Science.gov

Sample records for 20-year time period

  1. Environmental Volunteering and Health Outcomes over a 20-Year Period

    ERIC Educational Resources Information Center

    Pillemer, Karl; Fuller-Rowell, Thomas E.; Reid, M. C.; Wells, Nancy M.

    2010-01-01

    Purpose: This study tested the hypothesis that volunteering in environmental organizations in midlife is associated with greater physical activity and improved mental and physical health over a 20-year period. Design and Methods: The study used data from two waves (1974 and 1994) of the Alameda County Study, a longitudinal study of health and…

  2. Changes in plant species composition of coastal dune habitats over a 20-year period.

    PubMed

    Del Vecchio, Silvia; Prisco, Irene; Acosta, Alicia T R; Stanisci, Angela

    2015-01-01

    Coastal sandy ecosystems are increasingly being threatened by human pressure, causing loss of biodiversity, habitat degradation and landscape modifications. However, there are still very few detailed studies focussing on compositional changes in coastal dune plant communities over time. In this work, we investigated how coastal dune European Union (EU) habitats (from pioneer annual beach communities to Mediterranean scrubs on the landward fixed dunes) have changed during the last 20 years. Using phytosociological relevés conducted in 1989-90 and in 2010-12, we investigated changes in floristic composition over time. We then compared plant cover and the proportion of ruderal, alien and habitat diagnostic species ('focal species') in the two periods. Finally, we used Ellenberg indicator values to define the 'preferences' of the plant species for temperature and moisture. We found that only fore dune habitats showed significant differences in species cover between the two time periods, with higher plant cover in the more recent relevés and a significant increase in thermophilic species. Although previous studies have demonstrated consistent habitat loss in this area, we observed that all coastal dune plant communities remain well represented, after a 20-year period. However, fore dunes have been experiencing significant compositional changes. Although we cannot confirm whether the observed changes are strictly related to climatic changes, to human pressure or to both, we hypothesize that a moderate increment in average yearly temperature may have promoted the increase in plant cover and the spread of thermophilic species. Thus, even though human activities are major driving forces of change in coastal dune vegetation, at the community scale climatic factors may also play important roles. Our study draws on re-visitation studies which appear to constitute a powerful tool for the assessment of the conservation status of EU habitats. PMID:25750408

  3. Changes in plant species composition of coastal dune habitats over a 20-year period

    PubMed Central

    Del Vecchio, Silvia; Prisco, Irene; Acosta, Alicia T. R.; Stanisci, Angela

    2015-01-01

    Coastal sandy ecosystems are increasingly being threatened by human pressure, causing loss of biodiversity, habitat degradation and landscape modifications. However, there are still very few detailed studies focussing on compositional changes in coastal dune plant communities over time. In this work, we investigated how coastal dune European Union (EU) habitats (from pioneer annual beach communities to Mediterranean scrubs on the landward fixed dunes) have changed during the last 20 years. Using phytosociological relevés conducted in 1989–90 and in 2010–12, we investigated changes in floristic composition over time. We then compared plant cover and the proportion of ruderal, alien and habitat diagnostic species (‘focal species’) in the two periods. Finally, we used Ellenberg indicator values to define the ‘preferences’ of the plant species for temperature and moisture. We found that only fore dune habitats showed significant differences in species cover between the two time periods, with higher plant cover in the more recent relevés and a significant increase in thermophilic species. Although previous studies have demonstrated consistent habitat loss in this area, we observed that all coastal dune plant communities remain well represented, after a 20-year period. However, fore dunes have been experiencing significant compositional changes. Although we cannot confirm whether the observed changes are strictly related to climatic changes, to human pressure or to both, we hypothesize that a moderate increment in average yearly temperature may have promoted the increase in plant cover and the spread of thermophilic species. Thus, even though human activities are major driving forces of change in coastal dune vegetation, at the community scale climatic factors may also play important roles. Our study draws on re-visitation studies which appear to constitute a powerful tool for the assessment of the conservation status of EU habitats. PMID:25750408

  4. Comparison of Cardiovascular Risk Factors in Different Areas of Health Care Over a 20-Year Period

    PubMed Central

    Jardim, Thiago Veiga; Sousa, Ana Luiza Lima; Povoa, Thais Rolim; Barroso, Weimar Sebba; Chinem, Brunela; Jardim, Paulo Cesar Veiga

    2014-01-01

    Background Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Knowledge about cardiovascular risk factors (CVRFs) in young adults and their modification over time are measures that change the risks and prevent CVDs. Objectives To determine the presence of CVRFs and their changes in different health care professionals over a period of 20 years. Methods All students of medicine, nursing, nutrition, odontology, and pharmacy departments of Federal University of Goiás who agreed to participate in this study were evaluated when they started their degree courses and 20 years afterward. Questionnaires on CVRFs [systemic arterial hypertension (SAH), diabetes mellitus, dyslipidemia, and family history of early CVD, smoking, alcohol consumption, and sedentarism] were administered. Cholesterol levels, blood sugar levels, blood pressure, weight, height, and body mass index were determined. The Kolmogorov-Smirnov test was used to evaluate distribution, the chi-square test was used to compare different courses and sexes, and the McNemar test was used for comparing CVRFs. The significance level was set at a p value of < 0.05. Results The first stage of the study included 281 individuals (91% of all the students), of which 62.9% were women; the mean age was 19.7 years. In the second stage, 215 subjects were reassessed (76% of the initial sample), of which 59.07% were women; the mean age was 39.8 years. The sample mostly consisted of medical students (with a predominance of men), followed by nursing, nutrition, and pharmacy students, with a predominance of women (p < 0.05). Excessive weight gain, SAH, and dyslipidemia were observed among physicians and dentists (p < 0.05). Excessive weight gain and SAH and a reduction in sedentarism (p < 0.05) were observed among pharmacists. Among nurses there was an increase in excessive weight and alcohol consumption (p < 0.05). Finally, nutritionists showed an increase in dyslipidemia (p < 0.05). Conclusion In general

  5. Choledochal cysts in infants and children: experiences over a 20-year period at a single institution.

    PubMed

    Hung, Min-Hsuan; Lin, Lung-Huang; Chen, Der-Fang; Huang, Ching-Shui

    2011-09-01

    This analysis was undertaken to compare the clinicopathological features of infants with choledochal cysts to those of older children with these entities and to evaluate the surgical outcomes for both subject groups. The medical records of all children admitted to the Cathay General Hospital with choledochal cysts over a 20-year period were retrospectively reviewed. Twenty-five subjects were included and divided into the infant (<1 year at presentation; 8 subjects) and classical pediatric (1-18 years at presentation; 17 subjects) groups. Anatomical subtypes were: IA (16), IC (6), and IVA (3). The median biliary amylase value was markedly elevated for the pediatric group but not for the infant group. Most (82.4%) patients in the pediatric group, but none in the infant group, presented with abdominal pain. Jaundice and clay-colored stool were present in all patients in the infant group but only 35% of those in the pediatric group. All patients underwent choledochocystectomy and Roux-en-Y hepaticojejunostomy with good outcomes. Neonates/infants with choledochal cysts present differently from older children with these entities. Amylase measurements may serve to distinguish biliary atresia with cystic dilatation from choledochal cyst in neonates/infants. Prognosis following radical cyst excision and reconstruction with Roux-en-Y hepaticojejunostomy is excellent. PMID:21350805

  6. Bibliometric analysis of global environmental assessment research in a 20-year period

    SciTech Connect

    Li, Wei Zhao, Yang

    2015-01-15

    Based on the samples of 113,468 publications on environmental assessment (EA) from the past 20 years, we used a bibliometric analysis to study the literature in terms of trends of growth, subject categories and journals, international collaboration, geographic distribution of publications, and scientific research issues. By applying thresholds to network centralities, a core group of countries can be distinguished as part of the international collaboration network. A frequently used keywords analysis found that the priority in assessment would gradually change from project environmental impact assessment (EIA) to strategic environmental assessment (SEA). Decision-theoretic approaches (i.e., environmental indicator selection, life cycle assessment, etc.), along with new technologies and methods (i.e., the geographic information system and modeling) have been widely applied in the EA research field over the past 20 years. Hot spots such as “biodiversity” and “climate change” have been emphasized in current EA research, a trend that will likely continue in the future. The h-index has been used to evaluate the research quality among countries all over the world, while the improvement of developing countries' EA systems is becoming a popular research topic. Our study reveals patterns in scientific outputs and academic collaborations and serves as an alternative and innovative way of revealing global research trends in the EA research field.

  7. Insights into the dynamics of Etna volcano from 20-year time span microgravity and GPS observations

    NASA Astrophysics Data System (ADS)

    Bonforte, Alessandro; Fanizza, Giovanni; Greco, Filippo; Matera, Alfredo; Sulpizio, Roberto

    2016-04-01

    A common ground deformation and microgravity array of benchmarks lies on the southern slope of Mt. Etna volcano and is routinely measured by GPS and relative gravimetry methods. The array was installed for monitoring the ground motion and underground mass changes along the southern rift of the volcano and data are usually processed and interpreted independently. The benchmarks have been installed mainly along a main road crossing the southern side of the volcano with an E-W direction and reaching 2000 m of altitude. The gravity array covers the entire path of the road, while the ground deformation one only the upper one, due to the woods at lower altitude preventing good GPS measurements. Furthermore, microgravity surveys are usually carried out more frequently with respect to the GPS ones. In this work, an integrated analysis of microgravity and ground deformation is performed over a 20-year time span (1994-2014). Gravity variations have been first corrected for the free-air effect using the GPS observed vertical deformation and the theoretical vertical gravity gradient (-308.6 μGal/m). The free-air corrected gravity changes were then reduced from the high frequency variations (noise) and the seasonal fluctuations, mainly due to water-table fluctuations. This long-term dataset constitutes a unique opportunity to examine the behavior of Etna in a period in which the volcano exhibited different styles of activity characterized by recharging phases, flank eruptions and fountaining episodes. The gravity and deformation data allow investigating the response of the volcano in a wider perspective providing insights into the definition of its dynamic behavior and posing the basis to track the unrest evolution and to forecast the style of the eruption. The joint analysis highlights common periods, in which the signals underwent contemporaneous changes occurring mainly in the central and eastern stations. On the other hand, no significant changes in the behavior of

  8. Changes in Post-Operative Complication and Mortality Rates after Lung Cancer Resection in the 20-Year Period 1995-2014.

    PubMed

    Sawada, Shigeki; Suehisa, Hiroshi; Ueno, Tsuyoshi; Yamashita, Motohiro

    2016-06-01

    We reviewed post-operative complication and mortality rates from 1995 through 2014 and evaluated the changes in those rates across that 20-year period. Two thousand and three hundred sixteen patients with lung cancer underwent resection at our institution between 1995 and 2014. This timespan was divided into four 5-year periods. Each patient's age, Charlson comorbidity index score, and extent of surgery in each 5-year period were summarized, and the changes in these factors over the 20-year span were evaluated. The complication and mortality rates were calculated for each 5-year period, and the changes in those rates over the 20-years were evaluated. The number of patients with higher Charlson comorbidity index scores increased during the 20-year period. Of the 455 patients who developed complications, 97 developed life-threating complications. There were 16 post-operative deaths and 23 in-hospital deaths. There were no significant changes in the complication rate or mortality rate during the 20-year period. Both rates were significantly correlated with the extent of resection. Although the number of patients with comorbidities increased in the 20-year period, the post-operative complication and mortality rates, as well as in-hospital mortality, did not change significantly.

  9. Trend analysis of the 20 years time series of stratospheric ozone profiles observed by the GROMOS microwave radiometer at Bern

    NASA Astrophysics Data System (ADS)

    Moreira, L.; Hocke, K.; Eckert, E.; von Clarmann, T.; Kämpfer, N.

    2015-06-01

    The ozone radiometer GROMOS (GROund-based Millimeterwave Ozone Spectrometer) performs continuous observations of stratospheric ozone profiles since 1994 above Bern, Switzerland. GROMOS is part of the Network for the Detection of Atmospheric Composition Change (NDACC). From November 1994 to October 2011, the ozone line spectra were measured by a filter bench (FB). In July 2009, a Fast-Fourier-Transform spectrometer (FFTS) has been added as backend to GROMOS. The new FFTS and the original FB measured in parallel for over two years. The ozone profiles retrieved separately from the ozone line spectra of FB and FFTS agree within 5 % at pressure levels from 30 to 0.5 hPa, from October 2009 to August 2011. A careful harmonisation of both time series has been carried out by taking the FFTS as the reference instrument for the FB. This enables us to assess the long-term trend derived from more than 20 years of stratospheric ozone observations at Bern. The trend analysis has been performed by using a robust multilinear parametric trend model which includes a linear term, the solar variability, the El Niño-Southern Oscillation (ENSO) index, the quasi-biennial oscillation (QBO), the annual and semi-annual oscillation and several harmonics with period lengths between 3 and 24 months. Over the last years, some experimental and modelling trend studies have shown that the stratospheric ozone trend is levelling off or even turning positive. With our observed ozone profiles, we are able to support this statement by reporting a statistically significant trend of +3.14 % decade-1 at 4.36 hPa, covering the period from January 1997 to January 2015, above Bern. Additionally, we have estimated a negative trend over this period of -3.94 % decade-1 at 0.2 hPa.

  10. Determinants of Aortic Root Dilatation and Reference Values Among Young Adults Over a 20-Year Period: Coronary Artery Risk Development in Young Adults Study.

    PubMed

    Teixido-Tura, Gisela; Almeida, Andre L C; Choi, Eui-Young; Gjesdal, Ola; Jacobs, David R; Dietz, Harry C; Liu, Kiang; Sidney, Stephen; Lewis, Cora E; Garcia-Dorado, David; Evangelista, Artur; Gidding, Samuel; Lima, João A C

    2015-07-01

    Aortic size increases with age, but factors related to such dilatation in healthy young adult population have not been studied. We aim to evaluate changes in aortic dimensions and its principal correlates among young adults over a 20-year time period. Reference values for aortic dimensions in young adults by echocardiography are also provided. Healthy Coronary Artery Risk Development in Young Adults (CARDIA) study participants aged 23 to 35 years in 1990-1991 (n=3051) were included after excluding 18 individuals with significant valvular dysfunction. Aortic root diameter (ARD) by M-mode echocardiography at year-5 (43.7% men; age, 30.2 ± 3.6 years) and year-25 CARDIA exams was obtained. Univariable and multivariable analyses were performed to assess associations of ARD with clinical data at years-5 and -25. ARD from year-5 was used to establish reference values of ARD in healthy young adults. ARD at year-25 was greater in men (33.3 ± 3.7 versus 28.7 ± 3.4 mm; P<0.001) and in whites (30.9 ± 4.3 versus 30.5 ± 4.1 mm; P=0.006). On multivariable analysis, ARD at year-25 was positively correlated with male sex, white ethnicity, age, height, weight, 20-year gain in weight, active smoking at baseline, and 20-year increase in diastolic, systolic, and mean arterial pressure. A figure showing the estimated 95th percentile of ARD by age and body surface area stratified by race and sex is provided. This study demonstrates that smoking, blood pressure, and increase in body weight are the main modifiable correlates of aortic root dilation during young adulthood. Our study also provides reference values for ARD in young adults.

  11. Detecting trends in landscape pattern metrics over a 20-year period using a sampling-based monitoring programme

    USGS Publications Warehouse

    Griffith, J.A.; Stehman, S.V.; Sohl, T.L.; Loveland, T.R.

    2003-01-01

    Temporal trends in landscape pattern metrics describing texture, patch shape and patch size were evaluated in the US Middle Atlantic Coastal Plain Ecoregion. The landscape pattern metrics were calculated for a sample of land use/cover data obtained for four points in time from 1973-1992. The multiple sampling dates permit evaluation of trend, whereas availability of only two sampling dates allows only evaluation of change. Observed statistically significant trends in the landscape pattern metrics demonstrated that the sampling-based monitoring protocol was able to detect a trend toward a more fine-grained landscape in this ecoregion. This sampling and analysis protocol is being extended spatially to the remaining 83 ecoregions in the US and temporally to the year 2000 to provide a national and regional synthesis of the temporal and spatial dynamics of landscape pattern covering the period 1973-2000.

  12. Decline of semen quality among 10 932 males consulting for couple infertility over a 20-year period in Marseille, France.

    PubMed

    Geoffroy-Siraudin, Cendrine; Loundou, Anderson Dieudonné; Romain, Fanny; Achard, Vincent; Courbière, Blandine; Perrard, Marie-Hélène; Durand, Philippe; Guichaoua, Marie-Roberte

    2012-07-01

    Semen from 10 932 male partners of infertile couples was analysed and sperm parameter trends were evaluated at the Reproduction Biology Laboratory of the University Hospital of Marseille (France) between 1988 and 2007. After 3-6 days of abstinence, semen samples were collected. Measurements of seminal fluid volume, pH, sperm concentration, total sperm count, motility and detailed morphology of spermatozoa were performed. Sperm parameters were analysed on the entire population and in men with normal total numeration (≥40 million per ejaculate). The whole population demonstrated declining trends in sperm concentration (1.5% per year), total sperm count (1.6% per year), total motility (0.4% per year), rapid motility (5.5% per year) and normal morphology (2.2% per year). In the group of selected samples with total normal sperm count, the same trends of sperm quality deterioration with time were observed. Our results clearly indicate that the quality of semen decreased in this population over the study period.

  13. Trend analysis of the 20-year time series of stratospheric ozone profiles observed by the GROMOS microwave radiometer at Bern

    NASA Astrophysics Data System (ADS)

    Moreira, L.; Hocke, K.; Eckert, E.; von Clarmann, T.; Kämpfer, N.

    2015-10-01

    The ozone radiometer GROMOS (GROund-based Millimeter-wave Ozone Spectrometer) has been performing continuous observations of stratospheric ozone profiles since 1994 above Bern, Switzerland (46.95° N, 7.44° E, 577 m). GROMOS is part of the Network for the Detection of Atmospheric Composition Change (NDACC). From November 1994 to October 2011, the ozone line spectra were measured by a filter bench (FB). In July 2009, a fast Fourier transform spectrometer (FFTS) was added as a back end to GROMOS. The new FFTS and the original FB measured in parallel for over 2 years. The ozone profiles retrieved separately from the ozone line spectra of FB and FFTS agree within 5 % at pressure levels from 30 to 0.5 hPa, from October 2009 to August 2011. A careful harmonisation of both time series has been carried out by taking the FFTS as the reference instrument for the FB. This enables us to assess the long-term trend derived from stratospheric ozone observations at Bern. The trend analysis was performed by using a robust multilinear parametric trend model which includes a linear term, the solar variability, the El Niño-Southern Oscillation (ENSO) index, the quasi-biennial oscillation (QBO), the annual and semi-annual oscillation and several harmonics with period lengths between 3 and 24 months. Over the last years, some experimental and modelling trend studies have shown that the stratospheric ozone trend is levelling off or even turning positive. With our observed ozone profiles, we are able to support this statement by reporting a statistically significant trend of +3.14 % decade-1 at 4.36 hPa (37.76 km), covering the period from January 1997 to January 2015, above Bern. Additionally, we have estimated a negative trend over this period of -3.94 % decade-1 at 0.2 hPa (59 km).

  14. Genetic relatedness of selected clinical Vibrio cholerae O139 isolates from the southern coastal area of China over a 20-year period.

    PubMed

    Li, B S; Xiao, Y; Wang, D C; Tan, H L; Ke, B X; He, D M; Ke, C W; Zhang, Y H

    2016-09-01

    Vibrio cholerae O139 emerged as a causative agent of epidemic cholera in 1992 in India and Bangladesh, and was subsequently reported in China in 1993. The genetic relatedness and molecular characteristics of V. cholerae O139 in Guangdong Province, located in the southern coastal area of China, remains undetermined. In this study, we investigated 136 clinical V. cholerae O139 isolates from 1993 to 2013 in Guangdong. By conventional PCR, 123 (90·4%) isolates were positive for ctxB, ace and zot. Sequencing of the positive amplicons indicated 113 (91·7%) isolates possessed the El Tor allele of ctxB (genotype 3); seven carried the classical ctxB type (genotype 1) and three harboured a novel ctxB type (genotype 5). With respect to tcpA, 123 (90·4%) isolates were positive for the El Tor allele. In addition, pulsed-field gel electrophoresis (with NotI digestion) differentiated the isolates into clusters A and B. Cluster A contained seven of the non-toxigenic isolates from 1998 to 2000; another six non-toxigenic isolates (from 1998 and 2007) and all of the toxigenic isolates formed cluster B. Our results suggest that over a 20-year period, the predominant O139 clinical isolates have maintained a relatively tight clonal structure, although some genetic variance and shift has occurred. Our data highlight the persistence of toxigenic V. cholerae O139 in clinical settings in the southern coastal area of China.

  15. Genetic relatedness of selected clinical Vibrio cholerae O139 isolates from the southern coastal area of China over a 20-year period.

    PubMed

    Li, B S; Xiao, Y; Wang, D C; Tan, H L; Ke, B X; He, D M; Ke, C W; Zhang, Y H

    2016-09-01

    Vibrio cholerae O139 emerged as a causative agent of epidemic cholera in 1992 in India and Bangladesh, and was subsequently reported in China in 1993. The genetic relatedness and molecular characteristics of V. cholerae O139 in Guangdong Province, located in the southern coastal area of China, remains undetermined. In this study, we investigated 136 clinical V. cholerae O139 isolates from 1993 to 2013 in Guangdong. By conventional PCR, 123 (90·4%) isolates were positive for ctxB, ace and zot. Sequencing of the positive amplicons indicated 113 (91·7%) isolates possessed the El Tor allele of ctxB (genotype 3); seven carried the classical ctxB type (genotype 1) and three harboured a novel ctxB type (genotype 5). With respect to tcpA, 123 (90·4%) isolates were positive for the El Tor allele. In addition, pulsed-field gel electrophoresis (with NotI digestion) differentiated the isolates into clusters A and B. Cluster A contained seven of the non-toxigenic isolates from 1998 to 2000; another six non-toxigenic isolates (from 1998 and 2007) and all of the toxigenic isolates formed cluster B. Our results suggest that over a 20-year period, the predominant O139 clinical isolates have maintained a relatively tight clonal structure, although some genetic variance and shift has occurred. Our data highlight the persistence of toxigenic V. cholerae O139 in clinical settings in the southern coastal area of China. PMID:27305977

  16. Yearbook 1988. IWGIA: 20 Years.

    ERIC Educational Resources Information Center

    Gray, Andrew

    The theme of this yearbook is the work of the International Work Group for Indigenous Affairs (IWGIA) during the 20 years of its existence and the enormous growth of the indigenous movement in that time. Section 1 traces IWGIA's history and includes the annual report for 1988. Section 2 is a global view of the main events in the indigenous world…

  17. Does Cancer Literature Reflect Multidisciplinary Practice? A Systematic Review of Oncology Studies in the Medical Literature Over a 20-Year Period

    SciTech Connect

    Holliday, Emma B.; Ahmed, Awad A.; Yoo, Stella K.; Jagsi, Reshma; Hoffman, Karen E.

    2015-07-15

    Purpose: Quality cancer care is best delivered through a multidisciplinary approach requiring awareness of current evidence for all oncologic specialties. The highest impact journals often disseminate such information, so the distribution and characteristics of oncology studies by primary intervention (local therapies, systemic therapies, and targeted agents) were evaluated in 10 high-impact journals over a 20-year period. Methods and Materials: Articles published in 1994, 2004, and 2014 in New England Journal of Medicine, Lancet, Journal of the American Medical Association, Lancet Oncology, Journal of Clinical Oncology, Annals of Oncology, Radiotherapy and Oncology, International Journal of Radiation Oncology, Biology, Physics, Annals of Surgical Oncology, and European Journal of Surgical Oncology were identified. Included studies were prospectively conducted and evaluated a therapeutic intervention. Results: A total of 960 studies were included: 240 (25%) investigated local therapies, 551 (57.4%) investigated systemic therapies, and 169 (17.6%) investigated targeted therapies. More local therapy trials (n=185 [77.1%]) evaluated definitive, primary treatment than systemic (n=178 [32.3%]) or targeted therapy trials (n=38 [22.5%]; P<.001). Local therapy trials (n=16 [6.7%]) also had significantly lower rates of industry funding than systemic (n=207 [37.6%]) and targeted therapy trials (n=129 [76.3%]; P<.001). Targeted therapy trials represented 5 (2%), 38 (10.2%), and 126 (38%) of those published in 1994, 2004, and 2014, respectively (P<.001), and industry-funded 48 (18.9%), 122 (32.6%), and 182 (54.8%) trials, respectively (P<.001). Compared to publication of systemic therapy trial articles, articles investigating local therapy (odds ratio: 0.025 [95% confidence interval: 0.012-0.048]; P<.001) were less likely to be found in high-impact general medical journals. Conclusions: Fewer studies evaluating local therapies, such as surgery and radiation, are published in

  18. Celebrating 20 Years of Hubble

    NASA Video Gallery

    NASA's Hubble Space Telescope began a remarkable journey of discovery on April 24, 1990. After 20 years in space, the observatory has shown humanity more of the universe than ever before. With the ...

  19. Incorporating Spectra Into Periodic Timing

    NASA Astrophysics Data System (ADS)

    Connors, Alanna; Hong, J.; Protopapas, P.; Kashyap, V.

    2011-09-01

    The Chandra surveys have resulted in a wealth of data on low-luminosity X-ray sources (Lx 1030-34 erg/s) of Galactic scales beyond the local solar neighborhood. Many of these are compact binaries, in particular, cataclysmic variables, often identified by their periodic X-ray variability and spectra. Hong et al. (2009, 2011) have used energy quantiles (Hong, Schlegel & Grindlay, 2004) as a fast, robust indicator of spectral hardness and absorption of the X-ray sources. Energy quantiles also enable a simple but effective illustration of spectral changes with phase in these periodic systems: e.g. absorption by the accreting material is understood to drive the periodic light-curves. An interesting question is how to best make use of the information encapsulated in the periodic change in energy spectrum, along with the periodic change in intensity, especially for cases of ambiguous period determination? And, how to do it computationally efficiently? A first approach is to do the period search in intensity, as is standard; and then use a criterion of spectral variation to verify possible periods. Huijse, Zegers & Protopapas (2011) recently demonstrated a powerful period estimation technique using information potential and correntropy embedded in the light curve. Similar quantities based on energies (or energy quantiles) of X-ray photons can serve as criteria of spectral variation. A different approach treats the spectrum variations and intensity variations completely independently, searching through period-space in each, and then combining the results. A more general method would include both at the same time, looking for statistically significant variations above what is expected for a constant (in intensity and spectrum).

  20. SeaWiFS technical report series. Volume 17: Ocean color in the 21st century. A strategy for a 20-year time series

    NASA Technical Reports Server (NTRS)

    Abbott, Mark R.; Brown, Otis B.; Evans, Robert H.; Gordon, Howard R.; Carder, Kendall L.; Mueller-Karger, Frank E.; Esaias, Wayne E.; Hooker, Stanford B.; Firestone, Elaine R.

    1994-01-01

    Beginning with the upcoming launch of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), there should be almost continuous measurements of ocean color for nearly 20 years if all of the presently planned national and international missions are implemented. This data set will present a unique opportunity to understand the coupling of physical and biological processes in the world ocean. The presence of multiple ocean color sensors will allow the eventual development of an ocean color observing system that is both cost effective and scientifically based. This report discusses the issues involved and makes recommendations intended to ensure the maximum scientific return from this unique set of planned ocean color missions. An executive summary is included with this document which briefly discusses the primary issues and suggested actions to be considered.

  1. 43 CFR 10010.45 - Time periods.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Time periods. 10010.45 Section 10010.45... Environmental Impact Statements § 10010.45 Time periods. (a) The minimum review period for a draft EIS will be... proposed reductions in time periods or any extensions of time periods proposed by those agencies....

  2. 43 CFR 10010.45 - Time periods.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Time periods. 10010.45 Section 10010.45... Environmental Impact Statements § 10010.45 Time periods. (a) The minimum review period for a draft EIS will be... proposed reductions in time periods or any extensions of time periods proposed by those agencies....

  3. 43 CFR 10010.45 - Time periods.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Time periods. 10010.45 Section 10010.45... Environmental Impact Statements § 10010.45 Time periods. (a) The minimum review period for a draft EIS will be... proposed reductions in time periods or any extensions of time periods proposed by those agencies....

  4. CT Angiography after 20 Years

    PubMed Central

    Rubin, Geoffrey D.; Leipsic, Jonathon; Schoepf, U. Joseph; Fleischmann, Dominik; Napel, Sandy

    2015-01-01

    Through a marriage of spiral computed tomography (CT) and graphical volumetric image processing, CT angiography was born 20 years ago. Fueled by a series of technical innovations in CT and image processing, over the next 5–15 years, CT angiography toppled conventional angiography, the undisputed diagnostic reference standard for vascular disease for the prior 70 years, as the preferred modality for the diagnosis and characterization of most cardiovascular abnormalities. This review recounts the evolution of CT angiography from its development and early challenges to a maturing modality that has provided unique insights into cardiovascular disease characterization and management. Selected clinical challenges, which include acute aortic syndromes, peripheral vascular disease, aortic stent-graft and transcatheter aortic valve assessment, and coronary artery disease, are presented as contrasting examples of how CT angiography is changing our approach to cardiovascular disease diagnosis and management. Finally, the recently introduced capabilities for multispectral imaging, tissue perfusion imaging, and radiation dose reduction through iterative reconstruction are explored with consideration toward the continued refinement and advancement of CT angiography. PMID:24848958

  5. Time domain period determination techniques

    NASA Technical Reports Server (NTRS)

    Stellingwerf, R. F.

    1980-01-01

    Two simple period determination schemes are discussed. They are well suited to problems involving non-sinusoidal periodic phenomena sampled at a few irregularly spaced points. Statistical properties are discussed. The techniques are applied to the double mode Cepheids BK Cen and TU Cas as test cases.

  6. [Neurogenic bladder, 20 years later].

    PubMed

    Perrigot, M

    1995-10-28

    The therapeutic armamentarium--physical therapy, drugs, surgery--developed over the last 20 years now gives us the means of providing curative care to nearly all patients with manifestations of neuropathic bladder, meaning that the clinical examination and complementary tests must be conducted under strictly controlled conditions to identify the underlying mechanism. The examination of the perineum almost always reveals a defect when the origin is neurological but is often normal when gynaecologic or urologic factors are involved. Motor command, tonus, reflexes and sensitivity should all be carefully explored to distinguish between central and peripheral causes. Much progress has been made in complementary examinations. For example, nearly 100% of the neurological aetiologies can be identified with precision. Tests include electromyography of the perineum, measurement of the latency of the bulbocavernous reflex and that of the distal part of the internal pudental nerve. Complementary tests evaluating bladder and sphincter function include urine sediment with cytology, intravenous pyelography and echography of the urinary tract. Pressure measurements with cystomanometry, sphincterometry and flowmetry add further precisions. Whether the underlying mechanism of bladder dysfunction is purely neurological as is the case in many young patients with multiple sclerosis, spina bifida or caudia equina syndrome, results from several causes as in patients with Parkinson's disease and enlargement of the prostate, or is among the increasing number of post-radiation sequellae, the essential step is careful clinical examination and detailed interpretation of complementary examinations. Thus the wide range of techniques now available for the management of the neuropathic bladder can be adapted to each individual case according to the pathological processes causing the clinical manifestations. PMID:8545359

  7. Change in predominance of Bovine viral diarrhea virus subgenotypes among samples submitted to a diagnostic laboratory over a 20-year time span.

    PubMed

    Ridpath, Julia F; Lovell, Gayla; Neill, John D; Hairgrove, Thomas B; Velayudhan, Binu; Mock, Richard

    2011-03-01

    Although the causative agent of bovine viral diarrhea was initially categorized as 1 species, phylogenetic analysis revealed that these viruses belong to 2 different species, Bovine viral diarrhea virus 1 (BVDV-1) and BVDV-2, with 2-11 subgenotypes within each species. Distribution of species and subgenotypes has been shown to vary with geographic region. Whether distribution shifts over time is not known. Surveys conducted between 1994 and 2008 reported 3 subgenotypes circulating among cattle in the United States: BVDV-1a, BVDV-1b, and BVDV-2a. The average percent prevalence of BVDV-1a, BVDV-1b, and BVDV-2a strains reported in surveys before 2001 were 21%, 43%, and 36%, respectively. Surveys conducted on viruses isolated after 2001 reported decreasing percentages of BVDV-1a and BVDV-2a strains, with BVDV-1b strains accounting for 75-100% of samples. Comparison of these surveys is confounded by differences in geographic location, collection methods, and sample type used in the survey. The purpose of the present study was to determine whether the prevalence of BVDV subgenotypes shifted in samples collected from the same geographic region and by the same laboratory over time. BVDV strains isolated in years 1988, 1998, and 2008, at the Texas Veterinary Medical Diagnostic Laboratory, Amarillo, Texas, were genotyped, and the prevalence of BVDV-1a, BVDV-1b, and BVDV-2a strains were determined. Typing, on the basis of phylogenetic analysis, was done on 148 samples. The strongest trend detected among these samples was a pronounced decrease in the number of BVDV-1a strains over time.

  8. [Vaccination against hepatitis B. Impact of vaccination programmes after 20 years of use in Spain. Is it time for a change?].

    PubMed

    Arístegui Fernández, Javier; Díez-Domingo, Javier; Marés Bermúdez, Josep; Martinón Torres, Federico

    2015-02-01

    The highest incidence rate of hepatitis B (HB) in Spain is detected in adults between 20 and 54 years old, whereas the incidence in children under 1 year old is almost nil. The low prevalence of HB in children under 1 year is mainly due to the success of gestational screening strategies for the detection of HBsAg(+) in pregnant women, and vaccination campaigns during childhood. Currently, in Spain, the last dose of the HB included in the national childhood immunization program is administered at 6 months of age, although some studies show that delaying the age of the administration of the last dose of HB vaccine and increasing the time between doses, may improve immune memory by offering greater protection against this virus in the adulthood. In this article, the impact of HB vaccination in Spain is reviewed, and other potential vaccination strategies in our environment are discussed, such as extending the interval between doses, and administering the last dose in the second year of life, adapting the valid strategy in Spain to the current epidemiological context in order to reduce the prevalence of HB in adulthood.

  9. 24 CFR 58.21 - Time periods.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Time periods. 58.21 Section 58.21...: Environmental Review Procedures § 58.21 Time periods. All time periods in this part shall be counted in calendar days. The first day of a time period begins at 12:01 a.m. local time on the day following...

  10. 24 CFR 58.21 - Time periods.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Time periods. 58.21 Section 58.21...: Environmental Review Procedures § 58.21 Time periods. All time periods in this part shall be counted in calendar days. The first day of a time period begins at 12:01 a.m. local time on the day following...

  11. 24 CFR 58.21 - Time periods.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Time periods. 58.21 Section 58.21...: Environmental Review Procedures § 58.21 Time periods. All time periods in this part shall be counted in calendar days. The first day of a time period begins at 12:01 a.m. local time on the day following...

  12. 24 CFR 58.21 - Time periods.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Time periods. 58.21 Section 58.21...: Environmental Review Procedures § 58.21 Time periods. All time periods in this part shall be counted in calendar days. The first day of a time period begins at 12:01 a.m. local time on the day following...

  13. 24 CFR 58.21 - Time periods.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Time periods. 58.21 Section 58.21...: Environmental Review Procedures § 58.21 Time periods. All time periods in this part shall be counted in calendar days. The first day of a time period begins at 12:01 a.m. local time on the day following...

  14. Hubble: 20 Years of Discovery

    NASA Video Gallery

    Hubble's discoveries have revolutionized nearly all areas of current astronomical research from planetary science to cosmology. Actor and writer Brent Spiner narrates a visual journey back in time ...

  15. Conversations: 20 Years in American Education.

    ERIC Educational Resources Information Center

    Green, Joslyn

    Eleven influential individuals who have brought breadth of vision to their work in education answer questions and give comments on the next 20 years of education by looking back on the past 20 years. The panelists are: Alonzo Crim, superintendent of schools in Atlanta, Georgia; Russell Edgerton, president of the American Association for Higher…

  16. New Horizons 20 Years On. Occasional Papers Series: No. 7.

    ERIC Educational Resources Information Center

    Gordon, Margaret

    New Horizons is a course offered by the University of Edinburgh's Centre for Continuing Education that is aimed at first-time returners to education. In the 20 years since New Horizons was developed for women returners to education and/or employment, it has retained its original developmental outcomes but broadened its target group in response to…

  17. Jovian electrons during solar quiet time periods

    NASA Astrophysics Data System (ADS)

    del Peral, L.; Gómez-Herrero, R.; Rodríguez-Frías, M. D.; Sequeiros, J.; Kunow, H.; Müller-Mellin, R.

    2002-03-01

    The electron spectrum in the energy range 150 keV to 10 MeV, measured by EPHIN sensor onboard SOHO observatory during 1996 quiet time periods, is presented. The results show that the dominant electron population is of jovian origin. The spectral indexes obtained range from 1.5 to 1.8. In this work an estimation of the emission intensity of electrons from the jovian magnetosphere is also obtained. Unexpected recurrence of jovian electrons at the middle of 1996 during poor Earth-Jupiter magnetic connection have been observed.

  18. Juvenile angiofibroma: the lessons of 20 years of modern imaging.

    PubMed

    Lloyd, G; Howard, D; Phelps, P; Cheesman, A

    1999-02-01

    Seventy-two patients with juvenile angiofibroma have been investigated by computerized tomography (CT) and/or magnetic resonance imaging (MRI) over a period of 20 years. The evidence from these studies indicates that angiofibroma takes origin in the pterygo-palatine fossa at the aperture of the pterygoid (vidian) canal. An important extension of the tumour is posteriorly along the pterygoid canal with invasion of the cancellous bone of the pterygoid base, and greater wing of the sphenoid (60 per cent of patients). Distinctive features of angiofibroma are the high recurrence rate, and the rapidity with which many tumours recur. It is postulated that the principal determinant of recurrence is a high tumour growth rate at the time of surgery coupled with incomplete surgical excision. The inability to remove the tumour in toto is principally due to deep invasion of the sphenoid, as described above. In this series 93 per cent of recurrences occurred with this type of tumour extension. A contributory cause in these patients is the use of pre-operative embolization. The treatment implications of these findings are examined.

  19. Human psychoneuroimmunology: 20 years of discovery.

    PubMed

    Irwin, Michael R

    2008-02-01

    An important component of psychoneuroimmunology research is to reveal the myriad ways that behaviors and health are inter-related, with a focus on the immunological mechanisms that underlie these interactions. Research in human psychoneuroimmunology has shown that immunoregulatory processes are an integral part of a complex network of adaptive responses. As such, this review provides a perspective from our laboratory over the last 20 years to define the inter-relationships between behavior and immunity; to identify the hypothalamic pituitary adrenal (HPA) and autonomic mechanisms that link the central nervous system and immune responses; to examine the clinical implications of immune alterations during depression or life stress on inflammatory and infectious disease risk; and to explore the reciprocal role of immune mediators on behavior in humans.

  20. Psychology and Aging: The First 20 Years

    PubMed Central

    Zacks, Rose T.; Blanchard-Fields, Fredda; Haley, William E.

    2006-01-01

    This article provides a review of the first 20 years of Psychology and Aging, the American Psychological Association’s first and only scholarly journal devoted to the topic of aging. The authors briefly summarize its history, its contributions to the study of aging, and its broader status as a scholarly publication. One theme highlighted in our review is the diversity of content in the journal throughout its history. Another is the strong impact that articles published in the journal have had on both basic and applied topics in aging. Efforts to encompass the breadth of topics and methodologies in aging research while retaining excellent quality remain the exciting but essential challenge for Psychology and Aging. PMID:16594786

  1. Psychology and Aging: the first 20 years.

    PubMed

    Zacks, Rose T; Blanchard-Fields, Fredda; Haley, William E

    2006-03-01

    This article provides a review of the first 20 years of Psychology and Aging, the American Psychological Association's first and only scholarly journal devoted to the topic of aging. The authors briefly summarize its history, its contributions to the study of aging, and its broader status as a scholarly publication. One theme highlighted in our review is the diversity of content in the journal throughout its history. Another is the strong impact that articles published in the journal have had on both basic and applied topics in aging. Efforts to encompass the breadth of topics and methodologies in aging research while retaining excellent quality remain the exciting but essential challenge for Psychology and Aging.

  2. The Forties field: 20 years young

    SciTech Connect

    Brand, P.J.; Clyne, P.A.; Kirkwood, F.G.; Williams, P.W.

    1996-04-01

    In Oct. 1970, BP`s semisubmersible drilling rig SeaQuest struck oil in Upper Paleocene (Tertiary) sandstones of U.K. Continental Shelf Block 21/10. Four appraisal wells drilled in 1970 and 1971 delineated a large oil reservoir at a depth of 7,000 ft., covering an area of 36 sq miles. The maximum thickness of the oil-bearing sandstone was estimated at 614 ft. Reserves were calculated to be 1,800 MMSTB from an oil in place (OIP) of 4,600 MMSTB, and production was projected to continue until Year 2000. In 1971, Shell/Esso drilled a successful well, Well 22/6-1, that demonstrated the southeastern extension of the field into Block 22/6. The field is a four-way-dip-closed anticline that overlies the Forties-Montrose Ridge and is close to the junction of the Central, South Viking, and Witch Ground grabens. The reservoir occurs in thick Upper Paleocene sandstones deposited as a sand-rich submarine fan sequence. This paper describes how the development of the Forties field has evolved over the past 20 years, the current issues and activities, and the direction for the future.

  3. 20 Years of Improvements to GEOSAT Altimetry

    NASA Astrophysics Data System (ADS)

    Lillibridge, J.; Smith, W. H. F.; Sandwell, D.; Scharroo, R.; Lemoine, F.; Zelensky, N.

    2006-07-01

    The U.S. N avy GEO SAT mission provided the first long-term altimetr ic record for studies of ocean circu lation , mar ine grav ity /bathymetry and continen tal ice. The Geodetic Mission (G M) data were declassified by the Navy in 1995 and released by NOAA togeth er with the Ex act Rep eat Mission data in the 1997 JG M-3 Geophysical Data Records (GDRs). We have now comp leted a major upgrade of the G M data by reprocessing the origin al Sensor D ata Records (SDRs) and Wav eform Data Records (WD Rs) . Th is has allowed us to retrack all the over-ocean waveforms from the G M to improve measuremen ts of sea surface heigh t and its slope and th ereby produce better models of marin e gravity and bathymetry . A unique two-pass retracking algorithm is used to r educe th e noise in along-track sea surface slope, and to reduce th e correlation in errors betw een r ange and SWH from th e waveform f itting. The precise orbit deter min ation uses the full set of 45 Doppler TRAN ET tracking stations and is b ased on a GRA CE grav ity model. W ith improved corrections and retracking mar ine gr avity and bathymetry reso lution ar e improved, while the new pr ecise orbits y ield better estimates of sea lev el r ise from th e GEOSA T time period.

  4. Calcium-sensing receptor 20 years later

    PubMed Central

    Alfadda, Tariq I.; Saleh, Ahmad M. A.; Houillier, Pascal

    2014-01-01

    The calcium-sensing receptor (CaSR) has played an important role as a target in the treatment of a variety of disease states over the past 20 plus years. In this review, we give an overview of the receptor at the cellular level and then provide details as to how this receptor has been targeted to modulate cellular ion transport mechanisms. As a member of the G protein-coupled receptor (GPCR) family, it has a high degree of homology with a variety of other members in this class, which could explain why this receptor has been identified in so many different tissues throughout the body. This diversity of locations sets it apart from other members of the family and may explain how the receptor interacts with so many different organ systems in the body to modulate the physiology and pathophysiology. The receptor is unique in that it has two large exofacial lobes that sit in the extracellular environment and sense changes in a wide variety of environmental cues including salinity, pH, amino acid concentration, and polyamines to name just a few. It is for this reason that there has been a great deal of research associated with normal receptor physiology over the past 20 years. With the ongoing research, in more recent years a focus on the pathophysiology has emerged and the effects of receptor mutations on cellular and organ physiology have been identified. We hope that this review will enhance and update the knowledge about the importance of this receptor and stimulate future potential investigations focused around this receptor in cellular, organ, and systemic physiology and pathophysiology. PMID:24871857

  5. 43 CFR 45.3 - How are time periods computed?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false How are time periods computed? 45.3... IN FERC HYDROPOWER LICENSES General Provisions § 45.3 How are time periods computed? (a) General. Time periods are computed as follows: (1) The day of the act or event from which the period begins...

  6. [Verrucous carcinoma of the larynx. An analysis of 20 years of experience].

    PubMed

    López Amado, M; Lozano Ramírez, A; Labella Caballero, T

    1997-01-01

    Retrospective study about 10 verrucous carcinomas of the larynx surgically treated in a 20-year-term. This variety accounted por the 1.9 percent of the cancers seen in that period of time. Tabagism and alcoholism predominated in 8 and 6 patients respectively. Glottis was the localization and dysphony the paramount symptom. In the paper are emphasized the most important histologic features. Koilocytosis was present in 6 cases. Four patients developed a second tumor of epidermoid carcinoma type. No one exitus due to the verrucous growth. Only in 3 the death was attributed to the second malignancy. PMID:9199100

  7. Review: R28 retinal precursor cells: The first 20 years

    PubMed Central

    2014-01-01

    The R28 retinal precursor cell line was established 20 years ago, originating from a postnatal day 6 rat retinal culture immortalized with the 12S E1A (NP-040507) gene of the adenovirus in a replication-incompetent viral vector. Since that time, R28 cells have been characterized and used for a variety of in vitro and in vivo studies of retinal cell behavior, including differentiation, neuroprotection, cytotoxicity, and light stimulation, as well as retinal gene expression and neuronal function. While no cell culture is equivalent to the intact eye, R28 cells continue to provide an important experimental system for the study of many retinal processes. PMID:24644404

  8. 7 CFR 1.603 - How are time periods computed?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false How are time periods computed? 1.603 Section 1.603 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Conditions in FERC Hydropower Licenses General Provisions § 1.603 How are time periods computed? (a) General. Time periods are...

  9. 7 CFR 1.603 - How are time periods computed?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false How are time periods computed? 1.603 Section 1.603 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Conditions in FERC Hydropower Licenses General Provisions § 1.603 How are time periods computed? (a) General. Time periods are...

  10. 7 CFR 1.603 - How are time periods computed?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false How are time periods computed? 1.603 Section 1.603 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Conditions in FERC Hydropower Licenses General Provisions § 1.603 How are time periods computed? (a) General. Time periods are...

  11. 7 CFR 1.603 - How are time periods computed?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false How are time periods computed? 1.603 Section 1.603 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Conditions in FERC Hydropower Licenses General Provisions § 1.603 How are time periods computed? (a) General. Time periods are...

  12. 38 CFR 8.6 - Calculation of time period.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Calculation of time period. 8.6 Section 8.6 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS NATIONAL SERVICE LIFE INSURANCE Calculation of Time Period § 8.6 Calculation of time period. If the last day of...

  13. 38 CFR 8.6 - Calculation of time period.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Calculation of time period. 8.6 Section 8.6 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS NATIONAL SERVICE LIFE INSURANCE Calculation of Time Period § 8.6 Calculation of time period. If the last day of...

  14. 38 CFR 8.6 - Calculation of time period.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Calculation of time period. 8.6 Section 8.6 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS NATIONAL SERVICE LIFE INSURANCE Calculation of Time Period § 8.6 Calculation of time period. If the last day of...

  15. 38 CFR 8.6 - Calculation of time period.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Calculation of time period. 8.6 Section 8.6 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS NATIONAL SERVICE LIFE INSURANCE Calculation of Time Period § 8.6 Calculation of time period. If the last day of...

  16. 50 CFR 221.3 - How are time periods computed?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false How are time periods computed? 221.3 Section 221.3 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC... Provisions § 221.3 How are time periods computed? (a) General. Time periods are computed as follows: (1)...

  17. 7 CFR 1.603 - How are time periods computed?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false How are time periods computed? 1.603 Section 1.603 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Conditions in FERC Hydropower Licenses General Provisions § 1.603 How are time periods computed? (a) General. Time periods are...

