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Sample records for 2-year study conducted

  1. MST with Conduct Disordered Youth in Sweden: Costs and Benefits after 2 Years

    ERIC Educational Resources Information Center

    Olsson, Tina M.

    2010-01-01

    Objectives: The purpose of this study was to investigate the costs and benefits associated with multisystemic therapy (MST) for conduct disordered youth, 2 years following intake. Methods: The study employed a secondary analysis of 156 youth enrolled in a randomized trial assessing the psychosocial and behavioral outcomes of MST. Results: MST cost…

  2. The Prevalence of Autism Spectrum Disorders in Toddlers: A Population Study of 2-Year-Old Swedish Children

    ERIC Educational Resources Information Center

    Nygren, Gudrun; Cederlund, Mats; Sandberg, Eva; Gillstedt, Fredrik; Arvidsson, Thomas; Gillberg, I. Carina; Andersson, Gunilla Westman; Gillberg, Christopher

    2012-01-01

    Autism Spectrum Disorder (ASD) is more common than previously believed. ASD is increasingly diagnosed at very young ages. We report estimated ASD prevalence rates from a population study of 2-year-old children conducted in 2010 in Gothenburg, Sweden. Screening for ASD had been introduced at all child health centers at child age 21/2 years. All…

  3. Low skin conductance activity in infancy predicts aggression in toddlers 2 years later.

    PubMed

    Baker, Erika; Shelton, Katherine H; Baibazarova, Eugenia; Hay, Dale F; van Goozen, Stephanie H M

    2013-06-01

    Low autonomic nervous system activity is claimed to be a biomarker for aggressive and antisocial behavior. Although there is evidence that low skin conductance activity (SCA) accounts for variation in the severity of antisocial behavior and predicts the onset of aggression in children and adults, it is unknown whether SCA measured in infancy can predict the development of aggression. We measured SCA in 70 typically developing 1-year-old infants at baseline, during an orienting habituation paradigm, and during a fear challenge. We also observed the infants' fear behavior, and each mother rated her infant's temperament and her attachment to her child. At follow-up, mothers rated the children at 3 years old for aggressive and nonaggressive behavior problems. Low infant SCA predicted aggressive behavior, but there was no association between SCA and nonaggressive behavior problems. Mothers' ratings of the infants' temperament and their maternal attachment and the infants' observed fearlessness did not predict later aggression. These results suggest that SCA is a specific biomarker for aggression in low-risk samples of infants.

  4. Learning, Memory, and Executive Function in New MDMA Users: A 2-Year Follow-Up Study

    PubMed Central

    Wagner, Daniel; Tkotz, Simon; Koester, Philip; Becker, Benjamin; Gouzoulis-Mayfrank, Euphrosyne; Daumann, Joerg

    2015-01-01

    3,4-Methylenedioxymethamphetamine (MDMA) is associated with changes in neurocognitive performance. Recent studies in laboratory animals have provided additional support for the neurodegeneration hypothesis. However, results from animal research need to be applied to humans with caution. Moreover, several of the studies that examine MDMA users suffer from methodological shortcomings. Therefore, a prospective cohort study was designed in order to overcome these previous methodological shortcomings and to assess the relationship between the continuing use of MDMA and cognitive performance in incipient MDMA users. It was hypothesized that, depending on the amount of MDMA taken, the continued use of MDMA over a 2-year period would lead to further decreases in cognitive performance, especially in visual paired association learning tasks. Ninety-six subjects were assessed, at the second follow-up assessment: 31 of these were non-users, 55 moderate-users, and 10 heavy-users. Separate repeated measures analyses of variance were conducted for each cognitive domain, including attention and information processing speed, episodic memory, and executive functioning. Furthermore, possible confounders including age, general intelligence, cannabis use, alcohol use, use of other concomitant substances, recent medical treatment, participation in sports, level of nutrition, sleep patterns, and subjective well-being were assessed. The Repeated measures analysis of variance (rANOVA) revealed that a marginally significant change in immediate and delayed recall test performances of visual paired associates learning had taken place within the follow-up period of 2 years. No further deterioration in continuing MDMA-users was observed in the second follow-up period. No significant differences with the other neuropsychological tests were noted. It seems that MDMA use can impair visual paired associates learning in new users. However, the groups differed in their use of concomitant use of

  5. Learning, Memory, and Executive Function in New MDMA Users: A 2-Year Follow-Up Study.

    PubMed

    Wagner, Daniel; Tkotz, Simon; Koester, Philip; Becker, Benjamin; Gouzoulis-Mayfrank, Euphrosyne; Daumann, Joerg

    2015-01-01

    3,4-Methylenedioxymethamphetamine (MDMA) is associated with changes in neurocognitive performance. Recent studies in laboratory animals have provided additional support for the neurodegeneration hypothesis. However, results from animal research need to be applied to humans with caution. Moreover, several of the studies that examine MDMA users suffer from methodological shortcomings. Therefore, a prospective cohort study was designed in order to overcome these previous methodological shortcomings and to assess the relationship between the continuing use of MDMA and cognitive performance in incipient MDMA users. It was hypothesized that, depending on the amount of MDMA taken, the continued use of MDMA over a 2-year period would lead to further decreases in cognitive performance, especially in visual paired association learning tasks. Ninety-six subjects were assessed, at the second follow-up assessment: 31 of these were non-users, 55 moderate-users, and 10 heavy-users. Separate repeated measures analyses of variance were conducted for each cognitive domain, including attention and information processing speed, episodic memory, and executive functioning. Furthermore, possible confounders including age, general intelligence, cannabis use, alcohol use, use of other concomitant substances, recent medical treatment, participation in sports, level of nutrition, sleep patterns, and subjective well-being were assessed. The Repeated measures analysis of variance (rANOVA) revealed that a marginally significant change in immediate and delayed recall test performances of visual paired associates learning had taken place within the follow-up period of 2 years. No further deterioration in continuing MDMA-users was observed in the second follow-up period. No significant differences with the other neuropsychological tests were noted. It seems that MDMA use can impair visual paired associates learning in new users. However, the groups differed in their use of concomitant use of

  6. Motor recovery after stroke depends on intact sustained attention: a 2-year follow-up study.

    PubMed

    Robertson, I H; Ridgeway, V; Greenfield, E; Parr, A

    1997-04-01

    The functional recovery of 47 right-brain-damaged stroke patients was studied over a 2-year period. The researchers hypothesized that sustained attention capacity should predict the degree of motor and functional recovery over this period because of a proposed privileged role of sustained attention in learning-based recovery of function. As predicted, significant correlations were found between sustained attention capacity at 2 months and functional status (including the Barthel Index) at 2 years. This relationship was shown to exist independently of 2-month functional status. Furthermore, compared with a left-brain-damaged group of cerebrovascular accident (CVA) patients, the right-brain CVA group did not recover functional ability as well over the 2-year period. This increasing difference in functional status over a 2-year period was mirrored by an emerging difference in sustained attention capacity, in favor of the left-brain CVA group.

  7. Improving Social Competence through Emotion Knowledge in 2-Year-Old Children: A Pilot Study

    ERIC Educational Resources Information Center

    Giménez-Dasí, Marta; Fernández-Sánchez, Marta; Quintanilla, Laura

    2015-01-01

    Research Findings: The goal of this study was to determine the efficacy of an educational intervention program to improve emotion knowledge, emotion regulation, and social competence in 2-year-old Spanish children. This study makes two original contributions because there are no validated education programs for such young children and because it…

  8. Treatment adherence among new triptan users: a 2-year cohort study in Taiwan

    PubMed Central

    2014-01-01

    Background The persistence of triptan use among newly prescribed users is low in the United States and European countries. However, triptan refill patterns in Asian primary care practices have not been well described. Methods Data from the National Health Insurance Research Database in Taiwan were used to conduct a retrospective cohort analysis from 2005 to 2008. All participants were followed for 2 years after receiving a new triptan prescription. Refill and 2-year retention rates of newly prescribed triptans were calculated, and predictors of the first triptan refill and 2-year retention were analyzed. Results Of the 13,951 participants with a new triptan prescription (99.9% sumatriptan), 67.4% were prescribed by a neurologist, 67.4% were prescribed at least one prophylactic agent for migraine. Of them, 34.3% adhered to the newly prescribed triptan at the first refill, 0.01% switched to another triptan, and 40.9% switched to a non-triptan acute migraine medication. The 2-year retention rate was 4.0%. The frequency of headache-related neurologic visits for 1 year before the index date, first prescription of triptan or other acute medications, first triptan prescription by a neurologist, and prophylactic use were associated with higher first refill rates. The frequency of headache-related neurologic visits 1 year before the index date and first triptan prescription by a neurologist were related to higher 2-year retention rates. Diabetes mellitus and first triptan prescription at a local medical clinic were associated with reduced probability of continued triptan use at the first refill and 2 years. Conclusions Similar to Western societies, the refill and 2-year retention rates were low in new users of triptans. Frequency of neurologic visits and triptan prescription by a neurologist were significant predictors of adherence. PMID:25117594

  9. Sexual abstinence in patients with HIV infection: a 2-year follow-up study.

    PubMed

    Jordan, W C

    1991-12-01

    Thirty-five human immunodeficiency virus (HIV)-positive patients were followed over a 2-year period. All agreed to abstain from sexual intercourse. This group had a low level of recurring infections. A comparison study of sexually active HIV males is underway.

  10. Residue level and dissipation pattern of spiromesifen in cabbage and soil from 2-year field study.

    PubMed

    Siddamallaiah, Lekha; Mohapatra, Soudamini

    2016-03-01

    Spiromesifen is a new class of insecticide used for the control of whiteflies and mites which have developed resistance to the more commonly used neonicotinoids. Dissipation pattern of spiromesifen on cabbage was evaluated over 2 years by conducting supervised field studies as per good agricultural practices. Cabbage and soil samples were extracted and purified using modified QuEChERS method and analyzed through gas chromatography (GC). Confirmatory studies were carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The recoveries of spiromesifen from cabbage and soil were between 85.44 and 103.37% with the relative standard deviation (RSD) between 3.2 and 9.4% (n = 6). The limit of detection (LOD) and limit of quantification (LOQ) were 0.003 μg mL(-1) and 0.01 mg kg(-1), respectively. The measurement uncertainties (MUs) were within 9.9-14.9%. Initial residues of spiromesifen on cabbage were 0.640 and 1.549 mg kg(-1) during 2013 and 0.723 and 1.438 mg kg(-1) during 2014 from treatments at standard and double doses of 125 and 250 g active ingredient (a.i.) ha(-1), respectively. Spiromesifen residue dissipation followed first-order rate kinetics, and it degraded within the half-lives of 2.9 and 3.9 days during 2013 and 3.2 and 4.5 days during 2014. The residue levels reached below the maximum residue limit (MRL; 0.02 mg kg(-1)) within 15-17 days at the standard dose and 24-27 days at the double dose. The field soil analyzed at harvest (30 days) was free from spiromesifen residues. Metabolite spiromesifen-enol was not detected in any sample which was confirmed through LC-MS/MS analysis.

  11. Residue level and dissipation pattern of spiromesifen in cabbage and soil from 2-year field study.

    PubMed

    Siddamallaiah, Lekha; Mohapatra, Soudamini

    2016-03-01

    Spiromesifen is a new class of insecticide used for the control of whiteflies and mites which have developed resistance to the more commonly used neonicotinoids. Dissipation pattern of spiromesifen on cabbage was evaluated over 2 years by conducting supervised field studies as per good agricultural practices. Cabbage and soil samples were extracted and purified using modified QuEChERS method and analyzed through gas chromatography (GC). Confirmatory studies were carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The recoveries of spiromesifen from cabbage and soil were between 85.44 and 103.37% with the relative standard deviation (RSD) between 3.2 and 9.4% (n = 6). The limit of detection (LOD) and limit of quantification (LOQ) were 0.003 μg mL(-1) and 0.01 mg kg(-1), respectively. The measurement uncertainties (MUs) were within 9.9-14.9%. Initial residues of spiromesifen on cabbage were 0.640 and 1.549 mg kg(-1) during 2013 and 0.723 and 1.438 mg kg(-1) during 2014 from treatments at standard and double doses of 125 and 250 g active ingredient (a.i.) ha(-1), respectively. Spiromesifen residue dissipation followed first-order rate kinetics, and it degraded within the half-lives of 2.9 and 3.9 days during 2013 and 3.2 and 4.5 days during 2014. The residue levels reached below the maximum residue limit (MRL; 0.02 mg kg(-1)) within 15-17 days at the standard dose and 24-27 days at the double dose. The field soil analyzed at harvest (30 days) was free from spiromesifen residues. Metabolite spiromesifen-enol was not detected in any sample which was confirmed through LC-MS/MS analysis. PMID:26869045

  12. Auditory sensory memory in 2-year-old children: an event-related potential study.

    PubMed

    Glass, Elisabeth; Sachse, Steffi; von Suchodoletz, Waldemar

    2008-03-26

    Auditory sensory memory is assumed to play an important role in cognitive development, but little is known about it in young children. The aim of this study was to estimate the duration of auditory sensory memory in 2-year-old children. We recorded the mismatch negativity in response to tone stimuli presented with different interstimulus intervals. Our findings suggest that in 2-year-old children the memory representation of the standard tone remains in the sensory memory store for at least 1 s but for less than 2 s. Recording the mismatch negativity with stimuli presented at various interstimulus intervals seems to be a useful method for studying the relationship between auditory sensory memory and normal and disturbed cognitive development.

  13. Natrelle 410 Extra-Full Projection Silicone Breast Implants: 2-Year Results from Two Prospective Studies

    PubMed Central

    McGuire, Patricia; Murphy, Diane K.

    2015-01-01

    Background: The safety and effectiveness of the Natrelle Style 410 highly cohesive silicone gel breast implant (Allergan, Inc., Irvine, Calif.) in full or moderate height and projection have been shown in a 10-year study. Extra-full projection implants may be an appropriate option for some women undergoing breast reconstruction. Methods: A total of 2795 women received at least one Natrelle 410 extra-full projection implant (X-style) for breast reconstruction in two similarly designed, prospective, multicenter studies. Data collected for 2 years after implantation in these studies were pooled to evaluate complication rates and subject and physician satisfaction. Results: Most subjects (76.0 percent) underwent bilateral reconstruction; a total of 4912 devices were implanted. Complication rates at 2 years were low. The most common complications were asymmetry (4.8 percent) and capsular contracture (3.3 percent). The cumulative risk of reoperation was 21.6 percent by subject and 16.6 percent by device; the most common reasons for reoperation were scarring (n = 97), asymmetry (n = 89), implant malposition (n = 78), and infection (n = 71). Subject and physician satisfaction rates exceeded 90 percent. At 2 years, 97 percent of physicians reported that the shape of the breast reflected the shape of the implant, and that the breast implant had maintained its original position. Conclusions: The safety profile of the Natrelle 410 extra-full projection implant mirrors that of its moderate projection and full projection counterparts. Both physicians and subjects were highly satisfied with the implants 2 years after surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV. PMID:26090764

  14. Uric acid in relapsing-remitting multiple sclerosis: a 2-year longitudinal study.

    PubMed

    Moccia, Marcello; Lanzillo, Roberta; Costabile, Teresa; Russo, Cinzia; Carotenuto, Antonio; Sasso, Gabriella; Postiglione, Emanuela; De Luca Picione, Carla; Vastola, Michele; Maniscalco, Giorgia Teresa; Palladino, Raffaele; Brescia Morra, Vincenzo

    2015-01-01

    Uric acid (UA) is reduced in multiple sclerosis (MS), and possibly relates to MS outcomes, with lower UA levels in subjects experiencing a relapse or presenting higher disability scores. The present retrospective longitudinal study evaluated UA variations in MS, in relation to clinical relapses, disability progression, and cognitive functions. We included 141 subjects with relapsing-remitting MS (RRMS) and performed expanded disability status scale (EDSS), symbol digit modalities test (SDMT) and UA evaluation at baseline visit and after 2-year follow-up. Paired t test showed significantly lower UA levels after 2-year follow-up than at baseline (3.987 ± 1.135 and 4.167 ± 1.207 mg/dL, respectively) (p = 0.001). The difference in UA levels between 2-year follow-up and baseline related to EDSS sustained progression (p < 0.001; OR = 0.099), and presented a trend for clinical relapses at logistic regression (p = 0.211; OR = 0.711) and for the time to relapse at Cox regression (p = 0.236; HR = 0.792). Analysis of variance showed reduced baseline UA levels in subjects with impaired SDMT at baseline (p = 0.045; adjusted R(2) = 0.473) and after 2-year follow-up (p = 0.034; adjusted R(2) = 0.470). This is the first study showing a progressive reduction of UA levels during the course of RRMS, suggesting a progressive decrease of antioxidant reserves, in relation to relapse risk, disability progression and cognitive function. PMID:25673130

  15. Financial Impact of Allogeneic Hematopoietic Cell Transplantation on Patients and Families over 2-years: Results from a Multicenter Pilot Study

    PubMed Central

    Denzen, Ellen M.; Thao, Viengneesee; Hahn, Theresa; Lee, Stephanie J.; McCarthy, Philip L.; Rizzo, J. Douglas; Ammi, Monique; Drexler, Rebecca; Flesch, Susan; James, Heather; Omondi, Nancy; Murphy, Elizabeth; Pederson, Kate; Majhail, Navneet S.

    2016-01-01

    Hematopoietic cell transplantation (HCT) is a procedure that can significantly influence the socioeconomic wellbeing of patients, caregivers and their families. Among 30 allogeneic HCT recipients and their caregivers enrolled on a pilot study evaluating the feasibility of studying financial impact of HCT, 16 agreed to participate in the long-term phase, completed a baseline questionnaire and received phone interviews at 6, 12, 18 and 24 months post-HCT. Analyses showed that by 2-years post-HCT, 54% of patients who previously contributed to household earnings had not returned to work and 80% of patients/caregivers reported transplant as having moderate to great impact on household income. However, patients’ level of confidence in their ability to meet household financial obligations increased from baseline to 2-years. A relatively large proportion of patients reported inability to pay for medical care through this time period. Case studies demonstrated patient individual perception of financial impact of HCT varies considerably, regardless of actual income. We demonstrate the feasibility of conducting a study to evaluate financial impact of allogeneic HCT through 2-years post-transplantation. Some patients/caregivers continue to experience significant long-term financial burden after this procedure. Our study lays the foundation for a larger evaluation of patient/caregiver financial burden associated with HCT. PMID:27088381

  16. Methylene chloride: a 2-year inhalation toxicity and oncogenicity study in rats

    SciTech Connect

    Nitschke, K.D.; Burek, J.D.; Bell, T.J.; Kociba, R.J.; Rampy, L.W.; McKenna, M.J.

    1988-07-01

    Male and female Sprague-Dawley rats were exposed to 0, 50, 200, or 500 ppm methylene chloride for 6 hr/day, 5 days/week for 2 years. Blood carboxyhemoglobin levels were elevated in a dose-dependent (less than linear) manner in rats exposed to 50-500 ppm methylene chloride. Histopathologic lesions related to methylene chloride exposure were confined to the liver and mammary tissue of rats. An increased incidence of hepatocellular vacuolization was observed in male and female rats exposed to 500 ppm methylene chloride. Female rats exposed to 500 ppm methylene chloride also had an increased incidence of multinucleated hepatocytes and number of spontaneous benign mammary tumors/tumor-bearing rat (adenomas, fibromas, and fibroadenomas with no progression toward malignancy); the incidence of benign mammary tumors in female rats exposed to 50 or 200 ppm methylene chloride was comparable to historical control values. No increase in the number of any malignant tumor type was observed in rats exposed to concentrations as high as 500 ppm methylene chloride. Additional groups of female rats were exposed to 500 ppm methylene chloride for the first 12 months or the last 12 months of the 24-month study. The response observed in female rats exposed to 500 ppm for the first 12 months was the same as that observed in female rats exposed to 500 ppm for 2 years. Conversely, the response observed in female rats exposed to 500 ppm during the last 12 months of the study was similar to that observed in control animals. Based upon the results of this study, the no-adverse-effect level for chronic inhalation exposure of Sprague-Dawley rats was judged to be 200 ppm methylene chloride.

  17. Prophylactic strategies in recurrent vulvovaginal candidiasis: a 2-year study testing a phytonutrient vs itraconazole.

    PubMed

    Chopra, V; Marotta, F; Kumari, A; Bishier, M P; He, F; Zerbinati, N; Agarwal, C; Naito, Y; Tomella, C; Sharma, A; Solimene, U

    2013-01-01

    The aim of the present study was to assess the clinical efficacy of a one week/month treatment with a phytocompound with antimycotic properties (K-712, with following 100 mg composition: 10 mg of oleoresin from Pseudowintera colorata at 30 percent concentration in Polygodial together with trace amounts of Olea europea) in recurrent vulvo-vaginal candidiasis (RVVC), as compared to once a week treatment with an azole drug for 24 months follow up. This prospective randomized study involving 122 women (19 to 63 years old) with a history of proven episodes of RVVC in the prior 12 months. Patients were allocated in two treatment groups of 61 patients each and given A) Itraconazole 200 mg orally once a week or B) 1 tab twice a day of K-712 for one week/month. Each treatment schedule was well tolerated with 19 patients in the azole group complaining of transient mild symptoms (nausea, abdominal discomfort, unpleasant taste), while only 3 patients on K-712 reported slight dyspepsia. The number of relapses was significantly lower in the K-712-treated group as compared to the itraconazole-group (22 vs 39, p less than 0.05). Moreover, the former group showed a significantly decreased number of cases resistant or dose-dependent susceptible as compared to group A (p less than 0.05 vs itraconazole) and the same occurred for the occurrence of non-albicans species (group A 64.1 percent vs group B 31.8 percent, p less than 0.05). The overall mycological cure at the end of the 2-year study showed a comparable benefit between the two groups. From these data it appears that the present antifungal phytonutrient is equally effective as itraconazole in the overall treatment of RVVC over a 2-year follow-up, but yielding a significantly better prophylactic effect and also maintenance benefit with lower relapse rate, antifungal susceptibility and growth of azole-resistant species.

  18. Equipping public health professionals for youth engagement: lessons learned from a 2-year pilot study.

    PubMed

    Sahay, Tina Binita; Rempel, Benjamin; Lodge, Jennifer

    2014-01-01

    There is strong evidence of the positive role that youth engagement programs and policies play in creating resiliency and producing positive outcomes among youth populations, such as delaying or avoiding the onset of risk-taking behaviors. Research also suggests that achieving positive outcomes ideally includes influence from the individual, the family, the school, the community, and the field of public health (available in A Research Report and Recommendations for Ontario Public Health Association). The authors conducted a comprehensive evaluation of a 2-year pilot project designed to increase the application of engagement and resiliency theory, knowledge, and skills among public health professionals engaging students from Grades 6, 7, and 8 (11- to 14-year-olds). Qualitative methods assessed public health satisfaction with training, resources, and networking activities, whereas quantitative methods assessed changes in capacity with respect to youth engagement knowledge, awareness, confidence, and skills. The findings have helped shed light on public health professional needs concerning capacity and confidence to undertake youth engagement work. Key lessons learned about making youth engagement possible and effective for public health professionals are presented. PMID:23271719

  19. Equipping public health professionals for youth engagement: lessons learned from a 2-year pilot study.

    PubMed

    Sahay, Tina Binita; Rempel, Benjamin; Lodge, Jennifer

    2014-01-01

    There is strong evidence of the positive role that youth engagement programs and policies play in creating resiliency and producing positive outcomes among youth populations, such as delaying or avoiding the onset of risk-taking behaviors. Research also suggests that achieving positive outcomes ideally includes influence from the individual, the family, the school, the community, and the field of public health (available in A Research Report and Recommendations for Ontario Public Health Association). The authors conducted a comprehensive evaluation of a 2-year pilot project designed to increase the application of engagement and resiliency theory, knowledge, and skills among public health professionals engaging students from Grades 6, 7, and 8 (11- to 14-year-olds). Qualitative methods assessed public health satisfaction with training, resources, and networking activities, whereas quantitative methods assessed changes in capacity with respect to youth engagement knowledge, awareness, confidence, and skills. The findings have helped shed light on public health professional needs concerning capacity and confidence to undertake youth engagement work. Key lessons learned about making youth engagement possible and effective for public health professionals are presented.

  20. [Influence of sport on isoinertial trunk muscle performance development: a 2 years prospective study].

    PubMed

    Rosset, E Bibbo; Mélot, C; Szpalski, M; Keller, T S; Balagué, F

    2013-07-17

    In this study, we investigate the relationship between either regular sports practice or a non sportive way of life, development of trunk muscle performance and occurrence of lower back pain between male schoolchildren. 93 schoolchildren were recruited, then stratified in 4 groups, according to sport practice or sedentary way of life. Participants were evaluated twice at an interval of 2 years with an interview, a physical examination and an evaluation of trunk muscle performance. We identified that basketball players have significantly better results and perfomance concerning isometric and isoinertial tests of trunk muscles than the other groups. Differences in trunk muscle performance exist following the practice of different types of sport. We can deduce that trunk muscle performance has some sport specificity.

  1. Sustained efficacy of risedronate in men with primary and secondary osteoporosis: results of a 2-year study.

    PubMed

    Ringe, Johann D; Farahmand, Parvis; Faber, Herbert; Dorst, Alfred

    2009-01-01

    The aim of this study was to assess the effect of treatment with risedronate 5 mg daily relative to control in men with primary or secondary osteoporosis over 2 years. Osteoporosis is a common condition in men that can have serious clinical consequences. In an earlier interim report, we found that 1 year of risedronate therapy resulted in significant increases in bone mineral density (BMD) and a significant reduction in vertebral fractures compared to control in men with osteoporosis. We conducted an open-label, prospective, match-control trial on men with primary or secondary osteoporosis in a single center, outpatient setting. Men with primary or secondary osteoporosis, as defined by a baseline lumbar spine BMD T-score < or = -2.5 and a baseline femoral neck BMD T-score < or = 2.0, were eligible for this study. Patients who had been treated with bisphosphonates or fluoride within the last 12 months were excluded. A total of 316 men were randomized to risedronate (n = 158) or control (n = 158). Patients were stratified by the presence of prevalent vertebral fractures at baseline and case by case allocated to either daily treatment with risedronate 5 mg daily plus calcium (1,000 mg) and vitamin D (800 IU) or to a control group (daily alfacalcidol (1 microg) plus calcium (500 mg) for those with prevalent vertebral fractures; daily vitamin D (800 IU) plus calcium (1,200 mg) for those without previous vertebral fractures). Primary study end points were identified prior to study initiation as the incidence of new vertebral fractures and changes in BMD at the lumbar spine, femoral neck, and total hip. Other end points included incidence of nonvertebral fractures and change in body height and back pain. Compared to control, the incidence of new vertebral fractures was significantly reduced in the risedronate 5 mg daily group at 2 years [14/152 (9.2%) for risedronate vs. 35/148 (23.6%) for control (61% risk reduction; P = 0.0026)]. Treatment with risedronate 5 mg daily

  2. Suppression of Alcohol Dependence Using Baclofen: A 2-Year Observational Study of 100 Patients

    PubMed Central

    de Beaurepaire, Renaud

    2012-01-01

    Aims: The purpose of this study was to examine the long-term effects of baclofen in a large cohort of alcohol-dependent patients compliant to baclofen treatment. Methods: A hundred patients with alcohol dependence, resistant to usual treatments, were treated with escalating doses of baclofen (no superior limit). Alcohol consumption (in grams) and craving for alcohol were assessed before treatment and at 3, 6, 12, and 24 months. Assessments were simply based on patients’ statements. The outcome measure was the consumption of alcohol, rated according to the World Health Organization criteria for risk of chronic harm. Results: While all patients were rated “at high risk” at baseline, approximately half of them were rated “at low risk” at 3, 6, 12, and 24 months. The sum of patients who were at “low risk” and at “moderate risk” (improved patients) was 84% at 3 months, 70% at 6 months, 63% at 1 year, and 62% at 2 years. The constancy of improvement over the 2-years was remarkable. The average maximal dose of baclofen taken was 147 mg/day. Ninety-two percentage of patients reported that they experienced the craving-suppressing effect of baclofen. Significant relationships were found between the amount in grams of alcohol taken before treatment and the maximal dose of baclofen required, and between the existence of a mental disorder and a lesser effect of baclofen. Conclusion: Baclofen produces an effortless decrease or suppression of alcohol craving when it is prescribed with no superior limit of dose. Potential limitations in the effectiveness of baclofen include the coexistence of a mental disorder, the concomitant use of other psychotropic drugs, a lack of real motivation in patients to stop drinking, and the impossibility to reach the optimal dose of baclofen because of unbearable side-effects (sometimes possibly related to too sharp a protocol of dose escalation). PMID:23316172

  3. Carbon Fibers Conductivity Studies

    NASA Technical Reports Server (NTRS)

    Yang, C. Y.; Butkus, A. M.

    1980-01-01

    In an attempt to understand the process of electrical conduction in polyacrylonitrile (PAN)-based carbon fibers, calculations were carried out on cluster models of the fiber consisting of carbon, nitrogen, and hydrogen atoms using the modified intermediate neglect of differential overlap (MINDO) molecular orbital (MO) method. The models were developed based on the assumption that PAN carbon fibers obtained with heat treatment temperatures (HTT) below 1000 C retain nitrogen in a graphite-like lattice. For clusters modeling an edge nitrogen site, analysis of the occupied MO's indicated an electron distribution similar to that of graphite. A similar analysis for the somewhat less stable interior nitrogen site revealed a partially localized II electron distribution around the nitrogen atom. The differences in bonding trends and structural stability between edge and interior nitrogen clusters led to a two-step process proposed for nitrogen evolution with increasing HTT.

  4. Clinical and biologic factors related to oral implant failure: a 2-year follow-up study.

    PubMed

    Moheng, Patrick; Feryn, Jean-Marc

    2005-09-01

    The purpose of this study is to evaluate urinary biomarkers of bone formation and resorption as predictive factors for oral implant failure, and to contribute to the knowledge of factors related to oral implant failure. A total of 93 patients between 18 and 85 years old, with an indication of oral implant, were eligible in this 2-year prospective, open, and nonrandomized study. Patients who had bone graft before implantation or presented with prosthetic difficulties (implant-to-crown ratio < 1, and/or unfavorable intermaxillary space) were excluded. All patients received either Frialit-2 (Friadent, Mannheim, Germany), cylinder, or screwed implants or IMZ Twin Plus (Friadent), cylinder implants, with FRIOS (Friadent) titanium coating. Serum osteocalcin, and urinary pyridinoline and deoxypyridinoline were measured, together with bone density at implant location. The primary endpoint (implant failure) was the implant removal (radiographic evidence of peri-implant bone loss and/or pockets). Factors related to implant failure were analyzed using multilevel logistic regression models to consider within-patient effects. Of the 93 patients included, 61% were female, and 16% were current smokers. A total of 266 oral implants were placed and analyzed, with a mean number of 3.1 implants by patient. Eleven and 15% of bone locations scored at D1 and D4, respectively, for the Misch bone density scoring. The majority of implants (72%) were placed more than 3 months after tooth extraction, using a Frialit-2 system in 73% of cases. The mean of osteocalcin was 17.3 (+/-9.4) ng/L; those of pyridinoline and deoxypyridinoline were 33.2 (+/-15.8) and 10.2 (+/-11.9) mmol per creatinine mmol, respectively. At one-year, 95.5% (95% confidence interval 92.5-97.5) of implants have not been removed. One year later, no further implant failed. In both univariate and multivariate analysis, osteocalcin, pyridinoline, and deoxypyridinoline were not significant predictive factors of oral implant

  5. Effect of exacerbations on quality of life in patients with chronic obstructive pulmonary disease: a 2 year follow up study

    PubMed Central

    Miravitlles, M; Ferrer, M; Pont, A; Zalacain, R; Alvarez-Sala, J; Masa, F; Verea, H; Murio, C; Ros, F; Vidal, R

    2004-01-01

    Background: A study was undertaken to evaluate exacerbations and their impact on the health related quality of life (HRQL) of patients with chronic obstructive pulmonary disease (COPD). Methods: A 2 year follow up study was performed in 336 patients with COPD of mean (SD) age 66 (8.2) years and mean (SD) forced expiratory volume in 1 second (FEV1) 33 (8)% predicted. Spirometric tests, questions regarding exacerbations of COPD, and HRQL measurements (St George's Respiratory Questionnaire (SGRQ) and SF-12 Health Survey) were conducted at 6 month intervals. Results: A total of 1015 exacerbations were recorded, and 103 (30.7%) patients required at least one hospital admission during the study. After adjustment for baseline characteristics and season of assessment, frequent exacerbations had a negative effect on HRQL in patients with moderate COPD (FEV1 35–50% predicted); the change in SGRQ total score of moderate patients with ⩾3 exacerbations was almost two points per year greater (worse) than those with <3 exacerbations during the follow up (p = 0.042). For patients with severe COPD (FEV1 <35% predicted) exacerbations had no effect on HRQL. The change in SGRQ total score of patients admitted to hospital was almost 2 points per year greater (worse) than patients not admitted, but this effect failed to show statistical significance in any severity group. There was a significant and independent seasonal effect on HRQL since SGRQ total scores were, on average, 3 points better in measurements performed in spring/summer than in those measured in the winter (p<0.001). Conclusions: Frequent exacerbations significantly impair HRQL of patients with moderate COPD. A significant and independent effect of seasonality was also observed. PMID:15115864

  6. Acinetobacter Infections among Adult Patients in Qatar: A 2-Year Hospital-Based Study

    PubMed Central

    Al Samawi, Musaed Saad; Khan, Fahmi Yousef; Eldeeb, Yasser; Almaslamani, Muna; Alkhal, Abdullatif; Alsoub, Hussam; Ghadban, Wissam; Howady, Faraj; Hashim, Samar

    2016-01-01

    This retrospective study was conducted at Hamad General Hospital, Qatar, to describe the demographic data, clinical features underlying diseases, antimicrobial susceptibility, and outcome of A. baumannii infection. It involved all adult patients 15 years of age or older who were managed at Hamad General Hospital for A. baumannii infection from January 1, 2012, to December 31, 2013. We identified a total of 239 patients with A. baumannii infection, of which 182 (76.2%) were males. The mean age was 49.10 ± 19.57 years. The majority of the episodes (25.1%) occurred in elderly patients (≥65 years) and the most commonly identified site of A. baumannii infection was the respiratory tract, 117 (48.9%). Most episodes of infection, 231 (96.7%), were hospital-acquired and high rate of nosocomial infections occurred in the medical intensive care unit, 66 (28.6%). All patients had underlying medical conditions. Maximum resistance was seen to cefotaxime, 147 (58.3%), and minimum resistance was seen to colistin, 2 (1.4%). Of the 239 isolates, 102 (42.7%) were susceptible and 137 (57.3%) were multidrug-resistant. The in-hospital mortality in our study was 31%. Male gender, multidrug resistance, and septic shock were found to be independent mortality predictors. PMID:27433169

  7. Anaphylaxis in an emergency department: a 2-year study in a tertiary-care hospital.

    PubMed

    Piromrat, Kanika; Chinratanapisit, Sasawan; Trathong, Sommai

    2008-01-01

    The aim of this study was to estimate the incidence of anaphylaxis in the emergency department of a tertiary-care hospital, describe the clinical features and the management of the patients and determine those with mild manifestations. A retrospective study was conducted from 2005 to 2006 using anaphylaxis-related ICD-10 terms. Two different sets of criteria for the diagnosis of anaphylaxis were applied, first the criteria previously accepted by emergency practice, followed by the recent criteria set forth at the 2005 international meeting. Sixty-four patients fulfilled the previous criteria with an average incidence of 52.5 per 100,000 patients per year with a shift towards females in 2006. The most common presentations were cutaneous, followed by respiratory symptoms. Food allergy was the most common cause, especially prawn. After applying the recent criteria, 13 patients (20.4%) were excluded, which reduced the incidence to 42.2 per 100,000 patients per year. Long term follow up is suggested for the possible or mild cases that were re-categorized.

  8. Sluggish Cognitive Tempo and ADHD Inattention as Predictors of Externalizing, Internalizing, and Impairment Domains: A 2-Year Longitudinal Study.

    PubMed

    Bernad, Maria del Mar; Servera, Mateu; Becker, Stephen P; Burns, G Leonard

    2016-05-01

    Although sluggish cognitive tempo (SCT) is distinct from attention-deficit/hyperactivity disorder inattention (ADHD-IN), few studies have examined whether SCT longitudinally predicts other symptom or impairment dimensions. This study used 4 sources (mothers, fathers, primary teachers, and secondary teachers) and 3 occasions of measurement (first, second, and third grades) with 758 first grade (55 % boys), 718 second grade (54 % boys), and 585 third grade (53 % boys) children from Spain to determine SCT's and ADHD-IN's unique longitudinal relationships with psychopathology, academic impairment, and social impairment over the 1- and 2-year intervals (i.e., first to third grade, second to third grade). For 1- and 2-year intervals using both mothers' and fathers' ratings, higher levels of SCT uniquely predicted higher levels of anxiety, depression, academic impairment, and social impairment whereas higher levels of ADHD-IN uniquely predicted higher levels of ADHD-HI, ODD, and academic impairment. For 1- and 2-year intervals across different primary and secondary teachers (i.e., first/second and third grade ratings were provided by different teachers), higher scores on ADHD-IN uniquely predicted poorer outcomes across domains whereas higher scores on SCT uniquely predicted lower levels of ADHD-HI and ODD for both intervals in addition to higher levels of depression (for primary teachers only), academic impairment (for 1-year interval only), and peer rejection (2-year interval only for primary teachers). Overall, SCT was significantly associated with important outcomes independent of ADHD-IN over 1- and 2-year intervals and across four different raters. This study provides further evidence for distinguishing between SCT and ADHD-IN in home and school settings.

  9. Treatment Compliance of Adolescents after Attempted Suicide: A 2-Year Follow-Up Study

    ERIC Educational Resources Information Center

    Burns, Craig D.; Cortell, Ranon; Wagner, Barry M.

    2008-01-01

    The study investigates compliance with mental health treatments among suicidal adolescents. Results show that child psychopathology and parental attitudes toward treatment plays an important part in increasing compliance with mental health treatment for adolescent suicide attempters.

  10. Diagnosis of Autism Spectrum Disorders in 2-Year-Olds: A Study of Community Practice

    ERIC Educational Resources Information Center

    Corsello, Christina M.; Akshoomoff, Natacha; Stahmer, Aubyn C.

    2013-01-01

    Background: Longitudinal research studies have demonstrated that experienced clinicians using standardized assessment measures can make a reliable diagnosis of autism spectrum disorders (ASDs) in children under age 3. Limited data are available regarding the sensitivity and specificity of these measures in community settings. The aims of this…

  11. Pubertal Timing and Substance Use in Middle Adolescence: A 2-Year Follow-Up Study

    ERIC Educational Resources Information Center

    Kaltiala-Heino, Riittakerttu; Koivisto, Anna-Maija; Marttunen, Mauri; Frojd, Sari

    2011-01-01

    Earlier research has associated early puberty with emotional and behavioral symptoms particularly among girls, while among boys, findings have been contradictory as to whether risks are associated with early or late pubertal timing. We studied the association between pubertal timing and substance use behaviors in middle adolescence in a 2-year…

  12. The Development of Falling Intonation in Young Children with Cochlear Implants: A 2-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Snow, David P.; Ertmer, David J.

    2013-01-01

    This article describes the development of intonation in 12 cochlear implant (CI) recipients. In a previously reported study of the first year of CI use, children who were implanted late (after 24 months) acquired intonation more rapidly than the younger participants. The older children's advantage is plausibly owing to their greater maturity.…

  13. Development of Orthographic Knowledge in German-Speaking Children: A 2-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Ise, Elena; Arnoldi, Carolin Judith; Schulte-Körne, Gerd

    2014-01-01

    There is growing evidence that children develop orthographic knowledge from the very beginning of literacy acquisition. This study investigated the development of German-speaking children's orthographic knowledge with a nonword choice task. One nonword in each pair contained a frequent consonant doublet ("zommul") and the other…

  14. Re-defining one's occupational self 2 years after breast cancer: a case study.

    PubMed

    Newman, Robin M

    2013-01-01

    Margaret*, a 56 year-old Caucasian Stage III breast cancer survivor, participated in a 5 week occupational therapy pilot program, called Take Action. This program was designed for breast cancer survivors who self-reported changes in cognitive function following completion of chemotherapy. The goals of the program were to improve participants' knowledge and use of strategies to enhance occupational performance and to improve satisfaction and performance of meaningful daily activities or occupations. Through a client-centered and evidence-based approach, this case study highlights the importance of incorporating the survivors' sense of self into an occupation-based intervention. Occupational therapists play an important role in facilitating exploration of sense of self in the survivorship phase of care to support occupational performance in self care, productivity, work, leisure and social participation. This case study highlights the important work of redefining oneself in the survivorship phase of care. (*denotes name change). PMID:24004739

  15. Involvement in bullying and suicidal ideation in middle adolescence: a 2-year follow-up study.

    PubMed

    Heikkilä, Hanna-Kaisa; Väänänen, Juha; Helminen, Mika; Fröjd, Sari; Marttunen, Mauri; Kaltiala-Heino, Riittakerttu

    2013-02-01

    The objective of the study was to ascertain whether involvement in bullying increases the risk for subsequent suicidal ideation. A total of 2,070 Finnish girls and boys aged 15 were surveyed in the ninth grade (age 15) in schools, and followed up 2 years later in the Adolescent Mental Health Cohort Study. Involvement in bullying was elicited at age 15 by two questions focusing on being a bully and being a victim of bullying. Suicidal ideation was elicited by one item of the short Beck Depression Inventory at age 17. Baseline depressive symptoms and externalizing symptoms, age and sex were controlled for. Statistical analyses were carried out using cross-tabulations with Chi-square/Fisher's exact test and logistic regression. Suicidal ideation at age 17 was 3-4 times more prevalent among those who had been involved in bullying at age 15 than among those not involved. Suicidal ideation at age 17 was most prevalent among former victims of bullying. Being a victim of bullying at age 15 continued to predict subsequent suicidal ideation when depressive and externalizing symptoms were controlled for. Being a bully at age 15 also persisted as borderline significantly predictive of suicidal ideation when baseline symptoms were controlled for. Findings indicate adolescent victims and perpetrators of bullying alike are at long-term risk for suicidal ideation. PMID:23053774

  16. Involvement in bullying and suicidal ideation in middle adolescence: a 2-year follow-up study.

    PubMed

    Heikkilä, Hanna-Kaisa; Väänänen, Juha; Helminen, Mika; Fröjd, Sari; Marttunen, Mauri; Kaltiala-Heino, Riittakerttu

    2013-02-01

    The objective of the study was to ascertain whether involvement in bullying increases the risk for subsequent suicidal ideation. A total of 2,070 Finnish girls and boys aged 15 were surveyed in the ninth grade (age 15) in schools, and followed up 2 years later in the Adolescent Mental Health Cohort Study. Involvement in bullying was elicited at age 15 by two questions focusing on being a bully and being a victim of bullying. Suicidal ideation was elicited by one item of the short Beck Depression Inventory at age 17. Baseline depressive symptoms and externalizing symptoms, age and sex were controlled for. Statistical analyses were carried out using cross-tabulations with Chi-square/Fisher's exact test and logistic regression. Suicidal ideation at age 17 was 3-4 times more prevalent among those who had been involved in bullying at age 15 than among those not involved. Suicidal ideation at age 17 was most prevalent among former victims of bullying. Being a victim of bullying at age 15 continued to predict subsequent suicidal ideation when depressive and externalizing symptoms were controlled for. Being a bully at age 15 also persisted as borderline significantly predictive of suicidal ideation when baseline symptoms were controlled for. Findings indicate adolescent victims and perpetrators of bullying alike are at long-term risk for suicidal ideation.

  17. Conducting Simulation Studies in Psychometrics

    ERIC Educational Resources Information Center

    Feinberg, Richard A.; Rubright, Jonathan D.

    2016-01-01

    Simulation studies are fundamental to psychometric discourse and play a crucial role in operational and academic research. Yet, resources for psychometricians interested in conducting simulations are scarce. This Instructional Topics in Educational Measurement Series (ITEMS) module is meant to address this deficiency by providing a comprehensive…

  18. Bioconversion study conducted by JPL

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J.

    1978-01-01

    The Jet Propulsion Laboratory (JPL) of Caltech conducted a study of bioconversion as a means of identifying the role of biomass for meeting the national energy fuel and chemical requirements and the role and means for JPL-Caltech involvement in bioconversion. The bioconversion study included the following categories; biomass sources, chemicals from biomass, thermochemical conversion of biomass to fuels, biological conversion of biomass to fuels and chemicals, and basic bioconversion sciences. A detailed review is included of the bioconversion fields cited with specific conclusions and recommendations given for future research and development and overall biomass system engineering and economic studies.

  19. Progression of fibromyalgia: results from a 2-year observational fibromyalgia and chronic pain study in the US

    PubMed Central

    Adams, Edgar H; McElroy, Heather J; Udall, Margarita; Masters, Elizabeth T; Mann, Rachael M; Schaefer, Caroline P; Cappelleri, Joseph C; Clair, Andrew G; Hopps, Markay; Daniel, Shoshana R; Mease, Philip; Silverman, Stuart L; Staud, Roland

    2016-01-01

    Background A previous fibromyalgia (FM) research reports that 20%–47% of diagnosed patients may not meet the study definition of FM 1–2 years after diagnosis. The aim of this study was to gain a better understanding of the progression of FM in a geographically diverse cohort over a 2-year time period. Methods This cohort study followed 226 subjects recruited online to assess FM and chronic widespread pain (CWP) diagnosis stability over time. At enrollment (baseline), subjects provided informed consent, completed an online questionnaire consisting of the London Fibromyalgia Epidemiology Study Screening Questionnaire to screen for CWP (bilateral pain above/below waist lasting ≥1 week in the past 3 months), visited a site for physician evaluation for FM, and completed a questionnaire with validated patient-reported outcome instruments. Subjects were classified into mutually exclusive groups: FM+CWP+ (screened positive for CWP and received physician diagnosis of FM), FM−CWP+ (screened positive for CWP but did not receive physician diagnosis of FM), and FM−CWP− (screened negative for CWP). Approximately 2 years later (follow-up), subjects were reassessed at the same study site and completed a questionnaire with the same patient-reported outcomes. Results Seventy-six FM+CWP+ subjects completed assessments at both time points; 56 (73.7%) met the FM study definition at follow-up. Twenty subjects no longer met the FM study definition (eleven became FM−CWP− and nine became FM−CWP+). Ten subjects (two from FM−CWP− and eight from FM−CWP+) transitioned into the FM+CWP+ group at follow-up; they reported more tender points and pain interference with sleep and worse physical function at baseline compared with subjects who did not transition to FM+CWP+. Most (76.7%) of the subjects who transitioned into/out of FM+CWP+ experienced changes in CWP, number of positive tender points, or both. Conclusion The results suggest that some FM+CWP+ patients experience

  20. NOAA's hydrolab conducts reef studies

    NASA Astrophysics Data System (ADS)

    This summer, scuba-diving scientists operating from Hydrolab, NOAA's undersea laboratory, are carrying out four experiments aimed at producing better management of coral reefs and their fishery resources. Hydrolab is located at a depth of 50 feet, near the mouth of the Salt River, off St. Croix, U.S. Virgin Islands. The lab houses four scientists for up to 2 weeks at a time, permitting them to swim out into the water to conduct research. The projects make use of both the natural coral reef near Hydrolab and the nearby artificial reef constructed for comparison studies.

  1. Disordered eating behaviors and body image in a longitudinal pilot study of adolescent girls: what happens 2 years later?

    PubMed

    Espinoza, Paola; Penelo, Eva; Raich, Rosa M

    2010-01-01

    We assessed the prospective association of risk factors for eating and body image disturbances after a 2-year follow-up in a community sample of Spanish adolescent girls. The participants included 128 Spanish girls aged 12-14, who took part in a 28-month prospective study. Aspects assessed were eating attitudes (Eating Attitudes Test), influence of the body shape model (questionnaire on influences of the aesthetic body shape model), extreme weight-control behaviors (Eating Disorder Examination-Questionnaire), body image (Body Image Questionnaire) and Body Mass Index (BMI). BMI, extreme weight-control behaviors and body image problems emerged as potential predictors of an increase in eating disturbances. An increased influence of the thinness model was significantly associated with reduced body satisfaction and body image problems. Preventive programs are needed to contribute reducing the impact of sociocultural influences with regard to thinness, the use of extreme weight-control behaviors and overweight in adolescents.

  2. Parental height and child growth from birth to 2 years in the WHO Multicentre Growth Reference Study.

    PubMed

    Garza, Cutberto; Borghi, Elaine; Onyango, Adelheid W; de Onis, Mercedes

    2013-09-01

    Linear growth from birth to 2 years of children enrolled in the World Health Organization Multicentre Growth Reference Study was similar despite substantial parental height differences among the six study sites. Within-site variability in child length attributable to parental height was estimated by repeated measures analysis of variance using generalized linear models. This approach was also used to examine relationships among selected traits (e.g. breastfeeding duration and child morbidity) and linear growth between 6 and 24 months of age. Differences in intergenerational adult heights were evaluated within sites by comparing mid-parental heights (average of the mother's and father's heights) to the children's predicted adult height. Mid-parental height consistently accounted for greater proportions of observed variability in attained child length than did either paternal or maternal height alone. The proportion of variability explained by mid-parental height ranged from 11% in Ghana to 21% in India. The average proportion of between-child variability accounted for by mid-parental height was 16% and the analogous within-child estimate was 6%. In the Norwegian and US samples, no significant differences were observed between mid-parental and children's predicted adult heights. For the other sites, predicted adult heights exceeded mid-parental heights by 6.2-7.8 cm. To the extent that adult height is predicted by height at age 2 years, these results support the expectation that significant community-wide advances in stature are attainable within one generation when care and nutrition approximate international recommendations, notwithstanding adverse conditions likely experienced by the previous generation.

  3. The effects of early headgear treatment on dental arches and craniofacial morphology: a report of a 2 year randomized study.

    PubMed

    Mäntysaari, Raimo; Kantomaa, Tuomo; Pirttiniemi, Pertti; Pykäläinen, Aila

    2004-02-01

    The aim of the present study was to determine the effects of early headgear treatment on dental arches and craniofacial morphology in children in the early mixed dentition. The total study group comprised 68 children of both sexes (40 boys and 28 girls) aged 7.6 years [standard deviation (SD) 0.3]. The children, who had a Class II tendency in occlusion and moderate crowding of the dental arches, were randomly divided into two groups of equal size, matched according to gender. In the headgear (HG) group, treatment was initiated immediately. The mean treatment time was 16 months. In the second group, which served as the control, only interceptive procedures were performed during the follow-up period. The records, which included dental casts and lateral cephalograms, were obtained after follow-up periods of 1 and 2 years. The lengths and the widths of the maxillary and mandibular dental arches were significantly increased in the HG group after the 2 year follow-up period. The mean increase in lower arch length and width was 2.4 mm (SD 1.7) and 2.2 mm (SD 1.2), respectively. On average, the space gain in the lower arch was half that of the upper arch. No significant changes were found in the arch dimensions of the control group. Maxillary growth restraint and labial tilting of the incisors were the most significant cephalometric findings in the HG group when compared with the controls. The use of headgear in the early mixed dentition is effective in the treatment of moderate crowding. It is noteworthy that significant space gain in the dimensions of the lower arch can be achieved by headgear application to the upper first molars.

  4. Prospective study of cognitive function in children receiving whole-brain radiotherapy and chemotherapy: 2-year results

    SciTech Connect

    Packer, R.J.; Sutton, L.N.; Atkins, T.E.; Radcliffe, J.; Bunin, G.R.; D'Angio, G.; Siegel, K.R.; Schut, L. )

    1989-05-01

    As survival rates have risen for children with malignant primary brain tumors, so has the concern that many survivors have significant permanent cognitive deficits. Cranial irradiation (CRT) has been implicated as the major cause for cognitive dysfunction. To clarify the etiology, incidence, and severity of intellectual compromise in children with brain tumors after CRT, a prospective study was undertaken comparing the neuropsychological outcome in 18 consecutive children with malignant brain tumors treated with CRT to outcome in 14 children harboring brain tumors in similar sites in the nervous system who had not received CRT. Children with cortical or subcortical brain tumors were not eligible for study. Neuropsychological testing was performed after surgery prior to radiotherapy, after radiotherapy, and at 1- and 2-year intervals thereafter. Children who had received CRT had a mean full-scale intelligence quotient (FSIQ) of 105 at diagnosis which fell to 91 by Year 2. Similar declines were noted in their performance intelligence quotient (IQ) and verbal IQ. After CRT, patients demonstrated a statistically significant decline from baseline in FSIQ (p less than 0.02) and verbal IQ (p less than 0.04). Children who had not received CRT did not demonstrate a fall in any cognitive parameter over time. The decline between baseline testing and testing performed at Year 2 in patients who had CRT was inversely correlated with age (p less than 0.02), as younger children demonstrated the greatest loss of intelligence. Children less than 7 years of age at diagnosis had a mean decline in FSIQ of 25 points 2 years posttreatment. No other clinical parameter correlated with the overall IQ or decline in IQ. After CRT, children demonstrated a wide range of dysfunction including deficits in fine motor, visual-motor, and visual-spatial skills and memory difficulties.

  5. Effect of Workplace Noise on Hearing Ability in Tile and Ceramic Industry Workers in Iran: A 2-Year Follow-Up Study

    PubMed Central

    Mirmohammadi, Seyyed Jalil; Mehrparvar, Amir Houshang; Mollasadeghi, Abolfazl

    2013-01-01

    Introduction. Noise as a common physical hazard may lead to noise-induced hearing loss, an irreversible but preventable disorder. Annual audiometric evaluations help detect changes in hearing status before clinically significant hearing loss develops. This study was designed to track hearing threshold changes during 2-year follow-up among tile and ceramic workers. Methods. This follow-up study was conducted on 555 workers (totally 1110 ears). Subjects were divided into four groups according to the level of noise exposure. Hearing threshold in conventional audiometric frequencies was measured and standard threshold shift was calculated for each ear. Results. Hearing threshold was increased during 2 years of follow-up. Increased hearing threshold was most frequently observed at 4000, 6000, and 3000 Hz. Standard threshold shift was observed in 13 (2.34%), 49 (8.83%), 22 (3.96%), and 63 (11.35%) subjects in the first and second years of follow-up in the right and left ears, respectively. Conclusions. This study has documented a high incidence of noise-induced hearing loss in tile and ceramic workers that would put stress on the importance of using hearing protection devices. PMID:24453922

  6. The impact of cognitive reserve in the outcome of first-episode psychoses: 2-year follow-up study.

    PubMed

    Amoretti, S; Bernardo, M; Bonnin, C M; Bioque, M; Cabrera, B; Mezquida, G; Solé, B; Vieta, E; Torrent, C

    2016-10-01

    The concept of cognitive reserve (CR) suggests that the premorbid intelligence quotient (IQ), years of education and leisure activities provide more efficient cognitive networks and therefore allow a better management of some conditions associated to cognitive impairment. Fifty-two DSM-IV diagnosed FEP subjects were matched with 41 healthy controls by age, gender and parental socio-economic status. All subjects were assessed clinically, neuropsychologically and functionally at baseline and after a two-year follow-up. To assess CR at baseline, three proxies have been integrated: premorbid IQ, years of education-occupation and leisure activities. Higher CR was associated with better cognitive, functional and clinical outcomes at baseline. The CR proxy was able to predict working memory, attention, executive functioning, verbal memory and global composite cognitive score accounting for 48.9%, 19.1%, 16.9%, 10.8% and 14.9% respectively of the variance at two-year follow-up. CR was also significantly predictive of PANSS negative scale score (12.5%), FAST global score (13.4%) and GAF (13%) at two-year follow-up. In addition, CR behaved as a mediator of working memory (B=4.123) and executive function (B=3.298) at baseline and of working memory (B=5.034) at 2-year follow-up. An additional analysis was performed, in order to test whether this mediation could be attributed mainly to the premorbid IQ. We obtained that this measure was not enough by itself to explain this mediation. CR may contribute to neuropsychological and functional outcome. Specific programs addressed to improve cognition and functioning conducted at the early stages of the illness may be helpful in order to prevent cognitive and functional decline.

  7. The impact of cognitive reserve in the outcome of first-episode psychoses: 2-year follow-up study.

    PubMed

    Amoretti, S; Bernardo, M; Bonnin, C M; Bioque, M; Cabrera, B; Mezquida, G; Solé, B; Vieta, E; Torrent, C

    2016-10-01

    The concept of cognitive reserve (CR) suggests that the premorbid intelligence quotient (IQ), years of education and leisure activities provide more efficient cognitive networks and therefore allow a better management of some conditions associated to cognitive impairment. Fifty-two DSM-IV diagnosed FEP subjects were matched with 41 healthy controls by age, gender and parental socio-economic status. All subjects were assessed clinically, neuropsychologically and functionally at baseline and after a two-year follow-up. To assess CR at baseline, three proxies have been integrated: premorbid IQ, years of education-occupation and leisure activities. Higher CR was associated with better cognitive, functional and clinical outcomes at baseline. The CR proxy was able to predict working memory, attention, executive functioning, verbal memory and global composite cognitive score accounting for 48.9%, 19.1%, 16.9%, 10.8% and 14.9% respectively of the variance at two-year follow-up. CR was also significantly predictive of PANSS negative scale score (12.5%), FAST global score (13.4%) and GAF (13%) at two-year follow-up. In addition, CR behaved as a mediator of working memory (B=4.123) and executive function (B=3.298) at baseline and of working memory (B=5.034) at 2-year follow-up. An additional analysis was performed, in order to test whether this mediation could be attributed mainly to the premorbid IQ. We obtained that this measure was not enough by itself to explain this mediation. CR may contribute to neuropsychological and functional outcome. Specific programs addressed to improve cognition and functioning conducted at the early stages of the illness may be helpful in order to prevent cognitive and functional decline. PMID:27511320

  8. Acute Chikungunya and persistent musculoskeletal pain following the 2006 Indian epidemic: a 2-year prospective rural community study.

    PubMed

    Chopra, A; Anuradha, V; Ghorpade, R; Saluja, M

    2012-05-01

    Chikungunya virus (CHIKV) data from population studies are sparse. During the 2006 epidemic, 509 clinical cases (43% attack rate) were identified in a village survey (West India); laboratory investigations demonstrated normal blood cell counts, elevated acute-phase reactants [erythrocyte sedimentation rate, C-reactive protein and interleukin-6 (IL-6)] and excluded malaria and dengue. Acute CHIKV was characterized by high fever, severe peripheral polyarthralgias, axial myalgias and intense fatigue in over 90% of cases; skin rash (34%) and headache (19%) were uncommon. There were 49% and 62% of survey cases seropositive for IgM (rapid assay) and IgG (immunofluorescence) anti-CHIKV antibodies, respectively. Sixty-five percent of cases recovered within 4 weeks. None of the cases died. Of the population, 4·1% and 1·6% suffered from persistent rheumatic pains, predominantly non-specific, at 1 and 2 years, respectively. Chronic inflammatory arthritis was uncommon (0·3% at 1 year) although serum IL-6 often remained elevated in chronic cases. A larger population study is required to describe post-CHIKV rheumatism and its prognosis.

  9. Differences in predictors of traditional and cyber-bullying: a 2-year longitudinal study in Korean school children.

    PubMed

    Yang, Su-Jin; Stewart, Robert; Kim, Jae-Min; Kim, Sung-Wan; Shin, Il-Seon; Dewey, Michael E; Maskey, Sean; Yoon, Jin-Sang

    2013-05-01

    Traditional bullying has received considerable research but the emerging phenomenon of cyber-bullying much less so. Our study aims to investigate environmental and psychological factors associated with traditional and cyber-bullying. In a school-based 2-year prospective survey, information was collected on 1,344 children aged 10 including bullying behavior/experience, depression, anxiety, coping strategies, self-esteem, and psychopathology. Parents reported demographic data, general health, and attention-deficit hyperactivity disorder (ADHD) symptoms. These were investigated in relation to traditional and cyber-bullying perpetration and victimization at age 12. Male gender and depressive symptoms were associated with all types of bullying behavior and experience. Living with a single parent was associated with perpetration of traditional bullying while higher ADHD symptoms were associated with victimization from this. Lower academic achievement and lower self esteem were associated with cyber-bullying perpetration and victimization, and anxiety symptoms with cyber-bullying perpetration. After adjustment, previous bullying perpetration was associated with victimization from cyber-bullying but not other outcomes. Cyber-bullying has differences in predictors from traditional bullying and intervention programmes need to take these into consideration. PMID:23640732

  10. Differences in predictors of traditional and cyber-bullying: a 2-year longitudinal study in Korean school children.

    PubMed

    Yang, Su-Jin; Stewart, Robert; Kim, Jae-Min; Kim, Sung-Wan; Shin, Il-Seon; Dewey, Michael E; Maskey, Sean; Yoon, Jin-Sang

    2013-05-01

    Traditional bullying has received considerable research but the emerging phenomenon of cyber-bullying much less so. Our study aims to investigate environmental and psychological factors associated with traditional and cyber-bullying. In a school-based 2-year prospective survey, information was collected on 1,344 children aged 10 including bullying behavior/experience, depression, anxiety, coping strategies, self-esteem, and psychopathology. Parents reported demographic data, general health, and attention-deficit hyperactivity disorder (ADHD) symptoms. These were investigated in relation to traditional and cyber-bullying perpetration and victimization at age 12. Male gender and depressive symptoms were associated with all types of bullying behavior and experience. Living with a single parent was associated with perpetration of traditional bullying while higher ADHD symptoms were associated with victimization from this. Lower academic achievement and lower self esteem were associated with cyber-bullying perpetration and victimization, and anxiety symptoms with cyber-bullying perpetration. After adjustment, previous bullying perpetration was associated with victimization from cyber-bullying but not other outcomes. Cyber-bullying has differences in predictors from traditional bullying and intervention programmes need to take these into consideration.

  11. Associations between weather conditions and clinical symptoms in patients with hip osteoarthritis: a 2-year cohort study.

    PubMed

    Dorleijn, Desirée M J; Luijsterburg, Pim A J; Burdorf, Alex; Rozendaal, Rianne M; Verhaar, Jan A N; Bos, Pieter K; Bierma-Zeinstra, Sita M A

    2014-04-01

    The goal of this study was to assess whether there is an association between ambient weather conditions and patients' clinical symptoms in patients with hip osteoarthritis (OA). The design was a cohort study with a 2-year follow-up and 3-monthly measurements and prospectively collected data on weather variables. The study population consisted of 222 primary care patients with hip OA. Weather variables included temperature, wind speed, total amount of sun hours, precipitation, barometric pressure, and relative humidity. The primary outcomes were severity of hip pain and hip disability as measured with the Western Ontario and McMasters University Osteoarthritis Index (WOMAC) pain and function subscales. Associations between hip pain and hip disability and the weather variables were assessed using crude and multivariate adjusted linear mixed-model analysis for repeated measurements. On the day of questionnaire completion, mean relative humidity was associated with WOMAC pain (estimate 0.1; 95% confidence interval=0.0-0.2; P=.02). Relative humidity contributed < or = 1% to the explained within-patient variance and between-patient variance of the WOMAC pain score. Mean barometric pressure was associated with WOMAC function (estimate 0.1; 95% confidence interval=0.0-0.1; P=.02). Barometric pressure contributed < or = 1% to the explained within-patient variance and between-patient variance of the WOMAC function score. The other weather variables were not associated with the WOMAC pain or function score. Our results support the general opinion of OA patients that barometric pressure and relative humidity influence perceived OA symptoms. However, the contribution of these weather variables (< or = 1%) to the severity of OA symptoms is not considered to be clinically relevant.

  12. Effects of galantamine in a 2-year, randomized, placebo-controlled study in Alzheimer’s disease

    PubMed Central

    Hager, Klaus; Baseman, Alan S; Nye, Jeffrey S; Brashear, H Robert; Han, John; Sano, Mary; Davis, Bonnie; Richards, Henry M

    2014-01-01

    Background Currently available treatments for Alzheimer’s disease (AD) can produce mild improvements in cognitive function, behavior, and activities of daily living in patients, but their influence on long-term survival is not well established. This study was designed to assess patient survival and drug efficacy following a 2-year galantamine treatment in patients with mild to moderately severe AD. Methods In this multicenter, double-blind study, patients were randomized 1:1 to receive galantamine or placebo. One primary end point was safety; mortality was assessed. An independent Data Safety Monitoring Board monitored mortality for the total deaths reaching prespecified numbers, using a time-to-event method and a Cox-regression model. The primary efficacy end point was cognitive change from baseline to month 24, as measured by the Mini-Mental State Examination (MMSE) score, analyzed using intent-to-treat analysis with the ‘last observation carried forward’ approach, in an analysis of covariance model. Results In all, 1,024 galantamine- and 1,021 placebo-treated patients received study drug, with mean age ~73 years, and mean (standard deviation [SD]) baseline MMSE score of 19 (4.08). A total of 32% of patients (661/2,045) completed the study, 27% (554/2,045) withdrew, and 41% (830/2,045) did not complete the study and were discontinued due to a Data Safety Monitoring Board-recommended early study termination. The mortality rate was significantly lower in the galantamine group versus placebo (hazard ratio [HR] =0.58; 95% confidence interval [CI]: 0.37; 0.89) (P=0.011). Cognitive impairment, based on the mean (SD) change in MMSE scores from baseline to month 24, significantly worsened in the placebo (−2.14 [4.34]) compared with the galantamine group (−1.41 [4.05]) (P<0.001). Functional impairment, based on mean (SD) change in the Disability Assessment in Dementia score (secondary end point), at month 24 significantly worsened in the placebo (−10.81 [18

  13. Determinants of “return to work in good health” among workers with back pain who consult in primary care settings: a 2-year prospective study

    PubMed Central

    Bourbonnais, Renée; Frémont, Pierre; Rossignol, Michel; Stock, Susan R.; Nouwen, Arie; Larocque, Isabelle; Demers, Eric

    2006-01-01

    Many factors have been linked to return to work after a back pain episode, but our understanding of this phenomenon is limited and cross-sectional dichotomous indices of return to work are not valid measures of this construct. To describe the course of “return to work in good health” (RWGH—a composite index of back pain outcome) among workers who consulted in primary care settings for back pain and identify its determinants, a 2-year prospective study was conducted. Subjects (n = 1,007, 68.4%) were workers who consulted in primary care settings of the Quebec City area for a nonspecific back pain. They completed five telephone interviews over 2 years (follow-up = 86%). Analyses linking baseline variables with 2-year outcome were conducted with polytomous logistic regression. The proportion of “success” in RWGH increased from 18% at 6 weeks to 57% at 2 years. In women, persistent pain, pain radiating to extremities, increasing job seniority, not having a unionized job, feeling that the physician did listen carefully and increasing fear-avoidance beliefs towards work and activity were determinants of “failure” in RWGH. In men, decreasing age, cigarette smoking, poor self-reported health status, pain in the thoracic area, previous back surgeries, a non-compensated injury, high pain levels, belief that job is below qualifications, likelihood of losing job, job status, satisfaction with health services and fear-avoidance beliefs towards work were all significant. RWGH among workers with back pain receives multiple influences, especially among men. In both genders, however, fear-avoidance beliefs about work are associated with failure and high self-efficacy is associated with success. PMID:16868783

  14. Minimally Invasive Periodontal Treatment Using the Er,Cr: YSGG Laser. A 2-year Retrospective Preliminary Clinical Study

    PubMed Central

    Dyer, Bret; Sung, Eric C.

    2012-01-01

    Minimally invasive surgery (MIS) using the erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser (Waterlase MD, Biolase, Irvine, CA) to treat moderate to advanced periodontal disease is presented as an alternative to conventional therapies. To date, there are few short- or long-term studies to demonstrate the effects of this laser in treating and maintaining periodontal health. Electronic clinical records from 16 patients – total of 126 teeth, with pocket depths ranging from 4 mm to 9 mm – were treated with the same protocol using the Er,Cr:YSGG laser. The mean baseline probing depths (PD) were 5 mm and clinical attachment levels (CAL) were 5 mm in the 4 - 6 mm pretreated laser group. The mean baseline probing depths were 7.5 and 7.6 mm for PD and CAL respectfully in the 7 – 9 mm pretreatment laser group. At the 2 year mark, the average PD was 3.2 ± 1.1 mm for the 4-6 mm pocket group and the 7-9 mm pocket group had a mean PD of 3.7 ± 1.2 mm. mean CAL was 3.1 ± 1.1 mm for the 4-6 mm group and 3.6 ± 1.2 for the 7-9 mm group with an overall reduction of 1.9 mm and 4.0 mm respectively. At one and two years, both groups remained stable with PD comparable to the three-month gains. The CAL measurements at one and two years were also comparable to the three-month gains. PMID:22615717

  15. Conducting and Reporting Case Studies.

    ERIC Educational Resources Information Center

    Lichtman, Merilyn; Taylor, Satomi Izumi

    Issues and elements of case study research are explored and illustrated with the example of a case study of a kindergarten in a suburb of Tokyo (Japan). Case study research is a type of qualitative research that concentrates on a single unit or entity, with boundaries established by the researcher. The case is an example drawn from a larger class,…

  16. Biologic resurfacing of the ankle and first metatarsophalangeal joint: case studies with a 2-year follow-up.

    PubMed

    Brigido, Stephen A; Troiano, Michael; Schoenhaus, Harold

    2009-10-01

    The goal of biologic resurfacing is to provide a smooth joint surface with a low coefficient of friction, which allows the joint to function with near normal biomechanics, as well as provide intermittent pressure, to the subchondral and cancellous bone. This unique combination often results in the formation of a "neocartilage-like" structure that can reduce pain and restore biomechanics. As well as giving a brief history of cutis arthroplasty, this article describes cases in which the ankle and first metatarsophalangeal joint underwent biologic resurfacing, with a 2-year postoperative follow up.

