WorldWideScience

Sample records for high activation barriers

  1. Zelda overcomes the high intrinsic nucleosome barrier at enhancers during Drosophila zygotic genome activation.

    Science.gov (United States)

    Sun, Yujia; Nien, Chung-Yi; Chen, Kai; Liu, Hsiao-Yun; Johnston, Jeff; Zeitlinger, Julia; Rushlow, Christine

    2015-11-01

    The Drosophila genome activator Vielfaltig (Vfl), also known as Zelda (Zld), is thought to prime enhancers for activation by patterning transcription factors (TFs). Such priming is accompanied by increased chromatin accessibility, but the mechanisms by which this occurs are poorly understood. Here, we analyze the effect of Zld on genome-wide nucleosome occupancy and binding of the patterning TF Dorsal (Dl). Our results show that early enhancers are characterized by an intrinsically high nucleosome barrier. Zld tackles this nucleosome barrier through local depletion of nucleosomes with the effect being dependent on the number and position of Zld motifs. Without Zld, Dl binding decreases at enhancers and redistributes to open regions devoid of enhancer activity. We propose that Zld primes enhancers by lowering the high nucleosome barrier just enough to assist TFs in accessing their binding motifs and promoting spatially controlled enhancer activation if the right patterning TFs are present. We envision that genome activators in general will utilize this mechanism to activate the zygotic genome in a robust and precise manner.

  2. Barriers for recess physical activity

    DEFF Research Database (Denmark)

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

    2014-01-01

    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. CONCLUSION: Based on the results from......BACKGROUND: 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....... This was verified by a thematic analysis of transcripts from the open discussions and go-along interviews. RESULTS: 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...

  3. Barriers to physical activity among working mothers.

    Science.gov (United States)

    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.

  4. Barriers to increasing market-oriented activity

    DEFF Research Database (Denmark)

    Bisp, Søren

    product development. Despite the increasing evidence of a positive relationship between above average business performance and a high level of market-oriented activity, normative recommendations on how to increase the level of market-oriented activity is sparse. The scientific contribution of the present...... research is to expand the understanding of what factors inhibit the increase of market-oriented activity and how these factors may interact. Identifying and describing the barriers is considered the first and necessary step in attempting to reach a higher level of market-oriented activity......Introduction: The Danish food processing industry faces a situation in which intensified competition in its primary markets and product categories forces several companies to rethink their relative focus in terms of marketing rather than production, or, in other words, in terms of value adding...

  5. Married men’s perceptions of barriers for HIV-positive pregnant women accessing highly active antiretroviral therapy in rural Uganda

    Directory of Open Access Journals (Sweden)

    Duff P

    2012-05-01

    Full Text Available Putu Duff,1 Tom Rubaale,2 Walter Kipp1,21School of Public Health, University of Alberta, Edmonton, Canada; 2Community ARV Project, Fort Portal, UgandaBackground: The aim of this study was to describe the perceptions of married men about barriers to accessing and accepting highly active antiretroviral therapy (HAART by pregnant/postnatal women positive for human immunodeficiency virus (HIV and registered in Kabarole District’s Program for the Prevention of HIV from Mother to Child (PMTCT-Plus.Materials and methods: Our study was a qualitative descriptive exploratory study using thematic analysis. Four focus group discussions were held with a convenience sample of 40 married men.Results: Lack of disclosure of a positive HIV diagnosis to the partner and stigmatization of persons with HIV were two major obstacles for women in accessing HAART. In addition, men felt that their low knowledge of HAART and their low HIV testing rate also constituted important barriers to these women taking treatment. Men complained that they were not sufficiently involved in the reproductive care of women and that couples’ counseling could be a step towards addressing this problem.Conclusion: Barriers to HAART experienced by pregnant/postnatal women need to be addressed in order to improve their uptake of treatment, increase their low treatment coverage, improve their survival, and at the same time dramatically reduce HIV transmission from mother to child.Keywords: men, highly active antiretroviral therapy, pregnant women, Uganda

  6. Understanding Motivators and Barriers to Physical Activity

    Science.gov (United States)

    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…

  7. Understanding Motivators and Barriers to Physical Activity

    Science.gov (United States)

    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…

  8. BARRIERS TO PHYSICAL ACTIVITY IN THE ELDERLY

    Directory of Open Access Journals (Sweden)

    Paulo Matias

    2015-04-01

    Full Text Available The population awareness of the physical exercise’s benefits is widely diffused. These benefits are particularly important in the elderly because, with increasing age, there is a decline of the musculoskeletal system and the maximum oxygen consumption which reduces the functional fitness of the elderly and can often lead to a significant decline in the quality of life. Despite this awareness, a large part of the population remains sedentary. It is important to know what the barriers are, so they can be circumvented in order to increase the engagement of the elderly population in existing physical activity programs.Objectives: This study aims to identify some of the personal, behavioral and environmental barriers that prevent older adults to be physically active.

  9. Barriers to increased market-oriented activity

    DEFF Research Database (Denmark)

    Bisp, Søren

    1999-01-01

    -oriented activity. A framework of six generic domains is suggested: Organizational structure, human resource management, market-oriented activity competence, psychological climate, managers' personality characteristics, and individually held beliefs. A model is suggested inter-relating the domains....... and related activities still seem to attract relatively few resources is not answered by supplying another checklist or package of facilitators. Based on published conceptual writings and empirical studies this article makes an account of what the intra-organizational barriers may be to increased market...

  10. Circularly polarized antennas for active holographic imaging through barriers

    Science.gov (United States)

    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.

  11. Barriers to increased market-oriented activity

    DEFF Research Database (Denmark)

    Bisp, Søren

    1999-01-01

    Most research on market orientation has dealt with assessing how market orientation behaviour is related to business performance. This work has established an intense market-oriented activity as significantly and positively related to business performance under most circumstances. In a maturing...... and related activities still seem to attract relatively few resources is not answered by supplying another checklist or package of facilitators. Based on published conceptual writings and empirical studies this article makes an account of what the intra-organizational barriers may be to increased market...

  12. High performance superluminescent diode with InAs quantum-dashes and chirped AlGaInAs barriers active region

    KAUST Repository

    Khan, Mohammed Zahed Mustafa

    2013-01-01

    The demonstration of high power, ultra-low ripple superluminescent diode using multiple quantum-dash-in-a-well layers with variable barrier thickness is reported. The device exhibits >20 mW power, < 0.3dB ripple, and > 80 nm 3dB bandwidth at ~1.55 μm.

  13. International Collaboration Activities on Engineered Barrier Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-08-31

    The Used Fuel Disposition Campaign (UFDC) within the DOE Fuel Cycle Technologies (FCT) program has been engaging in international collaborations between repository R&D programs for high-level waste (HLW) disposal to leverage on gathered knowledge and laboratory/field data of near- and far-field processes from experiments at underground research laboratories (URL). Heater test experiments at URLs provide a unique opportunity to mimetically study the thermal effects of heat-generating nuclear waste in subsurface repository environments. Various configurations of these experiments have been carried out at various URLs according to the disposal design concepts of the hosting country repository program. The FEBEX (Full-scale Engineered Barrier Experiment in Crystalline Host Rock) project is a large-scale heater test experiment originated by the Spanish radioactive waste management agency (Empresa Nacional de Residuos Radiactivos S.A. – ENRESA) at the Grimsel Test Site (GTS) URL in Switzerland. The project was subsequently managed by CIEMAT. FEBEX-DP is a concerted effort of various international partners working on the evaluation of sensor data and characterization of samples obtained during the course of this field test and subsequent dismantling. The main purpose of these field-scale experiments is to evaluate feasibility for creation of an engineered barrier system (EBS) with a horizontal configuration according to the Spanish concept of deep geological disposal of high-level radioactive waste in crystalline rock. Another key aspect of this project is to improve the knowledge of coupled processes such as thermal-hydro-mechanical (THM) and thermal-hydro-chemical (THC) operating in the near-field environment. The focus of these is on model development and validation of predictions through model implementation in computational tools to simulate coupled THM and THC processes.

  14. Promoting Physical Activity: Addressing Barriers and Moving Forward

    Science.gov (United States)

    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…

  15. Promoting Physical Activity: Addressing Barriers and Moving Forward

    Science.gov (United States)

    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…

  16. Perceived barriers to physical activity in university students.

    Science.gov (United States)

    Arzu, Daskapan; Tuzun, Emine Handan; Eker, Levent

    2006-01-01

    Many studies which were published in other countries identified certain benefits and barriers to physical activity among young people. But there is no data about the subject pertaining to Turkish adolescents. This study tries to rectify this with a study of Turkish university students. Undergraduate university students (n = 303) were recruited to the study. Current exercise habits and perceived barriers to physical activity were assessed in the sample. Using a Likert Type scale, participants responded an instrument with 12 items representing barriers to physical activity. Mean scores were computed. External barriers were more important than internal barriers. "Lack of time due to busy lesson schedule", "My parents give academic success priority over exercise. "and "lack of time due to responsibilities related to the family and social environment "were most cited items for physical activity barriers. There is a need for future research, which will be carried out with larger sample groups to develop national standardized instrument. It will be helpful for accurately identify perceived barriers and then recommend changes to enhance physical activity among young people. Key PointsThe purpose of this study was to analyze perceived barriers to physical activity in the university students.The results showed that not having enough time was the most important barrier for not participating in physical activity among our samples.This study with relatively small sample must be considered as pilot study for related studies in the future.

  17. Value-meaning Barriers in Research Activity of Junior Scientists

    Directory of Open Access Journals (Sweden)

    Shabalovskaya M.V.

    2017-08-01

    Full Text Available Contents of value-meaning barriers are covered that acquire certain specifics in research activity and influence formation of meaning-forming research motivation of junior scientists. Such barriers were assumed to be conditioned by dissonance between dominating values and degree of their realization in junior researchers. Sample of respondents included 88 beginners: postgraduate students (n=65 and masters (n=23 of Tomsk high schools aged between 21 and 35 years. As research methods the expanded version of technique by M. Rokeach (proposed by M.S. Yanitsky and A.V. Seryy, methods of statistical analysis of results (frequency analysis, Mann-Whitney test were used. Relevant value orientations of junior scientists are presented. Gender differences in value-meaning domain are revealed. Differences in values in postgraduate students and masters were found. Dissonance in degree of fulfillment of terminal and instrumental values has been established that indicates disturbances of value-meaning domain of the personality of junior scientists. Results add to scientific ideas about value-meaning barriers in research activity of junior scientists.

  18. PERCEIVED BARRIERS TO PHYSICAL ACTIVITY IN UNIVERSITY STUDENTS

    Directory of Open Access Journals (Sweden)

    Arzu Daskapan

    2006-12-01

    Full Text Available Many studies which were published in other countries identified certain benefits and barriers to physical activity among young people. But there is no data about the subject pertaining to Turkish adolescents. This study tries to rectify this with a study of Turkish university students. Undergraduate university students (n = 303 were recruited to the study. Current exercise habits and perceived barriers to physical activity were assessed in the sample. Using a Likert Type scale, participants responded an instrument with 12 items representing barriers to physical activity. Mean scores were computed. External barriers were more important than internal barriers. "Lack of time due to busy lesson schedule", "My parents give academic success priority over exercise." and "lack of time due to responsibilities related to the family and social environment" were most cited items for physical activity barriers. There is a need for future research, which will be carried out with larger sample groups to develop national standardized instrument. It will be helpful for accurately identify perceived barriers and then recommend changes to enhance physical activity among young people.

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

    Science.gov (United States)

    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.

  20. Modeling, analysis, and validation of an active T-shaped noise barrier.

    Science.gov (United States)

    Fan, Rongping; Su, Zhongqing; Cheng, Li

    2013-09-01

    With ever-increasing land traffic, abatement of traffic noise using noise barriers remains significant, yet it is a challenging task due to spatial competition with other infrastructure. In this study, a deep insight into the diffraction characteristics of acoustic fields near noise barriers of various geometries and surface conditions was achieved using numerical simulations. A T-shaped passive noise barrier with acoustically soft upper surfaces was demonstrated to outperform other candidates in a middle- or high-frequency range. Based on attributes of the acoustic field diffracted by T-shaped barriers, an active control strategy was developed to revamp the T-shaped barrier, in which a filtered minimax algorithm was established to drive the secondary sound sources. This algorithm resulted in more uniformly distributed residual sound fields than a filtered-X least mean square algorithm. Performance of the actively controlled barrier was evaluated at different positions and spacings of secondary sound sources and error sensors, leading to a series of optimal criteria for the design of active noise barriers. A prototype was fabricated and validated experimentally, manifesting particular effectiveness in insulating low-frequency noise, supplementing well the capacity of a passive T-shaped barrier which is effective in the middle- or high-frequency range.

  1. One Component Encapsulating Material Matrix as High Barrier Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA need for new flexible food packaging materials with effective high barrier against oxygen and moisture to protect food, minimize weight and...

  2. Polyelectrolyte Coacervates Deposited as High Gas Barrier Thin Films.

    Science.gov (United States)

    Haile, Merid; Sarwar, Owais; Henderson, Robert; Smith, Ryan; Grunlan, Jaime C

    2017-01-01

    Multilayer coatings consisting of oppositely charged polyelectrolytes have proven to be extraordinarily effective oxygen barriers but require many processing steps to fabricate. In an effort to prepare high oxygen barrier thin films more quickly, a polyelectrolyte complex coacervate composed of polyethylenimine and polyacrylic acid is prepared. The coacervate fluid is applied as a thin film using a rod coating process. With humidity and thermal post-treatment, a 2 µm thin film reduces the oxygen transmission rate of 0.127 mm poly(ethylene terephthalate) by two orders of magnitude, rivalling conventional oxygen barrier technologies. These films are fabricated in ambient conditions using low-cost, water-based solutions, providing a tremendous opportunity for single-step deposition of polymeric high barrier thin films.

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

    Science.gov (United States)

    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.

  4. Blood-Brain Barrier Changes in High Altitude.

    Science.gov (United States)

    Lafuente, José V; Bermudez, Garazi; Camargo-Arce, Lorena; Bulnes, Susana

    2016-01-01

    Cerebral syndromes related to high-altitude exposure are becoming more frequent as the number of trips to high altitudes has increased in the last decade. The commonest symptom is headache, followed by acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), which can be fatal. The pathophysiology of these syndromes is not fully understood. The classical "tight-fit hypothesis" posits that there are some anatomical variations that would obstruct the sinovenous outflow and worsen vasogenic edema and intracranial hypertension reactive to hypoxia. This could explain microhemorrhages seen in autopsies. However, recent magnetic resonance imaging studies have demonstrated some components of cytotoxic edema in HACE absent in AMS, suggesting a dysfunction in water balance at the cellular level. Currently, the "red-ox theory" supports trigemino-vascular system activation by free radicals formed after hypoxia and the consequent oxidative stress cascades. Apart from trigemino-vascular system activation, free radicals can also provoke membrane destabilisation mediated by lipid peroxidation, inflammation, and local hypoxia inducible factor-1α and vascular endothelial growth factor activation, resulting in gross blood-brain barrier (BBB) dysfunction. Besides alterations in endothelial cells such as increased pinocytotic vesicles and disassembly of interendothelial tight junction proteins, capillary permeability may also increase with subsequent swelling of astrocyte end-feet. In conclusion, although the pathophysiology of AMS and HACE is not completely understood, recent evidence proposes a multifactorial entity, with brain swelling and compromise of the BBB considered to play an important role. A fuller comprehension of these processes is crucial to reduce and prevent BBB alterations during high-altitude exposure.

  5. Do Perceived Cues, Benefits, and Barriers to Physical Activity Differ between Male and Female Adolescents?

    Science.gov (United States)

    Tergerson, Jennifer L.; King, Keith A.

    2002-01-01

    Surveyed adolescents at single-sex high schools to examine whether perceptions of physical activity differed by gender. The most helpful cue to physical activity for males and females was having a friend to exercise with. Parental encouragement and having a parent who exercised were also helpful. Wanting to do other things was a common barrier to…

  6. Biofuels Barrier Properties of Polyamide 6 and High Density Polyethylene

    Directory of Open Access Journals (Sweden)

    Fillot L.-A.

    2015-02-01

    Full Text Available In this paper, a comparison of the biofuels barrier properties of PolyAmide 6 (PA6 and High Density PolyEthylene (HDPE is presented. Model fuels were prepared as mixtures of toluene, isooctane and ethanol, the ethanol volume fraction varying between 0% and 100%. Barrier properties were determined at 40°C by gravimetric techniques or gas chromatography measurements, and it was shown that polyamide 6 permeability is lower than that of polyethylene on a wide range of ethanol contents up to 85% of ethanol (E85 in the biofuel, permeability of PA6 being 100 times lower than that of HDPE for low ethanol content fuels (E5, E0. The time-lags were also compared, and on the whole range of ethanol contents, HDPE permeation kinetics appears to be much faster than that of PA6, the time lag for a 1 mm thick specimens in presence of E10 being 50 days for PA6 and 0.5 days for HDPE. The compositions of the solvent fluxes were analyzed by FID gas chromatography, and it turned out that the solvent flux was mainly made up of ethanol (minimum 95% in the case of PA6, whereas in the case of HDPE, solvent flux was mainly made up of hydrocarbons. The implication of this difference in the solvent flux composition is discussed in the present article, and a side effect called the “fuel exhaustion process” is presented. The influence of the sample thickness was then studied, and for the different biofuels compositions, the pervaporation kinetics of polyamide 6 appeared to evolve with the square of the thickness, a long transitory regime being highlighted in the case of PA6. This result implies that the time needed to characterize the steady state permeability of thick PA6 parts such as fuel tanks can be very long (one year or more, this duration being far superior to the Euros 5 or Euro 6 standard emission measurements time scale. The influence of temperature on the permeability was finally assessed, and the activation energy that is the signature of the temperature

  7. Influences and Barriers on Physical Activity in Pediatric Oncology Patients

    Directory of Open Access Journals (Sweden)

    Larrilyn Yelton

    2016-12-01

    Full Text Available Objectives: To determine the influence of family, peers, school, and physicians on exercise in pediatric oncology patients and evaluate the barriers to physical activity levels in this population. Methods: A search of PubMed and Google Scholar resulted in 12 related articles. The articles were assessed for the influence of school systems, family, peers, self-efficacy, and physicians on exercise. Additionally barriers and interventions to physical activity were also assessed. Limitations and research methodologies of each article were also evaluated. Results: Many school systems were unsure of expectations in regards to physical activity for their returning students with cancer. Most schools acknowledged willingness to increase exercise for these students; however, there is a communication gap between the medical field and the school system on what expectations should be. Family is associated with increased physical activity levels and healthier diets in this population with children preferring mothers as exercise partners more than fathers. While physician interventions have been shown to positively impact physical activity, it has been reported that physicians are not engaging in exercise counseling with their patients. Conclusion: Several issues and barriers related to physical activity in pediatric oncology population were identified. Studies have demonstrated it is feasible to increase physical activity and self-efficacy in this population. Further research is needed to better understand and quantify these issues as well as further test the interventions that have been suggested in this review and have been successful in other pediatric populations.

  8. Current barriers to confine high frequency common mode currents

    NARCIS (Netherlands)

    Moonen, Dominicus Johannes Guilielmus; Buesink, Frederik Johannes Karel; Leferink, Frank Bernardus Johannes

    2016-01-01

    A commercially produced three phase power line filter is submitted to a Current Barrier (CB) Electro-Magnetic Compatibility (EMC) zoning strategy as an attempt to confine high frequency common mode currents. The intent of the paper is not to show how to build a ’perfect’ filter, since this is known.

  9. Barriers associated with reduced physical activity in COPD patients

    Directory of Open Access Journals (Sweden)

    Priscila Batista Amorim

    2014-10-01

    Full Text Available OBJECTIVE: To evaluate the ability of COPD patients to perform activities of daily living (ADL; to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT, and an ADL limitation score. METHODS: In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT. RESULTS: We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5 ± 25.8 min/day vs. 105.2 ± 49.4 min/day; p < 0.001, as was the distance walked (3.9 ± 1.9 km/day vs. 6.4 ± 3.2 km/day; p < 0.001. The COPD patients also walked fewer steps/day. The most common self-reported barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results. CONCLUSIONS: Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures.

  10. Adapting wood hydrolysate barriers to high humidity conditions.

    Science.gov (United States)

    Yaich, Anas Ibn; Edlund, Ulrica; Albertsson, Ann-Christine

    2014-01-16

    The incorporation of layered silicates in bio-based barrier films resulted in lower water vapor permeability, and significantly lowered oxygen permeability at a relative humidity (RH) as high as 80%, with reduced moisture sensitivity of the wood hydrolysate (WH) based films. The applicability of WH based films was accordingly extended over a wider relative humidity condition range. Crude aqueous process liquor, the WH, was extracted from hardwood and utilized as a feed-stock for films without any upgrading pretreatment, yet producing superior oxygen barrier performance compared to partially upgraded WH and highly purified hemicelluloses. Films composed of crude WH and either one of two types of naturally occurring layered silicates, montmorillonite (MMT) or talc, as mineral additives, were evaluated with respect to oxygen and water vapor permeability, morphological, tensile and dynamic thermo-mechanical properties. Films with an oxygen permeability as low as 1.5 (cm(3)μm)/(m(2)daykPa) at 80% RH was achieved.

  11. Synthesizing High-Quality Graphene Membranes for Engineering Diffusion Barriers

    Science.gov (United States)

    Singha Roy, Susmit

    We demonstrate significant advances in the fundamental understanding and engineering of scalable graphene diffusion barriers. Experimental studies have established that defect-free non-scalable graphene is an excellent barrier material, however its scalable counterparts are still well behind in terms of performance. The latter's ability to perform as a barrier membrane is compromised primarily by the presence of three major problems - high density of defects, self-degradation in ambient environment and induced electrochemical oxidation of the underlying material. First, we develop an in-depth understanding of how diffusion occurs through monolayer graphene grown via chemical vapor deposition. It is shown that the atomic membrane is impenetrable in the pristine regions, however it is easily penetrated by oxygen and water at grain boundaries and intrinsic pinholes. Second, we study in detail the self-deterioration of graphene in ambient and quantify the evolution, kinetics, and energetics of the degradation process both in the pristine and intrinsically defective regions of graphene. It is also found that the degradation process is accelerated in the presence of water vapor. Third, we find that the overall defect density of a graphene membrane is primarily determined by the density of its intrinsic pinholes and grain boundaries. We demonstrate that the density on intrinsic pinholes can be significantly reduced by reducing the surface roughness of the growth substrate which is achieved by regulating the pre-growth annealing time and temperature. The density of the grain boundaries can be altered by varying the internucleation distance during the growth of the membrane. Fourth, when graphene is used as a corrosion barrier for metals, we establish that the electrochemical corrosion of the metal can be drastically reduced by adding an ultra-thin electrically insulating layer between the graphene and the metal. In addition, the barrier performance is enhanced greatly by

  12. Barriers, activities and participation: Incorporating ICF into service planning datasets.

    LENUS (Irish Health Repository)

    O'Donovan, MA

    2009-05-21

    Purpose. Guided by the World Health Organization\\'s International Classification of Functioning, Disability and Health (ICF), a measure of activity and participation (MAP) was developed and incorporated into the National Physical and Sensory Disability Database in Ireland. The aims of this article are to investigate and explore the relationship between the barriers, participation restriction and functioning levels experienced by people with disabilities. Method. Seven thousand five hundred and sixty-two personal interviews with people meeting specific eligibility criteria for registering onto the database were conducted across four health service executive regions in Ireland. Results. Overall, differences in barriers, participation restriction and activity limitations experienced by people with different types of disabilities were found to be significant. Furthermore, low functioning and experience of barriers were indicators of participation restriction. Conclusions. This article has shown that elements of the ICF have been successfully operationalised in a service planning tool through the development of the MAP. This provides a more holistic view of disability and will enable the impact of service interventions to be measured over time.

  13. The Idefix enhancer-blocking insulator also harbors barrier activity.

    Science.gov (United States)

    Brasset, E; Hermant, C; Jensen, S; Vaury, C

    2010-01-15

    Chromatin insulators are cis-regulatory sequences participating in the regulation of gene expression. Their presence within the genome is associated with two main functions. One of them is an enhancer-blocking function that blocks enhancer-promoter communication when the insulator is located in between. The second is a boundary or barrier function that insulates independent units of transcription. This latter is observed when two insulators flanking a gene and its regulatory sequences block the regulatory influences of surrounding chromatin. Some years ago, we reported the presence of an insulator within the retrotransposon Idefix from Drosophila melanogaster. This insulator displays an enhancer-blocking activity toward an enhancer located within a second retrotransposon called ZAM. Here, we show that this insulator is not specific to the ZAM enhancer but has the capacity to interfere in the communication established between a broad range of cis-regulatory enhancer and a promoter. Furthermore, we show that, if it is placed on both sides of a transgene, this insulator acts as a barrier able to isolate the transgene from its repressive or enhancing environment. Thus, the Idefix insulator carries both an enhancer-blocking and a barrier activity. According to these properties, the Idefix insulator might prove to be a useful tool to isolate artificial transgenes from positive or negative influences from their integration sites.

  14. Active explosion barrier performance against methane and coal dust explosions

    Institute of Scientific and Technical Information of China (English)

    J J L du Plessis

    2015-01-01

    Preventing the propagation of methane or coal dust explosions through the use of active explosion-suppression systems remains one of the most underutilised explosion controls in underground coal mines. As part of the effort to develop better technologies to safeguard mines, the use of active barrier systems was investigated at Kloppersbos in South Africa. The system is designed to meet the requirements of the European Standard (EN 14591-4 2007) as well as the Mine Safety Standardisation in the Ministry of Coal Industry, Coal Industrial l Standard of the Peoples Republic of China (MT 694-1997). From the tests conducted, it can be concluded that the ExploSpot System was successful in stopping flame propagation for both methane and methane and coal dust hybrid explosions when ammonium phosphate powder was used as the suppression material. The use of this barrier will provide coal mine management with an additional explosion control close to the point of ignition and may find application within longwall faces further protecting mines against the risk of an explosion propagating throughout a mine.

  15. Physical Activity Pattern of Malaysian Preschoolers: Environment, Barriers, and Motivators for Active Play.

    Science.gov (United States)

    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.

  16. A high-powered view of the filtration barrier.

    Science.gov (United States)

    Peti-Peterdi, János; Sipos, Arnold

    2010-11-01

    Multiphoton excitation fluorescence microscopy is a powerful noninvasive imaging technique for the deep optical sectioning of living tissues. Its application in several intact tissues is a significant advance in our understanding of organ function, including renal pathophysiological mechanisms. The glomerulus, the filtering unit in the kidney, is one good example of a relatively inaccessible and complex structure, with cell types that are otherwise difficult to study at high resolution in their native environment. In this article, we address the application, advantages, and limitations of this imaging technology for the study of the glomerular filtration barrier and the controversy it recently generated regarding the glomerular filtration of macromolecules. More advanced and accurate multiphoton determinations of the glomerular sieving coefficient that are presented here dismiss previous claims on the filtration of nephrotic levels of albumin. The sieving coefficient of 70-kD dextran was found to be around 0.001. Using a model of focal segmental glomerulosclerosis, increased filtration barrier permeability is restricted only to areas of podocyte damage, consistent with the generally accepted role of podocytes and the glomerular origin of albuminuria. Time-lapse imaging provides new details and important in vivo confirmation of the dynamics of podocyte movement, shedding, replacement, and the role of the parietal epithelial cells and Bowman's capsule in the pathology of glomerulosclerosis.

  17. Optical Diagnostics for High-Temperature Thermal Barrier Coatings

    Science.gov (United States)

    Eldridge, Jeffrey I.

    2009-01-01

    Thermal barrier coatings (TBCs) are typically composed of translucent ceramic oxides that provide thermal protection for metallic components exposed to high-temperature environments, such as in jet turbine engines. Taking advantage of the translucent nature of TBCs, optical diagnostics have been developed that can provide an informed assessment of TBC health that will allow mitigating action to be taken before TBC degradation threatens performance or safety. In particular, rare-earth-doped luminescent sublayers have been integrated into the TBC structure to produce luminescence that monitors TBC erosion, delamination, and temperature gradients. Erosion monitoring of TBC-coated specimens is demonstrated by utilizing visible luminescence that is excited from a sublayer that is exposed by erosion. TBC delamination monitoring is achieved in TBCs with a base rare-earth-doped luminescent sublayer by the reflectance-enhanced increase in luminescence produced in regions containing buried delamination cracks. TBC temperature monitoring is demonstrated using the temperature-dependent decay time for luminescence originating from the specific coating depth associated with a rare-earth-doped luminescent sublayer. The design and implementation of these TBCs with integrated luminescent sublayers is discussed, including co-doping strategies to produce more penetrating near-infrared luminescence. It is demonstrated that integration of the rare-earth-doped sublayers is achieved with no reduction in TBC life. In addition, results for multilayer TBCs designed to also perform as radiation barriers are also presented.

  18. Physical activity in patients with heart failure: barriers and motivations with special focus on sex differences

    Directory of Open Access Journals (Sweden)

    Klompstra L

    2015-11-01

    Full Text Available Leonie Klompstra,1 Tiny Jaarsma,1 Anna Strömberg2,31Department of Social and Welfare Studies, Faculty of Health Sciences, 2Department of Medical and Health Sciences, Division of Nursing, 3Department of Cardiology, Linköping University, Linköping, SwedenBackground: Adherence to recommendations for physical activity is low in both male and female patients with heart failure (HF. Men are more physically active than women. In order to successfully promote physical activity, it is therefore essential to explore how much and why HF patients are physically active and if this is related to sex. The aim of this study was therefore to evaluate physical activity in HF patients, to describe the factors related to physical activity, and to examine potential barriers and motivations to physical activity with special focus on sex differences.Methods: The study had a cross-sectional survey design. HF patients living at home received a questionnaire during May–July 2014, with questions on physical activity (from the Short Form-International Physical Activity Questionnaire, and potential barriers and motivations to physical activity.Results: A total of 154 HF patients, 27% women, with a mean age of 70±10 were included. In total, 23% of the patients reported a high level of physical activity, 46% a moderate level, and 34% a low level. Higher education, self-efficacy, and motivation were significantly associated with a higher amount of physical activity. Symptoms or severity of the disease were not related to physical activity. All the potential barriers to exercise were reported to be of importance. Psychological motivations were most frequently rated as being the most important motivation (41% to be physically active. Physical motivations (33% and social motivations were rated as the least important ones (22%. Women had significantly higher total motivation to be physically active. These differences were found in social, physical, and psychological

  19. Nanomechanical Behavior of High Gas Barrier Multilayer Thin Films.

    Science.gov (United States)

    Humood, Mohammad; Chowdhury, Shahla; Song, Yixuan; Tzeng, Ping; Grunlan, Jaime C; Polycarpou, Andreas A

    2016-05-04

    Nanoindentation and nanoscratch experiments were performed on thin multilayer films manufactured using the layer-by-layer (LbL) assembly technique. These films are known to exhibit high gas barrier, but little is known about their durability, which is an important feature for various packaging applications (e.g., food and electronics). Films were prepared from bilayer and quadlayer sequences, with varying thickness and composition. In an effort to evaluate multilayer thin film surface and mechanical properties, and their resistance to failure and wear, a comprehensive range of experiments were conducted: low and high load indentation, low and high load scratch. Some of the thin films were found to have exceptional mechanical behavior and exhibit excellent scratch resistance. Specifically, nanobrick wall structures, comprising montmorillonite (MMT) clay and polyethylenimine (PEI) bilayers, are the most durable coatings. PEI/MMT films exhibit high hardness, large elastic modulus, high elastic recovery, low friction, low scratch depth, and a smooth surface. When combined with the low oxygen permeability and high optical transmission of these thin films, these excellent mechanical properties make them good candidates for hard coating surface-sensitive substrates, where polymers are required to sustain long-term surface aesthetics and quality.

  20. Compromised epidermal barrier stimulates Harderian gland activity and hypertrophy in ACBP−/− mice[S

    Science.gov (United States)

    Bek, Signe; Neess, Ditte; Dixen, Karen; Bloksgaard, Maria; Marcher, Ann-Britt; Chemnitz, John; Færgeman, Nils J.; Mandrup, Susanne

    2015-01-01

    Acyl-CoA binding protein (ACBP) is a small, ubiquitously expressed intracellular protein that binds C14-C22 acyl-CoA esters with very high affinity and specificity. We have recently shown that targeted disruption of the Acbp gene leads to a compromised epidermal barrier and that this causes delayed adaptation to weaning, including the induction of the hepatic lipogenic and cholesterogenic gene programs. Here we show that ACBP is highly expressed in the Harderian gland, a gland that is located behind the eyeball of rodents and involved in the production of fur lipids and lipids used for lubrication of the eye lid. We show that disruption of the Acbp gene leads to a significant enlargement of this gland with hypertrophy of the acinar cells and increased de novo synthesis of monoalkyl diacylglycerol, the main lipid species produced by the gland. Mice with conditional targeting of the Acbp gene in the epidermis recapitulate this phenotype, whereas generation of an artificial epidermal barrier during gland development reverses the phenotype. Our findings indicate that the Harderian gland is activated by the compromised epidermal barrier as an adaptive and protective mechanism to overcome the barrier defect. PMID:26142722

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

    DEFF Research Database (Denmark)

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

    barriers, there were both inter- and intra-gender differences in the children´s perceptions of these barriers. Weather was a barrier for all children, apart from the most active boys. Conflicts were perceived as a barrier particularly for 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. Conclusion: Based on the results from this study, we......Background: 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...

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

    Science.gov (United States)

    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

  3. Thermal barrier coatings (TBC's) for high heat flux thrust chambers

    Science.gov (United States)

    Bradley, Christopher M.

    -section components has become critical, but at the same time the service conditions have put our best alloy systems to their limits. As a result, implementation of cooling holes and thermal barrier coatings are new advances in hot-section technologies now looked at for modifications to reach higher temperature applications. Current thermal barrier coatings used in today's turbine applications is known as 8%yttria-stabilized zirconia (YSZ) and there are no coatings for current thrust chambers. Current research is looking at the applicability of 8%yttria-stabilized hafnia (YSH) for turbine applications and the implementation of 8%YSZ onto thrust chambers. This study intends to determine if the use of thermal barrier coatings are applicable for high heat flux thrust chambers using industrial YSZ will be advantageous for improvements in efficiency, thrust and longer service life by allowing the thrust chambers to be used more than once.

  4. High-resolution reconstruction of a coastal barrier system

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Andersen, Thorbjørn Joest; Nielsen, Lars Henrik

    2015-01-01

    from retreat of the barrier island and probably also due to formation of a tidal inlet close to the study area. Continued transgression and shoreface retreat created a distinct hiatus and wave ravinement surface in the seaward part of the CBS before the barrier shoreline stabilised between 5.0 and 4.......5 ka ago. Back-barrier shoreline erosion due to sediment starvation in the back-barrier basin, was pronounced from 4.5 to 2.5 ka ago but the last 2.5 kyr barrier sedimentation has kept up with and outpaced sea-level. The last 0.4 kyr the CBS has been episodically prograding. Sediment accumulation shows...

  5. High Operating Temperature Midwave Quantum Dot Barrier Infrared Detector (QD-BIRD)

    Science.gov (United States)

    Ting, David Z.; Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Mumolo, Jason M.; Gunapala, Sarath D.

    2012-01-01

    The nBn or XBn barrier infrared detector has the advantage of reduced dark current resulting from suppressed Shockley-Read-Hall (SRH) recombination and surface leakage. High performance detectors and focal plane arrays (FPAs) based on InAsSb absorber lattice matched to GaSb substrate, with a matching AlAsSb unipolar electron barrier, have been demonstrated. The band gap of lattice-matched InAsSb yields a detector cutoff wavelength of approximately 4.2 ??m when operating at 150K. We report results on extending the cutoff wavelength of midwave barrier infrared detectors by incorporating self-assembled InSb quantum dots into the active area of the detector. Using this approach, we were able to extend the detector cutoff wavelength to 6 ?m, allowing the coverage of the full midwave infrared (MWIR) transmission window. The quantum dot barrier infrared detector (QD-BIRD) shows infrared response at temperatures up to 225 K.

  6. High Operating Temperature Midwave Quantum Dot Barrier Infrared Detector (QD-BIRD)

    Science.gov (United States)

    Ting, David Z.; Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Mumolo, Jason M.; Gunapala, Sarath D.

    2012-01-01

    The nBn or XBn barrier infrared detector has the advantage of reduced dark current resulting from suppressed Shockley-Read-Hall (SRH) recombination and surface leakage. High performance detectors and focal plane arrays (FPAs) based on InAsSb absorber lattice matched to GaSb substrate, with a matching AlAsSb unipolar electron barrier, have been demonstrated. The band gap of lattice-matched InAsSb yields a detector cutoff wavelength of approximately 4.2 ??m when operating at 150K. We report results on extending the cutoff wavelength of midwave barrier infrared detectors by incorporating self-assembled InSb quantum dots into the active area of the detector. Using this approach, we were able to extend the detector cutoff wavelength to 6 ?m, allowing the coverage of the full midwave infrared (MWIR) transmission window. The quantum dot barrier infrared detector (QD-BIRD) shows infrared response at temperatures up to 225 K.

  7. [Construction and validation of a short scale of perception of barriers for the physical activity in adolescents].

    Science.gov (United States)

    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.

  8. Promoting physical activity participation among adolescents: The barriers and the suggestions

    Directory of Open Access Journals (Sweden)

    Niloofar Peykari

    2015-01-01

    Full Text Available Background: Physical activity is a complex behavior. To designing the effective intervention, qualitative researches may be allowed for greater understanding of the reasons behind the adolescences′ physical activity-related behaviors′. Methods: Using the grounded theory approach, including semi-structured focus group discussions (FGDs and in-depth interviews, we conducted a quantitative study to elicit the adolescents and key informants′ opinion regarding the satiation, needs, social and environmental barriers of adolescents′ physical activity. For FGDs, participants were selected from volunteered adolescent (aged 10-19 years of the populated western part of Tehran, which was selected as a research field. Key informants were invited from the health professionals and experts in the field of adolescents′ health. Results: According to findings, although the majority of participants agreed on the important role of physical activity, the lack of essential motivation and the pressure of educational assignments remove it from the daily program priorities. Lack of a safe environment for girls′ physical activity and high cost of professional sports were two first mentioned barriers. It was also suggested that future interventions should focus on improving more parents′ engagement and their direct participation in physical activities with their adolescents. Conclusions: We proposed the participatory strategies for adolescent′s physical activity promotion. Through which target groups participation during the designing, development, and implementation of health programs led to more effective interventions.

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

    Science.gov (United States)

    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…

  10. Flexible High-Barrier Polymers for Food Packaging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of a polymer laminate with water and oxygen barrier properties suitable for food packaging and preservation on 3-5 year manned space exploration...

  11. Thermal barrier coating on high temperature industrial gas turbine engines

    Science.gov (United States)

    Carlson, N.; Stoner, B. L.

    1977-01-01

    The thermal barrier coating used was a yttria stabilized zirconia material with a NiCrAlY undercoat, and the base engine used to establish improvements was the P&WA FT50A-4 industrial gas turbine engine. The design benefits of thermal barrier coatings include simplified cooling schemes and the use of conventional alloys in the engine hot section. Cooling flow reductions and improved heating rates achieved with thermal barrier coating result in improved performance. Economic benefits include reduced power production costs and reduced fuel consumption. Over the 30,000 hour life of the thermal barrier coated parts, fuel savings equivalent to $5 million are projected and specific power (megawatts/mass of engine airflow) improvements on the order of 13% are estimated.

  12. Design of noise barrier inspection system for high-speed railway

    Science.gov (United States)

    Liu, Bingqian; Shao, Shuangyun; Feng, Qibo; Ma, Le; Cholryong, Kim

    2016-10-01

    The damage of noise barriers will highly reduce the transportation safety of the high-speed railway. In this paper, an online inspection system of noise barrier based on laser vision for the safety of high-speed railway is proposed. The inspection system, mainly consisted of a fast camera and a line laser, installed in the first carriage of the high-speed CIT(Composited Inspection Train).A Laser line was projected on the surface of the noise barriers and the images of the light line were received by the camera while the train is running at high speed. The distance between the inspection system and the noise barrier can be obtained based on laser triangulation principle. The results of field tests show that the proposed system can meet the need of high speed and high accuracy to get the contour distortion of the noise barriers.

  13. Is the perception of time pressure a barrier to healthy eating and physical activity among women?

    Science.gov (United States)

    Welch, Nicky; McNaughton, Sarah A; Hunter, Wendy; Hume, Clare; Crawford, David

    2009-07-01

    To describe the proportion of women reporting time is a barrier to healthy eating and physical activity, the characteristics of these women and the perceived causes of time pressure, and to examine associations between perceptions of time as a barrier and consumption of fruit, vegetables and fast food, and physical activity. A cross-sectional survey of food intake, physical activity and perceived causes of time pressure. A randomly selected community sample. A sample of 1580 women self-reported their food intake and their perceptions of the causes of time pressure in relation to healthy eating. An additional 1521 women self-reported their leisure-time physical activity and their perceptions of the causes of time pressure in relation to physical activity. Time pressure was reported as a barrier to healthy eating by 41% of the women and as a barrier to physical activity by 73%. Those who reported time pressure as a barrier to healthy eating were significantly less likely to meet fruit, vegetable and physical activity recommendations, and more likely to eat fast food more frequently. Women reporting time pressure as a barrier to healthy eating and physical activity are less likely to meet recommendations than are women who do not see time pressure as a barrier. Further research is required to understand the perception of time pressure issues among women and devise strategies to improve women's food and physical activity behaviours.

  14. Research on the application of active sound barriers for the transformer noise abatement

    Directory of Open Access Journals (Sweden)

    Hu Sheng

    2016-01-01

    Full Text Available Sound barriers are a type of measure most commonly used in the noise abatement of transformers. In the noise abatement project of substations, the design of sound barriers is restrained by the portal frames which are used to hold up outgoing lines from the main transformers, which impacts the noise reduction effect. If active sound barriers are utilized in these places, the noise diffraction of sound barriers can be effectively reduced. At a 110kV Substation, an experiment using a 15-channel active sound barrier has been carried out. The result of the experiment shows that the mean noise reduction value (MNRV of the noise measuring points at the substation boundary are 1.5 dB (A. The effect of the active noise control system is impacted by the layout of the active noise control system, the acoustic environment on site and the spectral characteristic of the target area.

  15. Activated barrier crossing dynamics in the non-radiative decay of NADH and NADPH

    Energy Technology Data Exchange (ETDEWEB)

    Blacker, Thomas S., E-mail: t.blacker@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Marsh, Richard J., E-mail: richard.marsh@ucl.ac.uk [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Duchen, Michael R., E-mail: m.duchen@ucl.ac.uk [Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Bain, Angus J., E-mail: a.bain@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2013-08-30

    Highlights: ► NADH and NADPH have a high rate of non-radiative excited state decay. ► Conformational relaxation is shown to be a significant non-radiative pathway. ► The Kramers equation describes the barrier crossing dynamics of the relaxation. ► Conformational restriction upon enzyme binding will alter NAD(P)H lifetimes. - Abstract: In live tissue, alterations in metabolism induce changes in the fluorescence decay of the biological coenzyme NAD(P)H, the mechanism of which is not well understood. In this work, the fluorescence and anisotropy decay dynamics of NADH and NADPH were investigated as a function of viscosity in a range of water–glycerol solutions. The viscosity dependence of the non-radiative decay is well described by Kramers and Kramers–Hubbard models of activated barrier crossing over a wide viscosity range. Our combined lifetime and anisotropy analysis indicates common mechanisms of non-radiative relaxation in the two emitting states (conformations) of both molecules. The low frequencies associated with barrier crossing suggest that non-radiative decay is mediated by small scale motion (e.g. puckering) of the nicotinamide ring. Variations in the fluorescence lifetimes of NADH and NADPH when bound to different enzymes may therefore be attributed to differing levels of conformational restriction upon binding.

  16. [Current Status of Home Visit Programs: Activities and Barriers of Home Care Nursing Services].

    Science.gov (United States)

    Oh, Eui Geum; Lee, Hyun Joo; Kim, Yukyung; Sung, Ji Hyun; Park, Young Su; Yoo, Jae Yong; Woo, Soohee

    2015-10-01

    The purpose of this study was to examine the current status of home care nursing services provided by community health nurses and to identify barriers to the services. A cross-sectional survey was conducted with three types of community health care nurses. Participants were 257 nurses, 46 of whom were hospital based home care nurses, 176 were community based visiting nurses, and 35 were long term care insurance based visiting nurses. A structured questionnaire on 7 domains of home care nursing services with a 4-point Likert scale was used to measure activities and barriers to care. Data were analyzed using SPSS WIN 21.0 program. Hospital based home care nurses showed a high level of service performance activity in the domain of clinical laboratory tests, medications and injections, therapeutic nursing, and education. Community based visiting nurses had a high level of service performance in the reference domain. Long term care insurance based visiting nurses showed a high level of performance in the service domains of fundamental nursing and counseling. The results show that although health care service provided by the three types of community health nurse overlapped, the focus of the service is differentiated. Therefore, these results suggest that existing home care services will need to be utilized efficiently in the development of a new nursing care service for patients living in the community after hospital discharge.

  17. Barriers to physical activity in older adults in Germany: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Moschny Anna

    2011-11-01

    Full Text Available Abstract Background Data on barriers to physical activity in older adults in Germany are scarce. The aim of this study was to analyse barriers to physical activity in a cohort of older adults, allowing comparisons between men and women, and age groups. Methods 1,937 older adults with a median age of 77 (range 72-93 years (53.3% female took part in the 7-year follow-up telephone interviews of the getABI cohort. Participants who stated that they did not get enough physical activity were surveyed with respect to barriers to physical activity. Barriers were analysed for all respondents, as well as by sex and age group for cases with complete data. Multivariate logistic regression analysis was performed to evaluate differences between sexes and age groups. The level of significance (alpha Results 1,607 (83.0% participants stated that they were sufficiently physically active. 286 participants rated their physical activity as insufficient and responded to questions on barriers to physical activity completely. The three most frequently cited barriers were poor health (57.7%, lack of company (43.0%, and lack of interest (36.7%. Lack of opportunities for sports or leisure activities (30.3% vs. 15.6%, and lack of transport (29.0% vs. 7.1% were more frequently stated by female respondents than male respondents. These differences between men and women were significant (p = .003; p Conclusions The present study provides relevant data on barriers to physical activity in older adults. By revealing appreciable differences between men and women, and age groups, this study has implications for efforts to increase older adults' physical activity. Promotion and intervention strategies should consider the barriers and tailor measures to the specific needs of older adults in order to reduce their constraints to physical activity.

  18. ANALYSIS OF BARRIERS IN LISTENING COMPREHENSION AMONG JUNIOR HIGH SCHOOL STUDENTS

    Directory of Open Access Journals (Sweden)

    Setia Muljanto

    2012-12-01

    Full Text Available This research paper identifies barriers and difficulties in listening comprehension faced by junior high school students. The research questions were what barriers did students encounter and how did they used strategies to overcome those barriers. This study used a qualitative method and was a case study involving 40 students and one English teacher. The data were obtained by ways of conducting a test of listening taken from TOEIC test. The tests indicated that the results scores were not quite satisfactory. This is primarily caused by speech delivery of the native speaker which was too fast. This means that students faced listening barriers especially in processing information. The data also indicated that students were also nervous when doing the test as habitual barrier. Strategies used to overcome these barriers are by making students get used to listen and use English and making them familiar with certain contexts in real life.

  19. Method of recognizing the high-speed railway noise barriers based on the distance image

    Science.gov (United States)

    Ma, Le; Shao, Shuangyun; Feng, Qibo; Liu, Bingqian; Kim, Chol Ryong

    2016-10-01

    The damage or lack of the noise barriers is one of the important hidden troubles endangering the safety of high-speed railway. In order to obtain the vibration information of the noise barriers, the online detection systems based on laser vision were proposed. The systems capture images of the laser stripe on the noise barriers and export data files containing distance information between the detection systems on the train and the noise barriers. The vibration status or damage of the noise barriers can be estimated depending on the distance information. In this paper, we focused on the method of separating the area of noise barrier from the background automatically. The test results showed that the proposed method is in good efficiency and accuracy.

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

    DEFF Research Database (Denmark)

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

    (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 prioritize the children´s perceived barriers. This was verified...... 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 Methods: Data were collected through 17 focus groups consisting of 111 children...... by a thematic analysis of data from the open discussions and go-along interviews. Results: The most frequently identified barriers for both boys and girls were weather, conflicts, lack of space, lack of facilities and a newly-found barrier, use of electronic devices. While boys and girls identifying the same...

  1. Graphene Oxide Bionanocomposite Coatings with High Oxygen Barrier Properties

    Directory of Open Access Journals (Sweden)

    Ilke Uysal Unalan

    2016-12-01

    Full Text Available In this work, we present the development of bionanocomposite coatings on poly(ethylene terephthalate (PET with outstanding oxygen barrier properties. Pullulan and graphene oxide (GO were used as main polymer phase and nanobuilding block (NBB, respectively. The oxygen barrier performance was investigated at different filler volume fractions (ϕ and as a function of different relative humidity (RH values. Noticeably, the impermeable nature of GO was reflected under dry conditions, in which an oxygen transmission rate (OTR, mL·m−2·24 h−1 value below the detection limit of the instrument (0.01 mL·m−2·24 h−1 was recorded, even for ϕ as low as 0.0004. A dramatic increase of the OTR values occurred in humid conditions, such that the barrier performance was totally lost at 90% RH (the OTR of coated PET films was equal to the OTR of bare PET films. Modelling of the experimental OTR data by Cussler’s model suggested that the spatial ordering of GO sheets within the main pullulan phase was perturbed because of RH fluctuations. In spite of the presence of the filler, all the formulations allowed the obtainment of final materials with haze values below 3%, the only exception being the formulation with the highest loading of GO (ϕ ≈ 0.03. The mechanisms underlying the experimental observations are discussed.

  2. The Role of Career Barriers in High School Students' Career Choice Behavior in Taiwan

    Science.gov (United States)

    Tien, Hsiu-Lan Shelley; Wang, Ying-Fen; Liu, Ling-Chun

    2009-01-01

    The purpose of this study was to examine the role of career barriers in social cognitive career theory (R. W. Lent, S. D. Brown, & G. Hackett, 1994). The participants were 584 high school students in Taiwan, Republic of China. The gender differences in perceived career barriers and career self-efficacy were significant. Results of hierarchical…

  3. ASYMPTOTIC THEORY FOR A RISK PROCESS WITH A HIGH DIVIDEND BARRIER

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A modified classical model with a dividend barrier is considered. It is shown that there is a simple approximation formula for the time of ruin when the level of dividend barrier is high and the claim sizes have a distribution that belongs to S(γ) with γ> 0.

  4. Theory of gelation, vitrification, and activated barrier hopping in mixtures of hard and sticky spheres.

    Science.gov (United States)

    Viehman, Douglas C; Schweizer, Kenneth S

    2008-02-28

    Naive mode coupling theory (NMCT) and the nonlinear stochastic Langevin equation theory of activated dynamics have been generalized to mixtures of spherical particles. Two types of ideal nonergodicity transitions are predicted corresponding to localization of both, or only one, species. The NMCT transition signals a dynamical crossover to activated barrier hopping dynamics. For binary mixtures of equal diameter hard and attractive spheres, a mixture composition sensitive "glass-melting" type of phenomenon is predicted at high total packing fractions and weak attractions. As the total packing fraction decreases, a transition to partial localization occurs corresponding to the coexistence of a tightly localized sticky species in a gel-like state with a fluid of hard spheres. Complex behavior of the localization lengths and shear moduli exist because of the competition between excluded volume caging forces and attraction-induced physical bond formation between sticky particles. Beyond the NMCT transition, a two-dimensional nonequilibrium free energy surface emerges, which quantifies cooperative activated motions. The barrier locations and heights are sensitive to the relative amplitude of the cooperative displacements of the different species.

  5. Levels of physical activity, barriers, and stage of change in an urban population from a municipality in Colombia

    Directory of Open Access Journals (Sweden)

    Mónica María Arenas

    2011-09-01

    Full Text Available Objective: To assess the levels of physical activity, barriers, and stage of change in an urban population 25 to 50 yearsof age from the Municipality of Santa Rosa de Osos, department of Antioquia.Materials and methods: A prevalence study was conducted, with a two-stage random sampling among 357 individualsnot suffering from any known cardiovascular disease. A pre-designed survey was conducted to assess the levels of physicalactivity, the stage of change, and physical activity barriers.Results: The total low physical activity was 9%, and by domains: work 66.9%, transport 60.8%, household and garden(yard work 44.8%, and leisure-time 76.2%. The most important physical activity barriers were «lack of willpower» (70%and «lack of time» (46.2%. The most prevalent stages of change were «contemplation» (40.3% and «preparation» (17.1%.Conclusion: low physical activity levels were found in different domains of daily life, together with a high prevalenceof barriers and stages prior to physical activity practice, mainly among women and obese subjects.

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

    Science.gov (United States)

    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.

  7. Correlates of daily leisure-time physical activity in a community sample: Narrow personality traits and practical barriers.

    Science.gov (United States)

    Gallagher, Patrick; Yancy, William S; Denissen, Jaap J A; Kühnel, Anja; Voils, Corrine I

    2013-12-01

    Previous studies examining correlates of leisure time physical activity (LTPA) have identified personality factors that are correlated with LTPA and practical factors that impede LTPA. The purpose of the present study was to test how several narrow traits predict daily reports of LTPA and to test whether traits that predict LTPA moderate the effects of practical barriers. 1192 participants completed baseline measures of personality, then reported their LTPA and several situational and environmental factors daily for 25 days. We used generalized estimating equations to measure how personality traits, practical barriers, and interactions between these factors affected (1) the odds of engaging in LTPA and (2) the duration of daily LTPA. Higher standing on Activity and Discipline and lower standing on Assertiveness predicted greater odds of engaging in LTPA and longer duration of LTPA, and higher standing on Aesthetics predicted shorter duration of LTPA. Poor weather conditions and less leisure time were associated with less LTPA, and effects of these barriers were generally greater among participants 30 and older. In participants older than 30, poor weather was associated with less LTPA among those with lower standing on Activity but was not associated with LTPA among those high in Activity. Despite Discipline's overall positive association with LTPA, less leisure time and less routineness were greater barriers for those high in Discipline. Assessing narrow personality traits could help target LTPA interventions to individual patients' needs and could help identify important new personality dynamics that affect LTPA.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  10. Barriers to Physical Activity Among African American Women: An Integrative Review of the Literature.

    Science.gov (United States)

    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.

  11. A review of social and environmental barriers to physical activity for adults with intellectual disabilities.

    Science.gov (United States)

    Bodde, Amy E; Seo, Dong-Chul

    2009-04-01

    There is a higher prevalence of sedentary behavior among adults with intellectual disability (ID) compared to the general population. The majority of research on this topic has focused on assessing physical activity (PA) levels and there are relatively few studies addressing barriers to PA (including exercise) in this population. It is important to analyze the PA barriers faced by adults with ID in order to develop and implement intervention programs. A systematic research review was conducted to analyze the barriers to PA for adults with ID. Original research articles published after 1980 with primary intention of identifying PA determinants of age 18+ adults with ID were included. In total, 837 citations were returned, and after screening for repeated articles and inclusion criteria, 7 were included in the analysis. The primary barriers that reoccurred throughout the papers were transportation issues, financial limitations and lack of awareness of options. Other salient barriers included negative supports from caregivers and authority figures (e.g. teachers, coaches and parents) and lack of clear policies for engaging in regular activity in residential and day service programs. This study reveals clear barriers to PA to target. Of primary importance is the development of policies among agencies that serve individuals with ID that could help minimize transportation, financial, policy and educational barriers, which are more modifiable than negative supports.

  12. Colloidal Oatmeal (Avena Sativa) Improves Skin Barrier Through Multi-Therapy Activity.

    Science.gov (United States)

    Ilnytska, Olha; Kaur, Simarna; Chon, Suhyoun; Reynertson, Kurt A; Nebus, Judith; Garay, Michelle; Mahmood, Khalid; Southall, Michael D

    2016-06-01

    Oats (Avena sativa) are a centuries-old topical treatment for a variety of skin barrier conditions, including dry skin, skin rashes, and eczema; however, few studies have investigated the actual mechanism of action for the skin barrier strengthening activity of colloidal oatmeal. Four extracts of colloidal oatmeal were prepared with various solvents and tested in vitro for skin barrier related gene expression and activity. Extracts of colloidal oatmeal were found to induce the expression of genes related to epidermal differentiation, tight junctions and lipid regulation in skin, and provide pH-buffering capacity. Colloidal oatmeal boosted the expression of multiple target genes related to skin barrier, and resulted in recovery of barrier damage in an in vitro model of atopic dermatitis. In addition, an investigator-blinded study was performed with 50 healthy female subjects who exhibited bilateral moderate to severe dry skin on their lower legs. Subjects were treated with a colloidal oatmeal skin protectant lotion. Clinically, the colloidal oatmeal lotion showed significant clinical improvements in skin dryness, moisturization, and barrier. Taken together, these results demonstrate that colloidal oatmeal can provide clinically effective benefits for dry and compromised skin by strengthening skin barrier. J Drugs Dermatol. 2016;15(6):684-690.

  13. An Activity Theory Approach to Analyze Barriers to a Virtual Management Information Systems (MIS) Curriculum

    Science.gov (United States)

    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…

  14. Barriers and Facilitators of Breastfeeding for Primiparous Active Duty Military Mothers: A Qualitative Study

    Science.gov (United States)

    1999-05-11

    BARRIERS AND FACILITATORS OF BREASTFEEDING FOR PRIMIPAROUS ACTIVE DUTY MILITARY MOTHERS: A QUALITATIVE STUDY Kristine Markley Bristow APPROVED...BREASTFEEDING FOR PRIMIPAROUS ACTIVE DUTY MILITARY MOTHERS: A QUALITATIVE STUDY” beyond brief excerpts is with the permission of the copyright owner, and...breastfeeding for primiparous active duty military mothers, from their perspective, using a Husserlian phenomenological approach. A semi-structured

  15. The impact of peer victimization, parent distress and child depression on barrier formation and physical activity in overweight youth.

    Science.gov (United States)

    Gray, Wendy N; Janicke, David M; Ingerski, Lisa M; Silverstein, Janet H

    2008-02-01

    With the prevalence of childhood overweight reaching epidemic proportions, there is an increased need to identify factors which may aid in the development of successful weight intervention programs. Given that lower levels of physical activity are inversely correlated with weight status in children, research has focused on identifying and addressing reported barriers to physically activity. A relationship exists between the number of reported barriers and weight status such that children who are overweight report more barriers to being physically active. However, important demographic and psychosocial correlates of barriers have not been examined. This study investigates the relationship among parent distress, peer victimization, childhood depression, barriers to physical activity, and physical activity among a sample of 95 clinically overweight children and adolescents. Higher levels of parent distress, peer victimization, and childhood depression are predictive of a variety of barriers to physical activity, with peer victimization emerging as the strongest predictor of barriers. Barriers to physical activity mediate the relationships between peer victimization, parent distress, child depression and physical activity. These findings have significant implications for the development/design of weight intervention programs. Interventions targeting increases in physical activity should not only focus on the barriers children report, but should also include a psycho-emotional component to address factors such as parent distress, peer victimization and child mood that may contribute to barrier formation/maintenance. Future interventions may benefit from the identification of additional factors that impact barrier formation and physical activity levels among children.

  16. Heat-Activated Effect of Exchange Coupling Between Two Ferromagnets Separated by an Amorphous Semiconducting Barrier

    Institute of Scientific and Technical Information of China (English)

    肖明文; 李正中; 许望

    2002-01-01

    We try to extend our previous zero-temperature tunnelling theory for the exchange coupling between two ferromagnets separated by an amorphous semiconducting barrier to the case of finite temperature. The result exhibits that the tunnelling electrons can absorb or emit phonons when they tunnel through the amorphous barrier at finite temperatures so that the interlayer exchange coupling is heat activated. This agrees with the experiments.

  17. Children's active play: self-reported motivators, barriers and facilitators

    Directory of Open Access Journals (Sweden)

    Rowan Brockman

    2011-06-01

    Full Text Available Physical activity has important benefits for children's physical health and mental wellbeing, but many children do not meet recommended levels. Research suggests that active play has the potential to make a valuable contribution to children's overall physical activity, whilst providing additional cognitive, social and emotional benefits. However, relatively little is known about the determinants of UK children's active play. Understanding these factors provides the critical first step in developing interventions to increase children's active play, and therefore overall physical activity. Eleven focus groups were conducted with 77, 10-11 year old children from four primary schools in Bristol, UK. Focus groups examined: (i factors which motivate children to take part in active play; (ii factors which limit children's active play and (iii factors which facilitate children's active play. All focus groups were audio-taped and transcribed verbatim. Data were analysed using a thematic approach. Children were motivated to engage in active play because they perceived it to be enjoyable, to prevent boredom, to have physical and mental health benefits and to provide freedom from adult control, rules and structure. However, children's active play was constrained by a number of factors, including rainy weather and fear of groups of teenagers in their play spaces. Some features of the physical environment facilitated children's active play, including the presence of green spaces and cul-de-sacs in the neighbourhood. Additionally, children's use of mobile phones when playing away from home was reported to help to alleviate parents' safety fears, and therefore assist children's active play. Children express a range of motivational and environmental factors that constrain and facilitate their active play. Consideration of these factors should improve effectiveness of interventions designed to increase active play.

  18. Barrier-protective effects of activated protein C in human alveolar epithelial cells.

    Directory of Open Access Journals (Sweden)

    Ferranda Puig

    Full Text Available Acute lung injury (ALI is a clinical manifestation of respiratory failure, caused by lung inflammation and the disruption of the alveolar-capillary barrier. Preservation of the physical integrity of the alveolar epithelial monolayer is of critical importance to prevent alveolar edema. Barrier integrity depends largely on the balance between physical forces on cell-cell and cell-matrix contacts, and this balance might be affected by alterations in the coagulation cascade in patients with ALI. We aimed to study the effects of activated protein C (APC on mechanical tension and barrier integrity in human alveolar epithelial cells (A549 exposed to thrombin. Cells were pretreated for 3 h with APC (50 µg/ml or vehicle (control. Subsequently, thrombin (50 nM or medium was added to the cell culture. APC significantly reduced thrombin-induced cell monolayer permeability, cell stiffening, and cell contraction, measured by electrical impedance, optical magnetic twisting cytometry, and traction microscopy, respectively, suggesting a barrier-protective response. The dynamics of the barrier integrity was also assessed by western blotting and immunofluorescence analysis of the tight junction ZO-1. Thrombin resulted in more elongated ZO-1 aggregates at cell-cell interface areas and induced an increase in ZO-1 membrane protein content. APC attenuated the length of these ZO-1 aggregates and reduced the ZO-1 membrane protein levels induced by thrombin. In conclusion, pretreatment with APC reduced the disruption of barrier integrity induced by thrombin, thus contributing to alveolar epithelial barrier protection.

  19. A cluster expansion model for predicting activation barrier of atomic processes

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, Tafizur; Jaipal, M. [Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India); Chatterjee, Abhijit, E-mail: achatter@iitk.ac.in [Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India); Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400 076 (India)

    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 NEB 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.

  20. "My hair or my health:" Overcoming barriers to physical activity in African American women with a focus on hairstyle-related factors.

    Science.gov (United States)

    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 November 2012 to February 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.