  18. Reflections on 20+ Years of ESD

    ERIC Educational Resources Information Center

    Hopkins, Charles

    2012-01-01

    As one of 12 members of the drafting committee of Agenda 21's Chapter 36, "Education, Public Awareness and Training", Charles Hopkins reflects on the process of working on the now-famous document. Although it was noncontroversial at the time, Chapter 36 spawned education for sustainable development when it was given to UNESCO to administer within…

  19. Detecting unstable periodic orbits from transient chaotic time series

    PubMed

    Dhamala; Lai; Kostelich

    2000-06-01

    We address the detection of unstable periodic orbits from experimentally measured transient chaotic time series. In particular, we examine recurrence times of trajectories in the vector space reconstructed from an ensemble of such time series. Numerical experiments demonstrate that this strategy can yield periodic orbits of low periods even when noise is present. We analyze the probability of finding periodic orbits from transient chaotic time series and derive a scaling law for this probability. The scaling law implies that unstable periodic orbits of high periods are practically undetectable from transient chaos.

  20. Czech Republic 20 years after Chernobyl accident.

    PubMed

    Rosina, Jozef; Kvasnák, Eugen; Suta, Daniel; Kostrhun, Tomás; Drábová, Dana

    2008-01-01

    The territory of the Czech Republic was contaminated as a result of the breakdown in the Chernobyl nuclear power plant in 1986. The Czech population received low doses of ionising radiation which, though it could not cause a deterministic impact, could have had stochastic effects expressed in the years following the accident. Twenty years after the accident is a long enough time to assess its stochastic effects, primarily tumours and genetic impairment. The moderate amount of radioactive fallout received by the Czech population in 1986 increased thyroid cancer in the following years; on the other hand, no obvious genetic impact was found.

  1. Contact time periods in immunological synapse

    NASA Astrophysics Data System (ADS)

    Bush, Daniel R.; Chattopadhyay, Amit K.

    2014-10-01

    This paper resolves the long standing debate as to the proper time scale <τ> of the onset of the immunological synapse bond, the noncovalent chemical bond defining the immune pathways involving T cells and antigen presenting cells. Results from our model calculations show <τ> to be of the order of seconds instead of minutes. Close to the linearly stable regime, we show that in between the two critical spatial thresholds defined by the integrin:ligand pair (Δ2˜ 40-45 nm) and the T-cell receptor TCR:peptide-major-histocompatibility-complex pMHC bond (Δ1˜ 14-15 nm), <τ> grows monotonically with increasing coreceptor bond length separation δ (= Δ2-Δ1˜ 26-30 nm) while <τ> decays with Δ1 for fixed Δ2. The nonuniversal δ-dependent power-law structure of the probability density function further explains why only the TCR:pMHC bond is a likely candidate to form a stable synapse.

  2. Global satellite composites - 20 years of evolution

    NASA Astrophysics Data System (ADS)

    Kohrs, Richard A.; Lazzara, Matthew A.; Robaidek, Jerrold O.; Santek, David A.; Knuth, Shelley L.

    2014-01-01

    For two decades, the University of Wisconsin Space Science and Engineering Center (SSEC) and the Antarctic Meteorological Research Center (AMRC) have been creating global, regional and hemispheric satellite composites. These composites have proven useful in research, operational forecasting, commercial applications and educational outreach. Using the Man computer Interactive Data System (McIDAS) software developed at SSEC, infrared window composites were created by combining Geostationary Operational Environmental Satellite (GOES), and polar orbiting data from the SSEC Data Center and polar data acquired at McMurdo and Palmer stations, Antarctica. Increased computer processing speed has allowed for more advanced algorithms to address the decision making process for co-located pixels. The algorithms have evolved from a simplistic maximum brightness temperature to those that account for distance from the sub-satellite point, parallax displacement, pixel time and resolution. The composites are the state-of-the-art means for merging/mosaicking satellite imagery.

  3. Radium in man - 20 years later

    SciTech Connect

    Maletskos, C.J.

    1994-12-31

    In 1940, there was a need to set a standard for internal exposure to radium for the instrument industry that required luminous characters painted with radium paint. A committee was convened to review the existing information on the health effects of internal radium. Twenty-seven persons had been studied, seven with burdens of 0.5 {mu}g or less with no health effects and twenty with burdens of 1.2 {mu}g or more with health effects. The radium burden dividing the two groups was assumed at 1 {mu}g (an implied threshold), a safety factor of 10 was applied, and the internal radium standard was set at 0.1 {mu}g, a value that still stands today. Over the next five or six decades, about 2000 subjects were investigated, including many measurements on almost all the subjects. In the intervening years, several analyses of the data, available at each particular time, have been made with radical differences in interpretation.

  4. Student Instruction Should Be Distributed over Long Time Periods

    ERIC Educational Resources Information Center

    Rohrer, Doug

    2015-01-01

    In many academic courses, students encounter a particular fact or concept many times over a period of a few weeks and then do not see it again during the remainder of the course. Are these brief instructional periods sufficient, or should the same amount of instruction be distributed over longer periods of time? This question was the focus of…

  5. African Savanna-Forest Boundary Dynamics: A 20-Year Study.

    PubMed

    Cuni-Sanchez, Aida; White, Lee J T; Calders, Kim; Jeffery, Kathryn J; Abernethy, Katharine; Burt, Andrew; Disney, Mathias; Gilpin, Martin; Gomez-Dans, Jose L; Lewis, Simon L

    2016-01-01

    Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of the successional sequence of savanna to forest in Africa. Using long-term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4) in Lopé National Park, central Gabon, plus novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences. Over 20 years no plot changed to a new stage in the putative succession, but F1 forests strongly moved towards the structure, AGB and diversity of F2 forests. Overall, savanna plots showed no detectable change in structure, AGB or diversity using this method, with zero trees ≥10 cm diameter in 1993 and 2013. F1 and F2 forests increased in AGB, mainly as a result of adding recruited stems (F1) and increased Basal Area (F2), whereas F3 and F4 forests did not change substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multi-decadal monitoring is likely to be required to assess the speed of transition between vegetation types. PMID:27336632

  6. African Savanna-Forest Boundary Dynamics: A 20-Year Study

    PubMed Central

    Cuni-Sanchez, Aida; White, Lee J. T.; Calders, Kim; Jeffery, Kathryn J.; Abernethy, Katharine; Burt, Andrew; Disney, Mathias; Gilpin, Martin; Gomez-Dans, Jose L.; Lewis, Simon L.

    2016-01-01

    Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of the successional sequence of savanna to forest in Africa. Using long-term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4) in Lopé National Park, central Gabon, plus novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences. Over 20 years no plot changed to a new stage in the putative succession, but F1 forests strongly moved towards the structure, AGB and diversity of F2 forests. Overall, savanna plots showed no detectable change in structure, AGB or diversity using this method, with zero trees ≥10 cm diameter in 1993 and 2013. F1 and F2 forests increased in AGB, mainly as a result of adding recruited stems (F1) and increased Basal Area (F2), whereas F3 and F4 forests did not change substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multi-decadal monitoring is likely to be required to assess the speed of transition between vegetation types. PMID:27336632

  7. African Savanna-Forest Boundary Dynamics: A 20-Year Study.

    PubMed

    Cuni-Sanchez, Aida; White, Lee J T; Calders, Kim; Jeffery, Kathryn J; Abernethy, Katharine; Burt, Andrew; Disney, Mathias; Gilpin, Martin; Gomez-Dans, Jose L; Lewis, Simon L

    2016-01-01

    Recent studies show widespread encroachment of forest into savannas with important consequences for the global carbon cycle and land-atmosphere interactions. However, little research has focused on in situ measurements of the successional sequence of savanna to forest in Africa. Using long-term inventory plots we quantify changes in vegetation structure, above-ground biomass (AGB) and biodiversity of trees ≥10 cm diameter over 20 years for five vegetation types: savanna; colonising forest (F1), monodominant Okoume forest (F2); young Marantaceae forest (F3); and mixed Marantaceae forest (F4) in Lopé National Park, central Gabon, plus novel 3D terrestrial laser scanning (TLS) measurements to assess forest structure differences. Over 20 years no plot changed to a new stage in the putative succession, but F1 forests strongly moved towards the structure, AGB and diversity of F2 forests. Overall, savanna plots showed no detectable change in structure, AGB or diversity using this method, with zero trees ≥10 cm diameter in 1993 and 2013. F1 and F2 forests increased in AGB, mainly as a result of adding recruited stems (F1) and increased Basal Area (F2), whereas F3 and F4 forests did not change substantially in structure, AGB or diversity. Critically, the stability of the F3 stage implies that this stage may be maintained for long periods. Soil carbon was low, and did not show a successional gradient as for AGB and diversity. TLS vertical plant profiles showed distinctive differences amongst the vegetation types, indicating that this technique can improve ecological understanding. We highlight two points: (i) as forest colonises, changes in biodiversity are much slower than changes in forest structure or AGB; and (ii) all forest types store substantial quantities of carbon. Multi-decadal monitoring is likely to be required to assess the speed of transition between vegetation types.

  8. The Challenges in Metadata Management: 20+ Years of ESO Data

    NASA Astrophysics Data System (ADS)

    Vera, I.; Da Rocha, C.; Dobrzycki, A.; Micol, A.; Vuong, M.

    2015-09-01

    The European Southern Observatory Science Archive Facility has been in operations for more than 20 years. It contains data produced by ESO telescopes as well as the metadata needed for characterizing and distributing those data. This metadata is used to build the different archive services provided by the Archive. Over these years, services have been added, modified or even decommissioned creating a cocktail of new, evolved and legacy data systems. The challenge for the Archive is to harmonize the differences of those data systems to provide the community with a homogeneous experience when using ESO data. In this paper, we present ESO experience in three particular challenging areas. First discussion is dedicated to the problem of metadata quality over the time, second discusses how to integrate obsolete data models on the current services and finally we will present the challenges of ever growing databases. We describe our experience dealing with those issues and the solutions adopted to mitigate them.

  9. A Longitudinal Examination of Career Expectations and Outcomes of Academically Talented Students 10 and 20 Years Post-High School Graduation

    ERIC Educational Resources Information Center

    Perrone, Kristin M.; Tschopp, Molly K.; Snyder, Erin R.; Boo, Jenelle N.; Hyatt, Claudine

    2010-01-01

    The purpose of this study was to examine career expectations and outcomes for individuals who were identified as academically talented high school students. Data for this study were collected at two different time periods: 10 years and 20 years after participants' high school graduation. A decade after graduation from high school, participants…

  10. Multicultural Counseling Competencies Research: A 20-Year Content Analysis

    ERIC Educational Resources Information Center

    Worthington, Roger L.; Soth-McNett, Angela M.; Moreno, Matthew V.

    2007-01-01

    The authors conducted a 20-year content analysis of the entire field of empirical research on the multicultural counseling competencies (D. W. Sue et al., 1982). They conducted an exhaustive search for empirical research articles using PsycINFO, as well as complete reviews of the past 20 years of several journals (e.g., Journal of Counseling…

  11. 36 CFR 218.10 - Objection time periods and process.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... holidays. However, when the time period expires on a Saturday, Sunday, or Federal holiday, the time is extended to the end of the next Federal working day as stated in the legal notice or to the end of...

  12. 36 CFR 218.26 - Objection time periods.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROJECT-LEVEL PREDECISIONAL ADMINISTRATIVE REVIEW PROCESS Provisions Specific to Project-Level Proposals Not Authorized Under Healthy Forests Restoration Act § 218.26 Objection time periods. (a) Time to...

  13. 36 CFR 218.32 - Objection time periods.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROJECT-LEVEL PREDECISIONAL ADMINISTRATIVE REVIEW PROCESS Provisions Specific to Proposed Projects Authorized Under the Healthy Forests Restoration Act § 218.32 Objection time periods. (a) Time to file...

  14. 36 CFR 218.32 - Objection time periods.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROJECT-LEVEL PREDECISIONAL ADMINISTRATIVE REVIEW PROCESS Provisions Specific to Proposed Projects Authorized Under the Healthy Forests Restoration Act § 218.32 Objection time periods. (a) Time to file...

  15. 36 CFR 218.26 - Objection time periods.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROJECT-LEVEL PREDECISIONAL ADMINISTRATIVE REVIEW PROCESS Provisions Specific to Project-Level Proposals Not Authorized Under Healthy Forests Restoration Act § 218.26 Objection time periods. (a) Time to...

  16. 19 CFR 158.21a - Time period.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Time period. 158.21a Section 158.21a Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... While in Customs Custody § 158.21a Time period. An abatement or refund of duties shall be made in...

  17. 19 CFR 158.21a - Time period.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Time period. 158.21a Section 158.21a Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... While in Customs Custody § 158.21a Time period. An abatement or refund of duties shall be made in...

  18. 43 CFR 45.3 - How are time periods computed?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false How are time periods computed? 45.3 Section 45.3 Public Lands: Interior Office of the Secretary of the Interior CONDITIONS AND PRESCRIPTIONS IN FERC HYDROPOWER LICENSES General Provisions § 45.3 How are time periods computed? (a)...

  19. 43 CFR 45.3 - How are time periods computed?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true How are time periods computed? 45.3 Section 45.3 Public Lands: Interior Office of the Secretary of the Interior CONDITIONS AND PRESCRIPTIONS IN FERC HYDROPOWER LICENSES General Provisions § 45.3 How are time periods computed? (a) General....

  20. 43 CFR 45.3 - How are time periods computed?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false How are time periods computed? 45.3 Section 45.3 Public Lands: Interior Office of the Secretary of the Interior CONDITIONS AND PRESCRIPTIONS IN FERC HYDROPOWER LICENSES General Provisions § 45.3 How are time periods computed? (a)...

  1. 43 CFR 45.3 - How are time periods computed?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false How are time periods computed? 45.3 Section 45.3 Public Lands: Interior Office of the Secretary of the Interior CONDITIONS AND PRESCRIPTIONS IN FERC HYDROPOWER LICENSES General Provisions § 45.3 How are time periods computed? (a)...

  2. 19 CFR 158.21a - Time period.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Time period. 158.21a Section 158.21a Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... While in Customs Custody § 158.21a Time period. An abatement or refund of duties shall be made in...

  3. Threshold dynamics of a time periodic reaction-diffusion epidemic model with latent period

    NASA Astrophysics Data System (ADS)

    Zhang, Liang; Wang, Zhi-Cheng; Zhao, Xiao-Qiang

    2015-05-01

    In this paper, we first propose a time-periodic reaction-diffusion epidemic model which incorporates simple demographic structure and the latent period of infectious disease. Then we introduce the basic reproduction number R0 for this model and prove that the sign of R0 - 1 determines the local stability of the disease-free periodic solution. By using the comparison arguments and persistence theory, we further show that the disease-free periodic solution is globally attractive if R0 < 1, while there is an endemic periodic solution and the disease is uniformly persistent if R0 > 1.

  4. Choroidal osteoma: evidence of progression and decalcification over 20 years.

    PubMed

    Chen, Jennifer; Lee, Lawrence; Gass, J Donald M

    2006-03-01

    Choroidal osteoma is a rare, benign, ossifying tumour of the choroid of unknown aetiology. In contrast to other types of intraocular ossification, choroidal osteoma is found typically in young healthy females in the second or third decades of life with no history of systemic or ocular disease. Choroidal osteoma is a deep, pale yellow lesion with distinct geographic borders at the juxtapapillary or macular region, with branching 'spider' vessels on the surface of the tumour. These features should help differentiate choroidal osteoma from other types of intraocular tumour and the diagnosis can be confirmed with ultrasonography and computerised tomography. Here we report an initially unilateral case of choroidal osteoma, which decalcified over 20 years but during the same period the fellow eye also developed a choroidal osteoma to become a bilateral case. Despite the benign nature of the tumour, vision may be compromised by gradual atrophy of the overlying retina, serous retinal detachment, accumulation of sub-retinal fluid and sub-retinal haemorrhage associated with choroidal neovascularisation. Frequent examinations are recommended for patients with choroidal osteoma, for early detection of a subretinal neovascular membrane and potential treatment with laser photocoagulation.

  5. Period04: Statistical analysis of large astronomical time series

    NASA Astrophysics Data System (ADS)

    Lenz, Patrick; Breger, Michel

    2014-07-01

    Period04 statistically analyzes large astronomical time series containing gaps. It calculates formal uncertainties, can extract the individual frequencies from the multiperiodic content of time series, and provides a flexible interface to perform multiple-frequency fits with a combination of least-squares fitting and the discrete Fourier transform algorithm. Period04, written in Java/C++, supports the SAMP communication protocol to provide interoperability with other applications of the Virtual Observatory. It is a reworked and extended version of Period98 (Sperl 1998) and PERIOD/PERDET (Breger 1990).

  6. Water survival: 20 years Canadian Forces aircrew experience.

    PubMed

    Brooks, C J; Rowe, K W

    1984-01-01

    A 20 year review of Canadian Forces (CF) aircrew ejection/ditching, survival/rescue times and injury patterns in salt and fresh water is presented. Of the 595 A, B, and C category accidents which have been reviewed (1962-1982), 37 were water-entry. Of the 116 crew which were involved, 38 died (4 in fresh water). The Sea King helicopter is most at risk from sea water immersion, and the single-engine Otter has been the most vulnerable to fresh water immersion. A water immersion can be expected approximately once every 170,000 h of total flying time. In 92% of cases, the crew had less than 1 min warning that immersion was imminent and in 78% had less than 15 s to make a practical response. There were two clinical cases of hypothermia. In the absence of injuries, aircrew trained in water survival, qualified on the Dilbert Dunker, and who are strong swimmers or sports divers, have a better chance to survival. Time to rescue in all cases was under 3 h, and in 16 out of 24 cases crew members were rescued in under 15 min.

  7. Pustular psoriasis in childhood and adolescence: a 20-year single-center experience.

    PubMed

    Popadic, Svetlana; Nikolic, Milos

    2014-01-01

    Pustular psoriasis (PP) is rare in children. The small number of reported cases makes deciding on treatment and follow-up challenging. The current study was an evaluation of treatment approaches and courses of PP in 18 children diagnosed and followed over a 20-year period. From 1992 to 2011 we treated 1,447 children with psoriasis, 18 of whom had PP. Follow-up was 2 to 19 years. At the time of initial manifestation of PP, our patients were 1.5 months to 16 years old. Seven patients had a previous history of psoriasis vulgaris. Three children entered long-term remission after one pustular attack, 10 developed psoriasis vulgaris, 2 are currently under treatment, and 3 were lost to follow-up. Treatment with acitretin, cyclosporine, or methotrexate was efficacious and well tolerated. PP is rare, but according to our experience, it has a good prognosis in children.

  8. Average American 15 Pounds Heavier Than 20 Years Ago

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_160233.html Average American 15 Pounds Heavier Than 20 Years Ago ... since the late 1980s and early 1990s, the average American has put on 15 or more additional ...

  9. A time-periodic reaction-diffusion epidemic model with infection period

    NASA Astrophysics Data System (ADS)

    Zhang, Liang; Wang, Zhi-Cheng

    2016-10-01

    In this paper, we propose a time-periodic and diffusive SIR epidemic model with constant infection period. By introducing the basic reproduction number R_0 via a next generation operator for this model, we show that the disease goes extinction if R_0 < 1; while the disease is uniformly persistent if R_0 > 1.

  10. The odontogenic keratocyst: a 20-year clinicopathologic review.

    PubMed

    Meara, J G; Shah, S; Li, K K; Cunningham, M J

    1998-02-01

    The odontogenic keratocyst (OKC) is a jaw cyst with a proclivity for local invasion and recurrence. This 20-year retrospective study was conducted to evaluate methods of treatment and recurrence rates. Forty-nine patients were identified with an average age at presentation of 39.5 years. The molar region of either the mandible or maxilla was the principal primary location; the maxillary antrum was also a common site. The majority of cysts were unilocular and associated with adjacent dentition. Initial therapy was typically enucleation with or without extraction of associated teeth; seven cases of recurrent or second primary odontogenic keratocysts required more extensive surgery. Follow-up ranged from 1 to 15 years with an average duration of 4.3 years. The overall recurrence rate was 35%, and the average time to recurrence 4 years. A recurrence rate of 60% was documented for patients with basal cell nevus syndrome or a family history thereof. Long-term follow-up is necessary following initial OKC treatment. The high rate of recurrence in patients with documented or suspected basal cell nevus syndrome suggests the need for more aggressive initial surgical management in this selected patient population.

  11. Bringing Together Simulated ~20 Year Variability in Coupled Climate Models

    NASA Astrophysics Data System (ADS)

    Menary, M.; Hodson, D.; Robson, J.; Sutton, R.; Wood, R. A.

    2014-12-01

    Many climate models simulate significant spectral power in large scale, North Atlantic subpolar gyre indices at timescales of around 20 years. Despite similar periodicities, the underlying mechanisms reported in individual models can vary greatly. For example, the timescale can be set by any combination of geostrophic self advection, Rossby wave propagation, or advection by the mean circulation. The role of the overturning circulation can either be active or passive, and the ultimate driver of density changes in the deep water formation regions is split roughly evenly in the literature between salinity and temperature - with implications for any feedback mechanisms. These simulations typically span many centuries with constant external forcings to capture internal climate variability. The extent to which either this periodicity carries over to the real world under increasingly strong external forcing, or which, if any, of the modelled feedbacks are applicable, is unclear. We present new results from a state-of-the-art high resolution coupled climate model (HadGEM3) in which the mechanism of internal decadal variability in the North Atlantic is diagnosed and discuss the causes of differences from previous work. Due to the non-linear equation of state, biases in the simulated mean state can explain some of the inter-model differences via the relative importance of temperature or salinity in density changes. These biases can then propagate throughout the mechanistic chain resulting in fundamentally different simulated mechanisms. For example, whether temperature or salinity control densities in the Labrador Sea influences whether a strengthening overturning circulation acts as a negative or positive feedback. Although analysis of the model proceeds via lagged regressions, this is generally not possible with observational data. We use a combination of palaeo reconstructions and targeted process-based analysis to investigate whether there is any signal of bidecadal

  12. Particle energization through time-periodic helical magnetic fields.

    PubMed

    Mitra, Dhrubaditya; Brandenburg, Axel; Dasgupta, Brahmananda; Niklasson, Eyvind; Ram, Abhay

    2014-04-01

    We solve for the motion of charged particles in a helical time-periodic ABC (Arnold-Beltrami-Childress) magnetic field. The magnetic field lines of a stationary ABC field with coefficients A=B=C=1 are chaotic, and we show that the motion of a charged particle in such a field is also chaotic at late times with positive Lyapunov exponent. We further show that in time-periodic ABC fields, the kinetic energy of a charged particle can increase indefinitely with time. At late times the mean kinetic energy grows as a power law in time with an exponent that approaches unity. For an initial distribution of particles, whose kinetic energy is uniformly distributed within some interval, the probability density function of kinetic energy is, at late times, close to a Gaussian but with steeper tails.

  13. The Development of an African-Centered School--The First 20 Years

    ERIC Educational Resources Information Center

    Squire, Michelle Suzette

    2012-01-01

    This research study is a case study of the development of an African-centered school over a 20-year period. The study describes how the kindergarten-through-eighth-grade institution was established. Interview questions focused on: 1. Establishment of an African-centered institution 2. Challenges of setting up an African-centered institution 3.…

  14. Participation in Intellectual Disability Research: A Review of 20 Years of Studies

    ERIC Educational Resources Information Center

    Cleaver, S.; Ouellette-Kuntz, H.; Sakar, A.

    2010-01-01

    Background: Researchers have noted difficulties in attracting adequate numbers of participants with intellectual disabilities (ID) to their studies. Methods: This study was a review of participation by adults with ID in research conducted in South Eastern Ontario over a 20-year period (1987-2006). Original research studies were identified by local…

  15. Pharmacogenetics research on chemotherapy resistance in colorectal cancer over the last 20 years

    PubMed Central

    Panczyk, Mariusz

    2014-01-01

    During the past two decades the first sequencing of the human genome was performed showing its high degree of inter-individual differentiation, as a result of large international research projects (Human Genome Project, the 1000 Genomes Project International HapMap Project, and Programs for Genomic Applications NHLBI-PGA). This period was also a time of intensive development of molecular biology techniques and enormous knowledge growth in the biology of cancer. For clinical use in the treatment of patients with colorectal cancer (CRC), in addition to fluoropyrimidines, another two new cytostatic drugs were allowed: irinotecan and oxaliplatin. Intensive research into new treatment regimens and a new generation of drugs used in targeted therapy has also been conducted. The last 20 years was a time of numerous in vitro and in vivo studies on the molecular basis of drug resistance. One of the most important factors limiting the effectiveness of chemotherapy is the primary and secondary resistance of cancer cells. Understanding the genetic factors and mechanisms that contribute to the lack of or low sensitivity of tumour tissue to cytostatics is a key element in the currently developing trend of personalized medicine. Scientists hope to increase the percentage of positive treatment response in CRC patients due to practical applications of pharmacogenetics/pharmacogenomics. Over the past 20 years the clinical usability of different predictive markers has been tested among which only a few have been confirmed to have high application potential. This review is a synthetic presentation of drug resistance in the context of CRC patient chemotherapy. The multifactorial nature and volume of the issues involved do not allow the author to present a comprehensive study on this subject in one review. PMID:25110414

  16. Pharmacogenetics research on chemotherapy resistance in colorectal cancer over the last 20 years.

    PubMed

    Panczyk, Mariusz

    2014-08-01

    During the past two decades the first sequencing of the human genome was performed showing its high degree of inter-individual differentiation, as a result of large international research projects (Human Genome Project, the 1000 Genomes Project International HapMap Project, and Programs for Genomic Applications NHLBI-PGA). This period was also a time of intensive development of molecular biology techniques and enormous knowledge growth in the biology of cancer. For clinical use in the treatment of patients with colorectal cancer (CRC), in addition to fluoropyrimidines, another two new cytostatic drugs were allowed: irinotecan and oxaliplatin. Intensive research into new treatment regimens and a new generation of drugs used in targeted therapy has also been conducted. The last 20 years was a time of numerous in vitro and in vivo studies on the molecular basis of drug resistance. One of the most important factors limiting the effectiveness of chemotherapy is the primary and secondary resistance of cancer cells. Understanding the genetic factors and mechanisms that contribute to the lack of or low sensitivity of tumour tissue to cytostatics is a key element in the currently developing trend of personalized medicine. Scientists hope to increase the percentage of positive treatment response in CRC patients due to practical applications of pharmacogenetics/pharmacogenomics. Over the past 20 years the clinical usability of different predictive markers has been tested among which only a few have been confirmed to have high application potential. This review is a synthetic presentation of drug resistance in the context of CRC patient chemotherapy. The multifactorial nature and volume of the issues involved do not allow the author to present a comprehensive study on this subject in one review.

  17. Identifying multiple periodicities in sparse photon event time series

    NASA Astrophysics Data System (ADS)

    Koen, Chris

    2016-07-01

    The data considered are event times (e.g. photon arrival times, or the occurrence of sharp pulses). The source is multiperiodic, or the data could be multiperiodic because several unresolved sources contribute to the time series. Most events may be unobserved, either because the source is intermittent, or because some events are below the detection limit. The data may also be contaminated by spurious pulses. The problem considered is the determination of the periods in the data. A two-step procedure is proposed: in the first, a likely period is identified; in the second, events associated with this periodicity are removed from the time series. The steps are repeated until the remaining events do not exhibit any periodicity. A number of period-finding methods from the literature are reviewed, and a new maximum likelihood statistic is also introduced. It is shown that the latter is competitive compared to other techniques. The proposed methodology is tested on simulated data. Observations of two rotating radio transients are discussed, but contrary to claims in the literature, no evidence for multiperiodicity could be found.

  18. Optimal health insurance for multiple goods and time periods.

    PubMed

    Ellis, Randall P; Jiang, Shenyi; Manning, Willard G

    2015-05-01

    We examine the efficiency-based arguments for second-best optimal health insurance with multiple treatment goods and multiple time periods. Correlated shocks across health care goods and over time interact with complementarity and substitutability to affect optimal cost sharing. Health care goods that are substitutes or have positively correlated demand shocks should have lower optimal patient cost sharing. Positive serial correlations of demand shocks and uncompensated losses that are positively correlated with covered health services also reduce optimal cost sharing. Our results rationalize covering pharmaceuticals and outpatient spending more fully than is implied by static, one good, or one period models.

  19. Infrared Time Lags for the Periodic Quasar PG 1302-102

    NASA Astrophysics Data System (ADS)

    Jun, Hyunsung D.; Stern, Daniel; Graham, Matthew J.; Djorgovski, S. G.; Mainzer, Amy; Cutri, Roc M.; Drake, Andrew J.; Mahabal, Ashish A.

    2015-11-01

    The optical light curve of the quasar PG 1302-102 at z=0.278 shows a strong, smooth 5.2 year periodic signal, detectable over a period of ∼20 years. Although the interpretation of this phenomenon is still uncertain, the most plausible mechanisms involve a binary system of two supermassive black holes with a subparsec separation. At this close separation, the nuclear black holes in PG 1302-102 will likely merge within ∼ {10}5 years due to gravitational wave emission alone. Here, we report the rest-frame near-infrared time lags for PG 1302-102. Compiling data from WISE and Akari, we confirm that the periodic behavior reported in the optical light curve from Graham et al. is reproduced at infrared wavelengths, with best-fit observed-frame 3.4 and 4.6 μ {{m}} time lags of (2219 ± 153, 2408 ± 148) days for a near face-on orientation of the torus, or (4103 ± 153, 4292 ± 148) days for an inclined system with relativistic Doppler boosting in effect. The periodicity in the infrared light curves and the light-travel time of the accretion disk photons to reach the dust glowing regions support that a source within the accretion disk is responsible for the optical variability of PG 1302-102, echoed at the farther out dusty regions. The implied distance of this dusty, assumed toroidal region is ∼1.5 pc for a near face-on geometry or ∼1.1 pc for the relativistic Doppler-boosted case.

  20. Building-Based Budgeting and Decentralization: A 20 Year Perspective.

    ERIC Educational Resources Information Center

    Ilg, Timothy J.; Raisch, C. Daniel

    This paper examines the effects of site-based budgeting in education. It describes and presents a school-based budgetary decision-making model that was designed originally to shift the balance of power from the central office to the building level. The model has been refined and successfully utilized in one school district for 20 years, and its…

  1. The Rainbow Reading Programme: A Review 20 Years on

    ERIC Educational Resources Information Center

    Dobson, Emma

    2013-01-01

    It has been 20 years since the Rainbow Reading programme was developed and trialled by its New Zealand creator, Meryl-Lynn Pluck. Rainbow Reading is an audio-facilitated reading programme, and is based on the method of assisted repeated reading. The programme is designed to provide older students reading below their chronological age with the…

  2. Lavoisier Preempted Gay-Lussac by 20 Years!

    ERIC Educational Resources Information Center

    Laing, Michael

    1998-01-01

    Lavoisier showed that water was formed by chemical reaction between hydrogen and oxygen. In Lavoisier's "Traite Elementaire" of 1789, he states that the reaction to form water requires exactly two volumes of hydrogen gas to react completely with one volume of oxygen gas. This was 20 years before Gay-Lussac studied the reactions between different…

  3. Support-Staff Jobs Double in 20 Years, Outpacing Enrollment

    ERIC Educational Resources Information Center

    Brainard, Jeffrey; Fain, Paul; Masterson, Kathryn

    2009-01-01

    Colleges have added managers and support personnel at a steady, vigorous clip over the past 20 years, new research shows, far outpacing the growth in student enrollment and instructors. Support staff--like budget analysts, computer specialists, and loan counselors--nearly doubled from 1987 to 2007. Meanwhile, jobs for instructors increased by only…

  4. Adenomatoid odontogenic tumour in a 20-year-old woman

    PubMed Central

    Virupakshappa, Deepti; Rajashekhara, Bhari Sharanesha; Manjunatha, Bhari Sharanesha; Das, Nagarajappa

    2014-01-01

    Adenomatoid odontogenic tumour is a relatively rare and distinct odontogenic tumour that is exclusively odontogenic epithelium in origin. It comprises 3% of all odontogenic tumours. This report describes the surgical therapy, clinical course and morphological characteristics of an adenomatoid odontogenic tumour that developed in the left maxilla of a 20-year-old patient. PMID:24810436

  5. Teacher Education 1992 and 2012: Reflecting on 20 Years

    ERIC Educational Resources Information Center

    McKeown, Rosalyn

    2012-01-01

    Over the past 20 years education for sustainable development (ESD) has become part of the discourse in teacher education and the teaching community has a better grasp of ESD's action-oriented and participatory pedagogies. The International Network of Teacher Education Institutions (TEIs) associated with the UNESCO Chair on Reorienting Teacher…

  6. Are History Textbooks More "Considerate" after 20 Years?

    ERIC Educational Resources Information Center

    Berkeley, Sheri; King-Sears, Margaret E.; Hott, Brittany L.; Bradley-Black, Katherine

    2014-01-01

    Features of eighth-grade history textbooks were examined through replication of a 20-year-old study that investigated "considerateness" of textbooks. Considerate texts provide clear, coherent information and include features that promote students' comprehension, such as explicit use of organizational structures, a range of question…

  7. Pseudo analytical solution to time periodic stiffness systems

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Zhong; Zhou, Yuan-Zi

    2011-04-01

    An analytical form of state transition matrix for a system of equations with time periodic stiffness is derived in order to solve the free response and also allow for the determination of system stability and bifurcation. A pseudo-closed form complete solution for parametrically excited systems subjected to inhomogeneous generalized forcing is developed, based on the Fourier expansion of periodic matrices and the substitution of matrix exponential terms via Lagrange—Sylvester theorem. A Mathieu type of equation with large amplitude is presented to demonstrate the method of formulating state transition matrix and Floquet multipliers. A two-degree-of-freedom system with irregular time periodic stiffness characterized by spiral bevel gear mesh vibration is presented to find forced response in stability and instability. The obtained results are presented and discussed.

  8. Prediction of the 20-year incidence of diabetes in older Chinese

    PubMed Central

    Liu, Xiangtong; Fine, Jason Peter; Chen, Zhenghong; Liu, Long; Li, Xia; Wang, Anxin; Guo, Jin; Tao, Lixin; Mahara, Gehendra; Tang, Zhe; Guo, Xiuhua

    2016-01-01

    Abstract The competing risk method has become more acceptable for time-to-event data analysis because of its advantage over the standard Cox model in accounting for competing events in the risk set. This study aimed to construct a prediction model for diabetes using a subdistribution hazards model. We prospectively followed 1857 community residents who were aged ≥ 55 years, free of diabetes at baseline examination from August 1992 to December 2012. Diabetes was defined as a self-reported history of diabetes diagnosis, taking antidiabetic medicine, or having fasting plasma glucose (FPG) ≥ 7.0 mmol/L. A questionnaire was used to measure diabetes risk factors, including dietary habits, lifestyle, psychological factors, cognitive function, and physical condition. Gray test and a subdistribution hazards model were used to construct a prediction algorithm for 20-year risk of diabetes. Receiver operating characteristic (ROC) curves, bootstrap cross-validated Wolber concordance index (C-index) statistics, and calibration plots were used to assess model performance. During the 20-year follow-up period, 144 cases were documented for diabetes incidence with a median follow-up of 10.9 years (interquartile range: 8.0–15.3 years). The cumulative incidence function of 20-year diabetes incidence was 11.60% after adjusting for the competing risk of nondiabetes death. Gray test showed that body mass index, FPG, self-rated heath status, and physical activity were associated with the cumulative incidence function of diabetes after adjusting for age. Finally, 5 standard risk factors (poor self-rated health status [subdistribution hazard ratio (SHR) = 1.73, P = 0.005], less physical activity [SHR = 1.39, P = 0.047], 55–65 years old [SHR = 4.37, P < 0.001], overweight [SHR = 2.15, P < 0.001] or obesity [SHR = 1.96, P = 0.003], and impaired fasting glucose [IFG] [SHR = 1.99, P < 0.001]) were significantly associated with incident

  9. Analysis of time-domain scattering by periodic structures

    NASA Astrophysics Data System (ADS)

    Gao, Yixian; Li, Peijun

    2016-11-01

    This paper is devoted to the mathematical analysis of a time-domain electromagnetic scattering by periodic structures which are known as diffraction gratings. The scattering problem is reduced equivalently into an initial-boundary value problem in a bounded domain by using an exact transparent boundary condition. The well-posedness and stability of the solution are established for the reduced problem. Moreover, a priori energy estimates are obtained with minimum regularity requirement for the data and explicit dependence on the time.

  10. 36 CFR 215.15 - Appeal time periods and process.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Appeal time periods and process. 215.15 Section 215.15 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE NOTICE, COMMENT, AND APPEAL PROCEDURES FOR NATIONAL FOREST SYSTEM PROJECTS AND ACTIVITIES §...

  11. 36 CFR 215.15 - Appeal time periods and process.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Appeal time periods and process. 215.15 Section 215.15 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE NOTICE, COMMENT, AND APPEAL PROCEDURES FOR NATIONAL FOREST SYSTEM PROJECTS AND ACTIVITIES §...

  12. 36 CFR 215.15 - Appeal time periods and process.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Appeal time periods and process. 215.15 Section 215.15 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE NOTICE, COMMENT, AND APPEAL PROCEDURES FOR NATIONAL FOREST SYSTEM PROJECTS AND ACTIVITIES §...

  13. 36 CFR 215.15 - Appeal time periods and process.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Appeal time periods and process. 215.15 Section 215.15 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE NOTICE, COMMENT, AND APPEAL PROCEDURES FOR NATIONAL FOREST SYSTEM PROJECTS AND ACTIVITIES §...

  14. 36 CFR 215.15 - Appeal time periods and process.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Appeal time periods and process. 215.15 Section 215.15 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE NOTICE, COMMENT, AND APPEAL PROCEDURES FOR NATIONAL FOREST SYSTEM PROJECTS AND ACTIVITIES §...

  15. 50 CFR 221.3 - How are time periods computed?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false How are time periods computed? 221.3 Section 221.3 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS PRESCRIPTIONS IN FERC HYDROPOWER LICENSES...

  16. 50 CFR 221.3 - How are time periods computed?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false How are time periods computed? 221.3 Section 221.3 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS PRESCRIPTIONS IN FERC HYDROPOWER LICENSES...

  17. 50 CFR 221.3 - How are time periods computed?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false How are time periods computed? 221.3 Section 221.3 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS PRESCRIPTIONS IN FERC HYDROPOWER LICENSES...

  18. 50 CFR 221.3 - How are time periods computed?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false How are time periods computed? 221.3 Section 221.3 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS PRESCRIPTIONS IN FERC HYDROPOWER LICENSES...

  19. Physical Activity in High School during "Free-Time" Periods

    ERIC Educational Resources Information Center

    Silva, Pedro; Sousa, Michael; Sá, Carla; Ribeiro, José; Mota, Jorge

    2015-01-01

    The purpose of this study was to examine youth physical activity (PA) in free-time periods during high school days and their contribution to total PA. Differences in terms of sex, age, body mass index and school level were assessed in a sample of Portuguese adolescents. Participants totalled 213 (135 girls), aged 14.6 ± 1.7, from two different…

  20. Time-periodic solutions of the Benjamin-Ono equation

    SciTech Connect

    Ambrose , D.M.; Wilkening, Jon

    2008-04-01

    We present a spectrally accurate numerical method for finding non-trivial time-periodic solutions of non-linear partial differential equations. The method is based on minimizing a functional (of the initial condition and the period) that is positive unless the solution is periodic, in which case it is zero. We solve an adjoint PDE to compute the gradient of this functional with respect to the initial condition. We include additional terms in the functional to specify the free parameters, which, in the case of the Benjamin-Ono equation, are the mean, a spatial phase, a temporal phase and the real part of one of the Fourier modes at t = 0. We use our method to study global paths of non-trivial time-periodic solutions connecting stationary and traveling waves of the Benjamin-Ono equation. As a starting guess for each path, we compute periodic solutions of the linearized problem by solving an infinite dimensional eigenvalue problem in closed form. We then use our numerical method to continue these solutions beyond the realm of linear theory until another traveling wave is reached (or until the solution blows up). By experimentation with data fitting, we identify the analytical form of the solutions on the path connecting the one-hump stationary solution to the two-hump traveling wave. We then derive exact formulas for these solutions by explicitly solving the system of ODE's governing the evolution of solitons using the ansatz suggested by the numerical simulations.

  1. False periodicities in quasar time-domain surveys

    NASA Astrophysics Data System (ADS)

    Vaughan, S.; Uttley, P.; Markowitz, A. G.; Huppenkothen, D.; Middleton, M. J.; Alston, W. N.; Scargle, J. D.; Farr, W. M.

    2016-09-01

    There have recently been several reports of apparently periodic variations in the light curves of quasars, e.g. PG 1302-102 by Graham et al. Any quasar showing periodic oscillations in brightness would be a strong candidate to be a close binary supermassive black hole and, in turn, a candidate for gravitational wave studies. However, normal quasars - powered by accretion on to a single, supermassive black hole - usually show stochastic variability over a wide range of time-scales. It is therefore important to carefully assess the methods for identifying periodic candidates from among a population dominated by stochastic variability. Using a Bayesian analysis of the light curve of PG 1302-102, we find that a simple stochastic process is preferred over a sinusoidal variation. We then discuss some of the problems one encounters when searching for rare, strictly periodic signals among a large number of irregularly sampled, stochastic time series, and use simulations of quasar light curves to illustrate these points. From a few thousand simulations of steep spectrum (`red noise') stochastic processes, we find many simulations that display few-cycle periodicity like that seen in PG 1302-102. We emphasize the importance of calibrating the false positive rate when the number of targets in a search is very large.

  2. The New 20-Year Global Precipitation Climatology Project (GPCP) Merged Satellite and Rainguage Monthly Analysis

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Xie, Ping Ping; Rudolf, Bruno; Gruber, Arnold; Janowiak, John

    1999-01-01

    A new 20-year, monthly, globally complete precipitation analysis has been completed as part of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP). This Version 2 of the community generated data set is a result of combining the procedures and data sets as described. The global, monthly, 2.5x 2.5 degree latitude-longitude product utilizes precipitation estimates from low-orbit microwave sensors (SSM/1) and geosynchronous IR sensors and raingauge information over land. The low-orbit microwave estimates are used to adjust or correct the geosynchronous IR estimates, thereby maximizing the utility of the more physically-based microwave estimates and the finer time sampling of the geosynchronous observations. Information from raingauges is blended into the analyses over land. In the 1986-present period TOVS-based precipitation estimates are adjusted to GPCP fields and used in polar regions to produce globally-complete results. The extension back to 1979 utilizes the procedures of Xie and Arkin and their OLR Precipitation Index (OPI). The 20-year climatology of the Version 2 GPCP analysis indicates the expected features of a very strong Pacific Ocean ITCZ and SPCZ with maximum 20-year means approaching 10 mm/day. A similar strength maximum over land is evident over Borneo. Weaker maxima in the tropics occur in the Atlantic ITCZ and over South America and Africa. In mid-latitudes of the Northern Hemisphere the Western Pacific and Western Atlantic maxima have values of approximately 7 mm/day, while in the Southern Hemisphere the mid-latitude maxima are located southeast of Africa, in mid-Pacific as an extension of the SPCZ and southeast of South America. In terms of global totals the GPCP analysis shows 2.7 mm/day (3.0 mm/day over ocean; 2.1 mm/day over land), similar to the Jaeger climatology, but not other climatologies. Zonal averages peak at 6 mm/day at 7*N with mid-latitude peaks of about 3 mm/day at 40-45* latitude

  3. Periodicity detection method for small-sample time series datasets.

    PubMed

    Tominaga, Daisuke

    2010-01-01

    Time series of gene expression often exhibit periodic behavior under the influence of multiple signal pathways, and are represented by a model that incorporates multiple harmonics and noise. Most of these data, which are observed using DNA microarrays, consist of few sampling points in time, but most periodicity detection methods require a relatively large number of sampling points. We have previously developed a detection algorithm based on the discrete Fourier transform and Akaike's information criterion. Here we demonstrate the performance of the algorithm for small-sample time series data through a comparison with conventional and newly proposed periodicity detection methods based on a statistical analysis of the power of harmonics.We show that this method has higher sensitivity for data consisting of multiple harmonics, and is more robust against noise than other methods. Although "combinatorial explosion" occurs for large datasets, the computational time is not a problem for small-sample datasets. The MATLAB/GNU Octave script of the algorithm is available on the author's web site: http://www.cbrc.jp/%7Etominaga/piccolo/. PMID:21151841

  4. The Chilean health system: 20 years of reforms.

    PubMed

    Manuel, Annick

    2002-01-01

    The Chilean health care system has been intensively reformed in the past 20 years. Reforms under the Pinochet government (1973-1990) aimed mainly at the decentralization of the system and the development of a private sector. Decentralization involved both a deconcentration process and the devolution of primary health care to municipalities. The democratic governments after 1990 chose to preserve the core organization but introduced reforms intended to correct the system's failures and to increase both efficiency and equity. The present article briefly explains the current organization of the Chilean health care system. It also reviews the different reforms introduced in the past 20 years, from the Pinochet regime to the democratic governments. Finally, a brief discussion describes the strengths and weaknesses of the system, as well as the challenges it currently faces.

  5. The time-transgressive termination of the African Humid Period

    NASA Astrophysics Data System (ADS)

    Shanahan, Timothy M.; McKay, Nicholas P.; Hughen, Konrad A.; Overpeck, Jonathan T.; Otto-Bliesner, Bette; Heil, Clifford W.; King, John; Scholz, Christopher A.; Peck, John

    2015-02-01

    During the African Humid Period about 14,800 to 5,500 years ago, changes in incoming solar radiation during Northern Hemisphere summers led to the large-scale expansion and subsequent collapse of the African monsoon. Hydrologic reconstructions from arid North Africa show an abrupt onset and termination of the African Humid Period. These abrupt transitions have been invoked in arguments that the African monsoon responds rapidly to gradual forcing as a result of nonlinear land surface feedbacks. Here we present a reconstruction of precipitation in humid tropical West Africa for the past 20,000 years using the hydrogen isotope composition of leaf waxes preserved in sediments from Lake Bosumtwi, Ghana. We show that over much of tropical and subtropical Africa the monsoon responded synchronously and predictably to glacial reorganizations of overturning circulation in the Atlantic Ocean, but the response to the relatively weaker radiative forcing during the African Humid Period was more spatially and temporally complex. A synthesis of hydrologic reconstructions from across Africa shows that the termination of the African Humid Period was locally abrupt, but occurred progressively later at lower latitudes. We propose that this time-transgressive termination of the African Humid Period reflects declining rainfall intensity induced directly by decreasing summer insolation as well as the gradual southward migration of the tropical rainbelt that occurred during this interval.

  6. Evolution of US DOE Performance Assessments Over 20 Years - 13597

    SciTech Connect

    Suttora, Linda C.; Seitz, Roger R.

    2013-07-01

    Performance assessments (PAs) have been used for many years for the analysis of post-closure hazards associated with a radioactive waste disposal facility and to provide a reasonable expectation of the ability of the site and facility design to meet objectives for the protection of members of the public and the environment. The use of PA to support decision-making for LLW disposal facilities has been mandated in United States Department of Energy (US DOE) directives governing radioactive waste management since 1988 (currently DOE Order 435.1, Radioactive Waste Management). Prior to that time, PAs were also used in a less formal role. Over the past 20+ years, the US DOE approach to conduct, review and apply PAs has evolved into an efficient, rigorous and mature process that includes specific requirements for continuous improvement and independent reviews. The PA process has evolved through refinement of a graded and iterative approach designed to help focus efforts on those aspects of the problem expected to have the greatest influence on the decision being made. Many of the evolutionary changes to the PA process are linked to the refinement of the PA maintenance concept that has proven to be an important element of US DOE PA requirements in the context of supporting decision-making for safe disposal of LLW. The PA maintenance concept is central to the evolution of the graded and iterative philosophy and has helped to drive the evolution of PAs from a deterministic compliance calculation into a systematic approach that helps to focus on critical aspects of the disposal system in a manner designed to provide a more informed basis for decision-making throughout the life of a disposal facility (e.g., monitoring, research and testing, waste acceptance criteria, design improvements, data collection, model refinements). A significant evolution in PA modeling has been associated with improved use of uncertainty and sensitivity analysis techniques to support efficient

  7. Evolution Of USDOE Performance Assessments Over 20 Years

    SciTech Connect

    Seitz, Roger R.; Suttora, Linda C.