  17. Developmental milestones record - 2 years

    MedlinePlus

    Growth milestones for children - 2 years; Normal childhood growth milestones - 2 years; Childhood growth milestones - 2 years ... cause for concern if not seen by 2 years.) Can run with better coordination . (May still have ...

  18. Conducting a wind sensing study

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1985-01-01

    Signal-to-noise requirements, and how signal-to-noise determines wind velocity measurement accuracy were studied. A Nd:YAG-based system was found to be competitive with a CO2-based system. Hardware was developed for a coherent Nd:YAG LIDAR system, and is being integrated into a functioning system. A diode-pumped monolithic rod laser to be used as a reference oscillator, a high-power, single-mode ring laser, for use as a master oscillator, and a high-gain, multipass amplifier were constructed.

  19. Quality of life after laparoscopic gastric banding: Prospective study (152 cases) with a follow-up of 2 years.

    PubMed

    Champault, Axèle; Duwat, Olivier; Polliand, Claude; Rizk, Nabil; Champault, Gérard G

    2006-06-01

    To evaluate influence of laparoscopic gastric banding (LGB) on quality of life (QOL) in patients with morbid obesity. Laparoscopic adjustable gastric banding is a popular bariatric operation in Europe. The objectives of surgical therapy in patients with morbid obesity are reduction of body weight, and a positive influence on the obesity-related comorbidity as well the concomitant psychologic and social restrictions of these patients. In a prospective clinical trial, development of the individual patient QOL was analyzed, after LGB in patients with morbid obesity. From October 1999 to January 2001, 152 patients [119 women, 33 men, mean age 38.4 y (range 24 to 62), mean body mass index 44.3 (range 38 to 63)] underwent evaluation for LGB according the following protocol: history of obesity; concise counseling of patients and relative on nonsurgical treatment alternatives, risk of surgery, psychologic testing, questionnaire for eating habits, necessity of lifestyle change after surgery; medical evaluation including endocrinologic and nutritionist work-up, upper GI endoscopy, evaluation of QOL using the Gastro Intestinal Quality of Life Index (GIQLI). Decision for surgery was a multidisciplinary consensus. This group was follow-up at least 2 years, focusing on weight loss and QOL. Mean operative time was 82 minutes; mean hospital stay was 2.3 days and the mean follow-up period was 34 months. The BMI dropped from 44.3 to 29.6 kg/m and all comorbid conditions improved markedly: diabetes melitus resolved in 71% of the patients, hypertension in 33%, and sleep apnea in 90%. However, 26 patients (17%) had late complications requiring reoperation. Preoperative global GIQLI score was 95 (range 56 to 140), significant different of the healthy volunteers score (120) (70 to 140) P < 0.001. Correlated with weight loss (percentage loss of overweight and BMI), the global score of the group increased to 100 at 3 months, 104 at 6, 111 at 1 year to reach 119 at 2 years which is no

  20. Longitudinal 2 years field study of conventional vaccination against highly pathogenic avian influenza H5N1 in layer hens.

    PubMed

    Rudolf, Miriam; Pöppel, Manfred; Fröhlich, Andreas; Breithaupt, Angele; Teifke, Jens; Blohm, Ulrike; Mettenleiter, Thomas; Beer, Martin; Harder, Timm

    2010-10-01

    A licensed, inactivated vaccine based on a low pathogenic avian influenza virus strain (H5N2) was evaluated in layer hens kept under field conditions during a 2-year period. Vaccine efficacy was investigated by specific antibodies and by challenge-contact experiments using highly pathogenic avian influenza viruses (HPAIV) H5N1. Basic immunization with two applications induced clinical protection. Virus excretion by vaccinated hens was significantly reduced compared to non-vaccinated controls; transmission to non-vaccinated and vaccinated contact birds was not fully interrupted. Vaccination efficacy is influenced by several factors including antigenic relatedness between vaccine and field strains, but also by species, age and type of commercial uses of the host. Limitations and risks of HPAIV vaccination as silent spread of HPAIV and emergence of escape mutants must be considered a priori and appropriate corrective measures have to be installed. PMID:20727963

  1. Towards a validation of a cellular biomarker suite in native and transplanted zebra mussels: a 2-year integrative field study of seasonal and pollution-induced variations.

    PubMed

    Guerlet, Edwige; Ledy, Karine; Meyer, Antoinette; Giambérini, Laure

    2007-03-30

    Two of the questions raised in the validation process of biomarkers are their relevance in the identification and discrimination of environmental perturbations, and the influence of seasonal factors on these biological endpoints. Determining the advantages and restrictions associated with the use of native or transplanted animals and comparing their responses is also needed. To obtain this information, a 2-year integrative field study was conducted in the vicinity of a nuclear power plant in northeastern France. A station was located in the reservoir receiving the cooling waters of the plant, and two other sites were studied 2 km upstream and 5 km downstream from the reservoir's discharge in the Moselle river. Elevated temperatures, copper contamination and a 1.4-fold-concentration factor of dissolved salts affected water quality of the reservoir. Native and transplanted zebra mussels (Dreissena polymorpha) were collected monthly and their digestive glands were processed for histochemical determinations of the lysosomal and peroxisomal systems and of the lipofuscin and neutral lipid contents. The responses were quantified using automated image analysis and stereology. Apart from neutral lipid contents, there were no systematic seasonal patterns in mussel populations or from 1 year to another. Principal Component Analyses showed a general higher discrimination potential of biological responses in transplanted organisms compared to native ones. They also pointed out the relationships between the cellular and physiological markers and abiotic factors. The present multiple biomarker integrative approach in transplanted D. polymorpha brings promising elements in their validation process as relevant biomonitoring tools.

  2. Iron-Folic Acid Supplementation During Pregnancy Reduces the Risk of Stunting in Children Less Than 2 Years of Age: A Retrospective Cohort Study from Nepal

    PubMed Central

    Nisar, Yasir Bin; Dibley, Michael J.; Aguayo, Victor M.

    2016-01-01

    The aim of the study was to investigate the effect of antenatal iron-folic acid (IFA) supplementation on child stunting in Nepalese children age <2 years. A retrospective cohort study design was used, in which a pooled cohort of 5235 most recent live births 2 years prior to interview from three Nepal Demographic and Health Surveys (2001, 2006 and 2011) was analysed. The primary outcome was stunting in children age <2 years. The main exposure variable was antenatal IFA supplementation. Multivariate Poisson regression analysis was performed. In our sample, 31% and 10% of Nepalese children age <2 years were stunted and severely stunted, respectively. The adjusted relative risk of being stunted was 14% lower in children whose mothers used IFA supplements compared to those whose mothers did not use (aRR = 0.86, 95% CI = 0.77–0.97). Additionally, the adjusted relative risk of being stunted was significantly reduced by 23% when antenatal IFA supplementation was started ≤6 months with ≥90 IFA supplements used during pregnancy (aRR = 0.77, 95% CI = 0.64–0.92). Antenatal IFA supplementation significantly reduced the risk of stunting in Nepalese children age <2 years. The greatest impact on the risk reduction of child stunting was when IFA supplements were started ≤6 months with ≥90 supplements were used. PMID:26828515

  3. Iron-Folic Acid Supplementation During Pregnancy Reduces the Risk of Stunting in Children Less Than 2 Years of Age: A Retrospective Cohort Study from Nepal.

    PubMed

    Nisar, Yasir Bin; Dibley, Michael J; Aguayo, Victor M

    2016-01-27

    The aim of the study was to investigate the effect of antenatal iron-folic acid (IFA) supplementation on child stunting in Nepalese children age <2 years. A retrospective cohort study design was used, in which a pooled cohort of 5235 most recent live births 2 years prior to interview from three Nepal Demographic and Health Surveys (2001, 2006 and 2011) was analysed. The primary outcome was stunting in children age <2 years. The main exposure variable was antenatal IFA supplementation. Multivariate Poisson regression analysis was performed. In our sample, 31% and 10% of Nepalese children age <2 years were stunted and severely stunted, respectively. The adjusted relative risk of being stunted was 14% lower in children whose mothers used IFA supplements compared to those whose mothers did not use (aRR = 0.86, 95% CI = 0.77-0.97). Additionally, the adjusted relative risk of being stunted was significantly reduced by 23% when antenatal IFA supplementation was started ≤6 months with ≥90 IFA supplements used during pregnancy (aRR = 0.77, 95% CI = 0.64-0.92). Antenatal IFA supplementation significantly reduced the risk of stunting in Nepalese children age <2 years. The greatest impact on the risk reduction of child stunting was when IFA supplements were started ≤6 months with ≥90 supplements were used.

  4. Continuity, Comorbidity and Longitudinal Associations between Depression and Antisocial Behaviour in Middle Adolescence: A 2-Year Prospective Follow-Up Study

    ERIC Educational Resources Information Center

    Ritakallio, Minna; Koivisto, Anna-Maija; von der Pahlen, Bettina; Pelkonen, Mirjami; Marttunen, Mauri; Kaltiala-Heino, Riittakerttu

    2008-01-01

    The study investigated continuity, comorbidity and longitudinal associations between depression Beck depression inventory (RBDI) and antisocial behaviour Youth self-report (YSR) in middle adolescence. Data were used from a community sample of 2070 adolescents who participated in a 2-year prospective follow-up study. The results indicate that both…

  5. Corrosion-induced release of Cu and Zn into rainwater from brass, bronze and their pure metals. A 2-year field study.

    PubMed

    Herting, Gunilla; Goidanich, Sara; Odnevall Wallinder, Inger; Leygraf, Christofer

    2008-09-01

    A 2-year field study has been conducted in an urban environment to provide annual release rates of copper and zinc from brass (20 wt% Zn) and copper and tin from bronze (6 wt% Sn) compared to sheets of their pure alloy constituents, copper and zinc. Despite relatively low nominal bulk alloy content, substantially more zinc was released from brass compared to copper. Both metals were released at a significantly slower rate from the brass alloy, compared to the pure metals. The proportion of release rates of copper and zinc from the alloy differed significantly from their proportions in the bulk alloy. Bronze showed relatively constant release rates of copper, being similar to that of pure copper sheet. The release of tin from bronze was negligible. The results clearly show that alloys and the pure metals behave very differently when exposed to rainwater. Accordingly, release rates from pure metals cannot be used to predict release rates of individual constituents from their alloys. Generated data are of importance within REACH, the new chemical policy of the European commission, where metal alloys erroneously are being treated as mixtures of chemical substances.

  6. P-Nitrobenzoic acid alpha2u nephropathy in 13-week studies is not associated with renal carcinogenesis in 2-year feed studies.

    PubMed

    Williams, K D; Dunnick, J; Horton, J; Greenwell, A; Eldridge, S R; Elwell, M; Sills, R C

    2001-01-01

    The objective of this study was to characterize the renal toxicity and carcinogenicity of p-nitrobenzoic acid in F344 rats. Dose levels in 13-week and 2-year studies ranged from 630-10,000 ppm and 1,250-5,000 ppm, respectively. At 13 weeks, renal lesions included minimal to mild hyaline droplet accumulation in male rats and karyomegaly in male and female rats. At 2 years, renal lesions included proximal tubule epithelial cell hyperplasia in male rats and oncocytic hyperplasia in high-dose male and female rats, and a decreased severity of nephropathy in males and females. The hvaline droplets in renal tubular epithelial cells of male rats at 13 weeks were morphologically similar to those described in alpha2u-globulin nephropathy. Using immunohistochemical methods, alpha2u-globulin accumulation was associated with the hyaline droplets. In addition, at 13 weeks, cell proliferation as detected by PCNA immunohistochemistry was significantly increased in males exposed to 5,000 and 10,000 ppm when compared to controls. Cytotoxicity associated with alpha2U-globulin nephropathy such as single-cell necrosis of the P2 segment epithelium or accumulation of granular casts in the outer medulla did not occur in the 13-week study. In addition, chronic treatment related nephrotoxic lesions attributed to accumulation of alpha2u-globulin such as linear foci of mineralization within the renal papilla, hyperplasia of the renal pelvis urothelium and kidney tumors were not observed. Although there was histologic evidence of alpha2u-globulin accumulation in male rats at 13 weeks, the minimal severity of nephropathy suggests that the degree of cytotoxicity was below the threshold, which would contribute to the development of renal tumors at 2 years.

  7. The Prognosis of Acute Low Back Pain in Primary Care in the U.S. A 2-Year Prospective Cohort Study

    PubMed Central

    Mehling, Wolf E.; Gopisetty, Viranjini; Bartmess-LeVasseur, Elizabeth; Acree, Mike; Pressman, Alice; Goldberg, Harley; Hecht, Frederick M; Carey, Tim; Avins, Andrew L

    2011-01-01

    Study Design Prospective cohort study Objective to assess the prognosis of patients presenting with acute low back pain (LBP) in a primary care setting in the U.S. Summary of Background Data Practice guidelines for acute LBP based on return-to-work outcomes underestimate the development of chronic pain in the primary care setting. Due to differences in inclusion criteria, chronic pain definitions and national health systems, prognostic cohort studies have reported a wide range of results limiting interpretation and generalization. Current data from carefully designed prognostic studies of acute LBP are lacking for the U.S. primary care system. Methods Members of a large health service organization were enrolled after seeking medical care for acute LBP, with or without sciatica, of up to 30 days duration, with no prior episode in the past 12 months and no history of spine surgery. We conducted phone interviews at baseline, six months and two years. Based on receiver operating characteristic analyses, a combination of global perceived recovery with pain intensity was used as primary outcome for chronic pain. Recurrence and multiple secondary outcomes were assessed to allow for comparison with other studies. Results 605 patients had an average pain intensity of 5.6 (numeric rating scale 0–10) and disability of 15.8 (Roland Morris scale 0–24). Eight percent had declared sick leave between pain onset and baseline interview. 13% of 521 patients (86% follow-up) suffered from chronic pain at six months and 19% of 443 patients at 2 years. At six months, 54% had experienced at least one LBP recurrence, and 47% in the subsequent 18 months. Conclusion The prognosis of strictly-defined acute LBP, with or without sciatica, is less favorable than commonly stated in practice guidelines based on failure to return to work. Broad initiatives to develop new means for the primary and secondary prevention of recurrent and chronic LBP are urgently needed. PMID:22504516

  8. The Role of Pictures and Gestures as a Support Mechanism for Novel Word Learning: A Training Study with 2-Year-Old Children

    ERIC Educational Resources Information Center

    Kapalková, Svetlana; Polišenská, Kamila; Süssová, Martina

    2016-01-01

    A training study examined novel word learning in 2-year-old children and assessed two nonverbal mechanisms, pictures and gestures, which are commonly used as communication support. The aim was to (1) compare these two support mechanisms and measure their effects on expressive word learning and (2) to investigate these effects on word production…

  9. Do Deviant Peer Associations Mediate the Contributions of Self-Esteem to Problem Behavior During Early Adolescence? A 2-Year Longitudinal Study

    ERIC Educational Resources Information Center

    DuBois, David L.; Silverthorn, Naida

    2004-01-01

    We investigated deviant peer associations as a mediator of the influences of general and peer-oriented self-esteem on problem behavior using data from a 2-year longitudinal study of 350 young adolescents. Measures of problem behavior included substance use (alcohol use, smoking) and antisocial behavior (fighting, stealing). Using latent growth…

  10. Exploring the Relationship between Autistic-Like Traits and ADHD Behaviors in Early Childhood: Findings from a Community Twin Study of 2-Year-Olds

    ERIC Educational Resources Information Center

    Ronald, Angelica; Edelson, Lisa R.; Asherson, Philip; Saudino, Kimberly J.

    2010-01-01

    Behaviors characteristic of autism and ADHD emerge in early childhood, yet research investigating their comorbidity has focused on older children. This study aimed to explore the nature of the relationship between autistic-like traits and ADHD behaviors in a community sample of 2-year-olds. Twins from the Boston University Twin Project (N = 312…

  11. A retrospective study of radiographic abnormalities in the repositories of 2-year-old Thoroughbred in-training sales in Japan

    PubMed Central

    MIYAKOSHI, Daisuke; SENBA, Hiroyuki; SHIKICHI, Mitsumori; MAEDA, Masaya; SHIBATA, Ryo; MISUMI, Kazuhiro

    2016-01-01

    ABSTRACT This study aimed to evaluate the influence of radiographic abnormalities of 2-year-old Thoroughbred horses that were listed at in-training sales in Japan, on whether they started to race or not at 2–3 years of age. Radiographs of 850 2-year-old Thoroughbreds in the in-training sales repository from 2007 to 2010 were reviewed, and 26 categories of radiographic abnormalities were found. Forty-three horses (5.1%, 43/850) did not start a race at 2–3 years of age. In accordance with the racing results for this age category, as determined by Fisher’s exact test and multiple logistic regression analysis, none of the radiographic abnormalities were significantly related to failure to start a race. At 2 years of age, 198 horses (23.3%, 198/850) did not start a race. Horses with enlargement of the proximal sesamoid bones in the fore (9 of 19 horses) and hind limbs (5 of 9 horses) did not start a race at the age of 2 years, and fewer of these horses (fore, P=0.021; hind, P=0.030) started a race at the age of 2 years compared with the population of horses without these radiographic abnormalities. These results suggest that identification of radiographic enlargement of the proximal sesamoid bones during training sales could derail the racing debut of horses at the age of 2 years. However, this might not necessarily indicate a poor prognosis and resulting in retirement from racing at 2–3 years of age. PMID:27330400

  12. Long-term impact of a chef on school lunch consumption: findings from a 2-year pilot study in Boston middle schools.

    PubMed

    Cohen, Juliana F W; Smit, Liesbeth A; Parker, Ellen; Austin, S Bryn; Frazier, A Lindsay; Economos, Christina D; Rimm, Eric B

    2012-06-01

    School cafeterias can play an important role in providing healthy meals. Although schools participating in the National School Lunch Program are required to meet minimum program standards, advocates recommend that innovations be sought to enhance menu dietary quality. This study evaluated the Chef Initiative, a 2-year pilot study in two Boston middle schools, designed to increase the availability and consumption of healthier school foods. Between 2007 and 2009, a professional chef trained cafeteria staff to prepare healthier school lunches (ie, more whole grains, fresh/frozen fruits and vegetables, and less sugar, salt, saturated fats, and trans fats). Meal nutrient compositions were monitored from 2007 to 2009, and a plate waste study conducted in the spring of 2009 compared food selection and consumption patterns among students at Chef Initiative schools, with students receiving standard school lunches at two matched control schools. Paired t tests and descriptive statistics were used to examine differences in menus and mixed-model analysis of variance was used to analyze differences in students' food selection and consumption between Chef Initiative and control schools. Overall, the Chef Initiative schools provided healthier lunches and the percent of foods consumed at Chef Initiative and control schools were similar (61.6% vs 57.3%; P=0.63). Of the areas targeted, there was greater whole-grain selection and vegetable consumption; 51% more students selected whole grains (P=0.02) and students consumed 0.36 more vegetable servings/day (P=0.01) at Chef Initiative schools. The potential of chefs collaborating with cafeteria staff to improve the availability, selection, and consumption of healthier meals is promising. PMID:22504283

  13. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the removal process, remedial investigation/ feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response...

  14. Trait and State Attributes of Insight in First Episodes of Early-Onset Schizophrenia and Other Psychoses: A 2-Year Longitudinal Study

    PubMed Central

    Parellada, Mara; Boada, Leticia; Fraguas, David; Reig, Santiago; Castro-Fornieles, Josefina; Moreno, Dolores; Gonzalez-Pinto, Ana; Otero, Soraya; Rapado-Castro, Marta; Graell, Montserrat; Baeza, Inmaculada; Arango, Celso

    2011-01-01

    Background: Increasing evidence supports the important role of illness state and individual characteristics in insight. Methods: Insight, as measured with the Scale to Assess Unawareness of Mental Disorder, over the first 2 years of early-onset first-episode psychosis and its correlations with clinical, socio-demographic, cognitive, and structural brain variables are studied. Results: (1) insight at 2 years is poorer in schizophrenia spectrum disorders (SSDs) than in subjects with other psychoses; (2) the more severe the psychosis, the worse the insight. In SSD, depressive symptoms, poorer baseline executive functioning, lower IQ, longer duration of untreated psychosis (DUP), and poorer premorbid infancy adjustment are associated with poorer insight; frontal and parietal gray matter (GM) reductions at baseline correlate with worse insight into having psychotic symptoms at 2 years; (3) insight into having a mental disorder (Scale to Assess Unawareness of Mental Disorder [SUMD]1) at 1 year, DUP, and baseline IQ are the most consistent variables explaining different aspects of insight at 2 years in SSD patients. IQ and SUMD1 at 1 year, together with left frontal and parietal GM volumes, explain 80% of the variance of insight into having specific psychotic symptoms in SSD patients (adjusted R2 = 0.795, F = 15.576, P < .001). Conclusion: Insight is a complex phenomenon that depends both on severity of psychopathology and also on disease and subject characteristics, such as past adjustment, IQ, DUP, cognitive functioning, frontal and parietal GM volumes, and age, gender, and ethnicity. PMID:20884756

  15. Diurnal Cortisol Secretion at Home and in Child Care: A Prospective Study of 2-Year-Old Toddlers

    ERIC Educational Resources Information Center

    Ouellet-Morin, Isabelle; Tremblay, Richard E.; Boivin, Michel; Meaney, Michael; Kramer, Michael; Cote, Sylvana M.

    2010-01-01

    Background: Previous studies indicate that children may experience disrupted cortisol secretion in child care. The extent to which this is a transient or long-term disruption is not known, as most studies have relied on cross-sectional designs, and age-heterogeneous small sample sizes. This study aims to (a) compare cortisol secretion measured at…

  16. The Role of Behavioral Self-Regulation in Learning to Read: A 2-Year Longitudinal Study of Icelandic Preschool Children

    ERIC Educational Resources Information Center

    Birgisdóttir, Freyja; Gestsdóttir, Steinunn; Thorsdóttir, Fanney

    2015-01-01

    Research Findings: Research suggests that behavioral self-regulation skills are critical for early school success, including success in literacy, but few studies have explored the relations that behavioral self-regulation may have with different components of early literacy development. The present study investigated the longitudinal contribution…

  17. The Predictive Relationship between Temperament, School Adjustment, and Academic Achievement: A 2-Year Longitudinal Study of Children At-Risk

    ERIC Educational Resources Information Center

    Al-Hendawi, Maha

    2010-01-01

    Individual differences in temperament can be a risk or a protective factor for a child, especially for children at-risk who possess single or multiple risk factors that may interfere with their educational success and affect their healthy development and their life-long outcomes. This research study examined the concurrent and longitudinal…

  18. Instructional Faculty and Staff in Public 2-year Colleges. Statistical Analysis Report. 1993 National Study of Postsecondary Faculty (NSOPF:93).

    ERIC Educational Resources Information Center

    Palmer, James C.

    Drawing on data from the 1993 National Study of Postsecondary Faculty, this analysis sought to differentiate instructional faculty and staff at public two-year colleges by age (under 35 vs. 55-64) and by years of experience in the current job (under 10 years vs. 20 or more years). The report examines differences by primary teaching field,…

  19. Self-Regulation in Children Born with Extremely Low Birth Weight at 2 Years Old: A Comparison Study

    ERIC Educational Resources Information Center

    Lynn, Lisa N.; Cuskelly, Monica; Gray, Peter H.; O'Callaghan, Michael J.

    2012-01-01

    Survival rates for children born with extremely low birth weight (ELBW) are increasing; however, many of these children experience later problems with learning. This study adopted an integrated approach to these problems, involving the self-regulatory tasks of inhibition and delay of gratification and relevant individual factors including…

  20. Acoustic evidence for the development of gestural coordination in the speech of 2-year-olds: a longitudinal study.

    PubMed

    Goodell, E W; Studdert-Kennedy, M

    1993-08-01

    Studies of child phonology have often assumed that young children first master a repertoire of phonemes and then build their lexicon by forming combinations of these abstract, contrastive units. However, evidence from children's systematic errors suggests that children first build a repertoire of words as integral sequences of gestures and then gradually differentiate these sequences into their gestural and segmental components. Recently, experimental support for this position has been found in the acoustic records of the speech of 3-, 5-, and 7-year-old children, suggesting that even in older children some phonemes have not yet fully segregated as units of gestural organization and control. The present longitudinal study extends this work to younger children (22- and 32-month-olds). Results demonstrate clear differences in the duration and coordination of gestures between children and adults, and a clear shift toward the patterns of adult speakers during roughly the third year of life. Details of the child-adult differences and developmental changes vary from one aspect of an utterance to another. PMID:8377484

  1. 2-year study of chemical composition of bulk deposition in a south China coastal city: comparison with east Asian cities.

    PubMed

    Wai, K M; Tanner, P A; Tam, C W F

    2005-09-01

    Using the emission strengths of the precursor gases, the nature of soil in China, the ventilation power and half value rainout region length, the nss-SO42-, NO3-, Ca2+, and NH4+ concentrations, and pH of rainwater at Hong Kong and other cities of China and Japan are compared and rationalized. The chemical composition of Hong Kong bulk deposition from 1998 to 2000 is taken from our collection and analysis of 156 daily samples. The volume-weighted average (VWA) pH is 4.2 over the whole study period. Nonsea salt- (nss-) sulfate is the most abundant species in the samples, and the pH mostly depended upon the concentrations of the major species nss-SO42, NO3-, Ca2+, and NH4+. All species concentrations show higher levels in the cold season (especially NO3- and Ca2+), which indicates the dominant dilution effects in the warm season due to heavy rainfall and the influence of the continental outflow of pollutants during the cold season. For Hong Kong bulk deposition, the VWA pH is slightly lower in the cold season, and there is a slight decrease in VWA pH over the period from 1994 to 2000. The impact of acid rain in Hong Kong is briefly discussed.

  2. 2-year study of chemical composition of bulk deposition in a South China coastal city: comparison with East Asian cities

    SciTech Connect

    K.M. Wai; P.A. Tanner; C.W.F. Tam

    2005-09-01

    Using the emission strengths of the precursor gases, the nature of soil in China, the ventilation power and half value rainout region length, the nss-SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, Ca{sup 2+}, and NH{sub 4}{sup +} concentrations, and pH of rainwater at Hong Kong and other cities of China and Japan are compared and rationalized. The chemical composition of Hong Kong bulk deposition from 1998 to 2000 is taken from the collection and analysis of 156 daily samples. The volume-weighted average (VWA) pH is 4.2 over the whole study period. Nonsea salt- (nss-) sulfate is the most abundant species in the samples, and the pH mostly depended upon the concentrations of the major species nss-SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, Ca{sup 2+}, and NH{sub 4}{sup +}. All species concentrations show higher levels in the cold season (especially NO{sub 3}- and Ca{sup 2+}), which indicates the dominant dilution effects in the warm season due to heavy rainfall and the influence of the continental outflow of pollutants during the cold season. For Hong Kong bulk deposition, the VWA pH is slightly lower in the cold season, and there is a slight decrease in VWA pH over the period from 1994 to 2000. The impact of acid rain in Hong Kong is briefly discussed. 36 refs., 3 figs., 5 tabs.

  3. 2-year study of chemical composition of bulk deposition in a south China coastal city: comparison with east Asian cities.

    PubMed

    Wai, K M; Tanner, P A; Tam, C W F

    2005-09-01

    Using the emission strengths of the precursor gases, the nature of soil in China, the ventilation power and half value rainout region length, the nss-SO42-, NO3-, Ca2+, and NH4+ concentrations, and pH of rainwater at Hong Kong and other cities of China and Japan are compared and rationalized. The chemical composition of Hong Kong bulk deposition from 1998 to 2000 is taken from our collection and analysis of 156 daily samples. The volume-weighted average (VWA) pH is 4.2 over the whole study period. Nonsea salt- (nss-) sulfate is the most abundant species in the samples, and the pH mostly depended upon the concentrations of the major species nss-SO42, NO3-, Ca2+, and NH4+. All species concentrations show higher levels in the cold season (especially NO3- and Ca2+), which indicates the dominant dilution effects in the warm season due to heavy rainfall and the influence of the continental outflow of pollutants during the cold season. For Hong Kong bulk deposition, the VWA pH is slightly lower in the cold season, and there is a slight decrease in VWA pH over the period from 1994 to 2000. The impact of acid rain in Hong Kong is briefly discussed. PMID:16190210

  4. Changes in Intra-pelvic Obliquity Angle 0–2 Years After Total Hip Arthroplasty and Its Effects on Leg Length Discrepancy: A Retrospective Study

    PubMed Central

    Zhang, Yin; Cheng, Tao; Zhang, Xian-Long

    2015-01-01

    Background: Total hip arthroplasty (THA) is one of the most effective treatments for phase III and IV hip arthrosis. Lower limb length balancing is one of the determining factors of a successful surgery, particularly in patients with developmental dysplasia of the hip (DDH). The purpose of this study was to evaluate the postoperative change in intra-pelvic obliquity (intra-PO) angle in the coronal plane and its effects on leg length discrepancy (LLD) within 2 years. Methods: A total of 78 patients (70 females, 8 males) were enrolled in this study. All patients were suffering from DDH with varying degrees of LLD. Pelvic plain radiographs were collected before and after the operation. The intra-PO angles were measured 0, 0.5, 1 and 2 years after THA. At the same time, postoperative LLD was measured with blocking test. Results: PO changed significantly in the first year after THA surgery (0 year vs. 0.5 year, P < 0.01; 0.5 year vs. 1 year, P < 0.01), and the changing value of intra-PO angle (ΔPO) slowed down substantially during the first 2 years after THA (0.5 year vs. 0.5–1 year, P < 0.01; 0.5–1 year vs. 1–2 years, P < 0.01). With the change in intra-PO angle, LLD also got narrow within the 1st year (0 year vs. 0.5 year, P < 0.01; 0.5 year vs. 1 year, P < 0.01). Elderly patients had a smaller intra-PO angle reduction (Group A vs. Group B, P = 0.01; Group B vs. Group C, P < 0.01). Conclusions: Intra-PO angle and LLD gap narrowed with time after THA surgery. In particular, elderly patients had smaller change in intra-PO angle. PMID:25963356

  5. Prospective Study Evaluating Postoperative Radiotherapy Plus 2-Year Androgen Suppression for Post-Radical Prostatectomy Patients With Pathologic T3 Disease and/or Positive Surgical Margins

    SciTech Connect

    Choo, Richard Danjoux, Cyril; Gardner, Sandra; Morton, Gerard; Szumacher, Ewa; Loblaw, D. Andrew; Cheung, Patrick; Pearse, Maria

    2009-10-01

    Purpose: To determine the efficacy of a combined approach of postoperative radiotherapy (RT) plus 2-year androgen suppression (AS) for patients with pathologic T3 disease (pT3) and/or positive surgical margins (PSM) after radical prostatectomy (RP). Methods and Materials: A total of 78 patients with pT3 and/or PSM after RP were treated with RT plus 2-year AS, as per a pilot, prospective study. Androgen suppression started within 1 month after the completion of RT and consisted of nilutamide for 4 weeks and buserelin acetate depot subcutaneously every 2 months for 2 years. Relapse-free rate, including freedom from prostate-specific antigen (PSA) relapse, was estimated using the Kaplan-Meier method. A Cox regression analysis was performed to evaluate prognostic factors for relapse. Prostate-specific antigen relapse was defined as a PSA rise above 0.2 ng/mL, with two consecutive increases over a minimum of 3 months. Results: The median age was 61 years at the time of RP. The median interval between RP and postoperative RT was 4.2 months. Forty-nine patients had undetectable PSA (<0.2 ng/mL), and 29 had persistently detectable postoperative PSA at the time of the protocol treatment. Median follow-up from RT was 6.4 years. Relapse-free rates at 5 and 7 years were 94.4% and 86.3%, respectively. Survival rates were 96% at 5 years and 93.1% at 7 years. On Cox regression analysis, persistently detectable postoperative PSA and pT3b-T4 were significant predictors for relapse. Conclusion: The combined treatment of postoperative RT plus 2-year AS yielded encouraging results for patients with pT3 and/or PSM and warrants a confirmatory study.

  6. Cementless anatomical prosthesis for the treatment of 3-part and 4-part proximal humerus fractures: cadaver study and prospective clinical study with minimum 2 years followup

    PubMed Central

    Obert, Laurent; Saadnia, Rachid; Loisel, François; Uhring, Julien; Adam, Antoine; Rochet, Séverin; Clappaz, Pascal; Lascar, Tristan

    2016-01-01

    Introduction: The purpose of this study was to evaluate the functional and radiological outcomes of a cementless, trauma-specific locked stem for 3- and 4-part proximal humeral fractures. Materials and methods: This study consisted of two parts: a cadaver study with 22 shoulders and a multicenter prospective clinical study of 23 fracture patients evaluated at least 2 years after treatment. In the cadaver study, the locked stem (HumelockTM, FX Solutions) and its instrumentation were evaluated. In the clinical study, five senior surgeons at four different hospitals performed the surgical procedures. An independent surgeon evaluated the patients using clinical (Constant score, QuickDASH) and radiological (X-rays, CT scans) outcome measures. Results: The cadaver study allowed us to validate the height landmarks relative to the pectoralis major tendon. In the clinical study, at the review, abduction was 95° (60–160), forward flexion was 108° (70–160), external rotation (elbow at body) was 34° (0–55), the QuickDASH was 31 (4.5–59), the overall Constant score was 54 (27–75), and the weighted Constant score was 76 (31.5–109). Discussion: This preliminary study of hemiarthroplasty (HA) with a locked stem found results that were at least equivalent to published series. As all patients had at least a 2-year follow-up, integration of the locked stem did not cause any specific complications. These results suggest that it is possible to avoid using cement when hemiarthroplasty is performed for the humeral stem. This implant makes height adjustment and transosseous suturing of the tuberosities more reproducible. PMID:27194107

  7. Joint unloading implant modifies subchondral bone trabecular structure in medial knee osteoarthritis: 2-year outcomes of a pilot study using fractal signature analysis

    PubMed Central

    Miller, Larry E; Sode, Miki; Fuerst, Thomas; Block, Jon E

    2015-01-01

    Background Knee osteoarthritis (OA) is largely attributable to chronic excessive and aberrant joint loading. The purpose of this pilot study was to quantify radiographic changes in subchondral bone after treatment with a minimally invasive joint unloading implant (KineSpring® Knee Implant System). Methods Nine patients with unilateral medial knee OA resistant to nonsurgical therapy were treated with the KineSpring System and followed for 2 years. Main outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, function, and stiffness subscores and independent core laboratory determinations of joint space width and fractal signature of the tibial cortex. Results WOMAC scores, on average, improved by 92% for pain, 91% for function, and 79% for stiffness over the 2-year follow-up period. Joint space width in the medial compartment of the treated knee significantly increased from 0.9 mm at baseline to 3.1 mm at 2 years; joint space width in the medial compartment of the untreated knee was unchanged. Fractal signatures of the vertically oriented trabeculae in the medial compartment decreased by 2.8% in the treated knee and increased by 2.1% in the untreated knee over 2 years. No statistically significant fractal signature changes were observed in the horizontally oriented trabeculae in the medial compartment or in the horizontal or vertical trabeculae of the lateral compartment in the treated knee. Conclusion Preliminary evidence suggests that the KineSpring System may modify knee OA disease progression by increasing joint space width and improving subchondral bone trabecular integrity, thereby reducing pain and improving joint function. PMID:25670891

  8. Conductivity study of chitosan based nanocomposites

    NASA Astrophysics Data System (ADS)

    Mohan, C. Raja; Murugan, S.; Jayakumar, K.

    2012-06-01

    Bio polymer like chitosan is dissolved in acids like formic and acetic acid and CdS nano particle prepared by chemical methods has been embedded in the salts of chitosan matrix. The viscous solution is cast into film on the glass substrate using spin coating method and their ionic conductivity has been studied for various frequencies and temperatures.

  9. Framework for planning and conducting pilot studies.

    PubMed

    Smith, Lisa Janette; Harrison, Margaret B

    2009-12-01

    Researchers working with partners in home care to plan a pragmatic multicenter community-based, randomized, controlled trial for leg ulcer compression treatment realized a smaller pilot study would be necessary. Because no framework for conducting pilot studies could be found, the authors developed a framework for pilot study methodology to inform the planning of such research. To this end, an integrative literature review was conducted, guided by an explicit search strategy, retrieval procedures, and appraisal process, to identify recognized pilot study aims, processes, and methodologies used in previously reported community pilot studies. Factors influencing study inclusion were recognized pilot study aims and purposes and a concise working definition of pilot study. Methodologies used in previously conducted community pilot studies were reviewed. Although relevant published research was limited, 11 pilot studies met the inclusion criteria for this review and contained suggestions to further develop or improve plans for larger definitive trials to enable a better fit of protocols within the delivery systems and scopes of practice. Pilot research processes could be divided into two stages: early planning and pilot trial. Direction for procedures and methods was gained relative to planning for an effective pilot study regarding eligibility, recruitment and data collection, management, and analysis. The results were used to develop an organizing framework for the authors' pilot study and named the Pilot Research Process (PReP) Framework. The process was instrumental in working with the authors' research team and clinical partners in the planning of their leg ulcer treatment pilot study. This framework may provide a foundation for others to analyze or develop a pilot study methodology in planning a large-scale study. PMID:20038790

  10. A randomized study on migration of the Spectron EF and the Charnley flanged 40 cemented femoral components using radiostereometric analysis at 2 years

    PubMed Central

    2011-01-01

    Background and purpose We performed a randomized study to determine the migration patterns of the Spectron EF femoral stem and to compare them with those of the Charnley stem, which is regarded by many as the gold standard for comparison of implants due to its extensive documentation. Patients and methods 150 patients with a mean age of 70 years were randomized, single-blinded, to receive either a cemented Charnley flanged 40 monoblock, stainless steel, vaquasheen surface femoral stem with a 22.2-mm head (n = 30) or a cemented Spectron EF modular, matte, straight, collared, cobalt-chrome femoral stem with a 28-mm femoral head and a roughened proximal third of the stem (n = 120). The patients were followed with repeated radiostereometric analysis for 2 years to assess migration. Results At 2 years, stem retroversion was 2.3° and 0.7° (p < 0.001) and posterior translation was 0.44 mm and 0.17 mm (p = 0.002) for the Charnley group (n = 26) and the Spectron EF group (n = 74), respectively. Subsidence was 0.26 mm for the Charnley and 0.20 mm for the Spectron EF (p = 0.5). Interpretation The Spectron EF femoral stem was more stable than the Charnley flanged 40 stem in our study when evaluated at 2 years. In a report from the Norwegian arthroplasty register, the Spectron EF stem had a higher revision rate due to aseptic loosening beyond 5 years than the Charnley. Initial stability is not invariably related to good long-term results. Our results emphasize the importance of prospective long-term follow-up of prosthetic implants in clinical trials and national registries and a stepwise introduction of implants. PMID:21895504

  11. Co-occurrence of and remission from general anxiety, depression, and posttraumatic stress disorder symptoms after acute lung injury: a 2-year longitudinal study

    PubMed Central

    Bienvenu, O. Joseph; Colantuoni, Elizabeth; Mendez-Tellez, Pedro A.; Shanholtz, Carl; Dennison-Himmelfarb, Cheryl R.; Pronovost, Peter J.; Needham, Dale M.

    2014-01-01

    Objective To evaluate the co-occurrence, and predictors of remission, of general anxiety, depression, and posttraumatic stress disorder (PTSD) symptoms during 2-year follow-up in survivors of acute lung injury (ALI) treated in an intensive care unit (ICU). Design, Setting, and Patients This prospective cohort study enrolled 520 patients from 13 medical and surgical ICUs in 4 hospitals, with follow-up at 3, 6, 12, and 24 months post-ALI. Measurements and Main Results The outcomes of interest were measured using the Hospital Anxiety and Depression Scale (HADS) anxiety and depression subscales (scores ≥8 indicating substantial symptoms) and the Impact of Event Scale-Revised (IESR, scores ≥1.6 indicating substantial PTSD symptoms). Of the 520 enrolled patients, 274 died before 3-month follow-up; 186/196 consenting survivors (95%) completed at least one HADS and IESR assessment during 2-year follow-up, and most completed multiple assessments. Across follow-up time points, the prevalence of supra-threshold general anxiety, depression, and PTSD symptoms ranged from 38–44%, 26–33%, and 22–24%, respectively; more than half of the patients had supra-threshold symptoms in at least one domain during 2-year follow-up. The majority (59%) of survivors with any supra-threshold symptoms were above threshold for 2 or more types of symptoms (i.e., of general anxiety, depression, and/or PTSD). In fact, the most common pattern involved simultaneous general anxiety, depression, and PTSD symptoms. Most patients with general anxiety, depression, or PTSD symptoms during 2-year follow-up had supra-threshold symptoms at 24-month (last) follow-up. Higher SF-36 physical functioning domain scores at the prior visit were associated with a greater likelihood of remission from general anxiety and PTSD symptoms during follow-up. Conclusions The majority of ALI survivors had clinically significant general anxiety, depressive, or PTSD symptoms, and these symptoms tended to co-occur across

  12. Two phase detonation studies conducted in 1971

    NASA Technical Reports Server (NTRS)

    Nicholls, J. A.

    1972-01-01

    A report is presented describing the research conducted on five phases: (1) ignition of fuel drops by a shock wave and passage of a shock wave over a burning drop, (2) the energy release pattern of a two-phase detonation with controlled drop sizes, (3) the attenuation of shock and detonation waves passing over an acoustic liner, (4) experimental and theoretical studies of film detonations, and (5) a simplified analytical model of a rotating two-phase detonation wave in a rocket motor.

  13. Evaluation of psychic change through the application of empirical and clinical techniques for a 2-year treatment: a single case study.

    PubMed

    Moreno, Clara M López; Schalayeff, Cristina; Acosta, Silvia R; Vernengo, Pía; Roussos, Andrés J; Lerner, Beatríz Dorfman

    2005-07-01

    Abstract The authors present results obtained by a combination of clinical and empirical methods used in the evaluation of psychic change involving a single case study carried out during 2 years of nonmanualized psychodynamic psychotherapy (Barber & Crits-Christoph, 1993 ; Barber, Foltz, DeRubeis, & Landis, 2002 ). A multidimensional definition of change that includes clinical (psychoanalytic) and empirical perspectives is provided. The authors used material from supervision sessions and clinical meetings to assess the psychodynamic diagnosis and evolution. The following empirical techniques and instruments were used: core conflictual relationship theme (Luborsky & Crits-Christoph, 1990), Symptom Checklist-90-Revised (Derogatis, 1983), and Differential Elements for a Psychodynamic Diagnostic (C. M. López Moreno et al., 1998 ). Several markers of psychic change along the therapeutic process were found. The instruments proved to be sensitive to the changes obtained during the psychotherapy. Used together, the instruments allowed an integrated evaluation of the patient's evolution during the treatment.

  14. Do deviant peer associations mediate the contributions of self-esteem to problem behavior during early adolescence? A 2-year longitudinal study.

    PubMed

    DuBois, David L; Silverthorn, Naida

    2004-06-01

    We investigated deviant peer associations as a mediator of the influences of general and peer-oriented self-esteem on problem behavior using data from a 2-year longitudinal study of 350 young adolescents. Measures of problem behavior included substance use (alcohol use, smoking) and antisocial behavior (fighting, stealing). Using latent growth curve modeling and covariance structure analysis, an extension of a model proposed by DuBois et al. (2002) was evaluated for each type of problem behavior. Findings revealed that lower general self-esteem and greater peer orientation in self-esteem each predicted deviant associations with peers and that deviant peer associations, in turn, were associated with higher levels and rates of change in problem behavior. Deviant peer associations mediated the associations of general and peer-oriented self-esteem with levels and rates of change in problem behavior such that direct paths from self-esteem to problem behavior generally were nonsignificant.

  15. Improvement in hematological, visceral, and skeletal manifestations of Gaucher disease type 1 with oral eliglustat tartrate (Genz-112638) treatment: 2-year results of a phase 2 study

    PubMed Central

    Lukina, Elena; Watman, Nora; Arreguin, Elsa Avila; Dragosky, Marta; Iastrebner, Marcelo; Rosenbaum, Hanna; Phillips, Mici; Pastores, Gregory M.; Kamath, Ravi S.; Rosenthal, Daniel I.; Kaper, Mathilde; Singh, Tejdip; Puga, Ana Cristina

    2010-01-01

    Eliglustat tartrate is an investigational oral substrate reduction therapy for Gaucher disease type 1 that is pharmacologically distinct from intravenous enzyme replacement therapy. Eliglustat tartrate improved clinical manifestations in patients who received 50 or 100 mg twice daily for 1 year during an open-label phase 2 study (Blood. 2010;116(6):893-899). We report further improvements after 2 years of treatment in 20 patients (11 females, 9 males; mean age, 33 years) with baseline splenomegaly and thrombocytopenia and/or anemia. Statistically significant (P < .001) percentage improvements from baseline occurred in platelet count (mean ± SD, 81% ± 56%), hemoglobin level (20% ± 15%), spleen volume (−52% ± 11%), and liver volume (−24% ± 13%). Mean platelet count increased ∼ 50 000/mm3. Mean hemoglobin level increased 2.1 g/dL overall and 3.1 g/dL in 10 patients with baseline anemia. Organ volume reductions were greatest in patients with severe baseline organomegaly. Seventeen (85%) patients met established therapeutic goals for ≥ 3 of the 4 parameters. Lumbar spine bone mineral density increased 7.8% ± 10.6% (P = .01) and T-score 0.6 ± 0.8 (P = .012), with major gains in osteoporotic and osteopenic patients. Magnetic resonance imaging assessment showed that bone marrow infiltration by Gaucher cells was decreased (8/18 patients) or stable (10/18 patients). No safety-related trends emerged during 2 years of treatment. This multisite, open-label, single-arm phase 2 study is registered at www.clinicaltrials.gov as NCT00358150. PMID:20713962

  16. Efficacy, safety and patient-reported outcomes of combination etanercept and sulfasalazine versus etanercept alone in patients with rheumatoid arthritis: a double-blind randomised 2-year study

    PubMed Central

    Combe, B; Codreanu, C; Fiocco, U; Gaubitz, M; Geusens, P P; Kvien, T K; Pavelka, K; Sambrook, P N; Smolen, J S; Khandker, R; Singh, A; Wajdula, J; Fatenejad, S

    2009-01-01

    Objective: To determine the efficacy and safety of etanercept and etanercept plus sulfasalazine versus sulfasalazine in patients with rheumatoid arthritis (RA) despite sulfasalazine therapy. Methods: Patients were randomly assigned to etanercept (25 mg twice weekly; sulfasalazine was discontinued at baseline), etanercept plus sulfasalazine (unchanged regimen of 2–3 g/day) or sulfasalazine in a double-blind, randomised, 2-year study in adult patients with active RA despite sulfasalazine therapy. Efficacy was assessed using the American College of Rheumatology criteria, disease activity scores (DAS) and patient-reported outcomes (PRO). Results: Demographic variables and baseline disease characteristics were comparable among treatment groups; mean DAS 5.1, 5.2 and 5.1 for etanercept (n  =  103), etanercept plus sulfasalazine (n  =  101) and sulfasalazine (n  =  50), respectively. Withdrawal due to lack of efficacy was highest with sulfasalazine (26 (52%) vs 6 (6%) for either etanercept group, p<0.001). Patients receiving etanercept or etanercept plus sulfasalazine had a more rapid initial response, which was sustained at 2 years, than those receiving sulfasalazine: mean DAS 2.8, 2.5 versus 4.5, respectively (p<0.05); ACR 20 response was achieved by 67%, 77% versus 34% of patients, respectively (p<0.01) Overall, PRO followed a similar pattern; a clinically significant improvement in health assessment questionnaire was achieved by 76%, 78% versus 40% of patients, respectively (p<0.01). Commonly reported adverse events occurring in the etanercept groups were injection site reactions and pharyngitis/laryngitis (p<0.01). Conclusion: Etanercept and etanercept plus sulfasalazine are efficacious for the long-term management of patients with RA. The addition of etanercept or substitution with etanercept should be considered as treatment options for patients not adequately responding to sulfasalazine. PMID:18794178

  17. Social Development:: 2 Year Olds

    MedlinePlus

    ... Español Text Size Email Print Share Social Development: 2 Year Olds Page Content Article Body By nature, ... probably are acting the same way. At age two, children view the world almost exclusively through their ...

  18. Language Development: 2 Year Olds

    MedlinePlus

    ... Stages Listen Español Text Size Email Print Share Language Development: 2 Year Olds Page Content Article Body ... Pay attention to how he also is using language to describe ideas and information and to express ...

  19. Impact on malaria morbidity of a programme supplying insecticide treated nets in children aged under 2 years in Tanzania: community cross sectional study

    PubMed Central

    Abdulla, Salim; Schellenberg, Joanna Armstrong; Nathan, Rose; Mukasa, Oscar; Marchant, Tanya; Smith, Tom; Tanner, Marcel; Lengeler, Christian

    2001-01-01

    Objective To assess the impact of a social marketing programme for distributing nets treated with insecticide on malarial parasitaemia and anaemia in very young children in an area of high malaria transmission. Design Community cross sectional study. Annual, cross sectional data were collected at the beginning of the social marketing campaign (1997) and the subsequent two years. Net ownership and other risk and confounding factors were assessed with a questionnaire. Blood samples were taken from the children to assess prevalence of parasitaemia and haemoglobin levels. Setting 18 villages in the Kilombero and Ulanga districts of southwestern Tanzania. Participants A random sample of children aged under 2 years. Main outcome measures The presence of any parasitaemia in the peripheral blood sample and the presence of anaemia (classified as a haemoglobin level of <80 g/l). Results Ownership of nets increased rapidly (treated or not treated nets: from 58% to 83%; treated nets: from 10% to 61%). The mean haemoglobin level rose from 80 g/l to 89 g/l in the study children in the successive surveys. Overall, the prevalence of anaemia in the study population decreased from 49% to 26% in the two years studied. Treated nets had a protective efficacy of 62% (95% confidence interval 38% to 77%) on the prevalence of parasitaemia and of 63% (27% to 82%) on anaemia. Conclusions These results show that nets treated with insecticide have a substantial impact on morbidity when distributed in a public health setting. PMID:11157527

  20. Conducting a pilot study: case study of a novice researcher.

    PubMed

    Doody, Owen; Doody, Catriona M

    Pilot studies play a vital role in health research, but are often misused, mistreated and misrepresented. A well-conducted pilot study with clear aims and objectives within a formal framework ensures methodological rigour, can lead to higher-quality research and scientifically valid work that is publishable and can benefit patients and health service delivery. A pilot study contributes valuable information to assist researchers in the conduct of their study. Conducting a pilot study provides the researcher with the opportunity to develop and enhance the skills necessary before commencing the larger study. By conducting a pilot the researcher obtains preliminary data, can evaluate their data-analysis method and clarify the financial and human resources required. This article presents an overview of pilot studies, why they are conducted, what to consider when reporting pilot studies and the authors' experience of conducting a pilot study. To conduct a successful study, researchers need to develop their skills, choose the right methods and carefully plan for all aspects of the process. PMID:26618678

  1. Conducting a multi family member interview study.

    PubMed

    Reczek, Corinne

    2014-06-01

    Family researchers have long recognized the utility of incorporating interview data from multiple family members. Yet, relatively few contemporary scholars utilize such an approach due to methodological underdevelopment. This article contributes to family scholarship by providing a roadmap for developing and executing in-depth interview studies that include more than one family member. Specifically, it outlines the epistemological frames that most commonly underlie this approach, illustrates thematic research questions that it best addresses, and critically reviews the best methodological practices of conducting research with this approach. The three most common approaches are addressed in depth: separate interviews with each family member, dyadic or group interviews with multiple family members, and a combined approach that uses separate and dyadic or group interviews. This article speaks to family scholars who are at the beginning stages of their research project but are unsure of the best qualitative approach to answer a given research question.

  2. Attitudes to medication after kidney transplantation and their association with medication adherence and graft survival: a 2-year follow-up study.

    PubMed

    Tielen, Mirjam; van Exel, Job; Laging, Mirjam; Beck, Denise K; Khemai, Roshni; van Gelder, Teun; Betjes, Michiel G H; Weimar, Willem; Massey, Emma K

    2014-01-01

    Background. Nonadherence to medication is a common problem after kidney transplantation. The aim of this study was to explore attitudes towards medication, adherence, and the relationship with clinical outcomes. Method. Kidney recipients participated in a Q-methodological study 6 weeks after transplantation. As a measure of medication adherence, respondents completed the Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS(©)-interview). Moreover, the intrapatient variability in the pharmacokinetics of tacrolimus was calculated, which measures stability of drug intake. Data on graft survival was retrieved from patient records up to 2 years after transplantation. Results. 113 renal transplant recipients (19-75 years old) participated in the study. Results revealed three attitudes towards medication adherence-attitude 1: "confident and accurate," attitude 2: "concerned and vigilant," and attitude 3: "appearance oriented and assertive." We found association of attitudes with intrapatient variability in pharmacokinetics of tacrolimus, but not with self-reported nonadherence or graft survival. However, self-reported nonadherence immediately after transplantation was associated with lower two-year graft survival. Conclusion. These preliminary findings suggest that nonadherence shortly after kidney transplantation may be a risk factor for lower graft survival in the years to follow. The attitudes to medication were not a risk factor.

  3. Acquired hemophilia A in the United Kingdom: a 2-year national surveillance study by the United Kingdom Haemophilia Centre Doctors' Organisation.

    PubMed

    Collins, Peter W; Hirsch, Sybil; Baglin, Trevor P; Dolan, Gerard; Hanley, John; Makris, Michael; Keeling, David M; Liesner, Ri; Brown, Simon A; Hay, Charles R M

    2007-03-01

    Acquired hemophilia A is a severe bleeding disorder caused by an autoantibody to factor VIII. Previous reports have focused on referral center patients and it is unclear whether these findings are generally applicable. To improve understanding of the disease, a 2-year observational study was established to identify and characterize the presenting features and outcome of all patients with acquired hemophilia A in the United Kingdom. This allowed a consecutive cohort of patients, unbiased by referral or reporting practice, to be studied. A total of 172 patients with a median age of 78 years were identified, an incidence of 1.48/million/y. The cohort was significantly older than previously reported series, but bleeding manifestations and underlying diseases were similar. Bleeding was the cause of death in 9% of the cohort and remained a risk until the inhibitor had been eradicated. There was no difference in inhibitor eradication or mortality between patients treated with steroids alone and a combination of steroids and cytotoxic agents. Relapse of the inhibitor was observed in 20% of the patients who had attained first complete remission. The data provide the most complete description of acquired hemophilia A available and are applicable to patients presenting to all centers.

  4. Bacterial community shift is induced by dynamic environmental parameters in a changing coastal ecosystem (northern Adriatic, northeastern Mediterranean Sea)--a 2-year time-series study.

    PubMed

    Tinta, T; Vojvoda, J; Mozetič, P; Talaber, I; Vodopivec, M; Malfatti, F; Turk, V

    2015-10-01

    The potential link between the microbial dynamics and the environmental parameters was investigated in a semi-enclosed and highly dynamic coastal system (Gulf of Trieste, northern Adriatic Sea, NE Mediterranean Sea). Our comprehensive 2-year time-series study showed that despite the shallowness of this area, there was a significant difference between the surface and the bottom bacterial community structure. The bottom bacterial community was more diverse than the surface one and influenced by sediment re-suspension. The surface seawater temperature had a profound effect on bacterial productivity, while the bacterial community structure was more affected by freshwater-borne nutrients and phytoplankton blooms. Phytoplankton blooms caused an increase of Gammaproteobacteria (Alteromonadaceae, SAR86 and Vibrionaceae) and shift in dominance from SAR11 to Rhodobacteraceae taxon at the surface. Our results propose the importance of the water mass movements as drivers of freshwater-borne nutrients and of allochthonous microbial taxa. This study emphasizes the prediction power based on association networks analyses that are fed with long-term measurements of microbial and environmental parameters. These interaction maps offer valuable insights into the response of marine ecosystem to climate- and anthropogenic-driven stressors.

  5. Influence of Anti-TNF and Disease Modifying Antirheumatic Drugs Therapy on Pulmonary Forced Vital Capacity Associated to Ankylosing Spondylitis: A 2-Year Follow-Up Observational Study

    PubMed Central

    Rocha-Muñoz, Alberto Daniel; Brambila-Tapia, Aniel Jessica Leticia; Zavala-Cerna, María Guadalupe; Vásquez-Jiménez, José Clemente; De la Cerda-Trujillo, Liliana Faviola; Vázquez-Del Mercado, Mónica; Rodriguez-Jimenez, Norma Alejandra; Díaz-Rizo, Valeria; Díaz-González, Viviana; Cardona-Muñoz, Ernesto German; Dávalos-Rodríguez, Ingrid Patricia; Salazar-Paramo, Mario; Gamez-Nava, Jorge Ivan; Nava-Zavala, Arnulfo Hernan; Gonzalez-Lopez, Laura

    2015-01-01

    Objective. To evaluate the effect of anti-TNF agents plus synthetic disease modifying antirheumatic drugs (DMARDs) versus DMARDs alone for ankylosing spondylitis (AS) with reduced pulmonary function vital capacity (FVC%). Methods. In an observational study, we included AS who had FVC% <80% at baseline. Twenty patients were taking DMARDs and 16 received anti-TNF + DMARDs. Outcome measures: changes in FVC%, BASDAI, BASFI, 6-minute walk test (6MWT), Borg scale after 6MWT, and St. George's Respiratory Questionnaire at 24 months. Results. Both DMARDs and anti-TNF + DMARDs groups had similar baseline values in FVC%. Significant improvement was achieved with anti-TNF + DMARDs in FVC%, at 24 months, when compared to DMARDs alone (P = 0.04). Similarly, patients in anti-TNF + DMARDs group had greater improvement in BASDAI, BASFI, Borg scale, and 6MWT when compared to DMARDs alone. After 2 years of follow-up, 14/16 (87.5%) in the anti-TNF + DMARDs group achieved the primary outcome: FVC% ≥80%, compared with 11/20 (55%) in the DMARDs group (P = 0.04). Conclusions. Patients with anti-TNF + DMARDs had a greater improvement in FVC% and cardiopulmonary scales at 24 months compared with DMARDs. This preliminary study supports the fact that anti-TNF agents may offer additional benefits compared to DMARDs in patients with AS who have reduced FVC%. PMID:26078986

  6. Comparison of olanzapine long-acting injection and oral olanzapine: a 2-year, randomized, open-label study in outpatients with schizophrenia.

    PubMed

    Detke, Holland C; Weiden, Peter J; Llorca, Pierre-Michel; Choukour, Moutaz; Watson, Susan B; Brunner, Elizabeth; Ascher-Svanum, Haya

    2014-08-01

    We compared long-term treatment effectiveness of monthly olanzapine long-acting injection (LAI) with that of oral olanzapine. Outpatients with 2 or more episodes of psychotic worsening in the past 24 months with Positive and Negative Syndrome Scale total score of lower than 70 were randomized to 405 mg/4 weeks of olanzapine LAI (n = 264) or 10 mg/d of oral olanzapine (n = 260) for 2 years of open-label treatment. Dosing thereafter was flexible (150-405 mg/4 weeks of LAI vs 5-20 mg/d of oral). Primary outcome was time to all-cause discontinuation. At baseline, patients were clinically stable (mean Positive and Negative Syndrome Scale total score of 57). Seventeen percent of patients had been psychiatrically hospitalized in the previous 6 months, and 4.6% were rated nonadherent in the month before study entry. The groups did not differ significantly in median time to all-cause discontinuation (645 days for LAI, 678 days for oral; P = 0.61), discontinuation rate (53.8% for LAI, 51.2% for oral; P = 0.60), or relapse rate (20.1% for LAI, 18.5% for oral; P = 0.66). Postbaseline psychiatric hospitalization rate was low for both groups (7.6% for LAI, 9.2% for oral), but mean hospitalization duration was significantly longer for oral patients (1.80 days [20 for those hospitalized] vs 0.43 days [6 for those hospitalized], P = 0.02). There were no clinically significant group differences in adverse events or safety measures. No post-injection delirium/sedation syndrome events occurred. In conclusion, olanzapine LAI and oral olanzapine were similarly effective and well tolerated for up to 2 years of treatment in patients with schizophrenia. Treatment discontinuation for olanzapine LAI was similar to that of oral olanzapine, despite the 3-hour post-injection observation period and other precautionary procedures related to risk of post-injection delirium/sedation syndrome. PMID:24781441

  7. Effects of a 2-year school-based daily physical activity intervention on cardiovascular disease risk factors: the Sogndal school-intervention study.

    PubMed

    Resaland, G K; Anderssen, S A; Holme, I M; Mamen, A; Andersen, L B

    2011-12-01

    The aim of this study was to investigate the effect of a 2-year school-based physical activity (PA) intervention in 9-year-old children on cardiovascular disease (CVD) risk factors. One intervention school (I-school) (n=125) and one control school (C-school) (n=131) were included. The children at the I-school carried out 60 min of PA daily. The PA lessons were planned, organized and led by expert physical education (PE) teachers. In the C-school, children were offered the normal 45 min of PE twice weekly. The intervention resulted in a greater beneficial development in systolic (P=0.003) and diastolic (P=0.002) blood pressure, total cholesterol-to-high-density lipoprotein cholesterol ratio (P=0.011), triglyceride (P=0.030) and peak oxygen uptake (P<0.001) in I-school children than in C-school children. No significant differences were observed in waist circumference, body mass index and the homeostasis model assessment for insulin resistance between the two groups. Furthermore, the intervention, primarily carried out at moderate intensity, had the strongest impact in children with the least favorable starting point. In conclusion, a daily school-based PA intervention can beneficially modify children's CVD risk profile if the intervention has sufficient duration and includes a substantial amount of daily PA, and if the PA is implemented by expert PE teachers.

  8. Serum paraoxonase and arylesterase activities of paraoxonase-1 (PON-1), mild cognitive impairment, and 2-year conversion to dementia: A pilot study.

    PubMed

    Cervellati, Carlo; Trentini, Alessandro; Romani, Arianna; Bellini, Tiziana; Bosi, Cristina; Ortolani, Beatrice; Zurlo, Amedeo; Passaro, Angelina; Seripa, Davide; Zuliani, Giovanni

    2015-10-01

    Converging lines of evidence suggest that paraoxonase-1 (PON-1) may confer protection against inflammatory and oxidative challenge which, in turn, plays a key-role in the onset and progression of dementia. The aim of this study was to evaluate whether serum PON-1 paraoxonase/arylesterase activities might predict the clinical conversion of mild cognitive impairment (MCI) to late-onset Alzheimer's disease (LOAD) or vascular dementia (VAD). Serum paraoxonase and arylesterase activities were measured by spectrophotometric assays at baseline in 141 MCI patients (median age: 77 years; interquartile range 71-81) and in 78 healthy controls (median age: 76 years; interquartile range 73-79). After 2 years of follow-up, 86 MCI remained stable (MCI/MCI), 34 converted to LOAD (MCI/LOAD), whereas 21 converted to VAD (MCI/VAD). Baseline arylesterase activity was lower in all MCI groups compared with controls (all p < 0.01), whereas paraoxonase activity was lower in MCI/VAD group compared to controls (p < 0.05) and MCI/MCI patients (p = 0.009). Low paraoxonase and arylesterase activities (I quartile) were associated to higher risk of conversion to VAD (OR: 3.74, 95% CI: 1.37-10.25 and OR: 3.16, 95% CI: 1.17-8.56, respectively). Our results suggest that in MCI patients low PON-1 activity might contribute to identify individuals susceptible to develop vascular dementia.

  9. Working memory arrest in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder: results from a 2-year longitudinal study.

    PubMed

    Andersen, Per N; Skogli, Erik W; Hovik, Kjell T; Geurts, Hilde; Egeland, Jens; Øie, Merete

    2015-05-01

    The aim of this study was to analyse the development of verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. A total of 34 children with high-functioning autism, 72 children with attention-deficit/hyperactivity disorder and 45 typically developing children (age 9-16 years) were included at baseline and followed up approximately 25 months later. The children were given a letter/number sequencing task to assess verbal working memory. The performance of children with high-functioning autism on verbal working memory did not improve after 2 years, while improvement was observed in children with attention-deficit/hyperactivity disorder and typically developing children. The results indicate a different developmental trajectory for verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. More research is needed to construct a developmental framework more suitable for children with autism spectrum disorder.

  10. The performance of moss, grass, and 1- and 2-year old spruce needles as bioindicators of contamination: a comparative study at the scale of the Czech Republic.

    PubMed

    Suchara, Ivan; Sucharova, Julie; Hola, Marie; Reimann, Clemens; Boyd, Rognvald; Filzmoser, Peter; Englmaier, Peter

    2011-05-01

    Moss (Pleurozium schreberi), grass (Avenella flexuosa), and 1- and 2-year old spruce (Picea abies) needles were collected over the territory of the Czech Republic at an average sample density of 1 site per 290km(2). The samples were analysed for 39 elements (Ag, Al, As, Ba, Be, Bi, Ca, Cd, Ce, Co, Cr, Cs, Cu, Fe, Ga, Hg, K, La, Li, Mg, Mn, Mo, Na, Nd, Ni, Pb, Pr, Rb, S, Sb, Se, Sn, Sr, Th, Tl, U, V, Y and Zn) using ICP-MS and ICP-AES techniques (the major nutrients Ca, K, Mg and Na were not analysed in moss). Moss showed by far the highest element concentrations for most elements. Exceptions were Ba (spruce), Mn (spruce), Mo (grass), Ni (spruce), Rb (grass) and S (grass). Regional distribution maps and spatial trend analysis were used to study the suitability of the four materials as bioindicators of anthropogenic contamination. The highly industrialised areas in the north-west and the far east of the country and several more local contamination sources were indicated in the distribution maps of one or several sample materials. At the scale of the whole country moss was the best indicator of known contamination sources. However, on a more local scale, it appeared that spruce needles were especially well suited for detection of urban contamination.

  11. Serum paraoxonase and arylesterase activities of paraoxonase-1 (PON-1), mild cognitive impairment, and 2-year conversion to dementia: A pilot study.

    PubMed

    Cervellati, Carlo; Trentini, Alessandro; Romani, Arianna; Bellini, Tiziana; Bosi, Cristina; Ortolani, Beatrice; Zurlo, Amedeo; Passaro, Angelina; Seripa, Davide; Zuliani, Giovanni

    2015-10-01

    Converging lines of evidence suggest that paraoxonase-1 (PON-1) may confer protection against inflammatory and oxidative challenge which, in turn, plays a key-role in the onset and progression of dementia. The aim of this study was to evaluate whether serum PON-1 paraoxonase/arylesterase activities might predict the clinical conversion of mild cognitive impairment (MCI) to late-onset Alzheimer's disease (LOAD) or vascular dementia (VAD). Serum paraoxonase and arylesterase activities were measured by spectrophotometric assays at baseline in 141 MCI patients (median age: 77 years; interquartile range 71-81) and in 78 healthy controls (median age: 76 years; interquartile range 73-79). After 2 years of follow-up, 86 MCI remained stable (MCI/MCI), 34 converted to LOAD (MCI/LOAD), whereas 21 converted to VAD (MCI/VAD). Baseline arylesterase activity was lower in all MCI groups compared with controls (all p < 0.01), whereas paraoxonase activity was lower in MCI/VAD group compared to controls (p < 0.05) and MCI/MCI patients (p = 0.009). Low paraoxonase and arylesterase activities (I quartile) were associated to higher risk of conversion to VAD (OR: 3.74, 95% CI: 1.37-10.25 and OR: 3.16, 95% CI: 1.17-8.56, respectively). Our results suggest that in MCI patients low PON-1 activity might contribute to identify individuals susceptible to develop vascular dementia. PMID:26178739

  12. A 2-Year Field Study Shows Little Evidence That the Long-Term Planting of Transgenic Insect-Resistant Cotton Affects the Community Structure of Soil Nematodes

    PubMed Central

    Li, Xiaogang; Liu, Biao

    2013-01-01

    Transgenic insect-resistant cotton has been released into the environment for more than a decade in China to effectively control the cotton bollworm (Helicoverpa armigera) and other Lepidoptera. Because of concerns about undesirable ecological side-effects of transgenic crops, it is important to monitor the potential environmental impact of transgenic insect-resistant cotton after commercial release. Our 2-year study included 1 cotton field where non-transgenic cotton had been planted continuously and 2 other cotton fields where transgenic insect-resistant cotton had been planted for different lengths of time since 1997 and since 2002. In 2 consecutive years (2009 and 2010), we took soil samples from 3 cotton fields at 4 different growth stages (seedling, budding, boll-forming and boll-opening stages), collected soil nematodes from soil with the sugar flotation and centrifugation method and identified the soil nematodes to the genus level. The generic composition, individual densities and diversity indices of the soil nematodes did not differ significantly between the 2 transgenic cotton fields and the non-transgenic cotton field, but significant seasonal variation was found in the individual densities of the principal trophic groups and in the diversity indices of the nematodes in all 3 cotton fields. The study used a comparative perspective to monitor the impact of transgenic insect-resistant cotton grown in typical ‘real world’ conditions. The results of the study suggested that more than 10 years of cultivation of transgenic insect-resistant cotton had no significant effects–adverse or otherwise–on soil nematodes. This study provides a theoretical basis for ongoing environmental impact monitoring of transgenic plants. PMID:23613899

  13. Emotional Development: 2 Year Olds

    MedlinePlus

    ... Español Text Size Email Print Share Emotional Development: 2 Year Olds Page Content Article Body It’s so ... to follow the ups and downs of a two-year-old. One moment he’s beaming and friendly; ...