  1. Degradation of Organic Compounds by Active Species Sprayed in a Dielectric Barrier Corona Discharge System

    Institute of Scientific and Technical Information of China (English)

    LI Jie; SONG Ling; LIU Qiang; QU Guangzhou; LI Guofeng; WU Yan

    2009-01-01

    Investigation was made into the degradation of organic compounds by a dielectric barrier corona discharge (DBCD) system. The DBCD, consisting of a quartz tube, a concentric high voltage electrode and a net wrapped to the external wall (used as ground electrode), was introduced to generate active species which were sprayed into the organic solution through an aerator fixed on the bottom of the tube. The effect of four factors-the discharge voltage, gas flow rate, solution conductivity, and pH of wastewater, on the degradation efficiency of phenol was assessed. The obtained results demonstrated that this process was an effective method for phenol degradation. The degradation rate was enhanced with the increase in power supplied. The degradation efficiency in alkaline conditions was higher than those in acid and neutral conditions.The optimal gas flow rate for phenol degradation in the system was 1.6 L/min, while the solution conductivity had little effect on the degradation.

  2. Physical Activity and Reported Barriers to Activity Among Type 2 Diabetic Patients in the United Arab Emirates

    Science.gov (United States)

    Al-Kaabi, Juma; Al-Maskari, Fatma; Afandi, Bachar; Parkar, Hasratali; Nagelkerke, Nicolaas

    2009-01-01

    OBJECTIVES: This study was designed to assess the physical activity practice among type 2 diabetic patients in the United Arab Emirates (UAE). METHODS: This is a cross-sectional study of type 2 diabetic patients who participated in the outpatient clinics in Al-Ain District, during 2006. The patients completed an interviewer-administered questionnaire, and measurements of blood pressure, body mass index, body fat, abdominal circumference, glycemic control (HbA1c), and fasting lipid profile. RESULTS: Of the 390 patients recruited, only 25% reported an increase in their physical activity levels following the diagnosis of diabetes, and only 3% reported physical activity levels that meet the recommended guidelines. More than half of the study subjects had uncontrolled hypertension (53%) and unacceptable lipid profiles; 71% had a high low-density lipoprotein (LDL), 73% had low high-density lipoprotein (HDL), and 59% had hypertriglyceridemia. Forty-four percent were obese and a further 34% were overweight. Abdominal obesity was also common (59%). Only 32% had an acceptable glycemic control. CONCLUSIONS: The physical activity practice of type 2 diabetic patients in the UAE is largely inadequate to meet the recommended level necessary to prevent or ameliorate diabetic complications. Interventions aiming at overcoming the barriers to physical activity are urgently needed. PMID:20043039

  3. A high rotational barrier for physisorbed hydrogen in an fcu-metal-organic framework

    KAUST Repository

    Pham, Tony T.

    2014-01-01

    A combined inelastic neutron scattering (INS) and theoretical study of H2 sorption in Y-FTZB, a recently reported metal-organic framework (MOF) with fcu topology, reveals that the strongest binding site in the MOF causes a high barrier to rotation on the sorbed H2. This rotational barrier for H2 is the highest yet of reported MOF materials based on physisorption. This journal is

  4. Identifying Facilitators and Barriers to Physical Activity for Adults with Down Syndrome

    Science.gov (United States)

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

    2010-01-01

    Background: 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. Method: Semi-structured interviews were conducted to elicit the views of adults with Down…

  5. Identifying the Barriers and Facilitators to Participation in Physical Activity for Children with Down Syndrome

    Science.gov (United States)

    Barr, M.; Shields, N.

    2011-01-01

    Background: Many children with Down syndrome do not undertake the recommended amount of daily physical activity. The aim of this study was to explore the barriers and facilitators to physical activity for this group. Methods: Eighteen in-depth interviews were conducted with 20 parents (16 mothers, 4 fathers) of children with Down syndrome aged…

  6. Identifying the Barriers and Facilitators to Participation in Physical Activity for Children with Down Syndrome

    Science.gov (United States)

    Barr, M.; Shields, N.

    2011-01-01

    Background: Many children with Down syndrome do not undertake the recommended amount of daily physical activity. The aim of this study was to explore the barriers and facilitators to physical activity for this group. Methods: Eighteen in-depth interviews were conducted with 20 parents (16 mothers, 4 fathers) of children with Down syndrome aged…

  7. Barriers to Physical Activity for People with Long-Term Neurological Conditions: A Review Study

    Science.gov (United States)

    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…

  8. Barriers in the implementation of a physical activity intervention in primary care settings: lessons learned.

    Science.gov (United States)

    Josyula, Lakshmi K; Lyle, Roseann M

    2013-01-01

    Barriers encountered in implementing a physical activity intervention in primary health care settings, and ways to address them, are described in this paper. A randomized comparison trial was designed to examine the impact of health care providers' written prescriptions for physical activity, with or without additional physical activity resources, to adult, nonpregnant patients on preventive care or chronic disease monitoring visits. Following abysmal recruitment outcomes, the research protocol was altered to make it more appealing to all the participants, i.e., health care providers, office personnel, and patients. Various barriers--financial, motivational, and executive--to the implementation of health promotion interventions in primary health care settings were experienced and identified. These barriers have been classified by the different participants in the research process, viz., healthcare providers, administrative personnel, researchers, and patients. Some of the barriers identified were lack of time and reimbursement for health promotion activities, and inadequate practice capacity, for health care providers; increased time and labor demands for administrative personnel; constrained access to participants, and limited funding, for researchers; and superseding commitments, and inaccurate comprehension of the research protocol, for patients. Solutions suggested to overcome these barriers include financial support, e.g., funding for researchers, remuneration for health care organization personnel, reimbursement for providers, payment for participants, and free or subsidized postage, and use of health facilities; motivational strategies such as inspirational leadership, and contests within health care organizations; and partnerships, with other expert technical and creative entities, to improve the quality, efficiency, and acceptability of health promotion interventions.

  9. Active explosion barrier performance against methane and coal dust explosions

    National Research Council Canada - National Science Library

    J. J. L. du Plessis

    2015-01-01

    Preventing the propagation of methane or coal dust explosions through the use of active explosion-suppression systems remains one of the most underutilised explosion controls in underground coal mines...

  10. Removing the barrier to the calculation of activation energies

    Science.gov (United States)

    Mesele, Oluwaseun O.; Thompson, Ward H.

    2016-10-01

    Approaches for directly calculating the activation energy for a chemical reaction from a simulation at a single temperature are explored with applications to both classical and quantum systems. The activation energy is obtained from a time correlation function that can be evaluated from the same molecular dynamics trajectories or quantum dynamics used to evaluate the rate constant itself and thus requires essentially no extra computational work.

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

    Directory of Open Access Journals (Sweden)

    Samara A

    2015-03-01

    Full Text Available Anastasia Samara,1 Anne Nistrup,1 Tamader Y AL-Rammah,2 Arja R Aro11Unit for Health Promotion and Research, University of Southern Denmark, Esbjerg, Denmark; 2Faculty of Rehabilitation and Health Sciences, Princess Nora Bint Abdul Rahman University, Riyadh, Kingdom of Saudi ArabiaPurpose: 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.Patients and methods: 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.Results: 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.Conclusion: The lack of facilities and lack of encouragement from the university, but not a lack of knowledge (a high level of

  12. Internet Integration in High Schools: Patterns, Opportunities, and Barriers.

    Science.gov (United States)

    Thomas, Ruth; Adams, Marilyn; Meghani, Naheed; Smith, Maria

    Internet integration in high schools on a schoolwide scale was examined through case studies of five high schools in inner city, urban, suburban, and rural communities across the United States. A total of 322 teachers, 19 administrators, 19 counselors, 7 technology coordinators, and 3,822 students were surveyed, and 219 staff and students were…

  13. AN ACTIVITY THEORY APPROACH TO STUDY BARRIERS OF FACULTY REGARDING TECHNOLOGY INTEGRATION IN HIGHER EDUCATION

    DEFF Research Database (Denmark)

    Castro Guzman, Willy

    2016-01-01

    Information and communication technologies are instruments for supporting new ways of teaching and learning. Nevertheless, its impact concerning scope has not reached the expected level. This strain between benefits and impact has been inquired from the perspective of barriers of teachers to use...... for a reconceptualization in the study of barriers arguing that the teaching process is a complex and dynamic activity that needs to be examined from a collective perspective. Cultural-Historical Activity Theory is the theoretical framework used in the study. It concludes with the necessity of overcoming the existing...

  14. Etk/Bmx activation modulates barrier function in epithelial cells.

    Science.gov (United States)

    Hamm-Alvarez, S F; Chang, A; Wang, Y; Jerdeva, G; Lin, H H; Kim, K J; Ann, D K

    2001-06-01

    Etk/Bmx is a member of the Tec family of cytoplasmic non-receptor tyrosine kinases known to express in epithelial cells. We demonstrate herein that Etk activation in stably Etk-transfected epithelial Pa-4 cells resulted in a consistently increased transepithelial resistance (TER). After 24 h of hypoxic (1% O(2)) exposure, the TER and equivalent active ion transport rate (I(eq)) were reduced to <5% of the normoxia control in Pa-4 cells, whereas both TER and I(eq) were maintained at comparable and 60% levels, respectively, relative to their normoxic controls in cells with Etk activation. Moreover, Pa-4 cells exhibited an abundant actin stress fiber network with a diffuse distribution of beta-catenin at the cell periphery. By contrast, Etk-activated cells displayed a redistribution of actin to an exclusively peripheral network, with a discrete band of beta-catenin also concentrated at the cell periphery, and an altered occludin distribution profile. On the basis of these findings, we propose that Etk may be a novel regulator of epithelial junctions during physiological and pathophysiological conditions.

  15. Motivators and barriers for physical activity in the oldest old: a systematic review.

    Science.gov (United States)

    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.

  16. Saudi high school students' attitudes and barriers toward the use of computer technologies in learning English.

    Science.gov (United States)

    Sabti, Ahmed Abdulateef; Chaichan, Rasha Sami

    2014-01-01

    This study examines the attitudes of Saudi Arabian high school students toward the use of computer technologies in learning English. The study also discusses the possible barriers that affect and limit the actual usage of computers. Quantitative approach is applied in this research, which involved 30 Saudi Arabia students of a high school in Kuala Lumpur, Malaysia. The respondents comprised 15 males and 15 females with ages between 16 years and 18 years. Two instruments, namely, Scale of Attitude toward Computer Technologies (SACT) and Barriers affecting Students' Attitudes and Use (BSAU) were used to collect data. The Technology Acceptance Model (TAM) of Davis (1989) was utilized. The analysis of the study revealed gender differences in attitudes toward the use of computer technologies in learning English. Female students showed high and positive attitudes towards the use of computer technologies in learning English than males. Both male and female participants demonstrated high and positive perception of Usefulness and perceived Ease of Use of computer technologies in learning English. Three barriers that affected and limited the use of computer technologies in learning English were identified by the participants. These barriers are skill, equipment, and motivation. Among these barriers, skill had the highest effect, whereas motivation showed the least effect.

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

    Science.gov (United States)

    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

  18. Redox-active media for permeable reactive barriers

    Energy Technology Data Exchange (ETDEWEB)

    Sivavec, T.M. [General Electric Corp. Research and Development Center, Schenectady, NY (United States); Mackenzie, P.D.; Horney, D.P.; Baghel, S.S.

    1997-12-31

    In this paper, three classes of redox-active media are described and evaluated in terms of their long-term effectiveness in treating TCE-contaminated groundwater in permeable reactive zones. Zero-valent iron, in the form of recycled cast iron filings, the first class, has received considerable attention as a reactive media and has been used in about a dozen pilot- and full-scale subsurface wall installations. Criteria used in selecting commercial sources of granular iron, will be discussed. Two other classes of redox-active media that have not yet seen wide use in pilot- or full-scale installations will also be described: Fe(II) minerals and bimetallic systems. Fe(II) minerals, including magnetite (Fe{sub 3}O{sub 4}), and ferrous sulfide (troilite, FeS), are redox-active and afford TCE reduction rates and product distributions that suggest that they react via a reductive mechanism similar to that which operates in the FeO system. Fe(II) species within the passive oxide layer coating the iron metal may act as electron transfer mediators, with FeO serving as the bulk reductant. Bimetallic systems, the third class of redox-active media, are commonly prepared by plating a second metal onto zero-valent iron (e.g., Ni/Fe and Pd/Fe) and have been shown to accelerate solvent degradation rates relative to untreated iron metal. The long-term effectiveness of this approach, however, has not yet been determined in groundwater treatability tests. The results of a Ni-plated iron column study using site groundwater indicate that a change in reduction mechanism (to catalytic dehydrohalogenation/hydrogenation) accounts for the observed rate enhancement. A significant loss in media reactivity was observed over time, attributable to Ni catalyst deactivation or poisoning. Zero-valent iron systems have not shown similar losses in reactivity in long-term laboratory, pilot or field investigations.

  19. Barriers, enjoyment, and preference for physical activity among adults with intellectual disability.

    Science.gov (United States)

    Temple, Viviene A

    2007-12-01

    Many adults with an intellectual disability exhibit low physical activity levels. The aim of this study was to examine the relationships between participation in physical activity/sedentary behaviour and factors consistent with behavioural choice theory: enjoyment, preference, and barriers. Examination of these relationships increases our understanding of physical activity behaviour among adults with an intellectual disability. A descriptive correlational design was used. Steps per day of adults with intellectual disability (n = 37) were measured using pedometers for 1 week and associations with barriers, enjoyment, and preference were computed from participant's survey responses. Average steps per day ranged from 1658 to 19 303 (M = 8100.5+/-3735.4). Linear regression showed that barriers to physical activity and preference for sedentary behaviour were significant predictors of steps per day R = 0.533 (P = 0.009); which accounted for 28.4% of the variance in steps per day. The factor that stands out from this study for the least active individuals was accessibility of physical activity options. Ensuring that the effort needed to engage in physical activity is manageable and perceived as achievable is important. In addition, the higher preference for sedentary activity among the least active individuals suggests that it will be valuable to examine what attracts adults with an intellectual disability to particular physical activities and what aspects of participation they find reinforcing.

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

    OpenAIRE

    Blake, Holly; Stanulewicz, Natalia; McGill, Francesca

    2016-01-01

    Aims\\ud \\ud 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.\\ud Background\\ud \\ud Healthcare professionals have low levels of physical activity, which increases their health risk and may influence their health promotion practices with patients.\\ud Design\\ud \\ud We surveyed 361 nursing (n=193) and medicine (n=168) students studying at a UK medical school.\\...

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

    OpenAIRE

    Blake, Holly; Stanulewicz, Natalia; McGill, Francesca

    2016-01-01

    Aims 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. Background Healthcare professionals have low levels of physical activity, which increases their health risk and may influence their health promotion practices with patients. Design We surveyed 361 nursing (n=193) and medicine (n=168) students studying at a UK medical school. Method...

  2. Surface alkaline phosphatase activities of macroalgae on coral reefs of the central Great Barrier Reef, Australia

    Science.gov (United States)

    Schaffelke, B.

    2001-05-01

    Inshore reefs of the Great Barrier Reef (GBR) are subject to episodic nutrient supply, mainly by flood events, whereas midshelf reefs have a more consistent low nutrient availability. Alkaline phosphatase activity (APA) enables macroalgae to increase their phosphorus (P) supply by using organic P. APA was high (~4.0 to 15.5 µmol PO4 3- g DW-1 h-1) in species colonising predominantly inshore reefs and low (study were much lower than data reported from other coral reef systems. In experiments with two Sargassum species tissue P levels were correlated negatively, and N:P ratios were positively correlated with APA. High APA can compensate for a relative P-limitation of macroalgae in coral reef systems that are subject to significant N-inputs, such as the GBR inshore reefs. APA and other mechanisms to acquire a range of nutrient species allow inshore species to thrive in habitats with episodic nutrient supply. These species also are likely to benefit from an increased nutrient supply caused by human activity, which currently is a global problem.

  3. Removal of atrazine in water by combination of activated carbon and dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Vanraes, Patrick, E-mail: patrick.vanraes@ugent.be [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Willems, Gert; Nikiforov, Anton [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium); Surmont, Pieter; Lynen, Frederic [Separation Science Group, Department of Organic Chemistry, Ghent University, Krijgslaan 281 S4-bis, 9000 Gent (Belgium); Vandamme, Jeroen; Van Durme, Jim [Research Group Molecular Odor Chemistry, Department of Microbial and Molecular Systems (M2S), KU Leuven, Technology Campus, Gebroeders De Smetstraat 1, 9000 Gent (Belgium); Verheust, Yannick P.; Van Hulle, Stijn W.H.; Dumoulin, Ann [Department of Industrial Biological Sciences, Ghent University, Graaf Karel de Goedelaan 5, 8500 Kortrijk (Belgium); Leys, Christophe [Department of Applied Physics, Ghent University, Sint-Pietersnieuwstraat 41 B4, 9000 Gent (Belgium)

    2015-12-15

    Highlights: • Increasing input power with a factor 3.5 leads to deeper atrazine oxidation without significantly changing energy yield of atrazine removal. • Chlorine containing oxidation by-products of first and later generations are detected with HPLC–MS analysis, in agreement with literature. • Desorption analysis shows lower atrazine concentration and higher by-product concentration on activated carbon textile after plasma treatment. • Comparison with plasma reactors described in literature for atrazine decomposition confirms relatively high energy efficiency of our reactor. - Abstract: Efficiency of modern wastewater treatment plants to remove or decompose persistent contaminants in low concentration is often insufficient to meet the demands imposed by governmental laws. Novel, efficient and cheap methods are required to address this global issue. We developed a new type of plasma reactor, in which atrazine decomposition by atmospheric dielectric barrier discharge (DBD) in dry air is combined with micropollutant adsorption on activated carbon textile and with extra bubbling of generated ozone. Investigation of reaction kinetics and by-product analysis shows that increasing input power with a factor 3.5 leads to deeper atrazine oxidation without significantly changing energy yield of atrazine removal. By-products of first and later generations are detected with HPLC–MS analysis in water and adsorbed on the activated carbon textile. Our reactor is compared in energy efficiency with reactors described in literature, showing that combination of plasma discharge with pollutant adsorption and ozone recycling is attractive for future applications of water treatment.

  4. A High-Powered View of the Filtration Barrier

    OpenAIRE

    Peti-Peterdi, János; Sipos, Arnold

    2010-01-01

    Multiphoton excitation fluorescence microscopy is a powerful noninvasive imaging technique for the deep optical sectioning of living tissues. Its application in several intact tissues is a significant advance in our understanding of organ function, including renal pathophysiological mechanisms. The glomerulus, the filtering unit in the kidney, is one good example of a relatively inaccessible and complex structure, with cell types that are otherwise difficult to study at high resolution in the...

  5. Perceived Reasons, Incentives, and Barriers to Physical Activity in Swedish Elderly Men

    Science.gov (United States)

    Bonn, Stephanie E; Trolle Lagerros, Ylva; Sjölander, Arvid; Bälter, Katarina

    2014-01-01

    Background Knowledge about factors influencing physical activity behavior is needed in order to tailor physical activity interventions to the individual. Objective 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. Methods 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). Results 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. Conclusions Enjoyment and maintaining a good health were important reasons for engaging in physical activity among Swedish elderly men. PMID:25488655

  6. Barriers, Motivations, and Preferences for Physical Activity Among Female African American Older Adults

    Directory of Open Access Journals (Sweden)

    Neha P. Gothe PhD

    2016-11-01

    Full Text Available 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.

  7. Investigation of significantly high barrier height in Cu/GaN Schottky diode

    Directory of Open Access Journals (Sweden)

    Manjari Garg

    2016-01-01

    Full Text Available Current-voltage (I-V measurements combined with analytical calculations have been used to explain mechanisms for forward-bias current flow in Copper (Cu Schottky diodes fabricated on Gallium Nitride (GaN epitaxial films. An ideality factor of 1.7 was found at room temperature (RT, which indicated deviation from thermionic emission (TE mechanism for current flow in the Schottky diode. Instead the current transport was better explained using the thermionic field-emission (TFE mechanism. A high barrier height of 1.19 eV was obtained at room temperature. X-ray photoelectron spectroscopy (XPS was used to investigate the plausible reason for observing Schottky barrier height (SBH that is significantly higher than as predicted by the Schottky-Mott model for Cu/GaN diodes. XPS measurements revealed the presence of an ultrathin cuprous oxide (Cu2O layer at the interface between Cu and GaN. With Cu2O acting as a degenerate p-type semiconductor with high work function of 5.36 eV, a high barrier height of 1.19 eV is obtained for the Cu/Cu2O/GaN Schottky diode. Moreover, the ideality factor and barrier height were found to be temperature dependent, implying spatial inhomogeneity of barrier height at the metal semiconductor interface.

  8. Investigation of significantly high barrier height in Cu/GaN Schottky diode

    Energy Technology Data Exchange (ETDEWEB)

    Garg, Manjari, E-mail: meghagarg142@gmail.com; Kumar, Ashutosh; Singh, R. [Department of Physics, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi-110016 (India); Nagarajan, S.; Sopanen, M. [Department of Micro and Nanosciences, Aalto University, P.O. Box 13500, FI-00076, Aalto (Finland)

    2016-01-15

    Current-voltage (I-V) measurements combined with analytical calculations have been used to explain mechanisms for forward-bias current flow in Copper (Cu) Schottky diodes fabricated on Gallium Nitride (GaN) epitaxial films. An ideality factor of 1.7 was found at room temperature (RT), which indicated deviation from thermionic emission (TE) mechanism for current flow in the Schottky diode. Instead the current transport was better explained using the thermionic field-emission (TFE) mechanism. A high barrier height of 1.19 eV was obtained at room temperature. X-ray photoelectron spectroscopy (XPS) was used to investigate the plausible reason for observing Schottky barrier height (SBH) that is significantly higher than as predicted by the Schottky-Mott model for Cu/GaN diodes. XPS measurements revealed the presence of an ultrathin cuprous oxide (Cu{sub 2}O) layer at the interface between Cu and GaN. With Cu{sub 2}O acting as a degenerate p-type semiconductor with high work function of 5.36 eV, a high barrier height of 1.19 eV is obtained for the Cu/Cu{sub 2}O/GaN Schottky diode. Moreover, the ideality factor and barrier height were found to be temperature dependent, implying spatial inhomogeneity of barrier height at the metal semiconductor interface.

  9. A comparison of professional-level faculty and student perceptions of active learning: its current use, effectiveness, and barriers

    Science.gov (United States)

    Metz, Michael J.

    2014-01-01

    Active learning is an instructional method in which students become engaged participants in the classroom through the use of in-class written exercises, games, problem sets, audience-response systems, debates, class discussions, etc. Despite evidence supporting the effectiveness of active learning strategies, minimal adoption of the technique has occurred in many professional programs. The goal of this study was to compare the perceptions of active learning between students who were exposed to active learning in the classroom (n = 116) and professional-level physiology faculty members (n = 9). Faculty members reported a heavy reliance on lectures and minimal use of educational games and activities, whereas students indicated that they learned best via the activities. A majority of faculty members (89%) had observed active learning in the classroom and predicted favorable effects of the method on student performance and motivation. The main reported barriers by faculty members to the adoption of active learning were a lack of necessary class time, a high comfort level with traditional lectures, and insufficient time to develop materials. Students hypothesized similar obstacles for faculty members but also associated many negative qualities with the traditional lecturers. Despite these barriers, a majority of faculty members (78%) were interested in learning more about the alternative teaching strategy. Both faculty members and students indicated that active learning should occupy portions (29% vs. 40%) of face-to-face class time. PMID:25179615

  10. A Comparison of Motivational Factors and Barriers to Physical Activity among Traditional versus Nontraditional College Students

    Science.gov (United States)

    Kulavic, Kimberly; Hultquist, Cherilyn N.; McLester, John R.

    2013-01-01

    Objective: To investigate the motivational factors and the barriers to physical activity (PA) in traditional college students (TS) and nontraditional college students (NTS) and determine if differences exist between these 2 groups. Participants: A total of 746 college students; 628 were TS (19.1 [plus-minus] 1.2 years), and 118 were NTS (31.2…

  11. Adolescents' Perspectives on the Barriers and Facilitators of Physical Activity: A Systematic Review of Qualitative Studies

    Science.gov (United States)

    Martins, João; Marques, Adilson; Sarmento, Hugo; Carreiro da Costa, Francisco

    2015-01-01

    This article examined qualitative studies of adolescents' perspectives about the facilitators and barriers of physical activity, published from 2007 to 2014. A systematic review of "Web of Science", "EBSCO", "Psychinfo" and "ERIC" databases was performed according to Preferred Reporting Items for Systematic…

  12. Confronting Physical Activity Programming Barriers for People with Disabilities: The Empowerment Model

    Science.gov (United States)

    Moran, Thomas Eugene; Taliaferro, Andrea R.; Pate, Joshua R.

    2014-01-01

    Community-based physical activity programs for people with disabilities have barriers that are unique to their program leader qualifications and the population they serve. Moran and Block (2010) argued that there is a need for practical strategies that are easy for communities to implement, maximize resources, and minimize the impact of barriers…

  13. Parent Support for Children's Physical Activity: A Qualitative Investigation of Barriers and Strategies

    Science.gov (United States)

    Bassett-Gunter, Rebecca; Rhodes, Ryan; Sweet, Shane; Tristani, Lauren; Soltani, Yasaman

    2017-01-01

    Purpose: Parents play an important role in supporting children's physical activity (PA) behavior. Parent PA support is a behavior unto itself that has been examined within the framework of an adapted theory of planned behavior (TPB). The primary purpose of this research was to identify key barriers to parent PA support to understand perceptions of…

  14. Young adult males' motivators and perceived barrier towards eating healthily and being active: A qualitative study

    Science.gov (United States)

    There is a lack of understanding of young men's perspectives in obesity-related research. This study aims to: (1) identify young men's perceived motivators and barriers in adopting healthy eating and physical activity behaviors, and (2) explore any differences in responses by weight status categorie...

  15. Adolescents' Perspectives on the Barriers and Facilitators of Physical Activity: A Systematic Review of Qualitative Studies

    Science.gov (United States)

    Martins, João; Marques, Adilson; Sarmento, Hugo; Carreiro da Costa, Francisco

    2015-01-01

    This article examined qualitative studies of adolescents' perspectives about the facilitators and barriers of physical activity, published from 2007 to 2014. A systematic review of "Web of Science", "EBSCO", "Psychinfo" and "ERIC" databases was performed according to Preferred Reporting Items for Systematic…

  16. A Qualitative Examination of Perceived Barriers and Facilitators of Physical Activity for Urban and Rural Youth

    Science.gov (United States)

    Moore, Justin B.; Jilcott, Stephanie B.; Shores, Kindal A.; Evenson, Kelly R.; Brownson, Ross C.; Novick, Lloyd F.

    2010-01-01

    Many adolescents, both rural and urban, are not meeting the recommended levels for physical activity (PA). This investigation was designed to elicit socioecologic barriers and facilitators for PA in rural and urban middle school youth and their parents. Thirteen focus groups were conducted with 41 youth and 50 parents from eastern North Carolina.…

  17. EFFECTS OF HIGH-INTENSITY ENDURANCE EXERCISE ON EPIDERMAL BARRIERS AGAINST MICROBIAL INVASION

    Directory of Open Access Journals (Sweden)

    Nobuhiko Eda

    2013-03-01

    Full Text Available For athletes, preventing infectious disease on skin is important. Examination measurement of epidermal barriers could provide valuable information on the risk of skin infections. The aim of this study was to determine the effects of high-intensity endurance exercise on epidermal barriers. Six healthy adult males (age; 22.3 ± 1.6 years performed bicycle exercise at 75%HRmax for 60 min from 18:30 to 19:30. Skin surface samples were measured 18:30 (pre, 19:30 (post, 20:30 (60 min, and 21:30 (120 min. Secretory immunoglobulin A (SIgA and human β-defensin 2 (HBD-2 concentrations were measured using an enzyme-linked immunosorbent assay (ELISA. SIgA concentration at pre was significantly higher than at post, 60 min and 120 min (p < 0.05. HBD-2 concentration at post and 120 min was significantly higher than at pre (p < 0. 05. Moisture content of the stratum corneum was significantly higher at post than at pre, 60 min, and 120 min (p < 0.05. On the chest, moisture content of the stratum corneum was significantly lower at 120 min than at pre (p < 0.05. The number of staphylococci was significantly higher at post than at pre (p < 0.05, and tended to be higher at 60 min than at pre on the chest (p = 0. 08. High-intensity endurance exercise might depress the immune barrier and physical barrier and enhance the risk of skin infection. On the other hand, the biochemical barrier increases after exercise, and our findings suggest that this barrier might supplement the compromised function of other skin barriers.

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

    Science.gov (United States)

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

    2017-01-19

    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.

  19. Application of CFRP with High Hydrogen Gas Barrier Characteristics to Fuel Tanks of Space Transportation System

    Science.gov (United States)

    Yonemoto, Koichi; Yamamoto, Yuta; Okuyama, Keiichi; Ebina, Takeo

    In the future, carbon fiber reinforced plastics (CFRPs) with high hydrogen gas barrier performance will find wide applications in all industrial hydrogen tanks that aim at weight reduction; the use of such materials will be preferred to the use of conventional metallic materials such as stainless steel or aluminum. The hydrogen gas barrier performance of CFRP will become an important issue with the introduction of hydrogen-fuel aircraft. It will also play an important role in realizing fully reusable space transportation system that will have high specific tensile CFRP structures. Such materials are also required for the manufacture of high-pressure hydrogen gas vessels for use in the fuel cell systems of automobiles. This paper introduces a new composite concept that can be used to realize CFRPs with high hydrogen gas barrier performance for applications in the cryogenic tanks of fully reusable space transportation system by the incorporation of a nonmetallic crystal layer, which is actually a dense and highly oriented clay crystal laminate. The preliminary test results show that the hydrogen gas barrier characteristics of this material after cryogenic heat shocks and cyclic loads are still better than those of other polymer materials by approximately two orders of magnitude.

  20. CB2 Receptor Activation Inhibits Melanoma Cell Transmigration through the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    János Haskó

    2014-05-01

    Full Text Available During parenchymal brain metastasis formation tumor cells need to migrate through cerebral endothelial cells, which form the morphological basis of the blood-brain barrier (BBB. The mechanisms of extravasation of tumor cells are highly uncharacterized, but in some aspects recapitulate the diapedesis of leukocytes. Extravasation of leukocytes through the BBB is decreased by the activation of type 2 cannabinoid receptors (CB2; therefore, in the present study we sought to investigate the role of CB2 receptors in the interaction of melanoma cells with the brain endothelium. First, we identified the presence of CB1, CB2(A, GPR18 (transcriptional variant 1 and GPR55 receptors in brain endothelial cells, while melanoma cells expressed CB1, CB2(A, GPR18 (transcriptional variants 1 and 2, GPR55 and GPR119. We observed that activation of CB2 receptors with JWH-133 reduced the adhesion of melanoma cells to the layer of brain endothelial cells. JWH-133 decreased the transendothelial migration rate of melanoma cells as well. Our results suggest that changes induced in endothelial cells are critical in the mediation of the effect of CB2 agonists. Our data identify CB2 as a potential target in reducing the number of brain metastastes originating from melanoma.

  1. CB2 Receptor Activation Inhibits Melanoma Cell Transmigration through the Blood-Brain Barrier

    Science.gov (United States)

    Haskó, János; Fazakas, Csilla; Molnár, Judit; Nyúl-Tóth, Ádám; Herman, Hildegard; Hermenean, Anca; Wilhelm, Imola; Persidsky, Yuri; Krizbai, István A.

    2014-01-01

    During parenchymal brain metastasis formation tumor cells need to migrate through cerebral endothelial cells, which form the morphological basis of the blood-brain barrier (BBB). The mechanisms of extravasation of tumor cells are highly uncharacterized, but in some aspects recapitulate the diapedesis of leukocytes. Extravasation of leukocytes through the BBB is decreased by the activation of type 2 cannabinoid receptors (CB2); therefore, in the present study we sought to investigate the role of CB2 receptors in the interaction of melanoma cells with the brain endothelium. First, we identified the presence of CB1, CB2(A), GPR18 (transcriptional variant 1) and GPR55 receptors in brain endothelial cells, while melanoma cells expressed CB1, CB2(A), GPR18 (transcriptional variants 1 and 2), GPR55 and GPR119. We observed that activation of CB2 receptors with JWH-133 reduced the adhesion of melanoma cells to the layer of brain endothelial cells. JWH-133 decreased the transendothelial migration rate of melanoma cells as well. Our results suggest that changes induced in endothelial cells are critical in the mediation of the effect of CB2 agonists. Our data identify CB2 as a potential target in reducing the number of brain metastastes originating from melanoma. PMID:24815068

  2. Assessment of active play, inactivity and perceived barriers in an inner city neighborhood

    OpenAIRE

    Kottyan, Gregg; Kottyan, Leah; Edwards, Nicholas M.; Unaka, Ndidi I.

    2014-01-01

    Avondale, a disadvantaged neighborhood in Cincinnati, lags behind on a number of indicators of child well-being. Childhood obesity has become increasingly prevalent, as one third of Avondale’s kindergarteners are obese or overweight. The study objective was to determine perceptions of the quantity of and obstacles to childhood physical activity in the Avondale community. Caregivers of children from two elementary schools were surveyed to assess their child’s physical activity and barriers to ...

  3. Disease activity in eosinophilic esophagitis is associated with impaired esophageal barrier integrity.

    Science.gov (United States)

    Warners, Marijn J; van Rhijn, Bram D; Verheij, Joanne; Smout, Andreas J P M; Bredenoord, Albert J

    2017-09-01

    In eosinophilic esophagitis (EoE), the esophageal barrier integrity is impaired. Integrity can be assessed with different techniques. To assess the correlations between esophageal eosinophilia and various measures of mucosal integrity and to evaluate whether endoscopic impedance measurements can predict disease activity, endoscopies and mucosal integrity measurements were performed in adult EoE patients with active disease (≥15 eosinophils/high-power field) at baseline (n = 32) and after fluticasone (n = 15) and elemental dietary treatment (n = 14) and in controls (n = 19). Mucosal integrity was evaluated during endoscopy using electrical tissue spectroscopy (ETIS) measuring mucosal impedance and transepithelial electrical resistance (TER) and transepithelial molecule-flux through biopsy specimens in Ussing chambers. We included 61 measurements; 32 of patients at baseline and 29 after treatment, 3 patients dropped out. After treatment, 20 patients were in remission (≤15 eosinophils/high-power field) and these measurements were compared with 41 measurements of patients with active disease (at baseline or after failed treatment). All four mucosal integrity measures showed significant impairment in active EoE compared with remission. Eosinophilia was negatively correlated with ETIS and TER and positively with transepithelial molecule flux (P ≤ 0.001). The optimal ETIS cutoff to predict disease activity was 6,000 Ω·m with a sensitivity of 79% [95% confidence interval (CI) 54-94%], specificity of 84% (95% CI 69-94%), positive predictive values of 89% (95% CI 77-95%) and negative predictive values of 71% (95% CI 54-84%). In EoE patients, markers of mucosal integrity correlate with esophageal eosinophilia. Additionally, endoscopic mucosal impedance measurements can predict disease activity.NEW & NOTEWORTHY In adult patients with eosinophilic esophagitis (EoE), the mucosal integrity, measured by making use of four different parameters, correlates strongly with

  4. High Performance MgO-barrier Magnetic Tunnel Junctions for Flexible and Wearable Spintronic Applications.

    Science.gov (United States)

    Chen, Jun-Yang; Lau, Yong-Chang; Coey, J M D; Li, Mo; Wang, Jian-Ping

    2017-02-02

    The magnetic tunnel junction (MTJ) using MgO barrier is one of most important building blocks for spintronic devices and has been widely utilized as miniaturized magentic sensors. It could play an important role in wearable medical devices if they can be fabricated on flexible substrates. The required stringent fabrication processes to obtain high quality MgO-barrier MTJs, however, limit its integration with flexible electronics devices. In this work, we have developed a method to fabricate high-performance MgO-barrier MTJs directly onto ultrathin flexible silicon membrane with a thickness of 14 μm and then transfer-and-bond to plastic substrates. Remarkably, such flexible MTJs are fully functional, exhibiting a TMR ratio as high as 190% under bending radii as small as 5 mm. The devices' robustness is manifested by its retained excellent performance and unaltered TMR ratio after over 1000 bending cycles. The demonstrated flexible MgO-barrier MTJs opens the door to integrating high-performance spintronic devices in flexible and wearable electronics devices for a plethora of biomedical sensing applications.

  5. High Performance MgO-barrier Magnetic Tunnel Junctions for Flexible and Wearable Spintronic Applications

    Science.gov (United States)

    Chen, Jun-Yang; Lau, Yong-Chang; Coey, J. M. D.; Li, Mo; Wang, Jian-Ping

    2017-02-01

    The magnetic tunnel junction (MTJ) using MgO barrier is one of most important building blocks for spintronic devices and has been widely utilized as miniaturized magentic sensors. It could play an important role in wearable medical devices if they can be fabricated on flexible substrates. The required stringent fabrication processes to obtain high quality MgO-barrier MTJs, however, limit its integration with flexible electronics devices. In this work, we have developed a method to fabricate high-performance MgO-barrier MTJs directly onto ultrathin flexible silicon membrane with a thickness of 14 μm and then transfer-and-bond to plastic substrates. Remarkably, such flexible MTJs are fully functional, exhibiting a TMR ratio as high as 190% under bending radii as small as 5 mm. The devices‘ robustness is manifested by its retained excellent performance and unaltered TMR ratio after over 1000 bending cycles. The demonstrated flexible MgO-barrier MTJs opens the door to integrating high-performance spintronic devices in flexible and wearable electronics devices for a plethora of biomedical sensing applications.

  6. High Performance MgO-barrier Magnetic Tunnel Junctions for Flexible and Wearable Spintronic Applications

    Science.gov (United States)

    Chen, Jun-Yang; Lau, Yong-Chang; Coey, J. M. D.; Li, Mo; Wang, Jian-Ping

    2017-01-01

    The magnetic tunnel junction (MTJ) using MgO barrier is one of most important building blocks for spintronic devices and has been widely utilized as miniaturized magentic sensors. It could play an important role in wearable medical devices if they can be fabricated on flexible substrates. The required stringent fabrication processes to obtain high quality MgO-barrier MTJs, however, limit its integration with flexible electronics devices. In this work, we have developed a method to fabricate high-performance MgO-barrier MTJs directly onto ultrathin flexible silicon membrane with a thickness of 14 μm and then transfer-and-bond to plastic substrates. Remarkably, such flexible MTJs are fully functional, exhibiting a TMR ratio as high as 190% under bending radii as small as 5 mm. The devices‘ robustness is manifested by its retained excellent performance and unaltered TMR ratio after over 1000 bending cycles. The demonstrated flexible MgO-barrier MTJs opens the door to integrating high-performance spintronic devices in flexible and wearable electronics devices for a plethora of biomedical sensing applications. PMID:28150807

  7. Motivation and Barriers for Leisure-Time Physical Activity in Socioeconomically Disadvantaged Women.

    Science.gov (United States)

    Santos, Inês; Ball, Kylie; Crawford, David; Teixeira, Pedro J

    2016-01-01

    The aim of this study was to examine cross-sectional and longitudinal associations between motivation and barriers for physical activity, and physical activity behavior in women living in socioeconomic disadvantage. This study also examined whether weight control intentions moderate those associations. Data from 1664 women aged 18-46 years was collected at baseline and three-year follow-up as part of the Resilience for Eating and Activity Despite Inequality study. In mail-based surveys, women reported sociodemographic and neighborhood environmental characteristics, intrinsic motivation, goals and perceived family barriers to be active, weight control intentions and leisure-time physical activity (assessed through the IPAQ-L). Linear regression models assessed the association of intrinsic motivation, goals and barriers with physical activity at baseline and follow-up, adjusting for environmental characteristics and also physical activity at baseline (for longitudinal analyses), and the moderating effects of weight control intentions were examined. Intrinsic motivation and, to a lesser extent, appearance and relaxation goals for being physically active were consistently associated with leisure-time physical activity at baseline and follow-up. Perceived family barriers, health, fitness, weight and stress relief goals were associated with leisure-time physical activity only at baseline. Moderated regression analyses revealed that weight control intentions significantly moderated the association between weight goals and leisure-time physical activity at baseline (β = 0.538, 99% CI = 0.057, 0.990) and between intrinsic motivation and leisure-time physical activity at follow-up (β = 0.666, 99% CI = 0.188, 1.145). For women actively trying to control their weight, intrinsic motivation was significantly associated with leisure-time physical activity at follow-up (β = 0.184, 99% CI = 0.097, 0.313). Results suggest that, especially in women trying to control their weight

  8. Motivation and Barriers for Leisure-Time Physical Activity in Socioeconomically Disadvantaged Women.

    Directory of Open Access Journals (Sweden)

    Inês Santos

    Full Text Available The aim of this study was to examine cross-sectional and longitudinal associations between motivation and barriers for physical activity, and physical activity behavior in women living in socioeconomic disadvantage. This study also examined whether weight control intentions moderate those associations.Data from 1664 women aged 18-46 years was collected at baseline and three-year follow-up as part of the Resilience for Eating and Activity Despite Inequality study. In mail-based surveys, women reported sociodemographic and neighborhood environmental characteristics, intrinsic motivation, goals and perceived family barriers to be active, weight control intentions and leisure-time physical activity (assessed through the IPAQ-L. Linear regression models assessed the association of intrinsic motivation, goals and barriers with physical activity at baseline and follow-up, adjusting for environmental characteristics and also physical activity at baseline (for longitudinal analyses, and the moderating effects of weight control intentions were examined.Intrinsic motivation and, to a lesser extent, appearance and relaxation goals for being physically active were consistently associated with leisure-time physical activity at baseline and follow-up. Perceived family barriers, health, fitness, weight and stress relief goals were associated with leisure-time physical activity only at baseline. Moderated regression analyses revealed that weight control intentions significantly moderated the association between weight goals and leisure-time physical activity at baseline (β = 0.538, 99% CI = 0.057, 0.990 and between intrinsic motivation and leisure-time physical activity at follow-up (β = 0.666, 99% CI = 0.188, 1.145. For women actively trying to control their weight, intrinsic motivation was significantly associated with leisure-time physical activity at follow-up (β = 0.184, 99% CI = 0.097, 0.313.Results suggest that, especially in women trying to control

  9. Predictors of high score patient-reported barriers to controlling cancer pain: a preliminary report.

    Science.gov (United States)

    Kwon, Jung Hye; Oh, Sung Yong; Chisholm, Gary; Lee, Jung-Ae; Lee, Jae Jin; Park, Keon Woo; Nam, Seung-Hyun; Song, Hun Ho; Lee, Keehyun; Zang, Dae Young; Kim, Ho Young; Choi, Dae Ro; Kim, Hyo Jung; Kim, Jung Han; Jung, Joo Young; Jang, Geundoo; Kim, Hyeong Su; Won, Ji Yun; Bruera, Eduardo

    2013-04-01

    Pain is one of the most common and devastating symptoms in cancer patients, and misunderstandings on the patient's part can cause major obstacles in pain management. We evaluated factors associated with patient's high barrier score to managing cancer-associated pain by having 201 patients complete the Korean Barriers Questionnaire II, the Brief Pain Inventory--Korean, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and the Korean Beck Depression Inventory. The Pain Management Index (PMI) was also assessed. The patients were from nine oncology clinics in university hospitals and a veterans' hospital in South Korea. The median pain score (0-10 scale) was 4, with a median percentage of pain improvement during the last 24 h of 70 %. A total of 150 patients (75 %) received strong opioids, and 177 (88 %) achieved adequate analgesia (positive PMI). Mean scores ± SD for the Barriers Questionnaire II ranged from 1.5 ± 1 to 2.8 ± 1.1, with the harmful effects subscale the highest. In the multiple regression model, depression was significantly associated with total barrier score to pain management (p Management of cancer pain should include screening for depression, and management of depression could reduce patient-reported barriers to pain management.

  10. High glucose induces dysfunction of airway epithelial barrier through down-regulation of connexin 43.

    Science.gov (United States)

    Yu, Hongmei; Yang, Juan; Zhou, Xiangdong; Xiao, Qian; Lü, Yang; Xia, Li

    2016-03-01

    The airway epithelium is a barrier to the inhaled antigens and pathogens. Connexin 43 (Cx43) has been found to play critical role in maintaining the function of airway epithelial barrier and be involved in the pathogenesis of the diabetic retinal vasculature, diabetes nephropathy and diabetes skin. Hyperglycemia has been shown to be an independent risk factor for respiratory infections. We hypothesize that the down-regulation of Cx43 induced by HG alters the expression of tight junctions (zonula occludens-1 (ZO-1) and occludin) and contributes to dysfunction of airway epithelial barrier, and Cx43 plays a critical role in the process in human airway epithelial cells (16 HBE). We show that high glucose (HG) decreased the expression of ZO-1 and occludin, disassociated interaction between Cx43 and tight junctions, and then increased airway epithelial transepithelial electrical resistance (TER) and permeability by down-regulation of Cx43 in human airway epithelial cells. These observations demonstrate an important role for Cx43 in regulating HG-induced dysfunction of airway epithelial barrier. These findings may bring new insights into the molecular pathogenesis of pulmonary infection related to diabetes mellitus and lead to novel therapeutic intervention for the dysfunction of airway epithelial barrier in chronic inflammatory airway diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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…

  12. Liquid crystal panel for high efficiency barrier type autostereoscopic three-dimensional displays.

    Science.gov (United States)

    Chen, Cheng-Huan; Huang, Yi-Pai; Chuang, Shang-Chih; Wu, Chi-Lin; Shieh, Han-Ping D; Mphepö, Wallen; Hsieh, Chiu-Ting; Hsu, Shih-Chia

    2009-06-20

    An autostereoscopic display with parallax barrier attached onto a liquid crystal panel suffers from the trade-off between brightness and crosstalk. One approach for making improvement by modifying the layout of light blocking components, such as thin film transistor, storage capacitor, and protrusion, in the liquid crystal pixel has been proposed. Ray tracing simulation shows that the aperture of the slanted barrier can be significantly increased, hence increasing efficiency, while keeping the same crosstalk level if those light blocking components can be shifted to the corner of the pixel. A six-view 2.83 in. (7.19 cm) prototype has shown improvement on both brightness and crosstalk compared to its counterpart using a traditional liquid crystal panel, which demonstrates an effective approach for a high-efficiency barrier-type autostereoscopic 3D display with a liquid crystal panel.

  13. Photochemical approach to high-barrier films for the encapsulation of flexible laminary electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Prager, L., E-mail: lutz.prager@iom-leipzig.de [Leibniz-Institut für Oberflächenmodifizierung e.V., Permoserstr. 15, 04318 Leipzig (Germany); Helmstedt, U. [Leibniz-Institut für Oberflächenmodifizierung e.V., Permoserstr. 15, 04318 Leipzig (Germany); Herrnberger, H. [Solarion AG, Pereser Höhe 1, Breitscheidstraße 45, 04442 Zwenkau (Germany); Kahle, O. [Fraunhofer-Einrichtung für Polymermaterialien und Composite PYCO, Kantstraße 55, 14513 Teltow (Germany); Kita, F. [AZ Electronic Materials Germany GmbH, Rheingaustraße 190-196, 65203 Wiesbaden (Germany); Münch, M. [Solarion AG, Pereser Höhe 1, Breitscheidstraße 45, 04442 Zwenkau (Germany); Pender, A.; Prager, A.; Gerlach, J.W. [Leibniz-Institut für Oberflächenmodifizierung e.V., Permoserstr. 15, 04318 Leipzig (Germany); Stasiak, M. [Fraunhofer-Einrichtung für Polymermaterialien und Composite PYCO, Kantstraße 55, 14513 Teltow (Germany)

    2014-11-03

    Based on results of preceding research and development, thin gas barriers were made by wet application of perhydropolysilazane solution onto polymer films and its subsequent photo-initiated conversion to dense silica layers applying vacuum ultraviolet irradiation. Compared to the state of the art, these layers were sufficiently improved and characterized by spectroscopic methods, by scanning electron microscopy and by gas permeation measurements. Water vapor transmission rates (WVTR) below 10{sup −2} g m{sup −2} d{sup −1} were achieved. In this way, single barrier films were developed and produced on a pilot plant from roll to roll, 250 mm wide, at speeds up to 10 m min{sup −1}. Two films were laminated using adhesives curable with ultraviolet (UV) light and evaluated by peel tests, gas permeation measurement and climate testing. It could be shown that the described high-barrier laminates which exhibit WVTR ≈ 5 × 10{sup −4} g m{sup −2} d{sup −1}, determined by the calcium mirror method, are suitable for encapsulation of flexible thin-film photovoltaic modules. Durability of the encapsulated modules could be verified in several climate tests including damp-heat, thermo-cycle (heating, freezing, wetting) and UV exposures which are equivalent to more than 20 years of endurance at outdoor conditions in temperate climate. In the frame of further research and technical development it seems to be possible to design a cost efficient industrial scale process for the production of encapsulation films for photovoltaic applications. - Highlights: • Dense silica barrier layers were developed by a photochemical approach. • Polymer based barrier films were laminated yielding flexible high-barrier films. • Using these laminates photovoltaic test modules were encapsulated and tested. • A durability of more than 20 years at outdoor conditions could be proved.

  14. Active barrier films of PET for solar cell application: Processing and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana [Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132 - 84084 Fisciano (Italy)

    2014-05-15

    A preliminary investigation was carried out on the possibility to improve the protective action offered by the standard multilayer structures used to encapsulate photovoltaic devices. With this aim, a commercial active barrier PET-based material, able to absorb oxygen when activated by liquid water, was used to produce flexible and transparent active barrier films, by means of a lab-scale film production plant. The obtained film, tested in terms of thermal, optical and oxygen absorption properties, shows a slow oxygen absorption kinetics, an acceptable transparency and an easy roll-to-roll processability, so proving itself as a good candidate for the development of protective coating for solar cells against the atmospheric degradation agents like the rain.

  15. Perceived barriers and facilitators to participation in physical activity for children with disability: a qualitative study.

    Science.gov (United States)

    Shields, Nora; Synnot, Anneliese

    2016-01-19

    Children with disability engage in less physical activity compared to their typically developing peers. Our aim was to explore the barriers and facilitators to participation in physical activity for this group. Ten focus groups, involving 63 participants (23 children with disability, 20 parents of children with disability and 20 sport and recreation staff), were held to explore factors perceived as barriers and facilitators to participation in physical activity by children with disability. Data were analysed thematically by two researchers. Four themes were identified: (1) similarities and differences, (2) people make the difference, (3) one size does not fit all, and (4) communication and connections. Key facilitators identified were the need for inclusive pathways that encourage ongoing participation as children grow or as their skills develop, and for better partnerships between key stakeholders from the disability, sport, education and government sectors. Children with disabilities' need for the early attainment of motor and social skills and the integral role of their families in supporting them were considered to influence their participation in physical activity. Children with disability were thought to face additional barriers to participation compared to children with typical development including a lack of instructor skills and unwillingness to be inclusive, negative societal attitudes towards disability, and a lack of local opportunities. The perspectives gathered in this study are relevant to the many stakeholders involved in the design and implementation of effective interventions, strategies and policies to promote participation in physical activity for children with disability. We outline ten strategies for facilitating participation.

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

    Directory of Open Access Journals (Sweden)

    Abdulrahman O. Musaiger

    2013-01-01

    Full Text Available 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.

  17. Topical antihistamines display potent anti-inflammatory activity linked in part to enhanced permeability barrier function.

    Science.gov (United States)

    Lin, Tzu-Kai; Man, Mao-Qiang; Santiago, Juan-Luis; Park, Kyungho; Roelandt, Truus; Oda, Yuko; Hupe, Melanie; Crumrine, Debra; Lee, Hae-Jin; Gschwandtner, Maria; Thyssen, Jacob P; Trullas, Carles; Tschachler, Erwin; Feingold, Kenneth R; Elias, Peter M

    2013-02-01

    Systemic antagonists of the histamine type 1 and 2 receptors (H1/2r) are widely used as anti-pruritics and central sedatives, but demonstrate only modest anti-inflammatory activity. Because many inflammatory dermatoses result from defects in cutaneous barrier function, and because keratinocytes express both Hr1 and Hr2, we hypothesized that H1/2r antagonists might be more effective if they were used topically to treat inflammatory dermatoses. Topical H1/2r antagonists additively enhanced permeability barrier homeostasis in normal mouse skin by the following mechanisms: (i) stimulation of epidermal differentiation, leading to thickened cornified envelopes; and (ii) enhanced epidermal lipid synthesis and secretion. As barrier homeostasis was enhanced to a comparable extent in mast cell-deficient mice, with no further improvement following application of topical H1/2r antagonists, H1/2r antagonists likely oppose mast cell-derived histamines. In four immunologically diverse, murine disease models, characterized by either inflammation alone (acute irritant contact dermatitis, acute allergic contact dermatitis) or by prominent barrier abnormalities (subacute allergic contact dermatitis, atopic dermatitis), topical H1/2r agonists aggravated, whereas H1/2r antagonists improved, inflammation and/or barrier function. The apparent ability of topical H1r/2r antagonists to target epidermal H1/2r could translate into increased efficacy in the treatment of inflammatory dermatoses, likely due to decreased inflammation and enhanced barrier function. These results could shift current paradigms of antihistamine utilization from a predominantly systemic to a topical approach.

  18. A role for VEGFR2 activation in endothelial responses caused by barrier disruptive OxPAPC concentrations.

    Directory of Open Access Journals (Sweden)

    Anna A Birukova

    Full Text Available Oxidation products of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine (OxPAPC differentially modulate endothelial cell (EC barrier function in a dose-dependent fashion. Vascular endothelial growth factor receptor-2 (VEGFR2 is involved in the OxPAPC-induced EC inflammatory activation. This study examined a role of VEGFR2 in barrier dysfunction caused by high concentrations of OxPAPC and evaluated downstream signaling mechanisms resulting from the effect of OxPAPC in EC from pulmonary and systemic circulation.EC monolayer permeability in human pulmonary artery endothelial cells (HPAEC and human aortic endothelial cells (HAEC was monitored by changes in transendothelial electrical resistance (TER across EC monolayers. Actin cytoskeleton was examined by immunostaining with Texas Red labeled phalloidin. Phosphorylation of myosin light chains (MLC and VE-Cadherin was examined by Western blot and immunofluorescence techniques. The role of VEGFR2 in OxPAPC-induced permeability and cytoskeletal arrangement were determined using siRNA-induced VEGFR2 knockdown.Low OxPAPC concentrations (5-20 µg/ml induced a barrier protective response in both HPAEC and HAEC, while high OxPAPC concentrations (50-100 µg/ml caused a rapid increase in permeability; actin stress fiber formation and increased MLC phosphorylation were observed as early as 30 min after treatment. VEGFR2 knockdown dramatically decreased the amount of MLC phosphorylation and stress fiber formation caused by high OxPAPC concentrations with modest effects on the amount of VE-cadherin phosphorylation at Y(731. We present evidence that activation of Rho is involved in the OxPAPC/VEGFR2 mechanism of EC permeability induced by high OxPAPC concentrations. Knockdown of VEGFR2 did not rescue the early drop in TER but prevented further development of OxPAPC-induced barrier dysfunction.This study shows that VEGFR2 is involved in the delayed phase of EC barrier dysfunction caused by high Ox

  19. Rap1 GTPase activation and barrier enhancement in rpe inhibits choroidal neovascularization in vivo.

    Directory of Open Access Journals (Sweden)

    Erika S Wittchen

    Full Text Available Loss of barrier integrity precedes the development of pathologies such as metastasis, inflammatory disorders, and blood-retinal barrier breakdown present in neovascular age-related macular degeneration. Rap1 GTPase is involved in regulating both endothelial and epithelial cell junctions; the specific role of Rap1A vs. Rap1B isoforms is less clear. Compromise of retinal pigment epithelium barrier function is a contributing factor to the development of AMD. We utilized shRNA of Rap1 isoforms in cultured human retinal pigment epithelial cells, along with knockout mouse models to test the role of Rap1 on promoting RPE barrier properties, with emphasis on the dynamic junctional regulation that is triggered when the adhesion between cells is challenged. In vitro, Rap1A shRNA reduced steady-state barrier integrity, whereas Rap1B shRNA affected dynamic junctional responses. In a laser-induced choroidal neovascularization (CNV model of macular degeneration, Rap1b(-/- mice exhibited larger CNV volumes compared to wild-type or Rap1a(-/- . In vivo, intravitreal injection of a cAMP analog (8CPT-2'-O-Me-cAMP that is a known Rap1 activator significantly reduced laser-induced CNV volume, which correlated with the inhibition of CEC transmigration across 8CPT-2'O-Me-cAMP-treated RPE monolayers in vitro. Rap1 activation by 8CPT-2'-O-Me-cAMP treatment increased recruitment of junctional proteins and F-actin to cell-cell contacts, increasing both the linearity of junctions in vitro and in cells surrounding laser-induced lesions in vivo. We conclude that in vitro, Rap1A may be important for steady state barrier integrity, while Rap1B is involved more in dynamic junctional responses such as resistance to junctional disassembly induced by EGTA and reassembly of cell junctions following disruption. Furthermore, activation of Rap1 in vivo inhibited development of choroidal neovascular lesions in a laser-injury model. Our data suggest that targeting Rap1 isoforms in vivo

  20. Nucleosome positioning and kinetics near transcription-start-site barriers are controlled by interplay between active remodeling and DNA sequence.

    Science.gov (United States)

    Parmar, Jyotsana J; Marko, John F; Padinhateeri, Ranjith

    2014-01-01

    We investigate how DNA sequence, ATP-dependent chromatin remodeling and nucleosome-depleted 'barriers' co-operate to determine the kinetics of nucleosome organization, in a stochastic model of nucleosome positioning and dynamics. We find that 'statistical' positioning of nucleosomes against 'barriers', hypothesized to control chromatin structure near transcription start sites, requires active remodeling and therefore cannot be described using equilibrium statistical mechanics. We show that, unlike steady-state occupancy, DNA site exposure kinetics near a barrier is dominated by DNA sequence rather than by proximity to the barrier itself. The timescale for formation of positioning patterns near barriers is proportional to the timescale for active nucleosome eviction. We also show that there are strong gene-to-gene variations in nucleosome positioning near barriers, which are eliminated by averaging over many genes. Our results suggest that measurement of nucleosome kinetics can reveal information about sequence-dependent regulation that is not apparent in steady-state nucleosome occupancy.

  1. Controlled formation of polymer nanocapsules with high diffusion-barrier properties and prediction of encapsulation efficiency.

    Science.gov (United States)

    Hofmeister, Ines; Landfester, Katharina; Taden, Andreas

    2015-01-02

    Polymer nanocapsules with high diffusion-barrier performance were designed following simple thermodynamic considerations. Hindered diffusion of the enclosed material leads to high encapsulation efficiencies (EEs), which was demonstrated based on the encapsulation of highly volatile compounds of different chemical natures. Low interactions between core and shell materials are key factors to achieve phase separation and a high diffusion barrier of the resulting polymeric shell. These interactions can be characterized and quantified using the Hansen solubility parameters. A systematic study of our copolymer system revealed a linear relationship between the Hansen parameter for hydrogen bonding (δh ) and encapsulation efficiencies which enables the prediction of encapsulated amounts for any material. Furthermore EEs of poorly encapsulated materials can be increased by mixing them with a mediator compound to give lower overall δh values.

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

    Science.gov (United States)

    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.

  3. Saudi high school students’ attitudes and barriers toward the use of computer technologies in learning English

    OpenAIRE

    Sabti, Ahmed Abdulateef; Chaichan, Rasha Sami

    2014-01-01

    This study examines the attitudes of Saudi Arabian high school students toward the use of computer technologies in learning English. The study also discusses the possible barriers that affect and limit the actual usage of computers. Quantitative approach is applied in this research, which involved 30 Saudi Arabia students of a high school in Kuala Lumpur, Malaysia. The respondents comprised 15 males and 15 females with ages between 16 years and 18 years. Two instruments, namely, Scale of Atti...

  4. Facilitators and barriers to physical activity as perceived by older adults with intellectual disability.

    Science.gov (United States)

    van Schijndel-Speet, Marieke; Evenhuis, Heleen M; van Wijck, Ruud; van Empelen, Pepijn; Echteld, Michael A

    2014-06-01

    Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID for specific physical activities, and to gain insight into facilitators and barriers to engaging into PA. Fourteen in-depth interviews and four focus groups were undertaken, with a total of 40 older adults with mild and moderate ID included in the analysis. NVivo software was used for analysing the transcribed verbatim interviews. In total, 30 codes for facilitators and barriers were identified. Themes concerning facilitators to PA were enjoyment, support from others, social contact and friendship, reward, familiarity, and routine of activities. Themes concerning barriers to PA were health and physiological factors, lack of self-confidence, lack of skills, lack of support, transportation problems, costs, and lack of appropriate PA options and materials. The results of the present study suggest that older adults with ID may benefit from specific PA programs, adapted to their individual needs and limitations. Results can be used for developing feasible health promotion programs for older adults with ID.

  5. Degradation of triclosan in aqueous solution by dielectric barrier discharge plasma combined with activated carbon fibers.

    Science.gov (United States)

    Xin, Lu; Sun, Yabing; Feng, Jingwei; Wang, Jian; He, Dong

    2016-02-01

    The degradation of triclosan (TCS) in aqueous solution by dielectric barrier discharge (DBD) plasma with activated carbon fibers (ACFs) was investigated. In this study, ACFs and DBD plasma coexisted in a planar DBD plasma reactor, which could synchronously achieve degradation of TCS, modification and in situ regeneration of ACFs, enhancing the effect of recycling of ACFs. The properties of ACFs before and after modification by DBD plasma were characterized by BET and XPS. Various processing parameters affecting the synergetic degradation of TCS were also investigated. The results exhibited excellent synergetic effects in DBD plasma-ACFs system on TCS degradation. The degradation efficiency of 120 mL TCS with initial concentration of 10 mg L(-1) could reach 93% with 1 mm thick ACFs in 18 min at input power of 80 W, compared with 85% by single DBD plasma. Meanwhile, the removal rate of total organic carbon increased from 12% at pH 6.26-24% at pH 3.50. ACFs could ameliorate the degradation efficiency for planar DBD plasma when treating TCS solution at high flow rates or at low initial concentrations. A possible degradation pathway of TCS was investigated according to the detected intermediates, which were identified by liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) combined with theoretical calculation of Gaussian 09 program.

  6. Intermittent hypoxia-induced endothelial barrier dysfunction requires ROS-dependent MAP kinase activation.

    Science.gov (United States)

    Makarenko, Vladislav V; Usatyuk, Peter V; Yuan, Guoxiang; Lee, May M; Nanduri, Jayasri; Natarajan, Viswanathan; Kumar, Ganesh K; Prabhakar, Nanduri R

    2014-04-15

    The objective of the present study was to determine the impact of simulated apnea with intermittent hypoxia (IH) on endothelial barrier function and assess the underlying mechanism(s). Experiments were performed on human lung microvascular endothelial cells exposed to IH-consisting alternating cycles of 1.5% O2 for 30s followed by 20% O2 for 5 min. IH decreased transendothelial electrical resistance (TEER) suggesting attenuated endothelial barrier function. The effect of IH on TEER was stimulus dependent and reversible after reoxygenation. IH-exposed cells exhibited stress fiber formation and redistribution of cortactin, vascular endothelial-cadherins, and zona occludens-1 junction proteins along with increased intercellular gaps at cell-cell boundaries. Extracellular signal-regulated kinase (ERK) and c-jun NH2-terminal kinase (JNK) were phosphorylated in IH-exposed cells. Inhibiting either ERK or JNK prevented the IH-induced decrease in TEER and the reorganization of the cytoskeleton and junction proteins. IH increased reactive oxygen species (ROS) levels, and manganese (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride, a membrane-permeable antioxidant, prevented ERK and JNK phosphorylation as well as IH-induced changes in endothelial barrier function. These results demonstrate that IH via ROS-dependent activation of MAP kinases leads to reorganization of cytoskeleton and junction proteins resulting in endothelial barrier dysfunction.