    2013-02-26

    Performance assessments (PAs) have been used for many years for the analysis of post-closure hazards associated with a radioactive waste disposal facility and to provide a reasonable expectation of the ability of the site and facility design to meet objectives for the protection of members of the public and the environment. The use of PA to support decision-making for LLW disposal facilities has been mandated in United States Department of Energy (USDOE) directives governing radioactive waste management since 1988 (currently DOE Order 435.1, Radioactive Waste Management). Prior to that time, PAs were also used in a less formal role. Over the past 20+ years, the USDOE approach to conduct, review and apply PAs has evolved into an efficient, rigorous and mature process that includes specific requirements for continuous improvement and independent reviews. The PA process has evolved through refinement of a graded and iterative approach designed to help focus efforts on those aspects of the problem expected to have the greatest influence on the decision being made. Many of the evolutionary changes to the PA process are linked to the refinement of the PA maintenance concept that has proven to be an important element of USDOE PA requirements in the context of supporting decision-making for safe disposal of LLW. The PA maintenance concept represents the evolution of the graded and iterative philosophy and has helped to drive the evolution of PAs from a deterministic compliance calculation into a systematic approach that helps to focus on critical aspects of the disposal system in a manner designed to provide a more informed basis for decision-making throughout the life of a disposal facility (e.g., monitoring, research and testing, waste acceptance criteria, design improvements, data collection, model refinements). A significant evolution in PA modeling has been associated with improved use of uncertainty and sensitivity analysis techniques to support efficient

  8. [False aneurysm on dacron prosthesis, 20 years after aortofemoral bypass].

    PubMed

    Illuminati, G; Bertagni, A; Nasti, A G; Montesano, G

    2001-10-01

    A 85-year-old male developed a false, non septic, non anastomotic aneurysm, 20 years after right aorto-femoral Dacron grafting for claudication. On account of the proximity to the femoral anastomosis, and the association with a profunda femoris stenosis, a conventional surgical repair was preferred to an endovascular treatment. The patient underwent a successful aneurysm resection followed by PTFE interposition between the primary graft and the profunda femoris artery, with uneventful recovery.

  9. LaRC 20-Year Center Revitalization Plan

    NASA Technical Reports Server (NTRS)

    Mangum, Cathy H.; Harris, Charles E.; Allen, Cheryl L.; Craft, Stephen J.; Hope, Drew J.; Kegelman, Jerome T.; Mastaler, Michael D; Weiser, Erik S.

    2012-01-01

    LaRC has developed a 20-Year Center Revitalization Plan. The objective of this plan is to assure that the center infrastructure is sustainable for the long-term and that the center will have the essential facilities and laboratories to execute the future NASA mission. The plan was developed by a centerwide team, VITAL, and was approved by the Center Leadership Council (CLC) in March 2012. The revitalization plan will be implemented through the Center Master Planning process.

  10. [False aneurysm on dacron prosthesis, 20 years after aortofemoral bypass].

    PubMed

    Illuminati, G; Bertagni, A; Nasti, A G; Montesano, G

    2001-10-01

    A 85-year-old male developed a false, non septic, non anastomotic aneurysm, 20 years after right aorto-femoral Dacron grafting for claudication. On account of the proximity to the femoral anastomosis, and the association with a profunda femoris stenosis, a conventional surgical repair was preferred to an endovascular treatment. The patient underwent a successful aneurysm resection followed by PTFE interposition between the primary graft and the profunda femoris artery, with uneventful recovery. PMID:11692765

  11. Periodic, Quasi-periodic and Chaotic Dynamics in Simple Gene Elements with Time Delays

    NASA Astrophysics Data System (ADS)

    Suzuki, Yoko; Lu, Mingyang; Ben-Jacob, Eshel; Onuchic, José N.

    2016-02-01

    Regulatory gene circuit motifs play crucial roles in performing and maintaining vital cellular functions. Frequently, theoretical studies of gene circuits focus on steady-state behaviors and do not include time delays. In this study, the inclusion of time delays is shown to entirely change the time-dependent dynamics for even the simplest possible circuits with one and two gene elements with self and cross regulations. These elements can give rise to rich behaviors including periodic, quasi-periodic, weak chaotic, strong chaotic and intermittent dynamics. We introduce a special power-spectrum-based method to characterize and discriminate these dynamical modes quantitatively. Our simulation results suggest that, while a single negative feedback loop of either one- or two-gene element can only have periodic dynamics, the elements with two positive/negative feedback loops are the minimalist elements to have chaotic dynamics. These elements typically have one negative feedback loop that generates oscillations, and another unit that allows frequent switches among multiple steady states or between oscillatory and non-oscillatory dynamics. Possible dynamical features of several simple one- and two-gene elements are presented in details. Discussion is presented for possible roles of the chaotic behavior in the robustness of cellular functions and diseases, for example, in the context of cancer.

  12. Periodic, Quasi-periodic and Chaotic Dynamics in Simple Gene Elements with Time Delays

    PubMed Central

    Suzuki, Yoko; Lu, Mingyang; Ben-Jacob, Eshel; Onuchic, José N.

    2016-01-01

    Regulatory gene circuit motifs play crucial roles in performing and maintaining vital cellular functions. Frequently, theoretical studies of gene circuits focus on steady-state behaviors and do not include time delays. In this study, the inclusion of time delays is shown to entirely change the time-dependent dynamics for even the simplest possible circuits with one and two gene elements with self and cross regulations. These elements can give rise to rich behaviors including periodic, quasi-periodic, weak chaotic, strong chaotic and intermittent dynamics. We introduce a special power-spectrum-based method to characterize and discriminate these dynamical modes quantitatively. Our simulation results suggest that, while a single negative feedback loop of either one- or two-gene element can only have periodic dynamics, the elements with two positive/negative feedback loops are the minimalist elements to have chaotic dynamics. These elements typically have one negative feedback loop that generates oscillations, and another unit that allows frequent switches among multiple steady states or between oscillatory and non-oscillatory dynamics. Possible dynamical features of several simple one- and two-gene elements are presented in details. Discussion is presented for possible roles of the chaotic behavior in the robustness of cellular functions and diseases, for example, in the context of cancer. PMID:26876008

  13. Periodic, Quasi-periodic and Chaotic Dynamics in Simple Gene Elements with Time Delays.

    PubMed

    Suzuki, Yoko; Lu, Mingyang; Ben-Jacob, Eshel; Onuchic, José N

    2016-02-15

    Regulatory gene circuit motifs play crucial roles in performing and maintaining vital cellular functions. Frequently, theoretical studies of gene circuits focus on steady-state behaviors and do not include time delays. In this study, the inclusion of time delays is shown to entirely change the time-dependent dynamics for even the simplest possible circuits with one and two gene elements with self and cross regulations. These elements can give rise to rich behaviors including periodic, quasi-periodic, weak chaotic, strong chaotic and intermittent dynamics. We introduce a special power-spectrum-based method to characterize and discriminate these dynamical modes quantitatively. Our simulation results suggest that, while a single negative feedback loop of either one- or two-gene element can only have periodic dynamics, the elements with two positive/negative feedback loops are the minimalist elements to have chaotic dynamics. These elements typically have one negative feedback loop that generates oscillations, and another unit that allows frequent switches among multiple steady states or between oscillatory and non-oscillatory dynamics. Possible dynamical features of several simple one- and two-gene elements are presented in details. Discussion is presented for possible roles of the chaotic behavior in the robustness of cellular functions and diseases, for example, in the context of cancer.

  14. Alboran jets, gyres and eddies in a 20-year high resolution simulation

    NASA Astrophysics Data System (ADS)

    Peliz, A.

    2012-04-01

    The circulation of the Alboran Sea has long been described as being in a quasi-steady state composed of the Atlantic Jet meandering on the northern bound of two conspicuous gyres: the Western Alboran Gyre and Eastern Alboran Gyre (WAG and EAG). Changes to this 2 gyre flow system (transitions or transient events) are not very well explored yet. Periodic disappearances of the WAG (collapses or migrations) have been reported, but a single event of WAG migration, observed in fall 1996, is described in detail. These studies suggested that WAG is more likely to disappear in winter after drastic changes in the inflow, and that 2-gyre steady states are essentially observed in summer. The transition periods and the occurrence of smaller eddies are episodically referred in the literature but poorly known. Using a 20 yr 2km resolution Regional Ocean Modeling System simulation of the Gulf of Cadiz-Alboran Sea basins (from the "Inter-basin Exchange in a changing Mediterranean Sea" project MedEX), a classification of the circulation types and mesoscale structures in the Alboran Sea is conducted, characterizing their duration and frequency of occurrence, and temporal evolution. The 2-gyre quasi-steady state (or blocking situation) is confirmed as the most common flow type in the Alboran (occurring during about 42% of the simulation time) and that it is more frequent in summer. However, periods of double gyre flow in winter are also present although the gyre organization is slightly different and this state is described as a 2-gyre winter type. Long stable periods of a single gyre blocking were also identified, and they occupy about 17% of the 20-year period This single gyre usually constitutes a larger version of the WAG somewhat displaced to the east and occurs all year round although it is more common in winter months. The remaining time, the Alboran Sea is in relatively fast evolving flow transitions. The transitions were classified into, WAG migrations (when the WAG clearly

  15. Krylov-subspace acceleration of time periodic waveform relaxation

    SciTech Connect

    Lumsdaine, A.

    1994-12-31

    In this paper the author uses Krylov-subspace techniques to accelerate the convergence of waveform relaxation applied to solving systems of first order time periodic ordinary differential equations. He considers the problem in the frequency domain and presents frequency dependent waveform GMRES (FDWGMRES), a member of a new class of frequency dependent Krylov-subspace techniques. FDWGMRES exhibits many desirable properties, including finite termination independent of the number of timesteps and, for certain problems, a convergence rate which is bounded from above by the convergence rate of GMRES applied to the static matrix problem corresponding to the linear time-invariant ODE.

  16. The impact of lean production on musculoskeletal and psychosocial risks: an examination of sociotechnical trends over 20 years.

    PubMed

    Koukoulaki, Theoni

    2014-03-01

    This paper provides an extensive review of studies carried out in lean production environments in the last 20 years. It aims to identify the effects of lean production (negative or positive) on occupational health and related risk factors. Thirty-six studies of lean effects were accepted from the literature search and sorted by sector and type of outcome. Lean production was found to have a negative effect on health and risk factors; the most negative outcomes being found in the earliest studies in the automotive industry. However, examples of mixed and positive effects were also found in the literature. The strongest correlations of lean production with stress were found for characteristics found in Just-In-Time production that related to reduced cycle time and reduction of resources. Increased musculoskeletal risk symptoms were related to increases of work pace and lack of recovery time also found in Just-In-Time systems. An interaction model is developed to propose a pathway from lean production characteristics to musculoskeletal and psychosocial risk factors and also positive outcomes. An examination is also made of the changing focus of studies investigating the consequences of lean production over a 20-year period. Theories about the effects of lean production have evolved from a conceptualization that it is an inherently harmful management system, to a view that it can have mixed effects depending on the management style of the organization and the specific way it is implemented.

  17. Posttraumatic Intrusion, Avoidance, and Social Functioning: A 20-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Solomon, Zahava; Mikulincer, Mario

    2007-01-01

    The study assesses posttraumatic intrusion, avoidance, and social functioning among 214 Israeli combat veterans from the first Lebanon War with and without combat stress reaction (CSR) 1, 2, 3, and 20 years after the war. CSR veterans reported higher intrusion and avoidance than did non-CSR veterans. With time, there was a decline in these…

  18. Adult Children and Their Fathers: Relationship Changes 20 Years after Parental Divorce.

    ERIC Educational Resources Information Center

    Ahrons, Constance R.; Tanner, Jennifer L.

    2003-01-01

    Examines adult children's reports of relationship changes with their fathers were 20 years after their parents' divorce. Findings indicated that most adult children felt that their relationships with their fathers had either improved or remained stable over time. Custody did not directly affect reported changes in the quality of their relationship…

  19. Elevation-dependent temperature trends in the Rocky Mountain Front Range: changes over a 56- and 20-year record.

    PubMed

    McGuire, Chris R; Nufio, César R; Bowers, M Deane; Guralnick, Robert P

    2012-01-01

    Determining the magnitude of climate change patterns across elevational gradients is essential for an improved understanding of broader climate change patterns and for predicting hydrologic and ecosystem changes. We present temperature trends from five long-term weather stations along a 2077-meter elevational transect in the Rocky Mountain Front Range of Colorado, USA. These trends were measured over two time periods: a full 56-year record (1953-2008) and a shorter 20-year (1989-2008) record representing a period of widely reported accelerating change. The rate of change of biological indicators, season length and accumulated growing-degree days, were also measured over the 56 and 20-year records. Finally, we compared how well interpolated Parameter-elevation Regression on Independent Slopes Model (PRISM) datasets match the quality controlled and weather data from each station. Our results show that warming signals were strongest at mid-elevations over both temporal scales. Over the 56-year record, most sites show warming occurring largely through increases in maximum temperatures, while the 20-year record documents warming associated with increases in maximum temperatures at lower elevations and increases in minimum temperatures at higher elevations. Recent decades have also shown a shift from warming during springtime to warming in July and November. Warming along the gradient has contributed to increases in growing-degree days, although to differing degrees, over both temporal scales. However, the length of the growing season has remained unchanged. Finally, the actual and the PRISM interpolated yearly rates rarely showed strong correlations and suggest different warming and cooling trends at most sites. Interpretation of climate trends and their seasonal biases in the Rocky Mountain Front Range are dependent on both elevation and the temporal scale of analysis. Given mismatches between interpolated data and the directly measured station data, we caution against

  20. Scheduling real-time, periodic jobs using imprecise results

    NASA Technical Reports Server (NTRS)

    Liu, Jane W. S.; Lin, Kwei-Jay; Natarajan, Swaminathan

    1987-01-01

    A process is called a monotone process if the accuracy of its intermediate results is non-decreasing as more time is spent to obtain the result. The result produced by a monotone process upon its normal termination is the desired result; the error in this result is zero. External events such as timeouts or crashes may cause the process to terminate prematurely. If the intermediate result produced by the process upon its premature termination is saved and made available, the application may still find the result unusable and, hence, acceptable; such a result is said to be an imprecise one. The error in an imprecise result is nonzero. The problem of scheduling periodic jobs to meet deadlines on a system that provides the necessary programming language primitives and run-time support for processes to return imprecise results is discussed. This problem differs from the traditional scheduling problems since the scheduler may choose to terminate a task before it is completed, causing it to produce an acceptable but imprecise result. Consequently, the amounts of processor time assigned to tasks in a valid schedule can be less than the amounts of time required to complete the tasks. A meaningful formulation of this problem taking into account the quality of the overall result is discussed. Three algorithms for scheduling jobs for which the effects of errors in results produced in different periods are not cumulative are described, and their relative merits are evaluated.

  1. Hydrographic changes during 20 years in the brine-filled basins of the Red Sea

    NASA Astrophysics Data System (ADS)

    Anschutz, Pierre; Blanc, Gérard; Chatin, Fabienne; Geiller, Magali; Pierret, Marie-Claire

    1999-10-01

    Many of the deep basins filled by hot brines in the Red Sea have not been investigated since their discovery in the early 1970s. Twenty years later, in September 1992, six of these deeps were revisited. The temperature and salinity of the Suakin, Port Sudan, Chain B, and Nereus deeps ranged from 23.25 to 44.60°C and from 144 to 270‰. These values were approximately the same in 1972, indicating that the budget of heat and salt was quite balanced. We measured strong gradients of properties in the transition zone between brines and overlying seawater. The contribution of salinity to the density gradient was more than one order of magnitude higher than the opposite contribution of temperature across the seawater-brine interface. Therefore the interface was extemely stable, and the transfer of properties across it was considered to be controlled mostly by molecular diffusion. We calculate that the diffusional transport of salt from the brines to seawater cannot affect significantly the salinity of the brines over a 20 year period, which agrees with the observations. The brine pools can persist for centuries with no salt input. Therefore, the persisence of brines does not correspond to a steady balance between diffusional loss and continuous input of hydrothermal solutions. Deeps that experience only episodical hydrothermal brine supplies may persist for a long time with salt inherited from past inputs. The theoretical loss of heat by diffusion from the brine to seawater was higher than the observed decrease in temperature of the brine pool during the 20 year period of observation. We calculated that the heat flux out of the pools into the overlying seawater was compensated by a heat flux into the pools of about 250-600 mW/m 2. This range of values corresponds to bottom heat flow values that have been reported earlier for the axial zone of the Red Sea. In contrast to the other brine pools, the temperature and salinity of the Valdivia Deep brine increased by 4.1°C and

  2. CANADARM: 20 Years of Mission Success Through Adaptation

    NASA Technical Reports Server (NTRS)

    Hiltz, Michael; Rice, Craig; Boyle, Keith; Allison, Ronald

    2001-01-01

    As part of the National Aeronautics and Space Administration's Space Shuttle Transportation System, the Shuttle Remote Manipulator System has played a vital role in the success of 60 space missions. This paper concludes that the robustness and success of the Canadarm over its 20 year life can be attributed to the adaptations that have been made to it to meet the increased demands that have been placed on the system. Enhancements that have been made to the arm to improve its operational capabilities, reduce risk and extend its life are examined in this paper. Potential future enhancements based on operational trends are also discussed.

  3. Mimicking Nonequilibrium Steady States with Time-Periodic Driving

    NASA Astrophysics Data System (ADS)

    Raz, O.; Subaşı, Y.; Jarzynski, C.

    2016-04-01

    Under static conditions, a system satisfying detailed balance generically relaxes to an equilibrium state in which there are no currents. To generate persistent currents, either detailed balance must be broken or the system must be driven in a time-dependent manner. A stationary system that violates detailed balance evolves to a nonequilibrium steady state (NESS) characterized by fixed currents. Conversely, a system that satisfies instantaneous detailed balance but is driven by the time-periodic variation of external parameters—also known as a stochastic pump (SP)—reaches a periodic state with nonvanishing currents. In both cases, these currents are maintained at the cost of entropy production. Are these two paradigmatic scenarios effectively equivalent? For discrete-state systems, we establish a mapping between nonequilibrium stationary states and stochastic pumps. Given a NESS characterized by a particular set of stationary probabilities, currents, and entropy production rates, we show how to construct a SP with exactly the same (time-averaged) values. The mapping works in the opposite direction as well. These results establish a proof of principle: They show that stochastic pumps are able to mimic the behavior of nonequilibrium steady states, and vice versa, within the theoretical framework of discrete-state stochastic thermodynamics. Nonequilibrium steady states and stochastic pumps are often used to model, respectively, biomolecular motors driven by chemical reactions and artificial molecular machines steered by the variation of external, macroscopic parameters. Our results loosely suggest that anything a biomolecular machine can do, an artificial molecular machine can do equally well. We illustrate this principle by showing that kinetic proofreading, a NESS mechanism that explains the low error rates in biochemical reactions, can be effectively mimicked by a constrained periodic driving.

  4. (abstract) Short Time Period Variations in Jupiter's Synchrotron Radiation

    NASA Technical Reports Server (NTRS)

    Bolton, S. J.; Klein, M. J.; Gulkis, S.; Foster, R.; Heiles, C.; Pater, I. de

    1994-01-01

    The long term time variability of Jupiter's synchrotron radiation on yearly time scales has been established for some time. For many years, theorists have speculated about the effects variations in the solar wind, solar flux, Io, the Io torus, and Jupiter's magnetic field have on the ultra-relativistic electron population responsible for the emission. Early observational results suggested the additional possibility of a short term time variability, on timescales of days to weeks. In 1989 a program designed to investigate the existence of short term time variability using the 85 foot Hat Creek radio telescope operating at 1400 MHz was initiated. The availability of a dedicated telescope provided the opportunity, for the first time, to obtain numerous observations over the full Jupiter rotation period. These and future observations will enable two important studies, characterization and confirmation of possible short term variations, and the investigation of the stability of Jupiter's synchrotron emission beaming curve. Analysis of Hat Creek observations and early results from the Maryland Point Naval research Laboratory will be presented.

  5. The evolution of complementary and alternative medicine (CAM) in the USA over the last 20 years.

    PubMed

    Jonas, Wayne B; Eisenberg, David; Hufford, David; Crawford, Cindy

    2013-01-01

    Medical practices that reside outside the mainstream medical structures have existed for centuries, often waxing and waning in prominence and use for various reasons. Recently, there has been a resurgence in interest and use of such practices in the USA generally referred to under the label of 'complementary and alternative medicine' (CAM). In this article we summarize some of the highlight events that punctuated this resurgence over the last 20 years. As in the past, social forces affecting these trends circulate around power, resources, and scope of practice. However, a prominent feature of this dynamic is a discussion about the role of science and 'evidence-based medicine' in addressing pluralistic healthcare-related practices. In the early years of this period, attempts to formulate the place of CAM practices as they relate to epistemology, nonconventional assumptions about health and healing, and the complexity of understanding 'whole systems' were discussed and often examined. Less attention is being paid to those core assumptions in more recent times. The focus now seems to be on how CAM practices can be judiciously and effectively 'integrated' into mainstream medicine. Examples of how this dynamic is evolving are described.

  6. 20 years of reprocessed Lyapunov Exponents from altimetry available on AVISO+

    NASA Astrophysics Data System (ADS)

    Pujol, Marie-Isabelle; Faugere, Yannice; D'Ovidio, Francesco; Morrow, Rosemary; Bronner, Emilie; Picot, Nicolas

    2015-04-01

    Altimetry-derived maps of Lyapunov exponents (LEs) provide proxies of (sub-)mesoscale transport fronts. They are being increasingly used in physical, biogeochemical, and ecological applications, ranging from real-time support to field studies to co-localisation of animal tracking with Lagrangian Coherent Structures. Their calculation however is more complex than standard Eulerian diagnostics, because it requires a Lagrangian algorithms which integrates the velocity field. During the past 20 years, in parallel with the altimeter measurement Level2 (a.k.a [O/I]GDR) to Level3 and Level4 (along-track cross-calibrated SLA, and multiple sensor merged maps) processing, different applications and derivated Level4+ products were developed by AVISO+. In order to better serve the users need, and in collaboration with different laboratories (LOCEAN and CTOH), the LEs and vectors are computed over the 21-year altimeter period and over the global ocean within the SSALTO/DUACS project. This product provides the position, and intensity, and orientation of fronts induced by the mesoscale eddies and underlining part of sub-mesoscale activity. We present here the Lyapunov products that will be available on AVISO+ early 2015, and some examples of applications.

  7. Life Course and Intergenerational Continuity of Intimate Partner Aggression and Physical Injury: A 20-Year Study.

    PubMed

    Knight, Kelly E; Menard, Scott; Simmons, Sara B; Bouffard, Leana A; Orsi, Rebecca

    2016-01-01

    The objective of this study is to examine continuity of intimate partner aggression (IPA), which is defined as repeated annual involvement in IPA, across respondents' life course and into the next generation, where it may emerge among adult children. A national, longitudinal, and multigenerational sample of 1,401 individuals and their adult children is analyzed. Annual data on IPA severity and physical injury were collected by the National Youth Survey Family Study across a 20-year period from 1984 to 2004. Three hypotheses and biological sex differences are tested and effect sizes are estimated. First, findings reveal evidence for life course continuity (IPA is a strong predictor of subsequent IPA), but the overall trend decreases over time. Second, intergenerational continuity is documented (parents' IPA predicts adult children's IPA), but the effect is stronger for female than for male adult children. Third, results from combined and separate, more restrictive, measures of victimization and perpetration are nearly identical except in the intergenerational analyses. Fourth, evidence for continuity is not found when assessing physical injury alone. Together, these findings imply that some but not all forms of IPA are common, continuous, and intergenerational. Life course continuity appears stronger than intergenerational continuity. PMID:27076093

  8. Earth observation photography: Looking back 20 years after Skylab

    NASA Technical Reports Server (NTRS)

    Nicholson, James H.

    1992-01-01

    A committee of trained classroom teachers, backed by a volunteer team of technical experts and academic advisors has developed a program for earth science based on photographs obtained from low earth orbit. In selecting targeting objectives, immediate note was made of the fact nearly one generation (20 years) has passed since the United States' ambitious SKYLAB program was conducted. A critical part of those missions was the acquisition of earth photography using a six camera, multi-spectral camera system. This objective was systematically furthered through the term of three separate crew visits to the Space Station. Not merely an exercise in randomly photographing the Earth below, the purpose of the Earth Resource Experiment Package (EREP) was to determine what kind, and how much, photographic data could be acquired of the broad variety of Earth features witnessed on the mission's ground track. The collection of 35,000 photos produced by EREP represents the most complete coverage of Earth. However, it remains under used. GAS 324 intends to revisit, and to add a tier of relevancy to this inventory. The photography of GAS 324 should allow a direct examination and comparison of the changes in the globe in the last 20 years. format in both coverage and quality. The photogra phy acquired by CAN DO should allow a direct examination and comparison of the changes that have occured to the Globe in the last twenty years.

  9. From quiescence to unrest: 20 years of satellite geodetic measurements at Santorini volcano, Greece

    NASA Astrophysics Data System (ADS)

    Parks, Michelle M.; Moore, James D. P.; Papanikolaou, Xanthos; Biggs, Juliet; Mather, Tamsin A.; Pyle, David M.; Raptakis, Costas; Paradissis, Demitris; Hooper, Andrew; Parsons, Barry; Nomikou, Paraskevi

    2015-02-01

    Periods of unrest at caldera-forming volcanic systems characterized by increased rates of seismicity and deformation are well documented. Some can be linked to eventual eruptive activity, while others are followed by a return to quiescence. Here we use a 20 year record of interferometric synthetic aperture radar (InSAR) and GPS measurements from Santorini volcano to further our understanding of geodetic signals at a caldera-forming volcano during the periods of both quiescence and unrest, with measurements spanning a phase of quiescence and slow subsidence (1993-2010), followed by a phase of unrest (January 2011 to April 2012) with caldera-wide inflation and seismicity. Mean InSAR velocity maps from 1993-2010 indicate an average subsidence rate of ~6 mm/yr over the southern half of the intracaldera island Nea Kameni. This subsidence can be accounted for by a combination of thermal contraction of the 1866-1870 lava flows and load-induced relaxation of the substrate. For the period of unrest, we use a joint inversion technique to convert InSAR measurements from three separate satellite tracks and GPS observations from 10 continuous sites into a time series of subsurface volume change. The optimal location of the inflating source is consistent with previous studies, situated north of Nea Kameni at a depth of ~4 km. However, the time series reveals two distinct pressure pulses. The first pulse corresponds to a volume change (ΔV) within the shallow magma chamber of (11.56 ± 0.14) × 106 m3, and the second pulse has a ΔV of (9.73 ± 0.10) × 106 m3. The relationship between the timing of these pulses and microseismicity observations suggests that these pulses may be driven by two separate batches of magma supplied to a shallow reservoir. We find no evidence suggesting a change in source location between the two pulses. The decline in the rates of volume change at the end of both pulses and the observed lag of the deformation signal behind cumulative seismicity

  10. Langevin Dynamics with Space-Time Periodic Nonequilibrium Forcing

    NASA Astrophysics Data System (ADS)

    Joubaud, R.; Pavliotis, G. A.; Stoltz, G.

    2015-01-01

    We present results on the ballistic and diffusive behavior of the Langevin dynamics in a periodic potential that is driven away from equilibrium by a space-time periodic driving force, extending some of the results obtained by Collet and Martinez in (J Math Biol, 56(6):765-792 2008). In the hyperbolic scaling, a nontrivial average velocity can be observed even if the external forcing vanishes in average. More surprisingly, an average velocity in the direction opposite to the forcing may develop at the linear response level—a phenomenon called negative mobility. The diffusive limit of the non-equilibrium Langevin dynamics is also studied using the general methodology of central limit theorems for additive functionals of Markov processes. To apply this methodology, which is based on the study of appropriate Poisson equations, we extend recent results on pointwise estimates of the resolvent of the generator associated with the Langevin dynamics. Our theoretical results are illustrated by numerical simulations of a two-dimensional system.

  11. Global Patterns of Precipitation Anomalies Related to ENSO as Determined by the 20-Year GPCP Analysis

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Curtis, Scott; Huffman, George; Bolvin, Dave; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The new 20-year, monthly, globally complete precipitation analysis of the Global Precipitation Climatology Project (GPCP) is used to analyze ENSO-related precipitation anomalies over the globe. This Version 2 of the community generated data set is global, monthly, at 2.5 deg x 2.5 deg latitude-longitude resolution and utilizes precipitation estimates from low-orbit microwave sensors (SSM/I) and geosynchronous IR sensors and raingauge information over land. In the 1987-present period the low-orbit microwave (SSM/I) estimates are used to adjust or correct the geosynchronous IR estimates, thereby maximizing the utility of the more physically-based microwave estimates and the finer time sampling of the geosynchronous observations. Information from raingauges is blended into the analyses over land. The extension back to 1979 utilizes the OLR Precipitation Index (OPI) for the satellite component. An ENSO Precipitation Index (ESPI) using gradients of precipitation anomalies in the Maritime-Continent/Pacific Ocean region is used to define El Nino/La Nina months during the 20-year record. Mean anomalies for El Nino and La Nina are examined along with variations with respect to season and for individual events. The El Nino and La Nina mean anomalies are near mirror images of each other and when combined produce an ENSO signal with significant spatial continuity over large distances. This El Nino minus La Nina standardized precipitation anomaly map shows the usual positive anomaly over the central and eastern Pacific Ocean with the negative anomaly over the maritime continent along with an additional negative anomaly over Brazil and the Atlantic Ocean extending into Africa and a positive anomaly over the Horn of Africa and the western Indian Ocean. From these features along the Equator narrow positive and negative anomalies extend into middle latitudes in a V-shaped pattern open to the East as described by previous investigators. A number of the features are shown to continue

  12. Desensitization to media violence over a short period of time.

    PubMed

    Fanti, Kostas A; Vanman, Eric; Henrich, Christopher C; Avraamides, Marios N

    2009-01-01

    This study investigated the desensitization to violence over a short period of time. Participants watched nine violent movie scenes and nine comedy scenes, and reported whether they enjoyed the violent or comedy scenes and whether they felt sympathetic toward the victim of violence. Using latent growth modeling, analyses were carried out to investigate how participants responded to the different scenes across time. The findings of this study suggested that repeated exposure to media violence reduces the psychological impact of media violence in the short term, therefore desensitizing viewers to media violence. As a result, viewers tended to feel less sympathetic toward the victims of violence and actually enjoy more the violence portrayed in the media. Additionally, desensitization to media violence was better represented by a curvilinear pattern, whereas desensitization to comedy scenes was better represented by a linear pattern. Finally, trait aggression was not related to the pattern of change over time, although significant effects were found for initial reports of enjoyment and sympathy. PMID:19172659

  13. Endoscopic-assisted epiphysiodesis: technique and 20-year experience.

    PubMed

    Ledesma, Justin B; Wang, Tianyi; Desmond, Elizabeth; Imrie, Meghan; Gamble, James G; Rinsky, Lawrence A

    2016-01-01

    The aim of the study was to describe the endoscopic-assisted epiphysiodesis technique and review our 20-year experience with it. A retrospective review of 44 patients who underwent proximal tibia and/or distal femur endoscopic-assisted epiphysiodesis was carried out. Only patients who had preoperative and postoperative scanograms with clinical follow-up of at least 6 months were included. The mean length of follow-up was 36.8 months. All patients had radiographic evidence of physeal fusion within 6-12 months from the index procedure. No patient required revision surgery. Endoscopic-assisted epiphysiodesis is safe, effective, and achieves predictable physeal fusion. Advantages over current techniques include reduced radiation exposure and lack of requirement for hardware placement.

  14. Leptin, 20 years of searching for glucose homeostasis.

    PubMed

    Fernández-Formoso, Gabriela; Pérez-Sieira, Sonia; González-Touceda, David; Dieguez, Carlos; Tovar, Sulay

    2015-11-01

    Leptin was discovered in 1994 (20 years ago). In addition to having well-characterized effects on the regulation of energy homeostasis, leptin clearly also plays a major role in metabolic homeostasis. In fact, leptin plays an important role in the regulation of glucose homeostasis independent of food intake and body weight. The mechanism underlying the modulation of glucose metabolism by leptin is not completely understood, although evidence indicates that the effect occurs at both the central and peripheral levels. In this review, we will focus on the role of leptin in glucose homeostasis at the central level and its role in insulin secretion and in counteracting hormones, such as glucagon, growth hormone, cortisol and catecholamines.

  15. Residential Transitions among Adults with Intellectual Disability across 20 Years

    PubMed Central

    Woodman, Ashley C.; Mailick, Marsha R.; Anderson, Kristy A.; Esbensen, Anna J.

    2014-01-01

    The present study addresses critical gaps in the literature by examining residential transitions among 303 adults with intellectual disability over 10 years (Part 1) and 75 adults with Down syndrome over 20 years (Part 2). All adults lived at home at the start of the study, but many moved to a variety of settings. Several characteristics of the adults with intellectual disability differed across settings, most notably adaptive behavior and the number of residential transitions, while characteristics such as age, type of disability, and behavior problems were less predictive of residential placements. The number of moves over the course of the study varied widely, with critical links to earlier family dynamics, social relationships, and health and adaptive behavior. PMID:25354121

  16. Carcinoma of the hand: a 20-year experience

    SciTech Connect

    Bean, D.J.; Rees, R.S.; O'Leary, J.P.; Lynch, J.B.

    1984-08-01

    We reviewed our 20-year experience with cutaneous carcinoma of the hand and identified 70 cases (basal cell 23%, squamous cell 77%). The documented risk factors included solar radiation, trauma, and irradiation. Lesions were treated surgically with amputation, excision, skin graft, or flap closure, and nonsurgically with cryosurgery, curettage, 5-fluorouracil, or irradiation. The recurrence was lower with surgical treatment (3%) than with nonsurgical (33%). Regional lymphadenectomy was required in four patients for metastatic squamous cell carcinoma. Recurrence was greater (9%) and metastasis more common (38%) in patients with Marjolin's type of secondary squamous cell carcinoma than with solar-induced lesions. Cause is an important factor in outcome and should be considered in initial treatment and long-term management.

  17. Carcinoma of the hand: a 20-year experience

    SciTech Connect

    Bean, D.J.; Rees, R.S.; O'Leary, J.P.; Lynch, J.B.

    1984-08-01

    The authors reviewed their 20-year experience with cutaneous carcinoma of the hand and identified 70 cases (basal cell 23%, squamous cell 77%). The documented risk factors included solar radiation, trauma, and irradiation. Lesions were treated surgically with amputation, excision, skin graft, or flap closure, and nonsurgically with cryosurgery, curettage, 5-fluorouracil, or irradiation. The recurrence was lower with surgical treatment (3%) than with nonsurgical (33%). Regional lymphadenectomy was required in four patients for metastatic squamous cell carcinoma. Recurrence was greater (9%) and metastasis more common (38%) in patients with Marjolin's type of secondary squamous cell carcinoma than with solar-induced lesions. Cause is an important factor in outcome and should be considered in initial treatment and long-term management.

  18. Swimming and transport of bacteria in time-periodic flows

    NASA Astrophysics Data System (ADS)

    Winter, Rebecca; Patteson, Alison; Gagnon, David; Arratia, Paulo

    The transport of bacteria can be highly influenced by external flows in oceans, rivers, and intestinal tracts. This has implications in biological systems for the performance of major biological processes, such as biofilm formation. In this study, we experimentally investigate the aggregation and transport of swimming Vibrio cholerae bacteria in time-periodic flows. Bacteria are placed in a well-characterized flow, and bacterial concentrations are recorded for a range of Reynolds numbers (Re) that spans two orders of magnitude, from 0.1 to 10. It is generally found that bacteria deplete from regions of high deformation rate and accumulate near vortices. This phenomenon seems to be dictated by a combination of bacterial activity and background flow vorticity. R.W. supported by NSF-GRFP.

  19. Relaxation Characteristics of 828 DGEBA Epoxy Over Long Time Periods

    NASA Astrophysics Data System (ADS)

    Hoo, Jasmine; Reprogle, Riley C.; Wisler, Brian; Arechederra, Gabriel K.; McCoy, John D.; Kropka, Jamie M.; Long, Kevin N.

    The mechanical relaxation response in uniaxial compression of a diglycidyl ether of bisphenol-A epoxy was studied over long time periods. The epoxy, 828DEA, was Epon 828 cured with diethanolamine (DEA). A sample was compressed at constant strain rate and held at various strain levels for days to allow the sample to relax. The sample was then compressed further and held once more. The relaxation curves were fit with a stretched exponential function. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  20. EDITORIAL: Nonlinearity is 20 years old in 2008!

    NASA Astrophysics Data System (ADS)

    Keating, J. P.; Neishtadt, A. I.

    2008-01-01

    During the past 20 years the journal has published many of the subject-defining papers in the field of nonlinear mathematics and its applications. These have ranged from fundamental developments in the theory of dynamical systems and differential equations to applications in atmospheric dynamics, astrophysics, biology, chemistry, fluid dynamics, networks, quantum chaos and statistical physics, to give just a few examples. The field has changed considerably since the journal was founded. In particular, some applications, once considered little more than wishful thinking, have now matured and spun off to form their own journals, or to find homes in journals that might once have thought them too esoteric or too mathematical. In their place have come exciting new applications for which the fundamental mathematical ideas are still to be developed. Nonlinearity has played a leading role in these developments and we look back with pride. But birthdays are also occasions when one should look forward, and with this in mind, as part of our birthday celebrations, we have commissioned for publication in 2008 a series of short articles, entitled Open Problems, from leading researchers in the field. Each article represents the author's personal selection of some interesting and/or important open problems or conjectures. They are not intended to be systematic lists, or encyclopaedic in coverage, but are, rather, individual perspectives on some of the problems and challenges, large and small, that would be worth solving. Our hope is that these articles will contribute to setting the agenda for the next 20 years, and beyond. We took great pleasure in inviting these articles and hope that readers of Nonlinearity will find them interesting, stimulating, and perhaps, in some cases, even provocative. We certainly look forward to seeing, and maybe even publishing, solutions to the problems they describe!

  1. Navy Global Predictions for the Dynamo Time Period

    NASA Astrophysics Data System (ADS)

    Reynolds, C. A.; Ridout, J. A.; Flatau, M. K.; Chen, J.; Richman, J. G.; Jensen, T. G.; Shriver, J. F.

    2014-12-01

    The performance of 30-day simulations of the Navy Global Environmental Model (NAVGEM) is evaluated under several metrics. The time period of interest is the DYNAMO (Dynamics of Madden Julian Oscillation) field experiment period, starting late October 2011. The NAVGEM experiments are run at an effective 37-km resolution with several different SST configurations. The in the first set of experiments, the initial SST analysis, provided by the NCODA (Navy Coupled Ocean Data Assimilation) system, is either held fixed to the initial value (fixed SST) or updated every 6 hours. These forecasts are compared with forecasts in which the SST is updated with 3-h analyses from the Hybrid Coordinate Ocean Model (HYCOM), and forecasts in which NAVGEM is interactively coupled to HYCOM. Experiments are also performed with different physical parameterization options. The extended integrations are verified using observed OLR, TRMM precipitation estimates, and global analyses. The use of fixed SSTs is clearly sub-optimal. Biases in monthly mean fields are far more pronounced in the simulations where the SST is held fixed as compared to those in simulations where updated SST analyses are used. Biases in the monthly mean fields are further reduced when NAVGEM is coupled to HYCOM. Differences in SST can "migrate" to substantial changes in the time-mean land-surface temperatures, illustrating the substantial impact of SSTs over the full domain. Concerning the simulation of the MJO, some improvement is noted when the system is fully coupled, although the simulations still exhibit deficiencies such as eastward propagation that is too slow, and difficulty propagating over the maritime continent. Simulations that are started every 5 days indicate that the NAVGEM uncoupled system has difficulty predicting MJO initiation, but simulations started when the MJO is active in the Indian Ocean are able to capture eastward propagation characteristics. The coupled NAVGEM-HYCOM system shows ability to

  2. 14 CFR 221.190 - Time for filing and computation of time periods.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Time for filing and computation of time periods. 221.190 Section 221.190 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Electronically Filed Tariffs § 221.190...

  3. 14 CFR 221.190 - Time for filing and computation of time periods.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Time for filing and computation of time periods. 221.190 Section 221.190 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS TARIFFS Electronically Filed Tariffs § 221.190...

  4. 12 CFR 116.10 - How does the OCC compute time periods under this part?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... commences the time period. When the last day of a time period is a Saturday, Sunday, or Federal holiday, the time period runs until the end of the next day that is not a Saturday, Sunday, or Federal holiday....

  5. 12 CFR 116.10 - How does the OCC compute time periods under this part?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... commences the time period. When the last day of a time period is a Saturday, Sunday, or Federal holiday, the time period runs until the end of the next day that is not a Saturday, Sunday, or Federal holiday....

  6. Adaptive stabilization of discrete-time systems using linear periodically time varying controllers

    NASA Technical Reports Server (NTRS)

    Ortega, Romeo; Albertos, Pedro; Lozano, Rogelio

    1988-01-01

    A direct adaptive scheme based on the use of linear time-varying periodic controllers is proposed which estimates online the periodic coefficients of the controller. It is shown that adaptive stabilization is attained for all possibly nonstably invertible plants of known order but unknown delay. Although no appeal is made to persistency of excitation arguments, a provision is needed to avoid the singularity of an estimated matrix, this property being required only for the analysis and not the control calculations.

  7. A 20-year simulated climatology of global dust aerosol deposition.

    PubMed

    Zheng, Yu; Zhao, Tianliang; Che, Huizheng; Liu, Yu; Han, Yongxiang; Liu, Chong; Xiong, Jie; Liu, Jianhui; Zhou, Yike

    2016-07-01

    Based on a 20-year (1991-2010) simulation of dust aerosol deposition with the global climate model CAM5.1 (Community Atmosphere Model, version 5.1), the spatial and temporal variations of dust aerosol deposition were analyzed using climate statistical methods. The results indicated that the annual amount of global dust aerosol deposition was approximately 1161±31Mt, with a decreasing trend, and its interannual variation range of 2.70% over 1991-2010. The 20-year average ratio of global dust dry to wet depositions was 1.12, with interannual variation of 2.24%, showing the quantity of dry deposition of dust aerosol was greater than dust wet deposition. High dry deposition was centered over continental deserts and surrounding regions, while wet deposition was a dominant deposition process over the North Atlantic, North Pacific and northern Indian Ocean. Furthermore, both dry and wet deposition presented a zonal distribution. To examine the regional changes of dust aerosol deposition on land and sea areas, we chose the North Atlantic, Eurasia, northern Indian Ocean, North Pacific and Australia to analyze the interannual and seasonal variations of dust deposition and dry-to-wet deposition ratio. The deposition amounts of each region showed interannual fluctuations with the largest variation range at around 26.96% in the northern Indian Ocean area, followed by the North Pacific (16.47%), Australia (9.76%), North Atlantic (9.43%) and Eurasia (6.03%). The northern Indian Ocean also had the greatest amplitude of interannual variation in dry-to-wet deposition ratio, at 22.41%, followed by the North Atlantic (9.69%), Australia (6.82%), North Pacific (6.31%) and Eurasia (4.36%). Dust aerosol presented a seasonal cycle, with typically strong deposition in spring and summer and weak deposition in autumn and winter. The dust deposition over the northern Indian Ocean exhibited the greatest seasonal change range at about 118.00%, while the North Atlantic showed the lowest seasonal

  8. The microbiologic profile of diabetic foot infections in Turkey: a 20-year systematic review: diabetic foot infections in Turkey.

    PubMed

    Hatipoglu, M; Mutluoglu, M; Uzun, G; Karabacak, E; Turhan, V; Lipsky, B A

    2014-06-01

    The causative pathogens in diabetic foot infections differ in studies of European compared with Asian populations. The purpose of this study was to determine the causative microorganisms and their antibiotic sensitivity patterns in diabetic patients with a foot infection in Turkey, a country at the crossroads of these two continents. We performed a comprehensive literature search to identify all published studies pertaining to DFIs in patients cared for in Turkey. To assess changes in causative organisms and their antibiotic sensitivity patterns over time, we compared the results of just the most recent 5 years (2007-2011) with those of the past 20-years (1989-2011). We identified 31 studies meeting our inclusion criteria. Overall, these studies reported 2,097 patients, from whom 1,974 microorganisms were isolated. The total percentage of gram-negative and gram-positive aerobic bacteria were similar in each of the assessed periods. The rate of isolation of Staphylococcus aureus during the entire period, compared with just the past 5 years, was 23.8% and 19.1%, respectively, while the rate of methicillin-resistant S. aureus was 7.8% and 5.7%, respectively. The isolation rate of Pseudomonas aeruginosa was 13.7% for the entire period and 14.9% for the past 5 years. While linezolid, vancomycin and teicoplanin were the most active agents against gram-positive microorganisms, imipenem and cefoperazone-sulbactam were the most active against gram-negative microorganisms. This systematic review demonstrated few substantial changes in diabetic foot microbiology over the past 20 years. The data may help develop and update local clinical guidelines regarding antibiotic therapy for diabetic foot infections in Turkey. Further studies, especially with optimal culture methods, would be useful to validate these findings.

  9. Who Needs a Revision? 20 Years of Cambridge Shunt Lab.

    PubMed

    Czosnyka, Zofia; Czosnyka, Marek; Pickard, John D; Chari, Aswin

    2016-01-01

    Shunt testing independent of manufacturers provides knowledge that can significantly improve the management of patients with hydrocephalus. The Cambridge Shunt Evaluation Laboratory was created 20 years ago. Thanks to financial support from the Department of Health (1993-1998), all shunts in use in the UK were systematically evaluated, with "blue reports" being published. Later new devices were tested as they appeared in public domain.Twenty-six models have been evaluated. The majority of the valves had a non-physiologically low hydrodynamic resistance that may result in over-drainage, both related to posture and during nocturnal cerebral vasogenic waves. A long distal catheter increases the resistance of these valves by 100-200 %. Drainage through valves without a siphon-preventing mechanism is very sensitive to body posture. Shunts with siphon-preventing accessories offer a reasonable resistance to negative outlet pressure. Bench parameters were used to test shunt performance in vivo using infusion tests. A criterion for correctly performing a shunt procedure was established. Pressure measured in the shunt prechamber during the plateau phase of infusion should not remain more than 5 mmHg above the le shunt's operating pressure plus hydrodynamic resistance of the valve multiplied by the infusion rate. "Critical levels" for every shunt and every performance level have been used in the shunt testing wizard of ICM+ software.

  10. 20 years of microplasma research: a status report

    NASA Astrophysics Data System (ADS)

    Schoenbach, Karl H.; Becker, Kurt

    2016-02-01

    The field of microplasmas gained recognition as a well-defined area of research and application within the larger field of plasma science and technology about 20 years ago. Since then, the activity in microplasma research and applications has continuously increased. A survey of peer reviewed papers on microplasmas published annually shows a steady increase from fewer than 20 papers in 1995 to about 75 in 2005 and more than 150 in 2014. This count excludes papers that deal exclusively with technological applications where the microplasma is used solely as a tool. This topical review aims to provide a snap shot of the current state of microplasma research and applications. Given the rapid proliferation of microplasma applications, the topical review will focus primarily on the status of microplasma science and our understanding of the physics principles that enable microplasma operation. Where appropriate, we will also address microplasma applications, however, we will limit the discussion of microplasma applications to examples where the application is closely tied to the plasma science. No attempt is made to provide a comprehensive and in-depth review of the diverse range of all microplasma applications, except for the inclusion of a few key references to recent reviews of microplasma applications.

  11. Infant feeding, growth and mortality: a 20-year study of an Australian Aboriginal community.

    PubMed

    Dugdale, A E

    1980-10-01

    The data are presented on infant mortality, growth and feeding for an Australian Aboriginal Settlement over 20 years from 1953 to 1972. During this period the infant mortality rate fell from about 280/1000 to about 40/1000 although the growth, infant feeding and health facilities remained almost the same. It is proposed, as a hypothesis worthy of further exploration, that major factors leading to improvement in infant mortality have been a changed attitude to small infants and an ability to use health services appropriately. These factors may be important in all developing communities. PMID:7453611

  12. 20 Years of persistent identifiers - Which systems are here to stay?