  14. Revision Total Hip Arthroplasty Using Tantalum Augment in Patients with Paprosky III or IV Acetabular Bone Defects: A Minimum 2-year Follow Up Study

    PubMed Central

    Jeong, Min; Kim, Hyung-Joo; Lim, Seung-Jae; Moon, Young-Wan

    2016-01-01

    Purpose The purpose of this study is to report the short-term outcomes of revision total hip arthroplasty (THA) using tantalum augments in patients with severe acetabular bone defects. Materials and Methods We retrospectively analyzed 15 revision THAs performed in 15 patients using tantalum augments between June 2010 and December 2013. Acetabular bone defects were Paprosky type IIIA in 7 hips, type IIIB in 7, and type IV in 1. The causes of revision surgery were aseptic loosening in 12 hips and deep infection in 3. Revisions were first in 1 hip, second in 3, and third in 11. Six patients were male and 9 female with a mean age of 59 years (range, 48-75 years). Mean follow-up was 29 months (range, 24-48 months). Results Mean Harris hip score was improved from 34 points (range, 12-54 points) preoperatively to 84 points (range, 38-90 points) at final follow-up. On the final follow-up radiographs, there were 12 hips (80.0%) with stable fixation of the acetabular cup, 2 (13.3%) with secondary stability after mild acetabular protrusion, and 1 (6.7%) with radiolucency around the acetabular cup without mechanical symptoms. Complications included one patient with acute hematogenous infection managed by surgical debridement and long-term antibiotic therapy. There were no cases with nerve palsy or dislocation during the follow-up period. Conclusion The present study showed satisfactory clinical and radiographic outcomes of revision THA using tantalum augments due to severe acetabular bone defects of Paprosky type III or IV at a minimum follow-up of 2 years. PMID:27536651

  15. Structural and Electrical Study of Conducting Polymers

    NASA Astrophysics Data System (ADS)

    Shaktawat, Vinodini; Dixit, Manasvi; Saxena, N. S.; Sharma, Kananbala

    2010-06-01

    Pure and oxalic acid doped conducting polymers (polyaniline and polypyrrole) were chemically synthesized using ammonium persulfate (APS) as an oxidant. These samples were characterized through Scanning Electron Microscopy (SEM), which provides information about the surface topography of polymers. I-V characteristics have been recorded at room temperature as well as in the temperature range from 313 K to 463 K. So obtained characteristic curves were found to be linear. Temperature dependence of conductivity suggests a semiconducting nature in polyaniline samples with increase in temperature, whereas oxalic acid doped polypyrrole sample suggests a transition from semiconducting to metallic nature with the increase of temperature.

  16. Scaling up family medicine training in Gezira, Sudan – a 2-year in-service master programme using modern information and communication technology: a survey study

    PubMed Central

    2014-01-01

    Background In 2010 the Gezira Family Medicine Project (GFMP) was initiated in Gezira state, Sudan, designed as an in-service training model. The project is a collaboration project between the University of Gezira, which aims to provide a 2-year master’s programme in family medicine for practicing doctors, and the Ministry of Health, which facilitates service provision and funds the training programme. This paper presents the programme, the teaching environment, and the first batch of candidates enrolled. Methods In this study a self-administered questionnaire was used to collect baseline data at the start of the project from doctors who joined the programme. A checklist was also used to assess the health centres where they work. A total of 188 out of 207 doctors responded (91%), while data were gathered from all 158 health centres (100%) staffed by the programme candidates. Results The Gezira model of in-service family medicine training has succeeded in recruiting 207 candidates in its first batch, providing health services in 158 centres, of which 84 had never been served by a doctor before. The curriculum is community oriented. The mean age of doctors was 32.5 years, 57% were males, and 32% were graduates from the University of Gezira. Respondents stated high confidence in practicing some skills such as asthma management and post-abortion uterine evacuation. They were least confident in other skills such as managing depression or inserting an intrauterine device. The majority of health centres was poorly equipped for management of noncommunicable diseases, as only 10% had an electrocardiography machine (ECG), 5% had spirometer, and 1% had a defibrillator. Conclusions The Gezira model has responded to local health system needs. Use of modern information and communication technology is used to facilitate both health service provision and training. The GFMP represents an example of a large-volume scaling-up programme of family medicine in Africa. PMID:24443978

  17. Neuroscience Investigations: An Overview of Studies Conducted

    NASA Technical Reports Server (NTRS)

    Reschke, Millard F.

    1999-01-01

    The neural processes that mediate human spatial orientation and adaptive changes occurring in response to the sensory rearrangement encountered during orbital flight are primarily studied through second and third order responses. In the Extended Duration Orbiter Medical Project (EDOMP) neuroscience investigations, the following were measured: (1) eye movements during acquisition of either static or moving visual targets, (2) postural and locomotor responses provoked by unexpected movement of the support surface, changes in the interaction of visual, proprioceptive, and vestibular information, changes in the major postural muscles via descending pathways, or changes in locomotor pathways, and (3) verbal reports of perceived self-orientation and self-motion which enhance and complement conclusions drawn from the analysis of oculomotor, postural, and locomotor responses. In spaceflight operations, spatial orientation can be defined as situational awareness, where crew member perception of attitude, position, or motion of the spacecraft or other objects in three-dimensional space, including orientation of one's own body, is congruent with actual physical events. Perception of spatial orientation is determined by integrating information from several sensory modalities. This involves higher levels of processing within the central nervous system that control eye movements, locomotion, and stable posture. Spaceflight operational problems occur when responses to the incorrectly perceived spatial orientation are compensatory in nature. Neuroscience investigations were conducted in conjunction with U. S. Space Shuttle flights to evaluate possible changes in the ability of an astronaut to land the Shuttle or effectively perform an emergency post-landing egress following microgravity adaptation during space flights of variable length. While the results of various sensory motor and spatial orientation tests could have an impact on future space flights, our knowledge of

  18. Thermal and electrical contact conductance studies

    NASA Technical Reports Server (NTRS)

    Vansciver, S. W.; Nilles, M.

    1985-01-01

    Prediction of electrical and thermal contact resistance for pressed, nominally flat contacts is complicated by the large number of variables which influence contact formation. This is reflected in experimental results as a wide variation in contact resistances, spanning up to six orders of magnitude. A series of experiments were performed to observe the effects of oxidation and surface roughness on contact resistance. Electrical contact resistance and thermal contact conductance from 4 to 290 K on OFHC Cu contacts are reported. Electrical contact resistance was measured with a 4-wire DC technique. Thermal contact conductance was determined by steady-state longitudinal heat flow. Corrections for the bulk contribution ot the overall measured resistance were made, with the remaining resistance due solely to the presence of the contact.

  19. Electrochemical corrosion studies in low conductivity propellants

    NASA Technical Reports Server (NTRS)

    Blue, G. D.; Moran, C. M.; Distefano, S.

    1986-01-01

    The Jet Propulsion Laboratory is investigating the possibility of developing advanced electrochemical techniques as accelerated compatibility tests for metal/propellant systems which overcome the problems associated with the low conductivity of the liquid propellants (e.g., hydrazines, nitrogen tetroxide). Both DC techniques and AC electrochemical impedance spectroscopy are being evaluated. Progress has been made in experiments involving stainless steel with hydrazine and nitrogen tetroxide propellants.

  20. Dietary arsenic consumption and urine arsenic in an endemic population: response to improvement of drinking water quality in a 2-year consecutive study.

    PubMed

    Biswas, Anirban; Deb, Debasree; Ghose, Aloke; Du Laing, Gijs; De Neve, Jan; Santra, Subhas Chandra; Guha Mazumder, Debendra Nath

    2014-01-01

    We assessed the association between arsenic intake through water and diet, and arsenic levels in first morning-void urine under variable conditions of water contamination. This was done in a 2-year consecutive study in an endemic population. Exposure of arsenic through water and diet was assessed for participants using arsenic-contaminated water (≥50 μg L(-1)) in a first year (group I) and for participants using water lower in arsenic (<50 μg L(-1)) in the next year (group II). Participants with and without arsenical skin lesions were considered in the statistical analysis. Median dose of arsenic intake through drinking water in groups I and II males was 7.44 and 0.85 μg kg body wt.(-1) day(-1) (p <0.0001). In females, it was 5.3 and 0.63 μg kg body wt.(-1) day(-1) (p <0.0001) for groups I and II, respectively. Arsenic dose through diet was 3.3 and 2.6 μg kg body wt.(-1) day(-1) (p = 0.088) in males and 2.6 and 1.9 μg kg body wt.(-1) day(-1) (p = 0.0081) in females. Median arsenic levels in urine of groups I and II males were 124 and 61 μg L(-1) (p = 0.052) and in females 130 and 52 μg L(-1) (p = 0.0001), respectively. When arsenic levels in the water were reduced to below 50 μg L(-1) (Indian permissible limit), total arsenic intake and arsenic intake through the water significantly decreased, but arsenic uptake through the diet was found to be not significantly affected. Moreover, it was found that drinking water mainly contributed to variations in urine arsenic concentrations. However, differences between male and female participants also indicate that not only arsenic uptake, but also many physiological factors affect arsenic behavior in the body and its excretion. As total median arsenic exposure still often exceeded 3.0 μg kg body wt.(-1) day(-1) (the permissible lower limit established by the Joint Expert Committee on Food Additives) after installation of the drinking water filters, it can be concluded that

  1. Gas release and conductivity modification studies

    NASA Technical Reports Server (NTRS)

    Linson, L. M.; Baxter, D. C.

    1979-01-01

    The behavior of gas clouds produced by releases from orbital velocity in either a point release or venting mode is described by the modification of snowplow equations valid in an intermediate altitude regime. Quantitative estimates are produced for the time dependence of the radius of the cloud, the average internal energy, the translational velocity, and the distance traveled. The dependence of these quantities on the assumed density profile, the internal energy of the gas, and the ratio of specific heats is examined. The new feature is the inclusion of the effect of the large orbital velocity. The resulting gas cloud models are used to calculate the characteristics of the field line integrated Pedersen conductivity enhancements that would be produced by the release of barium thermite at orbital velocity in either the point release or venting modes as a function of release altitude and chemical payload weight.

  2. Practical challenges in conducting respiratory studies

    PubMed Central

    Hake, Sanjay D.; Patil, Mahesh L.; Shah, Tapankumar M.; Gokhale, Partha M.; Suvarna, Viraj

    2015-01-01

    Respiratory studies are complex on account of specific therapeutic knowledge that is needed and various instruments that are used for the management of this condition. Monitoring a respiratory study requires knowledge of the specific disease and associated guidelines. The intent of this article is to help clinical research professionals understand the technicalities, challenges, and the nuances of performing respiratory studies. PMID:25657898

  3. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Conduct of studies. 5... Conduct of studies. (a) Implementation. The potential applicant must gather information and conduct studies as provided for in the approved study plan and schedule. (b) Progress reports. The...

  4. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Conduct of studies. 5... Conduct of studies. (a) Implementation. The potential applicant must gather information and conduct studies as provided for in the approved study plan and schedule. (b) Progress reports. The...

  5. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Conduct of studies. 5... Conduct of studies. (a) Implementation. The potential applicant must gather information and conduct studies as provided for in the approved study plan and schedule. (b) Progress reports. The...

  6. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Conduct of studies. 5... Conduct of studies. (a) Implementation. The potential applicant must gather information and conduct studies as provided for in the approved study plan and schedule. (b) Progress reports. The...

  7. 18 CFR 5.15 - Conduct of studies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Conduct of studies. 5... Conduct of studies. (a) Implementation. The potential applicant must gather information and conduct studies as provided for in the approved study plan and schedule. (b) Progress reports. The...

  8. Etiological Role and Repeated Infections of Sapovirus among Children Aged Less than 2 Years in a Cohort Study in a Peri-urban Community of Peru.

    PubMed

    Liu, Xiaofang; Jahuira, Helena; Gilman, Robert H; Alva, Alicia; Cabrera, Lilia; Okamoto, Michiko; Xu, Hang; Windle, Henry J; Kelleher, Dermot; Varela, Marco; Verastegui, Manuela; Calderon, Maritza; Sanchez, Gerardo; Sarabia, Vanessa; Ballard, Sarah B; Bern, Caryn; Mayta, Holger; Crabtree, Jean E; Cama, Vitaliano; Saito, Mayuko; Oshitani, Hitoshi

    2016-06-01

    Human sapovirus has been shown to be one of the most important etiologies in pediatric patients with acute diarrhea. However, very limited data are available about the causative roles and epidemiology of sapovirus in community settings. A nested matched case-control study within a birth cohort study of acute diarrhea in a peri-urban community in Peru from 2007 to 2010 was conducted to investigate the attributable fraction (AF) and genetic diversity of sapovirus. By quantitative reverse transcription-real-time PCR (qPCR) sapovirus was detected in 12.4% (37/299) of diarrheal and 5.7% (17/300) of nondiarrheal stools (P = 0.004). The sapovirus AF (7.1%) was higher in the second year (13.2%) than in the first year (1.4%) of life of children. Ten known genotypes and one novel cluster (n = 5) within four genogroups (GI, GII, GIV, and GV) were identified by phylogenetic analysis of a partial VP1 gene. Further sequence analysis of the full VP1 gene revealed a possible novel genotype, tentatively named GII.8. Notably, symptomatic reinfections with different genotypes within the same (n = 3) or different (n = 5) genogroups were observed in eight children. Sapovirus exhibited a high attributable burden for acute gastroenteritis, especially in the second year of life, of children in a Peruvian community. Further large-scale studies are needed to understand better the global burden, genetic diversity, and repeated infections of sapovirus.

  9. Etiological Role and Repeated Infections of Sapovirus among Children Aged Less than 2 Years in a Cohort Study in a Peri-urban Community of Peru.

    PubMed

    Liu, Xiaofang; Jahuira, Helena; Gilman, Robert H; Alva, Alicia; Cabrera, Lilia; Okamoto, Michiko; Xu, Hang; Windle, Henry J; Kelleher, Dermot; Varela, Marco; Verastegui, Manuela; Calderon, Maritza; Sanchez, Gerardo; Sarabia, Vanessa; Ballard, Sarah B; Bern, Caryn; Mayta, Holger; Crabtree, Jean E; Cama, Vitaliano; Saito, Mayuko; Oshitani, Hitoshi

    2016-06-01

    Human sapovirus has been shown to be one of the most important etiologies in pediatric patients with acute diarrhea. However, very limited data are available about the causative roles and epidemiology of sapovirus in community settings. A nested matched case-control study within a birth cohort study of acute diarrhea in a peri-urban community in Peru from 2007 to 2010 was conducted to investigate the attributable fraction (AF) and genetic diversity of sapovirus. By quantitative reverse transcription-real-time PCR (qPCR) sapovirus was detected in 12.4% (37/299) of diarrheal and 5.7% (17/300) of nondiarrheal stools (P = 0.004). The sapovirus AF (7.1%) was higher in the second year (13.2%) than in the first year (1.4%) of life of children. Ten known genotypes and one novel cluster (n = 5) within four genogroups (GI, GII, GIV, and GV) were identified by phylogenetic analysis of a partial VP1 gene. Further sequence analysis of the full VP1 gene revealed a possible novel genotype, tentatively named GII.8. Notably, symptomatic reinfections with different genotypes within the same (n = 3) or different (n = 5) genogroups were observed in eight children. Sapovirus exhibited a high attributable burden for acute gastroenteritis, especially in the second year of life, of children in a Peruvian community. Further large-scale studies are needed to understand better the global burden, genetic diversity, and repeated infections of sapovirus. PMID:27076657

  10. 40 CFR 160.130 - Conduct of a study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Conduct of a study. 160.130 Section 160.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.130 Conduct of a study. (a) The...

  11. 40 CFR 160.130 - Conduct of a study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Conduct of a study. 160.130 Section 160.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.130 Conduct of a study. (a) The...

  12. 40 CFR 160.130 - Conduct of a study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Conduct of a study. 160.130 Section 160.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.130 Conduct of a study. (a) The...

  13. 40 CFR 160.130 - Conduct of a study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Conduct of a study. 160.130 Section 160.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.130 Conduct of a study. (a) The...

  14. 40 CFR 160.130 - Conduct of a study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Conduct of a study. 160.130 Section 160.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.130 Conduct of a study. (a) The...

  15. Conductivity and electrical studies of plasticized carboxymethyl cellulose based proton conducting solid biopolymer electrolytes

    NASA Astrophysics Data System (ADS)

    Isa, M. I. N.; Noor, N. A. M.

    2015-12-01

    In this paper, a proton conducting solid biopolymer electrolytes (SBE) comprises of carboxymethyl cellulose (CMC) as polymer host, ammonium thiocyanate (NH4SCN) as doping salt and ethylene carbonate (EC) as plasticizer has been prepared via solution casting technique. Electrical Impedance Spectroscopy (EIS) was carried out to study the conductivity and electrical properties of plasticized CMC-NH4SCN SBE system over a wide range of frequency between 50 Hz and 1 MHz at temperature range of 303 to 353 K. Upon addition of plasticizer into CMC-NH4SCN SBE system, the conductivity increased from 10-5 to 10-2 Scm-1. The highest conductivity was obtained by the electrolyte containing 10 wt.% of EC. The conductivity of plasticized CMC-NH4SCN SBE system by various temperatures obeyed Arrhenius law where the ionic conductivity increased as the temperature increased. The activation energy, Ea was found to decrease with enhancement of EC concentration. Dielectric studies for the highest conductivity electrolyte obeyed non-Debye behavior. The conduction mechanism for the highest conductivity electrolyte was determined by employing Jonsher's universal power law and thus, can be represented by the quantum mechanical tunneling (QMT) model.

  16. 40 CFR 792.130 - Conduct of a study.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Conduct of a study. 792.130 Section 792.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study § 792.130 Conduct of...

  17. Age 2: Findings from the 2-Year-Old Follow-Up of the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B). E.D. TAB. NCES 2006-043

    ERIC Educational Resources Information Center

    Mulligan, Gail M.; Flanagan, Kristin Denton

    2006-01-01

    This E.D. TAB is the first report produced using data from the second round of data collection for the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B), a study of a nationally representative sample of children born in the year 2001. The report provides descriptive information about these children when they were about 2 years old. It…

  18. Effects of sediment dredging on nitrogen cycling in Lake Taihu, China: Insight from mass balance based on a 2-year field study.

    PubMed

    Yu, Juhua; Fan, Chengxin; Zhong, Jicheng; Zhang, Lu; Zhang, Lei; Wang, Changhui; Yao, Xiaolong

    2016-02-01

    Sediment dredging can permanently remove pollutants from an aquatic ecosystem, which is considered an effective approach to aquatic ecosystem restoration. In this work, a 2-year field simulation test was carried out to investigate the effect of dredging on nitrogen cycling across the sediment-water interface (SWI) in Lake Taihu, China. The results showed that simulated dredging applied to an area rich in total organic carbon (TOC) and total nitrogen (TN) slightly reduced the NH4(+)-N release from sediments while temporarily enhanced the NH4(+)-N release in an area with lower TOC and/or TN (in the first 180 days), although the application had a limited effect on the fluxes of NO2(-)-N and NO3(-)-N in both areas. Further analysis indicated that dredging induced decreases in nitrification, denitrification, and anaerobic ammonium oxidation (anammox) in sediments, notably by 76.9, 49.0, and 89.9%, respectively, in the TOC and/or TN-rich area. Therefore, dredging slowed down nitrogen cycling rates in sediments but did not increase N loading to overlying water. The main reason for the above phenomenon could be attributed to the removal of the surface sediments enriched with more TOC and/or TN (compared with the bottom sediments). Overall, to minimize internal N pollution, dredging may be more applicable to nutrient-rich sediments.

  19. Mental health service use by patients with dysthymic disorder: treatment use and dropout in a 7 1/2-year naturalistic follow-up study.

    PubMed

    McFarland, Brian R; Klein, Daniel N

    2005-01-01

    Little is known about long-term treatment use among patients with dysthymia. This paper describes patterns of treatment use by 85 outpatients with dysthymic disorder and a comparison group of 36 outpatients with nonchronic (episodic) major depression in a naturalistic follow-up. Patients with dysthymia had higher rates of treatment use across 7 1/2 years compared with patients with episodic major depression. Baseline variables that predicted which patients with dysthymia dropped out of treatment before recovering from dysthymic disorder included age, ethnicity, Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition Axis II pathology as obtained from informant reports, higher self-reported autonomy, and receiving psychotherapy alone as compared to receiving a combination of psychotherapy and medication. Dysthymic disorder places a significant burden on the mental health services system, yet many outpatients with dysthymia may be receiving inadequate treatment. Younger patients, ethnic minority patients, and patients with personality disorders may be at increased risk of dropping out from treatment for depression. Combination treatments may increase treatment retention.

  20. The Role of Depressive Symptoms, Family Invalidation and Behavioral Impulsivity in the Occurrence and Repetition of Non-Suicidal Self-Injury in Chinese Adolescents: A 2-Year Follow-Up Study

    ERIC Educational Resources Information Center

    You, Jianing; Leung, Freedom

    2012-01-01

    This study used zero-inflated poisson regression analysis to examine the role of depressive symptoms, family invalidation, and behavioral impulsivity in the occurrence and repetition of non-suicidal self-injury among Chinese community adolescents over a 2-year period. Participants, 4782 high school students, were assessed twice during the…

  1. Decrease in self-esteem mediates the association between symptoms of social phobia and depression in middle adolescence in a sex-specific manner: a 2-year follow-up of a prospective population cohort study

    PubMed Central

    2014-01-01

    Background Social phobia and depression are common, highly comorbid disorders in middle adolescence. The mechanism underlying this comorbidity, however, is unclear. Decrease in self-esteem caused by the initial disorder might play a decisive role in the development of the subsequent disorder. The present study aimed to determine whether the association between symptoms of social phobia and depression is mediated by decrease in self-esteem in mid-adolescent girls and boys. Methods As a part of the prospective Adolescent Mental Health Cohort (AMCH), subjects of this study were 9th grade pupils (mean age, 15.5) responding to a survey conducted in 2002–2003 (T1) and to a 2-year follow-up survey in 2004–2005 (T2) (N = 2070, mean age 17.6 years, 54.5% girls). Results Symptoms of social phobia without symptoms of depression at age 15 and symptoms of depression at age 17 were associated only among boys, and this association was mediated by decrease in self-esteem. Symptoms of depression without symptoms of social phobia at age 15 and symptoms of social phobia at age 17 were associated only among girls, and this association was partially mediated by decrease in self-esteem. Conclusions Decrease in self-esteem plays a decisive role in the association between social phobia and depression. Self-esteem should be a key focus in interventions for adolescents suffering from social phobia or depression. Efficient intervention for the first disorder might help to prevent the decline in self-esteem and thus the incidence of the subsequent disorder. These findings are based on a sample of Finnish adolescents and should be confirmed in other jurisdictions or in more ethnically diverse samples. PMID:24641987

  2. 40 CFR 792.130 - Conduct of a study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Conduct of a study. 792.130 Section 792.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study §...

  3. 40 CFR 792.130 - Conduct of a study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Conduct of a study. 792.130 Section 792.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study §...

  4. 40 CFR 792.130 - Conduct of a study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Conduct of a study. 792.130 Section 792.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study §...

  5. 40 CFR 792.130 - Conduct of a study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Conduct of a study. 792.130 Section 792.130 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study §...

  6. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Conducting the comparison study. 761.326 Section 761.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison study. Extract or analyze...

  7. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Conducting the comparison study. 761.326 Section 761.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison study. Extract or analyze...

  8. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Conducting the comparison study. 761.326 Section 761.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison study. Extract or analyze...

  9. 40 CFR 761.326 - Conducting the comparison study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Conducting the comparison study. 761.326 Section 761.326 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...-liquid PCB Remediation Waste Samples § 761.326 Conducting the comparison study. Extract or analyze...

  10. Maternal Attributions and Young Children's Conduct Problems: A Longitudinal Study

    ERIC Educational Resources Information Center

    Wilson, Charlotte; Gardner, Frances; Burton, Jennifer; Leung, Sarah

    2006-01-01

    The association between negative maternal attributions and child conduct problems is well established in correlational studies. However, little is known about how these variables influence each other over time. The present study examined patterns of prediction over time between maternal attributions and pre-school conduct problems. Sixty mothers…

  11. French multicenter phase III randomized study testing concurrent twice-a-day radiotherapy and cisplatin/5-fluorouracil chemotherapy (BiRCF) in unresectable pharyngeal carcinoma: Results at 2 years (FNCLCC-GORTEC)

    SciTech Connect

    Bensadoun, Rene-Jean . E-mail: rene-jean.bensadoun@nice.fnclcc.fr; Benezery, Karen; Dassonville, Olivier; Magne, Nicolas; Poissonnet, Gilles; Ramaioli, Alain; Lemanski, Claire; Bourdin, Sylvain; Tortochaux, Jacques; Peyrade, Frederic; Marcy, Pierre-Yves; Chamorey, Emmanuel Phar; Vallicioni, Jacques; Seng Hang; Alzieu, Claude; Gery, Bernard; Chauvel, Pierre; Schneider, Maurice; Santini, Jose; Demard, Francois; Calais, Gilles

    2006-03-15

    Background: Unresectable carcinomas of the oropharynx and hypopharynx still have a poor long-term prognosis. Following a previous phase II study, this phase III multicenter trial was conducted between November 1997 and March 2002. Methods: Nontreated, strictly unresectable cases were eligible. Twice-daily radiation: two fractions of 1.2 Gy/day, 5 days per week, with no split (D1{sup {yields}}D46). Total tumor doses: 80.4 Gy/46 day (oropharynx), 75.6 Gy/44 day (hypopharynx). Chemotherapy (arm B): Cisplatin 100 mg/m{sup 2} (D1, D22, D43); 5FU, continuous infusion (D1{sup {yields}}D5), 750 mg/m{sup 2}/day cycle 1; 430 mg/m{sup 2}/day cycles 2 and 3. Results: A total of 163 evaluable patients. Grade 3-4 acute mucositis 82.6% arm B/69.5% arm A (NS); Grade 3-4 neutropenia 33.3% arm B/2.4% arm A (p < 0.05). Enteral nutrition through gastrostomy tube was more frequent in arm B before treatment and at 6 months (p < 0.01). At 24 months, overall survival (OS), disease-free survival (DFS), and specific survival (SS) were significantly better in arm B. OS: 37.8% arm B vs. 20.1% arm A (p = 0.038); DFS: 48.2% vs. 25.2% (p = 0.002); SS: 44.5% vs. 30.2% (p 0.021). No significant difference between the two arms in the amount of side effects at 1 and 2 years. Conclusion: For these unresectable cases, chemoradiation provides better outcome than radiation alone, even with an 'aggressive' dose-intensity radiotherapy schedule.

  12. Predictors (0-10 Months) of Psychopathology at Age 1 1/2 Years--A General Population Study in the Copenhagen Child Cohort CCC 2000

    ERIC Educational Resources Information Center

    Skovgaard, A. M.; Olsen, E. M.; Christiansen, E.; Houmann, T.; Landorph, S. L.; Jorgensen, T.

    2008-01-01

    Background: Epidemiological studies of mental health problems in the first years of life are few. This study aims to investigate infancy predictors of psychopathology in the second year of life. Methods: A random general population sample of 210 children from the Copenhagen Child Birth Cohort CCC 2000 was investigated by data from National Danish…

  13. Working Memory Arrest in Children with High-Functioning Autism Compared to Children with Attention-Deficit/Hyperactivity Disorder: Results from a 2-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Andersen, Per N.; Skogli, Erik W.; Hovik, Kjell T.; Geurts, Hilde; Egeland, Jens; Øie, Merete

    2015-01-01

    The aim of this study was to analyse the development of verbal working memory in children with high-functioning autism compared to children with attention-deficit/hyperactivity disorder and typically developing children. A total of 34 children with high-functioning autism, 72 children with attention-deficit/hyperactivity disorder and 45 typically…

  14. A Simulation Study of Electrical Fiber Composite Conductivity

    NASA Astrophysics Data System (ADS)

    Mezdour, D.; Sahli, S.

    2008-11-01

    Percolation concept has been used in this study to estimate the amount of conductive fibers embedded in polymeric matrix, necessary to establish conduction in this kind of composites. The resistance of composite materials is calculated by simulating composite samples with different size, containing conductive fibers with various lengths Calculation is based on detecting conductive pathways through the insulating matrix, these pathways are assumed to be resistances in parallel. Electrical resistance curves showed a percolative behavior of the samples versus volume fraction of filler. Lower conduction thresholds are obtained for fiber aspect ratio of 20 and sample size of 100. The electrical resistivity and the conduction thresholds of the carbon fiber reinforced polycarbonate composites have been characterized. Simulation results are in good agreement with an experimental result found in the literature.

  15. [Growth of breastfed and bottle-fed infants up to 2 years of age: CLACYD (Lactation, Alimentation, Growth and Development) study 1993-1995].

    PubMed

    Agrelo, F; Lobo, B; Chesta, M; Berra, S; Sabulsky, J

    1999-07-01

    Studies done in various countries show important differences in the growth of breastfed and bottle-fed children. In addition, it has been found that breast-fed children grow more slowly beginning at the age of 2 or 3 months in comparison with the reference pattern of the U.S. National Center for Health Statistics (NCHS) and the World Health Organization (WHO). These results cast doubt on whether maximum growth is the same as optimal growth. The objective of this study was to compare the growth in weight and length, from birth to 24 months, for a group of children who were breast-fed with that of a group who were bottle-fed. The study was also intended to describe the growth of the breastfed group in relation to the NCHS/WHO norms and a WHO "12-month breast-fed pooled data set." For this research, data were analyzed from the "Cordoba: lactation, feeding, growth, and development" study (or CLACYD study, for its Spanish-language acronym). That study looked at a representative cohort, stratified by social class, of children born in 1993 in the city of Cordoba, Argentina. The researchers analyzed anthropometric data on 74 children who were breast-fed during the first year of life and on 108 bottle-fed children. The data had been recorded, using standardized techniques, at birth and at 6, 12, and 24 months of age. Both groups were homogenous with respect to the age and schooling of the parents, social stratum, birth order, maternal height, and child's weight and length at birth. The living conditions (housing construction and availability of water and sewer services) were better among the group that was bottle-fed (P = 0.04). The breast-fed children had a lower weight and a shorter length at 6, 12, and 24 months than did the bottle-fed children. The breast-fed children also showed a slowing in growth with respect to the NCHS/WHO guidelines beginning in the second semester. This indicates that the NCHS/WHO norms are not totally adequate for evaluating the growth of breast

  16. Efficacy and safety of finasteride therapy for benign prostatic hyperplasia: results of a 2-year randomized controlled trial (the PROSPECT study). PROscar Safety Plus Efficacy Canadian Two year Study.

    PubMed Central

    Nickel, J C; Fradet, Y; Boake, R C; Pommerville, P J; Perreault, J P; Afridi, S K; Elhilali, M M

    1996-01-01

    OBJECTIVE: To evaluate the efficacy and safety of 2 years' treatment of moderate benign prostatic hyperplasia (BPH) with finasteride. DESIGN: Double-blind, parallel-group, placebo-controlled, multicentre, prospective randomized study. SETTING: Outpatient care in 28 centres across Canada. PARTICIPANTS: Men aged 45 to 80, in good health, with moderate BPH and no evidence of prostate cancer. A total of 613 men were entered into the study; 472 completed the 2 years of treatment. INTERVENTION: After 1 month of receiving a placebo (run-in period), patients were given either finasteride (5 mg/d) or a placebo for 2 years. OUTCOME MEASURES: Efficacy: changes from baseline in BPH symptom scores, maximum urinary flow rates and prostate volume. Safety: onset, course and resolution of all adverse events during the treatment period. RESULTS: In the efficacy analyses the mean BPH symptom scores decreased 2.1 points (from 15.8 to 13.7) in the finasteride group, as compared with a decrease of 0.7 points (from 16.6 to 15.9) in the placebo group (P < or = 0.01). The maximum urinary flow rate increased by a mean of 1.4 mL/s (from 11.1 to 12.5 mL/s) in the finasteride group, as compared with an increase of 0.3 mL/s (from 10.9 to 11.2 mL/s) in the placebo group (p < or = 0.01). The mean prostate volume decreased by 21% (from a mean volume of 44.1 cm3 at baseline) in the treatment group; it increased by 8.4% (from a mean volume of 45.8 cm3 at baseline) in the placebo group (p < or = 0.01). In the safety analysis, the proportion of patients who experienced any adverse event was similar in the two groups (81.0% in the treatment group and 81.2% in the placebo group). However, the incidence of adverse events related to sexual dysfunction were significantly higher in the finasteride group than in the placebo group (ejaculation disorder 7.7% v. 1.7% and impotence 15.8% v. 6.3%; p < or = 0.01 for both parameters). CONCLUSION: Finasteride is a well-tolerated and effective alternative to watchful

  17. Predicting adolescent problematic online game use from teacher autonomy support, basic psychological needs satisfaction, and school engagement: a 2-year longitudinal study.

    PubMed

    Yu, Chengfu; Li, Xian; Zhang, Wei

    2015-04-01

    Problematic online game use (POGU) has become a serious global public health concern among adolescents. However, its influencing factors and mediating mechanisms remain largely unknown. This study provides the first longitudinal design to test stage-environment fit theory empirically in POGU. A total of 356 Chinese students reported on teacher autonomy support, basic psychological needs satisfaction, school engagement, and POGU in the autumn of their 7th-9th grade years. Path analyses supported the proposed pathway: 7th grade teacher autonomy support increased 8th grade basic psychological needs satisfaction, which in turn increased 9th grade school engagement, which ultimately decreased 9th grade POGU. Furthermore, 7th grade teacher autonomy support directly increased 9th grade school engagement, which in turn decreased 9th grade POGU. These findings suggest that teacher autonomy support is an important protective predictor of adolescent POGU, and basic psychological needs satisfaction and school engagement are the primary mediators in this association.

  18. Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

    NASA Astrophysics Data System (ADS)

    Shukur, M. F.; Yusof, Y. M.; Zawawi, S. M. M.; Illias, H. A.; Kadir, M. F. Z.

    2013-11-01

    This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH4SCN). The sample containing 40 wt% NH4SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10-4 S cm-1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10-3 S cm-1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (Ea) was calculated for both systems and it is found that the sample with 40 wt% NH4SCN in the salted system obtained an Ea value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH4SCN salt. Changes in the C-O stretching vibration band intensity are observed at 1067 cm-1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems.

  19. The Role of Human Coronaviruses in Children Hospitalized for Acute Bronchiolitis, Acute Gastroenteritis, and Febrile Seizures: A 2-Year Prospective Study

    PubMed Central

    Jevšnik, Monika; Steyer, Andrej; Pokorn, Marko; Mrvič, Tatjana; Grosek, Štefan; Strle, Franc; Lusa, Lara; Petrovec, Miroslav

    2016-01-01

    Human coronaviruses (HCoVs) are associated with a variety of clinical presentations in children, but their role in disease remains uncertain. The objective of our prospective study was to investigate HCoVs associations with various clinical presentations in hospitalized children up to 6 years of age. Children hospitalized with acute bronchiolitis (AB), acute gastroenteritis (AGE), or febrile seizures (FS), and children admitted for elective surgical procedures (healthy controls) were included in the study. In patients with AB, AGE, and FS, a nasopharyngeal (NP) swab and blood sample were obtained upon admission and the follow-up visit 14 days later, whereas in children with AGE a stool sample was also acquired upon admission; in healthy controls a NP swab and stool sample were taken upon admission. Amplification of polymerase 1b gene was used to detect HCoVs in the specimens. HCoVs-positive specimens were also examined for the presence of several other viruses. HCoVs were most often detected in children with FS (19/192, 9.9%, 95% CI: 6–15%), followed by children with AGE (19/218, 8.7%, 95% CI: 5.3–13.3%) and AB (20/308, 6.5%, 95% CI: 4.0–9.8%). The presence of other viruses was a common finding, most frequent in the group of children with AB (19/20, 95%, 95% CI: 75.1–99.8%), followed by FS (10/19, 52.6%, 95% CI: 28.9–75.6%) and AGE (7/19, 36.8%, 95% CI: 16.3–61.6%). In healthy control children HCoVs were detected in 3/156 (1.9%, 95% CI: 0.4–5.5%) NP swabs and 1/150 (0.7%, 95% CI: 0.02–3.3%) stool samples. It seems that an etiological role of HCoVs is most likely in children with FS, considering that they had a higher proportion of positive HCoVs results than patients with AB and those with AGE, and had the highest viral load; however, the co-detection of other viruses was 52.6%. Trial Registration: ClinicalTrials.gov NCT00987519 PMID:27171141

  20. Decreased use of glucocorticoids in biological-experienced patients with rheumatoid arthritis who initiated intravenous abatacept: results from the 2-year ACTION study

    PubMed Central

    Alten, Rieke; Nüßlein, Hubert; Galeazzi, Mauro; Lorenz, Hanns-Martin; Nurmohamed, Michael T; Bensen, William G; Burmester, Gerd R; Peter, Hans-Hartmut; Pavelka, Karel; Chartier, Mélanie; Poncet, Coralie; Rauch, Christiane; Elbez, Yedid; Le Bars, Manuela

    2016-01-01

    Introduction Prolonged glucocorticoid use may increase the risk of adverse safety outcomes, including cardiovascular events. The European League Against Rheumatism and the Canadian Rheumatology Association advise tapering glucocorticoid dose as rapidly as clinically feasible. There is a paucity of published data on RA that adequately describe concomitant treatment patterns. Methods ACTION (AbataCepT In rOutiNe clinical practice) is a non-interventional cohort study of patients from Europe and Canada that investigated the long-term retention of intravenous abatacept in clinical practice. We assessed concomitant glucocorticoids in patients with established RA who had participated in ACTION and received ≥1 biological agent prior to abatacept initiation. Results The analysis included 1009 patients. Glucocorticoids were prescribed at abatacept initiation in 734 (72.7%) patients at a median 7.5 mg/day dose (n=692). Of the patients who remained on abatacept at 24 months, 40.7% were able to decrease their dose of glucocorticoids, including 26.9% who decreased their dose from >5 mg/day to ≤5 mg/day. Conclusion Reduction and/or cessation of glucocorticoid therapy is possible with intravenous abatacept in clinical practice. PMID:26925253

  1. Risedronate prevents persistent bone loss in prostate cancer patients treated with androgen deprivation therapy: results of a 2-year follow-up study.

    PubMed

    Izumi, K; Mizokami, A; Sugimoto, K; Narimoto, K; Kitagawa, Y; Koh, E; Namiki, M

    2011-09-01

    Androgen deprivation therapy (ADT) for prostate cancer (PCa) causes bone loss. Although we reported previously that risedronate significantly recovers bone mineral density (BMD) for up to 12 months, there have been no reports with longer follow-up periods to date. This study extended our earlier series extending the follow-up period to 24 months. Eligible patients had histologically confirmed PCa without lumbar spine metastasis and underwent ADT. Lumbar spine BMD, urinary deoxypyridinoline (uDPD) and serum bone alkaline phosphatase were measured at 6, 12 and 24 months. Among the total of 96 patients, we analyzed 26 and 18 patients in risedronate administration and control groups, respectively. BMD relative to the young adult mean ratio, uDPD and serum bone alkaline phosphatase of the risedronate administration group recovered significantly after 24 months compared with the control group (P<0.0001, P=0.0001, and P<0.0001, respectively). Transient blurred vision, malaise and vertigo were observed in 1 patient each among the 46 patients treated with risedronate within 28 days after first administration. Oral administration of risedronate is safe and effective for the recovery of ADT-induced bone loss in PCa patients even at 24 months after commencement of treatment.

  2. Clinical instructors' perception of a faculty development programme promoting postgraduate year-1 (PGY1) residents' ACGME six core competencies: a 2-year study.

    PubMed

    Lee, Fa-Yauh; Yang, Ying-Ying; Hsu, Hui-Chi; Chuang, Chiao-Lin; Lee, Wei-Shin; Chang, Ching-Chih; Huang, Chia-Chang; Chen, Jaw-Wen; Cheng, Hao-Min; Jap, Tjin-Shing

    2011-01-01

    Objective The six core competencies designated by Accreditation Council for Graduate Medical Education (ACGME) are essential for establishing a patient centre holistic medical system. The authors developed a faculty programme to promote the postgraduate year 1 (PGY(1)) resident, ACGME six core competencies. The study aims to assess the clinical instructors' perception, attitudes and subjective impression towards the various sessions of the 'faculty development programme for teaching ACGME competencies.' Methods During 2009 and 2010, 134 clinical instructors participated in the programme to establish their ability to teach and assess PGY(1) residents about ACGME competencies. Results The participants in the faculty development programme reported that the skills most often used while teaching were learnt during circuit and itinerant bedside, physical examination teaching, mini-clinical evaluation exercise (mini-CEX) evaluation demonstration, training workshop and videotapes of 'how to teach ACGME competencies.' Participants reported that circuit bedside teaching and mini-CEX evaluation demonstrations helped them in the interpersonal and communication skills domain, and that the itinerant teaching demonstrations helped them in the professionalism domain, while physical examination teaching and mini-CEX evaluation demonstrations helped them in the patients' care domain. Both the training workshop and videotape session increase familiarity with teaching and assessing skills. Participants who applied the skills learnt from the faculty development programme the most in their teaching and assessment came from internal medicine departments, were young attending physician and had experience as PGY(1) clinical instructors. Conclusions According to the clinical instructors' response, our faculty development programme effectively increased their familiarity with various teaching and assessment skills needed to teach PGY(1) residents and ACGME competencies, and these clinical

  3. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    NASA Astrophysics Data System (ADS)

    Nagendra, K.; Babu, G. Satish; Reddy, C. Narayana; Gowda, Veeranna

    2011-07-01

    Glasses in the system xLi2SO4-20Li2O-(80-x) [80P2O5-20V2O5] (5⩾x⩾20 mol%) has been prepared by melt quenching method. Dc and ac conductivity has been studied over a wide range of frequency (10 Hz to 10 MHz) and temperature (298 K-523 K). The dc conductivity found to increase with increase of Li2SO4 concentration. The ac conductivities have been fitted to the Almond-West type single power law equation σ(ω) = σ(0)+Aωs where `s' is the power law exponent. The ac conductivity found to increase with increase of Li2SO4 concentration. An attempt is made to elucidate the enhancement of lithium ion conduction in phosphor-vanadate glasses by considering the expansion of network structure.

  4. Vagus nerve stimulation therapy: 2-year prospective open-label study of 40 subjects with refractory epilepsy and low IQ who are living in long-term care facilities.

    PubMed

    Huf, Roger L; Mamelak, Adam; Kneedy-Cayem, Kara

    2005-05-01

    Treating seizures among patients with mental retardation/developmental disabilities (MR/DD) is difficult owing in large part to the presence of additional comorbidities and the resulting need for polytherapy. Therefore, a nonpharmacological treatment option is needed for this population. This prospective, open-label study documented the long-term outcome of 40 low-IQ (<70) patients living in long-term care facilities who received vagus nerve stimulation (VNS) therapy for pharmacoresistant epilepsy. Subjects were seen every 1 to 3 months by their neurologist (R.H.). Seizure frequency, antiepileptic medication, and quality-of-life information were documented preimplantation and quarterly thereafter through 2 years. The surgery and therapy were well tolerated. Seizures were reduced by at least 50% for 11 subjects. Antiepileptic medications were reduced from 3.3 per subject at baseline to an average of 2.3 per subject after 2 years. According to caregiver reports, overall quality of life improved for the majority of subjects; also, using the Client Development Evaluation Report (CDER), statistically significant improvements were reported at both 1 and 2 years in attention span, word usage, clarity of speech, standing balance, washing dishes, and household chores. VNS is a viable treatment option for low-IQ patients with pharmacoresistant epilepsy who are living in long-term care facilities. PMID:15820352

  5. Comparison of 2-year clinical outcomes between diabetic versus nondiabetic patients with acute myocardial infarction after 1-month stabilization: Analysis of the prospective registry of DIAMOND (DIabetic acute myocardial infarctiON Disease) in Korea: an observational registry study.

    PubMed

    Hur, Seung-Ho; Won, Ki-Bum; Kim, In-Cheol; Bae, Jang-Ho; Choi, Dong-Ju; Ahn, Young-Keun; Park, Jong-Seon; Kim, Hyo-Soo; Choi, Rak-Kyeong; Choi, Donghoon; Kim, Joon-Hong; Han, Kyoo-Rok; Park, Hun-Sik; Choi, So-Yeon; Yoon, Jung-Han; Gwon, Hyeon-Cheol; Rha, Seung-Woon; Jang, Wooyeong; Bae, Jang-Whan; Hwang, Kyung-Kuk; Lim, Do-Sun; Jung, Kyung-Tae; Oh, Seok-Kyu; Lee, Jae-Hwan; Shin, Eun-Seok; Kim, Kee-Sik

    2016-06-01

    This study assessed the 2-year clinical outcomes of patients with diabetes mellitus (DM) after acute myocardial infarction (AMI) in a cohort of the DIAMOND (DIabetic Acute Myocardial infarctiON Disease) registry. Clinical outcomes were compared between 1088 diabetic AMI patients in the DIAMOND registry after stabilization of MI and 1088 nondiabetic AMI patients from the KORMI (Korean AMI) registry after 1 : 1 propensity score matching using traditional cardiovascular risk factors. Stabilized patients were defined as patients who did not have any clinical events within 1 month after AMI. Primary outcomes were the 2-year rate of major adverse cardiac events (MACEs), a composite of all-cause death, recurrent MI (re-MI), and target vessel revascularization (TVR). Matched comparisons revealed that diabetic patients exhibited significantly lower left ventricular ejection fraction (LVEF) and estimated glomerular filtration rate and smaller stent size. Diabetic patients exhibited significantly higher 2-year rates of MACE (8.0% vs 3.7%), all-cause death (3.9% vs 1.4%), re-MI (2.8% vs 1.2%), and TVR (3.5% vs 1.3%) than nondiabetic patients (all P < 0.01), and higher cumulative rates in Kaplan-Meier analyses of MACE, all-cause death, and TVR (all P < 0.05). A multivariate Cox regression analysis revealed that chronic kidney disease, LVEF < 35%, and long stent were independent predictors of MACE, and large stent diameter and the use of drug-eluting stents were protective factors against MACE. The 2-year MACE rate beyond 1 month after AMI was significantly higher in DM patients than non-DM patients, and this rate was associated with higher comorbidities, coronary lesions, and procedural characteristics in DM.

  6. Thermal conductivity of penta-graphene from molecular dynamics study.

    PubMed

    Xu, Wen; Zhang, Gang; Li, Baowen

    2015-10-21

    Using classical equilibrium molecular dynamics simulations and applying the original Tersoff interatomic potential, we study the thermal transport property of the latest two dimensional carbon allotrope, penta-graphene. It is predicted that its room-temperature thermal conductivity is about 167 W/mK, which is much lower than that of graphene. With normal mode decomposition, the accumulated thermal conductivity with respect to phonon frequency and mean free path is analyzed. It is found that the acoustic phonons make a contribution of about 90% to the thermal conductivity, and phonons with mean free paths larger than 100 nm make a contribution over 50%. We demonstrate that the remarkably lower thermal conductivity of penta-graphene compared with graphene results from the lower phonon group velocities and fewer collective phonon excitations. Our study highlights the importance of structure-property relationship and provides better understanding of thermal transport property and valuable insight into thermal management of penta-graphene.

  7. Electrical studies on silver based fast ion conducting glassy materials

    SciTech Connect

    Rao, B. Appa Kumar, E. Ramesh Kumari, K. Rajani Bhikshamaiah, G.

    2014-04-24

    Among all the available fast ion conductors, silver based glasses exhibit high conductivity. Further, glasses containing silver iodide enhances fast ion conducting behavior at room temperature. Glasses of various compositions of silver based fast ion conductors in the AgI−Ag{sub 2}O−[(1−x)B{sub 2}O{sub 3}−xTeO{sub 2}] (x=0 to1 mol% in steps of 0.2) glassy system have been prepared by melt quenching method. The glassy nature of the compounds has been confirmed by X-ray diffraction. The electrical conductivity (AC) measurements have been carried out in the frequency range of 1 KHz–3MHz by Impedance Analyzer in the temperature range 303–423K. The DC conductivity measurements were also carried out in the temperature range 300–523K. From both AC and DC conductivity studies, it is found that the conductivity increases and activation energy decreases with increasing the concentration of TeO{sub 2} as well as with temperature. The conductivity of the present glass system is found to be of the order of 10{sup −2} S/cm at room temperature. The ionic transport number of these glasses is found to be 0.999 indicating that these glasses can be used as electrolyte in batteries.

  8. Paraphasias in Multilingual Conduction Aphasia: A Single Case Study

    ERIC Educational Resources Information Center

    Hegde, Medha; Bhat, Sapna

    2007-01-01

    Conduction aphasia is a type of fluent aphasia, which is caused due to the damage to the supramarginal gyrus and arcuate fasciculus resulting in repetition disturbance. It has been speculated that linguistic system in bilingual aphasics can breakdown in different ways across languages. There is a lack of detailed linguistic studies in specific…

  9. Long-term effects of a diet loosely restricting carbohydrates on HbA1c levels, BMI and tapering of sulfonylureas in type 2 diabetes: a 2-year follow-up study.

    PubMed

    Haimoto, Hajime; Iwata, Mitsunaga; Wakai, Kenji; Umegaki, Hiroyuki

    2008-02-01

    The aim was to assess the long-term effect of a loose restriction of carbohydrate intake (carbohydrate-reduced diet: CARD) compared to a conventional diet (CD) in type 2 diabetes. One hundred and thirty-three type 2 diabetic outpatients followed the CD (n=57, 1734+/-410 kcal, carbohydrate:protein:fat ratio=57:16:26) or CARD (n=76, 1773+/-441 kcal, carbohydrate:protein:fat ratio=45:18:33) according to their own will, and were followed up for 2 years. Glycemic control, body mass index (BMI), serum cholesterols and dose of antidiabetic drugs were assessed at baseline and after 1 and 2 years. At baseline, hemoglobin A1c (HbA1c) and BMI levels were 7.1+/-1.0% and 24.2+/-2.9, respectively, in the CD group, and 7.4+/-1.1% and 25.1+/-3.4 in the CARD group, showing no significant differences. During the 2-year follow-up period, HbA1c levels were significantly improved in the CARD group (CD: 7.5+/-1.3%, CARD: 6.7+/-0.6%, P<0.001), and BMI decreased more significantly in the CARD group (CD: 23.8+/-3.0, CARD: 23.8+/-3.5, P<0.001). The doses of sulfonylureas clearly tapered, and serum cholesterol profiles improved significantly with the CARD. Our results warrant a long-term and large-scale randomized study of the diet for type 2 diabetes.

  10. Estimating Unsaturated Hydraulic Conductivity: Study the Effect of Tortuosity Factor

    NASA Astrophysics Data System (ADS)

    Ghanbarian-Alavijeh, Behzad; Abbasi, Fariborz

    2010-05-01

    Unsaturated soil hydraulic conductivity is one of the key soil hydraulic properties that, in one hand, is widely used in the studies of water and solute transport in soils, and on the other hand its direct measurement is time consuming and expensive. In this research, in order to study tortuosity factor (l) in the Burdine-Brooks-Corey (BBC hereafter), 59 soil samples from the GRIZZLY database were used. Using a sensitivity analysis, sensitive parameters of this model were determined. To study tortuosity factor, its different values e.g. 2, 1, 0.5, 0, -0.5, -1 and -2 were used in the estimation of unsaturated hydraulic conductivity. The results of sensitivity analysis showed that BBC model is more sensitive to the saturated water content and pore size distribution index. Whereas, the BBC model is less sensitive to tortuosity factor and saturated hydraulic conductivity. The calculated statistical parameter SAE in estimation of unsaturated hydraulic conductivity indicated that the BBC model error with l=2 is less than other values. The results also showed that tortuosity factor is linearly correlated with the power of BCC model with goodness of fit R2=0.96. Based on this approach, tortuosity factor was removed from BCC model, and a new empirical equation was developed to estimate unsaturated hydraulic conductivity. This model was verified using 33 samples of the UNSODA database. The results showed that the developed empirical equation estimated unsaturated hydraulic conductivity better than BCC model in which tortuosity factor was assumed to be equal to 2. Acknowledgments The authors are grateful to Drs. M.Th. van Genuchten and R. Haverkamp for providing the UNSODA and GRIZZLY data sets.

  11. Ab-initio study of napthelene based conducting polymer

    SciTech Connect

    Ruhela, Ankur; Kanchan, Reena; Srivastava, Anurag; Sinha, O. P.

    2014-04-24

    In this paper, we have identified structural and electronic properties of conducting polymers by using DFT based ATK-VNL ab-initio tool. Naphthalene derivative structures were stabilized by varying the bond length between two atoms of the molecule C-N and C-C. We have also studied the molecular energy spectrum of naphthalene derivatives and found the HOMOLUMO for the same. A comparison of structural and electronic properties of naphthalene derivatives by attaching the functional group of amine, have been performed and found that they show good semi conducting properties.

  12. Time resolved strain dependent morphological study of electrically conducting nanocomposites

    NASA Astrophysics Data System (ADS)

    Khan, Imran; Mitchell, Geoffrey; Mateus, Artur; Kamma-Lorger, Christina S.

    2015-10-01

    An efficient and reliable method is introduced to understand the network behaviour of nano-fillers in a polymeric matrix under uniaxial strain coupled with small angle x-ray scattering measurements. The nanoparticles (carbon nanotubes) are conductive and the particles form a percolating network that becomes apparent source of electrical conduction and consequently the samples behave as a bulk conductor. Polyurethane based nanocomposites containing 2% w/w multiwall carbon nanotubes are studied. The electrical conductivity of the nanocomposite was (3.28×10-5s/m).The sample was able to be extended to an extension ratio of 1.7 before fracture. A slight variation in the electrical conductivity is observed under uniaxial strain which we attribute to the disturbance of conductive pathways. Further, this work is coupled with in- situ time resolved small angle x-ray scattering measurements using a synchrotron beam line to enable its measurements to be made during the deformation cycle. We use a multiscale structure to model the small angle x-ray data. The results of the analysis are interpreted as the presence of aggregates which would also go some way towards understanding why there is no alignment of the carbon nanotubes.

  13. AC Conductivity Studies of Lithium Based Phospho Vanadate Glasses

    SciTech Connect

    Nagendra, K.; Babu, G. Satish; Gowda, Veeranna; Reddy, C. Narayana

    2011-07-15

    Glasses in the system xLi{sub 2}SO{sub 4}-20Li{sub 2}O-(80-x) [80P{sub 2}O{sub 5}-20V{sub 2}O{sub 5}](5{>=}x{>=}20 mol%) has been prepared by melt quenching method. Dc and ac conductivity has been studied over a wide range of frequency (10 Hz to 10 MHz) and temperature (298 K-523 K). The dc conductivity found to increase with increase of Li{sub 2}SO{sub 4} concentration. The ac conductivities have been fitted to the Almond-West type single power law equation {sigma}({omega}) = {sigma}(0)+A{omega}{sup s} where 's' is the power law exponent. The ac conductivity found to increase with increase of Li{sub 2}SO{sub 4} concentration. An attempt is made to elucidate the enhancement of lithium ion conduction in phosphor-vanadate glasses by considering the expansion of network structure.

  14. The role of depressive symptoms, family invalidation and behavioral impulsivity in the occurrence and repetition of non-suicidal self-injury in Chinese adolescents: a 2-year follow-up study.

    PubMed

    You, Jianing; Leung, Freedom

    2012-04-01

    This study used zero-inflated poisson regression analysis to examine the role of depressive symptoms, family invalidation, and behavioral impulsivity in the occurrence and repetition of non-suicidal self-injury among Chinese community adolescents over a 2-year period. Participants, 4782 high school students, were assessed twice during the follow-up period. Results indicate that while Year 1 depressive symptoms and family invalidation were significantly associated with the occurrence of Year 2 NSSI, Year 1 behavioral impulsivity contributed to both the occurrence and repetition of Year 2 NSSI. Findings of this study suggest that adolescents who display multiple impulsive behaviors may be at particular risk for engaging in repetitive NSSI. Clinical implications of these findings and future research directions were discussed.

  15. Studies on conducting polymer and conducting polymerinorganic composite electrodes prepared via a new cathodic polymerization method

    NASA Astrophysics Data System (ADS)

    Singh, Nikhilendra

    A novel approach for the electrodeposition of conducting polymers and conducting polymer-inorganic composite materials is presented. The approach shows that conducting polymers, such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) can be electrodeposited by the application of a cathodic bias that generates an oxidizing agent, NO+, via the in-situ reduction of nitrate anions. This new cathodic polymerization method allows for the deposition of PPy and PEDOT as three dimensional, porous films composed of spherical polymer particles. The method is also suitable for the co-deposition of inorganic species producing conducting polymer-inorganic composite electrodes. Such composites are used as high surface area electrodes in Li-ion batteries, electrochemical hydrogen evolution and in the development of various other conducting polymer-inorganic composite electrodes. New Sn-PPy and Sb-PPy composite electrodes where Sn and Sb nanoparticles are well dispersed among the PPy framework are reported. These structures allow for decreased stress during expansion and contraction of the active material (Sn, Sb) during the alloying and de-alloying processes of a Li-ion battery anode, significantly alleviating the loss of active material due to pulverization processes. The new electrochemical synthesis mechanism allows for the fabrication of Sn-PPy and Sb-PPy composite electrodes directly from a conducting substrate and eliminates the use of binding materials and conducting carbon used in modern battery anodes, which significantly simplifies their fabrication procedures. Platinum (Pt) has long been identified as the most efficient catalyst for electrochemical water splitting, while nickel (Ni) is a cheaper, though less efficient alternative to Pt. A new morphology of PPy attained via the aforementioned cathodic deposition method allows for the use of minimal quantities of Pt and Ni dispersed over a very high surface area PPy substrate. These composite electrodes

  16. Viscoelastic study of conducting polymers using quartz crystal microbalance

    NASA Astrophysics Data System (ADS)

    Bahrami Samani, Mehrdad; Whitten, Philip; Spinks, Geoffrey; Cook, Christopher

    2006-03-01

    Application of conducting polymers has been growing widely in different fields such as batteries, solar cells, capacitors and actuators. Mechanical properties of conducting polymers like flexibility, high power to mass ratio and high active strain make them potentially applicable to robotic and automation industries. Obviously, a dynamic model of the actuation phenomenon in conducting polymers is needed to study its controllability and also to optimize the mechanical performance. De Rossi and colleagues suggest treating the mechanical behaviour of conducting polymers separately from the viscoelastic structural model and electrochemical actuation [1]. But it has been observed that the effects of electrochemical actuation and diffusion of ions on the viscoelastic coefficients cannot be neglected in some conducting polymer actuators, as shown in [1]. In this paper, we present the effects of cyclic voltammetry actuation on shear modulus of polypyrrole in propylene carbonate and EMI.TSFI as measured by an electrochemical Quartz Crystal Microbalance (eQCM). The QCM consists basically of an AT-cut piezoelectric quartz crystal disc with metallic electrode films deposited on its faces. One face is exposed to the active medium. A driver circuit applies an AC signal to the electrodes, causing the crystal to oscillate in a shear mode, at a given resonance frequency. QCM has been routinely used for the determination of mass changes. Measured resonance frequency shifts are converted into mass changes by the wellknown Sauerbrey's equation. In this paper, we correlate the admittance output of QCM to the real shear modulus of polypyrrole. Then the results of the correlation which contains mechanical data are presented during actuation using two different types of electrolyte.

  17. Studies of Electronic Conduction in Some Small Gallium Arsenic Based.

    NASA Astrophysics Data System (ADS)

    Whittington, Geoffrey

    Available from UMI in association with The British Library. Requires signed TDF. This thesis describes experimental investigations of the physics involved with low temperature electronic conduction in three different semiconductor systems. The research relies upon technological advances in fabrication of such semiconductor samples. The first work deals with the effects of quantum interference of electrons in some submicron size, heavily doped Gallium Arsenide wire samples. The interesting effect of aperiodic fluctuations in the magnetoresistance of these samples is studied, making use of recently formulated theory on the subject, and with experimental data taken over the magnetic field range 0 to 10 tesla. The results verify the connection between the mean amplitude of the fluctuations and the field correlation period, in terms of the correlation function introduced in the theory. The second work is on the impurity-assisted tunnelling conduction in a magnetic field of three thin rm n^{+}/n^{-}/n^ {+} GaAs sandwich layer structures. The conduction of the system is shown to be determined by impurities lying in the centre of the middle layer. This allows the connection to be made between the conductivity of the system in a magnetic field, and the field-dependent shape of the donor electron wavefunction. The relative variation in resistance with angle to an applied magnetic field was measured, and is shown to be in agreement with predictions based on calculations of the shape of a normalised hydrogenic state wavefunction in high magnetic fields. The third work concerns the tunnelling conduction of a symmetrical GaAs/(AlGa)As/GaAs hetero-barrier system. The current-voltage characteristics at low temperature are fully modelled for applied voltages up to 180mV, using conventional theory of tunnelling and a position-dependent effective mass in the barrier. Low current oscillations in the Fowler-Nordheim tunnelling regime, corresponding to quantum reflection at the

  18. Transport studies of conducting, semiconducting and photoconducting star polymers

    NASA Astrophysics Data System (ADS)

    Ferguson, John Baker

    Star polymers are studied for their transport properties in the highly conducting state doped with NOPF6 and iodine, the undoped semiconducting state and the photoconducting state. Doped star polymers exhibit variable range hopping of charge carriers. Transport dimensionality and conductivity depend intricately on the processing conditions for doping and casting films. The highest conducting diffusion doped film (room temperature conductivity 50 S/cm) exhibits 2-dimensional variable range for all doping levels. Polymers doped in solution, then cast to form films have 1.4 dimensional variable range hopping for the highest conducting samples with 10 S/cm at room temperature. The hopping dimensionality varies as the conductivity decreases. The doped star polymers remain on the insulator side of the insulator metal transition with localized carriers as revealed with Kramer-Kronig analysis. Optical and near infrared absorbance and photoluminescence reveal the core of the star polymers exist in a solid state solution of the arms with similar absorbance and luminescence for both solution and films. The arms retain the optical properties of their linear analogs indicating the core and arms do not interact quantum mechanically to produce a new state. Excitons created by absorption in the wider band gap cores rapidly migrate to the arms. Photoconductive time of flight mobility measurements reveal an almost field independent mobility at room temperature. This is due to a unique cancellation of on diagonal and off diagonal disorder in the Bassler disorder formalism. The cores introduce heterogeneous regions with a net lower mobility predicted by correlated disorder models. Space charge limited current reveals trap densities several orders of magnitude higher than the carrier density. Photovoltaic performance of star polymer and fullerene blend devices with both 20 nm and 100 nm thick layers are investigated. The thin devices have low open circuit voltages due to space charge

  19. Hopping conduction in 3,4-cycloalkylpolypyrrole perchlorates: A model study of conductivity in polymers:

    NASA Astrophysics Data System (ADS)

    Ezquerra, T. A.; Rühe, J.; Wegner, G.

    1988-02-01

    The conductivity of 3,4-cycloalkyl-substituted polypyrrole perchlorates has been analyzed using hopping theory. The localization length of the charge carriers was found to be 0.8 nm, the actual conductivity at constant temperature being exponentially dependent on the minimum distance, R, between adjacent chains. R can be reasonably estimated from molecular models and was systematically varied between 0.38 nm (unsubstituted polypyrrole) and 1.38 nm (decamethylene chain attached in 3,4-position). The conduction is activated in the temperature range 150-300 K, the activation energy varying systematically from 0.012 to 0.066 eV on increasing R from 0.38 to 1.38 nm.

  20. Electronic conductivity studies on oxyhalide glasses containing TMO

    NASA Astrophysics Data System (ADS)

    Vijayatha, D.; Viswanatha, R.; Sujatha, B.; Narayana Reddy, C.

    2016-05-01

    Microwave-assisted synthesis is cleaner, more economical and much faster than conventional methods. The development of new routes for the synthesis of solid materials is an integral part of material science and technology. The electronic conductivity studies on xPbCl2 - 60 PbO - (40-x) V2O5 (1 ≥ x ≤ 10) glass system has been carried out over a wide range of composition and temperature (300 K to 423 K). X-ray diffraction study confirms the amorphous nature of the samples. The Scanning electron microscopic studies reveal the formation of cluster like morphology in PbCl2 containing glasses. The d.c conductivity exhibits Arrhenius behaviour and increases with V2O5 concentration. Analysis of the results is interpreted in view Austin-Mott's small polaron model of electron transport. Activation energies calculated using regression analysis exhibit composition dependent trend and the variation is explained in view of the structure of lead-vanadate glass.

  1. Conducting Simulation Studies in the R Programming Environment.

    PubMed

    Hallgren, Kevin A

    2013-10-12

    Simulation studies allow researchers to answer specific questions about data analysis, statistical power, and best-practices for obtaining accurate results in empirical research. Despite the benefits that simulation research can provide, many researchers are unfamiliar with available tools for conducting their own simulation studies. The use of simulation studies need not be restricted to researchers with advanced skills in statistics and computer programming, and such methods can be implemented by researchers with a variety of abilities and interests. The present paper provides an introduction to methods used for running simulation studies using the R statistical programming environment and is written for individuals with minimal experience running simulation studies or using R. The paper describes the rationale and benefits of using simulations and introduces R functions relevant for many simulation studies. Three examples illustrate different applications for simulation studies, including (a) the use of simulations to answer a novel question about statistical analysis, (b) the use of simulations to estimate statistical power, and (c) the use of simulations to obtain confidence intervals of parameter estimates through bootstrapping. Results and fully annotated syntax from these examples are provided.

  2. Conducting Simulation Studies in the R Programming Environment

    PubMed Central

    Hallgren, Kevin A.

    2014-01-01

    Simulation studies allow researchers to answer specific questions about data analysis, statistical power, and best-practices for obtaining accurate results in empirical research. Despite the benefits that simulation research can provide, many researchers are unfamiliar with available tools for conducting their own simulation studies. The use of simulation studies need not be restricted to researchers with advanced skills in statistics and computer programming, and such methods can be implemented by researchers with a variety of abilities and interests. The present paper provides an introduction to methods used for running simulation studies using the R statistical programming environment and is written for individuals with minimal experience running simulation studies or using R. The paper describes the rationale and benefits of using simulations and introduces R functions relevant for many simulation studies. Three examples illustrate different applications for simulation studies, including (a) the use of simulations to answer a novel question about statistical analysis, (b) the use of simulations to estimate statistical power, and (c) the use of simulations to obtain confidence intervals of parameter estimates through bootstrapping. Results and fully annotated syntax from these examples are provided. PMID:25067989

  3. Computer-Guided Implant Surgery in Fresh Extraction Sockets and Immediate Loading of a Full Arch Restoration: A 2-Year Follow-Up Study of 14 Consecutively Treated Patients.

    PubMed

    Daas, M; Assaf, A; Dada, K; Makzoumé, J

    2015-01-01

    Statement of Problem. Low scientific evidence is identified in the literature for combining implant placement in fresh extraction sockets with immediate function. Moreover, the few studies available on immediate implants in postextraction sites supporting immediate full-arch rehabilitation clearly lack comprehensive protocols. Purpose. The purpose of this study is to report outcomes of a comprehensive protocol using CAD-CAM technology for surgical planning and fabrication of a surgical template and to demonstrate that immediate function can be easily performed with immediate implants in postextraction sites supporting full-arch rehabilitation. Material and Methods. 14 subjects were consecutively rehabilitated (13 maxillae and 1 mandible) with 99 implants supporting full-arch fixed prostheses followed between 6 and 24 months (mean of 16 months). Outcome measures were prosthesis and implant success, biologic and prosthetic complications, pain, oedema evaluation, and radiographic marginal bone levels at surgery and then at 6, 12, 18, and 24 months. Data were analyzed with descriptive statistics. Results. The overall cumulative implant survival rate at mean follow-up time of 16 months was 97.97%. The average marginal bone loss was 0,9 mm. Conclusions. Within the limitations of this study, the results validate this treatment modality for full-arch rehabilitations with predictable outcomes and high survival rate after 2 years. PMID:26064119

  4. Thermal conductivity and rectification study of restructured Graphene

    NASA Astrophysics Data System (ADS)

    Arora, Anuj

    Electronics' miniaturization, has led to search for better thermal management techniques and discovery of important transport phenomenon. Thermal rectification, directionally preferential heat transport analogous to electrical diode, is one such technique, garnering tremendous interest. Its possibility has been explored through structural asymmetry, introducing a differential phonon density of states in hot and cold regions. As of now, mass and shape asymmetries have been studied, both experimentally and theoretically. However, strict requirements of material length being shorter than phonon mean free path and phonon coherence preservation at surface, makes connecting two materials with different temperature-dependent thermal conductivities, a more natural approach. To avoid resultant thermal boundary resistance and integration complexities, we achieve the affect in single material, by restructuring a region of Graphene by introducing defects. The asymmetry impedes ballistic phonon transport, modulating temperature dependence of thermal conductivity in the two regions. We perform deviational Monte Carlo simulations based on Energy-based formulation to microscopically investigate phonon transport, possibility and optimal conditions for thermal rectification. The proposed method uses phonon properties obtained from first principle, treat phonon-boundary scattering explicitly with properties drawn from Bose-Einstein Distribution.

