transitioning to home care. Understanding of readiness for change and barriers to physical activity could optimize recovery. Thirteen physical therapists enrolled in the study and invited patients who met the inclusion criteria to enroll (79 patients enrolled). The physical therapists provided the ICD-9 code, the physical therapist diagnosis, and completed the Barriers to Being Active Quiz as they perceived their patients would. The enrolled patients provided demographics and filled out the Satisfaction With Life Scale, the stages-of-change scale for physical activity, and the Barriers to Being Active Quiz. Patients were predominantly in the early stages of readiness for change. Both patients and physical therapists identified lack of willpower as the primary barrier to physical activity. Patients identified lack of willpower and social influence as critical barriers more often than physical therapists, whereas physical therapists identified fear of injury and lack of time more often than their patients did. Differences between physical therapists and their patients were noted for fear of injury (z = 2.66, P = .008) and lack of time (z = 3.46, P = .001). The stage of change for physical activity impacted perception of social influence (χ2 = 9.64, P<.05), lack of willpower (χ2 = 21.91, P<.01), and lack of skill (χ2 = 12.46, P<.05). Women ranked fear of injury higher than men did (χ2 = 6.76, P<.01). Understanding readiness for change in and barriers to physical activity may allow physical therapists to better tailor intervention strategies to impact physical activity behavior change.

Predictors of perceived barriers to physical activity in the general adult population: a cross-sectional study.

PubMed

Herazo-Beltrán, Yaneth; Pinillos, Yisel; Vidarte, José; Crissien, Estela; Suarez, Damaris; García, Rafael

The perception of personal barriers to physical activity varies according to the sociodemographic characteristics of individuals. To determine the predictors of the perception of barriers to physical activity in the adult population. A cross-sectional study with 1066 adult women and 1036 adult men. The sociodemographic variables (age, gender, marital status, socioeconomic level, level of education), the perception of barriers that do not allow performance of physical activity (i.e. lack of time, social support, energy, motivation, skill, resources, and fear of injury during practice); and the level of physical activity through the International Physical Activity Questionnaire in its short-form version were evaluated. Individuals from low socioeconomic level (1 and 2) have higher risks of perceiving barriers such as lack of motivation [OR 1.76 (95% CI (1.4-2.1))] and lack of resources [OR 1.37 (95% CI (1.1-1.6))]; individuals with partners did not perceive the lack of social support [OR 0.29 (95% CI (0.2-0.4))] and lack of motivation [OR 0.54 (95% CI (0.4-0.7))] as barriers to physical activity. Individuals with low schooling perceived lack of social support [OR 3.81 (95% CI (3-4.7))], lack of resources [OR 2.78 (95% CI (2.2-3.3))], and fear of injury [OR 2.70 (95% CI (2.2-3.3))] as barrier to physical activity. Factors such as socioeconomic level, marital status, level of education, and self-perception of health are predictors of barriers to physical activity. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

A prospective examination of exercise and barrier self-efficacy to engage in leisure-time physical activity during pregnancy.

PubMed

Cramp, Anita G; Bray, Steven R

2009-06-01

Pregnant women without medical contraindications should accumulate 30 min of moderate exercise on most days of the week, yet many pregnant women do not exercise at recommended levels. The purpose the study was to examine barriers to leisure-time physical activity (LTPA) and investigate barrier and exercise self-efficacy as predictors of self-reported LTPA during pregnancy. Pregnant women (n = 160) completed questionnaires eliciting barriers to LTPA, measures of exercise and barrier self-efficacy, and 6-week LTPA recall at gestational weeks 18, 24, 30, and 36. A total of 1,168 barriers were content-analyzed, yielding nine major themes including fatigue, time constraints, and physical limitations. Exercise self-efficacy predicted LTPA from gestational weeks 18 to 24 (beta = 0.32, R(2) = 0.26) and weeks 30 to 36 (beta = 0.41, R(2) = 0.37), while barrier self-efficacy predicted LTPA from weeks 24 to 30 (beta = 0.40, R(2) = 0.32). Pregnant women face numerous barriers to LTPA during pregnancy, the nature of which may change substantially over the course of pregnancy. Higher levels of self-efficacy to exercise and to overcome exercise barriers are associated with greater LTPA during pregnancy. Research and interventions to understand and promote LTPA during pregnancy should explore the dynamic nature of exercise barriers and foster women's confidence to overcome physical activity barriers.

Activation barriers for methylation of DNA bases by dimethyl sulfate

NASA Astrophysics Data System (ADS)

Eichler, Daniel R.; Papadantonakis, George A.

2017-12-01

The SN2 transition states of the methylation reaction of DNA bases with dimethyl sulfate were examined employing DFT/ M06-2X/6-31+G∗ and DFT/B3LYP-D3/6-311+G (2df, 2p) levels of theory. Solvation effects were examined using the conductor-like polarizable continuum model (CPCM). Calculation results and feedback from electrostatic potential maps show that in water, charge separation lowers the activation barriers relative to the gas phase for the reactions at N7 of guanine, N3 of adenine and cytosine. Also, the reaction at the O6 site of guanine is governed by steric interference and exhibits a higher activation barrier in water.

Overexpression of adhesion molecules and barrier molecules is associated with differential infiltration of immune cells in non-small cell lung cancer.

PubMed

Chae, Young Kwang; Choi, Wooyoung M; Bae, William H; Anker, Jonathan; Davis, Andrew A; Agte, Sarita; Iams, Wade T; Cruz, Marcelo; Matsangou, Maria; Giles, Francis J

2018-01-18

Immunotherapy is emerging as a promising option for lung cancer treatment. Various endothelial adhesion molecules, such as integrin and selectin, as well as various cellular barrier molecules such as desmosome and tight junctions, regulate T-cell infiltration in the tumor microenvironment. However, little is known regarding how these molecules affect immune cells in patients with lung cancer. We demonstrated for the first time that overexpression of endothelial adhesion molecules and cellular barrier molecule genes was linked to differential infiltration of particular immune cells in non-small cell lung cancer. Overexpression of endothelial adhesion molecule genes is associated with significantly lower infiltration of activated CD4 and CD8 T-cells, but higher infiltration of activated B-cells and regulatory T-cells. In contrast, overexpression of desmosome genes was correlated with significantly higher infiltration of activated CD4 and CD8 T-cells, but lower infiltration of activated B-cells and regulatory T-cells in lung adenocarcinoma. This inverse relation of immune cells aligns with previous studies of tumor-infiltrating B-cells inhibiting T-cell activation. Although overexpression of endothelial adhesion molecule or cellular barrier molecule genes alone was not predictive of overall survival in our sample, these genetic signatures may serve as biomarkers of immune exclusion, or resistance to T-cell mediated immunotherapy.

Perceived barriers to leisure-time physical activity and associated factors in adolescents.

PubMed

Dias, Douglas Fernando; Loch, Mathias Roberto; Ronque, Enio Ricardo Vaz

2015-11-01

The objective of this study was to identify the prevalence of perceived barriers to leisure-time physical activity in teenagers and to examine the possible association of these barriers with leisure-time physical inactivity. This cross-sectional study was conducted in 2011 and a representative sample of 1,409 high school students from public schools in the city of Londrina/Paraná was selected through multistage sampling. For data collection, the adolescents completed a questionnaire. The relationship between leisure-time physical inactivity (<300 minutes/week) and perceived barriers was analyzed by calculating the prevalence ratio (PR) in Poisson regression models. "Lack of friends company" was the most prevalent barrier for both girls (75.8%) and boys (58.7%). "Feel lazy" for girls (PR: 1.21; CI 95%: 1.08 to 1.36) and "prefer to do other things" for the boys (PR: 1.48; CI 95%: 1.01 to 2.15) were the barriers most strongly associated with leisure-time physical inactivity. For both genders, a strong dose-response relationship was observed between the number of perceived barriers and leisure-time physical inactivity. The perception of barriers was associated with a higher prevalence of leisure-time physical inactivity in adolescents and should therefore be considered in actions for promoting physical activity in this population.The objective of this study was to identify the prevalence of perceived barriers to leisure-time physical activity in teenagers and to examine the possible association of these barriers with leisure-time physical inactivity. This cross-sectional study was conducted in 2011 and a representative sample of 1,409 high school students from public schools in the city of Londrina/Paraná was selected through multistage sampling. For data collection, the adolescents completed a questionnaire. The relationship between leisure-time physical inactivity (<300 minutes/week) and perceived barriers was analyzed by calculating the prevalence ratio (PR) in Poisson regression models. "Lack of friends company" was the most prevalent barrier for both girls (75.8%) and boys (58.7%). "Feel lazy" for girls (PR: 1.21; CI 95%: 1.08 to 1.36) and "prefer to do other things" for the boys (PR: 1.48; CI 95%: 1.01 to 2.15) were the barriers most strongly associated with leisure-time physical inactivity. For both genders, a strong dose-response relationship was observed between the number of perceived barriers and leisure-time physical inactivity. The perception of barriers was associated with a higher prevalence of leisure-time physical inactivity in adolescents and should therefore be considered in actions for promoting physical activity in this population.

Barriers to physical activity and healthy eating in young breast cancer survivors: modifiable risk factors and associations with body mass index.

PubMed

Ventura, Emily E; Ganz, Patricia A; Bower, Julienne E; Abascal, Liana; Petersen, Laura; Stanton, Annette L; Crespi, Catherine M

2013-11-01

Physical activity (PA) and healthy eating (HE) are important behaviors to encourage in breast cancer survivors (BCS). We examined associations between various factors and barriers to PA (BPA) and barriers to HE (BHE), as well as relationships between barriers and body mass index (BMI) in younger BCS. Self-reported data from 162 BCS (mean age 48 years) were used. BPA were assessed with a 21-item scale and BHE with a 19-item scale. Participants were classified as high or low on each scale. Sociodemographic, medical, and psychosocial characteristics were compared by high/low barriers. Correlates of continuous BPA and BHE were assessed as were associations among BHE, BPA, and BMI. 61 % of participants were characterized as having low BHE and low BPA; 12 % were high for both. High BHE/high BPA participants had the least favorable scores for depression, perceived stress, social support, fatigue, bladder control, and weight problems. Factors associated with BHE were lower education, higher perceived stress, and more severe weight problems. Factors associated with BPA were more severe bladder control problems and lower physical well-being. Higher BHE and BPA were significantly and uniquely associated with higher BMI, controlling for covariates. Several biopsychosocial factors (e.g., depression, stress, and fatigue) characterize young BCS who experience barriers to both HE and PA. The correlates of BHE and BPA are distinct. Both BHE and BPA are associated with BMI. These results should be considered in designing interventions for younger women with breast cancer.

Physical activity levels and perceived benefits and barriers to physical activity in HIV-infected women living in the deep south of the United States.

PubMed

Rehm, Kristina E; Konkle-Parker, Deborah

2016-09-01

Engaging in regular physical activity (PA) is important in maintaining health and increasing the overall quality of life of people living with HIV (PLWH). The deep south of the USA is known for its high rate of sedentary behavior although data on the activity levels and perceptions of the benefits and barriers to exercise in women living with HIV in the deep south are lacking. Understanding the perceived benefits and barriers to exercise can guide the development of PA interventions. We conducted a cross-sectional study to determine the PA levels and perceived benefits and barriers to exercise associated with both age and depression level in a group of HIV+ women living in the deep south. We recruited a total of 50 participants from a cohort site for the Women's Interagency HIV Study. Depression was assessed using the Center for Epidemiological Studies Depression Scale (CES-D) and benefits/barriers to exercise were measured using the Exercise Benefits and Barriers Scale (EBBS). We measured PA both subjectively and objectively using the International Physical Activity Questionnaire (IPAQ) and a Fitbit PA monitor, respectively. Our sample was predominantly African-American (96%) and the mean ±SD age, body mass index, and CES-D score were 42 ± 8.8 years, 36.6 ± 11.5 kg/m(2), and 15.6 ± 11.4, respectively. Both subjective and objective measures of PA indicated that our participants were sedentary. The greatest perceived benefit to exercise was physical performance and the greatest barrier to exercise was physical exertion. Higher overall perceived benefits were reported by women ≥43 years and women reporting higher levels of depression. There was no difference in overall barriers associated with age and depression level, but women with depression felt more fatigued by exercise. The results of this study can be helpful when designing and implementing PA interventions in women living with HIV in the deep south.

Stigma, barriers to care, and use of mental health services among active duty and National Guard soldiers after combat.

PubMed

Kim, Paul Y; Thomas, Jeffrey L; Wilk, Joshua E; Castro, Carl A; Hoge, Charles W

2010-06-01

This study examined rates of utilization of mental health care among active duty and National Guard soldiers with mental health problems three and 12 months after they returned from combat in Iraq. Stigma and barriers to care were also reported for each component (active duty and National Guard). Cross-sectional, anonymous surveys were administered to 10,386 soldiers across both time points and components. Mean scores from 11 items measuring stigma and barriers to care were computed. Service utilization was assessed by asking soldiers whether they had received services for a mental health problem from a mental health professional, a medical doctor, or the Department of Veterans Affairs in the past month. Risk of mental problems was measured using the Patient Health Questionnaire, the PTSD Checklist, and items asking about aggressive behaviors and "stress, emotional, alcohol, or family" problems within the past month. A higher proportion of active duty soldiers than National Guard soldiers reported at least one type of mental health problem at both three months (45% versus 33%) and 12 months (44% versus 35%) postdeployment. Among soldiers with mental health problems, National Guard soldiers reported significantly higher rates of mental health care utilization 12 months after deployment, compared with active duty soldiers (27% versus 13%). Mean stigma scores were higher among active duty soldiers than among National Guard soldiers. Active duty soldiers with a mental health problem had significantly lower rates of service utilization than National Guard soldiers and significantly higher endorsements of stigma. Current and future efforts to improve care for veterans should work toward reducing the stigma of receiving mental health care.

Facilitators and Barriers to HIV Activities in Religious Congregations: Perspectives of Clergy and Lay Leaders from a Diverse Urban Sample

PubMed Central

Derose, Kathryn Pitkin; Werber, Laura; Palar, Kartika; Kanouse, David E.; Mata, Michael

2013-01-01

This paper examines facilitators and barriers to HIV activities within religious congregations, the relative internal or external sources of these influences, and suggestive differences across congregational types. Results are based on in-depth interviews with clergy and lay leaders (n = 57) from 14 congregations in Los Angeles County, California, purposively selected to reflect diversity in racial-ethnic composition, denomination, size, and HIV activity level. Many common facilitators and barriers were related to norms and attitudes, only a few of which appeared overtly associated with theological orientations. Clergy support was a facilitator particularly prevalent among congregations having higher HIV activity levels, indicating its importance in sustaining and expanding HIV programs. Resource issues were also prominent, with material resource barriers more frequently mentioned by smaller congregations and human resource barriers more among larger congregations. Organizational structure issues were mostly centered on external linkages with various social service, public health, and faith-based entities. Analysis of internal versus external sources highlights the roles of different stakeholders within and outside congregations in promoting HIV activities. Potential differences across congregational types represent fruitful areas for future research. PMID:23990037

Factors related to environmental barriers experienced by persons with and without disabilities in diverse African settings.

PubMed

Visagie, Surona; Eide, Arne H; Dyrstad, Karin; Mannan, Hasheem; Swartz, Leslie; Schneider, Marguerite; Mji, Gubela; Munthali, Alister; Khogali, Mustafa; van Rooy, Gert; Hem, Karl-Gerhard; MacLachlan, Malcolm

2017-01-01

This paper explores differences in experienced environmental barriers between individuals with and without disabilities and the impact of additional factors on experienced environmental barriers. Data was collected in 2011-2012 by means of a two-stage cluster sampling and comprised 400-500 households in different sites in South Africa, Sudan Malawi and Namibia. Data were collected through self-report survey questionnaires. In addition to descriptive statistics and simple statistical tests a structural equation model was developed and tested. The combined file comprised 9,307 participants. The Craig Hospital Inventory of Environmental Factors was used to assess the level of environmental barriers. Transportation, the natural environment and access to health care services created the biggest barriers. An exploratory factor analysis yielded support for a one component solution for environmental barriers. A scale was constructed by adding the items together and dividing by number of items, yielding a range from one to five with five representing the highest level of environmental barriers and one the lowest. An overall mean value of 1.51 was found. Persons with disabilities scored 1.66 and persons without disabilities 1.36 (F = 466.89, p < .001). Bivariate regression analyses revealed environmental barriers to be higher among rural respondents, increasing with age and severity of disability, and lower for those with a higher level of education and with better physical and mental health. Gender had an impact only among persons without disabilities, where women report more barriers than men. Structural equation model analysis showed that socioeconomic status was significantly and negatively associated with environmental barriers. Activity limitation is significantly associated with environmental barriers when controlling for a number of other individual characteristics. Reducing barriers for the general population would go some way to reduce the impact of these for persons with activity limitations, but additional and specific adaptations will be required to ensure an inclusive society.

Mediating Effects of Self-Efficacy, Benefits and Barriers on the Association between Peer and Parental Factors and Physical Activity among Adolescent Girls with a Lower Educational Level.

PubMed

Verloigne, Maite; Cardon, Greet; De Craemer, Marieke; D'Haese, Sara; De Bourdeaudhuij, Ilse

2016-01-01

The prevalence of physical activity among lower educated adolescent girls is low, suggesting it is important to have insights into the complex processes that may underlie their physical activity levels. Therefore, this study aimed to examine the mediating effects of self-efficacy, perceived benefits and barriers on the associations between peer and parental variables and physical activity among lower educated adolescent girls. In total, 226 girls (mean age 16.0±1.0 years; 53% technical education; 47% vocational education) from a convenience sample of 6 secondary schools in Flanders, Belgium, completed a questionnaire on their total physical activity level and related peer and parental variables (i.e. modeling of physical activity, co-participation in physical activities and encouragement to be active) and personal variables (i.e. self-efficacy to be active, and specific perceived benefits of physical activity and specific barriers to be active). Mediating effects were tested using MacKinnon's product-of-coefficients test based on multilevel linear regression analyses. Higher peer and parental modeling, co-participation and encouragement were significantly related to a higher physical activity level among adolescent girls (p<0.05). Self-efficacy, the perceived benefits of having fun, being around friends or meeting new people, and not being bored and the perceived barrier of not liking physical activity mediated several associations between peer and parental variables and girls' physical activity, with some of the mediated proportions exceeding 60%. This study contributed to a better understanding of the complexity of how parental and peer factors work together with personal factors to influence the physical activity levels of adolescent girls with a lower educational level. Interventions should involve both peers and parents, as they may influence girls' physical activity both directly and indirectly through the internalisation of several personal variables, such as self-efficacy to be active and the perceived benefit of having fun.

Compliance with barrier precautions during paediatric trauma resuscitations.

PubMed

Kelleher, Deirdre C; Carter, Elizabeth A; Waterhouse, Lauren J; Burd, Randall S

2013-03-01

Barrier precautions protect patients and providers from blood-borne pathogens. Although barrier precaution compliance has been shown to be low among adult trauma teams, it has not been evaluated during paediatric resuscitations in which perceived risk of disease transmission may be low. The purpose of this study was to identify factors associated with compliance with barrier precautions during paediatric trauma resuscitations. Video recordings of resuscitations performed on injured children (<18 years old) were reviewed to determine compliance with an established policy requiring gowns and gloves. Depending on activation level, trauma team members included up to six physicians, four nurses, and a respiratory therapist. Multivariate logistic regression was used to determine the effect of team role, resuscitation factors, and injury mechanism on barrier precaution compliance. Over twelve weeks, 1138 trauma team members participated in 128 resuscitations (4.7% penetrating injuries, 9.4% highest level activations). Compliance with barrier precautions was 81.3%, with higher compliance seen among roles primarily at the bedside compared to positions not primarily at the bedside (90.7% vs. 65.1%, p<0.001). Bedside residents (98.4%) and surgical fellows (97.6%) had the highest compliance, while surgical attendings (20.8%) had the lowest (p<0.001). Controlling for role, increased compliance was observed during resuscitations of patients with penetrating injuries (OR=3.97 [95% CI: 1.35-11.70], p=0.01), during resuscitations triaged to the highest activation level (OR=2.61 [95% CI: 1.34-5.10], p=0.005), and among team members present before patient arrival (OR=4.14 [95% CI: 2.29-7.39], p<0.001). Compliance with barrier precautions varies by trauma team role. Team members have higher compliance when treating children with penetrating and high acuity injuries and when arriving before the patient. Interventions integrating barrier precautions into the workflow of team members are needed to reduce this variability and improve compliance with universal precautions during paediatric trauma resuscitations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Access to Barrier Perches Improves Behavior Repertoire in Broilers

PubMed Central

Ventura, Beth A.; Siewerdt, Frank; Estevez, Inma

2012-01-01

Restriction of behavioral opportunities and uneven use of space are considerable welfare concerns in modern broiler production, particularly when birds are kept at high densities. We hypothesized that increased environmental complexity by provision of barrier perches would help address these issues by encouraging perching and enhancing use of the pen space across a range of stocking densities. 2,088 day-old broiler chicks were randomly assigned to one of the following barrier and density treatment combinations over four replications: simple barrier, complex barrier, or control (no barrier) and low (8 birds/m2), moderate (13 birds/m2), or high (18 birds/m2) density. Data were collected on focal birds via instantaneous scan sampling from 2 to 6 weeks of age. Mean estimates per pen for percent of observations seen performing each behavior, as well as percent of observations in the pen periphery vs. center, were quantified and submitted to an analysis of variance with week as the repeated measure. Barrier perches, density and age affected the behavioral time budget of broilers. Both simple and complex barrier perches effectively stimulated high perching rates. Aggression and disturbances were lower in both barrier treatments compared to controls (P<0.05). Increasing density to 18 birds/m2 compared to the lower densities suppressed activity levels, with lower foraging (P<0.005), decreased perching (P<0.0001) and increased sitting (P = 0.001) earlier in the rearing period. Disturbances also increased at higher densities (P<0.05). Use of the central pen area was higher in simple barrier pens compared to controls (P<0.001), while increasing density above 8 birds/m2 suppressed use of the central space (P<0.05). This work confirms some negative effects of increasing density and suggests that barrier perches have the potential to improve broiler welfare by encouraging activity (notably by providing accessible opportunities to perch), decreasing aggression and disturbances, and promoting more even distribution of birds throughout the pen space. PMID:22299026

Understanding the complex interplay of barriers to physical activity amongst black and minority ethnic groups in the United Kingdom: a qualitative synthesis using meta-ethnography.

PubMed

Koshoedo, Sejlo A; Paul-Ebhohimhen, Virginia A; Jepson, Ruth G; Watson, Margaret C

2015-07-12

To conduct a meta-ethnographic analysis of qualitative studies to identify barriers to Black and Minority Ethnic (BME) individuals engaging in physical activity in the UK context. A qualitative synthesis using meta-ethnographic methods to synthesis studies of barriers to engaging in physical activity among BME groups in the UK. A comprehensive search strategy of multiple databases was employed to identify qualitative research studies published up to October 2012. The eleven searched databases included ASSIA, MEDLINE, EMBASE, CINAHL, Health Technology Assessment (HTA), NHS Scotland Library, Physical Activity Health Alliance (PAHA), PsyINFO, Social Services Abstract, Sport discuss and Web of Science. The Noblit and Hare's meta-ethnographic approach was undertaken to develop an inductive and interpretive form of knowledge synthesis. Fourteen papers met the inclusion criteria. The synthesis indicated that barriers to physical activity among BME individuals were influenced by four main concepts: perceptions; cultural expectations; personal barriers; and factors limiting access to facilities. BME individuals had different understandings of physical activity were influenced by migration history, experiences, cultural and health beliefs. This in turn may have a disempowering effect on BME individuals in terms of adopting or maintaining physical activity. These barriers to physical activity were explained at a higher conceptual level by a socio-ecological model. The social construct 'individual perception and understanding of physical activity' was particularly relevant to theoretical models and interventions. Interventions to promote engagement with physical activity need to address perceptions of this behaviour. The elicited concepts and contexts could be used to enhance the development of tailored effective health promotion interventions for BME individuals.

What are the barriers to performing nonpharmacological interventions for behavioral symptoms in the nursing home?

PubMed

Cohen-Mansfield, Jiska; Thein, Khin; Marx, Marcia S; Dakheel-Ali, Maha

2012-05-01

Behavioral symptoms are common in persons with dementia, and nonpharmacological interventions are recommended as the first line of therapy. We describe barriers to conducting nonpharmacological interventions for behavioral symptoms. A descriptive study of barriers to intervention delivery in a controlled trial. The study was conducted in six nursing homes in Maryland. Participants were 89 agitated nursing home residents with dementia. Personalized interventions were developed using the Treatment Routes for Exploring Agitation decision tree protocol. Trained research assistants prepared and delivered the interventions. Feasibility of the interventions was determined. Barriers to Intervention Delivery Assessment, activities of daily living, cognitive functioning, depressed affect, pain, observed agitation, and observed affect. Barriers were observed for the categories of resident barriers (specifically, unwillingness to participate; resident attributes, such as unresponsive), barriers related to resident unavailability (resident asleep or eating), and external barriers (staff-related barriers, family-related barriers, environmental barriers, and system process variables). Interventions pertaining to food/drink and to 1-on-1 socializing were found to have the fewest barriers, whereas higher numbers of barriers occurred with puzzles/board games and arts and crafts activities. Moreover, when successful interventions were presented to participants after the feasibility period, we noted fewer barriers, presumably because barrier identification had been used to better tailor interventions to each participant and to the environment. Knowledge of barriers provides a tool by which to tailor interventions so as to anticipate or circumvent barriers, thereby maximizing intervention delivery. Copyright © 2012 American Medical Directors Association, Inc. Published by Elsevier Inc. All rights reserved.

Dissipated power and induced velocity fields data of a micro single dielectric barrier discharge plasma actuator for active flow control☆

PubMed Central

Pescini, E.; Martínez, D.S.; De Giorgi, M.G.; Francioso, L.; Ficarella, A.

2015-01-01

In recent years, single dielectric barrier discharge (SDBD) plasma actuators have gained great interest among all the active flow control devices typically employed in aerospace and turbomachinery applications [1,2]. Compared with the macro SDBDs, the micro single dielectric barrier discharge (MSDBD) actuators showed a higher efficiency in conversion of input electrical power to delivered mechanical power [3,4]. This article provides data regarding the performances of a MSDBD plasma actuator [5,6]. The power dissipation values [5] and the experimental and numerical induced velocity fields [6] are provided. The present data support and enrich the research article entitled “Optimization of micro single dielectric barrier discharge plasma actuator models based on experimental velocity and body force fields” by Pescini et al. [6]. PMID:26425667

Permeable reactive barrier of surface hydrophobic granular activated carbon coupled with elemental iron for the removal of 2,4-dichlorophenol in water.

PubMed

Yang, Ji; Cao, Limei; Guo, Rui; Jia, Jinping

2010-12-15

Granular activated carbon was modified with dimethyl dichlorosilane to improve its surface hydrophobicity, and therefore to improve the performance of permeable reactive barrier constructed with the modified granular activated carbon and elemental iron. X-ray photoelectron spectroscopy shows that the surface silicon concentration of the modified granular activated carbon is higher than that of the original one, leading to the increased surface hydrophobicity. Although the specific surface area decreased from 895 to 835 m(2)g(-1), the modified granular activated carbon could adsorb 20% more 2,4-dichlorophenol than the original one did in water. It is also proven that the permeable reactive barrier with the modified granular activated carbon is more efficient at 2,4-dichlorophenol dechlorination, in which process 2,4-dichlorophenol is transformed to 2-chlorophenol or 4-chlorophenol then to phenol, or to phenol directly. Copyright © 2010 Elsevier B.V. All rights reserved.

Exercise barriers and preferences among women and men with multiple sclerosis.

PubMed

Asano, Miho; Duquette, Pierre; Andersen, Ross; Lapierre, Yves; Mayo, Nancy E

2013-03-01

The primary objective of this study was to estimate the extent to which women and men with MS present different exercise barriers. The secondary objective was to estimate the extent to which women and men with MS present different perceived-health, depressive symptoms, and current exercise routines or preferences. This was a cross sectional survey. 417 people with MS completed a survey of exercise barriers and current exercise routines, perceived-health and depressive symptoms. The top three exercise barriers were: too tired; impairment; and lack of time, regardless of their gender. Regardless of their gender, three times/week and 60 min/session was identified as the most common current exercise structure among physically active participants. The top three currently preferred exercise by men included walking, strengthening/weights and flexibility/stretch exercise. Women reported the same three exercises but flexibility/stretch exercise were slightly more popular than other exercise. Similarities in perceived health status and depressive symptoms were seen between women and men; expect more men were diagnosed with progressive MS (20% higher) than women, leading to a higher rate of men reporting problems with mobility. Women and men with MS differed very little on exercise barriers and current exercise routines, perceived health and depressive symptoms. Even though MS is generally considered a woman's disease, this study did not find a strong need to develop gender specific exercise or physical activity interventions for this population.

Lack of facilities rather than sociocultural factors as the primary barrier to physical activity among female Saudi university students.

PubMed

Samara, Anastasia; Nistrup, Anne; Al-Rammah, Tamader Y; Aro, Arja R

2015-01-01

The Kingdom of Saudi Arabia is experiencing a dramatic increase in physical inactivity, with women having higher levels of inactivity than men among all age groups. It is assumed that factors such as dress codes, restrictions on going outdoors, and conservative norms are the main reasons for women's low physical activity. Our aim was to explore the different parameters related to physical activity, including self-efficacy, as well as the perceived barriers to and benefits of physical activity in young Saudi females. Ninety-four first-year female Saudi university students in Riyadh, Kingdom of Saudi Arabia, participated in the present study in 2014. The students were from eight bachelor's programs in health and well-being, and each completed a questionnaire with questions divided into five parts as follows: 1) socioeconomic status, 2) physical activity, 3) self-efficacy 4) social factors, and 5) barriers and facilitators related to physical activity. The students exercised at home and alone, and there was low self-efficacy for physical activity (mean score =42±14). Among social factors, attending university was the only factor that hindered physical activity (32%). Physical activity was positively perceived overall (mean score =131±10). Students showed awareness of the benefits of physical activity for health and well-being. The most important barrier was the lack of designated areas available for physical activity. Students disagreed that family or the Islamic community were barriers to physical activity. The lack of facilities and lack of encouragement from the university, but not a lack of knowledge (a high level of knowledge is to be expected given their health and well-being studies backgrounds) and/or restrictions from families and society, seem to hinder female students' physical activity, at least young Saudi students.

When ruthenia met titania: Achieving extraordinary catalytic activity at low temperature by nanostructuring of oxides

DOE PAGES

Graciani, J.; Stacchiola, D.; Yang, F.; ...

2015-09-09

Nanostructured RuO x/TiO 2(110) catalysts have a remarkable catalytic activity for CO oxidation at temperatures in the range of 350–375 K. Furthermore, the RuO 2(110) surface has no activity. The state-of-the-art DFT calculations indicate that the main reasons for such an impressive improvement in the catalytic activity are: (i) a decrease of the diffusion barrier of adsorbed O atoms by around 40%, from 1.07 eV in RuO 2(110) to 0.66 eV in RuO x/TiO 2(110), which explains the shift of the activity to lower temperatures and (ii) a lowering of the barrier by 20% for the association of adsorbed COmore » and O species to give CO 2 (the main barrier for the CO oxidation reaction) passing from around 0.7 eV in RuO 2(110) to 0.55 eV in RuO x/TiO 2(110). We show that the catalytic properties of ruthenia are strongly modified when supported as nanostructures on titania, attaining higher activity at temperatures 100 K lower than that needed for pure ruthenia. As in other systems consisting of ceria nanostructures supported on titania, nanostructured ruthenia shows strongly modified properties compared to the pure oxide, consolidating the fact that the nanostructuring of oxides is a main way to attain higher catalytic activity at lower temperatures.« less

The metabolite beta-aminoisobutyric acid and physical inactivity among hemodialysis patients.

PubMed

Molfino, Alessio; Amabile, Maria Ida; Ammann, Thomas; Farcomeni, Alessio; Lionetto, Luana; Simmaco, Maurizio; Lai, Silvia; Laviano, Alessandro; Rossi Fanelli, Filippo; Chiappini, Maria Grazia; Muscaritoli, Maurizio

2017-02-01

Physical inactivity is frequent in patients on hemodialysis (HD), and represents a reliable predictor of morbidity and mortality. Beta-aminoisobutyric acid (BAIBA) is a contraction-induced myokine, the plasma levels of which increase with exercise and are inversely associated with metabolic risk factors. The aim of this study was to ascertain whether physical inactivity and clinical parameters relate to plasma BAIBA levels in this patient population. Adult patients on HD were included, and the presence of physical inactivity was assessed. BAIBA levels were measured in these patients and in healthy individuals. We assessed barriers to physical activity, including 23 items regarding psychophysical and financial barriers. Body composition was assessed by bioimpedance and muscle strength by handgrip dynamometer. Nonparametric tests and logistic regression analyses were performed. Forty-nine patients on HD were studied; 49% were physically active and 51% were inactive. Of the patients, 43 reported barriers to physical activity and 61% of inactive patients reported three or more barriers. BAIBA levels were lower in patients on HD with respect to controls (P < 0.001). Stratifying HD patients as active and inactive, both groups showed significantly lower BAIBA levels versus controls (P = 0.0005, P < 0.001, respectively). Nondiabetic patients on HD showed increased BAIBA levels compared with diabetic patients (P < 0.001). Patients on HD endorsing the two most frequent barriers showed lower BAIBA levels than those not reporting these barriers (P = 0.006). Active patients showed higher intracellular water (%) (P = 0.008), and active and inactive patients showed significant correlation between total body muscle mass and handgrip strength (P = 0.04, P = 0.005, respectively). Physical inactivity is highly prevalent among patients on HD and BAIBA correlates with barriers to physical activity reported by inactive patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Chloroform Hydrodechlorination over Palladium–Gold Catalysts: A First-Principles DFT Study

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

Xu, Lang; Yao, Xiaoqian; Khan, Ahmad

2016-04-20

Hydrodechlorination is a promising method for treating toxic chlorocarbon compounds. Pd is among the most effective catalysts for chloroform hydrodechlorination, and experiments have shown that the Pd–Au alloy catalyst yields superior catalytic performance over pure Pd. In this paper, we examine the chloroform hydrodechlorination mechanism over Pd(1 1 1) and Pd ML/Au(1 1 1) surfaces using periodic, self-consistent density functional theory calculations (DFT, GGA–PW91) and maximum rate analysis. We suggest that the reaction occurs on both surfaces through complete dechlorination of chloroform followed by hydrogenation of CH* to methane, and that the initial dechlorination step is likely the rate-limiting step.more » Finally, on Pd(1 1 1), the chloroform dechlorination barrier is 0.24 eV higher than the desorption barrier, whereas on Pd ML/Au(1 1 1), the chloroform dechlorination barrier is 0.07 eV lower than the desorption barrier, which can explain the higher hydrodechlorination activity of the Pd–Au alloy catalyst.« less

First-principles investigation of the dissociation and coupling of methane on small copper clusters: Interplay of collision dynamics and geometric and electronic effects

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

Varghese, Jithin J.; Mushrif, Samir H., E-mail: shmushrif@ntu.edu.sg

Small metal clusters exhibit unique size and morphology dependent catalytic activity. The search for alternate minimum energy pathways and catalysts to transform methane to more useful chemicals and carbon nanomaterials led us to investigate collision induced dissociation of methane on small Cu clusters. We report here for the first time, the free energy barriers for the collision induced activation, dissociation, and coupling of methane on small Cu clusters (Cu{sub n} where n = 2–12) using ab initio molecular dynamics and metadynamics simulations. The collision induced activation of the stretching and bending vibrations of methane significantly reduces the free energy barriermore » for its dissociation. Increase in the cluster size reduces the barrier for dissociation of methane due to the corresponding increase in delocalisation of electron density within the cluster, as demonstrated using the electron localisation function topology analysis. This enables higher probability of favourable alignment of the C–H stretching vibration of methane towards regions of high electron density within the cluster and makes higher number of sites available for the chemisorption of CH{sub 3} and H upon dissociation. These characteristics contribute in lowering the barrier for dissociation of methane. Distortion and reorganisation of cluster geometry due to high temperature collision dynamics disturb electron delocalisation within them and increase the barrier for dissociation. Coupling reactions of CH{sub x} (x = 1–3) species and recombination of H with CH{sub x} have free energy barriers significantly lower than complete dehydrogenation of methane to carbon. Thus, competition favours the former reactions at high hydrogen saturation on the clusters.« less

Accelerometer-measured versus self-reported physical activity in college students: implications for research and practice.

PubMed

Downs, Andrew; Van Hoomissen, Jacqueline; Lafrenz, Andrew; Julka, Deana L

2014-01-01

To determine the level of moderate-vigorous-intensity physical activity (MVPA) assessed via self-report and accelerometer in the college population, and to examine intrapersonal and contextual variables associated with physical activity (PA). Participants were 77 college students at a university in the northwest sampled between January 2011 and December 2011. Participants completed a validated self-report measure of PA and measures of athletic identity and benefits and barriers to exercise. Participants' PA levels were assessed for 2 weeks via accelerometry. Participants' estimations of their time spent engaged in MVPA were significantly higher when measured via self-report versus accelerometry. Stronger athletic identity, perceived social benefits and barriers, and time-effort barriers were related to PA levels. Estimation of college students' level of PA may require interpretation of data from different measurement methods, as self-report and accelerometry generate different estimations of PA in college students who may be even less active than previously believed.

Non-Hematopoietic MLKL Protects Against Salmonella Mucosal Infection by Enhancing Inflammasome Activation.

PubMed

Yu, Shui-Xing; Chen, Wei; Liu, Zhen-Zhen; Zhou, Feng-Hua; Yan, Shi-Qing; Hu, Gui-Qiu; Qin, Xiao-Xia; Zhang, Jie; Ma, Ke; Du, Chong-Tao; Gu, Jing-Min; Deng, Xu-Ming; Han, Wen-Yu; Yang, Yong-Jun

2018-01-01

The intestinal mucosal barrier is critical for host defense against pathogens infection. Here, we demonstrate that the mixed lineage kinase-like protein (MLKL), a necroptosis effector, promotes intestinal epithelial barrier function by enhancing inflammasome activation. MLKL -/- mice were more susceptible to Salmonella infection compared with wild-type counterparts, with higher mortality rates, increased body weight loss, exacerbated intestinal inflammation, more bacterial colonization, and severe epithelial barrier disruption. MLKL deficiency promoted early epithelial colonization of Salmonella prior to developing apparent intestinal pathology. Active MLKL was predominantly expressed in crypt epithelial cells, and experiments using bone marrow chimeras found that the protective effects of MLKL were dependent on its expression in non-hematopoietic cells. Intestinal mucosa of MLKL -/- mice had impaired caspase-1 and gasdermin D cleavages and decreased interleukin (IL)-18 release. Moreover, administration of exogenous recombinant IL-18 rescued the phenotype of increased bacterial colonization in MLKL -/- mice. Thus, our results uncover the role of MLKL in enhancing inflammasome activation in intestinal epithelial cells to inhibit early bacterial colonization.

DFT Virtual Screening Identifies Rhodium–Amidinate Complexes As Potential Homogeneous Catalysts for Methane-to-Methanol Oxidation

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

Fu, Ross; Nielsen, Robert J.; Goddard, William A.

2014-11-11

In the search for new organometallic catalysts for low-temperature selective conversion of CH4 to CH3OH, we apply quantum mechanical virtual screening to select the optimum combination of ligand and solvent on rhodium to achieve low barriers for CH4 activation and functionalization to recommend for experimental validation. Here, we considered Rh because its lower electronegativity compared with Pt and Pd may allow it to avoid poisoning by coordinating media. We report quantum mechanical predictions (including implicit and explicit solvation) of the mechanisms for RhIII(NN) and RhIII(NNF) complexes [where (NN) = bis(N-phenyl)benzylamidinate and (NNF) = bis(N-pentafluorophenyl)pentafluorobenzylamidinate] to catalytically activate and functionalize methanemore » using trifluoroacetic acid (TFAH) or water as a solvent. In particular, we designed the (NNF) ligand as a more electrophilic analogue to the (NN) ligand, and our results predict the lowest transition state barrier (ΔG‡ = 27.6 kcal/mol) for methane activation in TFAH from a pool of four different classes of ligands. To close the catalytic cycle, the functionalization of methylrhodium intermediates was also investigated, involving carbon–oxygen bond formation via SN2 attack by solvent, or SR2 attack by a vanadium oxo. Activation barriers for the functionalization of methylrhodium intermediates via nucleophilic attack are lower when the solvent is water, but CH4 activation barriers are higher. In addition, we have found a correlation between CH4 activation barriers and rhodium–methyl bond energies that allow us to predict the activation transition state energies for future ligands, as well.« less

Physical activity in hypertrophic cardiomyopathy: prevalence of inactivity and perceived barriers

PubMed Central

Sweeting, Joanna; Ingles, Jodie; Timperio, Anna; Patterson, Jillian; Ball, Kylie; Semsarian, Christopher

2016-01-01

Objectives This study aimed to determine the prevalence of physical inactivity and perceived barriers to physical activity among individuals with hypertrophic cardiomyopathy (HCM), and to determine potential demographic, clinical and health-related factors influencing likelihood of meeting physical activity guidelines. Methods This was a cross-sectional study of consecutive patients (n=198) with HCM attending a specialist HCM centre from July 2014 to November 2015. The primary outcome measure was physical activity (minutes per day), as measured by self-report (International Physical Activity Questionnaire (IPAQ)) and objective means (ActiGraph accelerometer). For both, participants were classified as meeting guidelines if they did at least 150 min per week of physical activity. Quality of life (Short Form-36 V.2, SF-36v2), barriers to exercise and clinical–demographic data were also collected. Results In total, 54.8% of participants did not meet physical activity recommendations based on IPAQ, and 12.7% did not meet guidelines based on accelerometer data. The most commonly identified barriers to exercise were ‘pain interferes with my exercise’ (33%) and ‘I have an injury/disability that stops me’ (29%). Independent factors associated with meeting guidelines included older age (OR 0.66, 95% CI 0.51 to 0.85, p=0.002), higher education level (OR 2.31, 95% CI 1.08 to 4.93, p=0.03), better physical quality of life (OR 1.05, 95% CI 1.0 to 1.09, p=0.05) and more reported barriers (OR 0.71, 95% CI 0.56 to 0.91, p=0.01). Conclusions More than half of the patients with HCM did not meet minimum physical activity recommendations. Several barriers to exercise among individuals with HCM exist, and provide the basis for targeted interventions to promote physical activity and improve overall health in patients with HCM. PMID:27547438

Barriers to Increasing the Physical Activity of People with Intellectual Disabilities

ERIC Educational Resources Information Center

Cartwright, Luke; Reid, Marie; Hammersley, Richard; Walley, Robert M.

2017-01-01

Background: The prevalence of obesity, inactivity and related morbidity and mortality is higher amongst people with intellectual disabilities than in the population in general, an issue of global concern. This research examined the perspectives of people with intellectual disabilities and their carers, on exercise and activity. Materials and…

Effects of Participation in Immigration Activism on Undocumented Students in Higher Education

ERIC Educational Resources Information Center

Spinney, Samantha A.

2015-01-01

For undocumented students to go to college, they need to be highly resourceful and exceptionally motivated--and that might not be enough. Society confers numerous barriers on undocumented students regarding higher education attainment. Most undocumented students, who typically come from families living in poverty, cannot afford the high cost of a…

Faculty Challenges and Barriers for Research and Publication in Tajik Higher Education

ERIC Educational Resources Information Center

Kataeva, Zumrad; DeYoung, Alan J.

2018-01-01

This article investigates the current state of faculty research activity within Tajik higher education institutions (HEIs), where the level of research productivity has substantially decreased in the past three decades. As part of a larger ethnographic study on professional lives of Tajik faculty members, we investigated and found enormous…

Moving from Chasm to Convergence: Benefits and Barriers to Academic Activism for Social Justice and Equity

ERIC Educational Resources Information Center

Rose, Barbara

2017-01-01

There are many natural links between academic work and activism that can be used for social justice and equity, but remain underdeveloped in higher education. Using the concept of liminality and the inclusion of personal voice that is central in Scholarly Personal Narrative methodology, this article explores academic activism in multiple ways.…

Increasing Rural Adults' Participation in Collegial Programs: Exemplary Programs. Proceedings of the Rural Action Conference "Programs and Activities to Overcome Barriers to Rural Adult Participation in Postsecondary Education" (Blacksburg, Virginia, June 1-3, 1987).

ERIC Educational Resources Information Center

Sullins, W. Robert, Ed.; And Others

Approximately 85 educators from six states participated in a regional conference designed to showcase exemplary and collaborative programs to overcome many of the barriers faced by rural adults in pursuing higher education. After the keynote address, "The Role of Adult Learning in Revitalizing Rural Communities," by Cornelia Butler Flora, the…

Optimization of Silicon parameters as a betavoltaic battery: Comparison of Si p-n and Ni/Si Schottky barrier

NASA Astrophysics Data System (ADS)

Rahmani, Faezeh; Khosravinia, Hossein

2016-08-01

Theoretical studies on the optimization of Silicon (Si) parameters as the base of betavoltaic battery have been presented using Monte Carlo simulations and the state equations in semiconductor to obtain maximum power. Si with active area of 1 cm2 has been considered in p-n junction and Schottky barrier structure to collect the radiation induced-charge from 10 mCi cm-2 of Nickle-63 (63Ni) Source. The results show that the betavoltaic conversion efficiency in the Si p-n structure is about 2.7 times higher than that in the Ni/Si Schottky barrier structure.

Physical activity and mental health in women with Polycystic Ovary Syndrome

PubMed Central

2014-01-01

Background Physical activity is prescribed as a component of primary management for Polycystic Ovary Syndrome (PCOS). This study investigates the association between physical activity and mental health as well as the exercise barriers, motivators and support providers for younger women with and without PCOS to assist in physical activity uptake and prescription for these women. Methods Women aged 18-50 years with (n = 153) and without PCOS (n = 64) completed a questionnaire at one time point. The questionnaire included the Hospital Anxiety and Depression Scale and a survey regarding levels of physical activity, physical activity barriers, motivators and supports. A MANCOVA assessed associations between physical activity, PCOS and mental health (specifically depression and anxiety). Descriptive and Chi square goodness of fit statistics assessed the differences in perceived barriers, motivators and support providers amongst women with and without PCOS. Results Women with PCOS displayed higher severity of depression (F(1,210) = 8.32, p = 0.004) and anxiety (F(1,210) = 17.37, p < 0.001) symptoms compared to controls. Overall, for physically active women, depression was significantly less severe than in their inactive counterparts (F(2,210) = 13.62, p < 0.001). There were no differences in anxiety by physical activity status and no interaction effects between PCOS and activity status for depression or anxiety. Women with PCOS were more likely to report a lack of confidence about maintaining physical activity (Χ 2  = 3.65; p = 0.046), fear of injury (Χ 2  = 4.08; p = 0.043) and physical limitations (Χ 2  = 11.92; p = 0.001) as barriers to physical activity and were more likely to be motivated to be active to control a medical condition (Χ 2  = 7.48; p = 0.006). Women with PCOS identified more sources of support compared to women without PCOS. Conclusions Physical activity is associated with lower depression in women with PCOS and differences exist in the self-reported physical activity barriers, motivators and support providers, compared to controls. Being more active may offer mental health benefits in managing PCOS. Prescribing physical activity to women with PCOS should be individualized and consider both common and PCOS-specific barriers and motivators for successful engagement. PMID:24674140

Physical activity and mental health in women with polycystic ovary syndrome.

PubMed

Banting, Lauren K; Gibson-Helm, Melanie; Polman, Remco; Teede, Helena J; Stepto, Nigel K

2014-03-27

Physical activity is prescribed as a component of primary management for Polycystic Ovary Syndrome (PCOS). This study investigates the association between physical activity and mental health as well as the exercise barriers, motivators and support providers for younger women with and without PCOS to assist in physical activity uptake and prescription for these women. Women aged 18-50 years with (n = 153) and without PCOS (n = 64) completed a questionnaire at one time point. The questionnaire included the Hospital Anxiety and Depression Scale and a survey regarding levels of physical activity, physical activity barriers, motivators and supports. A MANCOVA assessed associations between physical activity, PCOS and mental health (specifically depression and anxiety). Descriptive and Chi square goodness of fit statistics assessed the differences in perceived barriers, motivators and support providers amongst women with and without PCOS. Women with PCOS displayed higher severity of depression (F(1,210) = 8.32, p = 0.004) and anxiety (F(1,210) = 17.37, p < 0.001) symptoms compared to controls. Overall, for physically active women, depression was significantly less severe than in their inactive counterparts (F(2,210) = 13.62, p < 0.001). There were no differences in anxiety by physical activity status and no interaction effects between PCOS and activity status for depression or anxiety. Women with PCOS were more likely to report a lack of confidence about maintaining physical activity (Χ2 = 3.65; p = 0.046), fear of injury (Χ2 = 4.08; p = 0.043) and physical limitations (Χ2 = 11.92; p = 0.001) as barriers to physical activity and were more likely to be motivated to be active to control a medical condition (Χ2 = 7.48; p = 0.006). Women with PCOS identified more sources of support compared to women without PCOS. Physical activity is associated with lower depression in women with PCOS and differences exist in the self-reported physical activity barriers, motivators and support providers, compared to controls. Being more active may offer mental health benefits in managing PCOS. Prescribing physical activity to women with PCOS should be individualized and consider both common and PCOS-specific barriers and motivators for successful engagement.

Understanding trends in C-H bond activation in heterogeneous catalysis.

PubMed

Latimer, Allegra A; Kulkarni, Ambarish R; Aljama, Hassan; Montoya, Joseph H; Yoo, Jong Suk; Tsai, Charlie; Abild-Pedersen, Frank; Studt, Felix; Nørskov, Jens K

2017-02-01

While the search for catalysts capable of directly converting methane to higher value commodity chemicals and liquid fuels has been active for over a century, a viable industrial process for selective methane activation has yet to be developed. Electronic structure calculations are playing an increasingly relevant role in this search, but large-scale materials screening efforts are hindered by computationally expensive transition state barrier calculations. The purpose of the present letter is twofold. First, we show that, for the wide range of catalysts that proceed via a radical intermediate, a unifying framework for predicting C-H activation barriers using a single universal descriptor can be established. Second, we combine this scaling approach with a thermodynamic analysis of active site formation to provide a map of methane activation rates. Our model successfully rationalizes the available empirical data and lays the foundation for future catalyst design strategies that transcend different catalyst classes.

Understanding trends in C–H bond activation in heterogeneous catalysis

DOE PAGES

Latimer, Allegra A.; Kulkarni, Ambarish R.; Aljama, Hassan; ...

2016-10-10

While the search for catalysts capable of directly converting methane to higher value commodity chemicals and liquid fuels has been active for over a century, a viable industrial process for selective methane activation has yet to be developed1. Electronic structure calculations are playing an increasingly relevant role in this search, but large-scale materials screening efforts are hindered by computationally expensive transition state barrier calculations. The purpose of the present letter is twofold. First, we show that, for the wide range of catalysts that proceed via a radical intermediate, a unifying framework for predicting C–H activation barriers using a single universalmore » descriptor can be established. Second, we combine this scaling approach with a thermodynamic analysis of active site formation to provide a map of methane activation rates. Lastly, our model successfully rationalizes the available empirical data and lays the foundation for future catalyst design strategies that transcend different catalyst classes.« less

Understanding trends in C-H bond activation in heterogeneous catalysis

NASA Astrophysics Data System (ADS)

Latimer, Allegra A.; Kulkarni, Ambarish R.; Aljama, Hassan; Montoya, Joseph H.; Yoo, Jong Suk; Tsai, Charlie; Abild-Pedersen, Frank; Studt, Felix; Nørskov, Jens K.

2017-02-01

While the search for catalysts capable of directly converting methane to higher value commodity chemicals and liquid fuels has been active for over a century, a viable industrial process for selective methane activation has yet to be developed. Electronic structure calculations are playing an increasingly relevant role in this search, but large-scale materials screening efforts are hindered by computationally expensive transition state barrier calculations. The purpose of the present letter is twofold. First, we show that, for the wide range of catalysts that proceed via a radical intermediate, a unifying framework for predicting C-H activation barriers using a single universal descriptor can be established. Second, we combine this scaling approach with a thermodynamic analysis of active site formation to provide a map of methane activation rates. Our model successfully rationalizes the available empirical data and lays the foundation for future catalyst design strategies that transcend different catalyst classes.

Non-Hematopoietic MLKL Protects Against Salmonella Mucosal Infection by Enhancing Inflammasome Activation

PubMed Central

Yu, Shui-Xing; Chen, Wei; Liu, Zhen-Zhen; Zhou, Feng-Hua; Yan, Shi-Qing; Hu, Gui-Qiu; Qin, Xiao-Xia; Zhang, Jie; Ma, Ke; Du, Chong-Tao; Gu, Jing-Min; Deng, Xu-Ming; Han, Wen-Yu; Yang, Yong-Jun

2018-01-01

The intestinal mucosal barrier is critical for host defense against pathogens infection. Here, we demonstrate that the mixed lineage kinase-like protein (MLKL), a necroptosis effector, promotes intestinal epithelial barrier function by enhancing inflammasome activation. MLKL−/− mice were more susceptible to Salmonella infection compared with wild-type counterparts, with higher mortality rates, increased body weight loss, exacerbated intestinal inflammation, more bacterial colonization, and severe epithelial barrier disruption. MLKL deficiency promoted early epithelial colonization of Salmonella prior to developing apparent intestinal pathology. Active MLKL was predominantly expressed in crypt epithelial cells, and experiments using bone marrow chimeras found that the protective effects of MLKL were dependent on its expression in non-hematopoietic cells. Intestinal mucosa of MLKL−/− mice had impaired caspase-1 and gasdermin D cleavages and decreased interleukin (IL)-18 release. Moreover, administration of exogenous recombinant IL-18 rescued the phenotype of increased bacterial colonization in MLKL−/− mice. Thus, our results uncover the role of MLKL in enhancing inflammasome activation in intestinal epithelial cells to inhibit early bacterial colonization. PMID:29456533

Promoting youth physical activity in rural southern communities: practitioner perceptions of environmental opportunities and barriers.

PubMed

Edwards, Michael B; Theriault, Daniel S; Shores, Kindal A; Melton, Karen M

2014-01-01

Research on youth physical activity has focused on urban areas. Rural adolescents are more likely to be physically inactive than urban youth, contributing to higher risk of obesity and chronic diseases. Study objectives were to: (1) identify perceived opportunities and barriers to youth physical activity within a rural area and (2) identify rural community characteristics that facilitate or inhibit efforts to promote youth physical activity. Thirty in-depth interviews were conducted with expert informants in 2 rural southern US counties. Interviewees were recruited from diverse positions across multiple sectors based on their expert knowledge of community policies and programs for youth physical activity. Informants saw ball fields, natural amenities, and school sports as primary resources for youth physical activity, but they were divided on whether opportunities were abundant or scarce. Physical distance, social isolation, lack of community offerings, and transportation were identified as key barriers. Local social networks facilitated political action and volunteer recruitment to support programs. However, communities often lacked human capital to sustain initiatives. Racial divisions influenced perceptions of opportunities. Despite divisions, there were also examples of pooling resources to create and sustain physical activity opportunities. Developing partnerships and leveraging local resources may be essential to overcoming barriers for physical activity promotion in rural areas. Involvement of church leaders, school officials, health care workers, and cooperative extension is likely needed to establish and sustain youth rural physical activity programs. Allocating resources to existing community personnel and volunteers for continuing education may be valuable. © 2014 National Rural Health Association.

The perceived benefits and barriers to exercise participation in persons with multiple sclerosis.

PubMed

Stroud, Nicole; Minahan, Clare; Sabapathy, Surendran

2009-01-01

The purpose of this study was to examine the perceived benefits and barriers to exercise participation in persons with multiple sclerosis (MS). A cross-sectional postal survey comprised of 93 adults with MS was conducted. Participants completed the Exercise Benefits and Barriers Scale (EBBS), Spinal Cord Injury Exercise Self-Efficacy Scale (EXSE), Multiple Sclerosis Impact Scale, Disease Steps Scale and International Physical Activity Questionnaire. Forty-three percent of the participants were classified as exercising individuals (EX group) as compared with non-exercising individuals (non-EX group). Participants in the EX group reported significantly higher scores on the EBBS and EXSE. Items related to physical performance and personal accomplishment were cited as the greatest perceived benefits to exercise participation and those items related to physical exertion as the greatest perceived barriers to both the EX and non-EX groups. When compared with previous studies conducted in the general population, the participants in the present study reported different perceived barriers to exercise participation. Furthermore, awareness of the benefits of physical activity is not sufficient to promote exercise participation in persons with MS. Perceived exercise self-efficacy is shown to play an important role in promoting exercise participation in persons with MS.

Gender Barriers in Higher Education: The Case of Taiwan.

ERIC Educational Resources Information Center

Wang, Ru-jer

2001-01-01

Used data from a variety of sources to examine gender barriers to higher education in Taiwan. Findings show that barriers remain, that women still suffer disadvantages in access to higher education, even though the expansion of higher education in Taiwan has substantially benefitted females over the past few decades. (SLD)

The involvement of Spanish older people in nondegree educational programs: reasons for and barriers to participation.

PubMed

Villar, Feliciano; Celdrán, Montserrat

2014-01-01

This article examines the reasons older Spanish people participate in nondegree educational programs and the barriers they may face when they want to do so. Data were drawn from the 2007 Survey on Adults' Involvement in Learning Activities (Encuesta sobre la Participación de la Población Adulta en Actividades de Aprendizaje: EADA) and correspond to a nationally representative sample of Spanish people aged between 60 and 74 years old (n=4,559). Overall, only 8.7% of the sample participated in a nondegree educational program. Predictors of participation were being a woman, being younger, having a higher educational level, and being employed. The most frequent reason given for participation was of an intrinsic nature (e.g., interest in the topic), although instrumental motives (e.g., utility of the content for daily life) were more common than suggested by previous research. As for barriers to participation, the vast majority of older people (95.6% of those who did not participate) did not even express a desire to participate. The most frequent barriers were internal (e.g., age/health restrictions). This kind of barrier was ascribed a greater importance by older and less educated groups as well as by those who participate less in cultural activities. Policies to promote older people's participation in nonformal educational activities are discussed in light of the data.

The main types of electron energy distribution determined by model fitting to optical emissions during HF wave ionospheric modification experiments

NASA Astrophysics Data System (ADS)

Vlasov, M. N.; Kelley, M. C.; Hysell, D. L.

2013-06-01

Enhanced optical emissions observed during HF pumping are induced by electrons accelerated by high-power electromagnetic waves. Using measured emission intensities, the energy distribution of accelerated electrons can be inferred. Energy loss from the excitation of molecular nitrogen vibrational levels (the vibrational barrier) strongly influences the electron energy distribution (EED). In airglow calculations, compensation for electron depletion within the 2-3 eV energy range, induced by the vibrational barrier, can be achieved via electrons with an EED similar to a Gaussian distribution and energies higher than 3 eV. This EED has a peak within the 5-10 eV energy range. We show that the main EED features depend strongly on altitude and solar activity. An EED similar to a power law distribution can occur above 270-300 km altitude. Below 270 km altitude, a Gaussian distribution for energies between 3 eV and 10 eV, together with a power law distribution for energies higher than 10 eV, is indicated. A Gaussian distribution combined with an exponential function is needed below 230 km altitude. The transition altitude from Gaussian to power law distribution depends strongly on solar activity, increasing for high solar activity. Electrons accelerated during the initial collisionless stage can inhibit the depletion of fast electrons within the vibrational barrier range, an effect that strongly depends on altitude and solar activity. The approach, based on the effective root square electric field, enables EED calculation, providing the observed red-line intensities for low and high solar activities.

Reevaluation of the non-lesional dry skin in atopic dermatitis by acute barrier disruption: an abnormal permeability barrier homeostasis with defective processing to generate ceramide.

PubMed

Sugiura, Ayumi; Nomura, Tsuyoshi; Mizuno, Atsuko; Imokawa, Genji

2014-07-01

Atopic dermatitis is characterized by disruption of the cutaneous barrier due to reduced ceramide levels even in non-lesional dry skin. Following further acute barrier disruption by repeated tape strippings, we re-characterized the non-lesional dry skin of subjects with atopic dermatitis, which shows significantly reduced levels of barrier function and ceramide but not of beta-glucocerebrosidase activity. For the first time, we report an abnormal trans-epidermal water loss homeostasis in which delayed recovery kinetics of trans-epidermal water loss occurred on the first day during the 4 days after acute barrier disruption compared with healthy control skin. Interestingly, whereas the higher ceramide level in the stratum corneum of healthy control skin was further significantly up-regulated at 4 days post-tape stripping, the lower ceramide level in the stratum corneum of subjects with atopic dermatitis was not significantly changed. In a parallel study, whereas beta-glucocerebrosidase activity at 4 days post-tape stripping was significantly up-regulated in healthy control skin compared with before tape stripping, the level of that activity remained substantially unchanged in atopic dermatitis. These findings indicate that subjects with atopic dermatitis have a defect in sphingolipid-metabolic processing that generates ceramide in the interface between the stratum corneum and the epidermis. The results also support the notion that the continued disruption of barrier function in atopic dermatitis non-lesional skin is associated with the impaired homeostasis of a ceramide-generating process, which underscores an atopy-specific inflammation-triggered ceramide deficiency that is distinct from other types of dermatitis.

Functional analysis of the sea urchin-derived arylsulfatase (Ars)-element in mammalian cells.

PubMed

Watanabe, Satoshi; Watanabe, Sachiko; Sakamoto, Naoaki; Sato, Masahiro; Akasaka, Koji

2006-09-01

An insulator is a DNA sequence that has both enhancer-blocking activity, through its ability to modify the influence of neighboring cis-acting elements, and a barrier function that protects a transgene from being silenced by surrounding chromatin. Previously, we isolated and characterized a 582-bp-long element from the sea urchin arylsulfatase gene (Ars). This Ars-element was effective in sea urchin and Drosophila embryos and in plant cells. To investigate Ars-element activity in mammalian cells, we placed the element between the cytomegalovirus enhancer and a luciferase (luc) expression cassette. In contrast to controls lacking the Ars-element, NIH3T3 and 293T cells transfected with the element-containing construct displayed reduced luciferase activities. The Ars-element therefore acts as an enhancer-blocking element in mammalian cells. We assessed the barrier activity of the Ars-element using vectors in which a luc expression cassette was placed between two elements. Transfection experiments demonstrated that luc activity in these vectors was approximately ten-fold higher than in vectors lacking elements. Luc activities were well maintained even after 12 weeks in culture. Our observations demonstrate that the Ars-element has also a barrier activity. These results indicated that the Ars-element act as an insulator in mammalian cells.

Primary Care Provider Perceptions of the Effectiveness of Two Self-Management Support Programs for Vulnerable Patients with Diabetes

PubMed Central

Ratanawongsa, Neda; Bhandari, Vijay K; Handley, Margaret; Rundall, Thomas; Hammer, Hali; Schillinger, Dean

2012-01-01

Background Primary care providers (PCPs) in safety net settings face barriers to optimizing care for patients with diabetes. We conducted this study to assess PCPs' perspectives on the effectiveness of two language-concordant diabetes self-management support programs. Methods One year postintervention, we surveyed PCPs whose patients with diabetes participated in a three-arm multiclinic randomized controlled trial comparing usual care (UC), weekly automated telephone self-management (ATSM) support with nurse care management, and monthly group medical visits (GMVs). We compared PCP perspectives on patient activation to create and achieve goals, quality of care, and barriers to care using regression models accounting for within-PCP clustering. Results Of 113 eligible PCPs caring for 330 enrolled patients, 87 PCPs (77%) responded to surveys about 245 (74%) enrolled patients. Intervention patients were more likely to be perceived by PCPs as activated to create and achieve goals for chronic care when compared with UC patients (standardized effect size, ATSM vs UC, +0.41, p = 0.01; GMV vs UC, +0.31, p = 0.05). Primary care providers rated quality of care as higher for patients exposed to ATSM compared to UC (odds ratio 3.6, p < 0.01). Compared with GMV patients, ATSM patients were more likely to be perceived by PCPs as overcoming barriers related to limited English proficiency (82% ATSM vs 44% GMV, p = 0.01) and managing medications (80% ATSM vs 53% GMV, p = 0.01). Conclusions Primary care providers perceived that patients receiving ATSM support had overcome barriers, participated more actively, and received higher quality diabetes care. These views of clinician stakeholders lend additional evidence for the potential to upscale ATSM more broadly to support PCPs in their care of diverse, multilinguistic populations. PMID:22401329

Multidimensional structure of a questionnaire to assess barriers to and motivators of physical activity in recipients of solid organ transplantation.

PubMed

van Adrichem, Edwin J; Krijnen, Wim P; Dekker, Rienk; Ranchor, Adelita V; Dijkstra, Pieter U; van der Schans, Cees P

2017-11-01

To explore the underlying dimensions of the Barriers and Motivators Questionnaire that is used to assess barriers to and motivators of physical activity experienced by recipients of solid organ transplantation and thereby improve the application in research and clinical settings. A cross-sectional study was performed in recipients of solid organ transplantation (n = 591; median (IQR) age = 59 (49; 66); 56% male). The multidimensional structure of the questionnaire was analyzed by exploratory principal component analysis. Cronbach's α was calculated to determine internal consistency of the entire questionnaire and individual components. The barriers scale had a Cronbach's α of 0.86 and was subdivided into four components; α of the corresponding subscales varied between 0.80 and 0.66. The motivator scale had an α of 0.91 and was subdivided into four components with an α between 0.88 to 0.70. Nine of the original barrier items and two motivator items were not included in the component structure. A four-dimensional structure for both the barriers and motivators scale of the questionnaire is supported. The use of the indicated subscales increases the usability in research and clinical settings compared to the overall scores and provide opportunities to identify modifiable constructs to be targeted in interventions. Implications for rehabilitation Organ transplant recipients are less active than the general population despite established health benefits of physical activity. A multidimensional structure is shown in the Barriers and Motivators Questionnaire, the use of the identified subscales increases applicability in research and clinical settings. The use of the questionnaire with its component structure in the clinical practice of a rehabilitation physician could result in a faster assessment of problem areas in daily practice and result in a higher degree of clarity as opposed to the use of the individual items of the questionnaire.

Barriers associated with frequency of leisure-time physical activity among Brazilian adults of different income strata.

PubMed

Silva, K S; Del Duca, G F; Garcia, L M T; da Silva, J A; Bertuol, C; de Oliveira, E S A; de Barros, M V G; Nahas, M V

2016-02-01

This study aimed to estimate the prevalence of the main perceived barriers to leisure-time physical activity (LTPA) and their associations with the frequency of LTPA in a representative sample of industrial workers from Brazil (n = 47,477), according to their income strata (low income: ≤$US280, middle income: $US281-$US1400, and high income: ≥$US1401). Data were collected between 2006 and 2008 via questionnaires about the main perceived barrier to LTPA and the frequency of LTPA. Multinomial logistic regression was performed to evaluate differences among groups. There was a lower prevalence of regular practice of LTPA in the low- (15.8%) and middle-income strata (18.2%) than among the individuals of the high-income stratum (27.6%). A large proportion of workers who regularly participated in LTPA reported no barriers (low: 43.1%; middle: 46.8%; high: 51.6%). Additional obligations and fatigue were the two most common perceived barriers in all family income strata among participants who engaged in different frequencies of LTPA. The odds for all perceived barriers showed a positive trend related to frequency of LTPA (from regular to no LTPA), with higher values according to income. In summary, the ordering of the main perceived barriers to LTPA differed according to workers' income stratum and frequency of engaging in LTPA. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Clinical physical therapists research activity reality and barriers to their utilizing research findings

PubMed Central

Park, Kyungyeon; Choi, Boram; Han, Dongwook

2015-01-01

[Purpose] This research study was performed to investigate the barriers to using the research findings of physical therapists on evidence-based practice. [Subjects] The subjects of this research were physical therapists employed by hospitals that agreed to cooperate with the research in B city. [Methods] A questionnaire made up of 6 research items, 8 physical therapist items, 6 presentation items, and 8 setting items, for a total of 28 items, was distributed. The responses were scored so the higher result scores indicate a higher barrier level to using research findings. Differences in barrier levels related to the likelihood of therapists using research findings in their practice varied according to the general characteristics of the result as according to the t-test and ANOVA. Scheffe’s test was used as a post hoc test. [Results] The analysis of 158 returned questionnaires revealed that there were significant relationships between the age, educational level, and professional satisfaction of the therapists and the barriers to using research finding. Significant relationships were also found between the items of “Research participation in clinical research”, “Frequency of reading research articles”, and “Support of manager to use research” and the barrier level. No relationship was demonstrated between the recognition level of evidence-based practice and the performance level with the barrier score to using research findings. [Conclusion] This study demonstrated that to improve the utilization of research findings, there is a need to provide therapists with continual education and opportunities to participate in research, and environments and ways in which the research results can be given practical applications. PMID:26311932

[Sexual behavior in adolescents aged 12 to 17 in Andalusia (Spain)].

PubMed

Rodríguez Carrión, José; Traverso Blanco, Clara Isabel

2012-01-01

To describe sexual behavior and activity among adolescents aged 12-17 years old in Andalusia (Spain) in 2007-2008. The data for this study were collected through an anonymous questionnaire distributed to a stratified random sample of 2,225 secondary school students in Andalusia. Participation was voluntary. A total of 388 respondents (18.2%) reported having had complete sexual intercourse, with no statistically significant differences between boys (18.0%) and girls (18.5%). However, boys initiated the following practices earlier than girls: sexual activity (14 years versus 14.4 years), masturbation (11.3 years versus 12.7 years), oral sex (13.8 years versus 14.6 years) and mutual masturbation (13.7 years versus 14.4 years). Other gender differences included the number of sexual partners (two in boys versus 1.6 in girls), recent sexual activity (higher in girls), internet sex (higher in boys), contraceptive use during the first coitus (lower in boys) and knowledge about double-barrier methods of contraception and sexually transmitted diseases (higher in girls). One out of six Andalusian secondary education students had had sexual intercourse. Two-thirds of the students were sexually active, especially girls, with limited knowledge of double-barrier methods and sexually transmitted diseases. The results of this study demonstrate the importance of including sex education as a core subject in the secondary education curriculum. Copyright © 2011 SESPAS. Published by Elsevier Espana. All rights reserved.

Activated dynamics in dense fluids of attractive nonspherical particles. II. Elasticity, barriers, relaxation, fragility, and self-diffusion

NASA Astrophysics Data System (ADS)

Tripathy, Mukta; Schweizer, Kenneth S.

2011-04-01

In paper II of this series we apply the center-of-mass version of Nonlinear Langevin Equation theory to study how short-range attractive interactions influence the elastic shear modulus, transient localization length, activated dynamics, and kinetic arrest of a variety of nonspherical particle dense fluids (and the spherical analog) as a function of volume fraction and attraction strength. The activation barrier (roughly the natural logarithm of the dimensionless relaxation time) is predicted to be a rich function of particle shape, volume fraction, and attraction strength, and the dynamic fragility varies significantly with particle shape. At fixed volume fraction, the barrier grows in a parabolic manner with inverse temperature nondimensionalized by an onset value, analogous to what has been established for thermal glass-forming liquids. Kinetic arrest boundaries lie at significantly higher volume fractions and attraction strengths relative to their dynamic crossover analogs, but their particle shape dependence remains the same. A limited universality of barrier heights is found based on the concept of an effective mean-square confining force. The mean hopping time and self-diffusion constant in the attractive glass region of the nonequilibrium phase diagram is predicted to vary nonmonotonically with attraction strength or inverse temperature, qualitatively consistent with recent computer simulations and colloid experiments.

AFRL Nanotechnology Initiative: Hybrid Nanomaterials in Photonic Crystal Cavities for Multi-Spectral Infrared Detector Arrays

DTIC Science & Technology

2010-03-31

the determination of bias - dependent EQD activation energies by Arrhenius plots. Fig. 4 shows the EQD activation energies as a function of bias ...consistent with thermal activation and field-assisted tunneling through the triangular potential barrier provided at higher bias voltages. In...contrast, three bias - dependent regions of the EQD activation energy can be identified for the doped samples, as shown in Fig. 4. In Region I (< 0.4 V

A Pilot Study of Determinants of Ongoing Participation in EnhanceFitness: A Community-Based Group Exercise Program for Older Adults.

PubMed

Gillette, David B; Petrescu-Prahova, Miruna; Herting, Jerald R; Belza, Basia

2015-01-01

Physical activity has many benefits for older adults, but adherence is often low. The purposes of this study were to (1) identify motivators and barriers for participation in EnhanceFitness (EF), a group-based exercise program; and (2) quantitatively examine the association between motivators, barriers and individual characteristics, and ongoing participation in the program. This was a prospective, cross-sectional study. We mailed a pilot, investigator-developed survey to assess motivators and barriers to exercising to 340 adults who started a new EF class, regardless of their attendance rate. We precoded surveys on the basis of class attendance, with former participants defined as having no attendance a month or more before a 4-month fitness check. Of the 241 respondents (71% response rate), 61 (25%) were precoded as former participants and 180 (75%) as current participants. The mean age of respondents was 71 years and they were predominately female (89%). More than half of respondents were whites (58%), and almost half were married (46%). Former participants reported lower total motivation scores than current participants (P < .01) and had a significantly higher mean total barrier score (P < .001). The effects of 5 barriers ("Class was too hard," "Class was too easy," "I don't like to exercise," "Personal illness," and "Exercise caused pain") and 2 motivators ("I want to exercise" and "I plan exercise as part of my day") were significantly different between current and former participants. Discrete event history models show that dropout was related positively to ethnicity (whites were more likely to drop out) and health-related barriers. In newly formed EF classes, participants who drop out report more program, psychosocial, and health barriers, and fewer program and psychosocial motivators. Total barrier score and health barriers significantly predict a participant's dropping out, and white ethnicity is associated with a higher likelihood of dropping out. Employing strategies that address health barriers to participation could improve attendance rates for group-based exercise programs.

Can human activities alter the drowning fate of barrier islands?

NASA Astrophysics Data System (ADS)

Lorenzo-Trueba, J.; Ashton, A. D.; Jin, D.; Hoagland, P.; Kite-Powell, H.

2012-12-01

Low-lying coastal barriers face an uncertain future over the coming century and beyond as sea levels rise, with many projections suggesting end-of-century rates of sea-level rise as high or higher than 1 cm/yr. Geologically, such rates of sea-level rise have been experienced several thousand years ago and we can use our understanding of geological processes and sedimentary evidence to help unravel the dynamics of natural barriers experiencing sea-level rise. Along many modern coastal barriers, however, anthropic change, such as beach nourishment, dune construction, and emplacement of hard structures, plays a dominant role in coastline dynamics. A fundamental question to be addressed is whether human activities intended to preserve infrastructure and beach recreation may make wholesale collapse, or 'drowning,' of barrier systems more likely. Here we present a numerical modeling tool that couples natural processes and the human responses to these changes (and the subsequent of human responses on natural processes). Recent theoretical model development suggests that barriers are intrinsically morphodynamic features, responding to sea-level rise in complex ways through the interactions of marine processes and barrier overwash. Undeveloped coastal barriers would therefore respond to an accelerated sea-level rise in complex, less predictable manners than suggested by existing long-term models. We have developed a model that examines non-equilibrium cross-shore evolution of barrier systems at decadal to centennial temporal scales, focusing on the interactions between processes of shoreface evolution and overwash deposition. Model responses demonstrate two means of barrier collapse during sea-level rise: 'height drowning', which occurs when overwash fluxes are insufficient to maintain the landward migration rate required to keep in pace with sea-level rise, and 'width drowning', which occurs when the shoreface response is insufficient to maintain the barrier geometry during landward migration. The model also demonstrates the potential for discontinuous shoreline retreat, with alternating periods of barrier stability and rapid migration, even for constant rates of sea-level rise. Anthropic activities can strongly interact with these behaviors. In particular, considering only cross-shore processes, beach nourishment activities widen the beach and can affect shoreface fluxes, and dune building, which curtails the overwash process, can potentially enhance barrier drowning by reducing overwash fluxes. Furthermore, coastal protection activities of adjacent communities or even individual property holders can be uncoordinated or coordinated, with their effects coupled along the coast through coastal reorientation and gradients in alongshore sediment transport. In the coordinated framework, owners act in concert to alter the barrier based upon community benefits, whereas in the non-coordinated framework owners alter only their own property. Another important role in management is the perception of future sea-level-rise-associated losses—communities manage their coast differently depending on their adopted forecast for sea-level rise. We find that coordinated behavior coupled with natural processes can substantially affect the drowning scenarios from the individual decision-making process.