    NASA Astrophysics Data System (ADS)

    Klump, Jens; Huber, Robert; Lehnert, Kerstin

    2016-04-01

    Web-based persistent identifiers have been around for more than 20 years, a period long enough to start observing patterns of success and failure. Persistent identifiers were invented to address challenges arising from the distributed and disorganised nature of the internet, which not only allowed new technologies to emerge, it also made it difficult to maintain a persistent record of science. Persistent identifiers now allow unambiguous identification of resources on the net. The expectations were that persistent identifiers would lead to greater accessibility, transparency and reproducibility of research results. Over the past two decades a number of persistent identifier systems have been built, one of them being Digital Object Identifiers (DOI). While DOI were originally invented by the publishing industry, they quickly became an established way for the identification of research resources. At first, these resources referred to scholarly literature and related resources. Other identifier systems, some of them using DOI as an example, were developed as grass-roots efforts by the scientific community. The concept of using persistent identifiers has since been expanded to other, non-textual resources, like datasets (DOI, EPIC) and geological specimens (IGSN), and more recently to authors and contributors of scholarly works (ORCID), and to software and instruments. A common witticism states that "a great thing about standards is that there are so many to choose from." Setting up identifier systems is technically trivial. The real challenge lies in creating a governance system for the respective identifiers. Which systems will stand the test of time? Drawing on data from the Registry of Research Data Repositories (re3data.org) and our own experience in the field, this presentation looks at the history and adoption of existing identifier systems and how this gives us some indications towards factors influencing sustainability of these systems.

  13. Accelerated 20-year sunlight exposure simulation of a photochromic foldable intraocular lens in a rabbit model

    PubMed Central

    Werner, Liliana; Abdel-Aziz, Salwa; Peck, Carolee Cutler; Monson, Bryan; Espandar, Ladan; Zaugg, Brian; Stringham, Jack; Wilcox, Chris; Mamalis, Nick

    2011-01-01

    PURPOSE To assess the long-term biocompatibility and photochromic stability of a new photochromic hydrophobic acrylic intraocular lens (IOL) under extended ultraviolet (UV) light exposure. SETTING John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN Experimental study. METHODS A Matrix Aurium photochromic IOL was implanted in right eyes and a Matrix Acrylic IOL without photochromic properties (n = 6) or a single-piece AcrySof Natural SN60AT (N = 5) IOL in left eyes of 11 New Zealand rabbits. The rabbits were exposed to a UV light source of 5 mW/cm2 for 3 hours during every 8-hour period, equivalent to 9 hours a day, and followed for up to 12 months. The photochromic changes were evaluated during slitlamp examination by shining a penlight UV source in the right eye. After the rabbits were humanely killed and the eyes enucleated, study and control IOLs were explanted and evaluated in vitro on UV exposure and studied histopathologically. RESULTS The photochromic IOL was as biocompatible as the control IOLs after 12 months under conditions simulating at least 20 years of UV exposure. In vitro evaluation confirmed the retained optical properties, with photochromic changes observed within 7 seconds of UV exposure. The rabbit eyes had clinical and histopathological changes expected in this model with a 12-month follow-up. CONCLUSIONS The new photochromic IOL turned yellow only on exposure to UV light. The photochromic changes were reversible, reproducible, and stable over time. The IOL was biocompatible with up to 12 months of accelerated UV exposure simulation. PMID:21241924

  14. The Shenandoah Watershed Study: 20 years of Catchment Hydrogeochemistry

    NASA Astrophysics Data System (ADS)

    Galloway, J.

    2002-05-01

    changes and understanding of landscape controls (especially geologic setting) on watershed processes. This poster will present an overview of the critical findings of this 20-year research program.

  15. Convergence Time towards Periodic Orbits in Discrete Dynamical Systems

    PubMed Central

    San Martín, Jesús; Porter, Mason A.

    2014-01-01

    We investigate the convergence towards periodic orbits in discrete dynamical systems. We examine the probability that a randomly chosen point converges to a particular neighborhood of a periodic orbit in a fixed number of iterations, and we use linearized equations to examine the evolution near that neighborhood. The underlying idea is that points of stable periodic orbit are associated with intervals. We state and prove a theorem that details what regions of phase space are mapped into these intervals (once they are known) and how many iterations are required to get there. We also construct algorithms that allow our theoretical results to be implemented successfully in practice. PMID:24736594

  16. Convergence time towards periodic orbits in discrete dynamical systems.

    PubMed

    San Martín, Jesús; Porter, Mason A

    2014-01-01

    We investigate the convergence towards periodic orbits in discrete dynamical systems. We examine the probability that a randomly chosen point converges to a particular neighborhood of a periodic orbit in a fixed number of iterations, and we use linearized equations to examine the evolution near that neighborhood. The underlying idea is that points of stable periodic orbit are associated with intervals. We state and prove a theorem that details what regions of phase space are mapped into these intervals (once they are known) and how many iterations are required to get there. We also construct algorithms that allow our theoretical results to be implemented successfully in practice.

  17. Convergence time towards periodic orbits in discrete dynamical systems.

    PubMed

    San Martín, Jesús; Porter, Mason A

    2014-01-01

    We investigate the convergence towards periodic orbits in discrete dynamical systems. We examine the probability that a randomly chosen point converges to a particular neighborhood of a periodic orbit in a fixed number of iterations, and we use linearized equations to examine the evolution near that neighborhood. The underlying idea is that points of stable periodic orbit are associated with intervals. We state and prove a theorem that details what regions of phase space are mapped into these intervals (once they are known) and how many iterations are required to get there. We also construct algorithms that allow our theoretical results to be implemented successfully in practice. PMID:24736594

  18. NIR Color vs Launch Date: A 20-year Analysis of Space Weathering Effects on the Boeing 376 Spacecraft

    NASA Astrophysics Data System (ADS)

    Frith, J.; Anz-Meador, P.; Lederer, S.; Cowardin, H.; Buckalew, B.

    The Boeing HS-376 spin stabilized spacecraft was a popular design that was launched continuously into geosynchronous orbit starting in 1980 with the last launch occurring in 2002. Over 50 of the HS-376 buses were produced to fulfill a variety of different communication missions for countries all over the world. The design of the bus is easily approximated as a telescoping cylinder that is covered with solar cells and an Earth facing antenna that is despun at the top of the cylinder. The similarity in design and the number of spacecraft launched over a long period of time make the HS-376 a prime target for studying the effects of solar weathering on solar panels as a function of time. A selection of primarily non-operational HS-376 spacecraft launched over a 20 year time period were observed using the United Kingdom Infrared Telescope on Mauna Kea and multi-band near-infrared photometry produced. Each spacecraft was observed for an entire night cycling through ZYJHK filters and time-varying colors produced to compare near-infrared color as a function of launch date. The resulting analysis shown here may help in the future to set launch date constraints on the parent object of unidentified debris objects or other unknown spacecraft.

  19. NIR Color vs Launch Date: A 20-Year Analysis of Space Weathering Effects on the Boeing 376 Spacecraft

    NASA Technical Reports Server (NTRS)

    Frith, James; Anz-Meador, Philip; Lederer, Sue; Cowardin, Heather; Buckalew, Brent

    2015-01-01

    The Boeing HS-376 spin stabilized spacecraft was a popular design that was launched continuously into geosynchronous orbit starting in 1980 with the last launch occurring in 2002. Over 50 of the HS-376 buses were produced to fulfill a variety of different communication missions for countries all over the world. The design of the bus is easily approximated as a telescoping cylinder that is covered with solar cells and an Earth facing antenna that is despun at the top of the cylinder. The similarity in design and the number of spacecraft launched over a long period of time make the HS-376 a prime target for studying the effects of solar weathering on solar panels as a function of time. A selection of primarily non-operational HS-376 spacecraft launched over a 20 year time period were observed using the United Kingdom Infrared Telescope on Mauna Kea and multi-band near-infrared photometry produced. Each spacecraft was observed for an entire night cycling through ZYJHK filters and time-varying colors produced to compare near-infrared color as a function of launch date. The resulting analysis shown here may help in the future to set launch date constraints on the parent object of unidentified debris objects or other unknown spacecraft.

  20. Logic Model Checking of Time-Periodic Real-Time Systems

    NASA Technical Reports Server (NTRS)

    Florian, Mihai; Gamble, Ed; Holzmann, Gerard

    2012-01-01

    In this paper we report on the work we performed to extend the logic model checker SPIN with built-in support for the verification of periodic, real-time embedded software systems, as commonly used in aircraft, automobiles, and spacecraft. We first extended the SPIN verification algorithms to model priority based scheduling policies. Next, we added a library to support the modeling of periodic tasks. This library was used in a recent application of the SPIN model checker to verify the engine control software of an automobile, to study the feasibility of software triggers for unintended acceleration events.

  1. Middle School Injuries: A 20-Year (1988–2008) Multisport Evaluation

    PubMed Central

    Beachy, Glenn; Rauh, Mitchell

    2014-01-01

    Context: Data on the incidence of injury in middle school sports are limited. Objective: To describe overall, practice, and game injury rate patterns in 29 middle school sports. Design: Descriptive epidemiology study. Setting: Injury data collected over a 20-year period (1988–2008) at a single school. Patients or Other Participants: Boy (n = 8078) and girl (n = 5960) athletes participating in 14 and 15 middle school sports, respectively. Main Outcome Measure(s): Injury status and athlete-exposures (AEs) were collected by certified athletic trainers. Incidence rates per 1000 AEs (injuries/AEs) were calculated for overall incidence, practices and games, injury location, injury type, and injury severity (time lost from participation). Rate ratios (RRs) and 95% confidence intervals (CIs) were used to compare injury rates for sex-matched sports. Results: Football had the highest injury rate for all injuries (16.03/1000 AEs) and for time-loss injuries (8.486/1000 AEs). In matched middle school sports, girls exhibited a higher injury rate for all injuries (7.686/1000 AEs, RR = 1.15, 95% CI = 1.1, 1.2) and time-loss injuries (2.944/1000 AEs, RR = 1.09, 95% CI = 1.0, 1.2) than boys (all injuries: 6.684/1000 AEs, time-loss injuries: 2.702/1000 AEs). Girls had a higher injury rate during practices (3.30/1000 AEs) than games (1.67/1000 AEs, RR = 1.97, 95% CI = 1.7, 2.4) for all sports. Only gymnastics (RR = 0.96, 95% CI = 0.3, 3.8) had a higher game injury rate for girls. Practice and game injury rates were nearly identical for boys in all sports (RR = 0.99, 95% CI = 0.9, 1.1). Only football (RR = 0.49, 95% CI = 0.4, 0.6) and boys' wrestling (RR = 0.50, 95% CI = 0.3, 0.8) reported higher game injury rates. Tendinitis injuries accounted for 19.1% of all middle school injuries. Conclusions: The risk for sport-related injury at the middle school level was greater during practices than games and greater for girls than boys in sex-matched sports. Conditioning programs may be

  2. Burning invariant manifolds in time-periodic and time-aperiodic vortex flows

    NASA Astrophysics Data System (ADS)

    Gowen, Savannah; Solomon, Tom

    2014-11-01

    We present experiments that study reaction fronts in a flow composed of a single, translating vortex. The fronts are produced by the excitable Belousov-Zhabotinsky (BZ) chemical reaction, and the vortex flow is driven magnetohydrodynamically by a radial current in a thin fluid layer above a Nd-Fe-Bo magnet. The magnet is mounted on a pair of perpendicular translation stages, allowing for controlled, two-dimensional movement of the magnet and the resulting vortex. We study reaction fronts that pin to the vortex for time-independent flows (produced by moving the vortex with a constant velocity) and for time-periodic and time-aperiodic flows produced by oscillating the vortex laterally. The steady-state front shape is analyzed in terms of burning invariant manifolds (BIMs) that act as one-way barriers against any propagating reaction fronts. For time independent and time-periodic flows, the location of the BIMs are calculated numerically and are compared with experimental images of the pinned reaction fronts. We investigate extensions of this BIM approach for analyzing fronts in time-aperiodic flows. Supported by NSF Grants DMR-1004744, DMR-1361881 and PHY-1156964.

  3. 29 CFR 4000.43 - How do I compute a time period?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false How do I compute a time period? 4000.43 Section 4000.43..., ISSUANCE, COMPUTATION OF TIME, AND RECORD RETENTION Computation of Time § 4000.43 How do I compute a time period? (a) In general. If you are computing a time period to which this part applies, whether you...

  4. 20 years of Black Carbon measurements in Germany

    NASA Astrophysics Data System (ADS)

    Kutzner, Rebecca; Quedenau, Jörn; Kuik, Friderike; von Schneidemesser, Erika; Schmale, Julia

    2016-04-01

    Black Carbon (BC) is an important short-lived climate-forcing pollutant contributing to global warming through absorption of sunlight. At the same time, BC, as a component of particulate matter (PM) exerts adverse health effects, like decreased lung function and exacerbated asthma. Globally, anthropogenic emission sources of BC include residential heating, transport, and agricultural fires, while the dominant natural emission sources are wildfires. Despite the various adverse effects of BC, legislation that requires mandatory monitoring of BC concentrations does not currently exist in the European Union. Instead, BC is only indirectly monitored as component of PM10 and PM2.5 (particulate matter with a diameter smaller 10 μm and 2.5 μm). Before the introduction of mandatory PM10 and PM2.5 monitoring in the European Union in 2005 and 2015, respectively, 'black smoke', a surrogate for BC, was a required measurement in Germany from the early 1990s. The annual mean limit value was 14 μg m-3 from 1995 and 8 μg m-3 from 1998 onwards. Many 'black smoke' measurements were stopped in 2004, with the repeal of the regulations obtaining at the time. However, in most German federal states a limited number BC monitoring stations continued to operate. Here we present a synthesis of BC data from 213 stations across Germany covering the period between 1994 and 2014. Due to the lack of a standardized method and respective legislation, the data set is very heterogeneous relying on twelve different measurement methods including chemical, optical, and thermal-optical methods. Stations include locations classified as background, urban-background, industrial and traffic among other types. Raw data in many different formats has been modelled and integrated in a relational database, allowing various options for further data analysis. We highlight results from the year 2009, as it is the year with the largest measurement coverage based on the same measurement method, with 30 stations. In

  5. Unsettled Times, Unsettled Prices: Periodical Price Survey 1997.

    ERIC Educational Resources Information Center

    Ketcham, Lee; Born, Kathleen

    1997-01-01

    Presents the results of the thirty-seventh annual periodical price survey conducted by "Library Journal". Highlights include canceling print subscriptions and electronic journals, cost trends by subject and by countries, prices for public and school libraries and for college and medium-sized university libraries, and budgeting for 1988. (LRW)

  6. Change in newspaper coverage of schizophrenia in Japan over 20-year period.

    PubMed

    Aoki, Ai; Aoki, Yuta; Goulden, Robert; Kasai, Kiyoto; Thornicroft, Graham; Henderson, Claire

    2016-08-01

    In Japan, schizophrenia was renamed in 2002 to reduce the stigma that people with schizophrenia are dangerous. However there has been little research on the potential anti-stigma effect of renaming. The present study aimed to examine whether portrayals of schizophrenia in newspapers as dangerous have been varied across renaming of the disease. To achieve this goal, newspaper articles containing the previous and new Japanese names for schizophrenia, published in the decades before and after the renaming, were identified through the database of the three largest Japanese national broadsheets. Identified articles were divided into two categories: a negative category, including a subcategory "danger"; and a positive category. Articles containing bipolar disorder were adopted as a control. The ratio of the number of articles on schizophrenia and danger to that of bipolar disorder was analysed as a variable of interest. The trend of this ratio was investigated to examine whether portrayals of schizophrenia changed after renaming. The search identified 4677 articles on schizophrenia, 53.0% of which were categorised as negative and 38.9% as danger. The search identified 525 articles on bipolar disorder, 24.6% of which were categorised as negative and 11.2% as danger. There was an increase of the ratio before schizophrenia was renamed (r=0.54, p=0.104), and a significant decrease after renaming (r=-0.69, p=0.028). Fisher's r-to-z transformation demonstrated a significant change in the trend of the ratio across renaming (Z=2.72, p=0.007). Renaming schizophrenia might be associated with mitigation in potentially stigmatised depiction of schizophrenia associated with violence in newspaper reports.

  7. Enzyme exposure, smoking and lung function in employees in the detergent industry over 20 years. Medical Subcommittee of the UK Soap and Detergent Industry Association.

    PubMed

    Cathcart, M; Nicholson, P; Roberts, D; Bazley, M; Juniper, C; Murray, P; Randell, M

    1997-11-01

    This study was undertaken to examine the long term relationship between lung function, smoking and exposure to enzymes in the detergent industry. A total of 731 male workers from five locations in the United Kingdom were subject to respiratory health surveillance including lung function testing over a period of 4-20 years. Exposure groups were defined by job history. Significantly different rates of fall in FEV1 and FVC with time were found by geographical location and by smoking habit, but there were no consistent trends with enzyme exposure.

  8. Using travel times to simulate multi-dimensional bioreactive transport in time-periodic flows.

    PubMed

    Sanz-Prat, Alicia; Lu, Chuanhe; Finkel, Michael; Cirpka, Olaf A

    2016-04-01

    In travel-time models, the spatially explicit description of reactive transport is replaced by associating reactive-species concentrations with the travel time or groundwater age at all locations. These models have been shown adequate for reactive transport in river-bank filtration under steady-state flow conditions. Dynamic hydrological conditions, however, can lead to fluctuations of infiltration velocities, putting the validity of travel-time models into question. In transient flow, the local travel-time distributions change with time. We show that a modified version of travel-time based reactive transport models is valid if only the magnitude of the velocity fluctuates, whereas its spatial orientation remains constant. We simulate nonlinear, one-dimensional, bioreactive transport involving oxygen, nitrate, dissolved organic carbon, aerobic and denitrifying bacteria, considering periodic fluctuations of velocity. These fluctuations make the bioreactive system pulsate: The aerobic zone decreases at times of low velocity and increases at those of high velocity. For the case of diurnal fluctuations, the biomass concentrations cannot follow the hydrological fluctuations and a transition zone containing both aerobic and obligatory denitrifying bacteria is established, whereas a clear separation of the two types of bacteria prevails in the case of seasonal velocity fluctuations. We map the 1-D results to a heterogeneous, two-dimensional domain by means of the mean groundwater age for steady-state flow in both domains. The mapped results are compared to simulation results of spatially explicit, two-dimensional, advective-dispersive-bioreactive transport subject to the same relative fluctuations of velocity as in the one-dimensional model. The agreement between the mapped 1-D and the explicit 2-D results is excellent. We conclude that travel-time models of nonlinear bioreactive transport are adequate in systems of time-periodic flow if the flow direction does not change.

  9. Using travel times to simulate multi-dimensional bioreactive transport in time-periodic flows

    NASA Astrophysics Data System (ADS)

    Sanz-Prat, Alicia; Lu, Chuanhe; Finkel, Michael; Cirpka, Olaf A.

    2016-04-01

    In travel-time models, the spatially explicit description of reactive transport is replaced by associating reactive-species concentrations with the travel time or groundwater age at all locations. These models have been shown adequate for reactive transport in river-bank filtration under steady-state flow conditions. Dynamic hydrological conditions, however, can lead to fluctuations of infiltration velocities, putting the validity of travel-time models into question. In transient flow, the local travel-time distributions change with time. We show that a modified version of travel-time based reactive transport models is valid if only the magnitude of the velocity fluctuates, whereas its spatial orientation remains constant. We simulate nonlinear, one-dimensional, bioreactive transport involving oxygen, nitrate, dissolved organic carbon, aerobic and denitrifying bacteria, considering periodic fluctuations of velocity. These fluctuations make the bioreactive system pulsate: The aerobic zone decreases at times of low velocity and increases at those of high velocity. For the case of diurnal fluctuations, the biomass concentrations cannot follow the hydrological fluctuations and a transition zone containing both aerobic and obligatory denitrifying bacteria is established, whereas a clear separation of the two types of bacteria prevails in the case of seasonal velocity fluctuations. We map the 1-D results to a heterogeneous, two-dimensional domain by means of the mean groundwater age for steady-state flow in both domains. The mapped results are compared to simulation results of spatially explicit, two-dimensional, advective-dispersive-bioreactive transport subject to the same relative fluctuations of velocity as in the one-dimensional model. The agreement between the mapped 1-D and the explicit 2-D results is excellent. We conclude that travel-time models of nonlinear bioreactive transport are adequate in systems of time-periodic flow if the flow direction does not change.

  10. Existence, Uniqueness and Asymptotic Stability of Time Periodic Traveling Waves for a Periodic Lotka-Volterra Competition System with Diffusion.

    PubMed

    Zhao, Guangyu; Ruan, Shigui

    2011-06-01

    We study the existence, uniqueness, and asymptotic stability of time periodic traveling wave solutions to a periodic diffusive Lotka-Volterra competition system. Under certain conditions, we prove that there exists a maximal wave speed c(*) such that for each wave speed c ≤ c(*), there is a time periodic traveling wave connecting two semi-trivial periodic solutions of the corresponding kinetic system. It is shown that such a traveling wave is unique modulo translation and is monotone with respect to its co-moving frame coordinate. We also show that the traveling wave solutions with wave speed c < c(*) are asymptotically stable in certain sense. In addition, we establish the nonexistence of time periodic traveling waves for nonzero speed c > c(*).

  11. Existence, Uniqueness and Asymptotic Stability of Time Periodic Traveling Waves for a Periodic Lotka-Volterra Competition System with Diffusion.

    PubMed

    Zhao, Guangyu; Ruan, Shigui

    2011-06-01

    We study the existence, uniqueness, and asymptotic stability of time periodic traveling wave solutions to a periodic diffusive Lotka-Volterra competition system. Under certain conditions, we prove that there exists a maximal wave speed c(*) such that for each wave speed c ≤ c(*), there is a time periodic traveling wave connecting two semi-trivial periodic solutions of the corresponding kinetic system. It is shown that such a traveling wave is unique modulo translation and is monotone with respect to its co-moving frame coordinate. We also show that the traveling wave solutions with wave speed c < c(*) are asymptotically stable in certain sense. In addition, we establish the nonexistence of time periodic traveling waves for nonzero speed c > c(*). PMID:21572575

  12. Periodization

    PubMed Central

    Lorenz, Daniel S.; Reiman, Michael P.; Walker, John C.

    2010-01-01

    Background: Clinicians are constantly faced with the challenge of designing training programs for injured and noninjured athletes that maximize healing and optimize performance. Periodization is a concept of systematic progression—that is, resistance training programs that follow predictable patterns of change in training variables. The strength training literature is abundant with studies comparing periodization schemes on uninjured, trained, and untrained athletes. The rehabilitation literature, however, is scarce with information about how to optimally design resistance training programs based on periodization principles for injured athletes. The purpose of this review is to discuss relevant training variables and methods of periodization, as well as periodization program outcomes. A secondary purpose is to provide an anecdotal framework regarding implementation of periodization principles into rehabilitation programs. Evidence Acquisition: A Medline search from 1979 to 2009 was implemented with the keywords periodization, strength training, rehabilitation, endurance, power, hypertrophy, and resistance training with the Boolean term AND in all possible combinations in the English language. Each author also undertook independent hand searching of article references used in this review. Results: Based on the studies researched, periodized strength training regimens demonstrate improved outcomes as compared to nonperiodized programs. Conclusions: Despite the evidence in the strength training literature supporting periodization programs, there is a considerable lack of data in the rehabilitation literature about program design and successful implementation of periodization into rehabilitation programs. PMID:23015982

  13. UNEP: Two Decades of Achievement and Challenge. 20 Years.

    ERIC Educational Resources Information Center

    El-Hinnawi, Essam

    This publication highlights major achievements of the United Nations Environment Program (UNEP) activities over the period 1970 to 1990. Chapter 1, "The Stockholm Conference and the Establishment of UNEP," describes the establishment of UNEP. Chapter 2, "The Role of UNEP," covers program development, environment and development, and UNEP's…

  14. Antimicrobial-Resistant Escherichia coli Survived in Dust Samples for More than 20 Years.

    PubMed

    Schulz, Jochen; Ruddat, Inga; Hartung, Jörg; Hamscher, Gerd; Kemper, Nicole; Ewers, Christa

    2016-01-01

    found that under particular conditions, dust from farm animal houses can be reservoirs for antimicrobial-resistant E. coli for at least 20 years. The survival strategies that allow E. coli to survive such long periods in environmental samples are not fully understood and could be an interesting research topic for future studies.

  15. Antimicrobial-Resistant Escherichia coli Survived in Dust Samples for More than 20 Years.

    PubMed

    Schulz, Jochen; Ruddat, Inga; Hartung, Jörg; Hamscher, Gerd; Kemper, Nicole; Ewers, Christa

    2016-01-01

    found that under particular conditions, dust from farm animal houses can be reservoirs for antimicrobial-resistant E. coli for at least 20 years. The survival strategies that allow E. coli to survive such long periods in environmental samples are not fully understood and could be an interesting research topic for future studies. PMID:27375587

  16. Antimicrobial-Resistant Escherichia coli Survived in Dust Samples for More than 20 Years

    PubMed Central

    Schulz, Jochen; Ruddat, Inga; Hartung, Jörg; Hamscher, Gerd; Kemper, Nicole; Ewers, Christa

    2016-01-01

    that under particular conditions, dust from farm animal houses can be reservoirs for antimicrobial-resistant E. coli for at least 20 years. The survival strategies that allow E. coli to survive such long periods in environmental samples are not fully understood and could be an interesting research topic for future studies. PMID:27375587

  17. Controlling mixing and segregation in time periodic granular flows

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Tathagata

    Segregation is a major problem for many solids processing industries. Differences in particle size or density can lead to flow-induced segregation. In the present work, we employ the discrete element method (DEM)---one type of particle dynamics (PD) technique---to investigate the mixing and segregation of granular material in some prototypical solid handling devices, such as a rotating drum and chute. In DEM, one calculates the trajectories of individual particles based on Newton's laws of motion by employing suitable contact force models and a collision detection algorithm. Recently, it has been suggested that segregation in particle mixers can be thwarted if the particle flow is inverted at a rate above a critical forcing frequency. Further, it has been hypothesized that, for a rotating drum, the effectiveness of this technique can be linked to the probability distribution of the number of times a particle passes through the flowing layer per rotation of the drum. In the first portion of this work, various configurations of solid mixers are numerically and experimentally studied to investigate the conditions for improved mixing in light of these hypotheses. Besides rotating drums, many studies of granular flow have focused on gravity driven chute flows owing to its practical importance in granular transportation and to the fact that the relative simplicity of this type of flow allows for development and testing of new theories. In this part of the work, we observe the deposition behavior of both mono-sized and polydisperse dry granular materials in an inclined chute flow. The effects of different parameters such as chute angle, particle size, falling height and charge amount on the mass fraction distribution of granular materials after deposition are investigated. The simulation results obtained using DEM are compared with the experimental findings and a high degree of agreement is observed. Tuning of the underlying contact force parameters allows the achievement

  18. A Developmental Perspective on Alcohol and Youths 16 to 20 Years of Age

    PubMed Central

    Brown, Sandra A.; McGue, Matthew; Maggs, Jennifer; Schulenberg, John; Hingson, Ralph; Swartzwelder, Scott; Martin, Christopher; Chung, Tammy; Tapert, Susan F.; Sher, Kenneth; Winters, Ken C.; Lowman, Cherry; Murphy, Stacia

    2009-01-01

    Late adolescence (ie, 16-20 years of age) is a period characterized by escalation of drinking and alcohol use problems for many and by the onset of an alcohol use disorder for some. This heightened period of vulnerability is a joint consequence of the continuity of risk from earlier developmental stages and the unique neurologic, cognitive, and social changes that occur in late adolescence. We review the normative neurologic, cognitive, and social changes that typically occur in late adolescence, and we discuss the evidence for the impact of these transitions on individual drinking trajectories. We also describe evidence linking alcohol abuse in late adolescence with neurologic damage and social impairments, and we discuss whether these are the bases for the association of adolescent drinking with increased risks of mental health, substance abuse, and social problems in adulthood. Finally, we discuss both the challenges and successes in the treatment and prevention of adolescent drinking problems. PMID:18381495

  19. Europe Unveils 20-Year Plan for Brilliant Future in Astronomy

    NASA Astrophysics Data System (ADS)

    2008-11-01

    Astronomy is enjoying a golden age of fundamental, exciting discoveries. Europe is at the forefront, thanks to 50 years of progress in cooperation. To remain ahead over the next two to three decades, Europe must prioritise and coordinate the investment of its financial and human resources even more closely. The ASTRONET network, backed by the entire European scientific community, supported by the European Commission, and coordinated by the CNRS, today presents its Roadmap for a brilliant future for European astronomy. ESO's European Extremely Large Telescope is ranked as one of two top-priority large ground-based projects. Astronet and the E-ELT ESO PR Photo 43a/08 The E-ELT Europe is a leader in astronomy today, with the world's most successful optical observatory, ESO's Very Large Telescope, and cutting-edge facilities in radio astronomy and in space. In an unprecedented effort demonstrating the potential of European scientific cooperation, all of European astronomy is now joining forces to define the scientific challenges for the future and construct a common plan to address them in a cost-effective manner. In 2007, a top-level Science Vision was prepared to assess the most burning scientific questions over the next quarter century, ranging from dark energy to life on other planets. European astronomy now presents its Infrastructure Roadmap, a comprehensive 20-year plan to coordinate national and community investments to meet these challenges in a cost-effective manner. The Roadmap not only prioritises the necessary new frontline research facilities from radio telescopes to planetary probes, in space and on the ground, but also considers such key issues as existing facilities, human resources, ICT infrastructure, education and outreach, and cost -- of operations as well as construction. This bold new initiative -- ASTRONET -- was created by the major European funding agencies with support from the European Commission and is coordinated by the National Institute

  20. Europe Unveils 20-Year Plan for Brilliant Future in Astronomy

    NASA Astrophysics Data System (ADS)

    2008-11-01

    Astronomy is enjoying a golden age of fundamental, exciting discoveries. Europe is at the forefront, thanks to 50 years of progress in cooperation. To remain ahead over the next two to three decades, Europe must prioritise and coordinate the investment of its financial and human resources even more closely. The ASTRONET network, backed by the entire European scientific community, supported by the European Commission, and coordinated by the CNRS, today presents its Roadmap for a brilliant future for European astronomy. ESO's European Extremely Large Telescope is ranked as one of two top-priority large ground-based projects. Astronet and the E-ELT ESO PR Photo 43a/08 The E-ELT Europe is a leader in astronomy today, with the world's most successful optical observatory, ESO's Very Large Telescope, and cutting-edge facilities in radio astronomy and in space. In an unprecedented effort demonstrating the potential of European scientific cooperation, all of European astronomy is now joining forces to define the scientific challenges for the future and construct a common plan to address them in a cost-effective manner. In 2007, a top-level Science Vision was prepared to assess the most burning scientific questions over the next quarter century, ranging from dark energy to life on other planets. European astronomy now presents its Infrastructure Roadmap, a comprehensive 20-year plan to coordinate national and community investments to meet these challenges in a cost-effective manner. The Roadmap not only prioritises the necessary new frontline research facilities from radio telescopes to planetary probes, in space and on the ground, but also considers such key issues as existing facilities, human resources, ICT infrastructure, education and outreach, and cost -- of operations as well as construction. This bold new initiative -- ASTRONET -- was created by the major European funding agencies with support from the European Commission and is coordinated by the National Institute

  1. 16 CFR 1502.2 - Computation of time periods.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... officer, or by the Commission, Saturdays, Sundays, and Federal holidays are included in computing time. However, if the last day for taking such action falls on a Saturday, Sunday, or Federal holiday,...

  2. 16 CFR 1502.2 - Computation of time periods.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... officer, or by the Commission, Saturdays, Sundays, and Federal holidays are included in computing time. However, if the last day for taking such action falls on a Saturday, Sunday, or Federal holiday,...

  3. Children's Rights and Youth Justice: 20 Years of No Progress

    ERIC Educational Resources Information Center

    Smith, Roger

    2010-01-01

    The adoption of the United Nations Convention on the Rights of the Child (UNCRC) in 1989 and its ratification by the UK government two years later came at a time of considerable progress in youth justice. The Convention itself set clear standards of treatment, in terms of both processes and disposals, which appeared at the time to provide positive…

  4. Serial extraction: 20 years of follow-up.

    PubMed

    Almeida, Renato Rodrigues de; Almeida, Marcio Rodrigues de; Oltramari-Navarro, Paula Vanessa Pedron; Conti, Ana Cláudia de Castro Ferreira; Navarro, Ricardo de Lima; Souza, Karen Regina Siqueira de

    2012-01-01

    This paper reports a case treated by a serial extraction program at the mixed dentition stage followed by a corrective orthodontic treatment, with a long-term follow-up period. Twenty years after the interceptive treatment, a harmonious face was observed along with treatment stability in the anterior posterior direction, deep overbite (which has been mentioned as a disadvantage of the serial extraction program), and a small relapse of anterior tooth crowding. All these conditions have been regarded as normal occurrences for most orthodontic treatments with a long-term follow-up period. This case report demonstrated that the establishment of a serial extraction protocol determined relevant esthetic changes that afforded an improvement of the patient's self-esteem, with a positive social impact. Furthermore, the low cost of this protocol permits the use of this therapy with underprivileged populations. It is important to emphasize that an early correction of tooth crowding by this protocol does not guarantee stability, but small relapses do not invalidate its accomplishment.

  5. Serial extraction: 20 years of follow-up

    PubMed Central

    de ALMEIDA, Renato Rodrigues; de ALMEIDA, Marcio Rodrigues; OLTRAMARI-NAVARRO, Paula Vanessa Pedron; CONTI, Ana Cláudia de Castro Ferreira; NAVARRO, Ricardo de Lima; de SOUZA, Karen Regina Siqueira

    2012-01-01

    This paper reports a case treated by a serial extraction program at the mixed dentition stage followed by a corrective orthodontic treatment, with a long-term follow-up period. Twenty years after the interceptive treatment, a harmonious face was observed along with treatment stability in the anterior posterior direction, deep overbite (which has been mentioned as a disadvantage of the serial extraction program), and a small relapse of anterior tooth crowding. All these conditions have been regarded as normal occurrences for most orthodontic treatments with a long-term follow-up period. This case report demonstrated that the establishment of a serial extraction protocol determined relevant esthetic changes that afforded an improvement of the patient's self-esteem, with a positive social impact. Furthermore, the low cost of this protocol permits the use of this therapy with underprivileged populations. It is important to emphasize that an early correction of tooth crowding by this protocol does not guarantee stability, but small relapses do not invalidate its accomplishment. PMID:23032213

  6. The nature of species interactions shifts profoundly between time periods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Species interactions change through time, for example ontogenetically, successionally, and evolutionarily. They also change as environmental conditions change, both within years (seasonally) and between years (year effects). The former are relatively well-studied, but the latter have received less a...

  7. Load Balancing Using Time Series Analysis for Soft Real Time Systems with Statistically Periodic Loads

    NASA Technical Reports Server (NTRS)

    Hailperin, Max

    1993-01-01

    This thesis provides design and analysis of techniques for global load balancing on ensemble architectures running soft-real-time object-oriented applications with statistically periodic loads. It focuses on estimating the instantaneous average load over all the processing elements. The major contribution is the use of explicit stochastic process models for both the loading and the averaging itself. These models are exploited via statistical time-series analysis and Bayesian inference to provide improved average load estimates, and thus to facilitate global load balancing. This thesis explains the distributed algorithms used and provides some optimality results. It also describes the algorithms' implementation and gives performance results from simulation. These results show that our techniques allow more accurate estimation of the global system load ing, resulting in fewer object migration than local methods. Our method is shown to provide superior performance, relative not only to static load-balancing schemes but also to many adaptive methods.

  8. Quasi-Periodic Oscillations: Energy Dependent Time-lags

    NASA Astrophysics Data System (ADS)

    Misra, R.; Mandal, S.

    2014-07-01

    We present a a generic model for alternating lags in QPO harmonics where variations in the photon spectrum are caused by oscillations in two parameters that characterize the spectrum. The model assumes that variations in one of the parameters are linearly driven by variations in the other after a time delay. We show that alternating lags will be observed for a range of time delays. We have further developed a phenomenological model based on this generic one that can explain the amplitude and phase lag variation with energy of the fundamental and the next three harmonics of the 67 mHz QPO observed in GRS 1915+105. The phenomenological model also predicts the variation of the Bicoherence phase with energy, which can be checked by further analysis of the observational data.

  9. 20 Years Later: Dynamics of the School-College Partnership

    ERIC Educational Resources Information Center

    Heimann, Revital

    2015-01-01

    This descriptive study examined the dynamics of partnership over time between a training school and a college of education. Its purpose was to provide a deeper understanding of the dynamics of collaboration within the context of the partnership between the school and the college. The dynamics of the changes occurring in this collaboration over a…

  10. Future Economics of Liver Transplantation: A 20-Year Cost Modeling Forecast and the Prospect of Bioengineering Autologous Liver Grafts.

    PubMed

    Habka, Dany; Mann, David; Landes, Ronald; Soto-Gutierrez, Alejandro

    2015-01-01

    During the past 20 years liver transplantation has become the definitive treatment for most severe types of liver failure and hepatocellular carcinoma, in both children and adults. In the U.S., roughly 16,000 individuals are on the liver transplant waiting list. Only 38% of them will receive a transplant due to the organ shortage. This paper explores another option: bioengineering an autologous liver graft. We developed a 20-year model projecting future demand for liver transplants, along with costs based on current technology. We compared these cost projections against projected costs to bioengineer autologous liver grafts. The model was divided into: 1) the epidemiology model forecasting the number of wait-listed patients, operated patients and postoperative patients; and 2) the treatment model forecasting costs (pre-transplant-related costs; transplant (admission)-related costs; and 10-year post-transplant-related costs) during the simulation period. The patient population was categorized using the Model for End-Stage Liver Disease score. The number of patients on the waiting list was projected to increase 23% over 20 years while the weighted average treatment costs in the pre-liver transplantation phase were forecast to increase 83% in Year 20. Projected demand for livers will increase 10% in 10 years and 23% in 20 years. Total costs of liver transplantation are forecast to increase 33% in 10 years and 81% in 20 years. By comparison, the projected cost to bioengineer autologous liver grafts is $9.7M based on current catalog prices for iPS-derived liver cells. The model projects a persistent increase in need and cost of donor livers over the next 20 years that's constrained by a limited supply of donor livers. The number of patients who die while on the waiting list will reflect this ever-growing disparity. Currently, bioengineering autologous liver grafts is cost prohibitive. However, costs will decline rapidly with the introduction of new manufacturing

  11. Environmental accounting as a management tool in the Mediterranean context: the Spanish economy during the last 20 years.

    PubMed

    Lomas, Pedro L; Alvarez, Sergio; Rodríguez, Marta; Montes, Carlos

    2008-07-01

    Although human presence is one of the main characteristics of the Mediterranean identity since ancient times, a false dialectic between conservation and social-economic development has emerged in recent decades. On the one hand, an economic growth policy is taken as the paradigm of social-economic development; on the other hand, there is a multi-scale conservation policy, in which natural protected areas, as patches of preserved nature, are used as one of the main tools to deal with the challenge of sustainability. The Mediterranean Basin is the habitat of many unique species and one of the 25 main biodiversity hotspots in the world, and as a consequence a strong conservation policy has been used to protect environmental values. At the same time, Mediterranean countries are deeply involved in promoting strong economic growth policies, which are not always compatible with environmental ones. In this paper, Spain has been studied as one model of this situation. Due to political reasons, Spanish economic growth and conservationist policies were pursued together during the last 20 years. As a result, Spain owns one of the largest networks of natural protected areas in Western Europe, and at the same time it has experienced one of the strongest periods of economic growths in the European and Mediterranean context during the 1980s and 1990s. An historical series of resource use in five annual periods in the last 20 years of conservation policy, and the effects on the preservation of natural capital have been investigated by means of the eMergy (spelled with an 'm') synthesis approach, which was used to characterize the flow of environmental services supplied by ecosystems, but not in monetary terms. This study shows that Spain is becoming less self-sufficient and more inefficient in resource use, comprehensively measured in eMergy terms. A large part of Spain's economy depends on imported goods and services, and most economic activities are based on tourist services and

  12. Environmental accounting as a management tool in the Mediterranean context: the Spanish economy during the last 20 years.

    PubMed

    Lomas, Pedro L; Alvarez, Sergio; Rodríguez, Marta; Montes, Carlos

    2008-07-01

    Although human presence is one of the main characteristics of the Mediterranean identity since ancient times, a false dialectic between conservation and social-economic development has emerged in recent decades. On the one hand, an economic growth policy is taken as the paradigm of social-economic development; on the other hand, there is a multi-scale conservation policy, in which natural protected areas, as patches of preserved nature, are used as one of the main tools to deal with the challenge of sustainability. The Mediterranean Basin is the habitat of many unique species and one of the 25 main biodiversity hotspots in the world, and as a consequence a strong conservation policy has been used to protect environmental values. At the same time, Mediterranean countries are deeply involved in promoting strong economic growth policies, which are not always compatible with environmental ones. In this paper, Spain has been studied as one model of this situation. Due to political reasons, Spanish economic growth and conservationist policies were pursued together during the last 20 years. As a result, Spain owns one of the largest networks of natural protected areas in Western Europe, and at the same time it has experienced one of the strongest periods of economic growths in the European and Mediterranean context during the 1980s and 1990s. An historical series of resource use in five annual periods in the last 20 years of conservation policy, and the effects on the preservation of natural capital have been investigated by means of the eMergy (spelled with an 'm') synthesis approach, which was used to characterize the flow of environmental services supplied by ecosystems, but not in monetary terms. This study shows that Spain is becoming less self-sufficient and more inefficient in resource use, comprehensively measured in eMergy terms. A large part of Spain's economy depends on imported goods and services, and most economic activities are based on tourist services and

  13. Characteristic features of suicidal drownings: a 20-year study.

    PubMed

    Byard, R W; Houldsworth, G; James, R A; Gilbert, J D

    2001-06-01

    A retrospective study of cases of drowning suicide was undertaken at the Forensic Science Centre in Adelaide, South Australia for the period April 1980 to March 2000. A total of 123 cases were found, with 76 males (age, 16-88 years; average, 50.5 years; standard deviation [SD], 20.1 years) and 47 females (age, 34-88 years; average, 60.6 years; SD, 13.9 years). There were 66 fresh water drownings and 57 saltwater drownings. Female victims were significantly older than male victims for both fresh water and saltwater drownings (P < .05 and P < .01, respectively). Deaths in young women were rare. No temporal trend in drowning suicides could be shown, with annual numbers varying from 0 to 12 cases (average, 6.15; median, 7). Women preferentially chose the ocean or bath to drown themselves in, whereas males chose rivers, ditches, and lakes. Swimming pools were rarely used for suicide in this population; alcohol use was not usual; and there was often a significant history of mental illness.

  14. Maintenance of recovery from schizophrenia at 20-year follow-up: what happened?

    PubMed

    Torgalsbøen, Anne-Kari; Rund, Bjørn Rishovd

    2010-01-01

    The present study reports longitudinal data on individuals who 20-years ago were fully recovered from previously diagnosed schizophrenia. Four subjects from the original sample consented and were interviewed at the present follow-up; data on two more subjects were secured elsewhere. A semistructured interview, the Positive and Negative Symptom Scale (PANSS) and Connor and Davidsons Resilience Scale (CD-RISC) were used to examine the psychosocial functioning and resilience of the subjects in the follow-up period. Out of the six subjects with a confirmed diagnosis of schizophrenia, two subjects were still fully recovered, one was recovered, one was in remission, one had a deteriorating course of illness, and one was deceased. The results indicate that full recovery was maintained for nearly half of the reexamined subjects when a criterion-based definition of full recovery is used. Good personality and attitudinal approaches (resilience) seem to play a role in sustaining recovery. PMID:20235619

  15. Pulmonary gas transfer 20 years after pneumonectomy for pulmonary tuberculosis.

    PubMed Central

    Gimeno, F; Kraan, J K; Orie, N G; Peset, R

    1977-01-01

    The changes in pulmonary function after pneumonectomy in 13 patients with pulmonary tuberculosis have been studied. The data at the time of two follow-up studies are compared with those obtained before the pneumonectomy. The first follow-up was carried out between 5 and 30 months postoperatively and the second between 20 and 24 years later. The results of this second follow-up show a relatively normal arterial oxygen saturation and gas transfer factor but an increased residual volume which cannot be explained by increasing age alone. PMID:841538

  16. 20 Years of Progress in Radiation Oncology: Prostate Cancer.

    PubMed

    Lanciano; Thomas; Eifel

    1997-04-01

    Carcinoma of the cervix remains of special interest to the Patterns of Care Study (PCS) because of the prominent role that radiotherapy plays in the definitive management of all stages and extents of disease. Five PCS surveys have been conducted for squamous cell cancer of the uterine cervix beginning in 1973 and repeated thereafter at 5-year intervals. The records of over 2,700 women have been reviewed for these surveys. Changes in the pretreatment investigations of cervical cancer patients have occurred during these years, with an increase in the use of computed tomography (CT) and a decrease in the use of intravenous pyelography and cystoscopy. A marked increase in the use of linear accelerators has also occurred, with 98% of all facilities having a linear accelerator as the highest energy treatment machine in the 1988 survey. There has been a change in brachytherapy prescription over the time of the surveys, with most institutions reporting point dose calculations and dose distributions instead of milligram hours. Mean point A dose has increased to approximately 80cGy, reflecting the PCS recommendations of dose intensity to the paracentral point through use of brachytherapy. The outcome for stage I and II cervical cancer has remained stable over the time of the surveys, while the results have improved for stage III disease. This improvement in survival and local control for stage III cervical cancer is due in part to the PCS, which has developed standards of treatment with the goal of radiation dose intensity. A number of patient, tumor, and treatment factors significant in multivariate analysis have been described by the PCS with large cohorts of patients. The most important treatment factors associated with a decrease in pelvic failure and improved survival are the use of brachytherapy and higher paracentral dose. A significant dose response has been described for stage III cervical cancer and optimal pelvic control has been demonstrated with point A doses

  17. Themes, Orientations, Synergies and a Shared Agenda: The First 20?Years of the SEDA Series of Books

    ERIC Educational Resources Information Center

    Pickford, Ruth; Brown, Sally

    2013-01-01

    Over 20?years, 25 books have been published to date in the SEDA series, and this review article aims to analyse the ways in which books within the series have contributed to thinking in higher education pedagogy over this time. We have approached the texts through three lenses, analysing them chronologically, thematically and by the orientation of…

  18. Trends in Avoidable Death over 20 Years in Korea

    PubMed Central

    Chung, Ji In; Choi, Ji Sook; Kim, Bo Mi

    2008-01-01

    To evaluate the achievement of health care services in Korea independent of other socioeconomic factors, we observed the time trend of avoidable death between 1983 and 2004. A list of avoidable causes of death was constructed based on the European Community Atlas of "Avoidable Death". We calculated sex- and age-standardized mortality rates of Korean aged 1-64 yr using data of the Korea National Statistical Office. The avoidable mortality rate (per 100,000 persons) decreased from 225 to 84 in men and from 122 to 41 in women. Accordingly, the proportion of avoidable deaths among all classifiable deaths was reduced by 8.1% in men and 6.4% in women. However, mortality rates from some preventable causes such as ischemic heart disease and malignant neoplasms of lung, breast, cervix, and colorectum have been on the rise. Mortality preventable by appropriate medical care showed the greatest reduction (by 77.8%), while the mortality preventable by primary prevention showed the least reduction (by 50.0%). These findings suggest that health care service has significantly contributed to the improvement of health in Korea. However, more effective intervention programs would be needed given the less reduction in mortality avoidable by primary or secondary prevention than expected and unexpectedly increasing mortality from several preventable causes. PMID:19119439

  19. 14 CFR 135.273 - Duty period limitations and rest time requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Duty period limitations and rest time requirements. 135.273 Section 135.273 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.273 Duty period...

  20. 14 CFR 135.273 - Duty period limitations and rest time requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Duty period limitations and rest time requirements. 135.273 Section 135.273 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.273 Duty period...

  1. 14 CFR 135.273 - Duty period limitations and rest time requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Duty period limitations and rest time requirements. 135.273 Section 135.273 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.273 Duty period...

  2. 14 CFR 135.273 - Duty period limitations and rest time requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Duty period limitations and rest time requirements. 135.273 Section 135.273 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.273 Duty period...

  3. 14 CFR 135.273 - Duty period limitations and rest time requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Duty period limitations and rest time requirements. 135.273 Section 135.273 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Crewmember Flight Time and Duty Period Limitations and Rest Requirements § 135.273 Duty period...