  5. Comparative study of atrial fibrillation and AV conduction in mammals.

    PubMed

    Meijler, F L; van der Tweel, I

    1987-01-01

    Atrial fibrillation is one of the most common cardiac arrhythmias in humans. It also occurs quite frequently in dogs and horses. Comparative study of this arrhythmia may contribute to better understanding of the pathophysiological mechanisms involved. In this study, we present a quantitative analysis of atrial fibrillation in humans, dogs, horses, and in a kangaroo, making use of histograms and serial autocorrelograms of the ventricular rhythm with and without digitalis medication. Increase in the size of the animal and thus in the size of the heart is accompanied by a decrease in ventricular rate. The ventricular rhythm was random in the dog, kangaroo, and man, but periodicity was present in the horse. Digitalis decreased the ventricular rate in all species studied and enforced the periodicity in the horse. The differences in the atrial excitation process, atrioventricular (AV) conduction, and ventricular behavior between the four species studied are small when compared with the differences in their heart size. We conclude that in evolution, as far as the heart is concerned, cell size and morphology probably prevail over cell-function.

  6. Comprehensive study of back and leg pain improvements after adult spinal deformity surgery: analysis of 421 patients with 2-year follow-up and of the impact of the surgery on treatment satisfaction.

    PubMed

    Scheer, Justin K; Smith, Justin S; Clark, Aaron J; Lafage, Virginie; Kim, Han Jo; Rolston, John D; Eastlack, Robert; Hart, Robert A; Protopsaltis, Themistocles S; Kelly, Michael P; Kebaish, Khaled; Gupta, Munish; Klineberg, Eric; Hostin, Richard; Shaffrey, Christopher I; Schwab, Frank; Ames, Christopher P

    2015-05-01

    OBJECT Back and leg pain are the primary outcomes of adult spinal deformity (ASD) and predict patients' seeking of surgical management. The authors sought to characterize changes in back and leg pain after operative or nonoperative management of ASD. Outcomes were assessed according to pain severity, type of surgical procedure, Scoliosis Research Society (SRS)-Schwab spine deformity class, and patient satisfaction. METHODS This study retrospectively reviewed data in a prospective multicenter database of ASD patients. Inclusion criteria were the following: age > 18 years and presence of spinal deformity as defined by a scoliosis Cobb angle ≥ 20°, sagittal vertical axis length ≥ 5 cm, pelvic tilt angle ≥ 25°, or thoracic kyphosis angle ≥ 60°. Patients were grouped into nonoperated and operated subcohorts and by the type of surgical procedure, spine SRS-Schwab deformity class, preoperative pain severity, and patient satisfaction. Numerical rating scale (NRS) scores of back and leg pain, Oswestry Disability Index (ODI) scores, physical component summary (PCS) scores of the 36-Item Short Form Health Survey, minimum clinically important differences (MCIDs), and substantial clinical benefits (SCBs) were assessed. RESULTS Patients in whom ASD had been operatively managed were 6 times more likely to have an improvement in back pain and 3 times more likely to have an improvement in leg pain than patients in whom ASD had been nonoperatively managed. Patients whose ASD had been managed nonoperatively were more likely to have their back or leg pain remain the same or worsen. The incidence of postoperative leg pain was 37.0% at 6 weeks postoperatively and 33.3% at the 2-year follow-up (FU). At the 2-year FU, among patients with any preoperative back or leg pain, 24.3% and 37.8% were free of back and leg pain, respectively, and among patients with severe (NRS scores of 7-10) preoperative back or leg pain, 21.0% and 32.8% were free of back and leg pain, respectively

  7. Phase behaviour and conductivity study of electrolytes in supercritical hydrofluorocarbons.

    PubMed

    Bartlett, Philip N; Cook, David C; George, Michael W; Ke, Jie; Levason, William; Reid, Gillian; Su, Wenta; Zhang, Wenjian

    2011-01-01

    The purpose of this work was to characterise supercritical hydrofluorocarbons (HFC) that can be used as solvents for electrodeposition. The phase behaviour of CHF(3), CH(2)F(2), and CH(2)FCF(3) containing [NBu(n)(4)][BF(4)], [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] and Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] was studied and the conditions for forming a single supercritical phase established. Although all three HFCs are good solvents for [NBu(n)(4)][BF(4)] the results show that the CH(2)F(2) system has the lowest p(r) for dissolving a given amount of [NBu(n)(4)][BF(4)]. The solubility of Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] in CH(2)F(2) was found to be unexpectedly high. Studies of the phase behaviour of CH(2)F(2) containing [NBu(n)(4)][BF(4)] and [Cu(CH(3)CN)(4)][BF(4)] showed that the copper complex was unstable in the absence of CH(3)CN. For CHF(3), [Cu(hfac)(2)] was more soluble and more stable than [Cu(CH(3)CN)(4)][BF(4)] and only increased the phase-separation pressure by a moderate amount. Studies of the conductivity of [NBu(n)(4)][B(C(6)F(5))(4)], [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)], [NR(f)Bu(n)(3)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] (R(f) = (CH(2))(3)C(7)F(15)), and Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] were carried out in scCH(2)F(2). The results show that these salts are more conducting than [NBu(n)(4)][BF(4)] under the same conditions although the increase is much less significant than that reported in previous work in supercritical CO(2) + CH(3)CN. Consequently, either [NBu(n)(4)][BF(4)] or the corresponding BARF salts would be suitable background electrolytes for electrodeposition from scCH(2)F(2). PMID:21072413

  8. A protocol for conducting rainfall simulation to study soil runoff.

    PubMed

    Kibet, Leonard C; Saporito, Louis S; Allen, Arthur L; May, Eric B; Kleinman, Peter J A; Hashem, Fawzy M; Bryant, Ray B

    2014-01-01

    Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24 hr after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff. PMID:24748061

  9. A protocol for conducting rainfall simulation to study soil runoff.

    PubMed

    Kibet, Leonard C; Saporito, Louis S; Allen, Arthur L; May, Eric B; Kleinman, Peter J A; Hashem, Fawzy M; Bryant, Ray B

    2014-04-03

    Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24 hr after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff.

  10. Stability assessment of a moderately conforming all-polyethylene tibial component in total knee arthroplasty: a prospective RSA study with 2 years of follow-up of the Kinemax Plus design.

    PubMed

    Adalberth, G; Nilsson, K G; Byström, S; Kolstad, K; Mallmin, H; Milbrink, J

    1999-01-01

    The magnitude and pattern of the migration of an all-polyethylene tibial component with moderately conforming articular surfaces in total knee arthroplasty was analyzed in 20 patients > or =60 years during a 2-year follow-up using radiostereometry (RSA). Most of the migration occurred during the initial 4 months, whereafter the migration diminished, reaching a mean maximum migration of 0.75 mm at 2 years. Similar patterns were found for rotation of the implant. Maximum subsidence at 2 years was 0.7 mm and was most commonly located at the posteromedial part of the tibial component. These results indicate that an all-polyethylene tibial component with moderately conforming articular geometry and with a thickness of 10-12 mm demonstrated migration patterns compatible with a favorable prognosis in regard to future aseptic loosening.

  11. Photoluminescence and conductivity studies of anthracene-functionalized ruthenium nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Pradhan, Sulolit; Chen, Shaowei

    2011-05-01

    studies indicate that anthracene functionalization may be exploited as an effective route towards the manipulation of nanoparticle optoelectronic properties.Carbene-stabilized ruthenium nanoparticles were functionalized with anthryl moieties by olefin metathesis reactions with 9-vinylanthracene, at a surface concentration of about 19.7%, as estimated by 1H NMR spectroscopic measurements. Because of the conjugated metal-ligand interfacial bonding interactions, UV-vis measurements of the resulting nanoparticles showed a new broad absorption band centered at 612 nm, in addition to the peaks observed with monomeric vinylanthracene. FTIR measurements depicted apparent red-shifts of the aromatic vibrational stretches as compared to those of the monomeric vinylanthracene, suggestive of decreasing bonding order of the aromatic moieties as a result of extended conjugation between the particle-bound anthracene groups. Photoluminescence measurements confirmed the notion that effective intraparticle charge delocalization occurred by virtue of the conjugated metal-ligand interfacial bonding interactions, with apparent red-shifts of the excitation peaks and blue-shifts of the emission features, as compared to those of the monomeric vinylanthracene. The diminishment of the Stokes shift was, at least in part, attributed to the different chemical environments surrounding the anthryl moieties on the nanoparticle surface. Electronic conductivity measurements showed that because of the conjugated Ru z.dbd C π bonds, the activation energy for interparticle charge transport was about one order of magnitude lower than that observed with particles passivated by alkanethiolates. Additionally, whereas the original carbene-stabilized nanoparticles exhibited a semiconductor-metal transition within the temperature range of 100 to 320 K, anthracene-functionalized nanoparticles displayed apparent semiconducting behaviors with the ensemble conductivity increasing monotonically with temperature, most

  12. Study for Electric Device Assembly Process Using Conductive Adhesive

    NASA Astrophysics Data System (ADS)

    Fujino, Junji

    Electric devices with semiconductors are applied to all apparatus including substation equipment, transport machines, home electronics, and cellular phones. Power modules deal large current, and high frequency/optical modules control GHz band signals. As a result, these semiconductors have more than 100 times heat density of memory or MPU chips. Pb-rich high temperature solder and expensive Au-rich solder are applied to these modules, however, thermal stress might be a problem not only for long-term reliability but also for the initial characteristics. The authors studied the assembly of these electric devices using conductive adhesive as a substitute bonding material. We proved that atmospheric aluminum oxides caused electric resistance and that power chips with long rectangle sides over 10 mm have a much larger thermal resistance than theoretical values. We found that it is effective to scratch and remove these oxides through transferred adhesive on aluminum electrodes and to diebond them onto the solder projection previously formed on the die pads.

  13. Repetitive Behaviours in Typically Developing 2-Year-Olds

    ERIC Educational Resources Information Center

    Leekam, Susan; Tandos, Jonathan; McConachie, Helen; Meins, Elizabeth; Parkinson, Kathryn; Wright, Charlotte; Turner, Michelle; Arnott, Bronia; Vittorini, Lucia; Le Couteur, Ann

    2007-01-01

    Background: Repetitive behaviours are an essential part of the diagnosis of autism but are also commonly seen in typically developing children. The current study investigated the frequency and factor structure of repetitive behaviours in a large community sample of 2-year-olds. Methods: A new measure, the Repetitive Behaviour Questionnaire (RBQ-2)…

  14. A numerical study of transient, thermally-conductive solar wind

    NASA Technical Reports Server (NTRS)

    Han, S. M.; Wu, S. T.; Dryer, M.

    1987-01-01

    A numerical analysis of transient solar wind starting at the solar surface and arriving at 1 AU is performed by an implicit numerical method. The model hydrodynamic equations include thermal conduction terms for both steady and unsteady simulations. Simulation results show significant influence of thermal conduction on both steady and time-dependent solar wind. Higher thermal conduction results in higher solar wind speed, higher temperature, but lower plasma density at 1 AU. Higher base temperature at the solar surface gives lower plasma speed, lower temperature, but higher density at 1 AU. Higher base density, on the other hand, gives lower velocity, lower temperature, but higher density at 1 AU.

  15. Comparative Study of the Thermal Conductivity of Solid Biomass Fuels

    PubMed Central

    2016-01-01

    The thermal conductivity of solid biomass fuels is useful information in the investigation of biomass combustion behavior and the development of modeling especially in the context of large scale power generation. There are little published data on the thermal conductivity of certain types of biomass such as wheat straw, miscanthus, and torrefied woods. Much published data on wood is in the context of bulk materials. A method for determining the thermal conductivities of small particles of biomass fuels has been developed using a custom built test apparatus. Fourteen different samples of various solid biomass fuel were processed to form a homogenized pellet for analysis. The thermal conductivities of the pelletized materials were determined and compared against each other and to existing data. PMID:27041819

  16. 'Schizoid' personality and antisocial conduct: a retrospective case not study.

    PubMed

    Wolff, S; Cull, A

    1986-08-01

    A retrospective case not analysis for 30 boys diagnosed as having a 'schizoid' personality disorder (Asperger's syndrome) in childhood, and for 30 matched clinic attenders (with systematic follow-up data for 19 matched pairs), showed the incidence of antisocial conduct to be the same in the two groups. However, the 'schizoid' boys stole less often and had fewer alcohol problems. In this group antisocial conduct was less related to family disruption and social disadvantage, and more to an unusual fantasy life. Clinical descriptions of a series of 'schizoid' boys and girls with conspicuous antisocial conduct follow. They suggest that characteristic patterns of antisocial conduct in such children are persistent expressions of hostility and, especially in girls, pathological lying, for which environmental circumstances provide no explanation.

  17. Carbonyl mediated conductance through metal bound peptides: a computational study

    NASA Astrophysics Data System (ADS)

    Perrine, Trilisa M.; Dunietz, Barry D.

    2007-10-01

    Large increases in the conductance of peptides upon binding to metal ions have recently been reported experimentally. The mechanism of the conductance switching is examined computationally. It is suggested that oxidation of the metal ion occurs after binding to the peptide. This is caused by the bias potential placed across the metal-peptide complex. A combination of configurational changes, metal ion involvement and interactions between carbonyl group oxygen atoms and the gold leads are all shown to be necessary for the large improvement in the conductance seen experimentally. Differences in the molecular orbitals of the nickel and copper complexes are noted and serve to explain the variation of the improvement in conductance upon binding to either a nickel or copper ion.

  18. Association between inflammatory cytokines and the risk of post-stroke depression, and the effect of depression on outcomes of patients with ischemic stroke in a 2-year prospective study

    PubMed Central

    Jiao, Jian-Tong; Cheng, Chao; Ma, Ying-Jun; Huang, Jin; Dai, Min-Chao; Jiang, Chen; Wang, Cheng; Shao, Jun-Fei

    2016-01-01

    The association between inflammatory cytokines and the risk of post-stroke depression (PSD) remains unclear. The aim of the present study was to investigate this association and the effect of PSD on the outcomes of ischemic stroke patients. A total of 355 patients who had experienced ischemic stroke participated in inflammatory cytokine detection by ELISA, in addition to depression, quality of life (QOL) and body performance testing. Cox regression was used to evaluate the associations between PSD risk, inflammatory cytokines and the outcomes of patients. Measurement data was evaluated using Student's t test, and counted data was measured by χ2 test. The incidence of PSD during the 2-year follow-up was 23.1%. The risk of PSD elevated with increased interleukin (IL)-6 expression levels [hazard ratio (HR)=3.18; 95% confidence interval (CI), 1.37–7.36] following the adjustment of confounders. However, no significant associations were identified between PSD and other inflammatory cytokines. QOL and body performance in the depressed group were significantly worse compared with those in the non-depressed group. The risk of stroke recurrence in patients with depression increased two-fold compared with patients without depression (HR=2.020; 95% CI, 1.123–3.635; Ptrend=0.019). No significant associations between PSD and the risk of mortality (HR=1.497; 95% CI, 0.547–4.098) were observed. In conclusion, depression is prevalent in patients following ischemic stroke. IL-6 is positively associated with the risk of PSD, and may predict its development in patients following ischemic stroke. PSD correlates with outcomes of patients, and the effective management of PSD may improve the prognosis of patients. PMID:27588080

  19. [Study on the conductivity properties of lightning channel by spectroscopy].

    PubMed

    Wang, Xue-Juan; Yuan, Ping; Cen, Jian-Yong; Wang, Jie; Zhang, Ting-Long

    2013-12-01

    Combining the spectra of cloud-to-ground lightning return obtained by a slit-less spectrograph with the transport theory of air plasma, the electrical conductivity in one discharge channel was calculated with different methods. The results show that the conductivity of the lightning channel core is of the order of 10(4) S m-1; the conductivity goes down with the increase in the channel height in the same channel; the contributions of the collisions between electron and first or second degree ionized atoms, and electron-electron as well as ion-ion collisions to the electrical conductivity of the lightning channel core can not be neglected; the collision integrals method is more reasonable for calculating the conductivity of the lightning channel core. Based on the conductivity, the discharge current was estimated and compared with the peak current of every return stroke, and the results are in the reasonable range, further, the correlation between the channel temperature and the discharge characteristics is discussed, which provides a practical way for this aspect. PMID:24611368

  20. [Study on the conductivity properties of lightning channel by spectroscopy].

    PubMed

    Wang, Xue-Juan; Yuan, Ping; Cen, Jian-Yong; Wang, Jie; Zhang, Ting-Long

    2013-12-01

    Combining the spectra of cloud-to-ground lightning return obtained by a slit-less spectrograph with the transport theory of air plasma, the electrical conductivity in one discharge channel was calculated with different methods. The results show that the conductivity of the lightning channel core is of the order of 10(4) S m-1; the conductivity goes down with the increase in the channel height in the same channel; the contributions of the collisions between electron and first or second degree ionized atoms, and electron-electron as well as ion-ion collisions to the electrical conductivity of the lightning channel core can not be neglected; the collision integrals method is more reasonable for calculating the conductivity of the lightning channel core. Based on the conductivity, the discharge current was estimated and compared with the peak current of every return stroke, and the results are in the reasonable range, further, the correlation between the channel temperature and the discharge characteristics is discussed, which provides a practical way for this aspect.

  1. Study of new proton conducting glasses for fuel cells

    NASA Astrophysics Data System (ADS)

    Tiple, S. R.; Deshpande, V. K.

    2015-08-01

    The glasses in the series (35-x) BaO:65 P2O5:x (NH4)2SO4 are synthesized and characterized by Tg, CTE, density and electrical conductivity measurements. The decrease in density and Tg is observed with addition of (NH4)2SO4. The increase in CTE compliments the observed variation in Tg. The protonic conductivity increases with addition of (NH4)2SO4 up to 7.5 mol% and decreases beyond this composition. The increase in the ratio of O/P, which in turn, creates more non-bridging oxygens, enhances the conductivity. Further, sulfur is mainly incorporated in sulfophosphate glasses as isolated SO42- group which also results in increase in conductivity. The glass with maximum conductivity [7.5(NH4)2SO4:27.5BaO:65 P2O5] is used to fabricate a fuel cell. It gives the power density of 12.43 μW/cm2. The power density of the fuel cell in the present work at room temperature is higher than that reported in literature at 473 K. The fuel cell has a potential of giving higher power density at higher temperature of 423 K.

  2. Electrical Characterization and Morphological Studies of Conducting Polymer Nanofibers

    NASA Technical Reports Server (NTRS)

    Pinto, N. J.; Zhou, Y. X.; Freitag, M.; Johnson, A. T.; MacDiarmid, A. G.; Mueller, C. H.; Theofylaktos, N.; Robinson, D. C.; Miranda, F. A.

    2003-01-01

    Doped polyaniline blended with poly(ethylene oxide) has been electrospun in air to give fibers with diameters in the range 3 nm 200 nm. These fibers were captured on wafers of degenerately doped Si/SiO2 by placing the wafer in the path of the fiber jet formed during the electrospinning process. Individual fibers were contacted using shadow mask evaporation and were also captured on prepatterned wafers. Fibers having diameters greater than 100 nm show a slight increase in the conductivity as compared to the bulk film, while fibers with diameters less than 30 nm had lower conductivity than the bulk. Data on Scanning Conductance Microscopy along the length of individual fibers will be presented. For fibers where the diameter was not uniform, we found that below a certain diameter ( approx.15 nm) the fiber was less conducting as compared to thicker diameter fibers. Dependence of the fiber conductivity on a gate bias is underway and these results will also be presented.

  3. A minimum 2-year comparative study of autologous cancellous bone grafting versus beta-tricalcium phosphate in anterior cervical discectomy and fusion using a rectangular titanium stand-alone cage.

    PubMed

    Yamagata, Toru; Naito, Kentaro; Arima, Hironori; Yoshimura, Masaki; Ohata, Kenji; Takami, Toshihiro

    2016-07-01

    Although titanium stand-alone cages are commonly used in anterior cervical discectomy and fusion (ACDF), there are several concerns such as cage subsidence after surgery. The efficacy of β-tricalcium phosphate (β-TCP) granules as a packing material in 1- or 2-level ACDF using a rectangular titanium stand-alone cage is not fully understood. The purpose of this study is to investigate the validity of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP. This retrospective study included 55 consecutive patients who underwent ACDF with autologous iliac cancellous bone grafting and 45 consecutive patients with β-TCP grafting. All patients completed at least 2-year postoperative follow-up. Univariate and multivariate analyses were performed to examine the associations between study variables and nonunion after surgery. Significant neurological recovery after surgery was obtained in both groups. Cage subsidence was noted in 14 of 72 cages (19.4 %) in the autograft group and 12 of 64 cages (18.8 %) in the β-TCP group. A total of 66 cages (91.7 %) in the autograft group showed osseous or partial union, and 58 cages (90.6 %) in the β-TCP group showed osseous or partial union by 2 years after surgery. There were no significant differences in cage subsidence and the bony fusion rate between the two groups. Multivariate analysis using a logistic regression model showed that fusion level at C6/7, 2-level fusion, and cage subsidence of grades 2-3 were significantly associated with nonunion at 2 years after surgery. Although an acceptable surgical outcome with negligible complication appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP, cage subsidence after surgery needs to be avoided to achieve acceptable bony fusion at the fused segments. Fusion level at C6/7 or 2-level fusion may be another risk factor of nonunion. PMID:27098659

  4. A minimum 2-year comparative study of autologous cancellous bone grafting versus beta-tricalcium phosphate in anterior cervical discectomy and fusion using a rectangular titanium stand-alone cage.

    PubMed

    Yamagata, Toru; Naito, Kentaro; Arima, Hironori; Yoshimura, Masaki; Ohata, Kenji; Takami, Toshihiro

    2016-07-01

    Although titanium stand-alone cages are commonly used in anterior cervical discectomy and fusion (ACDF), there are several concerns such as cage subsidence after surgery. The efficacy of β-tricalcium phosphate (β-TCP) granules as a packing material in 1- or 2-level ACDF using a rectangular titanium stand-alone cage is not fully understood. The purpose of this study is to investigate the validity of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP. This retrospective study included 55 consecutive patients who underwent ACDF with autologous iliac cancellous bone grafting and 45 consecutive patients with β-TCP grafting. All patients completed at least 2-year postoperative follow-up. Univariate and multivariate analyses were performed to examine the associations between study variables and nonunion after surgery. Significant neurological recovery after surgery was obtained in both groups. Cage subsidence was noted in 14 of 72 cages (19.4 %) in the autograft group and 12 of 64 cages (18.8 %) in the β-TCP group. A total of 66 cages (91.7 %) in the autograft group showed osseous or partial union, and 58 cages (90.6 %) in the β-TCP group showed osseous or partial union by 2 years after surgery. There were no significant differences in cage subsidence and the bony fusion rate between the two groups. Multivariate analysis using a logistic regression model showed that fusion level at C6/7, 2-level fusion, and cage subsidence of grades 2-3 were significantly associated with nonunion at 2 years after surgery. Although an acceptable surgical outcome with negligible complication appears to justify the use of rectangular titanium stand-alone cages in 1- and 2-level ACDF with β-TCP, cage subsidence after surgery needs to be avoided to achieve acceptable bony fusion at the fused segments. Fusion level at C6/7 or 2-level fusion may be another risk factor of nonunion.

  5. Materials characterization study of conductive flexible second surface mirrors

    NASA Technical Reports Server (NTRS)

    Levadou, F.; Bosma, S. J.; Paillous, A.

    1981-01-01

    The status of prequalification and qualification work on conductive flexible second surface mirrors is described. The basic material is FEP Teflon witn either aluminium or silver vacuum deposited reflectors. The top layer has been made conductive by deposition of layer of a indium oxide. The results of a prequalification program comprised of decontamination, humidity, thermal cycling, thermal shock and vibration tests are presented. Thermo-optical and electrical properties. The results of a prequalification program comprised of decontamination, humidity, thermal cycling, thermal shock and vibration tests are presented. Thermo-optical and electrical properties, the electrostatic behavior of the materials under simulated substorm environment and electrical conductivity at low temperatures are characterized. The effects of simulated ultra violet and particles irradiation on electrical and thermo-optical properties of the materials are also presented.

  6. Performance of p16INK4a ELISA as a primary cervical cancer screening test among a large cohort of HIV-infected women in western Kenya: a 2-year cross-sectional study

    PubMed Central

    Wu, Tara J; Smith-McCune, Karen; Reuschenbach, Miriam; von Knebel Doeberitz, Magnus; Maloba, May; Huchko, Megan J

    2016-01-01

    Objective A biomarker with increased specificity for cervical dysplasia compared with human papillomavirus (HPV) testing would be an attractive option for cervical cancer screening among HIV-infected women in resource-limited settings. p16INK4a has been explored as a biomarker for screening in general populations. Design A 2-year cross-sectional study. Setting 2 large HIV primary care clinics in western Kenya. Participants 1054 HIV-infected women in western Kenya undergoing cervical cancer screening as part of routine HIV care from October 2010 to November 2012. Interventions Participants underwent p16INK4a specimen collection and colposcopy. Lesions with unsatisfactory colposcopy or suspicious for cervical intraepithelial neoplasia 2+ (CIN2+; including CIN2/3 or invasive cervical cancer) were biopsied. Following biopsy, disease status was determined by histopathological diagnosis. Primary and secondary outcome measures We measured the sensitivity, specificity and predictive values of p16INK4a ELISA for CIN2+ detection among HIV-infected women and compared them to the test characteristics of current screening methods used in general as well as HIV-infected populations. Results Average p16INK4a concentration in cervical samples was 37.4 U/mL. After colposcopically directed biopsy, 127 (12%) women were determined to have CIN2+. Receiver operating characteristic analysis showed an area under the curve of 0.664 for p16INK4a to detect biopsy-proven CIN2+. At a p16INK4a cut-off level of 9 U/mL, sensitivity, specificity, positive and negative predictive values were 89.0%, 22.9%, 13.6% and 93.8%, respectively. The overall p16INK4a positivity at a cut-off level of 9 U/mL was 828 (78.6%) women. There were 325 (30.8%) cases of correct p16INK4a prediction to detect or rule out CIN2+, and 729 (69.2%) cases of incorrect p16INK4a prediction. Conclusions p16INK4a ELISA did not perform well as a screening test for CIN2+ detection among HIV-infected women due to low

  7. Mössbauer study of conductive oxide glass

    SciTech Connect

    Matsuda, Koken; Kubuki, Shiro; Nishida, Tetsuaki

    2014-10-27

    Heat treatment of barium iron vanadate glass, BaO‐Fe{sub 2}O{sub 3}‐V{sub 2}O{sub 5}, at temperatures higher than crystallization temperature causes a marked decrease in resistivity (ρ) from several MΩcm to several Ωcm. {sup 57}Fe Mössbauer spectrum of heat-treated vanadate glass shows a marked decrease in quadrupole splitting (Δ) of Fe{sup III}, reflecting a structural relaxation, i.e., an increased symmetry of 'distorted' FeO{sub 4} and VO{sub 4} tetrahedra which are connected to each other by sharing corner oxygen atoms. Structural relaxation of 3D-network of vanadate glass accompanies a decrease in the activation energy for the conduction, reflecting a decreased energy gap between the donor level and conduction band. A marked increase in the conductivity was observed in CuO- or Cu{sub 2}O-containing barium iron vanadate glass after heat treatment at 450 °C for 30 min or more. 'n-type semiconductor model combined with small polaron hopping theory' was proposed in order to explain the high conductivity.

  8. Mössbauer study of conductive oxide glass

    NASA Astrophysics Data System (ADS)

    Matsuda, Koken; Kubuki, Shiro; Nishida, Tetsuaki

    2014-10-01

    Heat treatment of barium iron vanadate glass, BaO - Fe2O3- V2O5, at temperatures higher than crystallization temperature causes a marked decrease in resistivity (ρ) from several MΩcm to several Ωcm. 57Fe Mössbauer spectrum of heat-treated vanadate glass shows a marked decrease in quadrupole splitting (Δ) of FeIII, reflecting a structural relaxation, i.e., an increased symmetry of "distorted" FeO4 and VO4 tetrahedra which are connected to each other by sharing corner oxygen atoms. Structural relaxation of 3D-network of vanadate glass accompanies a decrease in the activation energy for the conduction, reflecting a decreased energy gap between the donor level and conduction band. A marked increase in the conductivity was observed in CuO- or Cu2O -containing barium iron vanadate glass after heat treatment at 450 °C for 30 min or more. "n-type semiconductor model combined with small polaron hopping theory" was proposed in order to explain the high conductivity.

  9. Study on Thermal Conductivities of Aromatic Polyimide Aerogels.

    PubMed

    Feng, Junzong; Wang, Xin; Jiang, Yonggang; Du, Dongxuan; Feng, Jian

    2016-05-25

    Polyimide aerogels for low density thermal insulation materials were produced by 4,4'-diaminodiphenyl ether and 3,3',4,4'-biphenyltetracarboxylic dianhydride, cross-linked with 1,3,5-triaminophenoxybenzene. The densities of obtained polyimide aerogels are between 0.081 and 0.141 g cm(-3), and the specific surface areas are between 288 and 322 m(2) g(-1). The thermal conductivities were measured by a Hot Disk thermal constant analyzer. The value of the measured thermal conductivity under carbon dioxide atmosphere is lower than that under nitrogen atmosphere. Under pressure of 5 Pa at -130 °C, the thermal conductivity is the lowest, which is 8.42 mW (m K)(-1). The polyimide aerogels have lower conductivity [30.80 mW (m K)(-1)], compared to the value for other organic foams (polyurethane foam, phenolic foam, and polystyrene foam) with similar apparent densities under ambient pressure at 25 °C. The results indicate that polyimide aerogel is an ideal insulation material for aerospace and other applications.

  10. Study on Thermal Conductivities of Aromatic Polyimide Aerogels.

    PubMed

    Feng, Junzong; Wang, Xin; Jiang, Yonggang; Du, Dongxuan; Feng, Jian

    2016-05-25

    Polyimide aerogels for low density thermal insulation materials were produced by 4,4'-diaminodiphenyl ether and 3,3',4,4'-biphenyltetracarboxylic dianhydride, cross-linked with 1,3,5-triaminophenoxybenzene. The densities of obtained polyimide aerogels are between 0.081 and 0.141 g cm(-3), and the specific surface areas are between 288 and 322 m(2) g(-1). The thermal conductivities were measured by a Hot Disk thermal constant analyzer. The value of the measured thermal conductivity under carbon dioxide atmosphere is lower than that under nitrogen atmosphere. Under pressure of 5 Pa at -130 °C, the thermal conductivity is the lowest, which is 8.42 mW (m K)(-1). The polyimide aerogels have lower conductivity [30.80 mW (m K)(-1)], compared to the value for other organic foams (polyurethane foam, phenolic foam, and polystyrene foam) with similar apparent densities under ambient pressure at 25 °C. The results indicate that polyimide aerogel is an ideal insulation material for aerospace and other applications. PMID:27149155

  11. Comparative study of ion conducting pathways in borate glasses

    SciTech Connect

    Hall, Andreas; Swenson, Jan; Adams, Stefan

    2006-11-01

    The conduction pathways in metal-halide doped silver, lithium, and sodium diborate glasses have been examined by bond valence analysis of reverse Monte Carlo (RMC) produced structural models of the glasses. Although all glass compositions have basically the same short-range structure of the boron-oxygen network, it is evident that the intermediate-range structure is strongly dependent on the type of mobile ion. The topography of the pathways and the coordination of the pathway sites differ distinctly between the three glass systems. The mobile silver ions in the AgI-doped glass tend to be mainly iodine-coordinated and travel in homogeneously distributed pathways located in salt-rich channels of the borate network. In the NaCl-doped glass, there is an inhomogeneous spatial distribution of pathways that reflects the inhomogeneous introduction of salt ions into the glass. However, since the salt clusters are not connected, no long-range conduction pathways are formed without including also oxygen-rich regions. The pathways in the LiCl-doped glass are slightly more evenly distributed compared to the NaCl-doped glass (but not as ordered as in the AgI-doped glass), and the regions of mainly oxygen-coordinated pathway sites are of higher importance for the long-range migration. In order to more accurately investigate how these differences in the intermediate-range order of the glasses affect the ionic conductivity, we have compared the realistic structure models to more or less randomized structures. An important conclusion from this comparison is that we find no evidence that a pronounced intermediate-range order in the atomic structure or in the network of conduction pathways, as in the AgI-doped glass, is beneficial for the dc conductivity.

  12. Smoking Patterns, Attitudes and Motives: Unique Characteristics among 2-Year versus 4-Year College Students

    ERIC Educational Resources Information Center

    Berg, C. J.; An, L. C.; Thomas, J. L.; Lust, K. A.; Sanem, J. R.; Swan, D. W.; Ahluwalia, J. S.

    2011-01-01

    Given the previously documented higher rates of smoking among 2-year college students in comparison with 4-year university students, this study compares smoking patterns, attitudes and motives among 2-year and 4-year college students. Two thousand two hundred and sixty-five undergraduate students aged 18-25 years at a 2-year college and a 4-year…

  13. Spectroscopic ellipsometry study of novel nanostructured transparent conducting oxide structures

    NASA Astrophysics Data System (ADS)

    Khosroabadi, Akram A.; Norwood, R. A.

    2013-02-01

    Spectroscopic ellipsometry has been used to find the optical constants, including refractive index, extinction coefficient, thickness and volume fraction of nanostructured transparent conducting oxides including indium tin oxide (ITO) and indium zinc oxide (IZO). We observed sharp features in the ellipsometry data, with the spectral peaks and positions depending on the nanostructure dimensions and material. A superposition of Lorentzian oscillators and the effective medium approximation has been applied to determine the volume ratio of voids and nanopillars, thereby providing the effective optical constants.

  14. Conducting Online Expert panels: a feasibility and experimental replicability study

    PubMed Central

    2011-01-01

    Background This paper has two goals. First, we explore the feasibility of conducting online expert panels to facilitate consensus finding among a large number of geographically distributed stakeholders. Second, we test the replicability of panel findings across four panels of different size. Method We engaged 119 panelists in an iterative process to identify definitional features of Continuous Quality Improvement (CQI). We conducted four parallel online panels of different size through three one-week phases by using the RAND's ExpertLens process. In Phase I, participants rated potentially definitional CQI features. In Phase II, they discussed rating results online, using asynchronous, anonymous discussion boards. In Phase III, panelists re-rated Phase I features and reported on their experiences as participants. Results 66% of invited experts participated in all three phases. 62% of Phase I participants contributed to Phase II discussions and 87% of them completed Phase III. Panel disagreement, measured by the mean absolute deviation from the median (MAD-M), decreased after group feedback and discussion in 36 out of 43 judgments about CQI features. Agreement between the four panels after Phase III was fair (four-way kappa = 0.36); they agreed on the status of five out of eleven CQI features. Results of the post-completion survey suggest that participants were generally satisfied with the online process. Compared to participants in smaller panels, those in larger panels were more likely to agree that they had debated each others' view points. Conclusion It is feasible to conduct online expert panels intended to facilitate consensus finding among geographically distributed participants. The online approach may be practical for engaging large and diverse groups of stakeholders around a range of health services research topics and can help conduct multiple parallel panels to test for the reproducibility of panel conclusions. PMID:22196011

  15. A study of electron beam-induced conductivity in resists.

    PubMed

    Hwu, J J; Joy, D C

    1999-01-01

    The charging of polymeric resist materials during electron beam irradiation leads to significant problems during imaging and lithography processes. Charging occurs because of charge deposition in the polymer and charge generation/trapping due to formation of electron-hole pairs in the dielectric. The presence of such charge also results in the phenomena of electron beam-induced conductivity (EBIC). Electron beam-induced conductivity data have been obtained for three commercial e-beam resists under a variety of dose rate and temperature conditions. From the observed values of induced conductivity under varying conditions significant information about the generation of electron-hole pair and the transport of charge in the resist can be obtained. Three electron beam resists, EBR900, ZEP7000, and PBS are examined by an external bias method. The difference in resist chemistry is considered to play the role in the initial state EBIC behaviors among three resists even though the way that it affects the behaviors is not clear. A comparison of the power consumption comparison is proposed as a measure to give a preliminary estimate of the carrier concentration and carrier drift velocity differences among the resists. A simple single trap model with constant activation energy is proposed and provides good agreement with experiment.

  16. Nuclear Spin Lattice Relaxation and Conductivity Studies of the Non-Arrhenius Conductivity Behavior in Lithium Fast Ion Conducting Sulfide Glasses

    SciTech Connect

    Benjamin Michael Meyer

    2003-05-31

    As time progresses, the world is using up more of the planet's natural resources. Without technological advances, the day will eventually arrive when these natural resources will no longer be sufficient to supply all of the energy needs. As a result, society is seeing a push for the development of alternative fuel sources such as wind power, solar power, fuel cells, and etc. These pursuits are even occurring in the state of Iowa with increasing social pressure to incorporate larger percentages of ethanol in gasoline. Consumers are increasingly demanding that energy sources be more powerful, more durable, and, ultimately, more cost efficient. Fast Ionic Conducting (FIC) glasses are a material that offers great potential for the development of new batteries and/or fuel cells to help inspire the energy density of battery power supplies. This dissertation probes the mechanisms by which ions conduct in these glasses. A variety of different experimental techniques give a better understanding of the interesting materials science taking place within these systems. This dissertation discusses Nuclear Magnetic Resonance (NMR) techniques performed on FIC glasses over the past few years. These NMR results have been complimented with other measurement techniques, primarily impedance spectroscopy, to develop models that describe the mechanisms by which ionic conduction takes place and the dependence of the ion dynamics on the local structure of the glass. The aim of these measurements was to probe the cause of a non-Arrhenius behavior of the conductivity which has been seen at high temperatures in the silver thio-borosilicate glasses. One aspect that will be addressed is if this behavior is unique to silver containing fast ion conducting glasses. more specifically, this study will determine if a non-Arrhenius correlation time, {tau}, can be observed in the Nuclear Spin Lattice Relaxation (NSLR) measurements. If so, then can this behavior be modeled with a new single distribution

  17. Single molecule study of DNA conductivity in aqueous environment.

    PubMed

    Legrand, O; Côte, D; Bockelmann, U

    2006-03-01

    The dc electrical conductivity of double stranded DNA is investigated experimentally. Single DNA molecules are manipulated with subpiconewton force and deposited on gold nanoelectrodes by optical traps. The DNA is modified at its ends for specific bead attachments and along the chain to favor charge transfer between the DNA base pair stack and the electrodes. For an electrode separation of 70 nm we find, in aqueous environment, electrical resistances above 100 G Omega indicating that even for weak stretching the double helix is almost insulating at this length scale.

  18. Single molecule study of DNA conductivity in aqueous environment

    NASA Astrophysics Data System (ADS)

    Legrand, O.; Côte, D.; Bockelmann, U.

    2006-03-01

    The dc electrical conductivity of double stranded DNA is investigated experimentally. Single DNA molecules are manipulated with subpiconewton force and deposited on gold nanoelectrodes by optical traps. The DNA is modified at its ends for specific bead attachments and along the chain to favor charge transfer between the DNA base pair stack and the electrodes. For an electrode separation of 70nm we find, in aqueous environment, electrical resistances above 100GΩ indicating that even for weak stretching the double helix is almost insulating at this length scale.

  19. Structural and AC conductivity study of CdTe nanomaterials

    NASA Astrophysics Data System (ADS)

    Das, Sayantani; Banerjee, Sourish; Sinha, T. P.

    2016-04-01

    Cadmium telluride (CdTe) nanomaterials have been synthesized by soft chemical route using mercapto ethanol as a capping agent. Crystallization temperature of the sample is investigated using differential scanning calorimeter. X-ray diffraction and transmission electron microscope measurements show that the prepared sample belongs to cubic structure with the average particle size of 20 nm. Impedance spectroscopy is applied to investigate the dielectric relaxation of the sample in a temperature range from 313 to 593 K and in a frequency range from 42 Hz to 1.1 MHz. The complex impedance plane plot has been analyzed by an equivalent circuit consisting of two serially connected R-CPE units, each containing a resistance (R) and a constant phase element (CPE). Dielectric relaxation peaks are observed in the imaginary parts of the spectra. The frequency dependence of real and imaginary parts of dielectric permittivity is analyzed using modified Cole-Cole equation. The temperature dependence relaxation time is found to obey the Arrhenius law having activation energy ~0.704 eV. The frequency dependent conductivity spectra are found to follow the power law. The frequency dependence ac conductivity is analyzed by power law.

  20. Conducting systematic reviews of diagnostic studies: didactic guidelines

    PubMed Central

    Devillé, Walter L; Buntinx, Frank; Bouter, Lex M; Montori, Victor M; de Vet, Henrica CW; van der Windt, Danielle AWM; Bezemer, P Dick

    2002-01-01

    Background Although guidelines for critical appraisal of diagnostic research and meta-analyses have already been published, these may be difficult to understand for clinical researchers or do not provide enough detailed information. Methods Development of guidelines based on a systematic review of the evidence in reports of systematic searches of the literature for diagnostic research, of methodological criteria to evaluate diagnostic research, of methods for statistical pooling of data on diagnostic accuracy, and of methods for exploring heterogeneity. Results Guidelines for conducting diagnostic systematic reviews are presented in a stepwise fashion and are followed by comments providing further information. Examples are given using the results of two systematic reviews on the accuracy of the urine dipstick in the diagnosis of urinary tract infections, and on the accuracy of the straight-leg-raising test in the diagnosis of intervertebral disc hernia. PMID:12097142

  1. The Study of Diagnostic Efficacy of Nerve Conduction Study Parameters in Cervical Radiculopathy

    PubMed Central

    Pawar, Sachin; Kashikar, Aditi; Shende, Vinod; Waghmare, Satish

    2013-01-01

    Background: Cervical Radiculopathy (CR) is a neurologic condition characterised by dysfunction of a cervical spinal nerve, the roots of the nerve, or both. Diagnostic criteria for CR are not well defined, and no universally accepted criteria for its diagnosis have been established. Clinical examination, radiological imaging and electrophysiologic evaluation are the different modalities to diagnose CR. The incidence of Cervical Spondylosis and related conditions is increasing in the present scenario and the use of radiologic examination is time consuming and uneconomical for the common Indian setup. Thus, there is a definite need to establish a cost effective, reliable, and accurate means for establishing the diagnosis of cervical radiculopathy. Electrodiagnostic tests are the closest to fulfill these criteria. Aim: To evaluate diagnostic utility of various motor and sensory nerve conduction study parameters in cervical radiculopathy. Setting and Design: It was a cross-sectional study conducted on 100 subjects of age > 40 years. Material and Methods: The consecutive patients clinically diagnosed to have cervical radiculopathy, referred from department of Orthopaedics were prospectively recruited for the motor and sensory nerve conduction study using RMS EMG EP Mark-II. Parameters studied were Compound Muscle Action Potential (CMAP), Distal Motor Latency (DML) and Conduction Velocity (CV) for motor nerves and Sensory Nerve Action Potential (SNAP) and CV for sensory nerves. Statistical Analysis: Study observations and results were analysed to find the Specificity, Sensitivity, Positive Predictive Value and Negative Predictive Value using SPSS 16.0. Results: Among various motor nerve conduction parameters CMAP was found to be more sensitive with high positive predicative value. CV was found to have greater specificity and DML had least negative predictive value. Sensory nerve conduction parameters were found to have less sensitivity but higher specificity as compared

  2. Mechanistic study of silver nanoparticle formation on conducting polymer surfaces.

    PubMed

    Mack, Nathan H; Bailey, James A; Doorn, Stephen K; Chen, Chien-An; Gau, Han-Mou; Xu, Ping; Williams, Darrick J; Akhadov, Elshan A; Wang, Hsing-Lin

    2011-04-19

    Conducting polymer (polyaniline) sheets are shown to be active substrates to promote the growth of nanostructured silver thin films with highly tunable morphologies. Using the spontaneous electroless deposition of silver, we show that a range of nanostructured metallic features can be controllably and reproducibly formed over large surface areas. The structural morphology of the resulting metal-polymer nanocomposite is demonstrated to be sensitive to experimental parameters such as ion concentration, temperature, and polymer processing and can range from densely packed oblate nanosheets to bulk crystalline metals. The deposition mechanisms are explained using a diffusion-limited aggregation (DLA) model to describe the semi-fractal-like growth of the metal nanostructures. We find these composite films to exhibit strong surface-enhanced Raman (SERS) activity, and the nanostructured features are optimized with respect to SERS activity using a self-assembled monolayer of mercapto-benzoic acid as a model Raman reporter. SERS enhancements are estimated to be on the order of 10(7). Through micro-Raman SERS mapping, these materials are shown to exhibit uniform SERS responses over macroscopic areas. These metal-polymer nanocomposites benefit from the underlying polymer's processability to yield SERS-active materials of almost limitless shape and size and show significant promise for future SERS-based sensing and detection schemes. PMID:21434643

  3. Study of electrical resistivity and thermal conductivity into neutral plasma

    SciTech Connect

    Nath, G. Rout, R. K.

    2015-07-31

    The major portion of the bulk plasma in magnetospheric space, interplanetary plasma belts and the solar winds contain neutral particles. Evidently these neutral particles undergo binary collisions with the charged particles and among themselves so as to contribute significantly to the transport and diffusion process in a singly charged electron – ion magnetoplasma. The effects of the neutral particles collisions on various diffusion transport coefficients are studied for magnetised electron-ion plasma and appropriately modified coefficients are derived analytically. The results reveal that these coefficients increase significantly owing to the effect of the charge -neutral and neutral-neutral collisions.

  4. Multicollinearity in Regression Analyses Conducted in Epidemiologic Studies

    PubMed Central

    Vatcheva, Kristina P.; Lee, MinJae; McCormick, Joseph B.; Rahbar, Mohammad H.

    2016-01-01

    The adverse impact of ignoring multicollinearity on findings and data interpretation in regression analysis is very well documented in the statistical literature. The failure to identify and report multicollinearity could result in misleading interpretations of the results. A review of epidemiological literature in PubMed from January 2004 to December 2013, illustrated the need for a greater attention to identifying and minimizing the effect of multicollinearity in analysis of data from epidemiologic studies. We used simulated datasets and real life data from the Cameron County Hispanic Cohort to demonstrate the adverse effects of multicollinearity in the regression analysis and encourage researchers to consider the diagnostic for multicollinearity as one of the steps in regression analysis. PMID:27274911

  5. Probabilistic Study Conducted on Sensor-Based Engine Life Calculation

    NASA Technical Reports Server (NTRS)

    Guo, Ten-Huei

    2004-01-01

    Turbine engine life management is a very complicated process to ensure the safe operation of an engine subjected to complex usage. The challenge of life management is to find a reasonable compromise between the safe operation and the maximum usage of critical parts to reduce maintenance costs. The commonly used "cycle count" approach does not take the engine operation conditions into account, and it oversimplifies the calculation of the life usage. Because of the shortcomings, many engine components are regularly pulled for maintenance before their usable life is over. And, if an engine has been running regularly under more severe conditions, components might not be taken out of service before they exceed their designed risk of failure. The NASA Glenn Research Center and its industrial and academic partners have been using measurable parameters to improve engine life estimation. This study was based on the Monte Carlo simulation of 5000 typical flights under various operating conditions. First a closed-loop engine model was developed to simulate the engine operation across the mission profile and a thermomechanical fatigue (TMF) damage model was used to calculate the actual damage during takeoff, where the maximum TMF accumulates. Next, a Weibull distribution was used to estimate the implied probability of failure for a given accumulated cycle count. Monte Carlo simulations were then employed to find the profiles of the TMF damage under different operating assumptions including parameter uncertainties. Finally, probabilities of failure for different operating conditions were analyzed to demonstrate the importance of a sensor-based damage calculation in order to better manage the risk of failure and on-wing life.

  6. Parametric Study Conducted of Rocket- Based, Combined-Cycle Nozzles

    NASA Technical Reports Server (NTRS)

    Steffen, Christopher J., Jr.; Smith, Timothy D.

    1998-01-01

    Having reached the end of the 20th century, our society is quite familiar with the many benefits of recycling and reusing the products of civilization. The high-technology world of aerospace vehicle design is no exception. Because of the many potential economic benefits of reusable launch vehicles, NASA is aggressively pursuing this technology on several fronts. One of the most promising technologies receiving renewed attention is Rocket-Based, Combined-Cycle (RBCC) propulsion. This propulsion method combines many of the efficiencies of high-performance jet aircraft with the power and high-altitude capability of rocket engines. The goal of the present work at the NASA Lewis Research Center is to further understand the complex fluid physics within RBCC engines that govern system performance. This work is being performed in support of NASA's Advanced Reusable Technologies program. A robust RBCC engine design optimization demands further investigation of the subsystem performance of the engine's complex propulsion cycles. The RBCC propulsion system under consideration at Lewis is defined by four modes of operation in a singlestage- to-orbit configuration. In the first mode, the engine functions as a rocket-driven ejector. When the rocket engine is switched off, subsonic combustion (mode 2) is present in the ramjet mode. As the vehicle continues to accelerate, supersonic combustion (mode 3) occurs in the ramjet mode. Finally, as the edge of the atmosphere is approached and the engine inlet is closed off, the rocket is reignited and the final accent to orbit is undertaken in an all-rocket mode (mode 4). The performance of this fourth and final mode is the subject of this present study. Performance is being monitored in terms of the amount of thrust generated from a given amount of propellant.

  7. Prevalence and Antifungal Susceptibility of 442 Candida Isolates from Blood and Other Normally Sterile Sites: Results of a 2-Year (1996 to 1998) Multicenter Surveillance Study in Quebec, Canada

    PubMed Central

    St-Germain, G.; Laverdière, M.; Pelletier, R.; Bourgault, A.-M.; Libman, M.; Lemieux, C.; Noël, G.

    2001-01-01

    During a 2-year surveillance program (1996 to 1998) in Quebec, Canada, 442 strains of Candida species were isolated from 415 patients in 51 hospitals. The distribution of species was as follows: Candida albicans, 54%; C. glabrata, 15%; C. parapsilosis, 12%; C. tropicalis, 9%; C. lusitaniae, 3%; C. krusei, 3%; and Candida spp., 3%. These data, compared to those of a 1985 survey, indicate variations in species distribution, with the proportions of C. glabrata and C. parapsilosis increasing by 9 and 4%, respectively, and those of C. albicans and C. tropicalis decreasing by 10 and 7%, respectively. However, these differences are statistically significant for C. glabrata and C. tropicalis only. MICs of amphotericin B were ≥4 μg/ml for 3% of isolates, all of which were non-C. albicans species. Three percent of C. albicans isolates were resistant to flucytosine (≥32 μg/ml). Resistance to itraconazole (≥1 μg/ml) and fluconazole (≥64 μg/ml) was observed, respectively, in 1 and 1% of C. albicans, 14 and 9% of C. glabrata, 5 and 0% of C. tropicalis, and 0% of C. parapsilosis and C. lusitaniae isolates. Clinical data were obtained for 343 patients. The overall crude mortality rate was 38%, reflecting the multiple serious underlying illnesses found in these patients. Bloodstream infections were documented for 249 patients (73%). Overall, systemic triazoles had been administered to 10% of patients before the onset of candidiasis. The frequency of isolation of non-C. albicans species was significantly higher in this group of patients. Overall, only two C. albicans isolates were found to be resistant to fluconazole. These were obtained from an AIDS patient and a leukemia patient, both of whom had a history of previous exposure to fluconazole. At present, it appears that resistance to fluconazole in Quebec is rare and is restricted to patients with prior prolonged azole treatment. PMID:11230409

  8. The association of maternal vitamin D status with infant birth outcomes, postnatal growth and adiposity in the first 2 years of life in a multi-ethnic Asian population: the Growing Up in Singapore Towards healthy Outcomes (GUSTO) cohort study.

    PubMed

    Ong, Yi Lin; Quah, Phaik Ling; Tint, Mya Thway; Aris, Izzuddin M; Chen, Ling Wei; van Dam, Rob M; Heppe, Denise; Saw, Seang-Mei; Godfrey, Keith M; Gluckman, Peter D; Chong, Yap Seng; Yap, Fabian; Lee, Yung Seng; Foong-Fong Chong, Mary

    2016-08-01

    Maternal vitamin D status during pregnancy has been associated with infant birth and postnatal growth outcomes, but reported findings have been inconsistent, especially in relation to postnatal growth and adiposity outcomes. In a mother-offspring cohort in Singapore, maternal plasma vitamin D was measured between 26 and 28 weeks of gestation, and anthropometric measurements were obtained from singleton offspring during the first 2 years of life with 3-month follow-up intervals to examine birth, growth and adiposity outcomes. Associations were analysed using multivariable linear regression. Of a total of 910 mothers, 13·2 % were vitamin D deficient (<50 nmol/l) and 26·5 % were insufficient (50-75 nmol/l). After adjustment for potential confounders and multiple testing, no statistically significant associations were observed between maternal vitamin D status and any of the birth outcomes - small for gestational age (OR 1·00; 95 % CI 0·56, 1·79) and pre-term birth (OR 1·16; 95 % CI 0·64, 2·11) - growth outcomes - weight-for-age z-scores, length-for-age z-scores, circumferences of the head, abdomen and mid-arm at birth or postnatally - and adiposity outcomes - BMI, and skinfold thickness (triceps, biceps and subscapular) at birth or postnatally. Maternal vitamin D status in pregnancy did not influence infant birth outcomes, postnatal growth and adiposity outcomes in this cohort, perhaps due to the low prevalence (1·6 % of the cohort) of severe maternal vitamin D deficiency (defined as of <30·0 nmol/l) in our population. PMID:27339329

  9. HIV-Exposed Uninfected Infants Show Robust Memory B-Cell Responses in Spite of a Delayed Accumulation of Memory B Cells: an Observational Study in the First 2 Years of Life

    PubMed Central

    Nkumama, Irene N.; Gambo, Faith K.; Muema, Daniel M.; Hassan, Amin S.; Jahangir, Margaret N.; Etyang, Timothy J.; Berkley, James A.; Urban, Britta C.

    2016-01-01

    Improved HIV care has led to an increase in the number of HIV-exposed uninfected (HEU) infants born to HIV-infected women. Although they are uninfected, these infants experience increased morbidity and mortality. One explanation may be that their developing immune system is altered by HIV exposure, predisposing them to increased postnatal infections. We explored the impact of HIV exposure on the B-cell compartment by determining the B-cell subset distribution, the frequency of common vaccine antigen-specific memory B cells (MBCs), and the levels of antibodies to the respective antigens in HEU and HIV-unexposed uninfected (HUU) infants born to uninfected mothers, using flow cytometry, a B-cell enzyme-linked immunosorbent spot assay, and an enzyme-linked immunosorbent assay, respectively, during the first 2 years of life. For the majority of the B-cell subsets, there were no differences between HEU and HUU infants. However, HIV exposure was associated with a lower proportion of B cells in general and MBCs in particular, largely due to a lower proportion of unswitched memory B cells. This reduction was maintained even after correcting for age. These phenotypic differences in the MBC compartment did not affect the ability of HEU infants to generate recall responses to previously encountered antigens or reduce the antigen-specific antibody levels at 18 months of life. Although HIV exposure was associated with a transient reduction in the proportion of MBCs, we found that the ability of HEU infants to mount robust MBC and serological responses was unaffected. PMID:27170641

  10. Design and Conduct of the CALERIE Study: Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy

    PubMed Central

    Bales, Connie W.; Ravussin, Eric; Redman, Leanne M.; Holloszy, John O.; Racette, Susan B.; Roberts, Susan B.; Das, Sai Krupa; Romashkan, Sergei; Galan, Katherine M.; Hadley, Evan C.; Kraus, William E.

    2011-01-01

    Background. In a robust and consistent manner, sustained caloric restriction (CR) has been shown to retard the aging process in a variety of animal species. Nonhuman primate studies suggest that CR may have similar effects in longer-lived species. The CALERIE (Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy) research program is the first systematic investigation of CR in nonobese human beings. In the phase 2 study, it is hypothesized that 2 years of sustained CR, involving a 25% reduction of ad libitum energy intake, results in beneficial effects similar to those observed in animal studies. This article presents the design and implementation of this study. Methods. The study is a multicenter, parallel-group, randomized controlled trial. A sample of 225 participants (22.0 ≤ body mass index [BMI] < 28.0 kg/m2) is being enrolled with 2:1 allocation to CR. Results. An intensive dietary and behavioral intervention was developed to achieve 25% CR and sustain it over the 2 years. Adherence is monitored using a doubly labeled water technique. Primary outcomes are resting metabolic rate and core temperature, and are assessed at baseline and at 6-month intervals. Secondary outcomes address oxyradical formation, cardiovascular risk markers, insulin sensitivity and secretion, immune function, neuroendocrine function, quality of life and cognitive function. Biologic materials are stored in a central repository. Conclusions. An intricate protocol has been developed to conduct this study. Procedures have been implemented to safeguard the integrity of the data and the conclusions drawn. The results will provide insight into the detrimental changes associated with the human aging process and how CR mitigates these effects. PMID:20923909

  11. Clinical outcomes of pars plicata anterior vitrectomy: 2-year results

    PubMed Central

    Narang, Priya; Agarwal, Amar

    2015-01-01

    Purpose: To demonstrate the safety and outcome of a surgical approach that uses pars plicata site for anterior vitrectomy during phacoemulsification procedure complicated by posterior capsule rupture and residual cortical matter. Design: Single center, retrospective, interventional, noncomparative study. Materials and Methods: Medical records of a consecutive series of 35 eyes of 35 patients who underwent pars plicata anterior vitrectomy (PPAV) were reviewed. The main outcome measures were corrected and uncorrected distance visual acuity (CDVA, UDVA), early and late postoperative complications and intraocular pressure (IOP). Ultrasound biomicroscopic (UBM) evaluation of sclerotomy site and spectral domain optical coherence tomography analysis for central macular thickness (CMT) was performed. The final visual outcome at 2 years was evaluated. Results: At 2 years follow-up, the mean postoperative UDVA (logarithm of the minimum angle of resolution [logMAR]) and CDVA (logMAR) was 0.49 ± 0.26 and 0.19 ± 0.14, respectively. There was no significant change in the IOP (P = 0.061) and the mean CMT at 2 years was 192.5 ± 5.54 μm. The postoperative UBM image of the sclerotomy site at 8 weeks demonstrated a clear wound without any vitreous adhesion or incarceration. Intraoperative hyphema was seen in 1 (2.8%) case and postoperative uveitis was seen in 2 (5.7%) cases, which resolved with medications. No case of an iatrogenic retinal break or retinal detachment was reported. Conclusions: PPAV enables a closed chamber approach, allows thorough cleanup of vitreous in the pupillary plane and anterior chamber and affords better access to the subincisional and retropupillary cortical remnant with a significant visual outcome and an acceptable complication rate. PMID:26632124

  12. B-type natriuretic peptide and high sensitive C-reactive protein predict 2-year all cause mortality in chest pain patients: a prospective observational study from Salta, Argentina

    PubMed Central

    2011-01-01

    Background Several mechanisms are involved in the pathophysiology of the Acute Coronary Syndrome (ACS). We have addressed whether B-type natriuretic peptide (BNP) and high-sensitive C-reactive protein (hsCRP) in admission samples may improve risk stratification in chest pain patients with suspected ACS. Methods We included 982 patients consecutively admitted with chest pain and suspected ACS at nine hospitals in Salta, Northern Argentina. Total and cardiac mortality were recorded during a 2-year follow up period. Patients were divided into quartiles according to BNP and hsCRP levels, respectively, and inter quartile differences in mortality were statistically evaluated applying univariate and multivariate analyses. Results 119 patients died, and the BNP and hsCRP levels were significantly higher among these patients than in survivors. In a multivariable Cox regression model for total death and cardiac death in all patients, the hazard ratio (HR) in the highest quartile (Q4) as compared to the lowest quartile (Q1) of BNP was 2.32 (95% confidence interval (CI), 1.24-4.35), p = 0.009 and 3.34 (95% CI, 1.26-8.85), p = 0.015, respectively. In the TnT positive patients (TnT > 0.01 ng/mL), the HR for total death and cardiac death in Q4 as compared to Q1 was 2.12 (95% CI, 1.07-4.18), p = 0.031 and 3.42 (95% CI, 1.13-10.32), p = 0.029, respectively. The HR for total death for hsCRP in Q4 as compared to Q1 was 1.97 (95% CI, 1.17-3.32), p = 0.011, but this biomarker did not predict cardiac death (p = 0.21). No prognostic impact of these two biomarkers was found in the TnT negative patients. Conclusion BNP and hsCRP may act as clinically useful biomarkers when obtained at admission in a population with suspected ACS. Trial Registration ClinicalTrials.gov Identifier: NCT01377402. PMID:21958326

  13. Infantile Amnesia across the Years: A 2-Year Follow-Up of Children's Earliest Memories

    ERIC Educational Resources Information Center

    Peterson, Carole; Warren, Kelly L.; Short, Megan M.

    2011-01-01

    Although infantile amnesia has been investigated for many years in adults, only recently has it been investigated in children. This study was a 2-year follow-up and extension of an earlier study. Children (4-13 years old) were asked initially and 2 years later for their earliest 3 memories. At follow-up, their age at the time of these memories…

  14. Clinical neuroprediction: Amygdala reactivity predicts depressive symptoms 2 years later.

    PubMed

    Mattson, Whitney I; Hyde, Luke W; Shaw, Daniel S; Forbes, Erika E; Monk, Christopher S

    2016-06-01

    Depression is linked to increased amygdala activation to neutral and negatively valenced facial expressions. Amygdala activation may be predictive of changes in depressive symptoms over time. However, most studies in this area have focused on small, predominantly female and homogenous clinical samples. Studies are needed to examine how amygdala reactivity relates to the course of depressive symptoms dimensionally, prospectively and in populations diverse in gender, race and socioeconomic status. A total of 156 men from predominately low-income backgrounds completed an fMRI task where they viewed emotional facial expressions. Left and right amygdala reactivity to neutral, but not angry or fearful, facial expressions relative to a non-face baseline at age 20 predicted greater depressive symptoms 2 years later, controlling for age 20 depressive symptoms. Heightened bilateral amygdala reactivity to neutral facial expressions predicted increases in depressive symptoms 2 years later in a large community sample. Neutral facial expressions are affectively ambiguous and a tendency to interpret these stimuli negatively may reflect to cognitive biases that lead to increases in depressive symptoms over time. Individual differences in amygdala reactivity to neutral facial expressions appear to identify those at most risk for a more problematic course of depressive symptoms across time. PMID:26865423

  15. A Collection of Studies Conducted in Education about "Global Warming" Problem

    ERIC Educational Resources Information Center

    Bozdogan, Aykut Emre

    2011-01-01

    The studies global warming problem conducted in education discipline in the world and in Turkey were analysed for this study. The literature was reviewed extensively especially through the articles in the indexed journals of Ebsco Host, Science Direct, Taylor and Francis and Web of Science databases and this study was conducted according to the…

  16. 41 CFR 101-5.104-6 - Conduct of feasibility studies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... studies. 101-5.104-6 Section 101-5.104-6 Public Contracts and Property Management Federal Property... FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-6 Conduct of feasibility studies. An initial... and detailed procedures to be followed in the conduct of each feasibility study. Arrangements will...

  17. 41 CFR 101-5.104-6 - Conduct of feasibility studies.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... studies. 101-5.104-6 Section 101-5.104-6 Public Contracts and Property Management Federal Property... FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-6 Conduct of feasibility studies. An initial... and detailed procedures to be followed in the conduct of each feasibility study. Arrangements will...

  18. 41 CFR 101-5.104-6 - Conduct of feasibility studies.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... studies. 101-5.104-6 Section 101-5.104-6 Public Contracts and Property Management Federal Property... FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-6 Conduct of feasibility studies. An initial... and detailed procedures to be followed in the conduct of each feasibility study. Arrangements will...

  19. 41 CFR 101-5.104-6 - Conduct of feasibility studies.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... studies. 101-5.104-6 Section 101-5.104-6 Public Contracts and Property Management Federal Property... FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-6 Conduct of feasibility studies. An initial... and detailed procedures to be followed in the conduct of each feasibility study. Arrangements will...

  20. 41 CFR 101-5.104-6 - Conduct of feasibility studies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... studies. 101-5.104-6 Section 101-5.104-6 Public Contracts and Property Management Federal Property... FEDERAL BUILDINGS AND COMPLEXES 5.1-General § 101-5.104-6 Conduct of feasibility studies. An initial... and detailed procedures to be followed in the conduct of each feasibility study. Arrangements will...

  1. A study of the influence of conductive paths and their directions in randomly generated conductor network.

    NASA Astrophysics Data System (ADS)

    Mandolesi, E.; Moorkamp, M.; Jones, A. G.

    2014-12-01

    Most electromagnetic (EM) geophysical methods focus on the electrical conductivity of rocks and sediments to determine the geological structure of the subsurface. Electric conductivity itself is measured in the laboratory with a wide range of instruments and techniques. These measurements seldom return a compatible result. The presence of partially-interconnected random pathways of electrically conductive materials in resistive hosts has been studied for decades, and recently with increasing interest. To comprehend which conductive mechanism scales from the microstructures up to field electrical conductivity measurements, two main branch of studies have been undertaken: statistical probability of having a conductive pathways and mixing laws. Several numerical approaches have been tested to understand the effects of interconnected pathways of conductors at field scale. Usually these studies were restricted in two ways: the sources are considered constant in time (i.e., DC) and the domain is, with few exception, two-dimensional. We simulated the effects of time-varying EM sources on the conductivity measured on the surface of a three-dimensional randomly generated body embedded in an uniform host by using electromagnetic induction equations. We modelled a two-phase mixture of resistive and conductive elements with the goal of comparing the conductivity measured on field scale with the one proper of the elements constituting the random rock, and to test how the internal structures influence the directionality of the responses. Moreover, we modelled data from randomly generated bodies characterized by coherent internal structures, to check the effect of the named structures on the anisotropy of the effective conductivity. We compared these values with the electrical conductivity limits predicted by Hashin-Shtrikman bounds and the effective conductivity predicted by the Archie's law, both cast in its classic form and in an updated that allow to take in account two

  2. Conductivity study and fourier transform infrared (FTIR) characterization of methyl cellulose solid polymer electrolyte with sodium iodide conducting ion

    SciTech Connect

    Abiddin, Jamal Farghali Bin Zainal; Ahmad, Azizah Hanom

    2015-08-28

    Sodium ion (Na{sup +}) based solid polymer electrolyte (SPE) has been prepared using solution cast technique with distilled water as solvent and Methylcellulose (MC) as a polymer host. Methylcellulose polymer was chosen as the polymer host due to the abundance of lone pair electrons in the carbonyl and C-O-C constituents, which in turn provide multiple hopping sites for the Na{sup +} conducting ions. Variable compositions of sodium iodide (NaI) salt were prepared to investigate the optimum MC-NaI weight ratio. Results from Electrical Impedance Spectroscopy (EIS) technique show that pure methylcellulose has a low conductivity of 3.61 × 10{sup −11} S/cm.The conductivity increases as NaI content increases up to optimum NaIcomposition of 40 wt%, which yields an average conductivity of 2.70 × 10{sup −5} S/cm.

  3. Conductivity study and fourier transform infrared (FTIR) characterization of methyl cellulose solid polymer electrolyte with sodium iodide conducting ion

    NASA Astrophysics Data System (ADS)

    Abiddin, Jamal Farghali Bin Zainal; Ahmad, Azizah Hanom

    2015-08-01

    Sodium ion (Na+) based solid polymer electrolyte (SPE) has been prepared using solution cast technique with distilled water as solvent and Methylcellulose (MC) as a polymer host. Methylcellulose polymer was chosen as the polymer host due to the abundance of lone pair electrons in the carbonyl and C-O-C constituents, which in turn provide multiple hopping sites for the Na+ conducting ions. Variable compositions of sodium iodide (NaI) salt were prepared to investigate the optimum MC-NaI weight ratio. Results from Electrical Impedance Spectroscopy (EIS) technique show that pure methylcellulose has a low conductivity of 3.61 × 10-11 S/cm.The conductivity increases as NaI content increases up to optimum NaIcomposition of 40 wt%, which yields an average conductivity of 2.70 × 10-5 S/cm.

  4. Occupational exposure to pesticides and nerve conduction studies among Korean farmers.

    PubMed

    Park, Su Kyeong; Kong, Kyoung Ae; Cha, Eun Shil; Lee, Young Joo; Lee, Gyu Taek; Lee, Won Jin

    2012-01-01

    This study aimed to determine whether occupational exposure to pesticides was associated with decreased nerve conduction studies among farmers. On 2 separate occasions, the authors performed a cross-sectional study of a group of 31 male farmers who periodically applied pesticides. The study included questionnaire interviews and nerve conduction studies on the median, ulnar, posterior tibial, peroneal, and sural nerves. Although all mean values remained within laboratory normal limits, significant differences between the first and second tests were found in sensory conduction velocities on the median and sural nerves, and motor conduction velocities on the posterior tibial nerve. Lifetime days of pesticide application was negatively associated with nerve conduction velocities at most nerves after adjusting for potential confounders. These findings may reflect a link between occupational pesticide exposure and peripheral neurophysiologic abnormality that deserves further evaluation.

  5. Medical Care and Your 1- to 2-Year-Old

    MedlinePlus

    ... Zika & Pregnancy Medical Care and Your 1- to 2-Year-Old KidsHealth > For Parents > Medical Care and Your 1- to 2-Year-Old Print A A A Text Size ... Following simple instructions? Saying a few words? Combining two words by age 2? The doctor may ask ...

  6. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: THERMAL DESORPTION - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and Liab...

  7. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: AEROBIC BIODEGRADATION REMEDY SCREENING

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (KU FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and L...

  8. [Systematization of the experiences of 2 years of work. Arimao Population Council].