Transport of the moving barrier driven by chiral active particles

NASA Astrophysics Data System (ADS)

Liao, Jing-jing; Huang, Xiao-qun; Ai, Bao-quan

2018-03-01

Transport of a moving V-shaped barrier exposed to a bath of chiral active particles is investigated in a two-dimensional channel. Due to the chirality of active particles and the transversal asymmetry of the barrier position, active particles can power and steer the directed transport of the barrier in the longitudinal direction. The transport of the barrier is determined by the chirality of active particles. The moving barrier and active particles move in the opposite directions. The average velocity of the barrier is much larger than that of active particles. There exist optimal parameters (the chirality, the self-propulsion speed, the packing fraction, and the channel width) at which the average velocity of the barrier takes its maximal value. In particular, tailoring the geometry of the barrier and the active concentration provides novel strategies to control the transport properties of micro-objects or cargoes in an active medium.

Two-well terahertz quantum cascade lasers with suppressed carrier leakage

DOE PAGES

Albo, Asaf; Flores, Yuri V.; Hu, Qing; ...

2017-09-11

The mechanisms that limit the temperature performance of diagonal GaAs/Al 0.15GaAs 0.85-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated leakage of charge carriers through excited states into the continuum. THz-QCLs with energetically higher-laying excited states supported by sufficiently high barriers aim to eliminate these leakage mechanisms and lead to improved temperature performance. Although suppression of thermally activated carrier leakage was realized in a three-well THz-QCL based on a resonant-phonon scheme, no improvement in the temperature performance was reported thus far. Here, we report a major improvement in the temperature performance of a two-quantum-well direct-phonon THz-QCL structure.more » We show that the improved laser performance is due to the suppression of the thermally activated carrier leakage into the continuum with the increase in the injection barrier height. Furthermore, we demonstrate that high-barrier two-well structures can support a clean three-level laser system at elevated temperatures, which opens the opportunity to achieve temperature performance beyond the state-of-the-art.« less

Two-well terahertz quantum cascade lasers with suppressed carrier leakage

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

Albo, Asaf; Flores, Yuri V.; Hu, Qing

The mechanisms that limit the temperature performance of diagonal GaAs/Al 0.15GaAs 0.85-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated leakage of charge carriers through excited states into the continuum. THz-QCLs with energetically higher-laying excited states supported by sufficiently high barriers aim to eliminate these leakage mechanisms and lead to improved temperature performance. Although suppression of thermally activated carrier leakage was realized in a three-well THz-QCL based on a resonant-phonon scheme, no improvement in the temperature performance was reported thus far. Here, we report a major improvement in the temperature performance of a two-quantum-well direct-phonon THz-QCL structure.more » We show that the improved laser performance is due to the suppression of the thermally activated carrier leakage into the continuum with the increase in the injection barrier height. Furthermore, we demonstrate that high-barrier two-well structures can support a clean three-level laser system at elevated temperatures, which opens the opportunity to achieve temperature performance beyond the state-of-the-art.« less

Two-well terahertz quantum cascade lasers with suppressed carrier leakage

NASA Astrophysics Data System (ADS)

Albo, Asaf; Flores, Yuri V.; Hu, Qing; Reno, John L.

2017-09-01

The mechanisms that limit the temperature performance of diagonal GaAs/Al0.15GaAs0.85-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated leakage of charge carriers through excited states into the continuum. THz-QCLs with energetically higher-laying excited states supported by sufficiently high barriers aim to eliminate these leakage mechanisms and lead to improved temperature performance. Although suppression of thermally activated carrier leakage was realized in a three-well THz-QCL based on a resonant-phonon scheme, no improvement in the temperature performance was reported thus far. Here, we report a major improvement in the temperature performance of a two-quantum-well direct-phonon THz-QCL structure. We show that the improved laser performance is due to the suppression of the thermally activated carrier leakage into the continuum with the increase in the injection barrier height. Moreover, we demonstrate that high-barrier two-well structures can support a clean three-level laser system at elevated temperatures, which opens the opportunity to achieve temperature performance beyond the state-of-the-art.

Early mobilization in critically ill patients: patients' mobilization level depends on health care provider's profession.

PubMed

Garzon-Serrano, Jaime; Ryan, Cheryl; Waak, Karen; Hirschberg, Ronald; Tully, Susan; Bittner, Edward A; Chipman, Daniel W; Schmidt, Ulrich; Kasotakis, Georgios; Benjamin, John; Zafonte, Ross; Eikermann, Matthias

2011-04-01

To evaluate whether the level of mobilization achieved and the barriers for progressing to the next mobilization level differ between nurses and physical therapists. Prospective, observational study. Twenty-bed surgical intensive care unit (SICU) of the Massachusetts General Hospital. Sixty-three critically ill patients. Physical therapists and nurses performed 179 mobilization therapies with 63 patients. Mobilization was defined as the process of enhancing mobility in the SICU, including bed mobility, edge of bed activities, transfers out of bed to a chair, and gait training; the mobilization level was measured on the SICU optimal mobilization scale, a 5-point (0-4) numerical rating scale. Patients' level of mobilization achieved by physical therapists was significantly higher compared with that achieved by nurses (2.3 ± 1.2 mean ± SD versus 1.2 ± 1.2, respectively P < .0001). Different barriers for mobilization were identified by physical therapists and nurses: hemodynamic instability (26% versus 12%, P = .03) and renal replacement therapy (12% versus 1%, P = .03) were barriers rated higher by nurses, whereas neurologic impairment was rated higher by physical therapists providers (18% versus 38%, P = .002). No mobilization-associated adverse events were observed in this study. This study showed that physical therapists mobilize their critically ill patients to higher levels compared with nurses. Nurse and physical therapists identify different barriers for mobilization. Routine involvement of physical therapists in directing mobilization treatment may promote early mobilization of critically ill patients. Copyright © 2011 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Promoting Optimal Physical Exercise for Life: An Exercise and Self-Management Program to Encourage Participation in Physical Activity after Discharge from Stroke Rehabilitation—A Feasibility Study

PubMed Central

Mansfield, Avril; Knorr, Svetlana; Poon, Vivien; Inness, Elizabeth L.; Middleton, Laura; Biasin, Louis; Brunton, Karen; Howe, Jo-Anne; Brooks, Dina

2016-01-01

People with stroke do not achieve adequate levels of physical exercise following discharge from rehabilitation. We developed a group exercise and self-management program (PROPEL), delivered during stroke rehabilitation, to promote uptake of physical activity after discharge. This study aimed to establish the feasibility of a larger study to evaluate the effect of this program on participation in self-directed physical activity. Participants with subacute stroke were recruited at discharge from one of three rehabilitation hospitals; one hospital offered the PROPEL program whereas the other two did not (comparison group; COMP). A high proportion (11/16) of eligible PROPEL program participants consented to the study. Fifteen COMP participants were also recruited. Compliance with wearing an accelerometer for 6 weeks continuously and completing physical activity questionnaires was high (>80%), whereas only 34% of daily heart rate data were available. Individuals who completed the PROPEL program seemed to have higher outcome expectations for exercise, fewer barriers to physical activity, and higher participation in physical activity than COMP participants (Hedge's g ≥ 0.5). The PROPEL program delivered during stroke rehabilitation shows promise for reducing barriers to exercise and increasing participation in physical activity after discharge. This study supports feasibility of a larger randomized trial to evaluate this program. PMID:27313948

Opportunities to Strengthen Childhood Obesity Prevention in Two Mexican Health Care Settings

PubMed Central

Cespedes, Elizabeth; Andrade, Gloria Oliva Martínez; Rodríguez-Oliveros, Guadalupe; Perez-Cuevas, Ricardo; González-Unzaga, Marco A.; Trejo, Amalia Benitez; Haines, Jess; Gillman, Matthew W.; Taveras, Elsie M.

2014-01-01

Background The purpose of this study was to examine Mexican caregivers’ perceptions of the role of primary care in childhood obesity management, understand the barriers and facilitators of behavior change, and identify opportunities to strengthen obesity prevention and treatment in clinical settings. Methods We conducted 52 in-depth interviews with parents and caregivers of overweight and obese children age 2–5 years in 4 Ministry of Health (public, low SES) and 4 Social Security Institute (insured, higher SES) primary care clinics in Mexico City and did systematic thematic analysis. Results In both health systems, caregivers acknowledged childhood overweight but not its adverse health consequences. Although the majority of parents had not received nutrition or physical activity recommendations from health providers, many were open to clinician guidance. Despite knowledge of healthful nutrition and physical activity, parents identified several barriers to change including child feeding occurring in the context of competing priorities (work schedules, spouses’ food preferences), and cultural norms (heavy as healthy, food as nurturance) that take precedence over adherence to dietary guidelines. Physical activity, while viewed favorably, is not a structured part of most preschooler’s routines as reported by parents. Conclusions The likelihood of success for clinic-based obesity prevention among Mexican preschoolers will be higher by addressing contextual barriers such as cultural norms regarding children’s weight and support of family members for behavior change. Similarities in caregivers’ perceptions across 2 health systems highlight the possibility of developing comprehensive interventions for the population as a whole. PMID:25530836

Ocean barrier layers' effect on tropical cyclone intensification.

PubMed

Balaguru, Karthik; Chang, Ping; Saravanan, R; Leung, L Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

2012-09-04

Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are "quasi-permanent" features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

Ocean barrier layers’ effect on tropical cyclone intensification

PubMed Central

Balaguru, Karthik; Chang, Ping; Saravanan, R.; Leung, L. Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

2012-01-01

Improving a tropical cyclone’s forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone’s path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are “quasi-permanent” features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity. PMID:22891298

Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification

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

Balaguru, Karthik; Chang, P.; Saravanan, R.

2012-09-04

Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are 'quasi-permanent' features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropicalmore » cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.« less

Weight gain as a barrier to smoking cessation among military personnel.

PubMed

Russ, C R; Fonseca, V P; Peterson, A L; Blackman, L R; Robbins, A S

2001-01-01

To assess the relationships between active-duty military status, military weight standards, concern about weight gain, and anticipated relapse after smoking cessation. Cross-sectional study. Hospital-based tobacco cessation program. Two hundred fifty-two enrollees, of 253 eligible, to a tobacco cessation program in 1999 (135 men, 117 women; 43% on active duty in the military). Independent variables included gender, body mass index (weight/height2), and military status. Dependent variables included about weight gain with smoking cessation and anticipated relapse. In multivariate regression analyses that controlled for gender and body mass index, active-duty military status was associated with an elevated level of concern about weight gain (1.9-point increase on a 10-point scale; 95% confidence interval [CI], 1.0- to 2.8-point increase), as well as higher anticipated relapse (odds ratio [OR] = 3.6; 95% CI, 1.3 to 9.8). Among subjects who were close to or over the U.S. Air Force maximum allowable weight for height, the analogous OR for active-duty military status was 6.9 (p = .02). Occupational weight standards or expectations may pose additional barriers for individuals contemplating or attempting smoking cessation, as they do among active-duty military personnel. These barriers are likely to hinder efforts to decrease smoking prevalence in certain groups.

How do you exercise with epilepsy? Insights into the barriers and adaptations to successfully exercise with epilepsy.

PubMed

Collard, Sarah S; Ellis-Hill, Caroline

2017-05-01

Exercise has been shown to be a physiological and psychological benefit for people with epilepsy (PWE). However, barriers prevent many PWE from exercising safely and confidently. This research explored current perceived barriers to exercise and adaptation techniques used by PWE in order to maintain physical activity levels. Three focus groups (2-3 participants per group) and three semi-structured interviews were conducted (11 participants total). Constructive grounded theory was used to frame the study and analyse the findings, presenting new insight into the motivation, perceived barriers, and adaptation techniques used to exercise. The main motivator to maintain physical activity levels was the benefit of exercise on physical and mental health. This was shown in an increase in mood, higher social interaction, and perceived improvement in overall physical health as a result of exercise. Current barriers to exercise included a fear of injury, lack of social support, and exercise-induced seizures (e.g., through overheating and/or high exercise intensity level). Adaptation techniques used were self-monitoring through the use of technology, reducing exercise frequency and intensity level, and exercising at certain times of the day. The importance of social support was shown to provide increased confidence and positive encouragement to exercise, contrasting with family and friends worrying for his/her safety and medical professionals requesting termination of some physical activities. These findings provide new insight into current adaptation techniques that are used and developed by PWE to overcome common barriers to exercise. These new additions to the literature can lead to further development of such techniques as well as examine current medical professionals' knowledge of the benefits of exercise for PWE. Copyright © 2017 Elsevier Inc. All rights reserved.

Perceived somatic and affective barriers for self-efficacy and physical activity.

PubMed

Warner, Lisa M; Wolff, Julia K; Spuling, Svenja M; Wurm, Susanne

2017-05-01

According to Bandura's social-cognitive theory, perceptions of somatic and affective barriers are sources of self-efficacy. This longitudinal study compares general indicators of health barriers with measures of perceived somatic and affective barriers to predict self-efficacy and accelerometer-assessed physical activity in a subsample of n = 153 (selected at random from N = 310) community-dwelling German older adults. Perceived somatic and affective barriers longitudinally predicted physical activity mediated by self-efficacy, whereas general health barriers did not. Perceived health barriers to physical activity might be more important than more objective health barriers for older adults' physical activity levels.

Self-fulfillment despite barriers: volunteer work of people living with HIV.

PubMed

Samson, André; Lavigne, René M; MacPherson, Paul

2009-11-01

With the decline in the morbidity and mortality associated with HIV infection, the majority of people living with HIV (PWHIV) experience a higher quality of life and longer life expectancy. Since this diagnosis no longer prevents an active lifestyle, many PWHIV are re-integrating into the workplace or are contemplating this possibility. Despite the multiple advantages associated with a return to work, research has identified barriers related to work and HIV infection. These barriers could prevent an important minority of PWHIV who wish to return to work from re-integrating into this environment. In this context, volunteering could be an alternate way to regain an active lifestyle. This research found that volunteer work allowed participants to enrich their social lives, to regain a sense of psychological well-being, and to apply their abilities to the benefit of others. However, participants are restricted by their preference to volunteer for HIV-related organizations in order to avoid social stigma and rejection.

Barriers and Opportunities to Advancing Women in Leadership Roles in Vector Control: Perspectives from a Stakeholder Survey.

PubMed

Hayden, Mary H; Barrett, Erika; Bernard, Guyah; Toko, Eunice N; Agawo, Maurice; Okello, Amanda M; Gunn, Jayleen K L; Ernst, Kacey C

2018-05-01

Increasing the active participation of professional women in vector control (VC) activities may help promote greater gender equity in the workplace and reduce the burden of vector-borne diseases. This stakeholder survey examined the current roles and perspective of professionals employed in the VC sector in Kenya, Indonesia, India, and other countries. The largest barriers that women face in pursuing leadership roles in the VC sector include lack of awareness of career opportunities, limitations based on cultural norms, and the belief that VC is men's work. These barriers could be addressed through improving education and recruitment campaigns, as well as supporting higher education and mentoring programs. Females were almost six times more likely to be encouraged to pursue leadership positions in their organization compared with male respondents (odds ratio = 5.9, P > 0.03, 95% confidence interval: 1.19, 29.42). These findings suggest that once women are recruited into the VC workforce, they face minimal discrimination and have increased leadership opportunities.

Barriers to Leisure-Time Physical Activities in Individuals with Spinal Cord Injury.

PubMed

Hwang, Eric J; Groves, Mary D; Sanchez, Jacqueline N; Hudson, Cassandra E; Jao, Rachel G; Kroll, Meghan E

2016-07-01

This study investigated the personal, environmental, and activity barriers to leisure-time physical activities (LTPAs) among individuals with spinal cord injury (SCI). A survey instrument was administered to 85 participants with SCI. Personal barriers to LTPAs included issues involving motivation, pain, scheduling, and financial resources. Environmental barriers marked the issues regarding availability and accessibility to specialized programs, activities, and professional services. Activity barriers included limitations in equipment, training, and personal skills required by the selected activities. Significant negative correlations were found between these barriers and the levels of physical activity and satisfaction with physical activity. While working with clients with SCI, occupational therapists should identify those LTPA barriers and possible solutions in order to establish individualized action plans for enhancing participation in LTPAs.

Self-learning kinetic Monte Carlo simulations of diffusion in ferromagnetic α-Fe-Si alloys

NASA Astrophysics Data System (ADS)

Nandipati, Giridhar; Jiang, Xiujuan; Vemuri, Rama S.; Mathaudhu, Suveen; Rohatgi, Aashish

2018-01-01

Diffusion of Si atom and vacancy in the A2-phase of α-Fe-Si alloys in the ferromagnetic state, with and without magnetic order and in various temperature ranges, are studied using AKSOME, an on-lattice self-learning KMC code. Diffusion of the Si atom and the vacancy are studied in the dilute limit and up to 12 at.% Si, respectively, in the temperature range 350-700 K. Local Si neighborhood dependent activation energies for vacancy hops were calculated on-the-fly using a broken-bond model based on pairwise interaction. The migration barrier and prefactor for the Si diffusion in the dilute limit were obtained and found to agree with published data within the limits of uncertainty. Simulations results show that the prefactor and the migration barrier for the Si diffusion are approximately an order of magnitude higher, and a tenth of an electron-volt higher, respectively, in the magnetic disordered state than in the fully ordered state. However, the net result is that magnetic disorder does not have a significant effect on Si diffusivity within the range of parameters studied in this work. Nevertheless, with increasing temperature, the magnetic disorder increases and its effect on the Si diffusivity also increases. In the case of vacancy diffusion, with increasing Si concentration, its diffusion prefactor decreases while the migration barrier more or less remained constant and the effect of magnetic disorder increases with Si concentration. Important vacancy-Si/Fe atom exchange processes and their activation barriers were identified, and the effect of energetics on ordered phase formation in Fe-Si alloys are discussed.

Conditioning of participation of disabled males and females from eastern regions of Poland in tourism and recreation.

PubMed

Bergier, Józef; Dąbrowski, Dominik; Zbikowski, Jarosław

2011-01-01

Disability is a serious social, cultural and economic problem, the solving of which requires both legal regulations and coordinated activities by the State. A constantly increasing number of the disabled is an important premise for undertaking actions aimed at complex rehabilitation of this population group, and their engagement in social and economic life. Creating possibilities for spending free time in an attractive way, in accordance with ones interests and needs, is an essential area of rehabilitation activities. In 2005, the Institute of Tourism and Recreation at the State Higher Vocational School in Biał Podlaska launched representative, complex studies concerning the social conditioning of involvement of the disabled from the regions of Eastern Poland in tourism and mobile recreation. The presented material is an excerpt from this study report. It concerns barriers which limit or make it impossible for disabled males and females to participate in tourism and mobile recreation in the regions of Lublin, Rzeszow, and Białstok. Among barriers, which to the highest degree limit the participation of the disabled in tourism and recreation, the respondents indicated their poor material standard. Other important barriers were inconveniences associated with transport, lack of up-to-date information, and type of disability. The barriers limiting motor activity were also analyzed according to gender. Statistically significant differences were observed between males and females with respect to the following characteristics: transport, lack of adequate information, lack of off er of activities, and lack of assistance. It is noteworthy that males more strongly than females emphasized such barriers as lack of information, off er of assistance, while females indicated the problems with transport.

Current toxicological aspects on drug and chemical transport and metabolism across the human placental barrier.

PubMed

Giaginis, Constantinos; Theocharis, Stamatios; Tsantili-Kakoulidou, Anna

2012-10-01

Placenta plays an obligatory role in fetal growth and development by performing a multitude of functions, including embryo implantation, transport of nutrients and elimination of metabolic waste products and endocrine activity. Drugs and chemicals can transfer across the placental barrier from mother to fetus either by passive diffusion mechanisms and/or via a network of active transporters, which may lead to potential fetotoxicity effects. Placenta also expresses a wide variety of enzymes, being capable of metabolizing a large diversity of drugs and chemicals to metabolites of lower or even higher toxicity than parent compounds. The present review aims to summarize the current toxicological aspects in the emerging topic of drug transport and metabolism across the human placental barrier. There is an emerging demand for accurate assessment of drug transport and metabolism across the human placental barrier, on the basis of a high throughput screening process in the early stages of drug design, to avoid drug candidates from potential fetotoxicity effects. In this aspect, combined studies, which take into account in vivo and in vitro investigations, as well as the ex vivo perfusion method and the recently developed computer-aided technologies, may significantly contribute to this direction.

Reversible electrokinetic adsorption barriers for the removal of organochlorine herbicide from spiked soils.

PubMed

Rodrigo, S; Saez, C; Cañizares, P; Rodrigo, M A

2018-06-02

This work aims to describe the removal of clopyralid from clay soils using electrokinetically assisted soil flushing (EKSF) coupled with a permeable reactive barrier (PRB), consisting of beds of Granulated Activated Carbon (GAC). To do this, two strategies have been evaluated on bench-scale electroremediation facilities (175 dm 3 ): electrokinetic adsorption barrier (EKAB) and reversible electrokinetic adsorption barrier (REKAB). Likewise, to clarify the contribution of the different mechanisms to remediation process results are compared to those obtained in a reference test (without applying an electric field) and to results obtained in the EKSF of soils polluted with compounds with different polarity and vapour pressure. Results show that during EKAB and REKAB tests, clopyralid is removed from the soil by adsorption in PRB, electrokinetic transport and, very less decisively, by evaporation. The application of polarity reversion attains a higher retention of clopyralid in the activated carbon-PRB and a better regulation of pH because of the neutralization of H + and OH - generated in the electrolyte wells. After 30 days of operation, the removal of clopyralid by EKAB is 45% while it reaches 57% in the case of REKAB. Copyright © 2018. Published by Elsevier B.V.

Shear-transformation-zone theory of linear glassy dynamics.

PubMed

Bouchbinder, Eran; Langer, J S

2011-06-01

We present a linearized shear-transformation-zone (STZ) theory of glassy dynamics in which the internal STZ transition rates are characterized by a broad distribution of activation barriers. For slowly aging or fully aged systems, the main features of the barrier-height distribution are determined by the effective temperature and other near-equilibrium properties of the configurational degrees of freedom. Our theory accounts for the wide range of relaxation rates observed in both metallic glasses and soft glassy materials such as colloidal suspensions. We find that the frequency-dependent loss modulus is not just a superposition of Maxwell modes. Rather, it exhibits an α peak that rises near the viscous relaxation rate and, for nearly jammed, glassy systems, extends to much higher frequencies in accord with experimental observations. We also use this theory to compute strain recovery following a period of large, persistent deformation and then abrupt unloading. We find that strain recovery is determined in part by the initial barrier-height distribution, but that true structural aging also occurs during this process and determines the system's response to subsequent perturbations. In particular, we find by comparison with experimental data that the initial deformation produces a highly disordered state with a large population of low activation barriers, and that this state relaxes quickly toward one in which the distribution is dominated by the high barriers predicted by the near-equilibrium analysis. The nonequilibrium dynamics of the barrier-height distribution is the most important of the issues raised and left unresolved in this paper.

Physical activity behavior, barriers to activity, and opinions about a smartphone-based physical activity intervention among rural residents.

PubMed

Kurti, Allison N; Logan, Henrietta; Manini, Todd; Dallery, Jesse

2015-01-01

Rural Americans engage in less physical activity (PA) and experience higher rates of consequent health problems (i.e., obesity, cardiovascular disease) than urban Americans. Although geographic barriers have historically made this population hard to reach, rural individuals are increasingly gaining access to smartphones. Thus, the purpose of this study was to evaluate PA behavior and barriers to PA among rural residents and to gauge their receptiveness to a smartphone-based PA intervention that is currently in the development stage. Rural Floridian adults (n=113), 18 years of age and older, completed surveys to assess PA behavior, PA barriers, and opinions about an intervention to increase PA. Specifically, they were asked to imagine a program that would require them to do PA with their mobile phones and whether they viewed intended aspects of the program as helpful. The present work is therefore formative research that sought to determine the feasibility and acceptability of a smartphone-based intervention among rural residents. RESULTS of the survey will inform the development of a tailored, smartphone-based PA intervention. The 37.2% of participants with low PA levels (<600 metabolic equivalent [MET]-min per week) were more likely to report personal and environmental barriers to PA than the 47.8% of participants with moderate PA levels (≥600 MET-min per week). More barriers were reported among participants who self-reported as white and among participants of older age, lower education level, and lower socioeconomic status. Additionally, 75.9% of participants reported features of the intervention as at least somewhat helpful. The growing ubiquity of smartphones among rural residents, combined with participants' positive response to the program description, supports the acceptability of a smartphone-based PA intervention for rural communities. Given the participants' receptiveness, future research should evaluate the efficacy of smartphone-delivered health behavior interventions among this population.

Physical Activity Behavior, Barriers to Activity, and Opinions About a Smartphone-Based Physical Activity Intervention Among Rural Residents

PubMed Central

Logan, Henrietta; Manini, Todd; Dallery, Jesse

2015-01-01

Abstract Background: Rural Americans engage in less physical activity (PA) and experience higher rates of consequent health problems (i.e., obesity, cardiovascular disease) than urban Americans. Although geographic barriers have historically made this population hard to reach, rural individuals are increasingly gaining access to smartphones. Thus, the purpose of this study was to evaluate PA behavior and barriers to PA among rural residents and to gauge their receptiveness to a smartphone-based PA intervention that is currently in the development stage. Materials and Methods: Rural Floridian adults (n=113), 18 years of age and older, completed surveys to assess PA behavior, PA barriers, and opinions about an intervention to increase PA. Specifically, they were asked to imagine a program that would require them to do PA with their mobile phones and whether they viewed intended aspects of the program as helpful. The present work is therefore formative research that sought to determine the feasibility and acceptability of a smartphone-based intervention among rural residents. Results of the survey will inform the development of a tailored, smartphone-based PA intervention. Results: The 37.2% of participants with low PA levels (<600 metabolic equivalent [MET]-min per week) were more likely to report personal and environmental barriers to PA than the 47.8% of participants with moderate PA levels (≥600 MET-min per week). More barriers were reported among participants who self-reported as white and among participants of older age, lower education level, and lower socioeconomic status. Additionally, 75.9% of participants reported features of the intervention as at least somewhat helpful. Conclusions: The growing ubiquity of smartphones among rural residents, combined with participants' positive response to the program description, supports the acceptability of a smartphone-based PA intervention for rural communities. Given the participants' receptiveness, future research should evaluate the efficacy of smartphone-delivered health behavior interventions among this population. PMID:25379976

Third Mission Activities: University Managers' Perceptions on Existing Barriers

ERIC Educational Resources Information Center

Koryakina, Tatyana; Sarrico, Cláudia S.; Teixeira, Pedro N.

2015-01-01

In the context of increased international competition and financial austerity, an economic development mission has become an important strategic and policy issue for European higher education. This paper aims to contribute to knowledge regarding universities' engagement with the external environment and its impact on internal governance and…

The Utilization of Education Technology in Higher Education

ERIC Educational Resources Information Center

Brooks, Angela

2017-01-01

With the rise of technology, many educational organizations are scrambling to find ways to incorporate technology into effective learning strategies. Although there is a significant need to equip curriculum with active learning technology objectives, the challenges that are sometimes overlooked lies within faculty perceived barriers and how they…

Frequencies and predictors of barriers to mental health service use: a longitudinal study of Hurricane Ike survivors.

PubMed

Lowe, Sarah R; Fink, David S; Norris, Fran H; Galea, Sandro

2015-01-01

The majority of disaster survivors suffering from psychological symptoms do not receive mental health services. Research on barriers to service use among disaster survivors is limited by a lack of longitudinal studies of representative samples and investigations of predictors of barriers. The purpose of this study was to address these limitations through analysis of a three-wave population-based study of Hurricane Ike survivors (N = 658). Frequencies of preference, outcome expectancy, resource, and stigma barriers among participants with unmet mental health needs were documented and logistic regression using a generalized estimating equations approach explored predisposing (e.g., age), illness-related (e.g., posttraumatic stress) and enabling (e.g., insurance coverage) factors as predictors of each type of barrier. Preference barriers were most frequently cited at each wave, whereas stigma barriers were least frequently cited. Older age and higher emotional support predicted preference barriers; being a parent of a child under 18-years old at the time of the hurricane, higher generalized anxiety, and lack of insurance predicted resource barriers; and higher posttraumatic stress predicted stigma barriers. These findings suggest that postdisaster practices targeting subpopulations most likely to have barriers to service use may be indicated.

Perceived barriers to walking for physical activity.

PubMed

Dunton, Genevieve F; Schneider, Margaret

2006-10-01

Although the health benefits of walking for physical activity have received increasing research attention, barriers specific to walking are not well understood. In this study, questions to measure barriers to walking for physical activity were developed and tested among college students. The factor structure, test-retest and internal consistency reliability, and discriminant and criterion validity of the perceived barriers were evaluated. A total of 305 undergraduate students participated. Participants had a mean age (+/- SD) of 20.6 (+/- 3.02) years, and 70.3% were female. Participants responded to a questionnaire assessing barriers specific to walking for physical activity. Perceived barriers to vigorous exercise, walking for transportation and recreation, and participation in lifestyle activities (such as taking the stairs instead of the elevator) were also assessed. Subsamples completed the walking barriers instrument a second time after 5 days in order to determine test-retest reliability (n = 104) and wore an accelerometer to measure moderate-intensity physical activity (n = 85). Factor analyses confirmed the existence of three factors underlying the perceived barriers to walking questions: appearance (four items), footwear (three items), and situation (three items). Appearance and situational barriers demonstrated acceptable reliability, discriminant validity, and relations with physical activity criteria. After we controlled for barriers to vigorous exercise, appearance and situational barriers to walking explained additional variation in objectively-measured moderate physical activity. The prediction of walking for physical activity, especially walking that is unstructured and spontaneous, may be improved by considering appearance and situational barriers. Assessing barriers specific to walking may have important implications for interventions targeting walking as means for engaging in physical activity.

Low humidity environmental challenge causes barrier disruption and cornification of the mouse corneal epithelium via a c-jun N-terminal kinase 2 (JNK2) pathway.

PubMed

Pelegrino, F S A; Pflugfelder, S C; De Paiva, C S

2012-01-01

Patients with tear dysfunction often experience increased irritation symptoms when subjected to drafty and/or low humidity environmental conditions. The purpose of this study was to investigate the effects of low humidity stress (LHS) on corneal barrier function and expression of cornified envelope (CE) precursor proteins in the epithelium of C57BL/6 and c-jun N-terminal kinase 2 (JNK2) knockout (KO) mice. LHS was induced in both strains by exposure to an air draft for 15 (LHS15D) or 30 days (LHS30D) at a relative humidity <30%RH. Nonstressed (NS) mice were used as controls. Oregon-green-dextran uptake was used to measure corneal barrier function. Levels of small proline-rich protein (SPRR)-2, involucrin, occludin, and MMP-9 were evaluated by immunofluorescent staining in cornea sections. Wholemount corneas immunostained for occludin were used to measure mean apical cell area. Gelatinase activity was evaluated by in situ zymography. Expression of MMP, CE and inflammatory cytokine genes was evaluated by qPCR. C57BL/6 mice exposed to LHS15D showed corneal barrier dysfunction, decreased apical corneal epithelial cell area, higher MMP-9 expression and gelatinase activity and increased involucrin and SPRR-2 immunoreactivity in the corneal epithelium compared to NS mice. JNK2KO mice were resistant to LHS-induced corneal barrier disruption. MMP-3,-9,-13, IL-1α, IL-1β, involucrin and SPRR-2a RNA transcripts were significantly increased in C57BL/6 mice at LHS15D, while no change was noted in JNK2KO mice. LHS is capable of altering corneal barrier function, promoting pathologic alteration of the TJ complex and stimulating production of CE proteins by the corneal epithelium. Activation of the JNK2 signaling pathway contributes to corneal epithelial barrier disruption in LHS. Copyright © 2011 Elsevier Ltd. All rights reserved.

Glutamine alleviates heat stress-induced impairment of intestinal morphology, intestinal inflammatory response, and barrier integrity in broilers.

PubMed

Wu, Q J; Liu, N; Wu, X H; Wang, G Y; Lin, L

2018-05-17

The aim of this study was to investigate the protective effect of glutamine (Gln) on the intestinal morphology, intestinal inflammatory response, and barrier integrity in broilers exposed to high ambient temperature. Three-hundred-sixty 21-d-old Arbor Acres broilers (half male and half female) were randomly allocated to 4 treatment groups in a completely randomized design, each of which included 6 replicates with 15 birds per replicate, for 21 d. The 4 treatment groups were as follows: the control group, in which birds were kept in a thermoneutral room at 22 ± 1°C (no stress, NS; fed a basal diet); the heat stress group (36 ± 1°C for 10 h/d from 08:00 to 18:00 h and 22 ± 1°C for the remaining time, heat stress (HT); fed a basal diet); and heat stress + Gln group (0.5 and 1.0% Gln, respectively). Compared to the NS group, broilers in the HT group had lower villus height (P < 0.05), higher crypt depth (P < 0.05), higher D-lactic acid and diamine oxidase (DAO) activity (P < 0.05), higher soluble intercellular adhesion molecule-1 (sICAM-1) concentration (P < 0.05), higher tumor necrosis factor (TNF)-α/interleukin (IL)-10 (P < 0.05), and lower tight junction protein expression levels (P < 0.05). Compared with birds in the HT, birds in the HT + Gln group exhibited increased villus height (P < 0.05), decreased D-lactate and DAO activity (P < 0.05), decreased sICAM-1 concentration (P < 0.05), and mediate the secretion of cytokines (P < 0.05), as well as increased zonula occludens-1 (ZO-1), claudin-1, and occludin mRNA expression levels (P < 0.05). In conclusion, these results indicate that supplementation with Gln was effective in partially ameliorating the adverse effects of heat stress on intestinal barrier function in broilers by promoting epithelial cell proliferation and renewal, modifying the function of the intestinal mucosa barrier, and regulating the secretion of cytokines.

Regulation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity in murine epidermis. Modulation of enzyme content and activation state by barrier requirements.

PubMed Central

Proksch, E; Elias, P M; Feingold, K R

1990-01-01

Epidermal cholesterol biosynthesis is regulated by barrier function. We quantitated the amount and activation state (phosphorylation-dephosphorylation) of the rate-limiting enzyme, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, in epidermis before and after barrier disruption. In murine epidermis we found high enzyme activity (1.75 +/- 0.02 nmol/min per mg protein). After acute barrier disruption, enzyme activity began to increase after 1.5 h, reaching a maximum increase by 2.5 h, and returned to normal by 15 h. Chronic barrier disruption increased total enzyme activity by 83%. In normal epidermis, measurement of HMG CoA reductase activity in microsomes isolated in NaF- vs. NaCl-containing buffers demonstrated that 46 +/- 2% of the enzyme was in the active form. After acute or chronic barrier disruption, a marked increase in the percentage of HMG CoA reductase in the active form was observed. Acute disruption increased enzyme activation state as early as 15 min, reaching a maximum after 2.5 h, with an increase still present at 15 h, indicating that changes in activation state had a close temporal relationship with barrier function. Increases in total HMG CoA reductase activity occurred only after profound barrier disruption, whereas changes in activation state occur with lesser degrees of barrier disruption. Artificial correction of barrier function prevented the increase in total HMG CoA reductase activity, and partially prevented the increase in enzyme activation. These results show that barrier requirements regulate epidermal cholesterol synthesis by modulating both the HMG CoA reductase amount and activation state. Images PMID:2312730

Individual, social and environmental factors influencing physical activity levels and behaviours of multiethnic socio-economically disadvantaged urban mothers in Canada: A mixed methods approach

PubMed Central

2012-01-01

Background Existing data provide little insight into the physical activity context of multiethnic socio-economically disadvantaged mothers in Canada. Our primary objectives were: (1) to use focus group methodology to develop tools to identify the individual, social, and environmental factors influencing utilitarian and leisure time physical activities (LTPA) of multiethnic SED mothers; and (2) to use a women specific physical activity survey tool to assess psychosocial barriers and supports and to quantify individual physical activity (PA) levels of multi-ethnic SED mothers in Canada. Methods Qualitative focus group sessions were conducted in West, Central and Eastern Canada with multiethnic SED mothers (n = 6 focus groups; n = 42 SED mothers) and with health and recreation professionals (HRPs) (n = 5 focus groups; n = 25 HRPs) involved in community PA programming for multiethnic SED mothers. Administration of the women specific Kaiser Physical Activity Survey (KPAS) tool was completed by consenting SED mothers (n = 59). Results More than half of SED mothers were employed and had higher total PA scores with occupation included than unemployed mothers. However, nearly 60% of both groups were overweight or obese. Barriers to LTPA included the lack of available, affordable and accessible LTPA programs that responded to cultural and social needs. Concerns for safety, nonsupportive cultural and social norms and the winter climate were identified as key barriers to both utilitarian and LTPA. Conclusions Findings show that multiethnic SED mothers experience many barriers to utilitarian and LTPA opportunities within their communities. The varying LTPA levels among these multi-ethnic SED mothers and the occurrence of overweight and obesity suggests that current LTPA programs are likely insufficient to maintain healthy body weights. PMID:22500882

Long-Term Drainage from the Riprap Side Slope of a Surface Barrier

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

Zhang, Zhuanfang

Surface barriers designed to isolate underground nuclear waste in place are expected to function for at least 1000 years. To achieve this long design life, such barriers need to be protected with side slopes against wind- and water-induced erosion and damage by natural or human activities. However, the side slopes are usually constructed with materials coarser than the barrier. Their hydrological characteristics must be understood so that any drainage from them is considered in the barrier design and will not compromise the barrier function. The Prototype Hanford Barrier, an evapotranspiration-capillary (ETC) barrier, was constructed in 1994 at the Hanford Sitemore » in southeastern Washington state, with a gravel side slope and a riprap side slope. The soil water content in the gravel side slope and drainage from both side slopes have been monitored since the completion of construction. The monitoring results show that under natural precipitation the annual drainage rates from the two types of side slopes were very similar and about 5 times the typical recharge from local soil with natural vegetation and 40 times the barrier design criterion. The higher recharge from the side slopes results in some of the drainage migrating laterally to the region beneath the ETC barrier. This edge effect of the enhanced drainage was evaluated for a period of 1000 years by numerical simulation. The edge effect was quantified by the amount of water across the barrier edges and the affecting distance of the barrier edges. These results indicate that design features can be adjusted to reduce the edge effect when necessary.« less

Immigrating to the US: what Brazilian, Latin American and Haitian women have to say about changes to their lifestyle that may be associated with obesity.

PubMed

Tovar, Alison; Must, Aviva; Metayer, Nesly; Gute, David M; Pirie, Alex; Hyatt, Raymond R; Economos, Christina D

2013-04-01

Our goal was to explore the perceived determinants of obesity in Brazilian, Latin American and Haitian women. This is part of an ongoing community-based participatory intervention. Focus groups by immigrant group were conducted and themes extracted. Women expressed differences in beliefs, attitudes, and barriers regarding diet and physical activity in the US versus their home country. Participants thought food in the US is "less natural," there is less time for preparation, and there is more variety. The weather is a barrier to physical activity in the US and work is more physically demanding. Job-related efforts were not considered physical activity. They reported higher levels of stress, less control of their time and less social support in the US. Providing immigrants with appropriate support and education early in the acculturation process has the potential to help prevent obesity.

A reanalysis of the HCO(+)/HOC(+) abundance ratio in dense interstellar clouds

NASA Technical Reports Server (NTRS)

Jarrold, M. F.; Bowers, M. T.; Defrees, D. J.; Mclean, A. D.; Herbst, E.

1986-01-01

New theoretical and experimental results have prompted a reinvestigation of the HCO(+)/HOC(+) abundance ratio in dense interstellar clouds. These results pertain principally but not exclusively to the reaction between HOC(+) and H2, which was previously calculated by DeFrees et al. (1984) to possess a large activation energy barrier. New calculations, reported here, indicate that this activation energy barrier is quite small and may well be zero. In addition, experimental results at higher energy and temperature indicate strongly that the reaction proceeds efficiently at interstellar temperatures. If HOC(+) does indeed react efficiently with H2 in interstellar clouds, the calculated HCO(+)/HOC(+) abundance ratio rises to a substantially greater value under standard dense cloud conditions than is deduced via the tentative observation of HOC(+) in Sgr B2.

DFT study of CO2 conversion on InZr3(110) surface.

PubMed

Zhang, Minhua; Dou, Maobin; Yu, Yingzhe

2017-11-01

Methanol and methane synthesis from CO 2 hydrogenation on a InZr 3 (110) surface has been studied using density functional theory calculations. The CO 2 can be chemically adsorbed via a polydentated configuration and the H 2 molecule can dissociate to H atoms spontaneously. The methanol is primarily formed via the HCOO route instead of the RWGS route, due to its higher activation barrier of 1.35 eV for HCO hydrogenation. In the HCOO route, the adsorbed CO 2 consecutively hydrogenates to form HCOO, H 2 COO and the H 3 CO species. The H 3 COH is produced via the reaction of H 3 CO with a surface OH group. Furthermore, the C-O bonds of CO, CHO, CH 2 O and CH 3 O species prefer to dissociate to C, CH, CH 2 CH 3 and surface O species. Methane is formed via the hydrogenation of CH x (x = 0-3) monomers with the highest activation barrier of 1.19 eV for CH 3 hydrogenation, which is higher than that of the hydrogenation of H 2 COO in methanol synthesis via the HCOO route. The surface O species formed during CO 2 hydrogenation reacts with the adsorbed H 2 molecule to produce an OH group which reacts with a surface H atom to form H 2 O with an activation barrier of 1.13 eV, which then desorbs to the gas phase. Our calculated results indicate that the InZr 3 alloy is a potential candidate catalyst for CO 2 utilization and conversion.

Traditional and cyberbullying victimization as correlates of psychosocial distress and barriers to a healthy lifestyle among severely obese adolescents – a matched case–control study on prevalence and results from a cross-sectional study

PubMed Central

2014-01-01

Background Obese youth are at increased risk for peer victimization, which may heighten their risk of psychosocial problems and physical activity avoidance, and lower the effectiveness of professional and lifestyle weight-loss initiatives. Little is known about obese adolescents’ risk for victimization from cyber-bullying and how this relates to psychosocial functioning and healthy lifestyle barriers. The purpose of the study was to assess traditional and cyber-victimization among adolescents with severe obesity and its relation to psychosocial distress and barriers to healthy lifestyles. Methods A sample of 102 obese adolescents (mean age = 15.32 ±1.71) in residential treatment was matched with 102 normal-weight youngsters from the Health Behavior in School-aged Children (HBSC) study (mean age = 15.30 ±1.73). Results Adolescents with obesity were significantly more often cyber-victimized than normal-weight peers. Obese youth victimized by traditional bullying experienced lower quality of life, lower motivation for physical activity and higher avoidance and emotional coping towards healthy lifestyles than those non-victimized. Obese cyber-victims experienced significantly higher suicidal ideation. Conclusions Traditional and cyber-victimization may hinder treatment effectiveness and healthy lifestyle change in adolescents with obesity. Health professionals should pro-actively address peer victimization and psychosocial functioning during multidisciplinary obesity treatment. Schools could contribute to a better physical and psychosocial health of obese youth by implementing multi-behavioral health-promotion programs. PMID:24593118

Barriers and Enablers to the Implementation of School Wellness Policies: An Economic Perspective.

PubMed

Schuler, Brittany R; Saksvig, Brit I; Nduka, Joy; Beckerman, Susannah; Jaspers, Lea; Black, Maureen M; Hager, Erin R

2018-01-01

Local wellness policies (LWPs) are mandated among school systems to enhance nutrition/physical activity opportunities in schools. Prior research notes disparities in LWP implementation. This study uses mixed methods to examine barriers/enablers to LWP implementation, comparing responses by student body income. Schools ( n = 744, 24 systems) completed an LWP implementation barriers/enablers survey. Semistructured interviews ( n = 20 random subsample) described barriers/enablers. Responses were compared by majority of lower (≥50% free/reduced-price meals; lower income [LI]) versus higher income (HI) student body. In surveys, LI and HI schools identified common barriers (parents/families, federal/state regulations, students, time, funding) and enablers (school system, teachers, food service, physical education curriculum/resources, and staff). Interviews further elucidated how staffing and funding served as enablers for all schools, and provide context for how and why barriers differed by income: time, food service (HI schools), and parents/families (LI schools). Findings support commonalities in barriers and enablers among all schools, suggesting that regardless of economic context, schools would benefit from additional supports, such as physical education and nutrition education resources integrated into existing curricula, additional funding, and personnel time dedicated to wellness programming. LI schools may benefit from additional funding to support parent and community involvement.

Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer

NASA Astrophysics Data System (ADS)

Hedayati Kh, Hamed; Faizabadi, Edris

2018-02-01

In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

Dwell time, Hartman effect and transport properties in a ferromagnetic phosphorene monolayer.

PubMed

Hedayati Kh, Hamed; Faizabadi, Edris

2018-02-28

In this paper, spin-dependent dwell time, spin Hartman effect and spin-dependent conductance were theoretically investigated through a rectangular barrier in the presence of an exchange field by depositing a ferromagnetic insulator on the phosphorene layer in the barrier region. The existence of the spin Hartman effect was shown for all energies (energies lower than barrier height) and all incident angles in phosphorene. We also compared our results of the dwell time in the phosphorene structure with similar research performed on graphene. We reported a significant difference between the tunneling time values of incident quasiparticles with spin-up and spin-down. We found that the barrier was almost transparent for incident quasiparticles with a wide range of incident angles and energies higher than the barrier height in phosphorene. We also found that the maximum spin-dependent transmission probability for energies higher than barrier height does not necessarily occur in the zero incident angle. In addition, we showed that the spin conductance for energies higher (lower) than barrier height fluctuates (decays) in terms of barrier thickness. We discovered that, in contrast to graphene, the Klein paradox does not occur in the normal incident in the phosphorene structure. Furthermore, the results demonstrated the achievement of good total conductance at certain thicknesses of the barrier for energies higher than the barrier height. This study could serve as a basis for investigations of the basic physics of tunneling mechanisms and also for using phosphorene as a spin polarizer in designing nanoelectronic devices.

Barriers to activity and participation for stroke survivors in rural China.

PubMed

Zhang, Lifang; Yan, Tiebin; You, Liming; Li, Kun

2015-07-01

To investigate environmental barriers reported by stroke survivors in the rural areas of China and to determine the impact of environmental barriers on activity and participation relative to demographic characteristics and body functioning. Cross-sectional survey. Structured interviews in the participants' homes. Community-dwelling stroke survivors in the rural areas of China (N=639). Not applicable. Activity and participation (Chinese version of the World Health Organization Disability Assessment Schedule 2.0), environmental barriers (Craig Hospital Inventory of Environmental Factors), neurological function (Canadian Neurological Scale), cognitive function (Abbreviated Mental Test), and depression (6-item Hamilton Rating Scale for Depression). Physical/structural barriers are the major impediment to activity and participation for these participants (odds ratio, 1.86 and 1.99 for activity and participation, respectively; P<.01). Services/assistance barriers primarily impede participation rather than activity (odds ratio, 1.58 in participation; P<.05). Physical/structural and services/assistance barriers were considered the dominant barriers to activity and participation for stroke survivors in the rural areas of China. Attitudinal/support and policy barriers did not emerge as serious concerns. To generate an enabling environment, physical/structural and services/assistance barriers are the environmental barriers to be decreased and eliminated first. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Critical and Higher Order Thinking in Online Threaded Discussions in the Slovak Context

ERIC Educational Resources Information Center

Pisutova-Gerber, Katarina; Malovicova, Jana

2009-01-01

This article describes and analyzes efforts to use collaborative asynchronous discussion forums in a three semester online education program for NGO leaders and managers in Slovakia. Slovakia, as a country with autocratic styles of teacher-centered education, presents strong barriers to the implementation of collaborative learning activities. The…

Genetic and Transcriptomic Bases of Intestinal Epithelial Barrier Dysfunction in Inflammatory Bowel Disease.

PubMed

Vancamelbeke, Maaike; Vanuytsel, Tim; Farré, Ricard; Verstockt, Sare; Ferrante, Marc; Van Assche, Gert; Rutgeerts, Paul; Schuit, Frans; Vermeire, Séverine; Arijs, Ingrid; Cleynen, Isabelle

2017-10-01

Intestinal barrier defects are common in patients with inflammatory bowel disease (IBD). To identify which components could underlie these changes, we performed an in-depth analysis of epithelial barrier genes in IBD. A set of 128 intestinal barrier genes was selected. Polygenic risk scores were generated based on selected barrier gene variants that were associated with Crohn's disease (CD) or ulcerative colitis (UC) in our study. Gene expression was analyzed using microarray and quantitative reverse transcription polymerase chain reaction. Influence of barrier gene variants on expression was studied by cis-expression quantitative trait loci mapping and comparing patients with low- and high-risk scores. Barrier risk scores were significantly higher in patients with IBD than controls. At single-gene level, the associated barrier single-nucleotide polymorphisms were most significantly enriched in PTGER4 for CD and HNF4A for UC. As a group, the regulating proteins were most enriched for CD and UC. Expression analysis showed that many epithelial barrier genes were significantly dysregulated in active CD and UC, with overrepresentation of mucus layer genes. In uninflamed CD ileum and IBD colon, most barrier gene levels restored to normal, except for MUC1 and MUC4 that remained persistently increased compared with controls. Expression levels did not depend on cis-regulatory variants nor combined genetic risk. We found genetic and transcriptomic dysregulations of key epithelial barrier genes and components in IBD. Of these, we believe that mucus genes, in particular MUC1 and MUC4, play an essential role in the pathogenesis of IBD and could represent interesting targets for treatment.

Perceived barriers, benefits, and motives for physical activity: two primary-care physical activity prescription programs.

PubMed

Patel, Asmita; Schofield, Grant M; Kolt, Gregory S; Keogh J, W L

2013-01-01

This study examined whether perceived barriers, benefits, and motives for physical activity differed based on allocation to 2 different types of primary-care activity-prescription programs (pedometer-based vs. time-based Green Prescription). Eighty participants from the Healthy Steps study completed a questionnaire that assessed their perceived barriers, benefits, and motives for physical activity. Factor analysis was carried out to identify common themes of barriers, benefits, and motives for physical activity. Factor scores were then used to explore between-groups differences for perceived barriers, benefits, and motives based on group allocation and demographic variables. No significant differences were found in factor scores based on allocation. Demographic variables relating to the existence of chronic health conditions, weight status, and older age were found to significantly influence perceived barriers, benefits, and motives for physical activity. Findings suggest that the addition of a pedometer to the standard Green Prescription does not appear to increase perceived motives or benefits or decrease perceived barriers for physical activity in low-active older adults.

Barriers and facilitators to young children's physical activity and sedentary behaviour: a systematic review and synthesis of qualitative literature

PubMed Central

Lakshman, R.; van Sluijs, E. M. F.

2017-01-01

Summary Positive activity behaviours (i.e. higher physical activity [PA]/lower sedentary behaviour [SB]) are beneficial from infancy, yet evidence suggests that young children (0‐ to 6‐year‐olds) are relatively inactive. To better understand the perceived influences on these behaviours and to aid intervention development, this paper systematically synthesizes the extensive qualitative literature regarding perceived barriers and facilitators to PA and SB in young children (0–6 years old). A search of eight electronic databases (July 2016) identified 43 papers for inclusion. Data extraction and evidence synthesis were conducted using thematic content analysis, underpinned by the socio‐ecological model (i.e. individual, interpersonal, community, organizational and policy levels). Parents, childcare providers and children perceived seven broad themes to be important for PA and SB, including the child; the home; out‐of‐home childcare; parent–childcare provider interactions; environmental factors; safety; and weather. Each theme mapped onto between one and five levels of the socio‐ecological model; barriers and facilitators at the interpersonal level (e.g. parents, care providers and family) were most frequently cited, reflecting the important (perceived) role adults/peers play in shaping young children's behaviours. We provide an overarching framework to explain PA and SB in early childhood. We also highlight where gaps in the current literature exist (e.g. from male carers; in developing countries; and barriers and facilitators in the environmental and policy domains) and where future quantitative work may focus to provide novel insights about children's activity behaviours (e.g. safety and weather). PMID:28589678

Are barriers to physical activity similar for adults with and without abnormal glucose metabolism?

PubMed

Hume, Clare; Dunstan, David; Salmon, Jo; Healy, Genevieve; Andrianopoulos, Nick; Owen, Neville

2010-01-01

The purpose of this study was to examine perceived barriers to physical activity among adults with and without abnormal glucose metabolism (AGM), and whether barriers varied according to physical activity status. The 1999 to 2000 Australian Diabetes, Obesity, and Lifestyle Study (AusDiab) was a population-based cross-sectional study among adults aged > or =25 years. AGM was identified through an oral glucose tolerance test. The previous week's physical activity and individual, social, and environmental barriers to physical activity were self-reported. Logistic regression analyses examined differences in barriers to physical activity between those with and without AGM, and for those with and without AGM who did and did not meet the minimum recommendation of 150 minutes/week of moderate-to-vigorous intensity physical activity. Of the 7088 participants (47.5 +/- 12.7 years; 46% male), 18.5% had AGM. Approximately 47.5% of those with AGM met the physical activity recommendation, compared to 54.7% of those without AGM (P < .001). Key barriers to physical activity included lack of time, other priorities, and being tired. Following adjustment for sociodemographic and behavioral factors, there were few differences in barriers to physical activity between those with and without AGM, even after stratifying according to physical activity. Adults with AGM report similar barriers to physical activity, as do those without AGM. Programs for those with AGM can therefore focus on the known generic adult-reported barriers to physical activity.

Policy and political advocacy: Comparison study of nursing faculty to determine current practices, perceptions, and barriers to teaching health policy.

PubMed

Staebler, Suzanne; Campbell, Jane; Cornelius, Patsy; Fallin-Bennett, Amanda; Fry-Bowers, Eileen; Kung, Ying Mai; LaFevers, David; Miller, Janice

To better understand policy/advocacy concepts and methodology utilized in all levels of nursing educational programs and develop clarity concerning structure of policy content and integration across all levels of education. Cross-sectional analysis of data obtained from a survey sent to 19,043 nursing faculty in the United States; 598 total responses; 514 complete responses. Quantitative data points were analyzed using SPSS and qualitative data was grouped and analyzed by theme. Barriers and perceptions of student engagement and student learning outcomes along with institutional and faculty development barriers were explored in baccalaureate, masters, and doctoral level nursing programs. Thirty-six percent of respondents reported having experience in development and implementation of policy, ranging from local to international spheres and 21% reported active involvement in current state and federal policy development. Seventy percent of respondents have advocated for the nursing profession through professional organizations while 44% report current activity in legislative advocacy. The value of nursing policy education, advocacy, and analysis must be valued in higher education. Copyright © 2017 Elsevier Inc. All rights reserved.

Barriers to outdoor physical activity in wintertime among Somali youth.

PubMed

Rothe, Elizabeth; Holt, Christina; Kuhn, Celine; McAteer, Timothy; Askari, Isabella; O'Meara, Mary; Sharif, Abdimajid; Dexter, William

2010-10-01

To identify barriers to outdoor physical activity in winter among Somali youth in Maine. Despite the many proven health benefits of physical activity among children, such as cardiovascular fitness and health status as an adult, there has been a decrease in physical activity among children in recent years. Specifically, children who are of low socio-economic status or are from communities where many immigrants are at increased risk for developing obesity. Immigrants are also less likely to be physically active. There are many potential barriers to wintertime physical activity among Somali youth in Maine, such as lack of financial resources, transportation, proper winter clothing, and appropriate knowledge of winter safety, and language and cultural barriers. For females, different attire required for outdoor activity may be a barrier. Somali parents and children were recruited from Portland, Maine to participate in focus groups led by a trained facilitator with a Somali translator and cultural broker. Transcripts were coded using NVIVO software to identify barriers to physical activity among Somali youth outside in winter. Eight focus groups were conducted. Sixty-one Somali community members were recruited. Participants felt outdoor physical activity is important, but note that it is decreased in winter. Barriers to outdoor activity in winter cited by focus group participants were lack of resources, health concerns, gender barriers for females, and knowledge barriers. Concern over lack of supervision while children play outside was also cited. This study revealed many of the underlying beliefs, barriers and cultural issues that impact Somali families' intention to be active and ability to be active outdoors in winter. These findings can be used to generate research hypotheses and public health interventions regarding outdoor physical activity among Somali youth.

Deconstructing Barriers: Perceptions of Students Labeled with Learning Disabilities in Higher Education

ERIC Educational Resources Information Center

Denhart, Hazel

2008-01-01

This phenomenological study investigated barriers to higher education faced by 11 college students labeled with learning disabilities (LD) using their voice as the primary data. Data were analyzed and interpreted through a disability theory perspective revealing barriers stemmed largely from external social causes rather than individual pathology.…

Self-Reported Reasons for Smoking: Predicting Abstinence and Implications for Smoking Cessation Treatments Among Those With a Psychotic Disorder.

PubMed

Clark, Vanessa; Baker, Amanda; Lewin, Terry; Richmond, Robyn; Kay-Lambkin, Frances; Filia, Sacha; Castle, David; Williams, Jill; Todd, Juanita

2017-01-01

People living with a psychotic illness have higher rates of cigarette smoking and face unique barriers to quitting compared to the general population. We examined whether self-reported reasons for smoking are useful predictors of successful quit attempts among people with psychosis. As part of a randomized controlled trial addressing smoking and cardiovascular disease risk behaviors among people with psychosis, self-reported reasons for smoking were assessed at baseline (n = 235), 15 weeks (n = 151), and 12 months (n = 139). Three factors from the Reasons for Smoking Questionnaire (Coping, Physiological, and Stimulation/Activation) were entered into a model to predict short- and long-term abstinence. The relationship between these factors and mental health symptoms were also assessed. Participants scoring higher on the Stimulation/Activation factor (control of weight, enjoyment, concentration, and "peps me up") at baseline were just less than half as likely to be abstinent at 15 weeks. Female participants were five times more likely to abstinent at 15 weeks, and those with a higher global functioning at baseline were 5% more likely to be abstinent. There was a positive correlation between changes over time in the Stimulation/Activation factor from baseline to 12-month follow-up and the Brief Psychiatric Rating Scale total score at 12-month follow-up. This indicates that increasingly higher endorsement of the factor was associated with more psychological symptoms. There was also a negative correlation between the change over time in the Stimulation/Activation factor and global functioning at 12 months, indicating that increasingly higher endorsement of the factor led to lower global assessment of functioning. The Stimulation/Activation factor may be particularly important to assess and address among smokers with psychosis. It is recommended that further research use the Reasons for Smoking Questionnaire among smokers with psychosis as a clinical tool to identify specific quit barriers. Further research into why females have higher smoking cessation rates in the short term and relapse prevention interventions seem worthy of further investigation.

Nitride based quantum well light-emitting devices having improved current injection efficiency

DOEpatents

Tansu, Nelson; Zhao, Hongping; Liu, Guangyu; Arif, Ronald

2014-12-09

A III-nitride based device provides improved current injection efficiency by reducing thermionic carrier escape at high current density. The device includes a quantum well active layer and a pair of multi-layer barrier layers arranged symmetrically about the active layer. Each multi-layer barrier layer includes an inner layer abutting the active layer; and an outer layer abutting the inner layer. The inner barrier layer has a bandgap greater than that of the outer barrier layer. Both the inner and the outer barrier layer have bandgaps greater than that of the active layer. InGaN may be employed in the active layer, AlInN, AlInGaN or AlGaN may be employed in the inner barrier layer, and GaN may be employed in the outer barrier layer. Preferably, the inner layer is thin relative to the other layers. In one embodiment the inner barrier and active layers are 15 .ANG. and 24 .ANG. thick, respectively.

Diabetes risk factors in children: a partnership between nurse practitioner and high school students.

PubMed

Lipman, Terri H; Schucker, Mary McGrath; Ratcliffe, Sarah J; Holmberg, Tyler; Baier, Scott; Deatrick, Janet A

2011-01-01

This project was a 4-year university/community collaboration to (1) screen for diabetes risk factors in children from in an inner-city community; (2) assess children's knowledge of nutrition and measure their physical endurance; and (3) survey parents about barriers to healthy living. Descriptive cross-sectional study utilizing a community participatory-based research approach. For a 4-week period each year, nurse practitioner students and high school students partnered in an evaluation of elementary school children that included assessment of (1) height, weight, waist circumference, BMI, and acanthosis nigricans; (2) scores on a nutrition knowledge test; and (3) recovery heart rate after a dance activity. Parents of the children were surveyed regarding barriers to healthy eating and activity. A total of 240 African American children were evaluated: 25% were obese, 24% had a waist circumference >95th percentile, and 14% had acanthosis nigricans. The mean score of a nutrition knowledge test was 65%, and recovery heart rates were significantly higher than preexercise heart rates. Of 48 parents surveyed, the most common barrier to eating healthy reported was the children's picky eating (62%), and most common barrier to activity was lack of access to safe places to play (54%). Nurses working with children from inner-city communities should be especially aware of the children's many risk factors for diabetes. Clinicians who hope to make a difference in altering these risks should collaborate with the community to target high-risk populations for diabetes screening, promote good nutrition and exercise, and address barriers to healthy living. When developing plans of care for children, regardless of setting, it is critical to understand the community and incorporate the families as partners in developing culturally relevant interventions.

Perceived barriers to physical activity among Nigerian stroke survivors.

PubMed

Idowu, Opeyemi Ayodiipo; Adeniyi, Ade Fatai; Ogwumike, Omoyemi Olubunmi; Fawole, Henrietta Oluwafunmilola; Akinrolie, Olayinka

2015-01-01

Benefits of physical activity in the prevention and management of stroke are well documented in the literature. There is increasing evidence that stroke survivors in South-West Nigeria are physically inactive. Data on barriers to the achievement of the recommended physical activity levels including its differences along socio-demographic characteristics among stroke survivors in South-West Nigeria are needed. The Exercise Benefits and Barrier Scale and the International Physical Activity Questionnaire were administered on 121 stroke survivors to determine their perceived barriers to physical activity and physical activity levels respectively. Information on socio-demographic data and clinical variables were also collected. The sample included 70.2% males, with majority of the participants reporting low physical activity levels (80.2%) and high perceived barriers (Mean = 48.13, SD = 7.88). The four most reported common barriers among stroke survivors were access to exercise facilities (95.0%), being embarrassed to exercise (94.2%), economic cost demands of exercise (94.2%) and notion that people in exercise clothes look funny (94.2%) respectively. There were no significant differences found in barriers to physical activity between gender (U = 1471.00, P = 0.74) and across each of: occupational status (H = 4.37, P = 0.22), age group (H = 0.82, P = 0.84) and educational levels (H = 4.56, P = 0.33). Significant difference however existed in perceived barriers across marital status categories (H = 12.87, P = 0.05). Stroke survivors indicated high perceived barriers to physical activity and these barriers were associated with marital status.

Perceived barriers to healthy eating and physical activity among adolescents in seven Arab countries: a cross-cultural study.

PubMed

Musaiger, Abdulrahman O; Al-Mannai, Mariam; Tayyem, Reema; Al-Lalla, Osama; Ali, Essa Y A; Kalam, Faiza; Benhamed, Mofida M; Saghir, Sabri; Halahleh, Ismail; Djoudi, Zahra; Chirane, Manel

2013-01-01

To highlight the perceived personal, social, and environmental barriers to healthy eating and physical activity among Arab adolescents. A multistage stratified sampling method was used to select 4698 students aged 15-18 years (2240 males and 2458 females) from public schools. Seven Arab counties were included in the study, namely, Algeria, Jordan, Kuwait, Libya, Palestine, Syria, and the United Arab Emirates. Self-reported questionnaire was used to list the barriers to healthy eating and physical activity facing these adolescents. It was found that lack of information on healthy eating, lack of motivation to eat a healthy diet, and not having time to prepare or eat healthy food were the main barriers to healthy eating among both genders. For physical activity, the main barriers selected were lack of motivation to do physical activity, less support from teachers, and lack of time to do physical activity. In general, females faced more barriers to physical activity than males in all countries included. There were significant differences between males and females within each country and among countries for most barriers. Intervention programmes to combat obesity and other chronic noncommunicable diseases in the Arab world should include solutions to overcome the barriers to weight maintenance, particularly the sociocultural barriers to practising physical activity.

Management of Sodium-reduced Meals at Worksite Cafeterias: Perceptions, Practices, Barriers, and Needs among Food Service Personnel.

PubMed

Lee, Jounghee; Park, Sohyun

2016-04-01

The sodium content of meals provided at worksite cafeterias is greater than the sodium content of restaurant meals and home meals. The objective of this study was to assess the relationships between sodium-reduction practices, barriers, and perceptions among food service personnel. We implemented a cross-sectional study by collecting data on perceptions, practices, barriers, and needs regarding sodium-reduced meals at 17 worksite cafeterias in South Korea. We implemented Chi-square tests and analysis of variance for statistical analysis. For post hoc testing, we used Bonferroni tests; when variances were unequal, we used Dunnett T3 tests. This study involved 104 individuals employed at the worksite cafeterias, comprised of 35 men and 69 women. Most of the participants had relatively high levels of perception regarding the importance of sodium reduction (very important, 51.0%; moderately important, 27.9%). Sodium reduction practices were higher, but perceived barriers appeared to be lower in participants with high-level perception of sodium-reduced meal provision. The results of the needs assessment revealed that the participants wanted to have more active education programs targeting the general population. The biggest barriers to providing sodium-reduced meals were use of processed foods and limited methods of sodium-reduced cooking in worksite cafeterias. To make the provision of sodium-reduced meals at worksite cafeterias more successful and sustainable, we suggest implementing more active education programs targeting the general population, developing sodium-reduced cooking methods, and developing sodium-reduced processed foods.

Barriers for recess physical activity: a gender specific qualitative focus group exploration.

PubMed

Pawlowski, Charlotte Skau; Tjørnhøj-Thomsen, Tine; Schipperijn, Jasper; Troelsen, Jens

2014-06-23

Many children, in particular girls, do not reach the recommended amount of daily physical activity. School recess provides an opportunity for both boys and girls to be physically active, but barriers to recess physical activity are not well understood. This study explores gender differences in children's perceptions of barriers to recess physical activity. Based on the socio-ecological model four types of environmental barriers were distinguished: natural, social, physical and organizational environment. Data were collected through 17 focus groups (at 17 different schools) with in total 111 children (53 boys) from fourth grade, with a mean age of 10.4 years. The focus groups included an open group discussion, go-along group interviews, and a gender segregated post-it note activity. A content analysis of the post-it notes was used to rank the children's perceived barriers. This was verified by a thematic analysis of transcripts from the open discussions and go-along interviews. The most frequently identified barriers for both boys and girls were weather, conflicts, lack of space, lack of play facilities and a newly-found barrier, use of electronic devices. While boys and girls identified the same barriers, there were both inter- and intra-gender differences in the perception of these barriers. Weather was a barrier for all children, apart from the most active boys. Conflicts were perceived as a barrier particularly by those boys who played ballgames. Girls said they would like to have more secluded areas added to the school playground, even in large schoolyards where lack of space was not a barrier. This aligned with girls' requests for more "hanging-out" facilities, whereas boys primarily wanted activity promoting facilities. Based on the results from this study, we recommend promoting recess physical activity through a combination of actions, addressing barriers within the natural, social, physical and organizational environment.

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

Albo, Asaf, E-mail: asafalbo@gmail.com; Hu, Qing; Reno, John L.

The mechanisms that limit the temperature performance of GaAs/Al{sub 0.15}GaAs-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated LO-phonon scattering and leakage of charge carriers into the continuum. Consequently, the combination of highly diagonal optical transition and higher barriers should significantly reduce the adverse effects of both mechanisms and lead to improved temperature performance. Here, we study the temperature performance of highly diagonal THz-QCLs with high barriers. Our analysis uncovers an additional leakage channel which is the thermal excitation of carriers into bounded higher energy levels, rather than the escape into the continuum. Based on this understanding,more » we have designed a structure with an increased intersubband spacing between the upper lasing level and excited states in a highly diagonal THz-QCL, which exhibits negative differential resistance even at room temperature. This result is a strong evidence for the effective suppression of the aforementioned leakage channel.« less

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

Albo, Asaf; Hu, Qing; Reno, John L.

The mechanisms that limit the temperature performance of GaAs/Al 0.15GaAs-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated LO-phonon scattering and leakage of charge carriers into the continuum. Consequently, the combination of highly diagonal optical transition and higher barriers should significantly reduce the adverse effects of both mechanisms and lead to improved temperature performance. Here, we study the temperature performance of highly diagonal THz-QCLs with high barriers. Our analysis uncovers an additional leakage channel which is the thermal excitation of carriers into bounded higher energy levels, rather than the escape into the continuum. Based on this understanding,more » we have designed a structure with an increased intersubband spacing between the upper lasing level and excited states in a highly diagonal THz-QCL, which exhibits negative differential resistance even at room temperature. Furthermore, this result is a strong evidence for the effective suppression of the aforementioned leakage channel.« less

Faculty Perceptions about Barriers to Active Learning

ERIC Educational Resources Information Center

Michael, Joel

2007-01-01

Faculty may perceive many barriers to active learning in their classrooms. Four groups of participants in a faculty development workshop were asked to list their perceived barriers to active learning. Many of the problems identified were present on more than one list. The barriers fall into three categories: student characteristics, issues…

Barriers to physical activity among working mothers.

PubMed

Dombrowski, Jill J

2011-04-01

Working mothers experience several barriers to physical activity. If these barriers can be identified by occupational health nurses and they can partner with working mothers to reduce these perceived barriers, the health of these workers can be improved and chronic disease risk prevented. The purpose of this study was to measure the effect of self-regulatory efficacy on physical activity among working mothers and to describe specific barriers to physical activity. The Barriers Specific Self-Efficacy Scale (BARSE) and the Kaiser Physical Activity Survey (KPAS) were used to measure the variables. Self-regulatory efficacy was found to be a strong predictor of physical activity in a diverse sample of working mothers who did not meet current recommendations for physical activity. Occupational health nurses can use these findings to design programs for groups and for counseling individuals. Copyright 2011, SLACK Incorporated.

Effects of Different Waveforms on the Performance of Active Capillary Dielectric Barrier Discharge Ionization Mass Spectrometry

NASA Astrophysics Data System (ADS)

Dumlao, Morphy C.; Xiao, Dan; Zhang, Daming; Fletcher, John; Donald, William A.

2017-04-01

Active capillary dielectric barrier discharge ionization (DBDI) is emerging as a compact, low-cost, and robust method to form intact ions of small molecules for detection in near real time by portable mass spectrometers. Here, we demonstrate that by using a 10 kHz, 2.5 kVp-p high-voltage square-wave alternating current plasma, active capillary DBDI can consume less than 1 μW of power. In contrast, the power consumed using a sine and triangle alternating current waveform is more than two orders of magnitude higher than that for the square waveform to obtain a similar voltage for plasma generation. Moreover, the plasma obtained using a square waveform can be significantly more homogenous than that obtained using sine and triangle waveforms. Protonated dimethyl methylphosphonate (DMMP) and deprotonated perfluorooctanoic acid (PFOA) can be detected at about the same or higher abundances using square-wave DBDI mass spectrometry compared with the use of sine and triangle waveforms. By use of benzylammonium thermometer ions, the extent of internal energy deposition using square, sine, or triangle waveform excited plasmas are essentially the same at the optimum voltages for ion detection. Using an H-bridge circuit driving a transformer optimized to reduce losses, square-wave active capillary DBDI can be continuously powered for 50 h by common 9 V-battery (PP3).

Digital Based Media Design: The Innovative Contribution of Design Graduates from Vocational and Higher Education Sectors

ERIC Educational Resources Information Center

Doloswala, Kalika Navin; Thompson, Darrall; Toner, Phillip

2013-01-01

Design is increasingly being recognised as a key source of competitive advantage in the innovation economy of many countries. The key objective of this research was to understand the contribution by design graduates to creative industries innovative activities. Primary research was conducted to understand barriers and limitations of graduate…

78 FR 4983 - Proposed Information Collection; Women Veterans Healthcare Barriers Survey Activity: Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-23

... Veterans Healthcare Barriers Survey Activity: Comment Request AGENCY: Veterans Health Administration... Healthcare Barriers Survey'' in any correspondence. During the comment period, comments may be viewed online... Veterans Healthcare Barriers Survey . OMB Control Number: 2900-New (Women Veterans Healthcare Barriers...

Attempting to be active: Self-efficacy and barrier limitation differentiate activity levels of working mothers.

PubMed

Gierc, Madelaine; Locke, Sean; Jung, Mary; Brawley, Lawrence

2016-07-01

Working mothers are less physically active than working women without children and mothers who do not work. The purpose of this study was to examine concurrent self-regulatory efficacy and barriers to physical activity in a sample of working mothers. Women completed a mixed-methods survey which included measures of physical activity, concurrent self-regulatory efficacy, and barriers. Sufficiently active women experienced significantly greater concurrent self-regulatory efficacy and significantly less barrier limitation and frequency. No significant group differences were found for age, domestic duties performed, and children's extracurricular activities. Thematic analysis of barriers revealed six themes of common and unique factors, including limited time and family activities. © The Author(s) 2014.

Monitoring seasonal bat activity on a coastal barrier island in Maryland, USA.

PubMed

Johnson, Joshua B; Gates, J Edward; Zegre, Nicolas P

2011-02-01

Research on effects of wind turbines on bats has increased dramatically in recent years because of significant numbers of bats killed by rotating wind turbine blades. Whereas most research has focused on the Midwest and inland portions of eastern North America, bat activity and migration on the Atlantic Coast has largely been unexamined. We used three long-term acoustic monitoring stations to determine seasonal bat activity patterns on the Assateague Island National Seashore, a barrier island off the coast of Maryland, from 2005 to 2006. We recorded five species, including eastern red bats (Lasiurus borealis), big brown bats (Eptesicus fuscus), hoary bats (Lasiurus cinereus), tri-colored bats (Perimyotis subflavus), and silver-haired bats (Lasionycteris noctivagans). Seasonal bat activity (number of bat passes recorded) followed a cosine function and gradually increased beginning in April, peaked in August, and declined gradually until cessation in December. Based on autoregressive models, inter-night bat activity was autocorrelated for lags of seven nights or fewer but varied among acoustic monitoring stations. Higher nightly temperatures and lower wind speeds positively affected bat activity. When autoregressive model predictions were fitted to the observed nightly bat pass totals, model residuals>2 standard deviations from the mean existed only during migration periods, indicating that periodic increases in bat activity could not be accounted for by seasonal trends and weather variables alone. Rather, the additional bat passes were attributable to migrating bats. We conclude that bats, specifically eastern red, hoary, and silver-haired bats, use this barrier island during migration and that this phenomenon may have implications for the development of near and offshore wind energy.

Perceived Barriers to Healthy Eating and Physical Activity among Adolescents in Seven Arab Countries: A Cross-Cultural Study

PubMed Central

Musaiger, Abdulrahman O.; Tayyem, Reema; Al-Lalla, Osama; Ali, Essa Y. A.; Kalam, Faiza; Benhamed, Mofida M.; Saghir, Sabri; Halahleh, Ismail; Djoudi, Zahra; Chirane, Manel

2013-01-01

Objective. To highlight the perceived personal, social, and environmental barriers to healthy eating and physical activity among Arab adolescents. Method. A multistage stratified sampling method was used to select 4698 students aged 15–18 years (2240 males and 2458 females) from public schools. Seven Arab counties were included in the study, namely, Algeria, Jordan, Kuwait, Libya, Palestine, Syria, and the United Arab Emirates. Self-reported questionnaire was used to list the barriers to healthy eating and physical activity facing these adolescents. Results. It was found that lack of information on healthy eating, lack of motivation to eat a healthy diet, and not having time to prepare or eat healthy food were the main barriers to healthy eating among both genders. For physical activity, the main barriers selected were lack of motivation to do physical activity, less support from teachers, and lack of time to do physical activity. In general, females faced more barriers to physical activity than males in all countries included. There were significant differences between males and females within each country and among countries for most barriers. Conclusion. Intervention programmes to combat obesity and other chronic noncommunicable diseases in the Arab world should include solutions to overcome the barriers to weight maintenance, particularly the sociocultural barriers to practising physical activity. PMID:24348144

Developer and realtor perspectives on factors that influence development, sale, and perceived demand for activity-friendly communities.