  7. The benefits and barriers to physical activity and lifestyle interventions for osteoarthritis affecting the adult knee

    Directory of Open Access Journals (Sweden)

    Stevenson Jonathan

    2012-03-01

    Full Text Available Abstract Osteoarthritis prevalence is increasing, placing greater demands on healthcare and future socioeconomic costing models. Exercise and non-pharmacological methods should be employed to manage this common and disabling disease. Expectations at all stages of disease are increasing with a desire to remain active and independent. Three key areas have been reviewed; the evidence for physical activity, lifestyle changes and motivational techniques concerning knee osteoarthritis and the barriers to instituting such changes. Promotion of activity in primary care is discussed and evidence for compliance has been reviewed. This article reviews a subject that is integral to all professionals involved with osteoarthritis care.

  8. In Situ Measurement of Wind-Induced Pulse Response of Sound Barrier Based on High-Speed Imaging Technology

    OpenAIRE

    Chunli Zhu; Jie Guo; Dashan Zhang; Yuan Shen; Dongcai Liu

    2016-01-01

    The lifetime of the sound barrier is threatened by high-speed train-induced impulsive wind pressure as it passes by. The vibration response of the sound barrier during the process of train passing is difficult to be measured using conventional measurement methods because of the inconvenience of the installation of markers on the sound barrier. In this paper, the high-speed camera is used to record the whole process of the train passing by the sound barrier. Then, a displacement extraction alg...

  9. Activation barrier scaling and crossover for noise-induced switching in micromechanical parametric oscillators.

    Science.gov (United States)

    Chan, H B; Stambaugh, C

    2007-08-10

    We explore fluctuation-induced switching in parametrically driven micromechanical torsional oscillators. The oscillators possess one, two, or three stable attractors depending on the modulation frequency. Noise induces transitions between the coexisting attractors. Near the bifurcation points, the activation barriers are found to have a power law dependence on frequency detuning with critical exponents that are in agreement with predicted universal scaling relationships. At large detuning, we observe a crossover to a different power law dependence with an exponent that is device specific.

  10. Physical activity perceptions, context, barriers, and facilitators from a Hispanic child's perspective

    Science.gov (United States)

    Ross, Sharon E. Taverno; Francis, Lori A.

    2016-01-01

    Background In order to develop effective physical activity interventions and to address the burden of obesity in Hispanic children, qualitative studies are needed to build descriptive theory and expand the state of the science. The purpose of this study is to describe physical activity perceptions, context, facilitators, and barriers from the perspective of Hispanic immigrant-origin children. Method This in-depth, ethnographic study included 14, 6- to 11-year old, first- and second- generation Hispanic children recruited from an afterschool program in Southeastern Pennsylvania, USA. Methods included child observation, field notes, semi-structured interviews, and a PhotoVoice activity. Transcripts and field notes were coded and analyzed using the constant comparison method to identify overarching themes and patterns in the data. Results Data analysis yielded four overarching themes regarding children's perspectives on physical activity. Children engaged in a variety of physical activities and sedentary behaviors, which differed by physical (e.g., park, outside home, and afterschool programs) and social (e.g., parents, siblings, and friends) contexts. Children discussed specific benefits of physical activity. Children's negative attitudes toward physical activity were related to physical discomfort, low athletic competence, and safety concerns. Children perceived physical activity and play to be one in the same, and “fun” was identified as a primary driver of physical activity preferences. The facilitators and barriers to physical activity were related to specific parent/home, school, and neighborhood factors. Conclusion Findings from this study suggest that an emphasis on fun and active play, while taking into account family and neighborhood context, may be a desirable intervention approach in Hispanic immigrant-origin children. This study lays the groundwork for future studies to further explore some of the themes identified here to better understand children

  11. Physical activity perceptions, context, barriers, and facilitators from a Hispanic child's perspective

    Directory of Open Access Journals (Sweden)

    Sharon E. Taverno Ross

    2016-08-01

    Full Text Available Background: In order to develop effective physical activity interventions and to address the burden of obesity in Hispanic children, qualitative studies are needed to build descriptive theory and expand the state of the science. The purpose of this study is to describe physical activity perceptions, context, facilitators, and barriers from the perspective of Hispanic immigrant-origin children. Method: This in-depth, ethnographic study included 14, 6- to 11-year old, first- and second- generation Hispanic children recruited from an afterschool program in Southeastern Pennsylvania, USA. Methods included child observation, field notes, semi-structured interviews, and a PhotoVoice activity. Transcripts and field notes were coded and analyzed using the constant comparison method to identify overarching themes and patterns in the data. Results: Data analysis yielded four overarching themes regarding children's perspectives on physical activity. Children engaged in a variety of physical activities and sedentary behaviors, which differed by physical (e.g., park, outside home, and afterschool programs and social (e.g., parents, siblings, and friends contexts. Children discussed specific benefits of physical activity. Children's negative attitudes toward physical activity were related to physical discomfort, low athletic competence, and safety concerns. Children perceived physical activity and play to be one in the same, and “fun” was identified as a primary driver of physical activity preferences. The facilitators and barriers to physical activity were related to specific parent/home, school, and neighborhood factors. Conclusion: Findings from this study suggest that an emphasis on fun and active play, while taking into account family and neighborhood context, may be a desirable intervention approach in Hispanic immigrant-origin children. This study lays the groundwork for future studies to further explore some of the themes identified here to better

  12. A cross-sectional study on patterns, motivating factors and barriers for physical activity among undergraduate medical students

    Directory of Open Access Journals (Sweden)

    HN Harsha Kumar

    2014-10-01

    Full Text Available Introduction: There is little published information exploring the perceptions and physical activity patterns among undergraduate medical students in our country. So this study was conducted with the following objectives: 1. To assess the perceptions about knowledge regarding physical activities among undergraduate medical students; 2. To assess their self-reported physical activity practices. Materials and Methods: This cross sectional study was conducted in Kasturba Medical College, Mangalore from 12 th to 30 th April, 2012. A total number of 427 students were chosen at by using the formula for infinite population. Tools: 1. A semi-structured questionnaire to know perceptions, barriers, and practices about physical activity; 2. Physical activity was assessed using International Physical Activity Questionnaire (IPAQ. Analysis was done by using SPSS version 11. Significance of differences across various levels of physical activity between different age-groups and gender were made by chi square test. Results: 376 students participated. Majority of them had high physical activity (54.75%. Knowledge was poor about prevention of diabetes (68.9%, stroke (61.6%, and osteoporosis (33.8%. Majority (82.4% of them perceived health-related benefits of physical activity as motivating factors rather than prevention of chronic noncommunicable diseases. Most of them (72.3% have enrolled in life style modification activities like yoga, going to gymnasium, etc. Conclusion: Most of the students fall into moderate physical activity group. Health-related benefits were the driving force for doing physical activity.

  13. High-flux Thin-film Nanofibrous Composite Ultrafiltration Membranes Containing Cellulose Barrier Layer

    Energy Technology Data Exchange (ETDEWEB)

    Ma, H.; Yoon, K; Rong, L; Mao, Y; Mo, Z; Fang, D; Hollander, Z; Gaiteri, J; Hsiao , B; Chu, B

    2010-01-01

    A novel class of thin-film nanofibrous composite (TFNC) membrane consisting of a cellulose barrier layer, a nanofibrous mid-layer scaffold, and a melt-blown non-woven substrate was successfully fabricated and tested as an ultrafiltration (UF) filter to separate an emulsified oil and water mixture, a model bilge water for on-board ship bilge water purification. Two ionic liquids: 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate, were chosen as the solvent to dissolve cellulose under mild conditions. The regenerated cellulose barrier layer exhibited less crystallinity (determined by wide-angle X-ray diffraction, WAXD) than the original cotton linter pulps, but good thermal stability (determined by thermal gravimetric analysis, TGA). The morphology, water permeation, and mechanical stability of the chosen TFNCmembranes were thoroughly investigated. The results indicated that the polyacrylonitrile (PAN) nanofibrous scaffold was partially imbedded in the cellulose barrier layer, which enhanced the mechanical strength of the top barrier layer. The permeation flux of the cellulose-based TFNCmembrane was significantly higher (e.g. 10x) than comparable commercial UFmembranes (PAN10 and PAN400, Sepro) with similar rejection ratios for separation of oil/water emulsions. The molecular weight cut-off (MWCO) of TFNC membranes with cellulose barrier layer was evaluated using dextran feed solutions. The rejection was found to be higher than 90% with a dextran molecular weight of 2000 KDa, implying that the nominal pore size of the membrane was less than 50 nm. High permeation flux was also observed in the filtration of an emulsified oil/water mixture as well as of a sodium alginate aqueous solution, while high rejection ratio (above 99.5%) was maintained after prolonged operation. A variation of the barrier layer thickness could dramatically affect the permeation flux and the rejection ratio of the TFNCmembranes, while different sources of cellulose

  14. Motivators and Barriers to Engaging in Healthy Eating and Physical Activity.

    Science.gov (United States)

    Ashton, Lee M; Hutchesson, Melinda J; Rollo, Megan E; Morgan, Philip J; Collins, Clare E

    2017-03-01

    Many Australian young men (18-25 years) fail to meet recommendations in national dietary or physical activity (PA) guidelines. However, there is a lack of understanding of their perspectives on PA and diet to inform intervention design. This study examined young men's motivators and barriers to healthy eating and PA, along with differences by demographic and behavioral factors. A cross-sectional online survey was completed by 282 men aged 18 to 25 years in Australia. Results identified the most common motivators for healthy eating included improving health (63.5%), body image (52.3%), and increasing energy (32.1%). Motivators for PA included improving body image (44.6%), fitness (44.2%), and health (41.0%). Common barriers to healthy eating were access to unhealthy foods (61.1%), time to cook/prepare healthy foods (55.0%), and motivation to cook healthy foods (50.7%). Barriers for PA included motivation (66.3%), time (57.8%), and cost of equipment/facilities (33.3%). Significant differences ( p healthy eating and/or PA were identified for BMI category, marital status, PA level, alcohol intake, and stress levels. Significant differences were identified for barriers to healthy eating and/or PA by BMI, PA level, stress, and fruit and vegetable intake, assessed using Pearson's chi-square test. Findings suggest that promotion of benefits related to health, appearance/body image, increased energy and fitness, and addressing key barriers including motivation, time, financial restraints, and accessibility of unhealthy foods, could engage young men in improving lifestyle behaviors. Differences by demographic and behavioral factors suggest development of tailored programs to address diversity among young men may be required.

  15. Flow directionality, mountain barriers and functional traits determine diatom metacommunity structuring of high mountain streams.

    Science.gov (United States)

    Dong, Xiaoyu; Li, Bin; He, Fengzhi; Gu, Yuan; Sun, Meiqin; Zhang, Haomiao; Tan, Lu; Xiao, Wen; Liu, Shuoran; Cai, Qinghua

    2016-04-19

    Stream metacommunities are structured by a combination of local (environmental filtering) and regional (dispersal) processes. The unique characters of high mountain streams could potentially determine metacommunity structuring, which is currently poorly understood. Aiming at understanding how these characters influenced metacommunity structuring, we explored the relative importance of local environmental conditions and various dispersal processes, including through geographical (overland), topographical (across mountain barriers) and network (along flow direction) pathways in shaping benthic diatom communities. From a trait perspective, diatoms were categorized into high-profile, low-profile and motile guild to examine the roles of functional traits. Our results indicated that both environmental filtering and dispersal processes influenced metacommunity structuring, with dispersal contributing more than environmental processes. Among the three pathways, stream corridors were primary pathway. Deconstructive analysis suggested different responses to environmental and spatial factors for each of three ecological guilds. However, regardless of traits, dispersal among streams was limited by mountain barriers, while dispersal along stream was promoted by rushing flow in high mountain stream. Our results highlighted that directional processes had prevailing effects on metacommunity structuring in high mountain streams. Flow directionality, mountain barriers and ecological guilds contributed to a better understanding of the roles that mountains played in structuring metacommunity.

  16. Electrical properties of graphene tunnel junctions with high-κ metal-oxide barriers

    Science.gov (United States)

    Feng, Ying; Trainer, Daniel J.; Chen, Ke

    2017-04-01

    An insulating barrier is one of the key components in electronic devices that makes use of quantum tunneling principles. Many metal-oxides have been used as a good barrier material in a tunnel junction for their large band gap, stable chemical properties and superb properties for forming a thin and pin-hole-free insulating layer. The reduced dimensions of transistors have led to the need for alternative, high dielectric constant (high-κ) oxides to replace conventional silicon-based dielectrics to reduce the leaking current induced by electron tunneling. On the other hand, a tunnel junction with one or both electrodes made of graphene may lead to novel applications due to the massless Dirac fermions from the graphene. Here we have fabricated sandwich-type graphene tunnel junctions with high-κ metal-oxides as barriers, including Al2O3, HfO2, ZrO2, and TiO2. Tunneling properties are investigated by observing the temperature and time dependences of the tunneling spectra. Our results show the potential for applications of high-κ oxides in graphene tunnel junctions and bringing new opportunities for memory and logic electronic devices.

  17. P-glycoprotein activity in the blood-brain barrier is affected by virus-induced neuroinflammation and antipsychotic treatment

    NARCIS (Netherlands)

    Doorduin, Janine; de Vries, Erik F. J.; Dierckx, Rudi A.; Klein, Hans C.

    2014-01-01

    A large percentage of schizophrenic patients respond poorly to antipsychotic treatment. This could be explained by inefficient drug transport across the blood-brain barrier due to P-glycoprotein mediated efflux. P-glycoprotein activity and expression in the blood-brain barrier can be affected by

  18. Overcoming barriers to high performance seismic design using lessons learned from the green building industry

    Science.gov (United States)

    Glezil, Dorothy

    NEHRP's Provisions today currently governing conventional seismic resistant design. These provisions, though they ensure the life-safety of building occupants, extensive damage and economic losses may still occur in the structures. This minimum performance can be enhanced using the Performance-Based Earthquake Engineering methodology and passive control systems like base isolation and energy dissipation systems. Even though these technologies and the PBEE methodology are effective reducing economic losses and fatalities during earthquakes, getting them implemented into seismic resistant design has been challenging. One of the many barriers to their implementation has been their upfront costs. The green building community has faced some of the same challenges that the high performance seismic design community currently faces. The goal of this thesis is to draw on the success of the green building industry to provide recommendations that may be used overcome the barriers that high performance seismic design (HPSD) is currently facing.

  19. Investigation of Ozone Yield of Air Fed Ozonizer by High Pressure Homogeneous Dielectric Barrier Discharge

    Science.gov (United States)

    2013-07-01

    field strength in the discharge. In order to clarify this phenomenon, further study on the gas analysis within the ozone gas by an FTIR spectrometer...31st ICPIG, July 14-19, 2013, Granada, Spain Investigation of ozone yield of air fed ozonizer by high pressure homogeneous dielectric barrier... ozonizer and found that the ozone yield is higher by the homogeneous discharge mode than by the conventional filamentary discharge mode in larger

  20. Analytical modeling of trilayer graphene nanoribbon Schottky-barrier FET for high-speed switching applications.

    Science.gov (United States)

    Rahmani, Meisam; Ahmadi, Mohammad Taghi; Abadi, Hediyeh Karimi Feiz; Saeidmanesh, Mehdi; Akbari, Elnaz; Ismail, Razali

    2013-01-30

    Recent development of trilayer graphene nanoribbon Schottky-barrier field-effect transistors (FETs) will be governed by transistor electrostatics and quantum effects that impose scaling limits like those of Si metal-oxide-semiconductor field-effect transistors. The current-voltage characteristic of a Schottky-barrier FET has been studied as a function of physical parameters such as effective mass, graphene nanoribbon length, gate insulator thickness, and electrical parameters such as Schottky barrier height and applied bias voltage. In this paper, the scaling behaviors of a Schottky-barrier FET using trilayer graphene nanoribbon are studied and analytically modeled. A novel analytical method is also presented for describing a switch in a Schottky-contact double-gate trilayer graphene nanoribbon FET. In the proposed model, different stacking arrangements of trilayer graphene nanoribbon are assumed as metal and semiconductor contacts to form a Schottky transistor. Based on this assumption, an analytical model and numerical solution of the junction current-voltage are presented in which the applied bias voltage and channel length dependence characteristics are highlighted. The model is then compared with other types of transistors. The developed model can assist in comprehending experiments involving graphene nanoribbon Schottky-barrier FETs. It is demonstrated that the proposed structure exhibits negligible short-channel effects, an improved on-current, realistic threshold voltage, and opposite subthreshold slope and meets the International Technology Roadmap for Semiconductors near-term guidelines. Finally, the results showed that there is a fast transient between on-off states. In other words, the suggested model can be used as a high-speed switch where the value of subthreshold slope is small and thus leads to less power consumption.

  1. Polyphenol-Rich Propolis Extracts Strengthen Intestinal Barrier Function by Activating AMPK and ERK Signaling

    Directory of Open Access Journals (Sweden)

    Kai Wang

    2016-05-01

    Full Text Available Propolis has abundant polyphenolic constituents and is used widely as a health/functional food. Here, we investigated the effects of polyphenol-rich propolis extracts (PPE on intestinal barrier function in human intestinal epithelial Caco-2 cells, as well as in rats. In Caco-2 cells, PPE increased transepithelial electrical resistance and decreased lucifer yellow flux. PPE-treated cells showed increased expression of the tight junction (TJ loci occludin and zona occludens (ZO-1. Confocal microscopy showed organized expressions in proteins related to TJ assembly, i.e., occludin and ZO-1, in response to PPE. Furthermore, PPE led to the activation of AMPK, ERK1/2, p38, and Akt. Using selective inhibitors, we found that the positive effects of PPE on barrier function were abolished in cells in which AMPK and ERK1/2 signaling were inhibited. Moreover, rats fed a diet supplemented with PPE (0.3% in the diet exhibited increased colonic epithelium ZO-1 expression. Overall, these data suggest that PPE strengthens intestinal barrier function by activating AMPK and ERK signaling and provide novel insights into the potential application of propolis for human gut health.

  2. Polyphenol-Rich Propolis Extracts Strengthen Intestinal Barrier Function by Activating AMPK and ERK Signaling.

    Science.gov (United States)

    Wang, Kai; Jin, Xiaolu; Chen, Yifan; Song, Zehe; Jiang, Xiasen; Hu, Fuliang; Conlon, Michael A; Topping, David L

    2016-05-07

    Propolis has abundant polyphenolic constituents and is used widely as a health/functional food. Here, we investigated the effects of polyphenol-rich propolis extracts (PPE) on intestinal barrier function in human intestinal epithelial Caco-2 cells, as well as in rats. In Caco-2 cells, PPE increased transepithelial electrical resistance and decreased lucifer yellow flux. PPE-treated cells showed increased expression of the tight junction (TJ) loci occludin and zona occludens (ZO)-1. Confocal microscopy showed organized expressions in proteins related to TJ assembly, i.e., occludin and ZO-1, in response to PPE. Furthermore, PPE led to the activation of AMPK, ERK1/2, p38, and Akt. Using selective inhibitors, we found that the positive effects of PPE on barrier function were abolished in cells in which AMPK and ERK1/2 signaling were inhibited. Moreover, rats fed a diet supplemented with PPE (0.3% in the diet) exhibited increased colonic epithelium ZO-1 expression. Overall, these data suggest that PPE strengthens intestinal barrier function by activating AMPK and ERK signaling and provide novel insights into the potential application of propolis for human gut health.

  3. Coastal barrier stratigraphy for Holocene high-resolution sea-level reconstruction

    Science.gov (United States)

    Costas, Susana; Ferreira, Óscar; Plomaritis, Theocharis A.; Leorri, Eduardo

    2016-12-01

    The uncertainties surrounding present and future sea-level rise have revived the debate around sea-level changes through the deglaciation and mid- to late Holocene, from which arises a need for high-quality reconstructions of regional sea level. Here, we explore the stratigraphy of a sandy barrier to identify the best sea-level indicators and provide a new sea-level reconstruction for the central Portuguese coast over the past 6.5 ka. The selected indicators represent morphological features extracted from coastal barrier stratigraphy, beach berm and dune-beach contact. These features were mapped from high-resolution ground penetrating radar images of the subsurface and transformed into sea-level indicators through comparison with modern analogs and a chronology based on optically stimulated luminescence ages. Our reconstructions document a continuous but slow sea-level rise after 6.5 ka with an accumulated change in elevation of about 2 m. In the context of SW Europe, our results show good agreement with previous studies, including the Tagus isostatic model, with minor discrepancies that demand further improvement of regional models. This work reinforces the potential of barrier indicators to accurately reconstruct high-resolution mid- to late Holocene sea-level changes through simple approaches.

  4. Regulatory barriers for activating flexibility in the Nordic-Baltic electricity market

    DEFF Research Database (Denmark)

    Bergaentzlé, Claire; Skytte, Klaus; Soysal, Emilie Rosenlund

    2017-01-01

    The rapid growth of variable renewable energy (VRE) and the expected decrease of conventional generation capacities will generate more flexibility needs in power systems and require flexibility resources to be activated. Flexibility potentials do exist, whether they refer to installed generation......, load adjustment or to a greater coupling to other energy sectors. In this paper, we identify the framework conditions that influence the provision of VRE-friendly flexibility in the Nordic and Baltic electricity sector, i.e., the market and regulatory settings that act as drivers or barriers...... to flexibility. We find that the most restrictive barriers against flexibility are emitted by public authorities as part of broader policy strategies. Overall, we find that current regulatory and market framework conditions do not hinder flexibility. However, despite that, flexibility remains limited due...

  5. Barriers and Facilitators for Being Physically Active in Patients with Ankylosing Spondylitis: A Cross-sectional Comparative Study.

    Science.gov (United States)

    Fongen, Camilla; Sveaas, Silje Halvorsen; Dagfinrud, Hanne

    2015-06-01

    The aims of the present study were to explore the barriers and facilitators for being physically active and the perceived health benefits of physical activity in a group of patients with ankylosing spondylitis (AS), and to compare the findings with those in population controls. A total of 148 patients and 133 controls were included in a cross-sectional study. Barriers, facilitators and perceived health benefits were registered in a structured interview. Patients were significantly more likely to report barriers to being physically active compared with controls (78% versus 58%; p ≤ 0.001). The barriers most frequently reported by patients were pain (48%), stiffness (36%), fatigue (30%) and disability (21%). A similar proportion of patients (62%) and controls (61%) reported that they had the potential to become more physically active (p = 0.12). Time and motivation were the most frequently reported facilitators in both groups. Patients also reported stable disease (15%) and individually adapted physical activity (8%) as facilitators. An equal proportion of patients (96%) and controls (96%) reported that physical activity had a positive effect on their health (p = 0.94). Improved fitness and increased vitality were the most frequently reported health benefits in both groups. Patients also reported greater disease stability (37%) and reduced pain (33%) as benefits. A larger proportion of patients than controls reported barriers to being physically active. In addition to regular barriers, facilitators and health benefits, patients reported that disease-related factors influenced their participation in physical activity. Copyright © 2014 John Wiley & Sons, Ltd.

  6. Borate cross-linked graphene oxide-chitosan as robust and high gas barrier films

    Science.gov (United States)

    Yan, Ning; Capezzuto, Filomena; Lavorgna, Marino; Buonocore, Giovanna G.; Tescione, Fabiana; Xia, Hesheng; Ambrosio, Luigi

    2016-05-01

    Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical crosslinking between chitosan and GO nanoplatelets through borate ions, as well as the formation of a layered morphology with graphene nanoplatelets oriented parallel to the sample surface. The exceptional robust and high gas barrier film has promising application in the packaging industry. The borate-crosslinking chemistry represents the potential strategy for improving properties of other polymer nanocomposites.Chitosan (CS) is one of the most promising polymers due to its biocompatibility, biodegradability, and natural abundance. However, its poor mechanical and barrier properties make it difficult to satisfy a wide range of applications. Herein, borate ions, originating from the hydrolysis of sodium tetraborate decahydrate (borax), have been used to crosslink chitosan and graphene oxide (GO) nanocomposites. Chitosan films consisting of 1.0 wt% boron and 1.0 wt% GO exhibit a significant improvement in both the toughness and oxygen barrier properties compared to pristine chitosan. In particular the tensile strength of the samples after thermal treatment increases by ~160% compared to pristine chitosan, whereas their oxygen permeability reduces by ~90%. This is ascribed to the chemical

  7. Graphene oxide and laponite composite films with high oxygen-barrier properties

    Science.gov (United States)

    Yoo, Jongtae; Lee, Sang Bong; Lee, Chang Kee; Hwang, Sung Wook; Kim, Chaerin; Fujigaya, Tsuyohiko; Nakashima, Naotoshi; Shim, Jin Kie

    2014-08-01

    The design and fabrication of oxygen barrier films is important for both fundamental and industrial applications. We prepared three different thin films composed of graphene oxide (GO) and laponite (LN), a typical low cost inorganic clay, with the GO/LN volume ratios of 1.9/0.1, 1.7/0.3 and 1.5/0.5 together with a double layer film of the GO and LN. We found that the films with GO/LN = 1.9/0.1 and the double layers exhibited high oxygen barrier and oxygen transmission rate values that reached 0.55 and 0.37 cm3 per m2 per atm per day, respectively, which were much lower than those of the films prepared from the pure GO, only LN and GO/LN = 1.7/0.3 and 1.5/0.5. This study is important for the design and fabrication of a film from GO-based all inorganic nanomaterials for applications in gas-barrier membranes.The design and fabrication of oxygen barrier films is important for both fundamental and industrial applications. We prepared three different thin films composed of graphene oxide (GO) and laponite (LN), a typical low cost inorganic clay, with the GO/LN volume ratios of 1.9/0.1, 1.7/0.3 and 1.5/0.5 together with a double layer film of the GO and LN. We found that the films with GO/LN = 1.9/0.1 and the double layers exhibited high oxygen barrier and oxygen transmission rate values that reached 0.55 and 0.37 cm3 per m2 per atm per day, respectively, which were much lower than those of the films prepared from the pure GO, only LN and GO/LN = 1.7/0.3 and 1.5/0.5. This study is important for the design and fabrication of a film from GO-based all inorganic nanomaterials for applications in gas-barrier membranes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03429e

  8. The Role of Perceived Barriers and Relational Support in the Educational and Vocational Lives of Urban High School Students

    Science.gov (United States)

    Kenny, Maureen E.; Blustein, David L.; Chaves, Anna; Grossman, Jennifer M.; Gallagher, Laura A.

    2003-01-01

    Drawing on developmental contextual theory, the authors examined the relationship of perceived barriers and support with school engagement and vocational attitudes among 9th-grade urban high school students in 2 studies. Study 1 (N=174) showed that both perceived barriers and perceived support from family kin were associated with youths'…

  9. Polymeric hydrogen diffusion barrier, high-pressure storage tank so equipped, method of fabricating a storage tank and method of preventing hydrogen diffusion

    Science.gov (United States)

    Lessing, Paul A [Idaho Falls, ID

    2008-07-22

    An electrochemically active hydrogen diffusion barrier which comprises an anode layer, a cathode layer, and an intermediate electrolyte layer, which is conductive to protons and substantially impermeable to hydrogen. A catalytic metal present in or adjacent to the anode layer catalyzes an electrochemical reaction that converts any hydrogen that diffuses through the electrolyte layer to protons and electrons. The protons and electrons are transported to the cathode layer and reacted to form hydrogen. The hydrogen diffusion barrier is applied to a polymeric substrate used in a storage tank to store hydrogen under high pressure. A storage tank equipped with the electrochemically active hydrogen diffusion barrier, a method of fabricating the storage tank, and a method of preventing hydrogen from diffusing out of a storage tank are also disclosed.

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

    Science.gov (United States)

    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.

  11. Barriers, facilitators and attitudes influencing health promotion activities in general practice: an explorative pilot study

    Directory of Open Access Journals (Sweden)

    Geense Wytske W

    2013-02-01

    Full Text Available Abstract Background The number of chronically ill patients increases every year. This is partly due to an unhealthy lifestyle. However, the frequency and quality of (evidence-based health promotion activities conducted by Dutch general practitioners (GPs and practice nurses (PNs are limited. The aim of this pilot study was to explore which lifestyle interventions Dutch GPs and PNs carry out in primary care, which barriers and facilitators can be identified and what main topics are with respect to attitudes towards health promoting activities. These topic areas will be identified for a future, larger scale study. Method This qualitative study consisted of 25 semi-structured interviews with sixteen GPs and nine PNs. ATLAS.ti was used to analyse the transcripts of the interviews. Results All GPs and PNs said they discuss lifestyle with their patients. Next to this, GPs and PNs counsel patients, and/or refer them to other disciplines. Only few said they refer patients to specific lifestyle programs or interventions in their own practice or in the neighbourhood. Several barriers and facilitators were identified. The main topics as barriers are: a lack of patients’ motivation to make lifestyle changes, insufficient reimbursement, a lack of proven effectiveness of interventions and a lack of overview of health promoting programs in their neighbourhood. The most cited facilitators are availability of a PN, collaboration with other disciplines and availability of interventions in their own practice. With respect to attitudes, six different types of GPs were identified reflecting the main topics that relate to attitudes, varying from ‘ignorer’ to ‘nurturer’. The topics relating to PNs attitudes towards health promotion activities, were almost unanimously positive. Conclusion GPs and PNs all say they discuss lifestyle issues with their patients, but the health promotion activities that are organized in their practice vary. Main topics that hinder

  12. Checkpoint Kinase 1 Activation Enhances Intestinal Epithelial Barrier Function via Regulation of Claudin-5 Expression.

    Directory of Open Access Journals (Sweden)

    Akihiro Watari

    Full Text Available Several stressors are known to influence epithelial tight junction (TJ integrity, but the association between DNA damage and TJ integrity remains unclear. Here we examined the effects of daunorubicin and rebeccamycin, two anti-tumor chemicals that induce DNA damage, on TJ integrity in human intestinal epithelial cells. Daunorubicin and rebeccamycin dose-dependently enhanced transepithelial electrical resistance (TER and decreased flux of the 4 kDa FITC-dextran in Caco-2 cell monolayer. Daunorubicin- or rebeccamycin-induced enhancement of the TJ barrier function partly rescued attenuation of the barrier function by the inflammatory cytokines TNF-α and IFN-γ. Daunorubicin and rebeccamycin increased claudin-5 expression and the product was distributed in the actin cytoskeleton fraction, which was enriched with TJ proteins. Caffeine, which is an inhibitor of ataxia telangiectasia mutated protein (ATM and ataxia telangiectasia mutated and Rad3-related protein (ATR, and the Chk1 inhibitor inhibited the TER increases induced by daunorubicin and rebeccamycin, whereas a Chk2 inhibitor did not. Treatment with Chk1 siRNA also significantly inhibited the TER increases. Induction of claudin-5 expression was inhibited by Chk1 inhibitor and by siRNA treatment. Our results suggest that Chk1 activation by daunorubicin and rebeccamycin induced claudin-5 expression and enhanced TJ barrier function in Caco-2 cell monolayer, which suggests a link between DNA damage and TJ integrity in the human intestine.

  13. Checkpoint Kinase 1 Activation Enhances Intestinal Epithelial Barrier Function via Regulation of Claudin-5 Expression.

    Science.gov (United States)

    Watari, Akihiro; Hasegawa, Maki; Yagi, Kiyohito; Kondoh, Masuo

    2016-01-01

    Several stressors are known to influence epithelial tight junction (TJ) integrity, but the association between DNA damage and TJ integrity remains unclear. Here we examined the effects of daunorubicin and rebeccamycin, two anti-tumor chemicals that induce DNA damage, on TJ integrity in human intestinal epithelial cells. Daunorubicin and rebeccamycin dose-dependently enhanced transepithelial electrical resistance (TER) and decreased flux of the 4 kDa FITC-dextran in Caco-2 cell monolayer. Daunorubicin- or rebeccamycin-induced enhancement of the TJ barrier function partly rescued attenuation of the barrier function by the inflammatory cytokines TNF-α and IFN-γ. Daunorubicin and rebeccamycin increased claudin-5 expression and the product was distributed in the actin cytoskeleton fraction, which was enriched with TJ proteins. Caffeine, which is an inhibitor of ataxia telangiectasia mutated protein (ATM) and ataxia telangiectasia mutated and Rad3-related protein (ATR), and the Chk1 inhibitor inhibited the TER increases induced by daunorubicin and rebeccamycin, whereas a Chk2 inhibitor did not. Treatment with Chk1 siRNA also significantly inhibited the TER increases. Induction of claudin-5 expression was inhibited by Chk1 inhibitor and by siRNA treatment. Our results suggest that Chk1 activation by daunorubicin and rebeccamycin induced claudin-5 expression and enhanced TJ barrier function in Caco-2 cell monolayer, which suggests a link between DNA damage and TJ integrity in the human intestine.

  14. Barriers, motivators, and facilitators of physical activity in dementia patients: A systematic review.

    Science.gov (United States)

    van Alphen, Helena J M; Hortobágyi, Tibor; van Heuvelen, Marieke J G

    2016-01-01

    Physical activity (PA) has the potential to slow the progression of dementia patients' cognitive and physical decline. A better understanding of the factors that facilitate or hamper dementia patients' PA participation will increase the success rate of implementing PA in dementia patients' daily care. We systematically screened the barriers, motivators, and facilitators of PA participation in dementia patients, complementing previous analyses of quantitative correlates of PA in community-dwelling dementia patients. Systematic searches yielded 78 potential studies of which seven met the eligibility criteria including 39 dementia patients and 36 caregivers (33 spouses and three daughters). We identified 35 barriers, 26 motivators, and 21 facilitators related to PA. We reduced these factors to six themes within the social-ecological model. Prominent barriers to PA were physical and mental limitations and difficulties with guidance and organization of PA by caregivers. Motivators included the motivation to maintain physical and mental health and participate in preferred PA options. Facilitators included strategies to avoid health problems, providing support and guidance for PA, and access to convenient and personalized PA options. The emerging picture suggests that dementia patients' PA participation will increase if service providers become familiar with the health benefits of PA, the characteristics of PA programs, methods of delivery, and the concepts of how such programs can be personalized to and synchronized with patients' individual needs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Reducing Barriers To The Use of High-Efficiency Lighting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Peter Morante

    2005-12-31

    With funding from the U.S. Department of Energy (DOE), the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute completed the four-year research project, Reducing Barriers to the Use of High-Efficiency Lighting Systems. The initial objectives were: (1) identifying barriers to widespread penetration of lighting controls in commercial/industrial (C/I) applications that employ fluorescent lamp technologies, and (2) making recommendations to overcome these barriers. The addition of a fourth year expanded the original project objectives to include an examination of the impact on fluorescent lamps from dimming utilizing different lamp electrode heating and dimming ratios. The scope of the project was narrowed to identify barriers to the penetration of lighting controls into commercial-industrial (C/I) applications that employ fluorescent lamp technologies, and to recommend means for overcoming these barriers. Working with lighting manufacturers, specifiers, and installers, the project identified technological and marketing barriers to the widespread use of lighting controls, specifically automatic-off controls, occupancy sensors, photosensors, dimming systems, communication protocols and load-shedding ballasts. The primary barriers identified include cost effectiveness of lighting controls to the building owner, lack of standard communication protocols to allow different part of the control system to communicate effectively, and installation and commissioning issues. Overcoming the identified barriers requires lighting control products on the market to achieve three main goals: (1) Achieve sufficient functionality to meet the key requirements of their main market. (2) Allow significant cost reduction compared to current market standard systems. Cost should consider: hardware capital cost including wiring, design time required by the specifier and the control system manufacturer, installation time required by the electrician, and commissioning time and

  16. Barriers and motivators for physical activity among overweight and obese people with type 2 diabetes

    DEFF Research Database (Denmark)

    Lidegaard, Lærke; Schwennesen, Nete; Willaing, Ingrid

    2016-01-01

    and analysed thematically. Results We identified four main themes: 1) the body as a barrier to physical activity because of functional limitations; 2) logistical challenges, including lack of time and awareness of where to exercise in the local area; 3) being physically active with others, providing a sense...... with Type 2 diabetes aged 39–71 years. The facilitators used open-ended questions and probes such as images, statements and quotations about physical activity to foster active participation and interaction among participants. Focus groups were recorded on video and the discussions were transcribed...... is needed to investigate the effect of combining individually tailored exercise plans with the establishment of customized and locally based exercise communities that offer enjoyment and support. Additionally, it would be relevant to explore experiences of using self-tracking technologies to review short...

  17. Subthreshold Schottky-barrier thin-film transistors with ultralow power and high intrinsic gain

    Science.gov (United States)

    Lee, Sungsik; Nathan, Arokia

    2016-10-01

    The quest for low power becomes highly compelling in newly emerging application areas related to wearable devices in the Internet of Things. Here, we report on a Schottky-barrier indium-gallium-zinc-oxide thin-film transistor operating in the deep subthreshold regime (i.e., near the OFF state) at low supply voltages (400) that was both bias and geometry independent. The transistor reported here is useful for sensor interface circuits in wearable devices where high current sensitivity and ultralow power are vital for battery-less operation.

  18. Levels of physical activity, barriers, and stage of change in an urban population from a municipality in Colombia

    OpenAIRE

    Mónica María Arenas; Elkin Fernando Arango; Fredy Alonso Patiño; Mario Andrés Quintero

    2011-01-01

    Objective: To assess the levels of physical activity, barriers, and stage of change in an urban population 25 to 50 yearsof age from the Municipality of Santa Rosa de Osos, department of Antioquia.Materials and methods: A prevalence study was conducted, with a two-stage random sampling among 357 individualsnot suffering from any known cardiovascular disease. A pre-designed survey was conducted to assess the levels of physicalactivity, the stage of change, and physical activity barriers.Result...

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

    Directory of Open Access Journals (Sweden)

    Lisa Jahns

    2014-11-01

    Full Text Available 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.

  20. Patient-Reported Barriers to High-Quality, End-of-Life Care: A Multiethnic, Multilingual, Mixed-Methods Study.

    Science.gov (United States)

    Periyakoil, Vyjeyanthi S; Neri, Eric; Kraemer, Helena

    2016-04-01

    The study objective was to empirically identify barriers reported by multiethnic patients and families in receiving high-quality end-of-life care (EOLC). This cross-sectional, mixed-methods study in Burmese, English, Hindi, Mandarin, Tagalog, Spanish, and Vietnamese was held in multiethnic community centers in five California cities. Data were collected in 2013-2014. A snowball sampling technique was used to accrue 387 participants-261 women, 126 men, 133 Caucasian, 204 Asian Americans, 44 African Americans, and 6 Hispanic Americans. Measured were multiethnic patient-reported barriers to high-quality EOLC. A development cohort (72 participants) of responses was analyzed qualitatively using grounded theory to identify the six key barriers to high-quality EOLC. A new validation cohort (315 participants) of responses was transcribed, translated, and back-translated for verification. The codes were validated by analyses of responses from 50 randomly drawn subjects from the validation cohort. All the 315 validation cohort transcripts were coded for presence or absence of the six barriers. In the validation cohort, 60.6% reported barriers to receiving high-quality EOLC for persons in their culture/ethnicity. Primary patient-reported barriers were (1) finance/health insurance barriers, (2) doctor behaviors, (3) communication chasm between doctors and patients, (4) family beliefs/behaviors, (5) health system barriers, and (6) cultural/religious barriers. Age (χ(2) = 9.15, DF = 1, p = 0.003); gender (χ(2) = 6.605, DF = 1, p = 0.01); and marital status (χ(2) = 16.11 DF = 3, p = 0.001) were associated with reporting barriers; and women care. Efforts must be made to rapidly improve access to culturally competent EOLC for diverse populations.

  1. VE-cadherin trans-interactions modulate Rac activation and enhancement of lung endothelial barrier by iloprost.

    Science.gov (United States)

    Birukova, Anna A; Tian, Yufeng; Dubrovskyi, Oleksii; Zebda, Noureddine; Sarich, Nicolene; Tian, Xinyong; Wang, Yingxiao; Birukov, Konstantin G

    2012-10-01

    Small GTPase Rac is important regulator of endothelial cell (EC) barrier enhancement by prostacyclin characterized by increased peripheral actin cytoskeleton and increased interactions between VE-cadherin and other adherens junction (AJ) proteins. This study utilized complementary approaches including siRNA knockdown, culturing in Ca(2+) -free medium, and VE-cadherin blocking antibody to alter VE-cadherin extracellular interactions to investigate the role of VE-cadherin outside-in signaling in modulation of Rac activation and EC barrier regulation by prostacyclin analog iloprost. Spatial analysis of Rac activation in pulmonary EC by FRET revealed additional spike in iloprost-induced Rac activity at the sites of newly formed cell-cell junctions. In contrast, disruption of VE-cadherin extracellular trans-interactions suppressed iloprost-activated Rac signaling and attenuated EC barrier enhancement and cytoskeletal remodeling. These inhibitory effects were associated with decreased membrane accumulation and activation of Rac-specific guanine nucleotide exchange factors (GEFs) Tiam1 and Vav2. Conversely, plating of pulmonary EC on surfaces coated with extracellular VE-cadherin domain further promoted iloprost-induced Rac signaling. In the model of thrombin-induced EC barrier recovery, blocking of VE-cadherin trans-interactions attenuated activation of Rac pathway during recovery phase and delayed suppression of Rho signaling and restoration of EC barrier properties. These results suggest that VE-cadherin outside-in signaling controls locally Rac activity stimulated by barrier protective agonists. This control is essential for maximal EC barrier enhancement and accelerated barrier recovery. Copyright © 2011 Wiley Periodicals, Inc.

  2. Dissociation activation barrier and heat of chemisorption: A morse-type analytical approach

    Science.gov (United States)

    Shustorovich, Evgeny M.

    1985-02-01

    The activation barrier Δ E∗ABfor dissociation AB → A + B on transition-metal surfaces is analyzed within an additive Morse-type approach based on the bond-order conservation. It is shown that Δ E∗AB = DAB-( QA + QB + QAQB/( QA + QB) where DAB is the gas-phase dissociation energy and Q A(Q B) is the heat of atomic chemisorption. Estimates of Δ E∗ for H 2, N 2, O 2, and NO are shown to be in reasonable agreement with experiment. The two-dimensional potential diagram of the metal-AB interactions is defined analytically and discussed in some detail.

  3. Communications: Comparison of activation barriers for the Johari-Goldstein and alpha relaxations and its implications.

    Science.gov (United States)

    Goldstein, Martin

    2010-01-28

    The range of activation barrier heights for the Johari-Goldstein (JG) relaxation in glasses is shown to overlap the range for the main (alpha) relaxation, but to be on the average somewhat lower. This suggests the JG relaxation, like the alpha, involve transitions between megabasins in the energy landscape, and that the original conjecture by Johari and this author that the JG relaxation is an intrabasin one cannot be correct. A further possibility is that there is a closer connection of the JG relaxation to the phenomenon of dynamic heterogeneity in supercooled liquids than so far assumed.

  4. Highly compacted biodegradable DNA nanoparticles capable of overcoming the mucus barrier for inhaled lung gene therapy.

    Science.gov (United States)

    Mastorakos, Panagiotis; da Silva, Adriana L; Chisholm, Jane; Song, Eric; Choi, Won Kyu; Boyle, Michael P; Morales, Marcelo M; Hanes, Justin; Suk, Jung Soo

    2015-07-14

    Gene therapy has emerged as an alternative for the treatment of diseases refractory to conventional therapeutics. Synthetic nanoparticle-based gene delivery systems offer highly tunable platforms for the delivery of therapeutic genes. However, the inability to achieve sustained, high-level transgene expression in vivo presents a significant hurdle. The respiratory system, although readily accessible, remains a challenging target, as effective gene therapy mandates colloidal stability in physiological fluids and the ability to overcome biological barriers found in the lung. We formulated highly stable DNA nanoparticles based on state-of-the-art biodegradable polymers, poly(β-amino esters) (PBAEs), possessing a dense corona of polyethylene glycol. We found that these nanoparticles efficiently penetrated the nanoporous and highly adhesive human mucus gel layer that constitutes a primary barrier to reaching the underlying epithelium. We also discovered that these PBAE-based mucus-penetrating DNA nanoparticles (PBAE-MPPs) provided uniform and high-level transgene expression throughout the mouse lungs, superior to several gold standard gene delivery systems. PBAE-MPPs achieved robust transgene expression over at least 4 mo following a single administration, and their transfection efficiency was not attenuated by repeated administrations, underscoring their clinical relevance. Importantly, PBAE-MPPs demonstrated a favorable safety profile with no signs of toxicity following intratracheal administration.

  5. Minimized thermal conductivity in highly stable thermal barrier W/ZrO2 multilayers

    Science.gov (United States)

    Döring, Florian; Major, Anna; Eberl, Christian; Krebs, Hans-Ulrich

    2016-10-01

    Nanoscale thin-film multilayer materials are of great research interest since their large number of interfaces can strongly hinder phonon propagation and lead to a minimized thermal conductivity. When such materials provide a sufficiently small thermal conductivity and feature in addition also a high thermal stability, they would be possible candidates for high-temperature applications such as thermal barrier coatings. For this article, we have used pulsed laser deposition in order to fabricate thin multilayers out of the thermal barrier material ZrO2 in combination with W, which has both a high melting point and high density. Layer thicknesses were designed such that bulk thermal conductivity is governed by the low value of ZrO2, while ultrathin W blocking layers provide a high number of interfaces. By this phonon scattering, reflection and shortening of mean free path lead to a significant reduction in overall thermal conductivity even below the already low value of ZrO2. In addition to this, X-ray reflectivity measurements were taken showing strong Bragg peaks even after annealing such multilayers at 1300 K. Those results identify W/ZrO2 multilayers as desired thermally stable, low-conductivity materials.

  6. Minimized thermal conductivity in highly stable thermal barrier W/ZrO{sub 2} multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Doering, Florian; Major, Anna; Eberl, Christian; Krebs, Hans-Ulrich [University of Goettingen, Institut fuer Materialphysik, Goettingen (Germany)

    2016-10-15

    Nanoscale thin-film multilayer materials are of great research interest since their large number of interfaces can strongly hinder phonon propagation and lead to a minimized thermal conductivity. When such materials provide a sufficiently small thermal conductivity and feature in addition also a high thermal stability, they would be possible candidates for high-temperature applications such as thermal barrier coatings. For this article, we have used pulsed laser deposition in order to fabricate thin multilayers out of the thermal barrier material ZrO{sub 2} in combination with W, which has both a high melting point and high density. Layer thicknesses were designed such that bulk thermal conductivity is governed by the low value of ZrO{sub 2}, while ultrathin W blocking layers provide a high number of interfaces. By this phonon scattering, reflection and shortening of mean free path lead to a significant reduction in overall thermal conductivity even below the already low value of ZrO{sub 2}. In addition to this, X-ray reflectivity measurements were taken showing strong Bragg peaks even after annealing such multilayers at 1300 K. Those results identify W/ZrO{sub 2} multilayers as desired thermally stable, low-conductivity materials. (orig.)

  7. Survey of the Relationship Between Activity Energy Expenditure Metabolic Equivalents and Barrier Factors of Physical Activity in the Elderly in Kashan

    Science.gov (United States)

    Sadrollahi, Ali; Khalili, Zahra; Pour Nazari, Robab; Mohammadi, Majid; Ahmadi Khatir, Maryam; Mossadegh, Najima

    2016-01-01

    Background Physical activity in the elderly is influenced by aspects of aging that cause personal, mental, environmental, and social changes. Increases in factors that are barriers to activity cause physical energy expenditure to decrease. Objectives The aim of the present study was to survey the relationship between energy expenditure in metabolic equivalent units (MET) and factors that are barriers to physical activity in elderly people in Kashan, Iran Methods This is a descriptive analysis done in 2014. The study population was 400 people above 60 years old in medical facilities in Kashan. Multistage sampling was used in 10 clinics in 5 areas of Kashan. The sample size was varied according to gender and elderly population. Contributors were given questionnaires concerning energy expenditure levels in physical activity and factors that are barriers to being active. Results The average age among the study population was 67.6 ± 6.8 years median, and the interquartile range (IQR) of barriers to physical activity among Kashan’s elderly was (8.75) ± 33. Average energy expenditure was 326.21 ± 364.84 based on metabolic equivalent units (MET). In fact, 340 persons (85%) were practically without any active energy expenditure. The most common barrier was the lack of an appropriate place for doing physical activity; 298 (74%) of the participants cited this barrier. The results show the Spearman rank-order correlation is significant (P = 0.038, r = 0.104) between barriers to physical activity and activity energy expenditure in Kashan’s elderly. Conclusions Decreasing barriers to physical activity among the elderly causes physical activities to increase; therefore, energy expenditure is increased. Decreasing social and environmental problems for the elderly is effective in increasing physical activity and energy expenditure. PMID:28191341

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

    Science.gov (United States)

    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.

  9. Barriers to Incorporating Climate Change Science into High School and Community College Energy Course Offerings

    Science.gov (United States)

    Howell, C.

    2013-05-01

    In reviewing studies evaluating trends in greenhouse gasses, weather, climate and/or ecosystems, it becomes apparent that climate change is a reality. It has also become evident that the energy sector accounts for most of the greenhouse gas emissions with worldwide emissions of carbon dioxide increasing by 31 percent from 1990 to 2005, higher than in the previous thousands of years. While energy courses and topics are presented in high school and community college classes the topic of Climate Change Science is not always a part of the conversation. During the summer of 2011 and 2012, research undergraduates conducted interviews with a total of 39 national community college and 8 high school instructors who participated in a two week Sustainable Energy Education Training (SEET) workshop. Interview questions addressed the barriers and opportunities to the incorporation of climate change as a dimension of an energy/renewable energy curriculum. Barriers found included: there is not enough instruction time to include it; some school administrators including community members do not recognize climate change issues; quality information about climate change geared to students is difficult to find; and, most climate change information is too scientific for most audiences. A Solution to some barriers included dialogue on sustainability as a common ground in recognizing environmental changes/concerns among educators, administrators and community members. Sustainability discussions are already supported in school business courses as well as in technical education. In conclusion, we cannot expect climate change to dissipate without humans making more informed energy and environmental choices. With global population growth producing greater emissions resulting in increased climate change, we must include the topic of climate change to students in high school and community college classrooms, preparing our next generation of leaders and workforce to be equipped to find solutions

  10. High-performance 4H-SiC junction barrier Schottky diodes with double resistive termination extensions

    Science.gov (United States)

    Zheng, Liu; Zhang, Feng; Liu, Sheng-Bei; Dong, Lin; Liu, Xing-Fang; Fan, Zhong-Chao; Liu, Bin; Yan, Guo-Guo; Wang, Lei; Zhao, Wan-Shun; Sun, Guo-Sheng; He, Zhi; Yang, Fu-Hua

    2013-09-01

    4H-SiC junction barrier Schottky (JBS) diodes with a high-temperature annealed resistive termination extension (HARTE) are designed, fabricated and characterized in this work. The differential specific on-state resistance of the device is as low as 3.64 mΩ·cm2 with a total active area of 2.46 × 10-3 cm2. Ti is the Schottky contact metal with a Schottky barrier height of 1.08 V and a low onset voltage of 0.7 V. The ideality factor is calculated to be 1.06. Al implantation annealing is performed at 1250°C in Ar, while good reverse characteristics are achieved. The maximum breakdown voltage is 1000 V with a leakage current of 9 × 10-5 A on chip level. These experimental results show good consistence with the simulation results and demonstrate that high-performance 4H-SiC JBS diodes can be obtained based on the double HARTE structure.

  11. Modeling the long-term durability of concrete barriers in the context of low-activity waste storage

    Directory of Open Access Journals (Sweden)

    Samson E.

    2013-07-01

    Full Text Available The paper investigates the long-term durability of concrete barriers in contact with a cementitious wasteform designed to immobilize low-activity nuclear waste. The high-pH pore solution of the wasteform contains high concentration level of sulfate, nitrate, nitrite and alkalis. The multilayer concrete/wasteform system was modeled using a multiionic reactive transport model accounting for coupling between species, dissolution/ precipitation reactions, and feedback effect. One of the primary objectives was to investigate the risk associated with the presence of sulfate in the wasteform on the durability of concrete. Simulation results showed that formation of expansive phases, such as gypsum and ettringite, into the concrete barrier was not extensive. Based on those results, it was not possible to conclude that concrete would be severely damaged, even after 5,000 years. Lab work was performed to provide data to validate the modeling results. Paste samples were immersed in sulfate contact solutions and analyzed to measure the impact of the aggressive environment on the material. The results obtained so far tend to confirm the numerical simulations.

  12. High-pressure (>1-bar) dielectric barrier discharge lamps generating short pulses of high-peak power vacuum ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Carman, R J; Mildren, R P; Ward, B K; Kane, D M [Short Wavelength Interactions with Materials (SWIM), Physics Department, Macquarie University, North Ryde, Sydney, NSW 2109 (Australia)

    2004-09-07

    We have investigated the scaling of peak vacuum ultraviolet output power from homogeneous Xe dielectric barrier discharges excited by short voltage pulses. Increasing the Xe fill pressure above 1-bar provides an increased output pulse energy, a shortened pulse duration and increases in the peak output power of two to three orders of magnitude. High peak power pulses of up to 6 W cm{sup -2} are generated with a high efficiency for pulse rates up to 50 kHz. We show that the temporal pulse characteristics are in good agreement with results from detailed computer modelling of the discharge kinetics.

  13. Synthesis gas regeneration electrotechnology using volume high-voltage pulsed discharges: corona and barrier ones

    Directory of Open Access Journals (Sweden)

    M.I. Boyko

    2014-09-01

    Full Text Available Factory testing of a created high-voltage complex (plant has been conducted. The complex consists of two pulse generators with the repetition rate of up to 50,000 pulses per second and load reactors with pulsed discharges - corona and barrier ones. Transistor (IGBT keys are used as energy switches. The efficient mode of coke gas methane conversion (steam reforming to syngas has been obtained with application of the complex created. A unidirectional action of the pulsed discharges, the gas mixture temperature, and a nickel catalyst has reduced the specific energy consumption for synthesis gas regeneration during the conversion. A feasible mechanism of this conversion is described.

  14. High Temperature Damping Behavior of Plasma-Sprayed Thermal Barrier and Protective Coatings

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.; Duffy, Kirsten P.; Ghosn, Louis J.

    2010-01-01

    A high temperature damping test apparatus has been developed using a high heat flux CO 2 laser rig in conjunction with a TIRA S540 25 kHz Shaker and Polytec OFV 5000 Vibrometer system. The test rig has been successfully used to determine the damping performance of metallic and ceramic protective coating systems at high temperature for turbine engine applications. The initial work has been primarily focused on the microstructure and processing effects on the coating temperature-dependence damping behavior. Advanced ceramic coatings, including multicomponent tetragonal and cubic phase thermal barrier coatings, along with composite bond coats, have also been investigated. The coating high temperature damping mechanisms will also be discussed.

  15. Alteration of intestinal barrier function during activity-based anorexia in mice.

    Science.gov (United States)

    Jésus, Pierre; Ouelaa, Wassila; François, Marie; Riachy, Lina; Guérin, Charlène; Aziz, Moutaz; Do Rego, Jean-Claude; Déchelotte, Pierre; Fetissov, Sergueï O; Coëffier, Moïse

    2014-12-01

    Anorexia nervosa is a severe eating disorder often leading to malnutrition and cachexia, but its pathophysiology is still poorly defined. Chronic food restriction during anorexia nervosa may induce gut barrier dysfunction, which may contribute to disease development and its complications. Here we have characterized intestinal barrier function in mice with activity-based anorexia (ABA), an animal model of anorexia nervosa. Male C57Bl/6 ABA or limited food access (LFA) mice were placed respectively in cages with or without activity wheel. After 5 days of acclimatization, both ABA and LFA mice had progressively limited access to food from 6 h/d at day 6 to 3 h/d at day 9 and until the end of experiment at day 17. A group of pair-fed mice (PF) was also compared to ABA. On day 17, food intake was lower in ABA than LFA mice (2.0 ± 0.18 g vs. 3.0 ± 0.14 g, p anorexia nervosa. The role of these alterations in the pathophysiology of anorexia nervosa should be further evaluated. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  16. Understanding Barriers and Facilitators to Healthy Eating and Active Living in Rural Communities

    Directory of Open Access Journals (Sweden)

    Rebecca Seguin

    2014-01-01

    Full Text Available Objective. Studies demonstrate that people’s food and physical activity (PA environments influence behavior, yet research examining this in rural communities is limited. Methods. Focus groups of 8–15 women were conducted in rural communities in seven US states. Questions were designed to identify factors within residents’ food and PA environments they felt helped or hindered them from eating healthfully and being physically active. Results. Participants were aged 30–84 years; mean (SD = 61 (14 (N=95. On average, communities had fewer than 5,000 residents. Limited time, social norms, and distances from or lack of exercise facilities were common PA barriers. Facilitators for PA included social support, dog walking, and availability of affordable facilities. Healthy eating barriers included the perception that healthy foods were too expensive; calorically dense large portion sizes served at family meals; and frequency of eating foods away from home, which were perceived as generally unhealthy. Healthy eating supports included culture/value around local food gathering (e.g., hunting and gardening and preservation (e.g., canning and smoking. Friends and family were frequently identified as key influencers of eating and PA behavior. Conclusions. Targeting both social and built environment factors, particularly those unique to rural locales, may enhance support for healthy eating and PA behavior change interventions.

  17. Vibration damping of superalloys and thermal barrier coatings at high-temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Gregori, Giuliano [California NanoSystems Institute, University of California, Santa Barbara, CA 93160-5050 (United States)], E-mail: g.gregori@fkf.mpg.de; Li Li [Materials Department, University of California, Santa Barbara, CA 93160-5050 (United States); Nychka, John A. [Department of Chemical and Materials Engineering, University of Kentucky, Lexington, KY 40506-0046 (United States); Clarke, David R. [Materials Department, University of California, Santa Barbara, CA 93160-5050 (United States)

    2007-09-25

    A high-temperature mechanical spectroscopy system, based on non-contact laser vibrometry, has been developed to investigate the temperature dependence of the flexural damping properties of materials and coatings up to 900 deg. C. Results for the damping coefficient and Young's modulus have been obtained for several high temperature alloys (FeCrAlY and a single crystal, Ni-based superalloy PWA 1484), ceramics (polycrystalline alumina and yttria-stabilized zirconia) and an electron-beam deposited thermal barrier coating. The results indicate that the thermally grown oxide, formed by high-temperature oxidation does not confer significant damping, whereas, coatings of the yttria-stabilized zirconia produce measurable damping over the entire temperature range with a peak centered at {approx}200 deg. C. The damping peak appears to be an intrinsic property of the YSZ material whether in the form of a bulk material or a metastable coating. Data on the temperature dependent in-plane Young's modulus of the 7 wt.% yttria-stabilized zirconia thermal barrier coating between room temperature (22 GPa) and 900 deg. C (18 GPa) is also reported for the first time.

  18. Effect of high hydrostatic pressure on the barrier properties of polyamide-6 films

    Directory of Open Access Journals (Sweden)

    Schmerder A.

    2005-01-01

    Full Text Available Little is known about the barrier properties of polymer films during high pressure processing of prepackaged foods. In order to learn more about this, we examined the influence of high hydrostatic pressure on the permeation of raspberry ketone (dissolved in ethanol/water through polyamide-6 films at temperatures between 20 and 60ºC. Permeation was lowered by increasing pressure at all temperatures. At 23°C, the increasing pressure sequence 0.1, 50, 100, 150, and 200 MPa correlated with the decreasing permeation coefficients P/(10(9 cm² s-1 of 6.2, 3.8, 3.0, 2.2, and 1.6. Analysis of the permeation kinetics indicated that this effect was due to a reduced diffusion coefficient. Pressure and temperature acted antagonistically to each other. The decrease in permeation at 200 MPa was compensated for by a temperature increase of 20ºC. After release of pressure, the former permeation coefficients were recovered, which suggests that this `pressure effect' is reversible. Taken together, our data revealed no detrimental effects of high hydrostatic pressure on the barrier properties of polymer films.

  19. Self-efficacy as a mediator of the relationship between perceived union barriers and women's participation in union activities.

    Science.gov (United States)

    Bulger, C A; Mellor, S

    1997-12-01

    This study investigated the influence of union self-efficacy (expectations of success in pursuit of union activities) as a mediator of the relationship between perceptions of barriers to union participation and women's participation in union activities (N = 89). Perceived barriers were defined in 4 domains (community, family, union, work), and self-efficacy was operationalized based on C. Lee and P. Bobko's (1994) analysis of self-efficacy measures (self-efficacy magnitude, self-efficacy strength). Union self-efficacy was found to mediate the relationship between the magnitude of perceived union barriers and the magnitude of union participation, although mediation was limited to women with weak union self-efficacy. Implications for designing training and intervention programs to enhance women's participation in the face of perceived barriers are discussed.

  20. Counselling low-back-pain patients in secondary healthcare: a randomised trial addressing experienced workplace barriers and physical activity

    DEFF Research Database (Denmark)

    Jensen, Lone Donbæk; Maribo, Thomas; Schiøttz-Christensen, Berit;

    2012-01-01

    OBJECTIVE: To assess if counselling by an occupational physician (OP) addressing experienced workplace barriers and physical activity integrated as a part of low-back pain (LBP) outpatient treatment influences pain, function and sick leave. METHODS: Randomised controlled trial in the secondary...... addressing both workplace barriers and leisure-time physical activity. A workplace visit was performed if required. Pain, function and duration of sick leave due to LBP were primary outcomes. RESULTS: A reduction in bodily pain and improvement in physical function both measured by the 36-item short...... physical activity and maximum oxygen uptake, supported compliance and adherence to the part of the intervention focusing on enhanced physical activity. CONCLUSION: Two short counselling sessions by an OP combining advice on meeting workplace barriers and enhancing physical activity had a substantial effect...

  1. In Situ Measurement of Wind-Induced Pulse Response of Sound Barrier Based on High-Speed Imaging Technology

    Directory of Open Access Journals (Sweden)

    Chunli Zhu

    2016-01-01

    Full Text Available The lifetime of the sound barrier is threatened by high-speed train-induced impulsive wind pressure as it passes by. The vibration response of the sound barrier during the process of train passing is difficult to be measured using conventional measurement methods because of the inconvenience of the installation of markers on the sound barrier. In this paper, the high-speed camera is used to record the whole process of the train passing by the sound barrier. Then, a displacement extraction algorithm based on the theory of Taylor expansion is proposed to obtain the vibration response curve. Compared with the result simulated by using the finite element method, the video extraction result shows the same head wave and tail wave phenomenon, demonstrating that the vibration measurement by using the high-speed imaging technology is an effective measuring way. It can achieve noncontact and remote vibration measurement and has important practical value.

  2. “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

    Directory of Open Access Journals (Sweden)

    Rogerson Michelle C

    2012-11-01

    Full Text Available Abstract Background 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. Methods 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. Results 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. Conclusions 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

  3. Barriers and enablers of physical activity engagement for patients with COPD in primary care

    Directory of Open Access Journals (Sweden)

    Kosteli MC

    2017-03-01

    Full Text Available Maria-Christina Kosteli,1 Nicola R Heneghan,1 Carolyn Roskell,1 Sarah E Williams,1 Peymane Adab,2 Andrew P Dickens,2 Alexandra Enocson,2 David A Fitzmaurice,2 Kate Jolly,2 Rachel Jordan,2 Sheila Greenfield,2 Jennifer Cumming1 1School of Sport, Exercise and Rehabilitation Sciences, 2Institute of Applied Health Research, University of Birmingham, Edgbaston, Birmingham, UK Background: Given that physical activity (PA has a positive impact on COPD symptoms and prognosis, this study examined the factors that both encourage and limit participation in PA for individuals with COPD in a primary care setting from the perspective of social cognitive theory.Methods: A purposive sample of 26 individuals with a range of COPD severity (age range: 50–89 years; males =15 were recruited from primary care to participate in one of four focus groups. Thematic analysis was undertaken to identify key concepts related to their self-efficacy beliefs.Results: Several barriers and enablers closely related to self-efficacy beliefs and symptom severity were identified. The main barriers were health related (fatigue, mobility problems, breathing issues caused by the weather, psychological (embarrassment, fear, frustration/disappointment, attitudinal (feeling in control of their condition, PA perception, older age perception, and motivational. The main enabling factors were related to motivation (autonomous or controlled, attitudes, self-regulation, and performance accomplishments.Clinical implications: When designing interventions for individuals with COPD, it is important to understand the patient-specific social cognitive influences on PA participation. This information can then inform individually tailored management planning. Keywords: COPD, social cognitive theory, self-efficacy, barriers, enablers, primary care

  4. Inelastic deformation behavior of thermal barrier coatings exposed at a high-temperature environment

    Directory of Open Access Journals (Sweden)

    Arai M.