  4. Assessment of benthic changes during 20 years of monitoring the Mexican Salina Cruz Bay.

    PubMed

    González-Macías, C; Schifter, I; Lluch-Cota, D B; Méndez-Rodríguez, L; Hernández-Vázquez, S

    2009-02-01

    In this work a non-parametric multivariate analysis was used to assess the impact of metals and organic compounds in the macro infaunal component of the mollusks benthic community using surface sediment data from several monitoring programs collected over 20 years in Salina Cruz Bay, Mexico. The data for benthic mollusks community characteristics (richness, abundance and diversity) were linked to multivariate environmental patterns, using the Alternating Conditional Expectations method to correlate the biological measurements of the mollusk community with the physicochemical properties of water and sediments. Mollusks community variation is related to environmental characteristics as well as lead content. Surface deposit feeders are increasing their relative density, while subsurface deposit feeders are decreasing with respect to time, these last are expected to be more related with sediment and more affected then by its quality. However gastropods with predatory carnivore as well as chemosymbiotic deposit feeder bivalves have maintained their relative densities along time.

  5. [A glaucoma follow-up of 1500 persons over 20 years].

    PubMed

    Fitoussi, Y; Corbe, C; Hamard, H; Perdriel, G

    1988-01-01

    The parameters of glaucoma risk have been compiled and computer processed on 1,571 patients during 20 years at the C.P.E.M.P.N. (Medical Evaluation Center for the Aeronautic Staff) of Paris. The goal of this study is to follow in real time the évolution of these parameters and to determine their physiological variations across time in terms of age and professional categories. An average intra-ocular pressure of 15.1 mmHg as well as hypertonia and glaucoma percentages respectively of 3.88% and 0.6% have been recorded in this study. These results were below the results of other previous surveys due to the greater age range of our study the youngest being 15 years old. There was no significant difference among pilots and non pilots. The optic disc examination was not decisive for diagnostic screening.

  6. The timing behavior of magnetar Swift J1822.3-1606: timing noise or a decreasing period derivative?

    NASA Astrophysics Data System (ADS)

    Tong, Hao; Xu, Ren-Xin

    2013-10-01

    The different timing results of the magnetar Swift J1822.3-1606 are analyzed and understood theoretically. It is noted that different timing solutions are caused not only by timing noise, but also because the period derivative is decreasing after the outburst. Both the decreasing period derivative and the large timing noise may originate from wind braking associated with the magnetar. Future timing of Swift J1822.3-1606 will help clarify whether or not its period derivative is decreasing with time.

  7. Maintaining a High Physical Activity Level Over 20 Years and Weight Gain

    PubMed Central

    Hankinson, Arlene L.; Daviglus, Martha L.; Bouchard, Claude; Carnethon, Mercedes; Lewis, Cora E.; Schreiner, Pamela J.; Liu, Kiang; Sidney, Stephen

    2013-01-01

    Context Data supporting physical activity guidelines to prevent long-term weight gain are sparse, particularly during the period when the highest risk of weight gain occurs. Objective To evaluate the relationship between habitual activity levels and changes in body mass index (BMI) and waist circumference over 20 years. Design, Setting, and Participants The Coronary Artery Risk Development in Young Adults (CARDIA) study is a prospective longitudinal study with 20 years of follow-up, 1985-86 to 2005-06. Habitual activity was defined as maintaining high, moderate, and low activity levels based on sex-specific tertiles of activity scores at baseline. Participants comprised a population-based multi-center cohort (Chicago, Illinois; Birmingham, Alabama; Minneapolis, Minnesota; and Oakland, California) of 3554 men and women aged 18 to 30 years at baseline. Main Outcome Measures Average annual changes in BMI and waist circumference Results Over 20 years, maintaining high levels of activity was associated with smaller gains in BMI and waist circumference compared with low activity levels after adjustment for race, baseline BMI, age, education, cigarette smoking status, alcohol use, and energy intake. Men maintaining high activity gained 2.6 fewer kilograms (+ 0.15 BMI units per year; 95 % confidence interval [CI] 0.11-0.18 vs +0.20 in the lower activity group; 95% CI, 0.17-0.23) and women maintaining higher activity gained 6.1 fewer kilograms (+0.17 BMI units per year; 95 % CI, 0.12-0.21 vs. +0.30 in the lower activity group; 95 % CI, 0.25-0.34). Men maintaining high activity gained 3.1 fewer centimeters in waist circumference (+0.52 cm per year; 95 % CI, 0.43-0.61 cm vs 0.67 cm in the lower activity group; 95 % CI, 0.60-0.75) and women maintaining higher activity gained 3.8 fewer centimeters (+0.49 cm per year; 95 % CI, 0.39-0.58 vs 0.67 cm in the lower activity group; 95 % CI, 0.60-0.75). Conclusion Maintaining high activity levels through young adulthood may lessen

  8. Cytochrome P4501A biomarker indication of oil exposure in harlequin ducks up to 20 years after the Exxon Valdez oil spill.

    PubMed

    Esler, Daniel; Trust, Kimberly A; Ballachey, Brenda E; Iverson, Samuel A; Lewis, Tyler L; Rizzolo, Daniel J; Mulcahy, Daniel M; Miles, A Keith; Woodin, Bruce R; Stegeman, John J; Henderson, John D; Wilson, Barry W

    2010-05-01

    Hydrocarbon-inducible cytochrome P4501A (CYP1A) expression was measured, as ethoxyresorufin-O-deethylase (EROD) activity, in livers of wintering harlequin ducks (Histrionicus histrionicus) captured in areas of Prince William Sound, Alaska, USA, oiled by the 1989 Exxon Valdez spill and in birds from nearby unoiled areas, during 2005 to 2009 (up to 20 years following the spill). The present work repeated studies conducted in 1998 that demonstrated that in harlequin ducks using areas that received Exxon Valdez oil, EROD activity was elevated nearly a decade after the spill. The present findings strongly supported the conclusion that average levels of hepatic EROD activity were higher in ducks from oiled areas than those from unoiled areas during 2005 to 2009. This result was consistent across four sampling periods; furthermore, results generated from two independent laboratories using paired liver samples from one of the sampling periods were similar. The EROD activity did not vary in relation to age, sex, or body mass of individuals, nor did it vary strongly by season in birds collected early and late in the winter of 2006 to 2007, indicating that these factors did not confound inferences about observed differences between oiled and unoiled areas. We interpret these results to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 20 years after the original spill. This adds to a growing body of literature suggesting that oil spills have the potential to affect wildlife for much longer time frames than previously assumed.

  9. Cytochrome P4501A biomarker indication of oil exposure in harlequin ducks up to 20 years after the Exxon Valdez oil spill.

    PubMed

    Esler, Daniel; Trust, Kimberly A; Ballachey, Brenda E; Iverson, Samuel A; Lewis, Tyler L; Rizzolo, Daniel J; Mulcahy, Daniel M; Miles, A Keith; Woodin, Bruce R; Stegeman, John J; Henderson, John D; Wilson, Barry W

    2010-05-01

    Hydrocarbon-inducible cytochrome P4501A (CYP1A) expression was measured, as ethoxyresorufin-O-deethylase (EROD) activity, in livers of wintering harlequin ducks (Histrionicus histrionicus) captured in areas of Prince William Sound, Alaska, USA, oiled by the 1989 Exxon Valdez spill and in birds from nearby unoiled areas, during 2005 to 2009 (up to 20 years following the spill). The present work repeated studies conducted in 1998 that demonstrated that in harlequin ducks using areas that received Exxon Valdez oil, EROD activity was elevated nearly a decade after the spill. The present findings strongly supported the conclusion that average levels of hepatic EROD activity were higher in ducks from oiled areas than those from unoiled areas during 2005 to 2009. This result was consistent across four sampling periods; furthermore, results generated from two independent laboratories using paired liver samples from one of the sampling periods were similar. The EROD activity did not vary in relation to age, sex, or body mass of individuals, nor did it vary strongly by season in birds collected early and late in the winter of 2006 to 2007, indicating that these factors did not confound inferences about observed differences between oiled and unoiled areas. We interpret these results to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 20 years after the original spill. This adds to a growing body of literature suggesting that oil spills have the potential to affect wildlife for much longer time frames than previously assumed. PMID:20821550

  10. 45 CFR 402.26 - Time period for obligation and expenditure of grant funds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CFR 92.23(b). This time limit will not be extended. The time limit established by 45 CFR 92.23(b) does... STATE LEGALIZATION IMPACT ASSISTANCE GRANTS Administration of Grants § 402.26 Time period for...

  11. Clinical Features of Male Breast Cancer: Experiences from Seven Institutions Over 20 Years

    PubMed Central

    Hong, Ji Hyung; Ha, Kyung Sun; Jung, Yun Hwa; Won, Hye Sung; An, Ho Jung; Lee, Guk Jin; Kang, Donghoon; Park, Ji Chan; Park, Sarah; Byun, Jae Ho; Suh, Young Jin; Kim, Jeong Soo; Park, Woo Chan; Jung, Sang Seol; Park, Il Young; Chung, Su-Mi; Woo, In Sook

    2016-01-01

    Purpose Breast cancer treatment has progressed significantly over the past 20 years. However, knowledge regarding male breast cancer (MBC) is sparse because of its rarity. This study is an investigation of the clinicopathologic features, treatments, and clinical outcomes of MBC. Materials and Methods Clinical records of 59 MBC patients diagnosed during 1995-2014 from seven institutions in Korea were reviewed retrospectively. Results Over a 20-year period, MBC patients accounted for 0.98% among total breast cancer patients, and increased every 5 years. The median age of MBC patientswas 66 years (range, 24 to 87 years). Forty-three patients (73%) complained of a palpable breast mass initially. The median symptom duration was 5 months (range, 1 to 36 months). Mastectomy was performed in 96% of the patients. The most frequent histology was infiltrating ductal carcinoma (75%). Ninety-one percent of tumors (38/43) were estrogen receptor–positive, and 28% (11/40) showed epidermal growth factor receptor 2 (HER-2) overexpression. After curative surgery, 42% of patients (19/45) received adjuvant chemotherapy; 77% (27/35) received hormone therapy. Five out of ten patients with HER-2 overexpressing tumors did not receive adjuvant anti–HER-2 therapy, while two out of four patients with HER-2 overexpressing tumors received palliative trastuzumab for recurrent and metastatic disease. Letrozole was used for one patient in the palliative setting. The median overall survival durations were 7.2 years (range, 0.6 to 17.0 years) in patients with localized disease and 2.9 years (range, 0.6 to 4.3 years) in those with recurrent or metastatic disease. Conclusion Anti–HER-2 and hormonal therapy, except tamoxifen, have been underutilized in Korean MBC patients compared to female breast cancer patients. With the development of precision medicine, active treatment with targeted agents should be applied. Further investigation of the unique pathobiology of MBC is clinically warranted

  12. 20 CFR 404.996 - Increase in future benefits where time period for reopening expires.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Increase in future benefits where time period for reopening expires. 404.996 Section 404.996 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... § 404.996 Increase in future benefits where time period for reopening expires. If, after the time...

  13. Shifts in microbial biomass indicators track changes in carbon and nitrogen cycles during tree plantation development to 20 years

    NASA Astrophysics Data System (ADS)

    Munson, A. D.; Maillard, E.; Paré, D.

    2010-12-01

    In the context increasing atmospheric CO2 concentration, there is a growing interest for using afforestation and reforestation to claim emissions reductions. Establishment of plantations necessarily involves silvicultural treatments that affect environmental conditions and hence soil microbial communities, influencing carbon and nitrogen cycles and potential soil carbon sequestration. We have monitored soil microbial indicators during a twenty year period of ecosystem recovery from disturbance at the Petawawa Research Forest (Ontario, Canada), in plantations of white pine (Pinus strobus L.) and white spruce (Picea glauca). The first ten years was marked by important changes in Cmic:Corg and Cmic:Nmic, related to vegetation control that provoked modification of bacteria:fungi ratios, accelerated N cycling and loss, as well as shifts in vegetation composition that are still quite marked after twenty years. After another 10 years (at 20 yrs) we note a closing of the N cycle and again important shifts in microbial indicators. In the humus, biomass C has recovered over time, but the Cmic:Nmic is decreasing constantly from 4 to 20 years, with increases in the Nmic pool; in the surface mineral soil, this increase in the Nmic pool is even more striking. Plots treated to control vegetation are dominated by conifers versus deciduous vegetation after twenty years, provoking a higher Cmic:Nmic in the humus layer. We attempt to interpret differences in the labile carbon fraction in the humus and mineral soil at twenty years in light of these observed dynamics.

  14. Unintended compositional changes in genetically modified (GM) crops: 20 years of research.

    PubMed

    Herman, Rod A; Price, William D

    2013-12-01

    The compositional equivalency between genetically modified (GM) crops and nontransgenic comparators has been a fundamental component of human health safety assessment for 20 years. During this time, a large amount of information has been amassed on the compositional changes that accompany both the transgenesis process and traditional breeding methods; additionally, the genetic mechanisms behind these changes have been elucidated. After two decades, scientists are encouraged to objectively assess this body of literature and determine if sufficient scientific uncertainty still exists to continue the general requirement for these studies to support the safety assessment of transgenic crops. It is concluded that suspect unintended compositional effects that could be caused by genetic modification have not materialized on the basis of this substantial literature. Hence, compositional equivalence studies uniquely required for GM crops may no longer be justified on the basis of scientific uncertainty.

  15. Echoes of Bedford: a 20-year social psychology memoir on participatory action research hatched behind bars.

    PubMed

    Fine, Michelle

    2013-11-01

    Responding to Martin Luther King Jr.'s 1968 address at the American Psychological Association calling for a psychology that would educate Whites about racial injustice, this article challenges the widening epistemological gap between those who suffer from inequality and those who conduct social policy research on inequality. In this 20-year memoir on the echoes of a single piece of participatory policy research, Changing Minds: The Impact of College in a Maximum-Security Prison (Fine et al., 2001), readers are invited to explore how deep critical participation by a collaborative team of university and prisoner researchers has facilitated theoretical and methodological complexity, enhanced contextual and construct validity, thickened commitments to ethics and action, and fueled the political sustainability and generalizability of the findings over time and space.

  16. Echoes of Bedford: a 20-year social psychology memoir on participatory action research hatched behind bars.

    PubMed

    Fine, Michelle

    2013-11-01

    Responding to Martin Luther King Jr.'s 1968 address at the American Psychological Association calling for a psychology that would educate Whites about racial injustice, this article challenges the widening epistemological gap between those who suffer from inequality and those who conduct social policy research on inequality. In this 20-year memoir on the echoes of a single piece of participatory policy research, Changing Minds: The Impact of College in a Maximum-Security Prison (Fine et al., 2001), readers are invited to explore how deep critical participation by a collaborative team of university and prisoner researchers has facilitated theoretical and methodological complexity, enhanced contextual and construct validity, thickened commitments to ethics and action, and fueled the political sustainability and generalizability of the findings over time and space. PMID:24320653

  17. Zollinger-Ellison syndrome. Spontaneous regression of advanced intra-abdominal metastases with 20 year survival.

    PubMed Central

    Davis, C E; Vansant, J H

    1979-01-01

    A 35-year-old man with the Zollinger-Ellison syndrome who is alive and well 20 years following diagnosis at age 15, is represented. At the initial operation for a bleeding duodenal ulcer a ZE tumor of the pancreas also was excised. After two additional ineffective ulcer operations, total gastrectomy was performed. At that time, retroperitoneal and peripancreatic metastases were noted, and several were removed. Three years later at laparotomy, extensive hepatic metastases were biopsied as well. Spontaneous remission occurred and when re-explored at age 34, after 14 years, no metastases were identifiable in any area. The serum gastrin level has remained elevated, casting doubt upon its value as a criterion for evaluation of tumor recurrence or activity. Other additional interesting aspects are discussed. The importance of elimination of the acid-secreting cells by total gastrectomy is emphasized. The patient remains well. Images Fig. 1. Fig. 3. Fig. 4. PMID:443914

  18. 20 Years Experience with using Low Cost Launch Opportunities for 20 Small Satellite Missions

    NASA Astrophysics Data System (ADS)

    Meerman, Maarten; Sweeting, Martin, , Sir

    these larger 'small satellites' are too big to be carried 'piggy-back'. The entrepreneurial efforts of leading FSU rocket &missile organisations in converting existing vehicles to meet the small satellite launch market at an appropriate cost has resulted in the FSU now holding the prime position for providing launches for the small satellite community - and with an excellent track record of successful launches. However, negotiating and completing a Launch Services Agreement (LSA) for a nano-micro-minisatellite with any launcher organisation is a complex matter and risky territory for the unwary or inexperienced who may easily fall prey to unexpected additional costs and delays. Whilst this warning should be heeded when dealing with European and US organisations, it is particularly relevant when negotiating launches from the FSU where there is a plethora of agencies and organisations offering a bewildering range of launch vehicles and options. Furthermore, the FSU has developed a very different technical and managerial philosophy towards launchers when compared with the west and this can be unnerving to 'first-time buyers'. Organisations experienced in dealing in the FSU will encounter a different but excellent service - once the launch service agreement has been thoroughly and fiercely negotiated in every detail. The inexperienced, however, have encountered frustrating delays, lost opportunities, unexpected taxes and costs for additional services or facilities not originally specified, and bewilderment at the different procedures used in the FSU. Fortunately, all this can be avoided with proper experience and the FSU is the current mainstay for launching small satellites quickly, affordably and reliably. Surrey has unique experience gathered over 20 years in handling launches for 20 small satellites, ranging from a 6kg nanosatellite, 50-100kg microsatellites, and a 325kg minisatellite, using 7 different launchers from the USA, Russia, Ukraine, and Europe. By working

  19. Climate correlates of 20 years of trophic changes in a high-elevation riparian system

    USGS Publications Warehouse

    Martin, T.E.

    2007-01-01

    The consequences of climate change for ecosystem structure and function remain largely unknown. Here, I examine the ability of climate variation to explain long-term changes in bird and plant populations, as well as trophic interactions in a high-elevation riparian system in central Arizona, USA, based on 20 years of study. Abundances of dominant deciduous trees have declined dramatically over the 20 years, correlated with a decline in overwinter snowfall. Snowfall can affect overwinter presence of elk, whose browsing can significantly impact deciduous tree abundance. Thus, climate may affect the plant community indirectly through effects on herbivores, but may also act directly by influencing water availability for plants. Seven species of birds were found to initiate earlier breeding associated with an increase in spring temperature across years. The advance in breeding time did not affect starvation of young or clutch size. Earlier breeding also did not increase the length of the breeding season for single-brooded species, but did for multi-brooded species. Yet, none of these phenology-related changes was associated with bird population trends. Climate had much larger consequences for these seven bird species by affecting trophic levels below (plants) and above (predators) the birds. In particular, the climate-related declines in deciduous vegetation led to decreased abundance of preferred bird habitat and increased nest predation rates. In addition, summer precipitation declined over time, and drier summers also were further associated with greater nest predation in all species. The net result was local extinction and severe population declines in some previously common bird species, whereas one species increased strongly in abundance, and two species did not show clear population changes. These data indicate that climate can alter ecosystem structure and function through complex pathways that include direct and indirect effects on abundances and interactions

  20. Climate correlates of 20 years of trophic changes in a high-elevation riparian system.

    PubMed

    Martin, Thomas E

    2007-02-01

    The consequences of climate change for ecosystem structure and function remain largely unknown. Here, I examine the ability of climate variation to explain long-term changes in bird and plant populations, as well as trophic interactions in a high-elevation riparian system in central Arizona, USA, based on 20 years of study. Abundances of dominant deciduous trees have declined dramatically over the 20 years, correlated with a decline in overwinter snowfall. Snowfall can affect overwinter presence of elk, whose browsing can significantly impact deciduous tree abundance. Thus, climate may affect the plant community indirectly through effects on herbivores, but may also act directly by influencing water availability for plants. Seven species of birds were found to initiate earlier breeding associated with an increase in spring temperature across years. The advance in breeding time did not affect starvation of young or clutch size. Earlier breeding also did not increase the length of the breeding season for single-brooded species, but did for multi-brooded species. Yet, none of these phenology-related changes was associated with bird population trends. Climate had much larger consequences for these seven bird species by affecting trophic levels below (plants) and above (predators) the birds. In particular, the climate-related declines in deciduous vegetation led to decreased abundance of preferred bird habitat and increased nest predation rates. In addition, summer precipitation declined over time, and drier summers also were further associated with greater nest predation in all species. The net result was local extinction and severe population declines in some previously common bird species, whereas one species increased strongly in abundance, and two species did not show clear population changes. These data indicate that climate can alter ecosystem structure and function through complex pathways that include direct and indirect effects on abundances and interactions

  1. 20-Years of Population-Based Cancer Registration in Hepatitis B and Liver Cancer Prevention in The Gambia, West Africa

    PubMed Central

    Bah, Ebrima; Carrieri, Maria Patrizia; Hainaut, Pierre; Bah, Yusupha; Nyan, Ousman; Taal, Makie

    2013-01-01

    Background The Gambia Hepatitis Intervention Study (GHIS) was designed as a randomised control trial of infant hepatitis B vaccination applied to public health policy, with the main goal of preventing primary liver cancer later in adult life in The Gambia. To that effect, the National Cancer Registry of The Gambia (NCR), a population-based cancer registry (PBCR), was established in 1986 to actively collect data on all cancer diagnosis nation-wide. We extracted 20-years (1990-2009) of data to assess for the first time, the evolution of the most common cancers, also describe and demonstrate the role of the PBCR in a hepatitis B and liver cancer prevention programme in this population. Methods and Findings We estimated Age-Standardised Incidence Rates (ASR (W)) of the most common cancers registered during the period by gender. The registration period was divided into four 5-year intervals and incidence rates were estimated for each interval. The most common cancers in males were liver, prostate, lung plus bronchus, non-Hodgkin lymphoma (NHL) and stomach, accounting for 60%, 5%, 4%, 5% and 3%, respectively. Similarly, cancers of the cervix uteri, liver, breast and NHL, were the most common in females, accounting for 33%, 24%, 11% and 4% of the female cancers, respectively. Conclusions Cancer incidence has remained relatively stable over time, but as shown elsewhere in sub-Saharan Africa the disease is a threat in The Gambia. The infection related cancers which are mostly preventable (HBV in men and HPV/HIV in women) were the most common. At the moment the data is not enough to detect an effect of hepatitis B vaccination on liver cancer incidence in The Gambia. However, we observed that monitoring case occurrence through PBCR is a key public health pre-requisite for rational planning and implementation of targeted interventions for improving the health of the population. PMID:24098724

  2. Structure and dating errors in the geologic time scale and periodicity in mass extinctions

    NASA Technical Reports Server (NTRS)

    Stothers, Richard B.

    1989-01-01

    Structure in the geologic time scale reflects a partly paleontological origin. As a result, ages of Cenozoic and Mesozoic stage boundaries exhibit a weak 28-Myr periodicity that is similar to the strong 26-Myr periodicity detected in mass extinctions of marine life by Raup and Sepkoski. Radiometric dating errors in the geologic time scale, to which the mass extinctions are stratigraphically tied, do not necessarily lessen the likelihood of a significant periodicity in mass extinctions, but do spread the acceptable values of the period over the range 25-27 Myr for the Harland et al. time scale or 25-30 Myr for the DNAG time scale. If the Odin time scale is adopted, acceptable periods fall between 24 and 33 Myr, but are not robust against dating errors. Some indirect evidence from independently-dated flood-basalt volcanic horizons tends to favor the Odin time scale.

  3. Detection and Clinical Significance of Circulating Tumor Cells in Colorectal Cancer—20 Years of Progress

    PubMed Central

    Hardingham, Jennifer E; Grover, Phulwinder; Winter, Marnie; Hewett, Peter J; Price, Timothy J; Thierry, Benjamin

    2015-01-01

    Circulating tumor cells (CTC) may be defined as tumor- or metastasis-derived cells that are present in the bloodstream. The CTC pool in colorectal cancer (CRC) patients may include not only epithelial tumor cells, but also tumor cells undergoing epithelial–mesenchymal transition (EMT) and tumor stem cells. A significant number of patients diagnosed with early stage CRC subsequently relapse with recurrent or metastatic disease despite undergoing “curative” resection of their primary tumor. This suggests that an occult metastatic disease process was already underway, with viable tumor cells being shed from the primary tumor site, at least some of which have proliferative and metastatic potential and the ability to survive in the bloodstream. Such tumor cells are considered to be responsible for disease relapse in these patients. Their detection in peripheral blood at the time of diagnosis or after resection of the primary tumor may identify those early-stage patients who are at risk of developing recurrent or metastatic disease and who would benefit from adjuvant therapy. CTC may also be a useful adjunct to radiological assessment of tumor response to therapy. Over the last 20 years many approaches have been developed for the isolation and characterization of CTC. However, none of these methods can be considered the gold standard for detection of the entire pool of CTC. Recently our group has developed novel unbiased inertial microfluidics to enrich for CTC, followed by identification of CTC by imaging flow cytometry. Here, we provide a review of progress on CTC detection and clinical significance over the last 20 years. PMID:26605644

  4. Dynamics of phase slips in systems with time-periodic modulation

    NASA Astrophysics Data System (ADS)

    Gandhi, Punit; Knobloch, Edgar; Beaume, Cédric

    2015-12-01

    The Adler equation with time-periodic frequency modulation is studied. A series of resonances between the period of the frequency modulation and the time scale for the generation of a phase slip is identified. The resulting parameter space structure is determined using a combination of numerical continuation, time simulations, and asymptotic methods. Regions with an integer number of phase slips per period are separated by regions with noninteger numbers of phase slips and include canard trajectories that drift along unstable equilibria. Both high- and low-frequency modulation is considered. An adiabatic description of the low-frequency modulation regime is found to be accurate over a large range of modulation periods.

  5. 5 CFR 550.404 - Computation of advance payments and evacuation payments; time periods.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... evacuation payments; time periods. 550.404 Section 550.404 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Payments During Evacuation § 550.404 Computation of advance payments and evacuation payments; time periods. (a) Payments shall be based on the...

  6. 5 CFR 550.404 - Computation of advance payments and evacuation payments; time periods.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... evacuation payments; time periods. 550.404 Section 550.404 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Payments During Evacuation § 550.404 Computation of advance payments and evacuation payments; time periods. (a) Payments shall be based on the...

  7. 47 CFR 54.724 - Time periods for Commission approval of Administrator decisions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 3 2014-10-01 2014-10-01 false Time periods for Commission approval of Administrator decisions. 54.724 Section 54.724 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Review of Decisions Issued by the Administrator § 54.724 Time periods for...

  8. 47 CFR 54.724 - Time periods for Commission approval of Administrator decisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Time periods for Commission approval of...) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Review of Decisions Issued by the Administrator § 54.724 Time periods for Commission approval of Administrator decisions. (a) The Wireline...

  9. 47 CFR 54.724 - Time periods for Commission approval of Administrator decisions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Time periods for Commission approval of...) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Review of Decisions Issued by the Administrator § 54.724 Time periods for Commission approval of Administrator decisions. (a) The Wireline...

  10. 47 CFR 54.724 - Time periods for Commission approval of Administrator decisions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 3 2011-10-01 2011-10-01 false Time periods for Commission approval of...) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Review of Decisions Issued by the Administrator § 54.724 Time periods for Commission approval of Administrator decisions. (a) The Wireline...

  11. 47 CFR 54.724 - Time periods for Commission approval of Administrator decisions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Time periods for Commission approval of...) COMMON CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Review of Decisions Issued by the Administrator § 54.724 Time periods for Commission approval of Administrator decisions. (a) The Wireline...

  12. 12 CFR 516.10 - How does OTS compute time periods under this part?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false How does OTS compute time periods under this part? 516.10 Section 516.10 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY APPLICATION PROCESSING PROCEDURES § 516.10 How does OTS compute time periods under this part? In...

  13. 12 CFR 516.10 - How does OTS compute time periods under this part?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false How does OTS compute time periods under this part? 516.10 Section 516.10 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY APPLICATION PROCESSING PROCEDURES § 516.10 How does OTS compute time periods under this part? In...

  14. 17 CFR 260.7a-24 - Words relating to periods of time in the past.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Words relating to periods of time in the past. 260.7a-24 Section 260.7a-24 Commodity and Securities Exchanges SECURITIES AND... Requirements As to Contents § 260.7a-24 Words relating to periods of time in the past. Unless the...

  15. Future Economics of Liver Transplantation: A 20-Year Cost Modeling Forecast and the Prospect of Bioengineering Autologous Liver Grafts

    PubMed Central

    Habka, Dany; Mann, David; Landes, Ronald; Soto-Gutierrez, Alejandro

    2015-01-01

    During the past 20 years liver transplantation has become the definitive treatment for most severe types of liver failure and hepatocellular carcinoma, in both children and adults. In the U.S., roughly 16,000 individuals are on the liver transplant waiting list. Only 38% of them will receive a transplant due to the organ shortage. This paper explores another option: bioengineering an autologous liver graft. We developed a 20-year model projecting future demand for liver transplants, along with costs based on current technology. We compared these cost projections against projected costs to bioengineer autologous liver grafts. The model was divided into: 1) the epidemiology model forecasting the number of wait-listed patients, operated patients and postoperative patients; and 2) the treatment model forecasting costs (pre-transplant-related costs; transplant (admission)-related costs; and 10-year post-transplant-related costs) during the simulation period. The patient population was categorized using the Model for End-Stage Liver Disease score. The number of patients on the waiting list was projected to increase 23% over 20 years while the weighted average treatment costs in the pre-liver transplantation phase were forecast to increase 83% in Year 20. Projected demand for livers will increase 10% in 10 years and 23% in 20 years. Total costs of liver transplantation are forecast to increase 33% in 10 years and 81% in 20 years. By comparison, the projected cost to bioengineer autologous liver grafts is $9.7M based on current catalog prices for iPS-derived liver cells. The model projects a persistent increase in need and cost of donor livers over the next 20 years that’s constrained by a limited supply of donor livers. The number of patients who die while on the waiting list will reflect this ever-growing disparity. Currently, bioengineering autologous liver grafts is cost prohibitive. However, costs will decline rapidly with the introduction of new manufacturing

  16. 29 CFR 4000.43 - How do I compute a time period?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false How do I compute a time period? 4000.43 Section 4000.43..., ISSUANCE, COMPUTATION OF TIME, AND RECORD RETENTION Computation of Time § 4000.43 How do I compute a time... backwards. Suppose you are required to file an advance notice of reportable event for a transaction that...

  17. 29 CFR 4000.43 - How do I compute a time period?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false How do I compute a time period? 4000.43 Section 4000.43..., ISSUANCE, COMPUTATION OF TIME, AND RECORD RETENTION Computation of Time § 4000.43 How do I compute a time... backwards. Suppose you are required to file an advance notice of reportable event for a transaction that...

  18. Optimising treatment strategies in spinal ependymoma based on 20years of experience at a single centre.

    PubMed

    Keil, Vera C; Schmitt, Anne J; Martin, Sean C; Cadoux-Hudson, Tom A D; Pereira, Erlick A C

    2016-07-01

    Spinal ependymomas are rare tumours, with total resection favoured where possible. Several case series assessing the outcome following neurosurgical treatment for spinal ependymoma advocate the usage of adjuvant radiotherapy in cases of subtotal resection, or in unencapsulated tumours. We assessed the outcome of 61 consecutive cases of spinal ependymoma in a single centre over a 20year period using a variety of outcome measures. Sex distribution was equal, with a mean age at surgery of 43.6years (range 5-76years). Overall, most tumours occurred in the lumbosacral region (70.5%), with fewer in the thoracic (27.9%) and cervical regions (18.0%). Myxopapillary features were seen in 41.0% of tumours, and were more common when occurring in the lumbar region (51.2%). Gross total resection was achieved in 52.5%, subtotal resection in 37.7% and biopsy alone in 9.8% of patients and 31.1% received adjuvant radiotherapy. Two-thirds of patients achieved an excellent post-operative neurological outcome (Frankel grade E). Tumour recurrence was rare. Gross total resection and good preoperative neurological condition were most strongly predictive of good outcome. Post-operative radiotherapy did not seem to confer survival benefit in this case series, even in cases of incomplete resection, leading us to question its utility for all cases of spinal cord ependymoma. PMID:26944215

  19. Period, epoch, and prediction errors of ephemerides from continuous sets of timing measurements

    NASA Astrophysics Data System (ADS)

    Deeg, H. J.

    2015-06-01

    Space missions such as Kepler and CoRoT have led to large numbers of eclipse or transit measurements in nearly continuous time series. This paper shows how to obtain the period error in such measurements from a basic linear least-squares fit, and how to correctly derive the timing error in the prediction of future transit or eclipse events. Assuming strict periodicity, a formula for the period error of these time series is derived, σP = σT (12 / (N3-N))1 / 2, where σP is the period error, σT the timing error of a single measurement, and N the number of measurements. Compared to the iterative method for period error estimation by Mighell & Plavchan (2013), this much simpler formula leads to smaller period errors, whose correctness has been verified through simulations. For the prediction of times of future periodic events, usual linear ephemeris were epoch errors are quoted for the first time measurement, are prone to an overestimation of the error of that prediction. This may be avoided by a correction for the duration of the time series. An alternative is the derivation of ephemerides whose reference epoch and epoch error are given for the centre of the time series. For long continuous or near-continuous time series whose acquisition is completed, such central epochs should be the preferred way for the quotation of linear ephemerides. While this work was motivated from the analysis of eclipse timing measures in space-based light curves, it should be applicable to any other problem with an uninterrupted sequence of discrete timings for which the determination of a zero point, of a constant period and of the associated errors is needed.

  20. Head and Neck Schwannomas: 20-Year Experience of a Single Institution Excluding Cutaneous and Acoustic Sites.

    PubMed

    Butler, Randall T; Patel, Rajiv M; McHugh, Jonathan B

    2016-09-01

    While head and neck sites comprise the most common location of schwannomas, clinicopathologic data regarding those tumors occurring in non-acoustic and non-cutaneous locations are relatively sparse. In this study, therefore, we sought to examine retrospectively the clinical and pathologic features of head and neck schwannomas excised at our institution over a 20-year period. During this period, we identified a total cohort of 85 patients, which included 36 males (42.4 %) and 49 females with average age of 41.3 years, the majority of which presented asymptomatically with a mass. Localized symptoms were, however, associated with all of the schwannomas that arose in the oral cavity and larynx, while tumors within or adjacent to bone were often associated with neurologic complaints (7 of 15 such tumors [46.7 %]). Clinical follow-up data was available in 86.4 % of all cases and demonstrated no recurrences or mortality. Pathologically, the microscopic features were characteristic of those well-described for schwannomas in other sites, including alternating Antoni A and B areas and the presence of degenerative changes. Tumor encapsulation, however, was variable and was completely absent in schwannomas of the nasal cavity, paranasal sinuses, and larynx. Additionally, a significant minority of the tumors (28.2 %) exhibited foci that resembled neurofibroma. Non-acoustic, non-cutaneous schwannomas of the head and neck appear to have clinicopathologic features similar to their soft tissue counterparts with some subsite variation in presentation and/or microscopic features. PMID:26747460

  1. An unusual cause of fitting in a 20 year old girl.

    PubMed

    Beckett, Daniel; Malins, A; Watson, M L; Kelly, C A

    2006-01-01

    Native renal artery stenosis resulting in hypertensive encephalopathy is exceptionally rare, with only 3 previous case reports in adults. We report such a case in a previously well 20 year old female.

  2. Multilevel learning in the adaptive management of waterfowl harvests: 20 years and counting

    USGS Publications Warehouse

    Johnson, Fred A.; Boomer, G. Scott; Williams, Byron K.; Nichols, James D.; Case, David J.

    2015-01-01

    In 1995, the U.S. Fish and Wildlife Service implemented an adaptive harvest management program (AHM) for the sport harvest of midcontinent mallards (Anas platyrhynchos). The program has been successful in reducing long-standing contentiousness in the regulatory process, while integrating science and policy in a coherent, rigorous, and transparent fashion. After 20 years, much has been learned about the relationship among waterfowl populations, their environment, and hunting regulations, with each increment of learning contributing to better management decisions. At the same time, however, much has been changing in the social, institutional, and environmental arenas that provide context for the AHM process. Declines in hunter numbers, competition from more pressing conservation issues, and global-change processes are increasingly challenging waterfowl managers to faithfully reflect the needs and desires of stakeholders, to account for an increasing number of institutional constraints, and to (probabilistically) predict the consequences of regulatory policy in a changing environment. We review the lessons learned from the AHM process so far, and describe emerging challenges and ways in which they may be addressed. We conclude that the practice of AHM has greatly increased an awareness of the roles of social values, trade-offs, and attitudes toward risk in regulatory decision-making. Nevertheless, going forward the waterfowl management community will need to focus not only on the relationships among habitat, harvest, and waterfowl populations, but on the ways in which society values waterfowl and how those values can change over time

  3. 40 CFR 93.162 - Emissions beyond the time period covered by the SIP.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... covered by the SIP. 93.162 Section 93.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 93.162 Emissions beyond the time period covered by the SIP. If a Federal action would result in total... period covered by the SIP, the Federal agency can: (a) Demonstrate conformity with the last...

  4. 40 CFR 93.162 - Emissions beyond the time period covered by the SIP.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... covered by the SIP. 93.162 Section 93.162 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 93.162 Emissions beyond the time period covered by the SIP. If a Federal action would result in total... period covered by the SIP, the Federal agency can: (a) Demonstrate conformity with the last...

  5. Orthodontic treatment need, outcome and residual treatment need in 15- and 20-year-olds.

    PubMed

    Bjerklin, Krister; Lindsten, Rune; Tunge, Jannicke Sagevik; Sjövall, Christine

    2012-01-01

    The aim of the study was to investigate orthodontic treatment need and the outcome of orthodontic treatment in 15-, and 20-year-olds in Jönköping, Sweden, with special reference to residual treatment need. An offer to participate in a clinical investigation was extended to random samples of 130 15-year-olds and 130 20-year-olds. Ninety-six of the 15-year-olds (73.3%; 45 boys and 51 girls) and 82 of the 20-year-olds (62.6%; 47 males and 35 females) accepted and presented for examination The participants filled in a questionnaire and impressions were taken for study models, which were graded according to the ICON index. In all, 39 (40.6%) of the 15-year-olds and 38 (46.3%) of the 20-year-olds had undergone or were currently undergoing orthodontic treatment. Ninety-one per cent of the 15-year-olds and 84% of the 20-year-olds considered that the orthodontic treatment goals had been fully or almost fully attained. Two of the 15-year-olds and two of the 20-year-olds currently wanted orthodontic treatment. This indicates a residual treatment demand of about 2%.

  6. 45 CFR 402.26 - Time period for obligation and expenditure of grant funds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... CFR 92.23(b). This time limit will not be extended. The time limit established by 45 CFR 92.23(b) does... 45 Public Welfare 2 2011-10-01 2011-10-01 false Time period for obligation and expenditure of grant funds. 402.26 Section 402.26 Public Welfare Regulations Relating to Public Welfare OFFICE...

  7. 45 CFR 402.26 - Time period for obligation and expenditure of grant funds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... CFR 92.23(b). This time limit will not be extended. The time limit established by 45 CFR 92.23(b) does... 45 Public Welfare 2 2014-10-01 2012-10-01 true Time period for obligation and expenditure of grant funds. 402.26 Section 402.26 Public Welfare Regulations Relating to Public Welfare OFFICE OF...

  8. A 20 year review of punishment and alternative methods to treat problem behaviors in developmentally delayed persons.

    PubMed

    Matson, J L; Taras, M E

    1989-01-01

    Relevant journals were reviewed (n = 23) for a 20 year period (1967 to 1987) to assess the status of treatments for severe behavior problems of developmentally delayed persons. A hand search of journals was made; 382 studies were identified. Procedures were analyzed by problem behaviors treated, side effects reported, whether the procedure involved painful stimuli, nonpainful stimuli, food satiation, positive procedures, extinction or combinations of methods. The number of studies reported yearly was also plotted. The implication of these data for federal and state policy makers and for treatment programs dealing with difficult to treat clients is discussed. PMID:2648505

  9. Existence and exponential stability of positive almost periodic solution for Nicholson's blowflies models on time scales.

    PubMed

    Li, Yongkun; Li, Bing

    2016-01-01

    In this paper, we first give a new definition of almost periodic time scales, two new definitions of almost periodic functions on time scales and investigate some basic properties of them. Then, as an application, by using a fixed point theorem in Banach space and the time scale calculus theory, we obtain some sufficient conditions for the existence and exponential stability of positive almost periodic solutions for a class of Nicholson's blowflies models on time scales. Finally, we present an illustrative example to show the effectiveness of obtained results. Our results show that under a simple condition the continuous-time Nicholson's blowflies model and its discrete-time analogue have the same dynamical behaviors. PMID:27468397

  10. 20 Years of Developing Capacity for Action-Oriented Collaborative Regional Research in the Asia-Pacific Region

    NASA Astrophysics Data System (ADS)

    Tupas, L. M.; Stevenson, L. A.

    2015-12-01

    During its 3rd strategic phase, which ran from 2010 to 2015, the APN provided support for 123 projects through its competitive collaborative regional research and capacity development programmes. With over 250 peer-reviewed papers and the underlying philosophy that the regional research it undertakes engages at least two developing countries, the 3rd strategic phase is not only improving the research capabilities of nations in the region, but is engaging the developing country community in underpinning policy-relevant research. The extent to which science is contributing to policy is further evident in that 69% of the activities conducted had some form of science-policy mechanism built in to the project activities. The period of the 3rd Strategic Phase has been witness to significant changes in the make-up of the "conventional" global change arena, with the transition of some global change programmes into the new "Future Earth" initiative. At the same time, major events such as the Rio+20 Summit, the post-2015 Sustainable Development Goals, the establishment of an IPCC-related platform for biodiversity, i.e. IPBES, and the evolving engagement of science and policy communities has kept the APN busy at what it does best - networking and partnering with the international community. The APN has embraced these changes through its dynamism, allowing the APN to meet not only the needs of the scientists and decision makers its serves in the region but those of the international science communities as well. The challenge for the APN in its next two decades will be to ensure alignment with the transforming global change arena. With key phrases such as "policy-relevant science" and "science-policy interactions" being adopted broadly by the community at large these days, the APN's niche in the global community has received considerable recognition, particularly as other institutions strive to adopt similar practices that the APN has built over the last 20 years.

  11. Infrared variability of three hot stars on a time scale of 10-20 years

    NASA Astrophysics Data System (ADS)

    Taranova, O. G.; Shenavrin, V. I.

    2015-03-01

    Long-term (1994-2014) near-infrared observations of P Cyg, kDra, and BUTau are analyzed. It is shown that the observed brightness and color variations in P Cyg and k Dra can be explained by variations in the parameters of the stars themselves and their ionized circumstellar shells, whose excitation requires from 5 to 15% of the star's luminosity. The emission from BU Tau in the range 1.25-3.5 µm mimics blackbody radiation, and its variability is a consequence of variations in the star's temperature and, as a result, its radius and luminosity. No excess emission from BU Tau that could be associated with an additional source has been detected.

  12. An infinite branching hierarchy of time-periodic solutions of the Benjamin-Ono equation

    SciTech Connect

    Wilkening, Jon

    2008-07-01

    We present a new representation of solutions of the Benjamin-Ono equation that are periodic in space and time. Up to an additive constant and a Galilean transformation, each of these solutions is a previously known, multi-periodic solution; however, the new representation unifies the subset of such solutions with a fixed spatial period and a continuously varying temporal period into a single network of smooth manifolds connected together by an infinite hierarchy of bifurcations. Our representation explicitly describes the evolution of the Fourier modes of the solution as well as the particle trajectories in a meromorphic representation of these solutions; therefore, we have also solved the problem of finding periodic solutions of the ordinary differential equation governing these particles, including a description of a bifurcation mechanism for adding or removing particles without destroying periodicity. We illustrate the types of bifurcation that occur with several examples, including degenerate bifurcations not predicted by linearization about traveling waves.

  13. Termite (order Blattodea, infraorder Isoptera) baiting 20 years after commercial release.

    PubMed

    Evans, Theodore A; Iqbal, Naeem

    2015-07-01

    Termite baiting is now one of the two main management tools in developed countries after 20 years of commercial release. It has two main goals: to use small amounts of active ingredient and 'colony elimination', i.e. death of all individuals in the colony. We consider how well baiting has been evaluated from 100 studies in the scientific literature. Studies have included 15 active ingredients, 23 termite species and 16 countries, yet most studies have focused on the chitin synthesis inhibitor hexaflumuron, Reticulitermes and the United States. Baiting has mostly met its goals: typically about 0.5 g of active ingredient was used, and colony elimination achieved, albeit with rates varying from 0 to 100%, and sometimes supplemented with liquid insecticide. Baiting was most successful using chitin synthesis inhibitors against Reticulitermes and Coptotermes (Rhinotermitidae), in temperate locations, although colony elimination was usually inferred indirectly - mostly by termite absence from baits - and was often slow, from 25 to 450 days. Baiting has been less tested and less successful against higher termites in tropical locations, where they are most diverse and abundant. Future research may have to consider greater termite species diversity and other active ingredients to reduce control times in order to fulfil the potential of baiting. PMID:25244627

  14. Tobacco interests or the public interest: 20 years of industry strategies to undermine airline smoking restrictions

    PubMed Central

    Lopipero, Peggy Ann; Bero, Lisa A

    2006-01-01

    Objectives To understand the evolution of 20 years of tobacco industry strategies to undermine federal restrictions of smoking on aircraft in the United States. Design We searched and analysed internal tobacco industry records, public documents, and other related research. Results The industry viewed these restrictions as a serious threat to the social acceptability of smoking. Its initial efforts included covert letter‐writing campaigns and lobbying of the airline industry, but with the emergence of proposals to ban smoking, the tobacco companies engaged in ever increasing efforts to forestall further restrictions. Tactics to dominate the public record became especially rigorous. The industry launched an aggressive public relations campaign that began with the promotion of industry sponsored petition drives and public opinion surveys. Results from polling research that produced findings contrary to the industry's position were suppressed. In order to demonstrate smoker outrage against a ban, later efforts included the sponsorship of smokers' rights and other front groups. Congressional allies and industry consultants sought to discredit the science underlying proposals to ban smoking and individual tobacco companies conducted their own cabin air quality research. Faced with the potential of a ban on all domestic flights, the industry sought to intimidate an air carrier and a prominent policymaker. Despite the intensification of tactics over time, including mobilisation of an army of lobbyists and Congressional allies, the tobacco industry was ultimately defeated. Conclusions Our longitudinal analysis provides insights into how and when the industry changed its plans and provides public health advocates with potential counterstrategies. PMID:16885582

  15. Implant survival and radiographic outcome of total hip replacement in patients less than 20 years old

    PubMed Central

    Tsukanaka, Masako; Halvorsen, Vera; Nordsletten, Lars; EngesæTer, Ingvild Ø; EngesæTer, Lars B; Marie Fenstad, Anne; Röhrl, Stephan M

    2016-01-01

    Background and purpose Total hip replacement (THR) is not recommended for children and very young teenagers because early and repetitive revisions are likely. We investigated the clinical and radiographic outcomes of THR performed in children and teenage patients. Patients and methods We included 111 patients (132 hips) who underwent THR before 20 years of age. They were identified in the Norwegian Arthroplasty Register, together with information on the primary diagnosis, types of implants, and any revisions that required implant change. Radiographs and Harris hip score (HHS) were also evaluated. Results The mean age at primary THR was 17 (11–19) years and the mean follow-up time was 14 (3–26) years. The 10-year survival rate after primary THR (with the endpoint being any revision) was 70%. 39 patients had at least 1 revision and 16 patients had 2 or more revisions. In the latest radiographs, osteolysis and atrophy were observed in 19% and 27% of the acetabulae and 21% and 62% of the femurs, respectively. The mean HHS at the final follow-up was 83 (15–100). Interpretation The clinical score after THR in these young patients was acceptable, but many revisions had been performed. However, young patients with developmental dysplasia of the hip had lower implant survival. Moreover, the bone stock in these patients was poor, which could complicate future revisions. PMID:27435903

  16. Termite (order Blattodea, infraorder Isoptera) baiting 20 years after commercial release.

    PubMed

    Evans, Theodore A; Iqbal, Naeem

    2015-07-01

    Termite baiting is now one of the two main management tools in developed countries after 20 years of commercial release. It has two main goals: to use small amounts of active ingredient and 'colony elimination', i.e. death of all individuals in the colony. We consider how well baiting has been evaluated from 100 studies in the scientific literature. Studies have included 15 active ingredients, 23 termite species and 16 countries, yet most studies have focused on the chitin synthesis inhibitor hexaflumuron, Reticulitermes and the United States. Baiting has mostly met its goals: typically about 0.5 g of active ingredient was used, and colony elimination achieved, albeit with rates varying from 0 to 100%, and sometimes supplemented with liquid insecticide. Baiting was most successful using chitin synthesis inhibitors against Reticulitermes and Coptotermes (Rhinotermitidae), in temperate locations, although colony elimination was usually inferred indirectly - mostly by termite absence from baits - and was often slow, from 25 to 450 days. Baiting has been less tested and less successful against higher termites in tropical locations, where they are most diverse and abundant. Future research may have to consider greater termite species diversity and other active ingredients to reduce control times in order to fulfil the potential of baiting.