PubMed

Carnoske, Cheryl; Hoehner, Christine; Ruthmann, Nicholas; Frank, Lawrence; Handy, Susan; Hill, James; Ryan, Sherry; Sallis, James; Glanz, Karen; Brownson, Ross

2010-03-01

Although public support for physical activity-friendly Traditional Neighborhood Developments (TNDs) appears to be growing, information is lacking on private sector perspectives and how economic factors (eg, fuel prices) might influence the development and sale of TNDs. A sample of realtors from the National Association of Realtors (n = 4950) and developers from the National Association of Home Builders (n = 162) were surveyed in early 2009 to assess factors influencing homebuyers' decisions; incentives and barriers to developing TNDs; effects of depressed housing market conditions and financing on sales; trends in buying; and energy considerations (eg, green building). Realtors believed that homebuyers continue to rank affordability, safety and school quality higher than TND amenities. Developers reported numerous barriers to TNDs, including the inability to overcome governmental/political hurdles, lack of cooperation between government agencies, and lack of market demand. Yet, realtors believed clients are increasingly influenced by gas and oil prices, and developers reported that clients are looking for energy efficient homes, reduced commute time, and walkable neighborhoods. Respondents reported consumers are more interested in living in a TND than 5 years ago. Activity-friendly TNDs appear to be increasing in demand, but developers and realtors reported significant barriers to creating these communities.

Developer and Realtor Perspectives on Factors That Influence Development, Sale, and Perceived Demand for Activity-Friendly Communities

PubMed Central

Carnoske, Cheryl; Hoehner, Christine; Ruthmann, Nicholas; Frank, Lawrence; Handy, Susan; Hill, James; Ryan, Sherry; Sallis, James; Glanz, Karen; Brownson, Ross

2013-01-01

Background Although public support for physical activity-friendly Traditional Neighborhood Developments (TNDs) appears to be growing, information is lacking on private sector perspectives and how economic factors (eg, fuel prices) might influence the development and sale of TNDs. Methods A sample of realtors from the National Association of Realtors (n = 4950) and developers from the National Association of Home Builders (n = 162) were surveyed in early 2009 to assess factors influencing homebuyers’ decisions; incentives and barriers to developing TNDs; effects of depressed housing market conditions and financing on sales; trends in buying; and energy considerations (eg, green building). Results Realtors believed that homebuyers continue to rank affordability, safety and school quality higher than TND amenities. Developers reported numerous barriers to TNDs, including the inability to overcome governmental/political hurdles, lack of cooperation between government agencies, and lack of market demand. Yet, realtors believed clients are increasingly influenced by gas and oil prices, and developers reported that clients are looking for energy efficient homes, reduced commute time, and walkable neighborhoods. Respondents reported consumers are more interested in living in a TND than 5 years ago. Conclusions Activity-friendly TNDs appear to be increasing in demand, but developers and realtors reported significant barriers to creating these communities. PMID:20440012

Extracurricular research activities among senior medical students in Kuwait: experiences, attitudes, and barriers.

PubMed

Al-Halabi, Becher; Marwan, Yousef; Hasan, Mohammad; Alkhadhari, Sulaiman

2014-01-01

Research is the foundation of scientific advancement and improvement in quality of health care, which ensures the good health of the community. The aim of this study is to explore experiences, attitudes, and barriers of medical students in Kuwait University (KU) in regards to extracurricular research. A questionnaire about extracurricular research activities (ie, any research activity that is not part of the required undergraduate curriculum, such as publishing a paper, research elective, etc) was distributed to 175 senior medical students (years 6 and 7). Descriptive and chi-square analyses were used to analyze the responses, considering a P-value of <0.05 as the cut-off level for significance. The main outcome was defined as taking part in any of the extracurricular research activities. Of the 150 participants (response rate = 85.7%), 26 (17.3%), 68 (45.3%), 52 (34.7%), and 17 (11.3%) had published their required medical school research, presented abstracts in conferences, conducted extracurricular research, and completed a research elective/course, respectively; 99 (66.0%) took part in any of these activities. Participants who read medical journals regularly (81; 54%) reported higher participation in extracurricular research activities than those who did not read journals (P=0.003). Improving the availability of mentors for students' extracurricular research was ranked by the participants as the most important factor to improve their participation in extracurricular research (4.05/5.00). Despite the lack of adequate support, extracurricular research activities among medical students of KU were comparable to students from other countries. Barriers for these activities should be addressed by KU medical educators in order to enhance research activities among the students.

Extracurricular research activities among senior medical students in Kuwait: experiences, attitudes, and barriers

PubMed Central

Al-Halabi, Becher; Marwan, Yousef; Hasan, Mohammad; Alkhadhari, Sulaiman

2014-01-01

Background Research is the foundation of scientific advancement and improvement in quality of health care, which ensures the good health of the community. The aim of this study is to explore experiences, attitudes, and barriers of medical students in Kuwait University (KU) in regards to extracurricular research. Methods A questionnaire about extracurricular research activities (ie, any research activity that is not part of the required undergraduate curriculum, such as publishing a paper, research elective, etc) was distributed to 175 senior medical students (years 6 and 7). Descriptive and chi-square analyses were used to analyze the responses, considering a P-value of <0.05 as the cut-off level for significance. The main outcome was defined as taking part in any of the extracurricular research activities. Results Of the 150 participants (response rate = 85.7%), 26 (17.3%), 68 (45.3%), 52 (34.7%), and 17 (11.3%) had published their required medical school research, presented abstracts in conferences, conducted extracurricular research, and completed a research elective/course, respectively; 99 (66.0%) took part in any of these activities. Participants who read medical journals regularly (81; 54%) reported higher participation in extracurricular research activities than those who did not read journals (P=0.003). Improving the availability of mentors for students’ extracurricular research was ranked by the participants as the most important factor to improve their participation in extracurricular research (4.05/5.00). Conclusion Despite the lack of adequate support, extracurricular research activities among medical students of KU were comparable to students from other countries. Barriers for these activities should be addressed by KU medical educators in order to enhance research activities among the students. PMID:24812535

Unwilling Brides: "Phallic Attack" as a Barrier to Gender Balance in Higher Education in Nigeria

ERIC Educational Resources Information Center

Nwadigwe, Charles E.

2007-01-01

Gender balance in access to quality education is a crucial item on the agenda of the Millennium Development Goals. But this ideal appears beset by a number of barriers, especially at higher education level. This study investigated the problem of sexual harassment in the Nigerian university system as a barrier to the educational advancement of…

High School Teachers' Perspectives on Supporting Students with Visual Impairments toward Higher Education: Access, Barriers, and Success

ERIC Educational Resources Information Center

Reed, Maureen; Curtis, Kathryn

2011-01-01

The objective of the study presented here was to understand the experiences of teachers in assisting students with visual impairments in making the transition to higher education. The teachers reported barriers in high school that affect students' access to and success in higher education. Furthermore, institutions of higher education provided…

Preferences for and Barriers to Formal and Informal Athletic Training Continuing Education Activities

PubMed Central

Armstrong, Kirk J.; Weidner, Thomas G.

2011-01-01

Context: Our previous research determined the frequency of participation and perceived effect of formal and informal continuing education (CE) activities. However, actual preferences for and barriers to CE must be characterized. Objective: To determine the types of formal and informal CE activities preferred by athletic trainers (ATs) and barriers to their participation in these activities. Design: Cross-sectional study. Setting: Athletic training practice settings. Patients or Other Participants: Of a geographically stratified random sample of 1000 ATs, 427 ATs (42.7%) completed the survey. Main Outcome Measure(s): As part of a larger study, the Survey of Formal and Informal Athletic Training Continuing Education Activities (FIATCEA) was developed and administered electronically. The FIATCEA consists of demographic characteristics and Likert scale items (1 = strongly disagree, 5 = strongly agree) about preferred CE activities and barriers to these activities. Internal consistency of survey items, as determined by Cronbach α, was 0.638 for preferred CE activities and 0.860 for barriers to these activities. Descriptive statistics were computed for all items. Differences between respondent demographic characteristics and preferred CE activities and barriers to these activities were determined via analysis of variance and dependent t tests. The α level was set at .05. Results: Hands-on clinical workshops and professional networking were the preferred formal and informal CE activities, respectively. The most frequently reported barriers to formal CE were the cost of attending and travel distance, whereas the most frequently reported barriers to informal CE were personal and job-specific factors. Differences were noted between both the cost of CE and travel distance to CE and all other barriers to CE participation (F1,411 = 233.54, P < .001). Conclusions: Overall, ATs preferred formal CE activities. The same barriers (eg, cost, travel distance) to formal CE appeared to be universal to all ATs. Informal CE was highly valued by ATs because it could be individualized. PMID:22488195

Categories for Barriers to Adoption of Instructional Technologies

ERIC Educational Resources Information Center

Reid, Pat

2014-01-01

Although higher education has spent millions of dollars on instructional technologies, often higher education administration complains that instructors are not adopting them. Without a full understanding of possible barriers, higher education institutes are hard-pressed to develop either appropriate goals or sound strategies for the adoption of…

Parental perceptions of barriers to active commuting to school in Spanish children and adolescents.

PubMed

Huertas-Delgado, Francisco Javier; Herrador-Colmenero, Manuel; Villa-González, Emilio; Aranda-Balboa, María Jesús; Cáceres, María Victoria; Mandic, Sandra; Chillón, Palma

2017-06-01

: Understanding parental barriers is crucial to promote active commuting to school since the parental perceptions influence how young people commute. This study examined parental barriers to active commuting to school among Spanish children and adolescents, and their association with their gender and the usual mode of commuting. Parents of children ( n = 628) and parents of adolescents ( n = 151) from Granada (Spain) completed a paper-based questionnaire about perceived parental barriers to active commuting to school and mode of commuting. Data were analyzed using the Chi-square test. Among Spanish parents, the most common barriers reported by parents of children were traffic volume and dangerous intersections, whereas the most frequent barriers reported by parents of adolescents were distance to school and dangerous intersections. Compared to parents of children, a greater proportion of parents of adolescents reported distance to school and crime and smaller proportion reported traffic volume as barriers to active commuting to school. Among parents of children, crime was a more commonly reported as a barrier by parents of girls. Although some barriers reported by parents of passive commuters were similar for children and adolescents (such as distance to school and absence of a policeman at crosswalks), other barriers were specific to parents of children. The main parental barriers to active commuting in children were traffic volume and dangerous intersections whereas for adolescents were distance and dangerous intersections. Among Spanish parents, parental barriers to active commuting are influenced by children's age, gender and mode of commuting to school. © The Author 2017. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Immigrating to the US: What Brazilian, Latin American and Haitian Women Have to Say About Changes to Their Lifestyle That May be Associated with Obesity

PubMed Central

Tovar, Alison; Must, Aviva; Metayer, Nesly; Gute, David M.; Pirie, Alex; Hyatt, Raymond R.; Economos, Christina D.

2012-01-01

Our goal was to explore the perceived determinants of obesity in Brazilian, Latin American and Haitian women. This is part of an ongoing community-based participatory intervention. Focus groups by immigrant group were conducted and themes extracted. Women expressed differences in beliefs, attitudes, and barriers regarding diet and physical activity in the US versus their home country. Participants thought food in the US is “less natural,” there is less time for preparation, and there is more variety. The weather is a barrier to physical activity in the US and work is more physically demanding. Job-related efforts were not considered physical activity. They reported higher levels of stress, less control of their time and less social support in the US. Providing immigrants with appropriate support and education early in the acculturation process has the potential to help prevent obesity. PMID:22736266

Global Account of Barriers and Facilitators of Physical Activity Among Patients with Diabetes Mellitus: A Narrative Review of the Literature.

PubMed

Adeniyi, Ade F; Anjana, Ranjit M; Weber, Mary B

2016-01-01

With diabetes rates escalating globally, there is the need for a better integration of all aspects of diabetes care for improved population outcomes. An understanding, not only of regional but global literature on physical activity barriers and its facilitators is important if healthcare providers and policy makers are to create programs tailored to their populations. Herein, we report the results of a narrative review of the global barriers and facilitators of physical activity for patients with diabetes mellitus. An in-depth literature search was conducted to identify English-language studies that examined physical activity barriers and associated facilitators among patients with diabetes mellitus. Major electronic literature databases that were searched included Google Scholar, PubMed, Hub-Med, and Highwire. Studies were available from Africa, Asia, Australia, Europe, and, predominantly North America. A total of 34 predominantly internal barriers emerged globally. The most commonly reported were time constrains, fear of provoking additional disorders, exercise venue and weather related barriers. Facilitators of physical activity were reported for most of the internal barriers (e.g. time constraints, lack of knowledge etc) while the external barriers (e.g. weather, environmental pollution etc) received only a minimal attention. Globally, patients with diabetes are confronted with an enormous number of physical activity barriers. Unlike the robust solutions proffered for the internal barriers, the literature is largely silent about solutions to the external barriers, which though fewer, may be highly influential. Additional data is needed to better understand physical activity behaviors in populations outside of North America.

Deconstructing barriers: perceptions of students labeled with learning disabilities in higher education.

PubMed

Denhart, Hazel

2008-01-01

This phenomenological study investigated barriers to higher education faced by 11 college students labeled with learning disabilities (LD) using their voice as the primary data. Data were analyzed and interpreted through a disability theory perspective revealing barriers stemmed largely from external social causes rather than individual pathology. Barriers included being misunderstood by faculty, being reluctant to request accommodations for fear of invoking stigma, and having to work considerably longer hours than nonlabeled peers. Findings indicated barriers could be overcome through raising faculty awareness about LD issues, engaging the assistance of the college LD specialist, and participation in a LD democratic empowerment community on campus.

"What I Wish You Knew": Social Barriers toward Physical Activity in Youth with Congenital Heart Disease (CHD)

ERIC Educational Resources Information Center

Moola, Fiona; Fusco, Caroline; Kirsh, Joel A.

2011-01-01

Despite the benefits of physical activity for youth with congenital heart disease (CHD), most patients are inactive. Although literature has addressed medical and psychological barriers to participation, little is known about the social barriers that youth encounter. This qualitative study explored sociocultural barriers to physical activity from…

Circularly polarized antennas for active holographic imaging through barriers

DOEpatents

McMakin, Douglas L [Richland, WA; Severtsen, Ronald H [Richland, WA; Lechelt, Wayne M [West Richland, WA; Prince, James M [Kennewick, WA

2011-07-26

Circularly-polarized antennas and their methods of use for active holographic imaging through barriers. The antennas are dielectrically loaded to optimally match the dielectric constant of the barrier through which images are to be produced. The dielectric loading helps to remove barrier-front surface reflections and to couple electromagnetic energy into the barrier.

Perceived Barriers, Facilitators and Benefits for Regular Physical Activity and Exercise in Patients with Rheumatoid Arthritis: A Review of the Literature.

PubMed

Veldhuijzen van Zanten, Jet J C S; Rouse, Peter C; Hale, Elizabeth D; Ntoumanis, Nikos; Metsios, George S; Duda, Joan L; Kitas, George D

2015-10-01

Rheumatoid arthritis (RA) is an autoimmune disease, which not only affects the joints but can also impact on general well-being and risk for cardiovascular disease. Regular physical activity and exercise in patients with RA have numerous health benefits. Nevertheless, the majority of patients with RA are physically inactive. This indicates that people with RA might experience additional or more severe barriers to physical activity or exercise than the general population. This narrative review provides an overview of perceived barriers, benefits and facilitators of physical activity and exercise in RA. Databases were searched for articles published until September 2014 using the terms 'rheumatoid arthritis', 'physical activity', 'exercise', 'barriers', 'facilitators', 'benefits', 'motivation', 'motivators' and 'enablers'. Similarities were found between disease-specific barriers and benefits of physical activity and exercise, e.g. pain and fatigue are frequently mentioned as barriers, but reductions in pain and fatigue are perceived benefits of physical activity and exercise. Even though exercise does not influence the existence of barriers, physically active patients appear to be more capable of overcoming them. Therefore, exercise programmes should enhance self-efficacy for exercise in order to achieve long-term physical activity and exercise behaviour. Encouragement from health professionals and friends/family are facilitators for physical activity and exercise. There is a need for interventions that support RA patients in overcoming barriers to physical activity and exercise and help sustain this important health behaviour.

Mechanistic differences between methanol and dimethyl ether carbonylation in side pockets and large channels of mordenite.

PubMed

Boronat, Mercedes; Martínez, Cristina; Corma, Avelino

2011-02-21

The activity and selectivity towards carbonylation presented by Brønsted acid sites located inside the 8MR pockets or in the main 12MR channels of mordenite is studied by means of quantum-chemical calculations, and the mechanistic differences between methanol and DME carbonylation are investigated. The selectivity towards carbonylation is higher inside the 8MR pockets, where the competitive formation of DME and hydrocarbons that finally leads to catalyst deactivation is sterically impeded. Moreover, inclusion of dispersion interactions in the calculations leads to agreement between the calculated activation barriers for the rate determining step and the experimentally observed higher reactivity of methoxy groups located inside the 8MR channels.

A systematic review of perceived barriers and motivators to physical activity after stroke.

PubMed

Nicholson, Sarah; Sniehotta, Falko F; van Wijck, Frederike; Greig, Carolyn A; Johnston, Marie; McMurdo, Marion E T; Dennis, Martin; Mead, Gillian E

2013-07-01

Physical fitness is impaired after stroke, may contribute to disability, yet is amenable to improvement through regular physical activity. To facilitate uptake and maintenance of physical activity, it is essential to understand stroke survivors' perceived barriers and motivators. Therefore, we undertook a systematic review of perceived barriers and motivators to physical activity after stroke. Electronic searches of EMBASE, Medline, CINAHL, and PsychInfo were performed. We included peer-reviewed journal articles, in English, between 1 January 1966 and 30 August 2010 reporting stroke survivors' perceived barriers and motivators to physical activity. Searches identified 73,807 citations of which 57 full articles were retrieved. Six articles were included, providing data on 174 stroke survivors (range 10 to 83 per article). Two reported barriers and motivators, two reported only motivators, and two reported only barriers. Five were qualitative articles and one was quantitative. The most commonly reported barriers were lack of motivation, environmental factors (e.g. transport), health concerns, and stroke impairments. The most commonly reported motivators were social support and the need to be able to perform daily tasks. This review has furthered our understanding of the perceived barriers and motivators to physical activity after a stroke. This review will enable the development of tailored interventions to target barriers, while building upon perceived motivators to increase and maintain stroke survivors' physical activity. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Education for Sustainable Development in Higher Education: State-of-the-Art, Barriers and Challenges

ERIC Educational Resources Information Center

Fernández-Sánchez, Gonzalo; Bernaldo, María Olga; Castillejo, Ana; Manzanero, Ana María

2014-01-01

Education for Sustainable Development (ESD) is a new educational paradigm that allows Universities to lead and respond to social needs towards a more sustainable life. The ESD is a global preparedness and complex phenomena in relation to the effects of human activity on the environment, society and economy in spatial (global, regional and local)…

The Social Validation of Institutional Indicators to Promote System-Wide Web Accessibility in Postsecondary Institutions

ERIC Educational Resources Information Center

Mariger, Heather Ann

2011-01-01

The Internet is an integral part of higher education today. Students, faculty, and staff must have access to the institutional web for essential activities. For persons with disabilities, the web is a double-edged sword. While an accessibly designed website can mitigate or remove barriers, an inaccessible one can make access impossible. If…

The role of cell membranes in the regulation of lignification in pine cells

NASA Technical Reports Server (NTRS)

Hendrix, D. L.

1978-01-01

The identity of pine cell membranes bearing PAL enzyme activity, the isolation of a plasma membrane preparation from pine cells for testing as a regulatory barrier in lignification, and the measurement of the geopotential effect in pine stems are presented. A model to describe and predict the interaction of gravity and lignification of higher plants was developed.

Attitude toward physical activity in normal-weight, overweight and obese adolescents.

PubMed

Deforche, Benedicte I; De Bourdeaudhuij, Ilse M; Tanghe, Ann P

2006-05-01

To investigate differences in physical activity and attitude toward physical activity in adolescents with different degrees of overweight and explore whether the prediction of physical activity by attitude is moderated by level of overweight. Subjects were divided into a normal-weight group (n = 37, 18.8 +/- 1.2 kg/m2), an overweight group (n = 28, 25.9 +/- 1.3 kg/m2), and an obese group (n = 24, 33.7 +/- 4.1 kg/m2). Mean age was 14.6 +/- 1.2 years, with 72% girls. Physical activity was estimated using the Baecke Questionnaire. Attitude was measured by assessing perceived benefits and barriers. Participation in sports was higher in normal-weight compared with overweight (p < .05) and obese (p < .01) subjects. There was no difference in leisure-time physical activity between groups. Perceived benefits did not differ between groups, but normal-weight subjects perceived less barriers ('physical complaints', 'not being good at it', 'insecure about appearance', 'not liking it') than their overweight (p < .05) and obese (p < .001) counterparts. Obese adolescents had a less positive attitude compared with their normal-weight (p < .001) and overweight (p < .05) peers. Sport participation was significantly predicted by the perceived benefit 'pleasure' (p < .05) and by the perceived barrier 'not liking it' (p < .001), after taking into account level of overweight. The association between sport participation and attitude was not moderated by level of overweight. This study demonstrates that overweight and obese adolescents show lower sport participation and have a less positive attitude toward physical activity. Interventions in youngsters with weight problems should try to increase participation in sports by making activities more fun and attractive for these youngsters.

A qualitative theory guided analysis of stroke survivors' perceived barriers and facilitators to physical activity.

PubMed

Nicholson, Sarah L; Donaghy, Marie; Johnston, Marie; Sniehotta, Falko F; van Wijck, Frederike; Johnston, Derek; Greig, Carolyn; McMurdo, Marion E T; Mead, Gillian

2014-01-01

After stroke, physical activity and physical fitness levels are low, impacting on health, activity and participation. It is unclear how best to support stroke survivors to increase physical activity. Little is known about the barriers and facilitators to physical activity after stroke. Thus, our aim was to explore stroke survivors' perceived barriers and facilitators to physical activity. Semi-structured interviews with 13 ambulatory stroke survivors exploring perceived barriers and facilitators to physical activity post stroke were conducted in participants' homes, audio-recorded and transcribed verbatim. The Theoretical Domains Framework (TDF) informed content analysis of the interview transcripts. Data saturation was reached after interviews with 13 participants (median age of 76 years (inter-quartile range (IQR) = 69-83 years). The median time since stroke was 345 d (IQR = 316-366 d). The most commonly reported TDF domains were "beliefs about capabilities", "environmental context and resources" and "social influence". The most commonly reported perceived motivators were: social interaction, beliefs of benefits of exercise, high self-efficacy and the necessity of routine behaviours. The most commonly reported perceived barriers were: lack of professional support on discharge from hospital and follow-up, transport issues to structured classes/interventions, lack of control and negative affect. Stroke survivors perceive several different barriers and facilitators to physical activity. Stroke services need to address barriers to physical activity and to build on facilitators to promote physical activity after stroke. Physical activity post stroke can improve physical fitness and function, yet physical activity remains low among stroke survivors. Understanding stroke survivors' perceived barriers and facilitators to physical activity is essential to develop targeted interventions to increase physical activity. Beliefs about capabilities, environmental context and resources and social influences were the mostly commonly report influences on stroke survivors' perceived barriers and facilitators to physical activity.

Barriers to Physical Activity on University Student

NASA Astrophysics Data System (ADS)

Jajat; Sultoni, K.; Suherman, A.

2017-03-01

The purpose of the research is to analyze the factors that become barriers to physical activity in university students based on physical activity level. An internet-based survey was conducted. The participants were 158 University students from Universitas Pendidikan Indonesia. Barriers to Physical Activity Quiz (BPAQ) were used to assessed the factors that become barriers to physical activity in university students. IPAQ (short form) were used to assessed physical activity level. The results show there was no differences BPAQ based on IPAQ level. But when analyzed further based on seven factors barriers there are differences in factors “social influence and lack of willpower” based IPAQ level. Based on this it was concluded that the “influence from other and lack of willpower” an inhibiting factor on students to perform physical activity.

Perceived barriers to achieving a healthy weight: a qualitative study using focus groups at public and private schools in Guatemala City.

PubMed

Madrigal, Luisa; Adams, Inez; Chacon, Violeta; Barnoya, Joaquin

2017-01-05

Overweight prevalence among Guatemalan girls is higher in public than in private schools. Little is known about adolescent girls' perceptions of the right ways to achieve a healthy weight. This study examines public and private school adolescent girls' perceptions of a "healthy weight," and barriers and facilitators to achieving it. We conducted 4 focus groups in public and private schools in Guatemala City with girls from 13 to 15 years old. The discussion guide included open-ended questions and activities aimed at examining perceptions of "healthy weight" and barriers and motivators to achieving it within the school environment. Focus groups were audio-recorded and transcribed. Data analyses followed established methods of content analysis. Twenty-eight girls (private school, n = 12; public school, n = 16) of ages ranging from 13.1 to 15.9 years (median, 14, IQR, 13.6-14.9) participated in the study. Girls identified images of thin and fit women as healthy. They cited healthy eating and physical activity as ways to achieve a healthy weight. Within the school environment, barriers to maintaining a healthy weight included a lack of healthy food options and the prioritization of sports for boys over girls. In public schools, facilities were less than optimal; in private schools, girls' access to facilities was limited. Public school girls stated that their uniforms were inappropriate for exercising. Our findings support the need to provide more healthy food options in Guatemalan schools. In addition, physical activity for girls should be promoted and facilities made available for their use.

"I don't have the heart": a qualitative study of barriers to and facilitators of physical activity for people with coronary heart disease and depressive symptoms.

PubMed

Rogerson, Michelle C; Murphy, Barbara M; Bird, Stephen; Morris, Tony

2012-11-30

Physical activity has been shown to reduce depression in people with coronary heart disease (CHD), however many people with CHD do not engage in sufficient levels of physical activity to reap its positive effects. People with depression and CHD are at particular risk of non-adherence to physical activity. Little is known about the barriers to and facilitators of physical activity for people with CHD and depressive symptoms. Using qualitative interviews, the aim of this study was to explore the barriers to and facilitators of physical activity for cardiac patients with depressive symptoms. Fifteen participants with CHD and depressive symptoms (assessed using the Cardiac Depression Scale) participated in in-depth semi-structured interviews. The interviews were focussed on investigating participants' experiences of physical activity since their cardiac event. Interviews were content analysed to determine major themes. Participants identified a number of barriers to and facilitators of physical activity. Barriers included having negative perceptions towards health and life changes as a result of the cardiac event, having low mood and low motivation to exercise, feeling physically restricted towards or fearful of exercise, lacking knowledge regarding exercise and perceiving external barriers. Facilitators included having a reason for exercising, being able to identify the psychological benefits of exercise, having positive social support and using psychological strategies. 'Inactive' participants reported more barriers and fewer facilitators than did 'active' participants. The barriers reported in this study were highly salient for a number of participants. Health professionals and researchers can use this information to assist people with CHD and depressive symptoms to identify and possibly overcome barriers to physical activity. Relevant barriers and facilitators could be taken into account to increase their effectiveness when designing interventions to encourage physical activity maintenance in this population.

Structural requirements and reaction pathways in dimethyl ether combustion catalyzed by supported Pt clusters.

PubMed

Ishikawa, Akio; Neurock, Matthew; Iglesia, Enrique

2007-10-31

The identity and reversibility of the elementary steps required for catalytic combustion of dimethyl ether (DME) on Pt clusters were determined by combining isotopic and kinetic analyses with density functional theory estimates of reaction energies and activation barriers to probe the lowest energy paths. Reaction rates are limited by C-H bond activation in DME molecules adsorbed on surfaces of Pt clusters containing chemisorbed oxygen atoms at near-saturation coverages. Reaction energies and activation barriers for C-H bond activation in DME to form methoxymethyl and hydroxyl surface intermediates show that this step is more favorable than the activation of C-O bonds to form two methoxides, consistent with measured rates and kinetic isotope effects. This kinetic preference is driven by the greater stability of the CH3OCH2* and OH* intermediates relative to chemisorbed methoxides. Experimental activation barriers on Pt clusters agree with density functional theory (DFT)-derived barriers on oxygen-covered Pt(111). Measured DME turnover rates increased with increasing DME pressure, but decreased as the O2 pressure increased, because vacancies (*) on Pt surfaces nearly saturated with chemisorbed oxygen are required for DME chemisorption. DFT calculations show that although these surface vacancies are required, higher oxygen coverages lead to lower C-H activation barriers, because the basicity of oxygen adatoms increases with coverage and they become more effective in hydrogen abstraction from DME. Water inhibits reaction rates via quasi-equilibrated adsorption on vacancy sites, consistent with DFT results indicating that water binds more strongly than DME on vacancies. These conclusions are consistent with the measured kinetic response of combustion rates to DME, O2, and H2O, with H/D kinetic isotope effects, and with the absence of isotopic scrambling in reactants containing isotopic mixtures of 18O2-16O2 or 12CH3O12CH3-13CH3O13CH3. Turnover rates increased with Pt cluster size, because small clusters, with more coordinatively unsaturated surface atoms, bind oxygen atoms more strongly than larger clusters and exhibit lower steady-state vacancy concentrations and a consequently smaller number of adsorbed DME intermediates involved in kinetically relevant steps. These effects of cluster size and metal-oxygen bond energies on reactivity are ubiquitous in oxidation reactions requiring vacancies on surfaces nearly saturated with intermediates derived from O2.

[Climatic change and skin: diagnostic and therapeutic challenges].

PubMed

Llamas-Velasco, M; García-Díez, A

2010-06-01

Scientifics are warning us about a global warming tendency and diminished rainfalls. Quantity, causes and human activity influence remain controversial. Warming could increase prevalence of some cutaneous pathology. Sensible skin and skin xerosis would be more prevalent if relative humidity decreases. Alterations of skin barrier;s function would increase seriousness and prevalence of atopic dermatitis. Furthermore, the higher UVB proportion reaching Earth's surface, in conjunction with increased sunbathing population habits, will increase cutaneous cancer and photoaging rates without a correct photoprotection. Also, habitats of some infectious diseases; vectors are changing. The facing of these problems will be a real challenge for the dermatologist, who will have a very important role on prevention, diagnoses and early treatment of them.

Monitoring long-term evolution of engineered barrier systems using magnets: Magnetic response.

PubMed

Rigonat, N; Isnard, O; Harley, S L; Butler, I B

2018-01-05

Remote and non-destructive monitoring of the stability and performance of Engineered Barrier Systems for Geological Disposal Facility of is gaining considerable importance in establishing the safety cases for Higher Activity Wastes disposal. This study offers an innovative use of mineral magnetism for monitoring groundwater saturation of the barrier. Four mixtures of permanent magnets (Nd-Fe-B, coated and uncoated; SmCo and AlNiCo) and bentonite were reacted for 4, 8 and 12 months with mildly-saline, high-pH leachates, representing the fluids saturating a time-evolved engineered barrier. Coupled hysteresis and thermomagnetic analyses demonstrate how Nd-Fe-B feature a time-dependent transition from square-like ferromagnetic to superparamagnetic loop via pot-bellied and wasp-waist loops, whereas SmCo and AlNiCo do not show so extensive corrosion-related variations of the intrinsic and extrinsic magnetic properties. This study allowed to identify magnetic materials suitable for shorter- (Nd-Fe-B) and longer-term (SmCo and AlNiCo) monitoring purposes. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Promoting Physical Activity: Addressing Barriers and Moving Forward

ERIC Educational Resources Information Center

Beighle, Aaron; Morrow, James R.

2014-01-01

The barriers that keep individuals from adopting and maintaining active lifestyles are very complex. Strategies for overcoming these barriers and to incentivize and assist inactive individuals to benefit from physical activity are necessary. In addition, it is important to examine the impact of public policy on active living. As youth physical…

Patient perceptions about illness self-management in ANCA-associated small vessel vasculitis.

PubMed

Thorpe, C T; DeVellis, R F; Blalock, S J; Hogan, S L; Lewis, M A; DeVellis, B M

2008-06-01

To characterize patient perceptions, related to eight self-management behaviours relevant for adults with ANCA-associated small vessel vasculitis (ANCA-SVV), and to determine if these perceptions were associated with performance of each behaviour. Adults with ANCA-SVV (n = 202) completed a self-administered questionnaire that assessed eight self-management behaviours (adherence to recommendations for medication, health service use, diet, exercise, infection avoidance and symptom monitoring; prompt reporting of symptoms and side effects; and adjusting activities in response to symptoms), perceptions about these behaviours, socio-demographics, clinical factors and social desirability bias. Descriptive statistics were generated to characterize patients' perceptions about difficulty of, importance of, and specific barriers to performing each behaviour. Regression analyses explored whether these variables were associated with performing each behaviour, controlling for potential confounders. With few exceptions, higher perceived importance and lower perceived difficulty of each behaviour were associated with more frequent performance of the behaviour. For each behaviour, several specific barriers were frequently endorsed by patients and a number of these were associated with lower levels of self-management. This study reveals that patient perceptions about the illness and its treatment influence ANCA-SVV self-management. Perceived barriers to medication, health services, diet and exercise adherence were similar to those in other illnesses. This study also provides insight into barriers experienced by patients in performing behaviours (infection avoidance, symptom monitoring, reporting symptoms and side-effects and adjusting activities) not often previously studied. How the identification of these barriers can help inform future interventions for ANCA-SVV patients is to be discussed.

Management of Sodium-reduced Meals at Worksite Cafeterias: Perceptions, Practices, Barriers, and Needs among Food Service Personnel

PubMed Central

Lee, Jounghee; Park, Sohyun

2015-01-01

Objectives The sodium content of meals provided at worksite cafeterias is greater than the sodium content of restaurant meals and home meals. The objective of this study was to assess the relationships between sodium-reduction practices, barriers, and perceptions among food service personnel. Methods We implemented a cross-sectional study by collecting data on perceptions, practices, barriers, and needs regarding sodium-reduced meals at 17 worksite cafeterias in South Korea. We implemented Chi-square tests and analysis of variance for statistical analysis. For post hoc testing, we used Bonferroni tests; when variances were unequal, we used Dunnett T3 tests. Results This study involved 104 individuals employed at the worksite cafeterias, comprised of 35 men and 69 women. Most of the participants had relatively high levels of perception regarding the importance of sodium reduction (very important, 51.0%; moderately important, 27.9%). Sodium reduction practices were higher, but perceived barriers appeared to be lower in participants with high-level perception of sodium-reduced meal provision. The results of the needs assessment revealed that the participants wanted to have more active education programs targeting the general population. The biggest barriers to providing sodium-reduced meals were use of processed foods and limited methods of sodium-reduced cooking in worksite cafeterias. Conclusion To make the provision of sodium-reduced meals at worksite cafeterias more successful and sustainable, we suggest implementing more active education programs targeting the general population, developing sodium-reduced cooking methods, and developing sodium-reduced processed foods. PMID:27169011

Self-learning kinetic Monte Carlo simulations of diffusion in ferromagnetic α -Fe–Si alloys

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

Nandipati, Giridhar; Jiang, Xiujuan; Vemuri, Rama S.

Diffusion in α-Fe-Si alloys is studied using AKSOME, an on-lattice self-learning KMC code, in the ferromagnetic state. Si diffusivity in the α-Fe matrix were obtained with and without the magnetic disorder in various temperature ranges. In addition we studied vacancy diffusivity in ferromagnetic α-Fe at various Si concentrations up to 12.5at.% in the temperature range of 350–550 K. The results were compared with available experimental and theoretical values in the literature. Local Si-atom dependent activation energies for vacancy hops were calculated using a broken-model and were stored in a database. The migration barrier and prefactors for Si-diffusivity were found tomore » be in reasonable agreement with available modeling results in the literature. Magnetic disorder has a larger effect on the prefactor than on the migration barrier. Prefactor was approximately an order of magnitude and the migration barrier a tenth of an electron-volt higher with magnetic disorder when compared to a fully ferromagnetic ordered state. In addition, the correlation between various have a larger effect on the Si-diffusivity extracted in various temperature range than the magnetic disorder. In the case of vacancy diffusivity, the migration barrier more or less remained constant while the prefactor decreased with increasing Si concentration in the disordered or A2-phase of Fe-Si alloy. Important vacancy-Si/Fe atom exchange processes and their activation barriers were also identified and discuss the effect of energetics on the formation of ordered phases in Fe-Si alloys.« less

An internet survey of the characteristics and physical activity of community-dwelling Australian adults with acquired brain injury: Exploring interest in an internet-delivered self-management program focused on physical activity.

PubMed

Jones, Taryn M; Dean, Catherine M; Dear, Blake F; Hush, Julia M; Titov, Nickolai

2016-01-01

Individuals with acquired brain injury (ABI) are more likely to be physically inactive and experience barriers to accessing services to address inactivity. This study was designed to guide the development of an internet-delivered self-management program to increase physical activity after ABI. The aims of this study were to examine the current physical activity status of community-dwelling Australian adults with ABI, the barriers to physical activity they experience and to explore interest an internet-delivered self-management program aimed at increasing physical activity. An online survey of Australian adults with ABI was used to collect information about demographic characteristics; general health; emotional well-being; mobility and physical activity status, and satisfaction; barriers to physical activity; confidence in overcoming barriers, and; interest in an internet self-management program. Data were analyzed descriptively and correlational analyses examined relationships between variables. Data were analyzed from 59 respondents. Over half were not satisfied with their current physical activity status. The most frequently reported barriers were pain/discomfort, fatigue and fear, and confidence to overcome these barriers was very low. Interest in an internet-delivered self-management program was high (74%) and not related to the amount of physical activity, satisfaction with physical activity and mobility status or total number of barriers. Australian adults with ABI are not satisfied with their activity levels and experience barriers in maintaining their physical activity levels. Participants were interested in accessing an internet-delivered self-management program aimed at improving physical activity levels. Therefore such a program warrants development and evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

Barriers and enablers that influence sustainable interprofessional education: a literature review.

PubMed

Lawlis, Tanya Rechael; Anson, Judith; Greenfield, David

2014-07-01

The effective incorporation of interprofessional education (IPE) within health professional curricula requires the synchronised and systematic collaboration between and within the various stakeholders. Higher education institutions, as primary health education providers, have the capacity to advocate and facilitate this collaboration. However, due to the diversity of stakeholders, facilitating the pedagogical change can be challenging and complex, and brings a degree of uncertainty and resistance. This review, through an analysis of the barriers and enablers investigates the involvement of stakeholders in higher education IPE through three primary stakeholder levels: Government and Professional, Institutional and Individual. A review of eight primary databases using 21 search terms resulted in 40 papers for review. While the barriers to IPE are widely reported within the higher education IPE literature, little is documented about the enablers of IPE. Similarly, the specific identification and importance of enablers for IPE sustainability and the dual nature of some barriers and enablers have not been previously reported. An analysis of the barriers and enablers of IPE across the different stakeholder levels reveals five key "fundamental elements" critical to achieving sustainable IPE in higher education curricula.

Interaction of healthcare staff's attitude with barriers to physical activity in hemodialysis patients: A quantitative assessment.

PubMed

Regolisti, Giuseppe; Maggiore, Umberto; Sabatino, Alice; Gandolfini, Ilaria; Pioli, Sarah; Torino, Claudia; Aucella, Filippo; Cupisti, Adamasco; Pistolesi, Valentina; Capitanini, Alessandro; Caloro, Giorgia; Gregorini, Mariacristina; Battaglia, Yuri; Mandreoli, Marcora; Dani, Lucia; Mosconi, Giovanni; Bellizzi, Vincenzo; Di Iorio, Biagio Raffaele; Conti, Paolo; Fiaccadori, Enrico

2018-01-01

In hemodialysis patients, sedentarism is a potentially modifiable mortality risk factor. We explored whether healthcare staff's attitude towards exercise interacts with patient-perceived barriers in modifying the level of physical activity in this population. In this prospective, cross-sectional, multicenter study we recruited 608 adult patients and 330 members of the healthcare staff in 16 hemodialysis units in Italy. We assessed patient-perceived barriers to, and healthcare staff's attitude towards, exercise by specific questionnaires. We fitted multilevel linear models to analyze the relationships of either barriers or staff's attitude, and their interaction, with a measure of patient self-reported physical activity (the Human Activity Profile-Adjusted Activity Score [HAP-AAS]), adjusting for multiple confounders. We also employed latent class analysis to dichotomize patients into those endorsing or not endorsing barriers. Most barriers were negatively associated with the HAP-AAS (adjusted change attributable to a given barrier ranging between -5.1 ["Feeling too old", 95% Confidence Interval: -9.4 to -0.8] and -15.6 ["Ulcers on legs and feet", 95%CI: -24.8 to -6.5]. We found a significant interaction between staff's attitude and barriers (adjusted P values ranging between 0.03 ["I do not believe that it is physician's or nurse's role providing advice on exercise to patients on dialysis"] and 0.001 ["I do not often ask patients about exercise"]). A beneficial effect of a proactive staff's attitude was evident only in patients not endorsing barriers. Barriers and non-proactive staff's attitude reduce physical activity in hemodialysis patients. Patients not endorsing barriers benefit the most from a proactive staff's attitude.

Institutional Barriers for Adults' Participation in Higher Education in Thirteen European Countries

ERIC Educational Resources Information Center

Saar, Ellu; Täht, Kadri; Roosalu, Triin

2014-01-01

This study focuses on institutional barriers that adult learners experience while participating in higher education programmes. We developed a holistic measure of diversification, accessibility, flexibility and affordability of higher education for adults. Based on pre-economic-crisis data across Europe we then explored the impact of macro-level…

Financing Higher Education in the United States. OECD Economics Department Working Papers, No. 584

ERIC Educational Resources Information Center

Tulip, Peter

2007-01-01

America's higher education system is among the best in the world. Nevertheless, there is scope for improvement. In particular, there appear to be substantial financial barriers to higher education despite large government expenditures aimed at promoting access. Policy makers have proposed addressing these barriers by increasing student grants.…

Knowledge Management in Higher Education Institutions: Enablers and Barriers in Mauritius

ERIC Educational Resources Information Center

Veer Ramjeawon, Poonam; Rowley, Jennifer

2017-01-01

Purpose: The purpose of this study is to contribute to research on knowledge management in higher education institutions (HEIs), by studying the enablers and barriers to knowledge management in a country with a developing higher education sector, Mauritius. Design/methodology/approach: Semi-structured interviews were conducted with senior staff in…

Evaluating Cancer Patients' Expectations and Barriers Toward Traditional Chinese Medicine Utilization in China: A Patient-Support Group-Based Cross-Sectional Survey.

PubMed

Sun, Lingyun; Mao, Jun J; Vertosick, Emily; Seluzicki, Christina; Yang, Yufei

2018-06-01

Traditional Chinese medicine (TCM) is widely used among Chinese cancer patients. However, little is known about Chinese patients' expectations and barriers toward using TCM for cancer. We conducted a cross-sectional survey within a patient-support group, the Beijing Anti-Cancer Association. We measured the outcome, Chinese cancer survivors' expectations and barriers toward TCM utilization, using a modified version of ABCAM (Attitudes and Beliefs towards Complementary and Alternative Medicine), the ABTCM (Attitudes and Beliefs towards Traditional Chinese Medicine). We used multivariate models to evaluate the impact of socioeconomic status and clinical factors on their expectations and barriers (including treatment concerns and logistical challenges domain) toward TCM. Among 590 participants, most patients expected TCM to boost their immune system (96%), improve their physical health (96%), and reduce symptoms (94%). Many had logistical challenges (difficulty decocting herbs (58%) and finding a good TCM physician (55%)). A few were concerned that TCM might interfere with conventional treatments (7.6%), and that many TCM treatments are not based on scientific research (9.1%). In the multivariable regression model, age ≤60 years was independently associated with higher expectation score ( P = .031). Age ≤60 years (coefficient 5.0, P = .003) and localized disease (coefficient 9.5, P = .001) were both associated with higher treatment concerns. Active employment status (coefficient 9.0, P = .008) and localized disease (coefficient 7.5, P = .030) were related to more logistical challenges. Age and cancer stage were related to Chinese cancer patients' perceived expectations and barriers toward TCM use. Understanding these attitudes is important for reshaping the role that TCM plays in China's patient-centered comprehensive cancer care model.

Perceived physical activity barriers related to body weight status and sociodemographic factors among Malaysian men in Klang Valley

PubMed Central

2013-01-01

Background Physical inactivity has been acknowledged as a public health issue and has received increasing attention in recent years. This cross-sectional study was conducted to determine the barriers to physical activity among Malaysian men. These barriers were analyzed with regards to sociodemographic factors, physical activity level, BMI and waist circumference. Methods Subjects in this study included 308 Malay men and 422 Chinese men aged 20 years and older. Subjects completed the International Physical Activity Questionnaire (IPAQ) and a questionnaire on barriers to physical activity, categorized into personal and psychological, physical and social environment barriers. Weight, height and waist circumference were also measured and BMI was calculated. Results Descriptive analyses showed that 79.3% of subjects were married, 52.1% had secondary educational level, 68.8% were still working, and 39.7% had household income between RM1500 to RM3500. The perception that other recreational activities with family and friends were more fun was the most frequently reported barrier, followed by weather, lack of discipline, lack of free time, lack of money, and lack of friends. Marriage status, educational level, household income, BMI, and physical activity status were shown to be associated with perceived barriers. Conclusions To increase participation in physical activity, policy makers should consider significant personal, social and environmental barriers when developing appropriate intervention programmes. Health-promoting strategies that increase awareness, knowledge, skills and motivation related to physical activity are required. PMID:23530696

Perceived physical activity barriers related to body weight status and sociodemographic factors among Malaysian men in Klang Valley.

PubMed

Ibrahim, Suraya; Karim, Norimah A; Oon, Ng Lai; Ngah, Wan Zurinah Wan

2013-03-26

Physical inactivity has been acknowledged as a public health issue and has received increasing attention in recent years. This cross-sectional study was conducted to determine the barriers to physical activity among Malaysian men. These barriers were analyzed with regards to sociodemographic factors, physical activity level, BMI and waist circumference. Subjects in this study included 308 Malay men and 422 Chinese men aged 20 years and older. Subjects completed the International Physical Activity Questionnaire (IPAQ) and a questionnaire on barriers to physical activity, categorized into personal and psychological, physical and social environment barriers. Weight, height and waist circumference were also measured and BMI was calculated. Descriptive analyses showed that 79.3% of subjects were married, 52.1% had secondary educational level, 68.8% were still working, and 39.7% had household income between RM1500 to RM3500. The perception that other recreational activities with family and friends were more fun was the most frequently reported barrier, followed by weather, lack of discipline, lack of free time, lack of money, and lack of friends. Marriage status, educational level, household income, BMI, and physical activity status were shown to be associated with perceived barriers. To increase participation in physical activity, policy makers should consider significant personal, social and environmental barriers when developing appropriate intervention programmes. Health-promoting strategies that increase awareness, knowledge, skills and motivation related to physical activity are required.

Physical inactivity among physiotherapy undergraduates: exploring the knowledge-practice gap.

PubMed

Ranasinghe, Chathuranga; Sigera, Chathurani; Ranasinghe, Priyanga; Jayawardena, Ranil; Ranasinghe, Ayodya C R; Hills, Andrew P; King, Neil

2016-01-01

Physical inactivity is a common risk factor for several non-communicable diseases (NCDs). Increasing physical activity could reduce the burden of disease due to major NCDs and increase life expectancy. Undergraduate physiotherapy students represent a group of young-adults expected to have a good knowledge of physical activity. We evaluated physical activity levels of undergraduate physiotherapy students of University of Colombo, Sri Lanka and determined their motives and barriers for participation in physical activity. All physiotherapy undergraduates studying at the University of Colombo, Sri Lanka in 2013 were invited for the study. Phase one was a quantitative study to evaluate the physical activity levels and phase two was a qualitative study to identify motives and barriers for physical activity and sports in the same cohort. Physical activity levels (phase 1) were assessed using the interviewer administered International Physical Activity Questionnaire (long-version). The qualitative study (phase 2) was conducted in the same population using Focus Group Discussions ( n  = 3) and individual In-depth Interviews ( n  = 5). Sample size in phase 1 and phase 2 were 113 (response rate = 98%; [N-115]) and 87 (response rat = 97%; [N-90]) respectively. Mean age (±SD) of participants was 23.4 ± 1 years. The mean weekly total MET minutes (±SD) of the study population was 1791.25 ± 3097. According to the IPAQ categorical score a higher percentage of participants were 'inactive' (48.7%), while only 15.9% were in the 'Highly active' group. Lack of support and encouragement received during childhood to engage in sports activity seem to have played an important role in continuing their exercise behavior through to the adult life. Academic activities were given priority by both parents and teachers. The environment and support from teachers, family and friends were important to initiate and adhere to sports and physical activity. A higher percentage of participants were 'inactive', in spite of belonging to a group which is presumed to be knowledgeable regarding the benefits of physical activity. A significant negative attitude towards physical activity was observed in this cohort of young-adults. This seems to stem from earlier in life, due to lack of support and motivation for physical exercise and sports, received during primary and secondary schooling. This negative attitude has become a significant 'internal' barrier, which has not been changed in spite of their education.

Quantitative structure-activation barrier relationship modeling for Diels-Alder ligations utilizing quantum chemical structural descriptors.

PubMed

Nandi, Sisir; Monesi, Alessandro; Drgan, Viktor; Merzel, Franci; Novič, Marjana

2013-10-30

In the present study, we show the correlation of quantum chemical structural descriptors with the activation barriers of the Diels-Alder ligations. A set of 72 non-catalysed Diels-Alder reactions were subjected to quantitative structure-activation barrier relationship (QSABR) under the framework of theoretical quantum chemical descriptors calculated solely from the structures of diene and dienophile reactants. Experimental activation barrier data were obtained from literature. Descriptors were computed using Hartree-Fock theory using 6-31G(d) basis set as implemented in Gaussian 09 software. Variable selection and model development were carried out by stepwise multiple linear regression methodology. Predictive performance of the quantitative structure-activation barrier relationship (QSABR) model was assessed by training and test set concept and by calculating leave-one-out cross-validated Q2 and predictive R2 values. The QSABR model can explain and predict 86.5% and 80% of the variances, respectively, in the activation energy barrier training data. Alternatively, a neural network model based on back propagation of errors was developed to assess the nonlinearity of the sought correlations between theoretical descriptors and experimental reaction barriers. A reasonable predictability for the activation barrier of the test set reactions was obtained, which enabled an exploration and interpretation of the significant variables responsible for Diels-Alder interaction between dienes and dienophiles. Thus, studies in the direction of QSABR modelling that provide efficient and fast prediction of activation barriers of the Diels-Alder reactions turn out to be a meaningful alternative to transition state theory based computation.

Carbon-carbon bond activation of 2,2,6,6-tetramethyl-piperidine-1-oxyl by a Rh(II) metalloradical: a combined experimental and theoretical study.

PubMed

Chan, Kin Shing; Li, Xin Zhu; Dzik, Wojciech I; de Bruin, Bas

2008-02-13

Competitive major carbon-carbon bond activation (CCA) and minor carbon-hydrogen bond activation (CHA) channels are identified in the reaction between rhodium(II) meso-tetramesitylporphyrin [Rh(II)(tmp)] (1) and 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) (2). The CCA and CHA pathways lead to formation of [Rh(III)(tmp)Me] (3) and [Rh(III)(tmp)H] (5), respectively. In the presence of excess TEMPO, [Rh(II)(tmp)] is regenerated from [Rh(III)(tmp)H] with formation of 2,2,6,6-tetramethyl-piperidine-1-ol (TEMPOH) (4) via a subsequent hydrogen atom abstraction pathway. The yield of the CCA product [Rh(III)(tmp)Me] increased with higher temperature at the cost of the CHA product TEMPOH in the temperature range 50-80 degrees C. Both the CCA and CHA pathways follow second-order kinetics. The mechanism of the TEMPO carbon-carbon bond activation was studied by means of kinetic investigations and DFT calculations. Broken symmetry, unrestricted b3-lyp calculations along the open-shell singlet surface reveal a low-energy transition state (TS1) for direct TEMPO methyl radical abstraction by the Rh(II) radical (SH2 type mechanism). An alternative ionic pathway, with a somewhat higher barrier, was identified along the closed-shell singlet surface. This ionic pathway proceeds in two sequential steps: Electron transfer from TEMPO to [Rh(II)(por)] producing the [TEMPO]+ [RhI(por)]- cation-anion pair, followed by net CH3+ transfer from TEMPO+ to Rh(I) with formation of [Rh(III)(por)Me] and (DMPO-like) 2,2,6-trimethyl-2,3,4,5-tetrahydro-1-pyridiniumolate. The transition state for this process (TS2) is best described as an SN2-like nucleophilic substitution involving attack of the d(z)2 orbital of [Rh(I)(por)]- at one of the C(Me)-C(ring) sigma* orbitals of [TEMPO]+. Although the calculated barrier of the open-shell radical pathway is somewhat lower than the barrier for the ionic pathway, R-DFT and U-DFT are not likely comparatively accurate enough to reliably distinguish between these possible pathways. Both the radical (SH2) and the ionic (SN2) pathway have barriers which are low enough to explain the experimental kinetic data.

Activation of CH4 by Th(+) as studied by guided ion beam mass spectrometry and quantum chemistry.

PubMed

Cox, Richard M; Armentrout, P B; de Jong, Wibe A

2015-04-06

The reaction of atomic thorium cations with CH4 (CD4) and the collision-induced dissociation (CID) of ThCH4(+) with Xe are studied using guided ion beam tandem mass spectrometry. In the methane reactions at low energies, ThCH2(+) (ThCD2(+)) is the only product; however, the energy dependence of the cross-section is inconsistent with a barrierless exothermic reaction as previously assumed on the basis of ion cyclotron resonance mass spectrometry results. The dominant product at higher energies is ThH(+) (ThD(+)), with ThCH3(+) (ThCD3(+)) having a similar threshold energy. The latter product subsequently decomposes at still higher energies to ThCH(+) (ThCD(+)). CID of ThCH4(+) yields atomic Th(+) as the exclusive product. The cross-sections of all product ions are modeled to provide 0 K bond dissociation energies (in eV) of D0(Th(+)-H) ≥ 2.25 ± 0.18, D0(Th(+)-CH) = 6.19 ± 0.16, D0(Th(+)-CH2) ≥ 4.54 ± 0.09, D0(Th(+)-CH3) = 2.60 ± 0.30, and D0(Th(+)-CH4) = 0.47 ± 0.05. Quantum chemical calculations at several levels of theory are used to explore the potential energy surfaces for activation of methane by Th(+), and the effects of spin-orbit coupling are carefully considered. When spin-orbit coupling is explicitly considered, a barrier for C-H bond activation that is consistent with the threshold measured for ThCH2(+) formation (0.17 ± 0.02 eV) is found at all levels of theory, whereas this barrier is observed only at the BHLYP and CCSD(T) levels otherwise. The observation that the CID of the ThCH4(+) complex produces Th(+) as the only product with a threshold of 0.47 eV indicates that this species has a Th(+)(CH4) structure, which is also consistent with a barrier for C-H bond activation. This barrier is thought to exist as a result of the mixed ((4)F,(2)D) electronic character of the Th(+) J = (3)/2 ground level combined with extensive spin-orbit effects.

Active ageing and quality of life: factors associated with participation in leisure activities among institutionalized older adults, with and without dementia.

PubMed

Fernández-Mayoralas, Gloria; Rojo-Pérez, Fermina; Martínez-Martín, Pablo; Prieto-Flores, Maria-Eugenia; Rodríguez-Blázquez, Carmen; Martín-García, Salomé; Rojo-Abuín, José-Manuel; Forjaz, Maria-Joao

2015-01-01

Active ageing, considered from the perspective of participation in leisure activities, promotes life satisfaction and personal well-being. The aims of this work are to define and explain leisure activity profiles among institutionalized older adults, considering their sociodemographic characteristics and objective and subjective conditions in relation to their quality of life. Two samples of institutionalized people aged 60 and over were analysed together: 234 older adults without dementia and 525 with dementia. Sociodemographic, economic, family and social network, and health and functioning variables were selected. Cluster analysis was applied to obtain activity profiles according to the leisure activities, and ordinal regression models were performed to analyse factors associated to activity level. The sample was clustered into three groups of people: active (27%), moderately active (35%) and inactive people (38%). In the final regression model (Nagelkerke pseudo R(2) = 0.500), a higher level of activity was associated with better cognitive function (Pfeiffer scale), self-perceived health status and functional ability, as well as with a higher frequency of gathering with family and friends, and higher educational level. The decline in physical and mental health, the loss of functional capabilities and the weakening of family and social ties represent a significant barrier to active ageing in a context of institutionalization.

Physical activity correlates in people living with HIV/AIDS: a systematic review of 45 studies.

PubMed

Vancampfort, Davy; Mugisha, James; Richards, Justin; De Hert, Marc; Probst, Michel; Stubbs, Brendon

2018-07-01

Understanding barriers and facilitators of physical activity participation in persons living with HIV/AIDS is an essential first step in order to devise effective interventions. The present review provides a systematic quantitative review of the physical activity correlates in people with HIV/AIDS. Major electronic databases were searched till August 2016. Keywords included "physical activity" or "exercise" or "sports" and "AIDS" or "HIV". Out of 55 correlates from 45 studies (N = 13,167; mean age range = 30.5-58.3 years; 63.2% male) five consistent (i.e., reported in four or more studies) correlates were identified. Lower levels of physical activity were consistently associated with older age (6/10 studies), a lower educational level (6/7), a lower number of CD4 cells/μl (7/11), exposure to antiviral therapy (4/6), and the presence of lipodystrophy (4/4). Other important barriers were the presence of bodily pain (2/2), depression (3/3), and opportunistic infections (3/4). Facilitators were a higher cardiorespiratory fitness level (3/3), a higher self-efficacy (2/2), more perceived benefits (2/2), and a better health motivation (3/3). The current review has elucidated that participation in physical activity by people with HIV/AIDS is associated with a range of complex factors which should be considered in rehabilitation programs. Implications for Rehabilitation Health care professionals should consider HIV-related bodily pain and feelings of depression when assisting people living with HIV in inititiating and maintaining an active lifestyle. Interventions to improve self-efficacy and motivation, and to help people living with HIV in understanding the benefits of exercise, may encourage greater participation.

An exploration of barriers and facilitators to older adults' participation in higher impact physical activity and bone health: a qualitative study.

PubMed

Simmonds, B A J; Hannam, K J; Fox, K R; Tobias, J H

2016-03-01

This qualitative study explored the acceptability of high-impact physical activity for increasing bone strength in later life. Thematic analysis established the barriers and facilitators to this physical activity. They prioritised joint over skeletal health, of which they had little concept. Interventions need to clearly communicate the rationale and benefits. The aim of this study was to explore the acceptability of doing high-impact physical activity in later life. This qualitative study was embedded within a large-scale observational study and was designed to address specific objectives and feed into a subsequent intervention. Five focus groups with physically active men and women (over 50 years) were used to develop an interview topic guide to explore the acceptability of high-impact physical activity in older men and women (over 65 years) in South West England. A total of 28 semi-structured interviews with 31 participants were then conducted and transcripts analysed thematically. Three main barriers emerged: conceptualising bone, damage to joints and falling/safety concerns. Two main facilitators were also identified: the need to understand clear tangible benefits and incorporation of activity into everyday habits. Older adults were interested how high-impact physical activity would help to maintain their mobility, independence or social relationships. Some participants wanted tangible feedback from accelerometers, health care professionals and/or bone scans in order to develop a more intimate knowledge of their bone health. Interventions incorporating high-impact physical activity for older adults need to communicate how this activity can impact more broadly on health and lives; that physical activity will be safe, beneficial and not damaging to their joints will need to be clearly conveyed. Ways in which high-impact physical activity can be habitualised into everyday activities, be fun and interactive may help facilitate longer term adoption.

Perceived barriers to weight maintenance among university students in Kuwait: the role of gender and obesity.

PubMed

Musaiger, Abdulrahman O; Al-Kandari, Fawzia I; Al-Mannai, Mariam; Al-Faraj, Alaa M; Bouriki, Fajer A; Shehab, Fatima S; Al-Dabous, Lulwa A; Al-Qalaf, Wassin B

2014-05-01

To investigate the barriers to weight maintenance among university students in Kuwait by gender and obesity. A sample of 530 students was selected at convenience from four universities in Kuwait (2 public and 2 private). The age of students ranged from 19 to 26 years. A self-reported pretested questionnaire was used to obtain the barriers, which were divided into barriers to healthy eating and barriers to physical activity. Weight and height were based on self-reporting, and the students were grouped into non-obese and obese according to the WHO classification. The response options to barriers were: very important, somewhat important and not important. The main barriers to healthy eating for both genders were: "Do not have skills to plan, shop for, prepare or cook healthy foods" and "Not having time to prepare or eat healthy food". In general, there were no significant differences between men and women in barriers to healthy eating. There were highly significant differences between men and women regarding barriers to physical activity (P values ranged from <0.001 to <0.016). "Not having time to be physically active" and "The climate is not suitable for practising exercise" were the main barriers reported. Obese men were more likely to face barriers to healthy eating than non-obese men. There were no significant differences between obese and non-obese women regarding barriers to healthy eating and physical activity. The findings of this study can be utilized in intervention activities to promote a healthy lifestyle and to combat obesity in Kuwait, and maybe in other Arab countries.

Ferulic acid-coupled chitosan: thermal stability and utilization as an antioxidant for biodegradable active packaging film.

PubMed

Woranuch, Sarekha; Yoksan, Rangrong; Akashi, Mitsuru

2015-01-22

The aim of the present research was to study the thermal stability of ferulic acid after coupling onto chitosan, and the possibility of using ferulic acid-coupled chitosan (FA-CTS) as an antioxidant for biodegradable active packaging film. FA-CTS was incorporated into biodegradable film via a two-step process, i.e. compounding extrusion at temperatures up to 150°C followed by blown film extrusion at temperatures up to 175°C. Although incorporation of FA-CTS with a content of 0.02-0.16% (w/w) caused decreased water vapor barrier property and reduced extensibility, the biodegradable films possessed improved oxygen barrier property and antioxidant activity. Radical scavenging activity and reducing power of film containing FA-CTS were higher than those of film containing naked ferulic acid, by about 254% and 94%, respectively. Tensile strength and rigidity of the films were not significantly affected by the addition of FA-CTS with a content of 0.02-0.08% (w/w). The above results suggested that FA-CTS could potentially be used as an antioxidant for active packaging film. Copyright © 2014 Elsevier Ltd. All rights reserved.

The RNA-binding protein Rumpelstiltskin antagonizes gypsy chromatin insulator function in a tissue-specific manner

PubMed Central

King, Matthew R.; Matzat, Leah H.; Dale, Ryan K.; Lim, Su Jun; Lei, Elissa P.

2014-01-01

ABSTRACT Chromatin insulators are DNA–protein complexes that are situated throughout the genome that are proposed to contribute to higher-order organization and demarcation into distinct transcriptional domains. Mounting evidence in different species implicates RNA and RNA-binding proteins as regulators of chromatin insulator activities. Here, we identify the Drosophila hnRNP M homolog Rumpelstiltskin (Rump) as an antagonist of gypsy chromatin insulator enhancer-blocking and barrier activities. Despite ubiquitous expression of Rump, decreasing Rump levels leads to improvement of barrier activity only in tissues outside of the central nervous system (CNS). Furthermore, rump mutants restore insulator body localization in an insulator mutant background only in non-CNS tissues. Rump associates physically with core gypsy insulator proteins, and chromatin immunoprecipitation and sequencing analysis of Rump demonstrates extensive colocalization with a subset of insulator sites across the genome. The genome-wide binding profile and tissue specificity of Rump contrast with that of Shep, a recently identified RNA-binding protein that antagonizes gypsy insulator activity primarily in the CNS. Our findings indicate parallel roles for RNA-binding proteins in mediating tissue-specific regulation of chromatin insulator activity. PMID:24706949

[Effect of melatonin instillations on the clinical course of experimental uveitis and biochemical processes in tears and aqueous humor].

PubMed

Chesnokova, N B; Beznos, O V; Lozinskaya, N A; Beyshenova, G A; Nesterova, T V

2016-01-01

Acute immunogenic uveitis was modeled in rabbits via the subcutaneous and intravitreal injections of normal horse serum. We studied the effect of instillations of 0.1% melatonin solution on the clinical course of uveitis and biochemical parameters of tear fluid and aqueous humor: antioxi-dant activity, protein concentration and α(2)-macroglobulin level. Melatonin instillations decreased clinical manifestations of uveitis. We found that the antioxidant activity in tears of the rabbits treated with melatonin was substantially higher and the α(2)-macroglobulin level lower than in untreated animals. Antioxidant activity in aqueous humor taken on day 10 of uveitis was also twice higher while protein and α(2)-macroglobulin levels were 1.5-2 times lower than in untreated animals. These data indicate that instillations of melatonin increase the local antioxidant activity and decrease the acuity of inflammation and permeability of hematoophthalmic barrier in uveitis.

Mechanistic Insights on the Hydrogenation of α,β-Unsaturated Ketones and Aldehydes to Unsaturated Alcohols over Metal Catalysts

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

Ide, Matthew S.; Hao, Bing; Neurock, Matthew

The selective hydrogenation of unsaturated ketones (methyl vinyl ketone and benzalacetone) and unsaturated aldehydes (crotonaldehyde and cinnamaldehyde) was carried out with H₂ at 2 bar absolute over Pd/C, Pt/C, Ru/C, Au/C, Au/TiO₂, or Au/Fe₂O₃ catalysts in ethanol or water solvent at 333 K. Comparison of the turnover frequencies revealed Pd/C to be the most active hydrogenation catalyst, but the catalyst failed to produce unsaturated alcohols, indicating hydrogenation of the C=C bond was highly preferred over the C=O bond on Pd. The Pt and Ru catalysts were able to produce unsaturated alcohols from unsaturated aldehydes, but not from unsaturated ketones. Althoughmore » Au/ Fe₂O₃ was able to partially hydrogenate unsaturated ketones to unsaturated alcohols, the overall hydrogenation rate over gold was the lowest of all of the metals examined. First-principles density functional theory calculations were therefore used to explore the reactivity trends of methyl vinyl ketone (MVK) and benzalacetone (BA) hydrogenation over model Pt(111) and Ru(0001) surfaces. The observed selectivity over these metals is likely controlled by the significantly higher activation barriers to hydrogenate the C=O bond compared with those required to hydrogenate the C=C bond. Both the unsaturated alcohol and the saturated ketone, which are the primary reaction products, are strongly bound to Ru and can react further to the saturated alcohol. The lower calculated barriers for the hydrogenation steps over Pt compared with Ru account for the higher observed turnover frequencies for the hydrogenation of MVK and BA over Pt. The presence of a phenyl substituent α to the C=C bond in BA increased the barrier for C=C hydrogenation over those associated with the C=C bond in MVK; however, the increase in barriers with phenyl substitution was not adequate to reverse the selectivity trend.« less

Barriers to physical activity and restorative care for residents in long-term care: a review of the literature.

PubMed

Benjamin, Kathleen; Edwards, Nancy; Ploeg, Jenny; Legault, Frances

2014-01-01

Despite the benefits of physical activity, residents living in long-term care (LTC) are relatively sedentary. Designing successful physical activity and restorative care programs requires a good understanding of implementation barriers. A database search (2002-2013) yielded seven studies (nine articles) that met our inclusion criteria. We also reviewed 31 randomized controlled trials (RCTs) to determine if the authors explicitly discussed the barriers encountered while implementing their interventions. Eleven RCTs (13 articles) included a discussion of the barriers. Hence, a total of 18 studies (22 articles) were included in this review. Barriers occurred at resident (e.g., health status), environmental (e.g., lack of space for physical activity), and organizational (e.g., staffing and funding constraints) levels. These barriers intersect to adversely affect the physical activity of older people living in LTC. Future studies targeting physical activity interventions for residents living in LTC are needed to address these multiple levels of influence.

Comparative study on the deposition of silicon oxide permeation barrier coatings for polymers using hexamethyldisilazane (HMDSN) and hexamethyldisiloxane (HMDSO)

NASA Astrophysics Data System (ADS)

Mitschker, F.; Schücke, L.; Hoppe, Ch; Jaritz, M.; Dahlmann, R.; de los Arcos, T.; Hopmann, Ch; Grundmeier, G.; Awakowicz, P.

2018-06-01

The effect of the selection of hexamethyldisiloxane (HMDSO) and hexamethyldisilazane (HMDSN) as a precursor in a microwave driven low pressure plasma on the deposition of silicon oxide barrier coatings and silicon based organic interlayers on polyethylene terephthalate (PET) and polypropylene (PP) substrates is investigated. Mass spectrometry is used to quantify the absolute gas density and the degree of depletion of neutral precursor molecules under variation of oxygen admixture. On average, HMDSN shows a smaller density, a higher depletion and the production of smaller fragments. Subsequently, this is correlated with barrier performance and chemical structure as a function of barrier layer thickness and oxygen admixture on PET. For this purpose, the oxygen transmission rate (OTR) is measured and Fourier transformed infrared (FTIR) spectroscopy as well as x-ray photoelectron spectroscopy (XPS) is performed. HMDSN based coatings exhibit significantly higher barrier performances for high admixtures of oxygen (200 sccm). In comparison to HMDSO based processes, however, a higher supply of oxygen is necessary to achieve a sufficient degree of oxidation, cross-linking and, therefore, barrier performance. FTIR and XPS reveal a distinct carbon content for low oxygen admixtures (10 and 20 sccm) in case of HMDSN based coatings. The variation of interlayer thickness also reveals significantly higher OTR for HMDSO based coatings on PET and PP. Barrier performance of HMDSO based coatings improves with increasing interlayer thickness up to 10 nm for PET and PP. HMDSN based coatings exhibit a minimum of OTR without interlayer on PP and for 2 nm interlayer thickness on PET. Furthermore, HMDSN based coatings show distinctly higher bond strengths to the PP substrate.

Enhanced Thermionic Emission and Low 1/f Noise in Exfoliated Graphene/GaN Schottky Barrier Diode.

PubMed

Kumar, Ashutosh; Kashid, Ranjit; Ghosh, Arindam; Kumar, Vikram; Singh, Rajendra

2016-03-01

Temperature-dependent electrical transport characteristics of exfoliated graphene/GaN Schottky diodes are investigated and compared with conventional Ni/GaN Schottky diodes. The ideality factor of graphene/GaN and Ni/GaN diodes are measured to be 1.33 and 1.51, respectively, which is suggestive of comparatively higher thermionic emission current in graphene/GaN diode. The barrier height values for graphene/GaN diode obtained using thermionic emission model and Richardson plots are found to be 0.60 and 0.72 eV, respectively, which are higher than predicted barrier height ∼0.40 eV as per the Schottky-Mott model. The higher barrier height is attributed to hole doping of graphene due to graphene-Au interaction which shifts the Fermi level in graphene by ∼0.3 eV. The magnitude of flicker noise of graphene/GaN Schottky diode increases up to 175 K followed by its decrease at higher temperatures. This indicates that diffusion currents and barrier inhomogeneities dominate the electronic transport at lower and higher temperatures, respectively. The exfoliated graphene/GaN diode is found to have lower level of barrier inhomogeneities than conventional Ni/GaN diode, as well as earlier reported graphene/GaN diode fabricated using chemical vapor deposited graphene. The lesser barrier inhomogeneities in graphene/GaN diode results in lower flicker noise by 2 orders of magnitude as compared to Ni/GaN diode. Enhanced thermionic emission current, lower level of inhomogeneities, and reduced flicker noise suggests that graphene-GaN Schottky diodes may have the underlying trend for replacing metal-GaN Schottky diodes.

Perceived barriers to leisure-time physical activity during pregnancy: A literature review of quantitative and qualitative evidence.

PubMed

Coll, Carolina V N; Domingues, Marlos R; Gonçalves, Helen; Bertoldi, Andréa D

2017-01-01

Identify perceived barriers to leisure-time physical activity during pregnancy to inform future interventions aimed at improving physical activity levels in pregnancy. PubMed/Medline and Web of Science databases were systematically searched using a reference period between 1986 and January/2016. A comprehensive search strategy was developed combining the following keywords: (barriers OR constraints OR perceptions OR attitudes) AND (physical activity OR exercise OR motor activity) AND (pregnancy OR pregnant women OR antenatal OR prenatal). Thematic synthesis was conducted to analyze the data. A socioecological model was used to categorize the reported barriers. Twelve quantitative studies and 14 qualitative studies were included. Barriers belonging to the intrapersonal level of the socioecological model were the most reported in the studies and were categorized in five themes as follows: (1) Pregnancy-related symptoms and limitations; (2) Time constraints; (3) Perceptions of already being active, (4) Lack of motivation and (5) Mother-child safety concerns. At the interpersonal level, barriers were coded into two descriptive themes: (1) Lack of advice and information and (2) Lack of social support. Two other themes were used to summarize Environmental, Organizational and Policy barriers: (1) Adverse weather and (2) Lack of resources. A range of relevant barriers to leisure-time physical-activity engagement during pregnancy were identified in this literature review. Pregnancy-related symptoms and limitations barriers were the most reported in studies, regardless of study design. Mother-child safety concerns, lack of advice/information and lack of social support were also important emphasized pregnancy-related barriers to be targeted in future interventions. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Flexible plastic bioreactors for photobiological hydrogen production by hydrogenase-deficient cyanobacteria.

PubMed

Kitashima, Masaharu; Masukawa, Hajime; Sakurai, Hidehiro; Inoue, Kazuhito

2012-01-01

Uptake hydrogenase mutant cells of the cyanobacterium Nostoc sp. PCC 7422 photobiologically produced H(2) catalyzed by nitrogenase for several days in H(2)-barrier transparent plastic bags, and accumulated H(2) in the presence of O(2) evolved by photosynthesis. Their H(2) production activity was higher in the sealed flexible bags than in stoppered serum bottles of fixed gas volume.

Factors Related to Healthy Diet and Physical Activity in Hospital-Based Clinical Nurses.

PubMed

Albert, Nancy M; Butler, Robert; Sorrell, Jeanne

2014-09-30

Hospitals often promote healthy lifestyles, but little is known about nurses' actual diet and physical activity. Greater understanding about these lifestyle choices for clinical nurses may improve existing hospital-based programs and/or create desirable services. This article discusses a study that considered diet and physical activity of clinical nurses, using elements of Pender's self-care theory as a conceptual framework. Study methods included a cross-sectional, correlational design and a convenience sample of 278 nurses who worked on units with 24 hours/day and seven days-per-week responsibilities. Participants completed diet and exercise questionnaires about perceptions of attitudes and opinions, barriers, diet benefits/exercise motivators, self-efficacy, and locus of control, and personal and work characteristics. Diet and activity categories were created. Study results demonstrated that over 50% of nurses had moderately healthy diets but were insufficiently active. Healthy diet and physical activity levels were associated with higher self-efficacy, more diet benefits and physical activity motivators, fewer perceived barriers, and confidence in body image. The article discussion and conclusion sections note areas for future research and suggest that focused interventions that address benefits, motivators, and self-efficacy may increase participation in hospital-based programs and enhance healthy lifestyle for hospital-based clinical nurses.

Work-related barriers, facilitators, and strategies of breast cancer survivors working during curative treatment.