    PubMed

    Martínez Pérez, M

    1998-01-01

    The community and social participation as an action has been part of the daily life every group and community. A descriptive and qualitative study of the 2-year period 1994-1996 was conducted to determine the hygienic, sanitary, socioeconomic, sports, cultural and health transformation occurred at the circumscription # 73 of the ABalcón Arimao@ People's Council, in La Lisa municipality, which is located in an insalubrious suburb with a high criminal rate, school dropout and unemployment, that is subjected to social actions. The method of Experience Systematization of Oscar Hara in 5 times was applied and included in the living process of this community in addition to life histories. The most important achievement was to gather all the social members of the community, with their mobilization capacity, under the leadership of the main conductors of the process through an innovative methodology starting from its context. Positive changes were observed in the life style and the health status of the population.

  9. Note: optimization of the numerical data analysis for conductivity percolation studies of drying moist porous systems.

    PubMed

    Moscicki, J K; Sokolowska, D; Kwiatkowski, L; Dziob, D; Nowak, J

    2014-02-01

    A simplified data analysis protocol, for dielectric spectroscopy use to study conductivity percolation in dehydrating granular media is discussed. To enhance visibility of the protonic conductivity contribution to the dielectric loss spectrum, detrimental effects of either low-frequency dielectric relaxation or electrode polarization are removed. Use of the directly measurable monofrequency dielectric loss factor rather than estimated DC conductivity to parameterize the percolation transition substantially reduces the analysis work and time.

  10. Note: Optimization of the numerical data analysis for conductivity percolation studies of drying moist porous systems

    SciTech Connect

    Moscicki, J. K.; Sokolowska, D.; Dziob, D.; Nowak, J.; Kwiatkowski, L.

    2014-02-15

    A simplified data analysis protocol, for dielectric spectroscopy use to study conductivity percolation in dehydrating granular media is discussed. To enhance visibility of the protonic conductivity contribution to the dielectric loss spectrum, detrimental effects of either low-frequency dielectric relaxation or electrode polarization are removed. Use of the directly measurable monofrequency dielectric loss factor rather than estimated DC conductivity to parameterize the percolation transition substantially reduces the analysis work and time.

  11. Conducting Real-Time Videofluoroscopic Swallow Study via Telepractice: A Preliminary Feasibility and Reliability Study.

    PubMed

    Burns, Clare L; Ward, Elizabeth C; Hill, Anne J; Phillips, Nick; Porter, Linda

    2016-06-01

    A small number of studies have examined the feasibility of conducting videofluoroscopic swallow studies (VFSS) via telepractice. While the results have confirmed this potential, the systems tested to date have either reported issues that impacted the ability to analyze/interpret the VFSS recordings in real time, or they were not designed to enable real-time interpretation. Further system design is needed to establish a telepractice model that enables the VFSS assessment to be both guided and interpreted live in real time. The aim of this study was to test the feasibility and reliability of using a telepractice system to enable live VFSS assessment. Twenty adult patients underwent a VFSS assessment directed by a telepractice SLP with competency in VFSS located in another room of the hospital. The telepractice clinician led the sessions using a C20 Cisco TelePresence System. This was linked in real time via a secure telehealth network (at 4 megabits per second (Mbit/s)) to a C60 Cisco TelePresence System located in a fluoroscopy suite, connected to the digital fluoroscopy system. Levels of agreement were calculated between the telepractice clinician and a face-to-face clinician who simultaneously rated the VFSS in real time. High levels of agreement for swallowing parameters (range = 75-100 %; k = -0.34 to 1.0) and management decisions (range = 70-100 %, k = 0.64-1.0) were found. A post-session questionnaire revealed clinicians agreed that the telepractice system enabled successful remote assessment of VFSS. The findings support the potential to conduct live VFSS assessment via a telepractice model. PMID:26979971

  12. Immunogenicity, Safety, and Tolerability of 13-Valent Pneumococcal Conjugate Vaccine Followed by 23-Valent Pneumococcal Polysaccharide Vaccine in Recipients of Allogeneic Hematopoietic Stem Cell Transplant Aged ≥2 Years: An Open-Label Study

    PubMed Central

    Cordonnier, Catherine; Ljungman, Per; Juergens, Christine; Maertens, Johan; Selleslag, Dominik; Sundaraiyer, Vani; Giardina, Peter C.; Clarke, Keri; Gruber, William C.; Scott, Daniel A.; Schmoele-Thoma, Beate

    2015-01-01

    Background. Life-threatening Streptococcus pneumoniae infections often occur after hematopoietic stem cell transplant (HSCT); vaccination is important for prevention. Methods. In an open-label study, patients (n = 251) 3–6 months after allogeneic HSCT received 3 doses of 13-valent pneumococcal conjugate vaccine (PCV13) at 1-month intervals, a fourth dose 6 months later, and 1 dose of 23-valent pneumococcal polysaccharide vaccine (PPSV23) 1 month later. Immunogenicity at prespecified time points and vaccine safety were assessed. Results. In the evaluable immunogenicity population (N = 216; mean age, 37.8 years), geometric mean fold rises (GMFRs) of immunoglobulin G geometric mean concentrations from baseline to postdose 3 showed significant increases in antibody levels across all PCV13 serotypes (GMFR range, 2.99–23.85; 95% confidence interval lower limit, >1); there were significant declines over the next 6 months, significant increases from predose 4 to postdose 4 (GMFR range, 3.00–6.97), and little change after PPSV23 (GMFR range, 0.86–1.12). Local and systemic reactions were more frequent after dose 4. Six patients experienced serious adverse events possibly related to PCV13 (facial diplegia, injection-site erythema and pyrexia, autoimmune hemolytic anemia, and suspected lack of vaccine efficacy after dose 3 leading to pneumococcal infection), PCV13 and PPSV23 (Guillain-Barré syndrome), or PPSV23 (cellulitis). There were 14 deaths, none related to study vaccines. Conclusions. A 3-dose PCV13 regimen followed by a booster dose may be required to protect against pneumococcal disease in HSCT recipients. Dose 4 was associated with increased local and systemic reactions, but the overall safety profile of a 4-dose regimen was considered acceptable. Clinical Trials Registration. NCT00980655. PMID:25870329

  13. "Conducting Is Everywhere!" A Case Study of the Development of Preservice Music Teacher Occupational Identity in a Beginning Conducting Course

    ERIC Educational Resources Information Center

    Johnson, Erik

    2014-01-01

    Research on pre-service music teacher occupational identity often highlights two competing identities: performer and teacher (L'Roy, 1983; Roberts, 1991; Pellegrino, 2009). Of the many factors that contribute to the occupational identity of the pre-service music teacher (Woodford, 2002), conducting has the potential to integrate performer and…

  14. Experimental study of critical exponents of electrical conductivity in a two-dimensional continuum percolation system

    PubMed

    Okazaki; Horibe; Maruyama; Miyazima

    2000-06-01

    In this paper an experimental study is presented for critical exponents of electrical conductivity in an inverse Swiss-cheese model. Filled circles are drawn on random positions of square paper in drawing ink with an X-Y plotter, and electrical resistance between both opposite sides is measured automatically by the use of general purpose interface bus system. Electrical conductivity is obtained from the inverse of the electrical resistance. Electrical conductivity in a bond process is also measured with the same system. It is confirmed that the critical exponent of electrical conductivity of a continuum two-dimensional inverse Swiss-cheese model is different from that of a discrete one.

  15. First-Year Students' Expectations of Conduct and Consequence: A Case Study

    ERIC Educational Resources Information Center

    Crance Gutmann, Gina-Lyn

    2008-01-01

    Research on first-year students' expectations about college has explored areas of academic and social expectations, but not first-year college students' expectations about judicial conduct and consequence. The purpose of this study was to empirically explore two questions: what are first year students' expectations about campus conduct and…

  16. A 2-year dose-response study of lesion sequences during hepatocellular carcinogenesis in the male B6C3F(1) mouse given the drinking water chemical dichloroacetic acid.

    PubMed Central

    Carter, Julia H; Carter, Harry W; Deddens, James A; Hurst, Bernadette M; George, Michael H; DeAngelo, Anthony B

    2003-01-01

    Dichloroacetic acid (DCA) is carcinogenic to the B6C3F(1) mouse and the F344 rat. Given the carcinogenic potential of DCA in rodent liver and the known concentrations of this compound in drinking water, reliable biologically based models to reduce the uncertainty of risk assessment for human exposure to DCA are needed. Development of such models requires identification and quantification of premalignant hepatic lesions, identification of the doses at which these lesions occur, and determination of the likelihood that these lesions will progress to cancer. In this study we determined the dose response of histopathologic changes occurring in the livers of mice exposed to DCA (0.05-3.5 g/L) for 26-100 weeks. Lesions were classified as foci of cellular alteration smaller than one liver lobule (altered hepatic foci; AHF), foci of cellular alteration larger than one liver lobule (large foci of cellular alteration; LFCA), adenomas (ADs), or carcinomas (CAs). Histopathologic analysis of 598 premalignant lesions revealed that (a)) each lesion class had a predominant phenotype; (b)) AHF, LFCA, and AD demonstrated neoplastic progression with time; and (c)) independent of DCA dose and length of exposure effects, some toxic/adaptive changes in non-involved liver were related to this neoplastic progression. A lesion sequence for carcinogenesis in male B6C3F(1) mouse liver has been proposed that will enable development of a biologically based mathematical model for DCA. Because all classes of premalignant lesions and CAs were found at both lower and higher doses, these data are consistent with the conclusion that nongenotoxic mechanisms, such as negative selection, are relevant to DCA carcinogenesis at lower doses where DCA genotoxicity has not been observed. PMID:12515679

  17. Latino Community-Based Participatory Research Studies: A Model for Conducting Bilingual Translations

    PubMed Central

    Sánchez-Johnsen, Lisa; Escamilla, Julia; Rodriguez, Erin M.; Vega, Susan; Bolaños, Liliana

    2015-01-01

    Many behavioral health materials have not been translated into Spanish. Of those that are available in Spanish, some of them have not been translated correctly, many are only appropriate for a subgroup of Latinos, and/or multiple versions of the same materials exist. This article describes an innovative model of conducting bilingual English–Spanish translations as part of community-based participatory research studies and provides recommendations based on this model. In this article, the traditional process of conducting bilingual translations is reviewed, and an innovative model for conducting translations in collaboration with community partners is described. Finally, recommendations for conducting future health research studies with community partners are provided. Researchers, health care providers, educators, and community partners will benefit from learning about this innovative model that helps produce materials that are more culturally appropriate than those that are produced with the most commonly used method of conducting translations. PMID:25741929

  18. Electrical conductivity studies on CuBr containing Al2O3 particles

    NASA Technical Reports Server (NTRS)

    Dubec, P. M.; Wagner, J. B., Jr.

    1984-01-01

    The conductivity of CuBr was studied and the role of a second phase, Al2O3, dispersed in CuBr was tested. CuBr melts at 493 C and exhibits three phases in the solid state. CuBr is a good ionic conductor with a transport number for copper ions of virtually unity with weighed proportions of the appropriate chemicals used. The CuBr materials were heated above melting point of CuBr, and the samples were sandwiched between copper electrodes. The ac conductivity, was determined at 1 kHz between 25 and 440 C depending on the sample. It was shown that at low temperatures, the conductivity for CuBr (Al2O3) increased by as much as 100, whereas in the beta phase the conductivity of CuBr containing Al2O3 decreased. The electrical conductivity studies are in agreement with earlier data.

  19. Preliminary study on improvement of cementitious grout thermal conductivity for geothermal heat pump applications

    SciTech Connect

    Allan, M.L.

    1996-06-01

    Preliminary studies were preformed to determine whether thermal conductivity of cementitious grouts used to backfill heat exchanger loops for geothermal heat pumps could be improved, thus improving efficiency. Grouts containing selected additives were compares with conventional bentonite and cement grouts. Significant enhancement of grout alumina grit, steel fibers, and silicon carbide increased the thermal conductivity when compared to unfilled, high solids bentonite grouts and conventional cement grouts. Furthermore, the developed grouts retained high thermal conductivity in the dry state, where as conventional bentonite and cement grouts tend to act as insulators if moisture is lost. The cementitious grouts studied can be mixed and placed using conventional grouting equipment.

  20. Prevalence and comorbidity of eating disorders among a community sample of adolescents: 2-year follow-up.

    PubMed

    Rojo-Moreno, Luis; Arribas, Pilar; Plumed, Javier; Gimeno, Natalia; García-Blanco, Ana; Vaz-Leal, Francisco; Luisa Vila, María; Livianos, Lorenzo

    2015-05-30

    The previous literature about comorbidity between eating disorders (ED) and other DSM-IV psychiatric disorders in adolescence has employed cross-sectional studies with clinical samples, where the comorbid disorders were diagnosed retrospectively. The present study aims to overcome these limitations by the analysis of comorbidity in a community population during 2-year follow-up. A semi-structured interview was applied to a teenager sample. Firstly, a cross-sectional and non-randomized study on psychiatric morbidity was conducted with 993 teenagers between the ages of 12 and 16 from five schools. Secondly, 326 students between 14 and 17 years old of one school were reassessed 2 years later in order to detect ED new cases and find associations with previous psychiatric disorders. The ED prevalence was 3.6%. Cross-sectional analysis revealed that 62.9% of individuals with an ED had comorbid disorders: anxiety disorders (51.4%), Attention Deficit Hyperactivity Disorder (31.4%), oppositional defiant disorder (11.4%), and obsessive compulsive disorder (8.6%). Prospective longitudinal analysis showed an ED incidence rate of 2.76% over the course of 2 years. 22.2% of new cases had received previous psychiatric diagnoses, of which all were anxiety disorders. Thus, ED exhibited a high comorbidity rate among adolescent populations and anxiety disorders were the most common comorbid diagnosis.

  1. Prevalence and comorbidity of eating disorders among a community sample of adolescents: 2-year follow-up.

    PubMed

    Rojo-Moreno, Luis; Arribas, Pilar; Plumed, Javier; Gimeno, Natalia; García-Blanco, Ana; Vaz-Leal, Francisco; Luisa Vila, María; Livianos, Lorenzo

    2015-05-30

    The previous literature about comorbidity between eating disorders (ED) and other DSM-IV psychiatric disorders in adolescence has employed cross-sectional studies with clinical samples, where the comorbid disorders were diagnosed retrospectively. The present study aims to overcome these limitations by the analysis of comorbidity in a community population during 2-year follow-up. A semi-structured interview was applied to a teenager sample. Firstly, a cross-sectional and non-randomized study on psychiatric morbidity was conducted with 993 teenagers between the ages of 12 and 16 from five schools. Secondly, 326 students between 14 and 17 years old of one school were reassessed 2 years later in order to detect ED new cases and find associations with previous psychiatric disorders. The ED prevalence was 3.6%. Cross-sectional analysis revealed that 62.9% of individuals with an ED had comorbid disorders: anxiety disorders (51.4%), Attention Deficit Hyperactivity Disorder (31.4%), oppositional defiant disorder (11.4%), and obsessive compulsive disorder (8.6%). Prospective longitudinal analysis showed an ED incidence rate of 2.76% over the course of 2 years. 22.2% of new cases had received previous psychiatric diagnoses, of which all were anxiety disorders. Thus, ED exhibited a high comorbidity rate among adolescent populations and anxiety disorders were the most common comorbid diagnosis. PMID:25771751

  2. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Taşdemir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test. PMID:25342307

  3. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Taşdemir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test.

  4. Diameter Dependence of Lattice Thermal Conductivity of Single-Walled Carbon Nanotubes: Study from Ab Initio.

    PubMed

    Yue, Sheng-Ying; Ouyang, Tao; Hu, Ming

    2015-10-22

    The effects of temperature, tube length, defects, and surface functionalization on the thermal conductivity (κ) of single-walled carbon nanotubes (SWCNTs) were well documented in literature. However, diameter dependence of thermal conductivity of SWCNTs received less attentions. So far, diverse trends of the diameter dependence have been discussed by different methods and all the previous results were based on empirical interatomic potentials. In this paper, we emphasize to clarify accurate κ values of SWCNTs with different diameters and in-plane κ of graphene. All the studies were under the framework of anharmonic lattice dynamics and Boltzmann transport equation (BTE) based on first principle calculations. We try to infer the right trend of diameter dependent thermal conductivity of SWCNTs. We infer that graphene is the limitation as SWCNT with an infinite diameter. We analyzed the thermal conductivity contributions from each phonon mode in SWCNTs to explain the trend. Meanwhile, we also identify the extremely low thermal conductivity of ultra-thin SWCNTs.

  5. Communication: Minimum in the thermal conductivity of supercooled water: A computer simulation study

    SciTech Connect

    Bresme, F.; Biddle, J. W.; Sengers, J. V.; Anisimov, M. A.

    2014-04-28

    We report the results of a computer simulation study of the thermodynamic properties and the thermal conductivity of supercooled water as a function of pressure and temperature using the TIP4P-2005 water model. The thermodynamic properties can be represented by a two-structure equation of state consistent with the presence of a liquid-liquid critical point in the supercooled region. Our simulations confirm the presence of a minimum in the thermal conductivity, not only at atmospheric pressure, as previously found for the TIP5P water model, but also at elevated pressures. This anomalous behavior of the thermal conductivity of supercooled water appears to be related to the maximum of the isothermal compressibility or the minimum of the speed of sound. However, the magnitudes of the simulated thermal conductivities are sensitive to the water model adopted and appear to be significantly larger than the experimental thermal conductivities of real water at low temperatures.

  6. The Relationship between Nerve Conduction Study and Clinical Grading of Carpal Tunnel Syndrome

    PubMed Central

    Cheluvaiah, Janardhan D.; Agadi, Jagadish B.; Nagaraj, Karthik

    2016-01-01

    Introduction Carpal Tunnel Syndrome (CTS) is the most common nerve entrapment. Subjective sensory symptoms are common place in patients with CTS, but sometimes they are not supported by objective findings in the neurological examination. Electrodiagnostic (EDx) studies are a valid and reliable means of confirming the diagnosis. The amplitudes along with the conduction velocities of the sensory nerve action potential and motor nerve action potential reflect the functional state of axons, and are useful parameters and complement the clinical grading in the assessment of severity of CTS. Aim To conduct median nerve sensory and motor conduction studies on patients with carpal tunnel syndrome and correlate the relationship between nerve conduction study parameters and the clinical severity grading. Materials and Methods Based on clinical assessment, the study patients were divided into 03 groups with mild CTS, moderate CTS and severe CTS respectively as per Mackinnson’s classification. Median and ulnar nerve conduction studies were performed on bilateral upper limbs of 50 patients with symptoms of CTS and 50 age and sex matched healthy control subjects. The relationship between the clinical severity grade and various nerve conduction study parameters were correlated. Results In this prospective case control study, 50 patients with symptoms consistent with CTS and 50 age and sex matched healthy control subjects were examined over a 10 month period. A total of 30 patients had unilateral CTS (right upper limb in 19 and left upper limb in 11) and 20 patients had bilateral CTS. Female to male ratio was 3.54 to 1. Age ranged from 25 to 81 years. The mean age at presentation was 49.68±11.7 years. Tingling paresthesias of hand and first three fingers were the most frequent symptoms 48 (98%). Tinel’s and Phalen’s sign were positive in 36 (72%) and 44 (88%) patients respectively. The mean duration of symptoms at presentation was 52.68±99.81 weeks. 16 patients (32%) had

  7. The Relationship between Nerve Conduction Study and Clinical Grading of Carpal Tunnel Syndrome

    PubMed Central

    Cheluvaiah, Janardhan D.; Agadi, Jagadish B.; Nagaraj, Karthik

    2016-01-01

    Introduction Carpal Tunnel Syndrome (CTS) is the most common nerve entrapment. Subjective sensory symptoms are common place in patients with CTS, but sometimes they are not supported by objective findings in the neurological examination. Electrodiagnostic (EDx) studies are a valid and reliable means of confirming the diagnosis. The amplitudes along with the conduction velocities of the sensory nerve action potential and motor nerve action potential reflect the functional state of axons, and are useful parameters and complement the clinical grading in the assessment of severity of CTS. Aim To conduct median nerve sensory and motor conduction studies on patients with carpal tunnel syndrome and correlate the relationship between nerve conduction study parameters and the clinical severity grading. Materials and Methods Based on clinical assessment, the study patients were divided into 03 groups with mild CTS, moderate CTS and severe CTS respectively as per Mackinnson’s classification. Median and ulnar nerve conduction studies were performed on bilateral upper limbs of 50 patients with symptoms of CTS and 50 age and sex matched healthy control subjects. The relationship between the clinical severity grade and various nerve conduction study parameters were correlated. Results In this prospective case control study, 50 patients with symptoms consistent with CTS and 50 age and sex matched healthy control subjects were examined over a 10 month period. A total of 30 patients had unilateral CTS (right upper limb in 19 and left upper limb in 11) and 20 patients had bilateral CTS. Female to male ratio was 3.54 to 1. Age ranged from 25 to 81 years. The mean age at presentation was 49.68±11.7 years. Tingling paresthesias of hand and first three fingers were the most frequent symptoms 48 (98%). Tinel’s and Phalen’s sign were positive in 36 (72%) and 44 (88%) patients respectively. The mean duration of symptoms at presentation was 52.68±99.81 weeks. 16 patients (32%) had

  8. Smoking patterns, attitudes and motives: unique characteristics among 2-year versus 4-year college students.

    PubMed

    Berg, C J; An, L C; Thomas, J L; Lust, K A; Sanem, J R; Swan, D W; Ahluwalia, J S

    2011-08-01

    Given the previously documented higher rates of smoking among 2-year college students in comparison with 4-year university students, this study compares smoking patterns, attitudes and motives among 2-year and 4-year college students. Two thousand two hundred and sixty-five undergraduate students aged 18-25 years at a 2-year college and a 4-year university completed an online survey in 2008. Current (past 30-day) smoking was reported by 43.5% of 2-year and 31.9% of 4-year college students, and daily smoking was reported by 19.9% of 2-year and 8.3% of 4-year college students. Attending a 2-year college was associated with higher rates of current smoking [odds ratio (OR) = 1.72] and daily smoking (OR = 2.84), and with less negative attitudes regarding smoking, controlling for age, gender, ethnicity and parental education. Also, compared with 4-year college student smokers, 2-year college smokers had lower motivation to smoke for social reasons, but more motivation to smoke for affect regulation, after controlling for age, gender, ethnicity and parental education. Two- and 4-year college students report different smoking patterns, attitudes and motives. These distinctions might inform tobacco control messages and interventions targeting these groups of young adults.

  9. An Assessment of Treatment Integrity in Behavioral Intervention Studies Conducted with Persons with Mental Retardation

    ERIC Educational Resources Information Center

    Wheeler, John J.; Mayton, Michael R.; Carter, Stacy L.; Chitiyo, Morgan; Menendez, Anthony L.; Huang, Ann

    2009-01-01

    The purpose of this study was to assess the degree to which behavioral intervention studies conducted with persons with mental retardation operationally defined the independent variables and evaluated and reported measures of treatment integrity. The study expands the previous work in this area reported by Gresham, Gansle, and Noell (1993) and…

  10. Treatment Integrity: A Review of Intervention Studies Conducted with Children with Autism

    ERIC Educational Resources Information Center

    Wheeler, John J.; Baggett, Bob A.; Fox, James; Blevins, Leia

    2006-01-01

    The purpose of this study was to assess the degree to which behavioral intervention studies conducted with children diagnosed with autism operationally defined the independent variables (IVs) and evaluated treatment integrity (TI). The study replicated the criteria from Gresham, Gansle, and Noell (1993) and focused exclusively on research studies…

  11. Kindergarten Teachers' Perspectives on Developmentally Appropriate Practices (DAP): A Study Conducted in Mumbai (India)

    ERIC Educational Resources Information Center

    Hegde, Archana V.; Cassidy, Deborah J.

    2009-01-01

    A qualitative study examining teachers' beliefs regarding developmentally appropriate practices was conducted in the city of Mumbai, India. Twelve kindergarten teacher's were interviewed for this study, and a constant comparative method was used to analyze the interviews. Six themes were identified within this study. The themes highlighted…

  12. Cost and Schedule Analytical Techniques Development: Option 2 Year

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This Final Report summarizes the activities performed by Science Applications International Corporation (SAIC) for the Option 2 Year from December 1, 1996 through November 30, 1997. The Final Report is in compliance with Paragraph 5 of Section F of the contract. This CSATD contract provides products and deliverable in the form of models, data bases, methodologies, studies and analyses for the NASA Marshall Space Flight Center's (MSFC) Engineering Cost Office (PPO3) the Program Plans and Requirements Officer (PP02), and other user organizations. Detailed Monthly Progress reports were submitted to MSFC in accordance with the contract's Statement of Work, Section TV "Reporting and Documentation". These reports spelled out each month's specific work accomplishments, deliverables submitted, major meetings held, and other pertinent information. This Final Report will summarize these activities at higher level. During this contract Option Year, SAIC expended 29,830 man-hours in tile performance of tasks called out in the Statement of Work and reported oil in this yearly Final Report. This represents approximately 16 full-time EPs. Included are the basis Huntsville-based team, plus SAIC specialists in San Diego, Ames Research Center, Chicago, and Colorado Springs performing specific tasks for which they are uniquely qualified.

  13. Conductivity studies of Chitosan doped with different ammonium salts: Effect of ion size

    NASA Astrophysics Data System (ADS)

    Mohan, C. Raja; Senthilkumar, M.; Jayakumar, K.

    2015-06-01

    In the present investigation influence of ion size on the electrical properties of various ammonium salts of various concentrations doped with Chitosan liquid electrolyte has been studied. The attachment of ammonium salts with Chitosan has been confirmed through FTIR Spectrum. Polarizability is calculated from the refractive index data. Addition of ammonium salts increases the conductivity. It is also observed that increase in ion size, increases the ionic conductivity due to increase in amorphous nature of the material. Increase in concentration leads to increase in conductivity due to the presence of more number of free ions.

  14. Feasible Study for Multi-photon Stereolithography Method of Electro Conductive Polymer Actuator with Complex Shape

    NASA Astrophysics Data System (ADS)

    Sone, Junji; Asami, Akihisa; Yamada, Katsumi; Chen, Jun

    Recently, a soft actuator was developed using an electro-conducting polymer and an ionic conducting polymer. Moreover, stereolithography that uses a femtosecond laser was researched as a method of multiphoton-sensitized polymerization. In this study, we tried a more stable and more rapid stereolithography method for fabricating an electro-conducting polymer using a protein material. From the results of this study, we found that the method was 10 times faster when an aqueous solid that included an electro-conducting polymer, a catalyst, and gelatine was used. In addition, it was stable in that the temperature of the aqueous solid was controlled at 10 degree. We built a 3D shape using the newly developed method, and we will apply this method to a complex actuator.

  15. Molecular dynamics studies of material property effects on thermal boundary conductance.

    PubMed

    Zhou, X W; Jones, R E; Duda, J C; Hopkins, P E

    2013-07-14

    Thermal boundary resistance (inverse of conductance) between different material layers can dominate the overall thermal resistance in nanostructures and therefore impact the performance of the thermal property limiting nano devices. Because relationships between material properties and thermal boundary conductance have not been fully understood, optimum devices cannot be developed through a rational selection of materials. Here we develop generic interatomic potentials to enable material properties to be continuously varied in extremely large molecular dynamics simulations to explore the dependence of thermal boundary conductance on the characteristic properties of materials such as atomic mass, stiffness, and interfacial crystallography. To ensure that our study is not biased to a particular model, we employ different types of interatomic potentials. In particular, both a Stillinger-Weber potential and a hybrid embedded-atom-method + Stillinger-Weber potential are used to study metal-on-semiconductor compound interfaces, and the results are analyzed considering previous work based upon a Lennard-Jones (LJ) potential. These studies, therefore, reliably provide new understanding of interfacial transport phenomena particularly in terms of effects of material properties on thermal boundary conductance. Our most important finding is that thermal boundary conductance increases with the overlap of the vibrational spectra between metal modes and the acoustic modes of the semiconductor compound, and increasing the metal stiffness causes a continuous shift of the metal modes. As a result, the maximum thermal boundary conductance occurs at an intermediate metal stiffness (best matched to the semiconductor stiffness) that maximizes the overlap of the vibrational modes.

  16. AC conductivity and Dielectric Study of Chalcogenide Glasses of Se-Te-Ge System

    NASA Astrophysics Data System (ADS)

    Salman, Fathy

    2004-01-01

    The ac conductivity and dielectric properties of glassy system SexTe79 - xGe21, with x = 11, 14, 17 at.%, has been studied at temperatures 300 to 450 K and over a wide range of frequencies (50 Hz to 500 kHz). Experimental results indicate that the ac conductivity and the dielectric constants depend on temperature, frequency and Se content. The conductivity as a function of frequency exhibited two components: dc conductivity s dc, and ac conductivity s ac, where s ac ˜ w s. The mechanism of ac conductivity can be reasonably interpreted in terms of the correlated barrier hopping model (CBH). The activation energies are estimated and discussed. The dependence of ac conductivity and dielectric constants on the Se content x can be interpreted as the effect of Se fraction on the positional disorder. The impedance plot at each temperature appeared as a semicircle passes through the origin. Each semicircle is represented by an equivalent circuit of parallel resistance Rb and capacitance Cb.

  17. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Conduct of health assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND...

  18. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Conduct of health assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND...

  19. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES...

  20. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Conduct of health assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND...

  1. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES...

  2. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Conduct of health assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND...

  3. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES...

  4. 42 CFR 90.8 - Conduct of health assessments and health effects studies.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Conduct of health assessments and health effects studies. 90.8 Section 90.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND...

  5. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES...

  6. 42 CFR 90.7 - Decision to conduct health effects study.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Decision to conduct health effects study. 90.7 Section 90.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES...

  7. Study of the Kinetics of an S[subscript N]1 Reaction by Conductivity Measurement

    ERIC Educational Resources Information Center

    Marzluff, Elaine M.; Crawford, Mary A.; Reynolds, Helen

    2011-01-01

    Substitution reactions, a central part of organic chemistry, provide a model system in physical chemistry to study reaction rates and mechanisms. Here, the use of inexpensive and readily available commercial conductivity probes coupled with computer data acquisition for the study of the temperature and solvent dependence of the solvolysis of…

  8. 21 CFR 312.120 - Foreign clinical studies not conducted under an IND.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Miscellaneous § 312... examine data from such a study. (3) Marketing approval of a new drug based solely on foreign clinical data... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Foreign clinical studies not conducted under...

  9. Methodological, Theoretical, Infrastructural, and Design Issues in Conducting Good Outcome Studies

    ERIC Educational Resources Information Center

    Kelly, Michael P.; Moore, Tessa A.

    2011-01-01

    This article outlines a set of methodological, theoretical, and other issues relating to the conduct of good outcome studies. The article begins by considering the contribution of evidence-based medicine to the methodology of outcome research. The lessons which can be applied in outcome studies in nonmedical settings are described. The article…

  10. GUIDE TO CONDUCTING TREATABILITY STUDIES UNDER CERCLA: SOIL WASHING - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation, and Liab...

  11. Obstacles to Conducting Curriculum Research in Bilingual Education: A Case Study.

    ERIC Educational Resources Information Center

    Schon, Isabel; Hopkins, Kenneth D.

    The obstacles associated with conducting curricular research in school settings are discussed. A study of bilingual students in the Phoenix area demonstrated the difficulties associated with high absenteeism and drop out rates. In a study of Spanish reading materials, it proved difficult to identify schools where administrators would be willing to…

  12. GUIDE FOR CONDUCTING TREATABILITY STUDIES UNDER CERCLA: SOLVENT EXTRACTION - INTERIM GUIDANCE

    EPA Science Inventory

    Systematically conducted, well-documented treatability studies are an important component of the remedial investigation/feasibility study (RI/FS) process and the remedial design/remedial action (RD/RA) process under the Comprehensive Environmental Response, Compensation and Liabi...

  13. The conductive properties of single DNA molecules studied by torsion tunneling atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Wang, W.; Niu, D. X.; Jiang, C. R.; Yang, X. J.

    2014-01-01

    The conductive properties of single natural λ-DNA molecules are studied by torsion tunneling atomic force microscopy (TR-TUNA). The currents both parallel to and perpendicular to the DNA chains are investigated, but only weak or even no current signals are detected by TR-TUNA. To improve the conductance of DNA molecules, silver and copper metallized DNAs are fabricated and their conductivities are checked by TR-TUNA. It is found that for both Cu- and Ag-DNAs, the conductivity perpendicular to the DNA chain is enhanced significantly as the metal clusters are attached to the DNA chains. But parallel to the chain the electrical transport is still weak, most probably due to the ‘beads-on-a-string’ constructions of metallized DNAs.

  14. AC Conductivity Studies in Lithium-Borate Glass Containing Gold Nanoparticles

    NASA Astrophysics Data System (ADS)

    Shivaprakash, Y.; Anavekar, R. V.

    2011-07-01

    Gold nanoparticles have been synthesized in a base glass with composition 30Li2O-70B2O3 using gold chloride (HAuCl4.3H2O) as a dopant. The samples are characterized using XRD, ESR, SEM and optical absorption in the visible range. AC conductivity studies have been performed at RT over a frequency range 100 to 10 MHz. The dc conductivity is calculated from the complex impedence plot. The dc conductivity is found to be increasing with the increase of dopant concentration. AC conductivity data is fitted with Almond-West law with power exponent `s'. The values of `s' is found to lie in the range of 0.70-0.73.

  15. Thermal conductivity studies of metal dispersed multiwalled carbon nanotubes in water and ethylene glycol based nanofluids

    SciTech Connect

    Jha, Neetu; Ramaprabhu, S.

    2009-10-15

    High thermal conducting metal nanoparticles have been dispersed on the multiwalled carbon nanotubes (MWNTs) outer surface. Structural and morphological characterizations of metal dispersed MWNTs have been carried out using x-ray diffraction analysis, high resolution transmission electron microscopy, energy dispersive x-ray analysis, and Fourier transform infrared spectroscopy. Nanofluids have been synthesized using metal-MWNTs in de-ionized water (DI water) and ethylene glycol (EG) base fluids. It has been observed that nanofluids maintain the same sequence of thermal conductivity as that of metal nanoparticles Ag-MWNTs>Au-MWNTs>Pd-MWNTs. A maximum enhancement of 37.3% and 11.3% in thermal conductivity has been obtained in Ag-MWNTs nanofluid with DI water and EG as base fluids, respectively, at a volume fraction of 0.03%. Temperature dependence study also shows enhancement of thermal conductivity with temperature.

  16. Solid state electrical conductivity and thermal degradation studies on some phenothiazine derivatives

    NASA Astrophysics Data System (ADS)

    Achar, B. N.; Ashok, M. A.

    2007-02-01

    Electrical conductivity and thermal degradation studies of promethazine hydrochloride (PH); 2-chlorophenothiazine (CP); diethazine hydrochloride (DH) and trifluoperazine dihydrochloride (TFP) are reported. The activation energies are evaluated based on their electrical conductivity study conducted over the temperature range 30 150 °C. These energies for PH, CP, DH and TFP are found to be 0.86, 1.02, 0.68 and 1.08 eV, respectively. The materials are analyzed for the kinetic parameters like the activation energies for decomposition and the Arrhenious pre-exponential factors in their pyrolysis region using Broido's, Coats Redfern and Horowitz Metzger methods. Using these factors and the standard equations thermodynamic parameters such as enthalpy, entropy and free energies are calculated. Thermogravimetric study on these phenothiazine derivatives in air indicated that their stabilities are in the order CP>TFP>PH >DH.

  17. In Situ Study of Strain-Dependent Ion Conductivity of Stretchable Polyethylene Oxide Electrolyte.

    PubMed

    Kelly, Taylor; Ghadi, Bahar Moradi; Berg, Sean; Ardebili, Haleh

    2016-01-01

    There is a strong need in developing stretchable batteries that can accommodate stretchable or irregularly shaped applications including medical implants, wearable devices and stretchable electronics. Stretchable solid polymer electrolytes are ideal candidates for creating fully stretchable lithium ion batteries mainly due to their mechanical and electrochemical stability, thin-film manufacturability and enhanced safety. However, the characteristics of ion conductivity of polymer electrolytes during tensile deformation are not well understood. Here, we investigate the effects of tensile strain on the ion conductivity of thin-film polyethylene oxide (PEO) through an in situ study. The results of this investigation demonstrate that both in-plane and through-plane ion conductivities of PEO undergo steady and linear growths with respect to the tensile strain. The coefficients of strain-dependent ion conductivity enhancement (CSDICE) for in-plane and through-plane conduction were found to be 28.5 and 27.2, respectively. Tensile stress-strain curves and polarization light microscopy (PLM) of the polymer electrolyte film reveal critical insights on the microstructural transformation of stretched PEO and the potential consequences on ionic conductivity. PMID:26831948

  18. A Study of the Preparation and Properties of Antioxidative Copper Inks with High Electrical Conductivity.

    PubMed

    Tsai, Chia-Yang; Chang, Wei-Chen; Chen, Guan-Lin; Chung, Cheng-Huan; Liang, Jun-Xiang; Ma, Wei-Yang; Yang, Tsun-Neng

    2015-12-01

    Conductive ink using copper nanoparticles has attracted much attention in the printed electronics industry because of its low cost and high electrical conductivity. However, the problem of easy oxidation under heat and humidity conditions for copper material limits the wide applications. In this study, antioxidative copper inks were prepared by dispersing the nanoparticles in the solution, and then conductive copper films can be obtained after calcining the copper ink at 250 °C in nitrogen atmosphere for 30 min. A low sheet resistance of 47.6 mΩ/□ for the copper film was measured by using the four-point probe method. Importantly, we experimentally demonstrate that the electrical conductivity of copper films can be improved by increasing the calcination temperature. In addition, these highly conductive copper films can be placed in an atmospheric environment for more than 6 months without the oxidation phenomenon, which was verified by energy-dispersive X-ray spectroscopy (EDS). These observations strongly show that our conductive copper ink features high antioxidant properties and long-term stability and has a great potential for many printed electronics applications, such as flexible display systems, sensors, photovoltaic cells, and radio frequency identification. PMID:26370132

  19. In Situ Study of Strain-Dependent Ion Conductivity of Stretchable Polyethylene Oxide Electrolyte

    PubMed Central

    Kelly, Taylor; Ghadi, Bahar Moradi; Berg, Sean; Ardebili, Haleh

    2016-01-01

    There is a strong need in developing stretchable batteries that can accommodate stretchable or irregularly shaped applications including medical implants, wearable devices and stretchable electronics. Stretchable solid polymer electrolytes are ideal candidates for creating fully stretchable lithium ion batteries mainly due to their mechanical and electrochemical stability, thin-film manufacturability and enhanced safety. However, the characteristics of ion conductivity of polymer electrolytes during tensile deformation are not well understood. Here, we investigate the effects of tensile strain on the ion conductivity of thin-film polyethylene oxide (PEO) through an in situ study. The results of this investigation demonstrate that both in-plane and through-plane ion conductivities of PEO undergo steady and linear growths with respect to the tensile strain. The coefficients of strain-dependent ion conductivity enhancement (CSDICE) for in-plane and through-plane conduction were found to be 28.5 and 27.2, respectively. Tensile stress-strain curves and polarization light microscopy (PLM) of the polymer electrolyte film reveal critical insights on the microstructural transformation of stretched PEO and the potential consequences on ionic conductivity. PMID:26831948

  20. A study of electrical conductance of meridian in the obese during weight reduction.

    PubMed

    Weng, Ching-Sung; Hung, Yu-Li; Shyu, Liang-Yu; Chang, Yung-Hsien

    2004-01-01

    This study was designed to investigate the electrical conductance of meridian in the obese during weight reduction. Ten obese including overweight (Body Mass Index, BMI > 26) and 30 healthy (non-overweight) people were recruited from Chung Yuan Christian University. The obese subjects were instructed to follow a weight reduction program that included diet control, exercise and oral intake of Prozac. A device, the design of which is based on the Ryodoraku theorem, was used to measure the electrical conductance of 12 meridians on both sides of the subjects. The results showed that: (1) the average coefficient of variation of the electrical conductances in 24 meridians of the obese group was statistically different from that of the healthy group (p < 0.05); (2) the average coefficient of variation of electrical conductance in the obese after weight reduction was significantly decreased than before the weight reduction program (p < 0.05); (3) the BMI and the electrical conductance of meridian was correlated in the obese (r = -0.77, p < 0.001) as well as in the healthy group (r = -0.92, p < 0.001). These findings suggest that electrical conductance of meridians can be a parameter to monitor weight, especially for obese people. PMID:15344425

  1. In Situ Study of Strain-Dependent Ion Conductivity of Stretchable Polyethylene Oxide Electrolyte

    NASA Astrophysics Data System (ADS)

    Kelly, Taylor; Ghadi, Bahar Moradi; Berg, Sean; Ardebili, Haleh

    2016-02-01

    There is a strong need in developing stretchable batteries that can accommodate stretchable or irregularly shaped applications including medical implants, wearable devices and stretchable electronics. Stretchable solid polymer electrolytes are ideal candidates for creating fully stretchable lithium ion batteries mainly due to their mechanical and electrochemical stability, thin-film manufacturability and enhanced safety. However, the characteristics of ion conductivity of polymer electrolytes during tensile deformation are not well understood. Here, we investigate the effects of tensile strain on the ion conductivity of thin-film polyethylene oxide (PEO) through an in situ study. The results of this investigation demonstrate that both in-plane and through-plane ion conductivities of PEO undergo steady and linear growths with respect to the tensile strain. The coefficients of strain-dependent ion conductivity enhancement (CSDICE) for in-plane and through-plane conduction were found to be 28.5 and 27.2, respectively. Tensile stress-strain curves and polarization light microscopy (PLM) of the polymer electrolyte film reveal critical insights on the microstructural transformation of stretched PEO and the potential consequences on ionic conductivity.

  2. A Platform for the Remote Conduct of Gene-Environment Interaction Studies

    PubMed Central

    Gallacher, John; Collins, Rory; Elliott, Paul; Palmer, Stephen; Burton, Paul; Mitchell, Clive; John, Gareth; Lyons, Ronan

    2013-01-01

    Background Gene-environment interaction studies offer the prospect of robust causal inference through both gene identification and instrumental variable approaches. As such they are a major and much needed development. However, conducting these studies using traditional methods, which require direct participant contact, is resource intensive. The ability to conduct gene-environment interaction studies remotely would reduce costs and increase capacity. Aim To develop a platform for the remote conduct of gene-environment interaction studies. Methods A random sample of 15,000 men and women aged 50+ years and living in Cardiff, South Wales, of whom 6,012 were estimated to have internet connectivity, were mailed inviting them to visit a web-site to join a study of successful ageing. Online consent was obtained for questionnaire completion, cognitive testing, re-contact, record linkage and genotyping. Cognitive testing was conducted using the Cardiff Cognitive Battery. Bio-sampling was randomised to blood spot, buccal cell or no request. Results A heterogeneous sample of 663 (4.5% of mailed sample and 11% of internet connected sample) men and women (47% female) aged 50–87 years (median = 61 yrs) from diverse backgrounds (representing the full range of deprivation scores) was recruited. Bio-samples were donated by 70% of those agreeing to do so. Self report questionnaires and cognitive tests showed comparable distributions to those collected using face-to-face methods. Record linkage was achieved for 99.9% of participants. Conclusion This study has demonstrated that remote methods are suitable for the conduct of gene-environment interaction studies. Up-scaling these methods provides the opportunity to increase capacity for large-scale gene-environment interaction studies. PMID:23349852

  3. Media use by children younger than 2 years.

    PubMed

    Brown, Ari

    2011-11-01

    In 1999, the American Academy of Pediatrics (AAP) issued a policy statement addressing media use in children. The purpose of that statement was to educate parents about the effects that media--both the amount and the content--may have on children. In one part of that statement, the AAP recommended that "pediatricians should urge parents to avoid television viewing for children under the age of two years." The wording of the policy specifically discouraged media use in this age group, although it is frequently misquoted by media outlets as no media exposure in this age group. The AAP believed that there were significantly more potential negative effects of media than positive ones for this age group and, thus, advised families to thoughtfully consider media use for infants. This policy statement reaffirms the 1999 statement with respect to media use in infants and children younger than 2 years and provides updated research findings to support it. This statement addresses (1) the lack of evidence supporting educational or developmental benefits for media use by children younger than 2 years, (2) the potential adverse health and developmental effects of media use by children younger than 2 years, and (3) adverse effects of parental media use (background media) on children younger than 2 years.

  4. Early Intervention for Children Birth Through 2 Years.

    ERIC Educational Resources Information Center

    Wetherby, Catherine, Ed.

    1988-01-01

    Information is provided for parents of handicapped children, aged 0-2 years, on the uniqueness of each infant's learning processes and the valuable role that parents and others can play in helping their infants with special needs to make the most of their abilities. The digest examines parents' concerns during the infant's hospital stay and early…

  5. Minoxidil induced hypertrichosis in a 2 year-old child.

    PubMed

    Herskovitz, Ingrid; Freedman, Joshua; Tosti, Antonella

    2013-01-01

    We report a case of a 2 year-old male patient who developed generalized hypertrichosis after 2 months of treatment with 5% minoxidil foam for alopecia areata. This report highlights the danger of prescribing  topical minoxidil to young children and the need to correctly instruct caretakers about its administration. PMID:24555107

  6. Childhood Bereavement: Psychopathology in the 2 Years Postparental Death

    ERIC Educational Resources Information Center

    Cerel, Julie; Fristad, Mary A.; Verducci, Joseph; Weller, Ronald A.; Weller, Elizabeth B.

    2006-01-01

    Objective: Although the death of a parent is one of the most significant stressors a child can experience, the psychiatric sequelae of parental death are not fully understood. Method: A total of 360 parent-bereaved children (ages 6-17) and their surviving parents were directly interviewed four times during the first 2 years following the death (at…

  7. Ornamental Horticulture Technology; Suggested 2-Year Post High School Curriculums.

    ERIC Educational Resources Information Center

    Bureau of Adult, Vocational, and Technical Education (DHEW/OE), Washington, DC. Div. of Vocational and Technical Education.

    Developed by a technical education specialist, this guide is designed to aid school administrators in planning and developing 2-year post-high school programs or evaluating existing programs in ornamental horticulture technology. In addition to general information on the program, contents include course outlines with examples of tests and…

  8. A study on Effective Thermal Conductivity of Packed Bed of Adsorbent Including Water

    NASA Astrophysics Data System (ADS)

    Hirasawa, Yoshio; Ohta, Ryuma; Takegoshi, Eisyun

    In the present study, an effective thermal conductivity of the packed bed of an adsorbent including water was measured experimentally by using the transient hot wire method in temperature range from about -40°C to room temperature. Zeolite particle and activated carbon particle were employed as the adsorbent. The water included in the adsorbent was classified to three kinds; namely, the adsorbed water in the adsorption site with a nanometer order in particle, the osmosis water existing in gap with lager size than the adsorption site and the free water around particle. The measurement was performed with changing the mass ratio of adsorbed water and osmosis water and was also performed for the particle filled by the free water. As the results, the effective thermal conductivity of the packed bed increased with the increase of temperature except the case containing free water. In zeolite, the effective thermal conductivity of the packed bed of particles with adsorbed water became bigger than that of the desorbed particle about 10% though the adsorbed water was trapped in the adsorption site as a single molecular in zeolite particle. In activated carbon, the effective thermal conductivity was larger than that of desorbed particle about 20%. Next, in the packed bed of particle with the osmosis water, the effective thermal conductivity indicated about two times of that of particle with the adsorbed water. In the packed bed of particle filled by free water, the effective thermal conductivity increased suddenly under 0°C. It is considered that the thermal conductivity of ice affected seriously to the effective thermal conductivity because ice was the continuous phase in the bed.

  9. A study of rock matrix diffusion properties by electrical conductivity measurements

    SciTech Connect

    Ohlsson, Y.; Neretnieks, I.

    1999-07-01

    Traditional rock matrix diffusion experiments on crystalline rock are very time consuming due to the low porosity and extensive analysis requirements. Electrical conductivity measurements are, on the other hand, very fast and larger samples can be used than are practical in ordinary diffusion experiments. The effective diffusivity of a non-charged molecule is readily evaluated from the measurements, and influences from surface conductivity on diffusion of cations can be studied. A large number of samples of varying thickness can be measured within a short period, and the changes in transport properties with position in a rock core can be examined. In this study the formation factor of a large number of Aespoe diorite samples is determined by electrical conductivity measurements. The formation factor is a geometric factor defined as the ratio between the effective diffusivity of a non-charged molecule, to that of the same molecule in free liquid. The variation of this factor with position among a borecore and with sample length, and its coupling to the porosity of the sample is studied. Also the surface conductivity is studied. This was determined as the residual conductivity after leaching of the pore solution ions. The formation factor of most of the samples is in the range 1E-5 to 1E-4, with a mean value of about 5E-5. Even large samples (4--13 cm) give such values. The formation factor increases with increasing porosity and the change in both formation factor and porosity with position in the borecore can be large, even for samples close to each other. The surface conductivity increases with increasing formation factor for the various samples but the influence on the pore diffusion seems to be higher for samples of lower formation factor. This suggests that the relation between the pore surface area and the pore volume is larger for samples of low formation factor.

  10. [Study of sinus node function and atrioventricular conduction in patients with chagas disease (author's transl)].

    PubMed

    Carrasco, H A; Mora, R; Inglessis, G; Contreras, J M; Marval, J; Fuenmayor, A

    1982-01-01

    In order to detect possible abnormalities in sinus node function and atrio-ventricular conduction, one hundred and fourty three chagasic patients were subjected to electrophysiologic and pharmacologic studies. These patients were placed in four categories based on the their clinical, hemodynamic and angiographic characteristics. The chagasic patient without cardiac involvement (group IA), had no detectable abnormalities. Ten percent of those patients with early myocardial damage (group IB), had impaired sinus node automaticity. In three percent, the autonomic innervation was also altered and four percent had abnormally prolonged atrio-ventricular conduction. Among chagasic patients with abnormal EKG'S without heart failure (Group II), 45% had impaired sinus node automaticity, autonomic innervation was altered in 12%, and atrio-ventricular conduction was prolonged in 37%. Sinus node automaticity was impaired in 22% of those patients with abnormal EKG'S and heart failure (Group III). Autonomic innervation was altered in 33%, and atrio-ventricular conduction was prolonged in 47%. We conclude that over half of our patients with abnormal EKG'S will eventually require permanent pacing. Therefore, in these chagasic patients sinus node function and atrioventricular conduction should be routinely studied. PMID:7114967

  11. Electrochemical studies of thin films of conducting polymers and conducting polymer composites deposited on metal and semiconductor electrodes

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Di Stefano, S.; Moacanin, J.

    1987-01-01

    Electrochemical studies indicate that poly(Isothianaphthene) or PITN, can be p-doped only. Electrochemical properties of PITN and Nafion-PITN in acetonitrile solutions containing tetra-phenyl Phosphonium chloride as supporting electrolyte are compared. In both cases, the electrochemical behavior of thin films are different from that of thick films. In addition, Nafion does not seem to alter the electrochemical properties of PITN. Cyclic voltammetric and chronocoulometric measurements were made to compute the diffusion coefficient of the counter ions. Electrochemical behavior of both PITN and Nafion-PITN in acetonitrile solution containing different counter ions are described. PITN, when electrochemically deposited, apparently neither passivates surface states present nor forms ohmic contacts with p-Si or p(+)Si single-crystal electrodes.

  12. 43 CFR 404.18 - How can I request assistance to conduct a feasibility study?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false How can I request assistance to conduct a feasibility study? 404.18 Section 404.18 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR RECLAMATION RURAL WATER SUPPLY PROGRAM Overview § 404.18 How can...

  13. The Connoisseurship of Conducting: A Qualitative Study of Exemplary Wind Band Conductors

    ERIC Educational Resources Information Center

    Barry, Nancy; Henry, Daniel

    2015-01-01

    This study aimed to gain an in-depth perspective through examining how the conducting pedagogy of three selected exemplary high school and college instrumental music conductors function within the context of an actual rehearsal. A typical rehearsal was video recorded, followed by a "think-aloud" session in which the conductor viewed the…

  14. 21 CFR 320.25 - Guidelines for the conduct of an in vivo bioavailability study.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... absorption, the half-life of the therapeutic moiety in vivo, and the rate of excretion and/or metabolism... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Guidelines for the conduct of an in vivo bioavailability study. 320.25 Section 320.25 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH...

  15. 21 CFR 320.25 - Guidelines for the conduct of an in vivo bioavailability study.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... absorption, the half-life of the therapeutic moiety in vivo, and the rate of excretion and/or metabolism... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Guidelines for the conduct of an in vivo bioavailability study. 320.25 Section 320.25 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH...

  16. 21 CFR 320.25 - Guidelines for the conduct of an in vivo bioavailability study.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... absorption, the half-life of the therapeutic moiety in vivo, and the rate of excretion and/or metabolism... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Guidelines for the conduct of an in vivo bioavailability study. 320.25 Section 320.25 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH...

  17. USING CONTINUOUS MONITORS FOR CONDUCTING TRACER STUDIES IN WATER DISTRIBUTION SYSTEMS

    EPA Science Inventory

    The use of online monitors for conducting a distribution system tracer study is proving to be an essential tool to accurately understand the flow dynamics in a distribution system. In a series of field testing sponsored by U. S. Environmental Protection Agency (EPA) and Greater ...

  18. Conducting Studies of Transfer of Learning: A Practical Guide. Final Report.

    ERIC Educational Resources Information Center

    Payne, Thomas A.

    This document is a guide for use by the practical researcher concerned with conducting studies of transfer of learning from pretraining of pilots in ground-based environments to performance in aircraft. While the material addresses principally transfer of learning of pilots, many of the issues should be applicable to other contexts, to include…

  19. Treatment of Comorbid Conduct Problems and Depression in Youth: A Pilot Study

    ERIC Educational Resources Information Center

    Wolff, Jennifer C.; Ollendick, Thomas H.

    2012-01-01

    The purpose of this study was to pilot a cognitive behavioral treatment protocol for adolescents with co-occurring conduct problems and depression. A non-concurrent multiple baseline design was used to assess the effectiveness of the intervention. A sample of five adolescents, aged 11 to 14 years, participated; all five families completed the…

  20. Qualitative Research and Educational Leadership: Essential Dynamics to Consider When Designing and Conducting Studies

    ERIC Educational Resources Information Center

    Brooks, Jeffrey S.; Normore, Anthony H.

    2015-01-01

    Purpose: The purpose of this paper is to highlight issues relayed to appropriate design and conduct of qualitative studies in educational leadership. Design/Methodology/Approach: The paper is a conceptual/logical argument that centers around the notion that while scholars in the field have at times paid attention to such dynamics, it is important…

  1. Paychecks: A Guide to Conducting Salary-Equity Studies for Higher Education Faculty. Second Edition.

    ERIC Educational Resources Information Center

    Haignere, Lois

    This guidebook is designed as a resource for those in the higher education community who want to conduct analyses of bias in faculty salaries or to understand and interpret the results of studies presented to them. This edition will help readers detect gender and face bias in current rank, select a salary-equity consultant, understand different…

  2. Handbook for Conducting a Study of the Economic Impact of a Community College. (1981 Revised Edition).

    ERIC Educational Resources Information Center

    Wallhaus, Penny; Lach, Ivan J.

    Designed for use by community college personnel, this handbook provides information necessary to conduct a study of the impact of a community college on the business volume and other economic aspects of the community. Section I explains models for assessing the following seven types of economic impact: (1) college-related local business volume;…

  3. Effects of cognitive rehabilitation training on schizophrenia: 2 years of follow-up

    PubMed Central

    Tao, Jianqing; Zeng, Qiang; Liang, Jia; Zhou, Aihua; Yin, Xuebing; Xu, Ai

    2015-01-01

    Objective: Schizophrenia is a mental disorder and characterized by abnormal social behavior and failure to recognize what is real. The current study was to explore the long-term effects of cognitive rehabilitation training on schizophrenia. Methods: Eighty six cases of hospitalized patients with schizophrenia were randomly divided into study group and control group. The relapse and employment (attending school) rates were used as indicators to assess the treatment effect. All patients were followed up by 2 years. Kaplan-Meier survival analysis was conducted with relapse and employment (attending school) rates. Results: The rates of relapse in the study group and the control group were 18% and 41%, and relapse free survival time was 22.22 months and 18.55 months; the rates of employment (attending school) were 64% and 43%, and not employment (attending school) time were 10.68 months and 15.74 months, respectively. There was significant difference between the two groups (P<0.05). Conclusions: We found that the cognitive rehabilitation training could significantly reduce schizophrenic relapse rate, prolong the time of patients without relapse, improve the employment (attending school) rate, and shorten the discharged time, which is a powerful treatment method to improve social competence in schizophrenia patients. PMID:26629117

  4. Study of electrical conductivity response upon formation of ice and gas hydrates from salt solutions by a second generation high pressure electrical conductivity probe

    NASA Astrophysics Data System (ADS)

    Sowa, Barbara; Zhang, Xue Hua; Kozielski, Karen A.; Dunstan, Dave E.; Hartley, Patrick G.; Maeda, Nobuo

    2014-11-01

    We recently reported the development of a high pressure electrical conductivity probe (HP-ECP) for experimental studies of formation of gas hydrates from electrolytes. The onset of the formation of methane-propane mixed gas hydrate from salt solutions was marked by a temporary upward spike in the electrical conductivity. To further understand hydrate formation a second generation of window-less HP-ECP (MkII), which has a much smaller heat capacity than the earlier version and allows access to faster cooling rates, has been constructed. Using the HP-ECP (MkII) the electrical conductivity signal responses of NaCl solutions upon the formation of ice, tetrahydrofuran hydrates, and methane-propane mixed gas hydrate has been measured. The concentration range of the NaCl solutions was from 1 mM to 3M and the driving AC frequency range was from 25 Hz to 5 kHz. This data has been used to construct an "electrical conductivity response phase diagrams" that summarize the electrical conductivity response signal upon solid formation in these systems. The general trend is that gas hydrate formation is marked by an upward spike in the conductivity at high concentrations and by a drop at low concentrations. This work shows that HP-ECP can be applied in automated measurements of hydrate formation probability distributions of optically opaque samples using the conductivity response signals as a trigger.

  5. Study of electrical conductivity response upon formation of ice and gas hydrates from salt solutions by a second generation high pressure electrical conductivity probe.

    PubMed

    Sowa, Barbara; Zhang, Xue Hua; Kozielski, Karen A; Dunstan, Dave E; Hartley, Patrick G; Maeda, Nobuo

    2014-11-01

    We recently reported the development of a high pressure electrical conductivity probe (HP-ECP) for experimental studies of formation of gas hydrates from electrolytes. The onset of the formation of methane-propane mixed gas hydrate from salt solutions was marked by a temporary upward spike in the electrical conductivity. To further understand hydrate formation a second generation of window-less HP-ECP (MkII), which has a much smaller heat capacity than the earlier version and allows access to faster cooling rates, has been constructed. Using the HP-ECP (MkII) the electrical conductivity signal responses of NaCl solutions upon the formation of ice, tetrahydrofuran hydrates, and methane-propane mixed gas hydrate has been measured. The concentration range of the NaCl solutions was from 1 mM to 3M and the driving AC frequency range was from 25 Hz to 5 kHz. This data has been used to construct an "electrical conductivity response phase diagrams" that summarize the electrical conductivity response signal upon solid formation in these systems. The general trend is that gas hydrate formation is marked by an upward spike in the conductivity at high concentrations and by a drop at low concentrations. This work shows that HP-ECP can be applied in automated measurements of hydrate formation probability distributions of optically opaque samples using the conductivity response signals as a trigger.

  6. Numerical study of the periodic Anderson model with a quarter-filled conduction band

    NASA Astrophysics Data System (ADS)

    Yang, Shuxiang; Moreno, Juana; Jarrell, Mark

    2015-03-01

    Using the dynamical cluster approximation with continuous-time quantum Monte Carlo as the cluster solver and the recently introduced dual-fermion method, we study the underlying physics of the periodic Anderson model where the conduction band is near quarter-filling while the f-band electron band is half filled. For these parameters, the RKKY coupling changes its nature from ferromagnetic to anti-ferromagnetic, yielding an interesting phase-diagram. Especially, we find the charge ordering of the conduction band is strongly enhanced, which could be due to the proximity to a quantum critical point.

  7. Temporal changes of topsoil hydraulic conductivity studied by multiple-point tension disk infiltrometer

    NASA Astrophysics Data System (ADS)

    Klipa, Vladimir; Zumr, David; Snehota, Michal; Dohnal, Michal

    2015-04-01

    Hydraulic conductivity of cultivated soils is strongly affected by agrotechnical procedures, soil compaction, plant growth etc. This contribution is focused on series of measurement of topsoil unsaturated hydraulic conductivity using automated multipoint tension infiltrometer developed at CTU in Prague. The apparatus consists of two triplets of minidisk infiltrometers that are supported by a light aluminum frame. Therefore it allows simultaneous measurement of six tension infiltrations at two different pressure heads. Experiments were conducted at the experimental agricultural catchment Nučice (Central Bohemia, Czech Republic) as a part of the broader research of rainfall-runoff and soil erosion processes. The soil in the catchment is classified as Cambisol with texture that is ranging from loam to clay loam and is conservatively tilled. Series of ten infiltration campaigns (56 individual infiltration experiments) were carried out on a single experimental plot during period of two years. Dataset involves measurement under various agricultural activities and crop phenophases. The hydraulic conductivities were determined using extended semiempirical estimation procedure of Zhang. Additionally, large undisturbed soil samples were analyzed with use of X-ray computed tomography to assess the soil structure morphology in detail. Results show that unsaturated hydraulic conductivity was the lowest in early spring and did increase at beginning of summer. Unsaturated soil hydraulic conductivity was higher when the soil bulk density was high. During the summer and autumn the unsaturated hydraulic conductivity remained relatively unchanged. The impact of agricultural procedures was not apparent in the dataset.. The study has been supported by the Czech Science Foundation Project No. 13-20388P and by CTU in Prague funding via Student's Grant Competition SGS No. SGS14/131/OHK1/2T/11. The MultiDisk infiltrometer was developed within the framework of the project supported by the

  8. Electrical conductivity of activated carbon-metal oxide nanocomposites under compression: a comparison study.

    PubMed

    Barroso-Bogeat, A; Alexandre-Franco, M; Fernández-González, C; Macías-García, A; Gómez-Serrano, V

    2014-12-01

    From a granular commercial activated carbon (AC) and six metal oxide (Al2O3, Fe2O3, SnO2, TiO2, WO3 and ZnO) precursors, two series of AC-metal oxide nanocomposites were prepared by wet impregnation, oven-drying at 120 °C, and subsequent heat treatment at 200 or 850 °C in an inert atmosphere. Here, the electrical conductivity of the resulting products was studied under moderate compression. The influence of the applied pressure, sample volume, mechanical work, and density of the hybrid materials was thoroughly investigated. The DC electrical conductivity of the compressed samples was measured at room temperature by the four-probe method. Compaction assays suggest that the mechanical properties of the nanocomposites are largely determined by the carbon matrix. Both the decrease in volume and the increase in density were relatively small and only significant at pressures lower than 100 kPa for AC and most nanocomposites. In contrast, the bulk electrical conductivity of the hybrid materials was strongly influenced by the intrinsic conductivity, mean crystallite size, content and chemical nature of the supported phases, which ultimately depend on the metal oxide precursor and heat treatment temperature. The supported nanoparticles may be considered to act as electrical switches either hindering or favouring the effective electron transport between the AC cores of neighbouring composite particles in contact under compression. Conductivity values as a rule were lower for the nanocomposites than for the raw AC, all of them falling in the range of semiconductor materials. With the increase in heat treatment temperature, the trend is toward the improvement of conductivity due to the increase in the crystallite size and, in some cases, to the formation of metals in the elemental state and even metal carbides. The patterns of variation of the electrical conductivity with pressure and mechanical work were slightly similar, thus suggesting the predominance of the pressure

  9. Central motor conduction time by magnetic stimulation of the cortex and peripheral nerve conduction follow-up studies in Friedreich's ataxia.

    PubMed

    Cruz-Martínez, A; Palau, F

    1997-12-01

    A follow-up clinical study, peripheral motor and sensory nerve conduction velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9-12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained unchanged for several years. Central motor conduction times were abnormal in all patients. Clinical conditions worsened significantly between successive examinations with significant increments in threshold and significant decrement of the amplitude of motor evoked potentials. The results are consistent with progressive pyramidal and cerebellar pathways involvement as the cause of clinical worsening in FA.

  10. A Checklist for the Conduct, Reporting, and Appraisal of Microcosting Studies in Health Care: Protocol Development

    PubMed Central

    Reiff, Marian

    2016-01-01

    Background Microcosting is a cost estimation method that requires the collection of detailed data on resources utilized, and the unit costs of those resources in order to identify actual resource use and economic costs. Microcosting findings reflect the true costs to health care systems and to society, and are able to provide transparent and consistent estimates. Many economic evaluations in health and medicine use charges, prices, or payments as a proxy for cost. However, using charges, prices, or payments rather than the true costs of resources can result in inaccurate estimates. There is currently no existing checklist or guideline for the conduct, reporting, or appraisal of microcosting studies in health care interventions. Objective The aim of this study is to create a checklist and guideline for the conduct, reporting, and appraisal of microcosting studies in health care interventions. Methods Appropriate potential domains and items will be identified through (1) a systematic review of all published microcosting studies of health and medical interventions, strategies, and programs; (2) review of published checklists and guidelines for economic evaluations of health interventions, and selection of items relevant for microcosting studies; and (3) theoretical analysis of economic concepts relevant for microcosting. Item selection, formulation, and reduction will be conducted by the research team in order to develop an initial pool of items for evaluation by an expert panel comprising individuals with expertise in microcosting and economic evaluation of health interventions. A modified Delphi process will be conducted to achieve consensus on the checklist. A pilot test will be conducted on a selection of the articles selected for the previous systematic review of published microcosting studies. Results The project is currently in progress. Conclusions Standardization of the methods used to conduct, report or appraise microcosting studies will enhance the

  11. Capacitance and conductance studies on silicon solar cells subjected to 8 MeV electron irradiations

    NASA Astrophysics Data System (ADS)

    Sathyanarayana Bhat, P.; Rao, Asha; Sanjeev, Ganesh; Usha, G.; Priya, G. Krishna; Sankaran, M.; Puthanveettil, Suresh E.

    2015-06-01

    The space grade silicon solar cells were irradiated with 8 MeV electrons with doses ranging from 5-100 k Gy. Capacitance and conductance measurements were carried out in order to investigate the anomalous degradation of the cells in the radiation harsh environments and the results are presented in this paper. Detailed and systematic analysis of the frequency-dependent capacitance and conductance measurements were performed to extract the information about the interface trap states. The small increase in density of interface states was observed from the conductance-frequency measurements. The reduction in carrier concentration upon electron irradiation is due to the trapping of charge carriers by the radiation induced trap centres. The Drive Level Capacitance Profiling (DLCP) technique has been applied to study the properties of defects in silicon solar cells. A small variation in responding state densities with measuring frequency was observed and the defect densities are in the range 1015 -1016 cm-3.

  12. A study of phonon anisotropic scattering effect on silicon thermal conductivity at nanoscale

    SciTech Connect

    Bong, Victor N-S; Wong, Basil T.

    2015-08-28

    Previous studies have shown that anisotropy in phonon transport exist because of the difference in phonon dispersion relation due to different lattice direction, as observed by a difference in in-plane and cross-plane thermal conductivity. The directional preference (such as forward or backward scattering) in phonon propagation however, remains a relatively unexplored frontier. Our current work adopts a simple scattering probability in radiative transfer, which is called Henyey and Greenstein probability density function, and incorporates it into the phonon Monte Carlo simulation to investigate the effect of directional scattering in phonon transport. In this work, the effect of applying the anisotropy scattering is discussed, as well as its impact on the simulated thermal conductivity of silicon thin films. While the forward and backward scattering will increase and decrease thermal conductivity respectively, the extent of the effect is non-linear such that forward scattering has a more obvious effect than backward scattering.

  13. Theoretical study of optical conductivity of graphene with magnetic and nonmagnetic adatoms

    NASA Astrophysics Data System (ADS)

    Majidi, Muhammad Aziz; Siregar, Syahril; Rusydi, Andrivo

    2014-11-01

    We present a theoretical study of the optical conductivity of graphene with magnetic and nonmagnetic adatoms. First, by introducing an alternating potential in a pure graphene, we demonstrate a gap formation in the density of states and the corresponding optical conductivity. We highlight the distinction between such a gap formation and the so-called Pauli blocking effect. Next, we apply this idea to graphene with adatoms by introducing magnetic interactions between the carrier spins and the spins of the adatoms. Exploring various possible ground-state spin configurations of the adatoms, we find that the antiferromagnetic configuration yields the lowest total electronic energy and is the only configuration that forms a gap. Furthermore, we analyze four different circumstances leading to similar gaplike structures and propose a means to interpret the magneticity and the possible orderings of the adatoms on graphene solely from the optical conductivity data. We apply this analysis to the recently reported experimental data of oxygenated graphene.