  17. 20 Years Experience with using Low Cost Launch Opportunities for 20 Small Satellite Missions

    NASA Astrophysics Data System (ADS)

    Meerman, Maarten; Sweeting, Martin, , Sir

    these larger 'small satellites' are too big to be carried 'piggy-back'. The entrepreneurial efforts of leading FSU rocket &missile organisations in converting existing vehicles to meet the small satellite launch market at an appropriate cost has resulted in the FSU now holding the prime position for providing launches for the small satellite community - and with an excellent track record of successful launches. However, negotiating and completing a Launch Services Agreement (LSA) for a nano-micro-minisatellite with any launcher organisation is a complex matter and risky territory for the unwary or inexperienced who may easily fall prey to unexpected additional costs and delays. Whilst this warning should be heeded when dealing with European and US organisations, it is particularly relevant when negotiating launches from the FSU where there is a plethora of agencies and organisations offering a bewildering range of launch vehicles and options. Furthermore, the FSU has developed a very different technical and managerial philosophy towards launchers when compared with the west and this can be unnerving to 'first-time buyers'. Organisations experienced in dealing in the FSU will encounter a different but excellent service - once the launch service agreement has been thoroughly and fiercely negotiated in every detail. The inexperienced, however, have encountered frustrating delays, lost opportunities, unexpected taxes and costs for additional services or facilities not originally specified, and bewilderment at the different procedures used in the FSU. Fortunately, all this can be avoided with proper experience and the FSU is the current mainstay for launching small satellites quickly, affordably and reliably. Surrey has unique experience gathered over 20 years in handling launches for 20 small satellites, ranging from a 6kg nanosatellite, 50-100kg microsatellites, and a 325kg minisatellite, using 7 different launchers from the USA, Russia, Ukraine, and Europe. By working

  18. Clinical outcome and quality of life of patients surviving 20 years or longer after heart transplantation.

    PubMed

    Galeone, Antonella; Kirsch, Matthias; Barreda, Eleodoro; Fernandez, Flor; Vaissier, Elisabeth; Pavie, Alain; Leprince, Pascal; Varnous, Shaida

    2014-06-01

    To evaluate outcome and quality of life (QoL) in ≥ 20 years survivors after heart transplantation. Patients surviving ≥ 20 years with a single graft were retrospectively reviewed. Heterotopic, multiorgan and retransplantations were excluded. QoL was evaluated using the SF-36 survey. Eight hundred and twenty-seven heart transplants were performed from 1981 to 1993, and among these, 131 (16%) patients survived ≥ 20 years; 98 (75%) were male and mean age at transplant was 43 ± 13 years. Conditional survival in these 20 years survivors was 74.1 ± 4.3% at 23 years and 60.9 ± 5.3% at 25 years (45 deaths, 34%). Forty-four (34%) patients suffered rejection ≥ 2R. Conditional survival free from rejection ≥ 2R was 68 ± 4.1% at 5 years and 66.4 ± 4.2% at 10 years. Thirty-five (27%) patients had cardiac allograft vasculopathy (CAV) grade 2-3. Conditional CAV-free survival was 76 ± 3.8% at 20 years and 72.1 ± 4% at 25. Sixty-nine (53%) patients developed malignancy, mostly skin cancers. Conditional malignancy-free survival was 53.5 ± 4.4% at 20 years and 45.2 ± 4.6% at 25 years. At latest follow-up, 24.0 ± 3.0 years after transplantation, mean left ventricular ejection fraction was 62 ± 11% and mean physical and mental scores were 57 ± 23 and 58 ± 21, respectively. Sixteen per cent of heart recipients survived ≥ 20 years with good ventricular performance and QoL. CAV and malignancies account for late morbidity and mortality. PMID:24606025

  19. Dynamics of phase slips in systems with time-periodic modulation.

    PubMed

    Gandhi, Punit; Knobloch, Edgar; Beaume, Cédric

    2015-12-01

    The Adler equation with time-periodic frequency modulation is studied. A series of resonances between the period of the frequency modulation and the time scale for the generation of a phase slip is identified. The resulting parameter space structure is determined using a combination of numerical continuation, time simulations, and asymptotic methods. Regions with an integer number of phase slips per period are separated by regions with noninteger numbers of phase slips and include canard trajectories that drift along unstable equilibria. Both high- and low-frequency modulation is considered. An adiabatic description of the low-frequency modulation regime is found to be accurate over a large range of modulation periods. PMID:26764781

  20. Non-Markovian diffusion over a potential barrier in the presence of periodic time modulation

    SciTech Connect

    Kolomietz, V. M.; Radionov, S. V.

    2011-11-15

    The diffusive non-Markovian motion over a single-well potential barrier in the presence of a weak sinusoidal time modulation is studied. We found nonmonotonic dependence of the mean escape time from the barrier on a frequency of the periodic modulation that is analogous to the stochastic resonance phenomenon. The resonant increase of diffusion over the barrier occurs at the frequency inversely proportional to the mean first-passage time for the motion in the absence of the time modulation.

  1. Cytochrome P4501A biomarker indication of oil exposure in harlequin ducks up to 20 years after the Exxon Valdez oil spill

    USGS Publications Warehouse

    Esler, Daniel; Trust, Kimberly A.; Ballachey, Brenda E.; Iverson, Samuel A.; Lewis, Tyler L.; Rizzolo, Daniel; Mulcahy, Daniel M.; Miles, A. Keith; Woodin, Bruce R.; Stegeman, John J.; Henderson, John D.; Wilson, Barry W.

    2010-01-01

    Hydrocarbon-inducible cytochrome P4501A (CYP1A) expression was measured, as ethoxyresorufin-O-deethylase (EROD) activity, in livers of wintering harlequin ducks (Histrionicus histrionicus) captured in areas of Prince William Sound, Alaska, USA, oiled by the 1989 Exxon Valdez spill and in birds from nearby unoiled areas, during 2005 to 2009 (up to 20 years following the spill). The present work repeated studies conducted in 1998 that demonstrated that in harlequin ducks using areas that received Exxon Valdez oil, EROD activity was elevated nearly a decade after the spill. The present findings strongly supported the conclusion that average levels of hepatic EROD activity were higher in ducks from oiled areas than those from unoiled areas during 2005 to 2009. This result was consistent across four sampling periods; furthermore, results generated from two independent laboratories using paired liver samples from one of the sampling periods were similar. The EROD activity did not vary in relation to age, sex, or body mass of individuals, nor did it vary strongly by season in birds collected early and late in the winter of 2006 to 2007, indicating that these factors did not confound inferences about observed differences between oiled and unoiled areas. We interpret these results to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 20 years after the original spill. This adds to a growing body of literature suggesting that oil spills have the potential to affect wildlife for much longer time frames than previously assumed.

  2. When folic acid fails: Insights from 20 years of neural tube defect surveillance in South Carolina.

    PubMed

    Bupp, Caleb P; Sarasua, Sara M; Dean, Jane H; Stevenson, Roger E

    2015-10-01

    Neural tube defects (NTDs) are the most common of the severe malformations of the brain and spinal cord. Increased maternal intake of folic acid (FA) during the periconceptional period is known to reduce NTD risk. Data from 1046 NTD cases in South Carolina were gathered over 20 years of surveillance. It was possible to determine maternal periconceptional FA use in 615 NTD-affected pregnancies. In 163 occurrent (26.9%) and two recurrent (22%) NTD cases, the mothers reported periconceptional FA use. These women were older and more likely to be white. Maternal periconceptional FA usage was reported in 40.4% of cases of spina bifida with other anomalies but in only 25.2% of isolated spina bifida cases (P = 0.02). This enrichment for associated anomalies was not noted among cases of anencephaly or of encephalocele. Among the 563 subsequent pregnancies to mothers with previous NTD-affected pregnancies, those taking FA had a 0.4% NTD recurrence rate, but the recurrence without FA was 8.5%. NTDs with other associated findings were less likely to be prevented by FA, suggesting there is a background NTD rate that cannot be further reduced by FA. Nonetheless, the majority (73.9%) of NTDs in pregnancies in which the mothers reported periconceptional FA use were isolated NTDs of usual types. Cases in which FA failed in prevention of NTDs provide potential areas for further study into the causation of NTDs. The measures and techniques implemented in South Carolina can serve as an effective and successful model for prevention of NTD occurrence and recurrence. PMID:26108864

  3. [The agroecosystems flora status in restricted zone 20 years after the Chernobyl NPP accident].

    PubMed

    Sapegin, L M; Daĭneko, N M; Timofeev, S F

    2008-01-01

    The article presents the results of studying on agroecosystems flora status in restricted zone 20 years after the Chernobyl accident. There were preliminary identified 8 agroecosystems associations by Broaun-Blanquet ecologo-floristic classification: Phalacrolometum septentrionale, Agrostio tenuis Calamagrostietum epigeii, Agrostio tenuis--Elytrigietum repentis, Poo pratensis--Bromopsietum inermis, Poo pratensis--Dactylidetum glomeratae, Poo pratensis--Agrostietum tenuis, Elytrigio repentis--Poetum pratensis, Caricetum hirtae. First three associations were attributed to Agropyretea repentis class, to Agropyretalia repentis order, Convolvulo--Agropyrion union. We consider the association Phalacrolometum septentrionale as the initial stage of agroscosystems overgrowing which is continued with increase of its demonstration in association Agrostio tenuis--Calamagrostietum epigeii and Agrostio tenuis--Elytrigietum repentis. The associations Poo pratensis--Bromopsietum inermis, Poo pratensis--Dactylidetum glomeratae, Poo pratensis--Agrostietum tenuis and Elytrigio repentis--Poetum pratensis we attributed to class Molinio--Arrhenatheretea, to order Arrhenatheretalia and Festuncion pratensis union. The association Caricetum hirtae was attributed to class Plantaginetea majoris, to order Plantaginetalia majoris and to union Agrapyro--Rumicion crispi. For each of the allocated associations and rye sowing there was provided brief characteristic, including 137Cs and 90Sr radionuclids content in soil and air-dry herbage mass. During the period of studies there was marked stable soil and air-dry herbage mass contamination by radionuclides at absence of grass stabilization of studied agroecosystems. The limiting factor on using of meadow agroecosystems herbages is their high level of contamination by 90Sr. The herbage can be used only for obtaining of milk-raw material for processing. PMID:18666581

  4. Factors Associated with Persistant and Non-Persistant Chronic Constipation, Over 20 Years

    PubMed Central

    Choung, Rok Seon; Locke, G. Richard.; Rey, Enrique; Schleck, Cathy D.; Baum, Charles; Zinsmeister, Alan R.; Talley, Nicholas J.

    2012-01-01

    Background & Aims The prevalence of chronic constipation (CC) has been reported to be as high as 20% in the general population, but little is known about its natural history. We estimated the natural history of CC and characterized features of persistent CC and non-persistent CC, compared to individuals without constipation. Methods In a prospective cohort study, we analyzed data collected from multiple, validated surveys (minimum of 2) of 2853 randomly selected subjects, over a 20-year period (median, 11.6 years). Based on responses, subjects were characterized as having persistent CC, non-persistent CC, or no constipation. We assessed the association between constipation status and potential risk factors using logistic regression models, adjusting for age and sex. Results Of the respondents, 84 had persistent CC (3%), 605 had non-persistent CC (21%), and 2164 had no symptoms of constipation (76%). High scores from the somatic symptom checklist (odds ratio [OR] =2.1; 95% confidence interval [CI], 1.3–3.4) and frequent doctor visits (OR=2.0; 95% CI, 1.0–3.8) were significantly associated with persistent CC, compared to subjects with no constipation symptoms. The only factor that differed was increased use of laxatives or fiber among subjects with persistent CC (OR=3.0; 95% CI, 1.9–4.9). Conclusion The prevalence of constipation might be exaggerated—the proportion of the population with persistent CC is low (3%). Patients with persistent and non-persistent CC have similar clinical characteristics, although individuals with persistent CC use more laxatives or fiber. CC therefore appears and disappears among certain patients, but we do not have enough information to identify these individuals in advance. PMID:22289877

  5. Seroepidemiology of canine leishmaniosis in Évora (southern Portugal): 20-year trends

    PubMed Central

    2013-01-01

    Background Canine leishmaniosis (CanL) is an endemic zoonosis in the southern regions of Europe. This paper reports the trend in CanL seroprevalence in the municipality of Évora (southern Portugal), where the disease is endemic, over a period of 20 years. The work comprises three different studies that were conducted in the years of 1990 (n = 3,614), 1999 (n = 3,563) and 2010 (n = 1,485 dogs). Blood samples were collected during the anti-rabies vaccination campaigns. Anti-Leishmania antibodies were detected with the direct agglutination test (DAT). Findings The total percentages of DAT seropositive dogs were 3.9% (in 1990), 9.4% (in 1999) and 5.6% (in 2010). The overall seroprevalence was significantly higher in 1999 compared to 1990, but in 2010 a significant decrease was found in comparison with 1999. However, compared to 1990 the overall seroprevalence was still significantly higher in 2010. From 1990 to 2010 seroprevalence has switched from significantly lower to higher in the rural areas. Relatively few dogs showed clinical signs of overt disease (0.8% to 2.0%) with lymphadenopathy, onychogryphosis and skin involvement as most frequently observed. Gender associated differences in seroprevalence were not found, and most commonly seropositive dogs were working or stray animals. The mean age of seropositive dogs was significantly higher than seronegative dogs in all three sampling rounds. Conclusions A high proportion of dogs, which are apparently healthy, yet seropositive, may remain an important factor in limiting the outcome of zoonotic leishmaniosis control efforts. PMID:23587181

  6. Time Lapse Hydrogeophysical Monitoring of Near Surface Processes over Long Time Periods

    NASA Astrophysics Data System (ADS)

    Endres, A.; Beynon, A.; Hansen, J.; Toy, C.; Steelman, C. M.

    2012-12-01

    The capacity to provide non-invasive time lapse monitoring that gives valuable insight into complex near-surface processes is a well-recognized attribute of hydrogeophysical techniques. Many of the studies using time lapse hydrogeophysical monitoring have been done for durations ranging from a day to several months. However, the nature of these processes can significantly change over the annual cycle of hydrological conditions. Hence, studies using time lapse hydrogeophysical monitoring for duration of one or more annual cycles are needed to investigate these longer term effects. The hydrogeophysics group at the University of Waterloo has undertaken an extensive series of field studies using high-resolution geophysical techniques to monitor several annual cycles of shallow soil moisture dynamics typical in temperate climates. In this work, our group have been employing a variety of geoelectrical methods, such as electrical resistivity tomography (ERT), ground conductivity meters (GCM) and high-frequency (i.e., 225-900 MHz) ground penetrating radar (GPR). In particular, we have investigated the ability of these geoelectrical methods to characterize both the vertical soil moisture distribution within the shallow vadose zone and the nature of its coupling with soil moisture variations at the surface. Our results clearly demonstrate the ability of these geoelectrical methods to characterize the evolution of near-surface hydrological processes over the annual cycle. In particular, we have been able to perform detailed monitoring of winter freeze-thaw processes which have major hydrological impacts in temperate regions. Further, our multi-year data sets have allowed us to investigate variation in hydrological processes between contrasting annual cycles (e.g., wet versus dry summer conditions).

  7. Clinicopathological evaluation of renal allografts of four patients by 20-year protocol biopsies.

    PubMed

    Okamoto, Masahiko; Nobori, Shuji; Higuchi, Atsushi; Kadotani, Yayoi; Ushigome, Hidetaka; Nakamura, Kenji; Akioka, Kiyokazu; Omori, Yoshihiro; Yoshimura, Norio

    2003-01-01

    Twenty-year protocol biopsies were performed in four cases of renal transplant recipients with grafts that had survived 20 years or more. All four recipients received transplants from their parents, and never had episodes of acute rejection. They were maintained with the conventional immunosuppressive protocol including azathioprine, mizoribine, and prednisolone. Three of them had past history of malignant diseases such as breast cancer and tongue cancer. In spite of fair graft function, the microscopic findings of 20-year protocol biopsy showed various degrees of histological damage; e.g. obsolescence of the glomeruli, glomerulosclerosis, arteriole wall thickening, interstitial fibrosis and tubular atrophy. Although two of the four grafts were functioning with low serum creatinine levels (1.3-1.4 mg dL-1) at 24 years and 26 years following transplantation, respectively, the function of the other two grafts had decreased more than 20 years after transplantation. In the two grafts with decreased function, glomerulosclerosis and arteriole wall thickening tended to be more severe (Banff classification of chronic allograft nephropathy [CAN] grade II and III) at the 20-year protocol biopsy compared with the two well-functioning grafts (CAN grade I and II). We conclude that the protocol biopsies even at 20 years can contribute to predict the fate of renal allografts.

  8. Nitrogen isotopes of coral skeleton-bound organic matter and a 20-year record from Central Equatorial Pacific

    NASA Astrophysics Data System (ADS)

    Wang, X.; Sigman, D. M.; Sinclair, D.; Sherrell, R. M.; Rafter, P. A.; Ren, H.; Cobb, K.; Weigand, A.; Oleynik, S.

    2011-12-01

    We have developed a sensitive method for measuring nitrogen isotopes of coral skeleton-bound organic matter, requiring 5 mg of chemically cleaned coral skeleton powder and yielding a standard deviation for measured d15N of ~0.3%. This method allows for the generation of high-resolution d15N records of coral skeleton-bound organic matter, which we seek to advance as a proxy for the ocean nitrogen cycle in the past. A 20-year coral d15N record (1977-1997) from the Central Equatorial Pacific (Line Islands, Kiribati (2°N, 157°W)) yields an average d15N of 13%, which is similar to the d15N of mixed layer nitrate in this region but 6% higher than the subsurface nitrate being upwelled in this region. The 21 samples over this 20 year period yield a range of only 1.5% (12.5-14.0%), suggesting no substantial change of the mixed layer nitrogen pool over this period. There is some evidence for a lower d15N during El Nino events, but this requires testing by extension of the record and higher resolution sampling. If robust, this d15N decrease may reflect an increased reliance of corals on particulate organic nitrogen and recycled forms of nitrogen relative to nitrate during El Nino events, when mixed layer nitrate concentration declines in the Central Equatorial Pacific.

  9. The Pu'u 'O'o-Kupaianaha Eruption of Kilauea Volcano, Hawaii: The First 20 Years

    USGS Publications Warehouse

    Heliker, Christina C.; Swanson, Donald A.; Takahashi, Taeko Jane

    2003-01-01

    The Pu'u 'O'o-Kupaianaha eruption started on January 3, 1983. The ensuing 20-year period of nearly continuous eruption is the longest at Kilauea Volcano since the famous lava-lake activity of the 19th century. No rift-zone eruption in more than 600 years even comes close to matching the duration and volume of activity of these past two decades. Fortunately, such a landmark event came during a period of remarkable technological advancements in volcano monitoring. When the eruption began, the Global Positioning System (GPS) and the Geographic Information System (GIS) were but glimmers on the horizon, broadband seismology was in its infancy, and the correlation spectrometer (COSPEC), used to measure SO2 flux, was still very young. Now, all of these techniques are employed on a daily basis to track the ongoing eruption and construct models about its behavior. The 12 chapters in this volume, written by present or past Hawaiian Volcano Observatory staff members and close collaborators, celebrate the growth of understanding that has resulted from research during the past 20 years of Kilauea's eruption. The chapters range widely in emphasis, subject matter, and scope, but all present new concepts or important modifications of previous ideas - in some cases, ideas long held and cherished.

  10. A framework for periodic outlier pattern detection in time-series sequences.

    PubMed

    Rasheed, Faraz; Alhajj, Reda

    2014-05-01

    Periodic pattern detection in time-ordered sequences is an important data mining task, which discovers in the time series all patterns that exhibit temporal regularities. Periodic pattern mining has a large number of applications in real life; it helps understanding the regular trend of the data along time, and enables the forecast and prediction of future events. An interesting related and vital problem that has not received enough attention is to discover outlier periodic patterns in a time series. Outlier patterns are defined as those which are different from the rest of the patterns; outliers are not noise. While noise does not belong to the data and it is mostly eliminated by preprocessing, outliers are actual instances in the data but have exceptional characteristics compared with the majority of the other instances. Outliers are unusual patterns that rarely occur, and, thus, have lesser support (frequency of appearance) in the data. Outlier patterns may hint toward discrepancy in the data such as fraudulent transactions, network intrusion, change in customer behavior, recession in the economy, epidemic and disease biomarkers, severe weather conditions like tornados, etc. We argue that detecting the periodicity of outlier patterns might be more important in many sequences than the periodicity of regular, more frequent patterns. In this paper, we present a robust and time efficient suffix tree-based algorithm capable of detecting the periodicity of outlier patterns in a time series by giving more significance to less frequent yet periodic patterns. Several experiments have been conducted using both real and synthetic data; all aspects of the proposed approach are compared with the existing algorithm InfoMiner; the reported results demonstrate the effectiveness and applicability of the proposed approach.

  11. Finding hidden periodic signals in time series - an application to stock prices

    NASA Astrophysics Data System (ADS)

    O'Shea, Michael

    2014-03-01

    Data in the form of time series appear in many areas of science. In cases where the periodicity is apparent and the only other contribution to the time series is stochastic in origin, the data can be `folded' to improve signal to noise and this has been done for light curves of variable stars with the folding resulting in a cleaner light curve signal. Stock index prices versus time are classic examples of time series. Repeating patterns have been claimed by many workers and include unusually large returns on small-cap stocks during the month of January, and small returns on the Dow Jones Industrial average (DJIA) in the months June through September compared to the rest of the year. Such observations imply that these prices have a periodic component. We investigate this for the DJIA. If such a component exists it is hidden in a large non-periodic variation and a large stochastic variation. We show how to extract this periodic component and for the first time reveal its yearly (averaged) shape. This periodic component leads directly to the `Sell in May and buy at Halloween' adage. We also drill down and show that this yearly variation emerges from approximately half of the underlying stocks making up the DJIA index.

  12. High Overweight and Obesity in Fontan Patients: A 20-Year History.

    PubMed

    Chung, Stephanie T; Hong, Borah; Patterson, Lance; Petit, Christopher J; Ham, J Nina

    2016-01-01

    The prevalence of obesity in long-term survivors with complex congenital heart disease may be increasing, and little is known about the timing and onset of weight gain and growth patterns in these high-risk patients. Prevalence rates of overweight/obesity and longitudinal changes in body mass index (BMI) with age were determined in 606 patients with Fontan circulation seen at a tertiary care cardiology center from 1992 to 2012. The number of clinic encounters (n) was stratified by age group (n = 401, 2-5 years; n = 333, 6-11 years; n = 217, 12-19 years; and n = 129, >20 years). Among adults, 39% were overweight/obese at last clinic visit; 22% overweight, and 17% obese. Childhood anthropometric data were available for 82 adults, of which 15% (n = 12/82) were overweight/obese in childhood. The likelihood of being overweight/obese as an adult was three times higher if there was a BMI ≥ 85th percentile in childhood (CI 2.1-4.5, P < 0.01). Overweight/obesity in adulthood was associated with lower heart failure rates (4 vs. 19%, P = 0.03). Pediatric rates of overweight/obesity were comparable to national data (NHANES 2011-2012) in every age group: at 2-5 years, (25 vs. 23%), 6-11 years (26 vs. 34%), and 12-19 years (15 vs. 35%). Systolic blood pressure was higher in overweight/obese children as young as 2-5 years of age. Childhood and adult survivors with Fontan circulation have high rates of overweight/obesity. Childhood obesity is a strong predictor of future adiposity and is linked to changes in systolic blood pressure at a very young age.

  13. Rank One Strange Attractors in Periodically Kicked Predator-Prey System with Time-Delay

    NASA Astrophysics Data System (ADS)

    Yang, Wenjie; Lin, Yiping; Dai, Yunxian; Zhao, Huitao

    2016-06-01

    This paper is devoted to the study of the problem of rank one strange attractor in a periodically kicked predator-prey system with time-delay. Our discussion is based on the theory of rank one maps formulated by Wang and Young. Firstly, we develop the rank one chaotic theory to delayed systems. It is shown that strange attractors occur when the delayed system undergoes a Hopf bifurcation and encounters an external periodic force. Then we use the theory to the periodically kicked predator-prey system with delay, deriving the conditions for Hopf bifurcation and rank one chaos along with the results of numerical simulations.

  14. Area Spectrum of Btz Black Holes from the Periodicity in Euclidean Time

    NASA Astrophysics Data System (ADS)

    Larrañaga, Alexis

    2012-08-01

    In this paper, we analyze the area spectrum of BTZ three-dimensional black holes by considering an outgoing wave and relating its period of motion with the period of the gravitational system with respect to Euclidean time. The area spectra obtained for the rotating and non-rotating black holes are equally spaced and it is important to note that in this paper, we do not need to use the small angular momentum assumption which is necessary in the quasinormal mode approach for rotating black holes. The results suggest that the periodicity of the black hole gravitational system may be the origin of area quantization.

  15. Turn-over rate of academic faculty at the College of Health Sciences, Addis Ababa University: a 20-year analysis (1991 to 2011)

    PubMed Central

    2013-01-01

    Background Faculty turn-over affects both workers and organizations. Turnover of faculty and researchers is increasing alarmingly and costing the universities and the country at large. Fast turnover of health professionals from the health system and from academic institutions has recently received substantial attention from both academia and health sector managers. This paper calculates the faculty turnover rate at the College of Health Sciences of Addis Ababa University during the period of September 1991 to August 2011. Methods The study was conducted at the College of Health Sciences, Addis Ababa University. Retrospective analysis of employee records was done. All records of the faculty that were working in the College during the 20-year period, starting from September 1991 to August 2011 were retrospectively reviewed. Data were collected from the employee records accessed from the College’s human resources database and supplemented by payroll sheets and different reports. A structured checklist was used to extract the required data from the database. The crude turnover rate for academic faculty was calculated. Results Within the 20-year period of September 1991 to August 2011, a total of 120 faculty members left. The overall turn-over rate was 92.8 %. The rate in the most recent five years (172 %) is 8.5 times higher than the rate for the first five years (20 %). The average retention period before the termination of an employment contract was 4.9 years. The top five departments where employment contracts were relatively higher include: Nursing 15 (15.6 %), Internal Medicine 12 (12.5%), Public Health 10 (10.4%), Pediatrics 9 (9.4%) and Surgery 9 (9.4%). About two thirds (66.6%) of the faculty who were leaving were at the ranks of assistant professorship and above. Conclusion This study revealed that outflow of faculty has been continuously increasing in the period reviewed. This implies that the College had been losing highly skilled professionals with

  16. Identification of periods of clear sky irradiance in time series of GHI measurements

    DOE PAGES

    Reno, Matthew J.; Hansen, Clifford W.

    2016-01-18

    In this study, we present a simple algorithm for identifying periods of time with broadband global horizontal irradiance (GHI) similar to that occurring during clear sky conditions from a time series of GHI measurements. Other available methods to identify these periods do so by identifying periods with clear sky conditions using additional measurements, such as direct or diffuse irradiance. Our algorithm compares characteristics of the time series of measured GHI with the output of a clear sky model without requiring additional measurements. We validate our algorithm using data from several locations by comparing our results with those obtained from amore » clear sky detection algorithm, and with satellite and ground-based sky imagery.« less

  17. Reproductive numbers for nonautonomous spatially distributed periodic SIS models acting on two time scales.

    PubMed

    Marvá, M; Bravo de la Parra, R; Auger, P

    2012-06-01

    In this work we deal with a general class of spatially distributed periodic SIS epidemic models with two time scales. We let susceptible and infected individuals migrate between patches with periodic time dependent migration rates. The existence of two time scales in the system allows to describe certain features of the asymptotic behavior of its solutions with the help of a less dimensional, aggregated, system. We derive global reproduction numbers governing the general spatially distributed nonautonomous system through the aggregated system. We apply this result when the mass action law and the frequency dependent transmission law are considered. Comparing these global reproductive numbers to their non spatially distributed counterparts yields the following: adequate periodic migration rates allow global persistence or eradication of epidemics where locally, in absence of migrations, the contrary is expected.

  18. Periodic trim solutions with hp-version finite elements in time

    NASA Technical Reports Server (NTRS)

    Peters, David A.; Hou, Lin-Jun

    1990-01-01

    Finite elements in time as an alternative strategy for rotorcraft trim problems are studied. The research treats linear flap and linearized flap-lag response both for quasi-trim and trim cases. The connection between Fourier series analysis and hp-finite elements for periodic a problem is also examined. It is proved that Fourier series is a special case of space-time finite elements in which one element is used with a strong displacement formulation. Comparisons are made with respect to accuracy among Fourier analysis, displacement methods, and mixed methods over a variety parameters. The hp trade-off is studied for the periodic trim problem to provide an optimum step size and order of polynomial for a given error criteria. It is found that finite elements in time can outperform Fourier analysis for periodic problems, and for some given error criteria. The mixed method provides better results than does the displacement method.

  19. People's preference patterns for gains/losses in multiple time period situations.

    PubMed

    Chang, Shin-Shin; Chang, Jung-Hua

    2013-10-01

    Little research to date has been devoted to investigating whether people treat time differently from money when facing multiple gains or losses. This study tested the hypothesis that because time is characterized by perishability, fixed supply, and infungibility, people with strong motivation to obtain a long period of uninterrupted discretionary time would strive to trim the time needed for non-discretionary activities or to combine several non-discretionary activities. As a result, people prefer integration over segregation of multiple time losses or gains, which is not consistent with the prediction based on hedonic editing theory or the renewable resource model. This proposition is supported by results from four experiments.

  20. People's preference patterns for gains/losses in multiple time period situations.

    PubMed

    Chang, Shin-Shin; Chang, Jung-Hua

    2013-10-01

    Little research to date has been devoted to investigating whether people treat time differently from money when facing multiple gains or losses. This study tested the hypothesis that because time is characterized by perishability, fixed supply, and infungibility, people with strong motivation to obtain a long period of uninterrupted discretionary time would strive to trim the time needed for non-discretionary activities or to combine several non-discretionary activities. As a result, people prefer integration over segregation of multiple time losses or gains, which is not consistent with the prediction based on hedonic editing theory or the renewable resource model. This proposition is supported by results from four experiments. PMID:24597454

  1. Seasonal cycle of volume transport through Kerama Gap revealed by a 20-year global HYbrid Coordinate Ocean Model reanalysis

    NASA Astrophysics Data System (ADS)

    Yu, Zhitao; Metzger, E. Joseph; Thoppil, Prasad; Hurlburt, Harley E.; Zamudio, Luis; Smedstad, Ole Martin; Na, Hanna; Nakamura, Hirohiko; Park, Jae-Hun

    2015-12-01

    The temporal variability of volume transport from the North Pacific Ocean to the East China Sea (ECS) through Kerama Gap (between Okinawa Island and Miyakojima Island - a part of Ryukyu Islands Arc) is investigated using a 20-year global HYbrid Coordinate Ocean Model (HYCOM) reanalysis with the Navy Coupled Ocean Data Assimilation from 1993 to 2012. The HYCOM mean transport is 2.1 Sv (positive into the ECS, 1 Sv = 106 m3/s) from June 2009 to June 2011, in good agreement with the observed 2.0 Sv transport during the same period. This is similar to the 20-year mean Kerama Gap transport of 1.95 ± 4.0 Sv. The 20-year monthly mean volume transport (transport seasonal cycle) is maximum in October (3.0 Sv) and minimum in November (0.5 Sv). The annual variation component (345-400 days), mesoscale eddy component (70-345 days), and Kuroshio meander component (< 70 days) are separated to determine their contributions to the transport seasonal cycle. The annual variation component has a close relation with the local wind field and increases (decreases) transport into the ECS through Kerama Gap in summer (winter). Most of the variations in the transport seasonal cycle come from the mesoscale eddy component. The impinging mesoscale eddies increase the transport into the ECS during January, February, May, and October, and decrease it in March, April, November, and December, but have little effect in summer (June-September). The Kuroshio meander components cause smaller transport variations in summer than in winter.

  2. Adaptive time-delayed stabilization of steady states and periodic orbits.

    PubMed

    Selivanov, Anton; Lehnert, Judith; Fradkov, Alexander; Schöll, Eckehard

    2015-01-01

    We derive adaptive time-delayed feedback controllers that stabilize fixed points and periodic orbits. First, we develop an adaptive controller for stabilization of a steady state by applying the speed-gradient method to an appropriate goal function and prove global asymptotic stability of the resulting system. For an example we show that the advantage of the adaptive controller over the nonadaptive one is in a smaller controller gain. Second, we propose adaptive time-delayed algorithms for stabilization of periodic orbits. Their efficiency is confirmed by local stability analysis. Numerical examples demonstrate the applicability of the proposed controllers.

  3. A Time-Delayed Mathematical Model for Tumor Growth with the Effect of a Periodic Therapy.

    PubMed

    Xu, Shihe; Wei, Xiangqing; Zhang, Fangwei

    2016-01-01

    A time-delayed mathematical model for tumor growth with the effect of periodic therapy is studied. The establishment of the model is based on the reaction-diffusion dynamics and mass conservation law and is considered with a time delay in cell proliferation process. Sufficient conditions for the global stability of tumor free equilibrium are given. We also prove that if external concentration of nutrients is large the tumor will not disappear and the conditions under which there exist periodic solutions to the model are also determined. Results are illustrated by computer simulations.

  4. A Time-Delayed Mathematical Model for Tumor Growth with the Effect of a Periodic Therapy

    PubMed Central

    Xu, Shihe; Wei, Xiangqing; Zhang, Fangwei

    2016-01-01

    A time-delayed mathematical model for tumor growth with the effect of periodic therapy is studied. The establishment of the model is based on the reaction-diffusion dynamics and mass conservation law and is considered with a time delay in cell proliferation process. Sufficient conditions for the global stability of tumor free equilibrium are given. We also prove that if external concentration of nutrients is large the tumor will not disappear and the conditions under which there exist periodic solutions to the model are also determined. Results are illustrated by computer simulations. PMID:27274763

  5. A Time-Delayed Mathematical Model for Tumor Growth with the Effect of a Periodic Therapy.

    PubMed

    Xu, Shihe; Wei, Xiangqing; Zhang, Fangwei

    2016-01-01

    A time-delayed mathematical model for tumor growth with the effect of periodic therapy is studied. The establishment of the model is based on the reaction-diffusion dynamics and mass conservation law and is considered with a time delay in cell proliferation process. Sufficient conditions for the global stability of tumor free equilibrium are given. We also prove that if external concentration of nutrients is large the tumor will not disappear and the conditions under which there exist periodic solutions to the model are also determined. Results are illustrated by computer simulations. PMID:27274763

  6. Ecosystem development after mangrove wetland creation: plant-soil change across a 20-year chronosequence

    USGS Publications Warehouse

    Osland, Michael J.; Spivak, Amanda C.; Nestlerode, Janet A.; Lessmann, Jeannine M.; Almario, Alejandro E.; Heitmuller, Paul T.; Russell, Marc J.; Krauss, Ken W.; Alvarez, Federico; Dantin, Darrin D.; Harvey, James E.; From, Andrew S.; Cormier, Nicole; Stagg, Camille L.

    2012-01-01

    Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland losses. However, ecosystem development and functional equivalence in restored and created mangrove wetlands are poorly understood. We compared a 20-year chronosequence of created tidal wetland sites in Tampa Bay, Florida (USA) to natural reference mangrove wetlands. Across the chronosequence, our sites represent the succession from salt marsh to mangrove forest communities. Our results identify important soil and plant structural differences between the created and natural reference wetland sites; however, they also depict a positive developmental trajectory for the created wetland sites that reflects tightly coupled plant-soil development. Because upland soils and/or dredge spoils were used to create the new mangrove habitats, the soils at younger created sites and at lower depths (10-30 cm) had higher bulk densities, higher sand content, lower soil organic matter (SOM), lower total carbon (TC), and lower total nitrogen (TN) than did natural reference wetland soils. However, in the upper soil layer (0-10 cm), SOM, TC, and TN increased with created wetland site age simultaneously with mangrove forest growth. The rate of created wetland soil C accumulation was comparable to literature values for natural mangrove wetlands. Notably, the time to equivalence for the upper soil layer of created mangrove wetlands appears to be faster than for many other wetland ecosystem types. Collectively, our findings characterize the rate and trajectory of above- and below-ground changes associated with ecosystem development in created mangrove wetlands; this is valuable information for environmental managers planning to sustain existing mangrove wetlands or mitigate for mangrove wetland losses.

  7. Tracking 20 Years of Compound-to-Target Output from Literature and Patents

    PubMed Central

    Southan, Christopher; Varkonyi, Peter; Boppana, Kiran; Jagarlapudi, Sarma A.R.P.; Muresan, Sorel

    2013-01-01

    The statistics of drug development output and declining yield of approved medicines has been the subject of many recent reviews. However, assessing research productivity that feeds development is more difficult. Here we utilise an extensive database of structure-activity relationships extracted from papers and patents. We have used this database to analyse published compounds cumulatively linked to nearly 4000 protein target identifiers from multiple species over the last 20 years. The compound output increases up to 2005 followed by a decline that parallels a fall in pharmaceutical patenting. Counts of protein targets have plateaued but not fallen. We extended these results by exploring compounds and targets for one large pharmaceutical company. In addition, we examined collective time course data for six individual protease targets, including average molecular weight of the compounds. We also tracked the PubMed profile of these targets to detect signals related to changes in compound output. Our results show that research compound output had decreased 35% by 2012. The major causative factor is likely to be a contraction in the global research base due to mergers and acquisitions across the pharmaceutical industry. However, this does not rule out an increasing stringency of compound quality filtration and/or patenting cost control. The number of proteins mapped to compounds on a yearly basis shows less decline, indicating the cumulative published target capacity of global research is being sustained in the region of 300 proteins for large companies. The tracking of six individual targets shows uniquely detailed patterns not discernible from cumulative snapshots. These are interpretable in terms of events related to validation and de-risking of targets that produce detectable follow-on surges in patenting. Further analysis of the type we present here can provide unique insights into the process of drug discovery based on the data it actually generates. PMID

  8. Musk fragrances, DEHP and heavy metals in a 20 years old sludge treatment reed bed system.

    PubMed

    Matamoros, Víctor; Nguyen, Loc Xuan; Arias, Carlos A; Nielsen, Steen; Laugen, Maria Mølmer; Brix, Hans

    2012-08-01

    The Sludge Treatment Reed Bed (STRB) technology is a cost-efficient and environmentally friendly technology to dewater and mineralize surplus sludge from conventional wastewater treatment systems. Primary and secondary liquid sludge is loaded onto the surface of the bed over several years, where it is dewatered, mineralized and turned into a biosolid with a high dry matter content for use as an organic fertilizer on agricultural land. We analysed the concentrations of five organic micropollutants (galaxolide, tonalide, cashmeran, celestolide and DEHP) and six heavy metals (Pb, Ni, Cu, Cd, Zn and Cr) in the accumulated sludge in a 20-year old STRB in Denmark in order to assess the degradation and fate of these contaminants in a STRB and the relation to sludge composition. The results showed that the deposited sludge was dewatered to reach a dry matter content of 29%, and that up to a third of the organic content of the sludge was mineralized. The concentrations of heavy metals generally increased with depth in the vertical sludge profile due to the dewatering and mineralization of organic matter, but in all cases the concentrations were below the European Union legal limits for agricultural land disposal. The concentrations of fragrances and DEHP ranged from 10 to 9000 ng g(-1) dry mass. The attenuation of hydrophobic micropollutants from the top to the bottom layer of the reed bed ranged from 40 to 98%, except for tonalide which increased significantly with sludge depth, and consequently showed an unusual depth distribution of the galaxolide/tonalide ratio. This unexpected pattern may reflect changes imposed by a long storage time and/or different composition of the fresh sludge in the past. The lack of a significant decreasing DEHP concentration with sludge age might indicate that this compound is very persistent in STRBs. In conclusion the STRB was a feasible technology for sludge treatment before its land disposal.

  9. Where do patients treated for oral cancer die? A 20-year cohort study 1992-2011.

    PubMed

    Kamisetty, A; Magennis, P; Mayland, C; Jack, B; Lowe, D; Rogers, S N

    2015-12-01

    Of 1290 consecutive patients treated between 1992 and 2011 for primary squamous cell carcinoma of the oral cavity at a regional centre, 750 had died by August 2013. About half of them (n=373) died in hospital, 113 (15%) in a hospice, 180 (24%) at home, 57 (8%) in a care home, and 22 (3%) elsewhere. Cancer was the underlying cause of death in 64%, and of them, 56% were oral cancers. The place of death was strongly associated with the age at death and cancer being the underlying cause. The percentage of people who died from cancer at home or in a hospice rose over time across all age groups and, from 2010, accounted for two-thirds. In contrast, less than 1 in 5 who did not die from cancer, died at home or in a hospice, and in this there has been no discernible change over the last 20 years. The percentage of deaths from cancer in hospital and hospice ranged from 32%-38% and 20%-29%, respectively, across age groups. An increase in the number of deaths from cancer in care homes in those aged 75 years and over was mirrored by fewer at home. Most of those who did not die from cancer, died in hospital, two-thirds were under 65 years, 85% were aged 65-84, and 56% were older. This was mirrored by fewer deaths at home in those under 85 and more in care homes in those over 75. In conclusion, our findings suggest that patients' preferences not to die in hospital are being realised. However, at the end of their lives, patients and their carers need more support at home, and more research is required.

  10. The next 20 years: how customer and workforce attitudes will evolve.

    PubMed

    Howe, Neil; Strauss, William

    2007-01-01

    Business projects with very long time horizons--such as those involving product R&D, workplace design, and total compensation planning--have to contend with a crucial question: What will be the needs, demands, and desires of consumers and employees decades from now? If you think the answer is "Just more of the same," you're in for a surprise. Howe and Strauss, the authors of Generations, The Fourth Turning, Millennials Rising, and other books, have studied the differences among generations for some 30 years. Their extensive research has revealed a fascinating pattern--one so strong that it supports a measure of predictability. On the basis of historical precedent, they say, we can foresee how the generations that are alive today will think and act in decades to come. Three of those generations will still be vital forces in American society 20 years from now: Boomers, Generation X, and Millennials. Their attitudes and behaviors will have profound effects on the economy, the workplace, and social institutions in general. For example, as aging Boomers eschew high-tech medicine in favor of holistic self-care, natural foods, and mind-body healing techniques, some hospitals are opening new wings featuring alternative medicine and spiritual counseling. Gen Xers, having grown up in an era of failing schools and marriages, will remain alienated, disaffected, and pragmatic as they enter midlife. Already the greatest entrepreneurial generation in U.S. history, they will be highly effective at pushing innovation, efficiency, and mass customization. In contrast, young adult Millennials will favor teamwork, close family relationships, job security, and a bland popular culture. Their unprecedented digital empowerment and talent for organizing will create a political powerhouse and may even revitalize the union movement. PMID:17642125

  11. Musk fragrances, DEHP and heavy metals in a 20 years old sludge treatment reed bed system.

    PubMed

    Matamoros, Víctor; Nguyen, Loc Xuan; Arias, Carlos A; Nielsen, Steen; Laugen, Maria Mølmer; Brix, Hans

    2012-08-01

    The Sludge Treatment Reed Bed (STRB) technology is a cost-efficient and environmentally friendly technology to dewater and mineralize surplus sludge from conventional wastewater treatment systems. Primary and secondary liquid sludge is loaded onto the surface of the bed over several years, where it is dewatered, mineralized and turned into a biosolid with a high dry matter content for use as an organic fertilizer on agricultural land. We analysed the concentrations of five organic micropollutants (galaxolide, tonalide, cashmeran, celestolide and DEHP) and six heavy metals (Pb, Ni, Cu, Cd, Zn and Cr) in the accumulated sludge in a 20-year old STRB in Denmark in order to assess the degradation and fate of these contaminants in a STRB and the relation to sludge composition. The results showed that the deposited sludge was dewatered to reach a dry matter content of 29%, and that up to a third of the organic content of the sludge was mineralized. The concentrations of heavy metals generally increased with depth in the vertical sludge profile due to the dewatering and mineralization of organic matter, but in all cases the concentrations were below the European Union legal limits for agricultural land disposal. The concentrations of fragrances and DEHP ranged from 10 to 9000 ng g(-1) dry mass. The attenuation of hydrophobic micropollutants from the top to the bottom layer of the reed bed ranged from 40 to 98%, except for tonalide which increased significantly with sludge depth, and consequently showed an unusual depth distribution of the galaxolide/tonalide ratio. This unexpected pattern may reflect changes imposed by a long storage time and/or different composition of the fresh sludge in the past. The lack of a significant decreasing DEHP concentration with sludge age might indicate that this compound is very persistent in STRBs. In conclusion the STRB was a feasible technology for sludge treatment before its land disposal. PMID:22608611

  12. Survival and Competitiveness of Bradyrhizobium japonicum Strains 20 Years after Introduction into Field Locations in Poland

    PubMed Central

    Narożna, Dorota; Pudełko, Krzysztof; Króliczak, Joanna; Golińska, Barbara; Sugawara, Masayuki; Mądrzak, Cezary J.

    2015-01-01

    It was previously demonstrated that there are no indigenous strains of Bradyrhizobium japonicum forming nitrogen-fixing root nodule symbioses with soybean plants in arable field soils in Poland. However, bacteria currently classified within this species are present (together with Bradyrhizobium canariense) as indigenous populations of strains specific for nodulation of legumes in the Genisteae tribe. These rhizobia, infecting legumes such as lupins, are well established in Polish soils. The studies described here were based on soybean nodulation field experiments, established at the Poznań University of Life Sciences Experiment Station in Gorzyń, Poland, and initiated in the spring of 1994. Long-term research was then conducted in order to study the relation between B. japonicum USDA 110 and USDA 123, introduced together into the same location, where no soybean rhizobia were earlier detected, and nodulation and competitive success were followed over time. Here we report the extra-long-term saprophytic survival of B. japonicum strains nodulating soybeans that were introduced as inoculants 20 years earlier and where soybeans were not grown for the next 17 years. The strains remained viable and symbiotically competent, and molecular and immunochemical methods showed that the strains were undistinguishable from the original inoculum strains USDA 110 and USDA 123. We also show that the strains had balanced numbers and their mobility in soil was low. To our knowledge, this is the first report showing the extra-long-term persistence of soybean-nodulating strains introduced into Polish soils and the first analyzing the long-term competitive relations of USDA 110 and USDA 123 after the two strains, neither of which was native, were introduced into the environment almost 2 decades ago. PMID:26048934

  13. The next 20 years: how customer and workforce attitudes will evolve.

    PubMed

    Howe, Neil; Strauss, William

    2007-01-01

    Business projects with very long time horizons--such as those involving product R&D, workplace design, and total compensation planning--have to contend with a crucial question: What will be the needs, demands, and desires of consumers and employees decades from now? If you think the answer is "Just more of the same," you're in for a surprise. Howe and Strauss, the authors of Generations, The Fourth Turning, Millennials Rising, and other books, have studied the differences among generations for some 30 years. Their extensive research has revealed a fascinating pattern--one so strong that it supports a measure of predictability. On the basis of historical precedent, they say, we can foresee how the generations that are alive today will think and act in decades to come. Three of those generations will still be vital forces in American society 20 years from now: Boomers, Generation X, and Millennials. Their attitudes and behaviors will have profound effects on the economy, the workplace, and social institutions in general. For example, as aging Boomers eschew high-tech medicine in favor of holistic self-care, natural foods, and mind-body healing techniques, some hospitals are opening new wings featuring alternative medicine and spiritual counseling. Gen Xers, having grown up in an era of failing schools and marriages, will remain alienated, disaffected, and pragmatic as they enter midlife. Already the greatest entrepreneurial generation in U.S. history, they will be highly effective at pushing innovation, efficiency, and mass customization. In contrast, young adult Millennials will favor teamwork, close family relationships, job security, and a bland popular culture. Their unprecedented digital empowerment and talent for organizing will create a political powerhouse and may even revitalize the union movement.