PubMed

Sun, Wenjun; Chen, Karen; Terhaar, Abigail; Wiegmann, Douglas A; Heidrich, Susan M; Tevaarwerk, Amye J; Sesto, Mary E

2016-01-01

Research has identified barriers and facilitators affecting cancer survivors' return to work (RTW) following the end of active treatment (surgery, chemotherapy and/or radiation therapy). However, few studies have focused on barriers and facilitators that cancer survivors experience while working during active treatment. Strategies used by cancer survivors to solve work-related problems during active treatment are underexplored. The aim of this study was to describe factors that impact, either positively or negatively, breast cancer survivors' work activities during active treatment. Semi-structured, recorded interviews were conducted with 35 breast cancer survivors who worked during active treatment. Transcripts of interviews were analyzed using inductive content analysis to identify themes regarding work-related barriers, facilitators and strategies. Barriers identified included symptoms, emotional distress, appearance change, time constraints, work characteristics, unsupportive supervisors and coworkers, family issues and other illness. Facilitators included positive aspects of work, support outside of work, and coworker and supervisor support. Strategies included activities to improve health-related issues and changes to working conditions and tasks. Breast cancer survivors encounter various barriers during active treatment. Several facilitators and strategies can help survivors maintain productive work activities.

Work-related barriers, facilitators, and strategies of breast cancer survivors working during curative treatment

PubMed Central

Sun, Wenjun; Chen, Karen; Terhaar, Abigail; Wiegmann, Douglas A.; Heidrich, Susan M.; Tevaarwerk, Amye J.; Sesto, Mary E.

2017-01-01

BACKGROUND Research has identified barriers and facilitators affecting cancer survivors’ return to work (RTW) following the end of active treatment (surgery, chemotherapy and/or radiation therapy). However, few studies have focused on barriers and facilitators that cancer survivors experience while working during active treatment. Strategies used by cancer survivors to solve work-related problems during active treatment are underexplored. OBJECTIVE The aim of this study was to describe factors that impact, either positively or negatively, breast cancer survivors’ work activities during active treatment. METHODS Semi-structured, recorded interviews were conducted with 35 breast cancer survivors who worked during active treatment. Transcripts of interviews were analyzed using inductive content analysis to identify themes regarding work-related barriers, facilitators and strategies. RESULTS Barriers identified included symptoms, emotional distress, appearance change, time constraints, work characteristics, unsupportive supervisors and coworkers, family issues and other illness. Facilitators included positive aspects of work, support outside of work, and coworker and supervisor support. Strategies included activities to improve health-related issues and changes to working conditions and tasks. CONCLUSIONS Breast cancer survivors encounter various barriers during active treatment. Several facilitators and strategies can help survivors maintain productive work activities. PMID:28059814

Cultural Barriers to Change in Assessment Practices in Higher Education

ERIC Educational Resources Information Center

Jenkins, Deborah Bainer

2007-01-01

The culture at the authors' institution raised barriers to changing from traditional assessment to portfolio assessment in the doctoral program. A Culture of Independence presented barriers of time and functional inadequacy. A Culture of Compliance raised trust, group process, and membership issues. These barriers were managed and overcome using…

Perceived barriers to and facilitators of physical activity in young adults with childhood-onset physical disabilities.

PubMed

Buffart, Laurien M; Westendorp, Tessa; van den Berg-Emons, Rita J; Stam, Henk J; Roebroeck, Marij E

2009-11-01

To explore the main barriers to and facilitators of physical activity in young adults with childhood-onset physical disabilities. Qualitative study using focus groups. Sixteen persons (12 men and 4 women) aged 22.4 (standard deviation 3.4) years, of whom 50% were wheelchair-dependent, participated in the study. Eight were diagnosed with myelomeningocele, 4 with cerebral palsy, 2 with acquired brain injury and 2 with rheumatoid arthritis. Three focus group sessions of 1.5 h were conducted using a semi-structured question route to assess perceived barriers to and facilitators of physical activity. Tape recordings were transcribed verbatim and content analysed. According to the Physical Activity for People with a Physical Disability model, barriers and facilitators were subdivided into personal factors and environmental factors. Participants reported several barriers related to attitude and motivation. In addition, lack of energy, existing injury or fear of developing injuries or complications, limited physical activity facilities, and lack of information and knowledge, appeared to be barriers to physical activity. Fun and social contacts were mentioned as facilitators of engaging in physical activity, as well as improved health and fitness. Young adults with childhood-onset physical disabilities perceived various personal and environmental factors as barriers to or facilitators of physical activity. These should be taken into account when developing interventions to promote physical activity in this population.

Response of Phase Transformation Inducing Heat Treatments on Microstructure and Mechanical Properties of Reduced Activation Ferritic-Martensitic Steels of Varying Tungsten Contents

NASA Astrophysics Data System (ADS)

Chandravathi, K. S.; Laha, Kinkar; Sasmal, C. S.; Parameswaran, P.; Nandagopal, M.; Tailor, H. M.; Mathew, M. D.; Jayakumar, T.; Rajendra Kumar, E.

2014-09-01

Microstructure and mechanical properties of 9Cr-W-0.06Ta Reduced Activation Ferritic-Martensitic (RAFM) steels having various tungsten contents ranging from 1 to 2 wt pct have been investigated on subjecting the steels to isothermal heat treatments for 5 minutes at temperatures ranging from 973 K to 1473 K (700 °C to 1200 °C) (below Ac1 to above Ac3) followed by oil quenching and tempering at 1033 K (760 °C) for 60 minutes. The steels possessed tempered martensite structure at all the heat-treated conditions. Prior-austenitic grain size of the steels was found to decrease on heating in the intercritical temperature range (between Ac1 and Ac3) and at temperatures just above the Ac3 followed by increase at higher heating temperatures. All the steels suffered significant reduction in hardness, tensile, and creep strength on heating in the intercritical temperature range, and the reduction was less for steel having higher tungsten content. Strength of the steels increased on heating above Ac3 and was higher for higher tungsten content. Transmission Electron Microscopy (TEM) investigations of the steels revealed coarsening of martensitic substructure and precipitates on heating in the intercritical temperature range, and the coarsening was relatively less for higher tungsten content steel, resulting in less reduction in tensile and creep strength on intercritical heating. Tensile and creep strengths of the steels at different microstructural conditions have been rationalized based on the estimated inter-barrier spacing to dislocation motion. The study revealed the uniqueness of inter-barrier spacing to dislocation motion in determining the strength of tempered martensitic steels subjected to different heat treatments.

Room temperature negative differential resistance in terahertz quantum cascade laser structures

DOE PAGES

Albo, Asaf; Hu, Qing; Reno, John L.

2016-08-24

The mechanisms that limit the temperature performance of GaAs/Al 0.15GaAs-based terahertz quantum cascade lasers (THz-QCLs) have been identified as thermally activated LO-phonon scattering and leakage of charge carriers into the continuum. Consequently, the combination of highly diagonal optical transition and higher barriers should significantly reduce the adverse effects of both mechanisms and lead to improved temperature performance. Here, we study the temperature performance of highly diagonal THz-QCLs with high barriers. Our analysis uncovers an additional leakage channel which is the thermal excitation of carriers into bounded higher energy levels, rather than the escape into the continuum. Based on this understanding,more » we have designed a structure with an increased intersubband spacing between the upper lasing level and excited states in a highly diagonal THz-QCL, which exhibits negative differential resistance even at room temperature. Furthermore, this result is a strong evidence for the effective suppression of the aforementioned leakage channel.« less

Best Practices and Barriers to Obesity Prevention in Head Start: Differences Between Director and Teacher Perceptions.

PubMed

Byrd-Williams, Courtney; Dooley, Erin E; Sharma, Shreela V; Chuang, Ru-Jye; Butte, Nancy; Hoelscher, Deanna M

2017-12-21

Practices and barriers to promoting healthy eating and physical activity at Head Start centers may influence children's energy balance behaviors. We examined differences between directors' and teachers' perspectives on best practices and barriers to promoting healthy eating and physical activity in Head Start centers. We conducted a cross-sectional study of directors (n = 23) and teachers (n = 113) at 23 Head Start centers participating in the baseline assessment of the Texas Childhood Obesity Research Demonstration study. Participants completed surveys about practices and barriers to promoting healthy eating and physical activity. Multilevel regression models examined differences between director and teacher responses. More than half of directors and teachers reported meeting most best practices related to nutrition and physical activity; few directors or teachers (<25%) reported conducting physical activity for more than 60 minutes a day, and less than 40% of teachers helped children attend to satiety cues. Significantly more directors than teachers reported meeting 2 nutrition-related best practices: "Teachers rarely eat less healthy foods (especially sweets, salty snacks, and sugary drinks) in front of children" and "Teachers talk to children about trying/enjoying new foods" (P < .05). No barrier to healthy eating or physical activity was reported by more than 25% of directors or teachers. Significantly more teachers than directors reported barriers to healthy eating, citing lack of food service staff support, limited time, and insufficient funds (P < .05). More barriers to healthy eating were reported than were barriers to physical activity indicating that more support may be needed for healthy eating. Differences between responses of directors and teachers may have implications for future assessments of implementation of best practices and barriers to implementation related to nutrition and physical activity in early care and education centers.

Barriers Affecting Physical Activity in Rural Communities: Perceptions of Parents and Children

ERIC Educational Resources Information Center

McWhinney, Sharon; McDonald, Andrea; Dawkins-Moultin, Lenna; Outley, Corliss; McKyer, E. Lisako; Thomas, Audrene

2011-01-01

A comprehensive understanding of the barriers inhibiting physical activity among children is critical in the fight against childhood obesity. This qualitative interview study examined parents' and children's perceptions of the barriers to physical activity in rural communities of low socioeconomic status. Parents and children concurred that the…

Barriers and Facilitators to Being Physically Active on a Rural U.S. Northern Plains American Indian Reservation

PubMed Central

Jahns, Lisa; McDonald, Leander R.; Wadsworth, Ann; Morin, Charles; Liu, Yan

2014-01-01

The objective of the present study was to identify barriers to and facilitators of physical activity among American Indian adults living on a rural, U.S. Northern Plains reservation using the nominal group technique (NGT). NGT is a method of data generation and interpretation that combines aspects of qualitative (free generation of responses) and quantitative (systematic ranking of responses) methodologies. Adults participated in one of two NGT sessions asking about either barriers to (n = 6), or facilitators of (n = 5), being physically active. Participants nominated and ranked 21 barriers and 18 facilitators. Barriers indicated lack of knowledge of how to fit physical activity into a daily schedule, work, caring for family members, and prioritizing sedentary pursuits. Other responses included environmental barriers such as lack of access and transportation to a gym, unsafe walking conditions, and inclement weather. Facilitators to following recommendations included knowledge of health benefits of physical activity and the perception of physical activity as enjoyable, including feeling good when working out. Environmental facilitators included being outdoors walking and biking as well as parks and exercise facilities. Responses provided direction for locally designed community-based programs to promote facilitators and decrease barriers to individual’s engagement in physical activity. PMID:25421064

Barriers and facilitators to being physically active on a rural U.S. Northern Plains American Indian reservation.

PubMed

Jahns, Lisa; McDonald, Leander R; Wadsworth, Ann; Morin, Charles; Liu, Yan

2014-11-21

The objective of the present study was to identify barriers to and facilitators of physical activity among American Indian adults living on a rural, U.S. Northern Plains reservation using the nominal group technique (NGT). NGT is a method of data generation and interpretation that combines aspects of qualitative (free generation of responses) and quantitative (systematic ranking of responses) methodologies. Adults participated in one of two NGT sessions asking about either barriers to (n = 6), or facilitators of (n = 5), being physically active. Participants nominated and ranked 21 barriers and 18 facilitators. Barriers indicated lack of knowledge of how to fit physical activity into a daily schedule, work, caring for family members, and prioritizing sedentary pursuits. Other responses included environmental barriers such as lack of access and transportation to a gym, unsafe walking conditions, and inclement weather. Facilitators to following recommendations included knowledge of health benefits of physical activity and the perception of physical activity as enjoyable, including feeling good when working out. Environmental facilitators included being outdoors walking and biking as well as parks and exercise facilities. Responses provided direction for locally designed community-based programs to promote facilitators and decrease barriers to individual's engagement in physical activity.

Biological and Sociocultural Differences in Perceived Barriers to Physical Activity among 5th–7th Grade Urban Girls

PubMed Central

Vermeesch, Amber L.; Ling, Jiying; Voskuil, Vicki R.; Bakhoya, Marion; Wesolek, Stacey M.; Bourne, Kelly A.; Pfeiffer, Karin A.; Robbins, Lorraine B.

2015-01-01

Background Inadequate physical activity (PA) contributes to the high prevalence of overweight and obesity among U.S. adolescent girls. Barriers preventing adolescent girls from meeting PA guidelines have not been thoroughly examined. Objectives The threefold purpose of this study was to: (a) determine pubertal stage, racial/ethnic, and socioeconomic status (SES) differences in ratings of interference of barriers to PA; (b) examine relationships between perceived barriers and age, body mass index (BMI), recreational screen time, sedentary activity, and PA; and (c) identify girls’ top-rated perceived barriers to PA. Methods Girls (N = 509) from eight Midwestern U.S. schools participated. Demographic, pubertal stage, perceived barriers, and recreational screen time data were collected via surveys. Height and weight were measured. Accelerometers measured sedentary activity, moderate-to-vigorous physical activity (MVPA), and light plus MVPA. Results Girls of low SES reported greater interference of perceived barriers to PA than those who were not of low SES (1.16 vs. 0.97, p = .01). Girls in early/middle puberty had lower perceived barriers than those in late puberty (1.03 vs. 1.24, p < .001). Girls’ perceived barriers were negatively related to MVPA (r = −.10, p = .03) and light plus MVPA (r = −.11, p = .02). Girls’ top five perceived barriers included lack of skills, hating to sweat, difficulty finding programs, being tired, and having pain. Discussion Innovative interventions, particularly focusing on skill development, are needed to assist girls in overcoming their perceived barriers to PA. PMID:26325276

Perceived barriers and facilitators to physical activity in men with prostate cancer: possible influence of androgen deprivation therapy.

PubMed

Keogh, J W L; Patel, A; MacLeod, R D; Masters, J

2014-03-01

While physical activity is beneficial for men with prostate cancer, too few perform sufficient activity for such benefit. This study examined perceptions of men with prostate cancer of their barriers and facilitators to physical activity, and how androgen deprivation therapy (ADT) may influence these perceptions. Two focus groups were conducted, involving six ADT and eight non-ADT patients respectively. Data were transcribed verbatim and themes developed using a general inductive thematic approach. Facilitators to physical activity common to both groups of cancer survivors included clinician and spousal involvement, with pre-existing co-morbidities and increased age cited as barriers by both groups. The ADT subgroup cited personal involvement as a facilitator to physical activity, with fatigue, reduced motivation and a relative lack of specific advice from their clinician as additional barriers. The non-ADT subgroup had no additional facilitators to physical activity but cited time constraints as a barrier. These results highlight the important role that cancer clinicians and spouses play in promoting physical activity for men with prostate cancer and how ADT may influence their other facilitators and barriers. As physical activity is beneficial for prostate cancer survivors, especially those on ADT, cancer clinicians should regularly discuss physical activity with their patients. © 2013 John Wiley & Sons Ltd.

Yes I Need Help! A Day in the Journey of Adult Learners Pursuing Higher Education: A Caribbean Perspective

ERIC Educational Resources Information Center

Hunter-Johnson, Yvonne; Smith, Sharlene

2015-01-01

Within more recent years, there has been a gravitation of non-traditional adult learners to higher education. Despite the motivational factors associated with this decision, it is evident that compared to the traditional learner, the non-traditional learner journey in higher education is equipped with numerous barriers. Such barriers can hinder or…

Comfort and microbial barrier properties of garments worn next to the skin

NASA Astrophysics Data System (ADS)

Kopitar, D.; Rogina-Car, B.; Skenderi, Z.

2017-10-01

Compared with viscose fibre, modal fibre is characterized by some advantageous properties such as higher dry and wet tenacities, higher wet modulus, lower water retention capacity and lower level of swelling. Impact of different knitted fabric structure made of cotton and 97 % CMD/3 % EL fibres on thermo-physiological comfort and microbial barrier properties were investigated. All knitted fabrics have very good physiological properties. The microbial barrier permeability of knitted fabric after extreme contamination with bacterial spores in dry state showed that double jersey offered more effective microbial barrier than the single jersey knitted fabrics respectively the greater thickness of double jersey knitted fabric provide more difficult barrier to bacterial spores to pass. In wet state all knitted fabrics have more effective microbial barrier which could be explained by cellulose fibres swelling. In wet state 97 % CMD/3 % EL single jersey knitted fabric have more effective microbial barrier then cotton double and single jersey knitted fabrics.

Aryl nitrene rearrangements: spectroscopic observation of a benzazirine and its ring expansion to a ketenimine by heavy-atom tunneling.

PubMed

Inui, Hiroshi; Sawada, Kazuhiro; Oishi, Shigero; Ushida, Kiminori; McMahon, Robert J

2013-07-17

In the photodecompositions of 4-methoxyphenyl azide (1) and 4-methylthiophenyl azide (5) in argon matrixes at cryogenic temperatures, benzazirine intermediates were identified on the basis of IR spectra. As expected, the benzazirines photochemically rearranged to the corresponding ketenimines and triplet nitrenes. Interestingly, with the methylthio substituent, the rearrangement of benzazirine 8 to ketenimine 7 occurred at 1.49 × 10(-5) s(-1) even in the dark at 10 K, despite a computed activation barrier of 3.4 kcal mol(-1). Because this rate is 10(57) times higher than that calculated for passing over the barrier and because it shows no temperature dependence, the rearrangement mechanism is interpreted in terms of heavy-atom tunneling.

Quantitative data analysis of perceived barriers and motivators to physical activity in stroke survivors.

PubMed

Nicholson, S L; Greig, C A; Sniehotta, F; Johnston, M; Lewis, S J; McMurdo, M E; Johnston, D; Scopes, J; Mead, G E

2017-09-01

Levels of physical activity after stroke are low, despite multiple health benefits. We explored stroke survivors' perceived barriers, motivators, self-efficacy and intention to physical activity. Fifty independently mobile stroke survivors were recruited prior to hospital discharge. Participants rated nine possible motivators and four possible barriers based on the Mutrie Scale, as having 'no influence', 'some influence' or 'a major influence' on physical activity. Participants also rated their self-efficacy and intention to increasing walking. The most common motivator was 'physical activity is good for health' [34 (68%)]. The most common barrier was 'feeling too tired' [24 (48%)]. Intention and self-efficacy were high. Self-efficacy was graded as either 4 or 5 (highly confident) on a five-point scale by [34 (68%)] participants, while 42 (84%) 'strongly agreed' or 'agreed' that they intended to increase their walking. Participants felt capable of increasing physical activity but fatigue was often perceived as a barrier to physical activity. This needs to be considered when encouraging stroke survivors to be more active.

Understanding barriers and facilitators to healthy eating and physical activity from patients either before and after knee arthroplasty.

PubMed

Pellegrini, Christine A; Ledford, Gwendolyn; Chang, Rowland W; Cameron, Kenzie A

2017-05-05

We sought to identify patient-reported barriers and facilitators to healthy eating and physical activity among patients before or after knee arthroplasty. Twenty patients with knee osteoarthritis aged 40-79 years who had knee arthroplasty surgery scheduled or completed within 3 months were interviewed. Interview topics included perceived barriers and facilitators to healthy eating and activity before or after surgery. Interviews were coded and analyzed using constant comparative analysis. Interviews were completed with 11 pre-operative (67.1 ± 7.6 years, 45.5% female, BMI 31.2 ± 6.3) and nine post-operative patients (61.7 ± 11.7 years, 44.4% female, BMI 30.2 ± 4.7 kg/m 2 ). The most commonly identified personal barriers to healthy eating identified were desire for high-fat/high-calorie foods, managing overconsumption and mood. Factors related to planning, portion control and motivation to improve health were identified as healthy eating facilitators. Identified personal barriers for activity included pain, physical limitations and lack of motivation, whereas facilitators included having motivation to improve knee symptoms/outcomes, personal commitment to activity and monitoring activity levels. Identifying specific eating and activity barriers and facilitators, such as mood and motivation to improve outcomes, provides critical insight from the patient perspective, which will aid in developing weight management programs during rehabilitation for knee arthroplasty patients. Implications for rehabilitation This study provides insight into the identified barriers and facilitators to healthy eating and physical activity in knee arthroplasty patients, both before and after surgery. Intrapersonal barriers that may hinder engagement in physical activity and rehabilitation include pain, physical limitations and lack of motivation; factors that may help to improve activity and the rehabilitation process include being motivated to improve knee outcomes, having a personal commitment to activity and tracking activity levels. Barriers that may interfere with healthy eating behaviors and knee arthroplasty rehabilitation include the desire for high-fat/high-calorie foods, overeating and mood; whereas planning and portion control may help to facilitate healthy eating. Understanding barriers and facilitators to healthy eating and physical activity can help guide rehabilitation professionals with their discussions on weight management with patients who had or are contemplating knee arthroplasty.

Barriers to Taking Massive Open Online Courses (MOOCs)

ERIC Educational Resources Information Center

Semenova, Tatiana Vadimovna; Rudakova, Lyudmila Mikhailovna

2016-01-01

Researchers of the traditional higher education system identify a number of factors affecting admission to a university (barriers to entry) and factors of its successful completion (barriers to exit). Massive open online courses (MOOCs), available to any Internet user, remove barriers to entry because anyone can study there. But do all students…

“My hair or my health”: Overcoming Barriers to Physical Activity in African American women with a focus on hairstyle-related factors

PubMed Central

Huebschmann, Amy G.; Campbell, Lucille Johnson; Brown, Candace S.; Dunn, Andrea L.

2016-01-01

Physical activity disparities among African American (AA) women may be related to sociocultural barriers, including difficulties with restyling hair after exercise. We sought to identify physical activity barriers and facilitators in AA women with a focus on sociocultural factors related to hairstyle maintenance. Participants (n=51) were AA women aged 19–73 years who completed valid surveys and participated in structured focus groups, stratified by age and physical activity levels, from 11/2012 to 2/2013. The Constant Comparison method was used to develop qualitative themes for barriers and facilitators. The most frequently reported general physical activity barrier among exercisers was “lack of money” (27%) and among non-exercisers was “lack of self-discipline” (57%). A hairstyle-related barrier of “sweating out my hairstyle,” was reported by 7% of exercisers and 29% of non-exercisers. This hairstyle-related barrier included the need for extra time and money to restyle hair due to perspiration. Hairstyle-related facilitators included: prioritizing health over hairstyle and high self-efficacy to restyle hair after perspiration. Participants were interested in resources to simplify hairstyle maintenance. AA women whose hairstyle is affected by perspiration may avoid physical activity due to time and financial burdens. Increasing self-efficacy to restyle hair after perspiration may help to overcome this barrier. PMID:26495938

Effect of starch type on the physico-chemical properties of edible films.

PubMed

Basiak, Ewelina; Lenart, Andrzej; Debeaufort, Frédéric

2017-05-01

Food preservation is mostly related to packaging in oil-based plastics, inducing environmental problems, but this drawback could be limited by using edible/biodegradable films and coatings. Physical and chemical properties were assessed and reflect the role of the starch type (wheat, corn or potato) and thus that of the amylose/amylopectin ratio, which influences thickness, colour, moisture, wettability, thermal, surface and mechanical properties. Higher amylose content in films induces higher moisture sensitivity, and thus affects the mechanical and barrier properties. Films made from potato starch constitute a greater barrier for oxygen and water vapour though they have weaker mechanical properties than wheat and corn starch films. Starch species with higher amylose content have lower wettability properties, and better mechanical resistance, which strongly depends on the water content due to the hydrophilic nature of starch films, so they could be used for products with higher water activity, such as cheese, fruits and vegetables. It especially concerns wheat starch systems, and the contact angle indicates less hydrophilic surfaces (above 90°) than those of corn and potato starch films (below 90°). The starch origin influences optical properties and thickness: with more amylose, films are opalescent and thicker; with less, they are transparent and thinner. Copyright © 2017 Elsevier B.V. All rights reserved.

Barriers to delivering extracurricular school sport and physical activity in Wales: a qualitative study of 5x60 officers' views and perspectives.

PubMed

Rainer, Paul; Griffiths, Robert; Cropley, Brendan; Jarvis, Stuart

2015-02-01

In light of recent reports, schools must be realistic in that physical activity recommendations cannot be met through curriculum PE alone. However, extracurricular PE and school sport has the potential to further promote physical activity in adolescents. Consequently, the Welsh Government, UK, proposed through its Climbing Higher strategy (2006) for secondary school children to achieve 60 minutes of physical activity a day. This was implemented through Sport Wales and the 5×60 scheme. This study aimed to examine the experiences of the 5×60 officers responsible for implementing the program, with a view to gain an understanding of the barriers associated with increasing participation in physical activity. Officers from 14 unitary authorities across Wales were interviewed using a socioecological approach that considered the impact of: personal behaviors, physical environment, social environment, and policy. Participants reported a number of challenges affecting the delivery of the program, including: availability of facilities, lack of support from senior management, time, and conflict with PE staff. This study suggests that current methods used by personnel to facilitate extracurricular school sport may not be the most appropriate, and future direction should consider the place and contribution of physical activity to young people's lives.

Why do kids eat healthful food? Perceived benefits of and barriers to healthful eating and physical activity among children and adolescents.

PubMed

O'dea, Jennifer A

2003-04-01

The goal was to have children and adolescents identify and rank the major perceived benefits of and barriers to healthful eating and physical activity and to suggest strategies for overcoming barriers. Semistructured, in-depth focus groups were undertaken using standardized questions and prompts. Students in grades 2 through 11(ages 7 through 17; N=213) from 34 randomly selected schools participated in 38 focus groups. Major benefits of healthful eating included improvements to cognitive and physical performance, fitness, endurance, psychological benefits, physical sensation (feeling good physically), and production of energy. Barriers included convenience, taste, and social factors. Benefits of physical activity included social benefits, enhancement of psychological status, physical sensation, and sports performance. Barriers included a preference for indoor activities, lack of energy and motivation, time constraints, and social factors. Suggested strategies for overcoming barriers included support from parents and school staff, better planning, time management, self-motivation, education, restructuring the physical environment, and greater variety of physical activities.

[Perceived barriers to active commuting to school: reliability and validity of a scale].

PubMed

Molina-García, Javier; Queralt, Ana; Estevan, Isaac; Álvarez, Octavio; Castillo, Isabel

To examine the reliability and validity of a scale to measure perceived barriers to active commuting to school among Spanish young people. The validity of the scale was assessed in a sample of 465 adolescents (14-18 years) using a confirmatory factor analysis and studying its association with self-reported active commuting to school. The reliability of the instrument was evaluated in a sub-sample that completed the scale twice separated by a one-week interval. The results showed that the barriers scale had satisfactory fit indices, and two factors were determined. The first included environment- and safety-related items (α=0.72), while the other concerned planning and psychosocial items (α=0.64). Active commuting to school showed significant correlations with the total score of the barriers scale (rho=-0.27; p <0.001), with the environmental/safety barriers (rho=-0.22; p <0.001), as well as with the planning/psychosocial barriers (rho=-0.29; p <0.001). Test-retest ICCs for the barriers ranged from 0.68 to 0.77. The developed scale has acceptable validity and good reliability to assess barriers to active commuting to school among Spanish young people. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Gender comparisons of perceived benefits of and barriers to physical activity in middle school youth.

PubMed

Robbins, Lorraine B; Sikorskii, Alla; Hamel, Lauren M; Wu, Tsu-Yin; Wilbur, JoEllen

2009-04-01

Perceived benefits of and barriers to physical activity (PA) reported by 206 middle school boys and girls in a survey were compared. Only "take care of myself, stay in shape, and be healthier" emerged as a greater benefit for girls than boys. Among students not on a sports team, boys reported fewer barriers than girls. Among those selecting an active pursuit, boys perceived more barriers than girls. When controlling for sports team participation and perceived benefits and barriers, boys reported more minutes of vigorous PA than girls. As boys and girls reported relatively similar benefits of and barriers to PA, nurse counseling with both groups can focus on the same information. Effort is particularly needed to increase PA among girls.

A cluster expansion model for predicting activation barrier of atomic processes

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

Rehman, Tafizur; Jaipal, M.; Chatterjee, Abhijit, E-mail: achatter@iitk.ac.in

2013-06-15

We introduce a procedure based on cluster expansion models for predicting the activation barrier of atomic processes encountered while studying the dynamics of a material system using the kinetic Monte Carlo (KMC) method. Starting with an interatomic potential description, a mathematical derivation is presented to show that the local environment dependence of the activation barrier can be captured using cluster interaction models. Next, we develop a systematic procedure for training the cluster interaction model on-the-fly, which involves: (i) obtaining activation barriers for handful local environments using nudged elastic band (NEB) calculations, (ii) identifying the local environment by analyzing the NEBmore » results, and (iii) estimating the cluster interaction model parameters from the activation barrier data. Once a cluster expansion model has been trained, it is used to predict activation barriers without requiring any additional NEB calculations. Numerical studies are performed to validate the cluster expansion model by studying hop processes in Ag/Ag(100). We show that the use of cluster expansion model with KMC enables efficient generation of an accurate process rate catalog.« less

Perceived barriers and benefits to physical activity in colorectal cancer patients.

PubMed

Fisher, Abigail; Wardle, J; Beeken, R J; Croker, H; Williams, K; Grimmett, C

2016-02-01

There is emerging evidence for the benefits of physical activity (PA) post-diagnosis for colorectal cancer (CRC) survivors. However, population studies suggest activity levels in these patients are very low. Understanding perceived barriers and benefits to activity is a crucial step in designing effective interventions. Patients who were between 6 months and 5 years post-diagnosis with non-metastasised disease were identified from five London (UK) hospitals. Four hundred and ninety five completed a lifestyle survey that included open-ended questions on their perceived barriers (what things would stop you from doing more physical activity?) and benefits (what do you think you would gain from doing more physical activity?). Patients also recorded their activity levels using the Godin Leisure Time Exercise Questionnaire, along with sociodemographic and treatment variables. The most commonly reported barriers related to cancer and its treatments (e.g. fatigue). Age and mobility-related comorbidities (e.g. impaired mobility) were also frequently cited. Those who reported age and mobility as barriers, or reported any barrier, were significantly less active even after adjustment for multiple confounders. The most frequently reported benefits were physiological (e.g. improving health and fitness). Cancer-related benefits (such as prevention of recurrence) were rarely reported. Those perceiving physiological benefits or perceiving any benefits were more active in unadjusted models, but associations were not significant in adjusted models. We have identified important barriers and facilitators in CRC survivors that will aid in the design of theory-based PA interventions.

Sun-Induced Changes in Stratum Corneum Function Are Gender and Dose Dependent in a Chinese Population

PubMed Central

Liu, Z.; Fluhr, J.W.; Song, S.P.; Sun, Z.; Wang, H.; Shi, Y.J.; Elias, P.M.; Man, M.-Q.

2010-01-01

Previous studies have demonstrated that UVB radiation changes the epidermal permeability barrier and stratum corneum (SC) hydration. It is well known that sun exposure causes erythema, sunburn and melanoma. However, whether daily sun exposure alters SC integrity and epidermal permeability barrier function is largely unknown, especially in Chinese subjects. In the present study, we assess the SC integrity, SC hydration and epidermal permeability barrier function following various doses of sun exposure. A total of 258 subjects (124 males and 134 females) aged 18–50 years were enrolled. A multifunctional skin physiology monitor (Courage & Khazaka MPA5) was used to measure SC hydration and transepidermal water loss (TEWL) on the forearms. In males, basal TEWL was higher with higher doses of sun exposure than with lower doses and control, whereas in females, basal TEWL was higher with lower doses of sun exposure than with higher doses and control. In the group with higher doses of sun exposure, TEWL in females was significantly lower than that in males. The barrier recovery was faster in females than in males in both control and lower-dose groups. In both males and females, barrier recovery was delayed with higher doses of sun exposure. In males, sun exposure did not alter SC hydration, while in females SC hydration was lower with lower doses of sun exposure as compared with control and higher doses of sun exposure. These results demonstrated that sun-induced changes in SC function and SC hydration vary with gender and the extent of sun exposure. PMID:20571289

Barriers to physical activity in chronic hemodialysis patients: a single-center pilot study in an Italian dialysis facility.

PubMed

Fiaccadori, Enrico; Sabatino, Alice; Schito, Franco; Angella, Francesca; Malagoli, Martina; Tucci, Marco; Cupisti, Adamasco; Capitanini, Alessandro; Regolisti, Giuseppe

2014-01-01

In patients on chronic dialysis a sedentary lifestyle is a strong, yet potentially modifiable, predictor of mortality. The present single-center pilot study evaluated social, psychological and clinical barriers that may hinder physical activity in this population. We explored the association between barriers to physical activity and sedentarism in adult patients at a chronic dialysis facility in Parma, Italy. We used different questionnaries exploring participation in physical activity, physical functioning, patient attitudes and preferences, and barriers to physical activity perceived by either patients or dialysis doctors and nurses. We enrolled 104 patients, (67 males, 65%), mean age 69 years (79% of patients older than 60 years); median dialysis vintage 60 months (range 8-440); mean Charlson score 5.55, ADL (Activities of Daily Living) score 5.5. Ninety-two participants (88.5%) reported at least one barrier to physical activity. At multivariable analysis, after adjusting for age and sex, feeling to have too many medical problems (OR 2.99, 95% CI 1.27 to 7.07; P=0.012), chest pain (OR 10.78, 95% CI 1.28 to 90.28; P=0.029) and sadness (OR 2.59, 95% CI 1.10 to 6.09; P=0.030) were independently associated with physical inactivity. Lack of time for exercise counseling and the firm belief about low compliance/interest by the patients toward exercise were the most frequent barriers reported by doctors and nurses. We identified a number of patient-related and health personnel-related barriers to physical activity in patients on chronic dialysis. Solutions for these barriers should be addressed in future studies aimed at increasing the level of physical activity in this population. © 2014 S. Karger AG, Basel.

Therapeutic effect of Tripterygium wilfordii Hook F multiglycosides on gut barrier dysfunction in rats with acute necrotizing pancreatitis.

PubMed

Wang, Jie; Wu, Gang; Ma, Baojin; Wu, Jianhua; Cai, Duan

2013-02-01

The aim of the current study was to investigate the therapeutic effect of Tripterygium wilfordii Hook F multiglycosides (TWG) on gut barrier dysfunction in rats with acute necrotizing pancreatitis (ANP). ANP was induced in rats using 3.5% sodium taurocholate. The rats were divided into 3 groups: the sham operation (SO), ANP and ANP+TWG groups. Biochemical and pathological change of pancreatic tissue and ileal mucosa, bacterial cultures and the survival rate were measured following surgery and treatment. TWG treatment significantly decreased amylase and lipase activities and plasma endotoxin and D-lactate levels. Edema and inflammation in the pancreas and ileal mucosa were alleviated. Positive bacterial cultures were significantly reduced. The survival rate of the rats in the ANP+TWG group was higher than that of the rats in the ANP group. TWG treatment showed beneficial effects by protecting the pancreas from bacterial infection caused by gut barrier dysfunction and improving the outcomes of the rats with ANP.

Determinants of physical activity in primary school students using the health belief model.

PubMed

Ar-Yuwat, Sireewat; Clark, Mary Jo; Hunter, Anita; James, Kathy S

2013-01-01

Thailand is a middle-income country in which two-thirds of children demonstrate an insufficient level of physical activity. Physical inactivity is a major risk factor for obesity and many other health-related consequences in children. Thus, it is important to understand how primary school children perceive things in their daily life as determinants of physical activity. The purpose of this study was to investigate the impact of cues, perceived benefits, and perceived barriers on the level of physical activity among primary school students. A cross-sectional study was conducted in Phitsanulok Province, Thailand, in 2011. Multistage sampling selected a total of 123 primary school students. The Physical Activity Questionnaire for Older Children and the Cues, Perceived Benefits, and Barriers to Physical Activity Questionnaire were used to assess the student levels of physical activity, as well as the perceived benefits, barriers, and cues to action. The association between these factors and the level of physical activity was determined by correlation statistics and confirmed by robust regression. Multivariate analysis of variance compared health belief model determinants: perceived benefits, perceived barriers, and cues to action on physical activity between male and female students. Self-administered questionnaires were validated and tested in a pilot study. The level of activity among primary school children was significantly influenced by perceived barriers, such as fear of strangers when playing outdoors, bad weather, and too much homework. However, activity was not influenced by cues to action or perceived benefits. Perceived benefits, barriers, and cues to physical activity did not differ by gender. A safe environment and fewer barriers, such as amount of homework, could enhance physical activity in primary school children.

Experiencing the Barriers: Non-Traditional Students Entering Higher Education.

ERIC Educational Resources Information Center

Bowl, Marion

2001-01-01

Examined the educational experiences of nontraditional, ethnic minority, women students in the United Kingdom who were involved in a community-based, flexible access to higher education project in the inner city, highlighting financial and institutional barriers they experienced. Students were frustrated participants in an unresponsive…

Barriers to participation in physical activity and exercise among middle-aged and elderly individuals.

PubMed

Justine, Maria; Azizan, Azliyana; Hassan, Vaharli; Salleh, Zoolfaiz; Manaf, Haidzir

2013-10-01

INTRODUCTION Although the benefits of physical activity and exercise are widely acknowledged, many middle-aged and elderly individuals remain sedentary. This cross-sectional study aimed to identify the external and internal barriers to physical activity and exercise participation among middle-aged and elderly individuals, as well as identify any differences in these barriers between the two groups. METHODS Recruited individuals were categorised into either the middle-aged (age 45-59 years, n = 60) or elderly (age ≥ 60 years, n = 60) group. Data on demographics, anthropometry, as well as external and internal barriers to participation in physical activity and exercise were collected. RESULTS Analysis showed no significant differences in the total scores of all internal barriers between the two groups (p > 0.05). The total scores for most external barriers between the two groups also showed no significant differences (p > 0.05); only 'cost' (p = 0.045) and 'exercise interferes with social/family activities' (p = 0.011) showed significant differences. The most common external barriers among the middle-aged and elderly respondents were 'not enough time' (46.7% vs. 48.4%), 'no one to exercise with' (40.0% vs. 28.3%) and 'lack of facilities' (33.4% vs. 35.0%). The most common internal barriers for middle-aged respondents were 'too tired' (48.3%), 'already active enough' (38.3%), 'do not know how to do it' (36.7%) and 'too lazy' (36.7%), while those for elderly respondents were 'too tired' (51.7%), 'lack of motivation' (38.4%) and 'already active enough' (38.4%). CONCLUSION Middle-aged and elderly respondents presented with similar external and internal barriers to physical activity and exercise participation. These factors should be taken into account when healthcare policies are being designed and when interventions such as the provision of facilities to promote physical activity and exercise among older people are being considered.

Partial Synchronization of Stochastic Oscillators through Hydrodynamic Coupling

NASA Astrophysics Data System (ADS)

Curran, Arran; Lee, Michael P.; Padgett, Miles J.; Cooper, Jonathan M.; Di Leonardo, Roberto

2012-06-01

Holographic optical tweezers are used to construct a static bistable optical potential energy landscape where a Brownian particle experiences restoring forces from two nearby optical traps and undergoes thermally activated transitions between the two energy minima. Hydrodynamic coupling between two such systems results in their partial synchronization. This is interpreted as an emergence of higher mobility pathways, along which it is easier to overcome barriers to structural rearrangement.

Blood-brain barrier traversal by African trypanosomes requires calcium signaling induced by parasite cysteine protease

PubMed Central

Nikolskaia, Olga V.; de A. Lima, Ana Paula C.; Kim, Yuri V.; Lonsdale-Eccles, John D.; Fukuma, Toshihide; Scharfstein, Julio; Grab, Dennis J.

2006-01-01

In this study we investigated why bloodstream forms of Trypanosoma brucei gambiense cross human brain microvascular endothelial cells (BMECs), a human blood-brain barrier (BBB) model system, at much greater efficiency than do T. b. brucei. After noting that T. b. gambiense displayed higher levels of cathepsin L–like cysteine proteases, we investigated whether these enzymes contribute to parasite crossing. First, we found that T. b. gambiense crossing of human BMECs was abrogated by N-methylpiperazine-urea-Phe-homopheylalanine-vinylsulfone-benzene (K11777), an irreversible inhibitor of cathepsin L–like cysteine proteases. Affinity labeling and immunochemical studies characterized brucipain as the K11777-sensitive cysteine protease expressed at higher levels by T. b. gambiense. K11777-treated T. b. gambiense failed to elicit calcium fluxes in BMECs, suggesting that generation of activation signals for the BBB is critically dependant on brucipain activity. Strikingly, crossing of T. b. brucei across the BBB was enhanced upon incubation with brucipain-rich supernatants derived from T. b. gambiense. The effects of the conditioned medium, which correlated with ability to evoke calcium fluxes, were canceled by K11777, but not by the cathepsin B inhibitor CA074. Collectively, these in vitro studies implicate brucipain as a critical driver of T. b. gambiense transendothelial migration of the human BBB. PMID:16998589

Influence of chitosan concentration on mechanical and barrier properties of corn starch/chitosan films.

PubMed

Ren, Lili; Yan, Xiaoxia; Zhou, Jiang; Tong, Jin; Su, Xingguang

2017-12-01

The active packaging films based on corn starch and chitosan were prepared through mixing the starch solution and the chitosan solution (1:1) by casting. The aim of this work was to characterize and analyze the effects of the chitosan concentrations (0, 21, 41, 61 and 81wt% of starch) on physicochemical, mechanical and water vapor barrier properties as well as morphological characteristics of the corn starch/chitosan (CS/CH) films. Starch molecules and chitosan could interact through hydrogen bonding as confirmed from the shift of the main peaks to higher wavenumbers in FTIR and the reduction of crystallinity in XRD. Results showed that the incorporation of chitosan resulted in an increase in film solubility, total color differences, tensile strength and elongation at break and a decrease in Young's modulus and water vapor permeability (WVP). Elongation at break of the CS/CH films increased with increasing of chitosan concentration, and reached a maximum at 41 wt%, then declined at higher chitosan concentration. The WVP of CS/CH films increased with an increase of chitosan concentration and the same tendency observed for the moisture content. The results suggest that this biodegradable CS/CH films could potentially be used as active packaging films for food and pharmaceutical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Perceived barriers and facilitators to physical activity for children with disability: a systematic review.

PubMed

Shields, Nora; Synnot, Anneliese Jane; Barr, Megan

2012-11-01

The aim of this systematic review was to investigate the perceived barriers and facilitators to physical activity among children with disability. 10 electronic databases were searched from the earliest time available to September 2010 to identify relevant articles. Articles were included if they examined the barriers or facilitators to physical activity for children with disability and were written in English. Articles were excluded if they included children with an acute, transient or chronic medical condition, examined sedentary leisure activities, or societal participation in general. Two reviewers independently assessed the search yields, extracted the data and assessed trial quality. Data were analysed descriptively. 14 articles met the inclusion criteria. Barriers included lack of knowledge and skills, the child's preferences, fear, parental behaviour, negative attitudes to disability, inadequate facilities, lack of transport, programmes and staff capacity, and cost. Facilitators included the child's desire to be active, practising skills, involvement of peers, family support, accessible facilities, proximity of location, better opportunities, skilled staff and information. Personal, social, environmental, and policy and programme-related barriers and facilitators influence the amount of activity children with disability undertake. The barriers to physical activity have been studied more comprehensively than the facilitators.

Comparison of Methodologies of Activation Barrier Measurements for Reactions with Deactivation

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

Xie, Zhenhua; Yan, Binhang; Zhang, Li

In this work, methodologies of activation barrier measurements for reactions with deactivation were theoretically analyzed. Reforming of ethane with CO 2 was introduced as an example for reactions with deactivation to experimentally evaluate these methodologies. Both the theoretical and experimental results showed that due to catalyst deactivation, the conventional method would inevitably lead to a much lower activation barrier, compared to the intrinsic value, even though heat and mass transport limitations were excluded. In this work, an optimal method was identified in order to provide a reliable and efficient activation barrier measurement for reactions with deactivation.

Comparison of Methodologies of Activation Barrier Measurements for Reactions with Deactivation

DOE PAGES

Xie, Zhenhua; Yan, Binhang; Zhang, Li; ...

2017-01-25

In this work, methodologies of activation barrier measurements for reactions with deactivation were theoretically analyzed. Reforming of ethane with CO 2 was introduced as an example for reactions with deactivation to experimentally evaluate these methodologies. Both the theoretical and experimental results showed that due to catalyst deactivation, the conventional method would inevitably lead to a much lower activation barrier, compared to the intrinsic value, even though heat and mass transport limitations were excluded. In this work, an optimal method was identified in order to provide a reliable and efficient activation barrier measurement for reactions with deactivation.

High-fat enteral nutrition reduces intestinal mucosal barrier damage after peritoneal air exposure.

PubMed

Tan, Shan-Jun; Yu, Chao; Yu, Zhen; Lin, Zhi-Liang; Wu, Guo-Hao; Yu, Wen-Kui; Li, Jie-Shou; Li, Ning

2016-05-01

Peritoneal air exposure is needed in open abdominal surgery, but long-time exposure could induce intestinal mucosal barrier dysfunction followed by many postoperative complications. High-fat enteral nutrition can ameliorate intestinal injury and improve intestinal function in many gastrointestinal diseases. In the present study, we investigated the effect of high-fat enteral nutrition on intestinal mucosal barrier after peritoneal air exposure and the underlying mechanism. Male adult rats were administrated saline, low-fat or high-fat enteral nutrition via gavage before and after peritoneal air exposure for 3 h. Rats undergoing anesthesia without laparotomy received saline as control. Twenty four hours after surgery, samples were collected to assess intestinal mucosal barrier changes in serum D-lactate levels, intestinal permeability, intestinal tight junction protein ZO-1 and occludin levels, and intestinal histopathology. The levels of malondialdehyde and the activity of superoxide dismutase in the ileum tissue were also measured to assess the status of intestinal oxidative stress. High-fat enteral nutrition significantly decreased the serum D-lactate level and increased the intestinal tight junction protein ZO-1 level when compared to the group treated with low-fat enteral nutrition (P < 0.05). Meanwhile, histopathologic findings showed that the intestinal mucosal injury assessed by the Chiu's score and the intestinal epithelial tight junction were also improved much more in the high-fat enteral nutrition-treated group (P < 0.05). In addition, the intestinal malondialdehyde level was lower, and the intestinal superoxide dismutase activity was higher in the high-fat enteral nutrition-treated group than that in the low-fat enteral nutrition-treated group (P < 0.05). These results suggest that high-fat enteral nutrition could reduce intestinal mucosal barrier damage after peritoneal air exposure, and the underlying mechanism may be associated with its antioxidative action. Perioperative administration of high-fat enteral nutrition may be a promising intervention to preserve intestinal mucosal barrier function in open abdominal surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

Socio-demographic and behavioral variation in barriers to leisure-time physical activity.

PubMed

Borodulin, Katja; Sipilä, Noora; Rahkonen, Ossi; Leino-Arjas, Päivi; Kestilä, Laura; Jousilahti, Pekka; Prättälä, Ritva

2016-02-01

We examined the socio-demographic and behavioral determinants of perceived barriers to leisure-time physical activity (LTPA) in a population-based sample of working-aged adults. Data comprised the National FINRISK 2002 Study, a population-based health examination study. Analyses were restricted to those aged 25-64 years and who perceived that their amount of LTPA did not reach sufficient levels. They reported barriers to LTPA, defined as a lack of time, motivation and lack of companionship to be active with, as well as high expenses. Age, education, household income, employment status, family type, physical activity, smoking and body mass index (BMI) were included as explanatory variables. Lack of time was the most frequent barrier. Each barrier was explained by a different set of factors that also varied between genders. The strongest and most systematic associations with the barriers were found for age, employment status and family type. Lack of time was less often reported as a barrier among the unemployed, singles without children and older people. Lacking motivation as a barrier was most common among singles without children. High expenses as a barrier was more often reported by the unemployed, and less often reported in the highest income group. When considering actions to promote LTPA, there is not one single solution, because the perceived barriers vary by population subgroups. © 2015 the Nordic Societies of Public Health.

Biological and Sociocultural Differences in Perceived Barriers to Physical Activity Among Fifth- to Seventh-Grade Urban Girls.

PubMed

Vermeesch, Amber L; Ling, Jiying; Voskuil, Vicki R; Bakhoya, Marion; Wesolek, Stacey M; Bourne, Kelly A; Pfeiffer, Karin A; Robbins, Lorraine B

2015-01-01

Inadequate physical activity (PA) contributes to the high prevalence of overweight and obesity among U.S. adolescent girls. Barriers preventing adolescent girls from meeting PA guidelines have not been thoroughly examined. The threefold purpose of this study was to (a) determine pubertal stage, racial/ethnic, and socioeconomic status (SES) differences in ratings of interference of barriers to PA; (b) examine relationships between perceived barriers and age, body mass index, recreational screen time, sedentary activity, and PA; and (c) identify girls' top-rated perceived barriers to PA. Girls (N = 509) from eight Midwestern U.S. schools participated. Demographic, pubertal stage, perceived barriers, and recreational screen time data were collected via surveys. Height and weight were measured. Accelerometers measured sedentary activity, moderate-to-vigorous PA (MVPA), and light plus MVPA. Girls of low SES reported greater interference of perceived barriers to PA than those who were not of low SES (1.16 vs. 0.97, p = .01). Girls in early/middle puberty had lower perceived barriers than those in late puberty (1.03 vs. 1.24, p < .001). Girls' perceived barriers were negatively related to MVPA (r = -.10, p = .03) and light plus MVPA (r = -.11, p = .02). Girls' top five perceived barriers included lack of skills, hating to sweat, difficulty finding programs, being tired, and having pain. Innovative interventions, particularly focusing on skill development, are needed to assist girls in overcoming their perceived barriers to PA.

Mapping barriers and intervention activities to behaviour change theory for Mobilization of Vulnerable Elders in Ontario (MOVE ON), a multi-site implementation intervention in acute care hospitals.

PubMed

Moore, Julia E; Mascarenhas, Alekhya; Marquez, Christine; Almaawiy, Ummukulthum; Chan, Wai-Hin; D'Souza, Jennifer; Liu, Barbara; Straus, Sharon E

2014-10-30

As evidence-informed implementation interventions spread, they need to be tailored to address the unique needs of each setting, and this process should be well documented to facilitate replication. To facilitate the spread of the Mobilization of Vulnerable Elders in Ontario (MOVE ON) intervention, the aim of the current study is to develop a mapping guide that links identified barriers and intervention activities to behaviour change theory. Focus groups were conducted with front line health-care professionals to identify perceived barriers to implementation of an early mobilization intervention targeted to hospitalized older adults. Participating units then used or adapted intervention activities from an existing menu or developed new activities to facilitate early mobilization. A thematic analysis was performed on the focus group data, emphasizing concepts related to barriers to behaviour change. A behaviour change theory, the 'capability, opportunity, motivation-behaviour (COM-B) system', was used as a taxonomy to map the identified barriers to their root causes. We also mapped the behaviour constructs and intervention activities to overcome these. A total of 46 focus groups were conducted across 26 hospital inpatient units in Ontario, Canada, with 261 participants. The barriers were conceptualized at three levels: health-care provider (HCP), patient, and unit. Commonly mentioned barriers were time constraints and workload (HCP), patient clinical acuity and their perceived 'sick role' (patient), and lack of proper equipment and human resources (unit level). Thirty intervention activities to facilitate early mobilization of older adults were implemented across hospitals; examples of unit-developed intervention activities include the 'mobility clock' communication tool and the use of staff champions. A mapping guide was created with barriers and intervention activities matched though the lens of the COM-B system. We used a systematic approach to develop a guide, which maps barriers, intervention activities, and behaviour change constructs in order to tailor an implementation intervention to the local context. This approach allows implementers to identify potential strategies to overcome local-level barriers and to document adaptations.

200-BP-1 Prototype Hanford Barrier Annual Monitoring Report for Fiscal Year 2004

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

Ward, Andy L.; Linville, Jenifer K.; Keller, Jason M.

2005-01-03

In FY 2004, monitoring of the prototype Hanford barrier focused on barrier stability, vegetative cover, evidence of plant and animal intrusion, and the main components of the water balance. Monitored water-balance components included precipitation, runoff, storage, drainage, and deep percolation. Precipitation in FY 2004 was 26 percent less than in FY 2003 but was still higher than normal. The seasonal distribution in precipitation was also different from the previous year with a 43 percent reduction in spring precipitation and a 46 percent increase in summer precipitation. The cumulative amount of water received from October 1994, through September 2004, was 2,559.58more » mm on the northern half of the barrier, which is the formerly irrigated treatment, and 1,886.71 mm on the southern non-irrigated treatments. Water storage continued to show a cyclic pattern, increasing in the winter and declining in the spring and summer to a lower limit of about 100 mm in response to evapotranspiration. The 600-mm design storage has never been exceeded. Total drainage from the soil-covered plots range from 2.9E-4 mm to 0.22 mm or 0.003 6 0.004 percent of precipitation. Side-slope drainage was much higher at 20.9 6 2.3 percent of precipitation from the gravel and 18.6 6 5.1 percent from the riprap. There was no runoff from the barrier, but runoff from the BY tank farm following a thunderstorm in May eroded a 45-inch-deep channel into the structural fill at the toe of the riprap slope. Above-asphalt and below-asphalt moisture measurements show no evidence of deep percolation of water. Topographic surveys were conducted on the barrier surface, including the two settlement gauges and 12 creep gauges on the riprap slope using aerial photogrammetry (AP) and a global positioning system (GPS). Comparing the aerial photogrammetry (AP) and global positioning system (GPS) surveys with the traditional survey shows the barrier and side slopes to be stable. Both AP and GPS show potential for considerable cost savings without any loss in accuracy. A relatively high coverage of native plants still persists after the initial revegetation in 1994. The formerly irrigated treatments continue to show greater cover of grasses and litter than the non-irrigated treatments. On the formerly irrigated treatments, the mean cover class was 25 to 50 percent for both grasses and shrubs. On the non-irrigated treatments, the mean cover class was 5 to 25 percent from grasses and 25 to 50 percent for shrubs. Species diversity of the vegetative community appears to have stabilized over the past several years. In addition to 12 of 17 species present in 2003 being present in 2004, two additional species were encountered. Sagebrush continues to flourish with shrubs along the perimeter showing higher biomass yield than the interior shrubs. There is evidence of sagebrush seedlings recruitment but not of rabbitbrush; the presence of gray rabbitbrush appears is declining as the barrier surface continues to stabilize. Use of the barrier surface by insects and small mammals is also evident. Small mammal burrowing on the barrier surface has become more prevalent in recent years, suggesting that the restored barrier surface is beginning to function as a recovering ecosystem. Small-mammal burrowing on the top and sides of the barrier is most prevalent on the finer-grained and disturbed soils while active ant mounds were observed on the northern and western slopes.« less

Contextual barriers to lifestyle physical activity interventions in Hong Kong.

PubMed

Eves, Frank F; Masters, Rich S W; McManus, Alison; Leung, Moon; Wong, Peggy; White, Mike J

2008-05-01

Increased lifestyle physical activity, for instance, use of active transport, is a current public health target. Active transport interventions that target stair climbing are consistently successful in English-speaking populations yet unsuccessful in Hong Kong. We report two further studies on active transport in the Hong Kong Chinese. Pedestrians on a mass transit escalator system (study 1) and in an air-conditioned shopping mall (study 2) were encouraged to take the stairs for their cardiovascular health by point-of-choice prompts. Observers coded sex, age, and walking on the mass transit system, with the additional variables of presence of children and bags coded in the shopping mall. In the first study, a 1-wk baseline was followed by 4 wk of intervention (N = 76,710) whereas in the second study (shopping mall) a 2-wk baseline was followed by a 2-wk intervention period (N = 18,257). A small but significant increase in stair climbing (+0.29%) on the mass transit system contrasted with no significant changes in the shopping mall (+0.09%). The active transport of walking on the mass transit system was reduced at higher rates of humidity and temperature, with steeper slopes for the effects of climate variables in men than in women. These studies confirm that lifestyle physical activity interventions do not have universal application. The context in which the behavior occurs (e.g., climate) may act as a barrier to active transport.

In Situ Ramp Anneal X-ray Diffraction Study of Atomic Layer Deposited Ultrathin TaN and Ta 1-x Al x N y Films for Cu Diffusion Barrier Applications

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

Consiglio, S.; Dey, S.; Yu, K.

2016-01-01

Ultrathin TaN and Ta 1-xAl xN y films with x = 0.21 to 0.88 were deposited by atomic layer deposition (ALD) and evaluated for Cu diffusion barrier effectiveness compared to physical vapor deposition (PVD) grown TaN. Cu diffusion barrier effectiveness was investigated using in-situ ramp anneal synchrotron X-ray diffraction (XRD) on Cu/1.8 nm barrier/Si stacks. A Kissinger-like analysis was used to assess the kinetics of Cu 3Si formation and determine the effective activation energy (E a) for Cu silicidation. Compared to the stack with a PVD TaN barrier, the stacks with the ALD films exhibited a higher crystallization temperature (Tmore » c) for Cu silicidation. The Ea values of Cu 3Si formation for stacks with the ALD films were close to the reported value for grain boundary diffusion of Cu whereas the Ea of Cu 3Si formation for the stack with PVD TaN is closer to the reported value for lattice diffusion. For 3 nm films, grazing incidence in-plane XRD showed evidence of nanocrystallites in an amorphous matrix with broad peaks corresponding to high density cubic phase for the ALD grown films and lower density hexagonal phase for the PVD grown film further elucidating the difference in initial failure mechanisms due to differences in barrier crystallinity and associated phase.« less

Overcoming early barriers to PCMH practice improvement in family medicine residencies.

PubMed

Fernald, Douglas H; Deaner, Nicole; O'Neill, Caitlin; Jortberg, Bonnie T; degruy, Frank Verloin; Dickinson, W Perry

2011-01-01

Residency programs face inevitable challenges as they redesign their practices for higher quality care and resident training. Identifying and addressing early barriers can help align priorities and thereby augment the capacity to change. Evaluation of the Colorado Family Medicine Residency PCMH Project included iterative qualitative analysis of field notes, interviews, and documents to identify early barriers to change and strategies to overcome them. Nine common but not universal barriers were identified: (1) a practice's history reflected some negative past experiences with quality improvement or routines incompatible with transformative change, (2) leadership gaps were evident in unprepared practice leaders or hierarchical leadership, (3) resistance and skepticism about change were expressed through cynicism aimed at change or ability to change, (4) unproductive team processes were reflected in patterns of canceled meetings, absentee leaders, or lack of accountability, (5) knowledge gaps about the Patient-centered Medical Home (PCMH) were apparent from incomplete dissemination about the project or planned changes, (6) EHR implementation distracted focus or stalled improvement activity, (7) sponsoring organizations' constraints emerged from staffing rules and differing priorities, (8) insufficient staff participation resulted from traditional role expectations and structures, and (9) communication was hampered by ineffective methods and part-time faculty and residents. Early barriers responded to varying degrees to specific interventions by practice coaches. Some barriers that interfere with practices getting started with cultural and structural transformation can be addressed with persistent attention and reflection from on-site coaches and by realigning the talents, leaders, and priorities already in these residency programs.

Patient-Reported Barriers to the Prekidney Transplant Evaluation in an At-Risk Population in the United States.

PubMed

Lockwood, Mark B; Saunders, Milda R; Nass, Rachel; McGivern, Claire L; Cunningham, Patrick N; Chon, W James; Josephson, Michelle A; Becker, Yolanda T; Lee, Christopher S

2017-06-01

Despite our knowledge of barriers to the early stages of the transplant process, we have limited insight into patient-reported barriers to the prekidney transplant medical evaluation in populations largely at-risk for evaluation failure. One-hundred consecutive adults were enrolled at an urban, Midwestern transplant center. Demographic, clinical, and quality of life data were collected prior to patients visit with a transplant surgeon/nephrologist (evaluation begins). Patient-reported barriers to evaluation completion were collected using the Subjective Barriers Questionnaire 90-days after the initial medical evaluation appointment (evaluation ends), our center targeted goal for transplant work-up completion. At 90 days, 40% of participants had not completed the transplant evaluation. Five barrier categories were created from the 85 responses to the Subjective Barriers Questionnaire. Patient-reported barriers included poor communication, physical health, socioeconomics, psychosocial influences, and access to care. In addition, determinants for successful evaluation completion included being of white race, higher income, free of dialysis, a lower comorbid burden, and reporting higher scores on the Kidney Disease Quality of Life subscale role-emotional. Poor communication between patients and providers, and among providers, was the most prominent patient-reported barrier identified. Barriers were more prominent in marginalized groups such as ethnic minorities and people with low income. Understanding the prevalence of patient-reported barriers may aid in the development of patient-centered interventions to improve completion rates.

You Gotta Be Determined to Get in There: Voices of Women Higher Education Technology Leaders

ERIC Educational Resources Information Center

Drury, Marilyn

2010-01-01

Three women higher education Chief Information Officers (CIOs) provided their lived experiences and perspectives on barriers they encountered and methods used to overcome the barriers as they pursued and achieved their current positions. The conceptual framework intersects gendered organizational theory, feminist standpoint theory, and…

Barriers to Blacks' Educational Achievement in Higher Education: A Statistical and Conceptual Review.

ERIC Educational Resources Information Center

Lang, Marvel

1992-01-01

Examines trends in the educational achievement of African Americans at secondary and postsecondary levels using data from various national surveys. Barriers to educational achievement are described, and intervention strategies for improving African-American success in higher education are reviewed. Increasing minority participation will require…

Confronting Barriers to the Participation of Mexican American Women in Higher Education.

ERIC Educational Resources Information Center

Vasquez, Melba J. T.

1982-01-01

Barriers which may prevent Mexican American women from participating in higher education include: sex role restrictions, low socioeconomic status, lack of parental financial support, "culture shock," and traditional admissions criteria. Programs designed to provide financial and motivational support are desirable to help break down the…

Physical activity barriers and facilitators among working mothers and fathers.

PubMed

Mailey, Emily L; Huberty, Jennifer; Dinkel, Danae; McAuley, Edward

2014-06-27

The transition to parenthood is consistently associated with declines in physical activity. In particular, working parents are at risk for inactivity, but research exploring physical activity barriers and facilitators in this population has been scarce. The purpose of this study was to qualitatively examine perceptions of physical activity among working parents. Working mothers (n = 13) and fathers (n = 12) were recruited to participate in one of four focus group sessions and discuss physical activity barriers and facilitators. Data were analyzed using immersion/crystallization in NVivo 10. Major themes for barriers included family responsibilities, guilt, lack of support, scheduling constraints, and work. Major themes for facilitators included being active with children or during children's activities, being a role model for children, making time/prioritizing, benefits to health and family, and having support available. Several gender differences emerged within each theme, but overall both mothers and fathers reported their priorities had shifted to focus on family after becoming parents, and those who were fitting in physical activity had developed strategies that allowed them to balance their household and occupational responsibilities. The results of this study suggest working mothers and fathers report similar physical activity barriers and facilitators and would benefit from interventions that teach strategies for overcoming barriers and prioritizing physical activity amidst the demands of parenthood. Future interventions might consider targeting mothers and fathers in tandem to create an optimally supportive environment in the home.

Motivational readiness for active commuting by university students: incentives and barriers.

PubMed

Cole, Rachel; Leslie, Eva; Donald, Maria; Cerin, Ester; Neller, Anne; Owen, Neville

2008-12-01

Walking for transport can contribute significantly to health-enhancing physical activity. We examined the associations of stages of motivational readiness for active transport with perceived barriers and incentives to walking to and from university among students. Mail-back surveys were completed by 781 students in a regional university in south-east Queensland. They identified one of eight options on motivational readiness for active commuting, which were then classified as: pre-contemplation; contemplation-preparation; or, action-maintenance. Open-ended questions were used to identify relevant barriers and incentives. Logistic regressions were used to examine the barriers and incentives that distinguished between those at different stages of motivational readiness. Barriers most frequently reported were long travel distances, inconvenience and time constraints. Incentives most frequently reported were shorter travel distance, having more time, supportive infrastructure and better security. Those not considering active commuting (pre-contemplation) were significantly more likely to report shorter travel distance as an incentive compared to those in contemplation-preparation. Those in contemplation-preparation were significantly more likely to report lack of motivation, inadequate infrastructure, shorter travel distance and inconvenience as barriers; and, having more time, supportive infrastructure, social support and incentive programs as encouragement. Different barriers and incentives to walking to or from university exist for students in the different stages of motivational readiness for active commuting. Interventions targeted specifically to stage of motivational readiness may be potentially helpful in increasing activity levels, through active transport.

Physical inactivity is associated with low self efficacy and social support among patients with hypertension in Nigeria.

PubMed

Idowu, O A; Adeniyi, A F; Atijosan, O J; Ogwumike, O O

2013-06-01

BACKGROUND Physical inactivity is a major factor in the development of many chronic illnesses, including hypertension. Evidence highlighting links among physical activity participation and psychosocial constructs such as self efficacy, social support and perceived barriers among hypertensive patients in the Nigerian population is scarce. This study explored the associations between physical activity and each of self efficacy, social support and perceived barriers. METHODS Two hundred and twelve patients receiving treatment in two tertiary health institutions located in Ekiti State, Nigeria were surveyed cross-sectionally. Physical activity level, self efficacy, social support and perceived barriers were measured with the International Physical Activity Questionnaire, Exercise Self-Efficacy Scale, Medical Outcomes Social Support Scale and Exercise Benefits and Barrier Scale respectively. RESULTS Level of physical activity was significantly associated with self efficacy (r(s) = 0.67, p < 0.01, = 0.45) and social support (r(s) = 0.80, p < 0.01, = 0.64), with most participants (56.1%) being physically inactive. However, no association was found between physical activity level and perceived barriers (r(s) = 0.07, p > 0.01, = 0.005). CONCLUSION Most of the hypertensive patients presented with low levels of physical activity. Physical activity was associated with psychosocial constructs including self efficacy and social support but not with perceived barriers.

Increased Transendothelial Transport of CCL3 Is Insufficient to Drive Immune Cell Transmigration through the Blood-Brain Barrier under Inflammatory Conditions In Vitro.

PubMed

De Laere, Maxime; Sousa, Carmelita; Meena, Megha; Buckinx, Roeland; Timmermans, Jean-Pierre; Berneman, Zwi; Cools, Nathalie

2017-01-01

Many neuroinflammatory diseases are characterized by massive immune cell infiltration into the central nervous system. Identifying the underlying mechanisms could aid in the development of therapeutic strategies specifically interfering with inflammatory cell trafficking. To achieve this, we implemented and validated a blood-brain barrier (BBB) model to study chemokine secretion, chemokine transport, and leukocyte trafficking in vitro. In a coculture model consisting of a human cerebral microvascular endothelial cell line and human astrocytes, proinflammatory stimulation downregulated the expression of tight junction proteins, while the expression of adhesion molecules and chemokines was upregulated. Moreover, chemokine transport across BBB cocultures was upregulated, as evidenced by a significantly increased concentration of the inflammatory chemokine CCL3 at the luminal side following proinflammatory stimulation. CCL3 transport occurred independently of the chemokine receptors CCR1 and CCR5, albeit that migrated cells displayed increased expression of CCR1 and CCR5. However, overall leukocyte transmigration was reduced in inflammatory conditions, although higher numbers of leukocytes adhered to activated endothelial cells. Altogether, our findings demonstrate that prominent barrier activation following proinflammatory stimulation is insufficient to drive immune cell recruitment, suggesting that additional traffic cues are crucial to mediate the increased immune cell infiltration seen in vivo during neuroinflammation.

Music therapists' research activity and utilization barriers: a survey of the membership.

PubMed

Waldon, Eric G

2015-01-01

Music therapists have access to a rapidly expanding body of research supporting the use of music-based interventions. What is not known is the extent to which music therapists access these resources and what factors may prevent them from incorporating research findings into clinical work. After constructing the Music Therapists' Research Activity and Utilization Barrier (MTRAUB) database, the purposes of this study involved: assessing the extent to which American Music Therapy Association (AMTA) members engage in certain research-related activities; and identifying respondents' perceived barriers to integrating research into clinical practice. This study employed a quantitative, non-experimental approach using an online survey. Respondents included professional, associate, student/graduate student, retired, inactive, and honorary life members of AMTA. Instrumentation involved a researcher-designed Background Questionnaire as well as the Barriers to Research Utilization Scale (BARRIERS; Funk, Champagne, Wiese, & Tornquist, 1991), a tool designed to assess perceived barriers to incorporating research into practice. Of the 3,194 survey invitations distributed, 974 AMTA members replied (a response rate of 30%). Regarding research-related activities, descriptive findings indicate that journal reading is the most frequently reported research-related activity while conducting research is the least frequently reported activity. Results from the BARRIERS Scale indicated that Organizational and Communication factors are perceived as interfering most prominently with the ability to utilize research in clinical practice. Findings suggest that research-related activity and perceived barriers vary as a function of educational attainment, work setting, and occupational role. The author discusses these differential findings in detail, suggests supportive mechanisms to encourage increased research activity and utilization, and offers recommendations for further analysis of the MTRAUB data. © the American Music Therapy Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Improved Ethanol Production from Xylose by Candida shehatae Induced by Dielectric Barrier Discharge Air Plasma

NASA Astrophysics Data System (ADS)

Chen, Huixia; Xiu, Zhilong; Bai, Fengwu

2014-06-01

Xylose fermentation is essential for ethanol production from lignocellulosic biomass. Exposure of the xylose-fermenting yeast Candida shehatae (C. shehatae) CICC1766 to atmospheric pressure dielectric barrier discharge (DBD) air plasma yields a clone (designated as C81015) with stability, which exhibits a higher ethanol fermentation rate from xylose, giving a maximal enhancement in ethanol production of 36.2% compared to the control (untreated). However, the biomass production of C81015 is lower than that of the control. Analysis of the NADH (nicotinamide adenine dinucleotide)- and NADPH (nicotinamide adenine dinucleotide phosphate)-linked xylose reductases and NAD+-linked xylitol dehydrogenase indicates that their activities are enhanced by 34.1%, 61.5% and 66.3%, respectively, suggesting that the activities of these three enzymes are responsible for improving ethanol fermentation in C81015 with xylose as a substrate. The results of this study show that DBD air plasma could serve as a novel and effective means of generating microbial strains that can better use xylose for ethanol fermentation.

Motivations associated with physical activity in young breast cancer survivors.

PubMed

Voege, Patricia; Bower, Julienne E; Stanton, Annette L; Ganz, Patricia A

2015-01-01

Physical activity is associated with positive health outcomes in breast cancer survivors. However, factors that promote or discourage physical activity in this population are not fully understood. This cross-sectional study was designed to examine approach and avoidance motivations, barriers for exercise, and their association with physical activity in breast cancer survivors younger than 50 years old at time of diagnosis. Current physical activity levels, approach and avoidance motivations, and barriers to exercise were assessed through self-report questionnaires in young breast cancer survivors (N = 156). Results indicated that barriers to exercise were negatively associated with physical activity (p < .01) while approach motivations were positively associated with physical activity (p < .01) and were most relevant in the context of low perceived barriers (p < .05). Avoidance motivations were not associated with physical activity (p = .91).

InAs based terahertz quantum cascade lasers

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

Brandstetter, Martin, E-mail: martin.brandstetter@tuwien.ac.at; Kainz, Martin A.; Krall, Michael

2016-01-04

We demonstrate terahertz lasing emission from a quantum cascade structure, realized with InAs/AlAs{sub 0.16}Sb{sub 0.84} heterostructures. Due to the lower effective electron mass, InAs based active regions are expected to provide a higher optical gain compared to structures consisting of GaAs or InGaAs. The growth by molecular beam epitaxy enabled the fabrication of monolayer-thick barriers, required for the active region, which is based on a 3-well resonant phonon depletion design. Devices were processed in a double-metal waveguide geometry to ensure high mode confinement and low optical losses. Lasing emission at 3.8 THz was observed at liquid helium temperatures by applyingmore » a magnetic field perpendicular to the layered structure in order to suppress parasitic scattering channels. These results demonstrate the feasibility of InAs based active regions for terahertz quantum cascade lasers, potentially enabling higher operating temperatures.« less

LED structure with enhanced mirror reflectivity

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

Bergmann, Michael; Donofrio, Matthew; Heikman, Sten

2014-04-01

Embodiments of the present invention are generally related to LED chips having improved overall emission by reducing the light-absorbing effects of barrier layers adjacent mirror contacts. In one embodiment, a LED chip comprises one or more LEDs, with each LED having an active region, a first contact under the active region having a highly reflective mirror, and a barrier layer adjacent the mirror. The barrier layer is smaller than the mirror such that it does not extend beyond the periphery of the mirror. In another possible embodiment, an insulator is further provided, with the insulator adjacent the barrier layer andmore » adjacent portions of the mirror not contacted by the active region or by the barrier layer. In yet another embodiment, a second contact is provided on the active region. In a further embodiment, the barrier layer is smaller than the mirror such that the periphery of the mirror is at least 40% free of the barrier layer, and the second contact is below the first contact and accessible from the bottom of the chip.« less

A density functional theory study on the carbon chain growth of ethanol formation on Cu-Co (111) and (211) surfaces

NASA Astrophysics Data System (ADS)

Ren, Bohua; Dong, Xiuqin; Yu, Yingzhe; Wen, Guobin; Zhang, Minhua

2017-08-01

Calculations based on the first-principle density functional theory were carried out to study the most controversial reactions in ethanol formation from syngas on Cu-Co surfaces: CO dissociation mechanism and the key reactions of carbon chain growth of ethanol formation (HCO insertion reactions) on four model surfaces (Cu-Co (111) and (211) with Cu-rich or Co-rich surfaces) to investigate the synergy of the Cu and Co components since the complete reaction network of ethanol formation from syngas is a huge computational burden to calculate on four Cu-Co surface models. We investigated adsorption of important species involved in these reactions, activation barrier and reaction energy of H-assisted dissociation mechanism, directly dissociation of CO, and HCO insertion reactions (CHx + HCO → CHxCHO (x = 1-3)) on four Cu-Co surface models. It was found that reactions on Cu-rich (111) and (211) surfaces all have lower activation barrier in H-assisted dissociation and HCO insertion reactions, especially CH + HCO → CHCHO reaction. The PDOS of 4d orbitals of surface Cu and Co atoms of all surfaces were studied. Analysis of d-band center of Cu and Co atoms and the activation barrier data suggested the correlation between electronic property and catalytic performance. Cu-Co bimetallic with Cu-rich surface allows Co to have higher catalytic activity through the interaction of Cu and Co atom. Then it will improve the adsorption of CO and catalytic activity of Co. Thus it is more favorable to the carbon chain growth in ethanol formation. Our study revealed the factors influencing the carbon chain growth in ethanol production and explained the internal mechanism from electronic property aspect.

The Molecular Mechanism of the Catalase-like Activity in Horseradish Peroxidase.

PubMed

Campomanes, Pablo; Rothlisberger, Ursula; Alfonso-Prieto, Mercedes; Rovira, Carme

2015-09-02

Horseradish peroxidase (HRP) is one of the most relevant peroxidase enzymes, used extensively in immunochemistry and biocatalysis applications. Unlike the closely related catalase enzymes, it exhibits a low activity to disproportionate hydrogen peroxide (H2O2). The origin of this disparity remains unknown due to the lack of atomistic information on the catalase-like reaction in HRP. Using QM(DFT)/MM metadynamics simulations, we uncover the mechanism for reduction of the HRP Compound I intermediate by H2O2 at atomic detail. The reaction begins with a hydrogen atom transfer, forming a peroxyl radical and a Compound II-like species. Reorientation of the peroxyl radical in the active site, concomitant with the transfer of the second hydrogen atom, is the rate-limiting step, with a computed free energy barrier (18.7 kcal/mol, ∼ 6 kcal/mol higher than the one obtained for catalase) in good agreement with experiments. Our simulations reveal the crucial role played by the distal pocket residues in accommodating H2O2, enabling formation of a Compound II-like intermediate, similar to catalases. However, out of the two pathways for Compound II reduction found in catalases, only one is operative in HRP. Moreover, the hydrogen bond network in the distal side of HRP compensates less efficiently than in catalases for the energetic cost required to reorient the peroxyl radical at the rate-determining step. The distal Arg and a water molecule in the "wet" active site of HRP have a substantial impact on the reaction barrier, compared to the "dry" active site in catalase. Therefore, the lower catalase-like efficiency of heme peroxidases compared to catalases can be directly attributed to the different distal pocket architecture, providing hints to engineer peroxidases with a higher rate of H2O2 disproportionation.