  14. Electrical conductivity and dielectric studies of MnO2 doped V2O5

    NASA Astrophysics Data System (ADS)

    Tan, Foo Khoon; Hassan, Jumiah; Wahab, Zaidan Abd.; Azis, Raba'ah Syahidah

    The investigation on electrical conductivity and dielectric properties of mixed oxide of manganese (Mn) and vanadium (V) was carried out to study the mixed oxides response to different frequencies and different measuring temperatures. The frequency and temperature dependence of AC conductivity, dielectric constant and dielectric loss factor of mixed oxides were studied in the frequency range of 40 Hz-1 MHz and a temperature range of 30-250 °C. Since the mixed oxides are multi phase materials, hence the properties of the pure oxides are also presented in this study to discuss the multi phase behaviour of the mixed oxides. The XRD pattern shows the Mn-V oxide is multiphase and quantitative phase analysis was performed to determine the relative phases. The overall results indicate that with increasing temperature, the AC conductivity, dielectric constant, dielectric loss factor and loss tangent of the Mn-V mixed oxide increases. However, it shows an overlap in the dielectric constant at 225 °C and 250 °C due to the V2O5 phase in the mixed oxide. From the AC activation energy, the mixed oxides underwent conduction mechanism transition from band to hopping in the investigated frequency range. The MnV2O6 has relatively good resistivity, therefore the mixed oxide sintered at 550 °C with the highest composition of MnV2O6 gives the highest dielectric constant of 9845 at 1 kHz, and at 250 °C.

  15. Diameter Dependence of Lattice Thermal Conductivity of Single-Walled Carbon Nanotubes: Study from Ab Initio

    PubMed Central

    Yue, Sheng-Ying; Ouyang, Tao; Hu, Ming

    2015-01-01

    The effects of temperature, tube length, defects, and surface functionalization on the thermal conductivity (κ) of single-walled carbon nanotubes (SWCNTs) were well documented in literature. However, diameter dependence of thermal conductivity of SWCNTs received less attentions. So far, diverse trends of the diameter dependence have been discussed by different methods and all the previous results were based on empirical interatomic potentials. In this paper, we emphasize to clarify accurate κ values of SWCNTs with different diameters and in-plane κ of graphene. All the studies were under the framework of anharmonic lattice dynamics and Boltzmann transport equation (BTE) based on first principle calculations. We try to infer the right trend of diameter dependent thermal conductivity of SWCNTs. We infer that graphene is the limitation as SWCNT with an infinite diameter. We analyzed the thermal conductivity contributions from each phonon mode in SWCNTs to explain the trend. Meanwhile, we also identify the extremely low thermal conductivity of ultra-thin SWCNTs. PMID:26490342

  16. High-frequency hopping conductivity in the quantum Hall effect regime: Acoustical studies

    NASA Astrophysics Data System (ADS)

    Drichko, I. L.; Diakonov, A. M.; Smirnov, I. Yu.; Galperin, Yu. M.; Toropov, A. I.

    2000-09-01

    The high-frequency conductivity of Si δ-doped GaAs/AlGaAs heterostructures is studied in the integer quantum Hall effect (QHE) regime, using acoustic methods. Both the real and the imaginary parts of the complex conductivity are determined from the experimentally observed magnetic field and temperature dependencies of the velocity and the attenuation of a surface acoustic wave. It is demonstrated that in structures with carrier density (1.3-2.8)×1011 cm-2 and mobility (1-2)×105 cm2/V s the mechanism of low-temperature conductance near the QHE plateau centers is hopping. It is also shown that at magnetic fields corresponding to filling factors 2 and 4, the doped Si δ layer efficiently shunts the conductance in the two-dimensional electron gas (2DEG) channel. A method to separate the two contributions to the real part of the conductivity is developed, and the localization length in the 2DEG channel is estimated within the context of a nearest-neighbor hopping model.

  17. First principles study of thermal conductivity cross-over in nanostructured zinc-chalcogenides

    SciTech Connect

    Katre, Ankita; Madsen, Georg K. H.; Togo, Atsushi; Tanaka, Isao

    2015-01-28

    Systematic first principles studies of zinc-chalcogenides have been performed to understand their thermal transport behaviour. We have applied the Boltzmann transport equation in the relaxation time approximation to calculate the thermal conductivity of ZnS, ZnSe, and ZnTe. We find a thermal conductivity cross-over between ZnS and ZnSe at nanostructure sizes around 0.1–0.2 μm and explain this in terms of the different contributions of phonon modes in these materials. We study the effect of nanostructuring using both the diffusive boundary scattering and confined mean free path limit and discuss the variations in the results. Furthermore, we show the strong influence of isotope scattering on the thermal conductivity. The calculated thermal conductivity is found to be strongly dependent on the volume and we explain the observed differences between local density and generalized gradient approximation calculations. We compare further calculated thermal properties, such as the thermal expansion coefficient, to experiment to validate our approach.

  18. A Study of the Resonance Frequency of Conductive Grains in a Dusty Plasma

    NASA Astrophysics Data System (ADS)

    Zhang, Zhuanhao; Hyde, Truell; Matthews, Lorin; Kong, Jie; Carmona Reyes, Jorge; Qiao, Ke; Schmoke, Jimmy; Cook, Mike

    2009-11-01

    Over the past decade, the dynamic behavior of insulating (melamine formaldehyde) dust particles immersed in a complex plasma have been studied extensively. Phenomena such as disordered or ordered structures, the interaction of dust particles with the wake field produced by the ion flow, and the interaction between particles have all been the subject of both experimental and numerical investigation. However, the investigation of conducting materials in dusty plasmas has not yet received the same attention. In this work, the resonance frequency of conductive grains at various pressures and powers within a standard GEC reference cell is examined and the results compared to those for insulating grains (MF). Since the resonance frequency of a dust grain is proportional to its charge-to-mass ratio, such studies are beneficial in helping determine the particle charge. Preliminary results will be presented showing that in similar plasma environments, conducting grains do not exhibit the same behavior as non-conducting grains possibly due to differences in the charging process.

  19. Thermal conductivity of ordered-disordered material: a case study of superionic Ag2Te.

    PubMed

    Ouyang, Tao; Zhang, Xiaoliang; Hu, Ming

    2015-01-16

    Thermoelectric devices, which can generate electricity from waste heat, offer an attractive pathway for addressing an important niche in the globally growing landscape of energy demand. In the past few decades, the search for high-efficiency thermoelectrics has been guided by the concept of 'phonon-glass electron-crystal' (PGEC), i.e. an ideal thermoelectric material should have high carrier mobility and low thermal conductivity. Although remarkable progress has already been made along this line, the efficiency of thermoelectrics is still too poor to compete with other electricity producing methods. Ordered-disordered material, an emerging trend of high performance thermoelectrics under the concept of PGEC, is a new hot topic in the current thermoelectric research community. Taking superionic phase silver telluride (α-Ag2Te) as an example, we performed a comprehensive study of the thermal transport properties and of its physical mechanism by means of equilibrium molecular dynamic simulations. The results show that the thermal conductivity of α-Ag2Te is intrinsically very low. By analyzing the different contributions to the overall thermal conductivity, we revealed for the first time from atomistic simulations that the vibration of the Te(2-) sublattice dominates the thermal transport of α-Ag2Te, while the collision between the randomly diffusing Ag(+) ions and the Te(2-) sublattice yields a significant negative contribution to the thermal transport. We also studied the effect of isotropic compressive stain and carrier concentration on the thermal conductivity of α-Ag2Te. It has been found that the thermal conductivity can be largely reduced by applying compressive strain or with stoichiometric quantity modulation. Our studies shed light on the governing mechanism of thermal transport in ordered-disordered materials and could offer useful guidance for engineering the thermal transport properties of superionic conductors in terms of enhancing their thermoelectric

  20. A Study on the pH and conductivity of rural rainfall employing two collocated samplers

    NASA Astrophysics Data System (ADS)

    Sequeira, R.; Lai, C. C.; Peart, M. R.

    1999-02-01

    A set of about 100 daily rainfall samples were collected over a period of about one year during the 1995-1996 period using two collocated, automated samplers placed ˜4 m apart at the rural Kadoorie Agricultural Research Centre (KARC) in Hong Kong. The p H and conductivity of the rainwater were measured immediately after sample collection. There is a strong correlation between the two free hydrogen ion concentrations (R2 ≈ 0.92) and an even stronger one between the conductivities (R2 ≈ 0.99). Statistically, there is no difference at the 0.05 level of significance between the means of either the two free hydrogen ion concentrations or the two conductivities. The conductivity results suggest that the total dissolved solids in the two samplers is probably quite similar in magnitude. No relationship is observed between the free acid content and daily rainfall volume in either sampler, a result similar to that obtained in previous studies involving bulk fall at the KARC and wet fall in urban Hong Kong as a whole. A weak hyperbolic relationship exists between the rainfall volume and the conductivity, and their log-log plot indicates only a somewhat weak inverse linear relationship, with correlation coefficients of -0.60 and -0.61 for the two samplers, considered individually. Finally, the unbiased estimates of the product of rainfall volume and conductivity for the collocated samples suggest that the microscale variability (≳4 m) of the mean wet mass flux of total dissolved material in rural Hong Kong rainfall is negligible.

  1. Phase behaviour and conductivity study on multi-component mixtures for electrodeposition in supercritical fluids.

    PubMed

    Bartlett, Philip N; Cook, David C; George, Michael W; Ke, Jie; Levason, William; Reid, Gillian; Su, Wenta; Zhang, Wenjian

    2010-01-14

    Electrochemistry in supercritical CO(2) (scCO(2)) is difficult because the very low dielectric constant of the fluid restricts the solubility of ionic species and the conductivity of dissolved electrolytes. To overcome this problem to allow us to carry out electrodeposition at macroelectrodes from scCO(2) we have investigated the use of co-solvents and modified electrolyte salts chosen to increase their solubility and dissociation in the supercritical fluid. Here we report results of phase behaviour studies for mixtures of CO(2) with [NBu(n)(4)][BF(4)] and either methanol (CH(3)OH) or acetonitrile (CH(3)CN) as the co-solvent. These show that the solubility of [NBu(n)(4)][BF(4)] is approximately 5 times larger when CH(3)CN is the co-solvent rather than CH(3)OH. Consequently the phase behaviour of the ternary of CO(2)-[NBu(n)(4)][BF(4)]-CH(3)CN was studied in greater detail over a range of compositions. To enhance the conductivity of scCO(2)-CH(3)CN a range of electrolyte salts was synthesised in which the [NBu(n)(4)](+) and/or [BF(4)](-) ion were replaced by different derivatives. Results for the phase behaviour and conductivity of these modified electrolyte salts in scCO(2)-CH(3)CN are reported for several different compositions. We find that increasing the degree of fluorination and size of the ions increases the solubility of the electrolyte salt in scCO(2)-CH(3)CN. Of the 11 electrolytes investigated [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] appears the most suitable for use in scCO(2)-CH(3)CN with a molar conductivity of 22-26 S cm(2) mol(-1) and a maximum measured conductivity of approximately 3 mS cm(-1) for 0.07 M [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] dissolved in scCO(2)-CH(3)CN (molar ratio CH(3)CN : CO(2) approximately 0.12) at 20 MPa and 328.15 K. This is an order of magnitude improvement over similar results for the [NBu(n)(4)][BF(4)] parent. Studies of the conductance as a function of the electrolyte concentration suggest that triple ions make an

  2. Comparing the similarity of responses received from studies in Amazon's Mechanical Turk to studies conducted online and with direct recruitment.

    PubMed

    Bartneck, Christoph; Duenser, Andreas; Moltchanova, Elena; Zawieska, Karolina

    2015-01-01

    Computer and internet based questionnaires have become a standard tool in Human-Computer Interaction research and other related fields, such as psychology and sociology. Amazon's Mechanical Turk (AMT) service is a new method of recruiting participants and conducting certain types of experiments. This study compares whether participants recruited through AMT give different responses than participants recruited through an online forum or recruited directly on a university campus. Moreover, we compare whether a study conducted within AMT results in different responses compared to a study for which participants are recruited through AMT but which is conducted using an external online questionnaire service. The results of this study show that there is a statistical difference between results obtained from participants recruited through AMT compared to the results from the participant recruited on campus or through online forums. We do, however, argue that this difference is so small that it has no practical consequence. There was no significant difference between running the study within AMT compared to running it with an online questionnaire service. There was no significant difference between results obtained directly from within AMT compared to results obtained in the campus and online forum condition. This may suggest that AMT is a viable and economical option for recruiting participants and for conducting studies as setting up and running a study with AMT generally requires less effort and time compared to other frequently used methods. We discuss our findings as well as limitations of using AMT for empirical studies.

  3. Hydraulic conductivity study of compacted clay soils used as landfill liners for an acidic waste

    SciTech Connect

    Hamdi, Noureddine; Srasra, Ezzeddine

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Examined the hydraulic conductivity evolution as function of dry density of Tunisian clay soil. Black-Right-Pointing-Pointer Follow the hydraulic conductivity evolution at long-term of three clay materials using the waste solution (pH=2.7). Black-Right-Pointing-Pointer Determined how compaction affects the hydraulic conductivity of clay soils. Black-Right-Pointing-Pointer Analyzed the concentration of F and P and examined the retention of each soil. - Abstract: Three natural clayey soils from Tunisia were studied to assess their suitability for use as a liner for an acid waste disposal site. An investigation of the effect of the mineral composition and mechanical compaction on the hydraulic conductivity and fluoride and phosphate removal of three different soils is presented. The hydraulic conductivity of these three natural soils are 8.5 Multiplication-Sign 10{sup -10}, 2.08 Multiplication-Sign 10{sup -9} and 6.8 Multiplication-Sign 10{sup -10} m/s for soil-1, soil-2 and soil-3, respectively. Soil specimens were compacted under various compaction strains in order to obtain three wet densities (1850, 1950 and 2050 kg/m{sup 3}). In this condition, the hydraulic conductivity (k) was reduced with increasing density of sample for all soils. The test results of hydraulic conductivity at long-term (>200 days) using acidic waste solution (pH = 2.7, charged with fluoride and phosphate ions) shows a decrease in k with time only for natural soil-1 and soil-2. However, the specimens of soil-2 compressed to the two highest densities (1950 and 2050 kg/m{sup 3}) are cracked after 60 and 20 days, respectively, of hydraulic conductivity testing. This damage is the result of a continued increase in the internal stress due to the swelling and to the effect of aggressive wastewater. The analysis of anions shows that the retention of fluoride is higher compared to phosphate and soil-1 has the highest sorption capacity.

  4. Conduct of a personal radiofrequency electromagnetic field measurement study: proposed study protocol

    PubMed Central

    2010-01-01

    Background The development of new wireless communication technologies that emit radio frequency electromagnetic fields (RF-EMF) is ongoing, but little is known about the RF-EMF exposure distribution in the general population. Previous attempts to measure personal exposure to RF-EMF have used different measurement protocols and analysis methods making comparisons between exposure situations across different study populations very difficult. As a result, observed differences in exposure levels between study populations may not reflect real exposure differences but may be in part, or wholly due to methodological differences. Methods The aim of this paper is to develop a study protocol for future personal RF-EMF exposure studies based on experience drawn from previous research. Using the current knowledge base, we propose procedures for the measurement of personal exposure to RF-EMF, data collection, data management and analysis, and methods for the selection and instruction of study participants. Results We have identified two basic types of personal RF-EMF measurement studies: population surveys and microenvironmental measurements. In the case of a population survey, the unit of observation is the individual and a randomly selected representative sample of the population is needed to obtain reliable results. For microenvironmental measurements, study participants are selected in order to represent typical behaviours in different microenvironments. These two study types require different methods and procedures. Conclusion Applying our proposed common core procedures in future personal measurement studies will allow direct comparisons of personal RF-EMF exposures in different populations and study areas. PMID:20487532

  5. A phase-field study on the oxidation behavior of Ni considering heat conduction

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Ai, Shigang; Fang, Daining

    2016-08-01

    Phase-field modeling approach has been used to study the oxidation behavior of pure Ni when considering heat conduction. In this calculation, the dependence of the coefficient of the Cahn-Hilliard equation Lc on the temperature T was considered. To this end, high-temperature oxidation experiments and phase-field modeling for pure Ni were performed in air under atmospheric pressure at 600, 700, and 800° C. The oxidation rate was measured by thermogravimetry and Lc at these temperatures was determined via interactive algorithm. With the Lc {-}T relationship constructed, oxidation behavior of Ni when considering heat conduction was investigated. The influence of temperature boundaries on the oxidation degree, oxide film thickness, and specific weight gain were discussed. The phase-field modeling approach proposed in this study will give some highlights of the oxidation resistance analysis and cooling measures design of thermal protection materials.

  6. A facile approach for shape selective synthesis of rhodium nanostructures and conductivity studies

    SciTech Connect

    Sathe, Bhaskar R.

    2012-12-15

    Shape selective synthesis of Rh nanostructures has been demonstrated with the help of a single step chemical vapor deposition, where different shapes like cubes at 500 Degree-Sign C, pyramids and hexagons at 500 Degree-Sign C, 700 Degree-Sign C and 900 Degree-Sign C respectively have been obtained as a function of temperature. Scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and four probe conductivity measurements were used to study the morphology, crystallinity and phase purity of the structures. The conductivity values for as synthesised nanostructures have been obtained in the range of 2-7 kS/cm{sup 2}. On the basis of the experimental results, from TGA and XPS studies possible mechanistic pathway for the evolution of Rh nanostructures was discussed.

  7. Techniques for Conducting Effective Concept Design and Design-to-Cost Trade Studies

    NASA Technical Reports Server (NTRS)

    Di Pietro, David A.

    2015-01-01

    Concept design plays a central role in project success as its product effectively locks the majority of system life cycle cost. Such extraordinary leverage presents a business case for conducting concept design in a credible fashion, particularly for first-of-a-kind systems that advance the state of the art and that have high design uncertainty. A key challenge, however, is to know when credible design convergence has been achieved in such systems. Using a space system example, this paper characterizes the level of convergence needed for concept design in the context of technical and programmatic resource margins available in preliminary design and highlights the importance of design and cost evaluation learning curves in determining credible convergence. It also provides techniques for selecting trade study cases that promote objective concept evaluation, help reveal unknowns, and expedite convergence within the trade space and conveys general practices for conducting effective concept design-to-cost studies.

  8. Exploring the acceptability and feasibility of conducting a large longitudinal population-based study in Canada.

    PubMed

    Kirkland, Susan A; Raina, Parminder S; Wolfson, Christina; Strople, Geoff; Kits, Olga; Dukeshire, Steven; Angus, Camille L; Szala-Meneok, Karen; Uniat, Jennifer; Keshavarz, Homa; Furlini, Linda; Pelletier, Amélie

    2009-09-01

    ABSTRACTSuccessful recruitment and retention for population-based longitudinal studies requires understanding facilitators and barriers to participation. This study explored Canadians' views regarding one such study, the proposed Canadian Longitudinal Study on Aging (CLSA). Focus groups of participants > or =40 years of age were held in six proposed CLSA data collection sites (Halifax, Montreal, Hamilton, Winnipeg, Calgary, and Vancouver) to discuss participating in a long-term study of healthy aging. There was fundamental support for longitudinal research on health and aging. Altruism was a key motivation to participation, and universities were viewed as credible parties to conduct such studies. Participants had few worries about providing biological samples but expressed concern about potential misuse of genetic materials, commercialization of participant data, and privacy issues. These findings have already informed current, and will inform future, work on the CLSA, and will also provide useful information to researchers who undertake other population-based longitudinal studies.

  9. An experimental study on thermal conductivity and viscosity of nanofluids containing carbon nanotubes.

    PubMed

    Sadri, Rad; Ahmadi, Goodarz; Togun, Hussein; Dahari, Mahidzal; Kazi, Salim Newaz; Sadeghinezhad, Emad; Zubir, Nashrul

    2014-01-01

    Recently, there has been considerable interest in the use of nanofluids for enhancing thermal performance. It has been shown that carbon nanotubes (CNTs) are capable of enhancing the thermal performance of conventional working liquids. Although much work has been devoted on the impact of CNT concentrations on the thermo-physical properties of nanofluids, the effects of preparation methods on the stability, thermal conductivity and viscosity of CNT suspensions are not well understood. This study is focused on providing experimental data on the effects of ultrasonication, temperature and surfactant on the thermo-physical properties of multi-walled carbon nanotube (MWCNT) nanofluids. Three types of surfactants were used in the experiments, namely, gum arabic (GA), sodium dodecylbenzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS). The thermal conductivity and viscosity of the nanofluid suspensions were measured at various temperatures. The results showed that the use of GA in the nanofluid leads to superior thermal conductivity compared to the use of SDBS and SDS. With distilled water as the base liquid, the samples were prepared with 0.5 wt.% MWCNTs and 0.25% GA and sonicated at various times. The results showed that the sonication time influences the thermal conductivity, viscosity and dispersion of nanofluids. The thermal conductivity of nanofluids was typically enhanced with an increase in temperature and sonication time. In the present study, the maximum thermal conductivity enhancement was found to be 22.31% (the ratio of 1.22) at temperature of 45°C and sonication time of 40 min. The viscosity of nanofluids exhibited non-Newtonian shear-thinning behaviour. It was found that the viscosity of MWCNT nanofluids increases to a maximum value at a sonication time of 7 min and subsequently decreases with a further increase in sonication time. The presented data clearly indicated that the viscosity and thermal conductivity of nanofluids are influenced by the

  10. Reversible light induced conductance switching of asymmetric diarylethenes on gold: surface and electronic studies

    NASA Astrophysics Data System (ADS)

    Arramel, Affa; Pijper, Thomas C.; Kudernac, Tibor; Katsonis, Nathalie; van der Maas, Minko; Feringa, Ben L.; van Wees, Bart J.

    2013-09-01

    We report on the light-induced switching of conductance of a new generation of diarylethene switches embedded in an insulating matrix of dodecanethiol on Au(111), by using scanning tunneling microscopy (STM). The diarylethene switches we synthesize and study are modified diarylethenes where the thiophene unit at one side of the molecular backbone introduces an intrinsic asymmetry into the switch, which is expected to influence its photo-conductance properties. We show that reversible conversion between two distinguishable conductance states can be controlled via photoisomerisation of the switches by using alternative irradiation with UV (λ = 313 nm) or visible (λ > 420 nm) light. We addressed this phenomenon by using STM in ambient conditions, based on switching of the apparent height of the molecules which convert from 4-6 Å in their closed form to 0-1 Å in their open form. Furthermore, the levels of the frontier molecular orbital levels (HOMO and LUMO) were evaluated for these asymmetric switches by using Scanning Tunneling Spectroscopy at 77 K, which allowed us to determine a HOMO-LUMO energy gap of 2.24 eV.We report on the light-induced switching of conductance of a new generation of diarylethene switches embedded in an insulating matrix of dodecanethiol on Au(111), by using scanning tunneling microscopy (STM). The diarylethene switches we synthesize and study are modified diarylethenes where the thiophene unit at one side of the molecular backbone introduces an intrinsic asymmetry into the switch, which is expected to influence its photo-conductance properties. We show that reversible conversion between two distinguishable conductance states can be controlled via photoisomerisation of the switches by using alternative irradiation with UV (λ = 313 nm) or visible (λ > 420 nm) light. We addressed this phenomenon by using STM in ambient conditions, based on switching of the apparent height of the molecules which convert from 4-6 Å in their closed form to 0

  11. Identifying the barriers to conducting outcomes research in integrative health care clinic settings - a qualitative study

    PubMed Central

    2010-01-01

    Background Integrative health care (IHC) is an interdisciplinary blending of conventional medicine and complementary and alternative medicine (CAM) with the purpose of enhancing patients' health. In 2006, we designed a study to assess outcomes that are relevant to people using such care. However, we faced major challenges in conducting this study and hypothesized that this might be due to the lack of a research climate in these clinics. To investigate these challenges, we initiated a further study in 2008, to explore the reasons why IHC clinics are not conducting outcomes research and to identify strategies for conducting successful in-house outcomes research programs. The results of the latter study are reported here. Methods A total of 25 qualitative interviews were conducted with key participants from 19 IHC clinics across Canada. Basic content analysis was used to identify key themes from the transcribed interviews. Results Barriers identified by participants fell into four categories: organizational culture, organizational resources, organizational environment and logistical challenges. Cultural challenges relate to the philosophy of IHC, organizational leadership and practitioner attitudes and beliefs. Participants also identified significant issues relating to their organization's lack of resources such as funding, compensation, infrastructure and partnerships/linkages. Environmental challenges such as the nature of a clinic's patient population and logistical issues such as the actual implementation of a research program and the applicability of research data also posed challenges to the conduct of research. Embedded research leadership, integration of personal and professional values about research, alignment of research activities and clinical workflow processes are some of the factors identified by participants that support IHC clinics' ability to conduct outcomes research. Conclusions Assessing and enhancing the broader evaluation culture of IHC clinics

  12. Numerical study of conductive heat losses from a magmatic source at Phlegraean Fields

    NASA Astrophysics Data System (ADS)

    Di Maio, Rosa; Piegari, Ester; Mancini, Cecilia; Scandone, R.

    2015-01-01

    The thermal evolution of the Phlegraean magmatic system (southern Italy) is studied by analyzing the influence of the thermal property variations on the solution of the heat conduction equation. The aim of this paper is to verify if appropriate choices of thermal parameters can reproduce, at least to greater depths, the high temperatures measured in the geothermal wells, drilled inside the caldera, under the assumption of heat loss from a magma chamber by conduction. Since the main purpose is to verify the plausibility of such an assumption, rather simple models of the magmatic system are adopted and only major volcanic events (i.e., the Campanian Ignimbrite and the Neapolitan Yellow Tuff eruptions) are considered. The results of the simulated two-dimensional model scenarios show that by assuming an extended source region, whose emplacement time is longer than 40 ka, heat conduction mechanisms can provide temperatures as high as those measured at depths deeper than about 2000 m. On the other hand, the 1D simulations show that appropriate choices for the thermal conductivity depth profiles can reproduce the observed temperatures at depths deeper than about 1000 m. These findings question the apparent consensus that convection is the only dominant form of heat transfer at Phlegraean Fields and might motivate new research for reconstructing the thermal evolution of the Phlegraean magmatic system.

  13. Fluid stimulation elicits hearing in the absence of air and bone conduction--An animal study.

    PubMed

    Perez, Ronen; Adelman, Cahtia; Sohmer, Haim

    2016-01-01

    Conclusion Cochlea can be directly excited by fluid (soft-tissue) stimulation. Objective To determine whether there is no difference in auditory-nerve-brainstem evoked response (ABR) thresholds to fluid stimulation between normal and animal models of post radical-mastoidectomy, as seen in a previous human study. Background It has been shown in humans that hearing can be elicited with stimulation to fluid in the external auditory meatus (EAM), and radical-mastoidectomy cavity. These groups differed in age, initial hearing, and drilling exposure. To overcome this difference, experiments were conducted in sand-rats, first intact, and after inducing a radical-mastoidectomy. Methods The EAM of five sand-rats was filled with 0.3 ml saline. ABR thresholds were determined in response to vibratory stimulation by a clinical bone-vibrator with a plastic rod, applied to the saline in the EAM. Then the tympanic membrane was removed, and malleus dislocated (radical-mastoidectomy model). The cavity was filled with 0.45 ml saline and the ABR threshold was determined in response to vibratory stimulation to the cavity fluid. Results There was no difference in ABR fluid thresholds to EAM and mastoidectomy cavity stimulation. Air-conduction stimulation from the bone-vibrator was not involved (conductive loss due to fluid). Bone-conduction stimulation was not involved (large difference in acoustic impedance between fluid and bone).

  14. Conductivity study of nitrogen-doped calcium zinc oxide prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Hsu, Yu-Ting; Lan, Wen-How; Huang, Kai-Feng; Lin, Jia-Ching; Chang, Kuo-Jen

    2016-01-01

    In this study, the spray pyrolysis method was used to prepare unintentionally doped and nitrogen-doped calcium zinc oxide films by using zinc acetate, calcium nitrate precursor, and ammonium acetate precursor. Morphological and structural analyses were conducted using scanning electron microscopy and X-ray diffraction. The results indicated that film grain size decreased as the nitrogen doping was increased. Both calcium oxide and zinc oxide structures were identified in the unintentionally doped calcium zinc oxide. When nitrogen doping was introduced, the film mainly exhibited a zinc oxide structure with preferred (002) and (101) orientations. The concentration and mobility were investigated using a Hall measurement system. P-type films with a mobility and concentration of 10.6 cm2 V-1 s-1 and 2.8×1017 cm-3, respectively, were obtained. Moreover, according to a temperature-dependent conductivity analysis, an acceptor state with activation energy 0.266 eV dominated the p-type conduction for the unintentionally doped calcium zinc oxide. By contrast, a grain boundary with a barrier height of 0.274-0.292 eV dominated the hole conduction for the nitrogen-doped calcium zinc oxide films.

  15. Parallel plate waveguide time domain spectroscopy to study terahertz conductivity of utltrathin materials

    NASA Astrophysics Data System (ADS)

    Razanoelina, Manjakavahoaka; Bagsican, Filchito R.; Kawayama, Iwao; Zhang, Xiang; Ma, Lulu; Murakami, Hironaru; Vajtai, Robert; Ajayan, Pulickel M.; Kono, Junichiro; Mittleman, Daniel M.; Tonouchi, Masayoshi

    2016-04-01

    The newly discovered atomically thin and layered materials which host electronic system that respond to longwavelength light in extraordinary manner can lead to a major breakthrough in the field of terahertz (THz) optics and photonics. However, their low conductivities due to either low densities or low mobility make it challenging to characterize their basic THz properties with the standard spectroscopic method. Here, we develop a THz spectroscopic technique based on parallel plate waveguide (PPWG) to overcome the limitations of the conventional THz time domain spectroscopy (TDS) technique. The present method is particularly suitable to ultrathin conductive materials with low carrier density. We report in details the derivation of the dispersion equations of the terahertz wave propagation in a PPWG loaded by a thin conductive materials with zero-thickness. These dispersion equations for transverse magnetic (TM) and transverse electric (TE) waveguide modes are the core of the optical parameters extraction algorithm in the THz-PPWG-TDS analysis. We demonstrate the effectiveness of the waveguide approach by characterizing low conductive CVD graphene. The high sensitivity of THz-PPWG-TDS technique enables us to study the carrier dynamics in graphene with Drude and Drude-Smith model.

  16. Significance of Childhood Conduct Problems to Later Development of Conduct Disorder among Children with ADHD: A Prospective Follow-Up Study

    ERIC Educational Resources Information Center

    Mannuzza, Salvatore; Klein, Rachel G.; Abikoff, Howard; Moulton, John L., III

    2004-01-01

    This study investigates whether low to moderate levels of childhood oppositional defiant disorder (ODD) and conduct disorder (CD) behaviors contribute to the development of clinically diagnosed CD in adolescence, in children with attention deficit hyperactivity disorder (ADHD). Participants were 207 White boys (ages 6-12) with ADHD free of conduct…

  17. Communication Apprehension: Levels of First-Generation College Students at 2-Year Institutions

    ERIC Educational Resources Information Center

    Francis, Trevor A.; Miller, Michael T.

    2008-01-01

    The study explored the oral communication apprehension (CA) levels of first-generation college students at a 2-year case study community institution. Overall and general-context CA were measured using the Personal Report of Communication Apprehension-24 (PRCA-24). The survey was sent by e-mail to 2,040 institutionally-identified first-generation…

  18. Students with Disabilities at 2-Year Institutions in the United States: Factors Related to Success

    ERIC Educational Resources Information Center

    Mamiseishvili, Ketevan; Koch, Lynn C.

    2012-01-01

    This study used data from the Beginning Postsecondary Students Longitudinal Study to examine the demographic and in-college characteristics of students with disabilities at 2-year institutions, identify the types of educational services available to them, and determine how students' disability conditions and their selected demographic and…

  19. A study of single-crystal silicon diodes integrated on flexible substrates using conductive adhesives

    NASA Astrophysics Data System (ADS)

    Doran, C.; Chen, W.; Alford, T. L.; Lau, S. S.

    2012-02-01

    In this study, we investigated the possibility of fabricating flexible single-crystal Si-Pd diodes on polymer substrates using silver-filled conductive tape or epoxy. This simple technique mitigates the complexity of process-intensive metal-bonding schemes to achieve backside electrical contacts on semiconductor devices. The performance of such devices is evaluated while bent to a 1.2 cm radius of curvature. The longer-term stability of the devices fabricated is also briefly discussed.

  20. Studies and projections of hydraulic conductivity of Devonian Plavinu and Daugava carbonate aquifers in Latvia

    NASA Astrophysics Data System (ADS)

    Perkone, E.; Delina, A.; Saks, T.; Raga, B.; Jātnieks, J.; Klints, I.; Popovs, K.; Babre, A.; Bikše, J.; Kalvāns, A.; Retike, I.; Ukass, J.

    2012-04-01

    Carbonate aquifers show a very wide range of hydrogeological characteristics. Carbonate rock hydrogeology display two extremes: on one hand hydrogeological properties of the carbonates are governed by the pathways of the preferential groundwater flow typical in karstic regions, on the other - some carbonate aquifers behave almost like a homogeneous, isotropic, porous medium. Most lie between these extremes, but these case variations complicates the study of carbonate aquifer properties. In this study the results of the hydraulic conductivity in carbonate aquifers measurements, hydraulic conductivity correlation between sediments lithology and the aquifer surface depth and fractures research is presented. Upper Devonian Frasnian stage Pļaviņu and Daugava carbonate aquifers in the Latvian part of the Baltic basin is considered. The aim of this research is to elaborate characteristic hydraulic conductivity values for each aquifer based on existing data of the pumping test results and other aquifer properties. Pļaviņu and Daugava carbonate aquifers mainly consist of jointed dolomite with intermediate layers of dolomitic marlstone, limestone, clays and gypsum. These aquifers are prevalent in most of the study area, except Northern and South - Eastern parts of the territory. In geological structure Daugava aquifer lies above Pļaviņu aquifer. Daugava aquifer depth changes from 10 - 20 and even less meters in Eastern part to 250 - 300 m in South - West part of study area, but thickness varies from few meters to 30 m. Pļaviņu aquifer surface depth varies from 20 - 30 m, but in uplands surface depth reaches more than 120 m, in Eastern part to more than 300 m in South - West part of study area. Aquifer average thickness varies from 20 - 40 m, but in areas with buried valleys thickness can be less than 10 meters. Outcrops of these sediments are occurring in banks of largest rivers and in some areas aquifers are karstified. In studies of the carbonate aquifers it is

  1. Diagnosis of Severe Carpal Tunnel Syndrome Using Nerve Conduction Study and Ultrasonography.

    PubMed

    Fujimoto, Kazuhiro; Kanchiku, Tsukasa; Kido, Kenji; Imajo, Yasuaki; Funaba, Masahiro; Taguchi, Toshihiko

    2015-10-01

    This study investigated the correlation between nerve conduction study and ultrasonographic findings for assessment of the usefulness of ultrasonography in determining carpal tunnel syndrome severity. Hands of adults with carpal tunnel syndrome were assessed using ultrasound and nerve conduction studies and grouped according to median nerve cross-sectional area (CSA). There were significant differences (p < 0.01) in mean median nerve CSA between controls, patients with median sensory nerve conduction velocity ≤40 m/s and patients with absent sensory nerve action potential and between controls, patients with median nerve distal motor latency ≥4.5 ms and patients with absent compound muscle action potentials of the abductor pollicis brevis. This is the first report to define median nerve CSA cutoff values (18 mm(2)) for determining carpal tunnel syndrome severity in patients with absent compound muscle action potentials of the abductor pollicis brevis. Median nerve CSA values below the cutoff values should prompt clinicians to consider other disorders, such as cervical compressive myelopathy.

  2. Negative symptom improvement during cognitive rehabilitation: results from a 2-year trial of Cognitive Enhancement Therapy.

    PubMed

    Eack, Shaun M; Mesholam-Gately, Raquelle I; Greenwald, Deborah P; Hogarty, Susan S; Keshavan, Matcheri S

    2013-08-30

    Cognitive rehabilitation has shown beneficial effects on cognition in patients with schizophrenia, which may also help to improve negative symptoms due to overlapping pathophysiology between these two domains. To better understand the possible relationship between these areas, we conducted an exploratory analysis of the effects of Cognitive Enhancement Therapy (CET) on negative symptoms. Early course schizophrenia outpatients (n=58) were randomized to 2 years of CET or an Enriched Supportive Therapy (EST) control condition. Results revealed significant and medium-sized (d=0.61) differential improvements favoring CET in overall negative symptoms, particularly social withdrawal, affective flattening, and motor retardation. Neurocognitive improvement was associated with reduced negative symptoms in CET, but not EST patients. No relationships were observed between improvements in emotion processing aspects of social cognition, as measured by the Mayer-Salovey-Caruso Emotional Intelligence Test, and negative symptoms. CET represents an effective cognitive rehabilitation intervention for schizophrenia that may also have benefits to negative symptoms. Future studies specifically designed to examine negative symptoms during the course of cognitive rehabilitation are needed.

  3. Ethical issues in the conduct of longitudinal studies of addiction treatment.

    PubMed

    Scott, Christy K; White, William L

    2005-01-01

    Many complex ethical issues arise in the day-to-day conduct of longitudinal studies of addiction treatment. These issues are rooted, in part, in the sustained and potentially ambiguous relationship between research staff and study participants, the frequently changing clinical and legal status of study participants, the assertive methods required to generate high follow-up rates, and the numerous systems of care and control in which participants are involved. To identify common ethical issues that arise in such studies, the authors conducted individual and group interviews with seasoned members (case trackers, field trackers, interviewers, and supervisors) of the research team. The ethical dilemmas identified through these interviews fell into seven broad arenas: (1) informed consent for research participation, (2) confidentiality and information disclosure, (3) relationship boundaries between study participants and research staff, (4) duty to warn/report responsibilities, (5) questions of autonomy and privacy, (6) issues related to compensation for research participation, and (7) data integrity. Case studies that illustrate common ethical dilemmas within each of these seven areas are presented and discussed. Ethical dilemmas in the study of addiction treatment can be effectively managed via ethically informed research protocols, staff training in ethical decision-making, monitoring and supervision, and collective debriefing of critical events.

  4. Study of the solution thermal conductivity effect on nonlinear refraction of colloidal gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Sarkhosh, L.; Mansour, N.

    2015-06-01

    In nanoparticle colloidal systems, the thermal nonlinearity is affected by the thermal parameters of the surrounding solution. Having a low temperature gradient rate solution may be a key factor in producing high thermal nonlinear properties in colloids. In this manuscript, the effect of the thermal conductivity of the surrounding liquid environment on the thermal nonlinear refraction of gold nanoparticles (AuNPs) synthesized by laser ablation of a gold target in different solutions is investigated. Gold nanoparticles colloids have been fabricated by the nanosecond pulsed laser ablation of a pure gold plate in different liquid environments with a thermal conductivity range of 0.14-0.60 W mK-1 including cyclohexanone, castor oil, dimethyl sulfoxide, ethylene glycol, glycerin and water. The AuNPs colloids exhibit a UV-Vis absorption spectrum with a surface plasmon absorption peak at about 540  ±  20 nm. The thermal nonlinear optical responses of the gold colloids are measured using the Z-scan technique under low power CW laser irradiation at 532 nm near the surface plasmon peak of the nanoparticles. Our results show that the nonlinear refractive index of the nanoparticle colloids is considerably affected by the thermal conductivity of liquid medium. The largest nonlinear refractive index of -3.1  ×  10-7 cm2 W-1 is obtained for AuNP in cyclohexanone with the lowest thermal conductivity of 0.14 W mK-1 whereas the lowest one of -0.1  ×  10-7 cm2 W-1 is obtained for AuNP in water with the highest thermal conductivity of 0.60 W mK-1. This study shows that the nonlinear refractive index value of colloids can be controlled by the thermal conductivity of the used liquid’s environment. This allows us to design low threshold optical limiters by choosing a solution with low thermal conductivity for colloidal nanoparticles.

  5. Borderline personality disorder features predict negative outcomes 2 years later.

    PubMed

    Bagge, Courtney; Nickell, Angela; Stepp, Stephanie; Durrett, Christine; Jackson, Kristina; Trull, Timothy J

    2004-05-01

    In a sample of 351 young adults, the authors assessed whether borderline personality disorder (BPD) features prospectively predicted negative outcomes (poorer academic achievement and social maladjustment) over the subsequent 2 years, over and above gender and both Axis I and Axis II psychopathology. Borderline traits were significantly related to these outcomes, with impulsivity and affective instability the most highly associated. The present findings suggest that the impulsivity and affective instability associated with BPD leads to impairment in relating well with others, in meeting social role obligations, and in academic or occupational achievement. Therefore, these may be especially important features to target in interventions for BPD.

  6. Brainstem Auditory Evoked Potentials (BAEP)- A Pilot Study Conducted on Young Healthy Adults from Central India

    PubMed Central

    Gandhe, Mahendra Bhauraoji; Gandhe, Swapnali Mahendra; Puttewar, A.N.; Saraf, Chhaya; Singh, Ramji

    2014-01-01

    Objective: To Evaluate I, II, III, IV, V wave latencies and I-III, III-V, I-V inter-peak latencies and V/I wave amplitude ratio in Normal subjects in Central India. Methods: We recorded BAEP from 50 healthy normal subjects from the community of same sex and geographical setup. The absolute, interpeak and wave V/I amplitude ratio were measurement and recording was done using RMS EMG EP MARK II machine manufactured by RMS recorders and Medicare system, Chandigarh. Result: Absolute, interpeak and wave V/I amplitude ratio were measured in normal subjects and compared with other previous studies. Conclusion: This study was conducted as exploratory pilot study only on male healthy controls. Since, the study conducted in different regions, there are some differences in the latencies and interpeak latencies and amplitude ratio but they are within range, so reference range of this study can be used for future studies in this Wardha region of Central India. PMID:25120971

  7. Experimental and simulation studies on laser conduction welding of AA5083 aluminium alloys

    NASA Astrophysics Data System (ADS)

    Tobar, M. J.; Lamas, M. I.; Yáñez, A.; Sánchez-Amaya, J. M.; Boukha, Z.; Botana, F. J.

    In this paper, a three-dimensional numerical model was developed to study laser welding in an aluminium alloy (AA5083). The CFD model was used to solve the governing equations of conservation of mass, momentum and energy, so as to obtain the morphology, velocity field and temperature field of the melted zone in steady state. The predicted dimensions of the weld pool agreed well with experimental results obtained on laser conduction welding with a (CW) high power diode laser. The study allowed to determine the effect of different surface treatment (sandblasting, black painting) on the laser absorptivity of the alloy and analyze the heat transfer mechanism within the weld pool.

  8. Analytical study of electrophoretic characterization of kidney cells. [conducted during the Apollo Soyuz Test Project

    NASA Technical Reports Server (NTRS)

    Knox, R. J.

    1978-01-01

    Embryonic kidney cells were studied as a follow-up to the MA-011 Electrophoresis Technology Experiment which was conducted during the Apollo Soyuz Test Project (ASTP). The postflight analysis of the performance of the ASTP zone electrophoresis experiment involving embryonic kidney cells is reported. The feasibility of producing standard particles for electrophoresis was also studied. This work was undertaken in response to a need for standardization of methods for producing, calibrating, and storing electrophoretic particle standards which could be employed in performance tests of various types of electrophoresis equipment. Promising procedures were tested for their suitability in the production of standard test particles from red blood cells.

  9. Thermal conductivity imaging at micrometre-scale resolution for combinatorial studies of materials.

    PubMed

    Huxtable, Scott; Cahill, David G; Fauconnier, Vincent; White, Jeffrey O; Zhao, Ji-Cheng

    2004-05-01

    Combinatorial methods offer an efficient approach for the development of new materials. Methods for generating combinatorial samples of materials, and methods for characterizing local composition and structure by electron microprobe analysis and electron-backscatter diffraction are relatively well developed. But a key component for combinatorial studies of materials is high-spatial-resolution measurements of the property of interest, for example, the magnetic, optical, electrical, mechanical or thermal properties of each phase, composition or processing condition. Advances in the experimental methods used for mapping these properties will have a significant impact on materials science and engineering. Here we show how time-domain thermoreflectance can be used to image the thermal conductivity of the cross-section of a Nb-Ti-Cr-Si diffusion multiple, and thereby demonstrate rapid and quantitative measurements of thermal transport properties for combinatorial studies of materials. The lateral spatial resolution of the technique is 3.4 microm, and the time required to measure a 100 x 100 pixel image is approximately 1 h. The thermal conductivity of TiCr(2) decreases by a factor of two in crossing from the near-stoichiometric side of the phase to the Ti-rich side; and the conductivity of (Ti,Nb)(3)Si shows a strong dependence on crystalline orientation.

  10. Conductive Education as a Method of Stroke Rehabilitation: A Single Blinded Randomised Controlled Feasibility Study

    PubMed Central

    Jutley-Neilson, Jagjeet; Russell, Nicholas C. C.; Sackley, Catherine M.

    2016-01-01

    Background. Conductive Education for stroke survivors has shown promise but randomised evidence is unavailable. This study assessed the feasibility of a definitive randomised controlled trial to evaluate efficacy. Methods. Adult stroke survivors were recruited through local community notices. Those completing the baseline assessment were randomised using an online program and group allocation was independent. Intervention group participants received 10 weekly 1.5-hour sessions of Conductive Education at the National Institute of Conductive Education in Birmingham, UK. The control group participants attended two group meetings. The study evaluated the feasibility of recruitment procedures, delivery of the intervention, retention of participants, and appropriateness of outcome measures and data collection methods. Independent assessments included the Barthel Index, the Stroke Impact Scale, the Timed Up and Go test, and the Hospital Anxiety and Depression Scale. Results. Eighty-two patients were enrolled; 77 completed the baseline assessment (46 men, mean age 62.1 yrs.) and were randomised. 70 commenced the intervention (n = 37) or an equivalent waiting period (n = 33). 32/37 completed the 10-week training and 32/33 the waiting period. There were no missing items from completed questionnaires and no adverse events. Discussion. Recruitment, intervention, and assessment methods worked well. Transport issues for intervention and assessment appointments require review. Conclusion. A definitive trial is feasible. This trial is registered with ISRCTN84064492. PMID:27418997

  11. Study of the electrical conductivity at finite temperature in 2D Si- MOSFETs

    SciTech Connect

    Limouny, L. Kaaouachi, A. El Tata, O.; Daoudi, E.; Errai, M.; Dlimi, S.; Idrissi, H. El; Zatni, A.

    2014-01-27

    We investigate the low temperature density dependent conductivity of two dimensional electron systems in zero magnetic field for sample Si-15 MOSFETs. The first purpose of this paper is to establish that the knee of the conductivity σ{sub 0} (σ{sub 0} is the T = 0.3 conductivity obtained by linear extrapolation of the curves of σ (T) for different values of electron density, n{sub s}) as a function of the carrier densities n{sub s} for T = 0.3 K, observed by Lai et al. and Limouny et al. in previous work for two different samples, is independent of temperature. The second aim is the determination of the critical density, n{sub c}, of the metal-insulator transition. Many methods are used in this investigation of n{sub c} which have been already used for other samples. The motivation behind this last study is the observation of many values of n{sub c} that have been obtained from different methods and that are slightly different. We will use in this study three methods with the intention to infer which one is more appropriate to obtain n{sub c}.

  12. Compensated Arrhenius formalism applied to a conductivity study in poly(propylene glycol) diacrylate monomers

    NASA Astrophysics Data System (ADS)

    Dubois, F.; Derouiche, Y.; Leblond, J. M.; Maschke, U.; Douali, R.

    2015-09-01

    The temperature dependence of the ionic conductivity is studied in a series of poly(propylene glycol) diacrylate monomers. The experimental data are analyzed by means of the approach recently proposed by Petrowsky et al. [J. Phys. Chem. B. 113, 5996 (2009), 10.1021/jp810095g]. This so-called compensated Arrhenius formalism (CAF) approach takes into account the influence of the dielectric permittivity on the exponential prefactor in the classical Arrhenius equation. The experimental data presented in this paper show a good agreement with the CAF; this means that the exponential prefactor is principally dielectric permittivity dependent. The compensated data revealed two conduction processes with different activation energies; they correspond to low and high temperature ranges, respectively.

  13. Stratton Sagebrush Hydrology Study Area: An annotated bibliography of research conducted 1968-1990

    USGS Publications Warehouse

    Burgess, Leah M.; Schoenecker, Kathryn A.

    2004-01-01

    This annotated bibliography provides an overview of research projects conducted on the Stratton Sagebrush Hydrology Study Area (Stratton) since its designation as such in 1967. Sources include the Rocky Mountain Forest and Range Experiment Station records storage room, Laramie, Wyoming, the USGS and USFS online reference libraries, and scientific journal databases at the University of Wyoming and Colorado State University. This annotated bibliography summarizes publications from research conducted at Stratton during the prime of its tenure as a research lab from 1968 to 1990. In addition, an appendix is included that catalogues all data on file at the Rocky Mountain Forest and Range Experiment Station in Laramie, Wyoming. Each file folder was searched and its contents recorded here for the researcher seeking original data sets, charts, photographs and records.

  14. Combined ion conductance and fluorescence confocal microscopy for biological cell membrane transport studies

    NASA Astrophysics Data System (ADS)

    Shevchuk, A. I.; Novak, P.; Velazquez, M. A.; Fleming, T. P.; Korchev, Y. E.

    2013-09-01

    Optical visualization of nanoscale morphological changes taking place in living biological cells during such important processes as endo- and exocytosis is challenging due to the low refractive index of lipid membranes. In this paper we summarize and discuss advances in the powerful combination of two complementary live imaging techniques, ion conductance and fluorescence confocal microscopy, that allows cell membrane topography to be related with molecular-specific fluorescence at high spatial and temporal resolution. We demonstrate the feasibility of the use of ion conductance microscopy to image apical plasma membrane of mouse embryo trophoblast outgrowth cells at a resolution sufficient to depict single endocytic pits. This opens the possibility to study individual endocytic events in embryo trophoblast outgrowth cells where endocytosis plays a crucial role during early stages of embryo development.

  15. Doping and Thermal Conductivity Studies of CrSiTe3

    NASA Astrophysics Data System (ADS)

    Haglund, Amanda; Yan, Jiaqiang; Keppens, Veerle; Mandrus, David

    CrSiTe3 is a layered material with a 2-dimensional crystal structure, and has recently become of more interest due to the possibility of using its ferromagnetic and semiconducting properties for spintronics applications. To further investigate the properties of CrSiTe3, we doped it with various transition elements on the Cr site in an attempt to tune and control the magnetism, as well as study changes in the thermal conductivity. We synthesized pure CrSiTe3 and doped samples through flux growth, producing plate-like bulk crystals. Crystal quality was checked by x-ray diffraction and energy dispersive spectroscopy, and then thermal conductivity and magnetization measurements were obtained on the doped materials to compare variations from the pristine CrSiTe3.

  16. Compensated Arrhenius formalism applied to a conductivity study in poly(propylene glycol) diacrylate monomers.

    PubMed

    Dubois, F; Derouiche, Y; Leblond, J M; Maschke, U; Douali, R

    2015-09-01

    The temperature dependence of the ionic conductivity is studied in a series of poly(propylene glycol) diacrylate monomers. The experimental data are analyzed by means of the approach recently proposed by Petrowsky et al. [J. Phys. Chem. B. 113, 5996 (2009)10.1021/jp810095g]. This so-called compensated Arrhenius formalism (CAF) approach takes into account the influence of the dielectric permittivity on the exponential prefactor in the classical Arrhenius equation. The experimental data presented in this paper show a good agreement with the CAF; this means that the exponential prefactor is principally dielectric permittivity dependent. The compensated data revealed two conduction processes with different activation energies; they correspond to low and high temperature ranges, respectively.

  17. Biological studies and electrical conductivity of paper sheet based on PANI/PS/Ag-NPs nanocomposite.

    PubMed

    Youssef, A M; Mohamed, S A; Abdel-Aziz, M S; Abdel-Aziz, M E; Turky, G; Kamel, S

    2016-08-20

    Polyaniline (PANI) with/without polystyrene (PS), was successfully manufactured in the occurrence of dispersed pulp fibers via the oxidative polymerization reaction of aniline monomer to produce conductive paper sheets containing PANI, PANI/PS composites. Additionally, sliver nitrate (Ag-NO3) was added by varied loadings to the oxidative polymerization of aniline monomer to provide sliver nanoparticles (Ag-NPs) emptied into the prepared paper sheets. The prepared paper sheets were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR), the mechanical properties of the prepared paper sheets were evaluated. Moreover, the electrical conductivity and biological studies such as cellulases assay, Microorganism & culture condition and detection of the released of Ag-NPs were evaluated. Furthermore, the prepared paper sheets were displayed good antibacterial properties contrary to gram positive and gram negative bacteria. Consequently, the prepared paper sheet may be used as novel materials for packaging applications.

  18. Biological studies and electrical conductivity of paper sheet based on PANI/PS/Ag-NPs nanocomposite.

    PubMed

    Youssef, A M; Mohamed, S A; Abdel-Aziz, M S; Abdel-Aziz, M E; Turky, G; Kamel, S

    2016-08-20

    Polyaniline (PANI) with/without polystyrene (PS), was successfully manufactured in the occurrence of dispersed pulp fibers via the oxidative polymerization reaction of aniline monomer to produce conductive paper sheets containing PANI, PANI/PS composites. Additionally, sliver nitrate (Ag-NO3) was added by varied loadings to the oxidative polymerization of aniline monomer to provide sliver nanoparticles (Ag-NPs) emptied into the prepared paper sheets. The prepared paper sheets were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD) and infrared spectroscopy (IR), the mechanical properties of the prepared paper sheets were evaluated. Moreover, the electrical conductivity and biological studies such as cellulases assay, Microorganism & culture condition and detection of the released of Ag-NPs were evaluated. Furthermore, the prepared paper sheets were displayed good antibacterial properties contrary to gram positive and gram negative bacteria. Consequently, the prepared paper sheet may be used as novel materials for packaging applications. PMID:27178939

  19. Impedance study of tea with added taste compounds using conducting polymer and metal electrodes.

    PubMed

    Dhiman, Mopsy; Kapur, Pawan; Ganguli, Abhijit; Singla, Madan Lal

    2012-09-01

    In this study the sensing capabilities of a combination of metals and conducting polymer sensing/working electrodes for tea liquor prepared by addition of different compounds using an impedance mode in frequency range 1 Hz-100 KHz at 0.1 V potential has been carried out. Classification of six different tea liquor samples made by dissolving various compounds (black tea liquor + raw milk from milkman), (black tea liquor + sweetened clove syrup), (black tea liquor + sweetened ginger syrup), (black tea liquor + sweetened cardamom syrup), (black tea liquor + sweet chocolate syrup) and (black tea liquor + vanilla flavoured milk without sugar) using six different working electrodes in a multi electrode setup has been studied using impedance and further its PCA has been carried out. Working electrodes of Platinum (Pt), Gold (Au), Silver (Ag), Glassy Carbon (GC) and conducting polymer electrodes of Polyaniline (PANI) and Polypyrrole (PPY) grown on an ITO surface potentiostatically have been deployed in a three electrode set up. The impedance response of these tea liquor samples using number of working electrodes shows a decrease in the real and imaginary impedance values presented on nyquist plots depending upon the nature of the electrode and amount of dissolved salts present in compounds added to tea liquor/solution. The different sensing surfaces allowed a high cross-selectivity in response to the same analyte. From Principal Component Analysis (PCA) plots it was possible to classify tea liquor in 3-4 classes using conducting polymer electrodes; however tea liquors were well separated from the PCA plots employing the impedance data of both conducting polymer and metal electrodes. PMID:23035436

  20. Mass media and school interventions for cigarette smoking prevention: effects 2 years after completion.

    PubMed Central

    Flynn, B S; Worden, J K; Secker-Walker, R H; Pirie, P L; Badger, G J; Carpenter, J H; Geller, B M

    1994-01-01

    The long-term cigarette smoking prevention effects of mass media and school interventions were assessed. Adolescents in two communities received both mass media and school interventions; those in two matching communities received only school interventions. Surveys of 5458 students were conducted at baseline in grades 4 through 6 and 2 years after the 4-year interventions were completed, when students were in grades 10 through 12. Students exposed to the media-plus-school interventions were found to be at lower risk for weekly smoking (odds ratio = 0.62, 95% confidence interval = 0.49, 0.78) than those receiving school interventions only, indicating that the effects of the combined interventions persisted 2 years after the interventions' completion. PMID:8017542

  1. Alberta Science Achievement Study: A Study Conducted for the Minister's Advisory Committee on Student Achievement. Executive Summary.

    ERIC Educational Resources Information Center

    Treasure, Morris

    This report is an executive summary of a study conducted for the Minister's Advisory Committee on Student Achievement (MACOSA) of Alberta, Canada. It was designed to investigate levels of student achievement in science in Alberta at grades three, six, nine and twelve and to provide a data base for future assessment. Between 2,000 and 3,000…

  2. Hispanic Student Enrollment and Educational Attainment in Texas 2-Year Colleges: A Multi-Year Statewide Analysis

    ERIC Educational Resources Information Center

    Hernandez, Jack

    2012-01-01

    Purpose: The purpose of the study was to examine the numbers and percentages of Hispanic college students enrolled in Texas 2-year colleges from the 2000 through the 2011 academic years and to examine the numbers and percentages of Hispanic students obtaining associate degrees from Texas 2-year colleges for the 2000 through the 2011 academic…

  3. Potassium conductance of the squid giant axon. Single-channel studies

    PubMed Central

    1988-01-01

    The patch-clamp technique was implemented in the cut-open squid giant axon and used to record single K channels. We present evidence for the existence of three distinct types of channel activities. In patches that contained three to eight channels, ensemble fluctuation analysis was performed to obtain an estimate of 17.4 pS for the single-channel conductance. Averaged currents obtained from these multichannel patches had a time course of activation similar to that of macroscopic K currents recorded from perfused squid giant axons. In patches where single events could be recorded, it was possible to find channels with conductances of 10, 20, and 40 pS. The channel most frequently encountered was the 20-pS channel; for a pulse to 50 mV, this channel had a probability of being open of 0.9. In other single-channel patches, a channel with a conductance of 40 pS was present. The activity of this channel varied from patch to patch. In some patches, it showed a very low probability of being open (0.16 for a pulse to 50 mV) and had a pronounced lag in its activation time course. In other patches, the 40-pS channel had a much higher probability of being open (0.75 at a holding potential of 50 mV). The 40-pS channel was found to be quite selective for K over Na. In some experiments, the cut-open axon was exposed to a solution containing no K for several minutes. A channel with a conductance of 10 pS was more frequently observed after this treatment. Our study shows that the macroscopic K conductance is a composite of several K channel types, but the relative contribution of each type is not yet clear. The time course of activation of the 20-pS channel and the ability to render it refractory to activation only by holding the membrane potential at a positive potential for several seconds makes it likely that it is the predominant channel contributing to the delayed rectifier conductance. PMID:3171538

  4. Structural and conductivity studies of Y 10-xLa xW 2O 21

    NASA Astrophysics Data System (ADS)

    Lashtabeg, Anna; Bradley, John; Dicks, Andrew; Auchterlonie, Graeme; Drennan, John

    2010-05-01

    The aim of this work was to determine structural parameters of the Y 10-xLa xW 2O 21 ( x=0-10) solid solution series and investigate their electric properties. Crystallographic data shows a gradual increase in symmetry with increasing La content, as the structure evolves from orthorhombic, Y 10W 2O 21, towards the pseudo-cubic structure of Y 5La 5W 2O 21. The solubility limit of La 2O 3 was found to be 50% ( x=5). Above this level two phases were observed, La 6W 2O 15 and (La,Y) 10+xW 2-xO 21-δ. The conductivity of Y rich samples was very low, with σ of the order 2×10 -5-5×10 -5 S cm -1 at 1000 °C, whilst ionic conductivity was observed for most La rich doped samples. The highest conductivity was observed for La 10W 2O 21 and its doped analogues, at 1×10 -3-5×10 -3 S cm -1 at 1000 °C. Unit cell parameters were determined as a function of temperature from 0 to 1000°C, and thermal expansion of these materials was determined from temperature studies carried out at the Australian Synchrotron facility in Melbourne, Victoria, Australia.

  5. Distribution of cardiac myosin isozymes in human conduction system. Immunohistochemical study using monoclonal antibodies.

    PubMed Central

    Kuro-o, M; Tsuchimochi, H; Ueda, S; Takaku, F; Yazaki, Y

    1986-01-01

    To determine the presence and distribution of cardiac myosin isozymes in the human conduction system, we performed an immunohistochemical study using monoclonal antibodies CMA19 and HMC14, which are specific for myosin heavy chains of human atrial type (alpha-type) and ventricular type (beta-type), respectively. Serial frozen sections of human hearts were obtained from autopsy samples and examined by indirect immunofluorescence. Alpha-type was found in all myofibers of sinus node and atrio-ventricular node, and in 55.2 +/- 10.2% (mean +/- SD, n = 5) of the myofibers of ventricular conduction tissue, which consists of the bundle of His, bundle branches, and the Purkinje network. In contrast, beta-type was found in all myofibers of the atrio-ventricular node and ventricular conduction tissue, whereas almost all myofibers of the sinus node were unlabeled by HMC14. Although the number of ventricular myofibers labeled by CMA19 was small, the labeled myofibers were more numerous in the subepicardial region than in the subendocardial region. These findings show that the gene coding for alpha-type is expressed predominantly in specialized myocardium compared with the adjacent ordinary working myocardium. Images PMID:3511096

  6. Computational Study of Subdural Cortical Stimulation: Effects of Simulating Anisotropic Conductivity on Activation of Cortical Neurons

    PubMed Central

    Seo, Hyeon; Kim, Donghyeon; Jun, Sung Chan

    2015-01-01

    Subdural cortical stimulation (SuCS) is an appealing method in the treatment of neurological disorders, and computational modeling studies of SuCS have been applied to determine the optimal design for electrotherapy. To achieve a better understanding of computational modeling on the stimulation effects of SuCS, the influence of anisotropic white matter conductivity on the activation of cortical neurons was investigated in a realistic head model. In this paper, we constructed pyramidal neuronal models (layers 3 and 5) that showed primary excitation of the corticospinal tract, and an anatomically realistic head model reflecting complex brain geometry. The anisotropic information was acquired from diffusion tensor magnetic resonance imaging (DT-MRI) and then applied to the white matter at various ratios of anisotropic conductivity. First, we compared the isotropic and anisotropic models; compared to the isotropic model, the anisotropic model showed that neurons were activated in the deeper bank during cathodal stimulation and in the wider crown during anodal stimulation. Second, several popular anisotropic principles were adapted to investigate the effects of variations in anisotropic information. We observed that excitation thresholds varied with anisotropic principles, especially with anodal stimulation. Overall, incorporating anisotropic conductivity into the anatomically realistic head model is critical for accurate estimation of neuronal responses; however, caution should be used in the selection of anisotropic information. PMID:26057524

  7. A theoretical study of wave dispersion and thermal conduction for HMX/additive interfaces

    NASA Astrophysics Data System (ADS)

    Long, Yao; Chen, Jun

    2014-04-01

    The wave dispersion rule for non-uniform material is useful for ultrasonic inspection and engine life prediction, and also is key in achieving an understanding of the energy dissipation and thermal conduction properties of solid material. On the basis of linear response theory and molecular dynamics, we derive a set of formulas for calculating the wave dispersion rate of interface systems, and study four kinds of interfaces inside plastic bonded explosives: HMX/{HMX, TATB, F2312, F2313}. (HMX: octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine; TATB: 1,3,5-triamino-2,4,6-trinitrobenzene; F2312, F2313: fluoropolymers). The wave dispersion rate is obtained over a wide frequency range from kHz to PHz. We find that at low frequency, the rate is proportional to the square of the frequency, and at high frequency, the rate couples with the molecular vibration modes at the interface. By using the results, the thermal conductivities of HMX/additive interfaces are derived, and a physical model is built for describing the total thermal conductivity of mixture explosives, including HMX multi-particle systems and {TATB, F2312, F2313}-coated HMX.

  8. Phonetic Modification of Vowel Space in Storybook Speech to Infants up to 2 Years of Age

    ERIC Educational Resources Information Center

    Burnham, Evamarie B.; Wieland, Elizabeth A.; Kondaurova, Maria V.; McAuley, J. Devin; Bergeson, Tonya R.; Dilley, Laura C.

    2015-01-01

    Purpose: A large body of literature has indicated vowel space area expansion in infant-directed (ID) speech compared with adult-directed (AD) speech, which may promote language acquisition. The current study tested whether this expansion occurs in storybook speech read to infants at various points during their first 2 years of life. Method: In 2…

  9. How Joint Attention Relates to Cooperation in 1- and 2-Year-Olds

    ERIC Educational Resources Information Center

    Wu, Zhen; Pan, Jingtong; Su, Yanjie; Gros-Louis, Julie

    2013-01-01

    Joint attention has been suggested to contribute to children's development of cooperation; however, few empirical studies have directly tested this hypothesis. Children aged 1 and 2 years participated in two joint action activities to assess their cooperation with an adult partner, who stopped participating at a specific moment during the…

  10. Attitudes of College Students Enrolled in 2-Year Health Care Programs towards Online Learning

    ERIC Educational Resources Information Center

    Abdulla, Dalya

    2012-01-01

    Colleges offering 2-year diplomas to high-school graduates were among the forefront leaders in online learning however studies illustrating appropriate course construction for such student populations are scarce. Pharmacy Math (MATH16532) is a core course for students enrolled in the Practical Nursing (PN) and Pharmacy Technician (PT) programs at…

  11. Japanese Female Students' Perceptions of 2-Year Colleges as a Choice for Postsecondary Education

    ERIC Educational Resources Information Center

    Anzai, Shinobu; Paik, Chie Matsuzawa

    2012-01-01

    Two-year colleges have played an important role in providing postsecondary education for women in postwar Japan. More recently, a dwindling college-bound population in Japan has resulted in a drastic decrease in the number of and enrollment in 2-year colleges. This study explored the motivations and aspirations of 12 Japanese female students to…

  12. Developmental Assessment of Preterm Infants at 2 Years: Validity of Parent Reports

    ERIC Educational Resources Information Center

    Johnson, Samantha; Wolke, Dieter; Marlow, Neil

    2008-01-01

    Parental questionnaires are inexpensive alternatives to standardized testing for outcome measurement. The Parent Report of Children's Abilities has previously been revised (PARCA-R) and validated for use with very-preterm infants at 2 years of age. This study revalidated the PARCA-R for assessing cognition in a larger and more inclusive sample of…

  13. Behavior Predictors of Language Development over 2 Years in Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Bopp, Karen D.; Mirenda, Pat; Zumbo, Bruno D.

    2009-01-01

    Purpose: This exploratory study examined predictive relationships between 5 types of behaviors and the trajectories of vocabulary and language development in young children with autism over 2 years. Method: Participants were 69 children with autism assessed using standardized measures prior to the initiation of early intervention (T1) and 6 months…

  14. How Are 2-Year US Colleges Addressing Student Alcohol Use and Related Problems?

    ERIC Educational Resources Information Center

    Lenk, Kathleen M.; Nelson, Toben F.; Erickson, Darin J.; Toomey, Traci L.