    2010-06-01

    Full Text Available Thermal barrier coatings (TBCs are usually deposited onto the surface of the high-temperature component such as gas turbine, in order to protect it from a hightemperature environment. Coating stress generated by such a high-temperature brings serious damages in TBCs in service. For predicting numerically it, it is necessary to develop the constitutive equation suite to plasam-sprayed TBCs. Previous studies have made clear that the freestanding ceramic coat peeled from TBC coated substrate deforms nonlinearly with a mechanical loading, however the results there have been restricted to the test done using as-sprayed sample. In this study, effect of deposition parameter and high-temperature exposure condition on stress-strain curve of the freestanding ceramic coating sample was examined. The associated deformation process was discussed with the microstructure changes observed after performing a bending test for the exposed sample.

  5. High-efficiency silicon solar-cell design and practical barriers

    Science.gov (United States)

    Mokashi, A.

    1985-01-01

    A numerical evaluation technique is used to study the impact of practical barriers, such as heavy doping effects (Auger recombination, band gap narrowing), surface recombination, shadowing losses and minority-carrier lifetime (Tau), on a high efficiency silicon solar cell performance. Considering a high Tau of 1 ms, efficiency of a silicon solar cell of the hypothetical case is estimated to be around 29%. This is comparable with (detailed balance limit) maximum efficiency of a p-n junction solar cell of 30%. Value of Tau is varied from 1 second to 20 micro. Heavy doping effects, and realizable values of surface recombination velocities and shadowing, are then considered in succession and their influence on cell efficiency is evaluated and quantified. These practical barriers cause the cell efficiency to reduce from the maximum value of 29% to the experimentally achieved value of about 19%. Improvement in open circuit voltage V sub oc is required to achieve cell efficiency greater than 20%. Increased value of Tau reduces reverse saturation current and, hence, improves V sub oc. Control of surface recombination losses becomes critical at higher V sub oc. Substantial improvement in Tau and considerable reduction in surface recombination velocities is essential to achieve cell efficiencies greater than 20%.

  6. PLASMA THERMAL BARRIER COATINGS BASED ON ZIRCONIUM DIOXIDE WITH HIGH THERMAL STABILITY

    Directory of Open Access Journals (Sweden)

    O. G. Devoino

    2015-01-01

    Full Text Available The paper presents optimization of  processes for obtaining maximum content of tetragonal phase in the initial material and thermal barrier coatings (TBC based on zirconium dioxide and hafnium oxide.  Results of the investigations on phase composition of oxide HfO2 – ZrO2 – Y2O3  system have been given in the paper. The system represents  a microstructure which is similar to  zirconia dioxide and  transformed for its application at 1300 °C. The paper explains a mechanism of hafnium oxide influence on formation of the given microstructure. The research methodology has been based on complex metallography, X – ray diffraction and electron microscopic investigations of  structural elements of the composite plasma coating HfO2 – ZrO2 – Y2O system.In order to stabilize zirconium dioxide  dopant oxide should not only have an appropriate size of  metal ion, but also form a solid solution with the zirconia. This condition severely limits the number of possible stabilizers. In fact, such stabilization is possible only with the help of rare earth oxides (Y2O3, Yb2O3, CeO2, HfO2. Chemical purity of the applied materials plays a significant role for obtaining high-quality thermal barrier coatings. Hafnium oxide has been selected as powder for thermal barrier coatings instead of zirconium dioxide due to their similarities in structural modification, grating, chemical and physical properties and its high temperature structural transformations. It has been established that plasma thermal barrier HfO2 – ZrO2 – Y2O3 coatings consist of  one tetragonal phase. This phase is equivalent to a non-equilibrium tetragonal t' phase in the “zirconium dioxide stabilized with yttrium oxide” system. Affinity of  Hf+4 and Zr+4 cations leads to the formation of identical metastable phases during rapid quenching.

  7. Assessing Barriers and Motivators for Use of a Trail for Active Transportation in a College Town

    OpenAIRE

    FitzPatrick, Timothy Michael

    2017-01-01

    A high amount of the US population is not physically active, contributing to rates of heart disease and obesity. One strategy to increase physical activity is to use more active transportation, defined as walking or biking for transit. Besides increasing physical activity levels, active transportation can provide other benefits such as decreased air pollution from cars. College campuses provide opportunities for active transportation as most residences are close to campus. Therefore, we exami...

  8. Guard-ring termination for high-voltage SiC Schottky barrier diodes; Guard ring shutan kozo wo sonaeta kotaiatsu SiC Schottky barrier diode

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K.; Urushidani, T.; Seki, Y. [Fuji Electric Corporate Research and Development, Ltd., Kanagawa (Japan)

    1996-03-10

    Silicon carbide (SiC) has been attracting attention as a material for power devices, and has already demonstrated its favorable characteristics in Schottky barrier diodes (SBD) with gold or platinum. However, few researchers have discussed the device terminal structures, and the authors propose a simple, efficient guard-ring terminal structure. The SBD of SiC is prepared, with Al/Ti as the Schottky metals. The Al/Ti electrode forms a Schottky barrier with the n-type drift region, and an ohmic contact with the p-type region, i.e., guard-ring region. Resistance of this structure to voltage is determined by that of the mesa section of the p-n junction, and the mesa structure is formed by selective oxidation. The SBD shows a break-down voltage of 550V, which is roughly twice as high as that of an SBD having no guard-ring structure. 7 refs., 3 figs.

  9. Butyrate Enhances the Intestinal Barrier by Facilitating Tight Junction Assembly via Activation of AMP-Activated Protein Kinase in Caco-2 Cell Monolayers12

    Science.gov (United States)

    Peng, Luying; Li, Zhong-Rong; Green, Robert S.; Holzman, Ian R.; Lin, Jing

    2009-01-01

    Butyrate, one of the SCFA, promotes the development of the intestinal barrier. However, the molecular mechanisms underlying the butyrate regulation of the intestinal barrier are unknown. To test the hypothesis that the effect of butyrate on the intestinal barrier is mediated by the regulation of the assembly of tight junctions involving the activation of the AMP-activated protein kinase (AMPK), we determined the effect of butyrate on the intestinal barrier by measuring the transepithelial electrical resistance (TER) and inulin permeability in a Caco-2 cell monolayer model. We further used a calcium switch assay to study the assembly of epithelial tight junctions and determined the effect of butyrate on the assembly of epithelial tight junctions and AMPK activity. We demonstrated that the butyrate treatment increased AMPK activity and accelerated the assembly of tight junctions as shown by the reorganization of tight junction proteins, as well as the development of TER. AMPK activity was also upregulated by butyrate during calcium switch-induced tight junction assembly. Compound C, a specific AMPK inhibitor, inhibited the butyrate-induced activation of AMPK. The facilitating effect of butyrate on the increases in TER in standard culture media, as well as after calcium switch, was abolished by compound C. We conclude that butyrate enhances the intestinal barrier by regulating the assembly of tight junctions. This dynamic process is mediated by the activation of AMPK. These results suggest an intriguing link between SCFA and the intracellular energy sensor for the development of the intestinal barrier. PMID:19625695

  10. Butyrate enhances the intestinal barrier by facilitating tight junction assembly via activation of AMP-activated protein kinase in Caco-2 cell monolayers.

    Science.gov (United States)

    Peng, Luying; Li, Zhong-Rong; Green, Robert S; Holzman, Ian R; Lin, Jing

    2009-09-01

    Butyrate, one of the SCFA, promotes the development of the intestinal barrier. However, the molecular mechanisms underlying the butyrate regulation of the intestinal barrier are unknown. To test the hypothesis that the effect of butyrate on the intestinal barrier is mediated by the regulation of the assembly of tight junctions involving the activation of the AMP-activated protein kinase (AMPK), we determined the effect of butyrate on the intestinal barrier by measuring the transepithelial electrical resistance (TER) and inulin permeability in a Caco-2 cell monolayer model. We further used a calcium switch assay to study the assembly of epithelial tight junctions and determined the effect of butyrate on the assembly of epithelial tight junctions and AMPK activity. We demonstrated that the butyrate treatment increased AMPK activity and accelerated the assembly of tight junctions as shown by the reorganization of tight junction proteins, as well as the development of TER. AMPK activity was also upregulated by butyrate during calcium switch-induced tight junction assembly. Compound C, a specific AMPK inhibitor, inhibited the butyrate-induced activation of AMPK. The facilitating effect of butyrate on the increases in TER in standard culture media, as well as after calcium switch, was abolished by compound C. We conclude that butyrate enhances the intestinal barrier by regulating the assembly of tight junctions. This dynamic process is mediated by the activation of AMPK. These results suggest an intriguing link between SCFA and the intracellular energy sensor for the development of the intestinal barrier.

  11. Electron-phonon interaction in three-barrier nanosystems as active elements of quantum cascade detectors

    Energy Technology Data Exchange (ETDEWEB)

    Tkach, N. V., E-mail: ktf@chnu.edu.ua; Seti, Ju. A.; Grynyshyn, Yu. B. [Chernivtsy National University (Ukraine)

    2015-04-15

    The theory of electron tunneling through an open nanostructure as an active element of a quantum cascade detector is developed, which takes into account the interaction of electrons with confined and interface phonons. Using the method of finite-temperature Green’s functions and the electron-phonon Hamiltonian in the representation of second quantization over all system variables, the temperature shifts and electron-level widths are calculated and the contributions of different electron-phonon-interaction mechanisms to renormalization of the spectral parameters are analyzed depending on the geometrical configuration of the nanosystem. Due to weak electron-phonon coupling in a GaAs/Al{sub 0.34}Ga{sub 0.66}As-based resonant tunneling nanostructure, the temperature shift and rf field absorption peak width are not very sensitive to the electron-phonon interaction and result from a decrease in potential barrier heights caused by a difference in the temperature dependences of the well and barrier band gaps.

  12. Development of Advanced Thermal and Environmental Barrier Coatings Using a High-Heat-Flux Testing Approach

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.

    2003-01-01

    The development of low conductivity, robust thermal and environmental barrier coatings requires advanced testing techniques that can accurately and effectively evaluate coating thermal conductivity and cyclic resistance at very high surface temperatures (up to 1700 C) under large thermal gradients. In this study, a laser high-heat-flux test approach is established for evaluating advanced low conductivity, high temperature capability thermal and environmental barrier coatings under the NASA Ultra Efficient Engine Technology (UEET) program. The test approach emphasizes the real-time monitoring and assessment of the coating thermal conductivity, which initially rises under the steady-state high temperature thermal gradient test due to coating sintering, and later drops under the cyclic thermal gradient test due to coating cracking/delamination. The coating system is then evaluated based on damage accumulation and failure after the combined steady-state and cyclic thermal gradient tests. The lattice and radiation thermal conductivity of advanced ceramic coatings can also be evaluated using laser heat-flux techniques. The external radiation resistance of the coating is assessed based on the measured specimen temperature response under a laser- heated intense radiation-flux source. The coating internal radiation contribution is investigated based on the measured apparent coating conductivity increases with the coating surface test temperature under large thermal gradient test conditions. Since an increased radiation contribution is observed at these very high surface test temperatures, by varying the laser heat-flux and coating average test temperature, the complex relation between the lattice and radiation conductivity as a function of surface and interface test temperature may be derived.

  13. Barriers to and Facilitators of Physical Activity Program Use Among Older Adults

    Science.gov (United States)

    Bethancourt, Hilary J.; Rosenberg, Dori E.; Beatty, Tara; Arterburn, David E.

    2014-01-01

    Objective Regular physical activity (PA) is important for maintaining long-term physical, cognitive, and emotional health. However, few older adults engage in routine PA, and even fewer take advantage of programs designed to enhance PA participation. Though most managed Medicare members have free access to the Silver Sneakers and EnhanceFitness PA programs, the vast majority of eligible seniors do not utilize these programs. The goal of this qualitative study was to better understand the barriers to and facilitators of PA and participation in PA programs among older adults. Design This was a qualitative study using focus group interviews. Setting Focus groups took place at three Group Health clinics in King County, Washington. Participants Fifty-two randomly selected Group Health Medicare members between the ages of 66 to 78 participated. Methods We conducted four focus groups with 13 participants each. Focus group discussions were audio-recorded, transcribed, and analyzed using an inductive thematic approach and a social-ecological framework. Results Men and women were nearly equally represented among the participants, and the sample was largely white (77%), well-educated (69% college graduates), and relatively physically active. Prominent barriers to PA and PA program participation were physical limitations due to health conditions or aging, lack of professional guidance, and inadequate distribution of information on available and appropriate PA options and programs. Facilitators included the motivation to maintain physical and mental health and access to affordable, convenient, and stimulating PA options. Conclusion Older adult populations may benefit from greater support and information from their providers and health care systems on how to safely and successfully improve or maintain PA levels through later adulthood. Efforts among health care systems to boost PA among older adults may need to consider patient-centered adjustments to current PA programs, as

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

    Science.gov (United States)

    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.

  15. Perceived Barriers to and Facilitators of Physical Activity in Recipients of Solid Organ Transplantation, a Qualitative Study

    Science.gov (United States)

    van de Zande, Saskia C.; Dekker, Rienk; Verschuuren, Erik A. M.; Dijkstra, Pieter U.; van der Schans, Cees P.

    2016-01-01

    Background Sufficient physical activity is important for solid organ transplant recipients (heart, lung, liver, kidney). However, recipients do not meet the recommended amount or required type of physical activity. The perceived barriers to and facilitators of physical activity in this population are largely unknown. Methods Semi-structured in depth interviews were conducted with solid organ transplant recipients in order to explore experienced barriers and facilitators. Qualitative methodology with thematic line-by-line analysis was used for analysis, and derived themes were classified into personal and environmental factors. Results The most important indicated barriers were physical limitations, insufficient energy level, fear, and comorbidities. The most frequently mentioned facilitators included motivation, coping, consequences of (in)activity, routine/habit, goals/goal priority, and responsibility for the transplanted organ. Neutral factors acting as a barrier or facilitator were self-efficacy and expertise of personnel. A comparison of barriers and facilitators between transplant recipient groups yielded no overt differences. Conclusion Several personal and environmental factors were indicated that should be considered in intervention development to increase physical activity behavior in solid organ transplant recipients. PMID:27622291

  16. Abusive behavior is barrier to high-reliability health care systems, culture of patient safety.

    Science.gov (United States)

    Cassirer, C; Anderson, D; Hanson, S; Fraser, H

    2000-11-01

    Addressing abusive behavior in the medical workplace presents an important opportunity to deliver on the national commitment to improve patient safety. Fundamentally, the issue of patient safety and the issue of abusive behavior in the workplace are both about harm. Undiagnosed and untreated, abusive behavior is a barrier to creating high reliability service delivery systems that ensure patient safety. Health care managers and clinicians need to improve their awareness, knowledge, and understanding of the issue of workplace abuse. The available research suggests there is a high prevalence of workplace abuse in medicine. Both administrators at the blunt end and clinicians at the sharp end should consider learning new approaches to defining and treating the problem of workplace abuse. Eliminating abusive behavior has positive implications for preventing and controlling medical injury and improving organizational performance.

  17. High frequency excitation waveform for efficient operation of a xenon excimer dielectric barrier discharge lamp

    Energy Technology Data Exchange (ETDEWEB)

    Beleznai, Sz; Mihajlik, G; Richter, P [Department of Atomic Physics, Budapest University of Technology and Economics, 3-9.Muegyetem rkp., Budapest H-1111 (Hungary); Maros, I; Balazs, L, E-mail: beleznai@dept.phy.bme.h [GE Consumer and Industrial-Lighting, 77 Vaci ut, Budapest H-1344 (Hungary)

    2010-01-13

    The application of a high frequency ({approx}2.5 MHz) burst (amplitude-modulated sinusoidal) excitation voltage waveform is investigated for driving a fluorescent dielectric barrier discharge (DBD) light source. The excitation waveform presents a novel method for generating spatially stable homogeneous Xe DBD possessing a high conversion efficiency from electrical energy to VUV Xe{sub 2}{sup *} excimer radiation ({approx}172 nm), even at a significantly higher electrical energy deposition than realized by pulsed excitation. Simulation and experimental results predict discharge efficiencies around 60%. Lamp efficacy above 74 lm W{sup -1} has been achieved. VUV emission and loss mechanisms are investigated extensively and the performance of burst and pulsed waveforms is compared both theoretically and experimentally.

  18. High frequency excitation waveform for efficient operation of a xenon excimer dielectric barrier discharge lamp

    Science.gov (United States)

    Beleznai, Sz; Mihajlik, G.; Maros, I.; Balázs, L.; Richter, P.

    2010-01-01

    The application of a high frequency (~2.5 MHz) burst (amplitude-modulated sinusoidal) excitation voltage waveform is investigated for driving a fluorescent dielectric barrier discharge (DBD) light source. The excitation waveform presents a novel method for generating spatially stable homogeneous Xe DBD possessing a high conversion efficiency from electrical energy to VUV Xe_{2}^{\\ast} excimer radiation (~172 nm), even at a significantly higher electrical energy deposition than realized by pulsed excitation. Simulation and experimental results predict discharge efficiencies around 60%. Lamp efficacy above 74 lm W-1 has been achieved. VUV emission and loss mechanisms are investigated extensively and the performance of burst and pulsed waveforms is compared both theoretically and experimentally.

  19. Substrate Effects on the High-Temperature Oxidation Behavior of Thermal Barrier Coatings

    Institute of Scientific and Technical Information of China (English)

    Limin He; Zhenhua Xu; Jianping Li; Rende Mu; Shimei He; Guanghong Huang

    2009-01-01

    The high-temperature oxidation behaviors of the NiCrAIYSi/P-YSZ thermal barrier coatings (TBCs) pro-duced by electron beam-physical vapor deposition (EB-PVD) on directionally solidified (DS) and single crys-talline (SC) Ni-based superalloy substrates were investigated. The cross-sectional microstructure investigation, isothermal and cyclic oxidation tests were conducted for the comparison of oxidation behaviors of TBCs on different substrates. Although TBC on DS substrate has a relatively higher oxidation rate, it has a longer thermal cycling lifetime than that on SC substrate. The primary factor for TBC spallation is the mismatch of thermal expansion coefficient (TEC) of the bond coat and substrate. The morphological feature of thermally grown oxide (TGO) has a strong influence on the TBC performance. By optimizing the elemental interdiffusion between bond coat and substrate, a high quality TGO layer is formed on the DS substrate, and therefore the TBC oxidation behavior is improved.

  20. Effectiveness of cuticular transpiration barriers in a desert plant at controlling water loss at high temperatures.

    Science.gov (United States)

    Schuster, Ann-Christin; Burghardt, Markus; Alfarhan, Ahmed; Bueno, Amauri; Hedrich, Rainer; Leide, Jana; Thomas, Jacob; Riederer, Markus

    2016-01-01

    Maintaining the integrity of the cuticular transpiration barrier even at elevated temperatures is of vital importance especially for hot-desert plants. Currently, the temperature dependence of the leaf cuticular water permeability and its relationship with the chemistry of the cuticles are not known for a single desert plant. This study investigates whether (i) the cuticular permeability of a desert plant is lower than that of species from non-desert habitats, (ii) the temperature-dependent increase of permeability is less pronounced than in those species and (iii) whether the susceptibility of the cuticular permeability barrier to high temperatures is related to the amounts or properties of the cutin or the cuticular waxes. We test these questions with Rhazya stricta using the minimum leaf water vapour conductance (gmin) as a proxy for cuticular water permeability. gmin of R. stricta (5.41 × 10(-5) m s(-1) at 25 °C) is in the upper range of all existing data for woody species from various non-desert habitats. At the same time, in R. stricta, the effect of temperature (15-50 °C) on gmin (2.4-fold) is lower than in all other species (up to 12-fold). Rhazya stricta is also special since the temperature dependence of gmin does not become steeper above a certain transition temperature. For identifying the chemical and physical foundation of this phenomenon, the amounts and the compositions of cuticular waxes and cutin were determined. The leaf cuticular wax (251.4 μg cm(-2)) is mainly composed of pentacyclic triterpenoids (85.2% of total wax) while long-chain aliphatics contribute only 3.4%. In comparison with many other species, the triterpenoid-to-cutin ratio of R. stricta (0.63) is high. We propose that the triterpenoids deposited within the cutin matrix restrict the thermal expansion of the polymer and, thus, prevent thermal damage to the highly ordered aliphatic wax barrier even at high temperatures.

  1. Fifteen-year trends in the prevalence of barriers to healthy eating in a high-income country.

    Science.gov (United States)

    de Mestral, Carlos; Khalatbari-Soltani, Saman; Stringhini, Silvia; Marques-Vidal, Pedro

    2017-03-01

    Background: Despite increasing levels of education and income in the Swiss population over time and greater food diversity due to globalization, adherence to dietary guidelines has remained persistently low. This may be because of barriers to healthy eating hampering adherence, but whether these barriers have evolved in prevalence over time has never been assessed, to our knowledge.Objective: We assessed 15-y trends in the prevalence of self-reported barriers to healthy eating in Switzerland overall and according to sex, age, education, and income.Design: We used data from 4 national Swiss Health Surveys conducted between 1997 and 2012 (52,238 participants aged ≥18 y, 55% women), applying multivariable-adjusted logistic regression models to assess trends in prevalence of 6 barriers to healthy eating (taste, price, daily habits, time, lack of willpower, and limited options).Results: The prevalence of 3 barriers exhibited an increasing trend until 2007, followed by a decrease in 2012 (from 44% in 1997 to 50% in 2007 and then to 44% in 2012 for taste, from 40% to 52% and then to 39% for price, and from 29% to 34% and then to 32% for time; quadratic P-trend trend trend trend Trends were similar for all barriers irrespective of sex, age, education, and income.Conclusion: Between 1997 and 2012, barriers to healthy eating remained highly prevalent (≥20%) in the Swiss population and evolved similarly irrespective of age, sex, education, and income. © 2017 American Society for Nutrition.

  2. Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

    Science.gov (United States)

    Rodríguez, Martín A.

    2014-03-01

    Metallic engineered barriers must provide a period of absolute containment to high-level radioactive waste in geological repositories. Candidate materials include copper alloys, carbon steels, stainless steels, nickel alloys, and titanium alloys. The national programs of nuclear waste management have to identify and assess the anticipated degradation modes of the selected materials in the corresponding repository environment, which evolves in time. Commonly assessed degradation modes include general corrosion, localized corrosion, stress-corrosion cracking, hydrogen-assisted cracking, and microbiologically influenced corrosion. Laboratory testing and modeling in metallurgical and environmental conditions of similar and higher aggressiveness than those expected in service conditions are used to evaluate the corrosion resistance of the materials. This review focuses on the anticipated degradation modes of the selected or reference materials as corrosion-resistant barriers in nuclear repositories. These degradation modes depend not only on the selected alloy but also on the near-field environment. The evolution of the near-field environment varies for saturated and unsaturated repositories considering backfilled and unbackfilled conditions. In saturated repositories, localized corrosion and stress-corrosion cracking may occur in the initial aerobic stage, while general corrosion and hydrogen-assisted cracking are the main degradation modes in the anaerobic stage. Unsaturated repositories would provide an oxidizing environment during the entire repository lifetime. Microbiologically influenced corrosion may be avoided or minimized by selecting an appropriate backfill material. Radiation effects are negligible provided that a thick-walled container or an inner shielding container is used.

  3. Electrical Characterization of High Energy Electron Irradiated Ni/4 H-SiC Schottky Barrier Diodes

    Science.gov (United States)

    Paradzah, A. T.; Omotoso, E.; Legodi, M. J.; Auret, F. D.; Meyer, W. E.; Diale, M.

    2016-08-01

    The effect of high energy electron irradiation on Ni/4 H-SiC Schottky barrier diodes was evaluated by current-voltage ( I- V) and capacitance-voltage ( C- V) measurements at room temperature. Electron irradiation was achieved by using a radioactive strontium source with peak emission energy of 2.3 MeV. Irradiation was performed in fluence steps of 4.9 × 1013 cm-2 until a total fluence of 5.4 × 1014 cm-2 was reached. The Schottky barrier height determined from I- V measurements was not significantly changed by irradiation while that obtained from C- V measurements increased with irradiation. The ideality factor was obtained before irradiation as 1.05 and this value did not significantly change as a result of irradiation. The series resistance increased from 47 Ω before irradiation to 74 Ω after a total electron fluence of 5.4 × 1014 cm-2. The net donor concentration decreased with increasing irradiation fluence from 4.6 × 1014 cm-3 to 3.0 × 1014 cm-3 from which the carrier removal rate was calculated to be 0.37 cm-1.

  4. Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion.

    Science.gov (United States)

    Ryham, Rolf J; Klotz, Thomas S; Yao, Lihan; Cohen, Fredric S

    2016-03-08

    We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm.

  5. 75 FR 9431 - Small and Medium-Sized Enterprises: U.S. and EU Export Activities, and Barriers and Opportunities...

    Science.gov (United States)

    2010-03-02

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Small and Medium-Sized Enterprises: U.S. and EU Export Activities, and Barriers and Opportunities... investigations, investigation No. 332-509, Small and Medium-Sized Enterprises: U.S. and EU Export Activities,...

  6. [Activating physiotherapy for chronic pain in elderly patients. Recommendations, barriers and resources].

    Science.gov (United States)

    Kuss, K; Laekeman, M

    2015-08-01

    Elderly patients with chronic pain are particularly at risk of functional limitations up to the loss of autonomy and social life. To facilitate autonomy, mobility and quality of life, physiotherapy plays an essential role in pain management. Nevertheless, programs that are specifically geared towards the needs of older patients are still uncommon. This article offers recommendations for structuring physiotherapy programs based on international guideline recommendations. First examples of pain management concepts for older adults demonstrate the positive results of activating therapy. Additionally, this article provides insights into barriers and resources of affected patients and all actors involved. However, physiotherapeutic treatment for aged chronic pain patients in Germany still shows considerable shortcomings but also offers an exciting challenge for the future.

  7. MALT1 Protease Activation Triggers Acute Disruption of Endothelial Barrier Integrity via CYLD Cleavage.

    Science.gov (United States)

    Klei, Linda R; Hu, Dong; Panek, Robert; Alfano, Danielle N; Bridwell, Rachel E; Bailey, Kelly M; Oravecz-Wilson, Katherine I; Concel, Vincent J; Hess, Emily M; Van Beek, Matthew; Delekta, Phillip C; Gu, Shufang; Watkins, Simon C; Ting, Adrian T; Gough, Peter J; Foley, Kevin P; Bertin, John; McAllister-Lucas, Linda M; Lucas, Peter C

    2016-09-27

    Microvascular endothelial cells maintain a tight barrier to prevent passage of plasma and circulating immune cells into the extravascular tissue compartment, yet endothelial cells respond rapidly to vasoactive substances, including thrombin, allowing transient paracellular permeability. This response is a cornerstone of acute inflammation, but the mechanisms responsible are still incompletely understood. Here, we demonstrate that thrombin triggers MALT1 to proteolytically cleave cylindromatosis (CYLD). Fragmentation of CYLD results in microtubule disruption and a cascade of events leading to endothelial cell retraction and an acute permeability response. This finding reveals an unexpected role for the MALT1 protease, which previously has been viewed mostly as a driver of pro-inflammatory NF-κB signaling in lymphocytes. Thus, MALT1 not only promotes immune cell activation but also acutely regulates endothelial cell biology, actions that together facilitate tissue inflammation. Pharmacologic inhibition of MALT1 may therefore have synergistic impact by targeting multiple disparate steps in the overall inflammatory response.

  8. MALT1 Protease Activation Triggers Acute Disruption of Endothelial Barrier Integrity via CYLD Cleavage

    Directory of Open Access Journals (Sweden)

    Linda R. Klei

    2016-09-01

    Full Text Available Microvascular endothelial cells maintain a tight barrier to prevent passage of plasma and circulating immune cells into the extravascular tissue compartment, yet endothelial cells respond rapidly to vasoactive substances, including thrombin, allowing transient paracellular permeability. This response is a cornerstone of acute inflammation, but the mechanisms responsible are still incompletely understood. Here, we demonstrate that thrombin triggers MALT1 to proteolytically cleave cylindromatosis (CYLD. Fragmentation of CYLD results in microtubule disruption and a cascade of events leading to endothelial cell retraction and an acute permeability response. This finding reveals an unexpected role for the MALT1 protease, which previously has been viewed mostly as a driver of pro-inflammatory NF-κB signaling in lymphocytes. Thus, MALT1 not only promotes immune cell activation but also acutely regulates endothelial cell biology, actions that together facilitate tissue inflammation. Pharmacologic inhibition of MALT1 may therefore have synergistic impact by targeting multiple disparate steps in the overall inflammatory response.

  9. International Collaborations on Engineered Barrier Systems: Brief Overview of SKB-EBS Activities.

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-01

    Research collaborations with international partners on the behavior and performance of engineered barrier systems (EBS) are an important aspect of the DOE-NE Used Fuel Disposition Campaign strategy in the evaluation of disposal design concepts. These international partnerships are a cost-effective way of engaging in key R&D activities with common goals resulting in effective scientific knowledge exchanges thus enhancing existing and future research programs in the USA. This report provides a brief description of the activities covered by the Swedish Nuclear Fuel and Waste Management Company (SKB) EBS Task Force (TF) (referred hereafter as SKB EBS TF) and potential future directions for engagement of the DOE-NE UFDC program in relevant R&D activities. Emphasis is given to SKB EBS TF activities that are still ongoing and aligned to the UFDC R&D program. This include utilization of data collected in the bentonite rock interaction experiment (BRIE) and data sets from benchmark experiments produced by the chemistry or “C” part of the SKB EBS TF. Potential applications of information generated by this program include comparisons/tests between model and data (e.g., reactive diffusion), development and implementation of coupled-process models (e.g., HM), and code/model benchmarking.

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

    Science.gov (United States)

    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.

  11. Barriers to the Application of High-Temperature Coolants in Hybrid Electric Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Staunton, Robert H [ORNL; Hsu, John S [ORNL; Starke, Michael R [ORNL

    2006-09-01

    This study was performed by the Oak Ridge National Laboratory (ORNL) to identify practical approaches, technical barriers, and cost impacts to achieving high-temperature coolant operation for certain traction drive subassemblies and components of hybrid electric vehicles (HEV). HEVs are unique in their need for the cooling of certain dedicated-traction drive subassemblies/components that include the electric motor(s), generators(s), inverter, dc converter (where applicable), and dc-link capacitors. The new coolant system under study would abandon the dedicated 65 C coolant loop, such as used in the Prius, and instead rely on the 105 C engine cooling loop. This assessment is important because automotive manufacturers are interested in utilizing the existing water/glycol engine cooling loop to cool the HEV subassemblies in order to eliminate an additional coolant loop with its associated reliability, space, and cost requirements. In addition, the cooling of power electronic devices, traction motors, and generators is critical in meeting the U.S. Department of Energy (DOE) FreedomCAR and Vehicle Technology (FCVT) goals for power rating, volume, weight, efficiency, reliability, and cost. All of these have been addressed in this study. Because there is high interest by the original equipment manufacturers (OEMs) in reducing manufacturing cost to enhance their competitive standing, the approach taken in this analysis was designed to be a positive 'can-do' approach that would be most successful in demonstrating the potential or opportunity of relying entirely on a high-temperature coolant system. Nevertheless, it proved to be clearly evident that a few formidable technical and cost barriers exist and no effective approach for mitigating the barriers was evident in the near term. Based on comprehensive thermal tests of the Prius reported by ORNL in 2005 [1], the continuous ratings at base speed (1200 rpm) with different coolant temperatures were projected from

  12. Barriers to the Application of High-Temperature Coolants in Hybrid Electric Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, J.S.; Staunton, M.R.; Starke, M.R.

    2006-09-30

    This study was performed by the Oak Ridge National Laboratory (ORNL) to identify practical approaches, technical barriers, and cost impacts to achieving high-temperature coolant operation for certain traction drive subassemblies and components of hybrid electric vehicles (HEV). HEVs are unique in their need for the cooling of certain dedicated-traction drive subassemblies/components that include the electric motor(s), generators(s), inverter, dc converter (where applicable), and dc-link capacitors. The new coolant system under study would abandon the dedicated 65 C coolant loop, such as used in the Prius, and instead rely on the 105 C engine cooling loop. This assessment is important because automotive manufacturers are interested in utilizing the existing water/glycol engine cooling loop to cool the HEV subassemblies in order to eliminate an additional coolant loop with its associated reliability, space, and cost requirements. In addition, the cooling of power electronic devices, traction motors, and generators is critical in meeting the U.S. Department of Energy (DOE) FreedomCAR and Vehicle Technology (FCVT) goals for power rating, volume, weight, efficiency, reliability, and cost. All of these have been addressed in this study. Because there is high interest by the original equipment manufacturers (OEMs) in reducing manufacturing cost to enhance their competitive standing, the approach taken in this analysis was designed to be a positive 'can-do' approach that would be most successful in demonstrating the potential or opportunity of relying entirely on a high-temperature coolant system. Nevertheless, it proved to be clearly evident that a few formidable technical and cost barriers exist and no effective approach for mitigating the barriers was evident in the near term. Based on comprehensive thermal tests of the Prius reported by ORNL in 2005 [1], the continuous ratings at base speed (1200 rpm) with different coolant temperatures were projected from

  13. Motivators and barriers to healthful eating and physical activity among low-income overweight and obese mothers.

    Science.gov (United States)

    Chang, Mei-Wei; Nitzke, Susan; Guilford, Eileen; Adair, Constance H; Hazard, Diana L

    2008-06-01

    Low-income women who are overweight and obese are at high risk for long-term retention of weight gain during pregnancy, in part because they may have poor diets and inadequate physical activity, both of which may be exacerbated by stressful situations. This study identified motivators and barriers to healthful eating and physical activity among low-income overweight and obese non-Hispanic black and non-Hispanic white mothers. Qualitative data were collected via eight focus group interviews. Eighty low-income overweight and obese non-Hispanic black (n=41) and non-Hispanic white (n=39) mothers, age 18 to 35 years, were recruited from the Special Supplemental Nutrition Program for Women, Infants, and Children sites in six counties in Michigan. Personal appearance, fit in clothes, inability to play with their children, and social support were motivating factors for healthful eating and physical activity. Stressful experiences triggered emotional eating and reduced participants' ability to practice these behaviors. Other factors-for example, wanting quick weight-loss results-made it difficult for these mothers to follow recommended healthful lifestyle practices. Nutrition educators can address these concerns by including information about ways to deal with stress and emotional eating and emphasizing the benefits of healthful eating and physical activity in their program plans.

  14. Barriers to and enablers of physical activity in patients with COPD following a hospital admission: a qualitative study

    Directory of Open Access Journals (Sweden)

    Thorpe O

    2014-01-01

    Full Text Available Olivia Thorpe, Saravana Kumar, Kylie JohnstonInternational Centre for Allied Health Evidence, The Samson Institute for Health Research, School of Health Sciences, University of South Australia, Adelaide, SA, AustraliaBackground: Chronic obstructive pulmonary disease (COPD is characterized by a persistent blockage of airflow, prompting episodes of shortness of breath, commonly leading to hospitalization. Hospitalization may lead to a decline in physical activity following discharge. Physical activity has been shown to improve symptoms of COPD and reduce readmissions, and to decrease morbidity and mortality. This study aims to explore, from the perspectives of people with COPD, the barriers to and enablers of participation in physical activity following hospitalization for COPD.Methods: This study had a qualitative descriptive design and included semistructured interviews with 28 adult COPD patients who had been admitted to hospital with a primary diagnosis of exacerbation of COPD.Results: A plethora of barriers to but fewer enablers of participation in physical activity and pulmonary rehabilitation were identified for this cohort of people. The main barriers identified were health-related (comorbidities, COPD symptoms, and physical injury or illness environment-related (weather, transport, and finance, and self-related. The main enabling factors reported were access to health professionals and equipment, social support, routine and extracurricular activities, personal goals and motivation, and the effect of physical activity and "feeling better".Conclusion: This research provides a snapshot of the barriers to and enablers of physical activity and pulmonary rehabilitation in people with COPD. It is evident that there are significant barriers which hinder the ability of people with COPD to undertake and continue participation in physical activity and pulmonary rehabilitation. While there are some enablers that may counter these barriers, it is

  15. Fabrication of 4H-SiC Schottky barrier diodes with high breakdown voltages

    CERN Document Server

    Kum, B H; Shin, M W; Park, J D

    1999-01-01

    This paper discusses the fabrication and the breakdown characteristics of 4H-SiC Schottky barrier diodes (SBDs). Optimal processing conditions for the ohmic contacts were extracted using the transmission-line method (TLM) and were applied to the device fabrication. The Ti/4H-SiC SBDs with Si sub x B sub y passivation showed a maximum reverse breakdown voltage of 268 V with a forward current density as high as 70 mA/cm sup 2 at a forward voltage of 2 V. The breakdown of the Pt. 4H-SiC SBDs without any passivation occurred at near 110 V. It is concluded that the breakdown enhancement in the Ti/4H-SiC SBDs can be attributed to the passivation; otherwise, excess surface charge near the edge of the Schottky contact would lead to electric fields of sufficient magnitude to cause field emission.

  16. Volume Diffuse Dielectric Barrier Discharge Plasma Produced by Nanosecond High Voltage Pulse in Airflow

    Institute of Scientific and Technical Information of China (English)

    QI Haicheng; GAO Wei; FAN Zhihui; LIU Yidi; REN Chunsheng

    2016-01-01

    Volume diffuse dielectric barrier discharge (DBD) plasma is produced in subsonic airflow by nanosecond high-voltage pulse power supply with a plate-to-plate discharge cell at 6 mm air gap length.The discharge images,optical emission spectra (OES),the applied voltage and current waveforms of the discharge at the changed airflow rates are obtained.When airflow rate is increased,the transition of the discharge mode and the variations of discharge intensity,breakdown characteristics and the temperature of the discharge plasma are investigated.The results show that the discharge becomes more diffuse,discharge intensity is decreased accompanied by the increased breakdown voltage and time lag,and the temperature of the discharge plasma reduces when airflow of small vclocity is introduced into the discharge gap.These phenomena are because that the airflow changes the spatial distribution of the heat and the space charge in the discharge gap.

  17. Volume Diffuse Dielectric Barrier Discharge Plasma Produced by Nanosecond High Voltage Pulse in Airflow

    Science.gov (United States)

    Qi, Haicheng; Gao, Wei; Fan, Zhihui; Liu, Yidi; Ren, Chunsheng

    2016-05-01

    Volume diffuse dielectric barrier discharge (DBD) plasma is produced in subsonic airflow by nanosecond high-voltage pulse power supply with a plate-to-plate discharge cell at 6 mm air gap length. The discharge images, optical emission spectra (OES), the applied voltage and current waveforms of the discharge at the changed airflow rates are obtained. When airflow rate is increased, the transition of the discharge mode and the variations of discharge intensity, breakdown characteristics and the temperature of the discharge plasma are investigated. The results show that the discharge becomes more diffuse, discharge intensity is decreased accompanied by the increased breakdown voltage and time lag, and the temperature of the discharge plasma reduces when airflow of small velocity is introduced into the discharge gap. These phenomena are because that the airflow changes the spatial distribution of the heat and the space charge in the discharge gap. supported by National Natural Science Foundation of China (No. 51437002)

  18. Sintering Characteristics of Multilayered Thermal Barrier Coatings Under Thermal Gradient and Isothermal High Temperature Annealing Conditions

    Science.gov (United States)

    Rai, Amarendra K.; Schmitt, Michael P.; Bhattacharya, Rabi; Zhu, Dongming; Wolfe, Douglas E.

    2014-01-01

    Pyrochlore oxides have most of the relevant attributes for use as next generation thermal barrier coatings such as phase stability, low sintering kinetics and low thermal conductivity. One of the issues with the pyrochlore oxides is their lower toughness and therefore higher erosion rate compared to the current state-of-the-art TBC material, yttria (6 to 8 wt%) stabilized zirconia (YSZ). In this work, sintering characteristics were investigated for novel multilayered coating consisted of alternating layers of pyrochlore oxide viz Gd2Zr2O7 and t' low k (rare earth oxide doped YSZ). Thermal gradient and isothermal high temperature (1316 C) annealing conditions were used to investigate sintering and cracking in these coatings. The results are then compared with that of relevant monolayered coatings and a baseline YSZ coating.

  19. Impedance Analysis of 7YSZ Thermal Barrier Coatings During High-Temperature Oxidation

    Science.gov (United States)

    Chen, Wen-Long; Liu, Min; Zhang, Ji-Fu

    2016-12-01

    ZrO2-7 wt.%Y2O3 (7YSZ) thermal barrier coatings (TBCs) were prepared by atmospheric plasma spraying. High-temperature oxidation of 7YSZ TBCs was accomplished at 950 °C and characterized by impedance spectroscopy and scanning electron microscopy with energy-dispersive spectrometry. The results indicated that the thermally grown oxide (TGO) mainly contained alumina. The increase of the thickness of the TGO layer appeared to follow a parabolic law. Impedance analysis demonstrated that the resistance of the TGO increased with increasing oxidation time, also following a parabolic law, and that characterization of the TGO thickness based on fitting an equivalent circuit to its measured resistance is feasible. The YSZ grain-boundary resistance increased due to increasing cracks within the coating for oxidation time less than 50 h. However, beyond 150 h, the YSZ grain-boundary resistance slightly decreased, mainly due to sintering of the coating during the oxidation process.

  20. Designing a highly sensitive Eddy current sensor for evaluating damage on thermal barrier coating

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Min; Kim, Hak Joon; Song, Sung Jin; Seok, Chang Seong; Lee, Yeong Ze [Dept. of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Lee, Seul Gi [LG Electronics, Seoul (Korea, Republic of)

    2016-06-15

    A thermal barrier coating (TBC) has been widely applied to machine components working under high temperature as a thermal insulator owing to its critical financial and safety benefits to the industry. However, the nondestructive evaluation of TBC damage is not easy since sensing of the microscopic change that occurs on the TBC is required during an evaluation. We designed an eddy current probe for evaluating damage on a TBC based on the finite element method (FEM) and validated its performance through an experiment. An FEM analysis predicted the sensitivity of the probe, showing that impedance change increases as the TBC thermally degrades. In addition, the effect of the magnetic shield concentrating magnetic flux density was also observed. Finally, experimental validation showed good agreement with the simulation result.

  1. Stability of tokamak plasmas with internal transport barriers against high n ideal magnetohydrodynamic ballooning mode

    Institute of Scientific and Technical Information of China (English)

    Shi Bing-Ren; Qu Wen-Xiao

    2006-01-01

    A ballooning mode equation for tokamak plasma, with the toroidicity and the Shafranov shift effects included, is derived for a shift circular flux tokamak configuration. Using this equation, the stability of the plasma configuration with an internal transport barrier (IT2 against the high n (the toroidal mode number) ideal magnetohydrodynamic (MHD) ballooning mode is analysed. It is shown that both the toroidicity and the Shafranov shift effects are stabilizing.In the ITB region, these effects give rise to a low shear stable channel between the first and the second stability regions.Out of the ITB region towards the plasma edge, the stabilizing effect of the Shafranov shift causes the unstable zone to be significantly narrowed.

  2. ¿Y ahora qué? Anticipated immigration status barriers and Latina/o high school students' future expectations.

    Science.gov (United States)

    McWhirter, Ellen Hawley; Ramos, Karina; Medina, Cynthia

    2013-07-01

    Latina/o high school students without documentation face a challenging situation when they graduate from high school, with pathways to work and postsecondary education stymied by their immigration status. We examined the effects of anticipated barriers associated with immigration status, age, and sex on the dependent variables of vocational outcome expectations, anticipated external and internal barriers, and postsecondary schooling plans in a sample of 475 Latina/o high school students. Findings include that students anticipating immigration status problems had lower vocational outcome expectations and anticipated more external barriers to pursuing their postsecondary plans. Latina girls and older high school students anticipating immigration status problems were more likely to plan to attend 2-year rather than 4-year colleges, and less likely to plan on postsecondary education, respectively. Implications for practice, policy, and research are discussed.

  3. Blood-brain barrier breakdown and myeloperoxidase activity in silver catfish experimentally infected with Pseudomonas aeruginosa.

    Science.gov (United States)

    Baldissera, M D; Souza, C F; Santos, R C V; Baldisserotto, B

    2017-08-24

    Central nervous system (CNS) infections continue to be an important cause of morbidity and mortality, and microbial invasion of the blood-brain barrier (BBB) is considered a prerequisite for CNS infections, which contribute to behavioural abnormalities and disease pathogenesis. Based on this information, the aim of this study was to evaluate whether Pseudomonas aeruginosa causes disruption of the BBB, and to investigate the involvement of cerebral myeloperoxidase (MPO) activity in this process in experimentally infected silver catfish. The permeability of the BBB to Evans blue dye increased in the infected animals on days three and six post-infection (PI) compared to the control group. Moreover, cerebral MPO activity and reactive oxygen species (ROS) levels also increased in the infected animals on days three and six PI compared to the control group. Based on this evidence, we concluded that P. aaeruginosa causes a disruption of the BBB, which may contribute to disease pathogenesis in the CNS. Moreover, the increase in cerebral MPO activity and ROS levels may be considered a pathway involved in BBB breakdown, allowing the passage of bacteria to the CNS. © 2017 John Wiley & Sons Ltd.

  4. High-voltage (> 1 kV) SiC Schottky barrier diodes with low on-resistance

    Energy Technology Data Exchange (ETDEWEB)

    Kimoto, Tsunenobu; Urushidani, Tatsuo; Kobayashi, Sota; Matsunami, Hiroyuki (Kyoto Univ. (Japan). Dept. of Electrical Engineering)

    1993-12-01

    Au/6H-SiC Schottky barrier diodes with high blocking voltages were successfully fabricated using layers grown by step-controlled epitaxy. A breakdown voltage over 1,100 V could be achieved, which is the highest ever reported for silicon carbide (SiC) Schottky barrier diodes. These high-voltage SiC rectifiers had specific on-resistances lower than the theoretical limits of Si rectifiers by more than one order of magnitude. The specific on-resistance increased with temperature according to T[sup 2.0] dependence. The diodes showed good characteristics at temperature as high as 400 C.

  5. Exocyst Sec10 protects epithelial barrier integrity and enhances recovery following oxidative stress, by activation of the MAPK pathway.

    Science.gov (United States)

    Park, Kwon Moo; Fogelgren, Ben; Zuo, Xiaofeng; Kim, Jinu; Chung, Daniel C; Lipschutz, Joshua H

    2010-03-01

    Cell-cell contacts are essential for epithelial cell function, and disruption is associated with pathological conditions including ischemic kidney injury. We hypothesize that the exocyst, a highly-conserved eight-protein complex that targets secretory vesicles carrying membrane proteins, is involved in maintaining renal epithelial barrier integrity. Accordingly, increasing exocyst expression in renal tubule cells may protect barrier function from oxidative stress resulting from ischemia and reperfusion (I/R) injury. When cultured on plastic, Madin-Darby canine kidney (MDCK) cells overexpressing Sec10, a central exocyst component, formed domes showing increased resistance to hydrogen peroxide (H2O2). Transepithelial electric resistance (TER) of Sec10-overexpressing MDCK cells grown on Transwell filters was higher than in control MDCK cells, and the rate of TER decrease following H2O2 treatment was less in Sec10-overexpressing MDCK cells compared with control MDCK cells. After removal of H2O2, TER returned to normal more rapidly in Sec10-overexpressing compared with control MDCK cells. In collagen culture MDCK cells form cysts, and H2O2 treatment damaged Sec10-overexpressing MDCK cell cysts less than control MDCK cell cysts. The MAPK pathway has been shown to protect animals from I/R injury. Levels of active ERK, the final MAPK pathway step, were higher in Sec10-overexpressing compared with control MDCK cells. U0126 inhibited ERK activation, exacerbated the H2O2-induced decrease in TER and cyst disruption, and delayed recovery of TER following H2O2 removal. Finally, in mice with renal I/R injury, exocyst expression decreased early and returned to normal concomitant with functional recovery, suggesting that the exocyst may be involved in the recovery following I/R injury.

  6. High-Heat-Flux Cyclic Durability of Thermal and Environmental Barrier Coatings

    Science.gov (United States)

    Zhu, Dongming; Ghosn, Louis L.; Miller, Robert A.

    2007-01-01

    Advanced ceramic thermal and environmental barrier coatings will play an increasingly important role in future gas turbine engines because of their ability to protect the engine components and further raise engine temperatures. For the supersonic vehicles currently envisioned in the NASA fundamental aeronautics program, advanced gas turbine engines will be used to provide high power density thrust during the extended supersonic flight of the aircraft, while meeting stringent low emission requirements. Advanced ceramic coating systems are critical to the performance, life and durability of the hot-section components of the engine systems. In this work, the laser and burner rig based high-heat-flux testing approaches were developed to investigate the coating cyclic response and failure mechanisms under simulated supersonic long-duration cruise mission. The accelerated coating cracking and delamination mechanism under the engine high-heat-flux, and extended supersonic cruise time conditions will be addressed. A coating life prediction framework may be realized by examining the crack initiation and propagation in conjunction with environmental degradation under high-heat-flux test conditions.

  7. High-Activity Dealloyed Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kongkanand, Anusorn [General Motors LLC, Pontiac, MI (United States)

    2014-09-30

    Reduction of costly Pt usage in proton exchange membrane fuel cell electrodes is one of the major challenges towards development and commercialization of fuel cell vehicles. Although few have met the initial-kinetic activity requirements in a realistic fuel cell device, no catalyst material has ever met the demanding fuel cell durability targets set by DOE. In this project, a team of 4 universities and 2 companies came together to investigate a concept that appeared promising in preliminary non-fuel cell tests then to further develop the catalyst to a mature level ready for vehicle implementation. The team consists of academia with technical leadership in their respective areas, a catalyst supplier, and a fuel cell system integrator.The tightly collaborative project enabled development of a highly active and durable catalyst with performance that significantly exceeds that of previous catalysts and meets the DOE targets for the first time (Figure 1A). The catalyst was then further evaluated in full-active-area stack in a realistic vehicle operating condition (Figure 1B). This is the first public demonstration that one can realize the performance benefit and Pt cost reduction over a conventional pure Pt catalyst in a long-term realistic PEMFC system. Furthermore, systematic analyses of a range of catalysts with different performance after fuel cell testing allowed for correlation between catalyst microstructure and its electrocatalytic activity and durability. This will in turn aid future catalyst development.

  8. Stakeholder Perceptions of Barriers and Solutions to Significant Expansion of Postsecondary Enrollment Options for High School Students

    Directory of Open Access Journals (Sweden)

    Carl Wozniak

    2013-02-01

    Full Text Available Post-secondary experiences for students still in high school have been promoted as a means to increase academic rigor and create a better-trained workforce. Yet little is known regarding supports needed to significantly increase such options. This study obtained input from 411 stakeholders in one Midwestern state, including 201 district superintendents, 181 high school principals, and 23 college dual enrollment officers regarding their use of these options, their perceptions of barriers to program expansion, and their ranking of possible solutions to overcome the barriers. Findings demonstrate that all parties find postsecondary options of value, with traditional dual enrollment the most used option. Although all groups identified funding as a primary barrier, other systemic barriers were of great concern. Participants suggest that expansion of Advanced Placement and early and middle college programs, financial assistance for dually enrolled students, and increased program availability for career and technical options would be beneficial.Wozniak, Carl, (2012. Stakeholder Perceptions of Barriers and Solutions to Significant Expansion of Postsecondary Enrollment Options for High School Students. 8(2. Retrieved from www.ijepl.org .

  9. Highly Segmented Thermal Barrier Coatings Deposited by Suspension Plasma Spray: Effects of Spray Process on Microstructure

    Science.gov (United States)

    Chen, Xiaolong; Honda, Hiroshi; Kuroda, Seiji; Araki, Hiroshi; Murakami, Hideyuki; Watanabe, Makoto; Sakka, Yoshio

    2016-12-01

    Effects of the ceramic powder size used for suspension as well as several processing parameters in suspension plasma spraying of YSZ were investigated experimentally, aiming to fabricate highly segmented microstructures for thermal barrier coating (TBC) applications. Particle image velocimetry (PIV) was used to observe the atomization process and the velocity distribution of atomized droplets and ceramic particles travelling toward the substrates. The tested parameters included the secondary plasma gas (He versus H2), suspension injection flow rate, and substrate surface roughness. Results indicated that a plasma jet with a relatively higher content of He or H2 as the secondary plasma gas was critical to produce highly segmented YSZ TBCs with a crack density up to 12 cracks/mm. The optimized suspension flow rate played an important role to realize coatings with a reduced porosity level and improved adhesion. An increased powder size and higher operation power level were beneficial for the formation of highly segmented coatings onto substrates with a wider range of surface roughness.

  10. Employees with mental illness – Possibilities and barriers in professional activity

    Directory of Open Access Journals (Sweden)

    Anna Cybula-Fujiwara

    2015-02-01

    Full Text Available 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 the stabilization 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. Med Pr 2015;66(1:57–69

  11. STUDY OF DESTRUCTION PROCESSES OF SYNTHETIC SURFACE-ACTIVE SUBSTENCES (SURFFACTANTS IN BARRIER DISCHARGE

    Directory of Open Access Journals (Sweden)

    V.I. Grinevich

    2012-06-01

    Full Text Available Kinetic data of degradation on aqueous solutions of surfactants in the plasma of barrier discharge are presented. The possible mechanism of proceeding processes is offered and considered. It is shown that the treatment in a barrier discharge results in decomposition efficiency of 95%. It is established that the main product of degradation are carboxylic acids.

  12. Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro

    NARCIS (Netherlands)

    Buist, H.E.; Sandt, J.J.M. van de; Burgsteden, J.A. van; Heer, C. de

    2005-01-01

    The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeate

  13. Barriers to and Suggestions for a Healthful, Active Lifestyle as Perceived by Rural and Urban Costa Rican Adolescents

    Science.gov (United States)

    Monge-Rojas, Rafael; Garita-Arce, Carlos; Sanchez-Lopez, Marta; Colon-Ramos, Uriyoan

    2009-01-01

    Objective: To assess the perceptions of rural and urban Costa Rican adolescents regarding which barriers and motivators affect their adoption of an active lifestyle. Design: Data were collected in focus group discussions. Participants: 108 male and female adolescents aged 12 to 18 from the 7th to 11th grades. Setting: Two urban and 1 rural high…

  14. Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro

    NARCIS (Netherlands)

    Buist, H.E.; Sandt, J.J.M. van de; Burgsteden, J.A. van; Heer, C. de

    2005-01-01

    The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeate

  15. Facilitators and barriers to HIV activities in religious congregations: perspectives of clergy and lay leaders from a diverse urban sample.

    Science.gov (United States)

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

    2014-10-01

    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.

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

    NARCIS (Netherlands)

    Buffart, L.M.; Westendorp, T.; Berg-Emons, van den R.J.; Stam, H.; Roebroeck, M.E.

    2009-01-01

    OBJECTIVE: To explore the main barriers to and facilitators of physical activity in young adults with childhood-onset physical disabilities. DESIGN: Qualitative study using focus groups. PARTICIPANTS: Sixteen persons (12 men and 4 women) aged 22.4 (standard deviation 3.4) years, of whom 50% were

  17. Epileptiform activity and spreading depolarization in the blood-brain barrier-disrupted peri-infarct hippocampus are associated with impaired GABAergic inhibition and synaptic plasticity.

    Science.gov (United States)

    Lippmann, Kristina; Kamintsky, Lyn; Kim, Soo Young; Lublinsky, Svetlana; Prager, Ofer; Nichtweiss, Julia Friederike; Salar, Seda; Kaufer, Daniela; Heinemann, Uwe; Friedman, Alon

    2017-05-01

    Peri-infarct opening of the blood-brain barrier may be associated with spreading depolarizations, seizures, and epileptogenesis as well as cognitive dysfunction. We aimed to investigate the mechanisms underlying neural network pathophysiology in the blood-brain barrier-dysfunctional hippocampus. Photothrombotic stroke within the rat neocortex was associated with increased intracranial pressure, vasogenic edema, and peri-ischemic blood-brain barrier dysfunction that included the ipsilateral hippocampus. Intrahippocampal recordings revealed electrographic seizures within the first week in two-thirds of animals, accompanied by a reduction in gamma and increase in theta frequency bands. Synaptic interactions were studied in parasagittal hippocampal slices at 24 h and seven days post-stroke. Field potential recordings in CA1 and CA3 uncovered multiple population spikes, epileptiform episodes, and spreading depolarizations at 24 h. Input-output analysis revealed that fEPSP-spike coupling was significantly enhanced at seven days. In addition, CA1 feedback and feedforward inhibition were diminished. Slices generating epileptiform activity at seven days revealed impaired bidirectional long-term plasticity following high and low-frequency stimulation protocols. Microarray and PCR data confirmed changes in expression of astrocyte-related genes and suggested downregulation in expression of GABAA-receptor subunits. We conclude that blood-brain barrier dysfunction in the peri-infarct hippocampus is associated with early disinhibition, hyperexcitability, and abnormal synaptic plasticity.

  18. Employing low-temperature barriers to achieve strain-relaxed and high-performance GaN-based LEDs.

    Science.gov (United States)

    Lin, Zhiting; Wang, Haiyan; Wang, Wenliang; Lin, Yunhao; Yang, Meijuan; Chen, Shuqi; Li, Guoqiang

    2016-05-30

    The epitaxial structure design of low-temperature barriers has been adopted to promote strain relaxation in multiple quantum well (MQWs) and achieve high-efficient GaN-based light-emitting diodes (LEDs). With these barriers, the relaxation value of wells increases from 0 to 4.59%. The strain-relaxed mechanism of low-temperature barriers is also discussed. The LED chip with the barriers grown at the TMIn flow of 75 sccm and the growth temperature of 830 °C has an optimal strain relaxation value of 1.53% in wells, and exhibits the largest light output power of 63.83 mW at the injection current of 65 mA, which is higher than that of conventional LED (51.89 mW) by 23%. In-depth studies reveal that the optimal low-temperature barriers remarkably promote the strain relaxation in wells without forming large density of crystalline defects. This achievement of high-efficiency LEDs sheds light on the future solid-state lighting applications.

  19. Facile synthesis of high strength hot-water wood extract films with oxygen-barrier performance

    Science.gov (United States)

    Chen, Ge-Gu; Fu, Gen-Que; Wang, Xiao-Jun; Gong, Xiao-Dong; Niu, Ya-Shuai; Peng, Feng; Yao, Chun-Li; Sun, Run-Cang

    2017-01-01

    Biobased nanocomposite films for food packaging with high mechanical strength and good oxygen-barrier performance were developed using a hot-water wood extract (HWE). In this work, a facile approach to produce HWE/montmorillonite (MMT) based nanocomposite films with excellent physical properties is described. The focus of this study was to determine the effects of the MMT content on the structure and mechanical properties of nanocomposites and the effects of carboxymethyl cellulose (CMC) on the physical properties of the HWE-MMT films. The experimental results suggested that the intercalation of HWE and CMC in montmorillonite could produce compact, robust films with a nacre-like structure and multifunctional characteristics. This results of this study showed that the mechanical properties of the film designated FCMC0.05 (91.5 MPa) were dramatically enhanced because the proportion of HWE, MMT and CMC was 1:1.5:0.05. In addition, the optimized films exhibited an oxygen permeability below 2.0 cm3 μm/day·m2·kPa, as well as good thermal stability due to the small amount of CMC. These results provide a comprehensive understanding for further development of high-performance nanocomposites which are based on natural polymers (HWE) and assembled layered clays (MMT). These films offer great potential in the field of sustainable packaging.

  20. High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

    2014-01-01

    Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

  1. Ghrelin ameliorates intestinal barrier dysfunction in experimental colitis by inhibiting the activation of nuclear factor-kappa B

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jian; Zhang, Lin [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China); Dai, Weiqi [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University, Shanghai (China); Mao, Yuqing [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China); Li, Sainan [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University, Shanghai (China); Wang, Jingjie; Li, Huanqing [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China); Guo, Chuanyong [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University, Shanghai (China); Fan, Xiaoming, E-mail: xiaomingfan57@sina.com [Department of Gastroenterology, Jinshan Hospital of Fudan University, Shanghai (China)

    2015-02-27

    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 also 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.

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

    Science.gov (United States)

    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

  3. Investigating Parental Beliefs Concerning Facilitators and Barriers to the Physical Activity in Down Syndrome and Typical Development

    Directory of Open Access Journals (Sweden)

    Marianna Alesi

    2017-01-01

    Full Text Available Family is a crucial factor to determine the amount, the duration, and the complexity of children’s sport activities. This study aims at comparing the beliefs concerning the involvement in sport activities among parents of children with Down syndrome (DS and parents of typically developing children (TDC. A phenomenological theoretical framework was adopted to realize semistructured interviews with the parents. The participants were 35 parents: 19 with children and adolescents with DS and 16 with TDC. The main facilitation/barrier themes identified by the parents of children with DS were the family and the expert at Adapted Physical Activity (APA instructors. Conversely, the parents of TDC identified social factors related to family as the only barrier. One of the issues that emerge from this study is the lack of home-based physical activity (PA intervention programs aimed at involving families and children.

  4. Degradation of organic compounds and production of activated species in Dielectric Barrier Discharges and Glidarc reactors

    CERN Document Server

    Cormier, Jean Marie; Khacef, Ahmed

    2008-01-01

    Major sterilization mechanisms are related to atoms and radicals, charged parti-cles, excited molecules, ozone, and UV radiation. The ROS (Reactive Oxygen Species) are well known as evildoers. These species are easily created in ambient air and water and they live long enough to reach the cell and attack the organic matter. Test molecules conversion in dry and wet air is studied using Dielectric Barrier Discharge (DBD) and Gliding Arc Reactors (GAR). The effects of tem-perature and energy deposition into the media on the active species production and then on the organic compounds degradation are presented for two non thermal plasma reactors: DBD and GAR. Main production species investigated are OH, O3, NOx, CO and CxHyOz by-products. It is shown from experiment analysis that the reactive species production is quite different from one reactor to another. GAR and pulsed DBD are two chemical processing ways in which the temperature of heavy species in ionized gas is determinant. By reviewing the species producti...

  5. Comparison Between Dielectric Barrier Discharge Plasma and Ozone Regenerations of Activated Carbon Exhausted with Pentachlorophenol

    Science.gov (United States)

    Qu, Guangzhou; Liang, Dongli; Qu, Dong; Huang, Yimei; Li, Jie

    2014-06-01

    In this study, two regeneration methods (dielectric barrier discharge (DBD) plasma and ozone (O3) regeneration) of saturated granular activated carbon (GAC) with pentachlorophenol (PCP) were compared. The results show that the two regeneration methods can eliminate contaminants from GAC and recover its adsorption properties to some extent. Comparing the DBD plasma with O3 regeneration, the adsorption rate and the capacity of the GAC samples after DBD plasma regeneration are greater than those after O3 regeneration. O3 regeneration decreases the specific surface area of GAC and increases the acidic surface oxygen groups on the surface of GAC, which causes a decrease in PCP on GAC uptake. With increasing regeneration cycles, the regeneration efficiencies of the two methods decrease, but the decrease in the regeneration efficiencies of GAC after O3 regeneration is very obvious compared with that after DBD plasma regeneration. Furthermore, the equilibrium data were fitted by the Freundlich and Langmuir models using the non-linear regression technique, and all the adsorption equilibrium isotherms fit the Langmuir model fairly well, which demonstrates that the DBD plasma and ozone regeneration processes do not appear to modify the adsorption process, but to shift the equilibrium towards lower adsorption concentrations. Analyses of the weight loss of GAC show that O3 regeneration has a lower weight loss than DBD plasma regeneration.