Knowledge, attitudes, practices, and barriers related to research utilization: a survey among pharmacists in Malaysia.

PubMed

Tan, Sin Yee; Hatah, Ernieda

2017-04-01

Background Research utilization is part of evidence-based practice referring to the process of reviewing and critiquing scientific research and applying the findings to one's own clinical practice. Many studies on research utilization have been conducted with doctors and nurses, but to our knowledge, none have been investigated amongst pharmacists. Objective To assess research utilization and its barriers among pharmacists and identify potential influencing factors. Setting Malaysia. Methods This cross-sectional survey was administered online and by mail to a convenient sample of pharmacists working in hospitals, health clinics, and retail pharmacies in rural and urban areas. Main outcome measure Pharmacists' research utilization knowledge, attitudes, and practices. Results Six hundred surveys were mailed to potential respondents, and 466 were returned (77.7% response rate). Twenty-eight respondents completed the survey online. The respondents' research utilization knowledge, attitudes, and practices were found to be moderate. Research utilization was associated with respondents' knowledge and attitude scores (P < 0.001). When factors related to research utilization were modelled, higher educational level was associated with higher level of research utilization (P < 0.001) while less involvement in journal clubs, more years of service (3-7 years and more than 7 years) were associated with low and moderate research utilization, respectively. The main reported barrier to research utilization was lack of sufficient authority to change patient care procedures. Conclusion Pharmacists' research utilization knowledge, attitudes, and practices can be improved by encouraging pharmacists to pursue higher degrees, promoting active participation in institutions' journal clubs, and introducing senior clinical pharmacist specialization.

Barriers to Health Care Among Adults Identifying as Sexual Minorities: A US National Study.

PubMed

Dahlhamer, James M; Galinsky, Adena M; Joestl, Sarah S; Ward, Brian W

2016-06-01

To assess the extent to which lesbian, gay, and bisexual (LGB) adults aged 18 to 64 years experience barriers to health care. We used 2013 National Health Interview Survey data on 521 gay or lesbian (291 men, 230 women), 215 bisexual (66 men, 149 women), and 25 149 straight (11 525 men, 13 624 women) adults. Five barrier-to-care outcomes were assessed (delayed or did not receive care because of cost, did not receive specific services because of cost, delayed care for noncost reasons, trouble finding a provider, and no usual source of care). Relative to straight adults, gay or lesbian and bisexual adults had higher odds of delaying or not receiving care because of cost. Bisexual adults had higher odds of delaying care for noncost reasons, and gay men had higher odds than straight men of reporting trouble finding a provider. By contrast, gay or lesbian women had lower odds of delaying care for noncost reasons than straight women. Bisexual women had higher odds than gay or lesbian women of reporting 3 of the 5 barriers investigated. Members of sexual minority groups, especially bisexual women, are more likely to encounter barriers to care than their straight counterparts.

Psychosocial correlates of physical activity in adolescents with haemophilia.

PubMed

Buxbaum, N P; Ponce, M; Saidi, P; Michaels, L A

2010-07-01

Boys with haemophilia are now encouraged to exercise and take part in physical activities, but actual measures of time spent in active participation is lacking. The aim of this study was to obtain an objective measure of daily physical activity in boys with haemophilia as compared with healthy controls. The study also aimed to ascertain the social and cognitive factors associated with exercise in this population. Seventeen patients (aged 11-18 years) with haemophilia were studied and compared with 44 healthy controls (aged 10-16.5 years). Physical activity was measured by accelerometry. Psychosocial correlates were assessed using validated questionnaires. Measured physical activity levels in subjects with haemophilia were slightly higher than for the control group. Both groups spent 70% of the day inactive, with similar proportions of time in moderate and vigorous activity. Subjects with haemophilia had a favourable self-image and similar levels of anxiety as peers without a bleeding disorder. Self-efficacy scores were lower than for controls suggesting increased sensitivity to barriers and lack of acceptance of alternatives. Health beliefs did not influence physical activity, but a negative correlation of time spent in high or vigorous activity with scores for support-seeking was observed. The data demonstrate that in the appropriate social environment and with medical support, patients with haemophilia may be as physically active as their peers without a bleeding disorder. Further investigation into the psychosocial barriers of physical activity in patients with haemophilia is needed to more effectively encourage healthy behaviours.

Short and long-term lifestyle coaching approaches used to address diverse participant barriers to weight loss and physical activity adherence.

PubMed

Venditti, Elizabeth M; Wylie-Rosett, Judith; Delahanty, Linda M; Mele, Lisa; Hoskin, Mary A; Edelstein, Sharon L

2014-02-12

Individual barriers to weight loss and physical activity goals in the Diabetes Prevention Program, a randomized trial with 3.2 years average treatment duration, have not been previously reported. Evaluating barriers and the lifestyle coaching approaches used to improve adherence in a large, diverse participant cohort can inform dissemination efforts. Lifestyle coaches documented barriers and approaches after each session (mean session attendance = 50.3 ± 21.8). Subjects were 1076 intensive lifestyle participants (mean age = 50.6 years; mean BMI = 33.9 kg/m²; 68% female, 48% non-Caucasian). Barriers and approaches used to improve adherence were ranked by the percentage of the cohort for whom they applied. Barrier groupings were also analyzed in relation to baseline demographic characteristics. Top weight loss barriers reported were problems with self-monitoring (58%); social cues (58%); holidays (54%); low activity (48%); and internal cues (thought/mood) (44%). Top activity barriers were holidays (51%); time management (50%); internal cues (30%); illness (29%), and motivation (26%). The percentage of the cohort having any type of barrier increased over the long-term intervention period. A majority of the weight loss barriers were significantly associated with younger age, greater obesity, and non-Caucasian race/ethnicity (p-values vary). Physical activity barriers, particularly thought and mood cues, social cues and time management, physical injury or illness and access/weather, were most significantly associated with being female and obese (p < 0.001 for all). Lifestyle coaches used problem-solving with most participants (≥75% short-term; > 90% long term) and regularly reviewed self-monitoring skills. More costly approaches were used infrequently during the first 16 sessions (≤10%) but increased over 3.2 years. Behavioral problem solving approaches have short and long term dissemination potential for many kinds of participant barriers. Given minimal resources, increased attention to training lifestyle coaches in the consistent use of these approaches appears warranted.

Splitting a C-O bond in dialkylethers with bis(1,2,4-tri-t-butylcyclopentadienyl) cerium-hydride does not occur by a sigma-bond metathesis pathway: a combined experimental and DFT computational study

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

Werkema, Evan; Yahia, Ahmed; Maron, Laurent

2010-04-06

Addition of diethylether to [1,2,4(Me3C)3C5H2]2CeH, abbreviated Cp'2CeH, gives Cp'2CeOEt and ethane. Similarly, di-n-propyl- or di-n-butylether gives Cp'2Ce(O-n-Pr) and propane or Cp'2Ce(O-n-Bu) and butane, respectively. Using Cp'2CeD, the propane and butane contain deuterium predominantly in their methyl groups. Mechanisms, formulated on the basis of DFT computational studies, show that the reactions begin by an alpha or beta-CH activation with comparable activation barriers but only the beta-CH activation intermediate evolves into the alkoxide product and an olefin. The olefin then inserts into the Ce-H bond forming the alkyl derivative, Cp'2CeR, that eliminates alkane. The alpha-CH activation intermediate is in equilibrium with themore » starting reagents, Cp'2CeH and the ether, which accounts for the deuterium label in the methyl groups of the alkane. The one-step sigma-bond metathesis mechanism has a much higher activation barrier than either of the two-step mechanisms.« less

Investigation on sodium benzoate release from poly(butylene adipate-co-terephthalate)/organoclay/sodium benzoate based nanocomposite film and their antimicrobial activity.

PubMed

Mondal, Dibyendu; Bhowmick, Biplab; Maity, Dipanwita; Mollick, Md Masud R; Rana, Dipak; Rangarajan, Vivek; Sen, Ramkrishna; Chattopadhyay, Dipankar

2015-03-01

Polymeric nanocomposites embedded with nontoxic antimicrobial agents have recently gained potential industrial significance, mainly for their applicability to preserve food quality and ensure safety. In this study, a poly(butylene adipate-co-terephthalate) (PBAT)/organoclay (CMMT) based nanocomposite film doped with sodium benzoate (SB) as antimicrobial agent was prepared by a solution mixing process. A homogenous dispersion of organoclay (cetyltrimethylammonium-modified montmorillonite [CMMT]) in PBAT matrix was observed by X-ray diffraction and transmission electron microscopy. PBAT/CMMT nanocomposite film showed higher barrier properties against water and methanol vapor compared to the PBAT film. The release of SB from PBAT and its nanocomposite film was measured and the relevant data were fitted to the Weibull model. The higher values of Weibull's shape factor and scale parameter as corroborated by experimental findings indicated faster rate of SB release from PBAT/CMMT/SB nanocomposite film, when compared to the pristine PBAT film. Bacterial inhibition studies were accomplished against 2 food pathogenic bacteria, Bacillus subtilis and Staphylococcus aureus, by determining the zone of inhibition and corresponding growth profiles. Both bacterial inhibition studies and growth profiles established that PBAT/CMMT/SB demonstrated better antimicrobial activity than PBAT/SB film. Therefore, PBAT/CMMT/SB nanocomposite film can be used for food packaging application as it showed good barrier properties and antimicrobial activity against food pathogenic bacteria. © 2015 Institute of Food Technologists®

Atmospheric Pressure Non-Thermal Plasma Activation of CO2 in a Packed-Bed Dielectric Barrier Discharge Reactor.

PubMed

Mei, Danhua; Tu, Xin

2017-11-17

Direct conversion of CO 2 into CO and O 2 is performed in a packed-bed dielectric barrier discharge (DBD) non-thermal plasma reactor at low temperatures and atmospheric pressure. The maximum CO 2 conversion of 22.6 % is achieved when BaTiO 3 pellets are fully packed into the discharge gap. The introduction of γ-Al 2 O 3 or 10 wt % Ni/γ-Al 2 O 3 catalyst into the BaTiO 3 packed DBD reactor increases both CO 2 conversion and energy efficiency of the plasma process. Packing γ-Al 2 O 3 or 10 wt % Ni/γ-Al 2 O 3 upstream of the BaTiO 3 bed shows higher CO 2 conversion and energy efficiency compared with that of mid- or downstream packing modes because the reverse reaction of CO 2 conversion-the recombination of CO and O to form CO 2 -is more likely to occur in mid- and downstream modes. Compared with the γ-Al 2 O 3 support, the coupling of the DBD with the Ni catalyst shows a higher CO 2 conversion, which can be attributed to the presence of Ni active species on the catalyst surface. The argon plasma treatment of the reacted Ni catalyst provides extra evidence to confirm the role of Ni active species in the conversion of CO 2 . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Physical activity, self-efficacy and self-esteem in breast cancer survivors: a panel model.

PubMed

Awick, Elizabeth A; Phillips, Siobhan M; Lloyd, Gillian R; McAuley, Edward

2017-10-01

Physical activity (PA) has been consistently associated with improved self-esteem in breast cancer survivors. However, this relationship is poorly understood. The purpose of this study was to examine whether changes in PA and self-efficacy influenced changes in self-esteem in breast cancer survivors across 6 months. Increases in PA were hypothesized to result in increases in self-efficacy, which were hypothesized to influence increases in physical self-worth (PSW) and global self-esteem. Breast cancer survivors (n = 370; M age  = 56.04) wore accelerometers to measure PA and completed measures of self-efficacy (e.g., exercise and barriers self-efficacy), PSW, and global self-esteem at baseline and 6 months. The hypothesized model provided a good fit to the data (χ 2  = 67.56, df = 26, p < 0.001; comparative fit index (CFI) = 0.98; standardized root mean residual = 0.05). Women with higher activity at baseline reported significantly higher levels of barrier (β = 0.29) and exercise (β = 0.23) self-efficacy. In turn, more efficacious women reported significantly higher PSW (β = 0.26, 0.16). Finally, higher PSW was significantly associated with greater global self-esteem (β = 0.47). Relationships were similar among changes in model constructs over 6 months. After controlling for covariates, the hypothesized model provided an excellent fit to the data (χ 2  = 59.93, df = 33, p = 0.003; comparative fit index = 0.99; standardized root mean residual = 0.03). Our findings provide support for the role played by PA and self-efficacy in positive self-esteem, a key component of well-being. Highlighting successful PA mastery experiences is likely to enhance self-efficacy and improve self-esteem in this population. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Geographically weighted regression as a generalized Wombling to detect barriers to gene flow.

PubMed

Diniz-Filho, José Alexandre Felizola; Soares, Thannya Nascimento; de Campos Telles, Mariana Pires

2016-08-01

Barriers to gene flow play an important role in structuring populations, especially in human-modified landscapes, and several methods have been proposed to detect such barriers. However, most applications of these methods require a relative large number of individuals or populations distributed in space, connected by vertices from Delaunay or Gabriel networks. Here we show, using both simulated and empirical data, a new application of geographically weighted regression (GWR) to detect such barriers, modeling the genetic variation as a "local" linear function of geographic coordinates (latitude and longitude). In the GWR, standard regression statistics, such as R(2) and slopes, are estimated for each sampling unit and thus are mapped. Peaks in these local statistics are then expected close to the barriers if genetic discontinuities exist, capturing a higher rate of population differentiation among neighboring populations. Isolation-by-Distance simulations on a longitudinally warped lattice revealed that higher local slopes from GWR coincide with the barrier detected with Monmonier algorithm. Even with a relatively small effect of the barrier, the power of local GWR in detecting the east-west barriers was higher than 95 %. We also analyzed empirical data of genetic differentiation among tree populations of Dipteryx alata and Eugenia dysenterica Brazilian Cerrado. GWR was applied to the principal coordinate of the pairwise FST matrix based on microsatellite loci. In both simulated and empirical data, the GWR results were consistent with discontinuities detected by Monmonier algorithm, as well as with previous explanations for the spatial patterns of genetic differentiation for the two species. Our analyses reveal how this new application of GWR can viewed as a generalized Wombling in a continuous space and be a useful approach to detect barriers and discontinuities to gene flow.

Motivators of and Barriers to Engaging in Physical Activity: Perspectives of Low-Income Culturally Diverse Adolescents and Adults

ERIC Educational Resources Information Center

Bragg, Marie A.; Tucker, Carolyn M.; Kaye, Lily B.; Desmond, Frederic

2009-01-01

Background: Obesity rates are rising in the United States, especially among low-income and racial/ethnic minority individuals. Exploring motivators and barriers relative to engaging in physical activity is imperative. Purpose: The purpose of this study was to identify motivators and barriers relative to engagement in physical activity as reported…

The role of perceived barriers and objectively measured physical activity in adults aged 65-100.

PubMed

Gellert, Paul; Witham, Miles D; Crombie, Iain K; Donnan, Peter T; McMurdo, Marion E T; Sniehotta, Falko F

2015-05-01

to test the predictive utility of perceived barriers to objectively measured physical activity levels in a stratified sample of older adults when accounting for social-cognitive determinants proposed by the Theory of Planned Behaviour (TPB), and economic and demographic factors. data were analysed from the Physical Activity Cohort Scotland survey, a representative and stratified (65-80 and 80+ years; deprived and affluent) sample of 584 community-dwelling older people, resident in Tayside, Scotland. Physical activity was measured objectively by accelerometry. perceived barriers clustered around the areas of poor health, lack of interest, lack of safety and lack of access. Perceived poor health and lack of interest, but not lack of access or concerns about personal safety, predicted physical activity after controlling for demographic, economic and TPB variables. perceived person-related barriers (poor health and lack of interest) seem to be more strongly associated with physical activity levels than perceived environmental barriers (safety and access) in a large sample of older adults. Perceived barriers are modifiable and may be a target for future interventions. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Barriers to Physical Activity in a Mass Transit Population: A Qualitative Study.

PubMed

Das, Bhibha M; Petruzzello, Steven J

2016-01-01

The physical inactivity epidemic continues be one of the greatest public health challenges in contemporary society in the United States. The transportation industry is at greater risk of physical inactivity, compared with individuals in other sectors of the workforce. The aim of this study was to use the Nominal Group Technique, a focus group technique, to examine mass transit employees' perceptions of the barriers to physical activity at their worksite. Three focus groups (n = 31) were conducted to examine mass transit employees' perceptions of barriers to physical activity at the worksite. Salient barriers included (1) changing work schedules, (2) poor weather conditions, and (3) lack of scheduled and timely breaks. Findings were consistent with previous research demonstrating shift work, poor weather, and lack of breaks can negatively impact mass transit employees' ability to be physically active. Although physical activity barriers for this population have been consistent for the last 20 years, public health practice and policy have not changed to address these barriers. Future studies should include conducing focus groups stratified by job classification (eg, operators, maintenance, and clerical) along with implementing and evaluating worksite-based physical activity interventions and policy changes.

Psychosocial Factors, Exercise Adherence, and Outcomes in Heart Failure Patients: Insights from HF-ACTION

PubMed Central

Cooper, Lauren B.; Mentz, Robert J.; Sun, Jie-Lena; Schulte, Phillip J; Fleg, Jerome L.; Cooper, Lawton S.; Piña, Ileana L.; Leifer, Eric S.; Kraus, William E.; Whellan, David J.; Keteyian, Steven J.; O’Connor, Christopher M.

2016-01-01

Background Psychosocial factors may influence adherence with exercise training for heart failure patients. We aimed to describe the association between social support and barriers to participation with exercise adherence and clinical outcomes. Methods and Results Of patients enrolled in HF-ACTION, 2279 (97.8%) completed surveys to assess social support and barriers to exercise, resulting in the perceived social support score (PSSS) and barriers to exercise score (BTES). Higher PSSS indicated higher levels of social support, while higher BTES indicated more barriers to exercise. Exercise time at 3 and 12 months correlated with PSSS (r= 0.09 and r= 0.13, respectively) and BTES (r= − 0.11 and r= − 0.12, respectively), with higher exercise time associated with higher PSSS and lower BTES (All p <0.005). For CV death or HF hospitalization, there was a significant interaction between randomization group and BTES (p=0.035), which corresponded to a borderline association between increasing BTES and CV death or HF hospitalization in the exercise group (HR 1.25, 95% CI: 0.99, 1.59) but no association in the usual care group (HR 0.83, 95% CI: 0.66, 1.06). Conclusions Poor social support and high barriers to exercise were associated with lower exercise time. PSSS did not impact the effect of exercise training on outcomes. However, for CV death or HF hospitalization, exercise training had a greater impact on patients with lower BTES. Given that exercise training improves outcomes in heart failure patients, assessment of perceived barriers may facilitate individualized approaches to implement exercise training therapy in clinical practice. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT00047437. PMID:26578668

Vented Cavity Radiant Barrier Assembly And Method

DOEpatents

Dinwoodie, Thomas L.; Jackaway, Adam D.

2000-05-16

A vented cavity radiant barrier assembly (2) includes a barrier (12), typically a PV module, having inner and outer surfaces (18, 22). A support assembly (14) is secured to the barrier and extends inwardly from the inner surface of the barrier to a building surface (14) creating a vented cavity (24) between the building surface and the barrier inner surface. A low emissivity element (20) is mounted at or between the building surface and the barrier inner surface. At least part of the cavity exit (30) is higher than the cavity entrance (28) to promote cooling air flow through the cavity.

Position of Proline Mediates the Reactivity of S-Palmitoylation.

PubMed

Khanal, Neelam; Pejaver, Vikas; Li, Zhiyu; Radivojac, Predrag; Clemmer, David E; Mukhopadhyay, Suchetana

2015-11-20

Palmitoylation, a post-translational modification in which a saturated 16-carbon chain is added predominantly to a cysteine residue, participates in various biological functions. The position of proline relative to other residues being post-translationally modified has been previously reported as being important. We determined that proline is statistically enriched around cysteines known to be S-palmitoylated. The goal of this work was to determine how the position of proline influences the palmitoylation of the cysteine residue. We established a mass spectrometry-based approach to investigate time- and temperature-dependent kinetics of autopalmitoylation in vitro and to derive the thermodynamic parameters of the transition state associated with palmitoylation; to the best of our knowledge, our work is the first to study the kinetics and activation properties of the palmitoylation process. We then used these thermochemical parameters to determine if the position of proline relative to the modified cysteine is important for palmitoylation. Our results show that peptides with proline at the -1 position of cysteine in their sequence (PC) have lower enthalpic barriers and higher entropic barriers in comparison to the same peptides with proline at the +1 position of cysteine (CP); interestingly, the free-energy barriers for both pairs are almost identical. Molecular dynamics studies demonstrate that the flexibility of the cysteine backbone in the PC-containing peptide when compared to the CP-containing peptide explains the increased entropic barrier and decreased enthalpic barrier observed experimentally.

Enhancing the Photocatalytic Hydrogen Evolution Performance of a Metal/Semiconductor Catalyst through Modulation of the Schottky Barrier Height by Controlling the Orientation of the Interface.

PubMed

Liu, Yang; Gu, Xin; Qi, Wen; Zhu, Hong; Shan, Hao; Chen, Wenlong; Tao, Peng; Song, Chengyi; Shang, Wen; Deng, Tao; Wu, Jianbo

2017-04-12

Construction of a metal-semiconductor heterojunction is a promising method to improve heterogeneous photocatalysis for various reactions. Although the structure and photocatalytic performance of such a catalyst system have been extensively studied, few reports have demonstrated the effect of interface orientation at the metal-semiconductor junction on junction-barrier bending and the electronic transport properties. Here, we construct a Pt/PbS heterojunction, in which Pt nanoparticles are used as highly active catalysts and PbS nanocrystals (NCs) with well-controlled shapes are used as light-harvesting supports. Experimental results show that the photoelectrocatalytic activities of the Pt/PbS catalyst are strongly dependent on the contacting facets of PbS at the junction. Pt/octahedral PbS NCs with exposed PbS(111) facets show the highest photoinduced enhancement of hydrogen evolution reaction activity, which is ∼14.38 times higher than that of the ones with only PbS(100) facets (Pt/cubic PbS NCs). This enhancement can further be rationalized by the different energy barriers of the Pt/PbS Schottky junction due to the specific band structure and electron affinity, which is also confirmed by the calculations based on density functional theory. Therefore, controlling the contacting interfaces of a metal/semiconductor material may offer an effective approach to form the desired heterojunction for optimization of the catalytic performance.

Hydrogenation of Carbon Dioxide to Methanol Catalyzed by Iron, Cobalt, and Manganese Cyclopentadienone Complexes: Mechanistic Insights and Computational Design.

PubMed

Ge, Hongyu; Chen, Xiangyang; Yang, Xinzheng

2017-07-03

Density functional theory study of the hydrogenation of carbon dioxide to methanol catalyzed by iron, cobalt, and manganese cyclopentadienone complexes reveals a self-promoted mechanism, which features a methanol- or water-molecule-assisted proton transfer for the cleavage of H 2 . The total free energy barrier of the formation of methanol from CO 2 and H 2 catalyzed by Knölker's iron cyclopentadienone complex, [2,5-(SiMe 3 ) 2 -3,4-(CH 2 ) 4 (η 5 -C 4 COH)]Fe(CO) 2 H, is 26.0 kcal mol -1 in the methanol solvent. We also evaluated the catalytic activities of 8 other experimentally reported iron cyclopentadienone complexes and 37 iron, cobalt, and manganese cyclopentadienone complexes proposed in this study. In general, iron and manganese complexes have relatively higher catalytic activities. Among all calculated complexes, [2,5-(SiMe 3 ) 2 -3,4-CH 3 CHSCH 2 (η 5 -C 4 COH)]Fe(CO) 2 H (1 Fe-Casey-S-CH3 ) is the most active one with a total free energy barrier of 25.1 kcal mol -1 in the methanol solvent. Such a low barrier indicates that 1 Fe-Casey-S-CH3 is a very promising low-cost and high efficiency catalyst for the conversion of CO 2 and H 2 to methanol under mild conditions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Implementation of a Non-Metallic Barrier in an Electric Motor

NASA Technical Reports Server (NTRS)

M?Sadoques, George; Carra, Michael; Beringer, Woody

2012-01-01

Electric motors that run in pure oxygen must be sealed, or "canned," for safety reasons to prevent the oxygen from entering into the electrical portion of the motor. The current canning process involves designing a metallic barrier around the rotor to provide the separation. This metallic barrier reduces the motor efficiency as speed is increased. In higher-speed electric motors, efficiency is greatly improved if a very thin, nonmetallic barrier can be utilized. The barrier thickness needs to be approximately 0.025-in. (.0.6-mm) thick and can be made of a brittle material such as glass. The motors, however, designed for space applications are typically subject to high-vibration environments. A fragile, non-metallic barrier can be utilized in a motor assembly if held in place by a set of standard rubber O-ring seals. The O-rings provide the necessary sealing to keep oxygen away from the electrical portion of the motor and also isolate the fragile barrier from the harsh motor vibration environment. The compliance of the rubber O-rings gently constrains the fragile barrier and isolates it from the harsh external motor environment. The use of a non-metallic barrier greatly improves motor performance, especially at higher speeds, while isolating the electronics from the working fluid with an inert liner.

Exercise barriers in Korean colorectal cancer patients.

PubMed

Kang, Dong-Woo; Chung, Jae Youn; Lee, Mi Kyung; Lee, Junga; Park, Ji-Hye; Kim, Dong-Il; Jones, Lee W; Ahn, Joong Bae; Kim, Nam Kyu; Jeon, Justin Y

2014-01-01

To identify barriers to exercise in Korean colorectal cancer patients and survivors, and to analyze differences in exercise barriers by age, gender, treatment status, and physical activity level. A total of 427 colorectal cancer patients and survivors from different stages and medical status completed a self-administered questionnaire that surveyed their barriers to exercise and exercise participation. The greatest perceived exercise barriers for the sampled population as a whole were fatigue, low level of physical fitness, and poor health. Those under 60-years old reported lack of time (p=0.008), whereas those over 60 reported low level of physical fitness (p=0.014) as greater exercise barriers than their counterparts. Women reported fatigue as a greater barrier than men (p<0.001). Those who were receiving treatment rated poor health (p=0.0005) and cancer-related factors as greater exercise barriers compared to those who were not receiving treatment. A multivariate model found that other demographic and medical status were not potential factors that may affect exercise participation. Further, for those who were not participating in physical activity, tendency to be physically inactive (p<0.001) and lack of exercise skill (p<0.001) were highly significant barriers, compared to those who were participating in physical activity. Also, for those who were not meeting ACSM guidelines, cancer-related exercise barriers were additionally reported (p<0.001), compared to those who were. Our study suggests that fatigue, low level of physical fitness, and poor health are most reported exercise barriers for Korean colorectal cancer survivors and there are differences in exercise barriers by age, sex, treatment status, and physical activity level. Therefore, support for cancer patients should be provided considering these variables to increase exercise participation.

In vitro permeation and disposition of niacinamide in silicone and porcine skin of skin barrier-mimetic formulations.

PubMed

Haque, Tasnuva; Lane, Majella E; Sil, Bruno C; Crowther, Jonathan M; Moore, David J

2017-03-30

Niacinamide (NIA) is an amide form of vitamin B3 which is used in cosmetic formulations to improve various skin conditions and it has also been shown to increase stratum corneum thickness following repeated application. In this study, three doses (5, 20 and 50μL per cm 2 ) of two NIA containing oil-in-water skin barrier-mimetic formulations were evaluated in silicone membrane and porcine ear skin and compared with a commercial control formulation. Permeation studies were conducted over 24h in Franz cells and at the end of the experiment membranes were washed and niacinamide was extracted. For the three doses, retention or deposition of NIA was generally higher in porcine skin compared with silicone membrane, consistent with the hydrophilic nature of the active. Despite the control containing a higher amount of active, comparable amounts of NIA were deposited in skin for all formulations for all doses; total skin absorption values (permeation and retention) of NIA were also comparable across all formulations. For infinite (50μL) and finite (5μL) doses the absolute permeation of NIA from the control formulation was significantly higher in porcine skin compared with both test formulations. This likely reflects differences in formulation components and/or presence of skin penetration enhancers in the formulations. Higher permeation for the 50 and 20μL dose was also evident in porcine skin compared with silicone membrane but the opposite is the case for the finite dose. The findings point to the critical importance of dose and occlusion when evaluating topical formulations in vitro and also the likelihood of exaggerated effects of excipients on permeation at infinite and pseudo-finite dose applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Barriers in Higher Education for Persons with Handicaps: A Continued Challenge.

ERIC Educational Resources Information Center

Stilwell, William E.; And Others

The degree to which Kentucky's public and private colleges and junior colleges are meeting the needs of persons with handicaps was evaluated. A 23-item questionnaire was sent to the state's 57 higher education institutions, and 45 responded. The findings are discussed in relation to admission and orientation procedures; social barriers; and…

Critical Barriers to the Adoption of Instructional Television in Higher Education.

ERIC Educational Resources Information Center

Koontz, F. R. (Bud)

1989-01-01

Examines barriers to the adoption of instructional television in higher education, for both the classroom and distance education. Characteristics that affect the adoption of innovations are described, the role and attitudes of faculty and administrators are discussed, and ways to make instructional television more effective are suggested. (12…

Effect of substitution group on dielectric properties of 4H-pyrano [3, 2-c] quinoline derivatives thin films

NASA Astrophysics Data System (ADS)

H, M. Zeyada; F, M. El-Taweel; M, M. El-Nahass; M, M. El-Shabaan

2016-07-01

The AC electrical conductivity and dielectrical properties of 2-amino-6-ethyl-5-oxo-4-(3-phenoxyphenyl)-5,6-dihydro-4H-pyrano[3, 2-c]quinoline-3-carbonitrile (Ph-HPQ) and 2-amino-4-(2-chlorophenyl)-6-ethyl-5-oxo-5,6-dihydro-4H-pyrano [3, 2-c] quinoline-3-carbonitrile (Ch-HPQ) thin films were determined in the frequency range of 0.5 kHz-5 MHz and the temperature range of 290-443 K. The AC electrical conduction of both compounds in thin film form is governed by the correlated barrier hopping (CBH) mechanism. Some parameters such as the barrier height, the maximum barrier height, the density of charges, and the hopping distance were determined as functions of temperature and frequency. The phenoxyphenyl group has a greater influence on those parameters than the chlorophenyl group. The AC activation energies were determined at different frequencies and temperatures. The dielectric behaviors of Ph-HPQ and Ch-HPQ were investigated using the impedance spectroscopy technique. The impedance data are presented in Nyquist diagrams for different temperatures. The Ch-HPQ films have higher impedance than the Ph-HPQ films. The real dielectric constant and dielectric loss show a remarkable dependence on the frequency and temperature. The Ph-HPQ has higher dielectric constants than the Ch-HPQ.

Identification of Management Information System (MIS) Strategies Barriers in Higher Education Institutions through Multi-Criteria Decision Making (MCDM) Approach: Case Study of Ferdowsi University of Mashhad

ERIC Educational Resources Information Center

Hosseini, Mirza Hasan; Karimzadegan, Davood; Sazvar, Azam

2012-01-01

Each organization or company, regardless to its restrictions, purposes, and type of the activity, in order to fulfill and manage the duties is in need of various data and pieces of information. The aforesaid cases are generated by managers and employees and used by all the staffs. The manifest issue of current days is that organizations and…

Major Barriers Responsible for Malnutrition in Hemodialysis Patients: Challenges to Optimal Nutrition

PubMed Central

Ekramzadeh, Maryam; Mazloom, Zohreh; Jafari, Peyman; Ayatollahi, Maryam; Sagheb, Mohammad Mahdi

2014-01-01

Background: Nutritional barriers may contribute to malnutrition in hemodialysis (HD) patients. Higher rates of morbidity and mortality rates have been reported in malnourished HD patients. These patients are faced with different challenges affecting their nutritional status. Objectives: The aim of this cross-sectional study was to identify most important barriers responsible for malnutrition in HD patients. Patients and Methods: We randomly selected 255 of 800 stable HD patients from three HD centers with an age range of 18-85 years, who had been on hemodialysis for at least three months without any acute illness. Each patient was interviewed to evaluate malnutrition [subjective global assessment (SGA), malnutrition inflammation score (MIS)], and potential medical, behavioral and socioeconomic barriers. Body composition of patients was checked through bioelectrical impedance analysis (BIA). Routine clinical markers of malnutrition such as serum albumin and total protein were measured using standard automated techniques. Binary logistic regression model was used to find the association between nutritional markers and potential barriers. Results: Patients with higher SGA had lower knowledge about general nutrition [odds ratio (OR), 1.3], potassium (OR, 1.89), difficulty chewing (OR, 1.16), and shopping (OR, 1.16). Those with greater MIS scores had poor appetite (OR, 1.3), depression (OR, 1.21), and difficulty with cooking (OR, 1.15). Lower BCM (body cell mass) was associated with poor appetite (OR, 0.92) and needed help for cooking (OR, 0.88). Patients with higher BFMI (body fat mass index) had insufficient general nutrition (OR, 1.15), and protein (OR, 1.27) knowledge, and needed help for shopping (OR, 1.14). Moreover, patients with higher SGA scores were those with older age and longer duration of HD. Conclusions: Three medical barriers (poor appetite, depression and difficulty chewing), one behavioral barrier (poor total nutrition, protein, and potassium knowledge), and one socioeconomic barrier (needing help for shopping and cooking) were independently associated with nutritional markers. PMID:25738117

Physical Activity With and Without TV Viewing: Effects on Enjoyment of Physical Activity and TV, Exercise Self-Efficacy, and Barriers to Being Active in Overweight Adults.

PubMed

Steeves, Jeremy A; Bassett, David R; Fitzhugh, Eugene C; Raynor, Hollie; Cho, Chi; Thompson, Dixie L

2016-04-01

Physical activity (PA) is enjoyable, but there are barriers to participation. TV viewing is highly enjoyable with limited barriers. Exercising while viewing TV may impact enjoyment, exercise self-efficacy, and barriers to PA, compared with exercising without TV. 58 sedentary, overweight adults were randomized to 1 of 2 PA prescriptions: one that increased PA during TV viewing (TV Commercial Stepping), and another that focused solely on PA (Walking). Random effects models tested changes in enjoyment of TV and PA, exercise self-efficacy, and barriers to PA across time (baseline, 3, and 6 months) and PA prescription during a 6-month PA intervention. At baseline, TV was more enjoyable than PA. Over the 6-month intervention, enjoyment of TV viewing did not change, but enjoyment of PA and exercise self-efficacy significantly increased, while barriers to PA significantly decreased for both groups compared with baseline (P < .05). While enjoyment of TV viewing remained constant, PA became more enjoyable, confidence to exercise increased, and barriers to being active were reduced for previously sedentary adults participating in a behavioral PA intervention. These findings highlight the importance of encouraging inactive adults to engage in some form of PA, whether it occurs with or without TV viewing.

Three-dimensional biomimetic vascular model reveals a RhoA, Rac1, and N-cadherin balance in mural cell-endothelial cell-regulated barrier function.

PubMed

Alimperti, Stella; Mirabella, Teodelinda; Bajaj, Varnica; Polacheck, William; Pirone, Dana M; Duffield, Jeremy; Eyckmans, Jeroen; Assoian, Richard K; Chen, Christopher S

2017-08-15

The integrity of the endothelial barrier between circulating blood and tissue is important for blood vessel function and, ultimately, for organ homeostasis. Here, we developed a vessel-on-a-chip with perfused endothelialized channels lined with human bone marrow stromal cells, which adopt a mural cell-like phenotype that recapitulates barrier function of the vasculature. In this model, barrier function is compromised upon exposure to inflammatory factors such as LPS, thrombin, and TNFα, as has been observed in vivo. Interestingly, we observed a rapid physical withdrawal of mural cells from the endothelium that was accompanied by an inhibition of endogenous Rac1 activity and increase in RhoA activity in the mural cells themselves upon inflammation. Using a system to chemically induce activity in exogenously expressed Rac1 or RhoA within minutes of stimulation, we demonstrated RhoA activation induced loss of mural cell coverage on the endothelium and reduced endothelial barrier function, and this effect was abrogated when Rac1 was simultaneously activated. We further showed that N -cadherin expression in mural cells plays a key role in barrier function, as CRISPR-mediated knockout of N -cadherin in the mural cells led to loss of barrier function, and overexpression of N -cadherin in CHO cells promoted barrier function. In summary, this bicellular model demonstrates the continuous and rapid modulation of adhesive interactions between endothelial and mural cells and its impact on vascular barrier function and highlights an in vitro platform to study the biology of perivascular-endothelial interactions.

Physical activity barriers and facilitators among working mothers and fathers

PubMed Central

2014-01-01

Background The transition to parenthood is consistently associated with declines in physical activity. In particular, working parents are at risk for inactivity, but research exploring physical activity barriers and facilitators in this population has been scarce. The purpose of this study was to qualitatively examine perceptions of physical activity among working parents. Methods Working mothers (n = 13) and fathers (n = 12) were recruited to participate in one of four focus group sessions and discuss physical activity barriers and facilitators. Data were analyzed using immersion/crystallization in NVivo 10. Results Major themes for barriers included family responsibilities, guilt, lack of support, scheduling constraints, and work. Major themes for facilitators included being active with children or during children’s activities, being a role model for children, making time/prioritizing, benefits to health and family, and having support available. Several gender differences emerged within each theme, but overall both mothers and fathers reported their priorities had shifted to focus on family after becoming parents, and those who were fitting in physical activity had developed strategies that allowed them to balance their household and occupational responsibilities. Conclusions The results of this study suggest working mothers and fathers report similar physical activity barriers and facilitators and would benefit from interventions that teach strategies for overcoming barriers and prioritizing physical activity amidst the demands of parenthood. Future interventions might consider targeting mothers and fathers in tandem to create an optimally supportive environment in the home. PMID:24974148

Parents' Perceived Barriers to Healthful Eating and Physical Activity for Low-Income Adolescents Who Are at Risk for Type 2 Diabetes

ERIC Educational Resources Information Center

Peterson, Sharon L.; Bell, Toya Wilson; Hasin, Afroza

2009-01-01

Healthful eating and regular physical activity are vitally important for low-income adolescents who are at risk for developing type 2 diabetes (T2DM). To design a relevant, community-based intervention for these at risk adolescents, parent perceptions of barriers to healthful eating and physical activity should be assessed. Such barriers have been…

Influence of cell shape, inhomogeneities and diffusion barriers in cell polarization models

NASA Astrophysics Data System (ADS)

Giese, Wolfgang; Eigel, Martin; Westerheide, Sebastian; Engwer, Christian; Klipp, Edda

2015-12-01

In silico experiments bear the potential for further understanding of biological transport processes by allowing a systematic modification of any spatial property and providing immediate simulation results. Cell polarization and spatial reorganization of membrane proteins are fundamental for cell division, chemotaxis and morphogenesis. We chose the yeast Saccharomyces cerevisiae as an exemplary model system which entails the shuttling of small Rho GTPases such as Cdc42 and Rho, between an active membrane-bound form and an inactive cytosolic form. We used partial differential equations to describe the membrane-cytosol shuttling of proteins. In this study, a consistent extension of a class of 1D reaction-diffusion systems into higher space dimensions is suggested. The membrane is modeled as a thin layer to allow for lateral diffusion and the cytosol is modeled as an enclosed volume. Two well-known polarization mechanisms were considered. One shows the classical Turing-instability patterns, the other exhibits wave-pinning dynamics. For both models, we investigated how cell shape and diffusion barriers like septin structures or bud scars influence the formation of signaling molecule clusters and subsequent polarization. An extensive set of in silico experiments with different modeling hypotheses illustrated the dependence of cell polarization models on local membrane curvature, cell size and inhomogeneities on the membrane and in the cytosol. In particular, the results of our computer simulations suggested that for both mechanisms, local diffusion barriers on the membrane facilitate Rho GTPase aggregation, while diffusion barriers in the cytosol and cell protrusions limit spontaneous molecule aggregations of active Rho GTPase locally.

Synthesis of [(Ca1-xSrx)2-2y](Ti2-2yLi2y)Si2yO6-y Ceramic and its Application in Efficient Plasma Decomposition of CO2

NASA Astrophysics Data System (ADS)

Li, Ruixing; Tang, Qing; Yin, Shu; Sato, Tsugio

According to both the first principle and materials chemistry, a method for fabricating [(Ca1-xSrx)2-2y](Ti2-2yLi2y)Si2yO6-y ceramic was investigated. It was considered that the sintering was promoted by self-accelerated diffusion due to the formation of point defects caused by doping with Li2Si2O5. Consequently, a concept of non-stoichiometrically activated sintering, which was enhanced by point defects without the help of a grain boundary phase, was systematically studied in the Ca1-xSrxTiO3-Li2Si2O5 system. The mechanical and dielectric properties of [(Ca1-xSrx)2-2y](Ti2-2yLi2y)Si2yO6-y were greatly enhanced by adding Li2Si2O5. To improve CO2 decomposition activity, [(Ca1-xSrx)2-2y](Ti2-2yLi2y)Si2yO6-y, which possesses both high permittivity and high dielectric strength was used as a dielectric barrier to decompose CO2 by dielectric barrier discharges (DBDs) plasma without using any catalyst and auxiliary substance. It successfully generated DBDs plasma and the CO2 conversion was much higher than that using an alumina or a silica glass barrier which was widely used as the dielectric barrier in previous studies.

Peristomal skin disorders in patients with intestinal and urinary ostomies: influence of adhesive forces of various hydrocolloid wafer skin barriers.

PubMed

Omura, Yuko; Yamabe, Motoko; Anazawa, Sadao

2010-01-01

This study examines the adhesiveness of hydrocolloid wafers and its relationship to physical damage of the underlying skin. Observational study. All subjects received ostomy care at the Tokyo Ostomy Center and outpatient departments of 4 hospitals in Tokyo, Japan. One hundred ninety-four of 917 patients receiving care over a 23-year span agreed to participate in the research. Subjects met 2 inclusion criteria: (1) ostomy management was performed using a combination of skin barriers and an adhesive ostomy pouch; and (2) the patient's medical file and color photographs were available, allowing analysis of the peristomal skin over time. Photographs were taken with an Olympus (OM2) camera equipped with an Olympus macro lens and a ring flash. We analyzed the impact of the adhesive force of various hydrocolloid wafers on the underlying skin. Photographs were digitized and systematically examined the peristomal skin exposed to regular use of skin barriers. The observation period varied among individual patients, ranging from 1 week to 30 years after surgery. The incidence of dermatologic changes (active, inactive, and area cutanea changes) was lower in patients who used skin barriers with adhesive force of not more than 2 Newtons(N) than among those using higher forces (>2 N). Specifically, there was a significant difference in change of the area cutanea. The incidence of papules and erosion was unrelated to the adhesive force of skin barriers. These results suggest that the peristomal skin is irritated by repeated peeling, resulting in physical damage to the horny layer of the skin. The presence of papules and erosion was not associated with the adhesive force of skin barriers. This finding suggests that these changes are associated with an inflammatory process, possibly caused by chemical substances within the skin barrier.

The Association Between Self-Management Barriers and Self-Efficacy in Chinese Patients with Type 2 Diabetes: The Mediating Role of Appraisal.

PubMed

Cheng, Li; Sit, Janet W H; Leung, Doris Y P; Li, Xiaomei

2016-10-01

Patients with higher levels of self-management barriers are more likely to exhibit a lower level of self-efficacy. However, the theoretically meaningful mechanisms underlying the association between the two variables have not yet been established. Informed by the Transactional Model of Stress and Coping, this study aimed to examine the potential role of diabetes appraisal on the association of self-management barriers and self-efficacy in patients with type 2 diabetes mellitus. This article presents the secondary data analyses of a multicenter, cross-sectional study. A sample of 346 adults with type 2 diabetes was interviewed, using the Personal Diabetes Questionnaire, the Appraisal of Diabetes scale, the Diabetes Empowerment Scale-Short Form, and the Summary of Diabetes Self-Care Activities. Structure equation modeling was performed with 10,000 bootstrap samples using Mplus 7. The hypothesized model provided a good fit to the data (χ 2 = 22.975, df = 33; p = .1144; CFI = 0.989; SRMR = 0.036; RMSEA = 0.042). The mediating effect of diabetes appraisal on the association of self-management barriers and self-efficacy was significant (β = -0.521; 95% CI: -0.865, -0.283), explaining 44.82% of the total effect of barriers on self-efficacy. Significant associations were also detected between diet knowledge and diabetes appraisal (β = 0.148, p = .047). Diabetes appraisal plays a mediating role in the association between self-management barriers and self-efficacy in patients with type 2 diabetes. Reflecting on patients' appraisal of diabetes can help to develop evidence-based and patient-centered interventions. Interventions that enhance individuals' positive appraisal of diabetes have the potential to buffer the negative effects of self-management barriers on self-efficacy. © 2016 Sigma Theta Tau International.

The contribution of general and cancer-related variables in explaining physical activity in a breast cancer population 3 weeks to 6 months post-treatment.

PubMed

Charlier, Caroline; Van Hoof, Elke; Pauwels, Evelyn; Lechner, Lilian; Spittaels, Heleen; De Bourdeaudhuij, Ilse

2013-01-01

Physical activity determinants are subject to change when confronted with the diagnosis of 'cancer' and new cancer-related determinants appear. The aim of the present study is to compare the contribution of cancer-related determinants with more general ones in explaining physical activity 3 weeks to 6 months post-treatment. A theory-based and validated questionnaire was used to identify physical activity levels (total and domain-specific) and associated determinants among 464 breast cancer survivors (aged 18 to 65 years) 3 weeks to 6 months post-treatment. Descriptive analyses showed higher scores for general determinants in comparison with cancer-related determinants. Nevertheless, regression analyses showed that both general and cancer-related determinants explained total and domain-specific physical activity. Self-efficacy, enjoyment, social support, lack of time and lack of company were important general determinants. The perception of returning to normal life, cancer-related barriers (fatigue, lack of energy and physical side effects) and self-efficacy in overcoming these barriers were important cancer-related determinants. Although results differed according to the women's working status and the physical activity domain, general self-efficacy explained most physical activity types in both groups. Comparable with the general population, enhancing breast cancer survivors' self-efficacy in being sufficiently physically active seems to be important in physical activity interventions post-treatment. However, interventions should be tailored to the experienced symptoms and working status of the women. Copyright © 2011 John Wiley & Sons, Ltd.

Assessment of physical inactivity and perceived barriers to physical activity among health college students, south-western Saudi Arabia.

PubMed

Awadalla, N J; Aboelyazed, A E; Hassanein, M A; Khalil, S N; Aftab, R; Gaballa, I I; Mahfouz, A A

2014-10-20

Physical inactivity is a public health problem in Saudi Arabia. A cross-sectional study was carried out to evaluate the pattern of physical activity, predictors of physical inactivity and perceived barriers to physical activity among health college students in King Khalid University. A total of 1257 students (426 males and 831 females) were recruited. The Arabic short form of the International Physical Activity Questionnaire was used. Overall, 58.0% of the students were physically inactive. Only 13.4% of the students performed vigorous physical activity, 14.8% moderate-intensity physical activity and 29.9% walking activities which met World Health Organization criteria of health-enhancing physical activities. The prevalence of inactive leisure time was 47.5%. The independent predictors of physical inactivity were non-membership of sports clubs and being a medical student. The top reported barrier to physical activity among inactive students was time limitations (51.3%). Overcoming perceived barriers may increase physical activity among students.

Barriers to Physical Activity in East Harlem, New York

PubMed Central

Fox, Ashley M.; Mann, Devin M.; Ramos, Michelle A.; Kleinman, Lawrence C.; Horowitz, Carol R.

2012-01-01

Background. East Harlem is an epicenter of the intertwining epidemics of obesity and diabetes in New York. Physical activity is thought to prevent and control a number of chronic illnesses, including diabetes, both independently and through weight control. Using data from a survey collected on adult (age 18+) residents of East Harlem, this study evaluated whether perceptions of safety and community-identified barriers were associated with lower levels of physical activity in a diverse sample. Methods. We surveyed 300 adults in a 2-census tract area of East Harlem and took measurements of height and weight. Physical activity was measured in two ways: respondents were classified as having met the weekly recommended target of 2.5 hours of moderate physical activity (walking) per week (or not) and reporting having engaged in at least one recreational physical activity (or not). Perceived barriers were assessed through five items developed by a community advisory board and perceptions of neighborhood safety were measured through an adapted 7-item scale. Two multivariate logistic regression models with perceived barriers and concerns about neighborhood safety were modeled separately as predictors of engaging in recommended levels of exercise and recreational physical activity, controlling for respondent weight and sociodemographic characteristics. Results. The most commonly reported perceived barriers to physical activity identified by nearly half of the sample were being too tired or having little energy followed by pain with exertion and lack of time. Multivariate regression found that individuals who endorsed a greater number of perceived barriers were less likely to report having met their weekly recommended levels of physical activity and less likely to engage in recreational physical activity controlling for covariates. Concerns about neighborhood safety, though prevalent, were not associated with physical activity levels. Conclusions. Although safety concerns were prevalent in this low-income, minority community, it was individual barriers that correlated with lower physical activity levels. PMID:22848797

Barriers and facilitators to participation in workplace health promotion (WHP) activities: results from a cross-sectional survey of public-sector employees in Tasmania, Australia.

PubMed

Kilpatrick, Michelle; Blizzard, Leigh; Sanderson, Kristy; Teale, Brook; Jose, Kim; Venn, Alison

2017-12-01

Issue addressed Workplaces are promising settings for health promotion, yet employee participation in workplace health promotion (WHP) activities is often low or variable. This study explored facilitating factors and barriers associated with participation in WHP activities that formed part of a comprehensive WHP initiative run within the Tasmanian State Service (TSS) between 2009 and 2013. Methods TSS employee (n=3228) completed surveys in 2013. Data included sociodemographic characteristics, employee-perceived availability of WHP activities, employee-reported participation in WHP activities, and facilitators and barriers to participation. Ordinal log-link regression was used in cross-sectional analyses. Results Significant associations were found for all facilitating factors and participation. Respondents who felt their organisation placed a high priority on WHP, who believed that management supported participation or that the activities could improve their health were more likely to participate. Time- and health-related barriers were associated with participation in fewer activities. All associations were independent of age, sex, work schedule and employee-perceived availability of programs. Part-time and shift-work patterns, and location of activities were additionally identified barriers. Conclusion Facilitating factors relating to implementation, peer and environmental support, were associated with participation in more types of activities, time- and health-related barriers were associated with less participation. So what? Large and diverse organisations should ensure WHP efforts have manager support and adopt flexible approaches to maximise employee engagement.

Differences in behavior, psychological factors, and environmental factors associated with participation in school sports and other activities in adolescence.

PubMed

Harrison, Patricia A; Narayan, Gopalakrishnan

2003-03-01

This study examined whether participation in school team sports, exclusively or in combination with other extracurricular activities, is associated with higher levels of psychosocial functioning and healthy behavior than participation in other extracurricular activities alone or nonparticipation. The study sample includes 50,168 ninth grade public school students who completed an anonymous, voluntary statewide survey in 2001. Students were classified into four groups based on their participation in sports and other activities (such as clubs, volunteer work, band, choir, or music lessons): neither, both, other activities only, and sports only. Odds ratios for the group involved in both types of activities were significantly higher than those for all the other groups for all healthy behaviors and measures of connectedness, and significantly lower for all but one of the unhealthy behaviors. Students involved in sports, alone or in combination with other activities, had significantly higher odds than the other two groups for exercise, milk consumption, and healthy self-image, and significantly lower odds for emotional distress, suicidal behavior, family substance abuse, and physical and sexual abuse victimization. Students involved in other activities, alone or in combination with sports, had significantly higher odds than the other two groups for doing homework and significantly lower odds for alcohol consumption, marijuana use, and vandalism. The finding that abuse victims appeared to avoid sports but not other group activities raises concern and merits further research. Considering the potential benefits of participation in sports and other activities, more research is needed to identify and overcome barriers or deterrents, particularly for youth from low-income families.

Current-induced transition from particle-by-particle to concurrent intercalation in phase-separating battery electrodes.

PubMed

Li, Yiyang; El Gabaly, Farid; Ferguson, Todd R; Smith, Raymond B; Bartelt, Norman C; Sugar, Joshua D; Fenton, Kyle R; Cogswell, Daniel A; Kilcoyne, A L David; Tyliszczak, Tolek; Bazant, Martin Z; Chueh, William C

2014-12-01

Many battery electrodes contain ensembles of nanoparticles that phase-separate on (de)intercalation. In such electrodes, the fraction of actively intercalating particles directly impacts cycle life: a vanishing population concentrates the current in a small number of particles, leading to current hotspots. Reports of the active particle population in the phase-separating electrode lithium iron phosphate (LiFePO4; LFP) vary widely, ranging from near 0% (particle-by-particle) to 100% (concurrent intercalation). Using synchrotron-based X-ray microscopy, we probed the individual state-of-charge for over 3,000 LFP particles. We observed that the active population depends strongly on the cycling current, exhibiting particle-by-particle-like behaviour at low rates and increasingly concurrent behaviour at high rates, consistent with our phase-field porous electrode simulations. Contrary to intuition, the current density, or current per active internal surface area, is nearly invariant with the global electrode cycling rate. Rather, the electrode accommodates higher current by increasing the active particle population. This behaviour results from thermodynamic transformation barriers in LFP, and such a phenomenon probably extends to other phase-separating battery materials. We propose that modifying the transformation barrier and exchange current density can increase the active population and thus the current homogeneity. This could introduce new paradigms to enhance the cycle life of phase-separating battery electrodes.

Free energy landscape of dissociative adsorption of methane on ideal and defected graphene from ab initio simulations

NASA Astrophysics Data System (ADS)

Wlazło, M.; Majewski, J. A.

2018-03-01

We study the dissociative adsorption of methane at the surface of graphene. Free energy profiles, which include activation energies for different steps of the reaction, are computed from constrained ab initio molecular dynamics. At 300 K, the reaction barriers are much lower than experimental bond dissociation energies of gaseous methane, strongly indicating that the graphene surface acts as a catalyst of methane decomposition. On the other hand, the barriers are still much higher than on the nickel surface. Methane dissociation therefore occurs at a higher rate on nickel than on graphene. This reaction is a prerequisite for graphene growth from a precursor gas. Thus, the growth of the first monolayer should be a fast and efficient process while subsequent layers grow at a diminished rate and in a more controllable manner. Defects may also influence reaction energetics. This is evident from our results, in which simple defects (Stone-Wales defect and nitrogen substitution) lead to different free energy landscapes at both dissociation and adsorption steps of the process.

Barriers to Accommodation Use for Students with Disabilities in Postsecondary Education

ERIC Educational Resources Information Center

Lyman, Michael James

2013-01-01

Students with disabilities at the postsecondary level face a number of different barriers to accommodation use. Past research has shown that students with disabilities that use accommodations obtain greater academic achievement and higher graduation rates. Limited research has been conducted to identify barriers to accommodation use, and the…

Perceived Benefits, Facilitators, Disadvantages, and Barriers for Physical Activity Amongst South Asian Adolescents in India and Canada.

PubMed

Rajaraman, Divya; Correa, Natasha; Punthakee, Zubin; Lear, Scott A; Jayachitra, Krishnaswamy G; Vaz, Mario; Swaminathan, Sumathi

2015-07-01

The purpose of this study was to understand perceived benefits, facilitators, disadvantages, and barriers for physical activity among South Asian adolescents in India and Canada. Thirteen focus group discussions with South Asian (origin) adolescent boys and girls of different nutritional status and socioeconomic status in rural and urban India and urban Canada. Across the groups, fitness and 'energy' were perceived to be major benefits of physical activity. In India, better academic performance was highlighted, while health benefits were well detailed in Canadian groups. In all settings, friends, family, and teachers were perceived as facilitators of as well as barriers to physical activity. Lack of a safe space to play was a major concern for urban adolescents, while academic pressures and preference for other sedentary recreational activities were common barriers across all groups. Girls were less likely than boys to be interested in physical activity, with girls' participation in India further limited by societal restrictions. The study suggests key areas for promotion of physical activity among South Asian adolescents: balance between academic pressure and opportunities for physical activity, especially in India; urban planning for a built environment conducive to physical activity; and gender-sensitive programming to promote girls' activity which also addresses culture-specific barriers.

Academic Workload: The Silent Barrier to the Implementation of Technology-Enhanced Learning Strategies in Higher Education

ERIC Educational Resources Information Center

Gregory, Mary Sarah-Jane; Lodge, Jason Michael

2015-01-01

The effect of technology-enhanced learning (TEL) strategies in higher education has arguably been transformative despite the not-insignificant barriers existing in this context. Throughout the discourse very little attention has been paid to those primarily responsible for this implementation--academic teaching staff. This paper aims to highlight…

DREAMing Big: Understanding the Current Context of Academic and Career Decision-Making for Undocumented Students

ERIC Educational Resources Information Center

Kantamneni, Neeta; Dharmalingam, Kavitha; Tate, Jessica M.; Perlman, Beth L.; Majmudar, Chaitasi R.; Shada, Nichole

2016-01-01

Undocumented student immigrants in the United States face substantial challenges in higher education including systemic, institutional, and cultural barriers that often impede access to and success in higher education. These barriers directly influence academic and work opportunities. The purpose of this article is to discuss the myriad of factors…

Older Adults' Acceptance of Activity Trackers

PubMed Central

Preusse, Kimberly C.; Mitzner, Tracy L.; Fausset, Cara Bailey; Rogers, Wendy A.

2016-01-01

Objective To assess the usability and acceptance of activity tracking technologies by older adults. Method First in our multi-method approach, we conducted heuristic evaluations of two activity trackers that revealed potential usability barriers to acceptance. Next, questionnaires and interviews were administered to 16 older adults (Mage=70, SDage=3.09, rangeage= 65-75) before and after a 28-day field study to understand facilitators and additional barriers to acceptance. These measurements were supplemented with diary and usage data and assessed if and why users overcame usability issues. Results The heuristic evaluation revealed usability barriers in System Status Visibility; Error Prevention; and Consistency and Standards. The field study revealed additional barriers (e.g., accuracy, format), and acceptance-facilitators (e.g., goal-tracking, usefulness, encouragement). Discussion The acceptance of wellness management technologies, such as activity trackers, may be increased by addressing acceptance-barriers during deployment (e.g., providing tutorials on features that were challenging, communicating usefulness). PMID:26753803

Barriers and facilitators to intraorganizational collaboration in public health: Relational coordination across public health services targeting individuals and populations.

PubMed

McCullough, J Mac; Eisen-Cohen, Eileen; Lott, Breanne

2018-05-09

Modern public health emphasizes population-focused services, which may require collaborative work both across and within organizations. Studies have explored interorganizational collaborations, but there are little data regarding collaborations within public health organizations. We measured intraorganizational collaboration and identified barriers and facilitators to collaboration within a large public health department through a mixed-methods study. Our study occurred at the Maricopa County (Arizona) Department of Public Health, the third largest local public health jurisdiction in the United States. To measure collaboration, we surveyed staff using the relational coordination tool. To identify barriers and facilitators to collaboration, we performed key informant interviews with department personnel. Relational coordination scores varied according to the focus of the service; clinical services had significantly lower levels of relational coordination than population-focused services (p < .01). We found high levels of mutual respect and lower levels of shared knowledge across services. Facilitators to collaboration included purposive cross-program meetings around specific topics, the organization's structure and culture, and individuals' social identities. Barriers included raised expectations for collaboration, low slack resources, member's self-interest, and trust. The relational coordination of services varied significantly according to the focus of the service. Population-focused public health services had higher levels of relational coordination than individually focused services. Collaboration was facilitated and impeded by both well-known and potentially emergent factors, such as purposive cross-service meetings and organizational culture. Population-focused services possessed higher levels of collaboration than individually focused services. Intraorganizational collaboration for improved population health relies on deliberate support from senior management and structured activities to increase shared knowledge and mutual respect.

Pigmented-MDCK (P-MDCK) Cell Line with Tunable Melanin Expression: An In Vitro Model for the Outer Blood-Retinal-Barrier

PubMed Central

Kadam, Rajendra S.; Scheinman, Robert. I.; Kompella, Uday B.

2013-01-01

Purpose Retinal pigment epithelium, which forms the outer blood-retinal-barrier, is a critical barrier for transport of drugs to the retina. The purpose of this study was to develop a pigmented MDCK (P-MDCK) cell line as a rapidly established in vitro model for the outer blood-retinal-barrier to assess the influence of melanin pigment on solute permeability. Methods A melanin synthesizing P-MDCK cell line was developed by lentiviral transduction of human tyrosinase and p-protein genes in MDCK (NBL-2) cells. Melanin content, tyrosinase activity (conversion of L-dopa to dopachrome), and transepithelial electrical resistance (TEER) were measured. Expression of tyrosinase protein and p-protein in P-MDCK cells was confirmed by confocal microscopy. Effect of L-tyrosine (0 to 2 mM) in culture medium on melanin synthesis in P-MDCK cells was evaluated. Cell uptake and transepithelial transport of pigment-binding chloroquine (Log D = 1.59) and a negative control salicylic acid (Log D = −1.14) were investigated. Results P-MDCK cells expressed tyrosinase and p-protein. Tyrosinase activity was 4.5 fold higher in P-MDCK cells as compared to wild-type MDCK cells. The transepithelial electrical resistance stabilized by day 4 in both cell types, with the TEER being 871 ± 30 and 876 ± 53 Ω.cm2 for P-MDCK and wild-type cells, respectively. Melanin content in P-MDCK cells depended on the concentration of L-tyrosine in culture medium, and increased from 3 to 54 µg/mg protein with an increase in L-tyrosine content from 0 to 2 mM. When the cells were grown in 2 mM L-tyrosine, uptake of chloroquine was 2.3 fold higher and the transepithelial transport was 2.2 fold lower in P-MDCK cells when compared to wild-type MDCK cells. No significant difference was observed for both cell uptake and transport of salicylic acid. Conclusions We developed a P-MDCK cell line with tunable melanin synthesis as a rapidly developing surrogate for retinal pigment epithelium. PMID:23003570

Obstacles to action in arthritis: a community case-control study.

PubMed

Hutton, Ingrid; Gamble, Greg; McLean, Grant; Butcher, Hugh; Gow, Peter; Dalbeth, Nicola

2009-07-01

Despite the benefits of physical activity, people with arthritis are less active than the general population. The aim of this study was to determine the motivators and obstacles to physical activity for adults with arthritis. Participants were identified from the Obstacles to Action Study, a community based study of 8163 adults, which explored barriers and motivators to physical activity. A 1:1 case-control study was designed; cases were identified as those participants who reported arthritis (n = 1106). Each case was matched with an age, sex and ethnicity-matched non-arthritis control (n = 1106). Cases were less likely to achieve recommended physical activity targets (58.8% vs. 68.1% P = 0.00001). Furthermore, fewer people with arthritis believed that physical activity would help them lead healthy lives (86.7% vs. 91.3% P = 0.006) or viewed physical activity as a priority (53.8% vs. 59.8% P = 0.005). Cases were less confident in their abilities to try a new activity (37.1% vs. 43.7% P = 0.002) or maintain a healthy weight (65.0% vs. 74.3% P = 0.00001). Cases also reported greater negative impact scores for barriers to activity, particularly arthritis, accessibility, cost and discomfort while exercising. Motivators and environmental barriers to activity were similar for cases and controls. These findings persisted after adjusting for educational level, body mass index and comorbidities. People with arthritis are less active and demonstrate different attitudes toward physical activity. Although people with arthritis identify similar environmental barriers, they have different psychosocial barriers. In order to design effective physical activity programs for people with arthritis, these barriers must be specifically addressed.

Motivators of and Barriers to Engaging in Physical Activity: Perspectives of Low-Income Culturally Diverse Adolescents and Adults.

PubMed

Bragg, Marie A; Tucker, Carolyn M; Kaye, Lily B; Desmond, Frederic

2009-01-01

Obesity rates are rising in the United States, especially among low-income and racial/ethnic minority individuals. Exploring motivators and barriers relative to engaging in physical activity is imperative. The purpose of this study was to identify motivators and barriers relative to engagement in physical activity as reported by culturally diverse low-income adolescents and adults. A total of 91 adolescent (11 to 15 years of age) and adult (18 years of age or older) participants who self-identified as African American, Hispanic, or non-Hispanic White engaged in age group-, race/ethnicity-, and gender-concordant focus groups. Qualitative data analysis indicated that the motivators and barriers most commonly identified among the adolescent and adult focus groups were: social influence; time and priorities; physical environment; fun and enjoyment; inherently physical activities; weight concerns; fatigue, physical discomfort and current fitness level; and immediate positive feelings. Findings were generally similar across age group, gender and race/ethnicity. Age group-specific, gender-specific and race/ethnicity-specific motivators and barriers were related to how commonly the motivators and barriers were identified among each group. Implications for increasing physical activity among low-income culturally diverse adolescents and adults are discussed.

Using self-regulation theory to examine patient goals, barriers, and facilitators for taking medication.

PubMed

Kucukarslan, Suzan N; Thomas, Sheena; Bazzi, Abraham; Virant-Young, Deborah

2009-12-01

: Self-regulation theory predicts that patient behavior is determined by the patient's assessment of his/her condition (illness presentation) and related health goals. Patients will adapt their behavior to achieve those goals. However, there are multiple levels of goals. In such cases, those lower-level goals (health goals) that are strongly correlated with higher-level goals (i.e. quality of life [QOL]) are more likely to drive patient behavior. Medication non-compliance is a health behavior that challenges healthcare practitioners. Thus, the primary aim of this paper is to explore the relationship between the lower-level goals for taking medication with higher-level goals. This paper also identifies patient-perceived barriers and facilitators toward achieving goals as they may relate to patients' illness representation. : To identify lower- and higher-level goals associated with medication use for chronic conditions. To determine if there is a relationship between higher-level (global) goals and lower-level (health-related) goals. To identify patient-perceived facilitators and barriers to achieving those goals. : This was a prospective, observational study using a mailed survey. The setting was a US Midwestern state-wide survey. Participants were patients living in the community with hypertension, heart disease, diabetes mellitus, or arthritis, and taking prescription medication for any one of those conditions. The main outcome measures were lower- and higher-level goals related to medication use. The survey asked the participants if they had achieved their goals and to identify factors that may pose as barriers or facilitators to achieving them. Pearson correlation was used to test the relationship between the lower- and higher-level goals at p < 0.05. : Responses from 292 qualifying patients were obtained. A significant relationship between lower- and higher-level goals existed (p = 0.03). Preventing future health problems was the most important lower-level goal for almost half of the respondents. Approximately 43% of the respondents said 'improving or maintaining quality of life' was their most important higher-level goal. Elderly respondents (65 years or older) said that being able to carry out daily activities on their own was their most important higher-level goal. To achieve this goal, they identified 'preventing future health problems' as the associated lower-level goal. One-third of the respondents stated that they had not yet achieved their medication-related goals. Patients identified good communication with their physicians (35%), the effectiveness of the drug product (32%), and their ability to monitor their condition (20%) as important factors toward helping them achieve their goals. Medication costs (30%), drug adverse effects (25%), and the lack of drug effectiveness (22%) were factors that patients identified as barriers to achieving their goals. : There is a significant and positive relationship between the lower- and higher-level goals. Healthcare providers can work with their patients to achieve their goals. Both good communication with the prescriber and the effectiveness of the drug product were identified as the most important facilitator by one-third of the respondents. Future research should study if relating the impact of good symptom control or the reduction of future health risks to QOL or longevity, as deemed relevant by the patient, influences medication adherence behavior.

Are thermal barriers "higher" in deep sea turtle nests?

PubMed

Santidrián Tomillo, Pilar; Fonseca, Luis; Paladino, Frank V; Spotila, James R; Oro, Daniel

2017-01-01

Thermal tolerances are affected by the range of temperatures that species encounter in their habitat. Daniel Janzen hypothesized in his "Why mountain passes are higher in the tropics" that temperature gradients were effective barriers to animal movements where climatic uniformity was high. Sea turtles bury their eggs providing some thermal stability that varies with depth. We assessed the relationship between thermal uniformity and thermal tolerance in nests of three species of sea turtles. We considered that barriers were "high" when small thermal changes had comparatively large effects and "low" when the effects were small. Mean temperature was lower and fluctuated less in species that dig deeper nests. Thermal barriers were comparatively "higher" in leatherback turtle (Dermochelys coriacea) nests, which were the deepest, as embryo mortality increased at lower "high" temperatures than in olive ridley (Lepidochelys olivacea) and green turtle (Chelonia mydas) nests. Sea turtles have temperature-dependent sex determination (TSD) and embryo mortality increased as temperature approached the upper end of the transitional range of temperatures (TRT) that produces both sexes (temperature producing 100% female offspring) in leatherback and olive ridley turtles. As thermal barriers are "higher" in some species than in others, the effects of climate warming on embryo mortality is likely to vary among sea turtles. Population resilience to climate warming may also depend on the balance between temperatures that produce female offspring and those that reduce embryo survival.

What prevents youth at clinical high risk for psychosis from engaging in physical activity? An examination of the barriers to physical activity.

PubMed

Newberry, Raeana E; Dean, Derek J; Sayyah, Madison D; Mittal, Vijay A

2018-06-13

Exercise has increasingly been proposed as a healthful intervention prior to and after the onset of psychosis. There is some evidence to suggest that youth at clinical high risk (CHR) for psychosis are less physically active and report more barriers to engaging in exercise; however, there has been relatively limited empirical work documenting this phenomenon, and to date, relationships between physical activity, barriers, and clinical phenomenology have been unclear. CHR (N = 51) and healthy control (N = 37) participants completed a structured clinical interview assessing attenuated psychotic symptoms and substance use, and an exercise survey that assessed current exercise practices, perceived physical fitness, and barriers related to engaging in exercise. CHR youth engaged in less physical activity, exhibited lower perception of fitness, and endorsed more barriers related to motivation for exercise. The CHR group showed significant negative correlations where lower perceptions of fitness were associated with increased negative, disorganized, and general symptoms. Decreased frequency of activity was related to more barriers of motivation. Interestingly, greater symptomatology in the CHR group was associated with more barriers of self-perception and motivation for engaging in exercise. However, findings suggested a nuanced relationship in this area; for example, increased physical activity was associated with increased substance use. The results of the current study support the notion that sedentary behavior is common in CHR youth, and more broadly, provide an impetus to target motivation through supervised exercise and fitness tracking to promote the health and well-being of CHR individuals. Copyright © 2018. Published by Elsevier B.V.

Qualitative exploration of nurses' decisions to activate rapid response teams.

PubMed

Astroth, Kim S; Woith, Wendy M; Stapleton, Stephen J; Degitz, R Joseph; Jenkins, Sheryl H

2013-10-01

To identify barriers and facilitators to nurses' decisions regarding activation of rapid response teams (RRTs) in hospitals. Hospitalised patients in the United States who experience cardiopulmonary arrest seldom recover. Most of these patients show signs of clinical deterioration prior to cardiopulmonary arrest. RRTs have been shown to decrease the incidence of cardiopulmonary arrest by bringing needed resources to unstable patients. Despite the evidence in support of the activation of RRTs, nurses do not always use this resource. Nurses' decisions to activate or not to activate the RRT are not clearly understood. We used a qualitative design for this study. A purposive sample of 15 medical/surgical nurses was recruited from a small medical centre in the Midwest. Researchers used semistructured, open-ended questions to elicit subject responses regarding facilitators and barriers to activating RRTs. Themes emerged and were categorised as facilitators and barriers to calling the RRT. Facilitators and barriers were then subdivided into distinct subthemes: RRT characteristics and unit culture. The expertise of the RRT members and support and encouragement from nursing unit colleagues and leaders emerged as two potential facilitators. Communication of the RRT members and calling the physician first emerged as two potential barriers. We also identified educational factors that were not clearly facilitators or barriers to calling the RRT. Further study is needed using quantitative designs with larger sample sizes. Nurses can build upon knowledge of facilitators and barriers related to RRT characteristics and nursing unit culture. © 2013 Blackwell Publishing Ltd.

A comparison of Australian families' expenditure on active and screen-based recreation using the ABS Household Expenditure Survey 2003/04.

PubMed

Aitken, Robert; King, Lesley; Bauman, Adrian

2008-06-01

This study aimed to investigate how much households with dependent children spend on active recreation (physical activity) compared with screen-based (sedentary) recreation, according to their household socioeconomic and demographic characteristics. The study analysed data from the 2003-04 Australian Bureau of Statistics Household Expenditure Survey, which collected information on household expenditure from a representational cross-section of private dwellings across Australia. In 2003-04, Australian households with dependent children spent an average of 1.5% and 3.3% of their weekly disposable income on active and screen recreation respectively, and 24.9% of their total active and screen recreation expenditure on active recreation. There was significant variation across household characteristics, with higher income and socioeconomic status households, and families with more than one dependent child more likely to spend a larger portion of their recreation budget on active recreation instead of screen recreation. Overall, Australian families spend more money on screen recreation items than they do on active recreation, although there are strong economic and cultural gradients in their patterns of expenditure on both active and screen recreation. This suggests that while the costs of active recreation may be a barrier to participation for some families, there are also social and cultural values influencing recreational choices. For the first time, specific information on Australian families' expenditure on active and screen recreation is available. These results contribute to identifying cultural and economic barriers influencing families' health-related behaviours and their participation in organised physical activity.

Identifying facilitators and barriers to physical activity for adults with Down syndrome.

PubMed

Mahy, J; Shields, N; Taylor, N F; Dodd, K J

2010-09-01

Adults with Down syndrome are typically sedentary, and many do not participate in the recommended levels of physical activity per week. The aim of this study was to identify the facilitators and barriers to physical activity for this group. Semi-structured interviews were conducted to elicit the views of adults with Down syndrome and their support people about what factors facilitate physical activity and what factors are barriers to activity. A sample of 18 participants (3 men, 15 women) was recruited through two agencies providing services for adults with disabilities; six participants were adults with Down syndrome and 12 participants were support people (four were parents of adults with Down syndrome and eight participants were employed by day programmes attended by the adults with Down syndrome). The interviews were recorded, transcribed verbatim and independently coded by two researchers. Three themes around facilitators to physical activity were identified: (1) support from others; (2) that the physical activity was fun or had an interesting purpose; and (3) routine and familiarity. Three themes around barriers were also identified: (1) lack of support; (2) not wanting to engage in physical activity; and (3) medical and physiological factors. The results suggest that support people play a key role, both as facilitators and barriers, in the participation by adults with Down syndrome in physical activity. Many of the barriers and facilitators of activity for adults with Down syndrome indentified are similar to those reported for adults without impairment. Our findings are also consistent with established theories in the field of health behaviour change.

Predictors of physical activity and barriers to exercise in nursing and medical students.

PubMed

Blake, Holly; Stanulewicz, Natalia; Mcgill, Francesca

2017-04-01

To investigate physical activity levels of nursing and medicine students, examine predictors of physical activity level and examine the most influential benefits and barriers to exercise. Healthcare professionals have low levels of physical activity, which increases their health risk and may influence their health promotion practices with patients. We surveyed 361 nursing (n = 193) and medicine (n = 168) students studying at a UK medical school. Questionnaire survey, active over 12 months in 2014-2015. Measures included physical activity level, benefits and barriers to exercise, social support, perceived stress and self-efficacy for exercise. Many nursing and medicine students did not achieve recommended levels of physical activity (nursing 48%; medicine 38%). Perceived benefits of exercise were health related, with medicine students identifying additional benefits for stress relief. Most notable barriers to exercise were as follows: lack of time, facilities having inconvenient schedules and exercise not fitting around study or placement schedules. Nursing students were less active than medicine students; they perceived fewer benefits and more barriers to exercise and reported lower social support for exercise. Physical activity of nursing and medicine students was best predicted by self-efficacy and social support, explaining 35% of the variance. Physical activity should be promoted in nursing and medicine students. Interventions should aim to build self-efficacy for exercise and increase social support. Interventions should be developed that are targeted specifically to shift-working frontline care staff, to reduce schedule-related barriers to exercise and to increase accessibility to workplace health and well-being initiatives. © 2016 John Wiley & Sons Ltd.