    2015-01-01

    A considerable amount of attention and research has been dedicated to addressing alcohol use and related problems among students at 4-year colleges; however, less attention has been given to alcohol-related issues among students at 2-year technical/community colleges. This article describes research that expands on a study by Chiauzzi and…

  15. Electrokinetic experimental study on saturated rock samples: zeta potential and surface conductance

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Hu, Hengshan; Guan, Wei; Li, Hui

    2015-05-01

    It is important to know the electrokinetic properties of crustal rocks for interpreting the conductivity mechanisms and seismoelectric phenomena during earthquakes and seismoelectric well logging. In this study, electrokinetic experiments are conducted using a special core-holder by employing an AC lock-in technique. A series of experiments are conducted on 10 sandstone samples to measure the streaming potentials and streaming currents, and the experiments on each sample are done at six different salinities. The streaming potential coefficient and streaming current coefficient are calculated from the measured streaming potentials and streaming currents. The experimental results show that streaming potential coefficient and streaming current coefficient decrease as the salinity increases. The dependence of these two coefficients on permeability and pore radius are analysed and compared with previous works. At low salinities, the streaming potential coefficient and streaming current coefficient increase with the increasing permeability and pore radius. At high salinities, the streaming potential coefficient (streaming current coefficient) almost share a same value for 10 different samples. This conclusion indicates that the differences of rock parameters can only be well recognized at lower salinities, and the electrokinetic signals are invalid at high salinities, which offers a restrictive condition for using the amplitude of electrokinetic signals to estimate rock parameters. The zeta-potential have also been estimated through combined measurements of streaming potential and streaming current. The surface conductivity and its contribution to electrokinetic effects are determined from a comparison of zeta-potentials by two different methods, and then the validation of the Helmholz-Smoluchowski equation for a capillary tube is tested in rocks. We also compare our date with theoretical and experimental works, and set up an expression about the relationship between

  16. Oxygen flux and dielectric response study of Mixed Ionic-Electronic Conducting (MIEC) heterogeneous functional materials

    NASA Astrophysics Data System (ADS)

    Rabbi, Fazle

    Dense mixed ionic-electronic conducting (MIEC) membranes consisting of ionic conductive perovskite-type and/or fluorite-type oxides and high electronic conductive spinel type oxides, at elevated temperature can play a useful role in a number of energy conversion related systems including the solid oxide fuel cell (SOFC), oxygen separation and permeation membranes, partial oxidization membrane reactors for natural gas processing, high temperature electrolysis cells, and others. This study will investigate the impact of different heterogeneous characteristics of dual phase ionic and electronic conductive oxygen separation membranes on their transport mechanisms, in an attempt to develop a foundation for the rational design of such membranes. The dielectric behavior of a material can be an indicator for MIEC performance and can be incorporated into computational models of MIEC membranes in order to optimize the composition, microstructure, and ultimately predict long term membrane performance. The dielectric behavior of the MIECs can also be an indicator of the transport mechanisms and the parameters they are dependent upon. For this study we chose a dual phase MIEC oxygen separation membrane consisting of an ionic conducting phase: gadolinium doped ceria-Ce0.8 Gd0.2O2 (GDC) and an electronic conductive phase: cobalt ferrite-CoFe2O4 (CFO). The membranes were fabricated from mixtures of Nano-powder of each of the phases for different volume percentages, sintered with various temperatures and sintering time to form systematic micro-structural variations, and characterized by structural analysis (XRD), and micro-structural analysis (SEM-EDS). Performance of the membranes was tested for variable partial pressures of oxygen across the membrane at temperatures from 850°C-1060°C using a Gas Chromatography (GC) system. Permeated oxygen did not directly correlate with change in percent mixture. An intermediate mixture 60%GDC-40%CFO had the highest flux compared to the 50%GDC

  17. A study of conductive hydrogel composites of pH-responsive microgels and carbon nanotubes.

    PubMed

    Cui, Zhengxing; Zhou, Mi; Greensmith, Paula J; Wang, Wenkai; Hoyland, Judith A; Kinloch, Ian A; Freemont, Tony; Saunders, Brian R

    2016-05-14

    Conductive gel composites are attracting considerable attention because of their interesting electrical and mechanical properties. Here, we report conductive gel composites constructed using only colloidal particles as building blocks. The composites were prepared from mixed dispersions of vinyl-functionalised pH-responsive microgel particles (MGs) and multi-walled carbon nanotubes (CNTs). MGs are crosslinked pH-responsive polymer colloid particles that swell when the pH approaches the pKa of the particles. Two MG systems were used which contained ethyl acrylate (EA) or methyl acrylate (MA) and around 30 mol% of methacrylic acid (MAA). The MA-based MG is a new pH-responsive system. The mixed MG/CNT dispersions formed thixotropic physical gels. Those gels were transformed into covalent interlinked electrically conducting doubly crosslinked microgel/CNT composites (DX MG/CNT) by free-radical reaction. The MGs provided the dual roles of dispersant for the CNTs and macro-crosslinker for the composite. TEM data showed evidence for strong attraction between the MG and the CNTs which facilitated CNT dispersion. An SEM study confirmed CNT dispersion throughout the composites. The mechanical properties of the composites were studied using dynamic rheology and uniaxial compression measurements. Surprisingly, both the ductility and the modulus of the gel composites increased with increasing CNT concentration used for their preparation. Human adipose-derived mesenchymal stem cells (AD-MSCs) exposed to DX MG/CNT maintained over 99% viability with metabolic activity retained over 7 days, which indicated non-cytotoxicity. The results of this study suggest that our approach could be used to prepare other DX MG/CNT gel composites and that these materials may lead to future injectable gels for advanced soft-tissue repair. PMID:27067636

  18. A study of conductive hydrogel composites of pH-responsive microgels and carbon nanotubes.

    PubMed

    Cui, Zhengxing; Zhou, Mi; Greensmith, Paula J; Wang, Wenkai; Hoyland, Judith A; Kinloch, Ian A; Freemont, Tony; Saunders, Brian R

    2016-05-14

    Conductive gel composites are attracting considerable attention because of their interesting electrical and mechanical properties. Here, we report conductive gel composites constructed using only colloidal particles as building blocks. The composites were prepared from mixed dispersions of vinyl-functionalised pH-responsive microgel particles (MGs) and multi-walled carbon nanotubes (CNTs). MGs are crosslinked pH-responsive polymer colloid particles that swell when the pH approaches the pKa of the particles. Two MG systems were used which contained ethyl acrylate (EA) or methyl acrylate (MA) and around 30 mol% of methacrylic acid (MAA). The MA-based MG is a new pH-responsive system. The mixed MG/CNT dispersions formed thixotropic physical gels. Those gels were transformed into covalent interlinked electrically conducting doubly crosslinked microgel/CNT composites (DX MG/CNT) by free-radical reaction. The MGs provided the dual roles of dispersant for the CNTs and macro-crosslinker for the composite. TEM data showed evidence for strong attraction between the MG and the CNTs which facilitated CNT dispersion. An SEM study confirmed CNT dispersion throughout the composites. The mechanical properties of the composites were studied using dynamic rheology and uniaxial compression measurements. Surprisingly, both the ductility and the modulus of the gel composites increased with increasing CNT concentration used for their preparation. Human adipose-derived mesenchymal stem cells (AD-MSCs) exposed to DX MG/CNT maintained over 99% viability with metabolic activity retained over 7 days, which indicated non-cytotoxicity. The results of this study suggest that our approach could be used to prepare other DX MG/CNT gel composites and that these materials may lead to future injectable gels for advanced soft-tissue repair.

  19. A study of laser-beam welding conducted at the Centre for Laser Technologies of Metals

    NASA Astrophysics Data System (ADS)

    Antoszewski, Bogdan; Gradoń, Ryszard; Trela, Paweł; Cendrowicz, Edward

    2013-01-01

    The study reported here is part of a larger research project on laser-beam welding conducted at the Centre for Laser Technologies of Metals. The primary objectives were to compare laser-beam welding with a conventional process when used for longitudinal seams in street lamp posts, to select the process parameters for girth welds in cylindrical high-strength steel machine elements, and to assess whether laser-beam welding can be used for magnesium alloys. The paper includes recommendations for the selection of welding parameters.

  20. Studying the conductance and transport in low-dimensional graphene nano ribbon under ballistic regime

    NASA Astrophysics Data System (ADS)

    Pratap, Surender; Sarkar, Niladri

    2016-05-01

    NEGF procedure has been discussed in detail to study the conductance in Graphene Nano-Ribbons (GNR). The discretization procedure for the GNRs and CNTs for zig-zag configurations has been discussed in detail. We have explained this with a block diagram where each block represents a block diagonal matrix. We have used tight-binding procedure to obtain the block diagonal matrices for GNRs. We have applied a recursive method to obtain the Green's function for GNR based channels. Also a self consistent procedure is shown here which can be used to calculate the I-V characteristic of a GNR based Nano-scale devices.

  1. Numerical study of 1-D, 3-vector component, thermally-conductive MHD solar wind

    NASA Technical Reports Server (NTRS)

    Han, S.; Wu, S. T.; Dryer, M.

    1993-01-01

    In the present study, transient, 1-dimensional, 3-vector component MHD equations are used to simulate steady and unsteady, thermally conductive MHD solar wind expansions between the solar surface and 1 AU (astronomical unit). A variant of SIMPLE numerical method was used to integrate the equations. Steady state solar wind properties exhibit qualitatively similar behavior with the known Weber-Davies Solutions. Generation of Alfven shock, in addition to the slow and fast MHD shocks, was attempted by the boundary perturbations at the solar surface. Property changes through the disturbance were positively correlated with the fast and slow MHD shocks. Alfven shock was, however, not present in the present simulations.

  2. Yusho and its latest findings-A review in studies conducted by the Yusho Group.

    PubMed

    Mitoma, Chikage; Uchi, Hiroshi; Tsukimori, Kiyomi; Yamada, Hideyuki; Akahane, Manabu; Imamura, Tomoaki; Utani, Atsushi; Furue, Masutaka

    2015-09-01

    The Yusho incident is an unprecedented mass food poisoning that occurred in Japan in 1968. It was caused by the ingestion of rice bran oil contaminated with polychlorinated biphenyls (PCBs) and various dioxins and dioxin-like compounds, such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The victims of Yusho have suffered from characteristic skin manifestations associated with systemic, ophthalmological, and mucosal symptoms for a long period of time. The Study Group of Yusho (the Yusho Group) has been conducting annual medical check-ups on Yusho victims for more than 45years. Since 2002, when concentrations of dioxins in the blood of Yusho patients started to be measured, the pharmacokinetics of dioxins, relationship between blood levels of dioxins and symptoms/signs in patients directly exposed to dioxins, and the adverse effects on the next generation have become dramatically clear. Herein we review recent findings of studies conducted by the Yusho Group to evaluate chronic dioxin-induced toxicity to the next generation as well as Yusho patients in comparison with a similar food mass poisoning, the Yucheng incident. Additionally, we summarized basic studies carried out by the Yusho Group to re-evaluate the mechanisms of dioxin toxicities in experimental models and various functions of the aryl hydrocarbon receptor (AhR), known as the dioxin receptor, pathway.

  3. Experimental study of heat conductivity of n-heptane-n-octane-isooctane liquid ternary mixtures at high pressure

    SciTech Connect

    Naziev, D.Ya.

    1994-03-20

    Heat conductivity of liquid ternary mixtures of various compositions at various pressures and temperatures was experimentally studied. Dependence of heat conductivities of ternary mixtures on concentration of components was established. An equation linking the heat conductivities of ternary mixtures through those of pure components and appropriate binary mixtures was proposed.

  4. Role Modeling in the First 2 Years of Medical School.

    PubMed

    Obadia, Sharon J

    2015-08-01

    Role modeling opportunities for osteopathic physician teachers during a student's first 2 years of medical school are emerging as more colleges of osteopathic medicine strive to connect basic science didactics with clinically based learning activities. Examples of positive modeling by physician teachers during the first years of medical school are illustrated by 10 vignettes that can be incorporated into faculty development programs to increase awareness of such opportunities. The physician teacher in each vignette interacts with the student demonstrating desired professional behaviors. These vignettes also illustrate the effect of a positive "hidden curriculum" on a student's professional development. By recognizing these valuable teachable moments, teachers can incorporate role modeling into their daily practice. PMID:26214824

  5. Child-directed action promotes 2-year-olds' imitation.

    PubMed

    Williamson, Rebecca A; Brand, Rebecca J

    2014-02-01

    Children are voracious learners and adults are ubiquitous teachers. This project investigated whether the special infant-directed action modifications parents use when teaching their children (called "motionese" by Brand et al., Developmental Science, 2002, Vol. 5, pp. 72-83) improves 2-year-olds' imitation. Children saw an adult perform a series of acts on four novel objects using either an infant-directed style (including larger range of motion and enhanced boundary marking) or an adult-directed style. Children's imitation of the acts was higher in the infant-directed condition relative to the adult-directed condition, and both types of demonstration increased imitation relative to baseline (no demonstration). We propose that motionese provides information about actions, objects, and intentionality, thereby enhancing toddlers' observational learning.

  6. Analytical and experimental studies for space boundary and geometry inverse heat conduction problems

    NASA Astrophysics Data System (ADS)

    Chen, Tzu-Fang

    Inverse Heat Conduction Problems (IHCPs) have been widely used in engineering fields in recent decades. IHCPs are not the same as direct heat conduction problems which are ``well-posed''. IHCPs are made more difficult since they are inherently ``ill-posed'' that is, a small error perturbation will lead to a large error in the solution reconstructed. Prediction of an unknown in an IHCP is not an easy event. An IHCP also handles the desired information from measurements containing noise. A stable and accurate reliable inversion solver shall be studied. This dissertation is split into four parts. The first part describes space boundary IHCPs, and attempts to utilize noisy measurement data to predict unknown surface temperatures or heat fluxes. A new algorithm, using a Kalman Filter to filter the measurement noise combined with an implicit time-marching finite difference scheme, solves a space boundary IHCP. In the second part, errors in reconstruction of the temperature at each boundary of a one-dimensional IHCP can be presented by a simple relation. Each relation contains an unknown coefficient, which can be determined by using one simulation through the inversion solver of a pair of specified sensor locations. This relation can then be used to estimate the other recovery errors at the boundary without using the inverse solver. In the third part, an experimental study of temperature drop between two rough surfaces is conducted. The experimental data are analyzed by utilizing an inversion solver developed in this dissertation. In the fourth part, an IHCP with a melting process using the measured temperature and heat flux at one surface is solved by a new geometry inversion solver with a heat flux limiter to reconstruct the melting front location and the temperature history inside the test domain.

  7. Prospective multicenter assessment of perioperative and minimum 2-year postoperative complication rates associated with adult spinal deformity surgery.

    PubMed

    Smith, Justin S; Klineberg, Eric; Lafage, Virginie; Shaffrey, Christopher I; Schwab, Frank; Lafage, Renaud; Hostin, Richard; Mundis, Gregory M; Errico, Thomas J; Kim, Han Jo; Protopsaltis, Themistocles S; Hamilton, D Kojo; Scheer, Justin K; Soroceanu, Alex; Kelly, Michael P; Line, Breton; Gupta, Munish; Deviren, Vedat; Hart, Robert; Burton, Douglas C; Bess, Shay; Ames, Christopher P

    2016-07-01

    OBJECTIVE Although multiple reports have documented significant benefit from surgical treatment of adult spinal deformity (ASD), these procedures can have high complication rates. Previously reported complications rates associated with ASD surgery are limited by retrospective design, single-surgeon or single-center cohorts, lack of rigorous data on complications, and/or limited follow-up. Accurate definition of complications associated with ASD surgery is important and may serve as a resource for patient counseling and efforts to improve the safety of patient care. The authors conducted a study to prospectively assess the rates of complications associated with ASD surgery with a minimum 2-year follow-up based on a multicenter study design that incorporated standardized data-collection forms, on-site study coordinators, and regular auditing of data to help ensure complete and accurate reporting of complications. In addition, they report age stratification of complication rates and provide a general assessment of factors that may be associated with the occurrence of complications. METHODS As part of a prospective, multicenter ASD database, standardized forms were used to collect data on surgery-related complications. On-site coordinators and central auditing helped ensure complete capture of complication data. Inclusion criteria were age older than 18 years, ASD, and plan for operative treatment. Complications were classified as perioperative (within 6 weeks of surgery) or delayed (between 6 weeks after surgery and time of last follow-up), and as minor or major. The primary focus for analyses was on patients who reached a minimum follow-up of 2 years. RESULTS Of 346 patients who met the inclusion criteria, 291 (84%) had a minimum 2-year follow-up (mean 2.1 years); their mean age was 56.2 years. The vast majority (99%) had treatment including a posterior procedure, 25% had an anterior procedure, and 19% had a 3-column osteotomy. At least 1 revision was required in 82

  8. Electrical and Nonlinear Optical Studies of Specific Organic Molecular and Nonconjugated Conductive Polymeric Systems

    NASA Astrophysics Data System (ADS)

    Narayanan, Ananthakrishnan

    In this research, structural, electrical and nonlinear optical characteristics of: (a) single crystal films involving a noncentrosymmetric molecule DAST and a laser dye IR125 and (b) specific nonconjugated conducting polymers including poly(beta-pinene) and polynorbornene have been studied. 4'-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) is a well known second order nonlinear optical material. This material has exceptionally high electro-optic coefficients, high thermal stability and ultrafast response time. In this work single crystal films involving a combination of DAST and IR125 have been prepared using modified shear method and the films have been characterized using polarized optical microscopy, X-ray diffraction, polarization dependent optical absorption and photoluminescence spectroscopy. The electro-optic coefficient of these films measured at 633nm was found to be 300pm/V. Since IR-125 has a strong absorption band from 500nm to 800nm, these films are promising for various applications in nonlinear optics at longer wavelength and for light emission. Nonconjugated conducting polymers are a class of polymers that have at least one double bond in their repeat units. 1,4-cis polyisoprene, polyalloocimene, styrene butadiene rubber, poly(ethylenepyrrolediyl) derivatives, and poly(beta-pinene) are some of the well known examples of nonconjugated conducting polymers. In this work, polynorborne, a new addition to the class of nonconjugated conducting polymers is discussed. Like other polymers in this class, polynorbornene exhibits increase in electrical conductivity by many orders of magnitude upon doping with iodine. The maximum electrical conductivity of this material is 0.01 S/cm. As shown by using FTIR microscopy, the C=C bonds are transformed into cation radicals when polynorborne is doped. This is due to the charge-transfer from the double bond to the dopant (iodine). These materials like other nonconjugated conducting polymers have significant

  9. Probing the role of Ga in amorphous conducting oxides through local structure studies

    NASA Astrophysics Data System (ADS)

    Moffitt, Stephanie; Zhu, Qimin; Ma, Qing; Buchholz, Donald; Chang, Robert; Mason, Thomas; Marks, Tobin; Bedzyk, Michael

    2015-03-01

    The study of amorphous (a-) conducting oxides is an emerging field. The lack of grain boundaries, smooth surfaces, and low temperature deposition position these materials as ideal candidates for large area applications and flexible electronics. Most impressively, these materials maintain high electron mobility in the amorphous state. These benefits have led the recent commercialization of a-IGZO (Ga and Zn doped indium oxide) as a replacement for a-Si as the channel layer of thin film transistors in display technology. Despite this success, fundamental understanding of structure-property relationships is still lacking and must be improved to guide further development of amorphous conducting oxides. X-ray absorption spectroscopy (XAS) is one of the few tools that can be used to probe the structure of amorphous materials. Amorphous indium oxide doped with Ga (a-IGO) is a model system to help develop the role of dopants in amorphous oxides. An in depth XAS study was carried out to determine inter-atomic distances, coordination numbers, and structural disorder parameters as a function of Ga doping level. The correlation between XAS-derived structural features and the dopant-dependent evolution of both electrical properties and thermal stability of a-IGO will be discussed. This work is supported by the NSF MRSEC Program No. DMR1121262.

  10. Nitrogen-doped ZnO shells: Studies on optical transparency and electrical conductivity

    SciTech Connect

    Gaikwad, Rajendra S.; Mane, Rajaram S.; Pawar, Bhagwat N.; Ambade, Rohan B.; Ahn, Hee Joon; Han, Sung-Hwan; Joo, Oh-Shim

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Chemical spray growth of high quality zinc oxide nitrogen-doped films is explored. Black-Right-Pointing-Pointer Effect of nitrogen doping on crystallinity, surface morphology, and optical properties is comprehensively studied. Black-Right-Pointing-Pointer ZnO structural properties are optimized. Black-Right-Pointing-Pointer Effect of nitrogen doping on a gas sensing application of ZnO is investigated. -- Abstract: Studies on optical and electrical conductivity in nitrogen (N)-doped ZnO shells are explored. On incorporating low levels of nitrogen, the (0 0 2) X-ray diffraction (XRD) peak was found to be intensified significantly. Closely packed spherical crystallites of ZnO were transformed into flat-flakes during 0.1-0.3 M nitrogen doping and finally to shells, flattered at the center and tapered at ends, at 0.4 M. Both pristine and N-doped ZnO films show hydrophilic character. It was also found that the degree of transparency and the nature of conductivity as estimated by optical absorbance and Hall measurement, respectively, were strongly influenced by the levels of N-doping. Higher nitrogen doping led to decline in electrical resistivity and mobility due to an enhancement of free charge carriers. Presence of both (N{sub 2}){sub O} donor and (N){sub O} acceptor peaks in X-ray photoelectron spectroscopy could be responsible for the formation of higher carrier concentration in ZnO films.

  11. Myopia Control with a Novel Peripheral Gradient Soft Lens and Orthokeratology: A 2-Year Clinical Trial

    PubMed Central

    Pauné, Jaime; Morales, Hari; Armengol, Jesús; Quevedo, Lluisa; Faria-Ribeiro, Miguel; González-Méijome, José M.

    2015-01-01

    Objective. To evaluate the degree of axial elongation with soft radial refractive gradient (SRRG) contact lenses, orthokeratology (OK), and single vision (SV) spectacle lenses (control) during a period of 1 year before treatment and 2 years after treatment. Methods. This was a prospective, longitudinal, nonrandomized study. The study groups consisted of 30, 29, and 41 children, respectively. The axial length (AL) was measured during 2 years after recruitment and lens fitting. Results. The baseline refractive sphere was correlated significantly (Spearman's Rho (ρ) correlation = 0.542; P < 0.0001) with the amount of myopia progression before baseline. After 2 years, the mean myopia progression values for the SRRG, OK, and SV groups were −0.56 ± 0.51, −0.32 ± 0.53, and −0.98 ± 0.58 diopter, respectively. The results represent reductions in myopic progression of 43% and 67% for the SRRG and OK groups, respectively, compared to the SV group. The AL increased 27% and 38% less in the SRRG and OK groups, respectively compared with the SV group at the 2-year visit (P < 0.05). Axial elongation was not significantly different between SRRG and OK (P = 0.430). Conclusion. The SRRG lens significantly decreased AL elongation compared to the SV control group. The SRRG lens was similarly effective to OK in preventing myopia progression in myopic children and adolescent. PMID:26605331

  12. The first BETS radical cation salts with dicyanamide anion: Crystal growth, structure and conductivity study

    SciTech Connect

    Kushch, N.D.; Buravov, L.I.; Chekhlov, A.N.; Spitsina, N.G.; Kushch, P.P.; Yagubskii, E.B.; Herdtweck, E.; Kobayashi, A.

    2011-11-15

    Electrochemical oxidation of bis(ethylenedithio)tetraselenafulvalene (BETS) has been investigated. Simple and complex dicyanamides of transition metals (Mn{sup 2+}, Ni{sup 2+} and Fe{sup 2+}) were used as electrolytes. The correlation between composition of prepared radical cation salts and metal nature in electrolytes was established. Manganese dicyanamides provide the formation of BETS salts with the {l_brace}Mn[N(CN){sub 2}]{sub 3}{r_brace}- and [N(CN){sub 2}]-XH{sub 2}O anions. When Ni- or Fe-containing electrolytes were used only metalless BETS salts, {alpha}''-BETS{sub 2}[N(CN){sub 2}].2H{sub 2}O (I) and {theta}-BETS{sub 2}[N(CN){sub 2}].3.6H{sub 2}O (II), formed. Structures and conducting properties of these salts were analyzed. Both salts exhibit layered structure. Conducting radical cation layers have {alpha}'' (I)- or {theta}-type (II). Anion sheets appear as two-dimensional polymer networks of different types. These networks are formed by [N(CN)]{sub 2}{sup -} anions and water molecules interlinked by hydrogen bonds. Salt I is a semiconductor and II demonstrates resistance drop down to150 K at normal pressure and down to 72 K at {approx}0.4 kbar pressure. - Graphical abstract: We studied electrochemical oxidation of BETS donor in the presence of simple and/or complex dicyanamides of transition metals (Ni, Fe, Mn) as electrolytes. New conducting salts {alpha}''-BETS{sub 2}[N(CN){sub 2}].2H{sub 2}O and {theta}-BETS{sub 2}[N(CN){sub 2}].3.8H{sub 2}O have been synthesized and characterized. Highlights: > We studied electrochemical oxidation of BETS donor. > Dicyanamides of transition metals (Ni, Fe, Mn) were used as electrolytes. > We found a well-reproducible synthesis of magnetic superconductor BETS{sub 2}Mn[N(CN){sub 2}]{sub 3}. > Two new metalless BETS salts form when Ni and Fe electrolytes were used. > Their structure and conductivity were investigated.

  13. Study on the preparation and structural performance of polyaniline/PP conductive fiber

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Wang, Lijiu

    2007-07-01

    Polyaniline/PP conductive fiber was obtained by in-situ adsorption polymerization. In this work, we discussed the influence of these reaction factors such as adulteration acid concentration, oxidizer concentration, polyaniline monomer content and reaction time to the polymerization and conduct property. In the meanwhile, surface handling with plasma have also been compared for examining the change of polymerization and conduct property. FT-IR spectra analysis and the physic mechanical properties have been used to investigate the structure and properties of conductive fibers. The result shows that with this method of polymerization the conductive property is superior and the conductivity can be reached by 4.5KΩ.

  14. Conducting Probe Atomic Force Microscope as a Relevant Tool for Studying Some Phenomena in MEMS Switches

    NASA Astrophysics Data System (ADS)

    Peschot, A.; Vincent, M.; Poulain, C.; Mariolle, D.; Houzé, F.; Delamare, J.

    2015-12-01

    As the reliability of electrical microcontacts has proved to be the main limitation to a fast-growing production of ultraminiaturized switches, a thorough understanding of their failure mechanisms is an all-important purpose. This paper aims at showing that conducting-probe Atomic Force Microscopy (cp-AFM) is an adequate tool to actuate and study electrical contacts. By choosing relevant cantilevers and operating mode of the cp-AFM, dimensions, gap and force level representative of existing microelectromechanical switches (MEMS switches) are obtained. With two examples, the advantages of using a cp-AFM in force mode for studying physical phenomena at very low scale are highlighted. The reported investigations concern material transfer between contact parts and contact bounces. Those two undesirable phenomena induce surface damages and impinge reliability of MEMS switches. In both cases an explanatory scenario of phenomena occurring at nanoscale is proposed and preventive recommendations for improving the lifetime of such devices are suggested.

  15. HCl-doped conducting Emeraldine polymer studied by ab initio Car-Parrinello molecular dynamics

    NASA Astrophysics Data System (ADS)

    Cavazzoni, Carlo; Colle, Renato; Farchioni, Riccardo; Grosso, Giuseppe

    2006-07-01

    We present a Car-Parrinello molecular dynamics study of the highly conducting Emeraldine salt, which definitely settles the controversy between the polaronic and the bipolaronic lattice models present in the literature. Our treatment is fully microscopic and takes into account interchain interactions, individual chain conformation, and the dynamics of the HCl protonation. We have highlighted the peculiar role of the Cl- counterions both for the polymer structure and for the interpretation of its metallic character. Our study indicates that this metallic character is due to the π electrons along each chain with chlorine counterions in polaronic arrangement and that only the Pc2a lattice symmetry provides an x-ray spectrum in complete agreement with the experiments.

  16. Characterizing diverse orthologues of the cystic fibrosis transmembrane conductance regulator protein for structural studies.

    PubMed

    Pollock, Naomi L; Rimington, Tracy L; Ford, Robert C

    2015-10-01

    As an ion channel, the cystic fibrosis transmembrane conductance regulator (CFTR) protein occupies a unique niche within the ABC family. Orthologues of CFTR are extant throughout the animal kingdom from sharks to platypods to sheep, where the osmoregulatory function of the protein has been applied to differing lifestyles and diverse organ systems. In humans, loss-of-function mutations to CFTR cause the disease cystic fibrosis, which is a significant health burden in populations of white European descent. Orthologue screening has proved fruitful in the pursuit of high-resolution structural data for several membrane proteins, and we have applied some of the princples developed in previous studies to the expression and purification of CFTR. We have overexpressed this protein, along with evolutionarily diverse orthologues, in Saccharomyces cerevisiae and developed a purification to isolate it in quantities sufficient for structural and functional studies. PMID:26517900

  17. Behavioral trends in young children with conductive hearing loss: a case-control study.

    PubMed

    Gouma, Panagiota; Mallis, Antonios; Daniilidis, Vasilis; Gouveris, Haralambos; Armenakis, Nikolaos; Naxakis, Stephanos

    2011-01-01

    Otitis media with effusion (OME) is a common condition affecting children and a well-known cause of conductive hearing loss that can potentially lead to speech development disorders. Recent studies, however, have demonstrated the influence of OME on development of attention disorders or social adaptation and acceptance. Hence, this study aimed to investigate the behavioral trends of children with OME based on the Achenbach test. A group of 117 patients with episodes of OME at the age of 4-5 was compared with a control group according to the Achenbach system of evaluation, by application of the Child Behavior Checklist questionnaire (CBCL). Patients suffering from OME had more anxiety/depression related disorders and attention disorders as compared with the control group. The psychological effect of OME in children of ages 6-8 is evident with anxiety and depression disorders being especially prominent among these patients. PMID:20665042

  18. Safety studies conducted on high-purity trans-resveratrol in experimental animals.

    PubMed

    Williams, Lonnie D; Burdock, George A; Edwards, James A; Beck, Mareike; Bausch, Jochen

    2009-09-01

    trans-Resveratrol is a naturally occurring polyphenolic compound found in a variety of foods, but predominantly in grapes. Safety studies were conducted on high-purity trans-resveratrol (Resvida), including skin and eye irritation, dermal sensitization, subchronic and reproductive toxicity, genotoxicity, and absorption, metabolism and excretion. Resvida was non-irritating to skin and eyes and non-sensitizing. It was non-mutagenic in a bacterial reverse mutation assay in Salmonella typhimurium and Escherichia coli, but exhibited clastogenic activity in a chromosomal aberration test in human lymphocytes. However, in an in vivo bone marrow micronucleus test in rats, Resvida was non-genotoxic. In a 28-day study, Resvida caused no adverse effects in rats at 50, 150 and 500 mg/kg bw/day. Similarly, in a 90-day study, Resvida did not cause any adverse effects in rats at up to 700 mg/kg bw/day; the highest dose tested. Resvida did not induce any adverse reproductive effects in an embryo-fetal toxicity study in rats at a dose of 750 mg/kg bw/day. Also, in vitro and in vivo absorption, metabolism, and excretion studies in Caco-2 cells, rat primary hepatocytes and male and female rats (in vivo) show that Resvida is readily absorbed, metabolized and excreted. These studies provide evidence that Resvida is well tolerated and non-toxic.

  19. Increased Food Insecurity Among Mothers of 2 Year Olds with Special Health Care Needs.

    PubMed

    Adams, Elizabeth J; Hoffmann, Laurel M; Rosenberg, Kenneth D; Peters, Dawn; Pennise, Melissa

    2015-10-01

    The objective of this study is to explore the association between having a child with special health care needs (CSHCN) and food insecurity when the child is 2 years old. We studied women who had a live birth in 2004-2005 and responded to Oregon's Pregnancy Risk Assessment Monitoring System (PRAMS) survey 3 months postpartum (Time 1) and the follow-up survey (PRAMS-2), when the child was 2 years old (Time 2). Women answering affirmatively to the PRAMS-2 question, "In the last 12 months, did you ever eat less than you felt you should because there was not enough money for food?" were considered food insecure. CSHCN status was identified by affirmative responses to questions about needs for ongoing services (Time 2). PRAMS and PRAMS-2 responses were weighted for study design and non-response. Results report weighted analyses, unless noted. Among 1812 mothers completing PRAMS-2, 13.6 % (unweighted) had a 2-year-old CSHCN and 11.9 % (unweighted) were food insecure at Time 2. The estimated prevalence of food insecurity at 2-year follow-up was 20.7 % among families of CSHCN and 9.7 % for others. After adjustment for Time 2 marital status, education, lifetime U.S. residence, income and health conditions, multivariable logistic regression revealed that odds of food insecurity were more than two times as great for CSHCN mothers 2 years post-partum compared to non-CSHCN mothers (adjusted odds ratio 2.6, 95 % confidence interval 1.3, 4.6). Families of CSHCN face increased risk for food insecurity. Improved understanding of causal determinants of food insecurity among households of CSHCN is needed.

  20. SODA CONSUMPTION AND OVERWEIGHT STATUS OF 2-YEAR-OLD MEXICAN-AMERICAN CHILDREN IN CALIFORNIA

    PubMed Central

    Warner, Marcella L; Harley, Kim; Bradman, Asa; Vargas, Gloria; Eskenazi, Brenda

    2015-01-01

    Objective The prevalence of overweight in United States children, 2 – 5 years, has increased two-fold since 1975, with the highest prevalence in Mexican-Americans. The objective of this study was to determine the association between current soda consumption and overweight in 2-year-old Mexican-American children. Research Methods and Procedures The CHAMACOS study is a longitudinal study of the health of low-income Latino pregnant women and their children living in the Salinas Valley, California. Six hundred pregnant women were enrolled (October 1999 – October 2000), and their children were followed until 2 years of age. This cross-sectional analysis includes the 354 children who completed the 2-year follow-up interview. Standing height (cm) and weight (g) were measured at 2 years. Overweight was defined as ≥ 95th percentile of the sex-specific body mass index for each child’s age. Results Fifty-five (15.5%) children were overweight. Over half (56%) reported consuming any soda in the last week. After covariate adjustment, compared to no soda consumption, <1 soda / day was not related to overweight (adj-OR = 0.97, 95% CI 0.47, 1.99), but ≥1 soda / day was significantly associated with overweight (adj-OR = 3.39, 95% CI 1.43, 8.07) and the test for trend was significant (p = 0.02). Discussion At 2 years of age, the prevalence of overweight among the CHAMACOS cohort is higher than the national prevalence estimate for Mexican-American, 2–5 year olds, and is significantly associated with current soda consumption. Interventions to reduce consumption of soda in young Mexican-American children should be considered. PMID:17135613

  1. First-Principles study of defects in transparent conducting oxide materials

    NASA Astrophysics Data System (ADS)

    Amini, Mozhgan

    The study of defects and impurities is an important area in semiconductor physics. Defects can be used to control the electronic and optoelectronic properties of materials. However, to achieve such control, knowledge of the fundamental processes that control doping is necessary. First-principles calculations have already made important contributions to the understanding of these fundamental processes of doping in different semiconductors. An important class of materials with an already widespread application area is the transparent conducting oxides (TCOs). These materials combine electrical conductivity and optical transparency and are essential for photovoltaic and optoelectronic applications. The electronic structure of TCOs has therefore been a subject of interest for a long time. In this thesis we provide a first-principles study of defects in TCO materials using density functional theory (DFT). An introduction to TCO materials, their properties, fabrications, and applications are presented in chapter 1. It is followed by a general explanation of the basics of DFT, a quantum mechanical approach for ground state calculations, in chapter 2. Then in chapter 3, different kinds of defects are classified and some important issues such as donor, acceptor, shallow, deep, formation energy, transition level, optical and thermal ionization energies are introduced. In chapter 4, we have used first principles calculations based on DFT to study point defects in CdO within the local density approximation and beyond (LDA+U). Chapter 5 presented the electronic structure and formation energies of group III elements (Al, Ga, In) doped in ZnO. Then in chapter 6, the effect of the presence of both hydrogen and an extrinsic defect (Al, Ga or In) in ZnO is studied. In chapter 7, ZnM2O4 (M=Co, Rh, Ir) spinels are considered as a class of potential p-type transparent conducting oxides and the formation energies of acceptor-like defects are reported with an advanced hybrid exchange

  2. Guidelines for the Design and Conduct of Clinical Studies in Knee Articular Cartilage Repair

    PubMed Central

    Mithoefer, Kai; Saris, Daniel B.F.; Farr, Jack; Kon, Elizaveta; Zaslav, Kenneth; Cole, Brian J.; Ranstam, Jonas; Yao, Jian; Shive, Matthew; Levine, David; Dalemans, Wilfried; Brittberg, Mats

    2011-01-01

    Objective: To summarize current clinical research practice and develop methodological standards for objective scientific evaluation of knee cartilage repair procedures and products. Design: A comprehensive literature review was performed of high-level original studies providing information relevant for the design of clinical studies on articular cartilage repair in the knee. Analysis of cartilage repair publications and synopses of ongoing trials were used to identify important criteria for the design, reporting, and interpretation of studies in this field. Results: Current literature reflects the methodological limitations of the scientific evidence available for articular cartilage repair. However, clinical trial databases of ongoing trials document a trend suggesting improved study designs and clinical evaluation methodology. Based on the current scientific information and standards of clinical care, detailed methodological recommendations were developed for the statistical study design, patient recruitment, control group considerations, study endpoint definition, documentation of results, use of validated patient-reported outcome instruments, and inclusion and exclusion criteria for the design and conduct of scientifically sound cartilage repair study protocols. A consensus statement among the International Cartilage Repair Society (ICRS) and contributing authors experienced in clinical trial design and implementation was achieved. Conclusions: High-quality clinical research methodology is critical for the optimal evaluation of current and new cartilage repair technologies. In addition to generally applicable principles for orthopedic study design, specific criteria and considerations apply to cartilage repair studies. Systematic application of these criteria and considerations can facilitate study designs that are scientifically rigorous, ethical, practical, and appropriate for the question(s) being addressed in any given cartilage repair research project

  3. IN-SERVICE HYDRAULIC CONDUCTIVITY OF GCLS IN LANDFILL COVERS - LABORATORY AND FIELD STUDIES

    EPA Science Inventory

    Laboratory experiments using multi-species inorganic solutions (containing calcium and sodium) were conducted on specimens of a new geosynthetic clay liner (GCL) containing sodium bentonite to determine how cation exchange and desiccation affected the hydraulic conductivity. Calc...

  4. Ion transport study in polymer-nanocomposite films by dielectric spectroscopy and conductivity scaling

    NASA Astrophysics Data System (ADS)

    Tripathi, Namrata; Thakur, Awalendra K.; Shukla, Archana; Marx, David T.

    2015-07-01

    The dielectric and conductivity response of polymer nanocomposite electrolytes (films of PMMA4LiClO4 dispersed with nano-CeO2 powder) have been investigated. The dielectric behavior was analyzed via the dielectric permittivity (ε‧) and dissipation factor (tan δ) of the samples. The analysis has shown the presence of space charge polarization at lower frequencies. The real part of ac conductivity spectra of materials obeys the Jonscher power law. Parameters such as dc conductivity, hopping rate, activation energies and the concentration of charge carriers were determined from conductivity data using the Almond West formalism. It is observed that the higher ionic conductivity at higher temperature is due to increased thermally-activated hopping rates accompanied by a significant increase in carrier concentration. The contribution of carrier concentration to the total conductivity is also confirmed from activation energy of migration conduction and from Summerfield scaling. The ac conductivity results are also well correlated with TEM results.

  5. Environmental studies conducted at the Fenton Hill Hot Dry Rock geothermal development site

    SciTech Connect

    Miera, F.R. Jr.; Langhorst, G.; McEllin, S.; Montoya, C.

    1984-05-01

    An environmental investigation of Hot Dry Rock (HDR) geothermal development was conducted at Fenton Hill, New Mexico, during 1976-1979. Activities at the Fenton Hill Site included an evaluation of baseline data for biotic and abiotic ecosystem components. Identification of contaminants produced by HDR processes that had the potential for reaching the surrounding environment is also discussed. Three dominant vegetative communities were identified in the vicinity of the site. These included grass-forb, aspen, and mixed conifer communities. The grass-forb area was identified as having the highest number of species encountered, with Phleum pratense and Dactylis glomerata being the dominant grass species. Frequency of occurrence and mean coverage values are also given for other species in the three main vegetative complexes. Live trapping of small mammals was conducted to determine species composition, densities, population, and diversity estimates for this component of the ecosystem. The data indicate that Peromyscus maniculatus was the dominant species across all trapping sites during the study. Comparisons of relative density of small mammals among the various trapping sites show the grass-forb vegetative community to have had the highest overall density. Comparisons of small mammal diversity for the three main vegetative complexes indicate that the aspen habitat had the highest diversity and the grass-forb habitat had the lowest. Analyses of waste waters from the closed circulation loop indicate that several trace contaminants (e.g., arsenic, cadmium, fluoride, boron, and lithium) were present at concentrations greater than those reported for surface waters of the region.

  6. Application of the thermoelectric phenomena to study the unsteady-state thermal conductivity

    NASA Astrophysics Data System (ADS)

    Poprawski, W.; Radojewska, E. B.

    2016-09-01

    We present an experimental set-up designed to investigate the unsteady-state thermal conductivity. A sine-shaped thermal wave is produced by a thermoelectric device and the change in temperature at two points in a metal rod is measured. The investigation is carried out for seven thermal wave frequencies. The thermal wave penetration depth and the thermal conductivity are determined by two methods: from the wave amplitude ratio and from the wave phase shift at two locations. The presented system also offers a determination of the thermal wave propagation velocity and the thermal diffusivity coefficient of the medium. The obtained measurement results are discussed. The specification of the measurement system is preceded by a theoretical and comprehensive description of the phenomena taking part in the experiment. With regard to the role of thermoelectric phenomena in contemporary science and technology the presented experiment is suitable for students in university laboratories studying metrology, electronics, space technology, energy harvesting, energo-mechanics, renewable energy science, chemical technology, bio-engineering and other similar courses.

  7. Density functional theory and conductivity studies of boron-based anion receptors

    DOE PAGES

    Leung, Kevin; Chaudhari, Mangesh I.; Rempe, Susan B.; Fenton, Kyle R.; Pratt, III, Harry D.; Staiger, Chad L.; Nagasubramanian, Ganesan

    2015-07-10

    Anion receptors that bind strongly to fluoride anions in organic solvents can help dissolve the lithium fluoride discharge products of primary carbon monofluoride (CFx) batteries, thereby preventing the clogging of cathode surfaces and improving ion conductivity. The receptors are also potentially beneficial to rechargeable lithium ion and lithium air batteries. We apply Density Functional Theory (DFT) to show that an oxalate-based pentafluorophenyl-boron anion receptor binds as strongly, or more strongly, to fluoride anions than many phenyl-boron anion receptors proposed in the literature. Experimental data shows marked improvement in electrolyte conductivity when this oxalate anion receptor is present. The receptor ismore » sufficiently electrophilic that organic solvent molecules compete with F– for boron-site binding, and specific solvent effects must be considered when predicting its F– affinity. To further illustrate the last point, we also perform computational studies on a geometrically constrained boron ester that exhibits much stronger gas-phase affinity for both F– and organic solvent molecules. After accounting for specific solvent effects, however, its net F– affinity is about the same as the simple oxalate-based anion receptor. Lastly, we propose that LiF dissolution in cyclic carbonate organic solvents, in the absence of anion receptors, is due mostly to the formation of ionic aggregates, not isolated F– ions.« less

  8. Density functional theory and conductivity studies of boron-based anion receptors

    SciTech Connect

    Leung, Kevin; Chaudhari, Mangesh I.; Rempe, Susan B.; Fenton, Kyle R.; Pratt, III, Harry D.; Staiger, Chad L.; Nagasubramanian, Ganesan

    2015-07-10

    Anion receptors that bind strongly to fluoride anions in organic solvents can help dissolve the lithium fluoride discharge products of primary carbon monofluoride (CFx) batteries, thereby preventing the clogging of cathode surfaces and improving ion conductivity. The receptors are also potentially beneficial to rechargeable lithium ion and lithium air batteries. We apply Density Functional Theory (DFT) to show that an oxalate-based pentafluorophenyl-boron anion receptor binds as strongly, or more strongly, to fluoride anions than many phenyl-boron anion receptors proposed in the literature. Experimental data shows marked improvement in electrolyte conductivity when this oxalate anion receptor is present. The receptor is sufficiently electrophilic that organic solvent molecules compete with F for boron-site binding, and specific solvent effects must be considered when predicting its F affinity. To further illustrate the last point, we also perform computational studies on a geometrically constrained boron ester that exhibits much stronger gas-phase affinity for both F and organic solvent molecules. After accounting for specific solvent effects, however, its net F affinity is about the same as the simple oxalate-based anion receptor. Lastly, we propose that LiF dissolution in cyclic carbonate organic solvents, in the absence of anion receptors, is due mostly to the formation of ionic aggregates, not isolated F ions.

  9. Influence of the "second gap" on the transparency of transparent conducting oxides: An ab initio study

    NASA Astrophysics Data System (ADS)

    Ha, Viet-Anh; Waroquiers, David; Rignanese, Gian-Marco; Hautier, Geoffroy

    2016-05-01

    Transparent conducting oxides (TCOs) are essential to many technologies. These materials are doped (n- or p-type) oxides with a large enough band gap (ideally >3 eV) to ensure transparency. However, the high carrier concentration present in TCOs leads additionally to the possibility for optical transitions from the occupied conduction bands to higher states for n-type materials and from lower states to the unoccupied valence bands for p-type TCOs. The "second gap" formed by these transitions might limit transparency, and a large second gap has been sometimes proposed as a design criteria for high performance TCOs. Here, we study the influence of this second gap on optical absorption using ab initio computations for several well-known n- and p-type TCOs. Our work demonstrates that most known n-type TCOs do not suffer from second gap absorption in the visible even at very high carrier concentrations. On the contrary, p-type oxides show lowering of their optical transmission for high carrier concentrations due to second gap effects. We link this dissimilarity to the different chemistries involved in n- versus typical p-type TCOs. Quantitatively, we show that second gap effects lead to only moderate loss of transmission (even in p-type TCOs) and suggest that a wide second gap, while beneficial, should not be considered as a needed criteria for a working TCO.

  10. Change over Time: Conducting Longitudinal Studies of Children’s Cognitive Development

    PubMed Central

    Grammer, Jennie K.; Coffman, Jennifer L.; Ornstein, Peter A.; Morrison, Frederick J.

    2014-01-01

    Developmental scientists have argued that the implementation of longitudinal methods is necessary for obtaining an accurate picture of the nature and sources of developmental change (Magnusson & Cairns, 1996; Morrison & Ornstein, 1996; Magnusson & Stattin, 2006). Developmentalists studying cognition have been relatively slow to embrace longitudinal research, and thus few exemplar studies have tracked individual children’s cognitive performance over time and even fewer have examined contexts that are associated with this growth. In this article we first outline some of the benefits of implementing longitudinal designs. Using illustrations from existing studies of children’s basic cognitive development and of their school-based academic performance, we discuss when it may be appropriate to employ longitudinal (versus other) methods. We then outline methods for integrating longitudinal data into one’s research portfolio, contrasting the leveraging of existing longitudinal data sets with the launching of new longitudinal studies in order to address specific questions concerning cognitive development. Finally, for those who are interested in conducting longitudinal investigations of their own, we provide practical on-the-ground guidelines for designing and carrying out such studies of cognitive development. PMID:24955035

  11. Efficacy of Salvage Radiotherapy Plus 2-Year Androgen Suppression for Postradical Prostatectomy Patients With PSA Relapse

    SciTech Connect

    Choo, Richard; Danjoux, Cyril; Gardner, Sandra; Morton, Gerard; Szumacher, Ewa; Loblaw, D. Andrew; Cheung, Patrick; Pearse, Maria

    2009-11-15

    Purpose: To determine the efficacy of a combined approach of radiotherapy (RT) plus 2-year androgen suppression (AS) as salvage treatment for prostate-specific antigen (PSA) relapse after radical prostatectomy (RP). Methods and Materials: Seventy-five patients with PSA relapse after RP were treated with salvage RT plus 2-year AS, as per a pilot, prospective study. AS started within 1 month after completion of salvage RT and consisted of nilutamide for 4 weeks and buserelin acetate depot subcutaneously every 2 months for 2 years. Relapse-free rate including freedom from PSA relapse was estimated using the Kaplan-Meier method. PSA relapse was defined as a PSA rise above 0.2 ng/mL with two consecutive increases over a minimum of 3 months. A Cox regression analysis was performed to evaluate prognostic factors for relapse. Results: Median age of the cohort was 63 years at the time of salvage RT. Median follow-up from salvage RT was 6.4 years. All achieved initially complete PSA response (< 0.2) with the protocol treatment. Relapse-free rate including the freedom from PSA relapse was 91.5% at 5 years and 78.6% at 7 years. Overall survival rate was 93.2% at both 5 and 7 years. On Cox regression analysis, pT3 stage and PSA relapse less than 2 years after RP were significant prognostic factors for relapse. Conclusion: The combined treatment of salvage RT plus 2-year AS yielded an encouraging result for patients with PSA relapse after RP and needs a confirmatory study.

  12. Optical studies of the charge localization and delocalization in conducting polymers

    NASA Astrophysics Data System (ADS)

    Kim, Youngmin

    A systematic charge transport study on the thermochromism of polyaniline (PAN) doped with a plasticizing dopant, and on a field effect device using conducting poly (3,4-ethylenedioxythiophene) (PEDOT) as its active material, was made at optical (20--45,000 cm-1) frequencies to probe the charge localization and delocalization phenomena and the insulator to metal transition (IMT) in the inhomogeneous conducting polymer system. Temperature dependent reflectance [20--8000 cm -1 (2.5 meV--1eV)] of the PAN sample, together with absorbance and do transport study done by Dr. Pron at the Laboratoire de Physique des Metaux Synthetiques in Grenoble, France, shows spectral weight loss in the infrared region but the reflectance in the very low frequency (below 100 cm-1) remains unaffected. There are two localization transitions. The origin of the 200 K localization transition that affect >˜15% of the electrons is the glass transition emanating from the dopants. The transition principally affects the IR response in the range of 200--8000 cm -1. The low temperature (<75K) localization transition affects the few electrons that provide the high conductivity. It is suggested that these electrons are localized by disorder at the lowest temperature and become delocalized through phonon induced delocalization as the temperature increases to 75K. It is noted that this temperature is typical of a Debye temperature in many organic materials. The thermocromism is attributed to the weak localization to strong localization transition through the glass transition temperature. Below the glass transition temperature (Tg), the lattice is "frozen" in configuration that reduces the charge delocalization and lead to cause increase of strongly localized polarons. Time variation of source-drain current, real-time IR reflectance [20--8000 cm-1 (2.5 meV--1eV)] modulation, and real-time UV/VIS/NIR absorbance [380--2400 nm (0.5--3.3 eV)] modulation were measured to investigate the field induced charge

  13. Synthesis, characterization and conductivity studies of ZnFe{sub 2}O{sub 4} nanoparticles

    SciTech Connect

    Narsimulu, D.; Satyanarayana, N.; Venkateswarlu, M.

    2015-06-24

    Transition metal ferrites with general formula AB{sub 2}O{sub 4} (A=Co, Cu, Mn, Zn, B=Fe{sup +3}) could be used as an anode materials in lithium ion battery (LIB), because, lithium ion batteries fabricated using ferrite materials show the high capacity than commonly used graphite. The ZnFe{sub 2}O{sub 4} with cubic spinel structured material was prepared by acrylamide assisted citrate combustion process. Phase, structural coordination and thermal behavior of the prepared ZnFe{sub 2}O{sub 4} were confirmed by powder X-ray diffraction, FTIR spectra and TG/DTA thermogram respectively. Morphology and specific surface area of the ZnFe{sub 2}O{sub 4} were identified by SEM and BET surface analyzer respectively and its conductivity studies were made through impedance spectroscopy.

  14. A simulation study of field-induced proton-conduction pathways in dry ionomers.

    PubMed

    Allahyarov, Elshad; Taylor, Philip L; Löwen, Hartmut

    2011-06-15

    The morphological changes that can be induced in a dry ionomer by application of a strong electric field have been studied by means of computer simulation. The internal energy of the membrane at first slowly decreases with increasing field, but then rapidly increases after a certain threshold field is reached. This effect is interpreted as the reorganization of interacting head group dipoles in response to the external perturbation. The resulting morphology contains continuous channels of hydrophilic material capable of facilitating proton conduction. Upon removal of the poling field, the system does not return to its original morphology, but retains the anisotropic structure of the poled material. The poled structure appears to be thermodynamically stable, as confirmed by calculations of the Helmholtz energy of the original and poled samples.

  15. Which motor nerve conduction study is best in ulnar neuropathy at the elbow?

    PubMed

    Shakir, Ali; Micklesen, Paula J; Robinson, Lawrence R

    2004-04-01

    There is debate regarding how best to utilize ulnar motor nerve conduction velocity (MNCV) to identify ulnar neuropathy at the elbow (UNE). We used receiver operator characteristic (ROC) curves to compare absolute across-elbow MNCV with MNCV difference between elbow and forearm segments (VDIF) when recording from abductor digiti minimi (ADM) and first dorsal interosseous (FDI) muscles. Also, we determined how their utility was impacted by low amplitudes of compound muscle action potentials (CMAPs). We studied 85 subjects with UNE and 77 subjects with carpal tunnel syndrome but without clinical evidence of UNE. The UNE group was divided into three subgroups based on CMAP amplitude. At 95% specificity, MNCV sensitivities were 80% at ADM and 77% at FDI, and VDIF sensitivities were 51% at ADM and 38% at FDI. The ROC curves showed MNCV to be superior to VDIF across all amplitude subgroups; however, confidence intervals overlapped when amplitude was high.

  16. Computational studies of solid-state alkali conduction in rechargeable alkali-ion batteries

    DOE PAGES

    Deng, Zhi; Mo, Yifei; Ong, Shyue Ping

    2016-03-25

    The facile conduction of alkali ions in a crystal host is of crucial importance in rechargeable alkali-ion batteries, the dominant form of energy storage today. In this review, we provide a comprehensive survey of computational approaches to study solid-state alkali diffusion. We demonstrate how these methods have provided useful insights into the design of materials that form the main components of a rechargeable alkali-ion battery, namely the electrodes, superionic conductor solid electrolytes and interfaces. We will also provide a perspective on future challenges and directions. Here, the scope of this review includes the monovalent lithium- and sodium-ion chemistries that aremore » currently of the most commercial interest.« less

  17. [Is it necessary to conduct a urodynamic study in the diagnosis of urinary incontinence?].

    PubMed

    Juarranz Sanz, M; Campos López-Carrión, M; Fernández-Micheltorena, C; Sánchez Sánchez, D

    2006-03-01

    Urinary incontinence is a dysfunction that affects 20%-50% of the women in Spain, depending on age. Even though it does not involve a prognosis of severity, it reduces self-esteem, limits independence and clear deteriorates quality of life. The diagnosis is generally made following the international criteria collected in the clinical practice guidelines. Even if it is true that the symptoms make it possible to suspect the nature of the functional disorder, this is not always sufficient or conclusive and there may be errors even in the clearest cases. Even so, the need to conduct a urodynamic study in the assessment of women with urinary incontinence diagnosed according to the symptoms mentioned continues to be debatable and there are no unified and defined criteria in our setting in regards to when it is necessary to request urodynamic tests. PMID:16597382

  18. Synthesis, characterization and conductivity studies of ZnFe2O4 nanoparticles

    NASA Astrophysics Data System (ADS)

    Narsimulu, D.; Venkateswarlu, M.; Satyanarayana, N.

    2015-06-01

    Transition metal ferrites with general formula AB2O4 (A=Co, Cu, Mn, Zn, B=Fe+3) could be used as an anode materials in lithium ion battery (LIB), because, lithium ion batteries fabricated using ferrite materials show the high capacity than commonly used graphite. The ZnFe2O4 with cubic spinel structured material was prepared by acrylamide assisted citrate combustion process. Phase, structural coordination and thermal behavior of the prepared ZnFe2O4 were confirmed by powder X-ray diffraction, FTIR spectra and TG/DTA thermogram respectively. Morphology and specific surface area of the ZnFe2O4 were identified by SEM and BET surface analyzer respectively and its conductivity studies were made through impedance spectroscopy.

  19. Epidemiology of 577 pediatric firearm fatalities: a 2-year review of the National Trauma Data Bank.

    PubMed

    Oyetunji, Tolulope A; Haider, Adil H; Obirieze, Augustine C; Fisher, Michael; Cornwell, Edward E; Qureshi, Faisal G; Abdullah, Fizan; Nwomeh, Benedict C

    2014-04-01

    The purpose of this study was to delineate the epidemiology of pediatric firearm injuries, including ethno-demographic patterns with impact on years of potential life lost (YPLL). A 2-year review of the National Trauma Data Bank (2007 to 2008) was conducted. Firearm fatalities in records of patients younger than 18 years were identified. Data were analyzed by demographic and injury characteristics and YPLL was calculated by ethnicity. A total of 577 deaths were identified in the pediatric group. Blacks accounted for 49.7 per cent of the fatalities; Hispanics, 19.2 per cent; whites, 17.7 per cent, and other ethnicity, 13.4 per cent. Median Injury Severity Score was 25 with a median Glasgow Coma Scale score of 3. Traumatic brain injury was present in 84.2 per cent of the records. Assault accounted for 72.8 per cent, self-inflicted injury 12.7 per cent, and unintentional injuries were 8.2 per cent. Most firearm fatalities occurred at home (33.6%). By emergency department (ED) disposition, 29.3 per cent died in the ED, 32.9 per cent were admitted to the intensive care unit, and 30.0 per cent taken to the operating room. Blacks had a total of 17,446 YPLL, Hispanics 6,776 YPLL, and whites 6,718 YPLL. Pediatric firearm fatalities still remain an important public health concern. Inclusive gun control policies focused on primary prevention of accidental injuries may be more effective in mitigating its impact. PMID:24887667

  20. Mapping Longitudinal Development of Local Cortical Gyrification in Infants from Birth to 2 Years of Age

    PubMed Central

    Li, Gang; Wang, Li; Shi, Feng; Lyall, Amanda E.; Lin, Weili; Gilmore, John H.

    2014-01-01

    Human cortical folding is believed to correlate with cognitive functions. This likely correlation may have something to do with why abnormalities of cortical folding have been found in many neurodevelopmental disorders. However, little is known about how cortical gyrification, the cortical folding process, develops in the first 2 years of life, a period of dynamic and regionally heterogeneous cortex growth. In this article, we show how we developed a novel infant-specific method for mapping longitudinal development of local cortical gyrification in infants. By using this method, via 219 longitudinal 3T magnetic resonance imaging scans from 73 healthy infants, we systemically and quantitatively characterized for the first time the longitudinal cortical global gyrification index (GI) and local GI (LGI) development in the first 2 years of life. We found that the cortical GI had age-related and marked development, with 16.1% increase in the first year and 6.6% increase in the second year. We also found marked and regionally heterogeneous cortical LGI development in the first 2 years of life, with the high-growth regions located in the association cortex, whereas the low-growth regions located in sensorimotor, auditory, and visual cortices. Meanwhile, we also showed that LGI growth in most cortical regions was positively correlated with the brain volume growth, which is particularly significant in the prefrontal cortex in the first year. In addition, we observed gender differences in both cortical GIs and LGIs in the first 2 years, with the males having larger GIs than females at 2 years of age. This study provides valuable information on normal cortical folding development in infancy and early childhood. PMID:24647943

  1. Cytokines as a predictor of clinical response following hip arthroscopy: minimum 2-year follow-up.

    PubMed

    Shapiro, Lauren M; Safran, Marc R; Maloney, William J; Goodman, Stuart B; Huddleston, James I; Bellino, Michael J; Scuderi, Gaetano J; Abrams, Geoffrey D

    2016-08-01

    Hip arthroscopy in patients with osteoarthritis has been shown to have suboptimal outcomes. Elevated cytokine concentrations in hip synovial fluid have previously been shown to be associated with cartilage pathology. The purpose of this study was to determine whether a relationship exists between hip synovial fluid cytokine concentration and clinical outcomes at a minimum of 2 years following hip arthroscopy. Seventeen patients without radiographic evidence of osteoarthritis had synovial fluid aspirated at time of portal establishment during hip arthroscopy. Analytes included fibronectin-aggrecan complex as well as a multiplex cytokine array. Patients completed the modified Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index and the International Hip Outcomes Tool pre-operatively and at a minimum of 2 years following surgery. Pre and post-operative scores were compared with a paired t-test, and the association between cytokine values and clinical outcome scores was performed with Pearson's correlation coefficient with an alpha value of 0.05 set as significant. Sixteen of seventeen patients completed 2-year follow-up questionnaires (94%). There was a significant increase in pre-operative to post-operative score for each clinical outcome measure. No statistically significant correlation was seen between any of the intra-operative cytokine values and either the 2-year follow-up scores or the change from pre-operative to final follow-up outcome values. No statistically significant associations were seen between hip synovial fluid cytokine concentrations and 2-year follow-up clinical outcome assessment scores for those undergoing hip arthroscopy.

  2. Cytokines as a predictor of clinical response following hip arthroscopy: minimum 2-year follow-up

    PubMed Central

    Shapiro, Lauren M.; Safran, Marc R.; Maloney, William J.; Goodman, Stuart B.; Huddleston, James I.; Bellino, Michael J.; Scuderi, Gaetano J.; Abrams, Geoffrey D.

    2016-01-01

    Hip arthroscopy in patients with osteoarthritis has been shown to have suboptimal outcomes. Elevated cytokine concentrations in hip synovial fluid have previously been shown to be associated with cartilage pathology. The purpose of this study was to determine whether a relationship exists between hip synovial fluid cytokine concentration and clinical outcomes at a minimum of 2 years following hip arthroscopy. Seventeen patients without radiographic evidence of osteoarthritis had synovial fluid aspirated at time of portal establishment during hip arthroscopy. Analytes included fibronectin–aggrecan complex as well as a multiplex cytokine array. Patients completed the modified Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index and the International Hip Outcomes Tool pre-operatively and at a minimum of 2 years following surgery. Pre and post-operative scores were compared with a paired t-test, and the association between cytokine values and clinical outcome scores was performed with Pearson’s correlation coefficient with an alpha value of 0.05 set as significant. Sixteen of seventeen patients completed 2-year follow-up questionnaires (94%). There was a significant increase in pre-operative to post-operative score for each clinical outcome measure. No statistically significant correlation was seen between any of the intra-operative cytokine values and either the 2-year follow-up scores or the change from pre-operative to final follow-up outcome values. No statistically significant associations were seen between hip synovial fluid cytokine concentrations and 2-year follow-up clinical outcome assessment scores for those undergoing hip arthroscopy. PMID:27583163

  3. Cytokines as a predictor of clinical response following hip arthroscopy: minimum 2-year follow-up.

    PubMed

    Shapiro, Lauren M; Safran, Marc R; Maloney, William J; Goodman, Stuart B; Huddleston, James I; Bellino, Michael J; Scuderi, Gaetano J; Abrams, Geoffrey D

    2016-08-01

    Hip arthroscopy in patients with osteoarthritis has been shown to have suboptimal outcomes. Elevated cytokine concentrations in hip synovial fluid have previously been shown to be associated with cartilage pathology. The purpose of this study was to determine whether a relationship exists between hip synovial fluid cytokine concentration and clinical outcomes at a minimum of 2 years following hip arthroscopy. Seventeen patients without radiographic evidence of osteoarthritis had synovial fluid aspirated at time of portal establishment during hip arthroscopy. Analytes included fibronectin-aggrecan complex as well as a multiplex cytokine array. Patients completed the modified Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index and the International Hip Outcomes Tool pre-operatively and at a minimum of 2 years following surgery. Pre and post-operative scores were compared with a paired t-test, and the association between cytokine values and clinical outcome scores was performed with Pearson's correlation coefficient with an alpha value of 0.05 set as significant. Sixteen of seventeen patients completed 2-year follow-up questionnaires (94%). There was a significant increase in pre-operative to post-operative score for each clinical outcome measure. No statistically significant correlation was seen between any of the intra-operative cytokine values and either the 2-year follow-up scores or the change from pre-operative to final follow-up outcome values. No statistically significant associations were seen between hip synovial fluid cytokine concentrations and 2-year follow-up clinical outcome assessment scores for those undergoing hip arthroscopy. PMID:27583163

  4. Developing and Conducting a Dissertation Study through the Community-Based Participatory Research Approach

    PubMed Central

    Nadimpalli, S.B.; Van Devanter, N.; Kavathe, R.; Islam, N.

    2016-01-01

    The community-based participatory research (CBPR) approach has been shown to be innovative and effective in conducting research with communities experiencing health disparities. Doctoral nursing students, and other doctoral students in the health sciences, who are interested in this approach can benefit through structured CBPR training experiences in learning how to engage with communities, build community capacity, share resources, implement CBPR study plans, and disseminate results of CBPR-focused studies. The objectives of this case-study are to demonstrate ways in which one doctoral student aligned with academic mentors and a funded CBPR project to build a relationship with the Sikh Asian Indian (AI) community of New York City to develop and implement a CBPR-focused doctoral dissertation study. The purpose of the research was to examine the relationship between the experience of perceived discrimination and health outcomes in this community. CBPR methods utilized in developing the study entailed the author partaking in formal and informal CBPR learning experiences, building relationships with community and academic partners early on through volunteering, developing a research plan in collaboration with members of the community and academic partners, identifying an appropriate setting and methods for recruitment and data collection, increasing capacity and resources for all partners (the author, community, and academic), and presenting dissertation study findings to the community. In conclusion, CBPR-focused doctoral experiences are novel pedagogical and professional approaches for nursing and health science students which can lead to mutual benefits for all involved, and ultimately successful and effective community-based health research. PMID:27489882

  5. A comparison study of the Eigenvalue method for the solution of the transient heat conduction equation

    NASA Astrophysics Data System (ADS)

    Gee, David B.

    1986-01-01

    This is a comparison study of the abilities of the eigenvalue method as a numerical method in solving the transient heat conduction equation. The eigenvalue method was compared to five other numerical methods; Runge-Kutta, Gears, extrapolation, fully implicit, and Crank-Nicolson. The latter were used to solve three physical problems: (1) a two dimensional slap which takes advantage of the symmetry of the problem; (2) the same slap problem without taking advantage of the symmetry; and (3) a cylindrical problem taking full advantage of symmetry. The scope of the study is to see which methods take less computer time while maintaining sufficient accuracy. The time it takes the computer to totally execute the program was used as the time comparison basis. The accuracy is a comparison of the exact solution to the numerical solution. A root mean square average of all the grid points per time step is used. The results of the study were surprising. The accuracy of the eigenvalue method is not any better than that of the Crank-Nicolson method. The computer times show that the eigenvalue is not the fastest for short transient times. A long transient problem with nonlinear terme was not used.

  6. The REporting of studies Conducted using Observational Routinely-collected health Data (RECORD) Statement

    PubMed Central

    Benchimol, Eric I.; Smeeth, Liam; Guttmann, Astrid; Harron, Katie; Moher, David; Petersen, Irene; Sørensen, Henrik T.; von Elm, Erik; Langan, Sinéad M.

    2015-01-01

    Routinely collected health data, obtained for administrative and clinical purposes without specific a priori research goals, are increasingly used for research. The rapid evolution and availability of these data have revealed issues not addressed by existing reporting guidelines, such as Strengthening the Reporting of Observational Studies in Epidemiology (STROBE). The REporting of studies Conducted using Observational Routinely collected health Data (RECORD) statement was created to fill these gaps. RECORD was created as an extension to the STROBE statement to address reporting items specific to observational studies using routinely collected health data. RECORD consists of a checklist of 13 items related to the title, abstract, introduction, methods, results, and discussion section of articles, and other information required for inclusion in such research reports. This document contains the checklist and explanatory and elaboration information to enhance the use of the checklist. Examples of good reporting for each RECORD checklist item are also included herein. This document, as well as the accompanying website and message board (http://www.record-statement.org), will enhance the implementation and understanding of RECORD. Through implementation of RECORD, authors, journals editors, and peer reviewers can encourage transparency of research reporting. PMID:26440803

  7. Thermal boundary conductance enhancement using experimentally achievable nanostructured interfaces - analytical study combined with molecular dynamics simulation.

    PubMed

    Lee, Eungkyu; Zhang, Teng; Hu, Ming; Luo, Tengfei

    2016-06-22

    Interfacial thermal resistance presents great challenges to the thermal management of modern electronics. In this work, we perform an analytical study to enhance the thermal boundary conductance (TBC) of nanostructured interfaces with square-shape pillar arrays, extendable to the characteristic lengths that can be fabricated in practice. As a representative system, we investigate a SiC substrate with the square-shape pillar array combined with epitaxial GaN as the nanostructured interface. By applying a first-order ray tracing method and molecular dynamics simulations to analyze phonon incidence and transmission at the nanostructured interface, we systematically study the impact of the characteristic dimensions of the pillar array on the TBC. Based on the multi-scale analysis we provide a general guideline to optimize the nanostructured interfaces to achieve higher TBC, demonstrating that the optimized TBC value of the nanostructured SiC/GaN interfaces can be 42% higher than that of the planar SiC/GaN interfaces without nanostructures. The model used and results obtained in this study will guide the further experimental realization of nanostructured interfaces for better thermal management in microelectronics. PMID:27275647

  8. Studies of structural, optical, dielectric relaxation and ac conductivity of different alkylbenzenesulfonic acids doped polypyrrole nanofibers

    NASA Astrophysics Data System (ADS)

    Hazarika, J.; Kumar, A.

    2016-01-01

    Polypyrrole (PPy) nanofibers doped with alkylbenzenesulfonic acids (ABSA) have been synthesized using interfacial polymerization method. HRTEM studies confirm the formation of PPy nanofibers with average diameter ranging from 13 nm to 25 nm. Broad X-ray diffraction peak in 2 θ range 20-23.46° reveals amorphous structure of PPy nanofibers. The ordering or crystallinity of polymer chains increases, while their interplanar spacing (d) and interchain separation (R) decreases for short alkyl chain ABSA doped PPy nanofibers. FTIR studies reveal that short alkyl chain ABSA doped PPy nanofibers show higher value of "effective conjugation length". PPy nanofibers doped with short alkyl chain ABSA dopant exhibit smaller optical band gap. TGA studies show enhanced thermal stability of short alkyl chain ABSA doped PPy nanofibers. Decrease in dielectric permittivity ε ‧ (ω) with increasing frequency suggests presence of electrode polarization effects. Linear decrease in dielectric loss ε ″ (ω) with increasing frequency suggests dominant effect of dc conductivity process. Low value of non-exponential exponent β (<1) reveals non-Debye relaxation of charge carriers. Scaling of imaginary modulus (M ″) reveals that the charge carriers follow the same relaxation mechanism. Moreover, the charge carriers in PPy nanofibers follow the correlated barrier hopping (CBH) transport mechanism.

  9. Study of thermally reworkable epoxy materials and thermal conductivity enhancement using carbon fiber for electronics packaging

    NASA Astrophysics Data System (ADS)

    Li, Haiying

    Epoxy resins are widely used as the underfill materials for the integrated circuit (IC) chips for the reliability enhancement and as the binder of electrically conductive adhesives (ECA). However, cured epoxy materials are infusible and insoluble networks which is a problem for the repair of a printed circuit board assembly packaged with epoxy materials. In this study, six diepoxides containing aromatic moieties and low temperature degradable linkages, secondary and tertiary benzoates, and carbonates, were synthesized and characterized. Underfills based on four of these epoxides were developed and evaluated respect to their properties and reworkabilility. One of the reworkable underfills was evaluated with the 85°C/85% relative humidity test as the underfill of several ball-grid-array components on a organic board, which showed a high enhanced reliability. Underfill materials based on a synthesized bisphenol-A diepoxide were developed for the no-flow underfill process and were evaluated regarding the application on both tin/lead and lead-free solders. The latent curing mechanism of the catalyst and the influence of fluxing agents were studied. The reworkable underfills showed satisfying overall properties on both Sn/Pb and Sn/Ag/Cu solders. A unique approach for solving the problem of low reliability of ECAs was demonstrated. Small amount of sacrificial metal and alloy powders were added in silver flake based ECA and applied on six pad surfaces. The aging of bulk resistivity and contact resistance of ECA/metal surface pairs were studied and two alloys stabilized the contact resistance on all tested metal surfaces. The internal heat generation of IC devices quickly increases which leads to deteriorated performance and low reliability. The thermally insulating property of polymeric underfills make this even worse with slow heat dissipation. In this study, a carbon fiber of high thermal conductivity was used together with silica in epoxy underfill materials and a 300

  10. Experimental and numerical study of the effective thermal conductivity of silica nanocomposites with thermal boundary resistance

    SciTech Connect

    Kothari, Rushabh M; Dinwiddie, Ralph Barton; Wang, Hsin

    2013-01-01

    . The current study presents experimental study of thermal boundary resistance for silica nano particles embedded inside epoxy resin. The bulk conductivity of the sample is measured and Rc is back calculated using Hasselman-Johnson s (H-J) equation. The numerical validation of the equation is also presented, including extrapolation study to predict effective conductivity of the nanocomposite TIM.