  6. Evaluation of the Antidepressant Activity, Hepatotoxicity and Blood Brain Barrier Permeability of Methyl Genipin

    Directory of Open Access Journals (Sweden)

    Xin Che

    2016-07-01

    Full Text Available Geniposide (GE is the main bioactive component of Gardeniae Fructus. The hepatotoxicity of geniposide limited clinical application. In order to get a new geniposide derivative that has less hepatotoxicity and still possesses the antidepressant activity, a new C-1 hydroxyl methylation derivative named methyl genipin (MG was synthesized from geniposide. In the present study, we demonstrated that MG did not increase the liver index, alanine aminotransferase (ALT and aspirate aminotransferase (AST. Histopathological examination suggested that no toxic damages were observed in rats treated orally with MG (0.72 mmol/kg. More importantly, a 7-day treatment with MG at 0.13, 0.26, and 0.52 mmol/kg/day could reduce the duration of immobility. It showed that the antidepressant-like effects of MG were similar to GE in the tail suspension test and the forced swim test. Furthermore, we found MG could be detected in the brain homogenate of mice treated orally with MG 0.52 mmol/kg/day for 1 day by HPLC. The area under the curve (AUC of MG in the brain homogenate was enhanced to 21.7 times that of GE. The brain amount and distribution speed of MG were improved significantly after oral administration. This study demonstrated that MG possessed the antidepressant effects and could cross the blood–brain barrier, but had less hepatotoxicity.

  7. Blood-brain barrier permeability mechanisms in view of quantitative structure-activity relationships (QSAR).

    Science.gov (United States)

    Bujak, Renata; Struck-Lewicka, Wiktoria; Kaliszan, Michał; Kaliszan, Roman; Markuszewski, Michał J

    2015-04-10

    The goal of the present paper was to develop a quantitative structure-activity relationship (QSAR) method using a simple statistical approach, such as multiple linear regression (MLR) for predicting the blood-brain barrier (BBB) permeability of chemical compounds. The "best" MLR models, comprised logP and either molecular mass (M) or isolated atomic energy (E(isol)), tested on a structurally diverse set of 66 compounds, is characterized the by correlation coefficients (R) around 0.8. The obtained models were validated using leave-one-out (LOO) cross-validation technique and the correlation coefficient of leave-one-out- R(LOO)(2) (Q(2)) was at least 0.6. Analysis of a case from legal medicine demonstrated informative value of our QSAR model. To best authors' knowledge the present study is a first application of the developed QSAR models of BBB permeability to case from the legal medicine. Our data indicate that molecular energy-related descriptors, in combination with the well-known descriptors of lipophilicity may have a supportive value in predicting blood-brain distribution, which is of utmost importance in drug development and toxicological studies.

  8. Motivations and barriers to prosthesis users participation in physical activity, exercise and sport: a review of the literature.

    Science.gov (United States)

    Deans, Sarah; Burns, David; McGarry, Anthony; Murray, Kevin; Mutrie, Nanette

    2012-09-01

    The UK will host the Paralympics in 2012 and the Commonwealth Games in 2014 showcasing the talents of elite athletes and aiming to inspire the population to become involved. However, low levels of physical activity are prevalent: only 40% of men and 28% of women meet the minimum UK physical activity recommendations. The population of people with limb absence is no exception. To determine if people with amputation are participating in physical activity and sport; whether post-amputation activity levels match pre-amputation levels; and if there are motivations and barriers to participation. Literature review. Five reviewers systematically searched all peer reviewed and gray literature in seven bibliographic databases and the Cochrane Library. Following rigorous elimination, 12 articles were finally included in the review and critically appraised. Four themes were identified: components; rehabilitation outcomes; body image; and motivations and barriers to participation. People with limb absence are not participating in physical activity conducive to health benefits, and only a minority participate in exercise and sports. Participation following amputation does not mirror that of pre-amputation levels, and more barriers than motivations exist to adopting or maintaining a physically active lifestyle.

  9. High Pressure Burner Rig Testing of Advanced Environmental Barrier Coatings for Si3N4 Turbine Components

    Science.gov (United States)

    Zhu, Dongming; Fox, Dennis S.; Pastel, Robert T.

    2007-01-01

    Advanced thermal and environmental barrier coatings are being developed for Si3N4 components for turbine engine propulsion applications. High pressure burner rig testing was used to evaluate the coating system performance and durability. Test results demonstrated the feasibility and durability of the coating component systems under the simulated engine environments.

  10. Self-Efficacy, Perceptions of Barriers, Vocational Identity, and the Career Exploration Behavior of Latino/a High School Students

    Science.gov (United States)

    Gushue, George V.; Clarke, Christine P.; Pantzer, Karen M.; Scanlan, Kolone R. L.

    2006-01-01

    This study explored the potential relationship between the social cognitive variables of career decision making self-efficacy and perceptions of barriers and the outcome variables of vocational identity and career exploration behaviors in a sample of 128 urban Latino/a high school students. The results indicated that higher levels of career…

  11. Noise control of a flow around a cylinder using high-frequency dielectric barrier discharge plasma actuators

    Science.gov (United States)

    Kopiev, V. F.; Belyaev, I. V.; Zaytsev, M. Yu.; Kazansky, P. N.; Kopiev, V. A.; Moralev, I. A.

    2015-03-01

    The effect of high-frequency dielectric barrier discharge plasma actuators on the noise of a flow around a circular cylinder is experimentally studied. It is shown that the plasma actuators are able to reduce the vortex noise of a cylinder within the range of velocities typical for aeroacoustic applications.

  12. Activation of the Epithelial-to-Mesenchymal Transition Factor Snail Mediated Acetaldehyde-Induced Intestinal Epithelial Barrier Disruption

    NARCIS (Netherlands)

    Elamin, E.; Masclee, A.; Troost, F.; Dekker, J.; Jonkers, D.

    2014-01-01

    Background : Acetaldehyde (AcH) is mutagenic and can reach high concentrations in colonic lumen after ethanol consumption and is associated with intestinal barrier dysfunction and an increased risk of progressive cancers, including colorectal carcinoma. Snail, the transcription factor of epithelial-

  13. Fish Movement Ecology in High Gradient Headwater Streams: Its Relevance to Fish Passage Restoration through Stream Culvert Barriers

    Science.gov (United States)

    Hoffman, Robert L.; Dunham, Jason B.

    2007-01-01

    Executive Summary Restoration of fish passage through culvert barriers has emerged as a major issue in the Pacific Northwest and nationwide. The problem has many dimensions, including the huge number of potential barriers, uncertainty about which structures are actually barriers, the benefits and risks involved with restoration, and the financial costs and timelines. This report attempts to address what we call 'thinking outside of the pipe' in terms of fish passage information needs. This means understanding the value of each potential passage restoration project in the context of other possible projects, and to view individual restoration projects within a larger landscape of habitats and population processes. In this report we provide a brief review of some essential characteristics of animal movement and examples from a focal group of fishes in Washington State: salmon, trout, and char. While several other fishes and many other species use streams where culvert passage barriers may occur, it is the salmonids that are by far the most widespread and in most cases extending furthest into the headwaters of stream networks in Washington. We begin this report by outlining some basic characteristics of animal movement and then apply that foundation to the case of salmonid fishes. Next we consider the consequences of disrupting fish movement with human-constructed barriers, such as culverts. Finally, this body of evidence is summarized and we propose a short list of what we view as high priority information needs to support more effective restoration of fish passage through culverts.

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

    Science.gov (United States)

    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…

  15. Accelerated high fidelity prion amplification within and across prion species barriers.

    Directory of Open Access Journals (Sweden)

    Kristi M Green

    Full Text Available Experimental obstacles have impeded our ability to study prion transmission within and, more particularly, between species. Here, we used cervid prion protein expressed in brain extracts of transgenic mice, referred to as Tg(CerPrP, as a substrate for in vitro generation of chronic wasting disease (CWD prions by protein misfolding cyclic amplification (PMCA. Characterization of this infectivity in Tg(CerPrP mice demonstrated that serial PMCA resulted in the high fidelity amplification of CWD prions with apparently unaltered properties. Using similar methods to amplify mouse RML prions and characterize the resulting novel cervid prions, we show that serial PMCA abrogated a transmission barrier that required several hundred days of adaptation and subsequent stabilization in Tg(CerPrP mice. While both approaches produced cervid prions with characteristics distinct from CWD, the subtly different properties of the resulting individual prion isolates indicated that adaptation of mouse RML prions generated multiple strains following inter-species transmission. Our studies demonstrate that combined transgenic mouse and PMCA approaches not only expedite intra- and inter-species prion transmission, but also provide a facile means of generating and characterizing novel prion strains.

  16. Counselling low-back-pain patients in secondary healthcare: a randomised trial addressing experienced workplace barriers and physical activity.

    Science.gov (United States)

    Jensen, Lone Donbæk; Maribo, Thomas; Schiøttz-Christensen, Berit; Madsen, Finn Hjorth; Gonge, Bigitte; Christensen, Michael; Frost, Poul

    2012-01-01

    To assess if counselling by an occupational physician (OP) addressing experienced workplace barriers and physical activity integrated as a part of low-back pain (LBP) outpatient treatment influences pain, function and sick leave. Randomised controlled trial in the secondary healthcare sector with 3 months' follow-up. The participants were LBP patients who, independently of sick-leave status, expressed concerns about the ability to maintain their current job. Patients referred for surgery were excluded. The intervention consisted of two counselling sessions conducted by an OP addressing both workplace barriers and leisure-time physical activity. A workplace visit was performed if required. Pain, function and duration of sick leave due to LBP were primary outcomes. A reduction in bodily pain and improvement in physical function both measured by the 36-item short-form health survey questionnaire in favour of the intervention group was found. The change in pain score was found to be clinically relevant. The risk of sick leave for at least 8 weeks due to LBP was significantly reduced in the intervention group. Two secondary outcomes, Fear Avoidance Beliefs about physical activity and maximum oxygen uptake, supported compliance and adherence to the part of the intervention focusing on enhanced physical activity. Two short counselling sessions by an OP combining advice on meeting workplace barriers and enhancing physical activity had a substantial effect on important prognostic factors for LBP patients with moderate to severe symptoms diagnosed in outpatient rheumatological clinics. Current Controlled Trials ISRCTN13071157.

  17. Physical Activity in Adolescents — Barriers and Impact on Depressed Affect

    OpenAIRE

    Langguth, Nadine

    2016-01-01

    Adolescence is a high-risk period for physical inactivity as well as depressed affect, both related to various short-, mid-, and long-term negative consequences for adolescents' physical and mental health. Therefore, this developmental period is ideally suited for studying the association between change processes of everyday physical activity and change processes of depressed affect within person by applying an intensive longitudinal design. Given that physical activity substantially decrease...

  18. Microstructural characterization of thermal barrier coating on Inconel 617 after high temperature oxidation

    Directory of Open Access Journals (Sweden)

    Mohammadreza Daroonparvar

    2013-06-01

    Full Text Available A turbine blade was protected against high temperature corrosion and oxidation by thermal barrier coatings (TBCsusing atmospheric plasma spraying technique (APS on a Ni-based superalloy (Inconel 617. The coatings (NiCr6AlY/ YSZ and NiCr10AlY/YSZ consist of laminar structure with substantial interconnected porosity transferred oxygen from Yittria stabilized Zirconia (YSZ layer toward the bond coat (NiCrAlY. Hence, a thermally grown oxide layer (TGO was formed on the metallic bond coat and internal oxidation of the bond coat occurred during oxidation. The TBC systems were oxidized in a normal electrically heated furnace at 1150 °C for 18, 22, 26, 32 and 40h.Microstructural characterization of coatings demonstrated that the growth of the TGO layer on the nickel alloy with 6wt. % Al is more rapid than TGO with 10wt. % Al. In addition, many micro-cracks were observed at the interface of NiCr6AlY/YSZ. X-ray diffraction analysis (XRD showed the existence of detrimental oxides such as NiCr2O4, NiCrO3 and NiCrO4 in the bond coat containing 6wt. % Al, accompanied by rapid volume expansion causing the destruction of TBC. In contrast, in the bond coat with 10wt. % Al, NiO, Al2O3and Cr2O3 oxides were formed while very low volume expansion occurred. The oxygen could not penetrate into the TGO layer of bond coat with 10 wt. % Al during high temperature oxidation and the detrimental oxides were not extensively formed within the bond coat as more oxygen was needed. The YSZ with higher Al content showed higher oxidation resistance.

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

    Science.gov (United States)

    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.

  20. Characterization of a dielectric barrier discharge in contact with liquid and producing a plasma activated water

    Science.gov (United States)

    Neretti, G.; Taglioli, M.; Colonna, G.; Borghi, C. A.

    2017-01-01

    In this work a low-temperature plasma source for the generation of plasma activated water (PAW) is developed and characterized. The plasma reactor was operated by means of an atmospheric-pressure air dielectric barrier discharge (DBD). The plasma generated is in contact with the water surface and is able to chemically activate the liquid medium. Electrodes were supplied by both sinusoidal and nanosecond-pulsed voltage waveforms. Treatment times were varied from 2 to 12 min to increase the energy dose released to the water by the DBD plasma. The physics of the discharge was studied by means of electrical, spectroscopic and imaging diagnostics. The interaction between the plasma and the liquid was investigated as well. Temperature and composition of the treated water were detected. Images of the discharges showed a filamentary behaviour in the sinusoidal case and a more homogeneous behaviour in the nanosecond-pulsed one. The images and the electrical measurements allowed to evaluate an average electron number density of about 4  ×  1019 and 6  ×  1017 m-3 for the sinusoidal and nanosecond-pulsed discharges respectively. Electron temperatures in the range of 2.1÷2.6 eV were measured by using spectroscopic diagnostics. Rotational temperatures in the range of 318-475 K were estimated by fitting synthetic spectra with the measured ones. Water temperature and pH level did not change significantly after the exposure to the DBD plasma. The production of ozone and hydrogen peroxide within the water was enhanced by increasing the plasma treatment time and the energy dose. Numerical simulations of the nanosecond-pulsed discharge were performed by using a self-consistent coupling of state-to-state kinetics of the air mixture with the Boltzmann equation of free electron kinetics. Temporal evolution of the electron energy distribution function shows departure from the Maxwellian distribution especially during the afterglow phase of the discharge. When

  1. Exploring physical activity engagement and barriers for asylum seekers in Australia coping with prolonged uncertainty and no right to work.

    Science.gov (United States)

    Hartley, Lisa; Fleay, Caroline; Tye, Marian E

    2017-05-01

    This paper explores the engagement in physical activity as a potential coping strategy for asylum seekers living in the Australian community without the right to work and with prolonged uncertainty, and benefits or barriers to undertaking such activity. Semi-structured in-depth interviews were held with 29 asylum seekers who had arrived to Australia by boat and were living in the community in the cities of Perth, Sydney or Melbourne in July-October 2013 after their release from immigration detention. The ratio of the numbers of men and women interviewed (23 men and 6 women) was comparable to the ratio of men and women who came by boat to Australia seeking asylum in 2012-2013. Nine participants reported that they participated in physical activity as a coping strategy. Seven other participants were so worried about their future and their families that they did not have the mental or physical energy to engage in physical activity. A further six wanted to participate in physical activity but faced a number of barriers to doing so. The seven remaining participants were either not asked about their physical activity engagement because they focused their discussion on other challenges or did not elaborate on why they were not engaging in physical activity. The findings suggest that physical activity, coupled with other coping strategies, are important for some asylum seekers in trying to manage the distress of being denied the right to work and living with prolonged uncertainty. In addition, these findings highlight the critical barrier that government policy plays in disabling engagement in physical activity, which further compounds social exclusion. This includes the lack of welfare support provided, which hinders people's financial ability to access activities and support in the community. © 2017 John Wiley & Sons Ltd.

  2. Elastically Cooperative Activated Barrier Hopping Theory of Relaxation in Viscous Fluids. II. Thermal Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Mirigian, Stephen [University of Illinois, Urbana-Champaign; Schweizer, Kenneth [University of Illinois

    2014-01-01

    Building on the elastically collective nonlinear Langevin equation theory developed for hard spheres in Paper I, we propose and implement a quasi-universal theory for the alpha relaxation of thermal liquids based on mapping them to an effective hard sphere fluid via the dimensionless compressibility. The result is a zero adjustable parameter theory that can quantitatively address in a unified manner the alpha relaxation time over 14 or more decades. The theory has no singularities above zero Kelvin, and relaxation in the equilibrium low temperature limit is predicted to be of a roughly Arrhenius form. The two-barrier (local cage and long range collective elastic) description results in a rich dynamic behavior including apparent Arrhenius, narrow crossover, and deeply supercooled regimes, and multiple characteristic or crossover times and temperatures of clear physical meaning. Application of the theory to nonpolar molecules, alcohols, rare gases, and liquids metals is carried out. Overall, the agreement with experiment is quite good for the temperature dependence of the alpha time, plateau shear modulus, and Boson-like peak frequency for van der Waals liquids, though less so for hydrogen-bonding molecules. The theory predicts multiple growing length scales upon cooling, which reflect distinct aspects of the coupled local hopping and cooperative elastic physics. Calculations of the growth with cooling of an activation volume, which is strongly correlated with a measure of dynamic cooperativity, agree quantitatively with experiment. Comparisons with elastic, entropy crisis, dynamic facilitation, and other approaches are performed, and a fundamental basis for empirically extracted crossover temperatures is established. The present work sets the stage for addressing distinctive glassy phenomena in polymer melts, and diverse liquids under strong confinement.

  3. Elastically cooperative activated barrier hopping theory of relaxation in viscous fluids. II. Thermal liquids

    Science.gov (United States)

    Mirigian, Stephen; Schweizer, Kenneth S.

    2014-05-01

    Building on the elastically collective nonlinear Langevin equation theory developed for hard spheres in Paper I, we propose and implement a quasi-universal theory for the alpha relaxation of thermal liquids based on mapping them to an effective hard sphere fluid via the dimensionless compressibility. The result is a zero adjustable parameter theory that can quantitatively address in a unified manner the alpha relaxation time over 14 or more decades. The theory has no singularities above zero Kelvin, and relaxation in the equilibrium low temperature limit is predicted to be of a roughly Arrhenius form. The two-barrier (local cage and long range collective elastic) description results in a rich dynamic behavior including apparent Arrhenius, narrow crossover, and deeply supercooled regimes, and multiple characteristic or crossover times and temperatures of clear physical meaning. Application of the theory to nonpolar molecules, alcohols, rare gases, and liquids metals is carried out. Overall, the agreement with experiment is quite good for the temperature dependence of the alpha time, plateau shear modulus, and Boson-like peak frequency for van der Waals liquids, though less so for hydrogen-bonding molecules. The theory predicts multiple growing length scales upon cooling, which reflect distinct aspects of the coupled local hopping and cooperative elastic physics. Calculations of the growth with cooling of an activation volume, which is strongly correlated with a measure of dynamic cooperativity, agree quantitatively with experiment. Comparisons with elastic, entropy crisis, dynamic facilitation, and other approaches are performed, and a fundamental basis for empirically extracted crossover temperatures is established. The present work sets the stage for addressing distinctive glassy phenomena in polymer melts, and diverse liquids under strong confinement.

  4. Peroxisome proliferator-activated receptors and Alzheimer's disease: hitting the blood-brain barrier.

    Science.gov (United States)

    Zolezzi, Juan M; Inestrosa, Nibaldo C

    2013-12-01

    The blood-brain barrier (BBB) is often affected in several neurodegenerative disorders, such as Alzheimer's disease (AD). Integrity and proper functionality of the neurovascular unit are recognized to be critical for maintenance of the BBB. Research has traditionally focused on structural integrity more than functionality, and BBB alteration has usually been explained more as a consequence than a cause. However, ongoing evidence suggests that at the early stages, the BBB of a diseased brain often shows distinct expression patterns of specific carriers such as members of the ATP-binding cassette (ABC) transport protein family, which alter BBB traffic. In AD, amyloid-β (Aβ) deposits are a pathological hallmark and, as recently highlighted by Cramer et al. (2012), Aβ clearance is quite fundamental and is a less studied approach. Current knowledge suggests that BBB traffic plays a more important role than previously believed and that pharmacological modulation of the BBB may offer new therapeutic alternatives for AD. Recent investigations carried out in our laboratory indicate that peroxisome proliferator-activated receptor (PPAR) agonists are able to prevent Aβ-induced neurotoxicity in hippocampal neurons and cognitive impairment in a double transgenic mouse model of AD. However, even when enough literature about PPAR agonists and neurodegenerative disorders is available, the problem of how they exert their functions and help to prevent and rescue Aβ-induced neurotoxicity is poorly understood. In this review, along with highlighting the main features of the BBB and its role in AD, we will discuss information regarding the modulation of BBB components, including the possible role of PPAR agonists as BBB traffic modulators.

  5. Listening to Those at the Frontline: Patient and Healthcare Personnel Perspectives on Tuberculosis Treatment Barriers and Facilitators in High TB Burden Regions of Argentina

    Directory of Open Access Journals (Sweden)

    Sarah J. Iribarren

    2014-01-01

    Full Text Available Purpose. In Argentina, tuberculosis (TB control measures have not achieved key treatment targets. The purpose of this study was to identify modes of treatment delivery and explore patient and healthcare personnel perceptions of barriers and facilitators to treatment success. Methods. We used semistructured group and individual interviews for this descriptive qualitative study. Eight high burden municipalities were purposively selected. Patients in treatment for active TB (n=16, multidisciplinary TB team members (n=26, and TB program directors (n=12 at local, municipal, regional, and national levels were interviewed. Interviews were recorded, transcribed verbatim, and analyzed using thematic analysis. Results. Modes of treatment delivery varied across municipalities and types of healthcare facility and were highly negotiated with patients. Self-administration of treatment was common in hospital-based and some community clinics. Barriers to TB treatment success were concentrated at the system level. This level relied heavily on individual personal commitment, and many system facilitators were operating in isolation or in limited settings. Conclusions. We outline experiences and perspectives of the facilitating and challenging factors at the individual, structural, social, and organizational levels. Establishing strong patient-healthcare personnel relationships, responding to patient needs, capitalizing on community resources, and maximizing established decentralized system could mitigate some of the barriers.

  6. A systematic review of barriers to optimal outpatient specialist services for individuals with prevalent chronic diseases: what are the unique and common barriers experienced by patients in high income countries?

    Science.gov (United States)

    Fradgley, Elizabeth A; Paul, Christine L; Bryant, Jamie

    2015-06-09

    Health utilization and need assessment data suggest there is considerable variation in access to outpatient specialist care. However, it is unclear if the types of barriers experienced are specific to chronic disease groups or experienced universally. This systematic review provides a detailed summary of common and unique barriers experienced by chronic disease groups when accessing and receiving care, and a synthesized list of possible health service initiatives to improve equitable delivery of optimal care in high-income countries. Quantitative articles describing barriers to specialist outpatient services were retrieved from CINAHL, MEDLINE, Embase, and PyscINFO. To be eligible for review, studies: were published from 2002 to May 2014; included samples with cancer, diabetes mellitus, osteoporosis, arthritis, ischaemic heart disease, stroke, asthma, chronic pulmonary disorder (COPD) or depression; and, were conducted in high-income countries. Using a previously validated model of access (Penchansky and Thomas' model of fit), barriers were grouped according to five overarching domains and defined in more detail using 33 medical subject headings. Results from reviewed articles, including the scope and frequency of reported barriers, are conceptualized using thematic analysis and framed as possible health service initiatives. A total of 3181 unique records were screened for eligibility, of which 74 studies were included in final analysis. The largest proportion of studies reported acceptability barriers (75.7 %), of which demographic disparities (44.6 %) were reported across all diseases. Other frequently reported barriers included inadequate need assessment (25.7 %), information provision (32.4 %), or health communication (20 %). Unique barriers were identified for oncology, mental health, and COPD samples. Based on the scope, frequency and measurement of reported barriers, eight key themes with associated implications for health services are presented. Examples

  7. Motivators and barriers to engaging in healthy eating and physical activity in young adult men

    Science.gov (United States)

    Internationally, young men (aged 18-25 years) have a high prevalence of overweight and obesity and many fail to meet recommended levels of physical activity or dietary guidelines. There is a lack of engagement and understanding of young men's needs in health-related research. Therefore, this study a...

  8. Separating effective high density polyethylene segments from olefin block copolymers using high temperature liquid chromatography with a preloaded discrete adsorption promoting solvent barrier.

    Science.gov (United States)

    Chatterjee, Tirtha; Rickard, Mark A; Pearce, Eric; Pangburn, Todd O; Li, Yongfu; Lyons, John W; Cong, Rongjuan; deGroot, A Willem; Meunier, David M

    2016-09-23

    Recent advances in catalyst technology have enabled the synthesis of olefin block copolymers (OBC). One type is a "hard-soft" OBC with a high density polyethylene (HDPE) block and a relatively low density polyethylene (VLDPE) block targeted as thermoplastic elastomers. Presently, one of the major challenges is to fractionate HDPE segments from the other components in an experimental OBC sample (block copolymers and VLDPE segments). Interactive high temperature liquid chromatography (HTLC) is ineffective for OBC separation as the HDPE segments and block copolymer chains experience nearly identical enthalpic interactions with the stationary phase and co-elute. In this work we have overcome this challenge by using liquid chromatography under the limiting conditions of desorption (LC LCD). A solvent plug (discrete barrier) is introduced in front of the sample which specifically promotes the adsorption of HDPE segments on the stationary phase (porous graphitic carbon). Under selected thermodynamic conditions, VLDPE segments and block copolymer chains crossed the barrier while HDPE segments followed the pore-included barrier solvent and thus enabled separation. The barrier solvent composition was optimized and the chemical composition of fractionated polymer chains was investigated as a function of barrier solvent strength using an online Fourier-transform infrared (FTIR) detector. Our study revealed that both the HDPE segments as well as asymmetric block copolymer chains (HDPE block length≫VLDPE block length) are retained in the separation and the barrier strength can be tailored to retain a particular composition. At the optimum barrier solvent composition, this method can be applied to separate effective HDPE segments from the other components, which has been demonstrated using an experimental OBC sample.

  9. Counselling low-back-pain patients in secondary healthcare: a randomised trial addressing experienced workplace barriers and physical activity

    DEFF Research Database (Denmark)

    Jensen, Lone Donbæk; Maribo, Thomas; Schiøttz-Christensen, Berit

    2012-01-01

    OBJECTIVE: To assess if counselling by an occupational physician (OP) addressing experienced workplace barriers and physical activity integrated as a part of low-back pain (LBP) outpatient treatment influences pain, function and sick leave. METHODS: Randomised controlled trial in the secondary...... addressing both workplace barriers and leisure-time physical activity. A workplace visit was performed if required. Pain, function and duration of sick leave due to LBP were primary outcomes. RESULTS: A reduction in bodily pain and improvement in physical function both measured by the 36-item short......-form health survey questionnaire in favour of the intervention group was found. The change in pain score was found to be clinically relevant. The risk of sick leave for at least 8 weeks due to LBP was significantly reduced in the intervention group. Two secondary outcomes, Fear Avoidance Beliefs about...

  10. Topical antihistamines display potent anti-inflammatory activity linked in part to enhanced permeability barrier function

    DEFF Research Database (Denmark)

    Lin, Tzu-Kai; Man, Mao-Qiang; Santiago, Juan-Luis

    2013-01-01

    express both Hr1 and Hr2, we hypothesized that H1/2r antagonists might be more effective if they were used topically to treat inflammatory dermatoses. Topical H1/2r antagonists additively enhanced permeability barrier homeostasis in normal mouse skin by the following mechanisms: (i) stimulation...... of epidermal differentiation, leading to thickened cornified envelopes; and (ii) enhanced epidermal lipid synthesis and secretion. As barrier homeostasis was enhanced to a comparable extent in mast cell-deficient mice, with no further improvement following application of topical H1/2r antagonists, H1/2r...... antagonists likely oppose mast cell-derived histamines. In four immunologically diverse, murine disease models, characterized by either inflammation alone (acute irritant contact dermatitis, acute allergic contact dermatitis) or by prominent barrier abnormalities (subacute allergic contact dermatitis, atopic...

  11. Thick Thermal Barrier Coatings (TTBCs) for Low Emission, High Efficiency Diesel Engine Components

    Energy Technology Data Exchange (ETDEWEB)

    M. Brad Beardsley, Caterpillar Inc.; Dr. Darrell Socie, University of Illinois; Dr. Ed Redja, University of Illinois; Dr. Christopher Berndt, State University of New York at Stony Brook

    2006-03-02

    The objective of this program was to advance the fundamental understanding of thick thermal barrier coating (TTBC) systems for application to low heat rejection diesel engine combustion chambers. Previous reviews of thermal barrier coating technology concluded that the current level of understanding of coating system behavior is inadequate and the lack of fundamental understanding may impede the application of thermal barrier coating to diesel engines.(1) Areas of TTBC technology examined in this program include powder characteristics and chemistry; bond coating composition, coating design, microstructure and thickness as they affect properties, durability, and reliability; and TTBC "aging" effects (microstructural and property changes) under diesel engine operating conditions. Fifteen TTBC ceramic powders were evaluated. These powders were selected to investigate the effects of different chemistries, different manufacturing methods, lot-to-lot variations, different suppliers and varying impurity levels. Each of the fifteen materials has been sprayed using 36 parameters selected by a design of experiments (DOE) to determine the effects of primary gas (Ar and N2), primary gas flow rate, voltage, arc current, powder feed rate, carrier gas flow rate, and spraying distance. The deposition efficiency, density, and thermal conductivity of the resulting coatings were measured. A coating with a high deposition efficiency and low thermal conductivity is desired from an economic standpoint. An optimum combination of thermal conductivity and disposition efficiency was found for each lot of powder in follow-on experiments and disposition parameters were chosen for full characterization.(2) Strengths of the optimized coatings were determined using 4-point bending specimens. The tensile strength was determined using free-standing coatings made by spraying onto mild steel substrates which were subsequently removed by chemical etching. The compressive strengths of the coatings

  12. A cross-sectional study of barriers to physical activity among overweight and obese patients with type 2 diabetes in Iran.

    Science.gov (United States)

    Halali, Faranak; Mahdavi, Reza; Asghari Jafarabadi, Mohammad; Mobasseri, Majid; Namazi, Nazli

    2016-09-01

    The objective of this study was to identify common barriers to physical activity practice among overweight/obese patients with type 2 diabetes in Iran and their associations with physical activity level. In this cross-sectional study, 146 overweight/obese volunteers with type 2 diabetes were recruited from diabetes clinics in Tabriz, Iran, between July 2012 and March 2013. A Persian version of the long-format International Physical Activity Questionnaire was used to assess physical activity level. A 12-item structured questionnaire was designed to assess physical activity barriers. The validity and reliability of the latter scale were assessed by related measures. An exploratory factor analysis with the principal component analysis extraction method and varimax rotation was performed to extract the underlying factors. Multivariate regression analysis was used to assess the relationship between barriers and physical activity level. About 73% of patients had moderate physical activity. Factor analysis yielded four factors as barriers to physical activity including: (i) negative attitude towards physical activity, (ii) discouragement, (iii) physical problems and (iv) cost/environmental factors. These factors explained about 51% of the total variance. There was a negative relationship between the factor 'physical problems' and physical activity level (P = 0.024). Overall, there were some barriers to physical activity. Health counsellors should address these barriers to increase the patients' adherence to physical activity recommendations. Physical conditions of the patients must be taken into account.

  13. Focal MMP-2 and MMP-9 activity at the blood-brain barrier promotes chemokine-induced leukocyte migration

    OpenAIRE

    Jian Song; Chuan Wu; Eva Korpos; Xueli Zhang; Smriti M. Agrawal; Ying Wang; Cornelius Faber; Michael Schäfers; Heinrich Körner; Ghislain Opdenakker; Rupert Hallmann; Lydia Sorokin

    2015-01-01

    Although chemokines are sufficient for chemotaxis of various cells, increasing evidence exists for their fine-tuning by selective proteolytic processing. Using a model of immune cell chemotaxis into the CNS (experimental autoimmune encephalomyelitis [EAE]) that permits precise localization of immigrating leukocytes at the blood-brain barrier, we show that, whereas chemokines are required for leukocyte migration into the CNS, additional MMP-2/9 activities specifically at the border of the CNS ...

  14. Staying physically active after spinal cord injury: a qualitative exploration of barriers and facilitators to exercise participation.

    Science.gov (United States)

    Kehn, Matthew; Kroll, Thilo

    2009-06-01

    While enhancing physical activity has been an essential goal of public health officials, people with physical impairments such as spinal cord injury (SCI) are more likely to live a sedentary lifestyle. Exercise has been shown to decrease the risk for many of the secondary conditions associated with SCI, including osteoporosis, cardiovascular disease, pressure ulcers, urinary tract infections, diabetes and arthritis, yet this population is rarely a target for health promotion efforts. This paper examines the self-reported exercise experiences of people with SCI using a qualitative-exploratory design. We enrolled 26 individuals with SCI (15 self-described 'exercisers' and 11 'non-exercisers') from a non-random pool of survey responders. Semi-structured phone interviews were conducted to record participants' experiences with exercise pre/post injury, barriers and facilitators to being active and perceived health impact. Regardless of exercise status, all participants reported physical activity prior to injury and expressed interest in becoming active or maintaining an active lifestyle. Participants identified a range of both motivational and socio-environmental factors that were either facilitating or constraining of such a lifestyle. Non-exercisers identified barriers to exercise, including a perceived low return on physical investment, lack of accessible facilities, unaffordable equipment, no personal assistance and fear of injury. Exercisers identified facilitators, including personal motivation, independence, availability of accessible facilities and personal assistants, fear of health complications, and weight management. Exercisers associated a greater range of specific health benefits with being active than non-exercisers. Despite motivation and interest in being exercise active, people with SCI face many obstacles. Removal of barriers coupled with promotion of facilitating factors, is vital for enhancing opportunities for physical activity and reducing the

  15. Staying physically active after spinal cord injury: a qualitative exploration of barriers and facilitators to exercise participation

    Directory of Open Access Journals (Sweden)

    Kroll Thilo

    2009-06-01

    Full Text Available Abstract Background While enhancing physical activity has been an essential goal of public health officials, people with physical impairments such as spinal cord injury (SCI are more likely to live a sedentary lifestyle. Exercise has been shown to decrease the risk for many of the secondary conditions associated with SCI, including osteoporosis, cardiovascular disease, pressure ulcers, urinary tract infections, diabetes and arthritis, yet this population is rarely a target for health promotion efforts. This paper examines the self-reported exercise experiences of people with SCI using a qualitative-exploratory design. Methods We enrolled 26 individuals with SCI (15 self-described 'exercisers' and 11 'non-exercisers' from a non-random pool of survey responders. Semi-structured phone interviews were conducted to record participants' experiences with exercise pre/post injury, barriers and facilitators to being active and perceived health impact. Results Regardless of exercise status, all participants reported physical activity prior to injury and expressed interest in becoming active or maintaining an active lifestyle. Participants identified a range of both motivational and socio-environmental factors that were either facilitating or constraining of such a lifestyle. Non-exercisers identified barriers to exercise, including a perceived low return on physical investment, lack of accessible facilities, unaffordable equipment, no personal assistance and fear of injury. Exercisers identified facilitators, including personal motivation, independence, availability of accessible facilities and personal assistants, fear of health complications, and weight management. Exercisers associated a greater range of specific health benefits with being active than non-exercisers. Conclusion Despite motivation and interest in being exercise active, people with SCI face many obstacles. Removal of barriers coupled with promotion of facilitating factors, is vital for

  16. Perceived barriers mediate the association between self-efficacy and fruit and vegetable consumption among students attending alternative high schools.

    Science.gov (United States)

    Bruening, Meg; Kubik, Martha Y; Kenyon, Denyelle; Davey, Cynthia; Story, Mary

    2010-10-01

    Compared to students attending regular high schools, alternative high school students are more likely to be racial/ethnic minorities, have higher levels of poverty, and higher rates of risky and poor health behaviors, including weight-related behaviors like limited fruit and vegetable intake. However, little is known about fruit/vegetable intake among alternative high school students. This study examined whether perceived barriers to healthy eating mediated the association between self-efficacy to eat healthy foods and fruit/vegetable consumption among alternative high school students. The cross-sectional study population consisted of students (N=145) attending six alternative high schools in the St Paul-Minneapolis, MN, area who were participants in an obesity prevention pilot study and completed a baseline survey during fall 2006. Mixed model linear regression, adjusting for sociodemographic characteristics, was used to test a series of regression models performed according to mediation analysis procedures. Students' mean age was 17.3 years; 52% were male, 63% were low-income, and 61% were from racial/ethnic minorities. Students reported a mean fruit/vegetable intake of 3.6 servings per day, mean self-efficacy to eat healthy score of 22.2 (range 3 to 35), and mean barriers to eating healthy score of 6.9 (range 3 to 13). Perceived barriers to healthy eating fully mediated the relationship between self-efficacy and fruit/vegetable consumption (Sobel test statistic 2.7, P=0.007). Interventions targeting the dietary practices of alternative high school students should include components to decrease perceived barriers as a way to increase self-efficacy and ultimately fruit/vegetable intake.

  17. Identification of multi-drug resistant Pseudomonas aeruginosa clinical isolates that are highly disruptive to the intestinal epithelial barrier

    Directory of Open Access Journals (Sweden)

    Shevchenko Olga

    2006-06-01

    Full Text Available Abstract Background Multi-drug resistant Pseudomonas aeruginosa nosocomial infections are increasingly recognized worldwide. In this study, we focused on the virulence of multi-drug resistant clinical strains P. aeruginosa against the intestinal epithelial barrier, since P. aeruginosa can cause lethal sepsis from within the intestinal tract of critically ill and immuno-compromised patients via mechanisms involving disruption of epithelial barrier function. Methods We screened consecutively isolated multi-drug resistant P. aeruginosa clinical strains for their ability to disrupt the integrity of human cultured intestinal epithelial cells (Caco-2 and correlated these finding to related virulence phenotypes such as adhesiveness, motility, biofilm formation, and cytotoxicity. Results Results demonstrated that the majority of the multi-drug resistant P. aeruginosa clinical strains were attenuated in their ability to disrupt the barrier function of cultured intestinal epithelial cells. Three distinct genotypes were found that displayed an extreme epithelial barrier-disrupting phenotype. These strains were characterized and found to harbor the exoU gene and to display high swimming motility and adhesiveness. Conclusion These data suggest that detailed phenotypic analysis of the behavior of multi-drug resistant P. aeruginosa against the intestinal epithelium has the potential to identify strains most likely to place patients at risk for lethal gut-derived sepsis. Surveillance of colonizing strains of P. aeruginosa in critically ill patients beyond antibiotic sensitivity is warranted.

  18. Diets high in fermentable protein and fibre alter tight junction protein composition with minor effects on barrier function in piglet colon.

    Science.gov (United States)

    Richter, Jan F; Pieper, Robert; Zakrzewski, Silke S; Günzel, Dorothee; Schulzke, Joerg D; Van Kessel, Andrew G

    2014-03-28

    Protein fermentation end products may damage the colonic mucosa, which could be counteracted by dietary inclusion of fermentable carbohydrates (fCHO). Although fermentable crude protein (fCP) and fCHO are known to affect microbial ecology, their interactive effects on epithelial barrier function are unknown. In the present study, in a 2 × 2 factorial experiment, thirty-two weaned piglets were fed low-fCP/low-fCHO (14·5 % crude protein (CP)/14·5 % total dietary fibre (TDF)), low-fCP/high-fCHO (14·8 % CP/16·6 % TDF), high-fCP/low-fCHO (19·8 % CP/14·5 % TDF) and high-fCP/high-fCHO (20·1 % CP/18·0 % TDF) diets. After 21-23 d, samples of proximal and distal colonic mucosae were investigated in Ussing chambers with respect to the paracellular and transcytotic passages of macromolecules and epithelial ion transport. The high-fCHO diets were found to reduce the permeability of the distal colon to the transcytotic marker horseradish peroxidase (HRP, 44 kDa; P ion transport), transepithelial resistance (barrier function) and charge selectivity were largely unaffected in both the segments. However, the high-fCP diets were found to suppress the aldosterone-induced epithelial Na channel activity (P composition in a compensatory way, so that colonic transport and barrier properties were only marginally affected.

  19. Osteoblast response (initial adhesion and alkaline phosphatase activity following exposure to a barrier membrane/enamel matrix derivative combination

    Directory of Open Access Journals (Sweden)

    Thangakumaran S

    2009-01-01

    Full Text Available Background and Objective: The enamel matrix derivative (EMD has been used in combination with barrier membranes to optimize regeneration in vertical osseous defects. However, the osteoblast response when exposed to the EMD/barrier membrane combination has not yet been evaluated. The osteoblast behavior when exposed to a combination of regenerative materials must be evaluated to fully understand their effect on bone regeneration. Therefore, the present study was undertaken to estimate the initial adhesion and alkaline phosphatase (ALP activity of an osteoblast cell line (SaOS-2 when exposed to four commercially available resorbable membranes and determine if the addition of EMD had any modulatory effect on osteoblast behavior. Materials and Methods: 5 x 104 SaOS-2 cells between passages 7-10 were cultured in two 24-well culture plates. Plate A was used for the adhesion assay and Plate B was used for the ALP assay. A MTT (3-[4, 5-dimethylthiazolyl-2]-2, 5-diphenyltetrazolium bromide assay was done after 24 hours to determine the adhesion of the osteoblastic cells to four barrier membranes: 1 a non cross-linked porcine Type I and III collagen membrane (BG, 2 a weakly cross-linked Type I collagen membrane (HG, 3 a glutaraldehyde cross-linked bovine Type I collagen (BM, and 4 a resorbable polymer membrane (CP. Osteoblast differentiation was studied using an ALP assay with p-nitro phenyl phosphate as the substrate at 24 hours, 72 hours, and 1 week. A total of 50 µg/ml of EMD dissolved in 10 mM acetic acid was added into each well and the entire experimental protocol outlined above was repeated. Results: The osteoblast adhesion to collagen barriers showed a statistically insignificant reduction following the addition of EMD. Adhesion to the polymer barrier, although significantly lower when compared with collagen barriers, was unaffected by the addition of EMD. ALP activity after 1 week among the various groups was as follows: EMD alone (75.59±2

  20. Low Thermal Conductivity, High Durability Thermal Barrier Coatings for IGCC Environments

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, Eric [Univ. of Connecticut, Storrs, CT (United States); Gell, Maurice [Univ. of Connecticut, Storrs, CT (United States)

    2015-01-15

    Advanced thermal barrier coatings (TBC) are crucial to improved energy efficiency in next generation gas turbine engines. The use of traditional topcoat materials, e.g. yttria-stabilized zirconia (YSZ), is limited at elevated temperatures due to (1) the accelerated undesirable phase transformations and (2) corrosive attacks by calcium-magnesium-aluminum-silicate (CMAS) deposits and moisture. The first goal of this project is to use the Solution Precursor Plasma Spray (SPPS) process to further reduce the thermal conductivity of YSZ TBCs by introducing a unique microstructural feature of layered porosity, called inter-pass boundaries (IPBs). Extensive process optimization accompanied with hundreds of spray trials as well as associated SEM cross-section and laser-flash measurements, yielded a thermal conductivity as low as 0.62 Wm⁻¹K⁻¹ in SPPS YSZ TBCs, approximately 50% reduction of APS TBCs; while other engine critical properties, such as cyclic durability, erosion resistance and sintering resistance, were characterized to be equivalent or better than APS baselines. In addition, modifications were introduced to SPPS TBCs so as to enhance their resistance to CMAS under harsh IGCC environments. Several mitigation approaches were explored, including doping the coatings with Al₂O₃ and TiO₂, applying a CMAS infiltration-inhibiting surface layer, and filling topcoat cracks with blocking substances. The efficacy of all these modifications was assessed with a set of novel CMAS-TBC interaction tests, and the moisture resistance was tested in a custom-built high-temperature moisture rig. In the end, the optimal low thermal conductivity TBC system was selected based on all evaluation tests and its processing conditions were documented. The optimal coating consisted on a thick inner layer of YSZ coating made by the SPPS process having a thermal conductivity 50% lower than standard YSZ coatings topped with a high temperature tolerant CMAS resistant gadolinium

  1. Evaluation of a barrier to inhibit lesser mealworm (Coleoptera: Tenebrionidae) and dermestidae movement in high-rise, caged-layer poultry facilities.

    Science.gov (United States)

    Kaufman, Phillip E; Reasor, Colleen; Murray, Kathleen D; Waldron, J Keith; Rutz, Donald A

    2005-10-01

    An evaluation of a mechanical barrier to prevent movement of adult and larval lesser mealworm, Alphitobius diaperinus (Panzer); larder beetle, Dermestes lardarius L.; and hide beetle, Dermestes maculatus De Geer was conducted in caged-layer poultry facilities in New York and Maine. The barrier, a plastic collar wrapped around building support posts, proved highly effective at preventing movement of adult lesser mealworms. Significantly more lesser mealworm larvae were recovered from cardboard collar beetle traps placed below both washed and unwashed barriers than from traps placed above washed and unwashed barriers. Similarly, significantly more adult Dermestes were recovered from traps placed below washed barriers than from above both washed and unwashed barriers. The level of fly specking on the barrier was found to have no significant impact on the numbers of adult lesser mealworms and adult and larval Dermestes recovered either above or below barriers. Fly specking level did significantly impact the numbers of lesser mealworm larvae recovered above the barrier. Although washed barriers provided the greatest deterrent to adult lesser mealworms, the presence of the barrier, regardless of the level of fly specking, provided a significant deterrent to beetle climbing success. Washed barriers further reduced climbing success by lesser mealworm larvae by 17%, Dermestes adults by 7-28%, and Dermestes larvae by 33-38%. The high level of climbing observed by adult lesser mealworms suggests that the impact of adult beetle movement toward birds should be considered in its importance in building damage, disease transmission, feed infestation, and bird productivity and health. Observations on cost and maintenance of the barrier are discussed.

  2. The role of midlatitude mixing barriers in creating the annual variation of total ozone in high northern latitudes

    Science.gov (United States)

    Gille, John; Karol, Svetlana; Kinnison, Douglas; Lamarque, Jean-Francois; Yudin, Valery

    2014-08-01

    Data from the HIgh Resolution Dynamics Limb Sounder (HIRDLS), the Microwave Limb Sounder (MLS), and the Whole Atmosphere Community Climate Model (WACCM) are used to investigate the annual variation of total column ozone in high northern latitudes. Downward transport of ozone-rich air by the residual mean circulation during autumn and winter bends ozone isopleths down and increases the high-latitude ozone amounts, leading to an ozone maximum at the end of the winter. During the summer months eddy mixing acts to restore pre-fall distributions of ozone. In this study the large-scale mixing in the lower stratosphere is analyzed using Nakamura's (1996) equivalent length formulation with observed and simulated ozone. The analysis of ozone mixing is performed in the tracer equivalent latitude-potential temperature coordinate system. Steep latitudinal gradients of ozone isopleths below about 500 K occur during the winter, where there are minima in the equivalent length, indicating barriers to mixing at 30°N-40°N. This transport barrier allows large ozone maxima to develop poleward of it. The barrier disappears over the summer, permitting latitudinal mixing of the high ozone air. Above 500 K mixing is more effective during the winter, so a large winter maximum does not occur. In both midlatitude and high latitude the lower stratospheric layer from 330 to 500 K doubles its ozone content from autumn to spring, compared with much smaller changes in the layer from 500 to 650 K. Our results confirm that the presence of the winter transport barrier in the lower stratosphere controls the seasonal variation of total ozone.

  3. Perceived barriers to pharmacist engagement in adverse drug event prevention activities in Ghana using semi-structured interview.

    Science.gov (United States)

    Acheampong, Franklin; Anto, Berko Panyin

    2015-09-07

    Pharmacist involvement in the prevention of medication errors is well documented. One such method, the process by which hospital pharmacists undertake these clinical interventions needs to be described and documented. The perceived barriers to pharmacists succeeding in getting their recommendations accepted could inform future safety strategy development. This study was therefore to trace the typical process involved and explore the perceived barriers to pharmacists' medication safety efforts. This study involved a retrospective evaluation of routine clinical interventions collected at a tertiary hospital in Ghana over 23 months. A sample of pharmacists who had submitted these reports were then interviewed. The interventions made related to drug therapy changes (76.0%), monitoring (13.0%), communication (5.4%), counselling (5.0%) and adverse drug events (0.6%). More than 90% of interventions were accepted. The results also showed that undertaking clinical interventions by pharmacists followed a sequential order with two interlinked subprocesses: Problem Identification and Problem Handling. In identifying the problem, as much information needed to be gathered, clinical issues identified and then the problems prioritised. During the problem handling stage, detailed assessment was made which led to the development of a pharmaceutical plan. The plan was then implemented and monitored to ensure appropriateness of desired outcomes. The main barrier mentioned by pharmacist related to the discrepant attitudes of doctors/nurses. The other barriers encountered during these tasks related to workload, and inadequate clinical knowledge. The attitudes were characterised by conflicts and egos resulting from differences in status/authority, responsibilities, and training. Though the majority of recommendations from pharmacists were accepted, the main barrier to hospital pharmacist engagement in medication error prevention activities related to discrepant attitudes of doctors and

  4. St. John's Wort constituents modulate P-glycoprotein transport activity at the blood-brain barrier.

    NARCIS (Netherlands)

    Ott, M.; Huls, M.; Cornelius, M.G.; Fricker, G.

    2010-01-01

    PURPOSE: The purpose of this study was to investigate the short-term signaling effects of St. John's Wort (SJW) extract and selected SJW constituents on the blood-brain barrier transporter P-glycoprotein and to describe the role of PKC in the signaling. METHODS: Cultured porcine brain capillary endo

  5. Barriers to Application of E-Learning in Training Activities of SMEs

    Science.gov (United States)

    Anderson, Randy J.; Wielicki, Tomasz; Anderson, Lydia E.

    2010-01-01

    This paper reports on the on-going study of Small and Mid-Size Enterprises (SMEs) in the Central California concerning their use of Information and Communication Technology (ICT). This research project analyzed data from a sample of 161 SMEs. Specifically, this part of the study is investigating the major barriers to applications of e-learning…

  6. Cichorium intybus root extract: A "vitamin D-like" active ingredient to improve skin barrier function.

    Science.gov (United States)

    Maia Campos, P M B G; G Mercurio, D; O Melo, M; Closs-Gonthier, B

    2017-02-01

    During the aging process, the human skin suffers many alterations including dryness, skin barrier function damage. The skin barrier function is important to the prevention of skin alterations and maintenance of homeostasis. So, the objective of this study was to assess the clinical efficacy on skin barrier function of Cichorium intybus root extract in cosmetic formulations with or without UV filters. Fifty women, aged between 45 and 60 years, were divided into two groups. One group received vehicle formulations containing UV filters, and the other group received formulations without UV filters. Both groups received a formulation containing the extract and the vehicle. The formulations were applied twice daily to the upper arms after washing with sodium lauryl sulphate. Transepidermal water loss (TEWL) and skin microrelief were evaluated before and after a 14- and 28-day period of treatment. The control regions and regions where the vehicles were applied showed an increase in the TEWL. For the formulations containing the extract, decreased TEWL and improved microrelief were observed when compared to the vehicle and control areas after a 28-day period. In conclusion, Cichorium intybus root extract showed protective and restructuring effects on the skin and stands out as an innovative ingredient to improve skin barrier function.

  7. Measurement of Plasma Density Produced in Dielectric Barrier Discharge for Active Aerodynamic Control with Interferometer

    Institute of Scientific and Technical Information of China (English)

    LI Gang; ZHANG Yi; XU Yan-Ji; LIN Bin; LI Yu-Tong; ZHU Jun-Qiang

    2009-01-01

    We utilize an interferometer to investigate the changes of the refractive index caused by dielectric barrier discharge plasma.The electronic density of the plasma produced is measured and analyzed tentatively.The results show that density of the plasma increases linearly with exciting voltages.

  8. Optimization of the configuration of a symmetric three-barrier resonant-tunneling structure as an active element of a quantum cascade detector

    Energy Technology Data Exchange (ETDEWEB)

    Tkach, N. V., E-mail: ktf@chnu.edu.ua; Seti, Ju. A. [Fedkovich Chernivtsy National University (Ukraine)

    2011-03-15

    On the basis of a model of rectangular potentials and different electron effective masses in wells and barriers of an open resonant-tunneling structure with identical outer barriers, a theory has been developed and the dynamic conductance caused by the interaction of the electromagnetic field with electrons passing through the structure has been calculated. Using the example of the three-barrier resonant-tunneling structure with In{sub 0.53}Ga{sub 0.47}As wells and In{sub 0.52}Al{sub 0.48}As barriers, it is shown that, independently of the geometrical sizes of potential wells and barriers, there exist three geometrical configurations (positions of the inner barrier with respect to outer ones) at which the nanosystem, as an active element, provides optimum operating conditions of the quantum cascade detector.

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

    Science.gov (United States)

    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  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

  10. The prevalence of barriers for Colombian college students engaging in physical activity.

    Science.gov (United States)

    Ramírez-Vélez, Robinson; Tordecilla-Sanders, Alejandra; Laverde, David; Hernández-Novoa, Juan Gilberto; Ríos, Marcelo; Rubio, Fernando; Correa-Bautista, Jorge Enrique; Martinez-Torres, Javier

    2014-09-18

    Objetivo: El objetivo de este trabajo fue analizar la prevalencia de barreras y su asociación con la práctica de AF en universitarios de Colombia. Métodos: Estudio descriptivo de corte transversal, en 5.663 sujetos (3.348 hombres), de tres ciudades de Colombia. Las razones que podrían impedir realizar AF, se evaluaron con el cuestionario de “Percepción de barreras para la práctica de la actividad física” (en inglés, Barriers to Being Active Quiz-21 ítems). Un análisis de regresión logística para cada barrera ajustado por las variables de confusión (sexo, edad e IMC) fue usado para verificar la asociación. Resultados: En la población general, el “miedo a lastimarse” (89,5%) y la “falta de habilidades” (82,1%) eran, en este orden, las razones más frecuentes como barreras auto-percibidas de la práctica de AF. El grupo de mujeres mostró una asociación protectora en relación con las barreras “falta de tiempo” (OR = 0,53 IC95% 0,47-0,60), “influencia social” (OR = 0,67 IC95% 0,60-0,75), “falta de energía” (OR = 0,54 IC95% 0,49-0,61), “falta de voluntad” (OR = 0,57 IC95% 0,51-0,64), “falta de habilidades” (OR = 0,76 IC95% 0,66-0,87) y “falta de recursos” (OR = 0,79 IC95% 0,71-0,89). Esta observación también aparece en el grupo de edades comprendidas entre los 20 y 23 años en la barrera “influencia social” (OR = 0,83 IC95% 0,74-0,94), y en los mayores a 23 años (OR = 0,86 IC95% 0,74-0,99) en la barrera “falta de energía”. Conclusión: Se encontró una importante prevalencia en la percepción de las barreras para cesar la práctica de AF. Estos resultados pueden servir de referencia para las acciones específicas para promover la AF y la salud en universitarios de Colombia.

  11. The biocompatibility of a polyelectrolyte vitreous body substitute on a high resistance in vitro model of the blood-retinal barrier.

    Science.gov (United States)

    Strotmann, Falko; Wolf, Isabel; Galla, Hans-Joachim

    2013-09-01

    The vitreous body can be regarded as a fascinating simple but important tissue, since it represents the main compartment of the eye and plays a crucial role for proper vision. Several diseases require its removal with following substitution using a liquid artificial vitreous body replacement. We explore the biocompatibility of a poly(AMPS-Na(+))-graft-poly(NIPAAm) polyelectrolyte following the innovative concept of thermo-responsive behaviour, exhibiting enhanced shear viscosity at physiological temperatures. As a powerful model for the blood-retinal barrier, we use the well-established in vitro cell culture model based on highly differentiated porcine brain capillary endothelial cells. Via the quantification of the transendothelial electrical resistance and immunocytochemical staining of tight junction proteins, we are able to show that a barrier integrity affecting impact of the polyelectrolyte was only transient and nearly reversible. Furthermore, the polyelectrolyte hydrogel is characterized by the absence of any acute cell morphology, cell vitality or proliferation affecting impacts. It does not trigger acute apoptotic processes, as can be substantiated via caspase-3 activity and DNA fragmentation assays. In view of the results of this study, it is shown that the polyelectrolyte does not affect the vitality parameters of our porcine brain capillary endothelial cells. It can be suggested that the tested thermo-responsive polyelectrolyte does not affect the sensitive retinal barrier integrity. Thus from the cellular tolerance it might serve as a potential liquid artificial vitreous body replacement to overcome the most prominent difficulties of common vitreal endotamponades.

  12. Temperature dependent electrical characteristics of Pt Schottky barriers fabricated on lightly and highly doped n-type 4H-SiC

    Science.gov (United States)

    Huang, Lingqin; Wang, Dejun

    2015-11-01

    The temperature dependent electronic characteristics of Pt Schottky barriers fabricated on lightly and relatively highly doped n-type 4H-SiC (1 × 1016 and 1 × 1018 cm-3) are comparatively investigated. It is found that the abnormal temperature dependence of barrier height and ideality factor estimated from the thermionic emission (TE) model for both lightly and highly doped samples could be successfully explained in terms of Gaussian distribution of inhomogeneous barrier heights. However, the estimated mean barrier height according to Gaussian distribution for the highly doped sample is much lower than the actual mean value from the capacitance-voltage (C-V) measurements. Interestingly, the values of barrier height from the thermionic field emission (TFE) model are found to be close to those from the C-V measurements, indicating that the TFE model is more appropriate to explain the electrical transport for the highly doped sample.

  13. High glucose, glucose fluctuation and carbonyl stress enhance brain microvascular endothelial barrier dysfunction: Implications for diabetic cerebral microvasculature

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-08-01

    Full Text Available We previously demonstrated that in normal glucose (5 mM, methylglyoxal (MG, a model of carbonyl stress induced brain microvascular endothelial cell (IHEC dysfunction that was associated with occludin glycation and prevented by N-acetylcysteine (NAC. Herein, we investigated the impact of high glucose and low GSH, conditions that mimicked the diabetic state, on MG-induced IHEC dysfunction. MG-induced loss of transendothelial electrical resistance (TEER was potentiated in IHECs cultured for 7 or 12 days in 25 mM glucose (hyperglycemia; moreover, barrier function remained disrupted 6 h after cell transfer to normal glucose media (acute glycemic fluctuation. Notably, basal occludin glycation was elevated under these glycemic states. TEER loss was exaggerated by inhibition of glutathione (GSH synthesis and abrogated by NAC, which corresponded to GSH decreases and increases, respectively. Significantly, glyoxalase II activity was attenuated in hyperglycemic cells. Moreover, hyperglycemia and GSH inhibition increased MG accumulation, consistent with a compromised capacity for MG elimination. α-Oxoaldehydes (MG plus glyoxal levels were elevated in streptozotocin-induced diabetic rat plasma. Immunohistochemistry revealed a prevalence of MG-positive, but fewer occludin-positive microvessels in the diabetic brain in vivo, and Western analysis confirmed an increase in MG–occludin adducts. These results provide the first evidence that hyperglycemia and acute glucose fluctuation promote MG–occludin formation and exacerbate brain microvascular endothelial dysfunction. Low occludin expression and high glycated-occludin contents in diabetic brain in vivo are factors that would contribute to the dysfunction of the cerebral microvasculature during diabetes.

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

    Science.gov (United States)

    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.

  15. Historical changes in the Mississippi-Alabama barrier islands and the roles of extreme storms, sea level, and human activities

    Science.gov (United States)

    Morton, Robert A.

    2007-01-01

    westward sediment transport by alongshore currents, and Cat Island is being reshaped as it adjusts to post-formation changes in wave and current patterns associated with deposition of the St. Bernard lobe of the Mississippi delta. The principal causes of barrier island land loss are frequent intense storms, a relative rise in sea level, and a deficit in the sediment budget. The only factor that has a historical trend that coincides with the progressive increase in rates of land loss is the progressive reduction in sand supply associated with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. Neither rates of relative sea level rise nor storm parameters have long-term historical rends that match the increased rates of land loss since the mid 1800s. The historical rates of relative sea level rise in the northern Gulf of Mexico have been relatively constant and storm frequencies and intensities occur in multidecal cycles. However, the most recent land loss accelerations likely related to the increased storm activity since 1995. Considering the predicted trends for storms and sea level related to global warming, it is clear that the barrier islands will continue to lose land area at a rapid rate without a reversal in trend of at least one of the causal factors. The reduction in sand supply related to disruption of the alongshore sediment transport system is the only factor contributing to land loss that can be managed directly. This can be accomplished by placing dredged material so that the adjacent barrier island shores revive it for island nourishment and rebuilding.

  16. Oxidation of limonene using activated carbon modified in dielectric barrier discharge plasma

    Science.gov (United States)

    Glonek, Karolina; Wróblewska, Agnieszka; Makuch, Edyta; Ulejczyk, Bogdan; Krawczyk, Krzysztof; Wróbel, Rafał. J.; Koren, Zvi C.; Michalkiewicz, Beata

    2017-10-01

    The waste from industrial fruits processing is utilized for the extraction of limonene, a renewable terpene biomass compound obtained from orange peels. This was followed by limonene oxidation, which produces highly useful oxygenated derivatives (carveol, and perillyl alcohol, 1,2-epoxylimonene and its diol). New catalysts were obtained by treating relatively inexpensive commercially available EuroPh and FPV activated carbons with plasma. These catalysts were characterized by the following instrumental methods XRD, sorption of N2 and CO2, SEM, EDS, TEM, XPS, and Raman spectroscopy. The activities of the plasma-treated catalysts were measured in the oxidation of limonene by means of either hydrogen peroxide or t-butyl hydroperoxide as the oxidizing agents. During the oxidation with hydrogen peroxide the new plasma-treated catalysts were more active than their untreated counterparts. This effect was noticeable in the considerable increase in the conversion of limonene. The mechanism explaining this property is proposed, and it takes into account the role of the appropriate functional groups on the surface of the catalysts. This work has shown for the first time that the commercial EuroPh and FPV activated carbons, after having been treated by plasma, are active catalysts for the selective limonene oxidation for the production of value-added industrial products.

  17. Thermal Barrier Coatings Chemically and Mechanically Resistant to High Temperature Attack by Molten Ashes

    Science.gov (United States)

    Gledhill, Andrew

    Thermal barrier coatings (TBCs) are ceramic coatings used on component in the hottest sections of gas turbine engines, used for power generation and aviation. These coatings insulate the underlying metal components and allow for much higher engine operating temperatures, improving the engine efficiency. These increase temperatures engender a new set of materials problems for TBCs. Operating temperatures in engines are now high enough for silicate impurities, either present in the fuel or ingested into the engines, to melt and adhere to the surface of the TBCs. The effects of four such impurities, two coal fly ashes, a petroleum coke-fly ash blend, and volcanic ash from the Eyjafjallajokull volcano were tested with conventional yttria-stabilized zirconia (YSZ) coatings, and found to penetrate through the entire thickness of the coating. This penetration reduces the strain tolerance of the coatings, and can result in premature failure. Testing on a newly built thermal gradient burner rig with simultaneous injection of ash impurities has shown a reduction of life up to 99.6% in these coatings when ash is present. Coatings of an alternative ceramic, gadolinium zirconate (Gd2Zr 2O7), were found to form a dense reaction layer with each of these impurities, preventing further penetration of the molten ash. This dense layer also reduces the strain tolerance, but these coatings were found to have a significantly higher life than the YSZ coatings. Testing with a small amount of ash baked onto the samples showed thirteen times the life of YSZ coatings. When the ash is continuously sprayed onto the hot sample, the life of the Gd2Zr2O7 coatings was nearly twice that of the YSZ. Finally, a delamination model was employed to explain the degradation of both types of coatings. This elastic model that takes into account the degree of penetration, differential cooling in thermal gradient testing, and thermal expansion mismatch with the underlying substrate, predicted the failure of

  18. Spatiotemporal dynamics of the nuclear pore complex transport barrier resolved by high-speed atomic force microscopy

    Science.gov (United States)

    Sakiyama, Yusuke; Mazur, Adam; Kapinos, Larisa E.; Lim, Roderick Y. H.