Safety-Net Hospitals Face More Barriers Yet Use Fewer Strategies to Reduce Readmissions

PubMed Central

Figueroa, Jose F.; Joynt, Karen E.; Zhou, Xiner; Orav, E. John; Jha, Ashish K.

2016-01-01

Objective U.S. hospitals that care for vulnerable populations, “safety-net hospitals” (SNHs), are more likely to incur penalties under the Hospital Readmissions Reduction Program (HRRP), which penalizes hospitals with higher-than-expected readmissions. Understanding whether SNHs face unique barriers to reducing readmissions or whether they underuse readmission-prevention strategies is important. Design We surveyed leadership at 1,600 U.S. acute care hospitals, of whom 980 participated, between June 2013–January 2014. Responses on 28 questions on readmission-related barriers and strategies were compared between SNHs and non-SNHs, adjusting for non-response and sampling strategy. We further compared responses between high-performing SNHs and low-performing SNHs. Results We achieved a 62% response rate. SNHs were more likely to report patient-related barriers, including lack of transportation, homelessness, and language barriers compared to non-SNHs (p-values<0.001). Despite reporting more barriers, SNHs were less likely to use e-tools to share discharge summaries (70.1% vs. 73.7%, p<0.04) or verbally communicate (31.5% vs. 39.8%, p<0.001) with outpatient providers, track readmissions by race/ethnicity (23.9% vs. 28.6%, p<0.001), or enroll patients in post-discharge programs (13.3% vs. 17.2%, p<0.001). SNHs were also less likely to use discharge coordinators, pharmacists, and post-discharge programs. When we examined the use of strategies within SNHs, we found trends to suggest that high-performing SNHs were more likely to use several readmission strategies. Conclusions Despite reporting more barriers to reducing readmissions, SNHs were less likely to use readmission-reduction strategies. This combination of higher barriers and lower use of strategies may explain why SNHs have higher rates of readmissions and penalties under the HRRP. PMID:28060053

Exercise barriers and the relationship to self-efficacy for exercise over 12 months of a lifestyle-change program for people with heart disease and/or diabetes.

PubMed

Alharbi, Muaddi; Gallagher, Robyn; Neubeck, Lis; Bauman, Adrian; Prebill, Gabrielle; Kirkness, Ann; Randall, Sue

2017-04-01

Barriers to exercise are common in people with coronary heart disease (CHD) and/or diabetes mellitus (DM), and may influence self-efficacy for exercise. The purpose of this study was to describe the exercise barriers experienced by people who have CHD and/or DM participating in the Healthy Eating and Exercise Lifestyle Program and to determine whether these barriers influence self-efficacy. Participants ( n = 134) identified their barriers to exercise and completed the self-efficacy for exercise survey at baseline, at 4 months (following structured and supervised exercise) and at 12 months (following home-based exercise with three follow-up calls). The sample mean age was 63.6 years (SD 8.5) and 58% were male. Barriers to exercise were reported by 88% at baseline, 76% at 4 months, and 47% at 12 months. The most common barriers were lack of motivation (40.3%), lack of time overall (30.6%), and lack of time due to family commitments (17.2%). Only motivation changed significantly over time from baseline (40%) to 4 months (23%, p = 0.040). Lower self-efficacy for exercise was associated with lack of motivation at 12 months only, more depressive symptoms at baseline and 4 months, and a CHD diagnosis and higher body mass index at 12 months. In contrast, male gender and having higher self-efficacy at baseline were associated with higher self-efficacy for exercise at 4 and 12 months. Patients identified many exercise barriers despite participating in a lifestyle-change program. Lack of motivation negatively influenced self-efficacy for exercise at 12 months. Other factors needing attention include baseline self-efficacy, depressive symptoms, being female, being more overweight, and having CHD.

Short and long-term lifestyle coaching approaches used to address diverse participant barriers to weight loss and physical activity adherence

PubMed Central

2014-01-01

Background Individual barriers to weight loss and physical activity goals in the Diabetes Prevention Program, a randomized trial with 3.2 years average treatment duration, have not been previously reported. Evaluating barriers and the lifestyle coaching approaches used to improve adherence in a large, diverse participant cohort can inform dissemination efforts. Methods Lifestyle coaches documented barriers and approaches after each session (mean session attendance = 50.3 ± 21.8). Subjects were 1076 intensive lifestyle participants (mean age = 50.6 years; mean BMI = 33.9 kg/m2; 68% female, 48% non-Caucasian). Barriers and approaches used to improve adherence were ranked by the percentage of the cohort for whom they applied. Barrier groupings were also analyzed in relation to baseline demographic characteristics. Results Top weight loss barriers reported were problems with self-monitoring (58%); social cues (58%); holidays (54%); low activity (48%); and internal cues (thought/mood) (44%). Top activity barriers were holidays (51%); time management (50%); internal cues (30%); illness (29%), and motivation (26%). The percentage of the cohort having any type of barrier increased over the long-term intervention period. A majority of the weight loss barriers were significantly associated with younger age, greater obesity, and non-Caucasian race/ethnicity (p-values vary). Physical activity barriers, particularly thought and mood cues, social cues and time management, physical injury or illness and access/weather, were most significantly associated with being female and obese (p < 0.001 for all). Lifestyle coaches used problem-solving with most participants (≥75% short-term; > 90% long term) and regularly reviewed self-monitoring skills. More costly approaches were used infrequently during the first 16 sessions (≤10%) but increased over 3.2 years. Conclusion Behavioral problem solving approaches have short and long term dissemination potential for many kinds of participant barriers. Given minimal resources, increased attention to training lifestyle coaches in the consistent use of these approaches appears warranted. PMID:24521153

Development of the Barriers to Physical Activity Questionnaire for People with Mobility Impairments.

PubMed

Vasudevan, Vijay; Rimmer, James H; Kviz, Frederick

2015-10-01

Despite the widely known benefits of physical activity, people with disabilities are more likely to be inactive when compared to people without disabilities. Previous questionnaires that measure barriers physical activity for people with disabilities do not measure barriers from an ecological perspective. The purpose of this study was to develop the Barriers to Physical Activity Questionnaire for People with Mobility Impairments (BPAQ-MI) that measures barriers using an ecological framework. This study consisted of two phases. In Phase one, developed the content validity by (a) developing an item bank, (b) identifying missing items and combining items using a Delphi panel, and (c) refine item wording via cognitive interviews. In Phase two, people with mobility impairments took part in in-person interviews to establish test-retest reliability, internal consistency, and construct validity of the BPAQ-MI. Exploratory factor analysis revealed the BPAQ-MI was comprised of eight subscales or factors: health; beliefs and attitudes; family; friends; fitness center built environment; staff and policy; community built environment; and safety. The BPAQ-MI demonstrated very good test-retest reliability. Cronbach's alpha ranged from 0.792 to 0.935. The BPAQ-MI showed significant negative correlations with exercise (minutes/week) and significant positive correlations between BPAQ-MI subscales and inactivity (hours/day). The BPAQ-MI is the first questionnaire that places greater equity at measuring barriers to physical activity across the intrapersonal, interpersonal, organizational, and community domains. The BPAQ-MI has the potential to assist researchers in understanding the complex relationship between barriers and ultimately develop physical activity interventions that address these barriers. Copyright © 2015 Elsevier Inc. All rights reserved.

Blood-cerebrospinal fluid barrier permeability in Alzheimer's disease.

PubMed

Chalbot, Sonia; Zetterberg, Henrik; Blennow, Kaj; Fladby, Tormod; Andreasen, Niels; Grundke-Iqbal, Inge; Iqbal, Khalid

2011-01-01

The role of blood-cerebrospinal fluid barrier (BCB) dysfunction in Alzheimer's disease (AD) has been addressed but not yet established. We evaluated the BCB integrity in 179 samples of cerebrospinal fluid (CSF) retrospectively collected from AD patients and control cases using both CSF/serum albumin ratio (QAlb) and CSF secretory Ca2+-dependent phospholipase A2 (sPLA2) activity. These analyses were supplemented with the measurement of total tau, amyloid-β1-42 (Aβ1-42), and ubiquitin CSF levels. We found that due to its higher sensitivity, CSF sPLA2 activity could 1) discriminate AD from healthy controls and 2) showed BCB impairment in neurological control cases while QAlb could not. Moreover, the CSF sPLA2 activity measurement showed that around half of the AD patients were characterized by a BCB impairment. The BCB dysfunction observed in AD was independent from Mini-Mental State Examination score as well as CSF levels of total tau, Aβ1-42, and ubiquitin. Finally, the BCB dysfunction was not limited to any of the CSF biomarkers-based previously identified subgroups of AD. These results suggest that the BCB damage occurs independent of and probably precedes both Aβ and tau pathologies in a restricted subgroup of AD patients.

Nurses’ Perceived Barriers to and Facilitators of Research Utilization in Mainland China: A Cross-Sectional Survey

PubMed Central

Chien, Wai-Tong; Bai, Qin; Wong, Wai-Kit; Wang, Huizhen; Lu, Xueqin

2013-01-01

Despite the drive towards evidence-based practice, the extent to which research evidence is being implemented in nursing practice is unclear, particularly in developing countries. This study was to assess the levels of perceived barriers to and facilitators of research utilization in practice among Chinese nurses and inter-relationships between these barriers and facilitators and their socio-demographic characteristics. A cross-sectional, descriptive survey was conducted in 2011 with 743 registered nurses randomly selected from four general hospitals in China. They completed the Barriers to Research Utilization and Facilitators of Research Utilization scales. Correlation tests were used to test the relationships between the nurses’ perceived barriers and facilitators, their demographic characteristics and research training and involvement. The Chinese nurses’ level of perceived barriers was moderate on average and lower than that in previous research. Among the 10 top-ranked items, six were from the subscale ‘Organizational Characteristics’. Their perceived barriers were correlated positively with age and post-registration experience and negatively with research training undertaken. Junior diplomatic nurses reported a significantly higher degree of barriers than those senior ones with postgraduate education. Higher and more diverse barriers to research utilization in practice are perceived by Chinese nurses than those in Western countries and they are associated with a few socio-demographic factors. Future research on these barriers/facilitators and their relationships with occupational and socio-cultural factors in Chinese and other Asian nurses is recommended. PMID:23919099

Barriers to hydroxyurea adherence and health-related quality of life in adolescents and young adults with sickle cell disease.

PubMed

Badawy, Sherif M; Thompson, Alexis A; Penedo, Frank J; Lai, Jin-Shei; Rychlik, Karen; Liem, Robert I

2017-06-01

To identify barriers to hydroxyurea adherence (negative beliefs, access, and/or recall barriers), and their relationship to adherence rates and health-related quality of life (HRQOL) among adolescents and young adults (AYA) with sickle cell disease (SCD). A cross-sectional survey was administered to 34 AYAs (12-22 years old) in SCD clinics from January to December 2015. Study measures included Brief Medication Questionnaire, Modified Morisky Adherence Scale 8-items, visual analog scale, and Patient Reported Outcomes Measurement Information System. Participants (59% male; 91% Black) had a median age of 13.5 years (IQR 12-18). Participants reported negative beliefs (32%), recall barriers (44%), and access barriers (32%). Participants with recall barriers reported worse pain (P=.02), fatigue (P=.05), and depression (P=.05). The number of adherence barriers inversely correlated with adherence level using ©MMAS-8 (r s =-.38, P=.02) and VAS dose (r s =-.25, P=.14) as well as MCV (r s =-.45, P=.01) and HbF% (r s =-.36, P=.05), suggesting higher hydroxyurea adherence in patients with fewer barriers. Patients with fewer barriers to hydroxyurea adherence were more likely to have higher adherence rates and better HRQOL scores. Routine assessment of hydroxyurea adherence and its related barriers could provide actionable information to improve adherence rates, HRQOL, and other clinical outcomes. © 2017 The Authors. European Journal of Haematology Published by John Wiley & Sons Ltd.

Barriers to Providing Physical Education and Physical Activity in Victorian State Secondary Schools

ERIC Educational Resources Information Center

Jenkinson, Kate A.; Benson, Amanda C.

2010-01-01

An on-line questionnaire was completed by 115 physical education teachers to establish the barriers to their implementation of physical education in Victorian state secondary schools. In addition, the barriers perceived by teachers to impact on students' participation in school-based physical education and physical activity were examined. The…

Emphasis on Cardiovascular Fitness as a Barrier toward Mobilizing the Sedentary Individual.

ERIC Educational Resources Information Center

Kasper, Mark J.

1990-01-01

Emphasizing cardiovascular fitness may be a barrier to mobilizing the sedentary individual. Instead, encouraging low-level physical activity may be an effective first step. Beliefs held toward cardiovascular fitness are presented, and ways in which these beliefs may present barriers to adoption of any level of physical activity are discussed. (IAH)

A qualitative exploration of barriers and motivators to physical activity participation in women treated for breast cancer.

PubMed

Brunet, Jennifer; Taran, Samantha; Burke, Shaunna; Sabiston, Catherine M

2013-01-01

The adoption and maintenance of a physically active lifestyle among women after breast cancer is an important priority for public health and rehabilitation science. The purpose of this qualitative study was to explore breast cancer survivors' perceptions of the factors influencing their ability to maintain a self-directed physical activity program. Nine women participated in semi-structured, in-depth interviews. Data were coded into perceived barriers and motivators to maintenance of physical activity using thematic analysis. Women identified a range of physical (e.g. cancer-related physical symptoms), environmental/organizational (e.g. bad weather, lack of equipment/facilities, lack of knowledge, time constraints) and psychosocial (e.g. lack of motivation, low social support, low confidence/skill) barriers. They also identified perceived physical (e.g. weight management, health improvement or maintenance, increase energy) and psychosocial (e.g. improve body image, experience enjoyment, social support, positive emotions) motivators. These findings are consistent with research on barriers and motivators to physical activity initiation, and can be used to develop self-directed physical activity programs that target active breast cancer survivors to sustain regular engagement. Furthermore, the barriers and motivators identified represent key variables for further investigation. The present study identifies a number of perceived physical, psychosocial and organizational/environmental barriers to naturally occurring physical activity participation among active breast cancer survivors that should be addressed to ensure they maintain a physically active lifestyle This study also provides evidence that comprehensive approaches that address physical and psychosocial motivators to physical activity should be developed to assist women with a history of breast cancer maintain their physical activity levels.

Evaluating the Longevity and Hydraulic Performance of Permeable Reactive Barriers at Department of Defense Sites

DTIC Science & Technology

2003-01-01

Army Ammunitions Plant) PRBs have become feasible with trenching. Other construction 5 methods, such as jetting, hydraulic fracturing , and vibratory...where the affected aquifer is deeper, innovative methods, such as jetting and hydraulic fracturing , are available, but there is not as much widespread...such as jetting and hydraulic fracturing ) can be used at relatively higher cost. The cost comparison of a PRB versus an active remedy, such as a

Technology enhanced learning for occupational and environmental health nursing: a global imperative.

PubMed

Olson, D K; Cohn, S; Carlson, V

2000-04-01

One strategy for decreasing the barriers to higher education and for increasing the competency and performance of the occupational and environmental health nurse in the information age is technology enhanced learning. Technology enhanced learning encompasses a variety of technologies employed in teaching and learning activities of presentation, interaction, and transmission to on campus and distant students. Web based learning is growing faster than any other instructional technology, offering students convenience and a wealth of information.

Socioeconomic differences in sport and physical activity among Italian adults.

PubMed

Federico, Bruno; Falese, Lavinia; Marandola, Diego; Capelli, Giovanni

2013-01-01

We aimed to assess the extent of socioeconomic differences in sport and physical activity among Italian adults. A secondary data analysis of a multipurpose survey carried out by the National Institute of Statistics in 2006 in Italy was performed. We found marked differences in the practice of physical activity and sport by socioeconomic position. Subjects with a higher educational level were more likely to be physically active, practising more frequently both sport and physical activity. The Odds Ratio (OR) of regular physical activity for the highest educated compared to the lowest educated males was 1.70 (95% Confidence Interval [CI]: 1.38, 2.08), and the OR of sport participation was 2.03 (95% CI: 1.51, 2.72). Among females, the corresponding ORs were 1.32 (95% CI: 1.08, 1.63) and 2.26 (95% CI: 1.51, 3.38). Similar differences in physical activity and sport were found in relation to occupation and material conditions. Almost all sports were more frequently practised by subjects of higher socioeconomic status. Socioeconomic differences in sport and physical activity may derive from economic or cultural barriers. Policies to reduce inequalities and ensure access to sport independently of socioeconomic position are strongly needed.

Ectomycorrhizal fungi contribute to soil organic matter cycling in sub-boreal forests.

PubMed

Phillips, Lori A; Ward, Valerie; Jones, Melanie D

2014-03-01

Soils of northern temperate and boreal forests represent a large terrestrial carbon (C) sink. The fate of this C under elevated atmospheric CO2 and climate change is still uncertain. A fundamental knowledge gap is the extent to which ectomycorrhizal fungi (EMF) and saprotrophic fungi contribute to C cycling in the systems by soil organic matter (SOM) decomposition. In this study, we used a novel approach to generate and compare enzymatically active EMF hyphae-dominated and saprotrophic hyphae-enriched communities under field conditions. Fermentation-humus (FH)-filled mesh bags, surrounded by a sand barrier, effectively trapped EMF hyphae with a community structure comparable to that found in the surrounding FH layer, at both trophic and taxonomic levels. In contrast, over half the sequences from mesh bags with no sand barrier were identified as belonging to saprotrophic fungi. The EMF hyphae-dominated systems exhibited levels of hydrolytic and oxidative enzyme activities that were comparable to or higher than saprotroph-enriched systems. The enzymes assayed included those associated with both labile and recalcitrant SOM degradation. Our study shows that EMF hyphae are likely important contributors to current SOM turnover in sub-boreal systems. Our results also suggest that any increased EMF biomass that might result from higher below-ground C allocation by trees would not suppress C fluxes from sub-boreal soils.

Reverse cope elimination of hydroxylamines and alkenes or alkynes: theoretical investigation of tether length and substituent effects.

PubMed

Krenske, Elizabeth H; Davison, Edwin C; Forbes, Ian T; Warner, Jacqueline A; Smith, Adrian L; Holmes, Andrew B; Houk, K N

2012-02-01

Quantum mechanical calculations have been used to study the intramolecular additions of hydroxylamines to alkenes and alkynes ("reverse Cope eliminations"). In intermolecular reverse Cope eliminations, alkynes are more reactive than alkenes. However, competition experiments have shown that tethering the hydroxylamine to the alkene or alkyne can reverse the reactivity order from that normally observed. The exact outcome depends on the length of the tether. In agreement with experiment, a range of density functional theory methods and CBS-QB3 calculations predict that the activation energies for intramolecular reverse Cope eliminations follow the order 6-exo-dig < 5-exo-trig < 5-exo-dig ≈ 7-exo-dig. The order of the barriers for the 5-, 6-, and 7-exo-dig reactions of alkynes arises mainly from differences in tether strain in the transition states (TSs), but is also influenced by the TS interaction between the hydroxylamine and alkyne. Cyclization onto an alkene in the 5-exo-trig fashion incurs slightly less tether strain than a 6-exo-dig alkyne cyclization, but its activation energy is higher because the hydroxylamine fragment must distort more before the TS is reached. If the alkene terminus is substituted with two methyl groups, the barrier becomes so much higher that it is also disfavored compared to the 5- and 7-exo-dig cyclizations. © 2012 American Chemical Society

The Reverse Cope Elimination of Hydroxylamines and Alkenes or Alkynes: Theoretical Investigation of Tether Length and Substituent Effects

PubMed Central

Krenske, Elizabeth H.; Davison, Edwin C.; Forbes, Ian T.; Warner, Jacqueline A.; Smith, Adrian L.; Holmes, Andrew B.; Houk, K. N.

2012-01-01

Quantum mechanical calculations have been used to study the intramolecular additions of hydroxylamines to alkenes and alkynes (“reverse Cope eliminations”). In intermolecular reverse Cope eliminations, alkynes are more reactive than alkenes. However, competition experiments have shown that tethering the hydroxylamine to the alkene or alkyne can reverse the reactivity order from that normally observed. The exact outcome depends on the length of the tether. In agreement with experiment, a range of density functional theory methods and CBS-QB3 calculations predict that the activation energies for intramolecular reverse Cope eliminations follow the order 6-exo-dig < 5-exo-trig < 5-exo-dig ≈ 7-exo-dig. The order of the barriers for the 5-, 6-, and 7-exo-dig reactions of alkynes arises mainly from differences in tether strain in the transition states, but is also influenced by the transition-state interaction between the hydroxylamine and alkyne. Cyclization onto an alkene in the 5-exo-trig fashion incurs slightly less tether strain than a 6-exo-dig alkyne cyclization, but its activation energy is higher because the hydroxylamine fragment must distort more before the TS is reached. If the alkene terminus is substituted with two methyl groups, the barrier becomes so much higher that it is also disfavored compared to the 5- and 7-exo-dig cyclizations. PMID:22280245

Ectomycorrhizal fungi contribute to soil organic matter cycling in sub-boreal forests

PubMed Central

Phillips, Lori A; Ward, Valerie; Jones, Melanie D

2014-01-01

Soils of northern temperate and boreal forests represent a large terrestrial carbon (C) sink. The fate of this C under elevated atmospheric CO2 and climate change is still uncertain. A fundamental knowledge gap is the extent to which ectomycorrhizal fungi (EMF) and saprotrophic fungi contribute to C cycling in the systems by soil organic matter (SOM) decomposition. In this study, we used a novel approach to generate and compare enzymatically active EMF hyphae-dominated and saprotrophic hyphae-enriched communities under field conditions. Fermentation-humus (FH)-filled mesh bags, surrounded by a sand barrier, effectively trapped EMF hyphae with a community structure comparable to that found in the surrounding FH layer, at both trophic and taxonomic levels. In contrast, over half the sequences from mesh bags with no sand barrier were identified as belonging to saprotrophic fungi. The EMF hyphae-dominated systems exhibited levels of hydrolytic and oxidative enzyme activities that were comparable to or higher than saprotroph-enriched systems. The enzymes assayed included those associated with both labile and recalcitrant SOM degradation. Our study shows that EMF hyphae are likely important contributors to current SOM turnover in sub-boreal systems. Our results also suggest that any increased EMF biomass that might result from higher below-ground C allocation by trees would not suppress C fluxes from sub-boreal soils. PMID:24173458

Comparative research on activation technique for GaAs photocathodes

NASA Astrophysics Data System (ADS)

Chen, Liang; Qian, Yunsheng; Chang, Benkang; Chen, Xinlong; Yang, Rui

2012-03-01

The properties of GaAs photocathodes mainly depend on the material design and activation technique. In early researches, high-low temperature two-step activation has been proved to get more quantum efficiency than high-temperature single-step activation. But the variations of surface barriers for two activation techniques have not been well studied, thus the best activation temperature, best Cs-O ratio and best activation time for two-step activation technique have not been well found. Because the surface photovoltage spectroscopy (SPS) before activation is only in connection with the body parameters for GaAs photocathode such as electron diffusion length and the spectral response current (SRC) after activation is in connection with not only body parameters but also surface barriers, thus the surface escape probability (SEP) can be well fitted through the comparative research between SPS before activation and SEP after activation. Through deduction for the tunneling process of surface barriers by Schrödinger equation, the width and height for surface barrier I and II can be well fitted through the curves of SEP. The fitting results were well proved and analyzed by quantitative analysis of angle-dependent X-ray photoelectron spectroscopy (ADXPS) which can also study the surface chemical compositions, atomic concentration percentage and layer thickness for GaAs photocathodes. This comparative research method for fitting parameters of surface barriers through SPS before activation and SRC after activation shows a better real-time in system method for the researches of activation techniques.

Mechanism of Oxidation of Ethane to Ethanol at Iron(IV)-Oxo Sites in Magnesium-Diluted Fe2(dobdc).

PubMed

Verma, Pragya; Vogiatzis, Konstantinos D; Planas, Nora; Borycz, Joshua; Xiao, Dianne J; Long, Jeffrey R; Gagliardi, Laura; Truhlar, Donald G

2015-05-06

The catalytic properties of the metal-organic framework Fe2(dobdc), containing open Fe(II) sites, include hydroxylation of phenol by pure Fe2(dobdc) and hydroxylation of ethane by its magnesium-diluted analogue, Fe0.1Mg1.9(dobdc). In earlier work, the latter reaction was proposed to occur through a redox mechanism involving the generation of an iron(IV)-oxo species, which is an intermediate that is also observed or postulated (depending on the case) in some heme and nonheme enzymes and their model complexes. In the present work, we present a detailed mechanism by which the catalytic material, Fe0.1Mg1.9(dobdc), activates the strong C-H bonds of ethane. Kohn-Sham density functional and multireference wave function calculations have been performed to characterize the electronic structure of key species. We show that the catalytic nonheme-Fe hydroxylation of the strong C-H bond of ethane proceeds by a quintet single-state σ-attack pathway after the formation of highly reactive iron-oxo intermediate. The mechanistic pathway involves three key transition states, with the highest activation barrier for the transfer of oxygen from N2O to the Fe(II) center. The uncatalyzed reaction, where nitrous oxide directly oxidizes ethane to ethanol is found to have an activation barrier of 280 kJ/mol, in contrast to 82 kJ/mol for the slowest step in the iron(IV)-oxo catalytic mechanism. The energetics of the C-H bond activation steps of ethane and methane are also compared. Dehydrogenation and dissociation pathways that can compete with the formation of ethanol were shown to involve higher barriers than the hydroxylation pathway.

Carcinogenesis of urethane: simulation versus experiment.

PubMed

Lajovic, Andrej; Nagy, Leslie D; Guengerich, F Peter; Bren, Urban

2015-04-20

The carcinogenesis of urethane (ethyl carbamate), a byproduct of fermentation that is consistently found in various food products, was investigated with a combination of kinetic experiments and quantum chemical calculations. The main objective of the study was to find ΔG(⧧), the activation free energy for the rate-limiting step of the SN2 reaction among the ultimate carcinogen of urethane, vinyl carbamate epoxide (VCE), and different nucleobases of the DNA. In the experimental part, the second-order reaction rate constants for the formation of the main 7-(2-oxoethyl)guanine adduct in aqueous solutions of deoxyguanosine and in DNA were determined. A series of ab initio, density functional theory (DFT), and semiempirical molecular orbital (MO) calculations was then performed to determine the activation barriers for the reaction between VCE and nucleobases methylguanine, methyladenine, and methylcytosine. Effects of hydration were incorporated with the use of the solvent reaction field method of Tomasi and co-workers and the Langevine dipoles model of Florian and Warshel. The computational results for the main adduct were found to be in good agreement with the experiment, thus presenting strong evidence for the validity of the proposed SN2 mechanism. This allowed us to predict the activation barriers of reactions leading to side products for which kinetic experiments have not yet been performed. Our calculations have shown that the main 7-(2-oxoethyl)deoxyguanosine adduct indeed forms preferentially because the emergence of other adducts either proceeds across a significantly higher activation barrier or the geometry of the reaction requires the Watson-Crick pairs of the DNA to be broken. The computational study also considered the questions of stereoselectivity, the ease of the elimination of the leaving group, and the relative contributions of the two possible reaction paths for the formation of the 1,N(2)-ethenodeoxyguanosine adduct.

Safety performance evaluation of cable median barriers on freeways in Florida.

PubMed

Alluri, Priyanka; Haleem, Kirolos; Gan, Albert; Mauthner, John

2016-07-03

This article aims to evaluate the safety performance of cable median barriers on freeways in Florida. The safety performance evaluation was based on the percentages of barrier and median crossovers by vehicle type, crash severity, and cable median barrier type (Trinity Cable Safety System [CASS] and Gibraltar system). Twenty-three locations with cable median barriers totaling about 101 miles were identified. Police reports of 6,524 crashes from years 2005-2010 at these locations were reviewed to verify and obtain detailed crash information. A total of 549 crashes were determined to be barrier related (i.e., crashes involving vehicles hitting the cable median barrier) and were reviewed in further detail to identify crossover crashes and the manner in which the vehicles crossed the barriers; that is, by either overriding, underriding, or penetrating the barriers. Overall, 2.6% of vehicles that hit the cable median barrier crossed the median and traversed into the opposite travel lane. Overall, 98.1% of cars and 95.5% of light trucks that hit the barrier were prevented from crossing the median. In other words, 1.9% of cars and 4.5% of light trucks that hit the barrier had crossed the median and encroached on the opposite travel lanes. There is no significant difference in the performance of cable median barrier for cars versus light trucks in terms of crossover crashes. In terms of severity, overrides were more severe compared to underrides and penetrations. The statistics showed that the CASS and Gibraltar systems performed similarly in terms of crossover crashes. However, the Gibraltar system experienced a higher proportion of penetrations compared to the CASS system. The CASS system resulted in a slightly higher percentage of moderate and minor injury crashes compared to the Gibraltar system. Cable median barriers are successful in preventing median crossover crashes; 97.4% of the cable median barrier crashes were prevented from crossing over the median. Of all of the vehicles that hit the barrier, 83.6% were either redirected or contained by the cable barrier system. Barrier crossover crashes were found to be more severe compared to barrier noncrossover crashes. In addition, overrides were found to be more severe compared to underrides and penetrations.

Benefits of barrier fuel on fuel cycle economics

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

Crowther, R.L.; Kunz, C.L.

1988-01-01

Barrier fuel rod cladding was developed to eliminate fuel rod failures from pellet/cladding stress/corrosion interaction and to eliminate the associated need to restrict the rate at which fuel rod power can be increased. The performance of barrier cladding has been demonstrated through extensive testing and through production application to many boiling water reactors (BWRs). Power reactor data have shown that barrier fuel rod cladding has a significant beneficial effect on plant capacity factor and plant operating costs and significantly increases fuel reliability. Independent of the fuel reliability benefit, it is less obvious that barrier fuel has a beneficial effect ofmore » fuel cycle costs, since barrier cladding is more costly to fabricate. Evaluations, measurements, and development activities, however, have shown that the fuel cycle cost benefits of barrier fuel are large. This paper is a summary of development activities that have shown that application of barrier fuel significantly reduces BWR fuel cycle costs.« less

Motives for and barriers to physical activity in twin pairs discordant for leisure time physical activity for 30 years.

PubMed

Aaltonen, S; Leskinen, T; Morris, T; Alen, M; Kaprio, J; Liukkonen, J; Kujala, U

2012-02-01

Long-term persistent physical activity is important in the prevention of chronic diseases, but a large number of people do not participate in physical activity to obtain health benefits. The purpose of this study was to examine the motives and perceived barriers to long-term engagement in leisure time physical activity. Same-sex twin pairs (N=16, mean age 60) discordant for physical activity over 30 years were identified from the Finnish Twin Cohort. We evaluated participants' physical activity motivation with the 73-item Recreational Exercise Motivation Measure and assessed barriers to physical activity with a 25-item questionnaire. The characteristics of physical activity motivation and perceived barriers between the active and inactive co-twins were analysed using paired tests. Motives related to the sub-dimensions of enjoyment and physical fitness and psychological state were the most important reasons for participation in physical activity among all the twin individuals analysed. The sub-dimensions mastery (p=0.018, Cohen's d=0.76), physical fitness (p=0.029, Cohen's d=0.69), and psychological state (p=0.039, Cohen's d=0.65) differed significantly between active and inactive co-twins. More than half of the participants reported no reasons for not being physically active. If reasons existed, participation in physical activity was deterred mostly by pain and various health problems. This study found no differences in perceived barriers between active and inactive co-twins. We conclude from our results that the main factors promoting persistent leisure time physical activity were participants' wish to improve or maintain their physical skills or techniques, a feeling that exercise would improve their mental and physical health and that they found the activity enjoyable. This study helps us understand the importance of the role of motives and the minor role of perceived barriers for engagement in persistent physical activity. © Georg Thieme Verlag KG Stuttgart · New York.

Direct carbon-carbon coupling of furanics with acetic acid over Brønsted zeolites

PubMed Central

Gumidyala, Abhishek; Wang, Bin; Crossley, Steven

2016-01-01

Effective carbon-carbon coupling of acetic acid to form larger products while minimizing CO2 emissions is critical to achieving a step change in efficiency for the production of transportation fuels from sustainable biomass. We report the direct acylation of methylfuran with acetic acid in the presence of water, all of which can be readily produced from biomass. This direct coupling limits unwanted polymerization of furanics while producing acetyl methylfuran. Reaction kinetics and density functional theory calculations illustrate that the calculated apparent barrier for the dehydration of the acid to form surface acyl species is similar to the experimentally measured barrier, implying that this step plays a significant role in determining the net reaction rate. Water inhibits the overall rate, but selectivity to acylated products is not affected. We show that furanic species effectively stabilize the charge of the transition state, therefore lowering the overall activation barrier. These results demonstrate a promising new route to C–C bond–forming reactions for the production of higher-value products from biomass. PMID:27652345

Direct carbon-carbon coupling of furanics with acetic acid over Bronsted zeolites

DOE PAGES

Gumidyala, Abhishek; Wang, Bin; Crossley, Steven

2016-09-16

Effective carbon-carbon coupling of acetic acid to form larger products while minimizing CO 2 emissions is critical to achieving a step change in efficiency for the production of transportation fuels from sustainable biomass. Here, we report the direct acylation of methylfuran with acetic acid in the presence ofwater, all ofwhich can be readily produced from biomass. This direct coupling limits unwanted polymerization of furanics while producing acetyl methylfuran. Reaction kinetics and density functional theory calculations illustrate that the calculated apparent barrier for the dehydration of the acid to form surface acyl species is similar to the experimentally measured barrier, implyingmore » that this step plays a significant role in determining the net reaction rate. Water inhibits the overall rate, but selectivity to acylated products is not affected.We show that furanic species effectively stabilize the charge of the transition state, therefore lowering the overall activation barrier. These results demonstrate a promising new route to C–C bond–forming reactions for the production of higher-value products from biomass.« less

Free energy profiles for two ubiquitous damaging agents: methylation and hydroxylation of guanine in B-DNA.

PubMed

Grüber, R; Aranda, J; Bellili, A; Tuñón, I; Dumont, E

2017-06-07

DNA methylation and hydroxylation are two ubiquitous reactions in DNA damage induction, yet insights are scarce concerning the free energy of activation within B-DNA. We resort to multiscale simulations to investigate the attack of a hydroxyl radical and of the primary diazonium onto a guanine embedded in a solvated dodecamer. Reaction free energy profiles characterize two strongly exergonic processes, yet allow unprecedented quantification of the barrier towards this damage reaction, not higher than 6 kcal mol -1 and sometimes inexistent, and of the exergonicities. In the case of the [G(C8)-OH]˙ intermediate, we challenge the functional dependence of such simulations: recently-proposed functionals, such as M06-2X and LC-BLYP, agree on a ∼4 kcal mol -1 barrier, whereas the hybrid GGA B3LYP functional predicts a barrier-less pathway. In the long term, multiscale approaches can help build up a unified panorama of DNA lesion induction. These results stress the importance of DFT/MM-MD simulations involving new functionals towards the sound modelling of biomolecule damage even in the ground state.

Modifiable barriers to leisure-time physical activity during pregnancy: a qualitative study investigating first time mother's views and experiences.

PubMed

Connelly, Megan; Brown, Helen; van der Pligt, Paige; Teychenne, Megan

2015-04-22

Evidence suggests physical activity often declines during pregnancy, however explanations for the decline are not well understood. The aim of this study was to identify modifiable barriers to leisure-time physical activity among women who did not meet physical activity guidelines during pregnancy. Analyses were based on data from 133 mothers (~3-months postpartum) who were recruited from the Melbourne InFANT Extend study (2012/2013). Women completed a self-report survey at baseline in which they reported their leisure-time physical activity levels during pregnancy as well provided an open-ended written response regarding the key barriers that they perceived prevented them from meeting the physical activity guidelines during their pregnancy. Thematic analyses were conducted to identify key themes. The qualitative data revealed six themes relating to the barriers of leisure-time physical activity during pregnancy. These included work-related factors (most commonly reported), tiredness, pregnancy-related symptoms, being active but not meeting the guidelines, lack of motivation, and a lack of knowledge of recommendations. Considering work-related barriers were suggested to be key factors to preventing women from meeting the physical activity guidelines during pregnancy, workplace interventions aimed at providing time management skills along with supporting physical activity programs for pregnant workers should be considered. Such interventions should also incorporate knowledge and education components, providing advice for undertaking leisure-time physical activity during pregnancy.

Municipal officials' perceived barriers to consideration of physical activity in community design decision making.

PubMed

Goins, Karin Valentine; Schneider, Kristin L; Brownson, Ross; Carnoske, Cheryl; Evenson, Kelly R; Eyler, Amy; Heinrich, Katie; Litt, Jill; Lyn, Rodney; Maddock, Jay; Reed, Hannah; Tompkins, Nancy Oʼhara; Lemon, Stephenie C

2013-01-01

Built environment-focused interventions and policies are recommended as sustainable approaches for promoting physical activity. Physical activity has not traditionally been considered in land use and transportation decision making. Effective collaboration with non-public health partners requires knowledge of their perceived barriers to such consideration. This analysis sought to (a) establish prevalence estimates of selected barriers to the consideration of physical activity in community design and layout decisions and (b) describe how barrier reporting by public health officials differs from other municipal officials among a wide range of job functions and departments in a geographically diverse sample. A Web-based survey was conducted among municipal officials in 94 cities and towns with populations of at least 50 000 residents in 8 states. A total of 453 municipal officials from public health, planning, transportation/public works, community and economic development, parks and recreation, city management, and municipal legislatures in 83 cities and towns responded to the survey. Five barriers to consideration of physical activity in community design and layout were assessed. The most common barriers included lack of political will (23.5%), limited staff (20.4%), and lack of collaboration across municipal departments (16.2%). Fewer participants reported opposition from the business community or residents as barriers. Public health department personnel were more likely to report the barriers of limited staff and lack of collaboration across municipal departments than other professionals. They were also more likely to report lack of political will than city managers or mayors and municipal legislators. Barriers to increasing consideration of physical activity in decision making about community design and layout are encouragingly low. Implications for public health practice include the need to strategically increase political will despite public health staffing constraints and perceived lack of collaboration with relevant departments such as planning and public works/transportation.

Perceived barriers to physical activity among Polish adolescents.

PubMed

Jodkowska, Maria; Mazur, Joanna; Oblacińska, Anna

2015-01-01

To identify barriers to physical activity (PA) for adolescents according to the gender and age and examine the association between these barriers and youths' physical activity. 3346 students aged 10-16 years (1759 girls) took part in the cross-sectional, nationally representative study. For this paper the dataset was created from adolescents who reported perceived barriers to PA, N = 2300, (1259 girls), range 13-16 years. Barriers and physical activity (MVPA) were analysed for all participants, as well as by gender, age group and place of residence. Multiple regression analysis was used to examine the relationships between perceived barriers and physical inactivity for all and than separately for boys and girls. Lack of energy, lack of time and lack of support were three of the five barriers reported by more than 40% of adolescents, statistically more likely by girls than boys and older youth than younger. For boys - lack of time (OR = 2.56; CI = 1.66-3.96), lack of skills (OR = 2.35; CI = 1.94-3.95), lack of willpower (OR = 1.71, CI = 1.05-2.80) and lack of support (OR = 1.64, CI = 1.11-2.41) were the predictors contributing to low level of PA. For girls lack of skills (OR = 3.16, CI = 1.62-6.18), lack of energy (OR = 1.84, CI = 1.14-2.96), lack of support (OR = 1.64, CI = 1.07-2.54) and lack of time (OR = 1.61,CI = 1.00-2.60) were positively and statistically significant associated with physical inactivity. 1. Perceived barriers to physical activity among adolescents have strong negative impact on recommended PA level. For girls lack of skills is the strongest predictor of low PA, for boys - lack of time. 2. Identification more precisely barriers to physical activity among adolescents will enable to developed more effective interventions in high-risk populations.

Are the Walls Really Down? Behavioral and Organizational Barriers to Faculty and Staff Diversity. ASHE Higher Education Report, Volume 33, Number 1

ERIC Educational Resources Information Center

Evans, Alvin, Ed.; Chun, Edna Breinig, Ed.

2007-01-01

This monograph focuses on the subtle behavioral and organizational barriers that hinder the recruitment, retention, and advancement of women and minority faculty and administrators in higher education today. Specifically the monograph explores the obstacles that face women and minorities who serve as full-time, tenure-track faculty and…

Lowering the Cost Barrier to Higher Education for Undocumented Students: A Promising University-Level Intervention

ERIC Educational Resources Information Center

Thangasamy, Andrew; Horan, Deborah

2016-01-01

Undocumented students, many of Hispanic origin, face among the strictest cost barriers to higher education in the United States. Lack of legal status excludes them from most state and all federal financial aid programs. Furthermore, most states require them to pay out-of-state tuition rates at publicly supported institutions. In a new direction,…

Breaking Down Cultural Barriers to Military Entry into Higher Education

ERIC Educational Resources Information Center

Hollis, Michael J.

2009-01-01

The purpose of this paper was to identify a problem in higher education that needed a new solution and draft a viable proposal for how to resolve it. I chose the problem of cultural barriers that veterans often face when attempting to return to many universities following military service. The method used was a combination of existing literature…

A Study of Perceived Admission and Achievement Barriers of Learning-Disabled Students in Postsecondary Institutions

ERIC Educational Resources Information Center

Lamberg, Catherine Denise

2012-01-01

Learning-disabled students face ongoing challenges in higher education. Despite efforts to promote recruitment and retention of students with learning disabilities to trade schools, colleges, and universities, barriers to enrollment and academic achievement persist. Barriers for learning-disabled students are not fully understood and might be…

New Way to Break Down Barriers to Higher Education: Build "Financial Capabilities"

ERIC Educational Resources Information Center

Savage, Sarah; Graves, Erin M.

2015-01-01

Community colleges have traditionally responded to the financial needs of their students by removing or minimizing financial barriers to attending. Efforts to make community college tuition free fit with this philosophy, but where efforts to minimize or remove financial barriers to attending community college fall short is in empowering students…

Limit Our Horizons in the Land of Enchantment? The Challenge for Education.

ERIC Educational Resources Information Center

Thomas, Gerald W.

This paper examines the trends in participation in higher education for New Mexico. Statistical data indicated that only 39 percent of the high school graduates in 1973 planned to enter college after graduation. Barriers to advanced education and training are discussed including intellectual barriers, financial barriers, and environmental and…

Paving the Way to Successful Implementation: Identifying Key Barriers to Use of Technology-Based Therapeutic Tools for Behavioral Health Care.

PubMed

Ramsey, Alex; Lord, Sarah; Torrey, John; Marsch, Lisa; Lardiere, Michael

2016-01-01

This study aimed to identify barriers to use of technology for behavioral health care from the perspective of care decision makers at community behavioral health organizations. As part of a larger survey of technology readiness, 260 care decision makers completed an open-ended question about perceived barriers to use of technology. Using the Consolidated Framework for Implementation Research (CFIR), qualitative analyses yielded barrier themes related to characteristics of technology (e.g., cost and privacy), potential end users (e.g., technology literacy and attitudes about technology), organization structure and climate (e.g., budget and infrastructure), and factors external to organizations (e.g., broadband accessibility and reimbursement policies). Number of reported barriers was higher among respondents representing agencies with lower annual budgets and smaller client bases relative to higher budget, larger clientele organizations. Individual barriers were differentially associated with budget, size of client base, and geographic location. Results are discussed in light of implementation science frameworks and proactive strategies to address perceived obstacles to adoption and use of technology-based behavioral health tools.

Paving the Way to Successful Implementation: Identifying Key Barriers to Use of Technology-Based Therapeutic Tools for Behavioral Health Care

PubMed Central

Ramsey, Alex; Lord, Sarah; Torrey, John; Marsch, Lisa; Lardiere, Michael

2014-01-01

This study aimed to identify barriers to use of technology for behavioral health care from the perspective of care decision-makers at community behavioral health organizations. As part of a larger survey of technology readiness, 260 care decision-makers completed an open-ended question about perceived barriers to use of technology. Using the Consolidated Framework for Implementation Research (CFIR), qualitative analyses yielded barrier themes related to characteristics of technology (e.g., cost, privacy), potential end-users (e.g., technology literacy, attitudes about technology), organization structure and climate (e.g., budget, infrastructure), and factors external to organizations (e.g., broadband accessibility, reimbursement policies). Number of reported barriers was higher among respondents representing agencies with lower annual budgets and smaller client bases relative to higher budget, larger clientele organizations. Individual barriers were differentially associated with budget, size of client base, and geographic location. Results are discussed in light of implementation science frameworks and proactive strategies to address perceived obstacles to adoption and use of technology-based behavioral health tools. PMID:25192755

Design and Application of a High-Temperature Linear Ion Trap Reactor

NASA Astrophysics Data System (ADS)

Jiang, Li-Xue; Liu, Qing-Yu; Li, Xiao-Na; He, Sheng-Gui

2018-01-01

A high-temperature linear ion trap reactor with hexapole design was homemade to study ion-molecule reactions at variable temperatures. The highest temperature for the trapped ions is up to 773 K, which is much higher than those in available reports. The reaction between V2O6 - cluster anions and CO at different temperatures was investigated to evaluate the performance of this reactor. The apparent activation energy was determined to be 0.10 ± 0.02 eV, which is consistent with the barrier of 0.12 eV calculated by density functional theory. This indicates that the current experimental apparatus is prospective to study ion-molecule reactions at variable temperatures, and more kinetic details can be obtained to have a better understanding of chemical reactions that have overall barriers. [Figure not available: see fulltext.

Selective control of electron and hole tunneling in 2D assembly

PubMed Central

Chu, Dongil; Lee, Young Hee; Kim, Eun Kyu

2017-01-01

Recent discoveries in the field of two-dimensional (2D) materials have led to the demonstration of exotic devices. Although they have new potential applications in electronics, thermally activated transport over a metal/semiconductor barrier sets physical subthermionic limitations. The challenge of realizing an innovative transistor geometry that exploits this concern remains. A new class of 2D assembly (namely, “carristor”) with a configuration similar to the metal-insulator-semiconductor structure is introduced in this work. Superior functionalities, such as a current rectification ratio of up to 400,000 and a switching ratio of higher than 106 at room temperature, are realized by quantum-mechanical tunneling of majority and minority carriers across the barrier. These carristors have a potential application as the fundamental building block of low–power consumption electronics. PMID:28439554

Exploring parent-reported barriers to supporting their child's health behaviors: a cross-sectional study.

PubMed

Jarvis, Jocelyn W; Harrington, Daniel W; Manson, Heather

2017-05-15

Parents can influence the health behaviors of their children by engaging in supportive behaviors (e.g., playing outside with their child, limiting recreational screen time). How, and the extent to which parents engage in supportive behaviors may be influenced by perceived barriers. The purpose of this study is to explore whether the frequency, and types, of barriers to providing parental support are dependent on the type of child health behavior being supported (i.e., physical activity, recreational screen time reduction, healthy eating, and sleep). Study participants were 1140 Ontario parents with at least one child under the age of 18 who completed a Computer Assisted Telephone Interview (CATI) survey about parental support behaviors. Open-ended responses about perceived barriers to parental support were coded, and aggregated to meta-categories adopted from the social-ecological model (i.e., individual child, individual parent, interpersonal, environmental). Freidman rank sum tests were used to assess differences across child behaviors. Wilcoxon rank sum tests with Bonferroni adjustments were used as a post hoc test for significant Freidman results. There were more barriers reported for supporting physical activity than for any other child behavior (ps < .01, As ≥ .53). Parents reported more parent level and environmental level barriers to supporting child physical activity versus other behaviors (ps < .001, As ≥ .55), child level barriers were more frequently reported for supporting healthy eating and sleep (ps < .001, As ≥ .57), and interpersonal barriers were more frequently reported for supporting recreational screen time reduction (ps < .001, As ≥ .52). Overall, parents reported more child and parent level barriers versus interpersonal and environmental barriers to supporting child health. Parents experience a variety of barriers to supporting their children's health behaviors. Differences in types of barriers across child health behaviors emerged; however, some frequently reported barriers (e.g., child preferences) were common across behaviors. Interventions promoting parental support should consider strategies that can accommodate parents' busy schedules, and relate to activities that children find enjoyable. Creating supportive environments that help facilitate support behaviors, while minimizing parent level barriers, may be of particular benefit. Future research should explore the impact of barriers on parental support behaviors, and effective strategies for overcoming common barriers.

The Role of Patient Activation in Preferences for Shared Decision Making: Results From a National Survey of U.S. Adults.

PubMed

Smith, Samuel G; Pandit, Anjali; Rush, Steven R; Wolf, Michael S; Simon, Carol J

2016-01-01

Studies investigating preferences for shared decision making (SDM) have focused on associations with sociodemographic variables, with few investigations exploring patient factors. We aimed to investigate the relationship between patient activation and preferences for SDM in 6 common medical decisions among a nationally representative cross-sectional survey of American adults. Adults older than 18 were recruited online (n = 2,700) and by telephone (n = 700). Respondents completed sociodemographic assessments and the Patient Activation Measure. They were also asked whether they perceived benefit (yes/no) in SDM in 6 common medical decisions. Nearly half of the sample (45.9%) reached the highest level of activation (Level 4). Activation was associated with age (p < .001), higher income (p = .001), higher education (p = .010), better self-rated health (p < .001), and fewer chronic conditions (p = .050). The proportion of people who agreed that SDM was beneficial varied from 53.1% (deciding the necessity of a diagnostic test) to 71.8% (decisions associated with making lifestyle changes). After we controlled for participant characteristics, higher activation was associated with greater perceived benefit in SDM across 4 of the 6 decisions. Preferences for SDM varied among 6 common medical scenarios. Low patient activation is an important barrier to SDM that could be ameliorated through the development of behavioral interventions.

Physical activity problem-solving inventory for adolescents: Development and initial validation

USDA-ARS?s Scientific Manuscript database

Youth encounter physical activity barriers, often called problems. The purpose of problem-solving is to generate solutions to overcome the barriers. Enhancing problem-solving ability may enable youth to be more physically active. Therefore, a method for reliably assessing physical activity problem-s...

Physical and social environmental characteristics of physical activity for Mexican-origin children: examining differences between school year and summer perceptions.

PubMed

Umstattd Meyer, M Renée; Walsh, Shana M; Sharkey, Joseph R; Morgan, Grant B; Nalty, Courtney C

2014-09-16

Colonias are substandard residential areas along the U.S.-Mexico border. Families of Mexican-origin living in colonias face health burdens characterized by environmental and socioeconomic hardships. Mexican Americans and low-income families, including colonias children, do not frequently participate in physical activity despite the known link to disease risk reduction. For colonias children, schools are the most commonly reported location for physical activity. School closures and extreme temperatures during summer months create a need to explore seasonal differences in environmental supports and barriers in this population. The purpose of this study was to examine the effect of seasonality on perceived environmental barriers, opportunities, and social support for physical activity among colonias children. As a secondary aim, mother-child discordance for each factor was analyzed. Promotora-researchers recruited mother-child dyads (n=101 dyads, n=202 participants) from colonias in Hidalgo County, Texas. Mothers and children were separately administered surveys at two time points to capture perceived barriers, opportunities, and social support for physical activity (school-year: February-May; summertime: July-August). Summative scores for each outcome were calculated and three multilevel longitudinal models for continuous outcomes were examined; children were nested within households. Mother-child discordance was measured using Cohen's Kappa statistic. Physical activity barriers and environmental opportunities (household and neighborhood) increased from school-year to summer by 1.16 and 2.83 points respectively (p≤0.01), after adjusting for covariates. Significant predictors of increased barriers included household income of >$900/month and having more household members. Children of mothers with significant others who were employed part-time or full-time saw significant decreases in barriers. Mother-child agreement of barriers, environmental opportunities, and social support across seasons was slight to fair (range: median κ=0.047 to κ=0.262). These results suggest a complex relationship between dimensions of economic hardship (employment status, household income, etc…) and perceived opportunities and barriers of children's physical activity engagement during the school-year and summer. In this study, both barriers and opportunities increased from school-year to summer, further demonstrating that interactions among these characteristics need to be better understood and addressed when considering physical activity initiatives for colonias and other Mexican-American children, specifically during summer when school-based physical activity resources are unavailable.

Gender Differences in Barriers to Physical Activity among College Students Reporting Varying Levels of Regular Physical Activity

ERIC Educational Resources Information Center

Munford, Shawn N.

2011-01-01

Researchers have studied the primary determinants of physical activity in an effort to enhance health promotion initiatives nationwide. These physical activity determinants have been observed to differ among various segments of the population, suggesting a further examination of physical activity barriers among differing populations. Little…

Perceived reasons, incentives, and barriers to physical activity in Swedish elderly men.

PubMed

Sjörs, Camilla; Bonn, Stephanie E; Trolle Lagerros, Ylva; Sjölander, Arvid; Bälter, Katarina

2014-11-12

Knowledge about factors influencing physical activity behavior is needed in order to tailor physical activity interventions to the individual. The aim of this study was to explore and describe the perceived reasons, barriers, and incentives to increased physical activity, as well as preferable activities, among elderly men in Sweden. In total, 150 men aged 50-86 years responded to a Web-based questionnaire. Men who reported that they exercised sometimes or often received questions about reasons for physical activity (n=104), while men who reported that they never or seldom exercised received questions about barriers (n=46). The most frequent perceived reason for being physically active was health (82%), followed by enjoyment (45%), and a desire to lose/maintain weight (27%). Lack of interest/motivation was identified as the primary perceived barrier (17%). Incentives for increasing the level of activity included becoming more motivated and having a training partner. Walking was the most preferred activity. Enjoyment and maintaining a good health were important reasons for engaging in physical activity among Swedish elderly men.

Stages of condom use and decisional balance among college students.

PubMed

Tung, W-C; Farmer, S; Ding, K; Tung, W-K; Hsu, C-H

2009-09-01

To explore sexual behaviours and condom use and differences in specific items of perceived benefits and barriers to condoms using the Transtheoretical Model (TTM) stages among college students in southern Taiwan. The TTM suggests that individuals in the action or maintenance stage exhibit higher levels of perceived benefits and lower levels of perceived barriers related to condom use than people in the precontemplation, contemplation or preparation stage. This was a descriptive, cross-sectional design with cluster sampling among college students from two universities in southern Taiwan. Participants completed self-administered questionnaires, including demographic data, Sexual History and Condom Use Scale and Condom Use Decisional Balance Scale. Of the 279 participants, 57% were sexually active, of these only 11.9% used condoms consistently. Respondents in the TTM stage of action/maintenance perceived greater benefits in relation to feeling more responsible (P = 0.031) and protecting their partners as well as themselves (P = 0.028), and perceived more barriers in believing that using condom needs to rely on partner's cooperation (P = 0.046) than participants in precontemplation. Participants in precontemplation and contemplation perceived more barriers related to worry about making their partner angry if condoms were used than those in action/maintenance (P = 0.008). Low levels of condom use among Taiwanese college students remain a significant public health concern. HIV prevention programmes for college students in Taiwan may be enhanced if they incorporate readiness to change and perceived benefits and barriers. Future research should include a larger sample with diverse groups.

Barriers to and Facilitators of Healthful Eating and Physical Activity in Low-Income Schools

ERIC Educational Resources Information Center

Hammerschmidt, Patricia; Tackett, Wendy; Golzynski, Matthew; Golzynski, Diane

2011-01-01

Objective: To identify barriers to and facilitators of healthful eating and physical activity in low-income schools as perceived by school-affiliated staff. Methods: Perceptions of barriers and facilitators were measured in low-income schools through two online surveys (Kindergarten-8th grade and high school). Sixty-nine (Kindergarten-8th grade)…

Mechanisms and energetics of hydride dissociation reactions on surfaces of plasma-deposited silicon thin films

NASA Astrophysics Data System (ADS)

Singh, Tejinder; Valipa, Mayur S.; Mountziaris, T. J.; Maroudas, Dimitrios

2007-11-01

We report results from a detailed analysis of the fundamental silicon hydride dissociation processes on silicon surfaces and discuss their implications for the surface chemical composition of plasma-deposited hydrogenated amorphous silicon (a-Si:H) thin films. The analysis is based on a synergistic combination of first-principles density functional theory (DFT) calculations of hydride dissociation on the hydrogen-terminated Si(001)-(2×1) surface and molecular-dynamics (MD) simulations of adsorbed SiH3 radical precursor dissociation on surfaces of MD-grown a-Si :H films. Our DFT calculations reveal that, in the presence of fivefold coordinated surface Si atoms, surface trihydride species dissociate sequentially to form surface dihydrides and surface monohydrides via thermally activated pathways with reaction barriers of 0.40-0.55eV. The presence of dangling bonds (DBs) results in lowering the activation barrier for hydride dissociation to 0.15-0.20eV, but such DB-mediated reactions are infrequent. Our MD simulations on a-Si :H film growth surfaces indicate that surface hydride dissociation reactions are predominantly mediated by fivefold coordinated surface Si atoms, with resulting activation barriers of 0.35-0.50eV. The results are consistent with experimental measurements of a-Si :H film surface composition using in situ attenuated total reflection Fourier transform infrared spectroscopy, which indicate that the a-Si :H surface is predominantly covered with the higher hydrides at low temperatures, while the surface monohydride, SiH(s ), becomes increasingly more dominant as the temperature is increased.

Mechanistic insight into the hydrazine decomposition on Rh(111): effect of reaction intermediate on catalytic activity.

PubMed

Deng, Zhigang; Lu, Xiaoqing; Wen, Zengqiang; Wei, Shuxian; Liu, Yunjie; Fu, Dianling; Zhao, Lianming; Guo, Wenyue

2013-10-14

Periodic density functional theory (DFT) calculations have been performed to systematically investigate the effect of reaction intermediate on catalytic activity for hydrazine (N2H4) decomposition on Rh(111). Reaction mechanisms via intramolecular and NH2-assisted N2H4 decompositions are comparatively analyzed, including adsorption configuration, reaction energy and barrier of elementary step, and reaction network. Our results show that the most favorable N2H4 decomposition pathway starts with the initial N-N bond scission to the NH2 intermediate, followed by stepwise H stripping from adsorbed N2Hx (x = 1-4) species, and finally forms the N2 and NH3 products. Comparatively, the stepwise intramolecular dehydrogenation via N2H4→ N2H3→ N2H2→ N2H → N2, and N2H4→ NH2→ NH → N with or without NH2 promotion effect, are unfavorable due to higher energy barriers encountered. Energy barrier analysis, reaction rate constants, and electronic structures are used to identify the crucial competitive route. The promotion effect of the NH2 intermediate is structurally reflected in the weakening of the N-H bond and strengthening of the N-N bond in N2Hx in the coadsorption system; it results intrinsically from the less structural deformation of the adsorbate, and weakening of the interaction between dehydrogenated fragment and departing H in transition state. Our results highlight the crucial effect of reaction intermediate on catalytic activity and provide a theoretical approach to analyze the effect.

Nutrients affecting gastric barrier.

PubMed

Gasbarrini, Antonio; D'Aversa, Francesca; Di Rienzo, Teresa; Franceschi, Francesco

2014-01-01

The gastric barrier could be considered an active tissue involved in many synthetic and metabolic functions, as the immunological defense, by activating mucosal immune system. Barrier integrity results from a balance between protective and aggressive endogenous factors and from their interaction with exogenous factors (steroidal or nonsteroidal anti-inflammatory drugs, dietary nitrates, nitrites and/or NaCl, stress, Helicobacter pylori infection, food allergens and contaminants, metals, chemicals, radiation, smoking and alcohol intake). Nutrients represent the most important exogenous factors affecting gastric barrier because of the impact on people's everyday life. We report evidence from the literature about nutrients affecting gastric barrier and we investigate the possible effect that nutrients can play to determining or maintaining a gastric barrier dysfunction. © 2014 S. Karger AG, Basel.

A Cross Sectional Comparison of Predisposing, Reinforcing and Enabling Factors for Lifestyle Health Behaviours and Weight Gain in Healthy and Overweight Pregnant Women.

PubMed

de Jersey, Susan J; Mallan, Kimberley; Callaway, Leonie; Daniels, Lynne A; Nicholson, Jan M

2017-03-01

Objectives Little is known about the antecedents to dietary and physical activity behaviours that can support healthy gestational weight gain (GWG) across different weight status groups in pregnancy. The aim of this study was to use constructs common to dominant health behaviour theories to determine if predisposing, reinforcing and enabling factors for healthy eating, physical activity and weight gain differed between healthy and overweight pregnant women. Methods Pregnant women (n = 664) aged 29 ± 5 (mean ± SD) years were recruited at 16 ± 2 weeks gestation. Measures were self-reported pre-pregnancy weight, psychosocial constructs for healthy eating, physical activity and GWG and demographic data. Height was measured at 16 weeks. Psychosocial constructs were compared between women with pre-pregnancy weight status of healthy (BMI < 25 kg/m 2 ) and overweight (BMI ≥ 25 kg/m 2 ). Results Health behaviour intentions, positive outcome expectations and social support for healthy eating and physical activity were not different between healthy (66 %) and overweight (34 %) women. Overweight women had lower self-efficacy for healthy eating, physical activity and GWG (p < 0.001), higher negative outcome expectations for GWG (p = 0.004), and higher barriers to healthy eating (p = 0.002), and physical activity (p = 0.006). Conclusions for practice Both healthy and overweight women appear motivated to follow a healthy diet, exercise and avoid excess gestational weight during pregnancy. However many psychosocial factors associated with achieving these goals were different between healthy and overweight women. Health behaviour interventions tailored to overweight pregnant women should consider improving self-efficacy, providing support to overcome perceived barriers, validate positive changes made, and assist in managing negative expectations.

Mexican Americans with type 2 diabetes: perspectives on definitions, motivators, and programs of physical activity.

PubMed

Mier, Nelda; Medina, Alvaro A; Ory, Marcia G

2007-04-01

Research documents that Mexican Americans bear excess health risk because of physical inactivity and have higher morbidity and mortality rates from chronic diseases than do other ethnic groups. Factors influencing physical activity in this minority population, however, are not well understood. This study examines perceptions of physical activity in a population of Mexican Americans who have type 2 diabetes and live in the Texas-Mexico border region and identifies motivators and barriers to physical activity in this group. This study used a qualitative research design and employed six focus groups comprising 39 Mexican Americans with type 2 diabetes who live in the Texas-Mexico border region. A team of bilingual Mexican American researchers systematically reviewed and analyzed focus group data by means of qualitative data analysis software. The study was conducted during 2005-2006. Most participants considered physical activity to be related not only to exercise but also to occupational and home activities. Walking was the preferred type of activity. Motivators to physical activity included family support and the sense of well-being derived from physical activity. Barriers to physical activity included individual and environmental factors, such as lack of time, physical pain, depression, being overweight, unsafe neighborhoods, and lack of facilities. Participants suggested that the ideal intervention would be low in cost, family-based, close to home, and led by bilingual instructors. Health promotion efforts to prevent or reduce the effects of chronic disease among Mexican Americans with type 2 diabetes in the Texas-Mexico border region should focus on implementing neighborhood-based, family-oriented walking interventions.

Barriers to a healthy lifestyle for three- to four-year-old children of Australian-born and overseas-born mothers with post-gestational diabetes: An Australian qualitative study.

PubMed

Zulfiqar, Tehzeeb; Nolan, Christopher J; Banwell, Cathy; Young, Rosemary; Boisseau, Lynelle; Ingle, Martha; Lithander, Fiona E

2018-01-01

Children of mothers affected by gestational diabetes mellitus (GDM) are at higher risk of long-term cardio-metabolic diseases. We explore the diet and physical activity knowledge and practices of Australian-born and overseas-born mothers with GDM history, for their three- to four-year-old children following antenatal health promotion education at a tertiary hospital. We conducted face-to-face, semi-structured interviews with 8 Australian-born and 15 overseas-born mothers with a history of GDM. Findings indicated that mothers of both groups were unaware of the increased health risks of their GDM for their children and could not recall receiving specific dietary or physical activity advice aimed at future child health. Their understanding of the diet and physical activity recommendations was inconsistent. Mothers of both groups expressed concern about the lack of reiteration of child health promotion messages following childbirth, particularly at postnatal follow-up visits. Diet and physical activity of the children of overseas-born mothers were adversely affected by inadequate maternal understanding of the recommendations due to language barriers, and child weight, healthy eating, and physical activity patterns derived from their home countries. We recommend enhanced health education for women with GDM on the future child health risks and their reduction by healthy lifestyle choices. This needs to be culturally relevant and reiterated after pregnancy.

Participation of chronic patients in medical consultations: patients' perceived efficacy, barriers and interest in support.

PubMed

Henselmans, Inge; Heijmans, Monique; Rademakers, Jany; van Dulmen, Sandra

2015-12-01

Chronic patients are increasingly expected to participate actively in medical consultations. This study examined (i) patients' perceived efficacy and barriers to participation in consultations, (ii) patients' interest in communication support and (iii) correlates of perceived efficacy and barriers, with an emphasis on differences across providers' disciplines. A representative panel of chronic patients (n = 1314) filled out the short Perceived Efficacy in Patient-Provider Interaction scale and were questioned about barriers to participation and interest in communication support. Potential correlates included socio-demographic (age, sex, education, living situation), clinical (discipline care provider, type of illness, comorbidity, illness duration, functional disabilities, health consultations in last year) and personal characteristics (information preference, health literacy, level of general patient activation). Most patients felt efficacious in consultations, although 46% reported barriers to participation and 39% had an interest in support. Barriers most frequently recognized were 'not wanting to be bothersome', 'perception there is too little time' and 'remembering subjects only afterwards'. Patients most frequently endorsed relatively simple support. Patients perceived the least barriers and were least likely to endorse support when seeing a nurse. In multivariate models, consistent risk factors for low efficacy and perceived barriers were low health literacy and a low general patient activation. Many chronically ill patients feel confident in medical interactions. Still, a significant number might benefit from support. Often this concerned more generally vulnerable patients, that is, the low literate and generally less activated. Relatively simple supportive interventions are likely to be endorsed and might overcome frequent barriers. © 2014 John Wiley & Sons Ltd.

[Intranasal epitalon infusion modulates neuronal activity in the rat neocortex].

PubMed

Sibarov, D A; Vol'nova, A B; Frolov, D S; Nosdrachev, A D

2006-08-01

Properties of tetrapeptide epitalon (Ala-Glu-Asp-Gly) constructed on the basis of pineal peptide extract, have been studied. The intranasal infusions: a noninvasive way to deliver this peptide to CNS hypassing the blood-brain barrier, was used. The aim of the study is to estimate epitalon action on rat motor cortex spontaneous activity. Wistar male rats were anesthetized with urethane (1 g/kg). Extracellular unit recording was made using glass microelectrodes (1-2 MOhm). After recording of spontaneous activity (10-15 min), epitalon intranasal infusion (2 ng) was followed by 30-minute recording. Within a few minutes after the infusion, significant activation of neural activity was observed (2-2.5-fold higher frequency of neuronal spikes). Complex response consisting of several phases was identified in some recordings. The spikes frequency growth during 5 to 7 min (first phase) after the infusion was followed by the second (11-12 min) and the third (17-18 min) phases. An increase of neuronal spontaneous activity was conditioned by the higher frequency of already active units and by the involvement of previously silent cells. At least the first phase of epitalon action can be explained by direct action of the peptide on the cells of the motor cortex.

Hydrolytic Glycosidic Bond Cleavage in RNA Nucleosides: Effects of the 2'-Hydroxy Group and Acid-Base Catalysis.

PubMed

Lenz, Stefan A P; Kohout, Johnathan D; Wetmore, Stacey D

2016-12-22

Despite the inherent stability of glycosidic linkages in nucleic acids that connect the nucleobases to sugar-phosphate backbones, cleavage of these bonds is often essential for organism survival. The current study uses DFT (B3LYP) to provide a fundamental understanding of the hydrolytic deglycosylation of the natural RNA nucleosides (A, C, G, and U), offers a comparison to DNA hydrolysis, and examines the effects of acid, base, or simultaneous acid-base catalysis on RNA deglycosylation. By initially examining HCOO - ···H 2 O mediated deglycosylation, the barriers for RNA hydrolysis were determined to be 30-38 kJ mol -1 higher than the corresponding DNA barriers, indicating that the 2'-OH group stabilizes the glycosidic bond. Although the presence of HCOO - as the base (i.e., to activate the water nucleophile) reduces the barrier for uncatalyzed RNA hydrolysis (i.e., unactivated H 2 O nucleophile) by ∼15-20 kJ mol -1 , the extreme of base catalysis as modeled using a fully deprotonated water molecule (i.e., OH - nucleophile) decreases the uncatalyzed barriers by up to 65 kJ mol -1 . Acid catalysis was subsequently examined by selectively protonating the hydrogen-bond acceptor sites of the RNA nucleobases, which results in an up to ∼80 kJ mol -1 barrier reduction relative to the corresponding uncatalyzed pathway. Interestingly, the nucleobase proton acceptor sites that result in the greatest barrier reductions match sites typically targeted in enzyme-catalyzed reactions. Nevertheless, simultaneous acid and base catalysis is the most beneficial way to enhance the reactivity of the glycosidic bonds in RNA, with the individual effects of each catalytic approach being weakened, additive, or synergistic depending on the strength of the base (i.e., degree of water nucleophile activation), the nucleobase, and the hydrogen-bonding acceptor site on the nucleobase. Together, the current contribution provides a greater understanding of the reactivity of the glycosidic bond in natural RNA nucleosides, and has fundamental implications for the function of RNA-targeting enzymes.

A multi-modal intervention for Activating Patients at Risk for Osteoporosis (APROPOS): Rationale, design, and uptake of online study intervention material.

PubMed

Danila, Maria I; Outman, Ryan C; Rahn, Elizabeth J; Mudano, Amy S; Thomas, Tammi F; Redden, David T; Allison, Jeroan J; Anderson, Fred A; Anderson, Julia P; Cram, Peter M; Curtis, Jeffrey R; Fraenkel, Liana; Greenspan, Susan L; LaCroix, Andrea Z; Majumdar, Sumit R; Miller, Michael J; Nieves, Jeri W; Safford, Monika M; Silverman, Stuart L; Siris, Ethel S; Solomon, Daniel H; Warriner, Amy H; Watts, Nelson B; Yood, Robert A; Saag, Kenneth G

2016-12-15

To develop an innovative and effective educational intervention to inform patients about the need for osteoporosis treatment and to determine factors associated with its online uptake. Postmenopausal women with a prior fracture and not currently using osteoporosis therapy were eligible to be included in the Activating Patients at Risk for OsteoPOroSis (APROPOS). Four nominal groups with a total of 18 racially/ethnically diverse women identified osteoporosis treatment barriers. We used the Information, Motivation, Behavior Skills conceptual model to develop a direct-to-patient intervention to mitigate potentially modifiable barriers to osteoporosis therapy. The intervention included videos tailored by participants' race/ethnicity and their survey responses: ranked barriers to osteoporosis treatment, deduced barriers to treatment, readiness to behavior change, and osteoporosis treatment history. Videos consisted of "storytelling" narratives, based on osteoporosis patient experiences and portrayed by actresses of patient-identified race/ethnicity. We also delivered personalized brief phone calls followed by an interactive voice-response phone messages aimed to promote uptake of the videos. To address the factors associated with online intervention uptake, we focused on participants assigned to the intervention arm (n = 1342). These participants were 92.9% Caucasian, with a mean (SD) age 74.9 (8.0) years and the majority (77.7%) had some college education. Preference for natural treatments was the barrier ranked #1 by most (n = 130; 27%), while concern about osteonecrosis of the jaw was the most frequently reported barrier (at any level; n = 322; 67%). Overall, 28.1% (n = 377) of participants in the intervention group accessed the videos online. After adjusting for relevant covariates, the participants who provided an email address had 6.07 (95% CI 4.53-8.14) higher adjusted odds of accessing their online videos compared to those who did not. We developed and implemented a novel tailored multi-modal intervention to improve initiation of osteoporosis therapy. An email address provided on the survey was the most important factor independently associated with accessing the intervention online. The design and uptake of this intervention may have implications for future studies in osteoporosis or other chronic diseases.

Motivators of and Barriers to Engaging in Physical Activity: Perspectives of Low-Income Culturally Diverse Adolescents and Adults

PubMed Central

Bragg, Marie A.; Tucker, Carolyn M.; Kaye, Lily B.; Desmond, Frederic

2017-01-01

Background Obesity rates are rising in the United States, especially among low-income and racial/ethnic minority individuals. Exploring motivators and barriers relative to engaging in physical activity is imperative. Purpose The purpose of this study was to identify motivators and barriers relative to engagement in physical activity as reported by culturally diverse low-income adolescents and adults. Methods A total of 91 adolescent (11 to 15 years of age) and adult (18 years of age or older) participants who self-identified as African American, Hispanic, or non-Hispanic White engaged in age group-, race/ethnicity-, and gender-concordant focus groups. Results Qualitative data analysis indicated that the motivators and barriers most commonly identified among the adolescent and adult focus groups were: social influence; time and priorities; physical environment; fun and enjoyment; inherently physical activities; weight concerns; fatigue, physical discomfort and current fitness level; and immediate positive feelings. Discussion Findings were generally similar across age group, gender and race/ethnicity. Age group-specific, gender-specific and race/ethnicity-specific motivators and barriers were related to how commonly the motivators and barriers were identified among each group. Translation to Health Education Practice Implications for increasing physical activity among low-income culturally diverse adolescents and adults are discussed. PMID:29527247

Corneal critical barrier against the penetration of dexamethasone and lomefloxacin hydrochloride: evaluation by the activation energy for drug partition and diffusion in cornea.

PubMed

Yasueda, Shin-ichi; Higashiyama, Masayo; Yamaguchi, Masazumi; Isowaki, Akiharu; Ohtori, Akira

2007-08-01

The cornea is a solid barrier against drug permeation. We searched the critical barrier of corneal drug permeation using a hydrophobic drug, dexamethasone (DM), and a hydrophilic drug, lomefloxacin hydrochloride (LFLX). The activation energies for permeability of DM and LFLX across the intact cornea were 88.0 and 42.1 kJ/mol, respectively. Their activation energies for permeability across the cornea without epithelium decreased to 33.1 and 16.6 kJ/mol, respectively. The results show that epithelium is the critical barrier on the cornea against the permeation of a hydrophobic drug of DM as well as a hydrophilic drug of LFLX. The activation energy of partition for DM (66.8 kJ/mol) was approximately 3-fold larger than that of diffusion (21.2 kJ/mol). The results indicate that the partition for the hydrophobic drug of DM to the corneal epithelium is the primary barrier. Thermodynamic evaluation of activation energy for the drug permeation parameters is a good approach to investigate the mechanism of drug permeability.

Physical Activity and Youth with Disabilities: Barriers and Supports

ERIC Educational Resources Information Center

Block, Martin E.; Taliaferro, Andrea; Moran, Tom

2013-01-01

Physical activity and active use of leisure time is important for everyone but particularly important for youth with disabilities. Unfortunately, youth with disabilities often have a difficult time or are even excluded from participating in physical activity due to limited physical and cognitive skills, attitudinal barriers in the community, lack…

Barriers to Research Activities from the Perspective of the Students of Isfahan University of Medical Sciences.