  14. Developmental critical windows and sensitive periods as three-dimensional constructs in time and space.

    PubMed

    Burggren, Warren W; Mueller, Casey A

    2015-01-01

    A critical window (sensitive period) represents a period during development when an organism's phenotype is responsive to intrinsic or extrinsic (environmental) factors. Such windows represent a form of developmental phenotypic plasticity and result from the interaction between genotype and environment. Critical windows have typically been defined as comprising discrete periods in development with a distinct starting time and end time, as identified by experiments following an on and an off protocol. Yet in reality, periods of responsiveness during development are likely more ambiguous that depicted. Our goal is to extend the concept of the developmental critical window by introducing a three-dimensional construct in which time during development, dose of the stressor applied, and the resultant phenotypic modification can be utilized to more realistically define a critical window. Using the example of survival of the brine shrimp (Artemia franciscana) during exposure to different salinity levels during development, we illustrate that it is not just stressor dose or exposure time but the interaction of these two factors that results in the measured phenotypic change, which itself may vary within a critical window. We additionally discuss a systems approach to critical windows, in which the components of a developing system--whether they be molecular, physiological, or morphological--may show differing responses with respect to time and dose. Thus, the plasticity of each component may contribute to a broader overall system response. PMID:25730265

  15. Union Movement at Private Colleges Awakens after a 20-Year Slumber.

    ERIC Educational Resources Information Center

    Leatherman, Courtney

    2000-01-01

    Reviews trends in union organization at private colleges following the U.S. Supreme Court's decision 20 years ago denying bargaining rights to faculty at Yeshiva University (New York). Focuses on a recent decision by a labor official granting bargaining rights to faculty at Manhattan College (New York) and efforts by faculty organizers at Seton…

  16. Psychology Studies' Drive to Educational Reform in the Last 20 Years in China

    ERIC Educational Resources Information Center

    Zhang, Da-jun; Xu, Xing-chun

    2006-01-01

    In order to better understand the relationship between educational psychology research and educational reform, this essay reviews the development of educational psychology studies in the last 20 years in China. The study shows that: (1) Rapid development has been made in the areas of establishing discipline systems; (2) Research fields have been…

  17. Reading Recovery 20 Years down the Track: Looking Forward, Looking Back

    ERIC Educational Resources Information Center

    Reynolds, Meree; Wheldall, Kevin

    2007-01-01

    Reading Recovery is an intensive literacy programme designed for young students who have been identified as being at-risk of reading failure after 1 year of schooling. The intervention was developed and trialled in New Zealand over 20 years ago and is now implemented in a number of education systems. The focus of this article is on recent research…

  18. Digital Distribution of Academic Journals and Its Impact on Scholarly Communication: Looking Back after 20 Years

    ERIC Educational Resources Information Center

    Solomon, David J.

    2013-01-01

    It has been approximately 20 years since distributing scholarly journals digitally became feasible. This article discusses the broad implications of the transition to digital distributed scholarship from a historical perspective and focuses on the development of open access (OA) and the various models for funding OA in the context of the roles…

  19. 20 Years after "The Ontogeny of Human Memory: A Cognitive Neuroscience Perspective," Where Are We?

    ERIC Educational Resources Information Center

    Jabès, Adeline; Nelson, Charles A.

    2015-01-01

    In 1995, Nelson published a paper describing a model of memory development during the first years of life. The current article seeks to provide an update on the original work published 20 years ago. Specifically, we review our current knowledge on the relation between the emergence of explicit memory functions throughout development and the…

  20. Intraflagellar transport—the “new motility” 20 years later

    PubMed Central

    Kozminski, Keith G.

    2012-01-01

    Intraflagellar transport is the rapid, bidirectional movement of protein complexes along the length of most eukaryotic cilia and flagella. Discovery of this intracellular process in Chlamydomonas reinhardtii 20 years ago led to a rapid discovery of cellular mechanisms that underlie a large number of human ciliopathies. Described herein are the events that led to this discovery. PMID:22379118

  1. College Student's Health, Drinking and Smoking Patterns: What Has Changed in 20 Years?

    ERIC Educational Resources Information Center

    Hensel, Desiree; Todd, Katherine Leigh; Engs, Ruth C.

    2014-01-01

    Problem: Institutes of higher learning are increasingly trying to address the issue of problem drinking. The purpose of this study was to determine how patterns in alcohol use and smoking by college students, as well as their illness patterns, have changed over 20 years. Methods: A cross-sectional serial survey design was used for this descriptive…

  2. Decreasing Sports Activity with Increasing Age? Findings from a 20-Year Longitudinal and Cohort Sequence Analysis

    ERIC Educational Resources Information Center

    Breuer, Christoph; Wicker, Pamela

    2009-01-01

    According to cross-sectional studies in sport science literature, decreasing sports activity with increasing age is generally assumed. In this paper, the validity of this assumption is checked by applying more effective methods of analysis, such as longitudinal and cohort sequence analyses. With the help of 20 years' worth of data records from the…

  3. Social Representations of Educability in Finland: 20 Years of Continuity and Change

    ERIC Educational Resources Information Center

    Raty, Hannu; Komulainen, Katri; Hirva, Laura

    2012-01-01

    This study set out to replicate a survey conducted 20 years ago on Finnish parents' social representations of educability. A nationwide sample of parents (N = 642) were asked to indicate their opinions on a set of statements pertaining to topical educational issues. The results indicated that educational discussion is still structured by two major…

  4. Family Discord, Parental Depression, and Psychopathology in Offspring: 20-Year Follow-up

    ERIC Educational Resources Information Center

    Pilowsky, Daniel J.; Wickramaratne, Priya; Nomura, Yoko; Weissman, Myrna M.

    2006-01-01

    Objective: To determine the independent effects of parental depression and family discord on offspring psychopathology among children at high and low risk of depression. Method: Family discord factors were assessed when subjects were approximately 17 years old, and offspring diagnoses were assessed about 20 years later. Parental and offspring…

  5. Four Themes from 20 Years of Research on Infant Perception and Cognition

    ERIC Educational Resources Information Center

    Bremner, J. Gavin

    2011-01-01

    This paper reviews progress over the past 20 years in four areas of research on infant perception and cognition. Work on perception of dynamic events has identified perceptual constraints on perception of object unity and object trajectory continuity that have led to a perceptual account of early development that supplements Nativist accounts.…

  6. The Politics of Educational Reform: The Alberta Charter School Experiment 20 Years Later

    ERIC Educational Resources Information Center

    Bosetti, Lynn; Butterfield, Phil

    2016-01-01

    In this paper we examine the public charter school movement in the Province of Alberta, Canada over the past 20 years to determine how charter school policy and regulations have limited and controlled the impact of charter schools on public education. Specifically we focus on the extent to which charter schools in Alberta fulfilled the aims and…

  7. Assessing Side Effects of Pharmacotherapy Treatment of Bipolar Disorder: A 20-Year Review of the Literature

    ERIC Educational Resources Information Center

    Matson, Johnny L.; Gonzalez, Melissa L.; Smith, Kimberly R.; Terlonge, Cindy; Thorson, Ryan T.; Dixon, Dennis R.

    2006-01-01

    A substantial literature on the effective treatment of bipolar disorder has begun to appear, particularly in the last 20 years.The majority of treatments studied have employed medications, particularly mood stabilizers, a typical antipsychotics and antidepressants. Most treatments produce side effects and medications are no exception. A review of…

  8. In Patience and Hope: A 20-Year Narrative Study of a Family, School, and Community Partnership

    ERIC Educational Resources Information Center

    Higgins, Ann; Deegan, James G.

    2009-01-01

    This case study describes a 20-year journey of educational transformation from 1985 to 2005 in a bellwether, or highly developed, instance of one school, family, and community partnership--the Kileely Community Project--situated in a large social housing project in Limerick City in the Midwestern region of the Republic of Ireland. The study is a…

  9. The Parent-Child Home Program in Western Manitoba: A 20-Year Evaluation

    ERIC Educational Resources Information Center

    Gfellner, Barbara M.; McLaren, Lorraine; Metcalfe, Arron

    2008-01-01

    This article is a 20-year evaluation of the Parent-Child Home Program (PCHP) of Child and Family Services in Western Manitoba. Following Levenstein's (1979, 1988) approach, home visitors model parent-child interchanges using books and toys to enhance children's cognitive development through appropriate parenting behaviors. The evaluation provides…

  10. Intellectual Capital: For 20 Years, American Indian College Fund Has Been Investing

    ERIC Educational Resources Information Center

    Horwedel, Dina M.

    2009-01-01

    For 20 years, the American Indian College Fund (the Fund) has been helping students to afford a higher education. In addition to providing more than 4,000 scholarships for American Indian students last year, it also provides tribal colleges with funding and programmatic support. The Fund was created in 1989 by the tribal colleges and universities…

  11. Looking Back and Ahead: 20 Years of Technologies for Language Learning

    ERIC Educational Resources Information Center

    Godwin-Jones, Robert

    2016-01-01

    Over the last 20 years Robert Godwin-Jones has written 48 columns on "Emerging Technologies"; an additional six columns have been written by guest columnists. Several topics have been re-examined in regular intervals of approximately five years, namely digital literacy (Vol. 4, Num. 2; Vol. 10, Num. 2; Vol. 14, Num. 3; Vol. 19, Num. 3)…

  12. Changes and Challenges in 20 Years of Research into the Development of Executive Functions

    ERIC Educational Resources Information Center

    Hughes, Claire

    2011-01-01

    This review of 20 years of developmental research on Executive Functions (EF) offers a broad-brushstroke picture that touches on multiple issues including: (i) findings from typical and atypical groups, from infancy to adolescence; (ii) advances in assessment tools and in statistical analysis; (iii) the interplay between EF and other cognitive…

  13. Understanding Rape and Sexual Assault: 20 Years of Progress and Future Directions

    ERIC Educational Resources Information Center

    Campbell, Rebecca; Wasco, Sharon M.

    2005-01-01

    During the past 20 years, researchers have documented the widespread problem of rape in American society. Approximately one in four women are raped in their adult lifetime, which causes severe psychological distress and long-term physical health problems. The impact of sexual assault extends far beyond rape survivors as their family, friends, and…

  14. Self-Rated Activity Levels and Longevity: Evidence from a 20 Year Longitudinal Study

    ERIC Educational Resources Information Center

    Mullee, Mark A.; Coleman, Peter G.; Briggs, Roger S. J.; Stevenson, James E.; Turnbull, Joanne C.

    2008-01-01

    The study reports on factors predicting the longevity of 328 people over the age of 65 drawn from an English city and followed over 20 years. Both the reported activities score and the individual's comparative evaluation of their own level of activity independently reduced the risk of death, even when health and cognitive status were taken into…

  15. 20 Years of Autonomy and Technology: How Far Have We Come and Where to Next?

    ERIC Educational Resources Information Center

    Reinders, Hayo; White, Cynthia

    2016-01-01

    Learner autonomy has become an assumed goal of language education in many parts of the world. In the 20 years since the launch of "Language Learning & Technology," the relationship among computer-assisted language learning research and practice and autonomy has become both more complex and more promising. This article traces how the…

  16. MOZAIC-IAGOS program : 20 years of in-situ data in the UTLS

    NASA Astrophysics Data System (ADS)

    Thouret, Valérie; Sauvage, Bastien; Nédélec, Philippe; Petzold, Andreas; Volz-Thomas, Andreas

    2014-05-01

    -latitudes thanks to 5 aircraft based in Europe flying westbound and eastbound since 1994; Transects over the African continent thanks to daily Air Namibia flights between 2006 and 2013; South Atlantic area thanks to regular flights between Europe and South America; The Asian monsoon region thanks to regular flights between Europe and the Indian-South East Asia area sampling the UT under the influence of the Asian Monsoon Anticyclone (AMA). - Ten years of CO measurements which show an increase in concentration on moving from the Western to Eastern hemisphere. In the US, Atlantic and European sectors CO concentrations have fallen by about 2% per year. - Almost 20 years of Ozone measurements at northern mid-latitudes showing a leveling-off of the mixing ratios for the last 10-12 years over the Atlantic sector while ozone is still increasing over Asia. - Almost 20 years of relative humidity measurements showing that the upper troposphere (10 - 12 km altitude, which corresponds to the aircraft cruise level) is much wetter than reflected in the model analyses of the ECMWF (European Centre for Medium range Weather Forecast).

  17. Acute increases in night-time plasma melatonin levels following a period of meditation.

    PubMed

    Tooley, G A; Armstrong, S M; Norman, T R; Sali, A

    2000-05-01

    To determine whether a period of meditation could influence melatonin levels, two groups of meditators were tested in a repeated measures design for changes in plasma melatonin levels at midnight. Experienced meditators practising either TM-Sidhi or another internationally well known form of yoga showed significantly higher plasma melatonin levels in the period immediately following meditation compared with the same period at the same time on a control night. It is concluded that meditation, at least in the two forms studied here, can affect plasma melatonin levels. It remains to be determined whether this is achieved through decreased hepatic metabolism of the hormone or via a direct effect on pineal physiology. Either way, facilitation of higher physiological melatonin levels at appropriate times of day might be one avenue through which the claimed health promoting effects of meditation occur.

  18. Periodic bifurcation of Duffing-van der Pol oscillators having fractional derivatives and time delay

    NASA Astrophysics Data System (ADS)

    Leung, A. Y. T.; Yang, H. X.; Zhu, P.

    2014-04-01

    In this paper, a Duffing-van der Pol oscillator having fractional derivatives and time delays is investigated by the residue harmonic method. The angular frequencies and limit cycles of periodic motions are expanded into a power series of an order-tracking parameter and the unbalanced residues resulting from the truncated Fourier series are considered iteratively to improve the accuracy. The periodic bifurcations are examined using the fractional order, feedback gain and time delay as continuation parameters. It is shown that jumps and hysteresis phenomena can be delayed or removed. Transition from discontinuous bifurcation to continuous bifurcation is observed. The approximations are verified by numerical integration. We find that the proposed method can easily be programmed and can predict accurate periodic approximations while the system parameters being unfolded.

  19. 20 years of ClO measurements in the Antarctic lower stratosphere

    NASA Astrophysics Data System (ADS)

    Nedoluha, Gerald E.; Connor, Brian J.; Mooney, Thomas; Barrett, James W.; Parrish, Alan; Gomez, R. Michael; Boyd, Ian; Allen, Douglas R.; Kotkamp, Michael; Kremser, Stefanie; Deshler, Terry; Newman, Paul; Santee, Michelle L.

    2016-08-01

    We present 20 years (1996-2015) of austral springtime measurements of chlorine monoxide (ClO) over Antarctica from the Chlorine Oxide Experiment (ChlOE1) ground-based millimeter wave spectrometer at Scott Base, Antarctica, as well 12 years (2004-2015) of ClO measurements from the Aura Microwave Limb Sounder (MLS). From August onwards we observe a strong increase in lower stratospheric ClO, with a peak column amount usually occurring in early September. From mid-September onwards we observe a strong decrease in ClO. In order to study interannual differences, we focus on a 3-week period from 28 August to 17 September for each year and compare the average column ClO anomalies. These column ClO anomalies are shown to be highly correlated with the average ozone mass deficit for September and October of each year. We also show that anomalies in column ClO are strongly anti-correlated with 30 hPa temperature anomalies, both on a daily and an interannual timescale. Making use of this anti-correlation we calculate the linear dependence of the interannual variations in column ClO on interannual variations in temperature. By making use of this relationship, we can better estimate the underlying trend in the total chlorine (Cly = HCl + ClONO2 + HOCl + 2 × Cl2 + 2 × Cl2O2 + ClO + Cl). The resultant trends in Cly, which determine the long-term trend in ClO, are estimated to be -0.5 ± 0.2, -1.4 ± 0.9, and -0.6 ± 0.4 % year-1, for zonal MLS, Scott Base MLS (both 2004-2015), and ChlOE (1996-2015) respectively. These trends are within 1σ of trends in stratospheric Cly previously found at other latitudes. The decrease in ClO is consistent with the trend expected from regulations enacted under the Montreal Protocol.

  20. DUACS DT2014: the new multi-mission altimeter data set reprocessed over 20 years

    NASA Astrophysics Data System (ADS)

    Pujol, Marie-Isabelle; Faugère, Yannice; Taburet, Guillaume; Dupuy, Stéphanie; Pelloquin, Camille; Ablain, Michael; Picot, Nicolas

    2016-09-01

    The new DUACS DT2014 reprocessed products have been available since April 2014. Numerous innovative changes have been introduced at each step of an extensively revised data processing protocol. The use of a new 20-year altimeter reference period in place of the previous 7-year reference significantly changes the sea level anomaly (SLA) patterns and thus has a strong user impact. The use of up-to-date altimeter standards and geophysical corrections, reduced smoothing of the along-track data, and refined mapping parameters, including spatial and temporal correlation-scale refinement and measurement errors, all contribute to an improved high-quality DT2014 SLA data set. Although all of the DUACS products have been upgraded, this paper focuses on the enhancements to the gridded SLA products over the global ocean. As part of this exercise, 21 years of data have been homogenized, allowing us to retrieve accurate large-scale climate signals such as global and regional MSL trends, interannual signals, and better refined mesoscale features.An extensive assessment exercise has been carried out on this data set, which allows us to establish a consolidated error budget. The errors at mesoscale are about 1.4 cm2 in low-variability areas, increase to an average of 8.9 cm2 in coastal regions, and reach nearly 32.5 cm2 in high mesoscale activity areas. The DT2014 products, compared to the previous DT2010 version, retain signals for wavelengths lower than ˜ 250 km, inducing SLA variance and mean EKE increases of, respectively, +5.1 and +15 %. Comparisons with independent measurements highlight the improved mesoscale representation within this new data set. The error reduction at the mesoscale reaches nearly 10 % of the error observed with DT2010. DT2014 also presents an improved coastal signal with a nearly 2 to 4 % mean error reduction. High-latitude areas are also more accurately represented in DT2014, with an improved consistency between spatial coverage and sea ice edge

  1. Molecular response properties from a Hermitian eigenvalue equation for a time-periodic Hamiltonian

    NASA Astrophysics Data System (ADS)

    Pawłowski, Filip; Olsen, Jeppe; Jørgensen, Poul

    2015-03-01

    The time-dependent Schrödinger equation for a time-periodic perturbation is recasted into a Hermitian eigenvalue equation, where the quasi-energy is an eigenvalue and the time-periodic regular wave function an eigenstate. From this Hermitian eigenvalue equation, a rigorous and transparent formulation of response function theory is developed where (i) molecular properties are defined as derivatives of the quasi-energy with respect to perturbation strengths, (ii) the quasi-energy can be determined from the time-periodic regular wave function using a variational principle or via projection, and (iii) the parametrization of the unperturbed state can differ from the parametrization of the time evolution of this state. This development brings the definition of molecular properties and their determination on par for static and time-periodic perturbations and removes inaccuracies and inconsistencies of previous response function theory formulations. The development where the parametrization of the unperturbed state and its time evolution may differ also extends the range of the wave function models for which response functions can be determined. The simplicity and universality of the presented formulation is illustrated by applying it to the configuration interaction (CI) and the coupled cluster (CC) wave function models and by introducing a new model—the coupled cluster configuration interaction (CC-CI) model—where a coupled cluster exponential parametrization is used for the unperturbed state and a linear parametrization for its time evolution. For static perturbations, the CC-CI response functions are shown to be the analytical analogues of the static molecular properties obtained from finite field equation-of-motion coupled cluster (EOMCC) energy calculations. The structural similarities and differences between the CI, CC, and CC-CI response functions are also discussed with emphasis on linear versus non-linear parametrizations and the size-extensivity of the

  2. A Gaussian Process Based Online Change Detection Algorithm for Monitoring Periodic Time Series

    SciTech Connect

    Chandola, Varun; Vatsavai, Raju

    2011-01-01

    Online time series change detection is a critical component of many monitoring systems, such as space and air-borne remote sensing instruments, cardiac monitors, and network traffic profilers, which continuously analyze observations recorded by sensors. Data collected by such sensors typically has a periodic (seasonal) component. Most existing time series change detection methods are not directly applicable to handle such data, either because they are not designed to handle periodic time series or because they cannot operate in an online mode. We propose an online change detection algorithm which can handle periodic time series. The algorithm uses a Gaussian process based non-parametric time series prediction model and monitors the difference between the predictions and actual observations within a statistically principled control chart framework to identify changes. A key challenge in using Gaussian process in an online mode is the need to solve a large system of equations involving the associated covariance matrix which grows with every time step. The proposed algorithm exploits the special structure of the covariance matrix and can analyze a time series of length T in O(T^2) time while maintaining a O(T) memory footprint, compared to O(T^4) time and O(T^2) memory requirement of standard matrix manipulation methods. We experimentally demonstrate the superiority of the proposed algorithm over several existing time series change detection algorithms on a set of synthetic and real time series. Finally, we illustrate the effectiveness of the proposed algorithm for identifying land use land cover changes using Normalized Difference Vegetation Index (NDVI) data collected for an agricultural region in Iowa state, USA. Our algorithm is able to detect different types of changes in a NDVI validation data set (with ~80% accuracy) which occur due to crop type changes as well as disruptive changes (e.g., natural disasters).

  3. Identifying the Critical Time Period for Information Extraction when Recognizing Sequences of Play

    ERIC Educational Resources Information Center

    North, Jamie S.; Williams, A. Mark

    2008-01-01

    The authors attempted to determine the critical time period for information extraction when recognizing play sequences in soccer. Although efforts have been made to identify the perceptual information underpinning such decisions, no researchers have attempted to determine "when" this information may be extracted from the display. The authors…

  4. The Role of Thermal Properties in Periodic Time-Varying Phenomena

    ERIC Educational Resources Information Center

    Marin, E.

    2007-01-01

    The role played by physical parameters governing the transport of heat in periodical time-varying phenomena within solids is discussed. Starting with a brief look at the conduction heat transport mechanism, the equations governing heat conduction under static, stationary and non-stationary conditions, and the physical parameters involved, are…

  5. Real-time control of the period of individual ELMs by EC power on TCV

    NASA Astrophysics Data System (ADS)

    Felici, F.; Rossel, J. X.; Duval, B. P.; Coda, S.; Goodman, T. P.; Martin, Y.; Moret, J.-M.; Sauter, O.; the TCV Team

    2013-11-01

    The period of individual type-I edge-localized modes (ELMs) in TCV H-mode plasmas is controlled by real-time controlled application of electron cyclotron (EC) power close to the plasma pedestal. An ELM pacing algorithm, closely related to sawtooth pacing (Goodman et al (2011 Phys. Rev. Lett. 106 245002)) has been implemented in the TCV control system. This algorithm switches the EC power to a low level after detecting an ELM, and subsequently increases the power to a higher level after a pre-set time interval, stimulating the advent of the next ELM. While the mean ELM period is observed to depend only on the mean power applied, ELM pacing is shown to significantly regularize the ELM period with respect to the case of continuously applied power. It is also shown that the ELM period can be changed from one ELM to the next on time scales shorter than the global energy confinement time. These results present a challenging benchmark to physics-based pedestal models and can point towards obtaining a deeper understanding of the physics of individual ELM cycles.

  6. 19 CFR 351.524 - Allocation of benefit to a particular time period.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 3 2014-04-01 2014-04-01 false Allocation of benefit to a particular time period. 351.524 Section 351.524 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE... support payments; discounts on electricity, water, and other utilities; freight subsidies;...

  7. 9 CFR 201.217 - Reasonable period of time to remedy a breach of contract.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Reasonable period of time to remedy a breach of contract. 201.217 Section 201.217 Animals and Animal Products GRAIN INSPECTION, PACKERS AND... contract or agreement where food safety or animal welfare is concerned. These criteria, include, but...

  8. 41 CFR 105-8.150-3 - Time period for compliance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false Time period for compliance. 105-8.150-3 Section 105-8.150-3 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION 8-ENFORCEMENT OF...

  9. 41 CFR 105-8.150-3 - Time period for compliance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false Time period for compliance. 105-8.150-3 Section 105-8.150-3 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION 8-ENFORCEMENT OF...

  10. 41 CFR 105-8.150-3 - Time period for compliance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 3 2013-07-01 2013-07-01 false Time period for compliance. 105-8.150-3 Section 105-8.150-3 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION 8-ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS...

  11. 41 CFR 105-8.150-3 - Time period for compliance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Time period for compliance. 105-8.150-3 Section 105-8.150-3 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION 8-ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS...

  12. 18 CFR 290.103 - Time of filing and reporting period.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Time of filing and reporting period. 290.103 Section 290.103 Conservation of Power and Water Resources FEDERAL ENERGY... 1978 COLLECTION OF COST OF SERVICE INFORMATION UNDER SECTION 133 OF THE PUBLIC UTILITY...

  13. 18 CFR 290.103 - Time of filing and reporting period.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Time of filing and reporting period. 290.103 Section 290.103 Conservation of Power and Water Resources FEDERAL ENERGY... 1978 COLLECTION OF COST OF SERVICE INFORMATION UNDER SECTION 133 OF THE PUBLIC UTILITY...

  14. 9 CFR 201.217 - Reasonable period of time to remedy a breach of contract.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Reasonable period of time to remedy a breach of contract. 201.217 Section 201.217 Animals and Animal Products GRAIN INSPECTION, PACKERS AND... termination. These criteria do not limit a packer, swine contractor or live poultry dealer's rights under...

  15. 9 CFR 201.217 - Reasonable period of time to remedy a breach of contract.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Reasonable period of time to remedy a breach of contract. 201.217 Section 201.217 Animals and Animal Products GRAIN INSPECTION, PACKERS AND... termination. These criteria do not limit a packer, swine contractor or live poultry dealer's rights under...

  16. 42 CFR 87.7 - For what period of time will grants be awarded?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false For what period of time will grants be awarded? 87.7 Section 87.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY...

  17. 5 CFR 550.404 - Computation of advance payments and evacuation payments; time periods.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Computation of advance payments and... Computation of advance payments and evacuation payments; time periods. (a) Payments shall be based on the rate... others, when applicable, shall be made before advance payments or evacuation payments are made....

  18. 5 CFR 550.404 - Computation of advance payments and evacuation payments; time periods.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Computation of advance payments and... Computation of advance payments and evacuation payments; time periods. (a) Payments shall be based on the rate... others, when applicable, shall be made before advance payments or evacuation payments are made....

  19. Forum Page Letters in the "Straits Times" of Singapore during Relatively Free and Restricted Press Periods.

    ERIC Educational Resources Information Center

    Ramaprasad, Jyotika; Ong, James

    In order to identify the scope or limits of the practice of development journalism, a study examined the content of the Forum page in the "Straits Times" of Singapore during relatively free (1979-1980) and restricted (1986-1987) press periods. The study had two major objectives: (1) to study the nature of the Forum page (a readers' letter page in…

  20. Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research.

    PubMed

    Harper, Liam D; Fothergill, Melissa; West, Daniel J; Stevenson, Emma; Russell, Mark

    2016-01-01

    Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery

  1. Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research.

    PubMed

    Harper, Liam D; Fothergill, Melissa; West, Daniel J; Stevenson, Emma; Russell, Mark

    2016-01-01

    Qualitative research investigating soccer practitioners' perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: 'importance of extra-time', 'rule changes', 'efficacy of extra-time hydro-nutritional provision', 'nutritional timing', 'future research directions', 'preparatory modulations' and 'recovery'. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses, acute injury risk, recovery

  2. Reliability of Fitness Tests Using Methods and Time Periods Common in Sport and Occupational Management

    PubMed Central

    Burnstein, Bryan D.; Steele, Russell J.; Shrier, Ian

    2011-01-01

    Context: Fitness testing is used frequently in many areas of physical activity, but the reliability of these measurements under real-world, practical conditions is unknown. Objective: To evaluate the reliability of specific fitness tests using the methods and time periods used in the context of real-world sport and occupational management. Design: Cohort study. Setting: Eighteen different Cirque du Soleil shows. Patients or Other Participants: Cirque du Soleil physical performers who completed 4 consecutive tests (6-month intervals) and were free of injury or illness at each session (n = 238 of 701 physical performers). Intervention(s): Performers completed 6 fitness tests on each assessment date: dynamic balance, Harvard step test, handgrip, vertical jump, pull-ups, and 60-second jump test. Main Outcome Measure(s): We calculated the intraclass coefficient (ICC) and limits of agreement between baseline and each time point and the ICC over all 4 time points combined. Results: Reliability was acceptable (ICC > 0.6) over an 18-month time period for all pairwise comparisons and all time points together for the handgrip, vertical jump, and pull-up assessments. The Harvard step test and 60-second jump test had poor reliability (ICC < 0.6) between baseline and other time points. When we excluded the baseline data and calculated the ICC for 6-month, 12-month, and 18-month time points, both the Harvard step test and 60-second jump test demonstrated acceptable reliability. Dynamic balance was unreliable in all contexts. Limit-of-agreement analysis demonstrated considerable intraindividual variability for some tests and a learning effect by administrators on others. Conclusions: Five of the 6 tests in this battery had acceptable reliability over an 18-month time frame, but the values for certain individuals may vary considerably from time to time for some tests. Specific tests may require a learning period for administrators. PMID:22488138

  3. Developmental histories of perceived racial discrimination and diurnal cortisol profiles in adulthood: A 20-year prospective study.

    PubMed

    Adam, Emma K; Heissel, Jennifer A; Zeiders, Katharine H; Richeson, Jennifer A; Ross, Emily C; Ehrlich, Katherine B; Levy, Dorainne J; Kemeny, Margaret; Brodish, Amanda B; Malanchuk, Oksana; Peck, Stephen C; Fuller-Rowell, Thomas E; Eccles, Jacquelynne S

    2015-12-01

    Perceived racial discrimination (PRD) has been associated with altered diurnal cortisol rhythms in past cross-sectional research. We investigate whether developmental histories of PRD, assessed prospectively, are associated with adult diurnal cortisol profiles. One-hundred and twelve (N=50 Black, N=62 White) adults from the Maryland Adolescent Development in Context Study provided saliva samples in adulthood (at approximately age 32 years) at waking, 30min after waking, and at bedtime for 7 days. Diurnal cortisol measures were calculated, including waking cortisol levels, diurnal cortisol slopes, the cortisol awakening response (CAR), and average daily cortisol (AUC). These cortisol outcomes were predicted from measures of PRD obtained over a 20-year period beginning when individuals were in 7th grade (approximately age 12). Greater average PRD measured across the 20-year period predicted flatter adult diurnal cortisol slopes for both Black and White adults, and a lower CAR. Greater average PRD also predicted lower waking cortisol for Black, but not White adults. PRD experiences in adolescence accounted for many of these effects. When adolescent and young adult PRD are entered together predicting cortisol outcomes, PRD experiences in adolescence (but not young adulthood) significantly predicted flatter diurnal cortisol slopes for both Black and White adults. Adolescent, but not young adult PRD, also significantly predicted lower waking and lower average cortisol for Black adults. Young adult PRD was, however, a stronger predictor of the CAR, predicting a marginally lower CAR for Whites, and a significantly larger CAR for Blacks. Effects were robust to controlling for covariates including health behaviors, depression, income and parent education levels. PRD experiences interacted with parent education and income to predict aspects of the diurnal cortisol rhythm. Although these results suggest PRD influences on cortisol for both Blacks and Whites, the key findings

  4. Time-space Variability of Weekly to Monthly Period Equatorial Waves in the Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Durland, T.; Farrar, J. T.

    2015-12-01

    Data from satellite altimetry are used to characterize wavelike variability in the tropical Pacific Ocean at periods of days to two months. This period band is of interest because the space-time scales of oceanic equatorial waves at these frequencies have historically made adequate observation of the variability difficult. These waves have zonal scales that are very large (exceeding 3000 km) and meridional scales that are relatively short (~100 km), making in situ measurements difficult, and the short temporal scales pose challenges for observation with satellite altimeters because the wave periods are short compared to orbit repeat periods. As a result, there has been relatively little progress since the early 1980s in characterizing and understanding these equatorial inertia-gravity and mixed Rossby-gravity waves. In this analysis, we seek to exploit the long zonal length scales of these high-frequency equatorial waves in an analysis of satellite scatterometer and altimeter data to shed new light on the properties and dynamics of these waves. At periods of 2-14 days, there is clear evidence for the presence of several basin-scale equatorial wave modes, including mixed Rossby-gravity waves and inertia-gravity waves associated with baroclinic modes one and two. Here, we focus on equatorial Kelvin waves and mixed Rossby-gravity waves forced in the western Pacific, and examine their variability in time and space and their relation to wind.

  5. The Varying Light Curve and Timings of the Ultrashort-period Contact Binary KIC 9532219

    NASA Astrophysics Data System (ADS)

    Lee, Jae Woo; Hong, Kyeongsoo; Koo, Jae-Rim; Park, Jang-Ho

    2016-03-01

    KIC 9532219 is a W UMa-type eclipsing binary with an orbital period of 0.1981549 days that is below the short-period limit (˜0.22 days) of the period distribution for contact binaries. The Kepler light curve of the system exhibits striking changes in both eclipse depths and light maxima. Applying third-body and spot effects, the light-curve synthesis indicates that the eclipsing pair is currently in a marginal contact stage with a mass ratio of q = 1.20, an orbital inclination of i = 66.°0, a temperature difference of T1-T2 = 172 K, and a third light of l3 = 75.9%. To understand the light variations with time, we divided up the light curve into 312 segments and analyzed them separately. The results reveal that variation of eclipse depth is primarily caused by changing amounts of contamination due to the nearby star KIC 9532228 between the Kepler Quarters and that the variable O’Connell effect originates from the starspot activity on the less massive primary component. Based on our light-curve timings, a period study of KIC 9532219 indicates that the orbital period has varied as a combination of a downward parabola and a light-travel-time (LTT) effect due to a third body, which has a period of 1196 days and a minimum mass of 0.0892 M⊙ in an orbit of eccentricity 0.150. The parabolic variation could be a small part of a second LTT orbit due to a fourth component in a wider orbit, instead of either mass transfer or angular momentum loss.

  6. Child Mortality Estimation: Appropriate Time Periods for Child Mortality Estimates from Full Birth Histories

    PubMed Central

    Pedersen, Jon; Liu, Jing

    2012-01-01

    Background Child mortality estimates from complete birth histories from Demographic and Health Surveys (DHS) surveys and similar surveys are a chief source of data used to track Millennium Development Goal 4, which aims for a reduction of under-five mortality by two-thirds between 1990 and 2015. Based on the expected sample sizes when the DHS program commenced, the estimates are usually based on 5-y time periods. Recent surveys have had larger sample sizes than early surveys, and here we aimed to explore the benefits of using shorter time periods than 5 y for estimation. We also explore the benefit of changing the estimation procedure from being based on years before the survey, i.e., measured with reference to the date of the interview for each woman, to being based on calendar years. Methods and Findings Jackknife variance estimation was used to calculate standard errors for 207 DHS surveys in order to explore to what extent the large samples in recent surveys can be used to produce estimates based on 1-, 2-, 3-, 4-, and 5-y periods. We also recalculated the estimates for the surveys into calendar-year-based estimates. We demonstrate that estimation for 1-y periods is indeed possible for many recent surveys. Conclusions The reduction in bias achieved using 1-y periods and calendar-year-based estimation is worthwhile in some cases. In particular, it allows tracking of the effects of particular events such as droughts, epidemics, or conflict on child mortality in a way not possible with previous estimation procedures. Recommendations to use estimation for short time periods when possible and to use calendar-year-based estimation were adopted in the United Nations 2011 estimates of child mortality. PMID:22952435

  7. Effects of combined linear and nonlinear periodic training on physical fitness and competition times in finswimmers

    PubMed Central

    Yu, Kyung-Hun; Suk, Min-Hwa; Kang, Shin-Woo; Shin, Yun-A

    2014-01-01

    The purpose of this study was to investigate the effect of combined linear and nonlinear periodic training on physical fitness and competition times in finswimmers. The linear resistance training model (6 days/week) and nonlinear underwater training (4 days/week) were applied to 12 finswimmers (age, 16.08± 1.44 yr; career, 3.78± 1.90 yr) for 12 weeks. Body composition measures included weight, body mass index (BMI), percent fat, and fat-free mass. Physical fitness measures included trunk flexion forward, trunk extension backward, sargent jump, 1-repetition-maximum (1 RM) squat, 1 RM dead lift, knee extension, knee flexion, trunk extension, trunk flexion, and competition times. Body composition and physical fitness were improved after the 12-week periodic training program. Weight, BMI, and percent fat were significantly decreased, and trunk flexion forward, trunk extension backward, sargent jump, 1 RM squat, 1 RM dead lift, and knee extension (right) were significantly increased. The 50- and 100-m times significantly decreased in all 12 athletes. After 12 weeks of training, all finswimmers who participated in this study improved their times in a public competition. These data indicate that combined linear and nonlinear periodic training enhanced the physical fitness and competition times in finswimmers. PMID:25426469

  8. The effect of entrainment on the timing of periodic eye movements.

    PubMed

    Richardson, Brian A; Balasubramaniam, Ramesh

    2010-01-18

    We performed an experiment in which eight healthy individuals made periodic eye movements at five pacing interval conditions (500 ms, 750 ms, 1000 ms, 1250 ms, and 1500 ms). Three methods of entrainment were used in the synchronization phase: saccade, continuous pursuit and discontinuous pursuit. The stimulus train was extinguished and in the continuation phase, subjects made saccadic eye movements at the entrained movement frequencies between two static targets. Using the Wing-Kristofferson model, clock and motor variance were extracted from the time series of continuation trials for all three entrainment conditions. Our results revealed a main effect of time interval on total variance clock variance (as predicted by Weber's law) and on motor variance. We also report that the pursuit entrainment conditions resulted in and mean duration and variance to the saccade entrainment. These results suggest that the neural networks recruited to support a periodic motor timing task depend on the method used to establish the temporal reference.

  9. Periodic trim solutions with HP-version finite elements in time

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Finite Element in Time has been proven to be a powerful alternative solving strategy for the rotor craft trim problem. Additionally, Finite Element Method in Time has been developed in various versions like time-marching framework, Galerkin framework, Rayleigh-Ritz framework, and mixed formulation. Recently, this method was applied to the rotorcraft trim problem to obtain linearized solutions. The rotorcraft trim problem consists of trying to find a period solution for period-coefficient, differential equations subject to side constraints where certain force and momentum balance equations are forced to be equal to zero. There are free (or trim) parameters that are chosen to meet these side constraints. This project aims at expanding the application, in terms of the rotorcraft trim problem, from a linearized solution to nonlinear solution.

  10. Association of intrinsic circadian period with morningness-eveningness, usual wake time, and circadian phase

    NASA Technical Reports Server (NTRS)

    Duffy, J. F.; Rimmer, D. W.; Czeisler, C. A.

    2001-01-01

    The biological basis of preferences for morning or evening activity patterns ("early birds" and "night owls") has been hypothesized but has remained elusive. The authors reported that, compared with evening types, the circadian pacemaker of morning types was entrained to an earlier hour with respect to both clock time and wake time. The present study explores a chronobiological mechanism by which the biological clock of morning types may be set to an earlier hour. Intrinsic period, a fundamental property of the circadian system, was measured in a month-long inpatient study. A subset of participants also had their circadian phase assessed. Participants completed a morningness-eveningness questionnaire before study. Circadian period was correlated with morningness-eveningness, circadian phase, and wake time, demonstrating that a fundamental property of the circadian pacemaker is correlated with the behavioral trait of morningness-eveningness.

  11. Estimating Periodic Software Rejuvenation Schedules under Discrete-Time Operation Circumstance

    NASA Astrophysics Data System (ADS)

    Iwamoto, Kazuki; Dohi, Tadashi; Kaio, Naoto

    Software rejuvenation is a preventive and proactive solution that is particularly useful for counteracting the phenomenon of software aging. In this article, we consider periodic software rejuvenation models based on the expected cost per unit time in the steady state under discrete-time operation circumstance. By applying the discrete renewal reward processes, we describe the stochastic behavior of a telecommunication billing application with a degradation mode, and determine the optimal periodic software rejuvenation schedule minimizing the expected cost. Similar to the earlier work by the same authors, we develop a statistically non-parametric algorithm to estimate the optimal software rejuvenation schedule, by applying the discrete total time on test concept. Numerical examples are presented to estimate the optimal software rejuvenation schedules from the simulation data. We discuss the asymptotic behavior of estimators developed in this paper.

  12. Sex difference in the near-24-hour intrinsic period of the human circadian timing system

    PubMed Central

    Duffy, Jeanne F.; Cain, Sean W.; Chang, Anne-Marie; Phillips, Andrew J. K.; Münch, Mirjam Y.; Gronfier, Claude; Wyatt, James K.; Dijk, Derk-Jan; Czeisler, Charles A.

    2011-01-01

    The circadian rhythms of melatonin and body temperature are set to an earlier hour in women than in men, even when the women and men maintain nearly identical and consistent bedtimes and wake times. Moreover, women tend to wake up earlier than men and exhibit a greater preference for morning activities than men. Although the neurobiological mechanism underlying this sex difference in circadian alignment is unknown, multiple studies in nonhuman animals have demonstrated a sex difference in circadian period that could account for such a difference in circadian alignment between women and men. Whether a sex difference in intrinsic circadian period in humans underlies the difference in circadian alignment between men and women is unknown. We analyzed precise estimates of intrinsic circadian period collected from 157 individuals (52 women, 105 men; aged 18–74 y) studied in a month-long inpatient protocol designed to minimize confounding influences on circadian period estimation. Overall, the average intrinsic period of the melatonin and temperature rhythms in this population was very close to 24 h [24.15 ± 0.2 h (24 h 9 min ± 12 min)]. We further found that the intrinsic circadian period was significantly shorter in women [24.09 ± 0.2 h (24 h 5 min ± 12 min)] than in men [24.19 ± 0.2 h (24 h 11 min ± 12 min); P < 0.01] and that a significantly greater proportion of women have intrinsic circadian periods shorter than 24.0 h (35% vs. 14%; P < 0.01). The shorter average intrinsic circadian period observed in women may have implications for understanding sex differences in habitual sleep duration and insomnia prevalence. PMID:21536890

  13. Global exponential periodicity and stability of discrete-time complex-valued recurrent neural networks with time-delays.

    PubMed

    Hu, Jin; Wang, Jun

    2015-06-01

    In recent years, complex-valued recurrent neural networks have been developed and analysed in-depth in view of that they have good modelling performance for some applications involving complex-valued elements. In implementing continuous-time dynamical systems for simulation or computational purposes, it is quite necessary to utilize a discrete-time model which is an analogue of the continuous-time system. In this paper, we analyse a discrete-time complex-valued recurrent neural network model and obtain the sufficient conditions on its global exponential periodicity and exponential stability. Simulation results of several numerical examples are delineated to illustrate the theoretical results and an application on associative memory is also given.

  14. A General Approach to Time Periodic Incompressible Viscous Fluid Flow Problems

    NASA Astrophysics Data System (ADS)

    Geissert, Matthias; Hieber, Matthias; Nguyen, Thieu Huy

    2016-06-01

    This article develops a general approach to time periodic incompressible fluid flow problems and semilinear evolution equations. It yields, on the one hand, a unified approach to various classical problems in incompressible fluid flow and, on the other hand, gives new results for periodic solutions to the Navier-Stokes-Oseen flow, the Navier-Stokes flow past rotating obstacles, and, in the geophysical setting, for Ornstein-Uhlenbeck and various diffusion equations with rough coefficients. The method is based on a combination of interpolation and topological arguments, as well as on the smoothing properties of the linearized equation.

  15. Continuous Time Random Walks in periodic systems: fluid limit and fractional differential equations on the circle

    SciTech Connect

    Calvo, Ivan; Carreras, Benjamin A; Sanchez, Raul; van Milligen, B. Ph.

    2007-01-01

    In this article, the continuous time random walk on the circle is studied. We derive the corresponding generalized master equation and discuss the effects of topology, especially important when Levy flights are allowed. Then, we work out the fluid limit equation, formulated in terms of the periodic version of the fractional Riemann-Liouville operators, for which we provide explicit expressions. Finally, we compute the propagator in some simple cases. The analysis presented herein should be relevant when investigating anomalous transport phenomena in systems with periodic dimensions.

  16. Plasticity of the Intrinsic Period of the Human Circadian Timing System

    PubMed Central

    Scheer, Frank A.J.L.; Wright, Kenneth P.; Kronauer, Richard E.; Czeisler, Charles A.

    2007-01-01

    Human expeditions to Mars will require adaptation to the 24.65-h Martian solar day-night cycle (sol), which is outside the range of entrainment of the human circadian pacemaker under lighting intensities to which astronauts are typically exposed. Failure to entrain the circadian time-keeping system to the desired rest-activity cycle disturbs sleep and impairs cognitive function. Furthermore, differences between the intrinsic circadian period and Earth's 24-h light-dark cycle underlie human circadian rhythm sleep disorders, such as advanced sleep phase disorder and non-24-hour sleep-wake disorders. Therefore, first, we tested whether exposure to a model-based lighting regimen would entrain the human circadian pacemaker at a normal phase angle to the 24.65-h Martian sol and to the 23.5-h day length often required of astronauts during short duration space exploration. Second, we tested here whether such prior entrainment to non-24-h light-dark cycles would lead to subsequent modification of the intrinsic period of the human circadian timing system. Here we show that exposure to moderately bright light (∼450 lux; ∼1.2 W/m2) for the second or first half of the scheduled wake episode is effective for entraining individuals to the 24.65-h Martian sol and a 23.5-h day length, respectively. Estimations of the circadian periods of plasma melatonin, plasma cortisol, and core body temperature rhythms collected under forced desynchrony protocols revealed that the intrinsic circadian period of the human circadian pacemaker was significantly longer following entrainment to the Martian sol as compared to following entrainment to the 23.5-h day. The latter finding of after-effects of entrainment reveals for the first time plasticity of the period of the human circadian timing system. Both findings have important implications for the treatment of circadian rhythm sleep disorders and human space exploration. PMID:17684566

  17. Particle Fluxes in the Marginal Seas of Antarctica: A 20-year Synthesis in Honor of Jack Dymond

    NASA Astrophysics Data System (ADS)

    Dunbar, R. B.; Langone, L.

    2004-12-01

    One of Jack Dymond's long-standing scientific passions was the study of particles moving through the ocean water column. Jack's pioneering work in this area in the 1970's and generous mentoring of others throughout his career lead directly to the first authors involvement in sediment trap studies. Here we present a synthesis of 20 years of particle flux studies in coastal Antarctic (including the work of Collier and Dymond et al.) and highlight some of the important features and unresolved issues related to integrating particle trap interceptor data with other measures of production, transport, and deposition. The first sediment trap arrays were deployed on the Antarctic shelf in 1981 and 1982 in the Antarctic Peninsula. Simple instruments were also deployed in 1984 and 1986 in the Ross Sea. Since then, several nations (US, Italy, New Zealand) have recovered time series sediment trap data on moorings in both of these areas. This current synthesis makes use of data from approximately 22 sites, the majority of which are in the Ross Sea, and includes about 900 discrete samples of particles in vertical transit through the water column. We now have many complete time series that extend through the winter, allowing several important generalizations to be made. For example, annual particle-mediated organic C fluxes to below 200 meters in the Ross Sea average 4.4±3.3 g C m-2 yr-1. These values are significantly less than export fluxes calculated using short-term surface water mass balance approaches or Th isotope techniques yet are higher than seabed sediment accumulation rates. Intriguingly, seasonal seabed arrival rates of organic C estimated from in-situ summertime benthic respirometry studies yield C flux values similar in magnitude to those from sediment traps deployed at the same time, lending strong support to trap data. The cause of current disagreements between various methods of flux estimation may in fact not be solved until process studies are accomplished

  18. Risk factors for incidence and case-fatality rates of healthcare-associated infections: a 20-year follow-up of a hospital-based cohort.

    PubMed

    Wang, R-F; Shen, S-H; Yen, A M-F; Wang, T-L; Jang, T-N; Lee, S-H; Wang, J-T; Chen, H-H

    2016-01-01

    Information is lacking on the integrated evaluation of mortality rates in healthcare-associated infections (HAIs). Our aim was to differentiate the risk factors responsible for the incidence from those for the case-fatality rates in association with HAIs. We therefore examined the time trends of both incidence and case-fatality rates over a 20-year period at a tertiary-care teaching medical centre in Taiwan and the mortality rate was expressed as the product of the incidence rate and the case-fatality rate. During the study period the overall mortality rate fell from 0·46 to 0·32 deaths/1000 patient-days and the incidence rate fell from 3·41 to 2·31/1000 patient-days, but the case-fatality rate increased marginally from 13·5% to 14·0%. The independent risk factors associated with incidence of HAIs were age, gender, infection site, admission type, and department of hospitalization. Significant prognostic factors for HAI case-fatality were age, infection site, intensive care, and clinical department. We conclude that the decreasing trend for the HAI mortality rate was accompanied by a significant decline in the incidence rate and this was offset by a slightly increasing trend in the case-fatality rate. This deconstruction approach could provide further insights into the underlying complex causes of mortality for HAIs.