    2016-08-01

    Nuclear pore complexes (NPCs) are biological nanomachines that mediate the bidirectional traffic of macromolecules between the cytoplasm and nucleus in eukaryotic cells. This process involves numerous intrinsically disordered, barrier-forming proteins known as phenylalanine-glycine nucleoporins (FG Nups) that are tethered inside each pore. The selective barrier mechanism has so far remained unresolved because the FG Nups have eluded direct structural analysis within NPCs. Here, high-speed atomic force microscopy is used to visualize the nanoscopic spatiotemporal dynamics of FG Nups inside Xenopus laevis oocyte NPCs at timescales of ∼100 ms. Our results show that the cytoplasmic orifice is circumscribed by highly flexible, dynamically fluctuating FG Nups that rapidly elongate and retract, consistent with the diffusive motion of tethered polypeptide chains. On this basis, intermingling FG Nups exhibit transient entanglements in the central channel, but do not cohere into a tightly crosslinked meshwork. Therefore, the basic functional form of the NPC barrier is comprised of highly dynamic FG Nups that manifest as a central plug or transporter when averaged in space and time.

  19. High barrier multilayer packaging by the coextrusion method: The effect of nanocomposites and biodegradable polymers on flexible film properties

    Science.gov (United States)

    Thellen, Christopher T.

    The objective of this research was to investigate the use of nanocomposite and multilayer co-extrusion technologies for the development of high gas barrier packaging that is more environmentally friendly than many current packaging system. Co-extruded bio-based and biodegradable polymers that could be composted in a municipal landfill were one direction that this research was aimed. Down-gauging of high performance barrier films using nanocomposite technology and co-extrusion was also investigated in order to reduce the amount of solid waste being generated by the packaging. Although the research is focused on military ration packaging, the technologies could easily be introduced into the commercial flexible packaging market. Multilayer packaging consisting of poly(m-xylylene adipamide) nanocomposite layers along with adhesive and tie layers was co-extruded using both laboratory and pilot-scale film extrusion equipment. Co-extrusion of biodegradable polyhydroxyalkanoates (PHA) along with polyvinyl alcohol (PVOH) and tie layers was also accomplished using similar co-extrusion technology. All multilayer films were characterized for gas barrier, mechanical, and thermal properties. The biodegradability of the PVOH and PHA materials in a marine environment was also investigated. The research has shown that co-extrusion of these materials is possible at a research and pilot level. The use of nanocomposite poly(m-xylylene adipamide) was effective in down-gauging the un-filled barrier film to thinner structures. Bio-based PHA/PVOH films required the use of a malefic anhydride grafted PHA tie layer to improve layer to layer adhesion in the structure to avoid delamination. The PHA polymer demonstrated a high rate of biodegradability/mineralization in the marine environment while the rate of biodegradation of the PVOH polymer was slower.

  20. A high performance ceria based interdiffusion barrier layer prepared by spin-coating

    DEFF Research Database (Denmark)

    Plonczak, Pawel; Joost, Mario; Hjelm, Johan

    2011-01-01

    A multiple spin-coating deposition procedure of Ce0.9Gd0.1O1.95 (CGO) for application in solid oxide fuel cells (SOFCs) was developed. The thin and dense CGO layer can be employed as a barrier layer between yttria stabilised zirconia (YSZ) electrolyte and a (La, Sr)(Co, Fe)O3 based cathode....... The decomposition of the polymer precursor used in the spin-coating process was studied. The depositions were performed on anode supported half cells. By controlling the sintering temperature between each spin-coating process, dense and crack-free CGO films with a thickness of approximately 1 μm were obtained....... The successive steps of dense layer production was investigated by scanning electron microscopy. X-ray diffraction was employed to monitor the crystal structure of the CGO layer sintered at different temperatures. The described spin coated barrier layer was evaluated using an anode supported cell...

  1. Water-soluble nanocrystalline cellulose films with highly transparent and oxygen barrier properties

    Science.gov (United States)

    Cheng, Shaoling; Zhang, Yapei; Cha, Ruitao; Yang, Jinliang; Jiang, Xingyu

    2015-12-01

    By mixing a guar gum (GG) solution with a nanocrystalline cellulose (NCC) dispersion using a novel circular casting technology, we manufactured biodegradable films as packaging materials with improved optical and mechanical properties. These films could act as barriers for oxygen and could completely dissolve in water within 5 h. We also compared the effect of nanocomposite films and commercial food packaging materials on the preservation of food.By mixing a guar gum (GG) solution with a nanocrystalline cellulose (NCC) dispersion using a novel circular casting technology, we manufactured biodegradable films as packaging materials with improved optical and mechanical properties. These films could act as barriers for oxygen and could completely dissolve in water within 5 h. We also compared the effect of nanocomposite films and commercial food packaging materials on the preservation of food. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07647a

  2. Synthesized High-Frequency Thyristor for Dielectric Barrier Discharge Excimer Lamps

    OpenAIRE

    2012-01-01

    International audience; Dielectric barrier discharge (DBD) lamps, being capacitive loads, must be associated with bidirectional current sources for an appropriate control of the transferred power. Pulsed current source supplies, which are known to offer very interesting performances, require specific power switches that are able to manage bidirectional voltage and unidirectional current at much higher frequencies (several hundreds of kilohertz) than commercial thyristors. This paper proposes t...

  3. Implement Obligations Seriously, Enjoy Rights Fully Make Active Countermeasure to the Barrier of Foreign Technology Trade

    Institute of Scientific and Technical Information of China (English)

    Li Changjiang

    2007-01-01

    @@ December 11th, 2006 is the fifth anniversary of China's entry into WTO. Over the past five years, what AQSIQ has done in implementing the obligations and enjoying the rights as a member of WTO? How's the performance? Facing with the current complicated barrier of technology trade worldwide, how will China reply to it? For these questions, reporters have made a special interview with Li Changjiang, Minister of AQSIQ.

  4. Activism on rifapentine pricing: removing cost barriers to improve the uptake of tuberculosis research innovations

    OpenAIRE

    Deluca, A; Frick, M; Lessem, E; Kanouse, J.; Wegener, D.; Mingote, L. Ruiz

    2014-01-01

    As recent advances have been made in developing tools to fight tuberculosis (TB), there is also a trend towards increasing advocacy by the civil society for TB research and access. One recent successful effort to increase access to treatment options for TB involved a collaborative effort to identify the need for and barriers to the use of rifapentine (RPT) use in the United States. Survey responses confirmed the under-utilization of RPT: 82% of survey respondents selected cost as a significan...

  5. Polyphenol-Rich Propolis Extracts Strengthen Intestinal Barrier Function by Activating AMPK and ERK Signaling

    OpenAIRE

    Kai Wang; Xiaolu Jin; Yifan Chen; Zehe Song; Xiasen Jiang; Fuliang Hu; Conlon, Michael A.; Topping, David L.

    2016-01-01

    Propolis has abundant polyphenolic constituents and is used widely as a health/functional food. Here, we investigated the effects of polyphenol-rich propolis extracts (PPE) on intestinal barrier function in human intestinal epithelial Caco-2 cells, as well as in rats. In Caco-2 cells, PPE increased transepithelial electrical resistance and decreased lucifer yellow flux. PPE-treated cells showed increased expression of the tight junction (TJ) loci occludin and zona occludens (ZO)-1. Confocal m...

  6. Physical activity in patients with type 2 diabetes and hypertension – insights into motivations and barriers from the MOBILE study

    Directory of Open Access Journals (Sweden)

    Duclos M

    2015-06-01

    Full Text Available Martine Duclos,1,2 Sylvie Dejager,3,4 Nicolas Postel-Vinay,5 Sylvie di Nicola,6 Stéphane Quéré,7 Béatrice Fiquet4,5 1Department of Sport Medicine and Functional Explorations, University-Hospital (CHU, G Montpied Hospital; INRA, UNH, CRNH Auvergne, 2Nutrition Department, University of Auvergne, Clermont-Ferrand, Auvergne, 3Department of Endocrinology and Metabolism, La Pitié-Salpétrière Hospital, Paris, 4Clinical and Scientific Affairs, Novartis Pharma SAS, Rueil-Malmaison, 5Department of Hypertension, Georges Pompidou European Hospital, Paris, 6Biostatistics, Inferential, Paris, 7Biostatistics, Novartis Pharma SAS, Rueil-Malmaison, France Background: Although physical activity (PA is key in the management of type 2 diabetes (T2DM and hypertension, it is difficult to implement in practice. Methods: Cross-sectional, observational study. Participating physicians were asked to recruit two active and four inactive patients, screened with the Ricci-Gagnon (RG self-questionnaire (active if score ≥16. Patients subsequently completed the International Physical Activity Questionnaire. The objective was to assess the achievement of individualized glycated hemoglobin and blood pressure goals (<140/90 mmHg in the active vs inactive cohort, to explore the correlates for meeting both targets by multivariate analysis, and to examine the barriers and motivations to engage in PA. Results: About 1,766 patients were analyzed. Active (n=628 vs inactive (n=1,138 patients were more often male, younger, less obese, had shorter durations of diabetes, fewer complications and other health issues, such as osteoarticular disorders (P<0.001 for all. Their diabetes and hypertension control was better and obtained despite a lower treatment burden. The biggest difference in PA between the active vs inactive patients was the percentage who declared engaging in regular leisure-type PA (97.9% vs 9.6%, also reflected in the percentage with vigorous activities in

  7. Tunable Schottky barrier and high responsivity in graphene/Si-nanotip optoelectronic device

    Science.gov (United States)

    Di Bartolomeo, Antonio; Giubileo, Filippo; Luongo, Giuseppe; Iemmo, Laura; Martucciello, Nadia; Niu, Gang; Fraschke, Mirko; Skibitzki, Oliver; Schroeder, Thomas; Lupina, Grzegorz

    2017-03-01

    We demonstrate tunable Schottky barrier height and record photo-responsivity in a new-concept device made of a single-layer CVD graphene transferred onto a matrix of nanotips patterned on n-type Si wafer. The original layout, where nano-sized graphene/Si heterojunctions alternate to graphene areas exposed to the electric field of the Si substrate, which acts both as diode cathode and transistor gate, results in a two-terminal barristor with single-bias control of the Schottky barrier. The nanotip patterning favors light absorption, and the enhancement of the electric field at the tip apex improves photo-charge separation and enables internal gain by impact ionization. These features render the device a photodetector with responsivity (3 {{A}} {{{W}}}-1 for white LED light at 3 {{mW}} {{{cm}}}-2 intensity) almost an order of magnitude higher than commercial photodiodes. We extensively characterize the voltage and the temperature dependence of the device parameters, and prove that the multi-junction approach does not add extra-inhomogeneity to the Schottky barrier height distribution. We also introduce a new phenomenological graphene/semiconductor diode equation, which well describes the experimental I-V characteristics both in forward and reverse bias.

  8. Simulation of crash tests for high impact levels of a new bridge safety barrier

    Science.gov (United States)

    Drozda, Jiří; Rotter, Tomáš

    2017-09-01

    The purpose is to show the opportunity of a non-linear dynamic impact simulation and to explain the possibility of using finite element method (FEM) for developing new designs of safety barriers. The main challenge is to determine the means to create and validate the finite element (FE) model. The results of accurate impact simulations can help to reduce necessary costs for developing of a new safety barrier. The introductory part deals with the creation of the FE model, which includes the newly-designed safety barrier and focuses on the application of an experimental modal analysis (EMA). The FE model has been created in ANSYS Workbench and is formed from shell and solid elements. The experimental modal analysis, which was performed on a real pattern, was employed for measuring the modal frequencies and shapes. After performing the EMA, the FE mesh was calibrated after comparing the measured modal frequencies with the calculated ones. The last part describes the process of the numerical non-linear dynamic impact simulation in LS-DYNA. This simulation was validated after comparing the measured ASI index with the calculated ones. The aim of the study is to improve professional public knowledge about dynamic non-linear impact simulations. This should ideally lead to safer, more accurate and profitable designs.

  9. Mapping of barley alpha-amylases and outer subsite mutants reveals dynamic high-affinity subsites and barriers in the long substrate binding cleft

    DEFF Research Database (Denmark)

    Kandra, L.; Abou Hachem, Maher; Gyemant, G.;

    2006-01-01

    as binding barriers. Barley a-amylase I mutants Y105A and T212Y at subsite -6 and +4 resulted in release or anchoring of bound substrate, thus modifying the affinities of other high-affinity subsites (-2 and +2) and barriers. The double mutant Y105A-T212Y displayed a hybrid subsite affinity profile...

  10. AN ANALYSIS OF THE THERMAL AND MECHANICAL BEHAVIOR OF ENGINEERED BARRIERS IN A HIGH-LEVEL RADIOACTIVE WASTE REPOSITORY

    Directory of Open Access Journals (Sweden)

    S. KWON

    2013-02-01

    Full Text Available Adequate design of engineered barriers, including canister, buffer and backfill, is important for the safe disposal of high-level radioactive waste. Three-dimensional computer simulations were carried out under different condition to examine the thermal and mechanical behavior of engineered barriers and rock mass. The research looked at five areas of importance, the effect of the swelling pressure, water content of buffer, density of compacted bentonite, emplacement type and the selection of failure criteria. The results highlighted the need to consider tensile stress in the outer shell of a canister due to thermal expansion of the canister and the swelling pressure from the buffer for a more reliable design of an underground repository system. In addition, an adequate failure criterion should be used for the buffer and backfill.

  11. Why some do but most don't. Barriers and enablers to engaging low-income groups in physical activity programmes: a mixed methods study

    Directory of Open Access Journals (Sweden)

    Fox Kenneth R

    2011-06-01

    Full Text Available Abstract Background The beneficial effect of physical activity for the prevention of a range of chronic diseases is widely acknowledged. These chronic conditions are most pronounced in economically disadvantaged groups where physical activity levels are consistently lower, yet this group is particularly difficult to recruit and retain in physical activity programmes. This study examined the perceptions of participants, non-participants, and exercise leaders in a low-income area regarding barriers, motives, and enabling factors for organised physical activity with a view to improving recruitment and retention. Methods A mixed methods research approach was adopted to guide data collection and analysis. A survey, incorporating the Motivation for Physical Activity Measure - Revised (MPAM-R, was used to assess the motivations of 152 physical activity session participants in a highly deprived suburban neighbourhood. The MPAM-R data were analysed using t tests, analyses of variance to estimate age, body mass index, and activity mode differences and Pearson's correlation coefficient to address associations. Semi-structured interviews were also conducted with 33 local residents who did not participate in activity sessions and with 14 activity session leaders. All interviews were audio-taped, transcribed verbatim and analyzed using an inductive thematic approach. Results Participants reported cost, childcare, lack of time and low awareness as barriers to joining activity classes. The need for support, confidence and competence in order to take up activity was widely expressed, particularly among women. Once people are active, high levels of social interaction, interest and enjoyment are associated with improved levels of retention, with different types of physical activity scoring differently on these factors. Conclusions This study suggests that some factors such as cost, the fear of 'walking in alone', accessibility of facilities, and appropriate

  12. Barriers, facilitators and preferences for the physical activity of school children. Rationale and methods of a mixed study

    Directory of Open Access Journals (Sweden)

    Martínez-Andrés María

    2012-09-01

    Full Text Available Abstract Background Physical activity interventions in schools environment seem to have shown some effectiveness in the control of the current obesity epidemic in children. However the complexity of behaviors and the diversity of influences related to this problem suggest that we urgently need new lines of insight about how to support comprehensive population strategies of intervention. The aim of this study was to know the perceptions of the children from Cuenca, about their environmental barriers, facilitators and preferences for physical activity. Methods/Design We used a mixed-method design by combining two qualitative methods (analysis of individual drawings and focus groups together with the quantitative measurement of physical activity through accelerometers, in a theoretical sample of 121 children aged 9 and 11 years of schools in the province of Cuenca, Spain. Conclusions Mixed-method study is an appropriate strategy to know the perceptions of children about barriers and facilitators for physical activity, using both qualitative methods for a deeply understanding of their points of view, and quantitative methods for triangulate the discourse of participants with empirical data. We consider that this is an innovative approach that could provide knowledges for the development of more effective interventions to prevent childhood overweight.

  13. Focal MMP-2 and MMP-9 Activity at the Blood-Brain Barrier Promotes Chemokine-Induced Leukocyte Migration

    Directory of Open Access Journals (Sweden)

    Jian Song

    2015-02-01

    Full Text Available Although chemokines are sufficient for chemotaxis of various cells, increasing evidence exists for their fine-tuning by selective proteolytic processing. Using a model of immune cell chemotaxis into the CNS (experimental autoimmune encephalomyelitis [EAE] that permits precise localization of immigrating leukocytes at the blood-brain barrier, we show that, whereas chemokines are required for leukocyte migration into the CNS, additional MMP-2/9 activities specifically at the border of the CNS parenchyma strongly enhance this transmigration process. Cytokines derived from infiltrating leukocytes regulate MMP-2/9 activity at the parenchymal border, which in turn promotes astrocyte secretion of chemokines and differentially modulates the activity of different chemokines at the CNS border, thereby promoting leukocyte migration out of the cuff. Hence, cytokines, chemokines, and cytokine-induced MMP-2/9 activity specifically at the inflammatory border collectively act to accelerate leukocyte chemotaxis across the parenchymal border.

  14. 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

    OpenAIRE

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

    2015-01-01

    Background 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. Methods 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...

  15. Barriers to Physical Activity in a Population-based Sample of Children and Adolescents in Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Roya Kelishadi

    2010-01-01

    Full Text Available Objectives: This study was conducted to explore the barriers to physical activity in a representative sample of Iranian children and adolescents.Methods: The studywas conducted in 2007 in urban and rural areas of Isfahan district in Iran. In the qualitative part,we used the grounded theory approach, including semi-structured focus group discussionsand in-depth interviews. The quantitative part comprised 600 randomly selected students.Results: The qualitative study included 34 school students (16 girls, 20 parents (11 mothers and 11 school staff. All students disclosed that studying was a priority.They pointed to lack of safe and easy-access place for physical activity and unsupportive family as the main barriers. Lack of self-confidence and low self-worth were the two other concepts developed in this context.Parents pointed to lack of safe and easy-access place for activity followed by the priority of studying. The concepts derived from interviews with school staff included unhealthy modeling of parents, priority of studying, and inadequate public know-ledge about how to integrate physical activity in routine daily life.The quantitative survey comprised 600 students including 286 (47.8% girls. Parents’ education level had inverse association with children’s physical activity level. Significant inverse associations of self-efficacy and physical activity levels were documented.Conclusions: Increasing the public knowledge about adopting physical activity habits in routinedaily life, informing the families and students about the benefits of physical activity to improvelearning, as well as providing safe places such as using the school facilities in non-school hoursshould be considered in planning effective preventive strategies and interventions.

  16. 高中英语教学中学生阅读理解的障碍因素及解决策略%Barriers and Strategies of Reading Comprehension in Senior High School English Teaching

    Institute of Scientific and Technical Information of China (English)

    杜铭花

    2016-01-01

    In this paper, we study the barriers and solutions of reading comprehension in senior high school English teaching. The article analyses the senior high school students English reading comprehension language barriers (lexical obstacles, syn-tactic disorders, textual barrier, genre barriers) and non language barriers (reading motivation, reading habits, cultural back-ground knowledge, intelligence factor), then separately according to the obstacle factors proposed for solutions, hope to be able to senior high school English reading comprehension teaching activities of science, to provide a theoretical reference.%本文研究的是高中英语教学中学生阅读理解的障碍因素和解决策略问题。文章首先分析了高中学生英语阅读理解中的语言障碍(词汇障碍、句法障碍、语篇障碍、体裁障碍)和非语言障碍(阅读动机、阅读习惯、文化背景知识、智力要素),然后又分别针对上述障碍性因素提出了有针对性的解决策略,希望能够为高中英语阅读理解教学活动的科学高效开展提供一定的理论参考。

  17. High-Pressure Plasma Deposition of a-C:H Films by Dielectric-Barrier Discharge

    Institute of Scientific and Technical Information of China (English)

    刘昌俊; 李阳; 杜海燕; 艾宝都

    2003-01-01

    The fabrication of a-C:H films from methane has been performed using dielectric-barrier discharges at atmospheric pressure. The effect of combined-feed gas, such as carbon dioxide,carbon monoxide or acetylene on the formation of a-C:H films has been investigated. It hasbeen demonstrated that the addition of carbon monoxide or acetylene into methane leads to aremarkable improvement in the fabrication of a-C:H films. The characterization of carbon filmobtained has been conducted using FT-IR, Raman and SEM.

  18. A Low-Symmetry Dysprosium Metallocene Single-Molecule Magnet with a High Anisotropy Barrier.

    Science.gov (United States)

    Pugh, Thomas; Chilton, Nicholas F; Layfield, Richard A

    2016-09-05

    The single-molecule magnet (SMM) properties of the isocarbonyl-ligated dysprosium metallocene [Cp*2 Dy{μ-(OC)2 FeCp}]2 (1Dy ), which contains a rhombus-shaped Dy2 Fe2 core, are described. Combining a strong axial [Cp*](-) ligand field with a weak equatorial field consisting of the isocarbonyl ligands leads to an anisotropy barrier of 662 cm(-1) in zero applied field. The dominant thermal relaxation pathways in 1Dy involves at least the fourth-excited Kramers doublet, thus demonstrating that prominent SMM behavior can be observed for dysprosium in low-symmetry environments.

  19. SPATIAL HETEROGENEITY OF PHOTOSYNTHETIC ACTIVITY WITHIN DISEASED CORALS FROM THE GREAT BARRIER REEF

    DEFF Research Database (Denmark)

    Roff, George; Ulstrup, Karin Elizabeth; Fine, Maoz

    2008-01-01

    Morphological diagnosis and descriptions of seven disease-like syndromes affecting scleractinian corals were characterized from the southern Great Barrier Reef (GBR). Chl a fluorescence of PSII was measured using an Imaging-PAM (pulse amplitude modulated) fluorometer, enabling visualization...... with white patch syndrome appeared to impact primarily on the symbiotic dinoflagellates, as evidenced by declines in minimum fluorescence (F0) and maximum quantum yield (Fv/Fm), with no indication of degeneration in the host tissues. Our results suggest that for the majority of coral syndromes from the GBR......, pathogenesis occurs in the host tissue, while the impact on the zooxanthellae populations residing in affected corals is minimal....

  20. Benefits and barriers to physical activity for individuals with disabilities: a social-relational model of disability perspective.

    Science.gov (United States)

    Martin, Jeffrey J

    2013-01-01

    To provide a qualitative overview of selected research on physical activity (PA) engagement by people with physical disabilities (1) from a social relational model perspective. Selected articles that exemplify some of the paradoxes, nuances, contrasting perspectives and complexities of the knowledge base in this area are discussed within a disability studies framework. PA is arguably more important for people with disabilities relative to people without disabilities although they are quite inactive. Individuals who are physically activity enjoy a range of benefits spanning physiological, emotional, cognitive and social categories. Unfortunately many people cannot enjoy the benefits of PA because of the many medical, psychological, social and environmental barriers they face making PA quite difficult. Rehabilitation professionals can provide a better standard of care to clients if they are aware of the benefits and barriers of PA. Rehabilitation professionals should understand behavior change strategies and their application to people with disabilities in order to help their clients initiate and maintain physical activity (PA). Rehabilitation professionals should be aware of how they might convey low PA expectations to their clients and simultaneously understand the unique challenges faced by their clients in attempting to incorporate PA into their lives on a regular basis. Rehabilitation professionals should be familiar with local disability friendly exercise facilities and adapted sport programs in order to steer their clients towards such opportunities.

  1. Validation and divergence of the activation energy barrier crossing transition at the AOT/lecithin reverse micellar interface.

    Science.gov (United States)

    Narayanan, S Shankara; Sinha, Sudarson Sekhar; Sarkar, Rupa; Pal, Samir Kumar

    2008-03-13

    In this report, the validity and divergence of the activation energy barrier crossing model for the bound to free type water transition at the interface of the AOT/lecithin mixed reverse micelle (RM) has been investigated for the first time in a wide range of temperatures by time-resolved solvation of fluorophores. Here, picosecond-resolved solvation dynamics of two fluorescent probes, ANS (1-anilino-8-naphthalenesulfonic acid, ammonium salt) and Coumarin 500 (C-500), in the mixed RM have been carefully examined at 293, 313, 328, and 343 K. Using the dynamic light scattering (DLS) technique, the size of the mixed RMs at different temperatures was found to have an insignificant change. The solvation process at the reverse micellar interface has been found to be the activation energy barrier crossing type, in which interface-bound type water molecules get converted into free type water molecules. The activation energies, Ea, calculated for ANS and C-500 are 7.4 and 3.9 kcal mol(-1), respectively, which are in good agreement with that obtained by molecular dynamics simulation studies. However, deviation from the regular Arrhenius type behavior was observed for ANS around 343 K, which has been attributed to the spatial heterogeneity of the probe environments. Time-resolved fluorescence anisotropy decay of the probes has indicated the existence of the dyes in a range of locations in RM. With the increase in temperature, the overall anisotropy decay becomes faster revealing the lability of the microenvironment at elevated temperatures.

  2. Basic and clinical research on the regulation of the intestinal barrier by Lactobacillus and its active protein components: a review with experience of one center.

    Science.gov (United States)

    Liu, Zhi-Hua; Kang, Liang; Wang, Jian-Ping

    2014-12-01

    Probiotics got protective effects on the intestinal barrier. Our present study is to review the basic and clinical progress on the regulation of the intestinal barrier by Lactobacillus and its active protein components, combing the study of our center. Our study have isolated the active component of micro integral membrane protein (MIMP) within the media place of the integral membrane protein of Lactobacillus plantarum, which was verified about the protective effects against the intestinal epithelial dysfunction. On the other hand, we also found the effects of perioperative use of probiotics in the prevention and treatment of postoperative intestinal barrier dysfunction, and reduction of the postoperative infective complications. In this review, we would like to report the founding of our center, involving in the basic and clinical research progress of regulation of intestinal barrier by Lactobacillus and its active protein component MIMP. Furthermore, we may also promote our following studies about the MIMP and its clinical verification.

  3. Histamine activates p38 MAP kinase and alters local lamellipodia dynamics, reducing endothelial barrier integrity and eliciting central movement of actin fibers.

    Science.gov (United States)

    Adderley, Shaquria P; Lawrence, Curtis; Madonia, Eyong; Olubadewo, Joseph O; Breslin, Jerome W

    2015-07-01

    The role of the actin cytoskeleton in endothelial barrier function has been debated for nearly four decades. Our previous investigation revealed spontaneous local lamellipodia in confluent endothelial monolayers that appear to increase overlap at intercellular junctions. We tested the hypothesis that the barrier-disrupting agent histamine would reduce local lamellipodia protrusions and investigated the potential involvement of p38 mitogen-activated protein (MAP) kinase activation and actin stress fiber formation. Confluent monolayers of human umbilical vein endothelial cells (HUVEC) expressing green fluorescent protein-actin were studied using time-lapse fluorescence microscopy. The protrusion and withdrawal characteristics of local lamellipodia were assessed before and after addition of histamine. Changes in barrier function were determined using electrical cell-substrate impedance sensing. Histamine initially decreased barrier function, lamellipodia protrusion frequency, and lamellipodia protrusion distance. A longer time for lamellipodia withdrawal and reduced withdrawal distance and velocity accompanied barrier recovery. After barrier recovery, a significant number of cortical fibers migrated centrally, eventually resembling actin stress fibers. The p38 MAP kinase inhibitor SB203580 attenuated the histamine-induced decreases in barrier function and lamellipodia protrusion frequency. SB203580 also inhibited the histamine-induced decreases in withdrawal distance and velocity, and the subsequent actin fiber migration. These data suggest that histamine can reduce local lamellipodia protrusion activity through activation of p38 MAP kinase. The findings also suggest that local lamellipodia have a role in maintaining endothelial barrier integrity. Furthermore, we provide evidence that actin stress fiber formation may be a reaction to, rather than a cause of, reduced endothelial barrier integrity.

  4. Activism on rifapentine pricing: removing cost barriers to improve the uptake of tuberculosis research innovations.

    Science.gov (United States)

    DeLuca, A; Frick, M; Lessem, E; Kanouse, J; Wegener, D; Mingote, L Ruiz

    2014-12-21

    As recent advances have been made in developing tools to fight tuberculosis (TB), there is also a trend towards increasing advocacy by the civil society for TB research and access. One recent successful effort to increase access to treatment options for TB involved a collaborative effort to identify the need for and barriers to the use of rifapentine (RPT) use in the United States. Survey responses confirmed the under-utilization of RPT: 82% of survey respondents selected cost as a significant or potential barrier to use. Survey results provided data to support a year-long advocacy campaign urging the drug company Sanofi to lower the price of RPT. This campaign was based on a common evidence base built in part by the stakeholders themselves. After multiple engagements with communities and providers, Sanofi US announced on 12 December 2013 that they would drop the price of RPT to US$32 per blister pack of 32 tablets for US public health programs. While further work remains to secure access to RPT in the United States and worldwide, the lowering of the price of RPT reflects the positive impact that collaborative advocacy can accomplish, and sets an example for other drug companies to follow.

  5. High-precision differential earthquake location in 3-D models: evidence for a rheological barrier controlling the microseismicity at the Irpinia fault zone in southern Apennines

    Science.gov (United States)

    De Landro, Grazia; Amoroso, Ortensia; Stabile, Tony Alfredo; Matrullo, Emanuela; Lomax, Antony; Zollo, Aldo

    2015-12-01

    A non-linear, global-search, probabilistic, double-difference earthquake location technique is illustrated. The main advantages of this method are the determination of comprehensive and complete solutions through the probability density function (PDF), the use of differential arrival times as data and the possibility to use a 3-D velocity model both for absolute and double-difference locations, all of which help to obtain accurate differential locations in structurally complex geological media. The joint use of this methodology and an accurate differential time data set allowed us to carry out a high-resolution, earthquake location analysis, which helps to characterize the active fault geometries in the studied region. We investigated the recent microseismicity occurring at the Campanian-Lucanian Apennines in the crustal volume embedding the fault system that generated the 1980 MS 6.9 earthquake in Irpinia. In order to obtain highly accurate seismicity locations, we applied the method to the P and S arrival time data set from 1312 events (ML models optimized for the area under study. Both manually refined and cross-correlation refined absolute arrival times have been used. The refined seismicity locations show that the events occur in a volume delimited by the faults activated during the 1980 MS 6.9 Irpinia earthquake on subparallel, predominantly normal faults. We find an abrupt interruption of the seismicity across an SW-NE oriented structural discontinuity corresponding to a contact zone between different rheology rock formations (carbonate platform and basin residuals). This `barrier' appears to be located in the area bounded by the fault segments activated during the first (0 s) and the second (18 s) rupture episodes of the 1980s Irpinia earthquake. We hypothesize that this geometrical barrier could have played a key role during the 1980 Irpinia event, and possibly controlled the delayed times of activation of the two rupture segments.

  6. High-pressure dielectric barrier discharge Xenon lamps generating short pulses of high-peak-power VUV radiation (172nm) with high pulse-to-pulse reproducibility.

    Science.gov (United States)

    Carman, Robert; Ward, Barry; Mildren, Richard; Kane, Deborah

    2003-10-01

    Dielectric barrier discharges (DBDs) are used to efficiently generate radiation in the ultraviolet and vacuum-ultraviolet spectral regions (88nm-350nm) by forming rare-gas and rare-gas halide excimers in a transient plasma. Usually, DBD lamps generate the light output quasi-continuously or in bursts with a high degree of stochastic or random variability in the instantaneous UV/VUV intensity. However, regular pulses of high-peak-power UV/VUV, with high pulse-to-pulse reproducibility, are of interest for applications in biology, surface treatment and cleaning, and time-resolved fluorescence spectroscopy. Such pulses can be generated from spatially homogeneous plasmas in a Xe DBD when the discharge is driven by uni-polar voltage pulses of short duration ( 100ns)^1. In the present study, we will report Xe DBD lamp performance and VUV output pulse characteristics for gas pressures up to 2.5bar and excitation conditions tailored for high-peak-power output. The experimental results will be compared to theoretical results from a detailed 1-D computer model of the spatio-temporal evolution of the plasma kinetics and Xe species population densities. ^1R.P.Mildren and R.J.Carman, J.Phys.D, 34, L1-L6, (2001)

  7. Perceived barriers and facilitators to increasing physical activity among people with musculoskeletal disorders: a qualitative investigation to inform intervention development

    Directory of Open Access Journals (Sweden)

    McPhail SM

    2014-12-01

    Full Text Available Steven M McPhail,1,2 Mandy Schippers,1,2 Alison L Marshall,1 Monique Waite,1,2 Pim Kuipers2,3 1Institute of Health and Biomedical Innovation and School of Public Health and Social Work, Queensland University of Technology, 2Centre for Functioning and Health Research, Metro South Health, 3Griffith Health Institute and School of Human Services and Social Work, Griffith University, Brisbane, QLD, Australia Purpose: Musculoskeletal conditions can impair people’s ability to undertake physical activity as they age. The purpose of this qualitative study was to investigate perceived barriers and facilitators to undertaking physical activity reported by patients accessing ambulatory hospital clinics for musculoskeletal disorders.Patients and methods: A questionnaire with open-ended items was administered to patients (n=217, 73.3% of 296 eligible from three clinics providing ambulatory services for nonsurgical treatment of musculoskeletal disorders. The survey included questions to capture the clinical and demographic characteristics of the sample. It also comprised two open-ended questions requiring qualitative responses. The first asked the participant to describe factors that made physical activity more difficult, and the second asked which factors made it easier for them to be physically active. Participants’ responses to the two open-ended questions were read, coded, and thematically analyzed independently by two researchers, with a third researcher available to arbitrate any unresolved disagreement. Results: The mean (standard deviation age of participants was 53 (15 years; n=113 (52.1% were male. A total of 112 (51.6% participants reported having three or more health conditions; n=140 (64.5% were classified as overweight or obese. Five overarching themes describing perceived barriers for undertaking physical activity were “health conditions”, “time restrictions”, “poor physical condition”, “emotional, social, and psychological

  8. Planning High-Risk High-Reward Activities.

    NARCIS (Netherlands)

    Casault, Sébastien

    2014-01-01

    This body of work addresses a gap in financial and economic theories related to assets that are typically associated with high uncertainty. Specifically, this thesis provides some foundational work towards a new way to quantify and explain how high-risk high-reward activities, such as exploration,

  9. Intrinsic activation barriers and coadsorption effects for reactions on metal surfaces: unified formalism within the UBI-QEP approach

    Science.gov (United States)

    Sellers, Harrell; Shustorovich, Evgeny

    2002-04-01

    We present a unified formulation of the unity bond index-quadratic exponential potential method (UBI-QEP, formerly known as the BOC-MP method) of determining metal surface reaction energetics. We give a unified treatment of enthalpies and intrinsic activation barriers for dissociation and recombination reactions as particular cases of disproportionation reactions. We discuss numerous examples of elementary reactions, which form a database for various reaction mechanisms. We start with the zero coverage limit and then focus on coadsorption effects on reaction energetics on monometallic and bimetallic (alloy) surfaces. We consider first the full treatment and then develop the “uniform scaling” approximation, with guidelines (and examples) where it may be efficiently used. We provide tables of numerical values covering most of practically important cases of coadsorption effects on fcc(1 1 1) and fcc(1 0 0) surfaces, which allow one to easily estimate coverage effects on activation barriers by simple interpolation. We also clarify the nature of basic UBI-QEP parameters and correlation between local and global adsorbate coverage. These developments, illustrated by various examples, make applications of the UBI-QEP method much easier for practitioners, particularly those who have no UBI-model computer program and make calculations by hand.

  10. The component content of active particles in a plasma-chemical reactor based on volume barrier discharge

    Science.gov (United States)

    Soloshenko, I. A.; Tsiolko, V. V.; Pogulay, S. S.; Terent'yeva, A. G.; Bazhenov, V. Yu; Shchedrin, A. I.; Ryabtsev, A. V.; Kuzmichev, A. I.

    2007-02-01

    In this paper the results of theoretical and experimental studies of the component content of active particles formed in a plasma-chemical reactor composed of a multiple-cell generator of active particles, based on volume barrier discharge, and a working chamber are presented. For calculation of the content of uncharged plasma components an approach is proposed which is based on averaging of the power introduced over the entire volume. Advantages of such an approach lie in an absence of fitting parameters, such as the dimensions of microdischarges, their surface density and rate of breakdown. The calculation and the experiment were accomplished with the use of dry air (20% relative humidity) as the plasma generating medium. Concentrations of O3, HNO3, HNO2, N2 O5 and NO3 were measured experimentally in the discharge volume and working chamber for the residence time of particles on a discharge of 0.3 s and more and discharge specific power of 1.5 W cm-3. It has been determined that the best agreement between the calculation and the experiment occurs at calculated gas medium temperatures in the discharge plasma of about 400-425 K, which correspond to the experimentally measured rotational temperature of nitrogen. In most cases the calculated concentrations of O3, HNO3, HNO2, N2O5 and NO3 for the barrier discharge and the working chamber are in fairly good agreement with the respective measured values.

  11. PAHs in the Great Barrier Reef Lagoon reach potentially toxic levels from coal port activities

    Science.gov (United States)

    Burns, Kathryn A.

    2014-05-01

    In view of the controversy over expanding the coastal coal ports bordering the Great Barrier Reef (GBR) Lagoon and the World Heritage Area, I re-evaluated the data published in Burns and Brinkman (2011). I used the US EPA procedures for the determination of Equilibrium Partitioning Sediment Benchmarks (ESBs) for the protection of benthic organisms (Hansen et al., 2003), and the new proposed ANZECC/ARMCANZ (2013) sediment quality guidelines (Simpson et al., 2013) and determined that the coastal sediments offshore from the Hay Point coal terminal and suspended sediments caught in sediment traps inshore and at the offshore coral reefs contained levels of PAHs that approach the estimates for toxicity to benthic and water column organisms. This result is discussed in relation to risks posed to the GBR ecosystem by the port practices and the imminent expansion of the Abbott Point, Hay Point and other coal terminals.

  12. Promoting Physical Activity for Students with Autism Spectrum Disorder: Barriers, Benefits, and Strategies for Success

    Science.gov (United States)

    Menear, Kristi S.; Neumeier, William H.

    2015-01-01

    Many students with autism spectrum disorder (ASD) fall short of the recommended physical activity levels and experience challenges in physical activity and physical education settings. This article reviews factors that can improve the physical activity statistics of students with ASD, outlines the researched benefits of physical activity for…

  13. Promoting Physical Activity for Students with Autism Spectrum Disorder: Barriers, Benefits, and Strategies for Success

    Science.gov (United States)

    Menear, Kristi S.; Neumeier, William H.

    2015-01-01

    Many students with autism spectrum disorder (ASD) fall short of the recommended physical activity levels and experience challenges in physical activity and physical education settings. This article reviews factors that can improve the physical activity statistics of students with ASD, outlines the researched benefits of physical activity for…

  14. Differential Effects of High-Protein Diets Derived from Soy and Casein on Blood-Brain Barrier Integrity in Wild-type Mice.

    Science.gov (United States)

    Snelson, Matthew; Mamo, John C L; Lam, Virginie; Giles, Corey; Takechi, Ryusuke

    2017-01-01

    A number of studies report that a diet high in protein influences cognitive performance, but the results are inconsistent. Studies demonstrated that protein from different food sources has differential effects on cognition. It is increasingly recognized that the integrity of cerebrovascular blood-brain barrier (BBB) is pivotal for central nervous system function. However, to date, no studies have reported the effects of high-protein diets on BBB integrity. Therefore, in this study, the effects of diets enriched in casein or soy protein on BBB permeability were investigated. Immunomicroscopy analyses of cerebral parenchymal immunoglobulin G extravasation indicated significant BBB disruption in the cortex of young adult mice maintained on high-casein diet for 12 weeks, while no signs of BBB dysfunction were observed in mice fed with control or high-soy protein diet. Moreover, cortical expression of glial fibrillary acidic protein (GFAP) was significantly greater in mice fed the high-casein diet compared to control mice, indicating heightened astrocyte activation, whereas mice maintained on a soy-enriched diet showed no increase of GFAP abundance. Plasma concentrations of homocysteine were markedly greater in mice maintained on a high-casein diet in comparison to control mice. Collectively, these findings suggest that a diet enriched in casein but not soy protein may induce astrocyte activation through exaggerated BBB permeability by increased plasma homocysteine. The outcomes indicate the differential effects of protein sources on BBB and neuroinflammation, which may provide an important implication for dietary guidelines for protein supplementation.

  15. Amine-containing film deposited in pulsed dielectric barrier discharge at a high pressure and its cell adsorption behaviours

    Institute of Scientific and Technical Information of China (English)

    Hu Wen-Juan; Xie Fen-Yan; Chen Qiang; Weng Jing

    2009-01-01

    With monomer allylamine, amine-containing functional films were prepared in alternative current pulsed dielectric barrier discharge (DBD) at a high pressure. This paper analyses in detail the film properties and structures, such as hydrophilicity, compounds and microstructures as well as amine density by the water contact angle, Fourier transform infrared spectroscopy, atomic force microscopy, and ultraviolet-visible measurement. The influence of discharge param-eters, in particular applied power, on amine density was investigated. As an application the cell adsorption behaviours on plasma polymerization films was performed in-vitro. The results show that at a high pressure pulsed DBD plasma can polymerize films with sufficient amine group on surface, through which the very efficient cell adsorption behaviours was demonstrated, and the high rate of cell proliferation was visualized.

  16. P-glycoprotein activity in the blood-brain barrier is affected by virus-induced neuroinflammation and antipsychotic treatment.

    Science.gov (United States)

    Doorduin, Janine; de Vries, Erik F J; Dierckx, Rudi A; Klein, Hans C

    2014-10-01

    A large percentage of schizophrenic patients respond poorly to antipsychotic treatment. This could be explained by inefficient drug transport across the blood-brain barrier due to P-glycoprotein mediated efflux. P-glycoprotein activity and expression in the blood-brain barrier can be affected by inflammation and pharmacotherapy. We therefore investigated the effect of herpes simplex virus type-1 (HSV-1) induced neuroinflammation and antipsychotic treatment on P-glycoprotein activity. Rats were inoculated with HSV-1 or PBS (control) on day 0 and treated with saline, clozapine or risperidone from day 0 up until day 4 post-inoculation. Positron emission tomography with the P-glycoprotein substrate [11C]verapamil was used to assess P-glycoprotein activity at day 6 post-inoculation. Disease symptoms in HSV-1 inoculated rats increased over time and were not significantly affected by treatment. The volume of distribution (VT) of [11C]verapamil was significantly lower (10-22%) in HSV-1 inoculated rats than in control rats. In addition, antipsychotic treatment significantly affected the VT of [11C]verapamil in all brain regions, although this effect was drug dependent. In fact, VT of [11C]verapamil was significantly increased (22-39%) in risperidone treated rats in most brain regions when compared to clozapine treated rats and in midbrain when compared to saline treated rats. No interaction between HSV-1 inoculation and antipsychotic treatment on VT of [11C]verapamil was found. In this study we demonstrated that HSV-1 induced neuroinflammation increased and risperidone treatment decreased P-glycoprotein activity. This finding is of importance for the understanding of treatment resistance in schizophrenia, and warrants further investigation of the underlying mechanism and the importance in clinical practice.

  17. Activation of VEGF/Flk-1-ERK Pathway Induced Blood-Brain Barrier Injury After Microwave Exposure.

    Science.gov (United States)

    Wang, Li-Feng; Li, Xiang; Gao, Ya-Bing; Wang, Shui-Ming; Zhao, Li; Dong, Ji; Yao, Bin-Wei; Xu, Xin-Ping; Chang, Gong-Min; Zhou, Hong-Mei; Hu, Xiang-Jun; Peng, Rui-Yun

    2015-08-01

    Microwaves have been suggested to induce neuronal injury and increase permeability of the blood-brain barrier (BBB), but the mechanism remains unknown. The role of the vascular endothelial growth factor (VEGF)/Flk-1-Raf/MAPK kinase (MEK)/extracellular-regulated protein kinase (ERK) pathway in structural and functional injury of the blood-brain barrier (BBB) following microwave exposure was examined. An in vitro BBB model composed of the ECV304 cell line and primary rat cerebral astrocytes was exposed to microwave radiation (50 mW/cm(2), 5 min). The structure was observed by scanning electron microscopy (SEM) and the permeability was assessed by measuring transendothelial electrical resistance (TEER) and horseradish peroxidase (HRP) transmission. Activity and expression of VEGF/Flk-1-ERK pathway components and occludin also were examined. Our results showed that microwave radiation caused intercellular tight junctions to broaden and fracture with decreased TEER values and increased HRP permeability. After microwave exposure, activation of the VEGF/Flk-1-ERK pathway and Tyr phosphorylation of occludin were observed, along with down-regulated expression and interaction of occludin with zonula occludens-1 (ZO-1). After Flk-1 (SU5416) and MEK1/2 (U0126) inhibitors were used, the structure and function of the BBB were recovered. The increase in expression of ERK signal transduction molecules was muted, while the expression and the activity of occludin were accelerated, as well as the interactions of occludin with p-ERK and ZO-1 following microwave radiation. Thus, microwave radiation may induce BBB damage by activating the VEGF/Flk-1-ERK pathway, enhancing Tyr phosphorylation of occludin, while partially inhibiting expression and interaction of occludin with ZO-1.

  18. Perceived Barriers to Teaching Movement and Physical Activity to Kindergarteners in Ghana

    Science.gov (United States)

    Sofo, Seidu; Asola, Eugene F.

    2015-01-01

    Regular participation in physical activity can improve students' health and academic achievement. It is important to develop a positive attitude toward participation in regular physical activity early in life. Thus, an understanding of factors that affect the activity levels of young children is essential. Therefore, the purpose of the study was…

  19. Facilitators and Barriers to Physical Activity as Perceived by Older Adults with Intellectual Disability

    Science.gov (United States)

    van Schijndel-Speet, Marieke; Evenhuis, Heleen M.; van Wijck, Ruud; van Empelen, Pepijn; Echteld, Michael A.

    2014-01-01

    Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID for specific physical activities, and to gain…

  20. A viable circulating tumor cell isolation device with high retrieval efficiency using a reversibly deformable membrane barrier

    Science.gov (United States)

    Kim, Yoonji; Bu, Jiyoon; Cho, Young-Ho; Son, Il Tae; Kang, Sung-Bum

    2017-02-01

    Circulating tumor cells (CTCs) contain prognostic information of the tumor, since they shed from the primary tumor and invade into the bloodstream. Therefore, the viable isolation is necessary for a consequent analysis of CTCs. Here, we present a device for the viable isolation and efficient retrieval of CTCs using slanted slot filters, formed by a reversibly deformable membrane barrier. Conventional filters have difficulties in retrieving captured cells, since they easily clog the slots. Moreover, large stress concentration at the sharp edges of squared slots, causes cell lysis. In contrast, the present device shows over 94% of high retrieval efficiency, since the slots can be opened simply by relieving the pressure. Furthermore, the inflated membrane barrier naturally forms the slanted slots, thus reducing the cell damage. By using cancer cell lines, we verified that the present device successfully isolate targeted cells, even at an extremely low concentrations (~10 cells/0.1 ml). In the clinical study, 85.7% of patients initially showed CTC positive while the numbers generally decreased after the surgery. We have also proved that the number of CTCs were highly correlated with tumour invasiveness. Therefore, the present device has potential for use in cancer diagnosis, surgical validation, and invasiveness analysis.

  1. High effective silica fume alkali activator

    Indian Academy of Sciences (India)

    Vladimír Živica

    2004-04-01

    Growing demands on the engineering properties of cement based materials and the urgency to decrease unsuitable ecologic impact of Portland cement manufacturing represent significant motivation for the development of new cement corresponding to these aspects. One category represents prospective alkali activated cements. A significant factor influencing their properties is alkali activator used. In this paper we present a new high effective alkali activator prepared from silica fume and its effectiveness. According to the results obtained this activator seems to be more effective than currently used activators like natrium hydroxide, natrium carbonate, and water glass.

  2. Low-Power Miniaturized Helium Dielectric Barrier Discharge Photoionization Detectors for Highly Sensitive Vapor Detection.

    Science.gov (United States)

    Zhu, Hongbo; Zhou, Menglian; Lee, Jiwon; Nidetz, Robert; Kurabayashi, Katsuo; Fan, Xudong

    2016-09-06

    This paper presents the design, fabrication, and characterization of a microhelium dielectric barrier discharge photoionization detector (μHDBD-PID) on chip with dimensions of only ∼15 mm × ∼10 mm × ∼0.7 mm and weight of only ∼0.25 g. It offers low power consumption (4 orders of magnitude), and maintenance-free operation. Furthermore, the μHDBD-PID can be driven with a miniaturized (∼5 cm × ∼2.5 cm × ∼2.5 cm), light (22 g), and low cost (∼$2) power supply with only 1.5 VDC input. The dependence of the μHDBD-PID performance on bias voltage, auxiliary helium flow rate, carrier gas flow rate, and temperature was also systematically investigated. Finally, the μHDBD-PID was employed to detect permanent gases and a sublist of the EPA 8260 standard reagents that include 51 analytes. The μHDBD-PID developed here can have a broad range of applications in portable and microgas chromatography systems for in situ, real-time, and sensitive gas analysis.

  3. Temperature-dependent Schottky barrier in high-performance organic solar cells

    Science.gov (United States)

    Li, Hui; He, Dan; Zhou, Qing; Mao, Peng; Cao, Jiamin; Ding, Liming; Wang, Jizheng

    2017-01-01

    Organic solar cells (OSCs) have attracted great attention in the past 30 years, and the power conversion efficiency (PCE) now reaches around 10%, largely owning to the rapid material developments. Meanwhile with the progress in the device performance, more and more interests are turning to understanding the fundamental physics inside the OSCs. In the conventional bulk-heterojunction architecture, only recently it is realized that the blend/cathode Schottky junction serves as the fundamental diode for the photovoltaic function. However, few researches have focused on such junctions, and their physical properties are far from being well-understood. In this paper based on PThBDTP:PC71BM blend, we fabricated OSCs with PCE exceeding 10%, and investigated temperature-dependent behaviors of the junction diodes by various characterization including current-voltage, capacitance-voltage and impedance measurements between 70 to 290 K. We found the Schottky barrier height exhibits large inhomogeneity, which can be described by two sets of Gaussian distributions.

  4. Plasma activated dissociation of CO2 studied in a dielectric barrier discharge

    Science.gov (United States)

    Engeln, Richard; Brehmer, Florian; Welzel, Stefan; Klarenaar, Bart; van de Sanden, Richard; Tu/E Collaboration; Afs Gmbh Collaboration; Differ Collaboration

    2014-10-01

    The ever-increasing emission of carbon dioxide into the atmosphere as well as the intermittency problem of electricity produced by renewable energy sources are challenges that urgently need to be addressed. An approach addressing both issues at the same time is converting CO2 to a fuel using plasma driven by electricity from renewable sources. We will present in this contribution the results of a study on the conversion of CO2 to CO in a dielectric barrier discharge in pure CO2 at pressures up to 1000 mbar: FTIR absorption and Raman spectroscopy were applied to measure CO number densities and gas temperatures as function of the specific injected energy. CO densities with a maximum at 1018 cm-3 (mixing ratio of 4.4%) at 46 kJ/sl, energy efficiencies in the range of a few percent and gas temperatures up to 550 K were detected. The CO production is directly linked with the total number of transferred charges q during the residence time tres of CO2 molecules. Also ozone has been detected with a maximum mixing ratio of 0.075%.

  5. Active species delivered by dielectric barrier discharge filaments to bacteria biofilms on the surface of apple

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, He; Liu, Xin; Lu, Xinpei [State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, WuHan, HuBei (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Dawei, E-mail: ldw636@msn.com [State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, WuHan, HuBei (China); IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an (China)

    2016-07-15

    The atmospheric pressure non-equilibrium plasma has shown a significant potential as a novel food decontamination technology. In this paper, we report a computational study of the intersection of negative streamer produced by air dielectric barrier discharge with bacteria biofilm on an apple surface. The structure, conductivities, and permittivities of bacteria biofilm have been considered in the Poisson's equations and transportation equations of charge and neutral species to realize self-consistent transportation of plasma between electrode and charging surfaces of apple. We find that the ionization near the biofilm facilitates the propagation of negative streamer when the streamer head is 1 mm from the biofilm. The structure of the biofilm results in the non-uniform distribution of ROS and RNS captured by flux and time fluence of these reactive species. The mean free path of charged species in μm scale permitted the plasma penetrate into the cavity of the biofilm, therefore, although the density of ROS and RNS decrease by 6–7 order of magnitude, the diffusion results in the uniform distribution of ROS and RNS inside the cavity during the pulse off period.

  6. Active species delivered by dielectric barrier discharge filaments to bacteria biofilms on the surface of apple

    Science.gov (United States)

    Cheng, He; Liu, Xin; Lu, Xinpei; Liu, Dawei

    2016-07-01

    The atmospheric pressure non-equilibrium plasma has shown a significant potential as a novel food decontamination technology. In this paper, we report a computational study of the intersection of negative streamer produced by air dielectric barrier discharge with bacteria biofilm on an apple surface. The structure, conductivities, and permittivities of bacteria biofilm have been considered in the Poisson's equations and transportation equations of charge and neutral species to realize self-consistent transportation of plasma between electrode and charging surfaces of apple. We find that the ionization near the biofilm facilitates the propagation of negative streamer when the streamer head is 1 mm from the biofilm. The structure of the biofilm results in the non-uniform distribution of ROS and RNS captured by flux and time fluence of these reactive species. The mean free path of charged species in μm scale permitted the plasma penetrate into the cavity of the biofilm, therefore, although the density of ROS and RNS decrease by 6-7 order of magnitude, the diffusion results in the uniform distribution of ROS and RNS inside the cavity during the pulse off period.

  7. Arhgap17, a RhoGTPase activating protein, regulates mucosal and epithelial barrier function in the mouse colon

    Science.gov (United States)

    Lee, So-young; Kim, Hwain; Kim, Kyoungmi; Lee, Hyunji; Lee, Seungbok; Lee, Daekee

    2016-01-01

    Coordinated regulation of the actin cytoskeleton by the Rho GTPase family is required for the maintenance of polarity in epithelial cells as well as for their proliferation and migration. A RhoGTPase-activating protein 17 (Arhgap17) is known to be involved in multiple cellular processes in vitro, including the maintenance of tight junctions and vesicle trafficking. However, the function of Arhgap17 has not been studied in the physiological context. Here, we generated Arhgap17-deficient mice and examined the effect in the epithelial and mucosal barriers of the intestine. Reporter staining revealed that Arhgap17 expression is limited to the luminal epithelium of intestine. Arhgap17-deficient mice show an increased paracellular permeability and aberrant localization of the apical junction complex in the luminal epithelium, but do not develop spontaneous colitis. The inner mucus layer is impervious to the enteric bacteria irrespective of Tff3 downregulation in the Arhgap17-deficient mice. Interestingly however, treatment with dextran sulfate sodium (DSS) causes an increased accumulation of DSS and TNF production in intraluminal cells and rapid destruction of the inner mucus layer, resulting in increased severity of colitis in mutant mice. Overall, these data reveal that Arhgap17 has a novel function in regulating transcellular transport and maintaining integrity of intestinal barriers. PMID:27229483

  8. Arhgap17, a RhoGTPase activating protein, regulates mucosal and epithelial barrier function in the mouse colon.

    Science.gov (United States)

    Lee, So-Young; Kim, Hwain; Kim, Kyoungmi; Lee, Hyunji; Lee, Seungbok; Lee, Daekee

    2016-01-01

    Coordinated regulation of the actin cytoskeleton by the Rho GTPase family is required for the maintenance of polarity in epithelial cells as well as for their proliferation and migration. A RhoGTPase-activating protein 17 (Arhgap17) is known to be involved in multiple cellular processes in vitro, including the maintenance of tight junctions and vesicle trafficking. However, the function of Arhgap17 has not been studied in the physiological context. Here, we generated Arhgap17-deficient mice and examined the effect in the epithelial and mucosal barriers of the intestine. Reporter staining revealed that Arhgap17 expression is limited to the luminal epithelium of intestine. Arhgap17-deficient mice show an increased paracellular permeability and aberrant localization of the apical junction complex in the luminal epithelium, but do not develop spontaneous colitis. The inner mucus layer is impervious to the enteric bacteria irrespective of Tff3 downregulation in the Arhgap17-deficient mice. Interestingly however, treatment with dextran sulfate sodium (DSS) causes an increased accumulation of DSS and TNF production in intraluminal cells and rapid destruction of the inner mucus layer, resulting in increased severity of colitis in mutant mice. Overall, these data reveal that Arhgap17 has a novel function in regulating transcellular transport and maintaining integrity of intestinal barriers.

  9. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation.

    Directory of Open Access Journals (Sweden)

    Dorien M Zelle

    Full Text Available Physical activity (PA and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal transplant recipients (RTR meet the PA guidelines. Identification of barriers to regular PA is important to identify targets for intervention to improve PA levels after renal transplantation. We investigated fear of movement and physical self-efficacy as barriers to PA in RTR.RTR were investigated between 2001-2003. The Tampa Score of Kinesiophobia-Dutch Version (TSK-11 was used to assess fear of movement. Physical self-efficacy was measured with the LIVAS-scale. PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire.A total of 487 RTR (age 51±12 years, 55% men were studied. Median score [interquartile range] on TSK-11 was 22 [17-26]. Low physical self-efficacy (Exp B:0.41[0.31-0.54], p<0.001 and history of myocardial infarction, transient ischemic attack and cerebrovascular accident (Exp B:1.30[1.03-1.63],p = 0.03 were independent determinants for fear of movement. Fear of movement was associated with lower daily PA, occupational, sports and leisure time PA. Mediation-analysis showed that a large part (73% of the effect of fear of movement on PA was explained by low physical self-efficacy.This study was the first to examine fear of movement and self-efficacy in relation to PA in RTR. Fear of movement was associated with a low PA level, and the larger part of this relation was mediated by low physical self-efficacy. Both fear of movement and physical self-efficacy level are important targets for intervention during rehabilitation after renal transplantation.

  10. Fear of Movement and Low Self-Efficacy Are Important Barriers in Physical Activity after Renal Transplantation

    Science.gov (United States)

    Zelle, Dorien M.; Corpeleijn, Eva; Klaassen, Gerald; Schutte, Elise; Navis, Gerjan; Bakker, Stephan J. L.

    2016-01-01

    Background Physical activity (PA) and exercise are commonly used as preventive measures for cardiovascular disease in the general population, and could be effective in the management of post-transplantation cardiovascular risk. PA levels are low after renal transplantation and very few renal transplant recipients (RTR) meet the PA guidelines. Identification of barriers to regular PA is important to identify targets for intervention to improve PA levels after renal transplantation. We investigated fear of movement and physical self-efficacy as barriers to PA in RTR. Methods RTR were investigated between 2001–2003. The Tampa Score of Kinesiophobia–Dutch Version (TSK-11) was used to assess fear of movement. Physical self-efficacy was measured with the LIVAS-scale. PA was assessed using validated questionnaires (Tecumseh Occupational Activity Questionnaire and the Minnesota Leisure Time Physical Activity Questionnaire). Results A total of 487 RTR (age 51±12 years, 55% men) were studied. Median score [interquartile range] on TSK-11 was 22 [17–26]. Low physical self-efficacy (Exp B:0.41[0.31–0.54], p<0.001) and history of myocardial infarction, transient ischemic attack and cerebrovascular accident (Exp B:1.30[1.03–1.63],p = 0.03) were independent determinants for fear of movement. Fear of movement was associated with lower daily PA, occupational, sports and leisure time PA. Mediation-analysis showed that a large part (73%) of the effect of fear of movement on PA was explained by low physical self-efficacy. Conclusions This study was the first to examine fear of movement and self-efficacy in relation to PA in RTR. Fear of movement was associated with a low PA level, and the larger part of this relation was mediated by low physical self-efficacy. Both fear of movement and physical self-efficacy level are important targets for intervention during rehabilitation after renal transplantation. PMID:26844883

  11. [Barriers and facilitators for physical activity during pregnancy and postpartum in women living in poverty of Mexico].

    Science.gov (United States)

    Lozada-Tequeanes, Ana Lilia; Campero-Cuenca, María de Lourdes Eugenia; Hernández, Bernardo; Rubalcava-Peñafiel, Luis; Neufeld, Lynnette Marie

    2015-01-01

    To explore perceptions of healthcare providers and beneficiaries of Oportunidades program on physical activity during pregnancy and post-partum; and identify current reported practices related to counseling on physical activity in the primary healthcare services in Mexico. A mixed methods approach was used which is part of a nutrition intervention of the Oportunidades program. Qualitative information was collected through interviews (50=women; 34=providers) and quantitative information was collected by questionnaires (n=88 women; n=64 provider; n=111 observations during consultation). The main barriers were: a) individual (lack of time and social support to childcare); b) sociocultural (gender bias derived from peer groups or family and lack of instructors), and c) environmental (lack of safe and adequate physical places). Only 38% of beneficiary women reported having been counseled on physical activity vs 63.4% of providers who reported having counseled on physical activity (p=0.002). There is a need to train healthcare providers and to promote physical activity during pregnancy and post-partum for reducing associated biases.

  12. Electrically stimulated high-frequency replicas of a resonant current in GaAs/AlAs resonant-tunneling double-barrier THz nanostructures

    Science.gov (United States)

    Aleksanyan, A. A.; Karuzskii, A. L.; Kazakov, I. P.; Mityagin, Yu. A.; Murzin, V. N.; Perestoronin, A. V.; Shmelev, S. S.; Tskhovrebov, A. M.

    2016-12-01

    The periodical-in-voltage features of the negative differential conductance (NDC) region in the current-voltage characteristics of a high-quality GaAs/AlAs terahertz resonant-tunneling diode have been detected. The found oscillations are considered taking account of the LO-phonon excitation stimulated by tunneling of electrons through the quantum active region in the resonance nanostructure where an undoped quantum well layer is sandwiched between two undoped barrier layers. Rearrangements in the I-V characteristics of the resonant-tunneling diode as a consequence of the topological transformation of a measurement circuit from the circuit with the series resistance Rs to the circuit with the shunt Rp have been experimentally studied and analyzed. The revealed substantial changes in the current-voltage characteristics of the resonant-tunneling diode are discussed schematically using Kirchhoff's voltage law.

  13. Application of a Barrier Filter at a High Purity Synthetic Graphite Plant, CRADA 99-F035, Final Report

    Energy Technology Data Exchange (ETDEWEB)

    National Energy Technology Laboratory

    2000-08-31

    Superior Graphite Company and the US Department of Energy have entered into a Cooperative Research and Development Agreement (CRADA) to study the application of ceramic barrier filters at its Hopkinsville, Kentucky graphite plant. Superior Graphite Company is a worldwide leader in the application of advanced thermal processing technology to produce high purity graphite and carbons. The objective of the CRADA is to determine the technical and economic feasibility of incorporating the use of high-temperature filters to improve the performance of the offgas treatment system. A conceptual design was developed incorporating the ceramic filters into the offgas treatment system to be used for the development of a capital cost estimate and economic feasibility assessment of this technology for improving particulate removal. This CRADA is a joint effort of Superior Graphite Company, Parsons Infrastructure and Technology Group, and the National Energy Technology Laboratory (NETL) of the US Department of Energy (DOE).