PubMed

Ashrafi-Rizi, Hasan; Fateme, Zarmehr; Khorasgani, Zahra Ghazavi; Kazempour, Zahra; Imani, Sona Taebi

2015-06-01

Necessity to establish a coherent and targeted research context in order to development of any country is increasingly important. But the basic step in creating an effective research context would be enrichment motivation of researchers especially students and resolve barriers of research. Therefore, the purpose of this study was to determine barriers of research activities from the perspective of students of Isfahan University of Medical Sciences. This is research. Data was collected with author made questionnaire. The study sample consisted of students from Isfahan medical university and sample size based on Krejcie and Morgan table was 357. Sampling was Stratified Random. The validity of questionnaire confirmed by Library and information professionals and reliability based on Cronbach's Alpha was 0.933, respectively. The type of descriptive statistics was (percentage, frequency and mean) and inferential statistics (T-test, ANOVA, one-Sample Statistics) and SPSS software was used. Results showed that the mean of barriers to research activities among students of Isfahan University of Medical Sciences was 3.89 ± 0. 483. The highest mean was related to density of students' curriculum (4.22± 0.968) and lowest mean related to lack of access to appropriate library resources. Also, the mean of research activities 's barriers, according to aspects showed that the mean in individual barriers level (4.06±0.635) was more than other aspects: social and cultural aspects (4.01± 0.661), economical aspect (4.04± 0.787) and organizational barriers (3.78±0.503). The lowest mean was related to organizational barriers. Also there is no difference between mean of research activities' barriers of student of Isfahan University of Medical Sciences with regarded of gender, level of education and college. According to results of this research, although, the main barriers between students was individual barriers such as: lack of sufficient familiarity with research methods, insufficient experience in research and lack of familiarity with the terms of the articles in publication, but other aspects like economic, cultural, social and organizational was in bad condition too. Therefore it is suggested that workshops related to research methodologies is executed, like proposal writing, writing articles in university especially for students and administrators support student's research activities, effectively.

Perceived benefits and barriers of physical activity: A social marketing formative study.

PubMed

Rundle-Thiele, Sharyn; Kubacki, Krzysztof; Gruneklee, Naomi

2016-01-01

The aim of this study was to gain formative research insights that can be used to design social marketing campaigns. One thousand four hundred fifty-nine people participated in an online survey. Factor analysis was undertaken to establish perceived benefits and barriers, and indexes were created for barriers, benefits, and healthy living knowledge. Four attitude groups were formed and analysis of variance was undertaken to explore group differences. Consumers with high perceived barriers report less physical activity than consumers with low perceived barriers to exercise. The current study provides evidence to suggest that exchange theory can offer important insights to inform social marketing intervention planning.

Self-efficacy toward physical activity and the physical activity behavior of children with and without Developmental Coordination Disorder.

PubMed

Batey, C A; Missiuna, C A; Timmons, B W; Hay, J A; Faught, B E; Cairney, J

2014-08-01

Affecting 5-6% of children, Developmental Coordination Disorder (DCD) is a prevalent chronic condition. The nature of the disorder - impaired motor coordination - makes avoidance of physical activity (PA) common. The purpose of this study was to examine the effect of barrier and task self-efficacy on PA behavior in children with DCD and a group of typically developing (TD) children. Children were compared on their perceived ability to complete different intensities and duration of PA (task efficacy) and their confidence in completing PA when faced with everyday barriers (barrier efficacy). An accelerometer was used to record their activity over the subsequent week. Children with DCD were found to have significantly lower task efficacy and barrier efficacy. They also spent significantly less time in moderate to vigorous physical activity (MVPA). Multivariate analyses revealed that gender modified the relationship for both groups. Separate multivariate regressions, were therefore conducted by gender. A direct effect of DCD on PA was observed for boys, but not for girls. Further analyses showed that neither task efficacy nor barrier efficacy influenced the relationship between DCD and PA. Results from this study confirm that children with DCD have lower task and barrier self-efficacy than TD children and that males have lower PA levels than their TD peers; however neither task or barrier self-efficacy mediated the relationship between DCD and PA. Copyright © 2013. Published by Elsevier B.V.

Barriers and facilitators to physical activity amongst overweight and obese women in an Afro-Caribbean population: A qualitative study.

PubMed

Alvarado, Miriam; Murphy, Madhuvanti M; Guell, Cornelia

2015-07-28

The proportion of obese women is nearly twice the proportion of obese men in Barbados, and physical inactivity may be a partial determinant. Using qualitative interviews and 'semi-structured' participant observation, the aim of this study was to identify modifiable barriers to physical activity and to explore the factors that facilitate physical activity amongst overweight and obese women in this low-resourced setting. Seventeen women aged 25 to 35 years with a BMI ≥25, purposefully sampled from a population-based cross-sectional study conducted in Barbados, were recruited in 2014 to participate in in-depth semi-structured interviews. Twelve of these women participated in one or more additional participant observation sessions in which the researcher joined and observed a routine activity chosen by the participant. More than 50 hours of participant observation data collection were accumulated and documented in field notes. Thematic content analysis was performed on transcribed interviews and field notes using the software Dedoose. Social, structural and individual barriers to physical activity were identified. Social factors related to gender norms and expectations. Women tended to be active with their female friends rather than partners or male peers, and reported peer support but also alienation. Being active also competed with family responsibilities and expectations. Structural barriers included few opportunities for active commuting, limited indoor space for exercise in the home, and low perceived access to convenient and affordable exercise classes. Several successful strategies associated with sustained activity were observed, including walking and highly social, low-cost exercise groups. Individual barriers related to healthy living strategies included perceptions about chronic disease and viewing physical activity as a possible strategy for desired weight loss but less effective than dieting. It is important to understand why women face barriers to physical activity, particularly in low-resourced settings, and to investigate how this could be addressed. This study highlights the role that gender norms and health beliefs play in shaping experiences of physical activity. In addition, structural barriers reflect a mix of resource-scarce and resource-rich factors which are likely to be seen in a wide variety of developing contexts.

Barriers and Strategies on Adoption of E-Learning in Tanzanian Higher Learning Institutions: Lessons for Adopters

ERIC Educational Resources Information Center

Kisanga, Dalton; Ireson, Gren

2015-01-01

Tanzanian Higher learning institutions (HLIs) are faced with challenges of adopting e-learning in education. This study involved experts in e-learning to examine barriers of adopting e-learning and the best strategies to address them. Data were gathered from a series of semi-structured interviews with e-learning experts from two HLIs in Tanzania.…

Toxicity, tunneling and feeding behavior of the termite, Coptotermes vastator, in sand treated with oil of the physic nut, Jatropha curcas.

PubMed

Acda, Menandro N

2009-01-01

Oil of the physic nut, Jatropha curcas L. (Malpighiales: Euphorbiaceae), was evaluated in the laboratory for its barrier and repellent activity against the Philippine milk termite Coptotermes vastator Light (Isoptera: Rhinotermitidae). The study showed that J. curcas oil had anti-feeding effect, induced reduction in tunneling activity and increased mortality in C. vastator. Behavior of termites exposed to sand treated with J. curcas oil indicated that it is toxic or repellent to C. vastator. Toxicity and repellent thresholds, were higher than those reported for other naturally occurring compounds tested against the Formosan subterranean termite.

Toxicity, Tunneling and Feeding Behavior of the Termite, Coptotermes vastator, in Sand Treated with Oil of the Physic Nut, Jatropha curcas

PubMed Central

Acda, Menandro N.

2009-01-01

Oil of the physic nut, Jatropha curcas L. (Malpighiales: Euphorbiaceae), was evaluated in the laboratory for its barrier and repellent activity against the Philippine milk termite Coptotermes vastator Light (Isoptera: Rhinotermitidae). The study showed that J. curcas oil had anti-feeding effect, induced reduction in tunneling activity and increased mortality in C. vastator. Behavior of termites exposed to sand treated with J. curcas oil indicated that it is toxic or repellent to C. vastator. Toxicity and repellent thresholds, were higher than those reported for other naturally occurring compounds tested against the Formosan subterranean termite. PMID:20053119

Internationalization of the animal science undergraduate curriculum: a survey of its current status, barriers to its implementation and its value.

PubMed

Forsberg, N E; Taur, J S; Xiao, Y; Chesbrough, H

2003-04-01

The goal of this project was to identify the current level at which internationalization has been adopted as a theme in the North American animal science curriculum and to identify its value and the barriers to its implementation. We surveyed animal, dairy, and poultry science departments across Canada and the United States. One hundred twenty-four surveys were mailed and 60% were returned. Associations between aspects of internationalization and student outcomes (admission to veterinary and graduate schools and starting salaries) were examined. Although administrators strongly believed internationalization had value, implementation was limited. The most common practices included international content in core animal science classes, advising, international internships, and participation of faculty in international scholarly activities. Few departments have incorporated internationalization into their mission statements or developed a specific international-themed class, scholarships devoted to international activities, or roles for international students. Few departments reported participation of students in international programs. Barriers included finances and limited commitment from higher administration. Student outcomes were positively associated with faculty size, percentage of international faculty, the ratio of international students to the total student population, international content in core animal science classes, a specific international-themed class, availability of international internships, and exchange of class material internationally via the Internet. Departments that did not offer international opportunities had a negative association (r = -0.79) with starting salary, but these relationships may not be causal. Alternatively, progressive departments may attract and retain exceptional students. The analysis indicated an awareness of the value of international programs, positive impacts in student outcomes, and financial barriers to implementation.

Barrier Island Morphology and Sediment Characteristics Affect the Recovery of Dune Building Grasses following Storm-Induced Overwash

PubMed Central

Brantley, Steven T.; Bissett, Spencer N.; Young, Donald R.; Wolner, Catherine W. V.; Moore, Laura J.

2014-01-01

Barrier islands are complex and dynamic systems that provide critical ecosystem services to coastal populations. Stability of these systems is threatened by rising sea level and the potential for coastal storms to increase in frequency and intensity. Recovery of dune-building grasses following storms is an important process that promotes topographic heterogeneity and long-term stability of barrier islands, yet factors that drive dune recovery are poorly understood. We examined vegetation recovery in overwash zones on two geomorphically distinct (undisturbed vs. frequently overwashed) barrier islands on the Virginia coast, USA. We hypothesized that vegetation recovery in overwash zones would be driven primarily by environmental characteristics, especially elevation and beach width. We sampled species composition and environmental characteristics along a continuum of disturbance from active overwash zones to relict overwash zones and in adjacent undisturbed environments. We compared species assemblages along the disturbance chronosequence and between islands and we analyzed species composition data and environmental measurements with Canonical Correspondence Analysis to link community composition with environmental characteristics. Recovering and geomorphically stable dunes were dominated by Ammophila breviligulata Fernaud (Poaceae) on both islands while active overwash zones were dominated by Spartina patens (Aiton) Muhl. (Poaceae) on the frequently disturbed island and bare sand on the less disturbed island. Species composition was associated with environmental characteristics only on the frequently disturbed island (p = 0.005) where A. breviligulata was associated with higher elevation and greater beach width. Spartina patens, the second most abundant species, was associated with larger sediment grain size and greater sediment size distribution. On the less frequently disturbed island, time since disturbance was the only factor that affected community composition. Thus, factors driving the abundance of dune-building grasses and subsequent recovery of dunes varied between the two geomorphically distinct islands. PMID:25148028

Food insecurity and low self-efficacy are associated with health care access barriers among Puerto-Ricans with type 2 diabetes.

PubMed

Kollannoor-Samuel, Grace; Vega-López, Sonia; Chhabra, Jyoti; Segura-Pérez, Sofia; Damio, Grace; Pérez-Escamilla, Rafael

2012-08-01

Racial/ethnic minorities are disproportionately affected by barriers to health care access and utilization. The primary objective was to test for an independent association between household food insecurity and health care access/utilization. In this cross-sectional survey, 211 Latinos (predominantly, Puerto-Ricans) with type 2 diabetes (T2D) were interviewed at their homes. Factor analyses identified four barriers for health care access/utilization: enabling factor, doctor access, medication access and forgetfulness. Multivariate logistic regression models examined the association between each of the barrier factors and food insecurity controlling for sociodemographic, cultural, psychosocial, and diabetes self-care variables. Higher food insecurity score was a risk factor for experiencing enabling factor (OR = 1.46; 95% CI = 1.17-1.82), medication access (OR = 1.26; 95 CI% = 1.06-1.50), and forgetfulness (OR = 1.22; 95 CI% = 1.04-1.43) barriers. Higher diabetes management self-efficacy was protective against all four barriers. Other variables associated with one or more barriers were health insurance, perceived health, depression, blood glucose, age and education. Findings suggest that addressing barriers such as food insecurity, low self-efficacy, lack of health insurance, and depression could potentially result in better health care access and utilization among low income Puerto-Ricans with T2D.

Fabrication of IrSi(3)/p-Si Schottky diodes by a molecular beam epitaxy technique

NASA Technical Reports Server (NTRS)

Lin, T. L.; Iannelli, J. M.

1990-01-01

IrSi(3)/p-Si Schottky diodes have been fabricated by a molecular beam epitaxy technique at 630 C. Good surface morphology was observed for IrSi(3) layers grown at temperatures below 680 C, and an increasing tendency to form islands is observed in samples grown at higher temperatures. Good diode current-voltage characteristics were observed and Schottky barrier heights of 0.14-0.18 eV were determined by activation energy analysis and spectral response measurement.

Cost And Performance Report Evaluating the Longevity and Hydraulic Performance of Permeable Reactive Barriers at Department of Defense Sites

DTIC Science & Technology

2003-12-01

construction methods, such as jetting, hydraulic fracturing , and vibratory beam, have been demonstrated at some sites, as they offer some cost... hydraulic fracturing , are available, but there is not as much widespread experience yet with these techniques for PRBs. Also, these innovative... hydraulic fracturing ) can be used at relatively higher cost. The cost comparison of a PRB versus an active remedy, such as a pump-and-treat system, often

Measuring Perceived Barriers to Physical Activity in Adolescents.

PubMed

Gunnell, Katie E; Brunet, Jennifer; Wing, Erin K; Bélanger, Mathieu

2015-05-01

Perceived barriers to moderate-to-vigorous physical activity (PA) may contribute to the low rates of moderate-to-vigorous PA in adolescents. We examined the psychometric properties of scores from the perceived barriers to moderate-to-vigorous PA scale (PB-MVPA) by examining composite reliability and validity evidence based on the internal structure of the PB-MVPA and relations with other variables. This study was a cross-sectional analysis of data collected in 2013 from adolescents (N = 507; Mage = 12.40, SD = .62) via self-report scales. Using exploratory and confirmatory factor analyses, we found that perceived barriers were best represented as two factors representing internal (e.g., "I am not interested in physical activity") and external (e.g., "I need equipment I don't have") dimensions. Composite reliability was over .80. Using multiple regression to examine the relationship between perceived barriers and moderate-to-vigorous PA, we found that perceived internal barriers were inversely related to moderate-to-vigorous PA (β = -.32, p < .05). Based on results of the analysis of variances, there were no known-group sex differences for perceived internal and external barriers (p > .26). The PB-MVPA scale demonstrated evidence of score reliability and validity. To improve the understanding of the impact of perceived barriers on moderate-to- vigorous PA in adolescents, researchers should examine internal and external barriers separately.

The [C{sub 6}H{sub 10}]{sup {sm{underscore}bullet}+} hypersurface: The parent radical cation Diels-Alder reaction

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

Hoffmann, M.; Schaefer, H.F. III

1999-07-21

Various possible reaction pathways between ethene and butadiene radical cation (cis- and trans-), have been investigated at different levels of theory up to UCCSD(T)/DZP/UMP2(fc)/DZP and with density functional theory at B3LYP/DZP. A stepwise addition involving open chain intermediates and leading to the Diels-Alder product, the cyclohexene radical cation, was found to have a total activation barrier {Delta}G{sup 298{ne}} = 6.3 kcal mol{sup {minus}1} and a change in free Gibbs energy, {Delta}G{sup 298}, of {minus}33.5 kcal mol{sup {minus}1}. On the E{degree} potential energy surface, all transition states are lower in energy than separated ethene and butadiene, the exothermicity {Delta}E = -45.6more » kcal mol{sup {minus}1}. A more direct path could be characterized as stepwise with one intermediate only at the SCF level but not at electron-correlated levels and hence might actually be a concerted strongly asynchronous addition with a very small or no activation barrier (UCCSD(T)/DZP/UHF/6-31G* gives a {Delta}G{sup 298{ne}} of 0.8 kcal mol{sup {minus}1}). The critical step for another alternative, the cyclobutanation-vinylcyclobutane/cyclohexene rearrangement, is a 1,3-alkyl shift which involves a barrier ({Delta}G{sup 298{ne}}) only 1.7 kcal mol{sup {minus}1} higher than that of stop use addition for both cis-, and trans-butadiene radical cation. However, from the (ethene and trans-butadiene) reactions, ring expansion of the vinylcyclobutane radical cation intermediate, to a methylene cyclopentane radical cation, requires an activation only 1.3 kcal mol{sup {minus}1} larger than for (trans-butadiene radical). While cis/trans isomerization of free butadiene radical cation requires a high activation (24.9 kcal mol{sup {minus}1}), a reaction sequence involving addition of ethene (to stepwise give an open chain intermediate and vinyl cyclobutane radical cation) has a barrier of only 3.5 kcal mol{sup {minus}1} ({Delta}G{sup 298{ne}}). This sequence also makes ethene and butadiene radical cations to exchange terminal methylene groups.« less

Designed to deter. Community barriers to physical activity for people with visual or motor impairments.

PubMed

Kirchner, Corinne E; Gerber, Elaine G; Smith, Brooke C

2008-04-01

People with disabilities are more likely to be obese, in poor health, and get less physical activity than the general population. However, research on community factors for physical activity has generally either excluded most people with disabilities, or overlooked relevant factors of community accessibility. This exploratory study investigated environmental factors affecting people with motor impairments and people with visual impairments in urban neighborhoods. Quantitative and qualitative methods were used with a nonrandom sample (n=134) of users of four types of assistive mobility technologies: guide dogs, long canes, and motorized and manual wheelchairs. From July 2005 to August 2006, the sample participated in two telephone surveys. Between the surveys, a stratified random subsample (n =32) engaged in an ethnographic phase of observation and interviews. Most participants in all groups using assistive mobility technologies rated their neighborhoods as accessible, although they also reported many specific barriers. Users of assistive mobility technologies differed in the amount of reported physical activity and on specific barriers. Problems with sidewalk pavement and puddles/poor drainage were the most frequently mentioned environmental barriers, by 90% and 80%, respectively. Users of assistive mobility technologies were more similar on main strategies for dealing with barriers. All groups reported having to plan routes for outings, to alter planned routes, to go more slowly than planned, or to wait for a different time. Despite legislative requirements for accommodation, people with disabilities face barriers to physical activity, both in the built and social environments. Determined people with disabilities were able to overcome barriers, but required additional expenditure of resources to do so. Community design that can include people with disabilities requires detailed understanding of barriers specific both to types of impairments and to different types of assistive mobility technologies.

Motivators and barriers for physical activity in the oldest old: a systematic review.

PubMed

Baert, Veerle; Gorus, Ellen; Mets, Tony; Geerts, Christel; Bautmans, Ivan

2011-09-01

Worldwide, people engage insufficiently in physical activity, particularly subjects aged 80 years and over. For optimal life-style campaigns, knowledge of motivators and barriers for physical activity is mandatory. Given their specific needs, it is conceivable that these would be different for the oldest old compared to younger subjects. Pubmed, Web of Science and Psychinfo were systematically screened for articles reporting motivators and barriers for physical activity. Papers were excluded if data regarding elderly aged >79 years were absent. Forty-four relevant articles were included, involving a total of 28,583 subjects. Sixty one motivators and 59 barriers for physical activity in the elderly were identified, including those who are relevant for persons aged 80 years and over. Based on the results of our literature review, we recommend that when promoting physical activity in the oldest old, special attention is paid to the health benefits of physical activity, to the subject's fears, individual preferences and social support, and to constraints related to the physical environment. However, no studies were found exclusively describing people aged 80 years and over, and future research is necessary to differentiate the barriers or motivators that are specific for the oldest old from those of younger elderly. Copyright © 2011 Elsevier B.V. All rights reserved.

Physical activity barriers and enablers in older Veterans with lower-limb amputation.

PubMed

Littman, Alyson J; Boyko, Edward J; Thompson, Mary Lou; Haselkorn, Jodie K; Sangeorzan, Bruce J; Arterburn, David E

2014-01-01

Little is known about the types of physical activities that older individuals with lower-limb loss perform, correlates of regular physical activity (PA), and barriers and facilitators to PA. We conducted an exploratory study in 158 older Veterans from the Pacific Northwest with a partial foot (35%), below-knee (39%) and above-knee (26%) amputation. Ninety-eight percent of survey respondents were male, on average 65 yr of age and 15 yr postamputation; 36% of amputations were trauma-related. The most commonly reported physical activities were muscle strengthening (42%), yard work and/or gardening (30%), and bicycling (11%). Forty-three percent were classified as physically active based on weekly moderate- and vigorous-intensity PA. History of vigorous preamputation PA was positively associated with being active, while low wealth and watching ≥5 h/d of television/videos were inversely associated. While pain- and resource-related barriers to PA were most frequently reported, only knowledge-related and interest/motivation-related barriers were inversely associated with being active. Family support and financial assistance to join a gym were the most commonly reported factors that would facilitate PA. To increase PA in the older amputee population, interventions should address motivational issues, knowledge gaps, and television watching; reduce financial barriers to exercising; and consider involving family members.

Parental perceptions of facilitators and barriers to physical activity for children with intellectual disabilities: A mixed methods systematic review.

PubMed

McGarty, Arlene M; Melville, Craig A

2018-02-01

There is a need increase our understanding of what factors affect physical activity participation in children with intellectual disabilities (ID) and develop effective methods to overcome barriers and increase activity levels. This study aimed to systematically review parental perceptions of facilitators and barriers to physical activity for children with ID. A systematic search of Embase, Medline, ERIC, Web of Science, and PsycINFO was conducted (up to and including August, 2017) to identify relevant papers. A meta-ethnography approach was used to synthesise qualitative and quantitative results through the generation of third-order themes and a theoretical model. Ten studies were included, which ranged from weak to strong quality. Seventy-one second-order themes and 12 quantitative results were extracted. Five third-order themes were developed: family, child factors, inclusive programmes and facilities, social motivation, and child's experiences of physical activity. It is theorised that these factors can be facilitators or barriers to physical activity, depending on the information and education of relevant others, e.g. parents and coaches. Parents have an important role in supporting activity in children with ID. Increasing the information and education given to relevant others could be an important method of turning barriers into facilitators. Copyright © 2017 Elsevier Ltd. All rights reserved.

Are characteristics of the school district associated with active transportation to school in Danish adolescents?

PubMed

Stock, Christiane; Bloomfield, Kim; Ejstrud, Bo; Vinther-Larsen, Mathilde; Meijer, Mathias; Grønbæk, Morten; Grittner, Ulrike

2012-06-01

This study sought to determine the influence of individual factors on active transportation to school among Danish seventh graders and whether school district factors are associated with such behaviour independently of individual factors. Mixed effects logistic regression models determined the effects of individual (gender, family affluence, enjoyment of school and academic performance) and school district factors (educational level, household savings, land use and size) on active transportation to school (by foot, bicycle or other active means) among 10 380 pupils aged 13-15 years nested in 407 school districts. Of all students, 64.4% used active transportation to school daily. Boys, those with perceived higher school performance and those with lower family affluence were more likely to use active transportation to school. After adjustment for all individual factors listed above, high household savings at the school district level was associated with higher odds of active transportation to school. As factors of land use, low level of farming land use and high proportion of single houses were associated with active transportation to school. Policies aiming at reducing social inequalities at the school district level may enhance active transportation to school. School districts with farming land use face barriers for active transportation to school, requiring special policy attention.

Rap1 and Rap2 Antagonistically Control Endothelial Barrier Resistance

PubMed Central

Pannekoek, Willem-Jan; Linnemann, Jelena R.; Brouwer, Patricia M.; Bos, Johannes L.; Rehmann, Holger

2013-01-01

Rap1 and Rap2 are closely related proteins of the Ras family of small G-proteins. Rap1 is well known to regulate cell-cell adhesion. Here, we have analysed the effect of Rap-mediated signalling on endothelial permeability using electrical impedance measurements of HUVEC monolayers and subsequent determination of the barrier resistance, which is a measure for the ease with which ions can pass cell junctions. In line with its well-established effect on cell-cell junctions, depletion of Rap1 decreases, whereas activation of Rap1 increases barrier resistance. Despite its high sequence homology with Rap1, depletion of Rap2 has an opposite, enhancing, effect on barrier resistance. This effect can be mimicked by depletion of the Rap2 specific activator RasGEF1C and the Rap2 effector MAP4K4, establishing Rap2 signalling as an independent pathway controlling barrier resistance. As simultaneous depletion or activation of both Rap1 and Rap2 results in a barrier resistance comparable to control cells, Rap1 and Rap2 control barrier resistance in a reciprocal manner. This Rap1-antagonizing effect of Rap2 is established independent of junctional actin formation. These data establish that endothelial barrier resistance is determined by the combined antagonistic actions of Rap1 and Rap2. PMID:23469100

Barriers to Physical Activity Among African American Women: An Integrative Review of the Literature.

PubMed

Joseph, Rodney P; Ainsworth, Barbara E; Keller, Colleen; Dodgson, Joan E

2015-01-01

A key aspect for researchers to consider when developing culturally appropriate physical activity (PA) interventions for African American (AA) women are the specific barriers AA women face that limit their participation in PA. Identification and critical examination of these barriers is the first step in developing comprehensive culturally relevant approaches to promote PA and help resolve PA-related health disparities in this underserved population. We conducted a systematic integrative literature review to identify barriers to PA among AA women. Five electronic databases were searched, and forty-two studies (twenty-seven qualitative, fourteen quantitative, one mixed method) published since 1990 (range 1998-2013) in English language journals met inclusion criteria for review. Barriers were classified as intrapersonal, interpersonal, or environment/community according to their respective level of influence within our social ecological framework. Intrapersonal barriers included lack of time, knowledge, and motivation; physical appearance concerns; health concerns; monetary cost of exercise facilities; and tiredness/fatigue. Interpersonal barriers included family/caregiving responsibilities; lack of social support; and lack of a PA partner. Environmental barriers included safety concerns; lack of facilities; weather concerns; lack of sidewalks; and lack of physically active AA role models. Results provide key leverage points for researchers to consider when developing culturally relevant PA interventions for AA women.

Bedside interprofessional rounds: perceptions of benefits and barriers by internal medicine nursing staff, attending physicians, and housestaff physicians.

PubMed

Gonzalo, Jed D; Kuperman, Ethan; Lehman, Erik; Haidet, Paul

2014-10-01

Interprofessional collaboration improves the quality of care, but integration into workflow is challenging. Although a shared conceptualization regarding bedside interprofessional rounds may enhance implementation, little work has investigated providers' perceptions of this activity. To evaluate the perceptions of nurses, attending physicians, and housestaff physicians regarding the benefits/barriers to bedside interprofessional rounds. Observational, cross-sectional survey of hospital-based medicine nurses, attending physicians, and housestaff physicians. Descriptive, nonparametric Wilcoxon rank sum and nonparametric correlation were used. Bedside interprofessional rounds were defined as "encounters including 2 physicians plus a nurse or other care provider discussing the case at the patient's bedside." Eighteen items related to "benefits" and 21 items related to "barriers" associated with bedside interprofessional rounds. Of 171 surveys sent, 149 were completed (87%). Highest-ranked benefits were related to communication/coordination, including "improves communication between nurses-physicians;" lowest-ranked benefits were related to efficiency, process, and outcomes, including "decreases length-of-stay" and "improves timeliness of consultations." Nurses reported most favorable ratings for all items (P < 0.05). Rank order for 3 provider groups showed high correlation (r = 0.92, P < 0.001). Highest-ranked barriers were related to time, including "nursing staff have limited time;" lowest-ranked barriers were related to provider- and patient-related factors, including "patient lack of comfort." Rank order of barriers among all groups showed moderate correlation (r = 0.62-0.82). Although nurses perceived greater benefit for bedside interprofessional rounds than physicians, all providers perceived coordination/teamwork benefits higher than outcomes. To the extent the results are generalizable, these findings lay the foundation for facilitating meaningful patient-centered interprofessional collaboration. © 2014 Society of Hospital Medicine.

Perceptions about exercise and intrinsic motivation of students attending a health-related physical education program.

PubMed

Papacharisis, Vassilios; Goudas, Marios

2003-12-01

The present study examined effects of sex, attitude towards physical activity, perceived barriers for participation in physical activity, and students' perception of their parents' participation in physical activity on the intrinsic motivation of students participating in a health related program in physical education. 643 students (303 boys and 340 girls) responded to questionnaires measuring intrinsic motivation, attitudes towards physical activity, perceived barriers to exercise and perceived parents' participation in physical activity. Mean age was 12.9 yr. (SD=1.2, range 11-14 years). Analysis indicated that students' intrinsic motivation towards the program was influenced by perceived barriers to exercise. Sex, attitudes towards physical activity, and perceived parents' participation in physical activity seem to be less important.

Perceived benefits and barriers to exercise for recently treated patients with multiple myeloma: a qualitative study.

PubMed

Craike, Melinda J; Hose, Kaye; Courneya, Kerry S; Harrison, Simon J; Livingston, Patricia M

2013-07-01

Understanding the physical activity experiences of patients with multiple myeloma (MM) is essential to inform the development of evidence-based interventions and to quantify the benefits of physical activity. The aim of this study was to gain an in-depth understanding of the physical activity experiences and perceived benefits and barriers to physical activity for patients with MM. This was a qualitative study that used a grounded theory approach. Semi-structured interviews were conducted in Victoria, Australia by telephone from December 2011-February 2012 with patients who had been treated for MM within the preceding 2-12 months. Interviews were transcribed and analysed using the constant comparison coding method to reduce the data to themes. Gender differences and differences between treatment groups were explored. Twenty-four interviews were completed. The sample comprised 13 females (54%), with a mean age of 62 years (SD = 8.8). Sixteen (67%) participants had received an autologous stem cell transplant (ASCT). All participants currently engaged in a range of light to moderate intensity physical activity; walking and gardening were the most common activities. Recovery from the symptoms of MM and side effects of therapy, psychological benefits, social factors and enjoyment were important benefits of physical activity. Barriers to physical activity predominately related to the symptoms of MM and side effects of therapy, including pain, fatigue, and fear of infection. Low self- motivation was also a barrier. Women participated in a more diverse range of physical activities than men and there were gender differences in preferred type of physical activity. Women were more likely to report psychological and social benefits; whereas men reported physical activity as a way to keep busy and self-motivation was a barrier. Patients treated with an ASCT more often reported affective benefits of participation in physical activity and fatigue as a barrier. Patients treated with other therapies (e.g., chemotherapy, radiotherapy) were more likely to report pain as a barrier. Patients with MM experience debilitating effects of their condition and therapy, which influences their level and intensity of physical activity participation. Physical activity programs should be individualised; take into consideration gender differences and the impact of different types of therapy on physical activity; and focus on meeting the psychological, coping and recovery needs of patients.

Exercise and physical activity in asylum seekers in Northern England; using the theoretical domains framework to identify barriers and facilitators.

PubMed

Haith-Cooper, Melanie; Waskett, Catherine; Montague, Jane; Horne, Maria

2018-06-19

Many asylum seekers have complex mental health needs which can be exacerbated by the challenging circumstances in which they live and difficulties accessing health services. Regular moderate physical activity can improve mental health and would be a useful strategy to achieve this. Evidence suggests there are barriers to engaging black and minority ethnic groups in physical activity, but there is little research around asylum seekers to address the key barriers and facilitators in this group. A two stage qualitative study used semi-structured interviews underpinned by the Theoretical Domains Framework. The interviews were conducted in voluntary sector groups in four towns/ cities in Northern England. Purposive sampling recruited 36 asylum seekers from 18 different countries. Interviews were audio recorded, transcribed verbatim and subject to framework analysis. Stage two involved a nominal group technique with five key stakeholders including asylum seekers and those that work with them. They followed a four stage process to rank and reach consensus on the key barrier to undertaking physical activity/ exercise that could be addressed locally through a future intervention. A number of barriers and facilitators were identified including a lack of understanding of the term physical activity and recommended levels but knowledge of the health benefits of physical activity/ exercise and the motivation to increase levels having engaged with activities back home. Living as an asylum seeker was considered a barrier due to the stress, poverty and temporary nature of living in an unfamiliar place. The outcome of the nominal group technique was that a lack of knowledge of facilities in the local area was the prevailing barrier that could be addressed. Public health practitioners could develop interventions which capitalise on the motivation and knowledge of asylum seekers to encourage an increase in physical activity which may in turn reduce the breadth and depth of mental health needs of this group.

[Construction and validation of a short scale of perception of barriers for the physical activity in adolescents].

PubMed

Cabanas-Sánchez, Verónica; Tejero-González, Carlos M; Veiga, Oscar L

2012-01-01

One of the main problems of health in the first world is the increase of physical inactivity. In this respect, adolescence has been identified as a critic period with high decline of physical activity. Therefore, a relevant line of research is the understanding of this social phenomenon. The aim of this study was to design a scale to assess perceived barriers to physical activity on adolescents. A convenience sample of 160 Spanish adolescents (84 girls), between 12 and 18 years old, was recruited for this study. Firstly, there were designed 40 items whose pertinence was evaluated through content validation by experts. Later, the participants were divided in two randomized groups, and Exploratory Factor Analysis and Confirmatory Factor Analysis were performed to define a short scale of 12 items. Cronbach Alfa Coefficent was used to evaluate internal consistence of the instrument. The scale reports four dimensions: incompatibility barriers (2 items), self-concept barriers (4 items), amotivation barriers (4 items) and social barriers (2 items). The scale showed enough construct validity (χ2=60.78; d.f.=48; p=0.100; GFI=0.88; CFI=0.94; RMSEA=0.58) and high internal reliability (α=0.80). Moreover, the scale was able to explain 67% of the data variance. The Short Scale of Perceived Barriers to Physical Activity in Adolescents is a valid and reliable instrument.

Exploring the relationship between perceived barriers to healthy eating and dietary behaviours in European adults.

PubMed

Pinho, M G M; Mackenbach, J D; Charreire, H; Oppert, J-M; Bárdos, H; Glonti, K; Rutter, H; Compernolle, S; De Bourdeaudhuij, I; Beulens, J W J; Brug, J; Lakerveld, J

2017-04-26

Dietary behaviours may be influenced by perceptions of barriers to healthy eating. Using data from a large cross-European study (N = 5900), we explored associations between various perceived barriers to healthy eating and dietary behaviours among adults from urban regions in five European countries and examined whether associations differed across regions and socio-demographic backgrounds. Frequency of consumption of fruit, vegetables, fish, fast food, sugar-sweetened beverages, sweets, breakfast and home-cooked meals were split by the median into higher and lower consumption. We tested associations between barriers (irregular working hours; giving up preferred foods; busy lifestyle; lack of willpower; price of healthy food; taste preferences of family and friends; lack of healthy options and unappealing foods) and dietary variables using multilevel logistic regression models. We explored whether associations differed by age, sex, education, urban region, weight status, household composition or employment. Respondents who perceived any barrier were less likely to report higher consumption of healthier foods and more likely to report higher consumption of fast food. 'Lack of willpower', 'time constraints' and 'taste preferences' were most consistently associated with consumption. For example, those perceiving lack of willpower ate less fruit [odds ratio (OR) 0.57; 95% confidence interval (CI) 0.50-0.64], and those with a busy lifestyle ate less vegetables (OR 0.54; 95% CI 0.47-0.62). Many associations differed in size, but not in direction, by region, sex, age and household composition. Perceived 'lack of willpower', 'time constraints' and 'taste preferences' were barriers most strongly related to dietary behaviours, but the association between various barriers and lower intake of fruit and vegetables was somewhat more pronounced among younger participants and women.

Barriers, benefits, and strategies for physical activity in patients with schizophrenia.

PubMed

Rastad, Cecilia; Martin, Cathrin; Asenlöf, Pernilla

2014-10-01

Patients with schizophrenia have a substantially increased risk of cardiovascular disease and premature death compared with the general population. High prevalence of an unhealthy lifestyle contributes to the increased risk in these patients. Patients with schizophrenia are often physically inactive, and there is limited knowledge on the factors, such as barriers and incentives, that can influence physical activity in this patient group. The aim was to study the perception and experience of barriers to and incentives for physical activity in daily living in patients with schizophrenia, as reported by the patients themselves. An explorative study applying conventional qualitative content analysis was conducted. A purposeful sample of 20 patients with schizophrenia or schizoaffective disorder (13 men, 7 women; 22-63 years of age) registered at 3 psychiatric outpatient clinics in Sweden were interviewed using semistructured interviews. The analysis resulted in 3 main themes: (1) barriers-factors that complicate or obstruct physical activity, (2) reward-the motivation for physical activity, and (3) helpful strategies. The results may not reflect important factors related to physical activity in older patients (>65 years of age), newly diagnosed patients, or inpatients. In accordance with patients' perceptions, there may be biopsychosocial determinants of physical activity behavior that are unique for this group of patients. Future studies should investigate whether physical activity interventions for patients with schizophrenia benefit from individual analyses of barriers and reward for physical activity in combination with the use of tailored strategies such as personal support and activity planning. © 2014 American Physical Therapy Association.

Cost-effectiveness of Maintenance Treatment with a Barrier-strengthening Moisturizing Cream in Patients with Atopic Dermatitis in Finland, Norway and Sweden.

PubMed

Norrlid, Hanna; Hjalte, Frida; Lundqvist, Adam; Svensson, Åke; Tennvall, Gunnel Ragnarson

2016-02-01

Atopic dermatitis is a chronic skin disorder with high prevalence, especially in the Nordic countries. Effective maintenance therapy during symptom-free episodes may prolong the time to eczema relapse according to a previously published clinical trial. The present study evaluates the cost-effectiveness of a barrier-strengthening moisturizer containing 5% urea, compared with a moisturizer with no active ingredients during eczema-free periods. A health economic microsimulation model, based on efficacy data from the randomized clinical trial, analysed the cost-effectiveness of the barrier-strengthening treatment in Finland, Norway and Sweden. The barrier-strengthening moisturizer was cost-saving compared with the moisturizer with no active ingredients in all 3 countries. The result was confirmed in all but one sensitivity analysis. In conclusion, the barrier-strengthening moisturizer is cost-effective as maintenance therapy for patients with atopic dermatitis compared with a moisturizer with no active ingredients.

Associations between physical activity and motivation, competence, functioning, and apathy in inhabitants with mental illness from a rural municipality: a cross-sectional study.

PubMed

Farholm, Anders; Sørensen, Marit; Halvari, Hallgeir; Hynnekleiv, Torfinn

2017-11-06

There is increasing evidence for physical activity (PA) having a positive impact on physical and mental health as well as illness symptoms in individuals with severe mental illness (SMI). However, individuals with SMI experience several barriers that makes it difficult to take advantage of the benefits associated with PA. One barrier consistently reported to impede PA is motivational issues. Thus, the main aim of the present study was to examine associations between PA and motivation for PA, perceived competence for PA, functioning, apathy, and demographic variables among individuals with SMI. This was conducted within a larger study aiming at including all inhabitants with SMI in one particular small, rural municipality. A total of 106 participants were recruited to the study. Questionnaire-based interviews conducted by two mental health nurses assessed self-reported PA, motivation and competence for PA, functioning, and apathy. Additionally, 71 participants accepted to wear an accelerometer-equipped wristwatch yielding an objective assessment of PA. The participants engaged in little PA. However, they did not lack motivation, as over 90% stated that they would like to be more active, and participants across PA level displayed high scores of a motivation reflecting that they valued the benefits of PA. Results showed that higher self-reported PA level was associated with higher levels of integrated regulated motivation and perceived competence for PA while it was unrelated to functioning and apathy. In the subpopulation with objectively measured PA, integrated regulated motivation for PA remained significantly associated with PA level, whereas poor scores on functioning lowered the odds ratio for higher PA level. The results show that PA specific motivation is associated with PA even when controlling for functioning and apathy. This highlight the importance of facilitating context specific motivation (i.e., motivation for PA) and that health care practitioners should emphasise helping people with SMI develop more intrinsic forms of motivation.

Lack of interest in physical activity - individual and environmental attributes in adults across Europe: The SPOTLIGHT project.

PubMed

Carraça, Eliana V; Mackenbach, Joreintje D; Lakerveld, Jeroen; Rutter, Harry; Oppert, Jean-Michel; De Bourdeaudhuij, Ilse; Compernolle, Sofie; Roda, Célina; Bardos, Helga; Teixeira, Pedro J

2018-06-01

A considerable proportion of European adults report little or no interest in physical activity. Identifying individual-level and environmental-level characteristics of these individuals can help designing effective interventions and policies to promote physical activity. This cross-sectional study additionally explored associations between level of interest and physical activity, after controlling for other individual and environmental variables. Measures of objective and perceived features of the physical environment of residence, self-reported physical activity and other lifestyle behaviors, barriers towards physical activity, general health, and demographics were obtained from 5205 European adults participating in the 2014 online SPOTLIGHT survey. t-Tests, chi-square tests, and generalized estimating equations with negative binomial log-link function were conducted. Adults not interested in physical activity reported a higher BMI and a lower self-rated health, were less educated, and to a smaller extent female and less frequently employed. They were more prone to have less healthy eating habits, and to perceive more barriers towards physical activity. Only minor differences were observed in environmental attributes: the non-interested were slightly more likely to live in neighborhoods objectively characterized as less aesthetic and containing more destinations, and perceived as less functional, safe, and aesthetic. Even after controlling for other individual and environmental factors, interest in physical activity remained a significant correlate of physical activity, supporting the importance of this association. This study is among the first to describe characteristics of individuals with reduced interest in physical activity, suggesting that (lack of) interest is a robust correlate of physical activity in several personal and environmental conditions. Copyright © 2018 Elsevier Inc. All rights reserved.

Patients' perceptions of physical activity before and after joint replacement: a systematic review with meta-ethnographic analysis.

PubMed

Smith, Toby O; Latham, Sarah; Maskrey, Vivienne; Blyth, Annie

2015-09-01

It has been perceived that people following total hip arthroplasty (THA) or total knee arthroplasty (TKA) have the capability, with reduced pain, to increase their levels of physical activity. To determine the attitudes and perceptions of people awaiting or having undergone THA or TKA to physical activity post-arthroplasty and to identify potential facilitators or barriers to engage in active living and physical activity pursuits. Systematic review of published and unpublished databases was undertaken from their inception to November 2014. Studies exploring the attitudes and perceptions of people awaiting or having undergone THA or TKA to physical activity post-arthroplasty were included. Data were analysed through a meta-ethnography approach. From 528 citations, 13 papers were eligible, sampling 282 people post-THA or TKA. The literature was judged moderate to high quality. Following THA and TKA, people either wished to return to their pre-pathology level of physical activity or simply be able to engage in less physically demanding activities that are meaningful to them and their lifestyles. Barriers to engaging in higher levels of physical activity were largely related to limited information, which culminated in fear surrounding 'doing the right thing' both for individual's recovery and the longevity of the joint replacement. While many people post-THA or TKA wish to return to pre-pathological physical activity status, there is limited interest in actually undertaking greater levels of physical activity post-arthroplasty either for pleasure or health gains. Improvement in education and awareness of this may be key drivers to improve habitualisation of physical activity post-arthroplasty. CRD42014014995. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Properties of active gelatin films incorporated with rutin-loaded nanoemulsions.

PubMed

Dammak, Ilyes; de Carvalho, Rosemary Aparecida; Trindade, Carmen Sílvia Fávaro; Lourenço, Rodrigo Vinicius; do Amaral Sobral, Paulo José

2017-05-01

Physico-chemical, mechanical, barrier, release profiles and antioxidant properties of composite gelatin based-films incorporated with rutin-loaded oil-in-water nanoemulsion, at various concentrations (5, 10, 15, or 20% (based on the weight of the gelatin powder)) were studied. All the gelatin/rutin-loaded nanoemulsion films displayed higher tensile strength and higher elongation at break than the gelatin control film. The composite films did not show significant differences in thickness, color, brightness and transparency. The structural properties evaluated by FTIR showed that the rutin-loaded nanoemulsion achieved complete miscibility within the gelatin matrix. All the gelatin/nanoemulsion films exhibited compact and homogenous microstructure. In addition, these films showed high antioxidant activities monitored by DPPH radical scavenging and reducing power activities. The Korsmeyer-Peppas model described well the rutin release profile. Rutin release was mainly governed by Fickian diffusion with simultaneous interfering swelling and disintegration phenomena. These results indicate that nanoemulsions-in-gelatin systems can function as potential active packaging systems to enhance shelf life of food products and then to provide a high-quality products (fresh/safe). Copyright © 2017 Elsevier B.V. All rights reserved.

The barriers to and benefits of conducting Q-sorts in the classroom.

PubMed

Killam, Laura; Timmermans, Katherine E; Raymond, June M

2013-11-01

To outline the barriers to and benefits of using Q methodology in a classroom. Q methodology has been established as a systematic way to measure subjectivity that is consistent with the naturalistic paradigm. While it is often confused with quantitative methods, it provides the qualitative researcher with powerful tools to investigate the diverse subjective experiences and perceptions of participants. Reflections in this paper stem from the experiences of the authors and are supported by literature. Barriers to conducting a Q-sort activity in the classroom are context dependent and may include limitations of the environment, time constraints as well as issues with comprehension. Despite these barriers, using a classroom for the activity can also enhance student learning, increase participation in research, clarify instructions, enrich study feedback and promote accessibility of the study population. With an understanding of potential pitfalls of using this methodology in the classroom setting, nurse researchers can develop strategies to reduce these barriers and enhance the quality of future research. Q-methodology is an alternate way of measuring the subjective views of individuals in a variety of settings such as clinical practice, research and educational institutions. Q-sorts may be used for research and/or classroom activities because the activity can promote discussion related to the content of a class. If using an activity like this one, educators and researchers need to be mindful of potential barriers to sorting in order to minimise them and maximise the potential of the activity.

Barriers to Student Mobilization and Service at Institutions of Higher Education: A Greenbuilding Initiative Case Study on a Historic, Urban Campus in Charleston, South Carolina, USA

ERIC Educational Resources Information Center

Zimmerman, Katherine S.; Halfacre-Hitchcock, Angela

2006-01-01

Purpose: To identify some of the barriers to mobilizing students of higher education in sustainable initiatives, in order to enhance project success on campuses. Design/methodology/approach: Uses a case study of a model green building retrofit on the College of Charleston campus in Charleston, South Carolina, USA. Several constraints already…

Equality Postponed: Continuing Barriers to Higher Education in the 1980s. Report from the Policy Conference on Postsecondary Programs for the Disadvantaged (Racine, Wisconsin, June 1982).

ERIC Educational Resources Information Center

Adolphus, Stephen H., Ed.

Major barriers to equal access of minority and disadvantaged students to higher education are considered in eight papers and five responses from the 1982 Wingspread Conference on Postsecondary Programs for the Disadvantaged. Included is a policy statement from the conference that covers: quality education for all, the interrelatedness of education…

The Relationship between Barriers to Birth Control Use and Actual Birth Control Use among Mexican-American Adolescents.

ERIC Educational Resources Information Center

Pesa, Jacqueline A.; Mathews, Jeff

2000-01-01

Examines the relationship between barriers to using birth control and actual use of birth control among Mexican American adolescents (N=26,666). Results show that nonusers had significantly higher barrier scores compared with users of birth control. These results indicate that attitudes toward birth control are associated with actual birth control…

Exploring the facilitators and barriers to engagement in physical activity for people with multiple sclerosis.

PubMed

Kayes, Nicola M; McPherson, Kathryn M; Schluter, Philip; Taylor, Denise; Leete, Marta; Kolt, Gregory S

2011-01-01

To explore the relationship that cognitive behavioural and other previously identified variables have with physical activity engagement in people with multiple sclerosis (MS). This study adopted a cross-sectional questionnaire design. Participants were 282 individuals with MS. Outcome measures included the Physical Activity Disability Survey--Revised, Cognitive and Behavioural Responses to Symptoms Questionnaire, Barriers to Health Promoting Activities for Disabled Persons Scale, Multiple Sclerosis Self-efficacy Scale, Self-Efficacy for Chronic Diseases Scales and Chalder Fatigue Questionnaire. Multivariable stepwise regression analyses found that greater self-efficacy, greater reported mental fatigue and lower number of perceived barriers to physical activity accounted for a significant proportion of variance in physical activity behaviour, over that accounted for by illness-related variables. Although fear-avoidance beliefs accounted for a significant proportion of variance in the initial analyses, its effect was explained by other factors in the final multivariable analyses. Self-efficacy, mental fatigue and perceived barriers to physical activity are potentially modifiable variables which could be incorporated into interventions designed to improve physical activity engagement. Future research should explore whether a measurement tool tailored to capture beliefs about physical activity identified by people with MS would better predict participation in physical activity.

Barriers, Motivations, and Preferences for Physical Activity Among Female African American Older Adults.

PubMed

Gothe, Neha P; Kendall, Bradley J

2016-01-01

According to the Centers for Disease Control and Prevention, less than 11% of adults more than the age of 65 meet the 2008 Physical Activity Guidelines for Americans. Among minority populations, only 5% of non-Hispanic Black older adults met the guidelines. Given our limited understanding of psychosocial and environmental factors that affect physical activity participation in these groups, the purpose of our focus groups was to investigate barriers, motivators, and preferences of physical activity for community-dwelling African American older adults. Three focus groups were conducted with female African American older adults ( N = 20). Questions posed to each focus group targeted motivations and barriers toward physical activity as well as their preferences for physical activity. The motivations included perceived health benefits of physical activity, social support, and enjoyment associated with engagement in physical activity. Prominent barriers included time and physical limitations, peer pressure and family responsibilities, and weather and poor neighborhood conditions. Group activities involving a dance component and novel exercises such as tai-chi or yoga were preferred choices. These findings should be taken into consideration when designing and implementing research or community physical activity programs for female African American older adults.

A Study of Female Students' Perceptions of the Barriers to Participate in Physical and Sports Activities at Al-Hussein Bin Talal University

ERIC Educational Resources Information Center

Al-Tawel, Adnan M.; AlJa'afreh, Ibraheem A.

2017-01-01

The study aimed to examine the perceived barriers to participate in physical and sports activities among female university students as well as the potential differences of their perceptions of the barriers based on their academic discipline, academic year, and Grade Point Average (GPA) level. The participants in this study were 221 female students…

Barriers and Facilitators to Healthy Lifestyle Changes in Minority Ethnic Populations in the UK: a Narrative Review.

PubMed

Patel, Naina; Ferrer, Harriet Batista; Tyrer, Freya; Wray, Paula; Farooqi, Azhar; Davies, Melanie J; Khunti, Kamlesh

2017-12-01

Minority ethnic populations experience a disproportionate burden of health inequalities compared with the rest of the population, including an increased risk of type 2 diabetes (T2DM). The purpose of this narrative review was to explore knowledge and attitudes around diabetes, physical activity and diet and identify barriers and facilitators to healthy lifestyle changes in minority ethnic populations in the UK. The narrative review focused on three key research topics in relation to barriers and facilitators to healthy lifestyle changes in minority adult ethnic populations: (i) knowledge and attitudes about diabetes risk; (ii) current behaviours and knowledge about physical activity and diet; and (iii) barriers and facilitators to living a healthier lifestyle. Nearly all of the studies that we identified reported on South Asian minority ethnic populations; we found very few studies on other minority ethnic populations. Among South Asian communities, there was generally a good understanding of diabetes and its associated risk factors. However, knowledge about the levels of physical activity required to gain health benefits was relatively poor and eating patterns varied. Barriers to healthy lifestyle changes identified included language barriers, prioritising work over physical activity to provide for the family, cultural barriers with regard to serving and eating traditional food, different perceptions of a healthy body weight and fear of racial harassment or abuse when exercising. Additional barriers for South Asian women included expectations to remain in the home, fear for personal safety, lack of same gender venues and concerns over the acceptability of wearing 'western' exercise clothing. Facilitators included concern that weight gain might compromise family/carer responsibilities, desire to be healthy, T2DM diagnosis and exercise classes held in 'safe' environments such as places of worship. Our findings suggest that South Asian communities are less likely to engage in physical activity than White populations and highlight the need for health promotion strategies to engage people in these communities. There is a gap in knowledge with regard to diabetes, physical activity, diet and barriers to healthy lifestyle changes among other ethnic minority populations in the UK; we recommend further research in this area.

Improved performance of high indium InGaAs photodetectors with InAlAs barrier

NASA Astrophysics Data System (ADS)

Du, Ben; Gu, Yi; Chen, Xing-You; Ma, Ying-Jie; Shi, Yan-Hui; Zhang, Jian; Zhang, Yong-Gang

2018-06-01

We report on the demonstration of an InP-based In0.83Ga0.17As photodetector with an In0.83Al0.17As barrier, which is lattice-matched to the absorption layer. According to the comprehensive comparison with the photodetector without the barrier, the dark current is markedly reduced by inserting the InAlAs barrier. Although the photoresponse slightly decreases for the device with the InAlAs barrier, the detectivity remains higher than that of the reference device at room temperature and significantly increases at lower temperatures. These results indicate that InAlAs is a promising barrier layer in high-indium InGaAs photodetectors.

Caspase vinyl sulfone small molecule inhibitors prevent axonal degeneration in human neurons and reverse cognitive impairment in Caspase-6-overexpressing mice.

PubMed

Pakavathkumar, Prateep; Noël, Anastasia; Lecrux, Clotilde; Tubeleviciute-Aydin, Agne; Hamel, Edith; Ahlfors, Jan-Eric; LeBlanc, Andrea C

2017-02-28

The activation of the aspartate-specific cysteinyl protease, Caspase-6, is proposed as an early pathogenic event of Alzheimer disease (AD) and Huntington's disease. Caspase-6 inhibitors could be useful against these neurodegenerative diseases but most Caspase-6 inhibitors have been exclusively studied in vitro or show acute liver toxicity in humans. Here, we assessed vinyl sulfone small molecule peptide caspase inhibitors for potential use in vivo. The IC 50 of NWL vinyl sulfone small molecule caspase inhibitors were determined on Caspase-1 to 10, and Caspase-6-transfected human colon carcinoma HCT116 cells. Inhibition of Caspase-6-mediated axonal degeneration was assessed in serum-deprived or amyloid precursor protein-transfected primary human CNS neurons. Cellular toxicity was measured by phase contrast microscopy, mitochondrial and lactate dehydrogenase colorimetric activity assays, or flow cytometry. Caspase inhibition was measured by fluorogenic activity assays, fluorescence microscopy, and western blot analyses. The effect of inhibitors on age-dependent cognitive deficits in Caspase-6 transgenic mice was assessed by the novel object recognition task. Liquid chromatography coupled to tandem mass spectrometry assessed the blood-brain barrier permeability of inhibitors in Caspase-6 mice. Vinyl sulfone NWL-117 caspase inhibitor has a higher selectivity against Caspase-6, -4, -8, -9, and -10 whereas NWL-154 has higher selectivity against Caspase-6, -8, and -10. The half-maximal inhibitory concentrations (IC 50 ) of NWL-117 and NWL-154 is 192 nM and 100 nM against Caspase-6 in vitro, and 4.82 μM and 3.63 μM in Caspase-6-transfected HCT116 cells, respectively. NWL inhibitors are not toxic to HCT116 cells or to human primary neurons. NWL-117 and NWL-154 inhibit serum deprivation-induced Caspase-6 activity and prevent amyloid precursor protein-mediated neurite degeneration in human primary CNS neurons. NWL-117 crosses the blood brain barrier and reverses age-dependent episodic memory deficits in Caspase-6 mice. NWL peptidic vinyl methyl sulfone inhibitors are potent, non-toxic, blood-brain barrier permeable, and irreversible caspase inhibitors with neuroprotective effects in HCT116 cells, in primary human CNS neurons, and in Caspase-6 mice. These results highlight the therapeutic potential of vinyl sulfone inhibitors as caspase inhibitors against neurodegenerative diseases and sanction additional work to improve their selectivity against different caspases.

Sex differences in theory-based predictors of leisure time physical activity in a population-based sample of adults with spinal cord injury.

PubMed

Stapleton, Jessie N; Martin Ginis, Kathleen A

2014-09-01

To examine sex differences in theory-based predictors of leisure time physical activity (LTPA) among men and women with spinal cord injury, and secondarily, to identify factors that might explain any sex differences in social cognitions. A secondary analysis of Study of Health and Activity in People with Spinal Cord Injury survey data. Community. Community-dwelling men (n=536) and women (n=164) recruited from 4 rehabilitation and research centers. Not applicable. Subjective norms, attitudes, barrier self-efficacy, perceived controllability (PC), and intentions. Men had stronger PC and barrier self-efficacy than women. Hierarchical regression analyses revealed that social support significantly predicted PC for both sexes, and health, pain, and physical independence also significantly predicted PC for men. Social support, health, and pain significantly predicted barrier self-efficacy for men. Social support was the only significant predictor of barrier self-efficacy for women. Women felt significantly less control over their physical activity behavior and had lower confidence to overcome barriers to physical activity than did men. Although social support predicted PC and barrier self-efficacy in both men and women, men seemed to take additional factors into consideration when formulating their control beliefs for LTPA. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Compensation effects and relation between the activation energy of spin transition and the hysteresis loop width for an iron(ii) complex.

PubMed

Bushuev, Mark B; Pishchur, Denis P; Nikolaenkova, Elena B; Krivopalov, Viktor P

2016-06-22

The enthalpy-entropy compensation was observed for the cooperative → spin transition (the phase is a mononuclear complex [FeL2](BF4)2, L is 4-(3,5-dimethyl-1H-pyrazol-1-yl)-2-(pyridin-2-yl)-6-methylpyrimidine). The physical origin of this effect is the fact that the → spin transition is the first order phase transition accompanied by noticeable variations in the Tonset↑, ΔH and ΔS values. Higher ΔH and ΔS values are correlated with higher Tonset↑ values. The higher the enthalpy and entropy of the spin transition, the wider the hysteresis loop. The kinetic compensation effect, i.e. a linear relationship between ln A and Ea, was observed for the → spin transition. Moreover, an isokinetic relationship was detected in this system: the Arrhenius lines (ln k vs. 1/T) obtained from magnetochemical data for different samples of the phase undergoing the → transition show a common point of intersection (Tiso = 490 ± 2 K, ln kiso = -6.0 ± 0.2). The validity of this conclusion was confirmed by the Exner-Linert statistical method. This means that the isokinetic relationship and the kinetic compensation effect (ln A vs. Ea) in this system are true ones. The existence of a true kinetic compensation effect is supported independently by the fact that the hysteresis loop width for the cooperative spin transition ↔ increases with increasing activation barrier height. Estimating the energy of excitations for the phase with Tiso ∼ 490 K yields wavenumbers of ca. 340 cm(-1) corresponding to the frequencies of the stretching vibrations of the Fe(LS)-N bonds, i.e. the bonds directly involved in the mechanism of the spin transition. This is the first observation of the kinetic compensation effect (ln A vs. Ea) and the isokinetic relationship for a cooperative spin crossover system showing thermal hysteresis. Our results provide the first experimental evidence that the higher the activation barrier for the spin transition, the wider the hysteresis loop for a series of related spin crossover systems.

Understanding Motivators and Barriers to Physical Activity

ERIC Educational Resources Information Center

Patay, Mary E.; Patton, Kevin; Parker, Melissa; Fahey, Kathleen; Sinclair, Christina

2015-01-01

The purpose of this study was to understand the factors that influence physical activity among year-round residents in an isolated summer resort community. Specifically, we explored the personal, environmental, social, and culture-specific perceived motivators and barriers to physical activity. Participants were formally interviewed about their…

An exploratory study of how sports and recreation industry personnel perceive the barriers and facilitators of physical activity in children with disability.

PubMed

Shields, Nora; Synnot, Anneliese J

2014-01-01

To explore the perceived barriers and facilitators to participation in physical activity among children with disability in physical activity and community sports from the perspective of sports and recreation industry personnel. A convenient sample of 24 participants was recruited from delegates attending a symposium on physical activity for organisations in the sport and recreation sector in Victoria, Australia. The participants completed a brief questionnaire. Data were analysed by content analysis using an inductive approach. The participants reported 25 facilitators and 20 barriers to participation for children with disability. The top five reported facilitators were: welcoming providers, support and encouragement from parents or others, inclusive providers, adaptable approaches and accessibility of facilities. The top five reported barriers were: inaccessible facilities, non-inclusive providers, transport, lack of relevant opportunities and cost. Sports industry personnel share a similar perspective to families of potential barriers and facilitators to engagement by children with disability in physical activity and community sports. Policy change was not considered as a facilitator of physical activity, even though four of the top five facilitators identified could be implemented through local policy change. Implications for Rehabilitation There are multiple factors that interact with each other which influence the participation by children with disability in physical activity and community sports. The sports and recreation industry should consider policy change as a relevant way to facilitate participation by children with disability in physical activity. More professional development and disability engagement opportunities for sports and recreation industry personnel may help address some of the barriers to participation for children with disability experience.

Protease and Protease-Activated Receptor-2 Signaling in the Pathogenesis of Atopic Dermatitis

PubMed Central

Lee, Sang Eun; Jeong, Se Kyoo

2010-01-01

Proteases in the skin are essential to epidermal permeability barrier homeostasis. In addition to their direct proteolytic effects, certain proteases signal to cells by activating protease-activated receptors (PARs), the G-protein-coupled receptors. The expression of functional PAR-2 on human skin and its role in inflammation, pruritus, and skin barrier homeostasis have been demonstrated. Atopic dermatitis (AD) is a multifactorial inflammatory skin disease characterized by genetic barrier defects and allergic inflammation, which is sustained by gene-environmental interactions. Recent studies have revealed aberrant expression and activation of serine proteases and PAR-2 in the lesional skin of AD patients. The imbalance between proteases and protease inhibitors associated with genetic defects in the protease/protease inhibitor encoding genes, increase in skin surface pH, and exposure to proteolytically active allergens contribute to this aberrant protease/PAR-2 signaling in AD. The increased protease activity in AD leads to abnormal desquamation, degradation of lipid-processing enzymes and antimicrobial peptides, and activation of primary cytokines, thereby leading to permeability barrier dysfunction, inflammation, and defects in the antimicrobial barrier. Moreover, up-regulated proteases stimulate PAR-2 in lesional skin of AD and lead to the production of cytokines and chemokines involved in inflammation and immune responses, itching sensation, and sustained epidermal barrier perturbation with easier allergen penetration. In addition, PAR-2 is an important sensor for exogenous danger molecules, such as exogenous proteases from various allergens, and plays an important role in AD pathogenesis. Together, these findings suggest that protease activity or PAR-2 may be a future target for therapeutic intervention for the treatment of AD. PMID:20879045

A charge-based model of Junction Barrier Schottky rectifiers

NASA Astrophysics Data System (ADS)

Latorre-Rey, Alvaro D.; Mudholkar, Mihir; Quddus, Mohammed T.; Salih, Ali

2018-06-01

A new charge-based model of the electric field distribution for Junction Barrier Schottky (JBS) diodes is presented, based on the description of the charge-sharing effect between the vertical Schottky junction and the lateral pn-junctions that constitute the active cell of the device. In our model, the inherently 2-D problem is transformed into a simple but accurate 1-D problem which has a closed analytical solution that captures the reshaping and reduction of the electric field profile responsible for the improved electrical performance of these devices, while preserving physically meaningful expressions that depend on relevant device parameters. The validation of the model is performed by comparing calculated electric field profiles with drift-diffusion simulations of a JBS device showing good agreement. Even though other fully 2-D models already available provide higher accuracy, they lack physical insight making the proposed model an useful tool for device design.

Electrical model of dielectric barrier discharge homogenous and filamentary modes

NASA Astrophysics Data System (ADS)

López-Fernandez, J. A.; Peña-Eguiluz, R.; López-Callejas, R.; Mercado-Cabrera, A.; Valencia-Alvarado, R.; Muñoz-Castro, A.; Rodríguez-Méndez, B. G.

2017-01-01

This work proposes an electrical model that combines homogeneous and filamentary modes of an atmospheric pressure dielectric barrier discharge cell. A voltage controlled electric current source has been utilized to implement the power law equation that represents the homogeneous discharge mode, which starts when the gas breakdown voltage is reached. The filamentary mode implies the emergence of electric current conducting channels (microdischarges), to add this phenomenon an RC circuit commutated by an ideal switch has been proposed. The switch activation occurs at a higher voltage level than the gas breakdown voltage because it is necessary to impose a huge electric field that contributes to the appearance of streamers. The model allows the estimation of several electric parameters inside the reactor that cannot be measured. Also, it is possible to appreciate the modes of the DBD depending on the applied voltage magnitude. Finally, it has been recognized a good agreement between simulation outcomes and experimental results.

Perceived benefits and barriers to exercise among persons with physical disabilities or chronic health conditions within action or maintenance stages of exercise.

PubMed

Malone, Laurie A; Barfield, J P; Brasher, Joel D

2012-10-01

Information regarding factors that affect the initial step to exercise behavior change among persons with physical disabilities or chronic health conditions is available in the literature but much less is known regarding perceived benefits and barriers to exercise among those who are regularly active. The purpose of this study was to examine the perceived benefits and barriers to exercise among persons with physical disabilities or chronic health conditions within action or maintenance stages of exercise. Participants (n = 152) completed the Exercise Benefits and Barriers Scale (EBBS). For data analyses, disabilities and health conditions were grouped as neuromuscular, orthopedic, cardiovascular/pulmonary, or multiple conditions. Multivariate analysis of variance (MANOVA) was conducted to determine if mean differences on EBBS benefits and barriers scores existed among disability types, between sexes, among age groups, and between physical activity levels. Sum scores were computed to determine the strongest benefit and barrier responses. No significant mean differences in EBBS scores were found between disability types, sexes, age groups, or physical activity levels (p > 0.05). Strongest benefit responses varied by group. Strongest barrier responses were the same for all demographic groups: "Exercise tires me," "Exercise is hard work for me," and "I am fatigued by exercise." EBBS scores were similar across disability/health condition, sex, age, and physical activity level. Primary benefits reported were in the areas of improved physical performance and psychological outlook whereas the primary barriers were in the area of physical exertion. Copyright © 2012 Elsevier Inc. All rights reserved.

Exploring perceptions and beliefs about the cost of fruit and vegetables and whether they are barriers to higher consumption.

PubMed

Chapman, Kathryn; Goldsbury, David; Watson, Wendy; Havill, Michelle; Wellard, Lyndal; Hughes, Clare; Bauman, Adrian; Allman-Farinelli, Margaret

2017-06-01

Fruit and vegetable (F&V) consumption is below recommendations, and cost may be a barrier to meeting recommendations. Limited evidence exists on individual perceptions about the cost, actual spending and consumption of F&V. This study investigated perceptions and beliefs about cost of F&V and whether this is a barrier to higher consumption. An online survey of Australian adults (n = 2474) measured F&V consumption; expenditure on F&V and food; and perceived barriers to consumption. Multivariable logistic regression examined associations between participants' responses about cost of F&V and demographic factors, and with actual consumption and expenditure on F&V. Cost was identified as a barrier for 29% of people not meeting recommended fruit servings and for 14% of people not meeting recommendations for vegetables. Cost was a more common barrier for those on lower incomes (fruit aOR 1.89; 95% CI 1.20-2.98 and vegetables aOR 2.94; 95% CI 1.97-4.39) and less common for older participants (fruit aOR 0.33; 95% CI 0.17-0.62 and vegetables aOR 0.31; 95% CI 0.18-0.52). There was no association between the perceived barriers and actual F&V spending. Twenty percent of participants said F&V were not affordable; 39% said cost made it difficult to buy F&V, and for 23% the cost of F&V meant they bought less than desired. A minority reported F&V were not affordable where they shopped and that cost was a barrier to higher consumption. However, it is apparent that young adults and those on low incomes eat less than they would like because of cost. Strategies that remove financial impediments to consumption are indicated for these population sub-groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

Matrix Metalloproteinase-Mediated Blood-Brain Barrier Dysfunction in Epilepsy.

PubMed

Rempe, Ralf G; Hartz, Anika M S; Soldner, Emma L B; Sokola, Brent S; Alluri, Satya R; Abner, Erin L; Kryscio, Richard J; Pekcec, Anton; Schlichtiger, Juli; Bauer, Björn

2018-05-02

The blood-brain barrier is dysfunctional in epilepsy, thereby contributing to seizure genesis and resistance to antiseizure drugs. Previously, several groups reported that seizures increase brain glutamate levels, which leads to barrier dysfunction. One critical component of barrier dysfunction is brain capillary leakage. Based on our preliminary data, we hypothesized that glutamate released during seizures mediates an increase in matrix-metalloproteinase (MMP) expression and activity levels, thereby contributing to barrier leakage. To test this hypothesis, we exposed isolated brain capillaries from male Sprague Dawley rats to glutamate ex vivo and used an in vivo / ex vivo approach of isolated brain capillaries from female Wistar rats that experienced status epilepticus as an acute seizure model. We found that exposing isolated rat brain capillaries to glutamate increased MMP-2 and MMP-9 protein and activity levels, and decreased tight junction protein levels, which resulted in barrier leakage. We confirmed these findings in vivo in rats after status epilepticus and in brain capillaries from male mice lacking cytosolic phospholipase A 2 Together, our data support the hypothesis that glutamate released during seizures signals an increase in MMP-2 and MMP-9 protein expression and activity levels, resulting in blood-brain barrier leakage. SIGNIFICANCE STATEMENT The mechanism leading to seizure-mediated blood-brain barrier dysfunction in epilepsy is poorly understood. In the present study, we focused on defining this mechanism in the brain capillary endothelium. We demonstrate that seizures trigger a pathway that involves glutamate signaling through cytosolic phospholipase A 2 , which increases MMP levels and decreases tight junction protein expression levels, resulting in barrier leakage. These findings may provide potential therapeutic avenues within the blood-brain barrier to limit barrier dysfunction in epilepsy and decrease seizure burden. Copyright © 2018 the authors 0270-6474/18/384301-15$15.00/0.

A Mixed-Methods Examination of Physical Activity and Sedentary Time in Overweight and Obese South Asian Men Living in the United Kingdom.

PubMed

Emadian, Amir; Thompson, Janice

2017-03-27

South Asian men living in the UK have higher rates of central obesity and Type 2 Diabetes Mellitus (T2DM) compared with their white British counterparts. Physical activity (PA) and sedentary time (ST) are important risk factors for the development of T2DM. The purpose of this study was to objectively measure PA, ST, and to explore the factors influencing these behaviours in this high-risk population. A mixed-methods cross-sectional research design was employed, including the quantification of PA and ST using the self-report International Physical Activity Questionnaire (IPAQ)-long form and accelerometry in overweight and obese UK South Asian men (n = 54), followed by semi-structured interviews in a purposive sub-sample to explore the factors influencing PA and ST (n = 31). Accelerometer-derived moderate-to-vigorous PA (MVPA) and ST were 298.9 ± 186.6 min/week and 551.4 ± 95.0 min/day, respectively. IPAQ-derived MVPA was significantly lower than accelerometer-derived MVPA (p < 0.001). IPAQ-derived ST was significantly higher than accelerometer-derived ST (p < 0.001). Lack of time and family commitments were identified as the main barriers to being more physically active, with group exercise identified as an important facilitator to being more active. A cultural norm of focusing on promoting education over sport participation during childhood was identified as an important factor influencing long-term PA behaviours. Work commitments and predominantly sedentary jobs were identified as the main barriers to reducing ST. Healthcare professionals and researchers need to consider the socio-cultural factors which affect PA engagement in overweight and obese South Asian men living in the UK, to ensure that advice and future interventions are tailored to address the needs of this population.

A Mixed-Methods Examination of Physical Activity and Sedentary Time in Overweight and Obese South Asian Men Living in the United Kingdom

PubMed Central

Emadian, Amir; Thompson, Janice L.

2017-01-01

South Asian men living in the UK have higher rates of central obesity and Type 2 Diabetes Mellitus (T2DM) compared with their white British counterparts. Physical activity (PA) and sedentary time (ST) are important risk factors for the development of T2DM. The purpose of this study was to objectively measure PA, ST, and to explore the factors influencing these behaviours in this high-risk population. A mixed-methods cross-sectional research design was employed, including the quantification of PA and ST using the self-report International Physical Activity Questionnaire (IPAQ)-long form and accelerometry in overweight and obese UK South Asian men (n = 54), followed by semi-structured interviews in a purposive sub-sample to explore the factors influencing PA and ST (n = 31). Accelerometer-derived moderate-to-vigorous PA (MVPA) and ST were 298.9 ± 186.6 min/week and 551.4 ± 95.0 min/day, respectively. IPAQ-derived MVPA was significantly lower than accelerometer-derived MVPA (p < 0.001). IPAQ-derived ST was significantly higher than accelerometer-derived ST (p < 0.001). Lack of time and family commitments were identified as the main barriers to being more physically active, with group exercise identified as an important facilitator to being more active. A cultural norm of focusing on promoting education over sport participation during childhood was identified as an important factor influencing long-term PA behaviours. Work commitments and predominantly sedentary jobs were identified as the main barriers to reducing ST. Healthcare professionals and researchers need to consider the socio-cultural factors which affect PA engagement in overweight and obese South Asian men living in the UK, to ensure that advice and future interventions are tailored to address the needs of this population. PMID:28346386

Participation in extracurricular activities for children with and without siblings with autism spectrum disorder.

PubMed

Wigston, Christine; Falkmer, Marita; Vaz, Sharmila; Parsons, Richard; Falkmer, Torbjörn

2017-01-01

To compare the number, frequency, enjoyment and performance in extracurricular activities of siblings of children with autism spectrum disorders (ASD) to their typically developing (TD) peers, and to identify differences between actual and desired participation. A case-control study with 30 siblings of children with ASD and 30 siblings of TD children was conducted using the Paediatric Interest Profiles and a questionnaire. Siblings of children with ASD participated in fewer extracurricular activities than those with TD siblings. ASD symptoms were significantly associated with the sibling participating in fewer extracurricular activities. Children with TD siblings had higher enjoyment scores in relaxation activities than children with siblings with ASD. While results were mainly positive, some differences indicated that having a sibling with ASD may impact participation in extracurricular activities. Assessments of participation barriers, as well as support to minimise participation restrictions among siblings of children with ASD are required.

Physical Activity Pattern of Malaysian Preschoolers: Environment, Barriers, and Motivators for Active Play.

PubMed

Lee, Shoo Thien; Wong, Jyh Eiin; Ong, Wei Wen; Ismail, Mohd Noor; Deurenberg, Paul; Poh, Bee Koon

2016-07-01

Children's physical activity has been correlated with child characteristics and social or physical environment. This study aimed to compare preschoolers' physical activity among various sociodemographic characteristics and to determine barriers, motivators, and environmental factors for active play. A total of 835 preschoolers were included in this analysis. Time spent on active play, quiet play, and screen time was reported by parents. Boys spent significantly more time on active play and screen time than girls. Time spent on quiet play was highest in East Coast Peninsular Malaysia and lowest in Sarawak. Some 40% of children achieved active play recommendation while 27% exceeded daily screen time recommendation. Most parents reported that their child played actively in the house area; and that the main barrier and motivator to active play were safety and child's enjoyment, respectively. These findings demonstrate that sociodemographic characteristics and environment should be considered in designing physical activity intervention programs. © 2016 APJPH.

Poly(3-hydroxybutyrate)/ZnO Bionanocomposites with Improved Mechanical, Barrier and Antibacterial Properties

PubMed Central

Díez-Pascual, Ana M.; Díez-Vicente, Angel L.

2014-01-01

Poly(3-hydroxybutyrate) (PHB)-based bionanocomposites incorporating different contents of ZnO nanoparticles were prepared via solution casting technique. The nanoparticles were dispersed within the biopolymer without the need for surfactants or coupling agents. The morphology, thermal, mechanical, barrier, migration and antibacterial properties of the nanocomposites were investigated. The nanoparticles acted as nucleating agents, increasing the crystallization temperature and the degree of crystallinity of the matrix, and as mass transport barriers, hindering the diffusion of volatiles generated during the decomposition process, leading to higher thermal stability. The Young’s modulus, tensile and impact strength of the biopolymer were enhanced by up to 43%, 32% and 26%, respectively, due to the strong matrix-nanofiller interfacial adhesion attained via hydrogen bonding interactions, as revealed by the FT-IR spectra. Moreover, the nanocomposites exhibited reduced water uptake and superior gas and vapour barrier properties compared to neat PHB. They also showed antibacterial activity against both Gram-positive and Gram-negative bacteria, which was progressively improved upon increasing ZnO concentration. The migration levels of PHB/ZnO composites in both non-polar and polar simulants decreased with increasing nanoparticle content, and were well below the current legislative limits for food packaging materials. These biodegradable nanocomposites show great potential as an alternative to synthetic plastic packaging materials especially for use in food and beverage containers and disposable applications. PMID:24941255

Poly(3-hydroxybutyrate)/ZnO bionanocomposites with improved mechanical, barrier and antibacterial properties.