  11. Glycosylated Conductive Polymer: A Multimodal Biointerface for Studying Carbohydrate-Protein Interactions.

    PubMed

    Zeng, Xiangqun; Qu, Ke; Rehman, Abdul

    2016-09-20

    Carbohydrate-protein interactions occur through glycoproteins, glycolipids, or polysaccharides displayed on the cell surface with lectins. However, studying these interactions is challenging because of the complexity and heterogeneity of the cell surface, the inherent structural complexity of carbohydrates, and the typically weak affinities of the binding reactions between the lectins and monovalent carbohydrates. The lack of chromophores and fluorophores in carbohydrate structures often drives such investigations toward fluorescence labeling techniques, which usually require tedious and complex synthetic work to conjugate fluorescent tags with additional risk of altering the reaction dynamics. Probing these interactions directly on the cell surface is even more difficult since cells could be too fragile for labeling or labile dynamics could be affected by the labeled molecules that may interfere with the cellular activities, resulting in unwanted cell responses. In contrast, label-free biosensors allow real-time monitoring of carbohydrate-protein interactions in their natural states. A prerequisite, though, for this strategy to work is to mimic the coding information on potential interactions of cell surfaces onto different biosensing platforms, while the complementary binding process can be transduced into a useful signal noninvasively. Through carbohydrate self-assembled monolayers and glycopolymer scaffolds, the multivalency of the naturally existing simple and complex carbohydrates can be mimicked and exploited with label-free readouts (e.g., optical, acoustic, mechanical, electrochemical, and electrical sensors), yet such inquiries reflect only limited aspects of complicated biointeraction processes due to the unimodal transduction. In this Account, we illustrate that functionalized glycosylated conductive polymer scaffolds are the ideal multimodal biointerfaces that not only simplify the immobilization process for surface fabrication via electrochemical

  12. Glycosylated Conductive Polymer: A Multimodal Biointerface for Studying Carbohydrate-Protein Interactions.

    PubMed

    Zeng, Xiangqun; Qu, Ke; Rehman, Abdul

    2016-09-20

    Carbohydrate-protein interactions occur through glycoproteins, glycolipids, or polysaccharides displayed on the cell surface with lectins. However, studying these interactions is challenging because of the complexity and heterogeneity of the cell surface, the inherent structural complexity of carbohydrates, and the typically weak affinities of the binding reactions between the lectins and monovalent carbohydrates. The lack of chromophores and fluorophores in carbohydrate structures often drives such investigations toward fluorescence labeling techniques, which usually require tedious and complex synthetic work to conjugate fluorescent tags with additional risk of altering the reaction dynamics. Probing these interactions directly on the cell surface is even more difficult since cells could be too fragile for labeling or labile dynamics could be affected by the labeled molecules that may interfere with the cellular activities, resulting in unwanted cell responses. In contrast, label-free biosensors allow real-time monitoring of carbohydrate-protein interactions in their natural states. A prerequisite, though, for this strategy to work is to mimic the coding information on potential interactions of cell surfaces onto different biosensing platforms, while the complementary binding process can be transduced into a useful signal noninvasively. Through carbohydrate self-assembled monolayers and glycopolymer scaffolds, the multivalency of the naturally existing simple and complex carbohydrates can be mimicked and exploited with label-free readouts (e.g., optical, acoustic, mechanical, electrochemical, and electrical sensors), yet such inquiries reflect only limited aspects of complicated biointeraction processes due to the unimodal transduction. In this Account, we illustrate that functionalized glycosylated conductive polymer scaffolds are the ideal multimodal biointerfaces that not only simplify the immobilization process for surface fabrication via electrochemical

  13. Excess protons in water-acetone mixtures. II. A conductivity study.

    PubMed

    Semino, Rocío; Longinotti, M Paula

    2013-10-28

    In the present work we complement a previous simulation study [R. Semino and D. Laria, J. Chem. Phys. 136, 194503 (2012)] on the disruption of the proton transfer mechanism in water by the addition of an aprotic solvent, such as acetone. We provide experimental measurements of the mobility of protons in aqueous-acetone mixtures in a wide composition range, for water molar fractions, xw, between 0.05 and 1.00. Furthermore, new molecular dynamics simulation results are presented for rich acetone mixtures, which provide further insight into the proton transport mechanism in water-non-protic solvent mixtures. The proton mobility was analyzed between xw 0.05 and 1.00 and compared to molecular dynamics simulation data. Results show two qualitative changes in the proton transport composition dependence at xw ∼ 0.25 and 0.8. At xw < 0.25 the ratio of the infinite dilution molar conductivities of HCl and LiCl, Λ(0)(HCl).Λ(0)(LiCl)(-1), is approximately constant and equal to one, since the proton diffusion is vehicular and equal to that of Li(+). At xw ∼ 0.25, proton mobility starts to differ from that of Li(+) indicating that above this concentration the Grotthuss transport mechanism starts to be possible. Molecular dynamics simulation results showed that at this threshold concentration the probability of interconversion between two Eigen structures starts to be non-negligible. At xw ∼ 0.8, the infinite molar conductivity of HCl concentration dependence qualitatively changes. This result is in excellent agreement with the analysis presented in the previous simulation work and it has been ascribed to the interchange of water and acetone molecules in the second solvation shell of the hydronium ion.

  14. Excess protons in water-acetone mixtures. II. A conductivity study.

    PubMed

    Semino, Rocío; Longinotti, M Paula

    2013-10-28

    In the present work we complement a previous simulation study [R. Semino and D. Laria, J. Chem. Phys. 136, 194503 (2012)] on the disruption of the proton transfer mechanism in water by the addition of an aprotic solvent, such as acetone. We provide experimental measurements of the mobility of protons in aqueous-acetone mixtures in a wide composition range, for water molar fractions, xw, between 0.05 and 1.00. Furthermore, new molecular dynamics simulation results are presented for rich acetone mixtures, which provide further insight into the proton transport mechanism in water-non-protic solvent mixtures. The proton mobility was analyzed between xw 0.05 and 1.00 and compared to molecular dynamics simulation data. Results show two qualitative changes in the proton transport composition dependence at xw ∼ 0.25 and 0.8. At xw < 0.25 the ratio of the infinite dilution molar conductivities of HCl and LiCl, Λ(0)(HCl).Λ(0)(LiCl)(-1), is approximately constant and equal to one, since the proton diffusion is vehicular and equal to that of Li(+). At xw ∼ 0.25, proton mobility starts to differ from that of Li(+) indicating that above this concentration the Grotthuss transport mechanism starts to be possible. Molecular dynamics simulation results showed that at this threshold concentration the probability of interconversion between two Eigen structures starts to be non-negligible. At xw ∼ 0.8, the infinite molar conductivity of HCl concentration dependence qualitatively changes. This result is in excellent agreement with the analysis presented in the previous simulation work and it has been ascribed to the interchange of water and acetone molecules in the second solvation shell of the hydronium ion. PMID:24182052

  15. An Experimental Study of the Effects of A Rotating Magnetic Field on Electrically Conducting Aqueous Solutions

    NASA Technical Reports Server (NTRS)

    Ramachandran Narayanan; Mazuruk, Konstantin

    1998-01-01

    The use of a rotating magnetic field for stirring metallic melts has been a commonly adopted practice for a fairly long period. The elegance of the technique stems from its non-intrusive nature and the intense stirring it can produce in an electrically conducting medium. A further application of the method in recent times has been in the area of crystal growth from melts (e.g. germanium). The latter experiments have been mainly research oriented in order to understand the basic physics of the process and to establish norms for optimizing such a technique for the commercial production of crystals. When adapted for crystal growth applications, the rotating magnetic field is used to induce a slow flow or rotation in the melt which in effect significantly curtails temperature field oscillations in the melt. These oscillations are known to cause dopant striations and thereby inhomogeneities in the grown crystal that essentially degrades the crystal quality. The applied field strength is typically of the order of milli-Teslas with a frequency range between 50-400 Hz. In this investigation, we report findings from experiments that explore the feasibility of applying a rotating magnetic field to aqueous salt solutions, that are characterized by conductivities that are several orders of magnitude smaller than semi-conductor melts. The aim is to study the induced magnetic field and consequently the induced flow in such in application. Detailed flow field description obtained through non-intrusive particle displacement tracking will be reported along with an analytical assessment of the results. It is anticipated that the obtained results will facilitate in establishing a parameter range over which the technique can be applied to obtain a desired flow field distribution. This method can find applicability in the growth of crystals from aqueous solutions and give an experimenter another controllable parameter towards improving the quality of the grown crystal.

  16. An experimental study of perovskite-structured mixed ionic- electronic conducting oxides and membranes

    NASA Astrophysics Data System (ADS)

    Zeng, Pingying

    In recent decades, ceramic membranes based on mixed ionic and electronic conducting (MIEC) perovskite-structured oxides have received many attentions for their applications for air separation, or as a membrane reactor for methane oxidation. While numerous perovskite oxide materials have been explored over the past two decades; there are hardly any materials with sufficient practical economic value and performance for large scale applications, which justifies continuing the search for new materials. The main purposes of this thesis study are: (1) develop several novel SrCoO3-delta based MIEC oxides, SrCoCo1-xMxO3-delta, based on which membranes exhibit excellent oxygen permeability; (2) investigate the significant effects of the species and concentration of the dopants M (metal ions with fixed valences) on the various properties of these membranes; (3) investigate the significant effects of sintering temperature on the microstructures and performance of oxygen permeation membranes; and (4) study the performance of oxygen permeation membranes as a membrane reactor for methane combustion. To stabilize the cubic phase structure of the SrCoO3-delta oxide, various amounts of scandium was doped into the B-site of SrCoO 3-delta to form a series of new perovskite oxides, SrScxCoCo 1-xO3-delta (SSCx, x = 0-0.7). The significant effects of scandium-doping concentration on the phase structure, electrical conductivity, sintering performance, thermal and structural stability, cathode performance, and oxygen permeation performance of the SSCx membranes, were systematically studied. Also for a more in-depth understanding, the rate determination steps for the oxygen transport process through the membranes were clarified by theoretical and experimental investigation. It was found that only a minor amount of scandium (5 mol%) doping into the B-site of SrCoO3-delta can effectively stabilize the cubic phase structure, and thus significantly improve the electrical conductivity and

  17. Sage grouse on the Yakima Training Center: A summary of studies conducted during 1989 and 1990

    SciTech Connect

    Eberhardt, L.E. ); Hofmann, L.A. . Coe-Truman Technologies)

    1991-03-01

    A two-year study, sponsored by the U.S. Department of the Army and conducted by Pacific Northwest Laboratory, was initiated in 1989 to study sage grouse on the Yakima Training Center (YTC). The specific objectives of this study were (1) to obtain detailed information on the distribution and relative density of sage grouse on the YTC, (2) to identify movement and habitat use patterns of sage grouse on the YTC, (3) to identify crucial habitat for sage grouse on the YTC, and (4) to provide management recommendations. Sage grouse were selected for study because they are a US Fish and Wildlife Service candidate species for the threatened and endangered list in Washington, and because the YTC probably contains the largest population of sage grouse left on federally owned lands in this state. The locations of 11 sage grouse leks, or breeding grounds, were determined on the YTC during extensive spring helicopter surveys. The maximum number of sage grouse observed during ground surveys of these leks varied from 2 to 55 birds. One lek, located near Range 19, was probably used by 40 to 50% of the YTC sage grouse population. Fifteen years of counts of males on leks indicate that the YTC sage grouse population was most numerous during the early to mid 1980s. Since the mid-1980s, sage grouse numbers appear to have declined on the YTC and in other locations in Washington. Forty-six sage grouse (17 females and 29 males) were captured and fitted with radio transmitters during 1989 and 1990. Movements by these sage grouse were both erratic and large when compared with other studies. We believe that many of the atypical movements were in response to military training activities. Sage grouse appeared to seek out areas on the YTC where human disturbance was low. Recommendations are made for improving the management of grouse habitat.

  18. Image reconstruction of anisotropic conductivity tensor distribution in MREIT: computer simulation study

    NASA Astrophysics Data System (ADS)

    Seo, Jin Keun; Pyo, Hyun Chan; Park, Chunjae; Kwon, Ohin; Woo, Eung Je

    2004-09-01

    We describe a novel method of reconstructing images of an anisotropic conductivity tensor distribution inside an electrically conducting subject in magnetic resonance electrical impedance tomography (MREIT). MREIT is a recent medical imaging technique combining electrical impedance tomography (EIT) and magnetic resonance imaging (MRI) to produce conductivity images with improved spatial resolution and accuracy. In MREIT, we inject electrical current into the subject through surface electrodes and measure the z-component Bz of the induced magnetic flux density using an MRI scanner. Here, we assume that z is the direction of the main magnetic field of the MRI scanner. Considering the fact that most biological tissues are known to have anisotropic conductivity values, the primary goal of MREIT should be the imaging of an anisotropic conductivity tensor distribution. However, up to now, all MREIT techniques have assumed an isotropic conductivity distribution in the image reconstruction problem to simplify the underlying mathematical theory. In this paper, we firstly formulate a new image reconstruction method of an anisotropic conductivity tensor distribution. We use the relationship between multiple injection currents and the corresponding induced Bz data. Simulation results show that the algorithm can successfully reconstruct images of anisotropic conductivity tensor distributions. While the results show the feasibility of the method, they also suggest a more careful design of data collection methods and data processing techniques compared with isotropic conductivity imaging.

  19. Effect of Elbow Position on Short-segment Nerve Conduction Study in Cubital Tunnel Syndrome

    PubMed Central

    Liu, Zhu; Jia, Zhi-Rong; Wang, Ting-Ting; Shi, Xin; Liang, Wei

    2016-01-01

    Background: The appropriate elbow position of short-segment nerve conduction study (SSNCS) to diagnose cubital tunnel syndrome (CubTS) is still controversial. The goal of this study was to determine the effect of different elbow positions at full extension and 70° flexion on SSNCS in CubTS. Methods: In this cross-sectional study, the clinical data of seventy elbows from 59 CubTS patients between September, 2011 and December, 2014 in the Peking University First Hospital were included as CubTS group. Moreover, thirty healthy volunteers were included as the healthy group. SSNCS were conducted in all subjects at elbow full extension and 70° elbow flexion. Paired nonparametric test, bivariate correlation, Bland–Altman, and Chi-squared test analysis were used to compare the effectiveness of elbow full extension and 70° flexion elbow positions on SSNCS in CubTS patients. Results: Data of upper limit was calculated from healthy group, and abnormal latency was judged accordingly. CubTS group's latency and compound muscle action potential (CMAP) of each segment at 70° elbow flexion by SSNCS was compared with full extension position, no statistically significant difference were found (all P > 0.05). Latency and CMAP of each segment at elbow full extension and 70° flexion were correlated (all P < 0.01), except the latency of segment of 4 cm to 6 cm above elbow (P = 0.43), and the latency (P = 0.15) and the CMAP (P = 0.06) of segment of 2 cm to 4 cm below elbow. Bivariate correlation and Bland–Altman analysis proved the correlation between elbow full extension and 70° flexion. Especially in segments across the elbow (2 cm above the elbow and 2 cm below it), latency at elbow full extension and 70° flexion were strong direct associated (r = 0.83, P < 0.01; r = 0.55, P < 0.01), and so did the CMAP (r = 0.49, P < 0.01; r = 0.72, P < 0.01). There was no statistically significant difference in abnormality of each segment at full extension as measured by SSNCS compared with

  20. Trajectories of adolescent conduct problems in relation to cortical thickness development: a longitudinal MRI study.

    PubMed

    Oostermeijer, S; Whittle, S; Suo, C; Allen, N B; Simmons, J G; Vijayakumar, N; van de Ven, P M; Jansen, L M C; Yücel, M; Popma, A

    2016-01-01

    Multiple cross-sectional imaging studies have identified structural abnormalities in prefrontal, temporal and limbic regions related to conduct problems (CPs). However, the relationship between development of such neurobiological deficits and developmental pathways of CPs has remained unclear. The current study investigated distinct trajectories of CP and related trajectories of cortical thickness within a community-based sample of adolescents (n=239), age range 12-19, to address this gap. Three trajectory classes were revealed using latent class growth analyses (LCGAs), comprising a 'desisting' CP group, an 'intermediate' CP group and a 'stable low' CP group. Structural magnetic resonance imaging (MRI) scans were collected with a subgroup of 171 adolescents at three waves throughout adolescence (ages 12, 16 and 19). Generalized estimating equation (GEE) analysis-comparing longitudinal changes in cortical thickness and subcortical volume between CP groups for several regions of interest (ROIs)-showed that these CP groups had differential trajectories of cortical thickness in the dorsolateral prefrontal cortex (dl-PFC), and the anterior cingulate cortex (ACC), and volume of the hippocampus. Adolescents in the desisting CP group showed an attenuation of the typical pattern of cortical thinning as present in the intermediate and stable low CP groups, in addition to an exaggeration of the typical pattern of hippocampal volume increase. These findings suggest that a deviant cortical thickness trajectory was related to a desisting CP pathway across adolescence. Such deviant neurodevelopmental growth trajectories may act as an underlying mechanism for developmental CP pathways, and possibly distinguish desisting antisocial adolescents. PMID:27327256

  1. Toxicity-directed approach of polyester manufacturing industry wastewater provides useful information for conducting treatability studies.

    PubMed

    Caffaro-Filho, Roberto A; Morita, Dione M; Wagner, Roger; Durrant, Lucia R

    2009-04-15

    A broader characterization of industrial wastewaters, especially in respect to hazardous compounds and their potential toxicity, is often necessary in order to determine the best practical treatment (or pretreatment) technology available to reduce the discharge of harmful pollutants to the environment or publicly owned treatment works. Using a toxicity-directed approach, this paper sets the base for a rational treatability study of polyester resin manufacturing. Relevant physical and chemical characteristics were determined. Respirometry was used for toxicity reduction evaluation after physical and chemical effluent fractionation. Of all the procedures investigated, only air stripping was significantly effective in reducing wastewater toxicity. Air stripping in pH 7 reduced toxicity in 18.2%, while in pH 11 a toxicity reduction of 62.5% was observed. Results indicated that toxicants responsible for the most significant fraction of the effluent's instantaneous toxic effect to unadapted activated sludge were organic compounds poorly or not volatilized in acid conditions. These results led to useful directions for conducting treatability studies which will be grounded on actual effluent properties rather than empirical or based on the rare specific data on this kind of industrial wastewater.

  2. Effect of superficial peroneal nerve fascial penetration site on nerve conduction studies.

    PubMed

    Park, Geun-Young; Im, Sun; Lee, Jong-In; Lim, Seong-Hoon; Ko, Young-Jin; Chung, Myung-Eun; Hong, Bo-Young; Kim, Hye-Won

    2010-02-01

    Using nerve conduction studies (NCS) and ultrasonography, we sought to determine the stimulation site that corresponds to the site at which the superficial peroneal nerve (SPN) penetrates the fascia and yields the most accurate NCS results. NCS parameters of the SPN sensory nerve action potential (SNAP) were recorded from 37 legs at 14, 12, 9, 7, and 5 cm (S1, S2, S3, S4, and S5, respectively) proximal to the recording electrode, and analyzed by one-way analysis of variance. SPN penetration sites were visualized by ultrasonography. The mean SNAP amplitude/area (17.2 +/- 6.7 microV/9.6 +/- 4.6 microV/ms) at S3-S5 differed significantly from that at S1-S2 (11.6 +/- 4.7 microV/9.2 +/- 4.4 microV/ms) (F = 10.2, P < 0.001; F = 5.09, P = 0.0007). Ultrasonography showed that the SPN became subcutaneous between S3 and S4. Clinical application of these results should help in obtaining more accurate data during electrodiagnostic studies of conditions that involve the SPN.

  3. Phrenic nerve conduction studies in spinal cord injury: applications for diaphragmatic pacing.

    PubMed

    Alshekhlee, Amer; Onders, Raymond P; Syed, Tanvir U; Elmo, Maryjo; Katirji, Bashar

    2008-12-01

    The diaphragm pacing system (DPS) is a minimally invasive alternative to mechanical ventilation in patients with quadriplegia due to cervical myelopathy primarily caused by high cervical spinal cord injury. We evaluated 36 patients, 29 of whom had traumatic spinal cord injury, two who had a history of remote meningitis and demyelinating disease, and five who had cervical myelopathies of unknown etiology. Phrenic nerve conduction studies were performed with simultaneous fluoroscopic observation of diaphragm excursion to assess diaphragm viability. In the preoperative evaluation, diaphragm compound muscle action potentials (CMAPs) were recorded only when the diaphragm moved on fluoroscopy with ipsilateral stimulation. Twenty-six patients who were determined to have a viable diaphragm underwent DPS. Following DPS the primary outcome was the time (hours per day) that patients were able to pace and stay off the ventilator. Of 26 implanted patients, 96% (25 patients) were able to pace and tolerate being off the ventilator for more than 4 h per day. This study demonstrates that the presence of a diaphragm CMAP is associated with diaphragm movement observed by fluoroscopy in cervical myelopathy. In addition, DPS can help patients with cervical spinal cord injury to breathe unassisted by a ventilator.

  4. Case-Control Studies of Sporadic Enteric Infections: A Review and Discussion of Studies Conducted Internationally from 1990 to 2009

    PubMed Central

    Fullerton, Kathleen E.; Scallan, Elaine; Kirk, Martyn D.; Mahon, Barbara E.; Angulo, Frederick J.; de Valk, Henriette; van Pelt, Wilfrid; Gauci, Charmaine; Hauri, Anja M.; Majowicz, Shannon; O’Brien, Sarah J.

    2015-01-01

    Epidemiologists have used case-control studies to investigate enteric disease outbreaks for many decades. Increasingly, case-control studies are also used to investigate risk factors for sporadic (not outbreak-associated) disease. While the same basic approach is used, there are important differences between outbreak and sporadic disease settings that need to be considered in the design and implementation of the case-control study for sporadic disease. Through the International Collaboration on Enteric Disease “Burden of Illness” Studies (the International Collaboration), we reviewed 79 case-control studies of sporadic enteric infections caused by nine pathogens that were conducted in 22 countries and published from 1990 through to 2009. We highlight important methodological and study design issues (including case definition, control selection, and exposure assessment) and discuss how approaches to the study of sporadic enteric disease have changed over the last 20 years (e.g., making use of more sensitive case definitions, databases of controls, and computer-assisted interviewing). As our understanding of sporadic enteric infections grows, methods and topics for case-control studies are expected to continue to evolve; for example, advances in understanding of the role of immunity can be used to improve control selection, the apparent protective effects of certain foods can be further explored, and case-control studies can be used to provide population-based measures of the burden of disease. PMID:22443481

  5. Experimental Study on the Electrical Conductivity of Pyroxene Andesite at High Temperature and High Pressure

    NASA Astrophysics Data System (ADS)

    Hui, KeShi; Dai, LiDong; Li, HePing; Hu, HaiYing; Jiang, JianJun; Sun, WenQing; Zhang, Hui

    2016-09-01

    The electrical conductivity of pyroxene andesite was in situ measured under conditions of 1.0-2.0 GPa and 673-1073 K using a YJ-3000t multi-anvil press and Solartron-1260 Impedance/Gain-phase analyzer. Experimental results indicate that the electrical conductivities of pyroxene andesite increase with increasing temperature, and the electrical conductivities decrease with the rise of pressure, and the relationship between electrical conductivity (σ) and temperature (T) conforms to an Arrhenius relation within a given pressure and temperature range. When temperature rises up to 873-923 K, the electrical conductivities of pyroxene andesite abruptly increase, and the activation enthalpy increases at this range, which demonstrates that pyroxene andesite starts to dehydrate. By the virtue of the activation enthalpy (0.35-0.42 eV) and the activation volume (-6.75 ± 1.67 cm3/mole) which characterizes the electrical properties of sample after dehydration, we consider that the conduction mechanism is the small polaron conduction before and after dehydration, and that the rise of carrier concentration is the most important reason of increased electrical conductivity.

  6. A Study of Master's Degrees in Orchestral Conducting in the United States

    ERIC Educational Resources Information Center

    St. John, Brian Allen

    2010-01-01

    In order to learn to be an orchestra conductor in the United States of America, students often begins their formal education by seeking to earn a master's degree in orchestral conducting. This project compiled a listing of American universities which offer a master's degree in orchestral conducting and categorized the component parts of their…

  7. Study on Unit Cell Models and the Effective Thermal Conductivities of Silica Aerogel.

    PubMed

    Liu, He; Li, Zeng-Yao; Zhao, Xin-Peng; Tao, Wen-Quan

    2015-04-01

    In this paper, two modified unit cell models, truncated octahedron and cubic array of intersecting square rods with 45-degree rotation, are developed in consideration of the tortuous path of heat conduction in solid skeleton of silica aerogel. The heat conduction is analyzed for each model and the expressions of effective thermal conductivity of the modified unit cell models are derived. Considering the random microstructure of silica aerogel, the probability model is presented. We also discuss the effect of the thermal conductivity of aerogel backbone. The effective thermal conductivities calculated by the proposed probability model are in good agreement with available experimental data when the density of the aerogel is 110 kg/m3.

  8. Development and study of high-Tc superconductor conductive polymer assemblies

    NASA Astrophysics Data System (ADS)

    Schougaard, Steen Brian

    2002-01-01

    This dissertation presents the development and study of organic polymeric conductor/High-Tc superconductor bilayers, for exploration of the superconductor proximity effect. A major obstacle to this research is the instability of the High-Tc superconductor towards H2O and CO2 as it is necessary to create hybrid structures where the two conductors have intimate contact. For this reason, a study of the corrosion characteristics of the RBa2Cu3O 7 (R=Y, Eu, Nd) series was undertaken. In this study, R=Nd was shown to have enhanced corrosion resistance. In an effort to develop chemical processing methods that allow for the production of intimate contact between the cuprate superconductor and the conductive polymer systems, a study of alkyl amine adsorbed onto the surface of the superconductor is presented. In the electrochemical part of the study, alkyl amine ferrocene adsorbed onto the surface revealed that the amines are strongly adhered to the superconductor while still allowing electrons to pass from the superconductor to the ferrocene moiety. The self-assembled monolayer (SAM) structure of CF3(CF2)3(CH2) 11NH2 atop the superconductor was elucidated by employing several techniques, including atomic scale atomic force microscopy (AFM). A novel multistep bilayer sample preparation protocol is presented involving thin film fabrication by pulsed laser deposition (PLD), patterning by shadow mask ablation, sample thinning by scanning probe and electropolymerization of the polymer. Scanning probe thinning yields a smooth superconductor surface, a known superconductor thickness, and if a blocking layer is employed prior to thinning, the localization of polymer growth. Studies of the response of a bilayer structure of Y0.6Ca 0.4Ba1.6La0.4 Cu3O7/poly pyrrole to polymer redox cycling showed a semi-reversible suppression of transition temperature qualitatively consistent with a combination of corrosion and superconductor proximity effect. Quantitative analysis in the framework of

  9. Electrical Conductivity Studies on Individual Conjugated Polymer Nanowires: Two-Probe and Four-Probe Results

    PubMed Central

    2010-01-01

    Two- and four-probe electrical measurements on individual conjugated polymer nanowires with different diameters ranging from 20 to 190 nm have been performed to study their conductivity and nanocontact resistance. The two-probe results reveal that all the measured polymer nanowires with different diameters are semiconducting. However, the four-probe results show that the measured polymer nanowires with diameters of 190, 95–100, 35–40 and 20–25 nm are lying in the insulating, critical, metallic and insulting regimes of metal–insulator transition, respectively. The 35–40 nm nanowire displays a metal–insulator transition at around 35 K. In addition, it was found that the nanocontact resistance is in the magnitude of 104Ω at room temperature, which is comparable to the intrinsic resistance of the nanowires. These results demonstrate that four-probe electrical measurement is necessary to explore the intrinsic electronic transport properties of isolated nanowires, especially in the case of metallic nanowires, because the metallic nature of the measured nanowires may be coved by the nanocontact resistance that cannot be excluded by a two-probe technique. PMID:20652139

  10. The heritability of the skin conductance orienting response: a longitudinal twin study.

    PubMed

    Tuvblad, Catherine; Gao, Yu; Isen, Joshua; Botwick, Theodore; Raine, Adrian; Baker, Laura A

    2012-01-01

    The orienting response is a widely used experimental paradigm that reflects the association between electrodermal activity and psychological processes. The present study examined the genetic and environmental etiology of skin conductance orienting response (SCOR) magnitude in a sample of twins assessed at ages 9-10, 11-13 and 14-16 years. Structural equation modeling at each visit showed that genetic influences explained 56%, 83%, and 48% of the total variance in SCOR at visits 1, 2, and 3, respectively, with the remaining variance explained by non-shared environmental factors. SCOR was moderately stable across ages, with phenotypic correlations between time points ranging from .35 to .45. A common genetic factor explained 36%, 45% and 49% of the variance in SCOR magnitude across development. Additional age-specific genetic effects were found at ages 9-10 and 11-13 years, explaining 18% and 35% of the variance, respectively. The genetic correlations among the three time points were high, ranging from .55 to .73, indicating a substantial continuity in genetic influences from ages 9 to 16. These findings suggest that genetic factors are important influences in SCOR magnitude during late childhood and adolescence.

  11. Studies on high electronic energy deposition in transparent conducting indium tin oxide thin films

    NASA Astrophysics Data System (ADS)

    Deshpande, N. G.; Gudage, Y. G.; Ghosh, A.; Vyas, J. C.; Singh, F.; Tripathi, A.; Sharma, Ramphal

    2008-02-01

    We have examined the effect of swift heavy ions using 100 MeV Au8+ ions on the electrical properties of transparent, conducting indium tin oxide polycrystalline films with resistivity of 0.58 × 10-4 Ω cm and optical transmission greater than 78% (pristine). We report on the modifications occurring after high electronic energy deposition. With the increase in fluency, x-ray line intensity of the peaks corresponding to the planes (1 1 0), (4 0 0), (4 4 1) increased, while (3 3 1) remained constant. Surface morphological studies showed a pomegranate structure of pristine samples, which was highly disturbed with a high dose of irradiation. For the high dose, there was a formation of small spherical domes uniformly distributed over the entire surface. The transmittance was seen to be decreasing with the increase in ion fluency. At higher doses, the resistivity and photoluminescence intensity was seen to be decreased. In addition, the carrier concentration was seen to be increased, which was in accordance with the decrease in resistivity. The observed modifications after high electronic energy deposition in these films may lead to fruitful device applications.

  12. A Unified Frequency Domain Model to Study the Effect of Demyelination on Axonal Conduction.

    PubMed

    Chaubey, Saurabh; Goodwin, Shikha J

    2016-01-01

    Multiple sclerosis is a disease caused by demyelination of nerve fibers. In order to determine the loss of signal with the percentage of demyelination, we need to develop models that can simulate this effect. Existing time-based models does not provide a method to determine the influences of demyelination based on simulation results. Our goal is to develop a system identification approach to generate a transfer function in the frequency domain. The idea is to create a unified modeling approach for neural action potential propagation along the length of an axon containing number of Nodes of Ranvier (N). A system identification approach has been used to identify a transfer function of the classical Hodgkin-Huxley equations for membrane voltage potential. Using this approach, we model cable properties and signal propagation along the length of the axon with N node myelination. MATLAB/Simulink platform is used to analyze an N node-myelinated neuronal axon. The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach. Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled. Using this approach, future studies can model the loss of myelin in various parts of nervous system. PMID:27103847

  13. Study of a guarded electrode system in the dc conductivity measurement of insulating liquid

    NASA Astrophysics Data System (ADS)

    Zhou, Yuan; Hao, Miao; Chen, George; Wilson, Gordon; Jarman, Paul

    2014-07-01

    The design and choice of an electrode system is important in dc conductivity measurement of insulating liquid. In this paper, the electric field distribution of an electrode system which consists of two parallel circular metallic electrodes and a guard electrode has been studied using Comsol Multiphysics software. A new parameter, which is not yet involved in current standards, the edge radius, has been mentioned in the literature formerly and is currently discussed in a CIGRE working group. In this paper, the influence of this parameter has been investigated by means of field calculation. As seen from the simulating result, there are regions in the vicinity of the edges of the guard and measuring electrode that are under high electric field. If the edges of these two electrodes are sharp, the maximum electric field in the test cell will be much higher than the average field between the measuring electrode and the high voltage electrode. An empirical equation has been proposed to calculate this maximum field. The classic correction expression for an effective radius has been re-evaluated with the edge radius being taken into account. Experimental work has been performed to confirm this conclusion. Three kinds of mineral oils with different ageing times have been tested under the dc field using a guarded electrode system and the electric strengths of these oils have been estimated. A recommendation has been made to current standards in insulating liquid measurement.

  14. Studies of high field conduction in diamond for electron beam controlled switching

    SciTech Connect

    Joshi, R.P.; Kennedy, M.K.; Schoenbach, K.H. ); Hofer, W.W. )

    1992-11-15

    Experimental studies on a vertical metal-diamond-silicon switch structure have been conducted for potential pulsed power applications. Both the dc current-voltage characteristics and the transient switching response have been measured for a range of voltages. With a 1 {mu}m diamond film, the switch has been seen to withstand electric fields up to 1.8 MV/cm. Our results show a polarity dependence which can be associated with current injection at the asymmetric contacts. Polarity effects were also observed in the presence of {ital e}-beam excitation, and arise due to nonuniform carrier generation near the diamond-silicon interface. Our switching transients were seen to follow the shape of the {ital e}-beam for a negative bias at the silicon substrate. For positive voltage values exceeding about 80 V however, the switch is seen to go into a persistent-photocurrent mode. This effect is a result of free carrier trapping within diamond and is enhanced by the double injection process.

  15. Vibrational study of lithium sulfate based fast ionic conducting borate glasses

    SciTech Connect

    Kamitsos, E.I.; Karakassides, M.A.; Chryssikos, G.D.

    1986-09-11

    The influence of the sulfate anion on the structure of the xLi/sub 2/O x yLi/sub 2/SO/sub 4/ x B/sub 2/O/sub 3/ fast ionic conducting glasses has been studied by Raman and Fourier-transform infrared spectroscopies, for compositions probing the whole glass-forming region (x = 0.20, 0.56; y = 0-0.50). Difference spectra are presented to elucidate the SO/sub 4//sup 2 -/-induced structural changes. Thus, for the x = 0.20 series, combined Raman and infrared results showed that Li/sub 2/SO/sub 4/ additions induce the formation of BO/sub 4/ tetrahedra. However, for high lithium oxide content ternary glasses (x = 0.56), while Raman spectra did not show obvious changes of the glass structure upon increasing y, infrared spectra clearly indicated that the numbers of BO/sub 4/ tetrahedra and nonbridging oxygen-containing borate groups both increase. It was concluded that the presence of SO/sub 4//sup 2 -/ anions, in the glass melt, favors the formation of borate groups, which are more polar than those of the corresponding binary glasses.

  16. A Unified Frequency Domain Model to Study the Effect of Demyelination on Axonal Conduction

    PubMed Central

    Chaubey, Saurabh; Goodwin, Shikha J.

    2016-01-01

    Multiple sclerosis is a disease caused by demyelination of nerve fibers. In order to determine the loss of signal with the percentage of demyelination, we need to develop models that can simulate this effect. Existing time-based models does not provide a method to determine the influences of demyelination based on simulation results. Our goal is to develop a system identification approach to generate a transfer function in the frequency domain. The idea is to create a unified modeling approach for neural action potential propagation along the length of an axon containing number of Nodes of Ranvier (N). A system identification approach has been used to identify a transfer function of the classical Hodgkin–Huxley equations for membrane voltage potential. Using this approach, we model cable properties and signal propagation along the length of the axon with N node myelination. MATLAB/Simulink platform is used to analyze an N node-myelinated neuronal axon. The ability to transfer function in the frequency domain will help reduce effort and will give a much more realistic feel when compared to the classical time-based approach. Once a transfer function is identified, the conduction as a cascade of each linear time invariant system-based transfer function can be modeled. Using this approach, future studies can model the loss of myelin in various parts of nervous system. PMID:27103847

  17. Conduct Disorder Symptoms and Subsequent Pregnancy, Child-Birth and Abortion: A Population-Based Longitudinal Study of Adolescents

    ERIC Educational Resources Information Center

    Pedersen, Willy; Mastekaasa, Arne

    2011-01-01

    Research on teenage pregnancy and abortion has primarily focused on socio-economic disadvantage. However, a few studies suggest that risk of unwanted pregnancy is related to conduct disorder symptoms. We examined the relationship between level of conduct disorder symptoms at age 15 and subsequent pregnancy, child-birth and abortion. A…

  18. Numerical study of magnetoacoustic signal generation with magnetic induction based on inhomogeneous conductivity anisotropy.

    PubMed

    Li, Xun; Hu, Sanqing; Li, Lihua; Zhu, Shanan

    2013-01-01

    Magnetoacoustic tomography with magnetic induction (MAT-MI) is a noninvasive imaging modality for generating electrical conductivity images of biological tissues with high spatial resolution. In this paper, we create a numerical model, including a permanent magnet, a coil, and a two-layer coaxial cylinder with anisotropic electrical conductivities, for the MAT-MI forward problem. We analyze the MAT-MI sources in two cases, on a thin conductive boundary layer and in a homogeneous medium, and then develop a feasible numerical approach to solve the MAT-MI sound source densities in the anisotropic conductive model based on finite element analysis of electromagnetic field. Using the numerical finite element method, we then investigate the magnetoacoustic effect of anisotropic conductivity under the inhomogeneous static magnetic field and inhomogeneous magnetic field, quantitatively compute the boundary source densities in the conductive model, and calculate the sound pressure. The anisotropic conductivity contributes to the distribution of the eddy current density, Lorentz force density, and acoustic signal. The proposed models and approaches provide a more realistic simulation environment for MAT-MI.

  19. The MAL-ED study: a multinational and multidisciplinary approach to understand the relationship between enteric pathogens, malnutrition, gut physiology, physical growth, cognitive development, and immune responses in infants and children up to 2 years of age in resource-poor environments.

    PubMed

    2014-11-01

    Highly prevalent conditions with multiple and complex underlying etiologies are a challenge to public health. Undernutrition, for example, affects 20% of children in the developing world. The cause and consequence of poor nutrition are multifaceted. Undernutrition has been associated with half of all deaths worldwide in children aged <5 years; in addition, its pernicious long-term effects in early childhood have been associated with cognitive and physical growth deficits across multiple generations and have been thought to suppress immunity to further infections and to reduce the efficacy of childhood vaccines. The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health (MAL-ED) Study, led by the Fogarty International Center of the National Institutes of Health and the Foundation for the National Institutes of Health, has been established at sites in 8 countries with historically high incidence of diarrheal disease and undernutrition. Central to the study is the hypothesis that enteropathogen infection contributes to undernutrition by causing intestinal inflammation and/or by altering intestinal barrier and absorptive function. It is further postulated that this leads to growth faltering and deficits in cognitive development. The effects of repeated enteric infection and undernutrition on the immune response to childhood vaccines is also being examined in the study. MAL-ED uses a prospective longitudinal design that offers a unique opportunity to directly address a complex system of exposures and health outcomes in the community-rather than the relatively rarer circumstances that lead to hospitalization-during the critical period of development of the first 2 years of life. Among the factors being evaluated are enteric infections (with or without diarrhea) and other illness indicators, micronutrient levels, diet, socioeconomic status, gut function, and the environment. MAL-ED aims to describe these

  20. The MAL-ED study: a multinational and multidisciplinary approach to understand the relationship between enteric pathogens, malnutrition, gut physiology, physical growth, cognitive development, and immune responses in infants and children up to 2 years of age in resource-poor environments.

    PubMed

    2014-11-01

    Highly prevalent conditions with multiple and complex underlying etiologies are a challenge to public health. Undernutrition, for example, affects 20% of children in the developing world. The cause and consequence of poor nutrition are multifaceted. Undernutrition has been associated with half of all deaths worldwide in children aged <5 years; in addition, its pernicious long-term effects in early childhood have been associated with cognitive and physical growth deficits across multiple generations and have been thought to suppress immunity to further infections and to reduce the efficacy of childhood vaccines. The Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health (MAL-ED) Study, led by the Fogarty International Center of the National Institutes of Health and the Foundation for the National Institutes of Health, has been established at sites in 8 countries with historically high incidence of diarrheal disease and undernutrition. Central to the study is the hypothesis that enteropathogen infection contributes to undernutrition by causing intestinal inflammation and/or by altering intestinal barrier and absorptive function. It is further postulated that this leads to growth faltering and deficits in cognitive development. The effects of repeated enteric infection and undernutrition on the immune response to childhood vaccines is also being examined in the study. MAL-ED uses a prospective longitudinal design that offers a unique opportunity to directly address a complex system of exposures and health outcomes in the community-rather than the relatively rarer circumstances that lead to hospitalization-during the critical period of development of the first 2 years of life. Among the factors being evaluated are enteric infections (with or without diarrhea) and other illness indicators, micronutrient levels, diet, socioeconomic status, gut function, and the environment. MAL-ED aims to describe these

  1. The data management of a phase III efficacy trial of an 11-valent pneumococcal conjugate vaccine and related satellite studies conducted in the Philippines

    PubMed Central

    2012-01-01

    Background A large phase III placebo-controlled, randomized efficacy trial of an investigational 11-valent pneumococcal conjugate vaccine against pneumonia in children less than 2 years of age was conducted in the Philippines from July 2000 to December 2004. Clinical data from 12,194 children who were given either study vaccine or placebo was collected from birth up to two years of age for the occurrence of radiologically proven pneumonia as the primary endpoint, and for clinical pneumonia and invasive pneumococcal disease as the secondary endpoints. Several tertiary endpoints were also explored. Along the core trial, several satellite studies on herd immunity, cost-effectiveness of the study vaccine, acute otitis media, and wheezing were conducted. Results We describe here in detail how the relevant clinical records were managed and how quality control procedures were implemented to ensure that valid data were obtained respectively for the core trial and for the satellite studies. We discuss how the task was achieved, what the challenges were and what might have been done differently. Conclusions There were several factors that made the task of data management doable and efficient. First, a pre-trial data management system was available. Secondly, local committed statisticians, programmers and support staff were available and partly familiar to clinical trials. Thirdly, the personnel had undergone training during trial and grew with the task they were supposed to do. Thus the knowledge needed to develop and operate clinical data system was fully transferred to local staff. Trial registration Current Controlled Trials ISRCTN62323832 PMID:22676626

  2. Characterization of indoor particle sources: A study conducted in the metropolitan Boston area.

    PubMed Central

    Abt, E; Suh, H H; Allen, G; Koutrakis, P

    2000-01-01

    An intensive particle monitoring study was conducted in homes in the Boston, Massachusetts, area during the winter and summer of 1996 in an effort to characterize sources of indoor particles. As part of this study, continuous particle size and mass concentration data were collected in four single-family homes, with each home monitored for one or two 6-day periods. Additionally, housing activity and air exchange rate data were collected. Cooking, cleaning, and the movement of people were identified as the most important indoor particle sources in these homes. These sources contributed significantly both to indoor concentrations (indoor-outdoor ratios varied between 2 and 33) and to altered indoor particle size distributions. Cooking, including broiling/baking, toasting, and barbecuing contributed primarily to particulate matter with physical diameters between 0.02 and 0.5 microm [PM((0.02-0.5))], with volume median diameters of between 0.13 and 0.25 microm. Sources of particulate matter with aerodynamic diameters between 0.7 and 10 microm [PM((0.7-10))] included sautéing, cleaning (vacuuming, dusting, and sweeping), and movement of people, with volume median diameters of between 3 and 4.3 microm. Frying was associated with particles from both PM((0.02-0.5)) and PM((0.7-10)). Air exchange rates ranged between 0.12 and 24.3 exchanges/hr and had significant impact on indoor particle levels and size distributions. Low air exchange rates (< 1 exchange/hr) resulted in longer air residence times and more time for particle concentrations from indoor sources to increase. When air exchange rates were higher (> 1 exchange/hr), the impact of indoor sources was less pronounced, as indoor particle concentrations tracked outdoor levels more closely. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 PMID:10620522

  3. Trajectories of adolescent conduct problems in relation to cortical thickness development: a longitudinal MRI study

    PubMed Central

    Oostermeijer, S; Whittle, S; Suo, C; Allen, N B; Simmons, J G; Vijayakumar, N; van de Ven, P M; Jansen, L M C; Yücel, M; Popma, A

    2016-01-01

    Multiple cross-sectional imaging studies have identified structural abnormalities in prefrontal, temporal and limbic regions related to conduct problems (CPs). However, the relationship between development of such neurobiological deficits and developmental pathways of CPs has remained unclear. The current study investigated distinct trajectories of CP and related trajectories of cortical thickness within a community-based sample of adolescents (n=239), age range 12–19, to address this gap. Three trajectory classes were revealed using latent class growth analyses (LCGAs), comprising a ‘desisting' CP group, an ‘intermediate' CP group and a ‘stable low' CP group. Structural magnetic resonance imaging (MRI) scans were collected with a subgroup of 171 adolescents at three waves throughout adolescence (ages 12, 16 and 19). Generalized estimating equation (GEE) analysis—comparing longitudinal changes in cortical thickness and subcortical volume between CP groups for several regions of interest (ROIs)—showed that these CP groups had differential trajectories of cortical thickness in the dorsolateral prefrontal cortex (dl-PFC), and the anterior cingulate cortex (ACC), and volume of the hippocampus. Adolescents in the desisting CP group showed an attenuation of the typical pattern of cortical thinning as present in the intermediate and stable low CP groups, in addition to an exaggeration of the typical pattern of hippocampal volume increase. These findings suggest that a deviant cortical thickness trajectory was related to a desisting CP pathway across adolescence. Such deviant neurodevelopmental growth trajectories may act as an underlying mechanism for developmental CP pathways, and possibly distinguish desisting antisocial adolescents. PMID:27327256

  4. Patient satisfaction and penile morphology changes with postoperative penile rehabilitation 2 years after Coloplast Titan prosthesis

    PubMed Central

    Pryor, Michael B; Carrion, Rafael; Wang, Run; Henry, Gerard

    2016-01-01

    A common complaint after inflatable penile prosthesis surgery is reduced penile length. We previously reported how using the Coloplast Titan inflatable penile prosthesis with aggressive new length measurement technique (NLMT) coupled with postoperative IPP rehabilitation of the implant for 1-year helped to improve patient satisfaction and erectile penile measurements. This is a 2 years follow-up of a prospective, three-center, study of 40 patients who underwent Titan prosthesis placement, with new length measurement technique for erectile dysfunction. Patient instructions were to inflate daily for 6 months and then inflate maximally for 1–2 h daily for 6–24 months. Fifteen penile measurements were taken before and immediately after surgery and at follow-up visits. Measurement changes were improved at 24 months as compared to immediately postoperative and at 12 months. 67.8% of subjects were satisfied with their length at 2 years, and 77% had perceived penile length that was longer (30.8%) or the same (46.2%) as prior to the surgery. 64.3% and 17.9% of subjects had increased and unchanged satisfaction, respectively, with penile length as compared to prior to penile implant surgery. All but one subject (96.5%) was satisfied with the overall function of his implant. This study suggests using the Coloplast Titan with aggressive cylinder sizing, and a postoperative penile rehabilitation inflation protocol can optimize patient satisfaction and erectile penile measurements at 2 years postimplant. PMID:26459782

  5. Patient satisfaction and penile morphology changes with postoperative penile rehabilitation 2 years after Coloplast Titan prosthesis.

    PubMed

    Pryor, Michael B; Carrion, Rafael; Wang, Run; Henry, Gerard

    2016-01-01

    A common complaint after inflatable penile prosthesis surgery is reduced penile length. We previously reported how using the Coloplast Titan inflatable penile prosthesis with aggressive new length measurement technique (NLMT) coupled with postoperative IPP rehabilitation of the implant for 1-year helped to improve patient satisfaction and erectile penile measurements. This is a 2 years follow-up of a prospective, three-center, study of 40 patients who underwent Titan prosthesis placement, with new length measurement technique for erectile dysfunction. Patient instructions were to inflate daily for 6 months and then inflate maximally for 1-2 h daily for 6-24 months. Fifteen penile measurements were taken before and immediately after surgery and at follow-up visits. Measurement changes were improved at 24 months as compared to immediately postoperative and at 12 months. 67.8% of subjects were satisfied with their length at 2 years, and 77% had perceived penile length that was longer (30.8%) or the same (46.2%) as prior to the surgery. 64.3% and 17.9% of subjects had increased and unchanged satisfaction, respectively, with penile length as compared to prior to penile implant surgery. All but one subject (96.5%) was satisfied with the overall function of his implant. This study suggests using the Coloplast Titan with aggressive cylinder sizing, and a postoperative penile rehabilitation inflation protocol can optimize patient satisfaction and erectile penile measurements at 2 years postimplant.

  6. Pial synangiosis in patients with moyamoya younger than 2 years of age.

    PubMed

    Jackson, Eric M; Lin, Ning; Manjila, Sunil; Scott, R Michael; Smith, Edward R

    2014-04-01

    Object Patients with moyamoya who are younger than 2 years of age represent a therapeutic challenge because of their frequent neurological instability and concomitant anesthetic risks. The authors report their experience with pial synangiosis revascularization in this population. Methods The authors reviewed the clinical and radiographic records of all patients with moyamoya in a consecutive series of patients under 2 years of age, who underwent cerebral revascularization surgery using pial synangiosis at a single institution. Results During a 12-year period (1994-2005), 34 procedures (bilateral in 15 patients, unilateral in 4) were performed in 19 patients younger than 2 years (out of a total of 456 procedures in 240 patients). Eighteen of these patients presented with either stroke or transient ischemic attack. The average age of the 19 patients at first surgery was 1.4 years (range 6 months-1.9 years). Unanticipated staged operations occurred in 3 patients, due to persistent electroencephalographic changes during the initial surgery in 2 cases and due to brain swelling during the procedure requiring ventriculostomy in the other. There were 2 perioperative strokes; both patients had postoperative seizures but made clinical recoveries. The average follow-up was 7 years (range 1-14 years). Long term, at follow-up, 13 patients (68%) were clinically independent for their age, with 8 (42%) having no significant deficit. Late complications included subdural hygroma evacuation (1), additional revascularization procedures performed years later for frontal lobe ischemia (2), late infarction (1), and asymptomatic ischemic change on routine follow-up MRI studies (1). All patients who had both pre- and postoperative angiography demonstrated progression of disease. Conclusions Despite the challenges inherent to this population, the majority of children with moyamoya under the age of 2 years have a good long-term prognosis. The data from this study support the use of pial

  7. Study on the temperature-dependent coupling among viscosity, conductivity and structural relaxation of ionic liquids.

    PubMed

    Yamaguchi, Tsuyoshi; Yonezawa, Takuya; Koda, Shinobu

    2015-07-15

    The frequency-dependent viscosity and conductivity of three imidazolium-based ionic liquids were measured at several temperatures in the MHz region, and the results are compared with the intermediate scattering functions determined by neutron spin echo spectroscopy. The relaxations of both the conductivity and the viscosity agree with that of the intermediate scattering function at the ionic correlation when the relaxation time is short. As the relaxation time increases, the relaxations of the two transport properties deviate to lower frequencies than that of the ionic structure. The deviation begins at a shorter relaxation time for viscosity than for conductivity, which explains the fractional Walden rule between the zero-frequency values of the shear viscosity and the molar conductivity.

  8. PATTERN RECOGNITION STUDIES OF HALOGENATED ORGANIC COMPOUNDS USING CONDUCTING POLYMER SENSOR ARRAYS. (R825323)

    EPA Science Inventory

    Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...

  9. Experimental study of thermal conductivity at high pressures: Implications for the deep Earth's interior

    NASA Astrophysics Data System (ADS)

    Goncharov, Alexander F.; Lobanov, Sergey S.; Tan, Xiaojing; Hohensee, Gregory T.; Cahill, David G.; Lin, Jung-Fu; Thomas, Sylvia-Monique; Okuchi, Takuo; Tomioka, Naotaka

    2015-10-01

    Lattice thermal conductivity of ferropericlase and radiative thermal conductivity of iron bearing magnesium silicate perovskite (bridgmanite) - the major mineral of Earth's lower mantle- have been measured at room temperature up to 30 and 46 GPa, respectively, using time-domain thermoreflectance and optical spectroscopy techniques in diamond anvil cells. The results provide new constraints for the pressure dependencies of the thermal conductivities of Fe bearing minerals. The lattice thermal conductivity of ferropericlase Mg0.9Fe0.1O is 5.7(6) W/(m * K) at ambient conditions, which is almost 10 times smaller than that of pure MgO; however, it increases with pressure much faster (6.1(7)%/GPa vs 3.6(1)%/GPa). The radiative conductivity of a Mg0.94Fe0.06SiO3 bridgmanite single crystal agrees with previously determined values for powder samples at ambient pressure; it is almost pressure-independent in the investigated pressure range. Our results confirm the reduced radiative conductivity scenario for the Earth's lower mantle, while the assessment of the heat flow through the core-mantle boundary still requires in situ measurements at the relevant pressure-temperature conditions.

  10. The Study of Simulated Space Radiation Environment Effect on Conductive Properties of ITO Thermal Control Materials

    NASA Astrophysics Data System (ADS)

    Wei-Quan, Feng; Chun-Qing, Zhao; Zi-Cai, Shen; Yi-Gang, Ding; Fan, Zhang; Yu-Ming, Liu; Hui-Qi, Zheng; Xue, Zhao

    In order to prevent detrimental effects of ESD caused by differential surface charging of spacecraft under space environments, an ITO transparent conductive coating is often deposited on the thermal control materials outside spacecraft. Since the ITO coating is exposed in space environment, the environment effects on electrical property of ITO coatings concern designers of spacecraft deeply. This paper introduces ground tests to simulate space radiation environmental effects on conductive property of ITO coating. Samples are made of ITO/OSR, ITO/Kapton/Al and ITO/FEP/Ag thermal control coatings. Simulated space radiation environment conditions are NUV of 500ESH, 40 keV electron of 2 × 1016 е/cm2, 40 keV proton of 2.5 × 1015 p/cm2. Conductive property is surface resistivity measured in-situ in vacuum. Test results proved that the surface resistivity for all ITO coatings have a sudden decrease in the beginning of environment test. The reasons for it may be the oxygen vacancies caused by vacuum and decayed RIC caused by radiation. Degradation in conductive properties caused by irradiation were found. ITO/FEP/Ag exhibits more degradation than other two kinds. The conductive property of ITO/kapton/Al is stable for vacuum irradiation. The analysis of SEM and XPS found more crackers and less Sn and In concentration after irradiation which may be the reason for conductive property degradation.

  11. Possible effects of depolarizing GABAA conductance on the neuronal input-output relationship: a modeling study.

    PubMed

    Morita, Kenji; Tsumoto, Kunichika; Aihara, Kazuyuki

    2005-06-01

    Recent in vitro experiments revealed that the GABAA reversal potential is about 10 mV higher than the resting potential in mature mammalian neocortical pyramidal cells; thus GABAergic inputs could have facilitatory, rather than inhibitory, effects on action potential generation under certain conditions. However, how the relationship between excitatory input conductances and the output firing rate is modulated by such depolarizing GABAergic inputs under in vivo circumstances has not yet been understood. We examine herewith the input-output relationship in a simple conductance-based model of cortical neurons with the depolarized GABAA reversal potential, and show that a tonic depolarizing GABAergic conductance up to a certain amount does not change the relationship between a tonic glutamatergic driving conductance and the output firing rate, whereas a higher GABAergic conductance prevents spike generation. When the tonic glutamatergic and GABAergic conductances are replaced by in vivo-like highly fluctuating inputs, on the other hand, the effect of depolarizing GABAergic inputs on the input-output relationship critically depends on the degree of coincidence between glutamatergic input events and GABAergic ones. Although a wide range of depolarizing GABAergic inputs hardly changes the firing rate of a neuron driven by noncoincident glutamatergic inputs, a certain range of these inputs considerably decreases the firing rate if a large number of driving glutamatergic inputs are coincident with them. These results raise the possibility that the depolarized GABAA reversal potential is not a paradoxical mystery, but is instead a sophisticated device for discriminative firing rate modulation.

  12. Laboratory studies of the electrical conductivity of silicate perovskites at high pressures and temperatures

    NASA Technical Reports Server (NTRS)

    Li, Xiaoyuan; Jeanloz, Raymond

    1990-01-01

    The electrical conductivities of two silicate perovskites and a perovskite-magnesiowuestite assemblage, all having an atomic ratio of Mg to Fe equal to 0.88/0.12, have been measured with alternating current and direct current (dc) techniques at simultaneously high pressures and temperatures. Measurements up to pressures of 80 GPa and temperatures of 3500 K, using a laser-heated diamond anvil cell, demonstrate that the electrical conductivity of these materials remains below 10-3 S/m at lower mantle conditions. The activation energies for electrical conduction are between 0.1 and 0.4 eV from the data, and the conduction in these perovskites is ascribed to an extrinsic electronic process. The new measurements are in agreement with a bound that was previously obtained from dc measurements for the high-PT conductivity of perovskite-dominated assemblages. The results show that the electrical conductivity of (Mg/0.88/Fe/0.12)SiO3 perovskite differs significantly from that of the earth's deep mantle, as inferred from geophysical observations.

  13. [Comparative study on hyperspectral inversion accuracy of soil salt content and electrical conductivity].

    PubMed

    Peng, Jie; Wang, Jia-Qiang; Xiang, Hong-Ying; Teng, Hong-Fen; Liu, Wei-Yang; Chi, Chun-Ming; Niu, Jian-Long; Guo, Yan; Shi, Zhou

    2014-02-01

    The objective of the present article is to ascertain the mechanism of hyperspectral remote sensing monitoring for soil salinization, which is of great importance for improving the accuracy of hyperspectral remote sensing monitoring. Paddy soils in Wensu, Hetian and Baicheng counties of the southern Xinjiang were selected. Hyperspectral data of soils were obtained. Soil salt content (S(t)) an electrical conductivity of 1:5 soil-to-water extracts (EC(1:5)) were determined. Relationships between S(t) and EC(1:5) were studied. Correlations between hyperspectral indices and S(t), and EC(1:5) were analyzed. The inversion accuracy of S(t) using hyperspectral technique was compared with that of EC(1:5). Results showed that: significant (p<0.01) relationships were found between S(t) and EC(1:5) for soils in Wensu and Hetian counties, and correlation coefficients were 0.86 and 0.45, respectively; there was no significant relationship between S(t) and EC(1:5) for soils in Baicheng county. Therefore, the correlations between S(t) and EC(1:5) varied with studied sites. S(t) and EC(1:5) were significantly related with spectral reflectance, first derivative reflectance and continuum-removed reflectance, respectively; but correlation coefficients between S(t) and spectral indices were higher than those between EC(1:5) and spectral indices, which was obvious in some sensitive bands for soil salinization such as 660, 35, 1229, 1414, 1721, 1738, 1772, 2309 nm, and so on. Prediction equations of St and EC(1:5) were established using multivariate linear regression, principal component regression and partial least-squares regression methods, respectively. Coefficients of determination, determination coefficients of prediction, and relative analytical errors of these equations were analyzed. Coefficients of determination and relative analytical errors of equations between S(t) and spectral indices were higher than those of equations between EC(1:5) and spectral indices. Therefore, the

  14. An inexpensive, interdisciplinary, methodology to conduct an impact study of homeless persons on hospital based services.

    PubMed

    Parker, R David; Regier, Michael; Brown, Zachary; Davis, Stephen

    2015-02-01

    Homelessness is a primary concern for community health. Scientific literature on homelessness is wide ranging and diverse. One opportunity to add to existing literature is the development and testing of affordable, easily implemented methods for measuring the impact of homeless on the healthcare system. Such methodological approaches rely on the strengths in a multidisciplinary approach, including providers, both healthcare and homeless services and applied clinical researchers. This paper is a proof of concept for a methodology which is easily adaptable nationwide, given the mandated implementation of homeless management information systems in the United States and other countries; medical billing systems by hospitals; and research methods of researchers. Adaptation is independent of geographic region, budget restraints, specific agency skill sets, and many other factors that impact the application of a consistent methodological science based approach to assess and address homelessness. We conducted a secondary data analysis merging data from homeless utilization and hospital case based data. These data detailed care utilization among homeless persons in a small, Appalachian city in the United States. In our sample of 269 persons who received at least one hospital based service and one homeless service between July 1, 2012 and June 30, 2013, the total billed costs were $5,979,463 with 10 people costing more than one-third ($1,957,469) of the total. Those persons were primarily men, living in an emergency shelter, with pre-existing disabling conditions. We theorize that targeted services, including Housing First, would be an effective intervention. This is proposed in a future study.

  15. A study of Mo-V and Mo-V-Fe alloys for conductive cermet applications

    SciTech Connect

    Stephens, J.J.; Damkroger, B.K.; Ewsuk, K.G.; Glass, S.J.; Monroe, S.L.; Reece, M.; Smugeresky, J.E.

    1998-06-01

    Molybdenum and alumina cermets are currently being used for small, simple geometry, electrical feed-throughs in insulating alumina ceramic bodies. However, with larger and more complex geometries, high residual stresses and cracking of the alumina ceramic occur due to differences in coefficient of thermal expansion (CTE) between cermet and the surrounding 94% alumina. The difference in CTE is caused by the Mo in the cermet, which lowers the CTE of the cermet relative to the 94% alumina ceramic. A study was conducted at Sandia National Laboratories to develop CTE-matched cermets based on binary Mo-V and ternary Mo-V-X alloy systems. It was found that the CTE of 94% alumina (over the range 1,000 C to room temperature) could be precisely matched by a binary Mo-32.5V alloy. However, to address concerns regarding the selective oxidation of V, Mo-V-X alloys with CTE`s similar to 94% alumina were made with Fe or Co additions. The ternary additions are limited to about 3 wt.% to maintain a single phase BCC alloy, and permit some reduction in the V addition. Powders were fabricated from both Mo-27V and Mo-22V-3Fe, and were evaluated in 3 hr./1,625 C cermet sintering trials. The results of those trials suggest that extensive reaction occurs between the Vanadium component of the alloy and the alumina ceramic. In view of these results the authors have begun to evaluate the feasibility of fabricating Iridium alumina cermets. Iridium is an attractive choice due to its close CTE match to 94% alumina ceramic. Preliminary results indicate there is no detrimental reaction between the Iridium and alumina phases.

  16. Using a sensitivity study to facilitate the design of a multi-electrode array to measure six cardiac conductivity values.

    PubMed

    Johnston, Barbara M

    2013-07-01

    When using the bidomain model to model the electrical activity of the heart, there are potentially six cardiac conductivity values involved: conductivity values in directions along and normal to the cardiac fibres with a sheet, as well as a conductivity value in the normal direction between the sheets, and these occur for both the extracellular and intracellular domains in the model. To date it has been common to assume that the two normal direction conductivity values are the same. However, recent work has demonstrated that six cardiac conductivity values, rather than four, are necessary for accurate modelling, which can then facilitate understanding of cardiovascular disease. To design a method to determine these conductivities, it is also necessary to design a suitable multi-electrode array, which can be used, in conjunction with an inversion technique, to retrieve conductivity values from measurements of potential made on the array. This work uses the results of a study, into the sensitivity of the measuring potentials to variability in the input conductivities, to facilitate the design of an array that could be used to retrieve six cardiac conductivity values, as well as fibre rotation angle. It is found that if an electrode in the array has a much lower value of potential than the other electrodes, then it tends to be much more sensitive to the input conductivities than the other electrodes. It also appears that inclusion of this type of electrode in the set of measuring electrodes is essential for accurately retrieving conductivity values. This technique is used to identify electrodes to be included in the array and using the final design it is demonstrated, using synthetic values of potential, that the six cardiac conductivity values, and the fibre rotation angle, can be retrieved very accurately.

  17. Strabismus at Age 2 Years in Children Born Before 28 Weeks' Gestation: Antecedents and Correlates.

    PubMed

    VanderVeen, Deborah K; Allred, Elizabeth N; Wallace, David K; Leviton, Alan

    2016-03-01

    Children born very preterm are at greater risk of ophthalmic morbidities, including strabismus, than children born at term. We evaluated perinatal factors associated with strabismus at age 2 years in a large population of infants delivered before 28 weeks' gestation. A total of 996 infants in the multicenter ELGAN (Extremely Low Gestational Age Newborn) study who had a retinal exam in infancy and a developmental assessment at 2 years corrected age are included. Their mothers were interviewed about the pregnancy, and both mother and newborn charts were reviewed. Certified examiners administered the Bayley Scales of Infant Development-II and performed an examination of ocular alignment. Time-oriented logistic regression risk models were created to evaluate the associations of characteristics and exposures with the development of strabismus. Overall, 14% (n = 141) of the children had strabismus at 2 years, and 80% of strabismic children had esotropia. Characteristics associated with strabismus were birth before 26 weeks' gestation, severe fetal growth restriction, and maternal history of aspirin ingestion. Associated postnatal factors included a SNAP-II (Score for Neonatal Acute Physiology) illness severity value ≥ 30, brain ventriculomegaly, type I retinopathy of prematurity, and ventilator-dependent severe bronchopulmonary dysplasia. Strabismus in very preterm populations is associated with a number of antenatal and postnatal antecedents as well as clinical and imaging correlates indicative of brain damage in these children. Routine ophthalmologic assessments in the early years can allow appropriate and timely interventions.

  18. [Endocardial Electrophysiological Study in an Asymptomatic Competitive Athlete With Ventricular Preexitation due to Conduction via Fasciculoventricular Accessory Pathway].

    PubMed

    Guseynova, R R; Zhelyakov, E G; Ardashev, A V; Belenkov, Yu N

    2015-01-01

    We present a clinical case of a rare form of the WPW phenomenon due to anterograde conduction over fasciculoventricular accessory pathway in 20-year-old competitive athlete. The patient had no history of palpitations or syncope. ECG revealed shortening of PQ interval (112 ms) and wide QRS complex due to conduction via accessory pathway. To address the question of participation in competitive activity and the need for ablation the patient underwent endocardial electrophysiological study in the course of which we verified conduction via fasciculoventricular accessory pathway. The result of the study was used in determination of strategy of further management.

  19. Thermal conductivities of single- and multi-layer phosphorene: a molecular dynamics study.

    PubMed

    Zhang, Ying-Yan; Pei, Qing-Xiang; Jiang, Jin-Wu; Wei, Ning; Zhang, Yong-Wei

    2016-01-01

    As a new two-dimensional (2D) material, phosphorene has drawn growing attention owing to its novel electronic properties, such as layer-dependent direct bandgaps and high carrier mobility. Herein we investigate the in-plane and cross-plane thermal conductivities of single- and multi-layer phosphorene, focusing on geometrical (sample size, orientation and layer number) and strain (compression and tension) effects. A strong anisotropy is found in the in-plane thermal conductivity with its value along the zigzag direction being much higher than that along the armchair direction. Interestingly, the in-plane thermal conductivity of multi-layer phosphorene is insensitive to the layer number, which is in strong contrast to that of graphene where the interlayer interactions strongly influence the thermal transport. Surprisingly, tensile strain leads to an anomalous increase in the in-plane thermal conductivity of phosphorene, in particular in the armchair direction. Both the in-plane and cross-plane thermal conductivities can be modulated by external strain; however, the strain modulation along the cross-plane direction is more effective and thus more tunable than that along the in-plane direction. Our findings here are of great importance for the thermal management in phosphorene-based nanoelectronic devices and for thermoelectric applications of phosphorene.

  20. Thermal conductivity of a two-dimensional phosphorene sheet: a comparative study with graphene.

    PubMed

    Hong, Yang; Zhang, Jingchao; Huang, Xiaopeng; Zeng, Xiao Cheng

    2015-11-28

    A recently discovered two-dimensional (2D) layered material phosphorene has attracted considerable interest as a promising p-type semiconducting material. In this work, thermal conductivity (κ) of monolayer phosphorene is calculated using large-scale classical non-equilibrium molecular dynamics (NEMD) simulations. The predicted thermal conductivities for infinite length armchair and zigzag phosphorene sheets are 63.6 and 110.7 W m(-1) K(-1) respectively. The strong anisotropic thermal transport is attributed to the distinct atomic structures at altered chiral directions and direction-dependent group velocities. Thermal conductivities of 2D graphene sheets with the same dimensions are also computed for comparison. The extrapolated κ of the 2D graphene sheet are 1008.5(+37.6)(-37.6) and 1086.9(+59.1)(-59.1) W m(-1) K(-1) in the armchair and zigzag directions, respectively, which are an order of magnitude higher than those of phosphorene. The overall and decomposed phonon density of states (PDOS) are calculated in both structures to elucidate their thermal conductivity differences. In comparison with graphene, the vibrational frequencies that can be excited in phosphorene are severely limited. The temperature effect on the thermal conductivity of phosphorene and graphene sheets is investigated, which reveals a monotonic decreasing trend for both structures.