  14. Highly organic natural media as permeable reactive barriers: TCE partitioning and anaerobic degradation profile in eucalyptus mulch and compost.

    Science.gov (United States)

    Öztürk, Zuhal; Tansel, Berrin; Katsenovich, Yelena; Sukop, Michael; Laha, Shonali

    2012-10-01

    Batch and column experiments were conducted with eucalyptus mulch and commercial compost to evaluate suitability of highly organic natural media to support anaerobic decomposition of trichloroethylene (TCE) in groundwater. Experimental data for TCE and its dechlorination byproducts were analyzed with Hydrus-1D model to estimate the partitioning and kinetic parameters for the sequential dechlorination reactions during TCE decomposition. The highly organic natural media allowed development of a bioactive zone capable of decomposing TCE under anaerobic conditions. The first order TCE biodecomposition reaction rates were 0.23 and 1.2d(-1) in eucalyptus mulch and compost media, respectively. The retardation factors in the eucalyptus mulch and compost columns for TCE were 35 and 301, respectively. The results showed that natural organic soil amendments can effectively support the anaerobic bioactive zone for remediation of TCE contaminated groundwater. The natural organic media are effective environmentally sustainable materials for use in permeable reactive barriers.

  15. Microstructural characterization of electron beam-physical vapor deposition thermal barrier coatings through high-resolution computed microtomography

    Science.gov (United States)

    Kulkarni, Anand; Herman, Herbert; Decarlo, Francesco; Subramanian, Ramesh

    2004-07-01

    Thermal barrier coatings (TBCs), deposited using the electron beam-physical vapor deposition (EB-PVD) process, comprise a unique architecture of porosity capable of bridging the technological gap between insulation/life extension and prime reliance. The TBC microstructures consist of columnar structure, nucleated via vapor condensation, along with a high degree of intercolumnar porosity, thus providing enhanced stress relief on thermomechanical loading and also accommodating misfit stresses resulting from CTE mismatch. In this article, we report the characterization of these coatings using high-resolution synchrotron-based X-ray computed microtomography (XMT) at 1.3- µm resolution. Experiments focused on quantitative characterization/visualization of imperfections in these coatings and on the relative changes in microstructural features upon isothermal annealing. The influence of time/temperature of exposure was investigated and the results were correlated with elastic modulus.

  16. High-performance room-temperature hydrogen sensors based on combined effects of Pd decoration and Schottky barriers

    Science.gov (United States)

    Liu, Bin; Cai, Daoping; Liu, Yuan; Li, Han; Weng, Chao; Zeng, Guoshi; Li, Qiuhong; Wang, Taihong

    2013-02-01

    A new hydrogen sensor was fabricated by coating a Pd-decorated In2O3 film on Au electrodes. In response to 1 vol% H2 at room temperature, an ultra high sensitivity of 4.6 × 107 was achieved. But after an annealing treatment in vacuum, its sensitivity degenerated by 4 orders of magnitude. In addition, the response time and recovery time were also extended from 28 s and 32 s to 242 s and 108 s, respectively. It was found from contrast experiments that Pd decoration was essential to make the sensor work at room temperature and Schottky barriers played a vital role in enhancing the sensor's performance. The methodology demonstrated in this paper shows that a combination of novel sensing materials and Schottky contact is an effective approach to design high-performance gas sensors.A new hydrogen sensor was fabricated by coating a Pd-decorated In2O3 film on Au electrodes. In response to 1 vol% H2 at room temperature, an ultra high sensitivity of 4.6 × 107 was achieved. But after an annealing treatment in vacuum, its sensitivity degenerated by 4 orders of magnitude. In addition, the response time and recovery time were also extended from 28 s and 32 s to 242 s and 108 s, respectively. It was found from contrast experiments that Pd decoration was essential to make the sensor work at room temperature and Schottky barriers played a vital role in enhancing the sensor's performance. The methodology demonstrated in this paper shows that a combination of novel sensing materials and Schottky contact is an effective approach to design high-performance gas sensors. Electronic supplementary information (ESI) available: Hydrogen sensing test details and detailed material characterizations before and after the annealing treatment at 120 °C. See DOI: 10.1039/c3nr33872j

  17. Facilitators and Barriers to Physical Activity as Perceived by Older Adults With Intellectual Disability

    NARCIS (Netherlands)

    van Schijndel-Speet, Marieke; Evenhuis, Heleen M.; van Wijck, Ruud; van Empelen, Pepijn; Echteld, Michael A.

    2014-01-01

    Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID

  18. Facilitators and barriers to physical activity as perceived by older adults with intellectual disability

    NARCIS (Netherlands)

    Schijndel-Speet, M. van; Evenhuis, H.M.; Wijck, R. van; Empelen, P. van; Echteld, M.A.

    2014-01-01

    Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID

  19. Facilitators and Barriers to Physical Activity as Perceived by Older Adults With Intellectual Disability

    NARCIS (Netherlands)

    van Schijndel-Speet, Marieke; Evenhuis, Heleen M.; van Wijck, Ruud; van Empelen, Pepijn; Echteld, Michael A.

    Older people with intellectual disability (ID) are characterized by low physical activity (PA) levels. PA is important for reducing health risks and maintaining adequate fitness levels for performing activities of daily living. The aim of this study was to explore preferences of older adults with ID

  20. High-temperature stability of yttria-stabilized zirconia thermal barrier coating on niobium alloy—C-103

    Indian Academy of Sciences (India)

    S S Panwar; T Umasankar Patro; K Balasubramanian; B Venkataraman

    2016-02-01

    Thermal barrier coatings (TBCs) of yttria-stabilized zirconia (YSZ) of different thicknesses with an intermediate bond coat were deposited on C-103 Nb alloy using the air plasma spraying technique. The coatings were subjected to rapid infra-red (IR) heating ($\\sim$25°C s$^{−1}$) up to $\\sim$1250°C and exposed up to 100 s at this temperature with heat flux varying from 55 to 61 Wcm$^{−2}$. The TBCs were found to be stable and intact after the heat treatment. In contrast, at the same conditions, the uncoated C-103 alloy specimen showed extensive oxidation followed by weight loss due to spallation. A maximum temperature drop of $\\sim$200°C was observed on the opposite side of the coated alloy with 600 $\\mu$m YSZ coat; as against negligible temperature drop in case of bare alloy specimen. The temperature drop was found to increase with the coating thickness of YSZ. The coatings before and after IR heating were investigated by scanning electron microscopy, X-ray diffraction, electron probe microanalysis, microhardness and residual stress measurements in order to understand the effect of thermal shock on the properties of the TBC. On account of these high-temperature properties, YSZ coating along with the bond coat is expected to find potential thermal barrier coating system on niobium alloys for supersonic vehicles.

  1. Research on ZrO2 Thermal Barrier Coatings Modified by High-Intensity Pulsed Ion Beam

    Institute of Scientific and Technical Information of China (English)

    WV Di; LIU Chen; ZHU Xiao-Peng; LEI Ming-Kai

    2008-01-01

    @@ We report a modification method for ZrO2 thermal barrier coatings (TBCs) by high-intensity pulsed ion beam (HIPIB) irradiation. Based on the temporal and spatial distribution models of the ion beam density detected by Faraday cup in the chamber and the ions accelerating voltage, the energy deposition of the beam ions in ZrO2 is calculated by Monte Carlo method. Taking this time-dependent nonlinear deposited energy as the source term of two-dimensional thermal conduction equation, we obtain the temporal and spatial ablation process of ZrO2 thermal barrier coatings during a pulse time. The top-layer TBC material in thickness of about 0.2μm is ablated by vaporization and the coating in thickness of 1 μm is melted after one shot at the ion current density of 200 A/cm2. This calculation is in reasonable agreement with those measured by HIPIB irradiation experiments.The melted top coat becoming a dense modification layer due to HIPIB irradiation seals the gaps among ZrO2crystal clusters, and hence barrels the direct tunnel of oxygen.

  2. Pregnane X Receptor Activation Attenuates Inflammation-Associated Intestinal Epithelial Barrier Dysfunction by Inhibiting Cytokine-Induced Myosin Light-Chain Kinase Expression and c-Jun N-Terminal Kinase 1/2 Activation.

    Science.gov (United States)

    Garg, Aditya; Zhao, Angela; Erickson, Sarah L; Mukherjee, Subhajit; Lau, Aik Jiang; Alston, Laurie; Chang, Thomas K H; Mani, Sridhar; Hirota, Simon A

    2016-10-01

    The inflammatory bowel diseases (IBDs) are chronic inflammatory disorders with a complex etiology. IBD is thought to arise in genetically susceptible individuals in the context of aberrant interactions with the intestinal microbiota and other environmental risk factors. Recently, the pregnane X receptor (PXR) was identified as a sensor for microbial metabolites, whose activation can regulate the intestinal epithelial barrier. Mutations in NR1I2, the gene that encodes the PXR, have been linked to IBD, and in animal models, PXR deletion leads to barrier dysfunction. In the current study, we sought to assess the mechanism(s) through which the PXR regulates barrier function during inflammation. In Caco-2 intestinal epithelial cell monolayers, tumor necrosis factor-α/interferon-γ exposure disrupted the barrier and triggered zonula occludens-1 relocalization, increased expression of myosin light-chain kinase (MLCK), and activation of c-Jun N-terminal kinase 1/2 (JNK1/2). Activation of the PXR [rifaximin and [[3,5-Bis(1,1-dimethylethyl)-4-hydroxyphenyl]ethenylidene]bis-phosphonic acid tetraethyl ester (SR12813); 10 μM] protected the barrier, an effect that was associated with attenuated MLCK expression and JNK1/2 activation. In vivo, activation of the PXR [pregnenolone 16α-carbonitrile (PCN)] attenuated barrier disruption induced by toll-like receptor 4 activation in wild-type, but not Pxr-/-, mice. Furthermore, PCN treatment protected the barrier in the dextran-sulfate sodium model of experimental colitis, an effect that was associated with reduced expression of mucosal MLCK and phosphorylated JNK1/2. Together, our data suggest that the PXR regulates the intestinal epithelial barrier during inflammation by modulating cytokine-induced MLCK expression and JNK1/2 activation. Thus, targeting the PXR may prove beneficial for the treatment of inflammation-associated barrier disruption in the context of IBD.

  3. Thermochemistry and Reaction Barriers for the Formation of Levoglucosenone from Cellobiose

    Energy Technology Data Exchange (ETDEWEB)

    Assary, Rajeev S.; Curtiss, Larry A.

    2012-02-06

    Cellobiose jumps the barrier: High-level quantum mechanical studies show that the ether bond cleavage in cellobiose occurs through internal hydrogen transfer in the gas phase and that the activation energy required is similar to that required for activating cellulose. The reaction barriers are computed for various pathways for the formation of levoglucosenone from levoglucosan, and the most likely pathway requires a relatively low activation barrier compared to that for the activation of cellobiose.

  4. Thermochemistry and reaction barriers for the formation of levoglucosenone from cellobiose.

    Energy Technology Data Exchange (ETDEWEB)

    Assary, R. S.; Curtiss, L. A. (Center for Nanoscale Materials); ( MSD); (Northwestern Univ.)

    2012-02-06

    Cellobiose jumps the barrier: High-level quantum mechanical studies show that the ether bond cleavage in cellobiose occurs through internal hydrogen transfer in the gas phase and that the activation energy required is similar to that required for activating cellulose. The reaction barriers are computed for various pathways for the formation of levoglucosenone from levoglucosan, and the most likely pathway requires a relatively low activation barrier compared to that for the activation of cellobiose.

  5. Identifying Barriers, Perceptions and Motivations Related to Healthy Eating and Physical Activity among 6th to 8th Grade, Rural, Limited-Resource Adolescents

    Science.gov (United States)

    Kumar, Janavi; Adhikari, Koushik; Li, Yijing; Lindshield, Erika; Muturi, Nancy; Kidd, Tandalayo

    2016-01-01

    Purpose: The purpose of this paper is to enable community members to discuss their perceptions of eating habits and physical activity in relation to sixth, seventh, and eighth graders, and reveal facilitators and barriers to healthy eating behavior and physical activity engagement. Design/methodology/approach: Nine focus groups, which included six…

  6. Identifying Barriers, Perceptions and Motivations Related to Healthy Eating and Physical Activity among 6th to 8th Grade, Rural, Limited-Resource Adolescents

    Science.gov (United States)

    Kumar, Janavi; Adhikari, Koushik; Li, Yijing; Lindshield, Erika; Muturi, Nancy; Kidd, Tandalayo

    2016-01-01

    Purpose: The purpose of this paper is to enable community members to discuss their perceptions of eating habits and physical activity in relation to sixth, seventh, and eighth graders, and reveal facilitators and barriers to healthy eating behavior and physical activity engagement. Design/methodology/approach: Nine focus groups, which included six…

  7. Research Progress of High-Barrier Packaging Materials%高阻隔包装材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘丹

    2014-01-01

    The preparation technology, barrier properties and research progress of high-barrier packaging materials have been concluded covering inorganic strengthened high barrier materials such as vapor deposited barrier materials and inorganic filler blend materials, biodegradable materials such as MFC composite materials, multilayer composite materials and smart barrier materials. The development of high-barrier packaging material researches should be conducted towards the direction of optimal properties, non-toxic, non-pollution, green for environment, market orientation and intelligence.%综述了蒸镀阻隔材料及无机物充填共混阻隔材料等无机物增强高阻隔材料、MFC 涂布材料及MFC 复合材料等可生物降解阻隔材料、多层复合材料以及智能阻隔材料的制备工艺、阻隔性能及其在国内外的研究进展,并指出今后高阻隔材料的研究应朝着性能最优化、无毒无污染、绿色环保、适应市场需求、智能化等方向发展。

  8. Efficiency of active barriers attaching biofilm as sediment capping to eliminate the internal nitrogen in eutrophic lake and canal

    Institute of Scientific and Technical Information of China (English)

    Tinglin Huang; Jinlan Xu; Daojian Cai

    2011-01-01

    Three active barrier materials (zeolite, ceramicite and light porous media) were applied for preventing nitrogen (N) release from eutrophic lake sediments. Long term experiment of two different lake sediments were carried out and the effect of zeolite dose was evaluated. The results indicated that about 90%-100% of total N in overlying water was eliminated by using zeolite. While the N removal efficiency by ceramic was lower than that by zeolite, and light porous media present the lowest efficiency of 59%. Long term sediment incubation experiments indicated that two eutrophic sediments were both effective in preventing N release in spite of different release characteristics. Bio-zeolite capping technology was able to effectively inhibit the release of N from the sediment, and the zeolite dose was independently from N removal.

  9. Regulation to create environments conducive to physical activity: understanding the barriers and facilitators at the Australian state government level.

    Directory of Open Access Journals (Sweden)

    Jane Shill

    Full Text Available INTRODUCTION: Policy and regulatory interventions aimed at creating environments more conducive to physical activity (PA are an important component of strategies to improve population levels of PA. However, many potentially effective policies are not being broadly implemented. This study sought to identify potential policy/regulatory interventions targeting PA environments, and barriers/facilitators to their implementation at the Australian state/territory government level. METHODS: In-depth interviews were conducted with senior representatives from state/territory governments, statutory authorities and non-government organisations (n = 40 to examine participants': 1 suggestions for regulatory interventions to create environments more conducive to PA; 2 support for preselected regulatory interventions derived from a literature review. Thematic and constant comparative analyses were conducted. RESULTS: POLICY INTERVENTIONS MOST COMMONLY SUGGESTED BY PARTICIPANTS FELL INTO TWO AREAS: 1 urban planning and provision of infrastructure to promote active travel; 2 discouraging the use of private motorised vehicles. Of the eleven preselected interventions presented to participants, interventions relating to walkability/cycling and PA facilities received greatest support. Interventions involving subsidisation (of public transport, PA-equipment and the provision of more public transport infrastructure received least support. These were perceived as not economically viable or unlikely to increase PA levels. Dominant barriers were: the powerful 'road lobby', weaknesses in the planning system and the cost of potential interventions. Facilitators were: the provision of evidence, collaboration across sectors, and synergies with climate change/environment agendas. CONCLUSION: This study points to how difficult it will be to achieve policy change when there is a powerful 'road lobby' and government investment prioritises road infrastructure over PA

  10. Performance of iron filings and activated sludge as media for permeable reactive barriers to treat zinc contaminated groundwater

    Directory of Open Access Journals (Sweden)

    Chayapat Hassapak

    2015-02-01

    Full Text Available Zinc is one of the important contaminants in groundwater. Removal of zinc by iron filings, activated sludge and lateritic soil was studied with batch test. The lowest optimum pH for removal of zinc by iron filings, activated sludge and lateritic soil was 6. From isotherm studies iron filings and activated sludge were chosen as media for permeable reactive barrier (PRB. The PRB of 0.5-m thick was simulated in the unconfined aquifer with the distance of 21.5 m downgradient of the zinc contaminated site having constant concentration of 100 mg/l. The groundwater flow in the site was induced by the hydraulic gradient of 0.02. Simulation results indicated that the concentration of zinc of treated groundwater was less than 5 mg/l, which met Thai Groundwater Quality Standard for Drinking Purposes. The continuous PRBs using iron filings and activated sludge could treat zinc for 2,170 and 2,248 days, respectively

  11. Effect of tannic acid-fish scale gelatin hydrolysate hybrid nanoparticles on intestinal barrier function and α-amylase activity.

    Science.gov (United States)

    Wu, Shao-Jung; Ho, Yi-Cheng; Jiang, Shun-Zhou; Mi, Fwu-Long

    2015-07-01

    Practical application of tannic acid is limited because it readily binds proteins to form insoluble aggregates. In this study, tannic acid was self-assembled with fish scale gelatin hydrolysates (FSGH) to form stable colloidal complex nanoparticles. The nanoparticles prepared from 4 mg ml(-1) tannic acid and 4 mg ml(-1) FSGH had a mean particle size of 260.8 ± 3.6 nm, and showed a positive zeta potential (20.4 ± 0.4 mV). The nanoparticles acted as effective nano-biochelators and free radical scavengers because they provided a large number of adsorption sites for interaction with heavy metal ions and scavenging free radicals. The maximum adsorption capacity for Cu(2+) ions was 123.5 mg g(-1) and EC50 of DPPH radical scavenging activity was 21.6 ± 1.2 μg ml(-1). Hydroxyl radical scavenging effects of the nanoparticles were investigated by electron spin resonance spectroscopy. The copper-chelating capacity and free radical scavenging activity of the nanoparticles were associated with their capacity to inhibit Cu(2+) ion-induced barrier impairment and hyperpermeability of Caco-2 intestinal epithelial tight junction (TJ). However, α-amylase inhibitory activity of the nanoparticles was significantly lower than that of free tannic acid. The results suggest that the nanoparticles can ameliorate Cu(2+) ion induced intestinal epithelial TJ dysfunction without severely inhibiting the activity of the digestive enzymes.

  12. CE: Original research: hospital system barriers to rapid response team activation: a cognitive work analysis.

    Science.gov (United States)

    Braaten, Jane Saucedo

    2015-02-01

    The goal of rapid response team (RRT) activation in acute care facilities is to decrease mortality from preventable complications, but such efforts have been only moderately successful. Although recent research has shown decreased mortality when RRTs are activated more often, many hospitals have low activation rates. This has been linked to various hospital, team, and nursing factors. Yet there is a dearth of research examining how hospital systems shape nurses' behavior with regard to RRT activation. Making systemic constraints visible and modifying them may be the key to improving RRT activation rates and saving more lives. The purpose of this study was to use cognitive work analysis to describe factors within the hospital system that shape medical-surgical nurses' RRT activation behavior. Cognitive work analysis offers a framework for the study of complex sociotechnical systems. This framework was used as the organizing element of the study. Qualitative descriptive design was used to obtain data to fill the framework's five domains: resources, tasks, strategies, social systems, and worker competency. Data were obtained from interviews with 12 medical-surgical nurses and document review. Directed content analysis was used to place the obtained data into the framework's predefined domains. Many system factors affected participants' decisions to activate or not activate an RRT. Systemic constraints, especially in cases of subtle or gradual clinical changes, included a lack of adequate information, the availability of multiple strategies, the need to justify RRT activation, a scarcity of human resources, and informal hierarchical norms in the hospital culture. The most profound constraint was the need to justify the call. Justification was based on the objective or subjective nature of clinical changes, whether the nurse expected to be able to "handle" these changes, the presence or absence of a physician, and whether there was an expectation of support from the RRT

  13. Physical activity in patients with heart failure: barriers and motivations with special focus on sex differences

    OpenAIRE

    Klompstra L; Jaarsma T; Strömberg A

    2015-01-01

    Leonie Klompstra,1 Tiny Jaarsma,1 Anna Strömberg2,31Department of Social and Welfare Studies, Faculty of Health Sciences, 2Department of Medical and Health Sciences, Division of Nursing, 3Department of Cardiology, Linköping University, Linköping, SwedenBackground: Adherence to recommendations for physical activity is low in both male and female patients with heart failure (HF). Men are more physically active than women. In order to successfully promote physical acti...

  14. Promoting Physical Activity Participation among Adolescents: The Barriers and the Suggestions

    OpenAIRE

    Niloofar Peykari; Monir Baradaran Eftekhari; Fahimeh Ramezani Tehrani; Hosein Malek Afzali; Farzaneh Hejazi; Mehrdad Kazemzadeh Atoofi; Mostafa Qorbani; Hamid Asayesh; Shirin Djalalinia

    2015-01-01

    Background: Physical activity is a complex behavior. To designing the effective intervention, qualitative researches may be allowed for greater understanding of the reasons behind the adolescences′ physical activity-related behaviors′. Methods: Using the grounded theory approach, including semi-structured focus group discussions (FGDs) and in-depth interviews, we conducted a quantitative study to elicit the adolescents and key informants′ opinion regarding the satiation, needs, social and...

  15. Filaggrin and Skin Barrier Function.

    Science.gov (United States)

    Kezic, Sanja; Jakasa, Ivone

    2016-01-01

    The skin barrier function is greatly dependent on the structure and composition of the uppermost layer of the epidermis, the stratum corneum (SC), which is made up of flattened anucleated cells surrounded by highly organized and continuous lipid matrix. The interior of the corneocytes consists mainly of keratin filaments aggregated by filaggrin (FLG) protein. Next, together with several other proteins, FLG is cross-linked into a mechanically robust cornified cell envelope providing a scaffold for the extracellular lipid matrix. In addition to its role for the SC structural and mechanical integrity, FLG degradation products account in part for the water-holding capacity and maintenance of acidic pH of the SC, both crucial for the epidermal barrier homoeostasis by regulating activity of multiple enzymes that control desquamation, lipid synthesis and inflammation. The major determinant of FLG expression in the skin are loss-of-function mutations in FLG, the strongest genetic risk factor for atopic dermatitis (AD), an inflammatory skin disease characterized by a reduced skin barrier function. The prevalence of FLG mutations varies greatly among different populations and ranges from about 10% in Northern Europeans to less than 1% in the African populations. An impaired skin barrier facilitates absorption of potentially hazardous chemicals, which might cause adverse effects in the skin, such as contact dermatitis, or systemic toxicity after their passage into blood. In another direction, a leaky epidermal barrier will lead to enhanced loss of water from the skin. A recent study has shown that even subtle increase in epidermal water loss in newborns increases the risk for AD. Although there are multiple modes of action by which FLG might affect skin barrier it is still unclear whether and how FLG deficiency leads to the reduced skin barrier function. This chapter summarizes the current knowledge in this field obtained from clinical studies, and animal and in vitro models

  16. Ceramide 1-Phosphate Increases P-Glycoprotein Transport Activity at the Blood-Brain Barrier via Prostaglandin E2 Signaling.

    Science.gov (United States)

    Mesev, Emily V; Miller, David S; Cannon, Ronald E

    2017-04-01

    P-glycoprotein, an ATP-driven efflux pump, regulates permeability of the blood-brain barrier (BBB). Sphingolipids, endogenous to brain tissue, influence inflammatory responses and cell survival in vitro. Our laboratory has previously shown that sphingolipid signaling by sphingosine 1-phosphate decreases basal P-glycoprotein transport activity. Here, we investigated the potential for another sphingolipid, ceramide 1-phosphate (C1P), to modulate efflux pumps at the BBB. Using confocal microscopy and measuring luminal accumulation of fluorescent substrates, we assessed the transport activity of several efflux pumps in isolated rat brain capillaries. C1P treatment induced P-glycoprotein transport activity in brain capillaries rapidly and reversibly. In contrast, C1P did not affect transport activity of two other major efflux transporters, multidrug resistance protein 2 and breast cancer resistance protein. C1P induced P-glycoprotein transport activity without changing transporter protein expression. Inhibition of the key signaling components in the cyclooxygenase-2 (COX-2)/prostaglandin E2 signaling cascade (phospholipase A2, COX-2, multidrug resistance protein 4, and G-protein-coupled prostaglandin E2 receptors 1 and 2), abolished P-glycoprotein induction by C1P. We show that COX-2 and prostaglandin E2 are required for C1P-mediated increases in P-glycoprotein activity independent of transporter protein expression. This work describes how C1P activates a signaling cascade to dynamically regulate P-glycoprotein transport at the BBB and offers potential clinical targets to modulate neuroprotection and drug delivery to the CNS.

  17. Supplementary Reading Instruction in Alternative High Schools: A Statewide Survey of Educator Reported Practices and Barriers

    Science.gov (United States)

    Wilkerson, Kimber L.; Yan, Min-Chi; Perzigian, Aaron B.; Cakiroglu, Orhan

    2016-01-01

    Recent data suggest that a majority of secondary students read below the level considered proficient on state standardized tests of reading. Alternative high schools, in particular, serve a high proportion of struggling readers. This survey study investigated reading instruction provided to struggling readers in alternative schools in one state by…

  18. The Effects of High Salinity Groundwater on the Performance of Clay Barriers

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David [Quintessa Ltd., Nottingham (United Kingdom)

    2005-07-01

    external electrolyte solution enter the clay volume, leading to decreased water activity in the clay. Introduced ions enter the swelling pressure-inducing volume in the clay. Swelling pressure is systematically reduced at all clay densities by interaction with saline fluids. SKB believes that if the buffer density exceeds 1.9 Mg/m{sup 3}, the functional requirements for the swelling pressure to exceed 1 MPa will be fulfilled, even with groundwater salinities equivalent to 3 M NaCl. Similarly, the functional requirement for buffer hydraulic conductivity of 10{sup -12} m/s will also be fulfilled if the buffer density is greater than 1.8 Mg/m{sup 3}, and with NaCl equivalent salinity equal to 3M ({approx}175 g/l TDS). A review of work carried out elsewhere related to the swelling of montmorillonitic clays shows that the mechanistic understanding of such processes is less well advanced than that presented by SKB. Backfill materials are even more susceptible to loss of swelling pressure in saline groundwaters. SKB is currently studying several different designs for tunnel and repository backfill. With regard to salinity effects, they state that a hydraulic conductivity of 10{sup -10} m/s and a swelling pressure > 0.1 MPa at a groundwater TDS of 35 g/l is the target for this assessment. According to the results of the Backfill and Plug test, the 'concept A' backfill (SKB's current reference backfill concept) had a density of 1.7 Mg/m{sup 3}, a hydraulic conductivity of 4x10{sup -10} m/s, a compressibility of 30 MPa and a swelling pressure of 0.15 - 0.2 MPa (all with a groundwater salinity of 1.2 % NaCl). These values are deemed acceptable by SKB, except for the slightly too high hydraulic conductivity. However, it should be noted that SKB had to increase the proportion of clay in the mixture from 15 % to 30 % to achieve these properties. SKB continues its research in this area in conjunction with Posiva to assess different backfill formulations. Research on tunnel

  19. Novel palladium germanide schottky contact for high performance schottky barrier ge MOSFETs and characterization of its leakage current mechanism.

    Science.gov (United States)

    Oh, Se-Kyung; Shin, Hong-Sik; Kang, Min-Ho; Lee, Ga-Won; Lee, Hi-Deok

    2012-07-01

    The leakage current mechanism of Palladium (Pd) germanide Schottky contact on n-type Ge-on-Si substrate is analyzed in depth. The electric field dependent analysis shows that the dominant leakage current mechanism is the Poole-Frenkel emission due to the existence of deep level traps in the depletion region of the Pd germanide/n-type Ge Schottky diode. The analysis of the dependence of leakage current on temperature also shows that the Poole-Frenkel emission and generation current are the dominant components below 100 degrees C and that the Schottky emission related to thermionic emission of majority carriers over a potential barrier is the main cause of this dominance at high temperature region.

  20. Intestinal Mucosal Barrier Is Injured by BMP2/4 via Activation of NF-κB Signals after Ischemic Reperfusion

    Directory of Open Access Journals (Sweden)

    Kang Chen

    2014-01-01

    Full Text Available Intestinal ischemic reperfusion (I/R can cause dysfunction of the intestinal mucosal barrier; however, the mechanism of the intestinal mucosal barrier dysfunction caused by I/R remains unclear. In this study, using intestinal epithelial cells under anaerobic cultivation and an in vivo rat intestinal I/R model, we found that hypoxia and I/R increased the expression of BMP2/4 and upregulated BMP type Ia receptor and BMP type II receptor expression. We also found that exogenous BMP2/4 can activate the ERK and AKT signaling pathways in rat small intestine (IEC-6 cells, thereby activating NF-κB signaling, which leads to increased levels of inflammatory factors, such as TNF-α and IL-6. Furthermore, recombinant BMP2/4 decreased the expression of the tight junction protein occludin via the activation of the NF-κB pathway; these effects were abolished by treatment with the BMP-specific antagonist noggin or the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC. All these factors can destroy the intestinal mucosal barrier, thereby leading to weaker barrier function. On the basis of these data, we conclude that BMP2/4 may act as the pathogenic basis for intestinal mucosal barrier dysfunction when the intestines suffer an I/R injury. Our results provide background for the development pharmacologic interventions in the management of I/R injury.

  1. Male Gender Role Strain as a Barrier to African American Men's Physical Activity

    Science.gov (United States)

    Griffith, Derek M.; Gunter, Katie; Allen, Julie Ober

    2011-01-01

    Despite the potential health consequences, African American men tend to treat their roles as providers, fathers, spouses, and community members as more important than engaging in health behaviors such as physical activity. We conducted 14 exploratory focus groups with 105 urban, middle-aged African American men from the Midwest to examine factors…

  2. Enhancing Tumor Drug Delivery by Laser-Activated Vascular Barrier Disruption

    Science.gov (United States)

    2009-12-01

    acting drugs enhance photo- sensitizer activity. FASEB J. 2003;17:1121–3. 130. James DA, Swamy N, Paz N, Hanson RN, Ray R. Synthesis and estrogen...Shoemaker, Wai Lau, Rebecca L. Shattuck, Ann P. Kwiatkowski, Paul E. Matrisian, Luis Guerra -Santos, Emily Wilson, Thomas J. Lukas, Linda J. Van Eldik, and

  3. Barriers to Increasing the Physical Activity of People with Intellectual Disabilities

    Science.gov (United States)

    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…

  4. Barriers, motivators, and facilitators of physical activity in dementia patients : A systematic review

    NARCIS (Netherlands)

    van Alphen, Helena J. M.; Hortobagyi, Tibor; van Heuvelen, Marieke J. G.

    2016-01-01

    Purpose: Physical activity (PA) has the potential to slow the progression of dementia patients' cognitive and physical decline. A better understanding of the factors that facilitate or hamper dementia patients' PA participation will increase the success rate of implementing PA in dementia patients'

  5. Barriers, motivators, and facilitators of physical activity in dementia patients : A systematic review

    NARCIS (Netherlands)

    van Alphen, Helena J. M.; Hortobagyi, Tibor; van Heuvelen, Marieke J. G.

    2016-01-01

    Purpose: Physical activity (PA) has the potential to slow the progression of dementia patients' cognitive and physical decline. A better understanding of the factors that facilitate or hamper dementia patients' PA participation will increase the success rate of implementing PA in dementia patients'

  6. Understanding and Dismantling Barriers for Partnerships for Inclusive Education: A Cultural Historical Activity Theory Perspective

    Science.gov (United States)

    Waitoller, Federico R.; Kozleski, Elizabeth B.

    2013-01-01

    Increasingly, universities and school districts share responsibility for teacher and student learning. Sharing responsibility demands that both institutions work to develop closer relationships through ongoing engagement, dialogue and negotiation. Drawing from Cultural Historical Activity Theory (CHAT), we examined one school/university…

  7. Barriers to Increasing the Physical Activity of People with Intellectual Disabilities

    Science.gov (United States)

    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…

  8. Office-based physical activity and nutrition intervention: barriers, enablers, and preferred strategies for workplace obesity prevention, Perth, Western Australia, 2012.

    Science.gov (United States)

    Blackford, Krysten; Jancey, Jonine; Howat, Peter; Ledger, Melissa; Lee, Andy H

    2013-09-12

    Workplace health promotion programs to prevent overweight and obesity in office-based employees should be evidence-based and comprehensive and should consider behavioral, social, organizational, and environmental factors. The objective of this study was to identify barriers to and enablers of physical activity and nutrition as well as intervention strategies for health promotion in office-based workplaces in the Perth, Western Australia, metropolitan area in 2012. We conducted an online survey of 111 employees from 55 organizations. The online survey investigated demographics, individual and workplace characteristics, barriers and enablers, intervention-strategy preferences, and physical activity and nutrition behaviors. We used χ(2) and Mann-Whitney U statistics to test for differences between age and sex groups for barriers and enablers, intervention-strategy preferences, and physical activity and nutrition behaviors. Stepwise multiple regression analysis determined factors that affect physical activity and nutrition behaviors. We identified several factors that affected physical activity and nutrition behaviors, including the most common barriers ("too tired" and "access to unhealthy food") and enablers ("enjoy physical activity" and "nutrition knowledge"). Intervention-strategy preferences demonstrated employee support for health promotion in the workplace. The findings provide useful insights into employees' preferences for interventions; they can be used to develop comprehensive programs for evidence-based workplace health promotion that consider environmental and policy influences as well as the individual.

  9. Enclosure for handling high activity materials

    Energy Technology Data Exchange (ETDEWEB)

    Jimeno de Osso, F.

    1977-07-01

    One of the most important problems that are met at the laboratories producing and handling radioisotopes is that of designing, building and operating enclosures suitable for the safe handling of active substances. With this purpose in mind, an enclosure has been designed and built for handling moderately high activities under a shielding made of 150 mm thick lead. In this report a description is given of those aspects that may be of interest to people working in this field. (Author)

  10. Ultra-High-Temperature-Ceramics: potentialities and barriers to the application in hot structures

    OpenAIRE

    Bellosi, Alida

    2009-01-01

    High performance Ultra-High-Temperature Composites (based on zirconium-, hafnium-, tantalum- borides and carbides) are characterized by relevant and unique thermo-physical and thermo-mechanical properties, suitable for applications in thermo-protection systems for aerospace applications. In spite of the difficult sinterability of borides and carbides of Zr, Hf, Ta, recent results highlighted that UHTC ceramics can be successfully produced with full density, fine and uniform microstructure and...

  11. Historical changes in the Mississippi-Alabama barrier-island chain and the roles of extreme storms, sea level, and human activities

    Science.gov (United States)

    Morton, R.A.

    2008-01-01

    Barrier-island chains worldwide are undergoing substantial changes, and their futures remain uncertain. An historical analysis of a barrier-island chain in the north-central Gulf of Mexico shows that the Mississippi barriers are undergoing rapid systematic land loss and translocation associated with: (1) unequal lateral transfer of sand related to greater updrift erosion compared to downdrift deposition; (2) barrier narrowing resulting from simultaneous erosion of shores along the Gulf and Mississippi Sound; and (3) barrier segmentation related to storm breaching. Dauphin Island, Alabama, is also losing land for some of the same reasons as it gradually migrates landward. The principal causes of land loss are frequent intense storms, a relative rise in sea level, and a sediment-budget deficit. Considering the predicted trends for storms and sea level related to global warming, it is certain that the Mississippi-Alabama (MS-AL) barrier islands will continue to lose land area at a rapid rate unless the trend of at least one causal factor reverses. Historical land-loss trends and engineering records show that progressive increases in land-loss rate correlate with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. This correlation indicates that channel-maintenance activities along the MS-AL barriers have impacted the sediment budget by disrupting the alongshore sediment transport system and progressively reducing sand supply. Direct management of this causal factor can be accomplished by strategically placing dredged sediment where adjacent barrier-island shores will receive it for island nourishment and rebuilding.

  12. Infrared gas phase study on plasma-polymer interactions in high-current diffuse dielectric barrier discharge

    Science.gov (United States)

    Liu, Y.; Welzel, S.; Starostin, S. A.; van de Sanden, M. C. M.; Engeln, R.; de Vries, H. W.

    2017-06-01

    A roll-to-roll high-current diffuse dielectric barrier discharge at atmospheric pressure was operated in air and Ar/N2/O2 gas mixtures. The exhaust gas from the discharge was studied using a high-resolution Fourier-transform infrared spectrometer in the range from 3000 to 750 cm-1 to unravel the plasma-polymer interactions. The absorption features of HxNyOz, COx, and HCOOH (formic acid) were identified, and the relative densities were deduced by fitting the absorption bands of the detected molecules. Strong interactions between plasma and polymer (Polyethylene-2,6-naphthalate, or PEN) in precursor-free oxygen-containing gas mixtures were observed as evidenced by a high COx production. The presence of HCOOH in the gas effluent, formed through plasma-chemical synthesis of COx, turns out to be a sensitive indicator for etching. By adding tetraethylorthosilicate precursor in the plasma, dramatic changes in the COx production were measured, and two distinct deposition regimes were identified. At high precursor flows, a good agreement with the precursor combustion and the COx production was observed, whereas at low precursor flows an etching-deposition regime transpires, and the COx production is dominated by polymer etching.

  13. Monitoring Delamination of Thermal Barrier Coating During Interrupted High-Heat Flux Laser Testing Using Upconversion Luminescence Imaging

    Science.gov (United States)

    Eldridge, Jeffrey I.; Zhu, Dongming; Wolfe, Douglas E.

    2011-01-01

    Upconversion luminescence imaging of thermal barrier coatings (TBCs) has been shown to successfully monitor TBC delamination progression during interrupted furnace cycling. However, furnace cycling does not adequately model engine conditions where TBC-coated components are subjected to significant heat fluxes that produce through-thickness temperature gradients that may alter both the rate and path of delamination progression. Therefore, new measurements are presented based on luminescence imaging of TBC-coated specimens subjected to interrupted high-heat-flux laser cycling exposures that much better simulate the thermal gradients present in engine conditions. The TBCs tested were deposited by electron-beam physical vapor deposition (EB-PVD) and were composed of 7wt% yttria-stabilized zirconia (7YSZ) with an integrated delamination sensing layer composed of 7YSZ co-doped with erbium and ytterbium (7YSZ:Er,Yb). The high-heat-flux exposures that produce the desired through-thickness thermal gradients were performed using a high power CO2 laser operating at a wavelength of 10.6 microns. Upconversion luminescence images revealed the debond progression produced by the cyclic high-heat-flux exposures and these results were compared to that observed for furnace cycling.

  14. Curcumin protects intestinal mucosal barrier function of rat enteritis via activation of MKP-1 and attenuation of p38 and NF-κB activation.

    Directory of Open Access Journals (Sweden)

    Wei-Bing Song

    Full Text Available BACKGROUND: Intestinal mucosa barrier (IMB dysfunction results in many notorious diseases for which there are currently few effective treatments. We studied curcumin's protective effect on IMB and examined its mechanism by using methotrexate (MTX induced rat enteritis model and lipopolysaccharide (LPS treated cell death model. METHODOLOGY/PRINCIPAL FINDINGS: Curcumin was intragastrically administrated from the first day, models were made for 7 days. Cells were treated with curcumin for 30 min before exposure to LPS. Rat intestinal mucosa was collected for evaluation of pathological changes. We detected the activities of D-lactate and diamine oxidase (DAO according to previous research and measured the levels of myeloperoxidase (MPO and superoxide dismutase (SOD by colorimetric method. Intercellular adhesion molecule-1 (ICAM-1, tumor necrosis factor α (TNF-α and interleukin 1β (IL-1β were determined by RT-PCR and IL-10 production was determined by ELISA. We found Curcumin decreased the levels of D-lactate, DAO, MPO, ICAM-1, IL-1β and TNF-α, but increased the levels of IL-10 and SOD in rat models. We further confirmed mitogen-activated protein kinase phosphatase-1 (MKP-1 was activated but phospho-p38 was inhibited by curcumin by western blot assay. Finally, NF-κB translocation was monitored by immunofluorescent staining. We showed that curcumin repressed I-κB and interfered with the translocation of NF-κB into nucleus. CONCLUSIONS/SIGNIFICANCE: The effect of curcumin is mediated by the MKP-1-dependent inactivation of p38 and inhibition of NF-κB-mediated transcription. Curcumin, with anti-inflammatory and anti-oxidant activities may be used as an effective reagent for protecting intestinal mucosa barrier and other related intestinal diseases.

  15. Beyond the Barriers: Marking the Place for Marijuana Use at a Canadian High School

    Science.gov (United States)

    Johnson, Joy L.; Moffat, Barbara; Bottorff, Joan; Shoveller, Jean; Fischer, Benedikt; Haines, Rebecca J.

    2008-01-01

    This ethnographic study aimed at developing a richer understanding of how youth, their schools, and the communities in which they are emplaced coincide to generate a set of local social processes that affect marijuana use. We trace the interplay between high school staff and students with regards to marijuana use in the proximity of a local high…

  16. Beyond the Barriers: Marking the Place for Marijuana Use at a Canadian High School

    Science.gov (United States)

    Johnson, Joy L.; Moffat, Barbara; Bottorff, Joan; Shoveller, Jean; Fischer, Benedikt; Haines, Rebecca J.

    2008-01-01

    This ethnographic study aimed at developing a richer understanding of how youth, their schools, and the communities in which they are emplaced coincide to generate a set of local social processes that affect marijuana use. We trace the interplay between high school staff and students with regards to marijuana use in the proximity of a local high…

  17. Obesity promotes oxidative stress and exacerbates blood-brain barrier disruption after high-intensity exercise

    Directory of Open Access Journals (Sweden)

    Hee-Tae Roh

    2017-06-01

    Conclusion: Our study suggests that episodic vigorous exercise can increase oxidative stress and blood neurotrophic factor levels and induce disruption of the BBB. Moreover, high levels of neurotrophic factor in the blood after exercise in the obese group may be due to BBB disruption, and it is assumed that oxidative stress was the main cause of this BBB disruption.

  18. The role of the spray pyrolysed Al2O3 barrier layer in achieving high efficiency solar cells on flexible steel substrates

    Science.gov (United States)

    Gledhill, Sophie E.; Zykov, Anton; Rissom, Thorsten; Caballero, Raquel; Kaufmann, Christian A.; Fischer, Christian-Herbert; Lux-Steiner, Martha; Efimova, Varvara; Hoffmann, Volker; Oswald, Steffen

    2011-07-01

    Thin film chalcopyrite solar cells grown on light-weight, flexible steel substrates are poised to enter the photovoltaic market. To guarantee good solar cell performance, the diffusion of iron from the steel into the CIGSe absorber material must be hindered during layer deposition. A barrier layer is thus required to isolate the solar module from the metal substrate, both electronically and chemically. Ideally the barrier layer would be deposited by a cheap roll-to-roll process suitable to coat flexible steel substrates. Aluminium oxide deposited by spray pyrolysis matches the criteria. The coating is homogeneous over rough substrates allowing comparatively thin barrier layers to be utilized. In this article, solar cell results are presented contrasting the device performance made with a barrier layer to that without a barrier layer. Secondary Ion Mass spectrometry (SIMS) measurements show that the spray pyrolysed barrier layer diminishes iron diffusion to the chalcopyrite absorber layer. The role of sodium, imperative for the growth of high efficiency chalcopyrite solar cells, and how it interacts with Al2O3 is discussed.

  19. Low-Dose Endothelial Monocyte-Activating Polypeptide-II Increases Blood-Tumor Barrier Permeability by Activating the RhoA/ROCK/PI3K Signaling Pathway.

    Science.gov (United States)

    Li, Zhen; Liu, Xiao-Bai; Liu, Yun-Hui; Xue, Yi-Xue; Liu, Jing; Teng, Hao; Xi, Zhuo; Yao, Yi-Long

    2016-06-01

    Previous studies have demonstrated that low-dose endothelial monocyte-activating polypeptide-II (EMAP-II) can increase blood-tumor barrier (BTB) permeability via both paracellular and transcellular pathways. In addition, we revealed that the RhoA/Rho kinase (ROCK) signaling pathway is involved in EMAP-II-induced BTB opening. This study further investigated the exact mechanisms by which the RhoA/ROCK signaling pathway affects EMAP-II-induced BTB hyperpermeability. In an in vitro BTB model, low-dose EMAP-II significantly activated phosphatidylinositol-3-kinase (PI3K) in rat brain microvascular endothelial cells (RBMECs) at 0.75 h. Pretreatment with RhoA inhibitor C3 exoenzyme or ROCK inhibitor Y-27632 completely blocked EMAP-II-induced activation of PI3K. PKC-α/β inhibitor GÖ6976 pretreatment caused no change in EMAP-II-induced activation of PI3K. Besides, pretreatment with LY294002, a specific inhibitor of PI3K, did not affect EMAP-II-induced activation of PKC-α/β. Furthermore, LY294002 pretreatment significantly diminished EMAP-II-induced changes in BTB permeability, phosphorylation of myosin light chain and cofilin, expression and distribution of tight junction-associated protein ZO-1, and actin cytoskeleton arrangement in RBMECs. In summary, this study demonstrates that low-dose EMAP-II can increase BTB permeability by activating the RhoA/ROCK/PI3K signaling pathway.

  20. Protective effects of Astragalus-Lilygranules on intestinal mucosal barrier of mice in high altitude hypoxia

    Directory of Open Access Journals (Sweden)

    Ling LI

    2016-10-01

    Full Text Available Objective  To investigate the protective effect of Astragalus-Lily Granules on intestinal mucosa and intestinal flora homeostasis in mice under high altitude hypoxia condition. Methods  We put mice into high altitude hypoxia cabin to establish high altitude hypoxia model mice. Sixty Kunming mice were randomly divided into control group, model group, Astragalus-Lily particles (ALP low, medium and high dose groups [1.75, 3.5, 7g/(kg•d] respectively. After three days of routine feeding, the ALP mice received drug by intragastric administration, once a day for continuous 17 days,control group and model group were given double distilled water in same volume. From the 15th day, all the mice but control group were exposed to simulated high altitude hypoxia condition for 3 days in a high altitude hypoxia cabin after they were gavaged for half an hour daily. By the 18th day, the fresh mouse feces were collected and smeared to observe the changes of microflora. The pathological changes of intestinal tissues were observed by HE staining and the expression of HIF-1αprotein in intestines was detected by immunohistochemistry. Results  The enterococci and gram negative bacteria showed a higher proportion (65.2%±2.4% and 56.7%±3.3%, respectively in the model group compared with the control group (24.7%±1.2%, 23.2%±1.5%, respectively, P<0.05. The pathological score of intestinal mucosal necrosis and edema (3.10±0.99, 3.30±0.67 respectively and inflammatory cell count (15.93±3.30, 16.40±3.97/ HP respectively was higher compared with the model group (0.70±0.67, 0.80±0.78; 4.07±2.12, 4.28±2.16/HP respectively; P<0.05. HIF-1αexpression increased significantly compared with the model group (P<0.05. The enterococci (46.7%±2.0%, 32.0%±2.6% respectively and gram negative bacteria rate (34.2%±1.6%, 38.0%±2.8% respectively in the ALP medium and high dose groups were lower compared with the model group (24.7%±1.2%, 23.2%±1.5% respectively, P<0

  1. High-activity liquid packaging design criteria

    Energy Technology Data Exchange (ETDEWEB)

    1994-05-01

    In recent studies, it has been acknowledged that there is an emerging need for packaging to transport high-activity liquid off the Hanford Site to support characterization and process development activities of liquid waste stored in underground tanks. These studies have dealt with specimen testing needs primarily at the Hanford Site; however, similar needs appear to be developing at other US Department of Energy (DOE) sites. The need to ship single and multiple specimens to offsite laboratories is anticipated because it is predicted that onsite laboratories will be overwhelmed by an increasing number and size (volume) of samples. Potentially, the specimen size could range from 250 mL to greater than 50 L. Presently, no certified Type-B packagings are available for transport of high-activity liquid radioactive specimens in sizes to support Site missions.

  2. Regulation of taurine transport at the blood-placental barrier by calcium ion, PKC activator and oxidative stress conditions

    Science.gov (United States)

    2010-01-01

    Background In the present study, we investigated the changes of uptake and efflux transport of taurine under various stress conditions using rat conditionally immortalized syncytiotrophoblast cell line (TR-TBT cells), as in vitro blood-placental barrier (BPB) model. Methods The transport of taurine in TR-TBT cells were characterized by cellular uptake study using radiolabeled taurine. The efflux of taurine was measured from the amount of radiolabeled taurine remaining in the cells after the uptake of radiolabeled taurine for 60 min. Results Taurine uptake was significantly decreased by phosphorylation of protein kinase C (PKC) activator in TR-TBT cells. Also, calcium ion (Ca2+) was involved in taurine transport in TR-TBT cells. Taurine uptake was inhibited and efflux was enhanced under calcium free conditions in the cells. In addition, oxidative stress induced the change of taurine transport in TR-TBT cells, but the changes were different depending on the types of oxidative stress inducing agents. Tumor necrosis factor-α (TNF-α), lipopolysaccharide (LPS) and diethyl maleate (DEM) significantly increased taurine uptake, but H2O2 and nitric oxide (NO) donor decreased taurine uptake in the cells. Taurine efflux was down-regulated by TNF-α in TR-TBT cells. Conclusion Taurine transport in TR-TBT cells were regulated diversely at extracellular Ca2+ level, PKC activator and oxidative stress conditions. It suggested that variable stresses affected the taurine supplies from maternal blood to fetus and taurine level of fetus. PMID:20804613

  3. The role of multidrug resistance protein (MRP-1) as an active efflux transporter on blood-brain barrier (BBB) permeability.

    Science.gov (United States)

    Lingineni, Karthik; Belekar, Vilas; Tangadpalliwar, Sujit R; Garg, Prabha

    2017-01-03

    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.

  4. Novel design of high voltage pulse source for efficient dielectric barrier discharge generation by using silicon diodes for alternating current

    Science.gov (United States)

    Truong, Hoa Thi; Hayashi, Misaki; Uesugi, Yoshihiko; Tanaka, Yasunori; Ishijima, Tatsuo

    2017-06-01

    This work focuses on design, construction, and optimization of configuration of a novel high voltage pulse power source for large-scale dielectric barrier discharge (DBD) generation. The pulses were generated by using the high-speed switching characteristic of an inexpensive device called silicon diodes for alternating current and the self-terminated characteristic of DBD. The operation started to be powered by a primary DC low voltage power supply flexibly equipped with a commercial DC power supply, or a battery, or DC output of an independent photovoltaic system without transformer employment. This flexible connection to different types of primary power supply could provide a promising solution for the application of DBD, especially in the area without power grid connection. The simple modular structure, non-control requirement, transformer elimination, and a minimum number of levels in voltage conversion could lead to a reduction in size, weight, simple maintenance, low cost of installation, and high scalability of a DBD generator. The performance of this pulse source has been validated by a load of resistor. A good agreement between theoretically estimated and experimentally measured responses has been achieved. The pulse source has also been successfully applied for an efficient DBD plasma generation.

  5. Anisotropic Mechanical Properties of Plasma-Sprayed Thermal Barrier Coatings at High Temperature Determined by Ultrasonic Method

    Science.gov (United States)

    Wei, Qin; Zhu, Jianguo; Chen, Wei

    2016-02-01

    The mechanical properties of plasma-sprayed thermal barrier coatings (TBC) are of great scientific and technological significance for the design and fabrication of TBC systems. The ultrasonic method combined with a sing-around method for mechanical properties measurement of TBC is deduced and the elastic modulus can be determined in the spray, or longitudinal, direction, and the transverse direction. Tested specimens of plasma-sprayed TBC are detached from the substrate and treated with thermal exposure at 1400 °C. The elastic moduli along the longitudinal and transverse directions of the TBCs are measured by different types of ultrasonic waves combined with a sing-around method, while the Poisson's ratio is also obtained simultaneously. The experimental results indicate that the magnitude of longitudinal elastic modulus is larger than that of the transverse one, and thus the plasma-sprayed TBC has an anisotropic mechanical property. Moreover, the elastic moduli along both longitudinal and transverse directions change with high-temperature exposure time, which consists of a rapid increasing stage followed by a slow decreasing stage. In addition, the magnitude of Poisson's ratio increases slightly from 0.05 to 0.2 with the high-temperature exposure time. Generally, the microstructures in the plasma-sprayed coatings and their evolution in a high-temperature environment are the main causes of the varying anisotropic mechanical properties.

  6. High activity carbon sorbents for mercury capture

    Energy Technology Data Exchange (ETDEWEB)

    George G. Stavropoulos; Irene S. Diamantopoulou; George E. Skodras; George P. Sakellaropoulos [Aristotle University of Thessaloniki, Thessaloniki (Greece). Chemical Process Engineering Laboratory

    2006-07-01

    High efficiency activated carbons have been prepared for removing mercury from gas streams. Starting materials used were petroleum coke, lignite, charcoal and olive seed waste, and were chemically activated with KOH. Produced adsorbents were primarily characterized for their porosity by N{sub 2} adsorption at 77K. Their mercury retention capacity was characterized based on the breakthrough curves. Compared with typical commercial carbons, they have exhibited considerably enhanced mercury adsorption capacity. An attempt has been made to correlate mercury entrapment and pore structure. It has been shown that physical surface area is increased during activation in contrast to the mercury adsorption capacity that initially increases and tends to decrease at latter stages. Desorption of active sites may be responsible for this behavior. 10 refs., 3 figs., 1 tab.

  7. MRX protects fork integrity at protein–DNA barriers, and its absence causes checkpoint activation dependent on chromatin context

    DEFF Research Database (Denmark)

    Bentsen, Iben Bach; Nielsen, Ida; Lisby, Michael

    2013-01-01

    To address how eukaryotic replication forks respond to fork stalling caused by strong non-covalent protein–DNA barriers, we engineered the controllable Fob-block system in Saccharomyces cerevisiae. This system allows us to strongly induce and control replication fork barriers (RFB) at their natural...

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang Ji, E-mail: yangji@ecust.edu.cn [School of Resources and Environmental Engineering, State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237 (China); Cao Limei; Guo Rui; Jia Jinping [School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    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{sup 2} g{sup -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.

  9. Corrigendum to "PAHs in the Great Barrier Reef Lagoon reach potentially toxic levels from coal port activities" [Estuar. Coast. Shelf Sci. 144, 39-45

    Science.gov (United States)

    Burns, Kathryn A.

    2014-08-01

    Erratum with respect to the paper: Burns, K A, 2014 PAHs in the Great Barrier Reef Lagoon reach potentially toxic levels from coal port activities. Estuarine Coastal and Shelf Science 144, 39-45. DOI 10.1016/j.ecss.2014.04.001.

  10. Facilitators and barriers in the collaboration between the primary care and the sport sector in order to promote physical activity: A systematic literature review

    NARCIS (Netherlands)

    Leenaars, K.E.; Smit, E.; Wagemakers, A.; Molleman, G.R.; Koelen, M.A.

    2015-01-01

    INTRODUCTION: The aim of this review was to identify collaborative initiatives between the primary care and the sport sector in order to promote physical activity (PA), and barriers and facilitators in these initiatives. METHOD: Pubmed, SportDiscus, Web of Science, and SOCindex were systematically s

  11. Facilitators and barriers in the collaboration between the primary care and the sport sector in order to promote physical activity: A systematic literature review

    NARCIS (Netherlands)

    Leenaars, K.E.F.; Smit, E.; Wagemakers, A.; Molleman, G.R.M.; Koelen, M.A.

    2015-01-01

    Introduction The aim of this review was to identify collaborative initiatives between the primary care and the sport sector in order to promote physical activity (PA), and barriers and facilitators in these initiatives. Method Pubmed, SportDiscus, Web of Science, and SOCindex were systematically sea

  12. Facilitators and barriers in the collaboration between the primary care and the sport sector in order to promote physical activity: A systematic literature review

    NARCIS (Netherlands)

    Leenaars, K.E.; Smit, E.; Wagemakers, A.; Molleman, G.R.; Koelen, M.A.

    2015-01-01

    INTRODUCTION: The aim of this review was to identify collaborative initiatives between the primary care and the sport sector in order to promote physical activity (PA), and barriers and facilitators in these initiatives. METHOD: Pubmed, SportDiscus, Web of Science, and SOCindex were systematically

  13. Facilitators and barriers in the collaboration between the primary care and the sport sector in order to promote physical activity: A systematic literature review

    NARCIS (Netherlands)

    Leenaars, K.E.F.; Smit, E.; Wagemakers, A.; Molleman, G.R.M.; Koelen, M.A.

    2015-01-01

    Introduction The aim of this review was to identify collaborative initiatives between the primary care and the sport sector in order to promote physical activity (PA), and barriers and facilitators in these initiatives. Method Pubmed, SportDiscus, Web of Science, and SOCindex were systematically

  14. The APPLE Project: An Investigation of the Barriers and Promoters of Healthy Eating and Physical Activity in New Zealand Children Aged 5-12 Years

    Science.gov (United States)

    Williden, Micalla; Taylor, Rachael W; McAuley, Kirsten A; Simpson, Jean C; Oakley, Maggie; Mann, Jim I

    2006-01-01

    Objective: To use the Analysis Grid for Environments Linked to Obesity (ANGELO) framework to determine the barriers and promoters of healthy eating and physical activity in children aged 5-12 years, as a basis for the development of a pilot community-based programme for preventing obesity in children (APPLE project: A Pilot Programme for Lifestyle…

  15. High performance and transparent multilayer MoS2 transistors: Tuning Schottky barrier characteristics

    Directory of Open Access Journals (Sweden)

    Young Ki Hong

    2016-05-01

    Full Text Available Various strategies and mechanisms have been suggested for investigating a Schottky contact behavior in molybdenum disulfide (MoS2 thin-film transistor (TFT, which are still in much debate and controversy. As one of promising breakthrough for transparent electronics with a high device performance, we have realized MoS2 TFTs with source/drain electrodes consisting of transparent bi-layers of a conducting oxide over a thin film of low work function metal. Intercalation of a low work function metal layer, such as aluminum, between MoS2 and transparent source/drain electrodes makes it possible to optimize the Schottky contact characteristics, resulting in about 24-fold and 3 orders of magnitude enhancement of the field-effect mobility and on-off current ratio, respectively, as well as transmittance of 87.4 % in the visible wavelength range.

  16. Regioselective modification of a xyloglucan hemicellulose for high-performance biopolymer barrier films.

    Science.gov (United States)

    Kochumalayil, Joby J; Zhou, Qi; Kasai, Wakako; Berglund, Lars A

    2013-04-01

    Biobased polymers such as starch and hemicelluloses from wood are of interest for packaging applications, but suffer from limitations in performance under moist conditions. Xyloglucan from industrial tamarind seed waste offers potential, but its Tg is too high for thermal processing applications. Regioselective modification is therefore performed using an approach involving periodate oxidation followed by reduction. The resulting polymer structures are characterized using MALDI-TOF-MS, size-exclusion chromatography, FTIR and carbohydrate analysis. Films are cast from water and characterized by thermogravimetry, dynamic mechanical thermal analysis, dynamic water vapor sorption, oxygen transmission and tensile tests. Property changes are interpreted from structural changes. These new polymers show much superior performance to current petroleum-based polymers in industrial use. Furthermore, this regioselective modification can be carefully controlled, and results in a new type of cellulose derivatives with preserved cellulose backbone without the need for harmful solvents.

  17. Perception of Export Barriers in a High-Tech Sector in a Less Developed Country: The Case of ICT SMEs in Malaysia

    Directory of Open Access Journals (Sweden)

    Christopher Richardson

    2011-10-01

    Full Text Available This paper investigates which export barriers are most pressing to small and medium sized enterprises (SME in a high-tech sector in a developing-country. It also examines whether exporters and non-exporters perceive different export barriers as being more pressing to their export development/initiation. The unit of analysis is SMEs in Malaysia’s information and communications technology (ICT sector. The findings suggest that the high cost of exporting is the most severe problem facing firms in the sample, with cultural differences posing the least important obstacle. Furthermore, with just two exceptions, there are no statistically significant differences in the perceptions of export barriers between exporting and non-exporting firms.

  18. Identifying barriers to patient acceptance of active surveillance: content analysis of online patient communications.

    Directory of Open Access Journals (Sweden)

    Mark V Mishra

    Full Text Available OBJECTIVES: Qualitative research aimed at identifying patient acceptance of active surveillance (AS has been identified as a public health research priority. The primary objective of this study was to determine if analysis of a large-sample of anonymous internet conversations (ICs could be utilized to identify unmet public needs regarding AS. METHODS: English-language ICs regarding prostate cancer (PC treatment with AS from 2002-12 were identified using a novel internet search methodology. Web spiders were developed to mine, aggregate, and analyze content from the world-wide-web for ICs centered on AS. Collection of ICs was not restricted to any specific geographic region of origin. NLP was used to evaluate content and perform a sentiment analysis. Conversations were scored as positive, negative, or neutral. A sentiment index (SI was subsequently calculated according to the following formula to compare temporal trends in public sentiment towards AS: [(# Positive IC/#Total IC-(#Negative IC/#Total IC x 100]. RESULTS: A total of 464 ICs were identified. Sentiment increased from -13 to +2 over the study period. The increase sentiment has been driven by increased patient emphasis on quality-of-life factors and endorsement of AS by national medical organizations. Unmet needs identified in these ICs include: a gap between quantitative data regarding long-term outcomes with AS vs. conventional treatments, desire for treatment information from an unbiased specialist, and absence of public role models managed with AS. CONCLUSIONS: This study demonstrates the potential utility of online patient communications to provide insight into patient preferences and decision-making. Based on our findings, we recommend that multidisciplinary clinics consider including an unbiased specialist to present treatment options and that future decision tools for AS include quantitative data regarding outcomes after AS.

  19. Large barrier, highly uniform and reproducible Ni-Si/4H-SiC forward Schottky diode characteristics: testing the limits of Tung's model

    Science.gov (United States)

    Omar, Sabih U.; Sudarshan, Tangali S.; Rana, Tawhid A.; Song, Haizheng; Chandrashekhar, M. V. S.

    2014-07-01

    We report highly ideal (n < 1.1), uniform nickel silicide (Ni-Si)/SiC Schottky barrier (1.60-1.67 eV with a standard deviation <2.8%) diodes, fabricated on 4H-SiC epitaxial layers grown by chemical vapour deposition. The barrier height was constant over a wide epilayer doping range of 1014-1016 cm-3, apart from a slight decrease consistent with image force lowering. This remarkable uniformity was achieved by careful optimization of the annealing of the Schottky interface to minimize non-idealities that could lead to inhomogeneity. Tung's barrier inhomogeneity model was used to quantify the level of inhomogeneity in the optimized annealed diodes. The estimated ‘bulk’ barrier height (1.75 eV) was consistent with the Shockley-Mott limit for the Ni-Si/4H-SiC interface, implying an unpinned Fermi level. But the model was not useful to explain the poor ideality in unoptimized, as-deposited Schottky contacts (n = 1.6 - 2.5). We show analytically and numerically that only idealities n < 1.21 can be explained using Tung's model, irrespective of material system, indicating that the barrier height inhomogeneity is not the only cause of poor ideality in Schottky diodes. For explaining this highly non-ideal behaviour, other factors (e.g. interface traps, morphological defects, extrinsic impurities, etc) need to be considered.