PubMed

Díez-Pascual, Ana M; Díez-Vicente, Angel L

2014-06-17

Poly(3-hydroxybutyrate) (PHB)-based bionanocomposites incorporating different contents of ZnO nanoparticles were prepared via solution casting technique. The nanoparticles were dispersed within the biopolymer without the need for surfactants or coupling agents. The morphology, thermal, mechanical, barrier, migration and antibacterial properties of the nanocomposites were investigated. The nanoparticles acted as nucleating agents, increasing the crystallization temperature and the degree of crystallinity of the matrix, and as mass transport barriers, hindering the diffusion of volatiles generated during the decomposition process, leading to higher thermal stability. The Young's modulus, tensile and impact strength of the biopolymer were enhanced by up to 43%, 32% and 26%, respectively, due to the strong matrix-nanofiller interfacial adhesion attained via hydrogen bonding interactions, as revealed by the FT-IR spectra. Moreover, the nanocomposites exhibited reduced water uptake and superior gas and vapour barrier properties compared to neat PHB. They also showed antibacterial activity against both Gram-positive and Gram-negative bacteria, which was progressively improved upon increasing ZnO concentration. The migration levels of PHB/ZnO composites in both non-polar and polar simulants decreased with increasing nanoparticle content, and were well below the current legislative limits for food packaging materials. These biodegradable nanocomposites show great potential as an alternative to synthetic plastic packaging materials especially for use in food and beverage containers and disposable applications.

Reported Barriers to Source Reduction in the 2015 TRI National Analysis

EPA Pesticide Factsheets

Source Reduction/Pollution Prevention - barriers to implementing source reduction activities as reported by facilities for the 2015 Toxics Release Inventory National Analysis, including examples of each type of barrier

Reported Barriers to Source Reduction in the 2016 TRI National Analysis

EPA Pesticide Factsheets

Source Reduction/Pollution Prevention - barriers to implementing source reduction activities as reported by facilities for the 2016 Toxics Release Inventory National Analysis, including examples of each type of barrier

Arctigenin from Fructus Arctii (Seed of Burdock) Reinforces Intestinal Barrier Function in Caco-2 Cell Monolayers

PubMed Central

Shin, Hee Soon; Jung, Sun Young; Back, Su Yeon; Do, Jeong-Ryong; Shon, Dong-Hwa

2015-01-01

Fructus Arctii is used as a traditional herbal medicine to treat inflammatory diseases in oriental countries. This study aimed to investigate effect of F. Arctii extract on intestinal barrier function in human intestinal epithelial Caco-2 cells and to reveal the active component of F. Arctii. We measured transepithelial electrical resistance (TEER) value (as an index of barrier function) and ovalbumin (OVA) permeation (as an index of permeability) to observe the changes of intestinal barrier function. The treatment of F. Arctii increased TEER value and decreased OVA influx on Caco-2 cell monolayers. Furthermore, we found that arctigenin as an active component of F. Arctii increased TEER value and reduced permeability of OVA from apical to the basolateral side but not arctiin. In the present study, we revealed that F. Arctii could enhance intestinal barrier function, and its active component was an arctigenin on the functionality. We expect that the arctigenin from F. Arctii could contribute to prevention of inflammatory, allergic, and infectious diseases by reinforcing intestinal barrier function. PMID:26550018

How does a lifestyle intervention during pregnancy influence perceived barriers to leisure-time physical activity? The Norwegian fit for delivery study, a randomized controlled trial.

PubMed

Haakstad, Lene A H; Vistad, Ingvild; Sagedal, Linda Reme; Lohne-Seiler, Hilde; Torstveit, Monica K

2018-05-03

To develop effective health promotional and preventive prenatal programs, it is important to understand perceived barriers to leisure-time physical activity during pregnancy, including exercise and sport participation. The aims of the present study was 1) to assess the effect of prenatal lifestyle intervention on the perceived barrier to leisure-time physical activity during pregnancy and the first year after delivery and 2) identify the most important perceived barriers to leisure-time physical activity at multiple time points during and after pregnancy. This secondary analysis was part of the Norwegian Fit for Delivery study, a combined lifestyle intervention evaluated in a blinded, randomized controlled trial. Healthy, nulliparous women with singleton pregnancy of ≤20 gestational weeks, age ≥ 18 years and body mass index ≥19 kg/m 2 were recruited via healthcare clinics in southern Norway, including urban and rural settings. Participants were randomized to either twice-weekly supervised exercise sessions and nutritional counselling (n = 303) or standard prenatal care (n = 303). The principal analysis was based on the participants who completed the standardized questionnaire assessing their perceived barriers to leisure-time physical activity at inclusion (gestational week 16, n = 589) and following intervention (gestational week 36, n = 509), as well as six months (n = 470) and 12 months (n = 424) postpartum. Following intervention (gestation week 35.4 ± 1.0), a significant between-group difference in perceived barriers to leisure-time physical activity was found with respect to time constraints: "... I do not have the time" (intervention: 22 vs. control: 38, p = 0.030), mother-child safety concerns: "... afraid to harm the baby" (intervention: 8 vs. control: 25, p = 0.002) and self-efficacy: "... I do not believe/think that I can do it" (intervention: 3 vs. control: 10, p = 0.050). No positive effect was seen at postpartum follow-up. Intrapersonal factors (lack of time, energy and interest) were the most frequently perceived barriers, and consistent over time among all participants. The intervention had effect on intrapersonal perceived barriers in pregnancy, but not in the postpartum period. Perceived barriers to leisure-time physical activity were similar from early pregnancy to 12 months postpartum. ClinicalTrials.gov: NCT01001689 , registered July 2, 2009.

Adolescent Girls' Perceived Barriers to Participation in Physical Activity

ERIC Educational Resources Information Center

Dwyer, John J. M.; Allison, Kenneth R.; Goldenberg, Ellie R.; Fein, Allan J.; Yoshida, Karen K.; Boutilier, Marie A.

2006-01-01

Research shows a decline in physical activity levels during adolescence, particularly among girls. This study explored perceived barriers to participation in moderate and vigorous physical activity among adolescent girls who live in a large ethnoracially and socioeconomically diverse city. A total of 73 adolescent girls in Toronto participated in…

Barriers to Physical Activity for People with Long-Term Neurological Conditions: A Review Study

ERIC Educational Resources Information Center

Mulligan, Hilda F.; Hale, Leigh A.; Whitehead, Lisa; Baxter, G. David

2012-01-01

People with disability are insufficiently physically active for health. This study identified the volume, quality, and findings of research that exposes environmental and personal barriers of physical activity participation for people with neurological conditions. CINAHL, Sport Discus, EMBASE, Medline, and AMED were systematically searched between…

Does a higher metal oxidation state necessarily imply higher reactivity toward H-atom transfer? A computational study of C-H bond oxidation by high-valent iron-oxo and -nitrido complexes.

PubMed

Geng, Caiyun; Ye, Shengfa; Neese, Frank

2014-04-28

In this work, the reactions of C-H bond activation by two series of iron-oxo ( (Fe(IV)), (Fe(V)), (Fe(VI))) and -nitrido model complexes ( (Fe(IV)), (Fe(V)), (Fe(VI))) with a nearly identical coordination geometry but varying iron oxidation states ranging from iv to vi were comprehensively investigated using density functional theory. We found that in a distorted octahedral coordination environment, the iron-oxo species and their isoelectronic nitrido analogues feature totally different intrinsic reactivities toward C-H bond cleavage. In the case of the iron-oxo complexes, the reaction barrier monotonically decreases as the iron oxidation state increases, consistent with the gradually enhanced electrophilicity across the series. The iron-nitrido complex is less reactive than its isoelectronic iron-oxo species, and more interestingly, a counterintuitive reactivity pattern was observed, i.e. the activation barriers essentially remain constant independent of the iron oxidation states. The detailed analysis using the Polanyi principle demonstrates that the different reactivities between these two series originate from the distinct thermodynamic driving forces, more specifically, the bond dissociation energies (BDEE-Hs, E = O, N) of the nascent E-H bonds in the FeE-H products. Further decomposition of the BDEE-Hs into the electron and proton affinity components shed light on how the oxidation states modulate the BDEE-Hs of the two series.

Development of a novel multi-functional active membrane capping barrier for the remediation of nitrobenzene-contaminated sediment.

PubMed

Wang, Qing; Li, Yi; Wang, Chao; Wu, Yue; Wang, Peifang

2014-07-15

A novel bio-reactive capping barrier composed of polysulfone/granular activated carbon (PS/GAC) hybrid membranes immobilized with microorganism was developed for the remediation of nitrobenzene in sediments. The SEM observation demonstrated that all the membranes had a dense top layer and a porous sublayer, this structure can block the transfer of nitrobenzene from sediment to the water and enhance nitrobenzene degradation. Adsorption behaviors of nitrobenzene on membranes showed that the membrane impregnated with GAC had better performance than the pure PS membrane. The values of Kads increased from 4.64 (without GAC) to 6.19 (1:2 GAC). 20mg/L nitrobenzene can be completely degraded by Pseudomonas putida immobilized on membranes. The biodegradation rate of activated carbon-filled membrane system was little higher than that of pure PS membrane system. For remediation experiments, only about 21.7, 28.3 and 43.9% of nitrobenzene in the sediment was removed by the end of the experiments for PS/GAC membrane, sand-alone and sand amended with activated carbon capping systems, respectively. While for PS/GAC+microorganisms capping system, more than 70% of nitrobenzene loss was observed. This demonstrated that nitrobenzene can be effectively removed from contaminated sediments by microbial degradation in the bio-reactive capping system. Copyright © 2014 Elsevier B.V. All rights reserved.

Theoretical Investigations of the Electrochemical Reduction of CO on Single Metal Atoms Embedded in Graphene

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

Kirk, Charlotte; Chen, Leanne D.; Siahrostami, Samira

Single transition metal atoms embedded at single vacancies of graphene provide a unique paradigm for catalytic reactions. We present a density functional theory study of such systems for the electrochemical reduction of CO. Theoretical investigations of CO electrochemical reduction are particularly challenging in that electrochemical activation energies are a necessary descriptor of activity. We determined the electrochemical barriers for key proton–electron transfer steps using a state-of-the-art, fully explicit solvent model of the electrochemical interface. The accuracy of GGA-level functionals in describing these systems was also benchmarked against hybrid methods. We find the first proton transfer to form CHO from COmore » to be a critical step in C 1 product formation. On these single atom sites, the corresponding barrier scales more favorably with the CO binding energy than for 211 and 111 transition metal surfaces, in the direction of improved activity. Intermediates and transition states for the hydrogen evolution reaction were found to be less stable than those on transition metals, suggesting a higher selectivity for CO reduction. We present a rate volcano for the production of methane from CO. We identify promising candidates with high activity, stability, and selectivity for the reduction of CO. As a result, this work highlights the potential of these systems as improved electrocatalysts over pure transition metals for CO reduction.« less

Cardiorespiratory Fitness in Internal Medicine Residents: Are Future Physicians Becoming Deconditioned?

PubMed

Daneshvar, Farshid; Weinreich, Michael; Daneshvar, Danial; Sperling, Michael; Salmane, Chadi; Yacoub, Harout; Gabriels, James; McGinn, Thomas; Smith, Marianne C

2017-02-01

Previous studies have shown a falloff in physicians' physical activity from medical school to residency. Poor fitness may result in stress, increase resident burnout, and contribute to mortality from cardiovascular disease and other causes. Physicians with poor exercise habits are also less likely to counsel patients about exercise. Prior studies have reported resident physical activity but not cardiorespiratory fitness age. The study was conducted in 2 residency programs (3 hospitals) to assess internal medicine residents' exercise habits as well as their cardiorespiratory fitness age. Data regarding physical fitness levels and exercise habits were collected in an anonymous cross-sectional survey. Cardiopulmonary fitness age was determined using fitness calculator based on the Nord-Trøndelag Health Study (HUNT). Of 199 eligible physicians, 125 (63%) responded to the survey. Of respondents, 11 (9%) reported never having exercised prior to residency and 45 (36%) reported not exercising during residency ( P < .001). In addition, 42 (34%) reported exercising every day prior to residency, while only 5 (4%) reported exercising daily during residency ( P < .001), with 99 (79%) participants indicating residency obligations as their main barrier to exercise. We found residents' calculated mean fitness age to be 5.6 years higher than their mean chronological age ( P < .001). Internal medicine residents reported significant decreases in physical activity and fitness. Residents attributed time constraints due to training as a key barrier to physical activity.

Theoretical Investigations of the Electrochemical Reduction of CO on Single Metal Atoms Embedded in Graphene

DOE PAGES

Kirk, Charlotte; Chen, Leanne D.; Siahrostami, Samira; ...

2017-12-18

Single transition metal atoms embedded at single vacancies of graphene provide a unique paradigm for catalytic reactions. We present a density functional theory study of such systems for the electrochemical reduction of CO. Theoretical investigations of CO electrochemical reduction are particularly challenging in that electrochemical activation energies are a necessary descriptor of activity. We determined the electrochemical barriers for key proton–electron transfer steps using a state-of-the-art, fully explicit solvent model of the electrochemical interface. The accuracy of GGA-level functionals in describing these systems was also benchmarked against hybrid methods. We find the first proton transfer to form CHO from COmore » to be a critical step in C 1 product formation. On these single atom sites, the corresponding barrier scales more favorably with the CO binding energy than for 211 and 111 transition metal surfaces, in the direction of improved activity. Intermediates and transition states for the hydrogen evolution reaction were found to be less stable than those on transition metals, suggesting a higher selectivity for CO reduction. We present a rate volcano for the production of methane from CO. We identify promising candidates with high activity, stability, and selectivity for the reduction of CO. As a result, this work highlights the potential of these systems as improved electrocatalysts over pure transition metals for CO reduction.« less

The Principal and Nurse Perspective on Gaps in Asthma Care and Barriers to Physical Activity in New York City Schools: A Qualitative Study

ERIC Educational Resources Information Center

Cain, Agnieszka; Reznik, Marina

2018-01-01

Background: School officials and nurses play an important role in facilitating asthma management in schools. Little is known about their perspectives on in-school asthma management and barriers to physical activity (PA) at school. Aims: The goal of this study is to explore school officials' and nurses' perspectives on asthma care and barriers to…

The role of multidrug resistance protein (MRP-1) as an active efflux transporter on blood-brain barrier (BBB) permeability.

PubMed

Lingineni, Karthik; Belekar, Vilas; Tangadpalliwar, Sujit R; Garg, Prabha

2017-05-01

Drugs acting on central nervous system (CNS) may take longer duration to reach the market as these compounds have a higher attrition rate in clinical trials due to the complexity of the brain, side effects, and poor blood-brain barrier (BBB) permeability compared to non-CNS-acting compounds. The roles of active efflux transporters with BBB are still unclear. The aim of the present work was to develop a predictive model for BBB permeability that includes the MRP-1 transporter, which is considered as an active efflux transporter. A support vector machine model was developed for the classification of MRP-1 substrates and non-substrates, which was validated with an external data set and Y-randomization method. An artificial neural network model has been developed to evaluate the role of MRP-1 on BBB permeation. A total of nine descriptors were selected, which included molecular weight, topological polar surface area, ClogP, number of hydrogen bond donors, number of hydrogen bond acceptors, number of rotatable bonds, P-gp, BCRP, and MRP-1 substrate probabilities for model development. We identified 5 molecules that fulfilled all criteria required for passive permeation of BBB, but they all have a low logBB value, which suggested that the molecules were effluxed by the MRP-1 transporter.

Beta-adrenergic stimulation contributes to maintenance of endothelial barrier functions under baseline conditions.

PubMed

Spindler, Volker; Waschke, Jens

2011-02-01

cAMP signaling within the endothelium is known to reduce paracellular permeability and to protect against loss of barrier functions under various pathological conditions. Because activation of β-adrenergic receptors elevates cellular cAMP, we tested whether β-adrenergic receptor signaling contributes to the maintenance of baseline endothelial barrier properties. We compared hydraulic conductivity of rat postcapillary venules in vivo with resistance measurements and with reorganization of endothelial adherens junctions in cultured microvascular endothelial cells downstream of β-adrenergic receptor-mediated changes of cAMP levels. Inhibition of β-adrenergic receptors by propranolol increased hydraulic conductivity, reduced both cAMP levels and TER of microvascular endothelial cell monolayers and induced fragmentation of VE-cadherin staining. In contrast, activation by epinephrine both increased cAMP levels and TER and resulted in linearized VE-cadherin distribution, however this was not sufficient to block barrier-destabilization by propranolol. Similarly, PDE inhibition did not prevent propranolol-induced TER reduction and VE-cadherin reorganization whereas increased cAMP formation by AC activation enhanced endothelial barrier functions under baseline conditions and under conditions of propranolol treatment. Our results indicate that generation of cAMP mediated by activation of β-adrenergic receptor signaling contributes to the maintenance of endothelial barrier properties under baseline conditions. © 2011 John Wiley & Sons Ltd.

Mechanisms of pertussis toxin-induced barrier dysfunction in bovine pulmonary artery endothelial cell monolayers.

PubMed

Patterson, C E; Stasek, J E; Schaphorst, K L; Davis, H W; Garcia, J G

1995-06-01

We have previously characterized several G proteins in endothelial cells (EC) as substrates for the ADP-ribosyltransferase activity of both pertussis (PT) and cholera toxin and described the modulation of key EC physiological responses, including gap formation and barrier function, by these toxins. In this study, we investigated the mechanisms involved in PT-mediated regulation of bovine pulmonary artery endothelial cells barrier function. PT caused a dose-dependent increase in albumin transfer, dependent upon action of the holotoxin, since neither the heat-inactivated PT, the isolated oligomer, nor the protomer induced EC permeability. PT-induced gap formation and barrier dysfunction were additive to either thrombin- or thrombin receptor-activating peptide-induced permeability, suggesting that thrombin and PT utilize distinct mechanisms. PT did not result in Ca2+ mobilization or alter either basal or thrombin-induced myosin light chain phosphorylation. However, PT stimulated protein kinase C (PKC) activation, and both PKC downregulation and PKC inhibition attenuated PT-induced permeability, indicating that PKC activity is involved in PT-induced barrier dysfunction. Like thrombin-induced permeability, the PT effect was blocked by prior increases in adenosine 3',5'-cyclic monophosphate. Thus PT-catalyzed ADP-ribosylation of a G protein (possibly other than Gi) may regulate cytoskeletal protein interactions, leading to EC barrier dysfunction.

Gut epithelial barrier dysfunction in human immunodeficiency virus-hepatitis C virus coinfected patients: Influence on innate and acquired immunity.

PubMed

Márquez, Mercedes; Fernández Gutiérrez del Álamo, Clotilde; Girón-González, José Antonio

2016-01-28

Even in cases where viral replication has been controlled by antiretroviral therapy for long periods of time, human immunodeficiency virus (HIV)-infected patients have several non-acquired immunodeficiency syndrome (AIDS) related co-morbidities, including liver disease, cardiovascular disease and neurocognitive decline, which have a clear impact on survival. It has been considered that persistent innate and acquired immune activation contributes to the pathogenesis of these non-AIDS related diseases. Immune activation has been related with several conditions, remarkably with the bacterial translocation related with the intestinal barrier damage by the HIV or by hepatitis C virus (HCV)-related liver cirrhosis. Consequently, increased morbidity and mortality must be expected in HIV-HCV coinfected patients. Disrupted gut barrier lead to an increased passage of microbial products and to an activation of the mucosal immune system and secretion of inflammatory mediators, which in turn might increase barrier dysfunction. In the present review, the intestinal barrier structure, measures of intestinal barrier dysfunction and the modifications of them in HIV monoinfection and in HIV-HCV coinfection will be considered. Both pathogenesis and the consequences for the progression of liver disease secondary to gut microbial fragment leakage and immune activation will be assessed.

Financial barriers and adverse clinical outcomes among patients with cardiovascular-related chronic diseases: a cohort study.

PubMed

Campbell, David J T; Manns, Braden J; Weaver, Robert G; Hemmelgarn, Brenda R; King-Shier, Kathryn M; Sanmartin, Claudia

2017-02-15

Some patients with cardiovascular-related chronic diseases such as diabetes and heart disease report financial barriers to achieving optimal health. Previous surveys report that the perception of having a financial barrier is associated with self-reported adverse clinical outcomes. We sought to confirm these findings using linked survey and administrative data to determine, among patients with cardiovascular-related chronic diseases, if there is an association between perceived financial barriers and the outcomes of: (1) disease-related hospitalizations, (2) all-cause mortality and (3) inpatient healthcare costs. We used ten cycles of the nationally representative Canadian Community Health Survey (administered between 2000 and 2011) to identify a cohort of adults aged 45 and older with hypertension, diabetes, heart disease or stroke. Perceived financial barriers to various aspects of chronic disease care and self-management were identified (including medications, healthful food and home care) from the survey questions, using similar questions to those used in previous studies. The cohort was linked to administrative data sources for outcome ascertainment (Discharge Abstract Database, Canadian Mortality Database, Patient Cost Estimator). We utilized Poisson regression techniques, adjusting for potential confounding variables (age, sex, education, multimorbidity, smoking status), to assess for associations between perceived financial barriers and disease-related hospitalization and all-cause mortality. We used gross costing methodology and a variety of modelling approaches to assess the impact of financial barriers on hospital costs. We identified a cohort of 120,752 individuals over the age of 45 years with one or more of the following: hypertension, diabetes, heart disease or stroke. One in ten experienced financial barriers to at least one aspect of their care, with the two most common being financial barriers to accessing medications and healthful food. Even after adjustment, those with at least one financial barrier had an increased rate of disease-related hospitalization and mortality compared to those without financial barriers with adjusted incidence rate ratios of 1.36 (95% CI: 1.29-1.44) and 1.24 (1.16-1.32), respectively. Furthermore, having a financial barrier to care was associated with 30% higher inpatient costs compared to those without financial barriers. This study, using novel linked national survey and administrative data, demonstrates that chronic disease patients with perceived financial barriers have worse outcomes and higher resource utilization, corroborating the findings from prior self-report studies. The overall exposure remained associated with the primary outcome even in spite of adjustment for income. This suggests that a patient's perception of a financial barrier might be used in clinical and research settings as an additional measure along with standard measures of socioeconomic status (ie. income, education, social status). After adjusting for relevant covariates, perceiving a financial barrier was associated with increased rates of hospitalization and mortality and higher hospital costs compared to those without financial barriers. The demonstrable association with adverse outcomes and increased costs seen in this study may provide an impetus for policymakers to seek to invest in interventions which minimize the impact of financial barriers.

Novel Nrf2 activators from microbial transformation products inhibit blood-retinal barrier permeability in rabbits.

PubMed

Nakagami, Yasuhiro; Masuda, Kayoko; Hatano, Emiko; Inoue, Tatsuya; Matsuyama, Takuya; Iizuka, Mayumi; Ono, Yasunori; Ohnuki, Takashi; Murakami, Yoko; Iwasaki, Masaru; Yoshida, Kazuhiro; Kasuya, Yuji; Komoriya, Satoshi

2015-03-01

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that binds to antioxidant response elements located in the promoter region of genes encoding many antioxidant enzymes and phase II detoxifying enzymes. Activation of the Nrf2 pathway seems protective for many organs, and although a well-known Nrf2 activator, bardoxolone methyl, was evaluated clinically for treating chronic kidney disease, it was found to induce adverse events. Many bardoxolone methyl derivatives, mostly derived by chemical modifications, have already been studied. However, we adopted a biotransformation technique to obtain a novel Nrf2 activator. The potent novel Nrf2 activator, RS9, was obtained from microbial transformation products. Its Nrf2 activity was evaluated by determining NADPH:quinone oxidoreductase-1 induction activity in Hepa1c1c7 cells. We also investigated the effects of RS9 on oxygen-induced retinopathy in rats and glycated albumin-induced blood-retinal barrier permeability in rabbits because many ocular diseases are associated with oxidative stress and inflammation. Bardoxolone methyl doubled the specific activity of Nrf2 in Hepa1c1c7 cells at a much higher concentration than RS9. Moreover, the induction of Nrf2-targeted genes was observed at a one-tenth lower concentration of RS9. Interestingly, the cytotoxicity of RS9 was substantially reduced compared with bardoxolone methyl. Oral and intravitreal administration of RS9 ameliorated the pathological scores and leakage in the models of retinopathy in rats and ocular inflammation in rabbits respectively. Nrf2 activators are applicable for treating ocular diseases and novel Nrf2 activators have potential as a unique method for prevention and treatment of retinovascular disease. © 2014 The British Pharmacological Society.

Novel Nrf2 activators from microbial transformation products inhibit blood–retinal barrier permeability in rabbits

PubMed Central

Nakagami, Yasuhiro; Masuda, Kayoko; Hatano, Emiko; Inoue, Tatsuya; Matsuyama, Takuya; Iizuka, Mayumi; Ono, Yasunori; Ohnuki, Takashi; Murakami, Yoko; Iwasaki, Masaru; Yoshida, Kazuhiro; Kasuya, Yuji; Komoriya, Satoshi

2015-01-01

Background and Purpose Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that binds to antioxidant response elements located in the promoter region of genes encoding many antioxidant enzymes and phase II detoxifying enzymes. Activation of the Nrf2 pathway seems protective for many organs, and although a well-known Nrf2 activator, bardoxolone methyl, was evaluated clinically for treating chronic kidney disease, it was found to induce adverse events. Many bardoxolone methyl derivatives, mostly derived by chemical modifications, have already been studied. However, we adopted a biotransformation technique to obtain a novel Nrf2 activator. Experimental Approach The potent novel Nrf2 activator, RS9, was obtained from microbial transformation products. Its Nrf2 activity was evaluated by determining NADPH:quinone oxidoreductase-1 induction activity in Hepa1c1c7 cells. We also investigated the effects of RS9 on oxygen-induced retinopathy in rats and glycated albumin-induced blood–retinal barrier permeability in rabbits because many ocular diseases are associated with oxidative stress and inflammation. Key Results Bardoxolone methyl doubled the specific activity of Nrf2 in Hepa1c1c7 cells at a much higher concentration than RS9. Moreover, the induction of Nrf2-targeted genes was observed at a one-tenth lower concentration of RS9. Interestingly, the cytotoxicity of RS9 was substantially reduced compared with bardoxolone methyl. Oral and intravitreal administration of RS9 ameliorated the pathological scores and leakage in the models of retinopathy in rats and ocular inflammation in rabbits respectively. Conclusion and Implications Nrf2 activators are applicable for treating ocular diseases and novel Nrf2 activators have potential as a unique method for prevention and treatment of retinovascular disease. PMID:25363737

Is fatigue after work a barrier for leisure-time physical activity? Cross-sectional study among 10,000 adults from the general working population.

PubMed

Bláfoss, Rúni; Micheletti, Jéssica K; Sundstrup, Emil; Jakobsen, Markus D; Bay, Hans; Andersen, Lars L

2018-04-01

In spite of the many health-related benefits of regular physical activity, fatiguing work may be a barrier to performing leisure-time physical activity. This study investigates the association between work-related fatigue and the duration of low- and high-intensity leisure-time physical activity in workers with sedentary and physically demanding jobs. From the 2010 round of the Danish Work Environment Cohort Study, currently employed wage earners from the general working population ( N=10,427) replied to questions about work-related fatigue (predictor) and duration of low- and high-intensity leisure-time physical activity (outcome). Associations were modelled using general linear models controlling for various confounders. Among workers with physically demanding jobs, higher levels of work-related fatigue were associated with gradually lower levels of leisure-time physical activity - for low, moderate and high levels of work-related fatigue the duration of high-intensity leisure-time physical activity was 133 (95% confidence interval (CI) 127-178), 134 (95% CI 109-160) and 113 (95% CI 86-140) min per week, respectively (trend test p<0.001). The duration of high-intensity leisure-time physical activity was lower among older workers (≥50 years) compared to younger workers (<50 years) (132 ± 126 vs 168 ± 150 min per week) ( p<0.0001). The duration of high-intensity leisure-time physical activity gradually decreases with increased work-related fatigue in workers with physically demanding jobs. Older workers perform less high-intensity physical activity than younger workers. Workplaces should consider initiatives to allow workers with physically demanding jobs and older workers to perform physical exercise during working hours and thereby increase physical capacity to meet the job demands.

Health and disability: partnerships in health care.

PubMed

Tracy, Jane; McDonald, Rachael

2015-01-01

Despite awareness of the health inequalities experienced by people with intellectual disability, their health status remains poor. Inequalities in health outcomes are manifest in higher morbidity and rates of premature death. Contributing factors include the barriers encountered in accessing and receiving high-quality health care. This paper outlines health inequalities experienced by people with intellectual disability and focuses on the opportunities medical education provides to address these. Strategies to ensure that health professional education is inclusive of and relevant to people with disabilities are highlighted. The barriers experienced by people with intellectual disabilities to the receipt of high-quality health care include the attitudes, knowledge and skills of doctors. Improving medical education to ensure doctors are better equipped is one strategy to address these barriers. Improving health enhances quality of life, enables engagement and optimizes opportunities to participate in and contribute to the social and economic life of communities. People with intellectual disabilities sometimes find it difficult to get the healthcare they need to stay well. Teaching student doctors about what people with disabilities want and need can help these students become better doctors. Good doctors help people get well and stay healthy and active. When people feel well they can enjoy their lives and join in activities in their community. This article talks about some of the things doctors need to learn, and some ways to teach them. People with disabilities have a very important role in teaching student doctors. © 2014 John Wiley & Sons Ltd.

Vacuum chamber with a supersonic flow aerodynamic window

DOEpatents

Hanson, Clark L.

1982-01-01

A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Implementing a Measurement Feedback System in Community Mental Health Clinics: A Case Study of Multilevel Barriers and Facilitators

PubMed Central

Gleacher, Alissa A.; Olin, Serene S.; Nadeem, Erum; Pollock, Michele; Ringle, Vanesa; Bickman, Leonard; Douglas, Susan; Hoagwood, Kimberly

2015-01-01

Measurement feedback systems (MFSs) have been proposed as a means of improving practice. The present study examined the implementation of a MFS, the Contextualized Feedback System (CFS), in two community-based clinic sites. Significant implementation differences across sites provided a basis for examining factors that influenced clinician uptake of CFS. Following the theoretical implementation framework of Aarons, Hurlburt & Horwitz (2011), we coded qualitative data collected from eighteen clinicians (13 from Clinic U and 5 from Clinic R) who participated in semi-structured interviews about their experience with CFS implementation. Results suggest that clinicians at both clinics perceived more barriers than facilitators to CFS implementation. Interestingly, clinicians at the higher implementing clinic reported a higher proportion of barriers to facilitators (3:1 vs. 2:1); however, these clinicians also reported a significantly higher level of organizational and leadership supports for CFS implementation. Implications of these findings are discussed. PMID:25735619

Vacuum chamber with a supersonic-flow aerodynamic window

DOEpatents

Hanson, C.L.

1980-10-14

A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

Harnessing Technology and Citizen Science to Support Neighborhoods that Promote Active Living in Mexico.

PubMed

Rosas, Lisa G; Salvo, Deborah; Winter, Sandra J; Cortes, David; Rivera, Juan; Rodriguez, Nicole M; King, Abby C

2016-12-01

Middle- and low-income countries bear 80 % of the global chronic disease burden. Population-level, multi-sectoral approaches to promoting healthful lifestyles that take into local physical, socioeconomic, and sociocultural characteristics of both the environment and the population are needed. The "Nuestra Voz (Our Voice)" is one such approach that involves neighborhood residents acting as "citizen scientists" to systematically gather information on the barriers and facilitators of physical activity in their neighborhoods and then use their data to collectively advocate for local environmental- and policy-level changes to support active living. We pilot tested this approach in Cuernavaca, Mexico with adults and adolescents. This community-engaged and participatory approach is driven by residents, who utilize a GPS-enabled electronic tablet-based application with simple audio-based instructions to take photographs and record audio narratives of facets of their neighborhood that promote or hinder active living. After collecting these data, the citizen scientists come together in a community meeting and use their data to prioritize realistic, multi-level changes for promoting active living in their neighborhoods. A survey assessed participants' acceptability of the approach. Participating citizen scientists included 32 adults and 9 adolescents. The citizen scientists rated the acceptability of five of the nine acceptability survey items with an average of 4.0 or higher out of 5.0, indicating they thought it was "fun," were comfortable carrying the tablet, were likely to use it again, and would recommend it to friends and family. Items with average scores of less than 4 were all related to safety concerns. The most common barriers reported by citizen scientists using the tablet were poor sidewalk quality, presence of trash, negative characteristics of the streets, unpleasant aesthetics (e.g., graffiti), and presence of parks and recreational facilities. The Our Voice citizen scientist approach using the Discovery Tool has high potential for assisting communities in diverse settings to begin to identify both local barriers to active living as well as potentially useful strategies for promoting physical activity in culturally congruent ways that are appropriate and feasible in the local context.

Survey nonresponse among ethnic minorities in a national health survey--a mixed-method study of participation, barriers, and potentials.

PubMed

Ahlmark, Nanna; Algren, Maria Holst; Holmberg, Teresa; Norredam, Marie Louise; Nielsen, Signe Smith; Blom, Astrid Benedikte; Bo, Anne; Juel, Knud

2015-01-01

The participation rate in the Danish National Health Survey (DNHS) 2010 was significantly lower among ethnic minorities than ethnic Danes. The purpose was to characterize nonresponse among ethnic minorities in DNHS, analyze variations in item nonresponse, and investigate barriers and incentives to participation. This was a mixed-method study. Logistic regression was used to analyze nonresponse using data from DNHS (N = 177,639 and chi-square tests in item nonresponse analyses. We explored barriers and incentives regarding participation through focus groups and cognitive interviews. Informants included immigrants and their descendants of both sexes, with and without higher education. The highest nonresponse rate was for non-Western descendants (80.0%) and immigrants 25 (72.3%) with basic education. Immigrants and descendants had higher odds ratios (OR = 3.07 and OR = 3.35, respectively) for nonresponse than ethnic Danes when adjusted for sex, age, marital status, and education. Non-Western immigrants had higher item nonresponse in several question categories. Barriers to non-participation related to the content, language, format, and layout of both the questionnaire and the cover letter. The sender and setting in which to receive the questionnaire also influenced answering incentives. We observed differences in barriers and incentives between immigrants and descendants. Nonresponse appears related to linguistic and/or educational limitations, to alienation generated by the questions' focus on disease and cultural assumptions, or mistrust regarding anonymity. Ethnic minorities seem particularly affected by such barriers. To increase survey participation, questions could be sensitized to reflect multicultural traditions, and the impact of sender and setting considered.

Solvent effects in acid-catalyzed dehydration of the Diels-Alder cycloadduct between 2,5-dimethylfuran and maleic anhydride

NASA Astrophysics Data System (ADS)

Salavati-fard, Taha; Caratzoulas, Stavros; Doren, Douglas J.

2017-03-01

Dehydration of the cycloadduct produced from the Diels-Alder reaction between 2,5-dimethylfuran and maleic anhydride to 3,6-dimethylphthalic anhydride exemplifies an important step in producing platform chemicals from biomass. The mechanisms of dehydration and catalytic effects of Lewis and Brønsted acids are investigated with density functional theory. The uncatalyzed reaction has a very high activation barrier (68.7 kcal/mol) in the gas phase and it is not significantly affected by solvation. With a Lewis acid catalyst, modeled as an alkali ion, the activation barriers are reduced, but intermediates are also stabilized. The net effect in vacuum is that the energetic span, or apparent activation energy of the catalytic cycle, is 77.9 kcal/mol, even higher than the barrier in the uncatalyzed case. In solution, however, the energetic span is reduced by as much as 20 kcal/mol, due to differences in the solvation energy of the transition states and intermediates. In the case of a Brønsted acid catalyst, modeled as a proton, the gas phase transition state energies are reduced even more than in the Lewis acid case, and there is no strong stabilization of the intermediates. The energetic span in vacuum is only 13.8 kcal/mol and is reduced even further in solution. Brønsted acid catalysis appears to be the preferred mechanism for dehydration of this cycloadduct. Since the Diels-Alder reaction that produced the molecule has previously been shown to be catalyzed by Brønsted acids, this suggests that a single catalyst could be used to accelerate both steps.

Association of Mediterranean diet and other health behaviours with barriers to healthy eating and perceived health among British adults of retirement age.

PubMed

Lara, Jose; McCrum, Leigh-Ann; Mathers, John C

2014-11-01

Health behaviours including diet, smoking, alcohol consumption, and physical activity, predict health risks at the population level. We explored health behaviours, barriers to healthy eating and self-rated health among individuals of retirement age. Study design 82 men and 124 women participated in an observational, cross-sectional online survey. Main outcome measures A 14-item Mediterranean diet score (MDPS), perceived barriers to healthy eating (PBHE), self-reported smoking, physical activity habits, and current and prior perceived health status (PHS) were assessed. A health behaviours score (HBS) including smoking, physical activity, body mass index (BMI) and MDPS was created to evaluate associations with PHS. Two-step cluster analysis identified natural groups based on PBHE. Analysis of variance was used to evaluate between group comparisons. PBHE number was associated with BMI (r=0.28, P<0.001), age (r=-0.19; P=0.006), and MDPS (r=-0.31; P<0.001). PHBE cluster analysis produced three clusters. Cluster-1 members (busy lifestyle) were significantly younger (57 years), more overweight (28kg/m(2)), scored lower on MDPS (4.7) and reported more PBHE (7). Cluster-3 members (no characteristic PBHE) were leaner (25kg/m(2)), reported the lowest number of PBHE (2), and scored higher on HBS (2.7) and MDPS (6.2). Those in PHS categories, bad/fair, good, and very good, reported mean HBS of 2.0, 2.4 and 3.0, respectively (P<0.001). Compared with the previous year, no significant associations between PHS and HBS were observed. PBHE clusters were associated with BMI, MDPS and PHS and could be a useful tool to tailor interventions for those of peri-retirement age. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Combining Photovoice and focus groups: engaging Latina teens in community assessment.

PubMed

Hannay, Jayme; Dudley, Robert; Milan, Stephanie; Leibovitz, Paula K

2013-03-01

Latino adolescents, especially girls, experience higher obesity rates and are more likely to be physically unfit than non-Latino white peers. Out-of-school programs to increase physical activity and fitness in older Latino teens are critical, but sustained engagement is challenging. This study combined a community-based participatory research methodology, Photovoice, with focus groups to engage Latina teens and their parents in identifying barriers to physical activity and initiating policy change actions to address them. The study investigates the effectiveness of applying Photovoice as both an evaluation tool and a leadership/advocacy intervention in a community-based obesity prevention program. Focus group data were collected between July 2009 and October 2010 and analyzed between November 2010 and July 2011. Five focus groups were held with adults (n = 41: 95% Latino) and four with teens (n = 36: 81% Latino, 10% non-Hispanic white, 9% African-American). All participants (19 teens, six adults) were Latino. Spanish-speaking staff of a community-based agency, program staff, high school guidance counselors, and a job development agency recruited participants. Teens aged 14-19 years enrolled in New Britain CT, high schools, and their parents were eligible. Data from Photovoice workshops (three with teens, two with parent-teen dyads) were collected and concurrently analyzed between July 2009 and August 2011. Teens criticized school-based physical exercise programs in favor of out-of-school exercise and career advice. Parental restrictions and work, transportation, and safety issues were cited as barriers to afterschool physical activity programs. Photovoice can empower teens and parents to address exercise barriers by promoting advocacy that leads to policy change (e.g., an out-of-school physical education option). Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Do perceived cues, benefits, and barriers to physical activity differ between male and female adolescents?

PubMed

Tergerson, Jennifer L; King, Keith A

2002-11-01

A four-page survey was administered to 535 adolescents at two single-sex (one male, one female) high schools in Cincinnati, Ohio, to examine whether perceptions of physical activity differed by gender. More specifically, the survey assessed perceived cues, benefits, and barriers to exercising. Results indicated that the most helpful cue to physical activity for both female and male students was "having a friend to exercise with." The most commonly reported benefit of exercising among females was "to stay in shape," whereas the most commonly reported benefit to exercising among males was "to become strong." Among females, the most common barrier to exercising was "having no time to exercise," whereas males were most likely to report "wanting to do other things with my time." Multivariate analyses of covariance revealed that perceived cues, benefits, and barriers to physical activity differed significantly based on gender. Recommendations on specific strategies to increasing male and female adolescent physical activity levels are offered.

Chromatin insulator elements: establishing barriers to set heterochromatin boundaries.

PubMed

Barkess, Gráinne; West, Adam G

2012-02-01

Epigenomic profiling has revealed that substantial portions of genomes in higher eukaryotes are organized into extensive domains of transcriptionally repressive chromatin. The boundaries of repressive chromatin domains can be fixed by DNA elements known as barrier insulators, to both shield neighboring gene expression and to maintain the integrity of chromosomal silencing. Here, we examine the current progress in identifying vertebrate barrier elements and their binding factors. We overview the design of the reporter assays used to define enhancer-blocking and barrier insulators. We look at the mechanisms vertebrate barrier proteins, such as USF1 and VEZF1, employ to counteract Polycomb- and heterochromatin-associated repression. We also undertake a critical analysis of whether CTCF could also act as a barrier protein. There is good evidence that barrier elements in vertebrates can form repressive chromatin domain boundaries. Future studies will determine whether barriers are frequently used to define repressive domain boundaries in vertebrates.

Mobile Exercise Apps and Increased Leisure Time Exercise Activity: A Moderated Mediation Analysis of the Role of Self-Efficacy and Barriers

PubMed Central

Rosen, Zohn; Spierer, David; Weinberger-Litman, Sarah; Goldschein, Akiva; Robinson, Jonathan

2015-01-01

Background There are currently over 1000 exercise apps for mobile devices on the market. These apps employ a range of features, from tracking exercise activity to providing motivational messages. However, virtually nothing is known about whether exercise apps improve exercise levels and health outcomes and, if so, the mechanisms of these effects. Objective Our aim was to examine whether the use of exercise apps is associated with increased levels of exercise and improved health outcomes. We also develop a framework within which to understand how exercise apps may affect health and test multiple models of possible mechanisms of action and boundary conditions of these relationships. Within this framework, app use may increase physical activity by influencing variables such as self-efficacy and may help to overcome exercise barriers, leading to improved health outcomes such as lower body mass index (BMI). Methods In this study, 726 participants with one of three backgrounds were surveyed about their use of exercise apps and health: (1) those who never used exercise apps, (2) those who used exercise apps but discontinued use, and (3) those who are currently using exercise apps. Participants were asked about their long-term levels of exercise and about their levels of exercise during the previous week with the International Physical Activity Questionnaire (IPAQ). Results Nearly three-quarters of current app users reported being more active compared to under half of non-users and past users. The IPAQ showed that current users had higher total leisure time metabolic equivalent of task (MET) expenditures (1169 METs), including walking and vigorous exercise, compared to those who stopped using their apps (612 METs) or who never used apps (577 METs). Importantly, physical activity levels in domains other than leisure time activity were similar across the groups. The results also showed that current users had lower BMI (25.16) than past users (26.8) and non-users (26.9) and that this association was mediated by exercise levels and self-efficacy. That relationship was also moderated by perceived barriers to exercise. Multiple serial mediation models were tested, which revealed that the association between app use and BMI is mediated by increased self-efficacy and increased exercise. Conclusions Exercise app users are more likely to exercise during their leisure time, compared to those who do not use exercise apps, essentially fulfilling the role that many of these apps were designed to accomplish. Data also suggest that one way that exercise apps may increase exercise levels and health outcomes such as BMI is by making it easier for users to overcome barriers to exercise, leading to increased self-efficacy. We discuss ways of improving the effectiveness of apps by incorporating theory-driven approaches. We conclude that exercise apps can be viewed as intervention delivery systems consisting of features that help users overcome specific barriers. PMID:26276227

Mobile Exercise Apps and Increased Leisure Time Exercise Activity: A Moderated Mediation Analysis of the Role of Self-Efficacy and Barriers.

PubMed

Litman, Leib; Rosen, Zohn; Spierer, David; Weinberger-Litman, Sarah; Goldschein, Akiva; Robinson, Jonathan

2015-08-14

There are currently over 1000 exercise apps for mobile devices on the market. These apps employ a range of features, from tracking exercise activity to providing motivational messages. However, virtually nothing is known about whether exercise apps improve exercise levels and health outcomes and, if so, the mechanisms of these effects. Our aim was to examine whether the use of exercise apps is associated with increased levels of exercise and improved health outcomes. We also develop a framework within which to understand how exercise apps may affect health and test multiple models of possible mechanisms of action and boundary conditions of these relationships. Within this framework, app use may increase physical activity by influencing variables such as self-efficacy and may help to overcome exercise barriers, leading to improved health outcomes such as lower body mass index (BMI). In this study, 726 participants with one of three backgrounds were surveyed about their use of exercise apps and health: (1) those who never used exercise apps, (2) those who used exercise apps but discontinued use, and (3) those who are currently using exercise apps. Participants were asked about their long-term levels of exercise and about their levels of exercise during the previous week with the International Physical Activity Questionnaire (IPAQ). Nearly three-quarters of current app users reported being more active compared to under half of non-users and past users. The IPAQ showed that current users had higher total leisure time metabolic equivalent of task (MET) expenditures (1169 METs), including walking and vigorous exercise, compared to those who stopped using their apps (612 METs) or who never used apps (577 METs). Importantly, physical activity levels in domains other than leisure time activity were similar across the groups. The results also showed that current users had lower BMI (25.16) than past users (26.8) and non-users (26.9) and that this association was mediated by exercise levels and self-efficacy. That relationship was also moderated by perceived barriers to exercise. Multiple serial mediation models were tested, which revealed that the association between app use and BMI is mediated by increased self-efficacy and increased exercise. Exercise app users are more likely to exercise during their leisure time, compared to those who do not use exercise apps, essentially fulfilling the role that many of these apps were designed to accomplish. Data also suggest that one way that exercise apps may increase exercise levels and health outcomes such as BMI is by making it easier for users to overcome barriers to exercise, leading to increased self-efficacy. We discuss ways of improving the effectiveness of apps by incorporating theory-driven approaches. We conclude that exercise apps can be viewed as intervention delivery systems consisting of features that help users overcome specific barriers.

Hole transport in pure and doped hematite

NASA Astrophysics Data System (ADS)

Liao, Peilin; Carter, Emily A.

2012-07-01

Hematite (α-Fe2O3) is a promising candidate for use in photovoltaic (PV) and photoelectrochemical devices. Its poor conductivity is one major drawback. Doping hematite either p-type or n-type greatly enhances its measured conductivity and is required for potential p-n junctions in PVs. Here, we study hole transport in pure and doped hematite using an electrostatically embedded cluster model with ab initio quantum mechanics (unrestricted Hartree-Fock theory). Consistent with previous work, the model suggests that hole hopping is via oxygen anions for pure hematite. The activation energy for hole mobility is predicted to be at least 0.1 eV higher than the activation energy for electron mobility, consistent with the trend observed in experiments. We examine four dopants—magnesium(II), nickel(II), copper(II), and manganese(II/III) in direct cation substitution sites—to gain insight into the mechanism by which conductivity is improved. The activation energies are used to assess qualitative effects of different dopants. The hole carriers are predicted to be attracted to O anions near the dopants. The magnitude of the trapping effect is similar among the four dopants in their +2 oxidation states. The multivalent character of Mn doping facilitates local hole transport around Mn centers via a low-barrier O-Mn-O pathway, which suggests that higher hole mobility can be achieved with increasing Mn doping concentration, especially when a network of these low-barrier pathways is produced. Our results suggest that the experimentally observed conductivity increase in Mg-, Ni-, and Cu-doped p-type hematite is mostly due to an increase in hole carriers rather than improved mobility, and that Mg-, Ni-, and Cu-doping perform similarly, while the conductivity of Mn-doped hematite might be significantly improved in the high doping concentration limit.

Health profile of deaf Canadians

PubMed Central

Woodcock, Kathryn; Pole, Jason D.

2007-01-01

OBJECTIVE To profile the health of deaf and hard-of-hearing Canadians inrelation to the population as a whole. DESIGN Using data from the Canada Community Health Survey 1.1, across-sectional survey conducted by Statistics Canada with a total of 131 535 respondents, a series of logistic regression models was fitted to estimate the odds, compared with the general population, of respondents classified as having hearing problems reporting the presence of various chronic health outcomes; of their utilizing the health care system; of their engaging in certain health promotion activities; and of their reporting certain perceptions about their overall health. For each odds ratio, 95% confidence intervals are provided. All analyses were adjusted for age and sex with some analyses being restricted to appropriate age ranges or having further adjustments made, depending on the outcomes. MAIN OUTCOME MEASURES In addition to indications of deafness or hearing loss, this study examined health care utilization, several commonly accepted health outcomes, engagement in health promotion activities, and perceptions of overall health. RESULTS Approximately 4% of respondents in the cross-sectional survey were considered to have hearing problems. The prevalence of hearing problems increased withage, with males having a slightly higher prevalence of hearing problems compared with females (4.52% versus 3.53%). Respondents classified as having hearing problems, whether hearing loss or deafness, were more likely to report adverse health conditions and low levels of physical activity, and to experience higher rates of depression. Respondents classified as having hearing problems were not more likely to smoke or to drink excessively. CONCLUSION Communication is essential to both health promotion and health care delivery. Deafness—both the disability and the culture—creates barriers to communication. Individual practitioners can and should consider the communication needs of individual patients with hearing loss or deafness to avoid barriers to optimal health. PMID:18077753

Uroplakins do not restrict CO2 transport through urothelium.

PubMed

Zocher, Florian; Zeidel, Mark L; Missner, Andreas; Sun, Tung-Tien; Zhou, Ge; Liao, Yi; von Bodungen, Maximilian; Hill, Warren G; Meyers, Susan; Pohl, Peter; Mathai, John C

2012-03-30

Lipid bilayers and biological membranes are freely permeable to CO(2), and yet partial CO(2) pressure in the urine is 3-4-fold higher than in blood. We hypothesized that the responsible permeability barrier to CO(2) resides in the umbrella cell apical membrane of the bladder with its dense array of uroplakin complexes. We found that disrupting the uroplakin layer of the urothelium resulted in water and urea permeabilities (P) that were 7- to 8-fold higher than in wild type mice with intact urothelium. However, these interventions had no impact on bladder P(CO2) (∼1.6 × 10(-4) cm/s). To test whether the observed permeability barrier to CO(2) was due to an unstirred layer effect or due to kinetics of CO(2) hydration, we first measured the carbonic anhydrase (CA) activity of the bladder epithelium. Finding none, we reduced the experimental system to an epithelial monolayer, Madin-Darby canine kidney cells. With CA present inside and outside the cells, we showed that P(CO2) was unstirred layer limited (∼7 × 10(-3) cm/s). However, in the total absence of CA activity P(CO2) decreased 14-fold (∼ 5.1 × 10(-4) cm/s), indicating that now CO(2) transport is limited by the kinetics of CO(2) hydration. Expression of aquaporin-1 did not alter P(CO2) (and thus the limiting transport step), which confirmed the conclusion that in the urinary bladder, low P(CO2) is due to the lack of CA. The observed dependence of P(CO2) on CA activity suggests that the tightness of biological membranes to CO(2) may uniquely be regulated via CA expression.

An Activity Theory Approach to Analyze Barriers to a Virtual Management Information Systems (MIS) Curriculum

ERIC Educational Resources Information Center

Jaradat, Suhair; Qablan, Ahmad; Barham, Areej

2011-01-01

This paper explains how the activity theory is used as a framework to analyze the barriers to a virtual Management Information Stream (MIS) Curriculum in Jordanian schools, from both the sociocultural and pedagogical perspectives. Taking the activity system as a unit of analysis, this study documents the processes by which activities shape and are…

Male Adolescents' Reasons for Participating in Physical Activity, Barriers to Participation, and Suggestions for Increasing Participation

ERIC Educational Resources Information Center

Allison, Kenneth R.; Dwyer, John J. M.; Goldenberg, Ellie; Fein, Allan; Yoshida, Karen K.; Boutilier, Marie

2005-01-01

This study explored male adolescents' reasons for participating in moderate and vigorous physical activity, perceived barriers to moderate and vigorous physical activity, and suggestions as to what can be done to increase participation in physical activity. A total of 26 male 15- and 16-year-old adolescents participated in focus group sessions,…

Self-Efficacy for Coping with Barriers Helps Students Stay Physically Active during Transition to Their First Year at a University

ERIC Educational Resources Information Center

Bray, Steven R.

2007-01-01

The present study examined undergraduate students' physical activity during transition from high school to first-year university. Students' (N = 127) self-efficacy for coping with barriers to physical activity was investigated both as a predictor of physical activity and mediator of the relationship between pretransition and first-year physical…

Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis by inhibiting the activation of nuclear factor-kappa B

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

Cheng, Jian; Zhang, Lin; Dai, Weiqi

Aim: This study aimed to investigate the effect and underlying mechanism of ghrelin on intestinal barrier dysfunction in dextran sulfate sodium (DSS)-induced colitis. Methods and results: Acute colitis was induced in C57BL/6J mice by administering 2.5% DSS. Saline or 25, 125, 250 μg/kg ghrelin was administrated intraperitoneally (IP) to mice 1 day before colitis induction and on days 4, 5, and 6 after DSS administration. IP injection of a ghrelin receptor antagonist, [D-lys{sup 3}]-GHRP-6, was performed immediately prior to ghrelin injection. Ghrelin (125 or 250 μg/kg) could reduce the disease activity index, histological score, and myeloperoxidase activities in experimental colitis, and alsomore » prevented shortening of the colon. Ghrelin could prevent the reduction of transepithelial electrical resistance and tight junction expression, and bolstered tight junction structural integrity and regulated cytokine secretion. Ultimately, ghrelin inhibited nuclear factor kappa B (NF-κB), inhibitory κB-α, myosin light chain kinase, and phosphorylated myosin light chain 2 activation. Conclusions: Ghrelin prevented the breakdown of intestinal barrier function in DSS-induced colitis. The protective effects of ghrelin on intestinal barrier function were mediated by its receptor GHSR-1a. The inhibition of NF-κB activation might be part of the mechanism underlying the effects of ghrelin that protect against barrier dysfunction. - Highlights: • Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis. • The effect of ghrelin is mediated by GHSR-1a. • Inhibition of NF-κB activation.« less

[Employees with mental illness - possibilities and barriers in professional activity].

PubMed

Cybula-Fujiwara, Anna; Merecz-Kot, Dorota; Walusiak-Skorupa, Jolanta; Marcinkiewicz, Andrzej; Wiszniewska, Marta

2015-01-01

In Poland patients with psychiatric problems form a large group; in 2010 there were almost 1.5 million people for whom outpatient psychiatric care was provided, whereas approximately 200 thousand ill individuals were treated in 24-h psychiatric wards. Only 17% of the mentally disabled are professionally active. The results of many researches show that despite the detrimental influence of mental disorders on the employment (e.g., lower productivity, absenteeism, presenteism, increased risk of accidents at the workplace), professional activity can play a key role in the7stabilization of the mental state, it can also help in disease recovery. People with mental disorders are a social group that is at the higher risk of exclusion from the job market. The opinion prevailing among employers is that mentally ill individuals have decreased ability to conduct professional activity, and social attitudes towards them tend to be based on marking and stigmatizing. This review tackles the advantages of working during the illness, barriers which people with mental disorders face on the job market when they want to either start or continue work, and professional functioning of people with diagnosed depression (e.g., affective disorders) and schizophrenia (representing psychotic disorders). The analysis of existing data show that to improve the situation of mentally ill people present on the job market close cooperation between the representatives of various medical specializations is necessary, as well as their active participation in the process of social and professional rehabilitation of people affected by mental disorders.

Finnish Dentists Find Smoking Cessation Important but Seldom Offer Practical Support for Their Patients.

PubMed

Grönholm, A; Litkey, D; Jokelainen, J; Keto, J; Pöyry, M; Linden, K; Heikkinen, A M

2017-12-01

To investigate Finnish dentists' smoking cessation related attitudes, consultation practices and familiarity with the local treatment guideline on smoking cessation. An online questionnaire was sent to 1740 dentists, which corresponds to 39% of dentists in Finland. A total of 456 dentists responded (response rate 26%), of whom 435 (95%) were clinicians. The dentists' smoking cessation practices were also compared to ones reported in a previous study in Finnish physicians. Dentists found smoking cessation important and often discussed and recommended quitting to the patients, but concrete withdrawal actions were seldom provided. The local treatment guideline on smoking cessation was actively utilized by 36% of the dentists. Adherence to the guideline was associated with higher rates of smoking cessation activities and success in them. Smoking cessation activity among dentists was significantly lower than in Finnish physicians. In accordance with the literature, among dentists, the most common barriers for smoking cessation were lack of time (44%) and education (42%). Although smoking cessation is discussed with patients, dentists are less active in taking concrete actions to support the patient on withdrawal. Adherence to the local treatment guideline was associated with better capabilities in dealing with tobacco withdrawal and a more active role in smoking cessation. The results suggest that more education on the local smoking cessation treatment guideline and cessation intervention is needed in order to overcome the remaining barriers to promoting effective smoking cessation in dental practice. Copyright© 2017 Dennis Barber Ltd.

Controlling the hydration of the skin though the application of occluding barrier creams

PubMed Central

Sparr, Emma; Millecamps, Danielle; Isoir, Muriel; Burnier, Véronique; Larsson, Åsa; Cabane, Bernard

2013-01-01

The skin is a barrier membrane that separates environments with profoundly different water contents. The barrier properties are assured by the outer layer of the skin, the stratum corneum (SC), which controls the transepidermal water loss. The SC acts as a responding membrane, since its hydration and permeability vary with the boundary condition, which is the activity of water at the outer surface of the skin. We show how this boundary condition can be changed by the application of a barrier cream that makes a film with a high resistance to the transport of water. We present a quantitative model that predicts hydration and water transport in SC that is covered by such a film. We also develop an experimental method for measuring the specific resistance to water transport of films made of occluding barrier creams. Finally, we combine the theoretical model with the measured properties of the barrier creams to predict how a film of cream changes the activity of water at the outer surface of the SC. Using the known variations of SC permeability and hydration with the water activity in its environment (i.e. the relative humidity), we can thus predict how a film of barrier cream changes SC hydration. PMID:23269846

Controlling the hydration of the skin though the application of occluding barrier creams.

PubMed

Sparr, Emma; Millecamps, Danielle; Isoir, Muriel; Burnier, Véronique; Larsson, Åsa; Cabane, Bernard

2013-03-06

The skin is a barrier membrane that separates environments with profoundly different water contents. The barrier properties are assured by the outer layer of the skin, the stratum corneum (SC), which controls the transepidermal water loss. The SC acts as a responding membrane, since its hydration and permeability vary with the boundary condition, which is the activity of water at the outer surface of the skin. We show how this boundary condition can be changed by the application of a barrier cream that makes a film with a high resistance to the transport of water. We present a quantitative model that predicts hydration and water transport in SC that is covered by such a film. We also develop an experimental method for measuring the specific resistance to water transport of films made of occluding barrier creams. Finally, we combine the theoretical model with the measured properties of the barrier creams to predict how a film of cream changes the activity of water at the outer surface of the SC. Using the known variations of SC permeability and hydration with the water activity in its environment (i.e. the relative humidity), we can thus predict how a film of barrier cream changes SC hydration.

Optical properties of thin gold films applied to Schottky barrier solar cells

NASA Technical Reports Server (NTRS)

YEH Y. M.

1974-01-01

The Schottky barrier solar cell is considered a possible candidate for converting solar to electrical energy both for space and terrestrial applications. Knowledge of the optical constants of the ultrathin metal film used in the cell is essential for analyzing and designing higher efficiency Schottky barrier cells. The optical constants of 7.5 -nm (75-A) gold films on gallium arsenide have been obtained. In addition, the absolute collection efficiency of Schottky barrier solar cells has been determined from measured spectral response and optical constants of the gold film.

Physical Activity Correlates in Middle School Adolescents: Perceived Benefits and Barriers and Their Determinants.

PubMed

Roth, Sarah E; Gill, Monique; Chan-Golston, Alec M; Rice, Lindsay N; Crespi, Catherine M; Koniak-Griffin, Deborah; Cole, Brian L; Upchurch, Dawn M; Prelip, Michael L

2018-01-01

The purpose of this study was to examine the determinants of benefits and barriers and their relationship with physical activity (PA) among predominantly Latino middle school students. Data were collected in a cross-sectional survey of 4,773 seventh-grade students recruited from a large, urban school district in Los Angeles. Hierarchical logistic regression models were used to assess determinants of benefits and barriers as well as their association with self-reported PA. Differences in benefits and barriers were observed by gender, ethnicity, and body size. Barriers were negatively correlated with all three PA outcomes while benefits were positively associated with exercising at least 60 min daily. A deeper understanding of benefits and barriers can facilitate the development of interventions and collaborative efforts among physical education teachers, school nurses, and administrators to implement comprehensive approaches that encourage students' participation in PA inside and outside of the classroom.

Diffusion and Stability of Hydrogen in Mg-Doped GaN: A Density Functional Study

NASA Astrophysics Data System (ADS)

Park, Ji-Sang; Chang, Kee Joo

2012-06-01

Using hybrid functional calculations, we study the diffusion and thermal stability of hydrogen in Mg-doped GaN. Compared with the generalized gradient approximation, we obtain a higher activation barrier for dissociating a Mg-H complex, which is attributed to the increase in the binding energy of Mg-H. Kinetic Monte Carlo simulations yield the annealing temperature of around 800 °C for activating Mg acceptors, close to the measured values. The results provide an insight to understanding the annealing effect such that the annealing temperature generally increases with the Mg-H concentration, and the retrapping of H is partly responsible for the low doping efficiencies at high Mg concentrations.

Toll pathway is required for wound-induced expression of barrier repair genes in the Drosophila epidermis

PubMed Central

Capilla, Amalia; Karachentsev, Dmitry; Patterson, Rachel A.; Hermann, Anita; Juarez, Michelle T.; McGinnis, William

2017-01-01

The epidermis serves as a protective barrier in animals. After epidermal injury, barrier repair requires activation of many wound response genes in epidermal cells surrounding wound sites. Two such genes in Drosophila encode the enzymes dopa decarboxylase (Ddc) and tyrosine hydroxylase (ple). In this paper we explore the involvement of the Toll/NF-κB pathway in the localized activation of wound repair genes around epidermal breaks. Robust activation of wound-induced transcription from ple and Ddc requires Toll pathway components ranging from the extracellular ligand Spätzle to the Dif transcription factor. Epistasis experiments indicate a requirement for Spätzle ligand downstream of hydrogen peroxide and protease function, both of which are known activators of wound-induced transcription. The localized activation of Toll a few cell diameters from wound edges is reminiscent of local activation of Toll in early embryonic ventral hypoderm, consistent with the hypothesis that the dorsal–ventral patterning function of Toll arose from the evolutionary cooption of a morphogen-responsive function in wound repair. Furthermore, the combinatorial activity of Toll and other signaling pathways in activating epidermal barrier repair genes can help explain why developmental activation of the Toll, ERK, or JNK pathways alone fail to activate wound repair loci. PMID:28289197

Bioassay evaluation of residual activity of attractive toxic sugar-treated barrier fence in the control of Phlebotomus papatasi (Diptera: Psychodidae).

PubMed

Saghafipour, Abedin; Vatandoost, Hassan; Zahraei-Ramazani, Ali Reza; Yaghoobi-Ershadi, Mohammad Reza; Rassi, Yavar; Shirzadi, Mohammad Reza; Akhavan, Amir Ahmad

2016-01-01

Phlebotomus papatasi is the main vector of the zoonotic cutaneous leishmaniasis (ZCL) in Qom Province and many other provinces of Iran. Attractive toxic sugar baits (ATSB) treated barrier fence is one of the new methods for controlling the vectors such as sandflies. The present study was designed to evaluate the residual activity of ATSB-treated barrier fence that was used in control of P. papatasi. Following the selection of villages in Markazi district of Qom Province, central Iran during 2015 for ATSB and ASB (bait containing no active ingredient) methods; barrier fences on the ground in front of the rodent's colony were installed. A total of four conical tubes were installed and fixed on surfaces of treated barrier net of dimension 25 Χ 25 cm at biweekly interval. In each conical tube, 10 sand flies were released and after 3 min of exposure they were transferred to sterile cups. After 24 h, the obtained results were recorded according to the survival and mortality rate of sandflies. These tests were carried out five days after the installation of barrier fences, and repeated every 15 days until the mortality rate decreased to 60-65%. The bioassay tests results showed that the mortality rate of P. papatasi on ATSB-treated barrier fence for 5, 15, 30 and 45 days after spraying was 100, 95.83, 88.18 and 66.67% respectively, which decreased to 50.83% after 60 days. Persistence and residual activity of the active ingredient of the bait in the hot and dry climatic conditions of Qom Province remained significantly effective for at most 45 days, which subsequently decreased at a high rate. Hence, every 45 days barrier fences need to be impregnated with ATSB bait. The method also appeared cost-effective and could be practical in implementation of vector control programmes against ZCL.

Edge-induced Schottky barrier modulation at metal contacts to exfoliated molybdenum disulfide flakes

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

Nouchi, Ryo, E-mail: r-nouchi@21c.osakafu-u.ac.jp

2016-08-14

Ultrathin two-dimensional semiconductors obtained from layered transition-metal dichalcogenides such as molybdenum disulfide (MoS{sub 2}) are promising for ultimately scaled transistors beyond Si. Although the shortening of the semiconductor channel is widely studied, the narrowing of the channel, which should also be important for scaling down the transistor, has been examined to a lesser degree thus far. In this study, the impact of narrowing on mechanically exfoliated MoS{sub 2} flakes was investigated according to the channel-width-dependent Schottky barrier heights at Cr/Au contacts. Narrower channels were found to possess a higher Schottky barrier height, which is ascribed to the edge-induced band bendingmore » in MoS{sub 2}. The higher barrier heights degrade the transistor performance as a higher electrode-contact resistance. Theoretical analyses based on Poisson's equation showed that the edge-induced effect can be alleviated by a high dopant impurity concentration, but this strategy should be limited to channel widths of roughly 0.7 μm because of the impurity-induced charge-carrier mobility degradation. Therefore, proper termination of the dangling bonds at the edges should be necessary for aggressive scaling with layered semiconductors.« less

Structural Shielding Design of a 6 MV Flattening Filter Free Linear Accelerator: Indian Scenario.

PubMed

Mishra, Bibekananda; Selvam, T Palani; Sharma, P K Dash

2017-01-01

Detailed structural shielding of primary and secondary barriers for a 6 MV medical linear accelerator (LINAC) operated with flattening filter (FF) and flattening filter free (FFF) modes are calculated. The calculations have been carried out by two methods, one using the approach given in National Council on Radiation Protection (NCRP) Report No. 151 and the other based on the monitor units (MUs) delivered in clinical practice. Radiation survey of the installations was also carried out. NCRP approach suggests that the primary and secondary barrier thicknesses are higher by 24% and 26%. respectively, for a LINAC operated in FF mode to that of a LINAC operated in both FF and FFF modes with an assumption that only 20% of the workload is shared in FFF mode. Primary and secondary barrier thicknesses calculated from MUs delivered on clinical practice method also show the same trend and are higher by 20% and 19%, respectively, for a LINAC operated in FF mode to that of a LINAC operated in both FF and FFF modes. Overall, the barrier thickness for a LINAC operated in FF mode is higher about 20% to that of a LINAC operated in both FF and FFF modes.

Structural Shielding Design of a 6 MV Flattening Filter Free Linear Accelerator: Indian Scenario

PubMed Central

Mishra, Bibekananda; Selvam, T. Palani; Sharma, P. K. Dash

2017-01-01

Detailed structural shielding of primary and secondary barriers for a 6 MV medical linear accelerator (LINAC) operated with flattening filter (FF) and flattening filter free (FFF) modes are calculated. The calculations have been carried out by two methods, one using the approach given in National Council on Radiation Protection (NCRP) Report No. 151 and the other based on the monitor units (MUs) delivered in clinical practice. Radiation survey of the installations was also carried out. NCRP approach suggests that the primary and secondary barrier thicknesses are higher by 24% and 26%. respectively, for a LINAC operated in FF mode to that of a LINAC operated in both FF and FFF modes with an assumption that only 20% of the workload is shared in FFF mode. Primary and secondary barrier thicknesses calculated from MUs delivered on clinical practice method also show the same trend and are higher by 20% and 19%, respectively, for a LINAC operated in FF mode to that of a LINAC operated in both FF and FFF modes. Overall, the barrier thickness for a LINAC operated in FF mode is higher about 20% to that of a LINAC operated in both FF and FFF modes. PMID:28405104

Potential Healthcare Insurance and Provider Barriers to Pre-Exposure Prophylaxis Utilization Among Young Men Who Have Sex with Men.

PubMed

Marks, Sarah J; Merchant, Roland C; Clark, Melissa A; Liu, Tao; Rosenberger, Joshua G; Bauermeister, Jose; Mayer, Kenneth H

2017-11-01

Young adult men-who-have-sex-with-men (YMSM) continue to have among the highest incidence of HIV infection in the United States. Pre-exposure prophylaxis (PrEP) is an effective and safe method of preventing HIV infection; however, despite US Food and Drug Administration approval, utilization remains low, in part, due to structural barriers, particularly access to healthcare. In this study, we used social media to recruit black, Hispanic, and white HIV-uninfected 18- to 24-year-old YMSM. Participants completed an online survey about their sexual behavior, healthcare access, and previous use of PrEP. Of the 2297 YMSM surveyed, only 3.4% had used PrEP. PrEP use was associated with higher levels of education, living alone, older age, higher levels of sexual activity, and greater healthcare access, specifically having healthcare insurance and a clinic or primary care provider (PCP) from whom they received care. Among PrEP nonusers, 65% met at least one of the US Centers for Disease Control and Prevention recommended indications for PrEP use, and of these, 59% had healthcare insurance and received care in a clinic and/or had a PCP. Multi-variable multi-nomial logistic regression modeling identified disparities in access to healthcare by age, race/ethnicity, education, and region. Specifically, older YMSM, blacks and Hispanics, those with fewer years of formal education, and residents of the southern and the western United States were more likely to lack healthcare access. These results demonstrate both potential opportunities and barriers to the scale-up of PrEP among YMSM.

Barrier inhomogeneities limited current and 1/f noise transport in GaN based nanoscale Schottky barrier diodes

PubMed Central

Kumar, Ashutosh; Heilmann, M.; Latzel, Michael; Kapoor, Raman; Sharma, Intu; Göbelt, M.; Christiansen, Silke H.; Kumar, Vikram; Singh, Rajendra

2016-01-01

The electrical behaviour of Schottky barrier diodes realized on vertically standing individual GaN nanorods and array of nanorods is investigated. The Schottky diodes on individual nanorod show highest barrier height in comparison with large area diodes on nanorods array and epitaxial film which is in contrast with previously published work. The discrepancy between the electrical behaviour of nanoscale Schottky diodes and large area diodes is explained using cathodoluminescence measurements, surface potential analysis using Kelvin probe force microscopy and 1ow frequency noise measurements. The noise measurements on large area diodes on nanorods array and epitaxial film suggest the presence of barrier inhomogeneities at the metal/semiconductor interface which deviate the noise spectra from Lorentzian to 1/f type. These barrier inhomogeneities in large area diodes resulted in reduced barrier height whereas due to the limited role of barrier inhomogeneities in individual nanorod based Schottky diode, a higher barrier height is obtained. PMID:27282258

Role of Geologic Framework, Paleotopography, Sediment Supply, and Human Modification in the Evolutionary Development of the Northeastern North Carolina Barrier Island System

NASA Astrophysics Data System (ADS)

Riggs, S. R.; Thieler, E. R.; Mallinson, D. A.; Culver, S. J.; Corbett, D. R.; Hoffman, C. W.

2002-12-01

The NE North Carolina coastal system contains an exceptionally thick and well preserved Quaternary stratigraphic record that is the focus of a five-year Cooperative Coastal Geology Program between the USGS, several academic institutions, and state agencies. The major goal is to map this Quaternary section on the inner continental shelf, Outer Banks barrier islands, Albemarle-Pamlico estuarine system, and adjacent land areas. The program objectives are to define the geologic framework, develop the detailed evolutionary history, and understand the ongoing process dynamics driving this large, complex, and rapidly changing, high-energy coastal system. Preliminary data synthesis demonstrates that the major controls dictating the present health and future evolution of this coastal system include the following. 1) The regional late Pleistocene morphology constitutes the underlying geologic framework that the Holocene system has inherited. 2) The controlling paleotopography is a series of lowstand drainage basins consisting of trunk and tributary streams and associated interstream divides that are being drowned. 3) Three major sediment sources dictate the highly variable sand resources available to specific barrier segments and include riverine channel and deltaic deposits associated with lowstand trunk streams, the large cross-shelf cape shoal sand deposits, and sand-rich units occurring within the adjacent shoreface and inner-self strata. 4) Wherever large sand supplies have historically been available, the barrier segments occur as complex islands with large sand volumes producing high and wide barriers, whereas barrier segments without adequate sand supplies are sediment starved and occur as simple overwash barriers. 5) Human modification of the barrier islands over the past seven decades represents a major force that has significantly changed the barrier island dynamics and evolution. 6) The Albemarle Embayment appears to have a slightly higher rate of sea-level rise than adjacent regions due to a slow rate of regional subsidence. Consequently, if the ongoing pattern of storm activity and sea-level rise either continues or increases during the next few decades to centuries, several simple overwash barrier segments on the Outer Banks, that are currently disintegrating, will ultimately collapse into Pamlico Sound. These barrier segments will likely back-step across the open marine Pamlico Embayment and reform on the landward side. A few sand-rich complex barrier segments will persist as isolated, but perched and eroding islands for some longer period of time. In contrast, simple overwash barrier segments that have received minimal human modification and are associated with narrow and shallow back-barrier sounds, appear to be maintaining themselves in their upward and landward migration in response to ongoing storms and sea-level rise.

Hydrogen inhalation ameliorated mast cell-mediated brain injury after intracerebral hemorrhage in mice.

PubMed

Manaenko, Anatol; Lekic, Tim; Ma, Qingyi; Zhang, John H; Tang, Jiping

2013-05-01

Hydrogen inhalation was neuroprotective in several brain injury models. Its mechanisms are believed to be related to antioxidative stress. We investigated the potential neurovascular protective effect of hydrogen inhalation especially effect on mast cell activation in a mouse model of intracerebral hemorrhage. Controlled in vivo laboratory study. Animal research laboratory. One hundred seventy-one 8-week-old male CD-1 mice were used. Collagenase-induced intracerebral hemorrhage model in 8-week-old male CD-1 mice was used. Hydrogen was administrated via spontaneous inhalation. The blood-brain barrier permeability and neurologic deficits were investigated at 24 and 72 hours after intracerebral hemorrhage. Mast cell activation was evaluated by Western blot and immuno-staining. The effects of hydrogen inhalation on mast cell activation were confirmed in an autologous blood injection model intracerebral hemorrhage. At 24 and 72 hours post intracerebral hemorrhage, animals showed blood-brain barrier disruption, brain edema, and neurologic deficits, accompanied with phosphorylation of Lyn kinase and release of tryptase, indicating mast cell activation. Hydrogen treatment diminished phosphorylation of Lyn kinase and release of tryptase, decreased accumulation and degranulation of mast cells, attenuated blood-brain barrier disruption, and improved neurobehavioral function. Activation of mast cells following intracerebral hemorrhage contributed to increase of blood-brain barrier permeability and brain edema. Hydrogen inhalation preserved blood-brain barrier disruption by prevention of mast cell activation after intracerebral hemorrhage.

Assessing To Address Barriers to Learning. An Introductory Packet.

ERIC Educational Resources Information Center

California Univ., Los Angeles. Center for Mental Health Schools.

Schools committed to the success of all children must have an array of activities designed to address barriers to learning. This introductory packet contains some aids to help school staff find new ways of thinking about how schools should assess barriers to learning. The following items are included in the packet: (1) a chart of "Barriers to…