  20. [The cultural barrier in care].

    Science.gov (United States)

    Djadaoudjee, Lisa

    2013-11-01

    French cultural diversity is evident within French hospitals, where nurses are confronted with communication problems resulting from the language barrier. While communication is indeed essential, there is another important aspect of caring for a patient for behind the language barrier lies a cultural barrier which must be taken into account in order to provide high-quality care.

  1. Highly variable acquisition rates of Ixodes scapularis (Acari: Ixodidae) by birds on an Atlantic barrier island.

    Science.gov (United States)

    Mitra, S S; Buckley, P A; Buckley, F G; Ginsberg, H S

    2010-11-01

    Acquisition of ticks by bird hosts is a central process in the transmission cycles of many tick-borne zoonoses, but tick recruitment by birds has received little direct study. We documented acquisition of Ixodes scapularis Say on birds at Fire Island, NY, by removing ticks from mist-netted birds, and recording the number of ticks on birds recaptured within 4 d of release. Eight bird species acquired at least 0.8 ticks bird(-1) day(-1) during the seasonal peak for at least one age class of I. scapularis. Gray Catbirds, Eastern Towhees, Common Yellowthroats, and Northern Waterthrushes collectively accounted for 83% of all tick acquisitions; and six individuals apportioned among Black-billed Cuckoo, Gray Catbird, Eastern Towhee, and Common Yellowthroat were simultaneously infested with both larvae and nymphs. Bird species with the highest acquisition rates were generally ground foragers, whereas birds that did not acquire ticks in our samples generally foraged above the ground. Tick acquisition by birds did not differ between deciduous and coniferous forests. Among the 15 bird species with the highest recruitment rates, acquisition of nymphs was not correlated with acquisition of larvae. Tick acquisition rates by individual bird species were not correlated with the reservoir competence of those species for Lyme borreliae. However, birds with high tick acquisition rates can contribute large numbers of infected ticks, and thus help maintain the enzootic cycle, even if their levels of reservoir competence are relatively low.

  2. Three case studies of three high school teachers' definitions, beliefs, and implementation practices of inquiry-based science method including barriers to and facilitators of successful implementation

    Science.gov (United States)

    Blackburn-Morrison, Kimberly D.

    This study involved three teachers in various stages of implementation of inquiry-based science method. The cases were chosen because one participant was a novice in using inquiry-based science method, one participant was in her second year of implementation, and the third participant was experienced with inquiry-based science method. The cases were set in a rural high school in three different science classrooms. One of the classrooms was a regular biology class. One of the classrooms was an honors oceanography class and another was an advanced placement environmental science classroom. Data sources included interviews, observations, and document collection. Interviews, observations, and document collection were used to triangulate data. Each classroom was observed five times. Interviews were conducted at the beginning of the semester with each participant and at the end of the semester. Follow-up interviews were conducted after each observation. Documents were collected such as each teacher's lesson plans, student work, and assignments. Data was initially organized according to the research areas of teacher's definition, teacher's beliefs, teacher's barriers to implementation, and teacher's enablers to implementation. Then, patterns emerging from each of these cases were organized. Lastly, patterns emerging across cases were compared in a cross-case analysis. Patterns shared between cases were: Participants related inquiry-based science method with hands-on learning activities. Participants saw students as the center of the learning process. Participants had positive beliefs about constructivist learning practices that were strengthened after implementation of inquiry-based teaching. Facilitators of successful implementation of inquiry-based science method were positive student motivation, students' retention of knowledge, and a positive experience for lower level students. Barriers to successful implementation were teachers not having complete control of the

  3. Esophagogastric junction contractile integral and morphology: Two high-resolution manometry metrics of the anti-reflux barrier.

    Science.gov (United States)

    Ham, Hyoju; Cho, Yu Kyung; Lee, Han Hee; Yoon, Seung Bae; Lim, Chul-Hyun; Kim, Jin Su; Park, Jae Myung; Choi, Myung-Gyu

    2017-08-01

    We evaluated associations of esophagogastric junction (EGJ) metrics as an anti-reflux barrier with impedance-pH, endoscopic esophagitis, and lower esophageal sphincter (LES) metrics. We reviewed high-resolution manometry data from consecutive patients with gastroesophageal reflux disease (GERD) symptoms who underwent impedance-pH and endoscopy, and asymptomatic volunteers. The EGJ contractile integral (CI) was calculated as the mean contractile integral/second during three respiratory cycles. EGJ morphology was classified according to LES-crural diaphragm (CD) separation. In total, 137 patients (65 male, age 55 years) and 23 (9 male, age 33 years) controls were enrolled. Twenty-five patients had erosive reflux disease (ERD), 16 had non-erosive reflux disease (NERD), 5 had reflux hypersensitivity, and 91 were not GERD. EGJ-CI were lower in patients with GERD (22.6 [13.8-29.2] mmHg cm) than non-GERD (50.3 [31-69.9] mmHg cm, P integral showed good diagnostic accuracy with high specificity in predicting GERD. LES-CD separation is associated with an increase in acid reflux, but EGJ-CI was associated more strongly with GERD than was EGJ morphology. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  4. Message maps for safety barrier awareness

    DEFF Research Database (Denmark)

    Jørgensen, Kirsten; Duijm, Nijs Jan; Troen, Hanne

    2011-01-01

    ’ performance parameters continuously, it is possible to create better risk awareness on the part of employers, managers and employees. Better risk awareness by these stakeholders will make it possible to: • acknowledge and continuously control risks; • discover and manage new risks; • keep safety barriers...... intact; • replace safety barriers with others, if necessary; • monitor and maintain the quality of safety barriers. This will contribute to maintain a high level of safety and prevent accidents. Some pro-active accident prevention can be obtained by making people aware of the risks in a given situation......, time, or place, and by enabling them to observe and judge whether the relevant safety barriers are in place and in good order. This can be considered “Situational Awareness” (SA), which is an essential competence enabling an employee to perform his/her job safely. This SA entails a number...

  5. Message maps for Safety Barrier Awareness

    DEFF Research Database (Denmark)

    ’ performance parameters continuously, it is possible to create better risk awareness of employers, managers and employees. Better risk awareness of these stakeholders will make it possible that: • Risks are acknowledged and controlled continuously; • New risks are discovered and managed; • Safety barriers...... are kept intact; • Safety barriers are replaced by other ones, if necessary • The quality of the safety barriers is monitored and maintained This will contribute to maintain a high level of safety and prevent accidents. Part of the pro-active accident prevention can be obtained by making people aware...... of the risks in a given situation, time or place, and by enabling them to observe and judge whether the relevant safety barriers are in place and in good order. This can be considered as “Situational Awareness (SA)”, which is an essential competence for at en employee can perform his/her job safely...

  6. Importance of sports during youth and exercise barriers in 20- to 29-year-old male nonathletes differently motivated for regular physical activities

    DEFF Research Database (Denmark)

    Leyk, Dieter; Witzki, Alexander; Sievert, Alexander

    2012-01-01

    subgroups in nonathletes differing in their amenability to physical exercise, (b) to analyze them for differences in barriers and intention to exercise, and (c) compare importance of sports during youth in nonathletes to trained peers. Using a health and fitness questionnaire 589 nonathletes were queried...... in the cross-sectional survey and compared with 270 trained peers. Athletic abstainers (A), lower (L), and higher (H) motivated nonathletes were separated based on previous engagement in sports. Of the nonathletes, 54.7% reported only 1 barrier to exercise. Although this feature was most prominent in H (71......The number of sedentary young adults has dramatically increased in past decades, and sedentary lifestyles are adopted at an increasingly earlier age. Little is known about barriers or predictors to (re)initiate regular physical activity in this group. The purpose of the study is to (a) identify...

  7. Individual, social, and environmental barriers to and facilitators of physical activity among Latinas living in San Diego County: focus group results.

    Science.gov (United States)

    Martinez, Suzanna M; Arredondo, Elva M; Perez, Gabriela; Baquero, Barbara

    2009-01-01

    The purpose of this study was to examine the barriers to and facilitators of physical activity (PA) relevant to a faith-based community living in a border region. Two focus groups were conducted with 25 Latina churchgoers. Latinas identified barriers to PA that included individual (eg, lack of motivation and time, language, economics, social support, family/household responsibilities), sociocultural (eg, fear of border patrol, machismo, and neighborhood safety), and environmental barriers (eg, traffic-related and dogs). Facilitators of PA were PA knowledge, child care, time management, and advocacy skills. The authors concluded that a church-based multilevel intervention targeting Latinas may be ideal for promoting PA and facilitating environmental changes.

  8. Shoes, Dues, and Other Barriers to College Attainment: Perspectives of Students Attending High-Poverty Urban High Schools

    Science.gov (United States)

    Drotos, Stephanie M.; Cilesiz, Sebnem

    2016-01-01

    Facilitating economically disadvantaged students' access to higher education is an important goal of educational policy. However, some practices toward this goal are based on theories and assumptions not informed by the students' conditions or needs. The purpose of this study was to understand the challenges faced by students from high poverty,…

  9. Production of high specific activity silicon-32

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, D.R. [Los Alamos National Lab., NM (United States); Brzezinski, M.A. [Univ. of California, Santa Barbara, CA (United States). Marine Biotechnology Center

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development Project (LDRD) at Los Alamos National Laboratory (LANL). There were two primary objectives for the work performed under this project. The first was to take advantage of capabilities and facilities at Los Alamos to produce the radionuclide {sup 32}Si in unusually high specific activity. The second was to combine the radioanalytical expertise at Los Alamos with the expertise at the University of California to develop methods for the application of {sup 32}Si in biological oceanographic research related to global climate modeling. The first objective was met by developing targetry for proton spallation production of {sup 32}Si in KCl targets and chemistry for its recovery in very high specific activity. The second objective was met by developing a validated field-useable, radioanalytical technique, based upon gas-flow proportional counting, to measure the dynamics of silicon uptake by naturally occurring diatoms.

  10. Beyond blood brain barrier breakdown – in vivo detection of occult neuroinflammatory foci by magnetic nanoparticles in high field MRI

    Directory of Open Access Journals (Sweden)

    Schnorr Joerg

    2009-08-01

    Full Text Available Abstract Background Gadopentate dimeglumine (Gd-DTPA enhanced magnetic resonance imaging (MRI is widely applied for the visualization of blood brain barrier (BBB breakdown in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE. Recently, the potential of magnetic nanoparticles to detect macrophage infiltration by MRI was demonstrated. We here investigated a new class of very small superparamagnetic iron oxide particles (VSOP as novel contrast medium in murine adoptive-transfer EAE. Methods EAE was induced in 17 mice via transfer of proteolipid protein specific T cells. MR images were obtained before and after application of Gd-DTPA and VSOP on a 7 Tesla rodent MR scanner. The enhancement pattern of the two contrast agents was compared, and correlated to histology, including Prussian Blue staining for VSOP detection and immunofluorescent staining against IBA-1 to identify macrophages/microglia. Results Both contrast media depicted BBB breakdown in 42 lesions, although differing in plaques appearances and shapes. Furthermore, 13 lesions could be exclusively visualized by VSOP. In the subsequent histological analysis, VSOP was localized to microglia/macrophages, and also diffusely dispersed within the extracellular matrix. Conclusion VSOP showed a higher sensitivity in detecting BBB alterations compared to Gd-DTPA enhanced MRI, providing complementary information of macrophage/microglia activity in inflammatory plaques that has not been visualized by conventional means.

  11. Beyond blood brain barrier breakdown – in vivo detection of occult neuroinflammatory foci by magnetic nanoparticles in high field MRI

    Science.gov (United States)

    Tysiak, Eva; Asbach, Patrick; Aktas, Orhan; Waiczies, Helmar; Smyth, Maureen; Schnorr, Joerg; Taupitz, Matthias; Wuerfel, Jens

    2009-01-01

    Background Gadopentate dimeglumine (Gd-DTPA) enhanced magnetic resonance imaging (MRI) is widely applied for the visualization of blood brain barrier (BBB) breakdown in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Recently, the potential of magnetic nanoparticles to detect macrophage infiltration by MRI was demonstrated. We here investigated a new class of very small superparamagnetic iron oxide particles (VSOP) as novel contrast medium in murine adoptive-transfer EAE. Methods EAE was induced in 17 mice via transfer of proteolipid protein specific T cells. MR images were obtained before and after application of Gd-DTPA and VSOP on a 7 Tesla rodent MR scanner. The enhancement pattern of the two contrast agents was compared, and correlated to histology, including Prussian Blue staining for VSOP detection and immunofluorescent staining against IBA-1 to identify macrophages/microglia. Results Both contrast media depicted BBB breakdown in 42 lesions, although differing in plaques appearances and shapes. Furthermore, 13 lesions could be exclusively visualized by VSOP. In the subsequent histological analysis, VSOP was localized to microglia/macrophages, and also diffusely dispersed within the extracellular matrix. Conclusion VSOP showed a higher sensitivity in detecting BBB alterations compared to Gd-DTPA enhanced MRI, providing complementary information of macrophage/microglia activity in inflammatory plaques that has not been visualized by conventional means. PMID:19660125

  12. Beyond blood brain barrier breakdown - in vivo detection of occult neuroinflammatory foci by magnetic nanoparticles in high field MRI.

    Science.gov (United States)

    Tysiak, Eva; Asbach, Patrick; Aktas, Orhan; Waiczies, Helmar; Smyth, Maureen; Schnorr, Joerg; Taupitz, Matthias; Wuerfel, Jens

    2009-08-06

    Gadopentate dimeglumine (Gd-DTPA) enhanced magnetic resonance imaging (MRI) is widely applied for the visualization of blood brain barrier (BBB) breakdown in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Recently, the potential of magnetic nanoparticles to detect macrophage infiltration by MRI was demonstrated. We here investigated a new class of very small superparamagnetic iron oxide particles (VSOP) as novel contrast medium in murine adoptive-transfer EAE. EAE was induced in 17 mice via transfer of proteolipid protein specific T cells. MR images were obtained before and after application of Gd-DTPA and VSOP on a 7 Tesla rodent MR scanner. The enhancement pattern of the two contrast agents was compared, and correlated to histology, including Prussian Blue staining for VSOP detection and immunofluorescent staining against IBA-1 to identify macrophages/microglia. Both contrast media depicted BBB breakdown in 42 lesions, although differing in plaques appearances and shapes. Furthermore, 13 lesions could be exclusively visualized by VSOP. In the subsequent histological analysis, VSOP was localized to microglia/macrophages, and also diffusely dispersed within the extracellular matrix. VSOP showed a higher sensitivity in detecting BBB alterations compared to Gd-DTPA enhanced MRI, providing complementary information of macrophage/microglia activity in inflammatory plaques that has not been visualized by conventional means.

  13. Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

    Science.gov (United States)

    Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

    2015-10-01

    This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR + PRB showed the lowest leaching value for each HM in the S2 and S3 regions.

  14. Active vibration isolation of high precision machines

    CERN Document Server

    Collette, C; Artoos, K; Hauviller, C

    2010-01-01

    This paper provides a review of active control strategies used to isolate high precisionmachines (e.g. telescopes, particle colliders, interferometers, lithography machines or atomic force microscopes) from external disturbances. The objective of this review is to provide tools to develop the best strategy for a given application. Firstly, the main strategies are presented and compared, using single degree of freedom models. Secondly, the case of huge structures constituted of a large number of elements, like particle colliders or segmented telescopes, is considered.

  15. Direct quantification of chemical warfare agents and related compounds at low ppt levels: comparing active capillary dielectric barrier discharge plasma ionization and secondary electrospray ionization mass spectrometry.

    Science.gov (United States)

    Wolf, Jan-Christoph; Schaer, Martin; Siegenthaler, Peter; Zenobi, Renato

    2015-01-06

    A novel active capillary dielectric barrier discharge plasma ionization (DBDI) technique for mass spectrometry is applied to the direct detection of 13 chemical warfare related compounds, including sarin, and compared to secondary electrospray ionization (SESI) in terms of selectivity and sensitivity. The investigated compounds include an intact chemical warfare agent and structurally related molecules, hydrolysis products and/or precursors of highly toxic nerve agents (G-series, V-series, and "new" nerve agents), and blistering and incapacitating warfare agents. Well-defined analyte gas phase concentrations were generated by a pressure-assisted nanospray with consecutive thermal evaporation and dilution. Identification was achieved by selected reaction monitoring (SRM). The most abundant fragment ion intensity of each compound was used for quantification. For DBDI and SESI, absolute gas phase detection limits in the low ppt range (in MS/MS mode) were achieved for all compounds investigated. Although the sensitivity of both methods was comparable, the active capillary DBDI sensitivity was found to be dependent on the applied AC voltage, thus enabling direct tuning of the sensitivity and the in-source fragmentation, which may become a key feature in terms of field applicability. Our findings underline the applicability of DBDI and SESI for the direct, sensitive detection and quantification of several CWA types and their degradation products. Furthermore, they suggest the use of DBDI in combination with hand-held instruments for CWAs on-site monitoring.

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

    OpenAIRE

    2015-01-01

    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...

  17. Pretreatment with high-fat enteral nutrition reduces ondotoxin and tumor necrosis factor-alpha and preserves gut barrier function early after hemorrhagic shock

    NARCIS (Netherlands)

    Luyer, M.D.; Buurman, W.A.; Hadfoune, M.; Jacobs, J.A.; Konstantinov, S.R.; Dejong, C.H.; Greve, J.W.

    2004-01-01

    Gram-negative sepsis is a potentially fatal clinical syndrome characterized by a proinflammatory response (tumor necrosis factor-alpha) to bacterial (endo)toxins and gut barrier function loss. Recently, we found that high-fat enteral nutrition protects against late bacterial translocation in a model

  18. Barriers to the provision of high-quality palliative care for people with dementia in England: a qualitative study of professionals' experiences

    NARCIS (Netherlands)

    Davies, N.; Maio, L.; Vedavanam, K.; Manthorpe, J.; Vernooij-Dassen, M.J.F.J.; Iliffe, S.

    2014-01-01

    Approaches to palliative care that were originally developed for people with cancer are now being adopted for people with dementia, as a response to many reports of poor-quality care for people with dementia at the end of life. This study explored perceived barriers to the delivery of high-quality p

  19. Pretreatment with high-fat enteral nutrition reduces ondotoxin and tumor necrosis factor-alpha and preserves gut barrier function early after hemorrhagic shock

    NARCIS (Netherlands)

    Luyer, M.D.; Buurman, W.A.; Hadfoune, M.; Jacobs, J.A.; Konstantinov, S.R.; Dejong, C.H.; Greve, J.W.

    2004-01-01

    Gram-negative sepsis is a potentially fatal clinical syndrome characterized by a proinflammatory response (tumor necrosis factor-alpha) to bacterial (endo)toxins and gut barrier function loss. Recently, we found that high-fat enteral nutrition protects against late bacterial translocation in a model

  20. High-barrier Schottky contact on n-type 4H-SiC epitaxial layer and studies of defect levels by deep level transient spectroscopy (DLTS)

    Science.gov (United States)

    Nguyen, Khai V.; Pak, Rahmi O.; Oner, Cihan; Mannan, Mohammad A.; Mandal, Krishna C.

    2015-08-01

    High barrier Schottky contact has been fabricated on 50 μm n-type 4H-SiC epitaxial layers grown on 350 μm thick substrate 8° off-cut towards the [11̅20] direction. The 4H-SiC epitaxial wafer was diced into 10 x 10 mm2 samples. The metal-semiconductor junctions were fabricated by photolithography and dc sputtering with ruthenium (Ru). The junction properties were characterized through current-voltage (I-V) and capacitance-voltage (C-V) measurements. Detectors were characterized by alpha spectroscopy measurements in terms of energy resolution and charge collection efficiency using a 0.1 μCi 241Am radiation source. It was found that detectors fabricated from high work function rare transition metal Ru demonstrated very low leakage current and significant improvement of detector performance. Defect characterization of the epitaxial layers was conducted by deep level transient spectroscopy (DLTS) to thoroughly investigate the defect levels in the active region. The presence of a new defect level induced by this rare transition metal-semiconductor interface has been identified and characterized.

  1. Calcium-activated potassium channels mediated blood-brain tumor barrier opening in a rat metastatic brain tumor model

    Directory of Open Access Journals (Sweden)

    Ong John M

    2007-03-01

    Full Text Available Abstract Background The blood-brain tumor barrier (BTB impedes the delivery of therapeutic agents to brain tumors. While adequate delivery of drugs occurs in systemic tumors, the BTB limits delivery of anti-tumor agents into brain metastases. Results In this study, we examined the function and regulation of calcium-activated potassium (KCa channels in a rat metastatic brain tumor model. We showed that intravenous infusion of NS1619, a KCa channel agonist, and bradykinin selectively enhanced BTB permeability in brain tumors, but not in normal brain. Iberiotoxin, a KCa channel antagonist, significantly attenuated NS1619-induced BTB permeability increase. We found KCa channels and bradykinin type 2 receptors (B2R expressed in cultured human metastatic brain tumor cells (CRL-5904, non-small cell lung cancer, metastasized to brain, human brain microvessel endothelial cells (HBMEC and human lung cancer brain metastasis tissues. Potentiometric assays demonstrated the activity of KCa channels in metastatic brain tumor cells and HBMEC. Furthermore, we detected higher expression of KCa channels in the metastatic brain tumor tissue and tumor capillary endothelia as compared to normal brain tissue. Co-culture of metastatic brain tumor cells and brain microvessel endothelial cells showed an upregulation of KCa channels, which may contribute to the overexpression of KCa channels in tumor microvessels and selectivity of BTB opening. Conclusion These findings suggest that KCa channels in metastatic brain tumors may serve as an effective target for biochemical modulation of BTB permeability to enhance selective delivery of chemotherapeutic drugs to metastatic brain tumors.

  2. On the influence of high voltage slope steepness on breakdown and development of pulsed dielectric barrier discharges

    Science.gov (United States)

    Höft, H.; Becker, M. M.; Loffhagen, D.; Kettlitz, M.

    2016-12-01

    The influence of the steepness of the applied high voltage (HV) waveform on the characteristics of pulsed dielectric barrier discharges (DBDs) is investigated using a single-filament arrangement with 1 mm gap in 0.1 vol% O2 in N2 at atmospheric pressure. The slope steepness was varied between 75 V ns-1 and 200 V ns-1. The discharge development was recorded with a combined iCCD and streak camera system accompanied by electrical measurements. The analysis was supported by time-dependent, spatially one-dimensional fluid model calculations. A steeper HV slope leads to a higher transferred charge and electrical energy per cycle. The DBD emission structure in the gap features a shorter ‘dark space’ in front of the cathode for steeper HV pulses. The starting velocity of the positive streamer-like propagation at the rising slope of the HV pulses increases with increasing slope steepness, but without influencing the maximal velocity in front of the cathode. At the falling slope, however, smaller propagation velocities for steeper pulses were measured. The modelling results and the measurements of the emission during the pre-phase suggest that the elevated pre-ionisation and higher electrical energy for steeper HV slopes is responsible for most of the observed effects.

  3. Application of High-Velocity Oxygen-Fuel (HVOF Spraying to the Fabrication of Yb-Silicate Environmental Barrier Coatings

    Directory of Open Access Journals (Sweden)

    Emine Bakan

    2017-04-01

    Full Text Available From the literature, it is known that due to their glass formation tendency, it is not possible to deposit fully-crystalline silicate coatings when the conventional atmospheric plasma spraying (APS process is employed. In APS, rapid quenching of the sprayed material on the substrate facilitates the amorphous deposit formation, which shrinks when exposed to heat and forms pores and/or cracks. This paper explores the feasibility of using a high-velocity oxygen-fuel (HVOF process for the cost-effective fabrication of dense, stoichiometric, and crystalline Yb2Si2O7 environmental barrier coatings. We report our findings on the HVOF process optimization and its resultant influence on the microstructure development and crystallinity of the Yb2Si2O7 coatings. The results reveal that partially crystalline, dense, and vertical crack-free EBCs can be produced by the HVOF technique. However, the furnace thermal cycling results revealed that the bonding of the Yb2Si2O7 layer to the Silicon bond coat needs to be improved.

  4. Overall and specific migration from multilayer high barrier food contact materials - kinetic study of cyclic polyester oligomers migration.

    Science.gov (United States)

    Úbeda, Sara; Aznar, Margarita; Vera, Paula; Nerín, Cristina; Henríquez, Luis; Taborda, Laura; Restrepo, Claudia

    2017-10-01

    Most multilayer high barrier materials used in food packaging have a polyurethane adhesive layer in their structures. In order to assess the safety of these materials, it is important to determine the compounds intentionally added to the adhesives (IAS) as well as those non-intentionally added substances (NIAS). During the manufacture of polyurethane adhesives, some by-products can be formed, such as cyclic polyester oligomers coming from the reaction between dicarboxylic acids and glycols. Since these compounds are not listed in the Regulation 10/2011/EU, they should not be found in migration above 0.01 mg/kg of simulant. In this study two flexible multilayer packaging materials were used and migration was evaluated in simulant A (ethanol 10% v/v), simulant B (acetic acid 3% w/v) and simulant ethanol 95% v/v during 10 days at 60ºC. Identification and quantification of non-volatile compounds was carried out by UPLC-MS-QTOF. Most of migrants were oligomers such as cyclic polyesters and caprolactam oligomers. Overall migration and specific migration of adipic acid-diethylene glycol and phthalic acid-diethylene glycol were monitored over time and analysed by UPLC-MS-TQ. In most cases, ethanol 95% v/v was the simulant with the highest concentration values. Overall migration kinetics followed a similar pattern than specific migration kinetics.

  5. Impact of barrier thickness on transistor performance in AlN/GaN high electron mobility transistors grown on free-standing GaN substrates

    Energy Technology Data Exchange (ETDEWEB)

    Deen, David A., E-mail: david.deen@alumni.nd.edu; Storm, David F.; Meyer, David J.; Bass, Robert; Binari, Steven C. [Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375-5347 (United States); Gougousi, Theodosia [Physics Department, University of Maryland Baltimore County, Baltimore, Maryland 21250 (United States); Evans, Keith R. [Kyma Technologies, Raleigh, North Carolina 27617 (United States)

    2014-09-01

    A series of six ultrathin AlN/GaN heterostructures with varied AlN thicknesses from 1.5–6 nm have been grown by molecular beam epitaxy on free-standing hydride vapor phase epitaxy GaN substrates. High electron mobility transistors (HEMTs) were fabricated from the set in order to assess the impact of barrier thickness and homo-epitaxial growth on transistor performance. Room temperature Hall characteristics revealed mobility of 1700 cm{sup 2}/V s and sheet resistance of 130 Ω/□ for a 3 nm thick barrier, ranking amongst the lowest room-temperature sheet resistance values reported for a polarization-doped single heterostructure in the III-Nitride family. DC and small signal HEMT electrical characteristics from submicron gate length HEMTs further elucidated the effect of the AlN barrier thickness on device performance.

  6. Mechanisms Underpinning Degradation of Protective Oxides and Thermal Barrier Coatings in High Hydrogen Content (HHC) - Fueled Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Mumm, Daniel

    2013-08-31

    The overarching goal of this research program has been to evaluate the potential impacts of coal-derived syngas and high-hydrogen content fuels on the degradation of turbine hot-section components through attack of protective oxides and thermal barrier coatings. The primary focus of this research program has been to explore mechanisms underpinning the observed degradation processes, and connections to the combustion environments and characteristic non-combustible constituents. Based on the mechanistic understanding of how these emerging fuel streams affect materials degradation, the ultimate goal of the program is to advance the goals of the Advanced Turbine Program by developing materials design protocols leading to turbine hot-section components with improved resistance to service lifetime degradation under advanced fuels exposures. This research program has been focused on studying how: (1) differing combustion environments – relative to traditional natural gas fired systems – affect both the growth rate of thermally grown oxide (TGO) layers and the stability of these oxides and of protective thermal barrier coatings (TBCs); and (2) how low levels of fuel impurities and characteristic non-combustibles interact with surface oxides, for instance through the development of molten deposits that lead to hot corrosion of protective TBC coatings. The overall program has been comprised of six inter-related themes, each comprising a research thrust over the program period, including: (i) evaluating the role of syngas and high hydrogen content (HHC) combustion environments in modifying component surface temperatures, heat transfer to the TBC coatings, and thermal gradients within these coatings; (ii) understanding the instability of TBC coatings in the syngas and high hydrogen environment with regards to decomposition, phase changes and sintering; (iii) characterizing ash deposition, molten phase development and infiltration, and associated corrosive

  7. Facilitators and barriers in the collaboration between the primary care and the sport sector in order to promote physical activity: A systematic literature review.

    Science.gov (United States)

    Leenaars, K E F; Smit, E; Wagemakers, A; Molleman, G R M; Koelen, M A

    2015-12-01

    The aim of this review was to identify collaborative initiatives between the primary care and the sport sector in order to promote physical activity (PA), and barriers and facilitators in these initiatives. Pubmed, SportDiscus, Web of Science, and SOCindex were systematically searched for publications published between 2000 and June 2014. Publications reporting on collaboration between the primary care and the sport sector to promote PA were included. Publications reporting on non-empirical data were excluded, except for study protocols. The search process yielded 1352 publications. After selection, 40 publications were included. Twenty-eight different initiatives were divided into four forms of collaboration, and two approaches to promote PA were distinguished with different kinds of facilitators and barriers. In the referral of patients, sport professionals' lack of medical knowledge, and health professionals' lack of time, were seen as barriers. In networks to organize activities to promote PA among the community, different shared interests and different cultures were seen as barriers. This review showed that performance of intersectoral collaboration and the collaboration between both sectors are still unexplored. This review provides a first step towards an insight into collaboration and factors that facilitate or hinder collaboration between these sectors. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. High Energy Activation Data Library (HEAD-2009)

    CERN Document Server

    Korovin, Yury A; Konobeyev, Alexander Yu; Stankovskiy, Alexey Yu; Mashnik, Stepan G

    2010-01-01

    A proton activation data library for 682 nuclides from 1-H to 210-Po in the energy range from 150 MeV up to 1 GeV was developed. To calculate proton activation data, the MCNPX 2.6.0 and CASCADE/INPE codes were chosen. Different intranuclear cascade, preequilibrium, and equilibrium nuclear reaction models and their combinations were used. The optimum calculation models have been chosen on the basis of statistical correlations for calculated and experimental proton data taken from the EXFOR library of experimental nuclear data. All the data are written in ENDF-6 format. The library is called HEPAD-2008 (High-Energy Proton Activation Data). A revision of IEAF-2005 neutron activation data library has been performed: A set of nuclides for which the cross-section data can be (and were) updated using more modern and improved models is specified, and the corresponding calculations have been made in the present work. The new version of the library is called IEAF-2009. The HEPAD-2008 and IEAF-2009 are merged to the fin...

  9. Development of a Dynamic Barrier Island (Sylt, Eastern North Sea) Based on High-Resolution Aerial Photographs and GIS

    Science.gov (United States)

    Dolch, T.; Hass, H. C.

    2004-12-01

    Wind and currents are the driving forces for the morphological development of coastlines and islands by giving them their shape, run and structure. This is especially true in highly dynamic areas such as the Wadden Sea in North-Western Europe. In this unique environment changes are continuous and distinct developments can be noticed within decades. The Island of Sylt, located in the Wadden Sea near the German-Danish border, is a sandy barrier island that protects the mainland against storm floods and waves. Thus, it experiences strong erosion (about 1 m coastal retreat per year). The North Atlantic Oscillation (NAO), that controls the atmospheric circulation over the North Sea, and northerly currents are the driving forces for the morphological development. Rising sea-level due to global change amplifies the erosion processes and forces people to protect the coastline (in this case beach nourishment). The Koenigshafen, a protected, semi-enclosed bay in the north of the Island of Sylt, can be regarded as representative for the study of many coastal processes that affect the island. In this case study, a long-term series of high resolution aerial photographs of the Koenigshafen (starting in 1936) shows the development of the survey area. Wind and currents affect not only the run of the coastline but also sediment composition and biodynamics in the bay. Looking at the hydrodynamics governing the bay, it should have mostly muddy sediments. Strong westerly winds, however, supply the bay with large amounts of sand from inland dunes and create sandy tidal flats. The long-term development of seagrass and mussel beds can also be retrieved from aerial photographs. In both cases a distinct decline in size can be noticed. Remote sensing and GIS techniques allow monitoring the conditions as well as to reconstruct the past development and to predict future developments.

  10. Eruca sativa and its flavonoid components, quercetin and isorhamnetin, improve skin barrier function by activation of peroxisome proliferator-activated receptor (PPAR)-α and suppression of inflammatory cytokines.

    Science.gov (United States)

    Kim, Bora; Choi, Yoon-E; Kim, Hyun-Soo

    2014-09-01

    Atopic dermatitis, which is related to dermatologic disorders and is associated with skin barrier dysfunction, represents an epidemic problem demanding effective therapeutic strategies. In the present study, we showed that the treatment with Eruca sativa extract resulted in a significant increase in the transactivation activity of peroxisome proliferator-activated receptor (PPAR) response element such as PPAR-α and suppression in the expression of inflammatory cytokine and antimicrobial peptides. In addition, E. sativa extract promotes the expression of filaggrin related to skin barrier protection. Quercetin and isorhamnetin, flavonoids' constituents of E. sativa, also promoted PPAR-α activity. These results indicate that E. sativa extract may be an appropriate material for improving skin barrier function as a skin therapeutic agent for atopic dermatitis.

  11. Short-Chain Fatty Acids Activate AMP-Activated Protein Kinase and Ameliorate Ethanol-Induced Intestinal Barrier Dysfunction in Caco-2 Cell Monolayers

    NARCIS (Netherlands)

    Eamin, E.E.; Masclee, A.A.; Dekker, J.; Pieters, H.J.; Jonkers, D.M.

    2013-01-01

    Short-chain fatty acids (SCFAs) have been shown to promote intestinal barrier function, but their protective effects against ethanol-induced intestinal injury and underlying mechanisms remain essentially unknown. The aim of the study was to analyze the influence of SCFAs on ethanol-induced barrier d

  12. Pathogenic Triad in Bacterial Meningitis: Pathogen Invasion, NF-κB Activation, and Leukocyte Transmigration that Occur at the Blood-Brain Barrier.

    Science.gov (United States)

    Wang, Shifu; Peng, Liang; Gai, Zhongtao; Zhang, Lehai; Jong, Ambrose; Cao, Hong; Huang, Sheng-He

    2016-01-01

    Bacterial meningitis remains the leading cause of disabilities worldwide. This life-threatening disease has a high mortality rate despite the availability of antibiotics and improved critical care. The interactions between bacterial surface components and host defense systems that initiate bacterial meningitis have been studied in molecular and cellular detail over the past several decades. Bacterial meningitis commonly exhibits triad hallmark features (THFs): pathogen penetration, nuclear factor-kappaB (NF-κB) activation in coordination with type 1 interferon (IFN) signaling and leukocyte transmigration that occur at the blood-brain barrier (BBB), which consists mainly of brain microvascular endothelial cells (BMEC). This review outlines the progression of these early inter-correlated events contributing to the central nervous system (CNS) inflammation and injury during the pathogenesis of bacterial meningitis. A better understanding of these issues is not only imperative to elucidating the pathogenic mechanism of bacterial meningitis, but may also provide the in-depth insight into the development of novel therapeutic interventions against this disease.

  13. Interrelations between blood-brain barrier permeability and matrix metalloproteinases are differently affected by tissue plasminogen activator and hyperoxia in a rat model of embolic stroke

    Directory of Open Access Journals (Sweden)

    Michalski Dominik

    2012-01-01

    Full Text Available Abstract Background In ischemic stroke, blood-brain barrier (BBB regulations, typically involving matrix metalloproteinases (MMPs and inhibitors (TIMPs as mediators, became interesting since tissue plasminogen activator (tPA-related BBB breakdown with risk of secondary hemorrhage was considered to involve these mediators too. Despite high clinical relevance, detailed interactions are purely understood. After a pilot study addressing hyperoxia as potential neuroprotective co-treatment to tPA, we analyzed interrelations between BBB permeability (BBB-P, MMPs and TIMPs. Findings Rats underwent embolic middle cerebral artery occlusion (eMCAO and treatment with normobaric (NBO or hyperbaric oxygen (HBO, tPA, tPA+HBO, or no treatment. BBB-P was assessed by intravenously applied FITC-albumin at 4 or 24 hours. MMP-2/-9 and TIMP-1/-2 serum levels were determined at 5 or 25 hours. Time point-corrected partial correlations were used to explore interrelations of BBB-P in ischemic regions (extra-/intravasal FITC-albumin ratio and related serum markers. BBB-P correlated positively with MMP-2 and MMP-9 in controls, whereas hyperoxia led to an inverse association, most pronounced for HBO/MMP-9 (r = -0.606; P Conclusions HBO was found to reverse the positively directed interrelation of BBB-P and MMPs after eMCAO, but this effect failed to sustain in the expected amount when HBO and tPA were given simultaneously.

  14. Pathogenic triad in bacterial meningitis: pathogen invasion, NF-κB activation and leukocyte transmigration that occur at the Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    Sheng-He eHuang

    2016-02-01

    Full Text Available Bacterial meningitis remains the leading cause of disabilities worldwide. This life-threatening disease has a high mortality rate despite the availability of antibiotics and improved critical care. The interactions between bacterial surface components and host defense systems that initiate bacterial meningitis have been studied in molecular and cellular detail over the past several decades. Bacterial meningitis commonly exhibits triad hallmark features (THFs: pathogen penetration, nuclear factor-kappaB (NF-B activation in coordination with type 1 interferon (IFN signaling and leukocyte transmigration that occur at the blood-brain barrier (BBB, which consists mainly of brain microvascular endothelial cells (BMEC. This review outlines the progression of these early inter-correlated events contributing to the central nervous system (CNS inflammation and injury during the pathogenesis of bacterial meningitis. A better understanding of these issues is not only imperative to elucidating the pathogenic mechanism of bacterial meningitis, but may also provide the in-depth insight into the development of novel therapeutic interventions against this disease.

  15. Activation of signaling pathways following localized delivery of systemically administered neurotrophic factors across the blood-brain barrier using focused ultrasound and microbubbles

    Science.gov (United States)

    Baseri, Babak; Choi, James J.; Deffieux, Thomas; Samiotaki, Gesthimani; Tung, Yao-Sheng; Olumolade, Oluyemi; Small, Scott A.; Morrison, Barclay, III; Konofagou, Elisa E.

    2012-04-01

    The brain-derived neurotrophic factor (BDNF) has been shown to have broad neuroprotective effects in addition to its therapeutic role in neurodegenerative disease. In this study, the efficacy of delivering exogenous BDNF to the left hippocampus is demonstrated in wild-type mice (n = 7) through the noninvasively disrupted blood-brain barrier (BBB) using focused ultrasound (FUS). The BDNF bioactivity was found to be preserved following delivery as assessed quantitatively by immunohistochemical detection of the pTrkB receptor and activated pAkt, pMAPK, and pCREB in the hippocampal neurons. It was therefore shown for the first time that systemically administered neurotrophic factors can cross the noninvasively disrupted BBB and trigger neuronal downstream signaling effects in a highly localized region in the brain. This is the first time that the administered molecule is tracked through the BBB and localized in the neuron triggering molecular effects. Additional preliminary findings are shown in wild-type mice with two additional neurotrophic factors such as the glia-derived neurotrophic factor (n = 12) and neurturin (n = 2). This further demonstrates the impact of FUS for the early treatment of CNS diseases at the cellular and molecular level and strengthens its premise for FUS-assisted drug delivery and efficacy.

  16. 女中学生滑冰课心理障碍的克服%To Overcome the Mental Barriers of Female High School Students in Skating Courses

    Institute of Scientific and Technical Information of China (English)

    杨忠强

    2013-01-01

      冬季滑冰课是黑龙江省学校的特色体育课程,教学实践表明滑冰课对学生的身心健康、运动技能的掌握具有积极促进的作用。在中学女生滑冰课程教学中,由于教师教法简单、形式单一,滑冰技术的难度较大,学生身体和心理素质的弱势导致其极易产生心理障碍,极大地降低了冬季体育教学的效果与质量,无法实现学校体育教学的总体目标。从培养和激发女中学生良好的滑冰学习动机入手,在教学中实施区别对待的原则,适当降低技术教学的难度,合理组织教学过程、采用多种教学方法逐步提高其身体和心理素质,克服她们对滑冰课的心理障碍,从而达到提高冬季滑冰课程教学的质量,实现素质教育的根本目标。%Winter skating is the characteristic sports course of schools in Heilongjiang Province .Teaching practice shows that skating course plays an active role in physical and mental health of students and maste -ring athletic skills.In skating teaching of female high school students , because the teaching method is simple and single form, skating technique is extremely difficult , weakness of physical and mental quality of students is very easy to produce mental barriers, it greatly reduce the effect and quality of winter sports teaching and unable to achieve the overall goal of school physical education .Starting with training and stimulating good skating motivation of female high school students , to implement the distinctive principles in teaching , appro-priately reduce the difficulty of technical teaching , rationally organize the teaching process, use a variety of teaching methods to improve their physical and mental quality , it will overcome their mental barriers of skat-ing course to improve the teaching quality of skating courses in winter and to achieve the ultimate goal of quality education.

  17. Thin tantalum-silicon-oxygen/tantalum-silicon-nitrogen films as high-efficiency humidity diffusion barriers for solar cell encapsulation

    Energy Technology Data Exchange (ETDEWEB)

    Heuer, H. [Institut fuer Halbleiter-und Mikrosystemtechnik (IHM) Technische Universitaet Dresden, Helmholtzstrasse 10, 01062 Dresden (Germany)]. E-mail: Henning.Heuer@izfp-d.fraunhofer.de; Wenzel, C. [Institut fuer Halbleiter-und Mikrosystemtechnik (IHM) Technische Universitaet Dresden, Helmholtzstrasse 10, 01062 Dresden (Germany); Herrmann, D. [Institut fuer Halbleiter-und Mikrosystemtechnik (IHM) Technische Universitaet Dresden, Helmholtzstrasse 10, 01062 Dresden (Germany); Zentrum fuer Sonnenenergie-und Wasserstoff-Forschung (ZSW) Industriestrasse 6, 70565 Stuttgart (Germany); Huebner, R. [Institut fuer Halbleiter-und Mikrosystemtechnik (IHM) Technische Universitaet Dresden, Helmholtzstrasse 10, 01062 Dresden (Germany); Leibniz Institut fuer Festkoerper-und Werkstoffforschung Dresden (IFW) Helmholtzstrasse 20, 01069, Dresden (Germany); Zhang, Z.L. [Institut fuer Halbleiter-und Mikrosystemtechnik (IHM) Technische Universitaet Dresden, Helmholtzstrasse 10, 01062 Dresden (Germany); Max-Planck-Gesellschaft fuer Metallforschung (MPI) Heisenbergstrasse 3, 70569 Stuttgart (Germany); Bartha, J.W. [Institut fuer Halbleiter-und Mikrosystemtechnik (IHM) Technische Universitaet Dresden, Helmholtzstrasse 10, 01062 Dresden (Germany)

    2006-12-05

    Flexible thin-film solar cells require flexible encapsulation to protect the copper-indium-2 selenide (CIS) absorber layer from humidity and aggressive environmental influences. Tantalum-silicon-based diffusion barriers are currently a favorite material to prevent future semiconductor devices from copper diffusion. In this work tantalum-silicon-nitrogen (Ta-Si-N) and tantalum-silicon-oxygen (Ta-Si-O) films were investigated and optimized for thin-film solar cell encapsulation of next-generation flexible solar modules. CIS solar modules were coated with tantalum-based barrier layers. The performance of the thin-film barrier encapsulation was determined by measuring the remaining module efficiency after a 1000 h accelerated aging test. A significantly enhanced stability against humidity diffusion in comparison to non-encapsulated modules was reached with a reactively sputtered thin-film system consisting of 250 nm Ta-Si-O and 15 nm Ta-Si-N.

  18. A cross sectional observational study of research activity of allied health teams: is there a link with self-reported success, motivators and barriers to undertaking research?

    Science.gov (United States)

    Wenke, Rachel J; Mickan, Sharon; Bisset, Leanne

    2017-02-06

    Team-based approaches to research capacity building (RCB) may be an efficient means to promote allied health research participation and activity. In order to tailor such interventions, a clearer understanding of current patterns of research participation within allied health teams is needed. Different self-report measures exist which evaluate a team's research capacity and participation, as well as associated barriers and motivators. However, it remains unclear how such measures are associated with a team's actual research activity (e.g., journal publications, funding received). In response, this observational study aimed to identify the research activity, self-reported success, and motivations and barriers to undertaking research of eight allied health professional (AHP) teams and to explore whether any relationships exist between the self-reported measures and actual research activity within each team. A total of 95 AHPs from eight teams completed the research capacity and culture survey to evaluate team success, barriers and motivators to undertaking research, and an audit of research activity from January 2013 to August 2014 was undertaken within each team. Kendell's correlation coefficients were used to determine the association between research activity (i.e., number of journal publications, ethically approved projects and funding received) and the self-reported measures. Seven out of eight teams rated their teams as having average success in research and demonstrated some form of research activity including at least two ethically approved projects. Research activity varied between teams, with funding received ranging from $0 to over $100,000, and half the teams not producing any journal publications. Team motivators demonstrated a stronger association with research activity compared to barriers, with the motivator "enhancing team credibility" being significantly associated with funding received. No significant association between self-reported research

  19. Persistent Supercooling of Reproductive Shoots Is Enabled by Structural Ice Barriers Being Active Despite an Intact Xylem Connection

    Science.gov (United States)

    Pfaller, Kristian; Wagner, Johanna

    2016-01-01

    Extracellular ice nucleation usually occurs at mild subzero temperatures in most plants. For persistent supercooling of certain plant parts ice barriers are necessary to prevent the entry of ice from already frozen tissues. The reproductive shoot of Calluna vulgaris is able to supercool down to below -22°C throughout all developmental stages (shoot elongation, flowering, fruiting) despite an established xylem conductivity. After localization of the persistent ice barrier between the reproductive and vegetative shoot at the base of the pedicel by infrared differential thermal analysis, the currently unknown structural features of the ice barrier tissue were anatomically analyzed on cross and longitudinal sections. The ice barrier tissue was recognized as a 250 μm long constriction zone at the base of the pedicel that lacked pith tissue and intercellular spaces. Most cell walls in this region were thickened and contained hydrophobic substances (lignin, suberin, and cutin). A few cell walls had what appeared to be thicker cellulose inclusions. In the ice barrier tissue, the area of the xylem was as much as 5.7 times smaller than in vegetative shoots and consisted of tracheids only. The mean number of conducting units in the xylem per cross section was reduced to 3.5% of that in vegetative shoots. Diameter of conducting units and tracheid length were 70% and 60% (respectively) of that in vegetative shoots. From vegetative shoots water transport into the ice barrier must pass pit membranes that are likely impermeable to ice. Pit apertures were about 1.9 μm x 0.7 μm, which was significantly smaller than in the vegetative shoot. The peculiar anatomical features of the xylem at the base of the pedicel suggest that the diameter of pores in pit membranes could be the critical constriction for ice propagation into the persistently supercooled reproductive shoots of C. vulgaris. PMID:27632365

  20. [ACTIVITY OF ANTIMICROBIAL NANOSTRUCTURED BARRIER LAYERS BASED ON POLYETHYLENETEREPHTHALATE IN RELATION TO CLINICAL STRAINES OF MICROORGANISMS FOR SICK PERSONS OF GASTROENTEROLOGICAL PROFILE].

    Science.gov (United States)

    Elinson, V M; Rusanova, E V; Vasilenko, I A; Lyamin, A N; Kostyuchenko, L N

    2015-01-01

    Homeostasis transgressions of enteral medium including disbiotic ones are often accompanying deseases of digestive tract. Espessially it touches upon sick persons connected with probe nourishing. One of the way for solving this problem is normalization of digestion microflore by means of wares with nanotechnological modifications of walls (probes, stomic tubes) which provide them antimicrobial properties and assist to normalization of digestive microbiotis and enteral homeostasis completely. The aim to study is research of antimicrobial activity of of nanostructured barrier layers based on polyethyleneterephthalate (PET) in relation to clinical straines of microorganisms. For barrier layer creation the approach on the base of methods of ion-plasma technology was used including ion-plasma treatment (nanostructuring) of the surface by ions noble and chemically active gases and following formation nanodimensional carbon films on the surface/ For the study of antimicrobial activity in relation to clinical straines of microorganisms we used the technique which allowed to establish the influence of parting degree of microorganisms suspension and time for samples exposing and microorganisms adsorbed on the surface. In experiment clinical straines obtained from different materials were used: Staphylococcus Hly+ and Calbicans--from pharyngeal mucosa, E. coli--from feces, K.pneumoniae--from urine. Sharing out and species identification of microorganisms were fulfilled according with legasy documents. In results of the study itwas obtained not only the presence of staticticaly confirmed antimicrobial activity of PET samples with nanostructured barrier layers in relation to different stimulators of nosocomical infections but also the influence of different factors connected with formation of nanostructured layers and consequently based with them physicochemical characteristics such as, in particular, surface energy, surface relief parameters, surface charg and others, as well

  1. Office-Based Physical Activity and Nutrition Intervention: Barriers, Enablers, and Preferred Strategies for Workplace Obesity Prevention, Perth, Western Australia, 2012

    OpenAIRE

    Blackford, Krysten; Jancey, Jonine; Howat, Peter; Ledger, Melissa; Andy H. Lee

    2013-01-01

    Introduction Workplace health promotion programs to prevent overweight and obesity in office-based employees should be evidence-based and comprehensive and should consider behavioral, social, organizational, and environmental factors. The objective of this study was to identify barriers to and enablers of physical activity and nutrition as well as intervention strategies for health promotion in office-based workplaces in the Perth, Western Australia, metropolitan area in 2012. Methods We cond...

  2. Analysis of Schottky barrier heights of metal/SiC contacts and its possible application to high-voltage rectifying devices

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, A. [Tokyo Inst. of Technol. (Japan). Dept. of Phys. Electron.; Matsunami, H. [Dept. of Electronic Science and Engineering, Kyoto Univ. (Japan)

    1997-07-16

    Schottky contacts of metal/3C-, 6H-, and 4H-SiC systems are investigated in this review. Most Schottky contacts having large barrier heights show good characteristics with low ideality factors. The barrier height depends on the metal work function without strong Fermi-level pinning for all polytypes, and linear relationships with slopes of about 0.2 to 0.7 are observed between the barrier height and the metal work function. Based on the analysis of metal/SiC systems, the fabrication of high-voltage rectifiers has been reported, and high voltages from 400 to 1100 V have been achieved using Pt/, Ti/, and Au/6H-SiC structures. In addition, high-temperature operation at 400 C is performed for an Au/6H-SiC structure while supporting a high reverse bias (460 V). Using Ti/4H-SiC structures, high-voltage ({approx}1000 V) and low-power loss characteristics are realized, which is superior to Ti/6H-SiC Schottky rectifiers. To improve the reverse bias characteristics, an edge termination technique is employed for Ti/4H-SiC Schottky rectifiers, and the devices show excellent characteristics with a higher blocking voltage up to 1750 V compared with unterminated devices. (orig.) 78 refs.

  3. Beneficial Effect of HHI-Ⅰ(活血化瘀注射液Ⅰ号)on Cerebral Microcirculation,Blood-Brain Barrier in Rats and Anti-hypoxic Activity in Mice

    Institute of Scientific and Technical Information of China (English)

    赵连根; 吴咸中; 伍孝先

    2009-01-01

    Objective:To investigate the effect of HHI-Ⅰ(活血化瘀注射液Ⅰ号) on the cerebral microcirculation,the blood-brain barrier permeability in rats and anti-hypoxic activity in mice.Methods:(1) The blood microcirculation of the brain in rats was investigated by laser Doppler flowmetry with the probes laid on the cerebral pia mater or inserted into the brain parenchyma.(2) The protective action of HHI-Ⅰagainst the brain microcirculation disturbance induced by intravenous injection of high-molecular dextran(10%,9 mL/kg)...

  4. A computational method for the systematic screening of reaction barriers in enzymes: Searching for Bacillus circulans xylanase mutants with greater activity towards a synthetic substrate

    CERN Document Server

    Hediger, Martin R; De Vico, Luca; Jensen, Jan H

    2013-01-01

    We present a semi-empirical (PM6-based) computational method for systematically estimating the effect of all possible single mutants, within a certain radius of the active site, on the barrier height of an enzymatic reaction. The intent of this method is not a quantitative prediction of the barrier heights, but rather to identify promising mutants for further computational or experimental study. The method is applied to identify promising single and double mutants of Bacillus circulans xylanase (BCX) with increased hydrolytic activity for the artificial substrate ortho-nitrophenyl \\beta-xylobioside (ONPX$_2$). The estimated reaction barrier for wild-type (WT) BCX is 18.5 kcal/mol, which is in good agreement with the experimental activation free energy value of 17.0 kcal/mol extracted from the observed k$_\\text{cat}$ using transition state theory (Joshi et al., Biochemistry 2001, 40, 10115). The PM6 reaction profiles for eight single point mutations are recomputed using FMO-MP2/PCM/6-31G(d) single points. PM6 ...

  5. Health system barriers to implementation of collaborative TB and HIV activities including prevention of mother to child transmission in South Africa.

    Science.gov (United States)

    Uwimana, J; Jackson, D; Hausler, H; Zarowsky, C

    2012-05-01

    In South Africa, the control of TB and HIV co-infection remains a major challenge despite the availability of international and national guidelines for integration of TB and HIV services. This study was undertaken in KwaZulu-Natal, one of the provinces most affected by both TB and HIV, to identify and understand managers' and community care workers' (CCWs) perceptions of health systems barriers related to the implementation of collaborative TB/HIV activities, including prevention of mother to child transmission of HIV (PMTCT). We conducted 29 in-depth interviews with health managers at provincial, district and facility level and with managers of NGOs involved in TB and HIV care, as well as six focus group discussions with CCWs. Thematic analysis of transcripts revealed a convergence of perspectives on the process and the level of the implementation of policy directives on collaborative TB and HIV activities across all categories of respondents (i.e. province-, district-, facility- and community-based organizations). The majority of participants felt that the implementation of the policy was insufficiently consultative and that leadership and political will were lacking. The predominant themes related to health systems barriers include challenges related to structure and organisational culture; management, planning and power issues; unequal financing; and human resource capacity and regulatory problems notably relating to scope of practice of nurses and CCWs. Accelerated implementation of collaborative TB/HIV activities including PMTCT will require political will and leadership to address these health systems barriers. © 2012 Blackwell Publishing Ltd.

  6. Concrete with Highly Active Rice Husk Ash

    Institute of Scientific and Technical Information of China (English)

    FENG Qing-ge; LIN Qing-yu; YU Qi-jun; ZHAO San-ying; YANG Lu-feng; Shuichi Sugita

    2004-01-01

    The overall aim was to investigate the effect of highly active rice husk ash (RHA) produced by an industrial furnace on some properties of concrete. The strength, pore volume and pore distribution of concrete and the Ca(OH)2 content in concrete were investigated by JIS A 1108 (Method of test for compressive strength of concrete), a mercury instrument porosimeter, and the thermogravimetric analysis, respectively. The results show that,with RHA replacement of cement,the compressive strength of concrete is increased evidently;the average pore radius of concrete is greatly decreased, especially the portion of the pores greater than 20nm in radius is decreased while the amount of smaller pores is increased, and the more the RHA replacement, the less the amount of Ca(OH)2 in concrete. The latter two results are the main reasons for the strength enhancement of concrete.

  7. 高阻隔性PET瓶的研究进展%Progresses and Developments of High Barrier PET Bottles

    Institute of Scientific and Technical Information of China (English)

    蔡亮珍; 赵建青

    2001-01-01

    对近年来提高聚酯(PET)阻隔性的先进方法和技术以及相关研究进展状况作了概述。%This article reviewes the advanced methods and technology ofimproving the barrier property of PET bottles and the related progresses and developments.

  8. Barriers to Screening and Possibilities for Active Detection of Family Medicine Attendees Exposed to Intimate Partner Violence

    Directory of Open Access Journals (Sweden)

    Kopčavar Guček Nena

    2016-03-01

    Full Text Available In 1996 the World Health Organization declared intimate partner violence (IPV the most important public health problem. Meta-analyses in 2013 showed every third female globally had been a victim of violence. Experts find screening controversial; family medicine is the preferred environment for identifying victims of violence, but barriers on both sides prevent patients from discussing it with doctors.

  9. Barriers and Facilitators to Healthy Eating and Activity in Head Start Staff: An Opportunity for Worksite Wellness

    Science.gov (United States)

    Hibbs-Shipp, Sarah K.; Milholland, Michelle; Bellows, Laura

    2015-01-01

    Background: Head Start (HS) staff are ideally positioned to promote healthy behaviors to over one million low-income children each year, however little is understood about their own health. Purpose: To conduct a needs assessment with HS staff to: 1) understand perceptions, barriers and motivators to healthful behaviors; and 2) ascertain interest…

  10. [Psychometric properties of the spanish version of the "Barriers to Being Active Quiz" among university students in Colombia].

    Science.gov (United States)

    Rubio-Henao, Rubén Fernando; Correa, Jorge Enrique; Ramírez-Vélez, Robinson

    2015-04-01

    Objetivo: El cuestionario Barriers to Being Active Quiz (BBAQ), indaga las barreras para ser físicamente activo. El cuestionario fue traducido al español por el mismo equipo que desarrolló la versión inglésa original, pero carece de estudios de validez en la versión española. El objetivo de esta investigación fue evaluar las propiedades psicométricas del BBAQ (en la versión completa de 21 ítems), centrándose en la fiabilidad y validez. Material y métodos: Un total de 2.634 (1.462 mujeres y 1.172 varones; 18-30 años de edad) estudiantes universitarios completaron el cuestionario BBAQ-21. El alfa de Crombach se estimó como indicador de consistencia interna. El coeficiente de correlación intra-clase (CCI) y el grado de acuerdo se calcularon para evaluar la estabilidad temporal con un periodo de 7 días entre ambas administraciones como estimadores de la reproducibilidad. Se aplicó un análisis factorial exploratorio (AFE) y confirmatorio (AFC) para analizar la validez del BBAQ-21 ítems. Resultados: El BBAQ-21 mostró valores de un alfa de Cronbach entre 0,812 y 0,844 y un CCI entre el 0,46 y 0,87. El porcentaje de acuerdo por todos los conceptos individuales varió de 45 a 80%. El AFE determinó cuatro factores que explicaron el 52,90% de la varianza y el AFC mostró moderadas cargas factoriales. Conclusiones: Los resultados obtenidos en este cuestionario avalan la utilización de este instrumento con este tipo de muestra, desde el punto de vista de la fiabilidad y validez. El BBAQ-21 está disponible para evaluar las barreras para la actividad física en América Latina.

  11. High critical current densities reproducibly observed for hot-isostatic-pressed PbMo6S8 wires with Mo barriers

    Science.gov (United States)

    Yamasaki, H.; Umeda, M.; Kosaka, S.

    1992-08-01

    Fabrication process, critical current densities (Jc), and microstructure of the superconducting PbMo6S8 wires with Mo barriers have been investigated. Reducing the volume fraction of the Mo barrier and using electron-beam-melted Mo with less deformation resistance than that of conventional powder-metallurgy-processed Mo, facilitate the densification of PbMo6S8 and Jc improvement by the hot-isostatic-pressing (HIP) treatments. It was possible to obtain reproducibly HIP-treated PbMo6S8 wires with homogeneously high Jc not less than 10 exp 8 A/sq m at 22 T and 4.2 K, which is promising for the production of future high field (greater than 20 T) superconducting magnets.

  12. High-voltage 4H-SiC trench MOS barrier Schottky rectifier with low forward voltage drop using enhanced sidewall layer

    Science.gov (United States)

    Cho, Doohyung; Sim, Seulgi; Park, Kunsik; Won, Jongil; Kim, Sanggi; Kim, Kwangsoo

    2015-12-01

    In this paper, a 4H-SiC trench MOS barrier Schottky (TMBS) rectifier with an enhanced sidewall layer (ESL) is proposed. The proposed structure has a high doping concentration at the trench sidewall. This high doping concentration improves both the reverse blocking and forward characteristics of the structure. The ESL-TMBS rectifier has a 7.4% lower forward voltage drop and a 24% higher breakdown voltage. However, this structure has a reverse leakage current that is approximately three times higher than that of a conventional TMBS rectifier owing to the reduction in energy barrier height. This problem is solved when ESL is used partially, since its use provides a reverse leakage current that is comparable to that of a conventional TMBS rectifier. Thus, the forward voltage drop and breakdown voltage improve without any loss in static and dynamic characteristics in the ESL-TMBS rectifier compared with the performance of a conventional TMBS rectifier.

  13. Study of the interactions bacteria - phenanthrene - activated carbon for the preparation of a permeable reactive barrier; Etude des interactions bacteries - phenanthrene - charbon en vue de l'elaboration d'une barriere permeable reactive

    Energy Technology Data Exchange (ETDEWEB)

    Leglize, P.

    2004-12-01

    Permeable Reactive Barrier (PRB) is a new way for the remediation of contaminated groundwater, but up to now Polycyclic Aromatic Hydrocarbons (PAHs) were rarely considered. We investigated PAH - bacteria - materials interactions in order to validate the feasibility of PRB for PAH contamination. PHE Adsorption/desorption kinetics onto different materials, activated carbons (CA), pozzolana (Pz) and pozzolana coated with heavy fuel (PzF), were investigated. PHE biodegradation were performed on batch using PAH degrading bacteria and the PRB materials. CA was a good media for PRB process: Phenanthrene sorption capacity is 100 to 10000 fold higher than PzF and Pz. Phenanthrene mineralization with CA was higher than without material. Bacterial properties affected PHE biodegradation. Bio-film production improved PHE biodegradation by PAH degrading bacteria. Column studies showed that inoculation of the column improved its efficiency: adsorbed PHE degradation and increased retardation of PHE. (author)

  14. Comparison of skin barrier function and sensory nerve electric current perception threshold between IgE-high extrinsic and IgE-normal intrinsic types of atopic dermatitis.

    Science.gov (United States)

    Mori, T; Ishida, K; Mukumoto, S; Yamada, Y; Imokawa, G; Kabashima, K; Kobayashi, M; Bito, T; Nakamura, M; Ogasawara, K; Tokura, Y

    2010-01-01

    Background Two types of atopic dermatitis (AD) have been proposed, with different pathophysiological mechanisms underlying this seemingly heterogeneous disorder. The extrinsic type shows high IgE levels presumably as a consequence of skin barrier damage and feasible allergen permeation, whereas the intrinsic type exhibits normal IgE levels and is not mediated by allergen-specific IgE. Objectives To investigate the relationship between pruritus perception threshold and skin barrier function of patients with AD in a comparison between the extrinsic and intrinsic types. Methods Enrolled in this study were 32 patients with extrinsic AD, 17 with intrinsic AD and 24 healthy individuals. The barrier function of the stratum corneum was assessed by skin surface hydration and transepidermal water loss (TEWL), and pruritus perception was evaluated by the electric current perception threshold (CPT) of sensory nerves upon neuroselective transcutaneous electric stimulation. Results Skin surface hydration was significantly lower and TEWL was significantly higher in extrinsic AD than intrinsic AD or normal controls. Although there was no statistically significant difference in CPT among extrinsic AD, intrinsic AD and normal controls, CPT was significantly correlated with skin surface hydration and inversely with TEWL in intrinsic AD and normal controls, but not extrinsic AD. Finally, CPT was correlated with the visual analogue scale of itch in the nonlesional skin of patients with extrinsic but not intrinsic AD. Conclusions Patients with extrinsic AD have an impaired barrier, which increases the pre-existing pruritus but rather decreases sensitivity to external stimuli. In contrast, patients with intrinsic AD retain a normal barrier function and sensory reactivity to external pruritic stimuli.