  19. Agreement between self-reported and measured height, weight and body mass index in old age—a longitudinal study with 20 years of follow-up

    PubMed Central

    Dahl, Anna K.; Hassing, Linda B.; Fransson, Eleonor I.; Pedersen, Nancy L.

    2010-01-01

    Background: self-reported body mass index (BMI) based on self-reported height and weight is a widely used measure of adiposity in epidemiological research. Knowledge about the accuracy of these measures in late life is scarce. Objective: the study aimed to evaluate the accuracy and changes in accuracy of self-reported height, weight and BMI calculated from self-reported height and weight in late life. Design: a longitudinal population-based study with five times of follow-up was conducted. Participants: seven hundred seventy-four community-living men and women, aged 40–88 at baseline (mean age 63.9), included in The Swedish Adoption/Twin Study of Aging. Methods: participants self-reported their height and weight in a questionnaire, and height and weight were measured by experienced research nurses at an in-person testing five times during a 20-year period. BMI was calculated as weight (kilogramme)/height (metre)2. Results: latent growth curve modelling showed an increase in the mean difference between self-reported and measured values over time for height (0.038 cm/year) and BMI (0.016 kg/m2/year), but not for weight. Conclusions: there is a very small increase in the mean difference between self-reported and measured BMI with ageing, which probably would not affect the results when self-reported BMI is used as a continuous variable in longitudinal studies. PMID:20453247

  20. Magnus' expansion for time-periodic systems: Parameter-dependent approximations

    NASA Astrophysics Data System (ADS)

    Butcher, Eric A.; Sari, Ma'en; Bueler, Ed; Carlson, Tim

    2009-12-01

    Magnus' expansion solves the nonlinear Hausdorff equation associated with a linear time-varying system of ordinary differential equations by forming the matrix exponential of a series of integrated commutators of the matrix-valued coefficient. Instead of expanding the fundamental solution itself, that is, the logarithm is expanded. Within some finite interval in the time variable, such an expansion converges faster than direct methods like Picard iteration and it preserves symmetries of the ODE system, if present. For time-periodic systems, Magnus expansion, in some cases, allows one to symbolically approximate the logarithm of the Floquet transition matrix (monodromy matrix) in terms of parameters. Although it has been successfully used as a numerical tool, this use of the Magnus expansion is new. Here we use a version of Magnus' expansion due to Iserles [Iserles A. Expansions that grow on trees. Not Am Math Soc 2002;49:430-40], who reordered the terms of Magnus' expansion for more efficient computation. Though much about the convergence of the Magnus expansion is not known, we explore the convergence of the expansion and apply known convergence estimates. We discuss the possible benefits to using it for time-periodic systems, and we demonstrate the expansion on several examples of periodic systems through the use of a computer algebra system, showing how the convergence depends on parameters.

  1. Stability and attractivity of periodic solutions of parabolic systems with time delays

    NASA Astrophysics Data System (ADS)

    Pao, C. V.

    2005-04-01

    This paper is concerned with the existence, stability, and global attractivity of time-periodic solutions for a class of coupled parabolic equations in a bounded domain. The problem under consideration includes coupled system of parabolic and ordinary differential equations, and time delays may appear in the nonlinear reaction functions. Our approach to the problem is by the method of upper and lower solutions and its associated monotone iterations. The existence of time-periodic solutions is for a class of locally Lipschitz continuous reaction functions without any quasimonotone requirement using Schauder fixed point theorem, while the stability and attractivity analysis is for quasimonotone nondecreasing and mixed quasimonotone reaction functions using the monotone iterative scheme. The results for the general system are applied to the standard parabolic equations without time delay and to the corresponding ordinary differential system. Applications are also given to three Lotka-Volterra reaction diffusion model problems, and in each problem a sufficient condition on the reaction rates is obtained to ensure the stability and global attractivity of positive periodic solutions.

  2. Primate enamel evinces long period biological timing and regulation of life history.

    PubMed

    Bromage, Timothy G; Hogg, Russell T; Lacruz, Rodrigo S; Hou, Chen

    2012-07-21

    The factor(s) regulating the combination of traits that define the overall life history matrix of mammalian species, comprising attributes such as brain and body weight, age at sexual maturity, lifespan and others, remains a complete mystery. The principal objectives of the present research are (1) to provide evidence for a key variable effecting life history integration and (2) to provide a model for how one would go about investigating the metabolic mechanisms responsible for this rhythm. We suggest here that a biological rhythm with a period greater than the circadian rhythm is responsible for observed variation in primate life history. Evidence for this rhythm derives from studies of tooth enamel formation. Enamel contains an enigmatic periodicity in its microstructure called the striae of Retzius, which develops at species specific intervals in units of whole days. We refer to this enamel rhythm as the repeat interval (RI). For primates, we identify statistically significant relationships between RI and all common life history traits. Importantly, RI also correlates with basal and specific metabolic rates. With the exception of estrous cyclicity, all relationships share a dependence upon body mass. This dependence on body mass informs us that some aspect of metabolism is responsible for periodic energy allocations at RI timescales, regulating cell proliferation rates and growth, thus controlling the pace, patterning, and co-variation of life history traits. Estrous cyclicity relates to the long period rhythm in a body mass-independent manner. The mass-dependency and -independency of life history relationships with RI periodicity align with hypothalamic-mediated neurosecretory anterior and posterior pituitary outputs. We term this period the Havers-Halberg Oscillation (HHO), in reference to Clopton Havers, a 17th Century hard tissue anatomist, and Franz Halberg, a long-time explorer of long-period rhythms. We propose a mathematical model that may help elucidate

  3. Neurotoxicity in young adults 20 years after childhood exposure to lead: the Bunker Hill experience

    PubMed Central

    Stokes, L.; Letz, R.; Gerr, F.; Kolczak, M.; McNeill, F. E.; Chettle, D. R.; Kaye, W. E.

    1998-01-01

    OBJECTIVES: An epidemiological study of young adults was conducted to determine whether environmental exposure to lead during childhood was associated with current adverse neurobehavioural effects. METHODS: The exposed group consisted of 281 young adults who had been exposed environmentally to lead as children and the unexposed referent group consisted of 287 age and sex frequency matched subjects. Information on demographics, past and current health, and past exposures to neurotoxicants, and responses to the Swedish Q16 questionnaire were collected by interview. Standard neurobehavioural and neurophysiological tests were administered by computer or trained technicians. K x ray fluorescence was used to estimate tibial bone lead concentrations among the exposed and unexposed groups. Associations were examined between the exposed group and referents and tibial bone lead concentration and the neurobehavioural and neurophysiological outcomes of interest. RESULTS: Among the measures of peripheral nerve function, after controlling for confounders, sural sensory nerve evoked response amplitude, peroneal motor nerve compound motor action potential amplitude, vibrotactile thresholds of fingers and toes, and standing steadiness were significantly associated with exposure group. Among the neurobehavioural tests, hand-eye coordination, simple reaction time latency, trails B latency, symbol digit latency, serial digit, and learning error score were also significantly associated with exposure group after controlling for confounders. Exposed subjects had significantly more neuropsychiatric symptoms than the referents. Associations between tibial bone lead concentration and scores for vocabulary, vibrotactile thresholds of the fingers, and vibrotactile thresholds of the toes approached significance. CONCLUSIONS: Significant adverse central and peripheral neurological effects were found in a group of young adults 20 years after childhood environmental exposure to lead when compared

  4. Left lung agenesis discovered by a spontaneous pneumothorax in a 20-year-old girl

    PubMed Central

    Hentati, Abdessalem; Neifar, Chawki; Abid, Walid; M’saad, Sameh

    2016-01-01

    Lung agenesis is a rare condition which prognosis widely depends on associated malformations. Clinical presentation is so variable and diagnosis is often made in childhood. Here, we present a case of a 20-year-old girl who was admitted because of a spontaneous pneumothorax. Explorations concluded at a left lung agenesis, a hyperinflated right lung crossing the midline with a corresponding pneumothorax. There was no malformation else. This congenital condition and treatment for this rare presentation are discussed in detail. PMID:27051112

  5. Progressive paranoid psychosis in a 20-year-old with central congenital hypoventilation syndrome.

    PubMed

    Dranovsky, Alex; Needleman, Joshua P; Sylvester, Jessica; VanHeertum, Ronald; Muskin, Philip R

    2014-09-01

    A 20-year-old man with a history of congenital central hypoventilation syndrome presented with recent-onset psychosis, catatonia, and a diagnosis of schizophrenia. Psychiatric symptoms were resistant to conventional treatment. A fluorodeoxyglucose positron emission tomography scan of the brain obtained during the hospitalization revealed a hypometabolism distribution more consistent with hypoperfusion than with primary central nervous system disease. Increased mechanical ventilation was successfully used to treat the psychiatric symptoms.

  6. Tracing temperature in a nanometer size region in a picosecond time period

    PubMed Central

    Nakajima, Kaoru; Kitayama, Takumi; Hayashi, Hiroaki; Matsuda, Makoto; Sataka, Masao; Tsujimoto, Masahiko; Toulemonde, Marcel; Bouffard, Serge; Kimura, Kenji

    2015-01-01

    Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model. PMID:26293488

  7. Tracing temperature in a nanometer size region in a picosecond time period.

    PubMed

    Nakajima, Kaoru; Kitayama, Takumi; Hayashi, Hiroaki; Matsuda, Makoto; Sataka, Masao; Tsujimoto, Masahiko; Toulemonde, Marcel; Bouffard, Serge; Kimura, Kenji

    2015-08-21

    Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.

  8. Tracing temperature in a nanometer size region in a picosecond time period

    NASA Astrophysics Data System (ADS)

    Nakajima, Kaoru; Kitayama, Takumi; Hayashi, Hiroaki; Matsuda, Makoto; Sataka, Masao; Tsujimoto, Masahiko; Toulemonde, Marcel; Bouffard, Serge; Kimura, Kenji

    2015-08-01

    Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model.

  9. Tracing temperature in a nanometer size region in a picosecond time period.

    PubMed

    Nakajima, Kaoru; Kitayama, Takumi; Hayashi, Hiroaki; Matsuda, Makoto; Sataka, Masao; Tsujimoto, Masahiko; Toulemonde, Marcel; Bouffard, Serge; Kimura, Kenji

    2015-01-01

    Irradiation of materials with either swift heavy ions or slow highly charged ions leads to ultrafast heating on a timescale of several picosecond in a region of several nanometer. This ultrafast local heating result in formation of nanostructures, which provide a number of potential applications in nanotechnologies. These nanostructures are believed to be formed when the local temperature rises beyond the melting or boiling point of the material. Conventional techniques, however, are not applicable to measure temperature in such a localized region in a short time period. Here, we propose a novel method for tracing temperature in a nanometer region in a picosecond time period by utilizing desorption of gold nanoparticles around the ion impact position. The feasibility is examined by comparing with the temperature evolution predicted by a theoretical model. PMID:26293488

  10. Periodic solutions of a nonautonomous predator-prey system with stage structure and time delays

    NASA Astrophysics Data System (ADS)

    Xu, Rui; Wang, Zhiqiang

    2006-11-01

    A nonautonomous Lotka-Volterra type predator-prey model with stage structure and time delays is investigated. It is assumed in the model that the individuals in each species may belong to one of two classes: the immatures and the matures, the age to maturity is presented by a time delay, and that the immature predators do not feed on prey and do not have the ability to reproduce. By some comparison arguments we first discuss the permanence of the model. By using the continuation theorem of coincidence degree theory, sufficient conditions are derived for the existence of positive periodic solutions to the model. By means of a suitable Lyapunov functional, sufficient conditions are obtained for the uniqueness and global stability of the positive periodic solutions to the model.

  11. Time functions of deep earthquakes from broadband and short-period stacks

    USGS Publications Warehouse

    Houston, H.; Benz, H.M.; Vidale, J.E.

    1998-01-01

    To constrain dynamic source properties of deep earthquakes, we have systematically constructed broadband time functions of deep earthquakes by stacking and scaling teleseismic P waves from U.S. National Seismic Network, TERRAscope, and Berkeley Digital Seismic Network broadband stations. We examined 42 earthquakes with depths from 100 to 660 km that occurred between July 1, 1992 and July 31, 1995. To directly compare time functions, or to group them by size, depth, or region, it is essential to scale them to remove the effect of moment, which varies by more than 3 orders of magnitude for these events. For each event we also computed short-period stacks of P waves recorded by west coast regional arrays. The comparison of broadband with short-period stacks yields a considerable advantage, enabling more reliable measurement of event duration. A more accurate estimate of the duration better constrains the scaling procedure to remove the effect of moment, producing scaled time functions with both correct timing and amplitude. We find only subtle differences in the broadband time-function shape with moment, indicating successful scaling and minimal effects of attenuation at the periods considered here. The average shape of the envelopes of the short-period stacks is very similar to the average broadband time function. The main variations seen with depth are (1) a mild decrease in duration with increasing depth, (2) greater asymmetry in the time functions of intermediate events compared to deep ones, and (3) unexpected complexity and late moment release for events between 350 and 550 km, with seven of the eight events in that depth interval displaying markedly more complicated time functions with more moment release late in the rupture than most events above or below. The first two results are broadly consistent with our previous studies, while the third is reported here for the first time. The greater complexity between 350 and 550 km suggests greater heterogeneity in

  12. Periodic Time-Domain Nonlocal Nonreflecting Boundary Conditions for Duct Acoustics

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Zorumski, William E.

    1996-01-01

    Periodic time-domain boundary conditions are formulated for direct numerical simulation of acoustic waves in ducts without flow. Well-developed frequency-domain boundary conditions are transformed into the time domain. The formulation is presented here in one space dimension and time; however, this formulation has an advantage in that its extension to variable-area, higher dimensional, and acoustically treated ducts is rigorous and straightforward. The boundary condition simulates a nonreflecting wave field in an infinite uniform duct and is implemented by impulse-response operators that are applied at the boundary of the computational domain. These operators are generated by convolution integrals of the corresponding frequency-domain operators. The acoustic solution is obtained by advancing the Euler equations to a periodic state with the MacCormack scheme. The MacCormack scheme utilizes the boundary condition to limit the computational space and preserve the radiation boundary condition. The success of the boundary condition is attributed to the fact that it is nonreflecting to periodic acoustic waves. In addition, transient waves can pass rapidly out of the solution domain. The boundary condition is tested for a pure tone and a multitone source in a linear setting. The effects of various initial conditions are assessed. Computational solutions with the boundary condition are consistent with the known solutions for nonreflecting wave fields in an infinite uniform duct.

  13. Time-varying singular value decomposition for periodic transient identification in bearing fault diagnosis

    NASA Astrophysics Data System (ADS)

    Zhang, Shangbin; Lu, Siliang; He, Qingbo; Kong, Fanrang

    2016-09-01

    For rotating machines, the defective faults of bearings generally are represented as periodic transient impulses in acquired signals. The extraction of transient features from signals has been a key issue for fault diagnosis. However, the background noise reduces identification performance of periodic faults in practice. This paper proposes a time-varying singular value decomposition (TSVD) method to enhance the identification of periodic faults. The proposed method is inspired by the sliding window method. By applying singular value decomposition (SVD) to the signal under a sliding window, we can obtain a time-varying singular value matrix (TSVM). Each column in the TSVM is occupied by the singular values of the corresponding sliding window, and each row represents the intrinsic structure of the raw signal, namely time-singular-value-sequence (TSVS). Theoretical and experimental analyses show that the frequency of TSVS is exactly twice that of the corresponding intrinsic structure. Moreover, the signal-to-noise ratio (SNR) of TSVS is improved significantly in comparison with the raw signal. The proposed method takes advantages of the TSVS in noise suppression and feature extraction to enhance fault frequency for diagnosis. The effectiveness of the TSVD is verified by means of simulation studies and applications to diagnosis of bearing faults. Results indicate that the proposed method is superior to traditional methods for bearing fault diagnosis.

  14. Rank One Chaos in Periodically-Kicked Time-Delayed Chen System

    NASA Astrophysics Data System (ADS)

    Dai, Yunxian; Lin, Yiping; Yang, Wenjie; Zhao, Huitao

    In this paper, we study the existence of rank one strange attractor in time-delayed system. First, we try to develop rank one theory for delayed differential equations. Then, we consider Chen system with time-delay, the conditions under which a supercritical Hopf bifurcation occurs are given by using the normal form method and center manifold theorem. Then, we add an external periodic force as an input and observe rank one strange attractors. Finally, several numerical simulations supporting the theoretical analysis are also given.

  15. Real-time Periodic Processing of RT-middleware Utilizing Linux Standard Functionalities

    NASA Astrophysics Data System (ADS)

    Shimizu, Masaharu; Toda, Kengo; Hayashibara, Yasuo; Yamato, Hideaki; Furuta, Takayuki

    A new methodology of real-time periodic processing on RT-middleware based on the Linux standard functionalities is presented in this paper. The central of discussion is on the realization of real-time processing while keeping the reusability of software modules ensured by the RT-middleware framework as well as the portability provided by the Linux development mainstream. In order to show the validity of the proposed approach, two robot systems, including an omnidirectional electric wheelchair steered by haptic joystick, are presented and the discussion about the evaluation result follows from the view point of practicality.

  16. Interpersonal emotional behaviors and physical health: A 20-year longitudinal study of long-term married couples.

    PubMed

    Haase, Claudia M; Holley, Sarah R; Bloch, Lian; Verstaen, Alice; Levenson, Robert W

    2016-10-01

    Objectively coded interpersonal emotional behaviors that emerged during a 15-min marital conflict interaction predicted the development of physical symptoms in a 20-year longitudinal study of long-term marriages. Dyadic latent growth curve modeling showed that anger behavior predicted increases in cardiovascular symptoms and stonewalling behavior predicted increases in musculoskeletal symptoms. Both associations were found for husbands (although cross-lagged path models also showed some support for wives) and were controlled for sociodemographic characteristics (age, education) and behaviors (i.e., exercise, smoking, alcohol consumption, caffeine consumption) known to influence health. Both associations did not exist at the start of the study, but only emerged over the ensuing 20 years. There was some support for the specificity of these relationships (i.e., stonewalling behavior did not predict cardiovascular symptoms; anger behavior did not predict musculoskeletal symptoms; neither symptom was predicted by fear nor sadness behavior), with the anger-cardiovascular relationship emerging as most robust. Using cross-lagged path models to probe directionality of these associations, emotional behaviors predicted physical health symptoms over time (with some reverse associations found as well). These findings illuminate longstanding theoretical and applied issues concerning the association between interpersonal emotional behaviors and physical health and suggest opportunities for preventive interventions focused on specific emotions to help address major public health problems. (PsycINFO Database Record

  17. A 20-Year Review of 75 Cases of Salivary Duct Carcinoma

    PubMed Central

    Gilbert, Mark R.; Sharma, Arun; Schmitt, Nicole C.; Johnson, Jonas T.; Ferris, Robert L.; Duvvuri, Umamaheswar; Kim, Seungwon

    2016-01-01

    IMPORTANCE Salivary duct carcinoma is a rare, aggressive malignancy of the salivary glands. Owing to its rare nature, clinical data are limited, and only a few clinical studies comprise more than 50 patients. OBJECTIVE To review the University of Pittsburgh Medical Center’s experience with salivary duct carcinoma over a 20-year period, focusing on demographics, presentation, treatment, and outcome. DESIGN, SETTING, AND PARTICIPANTS This investigation was a retrospective cohort study in a multihospital institution with tertiary referral. A pathology database was reviewed for all cases of histopathologically diagnosed salivary duct carcinoma from January 1, 1995, to October 20, 2014. Patients who were referrals for pathology review only and were never seen at the institution were excluded. In total, 75 study patients were identified. The electronic medical record was reviewed for details regarding demographics, presentation, treatment, and outcome, including overall survival (OS) and disease-free survival (DFS). This study was supplemented with a review of the institution’s Head and Neck Oncology Database for further clinical details. MAIN OUTCOMES AND MEASURES Primary outcome measures consisted of OS and DFS. RESULTS The study sample comprised 75 participants with a mean age at diagnosis of 66.0 years (age range, 33–93 years), and 29% (n = 22) were female. Most primary tumors were from the parotid gland (83%), with the next most frequent site being the submandibular gland (12%). Overall, 41% of the cases were carcinoma ex pleomorphic adenoma. Rates of other histologic features included the following: perineural invasion (69%), extracapsular spread (58%), ERBB2 (formerly HER2) positivity (31%) (62% of those who were tested), and vascular invasion (61%). The median OS was 3.1 years, and the median DFS was 2.7 years. Univariate Kaplan-Meier survival analyses demonstrated that facial nerve sacrifice and extracapsular spread were associated with lower OS (2.38 vs 5

  18. Quasiequilibrium directed hopping in a time-dependent two-well periodic potential

    NASA Astrophysics Data System (ADS)

    Rozenbaum, V. M.; Shapochkina, I. V.

    2011-11-01

    We consider the directed motion of a Brownian particle in a two-well periodic potential with time-varying barriers and wells described by arbitrary periodic functions of time, v(t) and u(t), alternating with the period τ. In the framework of the low-temperature kinetic approach, we obtain explicit formulas for the probabilities of finding the particle in potential wells, average velocity of directed motion, input energy Pin and useful work Pout against additionally introduced stationary load force f. These formulas are considerably simplified by the assumption of the quasiequilibrium regime of motion corresponding to small values of u(t) and f. It is shown that depending on the same or opposite parity of the functions v(t) and u(t) with respect to time reversal, the motion direction of a Brownian particle is retained or reversed under the reversal of the direction of movement along the (v-u) loop in the phase space of the functions v(t) and u(t), and the nondiagonal kinetic coefficients are mutually symmetric or antisymmetric. In the adiabatic limit τ→∞, the average velocity is proportional to τ-1 in two cases: (i) the above loop has a nonzero area, (ii) the functions v(t) and u(t) are proportional to each other (zero loop area) and include intervals of fast changes with small durations τ0 on the period τ of their variations. In both of these cases, the efficiency of energy conversion, η=Pout/Pin, tends to unity at large variations of the barriers v(t). In the second case, the deviation of η from unity can be split into two contributions: The former decreases exponentially with increasing amplitude v0 of v(t), while the latter is a small nonadiabatic correction proportional to v0-3/2. It is the nonadiabatic correction that limits high efficiencies at large variations of barriers.

  19. Assessment of the Main Natural Disturbances on Norwegian Forest Based on 20 Years of National Inventory.

    PubMed

    Díaz-Yáñez, Olalla; Mola-Yudego, Blas; Eriksen, Rune; González-Olabarria, José Ramón

    2016-01-01

    The re-measurement of permanent forest inventories offers a unique opportunity to assess the occurrence and impact of forest disturbances. The present study aims at exploring the main forest damages in Norway based on the extensive data of several consecutive national forest inventories during the period 1995-2014. Five of the most common disturbance agents in Norway are selected for analysis: wind, snow, browsing, fungus and insect damage. The analyses focuses on the frequency and variation along time, the average damage at stand level and the spatial patterns of damage occurrence, resulting in a characterization of the damage produced by disturbances in Norway. The highest damage occurrences by disturbance agent are due to browsing, snow and wind. Snow presents a decreasing temporally trend in damage frequency in the studied period. By forest type, mature and intermediate birch forest are found to be more affected by snow damage, whereas mature spruce forest is by wind damage. The results from this study provide support to the hypothesis that damages by autumnal moth (Epirrita autumnata) on birch are more common in mature stands. No major attacks from bark beetle (Ips typographus) are found, probably related to the lack of major storm damages in the period. Forest types susceptibility to fungus has no apparent variation over time except in the last years, as increased occurrence is observed on mature spruce stands probably correlated with warmer than average periods. Browsing damage causes the most severe losses, as expected, in young stands, and is allocated mainly on the most productive forests. Although some of the disturbances present locally moderate effects, the results show no major disturbances threatening Norwegian forests in the studied period. Finally, the Norwegian national forest inventory demonstrates its reliability as a basis to understand the occurrence and effects of major natural disturbances. PMID:27570973

  20. Assessment of the Main Natural Disturbances on Norwegian Forest Based on 20 Years of National Inventory

    PubMed Central

    Mola-Yudego, Blas; Eriksen, Rune; González-Olabarria, José Ramón

    2016-01-01

    The re-measurement of permanent forest inventories offers a unique opportunity to assess the occurrence and impact of forest disturbances. The present study aims at exploring the main forest damages in Norway based on the extensive data of several consecutive national forest inventories during the period 1995–2014. Five of the most common disturbance agents in Norway are selected for analysis: wind, snow, browsing, fungus and insect damage. The analyses focuses on the frequency and variation along time, the average damage at stand level and the spatial patterns of damage occurrence, resulting in a characterization of the damage produced by disturbances in Norway. The highest damage occurrences by disturbance agent are due to browsing, snow and wind. Snow presents a decreasing temporally trend in damage frequency in the studied period. By forest type, mature and intermediate birch forest are found to be more affected by snow damage, whereas mature spruce forest is by wind damage. The results from this study provide support to the hypothesis that damages by autumnal moth (Epirrita autumnata) on birch are more common in mature stands. No major attacks from bark beetle (Ips typographus) are found, probably related to the lack of major storm damages in the period. Forest types susceptibility to fungus has no apparent variation over time except in the last years, as increased occurrence is observed on mature spruce stands probably correlated with warmer than average periods. Browsing damage causes the most severe losses, as expected, in young stands, and is allocated mainly on the most productive forests. Although some of the disturbances present locally moderate effects, the results show no major disturbances threatening Norwegian forests in the studied period. Finally, the Norwegian national forest inventory demonstrates its reliability as a basis to understand the occurrence and effects of major natural disturbances. PMID:27570973

  1. Timing Studies of X Persei and the Discovery of Its Transient Quasi-periodic Oscillation Feature

    NASA Technical Reports Server (NTRS)

    Acuner, Z.; Inam,S. C.; Sahiner, S.; Serim, M. M.; Baykal, A.; Swank, J.

    2014-01-01

    We present a timing analysis of X Persei (X Per) using observations made between 1998 and 2010 with the Proportional Counter Array (PCA) onboard the Rossi X-ray Timing Explorer (RXTE) and with the INTEGRAL Soft Gamma-Ray Imager (ISGRI). All pulse arrival times obtained from the RXTE-PCA observations are phase-connected and a timing solution is obtained using these arrival times. We update the long-term pulse frequency history of the source by measuring its pulse frequencies using RXTE-PCA and ISGRI data. From the RXTEPCA data, the relation between the frequency derivative and X-ray flux suggests accretion via the companion's stellar wind. However, the detection of a transient quasi-periodic oscillation feature, peaking at approximately 0.2 Hz, suggests the existence of an accretion disc. We find that doublebreak models fit the average power spectra well, which suggests that the source has at least two different accretion flow components dominating the overall flow. From the power spectrum of frequency derivatives, we measure a power-law index of approximately - 1, which implies that, on short time-scales, disc accretion dominates over noise, while on time-scales longer than the viscous time-scales, the noise dominates. From pulse profiles, we find a correlation between the pulse fraction and the count rate of the source.

  2. Detection of faults in rotating machinery using periodic time-frequency sparsity

    NASA Astrophysics Data System (ADS)

    Ding, Yin; He, Wangpeng; Chen, Binqiang; Zi, Yanyang; Selesnick, Ivan W.

    2016-11-01

    This paper addresses the problem of extracting periodic oscillatory features in vibration signals for detecting faults in rotating machinery. To extract the feature, we propose an approach in the short-time Fourier transform (STFT) domain where the periodic oscillatory feature manifests itself as a relatively sparse grid. To estimate the sparse grid, we formulate an optimization problem using customized binary weights in the regularizer, where the weights are formulated to promote periodicity. In order to solve the proposed optimization problem, we develop an algorithm called augmented Lagrangian majorization-minimization algorithm, which combines the split augmented Lagrangian shrinkage algorithm (SALSA) with majorization-minimization (MM), and is guaranteed to converge for both convex and non-convex formulation. As examples, the proposed approach is applied to simulated data, and used as a tool for diagnosing faults in bearings and gearboxes for real data, and compared to some state-of-the-art methods. The results show that the proposed approach can effectively detect and extract the periodical oscillatory features.

  3. Transfer-matrix approach for finite-difference time-domain simulation of periodic structures.

    PubMed

    Deinega, Alexei; Belousov, Sergei; Valuev, Ilya

    2013-11-01

    Optical properties of periodic structures can be calculated using the transfer-matrix approach, which establishes a relation between amplitudes of the wave incident on a structure with transmitted or reflected waves. The transfer matrix can be used to obtain transmittance and reflectance spectra of finite periodic structures as well as eigenmodes of infinite structures. Traditionally, calculation of the transfer matrix is performed in the frequency domain and involves linear algebra. In this work, we present a technique for calculation of the transfer matrix using the finite-difference time-domain (FDTD) method and show the way of its implementation in FDTD code. To illustrate the performance of our technique we calculate the transmittance spectra for opal photonic crystal slabs consisting of multiple layers of spherical scatterers. Our technique can be used for photonic band structure calculations. It can also be combined with existing FDTD methods for the analysis of periodic structures at an oblique incidence, as well as for modeling point sources in a periodic environment. PMID:24329377

  4. Resonating Vector Strength: How to Find Periodicity in a Time Sequence

    NASA Astrophysics Data System (ADS)

    van Hemmen, J. Leo

    2013-03-01

    For a given periodic stimulus with angular frequency ω∘ = 2 π /T∘ we find responses as events at times {t1 ,t2 , ... ,tn } located on the real axis R. How periodic are they? And do they repeat in ``some'' sense in accordance with the stimulus period T∘? The question and the answer are at least as old as a classical paper of von Mises dating back to 1918. The key idea is simply this. We map the events tj onto the unit circle or torus through tj |-> exp (iωtj) and consider their center of gravity, ρ (ω) , a complex number in the unit disk. Its absolute value | ρ (ω∘) | with ω : =ω∘ is what von Mises studied and is now called the vector strength. We prove that the nearer | ρ (ω∘) | is to 1 the more periodic the events tj are w.r.t. T∘. Furthermore, we also show why it is useful to study ρ (ω) as a function of ω so as to obtain a `resonating' vector strength, an idea strongly deviating from the classical characteristic function. Work done in collaboration with A.N. Vollmayr. Partially supported by BCCN-Munich.

  5. Unstable and exact periodic solutions of three-particles time-dependent FPU chains

    NASA Astrophysics Data System (ADS)

    Liu, Qi-Huai; Xing, Ming-Yan; Li, Xin-Xiang; Wang, Chao

    2015-12-01

    For lower dimensional Fermi-Pasta-Ulam (FPU) chains, the α-chain is completely integrable and the Hamiltonian of the β-chain can be identified with the Hénon-Heiles Hamiltonian. When the strengths α, β of the nonlinearities depend on time periodically with the same frequencies as the natural angular frequencies, the resonance phenomenon is inevitable. In this paper, for certain periodic functions α(t) and β(t) with resonance frequencies, we give the existence and stability of some nontrivial exact periodic solutions for a one-dimensional αβ-FPU model composed of three particles with periodic boundary conditions. Project supported by the National Natural Science Foundation of China (Grant Nos. 11301106, 11201288, and 11261013), the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant No. 2014GXNSFBA118017), the Innovation Project of Graduate Education of Guangxi Zhuang Autonomous Region, China, (Grant No. YCSZ2014143), and the Guangxi Experiment Center of Information Science (Grant No. YB1410).

  6. Transfer-matrix approach for finite-difference time-domain simulation of periodic structures.

    PubMed

    Deinega, Alexei; Belousov, Sergei; Valuev, Ilya

    2013-11-01

    Optical properties of periodic structures can be calculated using the transfer-matrix approach, which establishes a relation between amplitudes of the wave incident on a structure with transmitted or reflected waves. The transfer matrix can be used to obtain transmittance and reflectance spectra of finite periodic structures as well as eigenmodes of infinite structures. Traditionally, calculation of the transfer matrix is performed in the frequency domain and involves linear algebra. In this work, we present a technique for calculation of the transfer matrix using the finite-difference time-domain (FDTD) method and show the way of its implementation in FDTD code. To illustrate the performance of our technique we calculate the transmittance spectra for opal photonic crystal slabs consisting of multiple layers of spherical scatterers. Our technique can be used for photonic band structure calculations. It can also be combined with existing FDTD methods for the analysis of periodic structures at an oblique incidence, as well as for modeling point sources in a periodic environment.

  7. Practitioners' Perceptions of the Soccer Extra-Time Period: Implications for Future Research

    PubMed Central

    Harper, Liam D.; Fothergill, Melissa; West, Daniel J.; Stevenson, Emma; Russell, Mark

    2016-01-01

    Qualitative research investigating soccer practitioners’ perceptions can allow researchers to create practical research investigations. The extra-time period of soccer is understudied compared to other areas of soccer research. Using an open-ended online survey containing eleven main and nine sub questions, we gathered the perceptions of extra-time from 46 soccer practitioners, all working for different professional soccer clubs. Questions related to current practices, views on extra-time regulations, and ideas for future research. Using inductive content analysis, the following general dimensions were identified: ‘importance of extra-time’, ‘rule changes’, ‘efficacy of extra-time hydro-nutritional provision’, ‘nutritional timing’, ‘future research directions’, ‘preparatory modulations’ and ‘recovery’. The majority of practitioners (63%) either agreed or strongly agreed that extra-time is an important period for determining success in knockout football match-play. When asked if a fourth substitution should be permitted in extra-time, 67% agreed. The use of hydro-nutritional strategies prior to extra-time was predominately considered important or very important. However; only 41% of practitioners felt that it was the most important time point for the use of nutritional products. A similar number of practitioners account (50%) and do not (50%) account for the potential of extra-time when training and preparing players and 89% of practitioners stated that extra-time influences recovery practices following matches. In the five minute break prior to extra-time, the following practices (in order of priority) were advocated to players: hydration, energy provision, massage, and tactical preparations. Additionally, 87% of practitioners advocate a particular nutritional supplementation strategy prior to extra-time. In order of importance, practitioners see the following as future research areas: nutritional interventions, fatigue responses

  8. Comparison of antimicrobial susceptibility of Citrobacter freundii isolates in two different time periods.

    PubMed

    Wang, J T; Chang, S C; Chen, Y C; Luh, K T

    2000-12-01

    Citrobacter freundii was first identified in 1932, since then it has been reported to cause a variety of infections in aged, immunocompromised, and debilitated patients. With the use of broad-spectrum antibiotics, C. freundii has become increasingly resistant to antimicrobial agents. In order to determine the chronological changes in susceptibility and current susceptibility status of C. freundii, we compared the antimicrobial susceptibility of C. freundii in two different time periods, from 1987 to 1988 and from 1997 to 1998. In both time periods, 61 isolates of C. freundii were randomly selected for study from all clinical isolates at National Taiwan University Hospital. The minimum inhibitory concentrations and susceptible rates of 15 antimicrobial agents were compared, and it was found that most C. freundii isolates were resistant to anti-pseudomonal penicillins, first, second, and third generation cephalosporins, gentamicin, tobramycin, and aztreonam. The results indicate that the susceptible rates of C. freundii to aminoglycosides and ciprofloxacin decreased markedly during the period from 1987 to 1998. Cefepime, cefpirome, imipenem, and meropenem remained the most active agents against C. freundii.

  9. Reaction time-related activity reflecting periodic, task-specific cognitive control.

    PubMed

    Barber, Anita D; Pekar, James J; Mostofsky, Stewart H

    2016-01-01

    Reaction time (RT) is associated with increased amplitude of the Blood Oxygen-Level Dependent (BOLD) response in cognitive control regions. The current study examined whether the Primary Condition (PC) effect and RT-BOLD effect both reflect the same cognitive control processes. In addition, RT-BOLD effects were examined in two Go/No-go tasks with different demands to determine whether RT-related activity is task-dependent, reflecting the recruitment of task-specific cognitive processes. Data simulations showed that RT-related activity could be distinguished from that of the primary condition if it is mean-centered. In that case, RT-related activity reflects periodically-engaged processes rather than "time-on-task" (ToT). RT-related activity was mostly distinct from that of the primary Go contrast, particularly for the perceptual decision task. Therefore, RT effects can reflect additional cognitive processes that are not captured by the PC contrast consistent with a periodic-engagement account. RT-BOLD effects occurred in a separate set of regions for the two tasks. For the task requiring a perceptual decision, RT-related activity occurred within occipital and posterior parietal regions supporting visual attention. For the task requiring a working memory decision, RT-related activity occurred within fronto-parietal regions supporting the maintenance and retrieval of task representations. The findings suggest that RT-related activity reflects task-specific processes that are periodically-engaged, particularly during less demanding tasks. PMID:26318935

  10. Periodical gait asymmetry assessment using real-time wireless gyroscopes gait monitoring system.

    PubMed

    Gouwanda, D; Senanayake, S M N A

    2011-11-01

    A real-time gait monitoring system that incorporates an immediate and periodical assessment of gait asymmetry is described. This system was designed for gait analysis and rehabilitation of patients with pathologic gait. It employs wireless gyroscopes to measure the angular rate of the thigh and shank in real time. Cross-correlation of the lower extremity (Cc(norm)), and normalized Symmetry Index (SI(norm)) are implemented as new approaches to periodically determine the gait asymmetry in each gait cycle. Cc(norm) evaluates the signal patterns measured by wireless gyroscopes in each gait cycle. SI(norm) determines the movement differences between the left and right limb. An experimental study was conducted to examine the viability of these methods. Artificial asymmetrical gait was simulated by placing a load on one side of the limbs. Results showed that there were significant differences between the normal gait and asymmetrical gait (p < 0.01). They also indicated that the system worked well in periodically assessing the gait asymmetry.

  11. Estimation of the Unextendable Dead Time Period in a Flow of Physical Events by the Method of Maximum Likelihood

    NASA Astrophysics Data System (ADS)

    Nezhel'skaya, L. A.

    2016-09-01

    A flow of physical events (photons, electrons, and other elementary particles) is studied. One of the mathematical models of such flows is the modulated MAP flow of events circulating under conditions of unextendable dead time period. It is assumed that the dead time period is an unknown fixed value. The problem of estimation of the dead time period from observations of arrival times of events is solved by the method of maximum likelihood.

  12. Performance of ROB's near real-time ionospheric product during normal and disturbed space weather periods.

    NASA Astrophysics Data System (ADS)

    Bergeot, Nicolas; Chevalier, Jean-Marie; Bruyninx, Carine

    2015-04-01

    Several agencies are routinely monitoring the vertical Total Electron Content (vTEC) using GNSS data. Derived maps are available with different latencies, area extents, and grid/time resolutions. However, no high-resolution maps are publically available over Europe in near real-time. In this frame, the Royal Observatory of Belgium (ROB) developed the ROB-IONO software which takes advantage of the dense EUREF Permanent GNSS Network (EPN) to monitor the ionosphere. The main ROB products consist of ionospheric vTEC maps over Europe and their variability estimated in near real-time every 15 min on 0.5° x 0.5° grids using GPS observations. The maps are available online with a latency of ~3 min in the IONEX format at ftp://gnss.oma.be and as interactive web pages at www.gnss.be. During normal ionospheric activity, the ROB-TEC maps show a good agreement with widely used post-processed global products from IGS, CODE and ESA, with mean differences of 1.3 ± 0.9, 0.6 ± 0.7 and 0.4 ± 1.6 TECu respectively for the period 2012 to mid-2013. For a disturbed period, such as the 2003 Halloween ionospheric storm, the mean differences with IGS, CODE and ESA maps are respectively 0.9 ± 2.2, 0.1 ± 2.0 and 0.6 ± 6.8 TECu, with maximum differences (>38 TECu) occurring during the major phase of the storm. These differences are due to the lower resolution of global products in time and space compared to the ROB-TEC maps. A description of two recent events, on March 17, 2013 and February 27, 2014 highlights the capability of the method adopted to detect in near real-time abnormal ionospheric behaviour over Europe. The potential of the variability maps as an indicator of rapid ionospheric variations during the 15 min of observations is also highlighted. More than 30 ionospheric events associated with Space weather were detected during the period 2012-2014. The ionospheric perturbations are associated with Coronal Mass Ejections (CMEs, ~70% of the time), active geomagnetic conditions

  13. Time-periodic forcing of Turing patterns in the Brusselator model

    NASA Astrophysics Data System (ADS)

    Peña, B.; Pérez-García, C.

    Experiments on periodic illumination of the CDIMA (chlorine dioxide-iodine-malonic acid) reaction have revealed that Turing patterns can be supressed for sufficiently high intensities [1]. The illumination modifies linearly the chemical kinetics. Here we present a preliminar work on Turing patterns under a time-periodic forcing of the control parameter in the Brusselator model. We have performed numerical simulations of the model under conditions for which reentrant hexagons appear. Surprisingly, the oscillating pattern can change its symmetry for a high enough amplitude forcing: a hexagonal pattern is replaced by oscillating squares, a kind of pattern still unobserved in chemical experiments. The theoretical mechanism underlying this change of symmetry is still under discussion.

  14. Practical time-delay synchronization of a periodically modulated self-excited oscillators with uncertainties.

    PubMed

    Kakmeni, F M Moukam; Bowong, S; Senthikumar, D V; Kurths, J

    2010-12-01

    This paper studies time-delay synchronization of a periodically modulated Duffing Van der Pol (DVP) oscillator subjected to uncertainties with emphasis on complete synchronization. A robust adaptive response system is designed to synchronize with the uncertain drive periodically modulated DVP oscillator. Adaptation laws on the upper bounds of uncertainties are proposed to guarantee the boundedness of both the synchronization error and the estimated feedback coupling gains. Numerical results are presented to check the effectiveness of the proposed synchronization scheme. The results suggest that the linear and nonlinear terms in the feedback coupling play a complementary role in increasing the synchronization regime in the parameter space of the synchronization manifold. The proposed method can be successfully applied to a large variety of physical systems. PMID:21198091

  15. Time-headway distribution for periodic totally asymmetric exclusion process with various updates

    NASA Astrophysics Data System (ADS)

    Hrabák, P.; Krbálek, M.

    2016-03-01

    The totally asymmetric exclusion process (TASEP) with periodic boundaries is considered as traffic flow model. The large-L approximation of the stationary state is used for the derivation of the time-headway distribution (an important microscopic characteristic of traffic flow) for the model with generalized update (genTASEP) in both, forward- and backward-sequential representations. The usually used updates, fully-parallel and regular forward- and backward-sequential, are analyzed as special cases of the genTASEP. It is shown that only for those cases, the time-headway distribution is determined by the flow regardless to the density. The qualitative comparison of the results with traffic data demonstrates that the genTASEP with backward order and attractive interaction evinces similar properties of time-headway distribution as the real traffic sample.

  16. Ultrafast time dynamics studies of periodic lattices with free electron laser radiation

    SciTech Connect

    Quevedo, W.; Busse, G.; Hallmann, J.; More, R.; Petri, M.; Rajkovic, I.; Krasniqi, F.; Rudenko, A.; Tschentscher, T.; Stojanovic, N.; Duesterer, S.; Treusch, R.; Tolkiehn, M.; Techert, S.

    2012-11-01

    It has been proposed that radiation from free electron laser (FEL) at Hamburg (FLASH) can be used for ultrafast time-resolved x-ray diffraction experiments based on the near-infrared (NIR) pump/FEL probe scheme. Here, investigation probing the ultrafast structural dynamics of periodic nano-crystalline organic matter (silver behenate) with such a scheme is reported. Excitation with a femtosecond NIR laser leads to an ultrafast lattice modification which time evolution has been studied through the scattering of vacuum ultraviolet FEL pulses. The found effect last for 6 ps and underpins the possibility for studying nanoperiodic dynamics down to the FEL source time resolution. Furthermore, the possibility of extending the use of silver behenate (AgBh) as a wavelength and temporal calibration tool for experiments with soft x-ray/FEL sources is suggested.

  17. Evaluation of indoor air composition time variation in air-tight occupied spaces during night periods

    NASA Astrophysics Data System (ADS)

    Markov, Detelin

    2012-11-01

    This paper presents an easy-to-understand procedure for prediction of indoor air composition time variation in air-tight occupied spaces during the night periods. The mathematical model is based on the assumptions for homogeneity and perfect mixing of the indoor air, the ideal gas model for non-reacting gas mixtures, mass conservation equations for the entire system and for each species, a model for prediction of basal metabolic rate of humans as well as a model for prediction of O2 consumption rate and both CO2 and H2O generation rates by breathing. Time variation of indoor air composition is predicted at constant indoor air temperature for three scenarios based on the analytical solution of the mathematical model. The results achieved reveal both the most probable scenario for indoor air time variation in air-tight occupied spaces as well as the cause for morning tiredness after having a sleep in a modern energy efficient space.

  18. Exclusive Alternating Chemotherapy and Radiotherapy in Nonmetastatic Inflammatory Breast Cancer: 20 Years of Follow-Up

    SciTech Connect

    Bourgier, Celine; Pessoa, Eduardo Lima; Dunant, Ariane; Heymann, Steve; Spielmann, Marc; Uzan, Catherine; Mathieu, Marie-Christine; Arriagada, Rodrigo; Marsiglia, Hugo

    2012-02-01

    Background: Locoregional treatment of inflammatory breast cancer (IBC) is crucial because local relapses may be highly symptomatic and are commonly associated with distant metastasis. With a median follow-up of 20 years, we report here the long-term results of a monocentric clinical trial combining primary chemotherapy (CT) with a schedule of anthracycline-based CT and an alternating split-course of radiotherapy (RT Asterisk-Operator CT) without mastectomy. Methods and Materials: From September 1983 to December 1989, 124 women with nonmetastatic IBC (T4d M0) were treated with three cycles of primary AVCMF chemotherapy (anthracycline, vincristine, cyclophosphamide, methotrexate, and 5-fluorouracil) and then an alternating RT Asterisk-Operator CT schedule followed by three cycles of FAC. Hormonal therapy was systematically administered: ovarian irradiation (12 Gy in four fractions) or tamoxifen 20 mg daily. Results: Local control was achieved in 82% of patients. The 10- and 20-year local relapse rates were 26% and 33%, respectively, but only 10% of locally controlled cases were not associated with concurrent distant metastasis. The 10- and 20-year overall survival rates were 39% and 19%, respectively. Severe fibrosis occurred in 54% of patients, grade 3 brachial plexus neuropathy in 4%, grade 2 pneumonitis in 9%. Grade 1, 2 and 3 cardiac toxicity was observed in 3.8%, 3.8% and 1.2% of cases respectively. Conclusions: This combined regimen allowed good long-term local control without surgery. Survival rates were similar to those obtained with conventional regimens (primary chemotherapy, total mastectomy, and adjuvant radiotherapy). Since IBC continues to be an entity with a dismal prognosis, this approach, safely combining preoperative or postoperative radiation therapy and systemic treatments, should be reassessed when suitable targeted agents are available.

  19. Climate-change-related shifts in annual phenology of a temperate snake during the last 20 years

    NASA Astrophysics Data System (ADS)

    Rugiero, Lorenzo; Milana, Giuliano; Petrozzi, Fabio; Capula, Massimo; Luiselli, Luca

    2013-08-01

    Global warming is thought to be a far-reaching threat to biodiversity, and is supposed to influence several aspects of the ecology of animals. Global warming should influence especially the ectotherm vertebrates, which depend directly from the external thermal conditions for their activities and performances. Here, we analyze the changes in phenology which have occurred in the last 20 years in a marked population of vipers, Vipera aspis, and we try to relate these changes with the intervening climatic changes. We analyzed three metrics of viper's annual phenology: (i) annual onset of above-ground activity (hereby AOA); (ii) annual onset of feeding period (AOF); (iii) annual onset of the hibernation (AOH). The annual variations of these three phenological metrics were correlated to five variables of climatic data: (1) mean annual air temperature, (2) mean February air temperature, (3) mean July air temperature, (4) yearly number of rainy days, and (5) yearly number of days with rainstorm. We observed a statistically significant reduction of AOA values from >28 days between 1987 and 1997, to approximately 20 days from 1998 to 2011, with a similar statistical trend also found for AOF values. The number of days of delay in entering hibernation increased significantly since 1998. Three sets of relationships between climatic variables and metrics of viper phenology were statistically significant, i.e. the correlation (i) between annual mean temperature and AOA (negative), (ii) between annual mean temperature and AOF (negative), and (iii) between annual mean temperature and AOH (positive). The percent of field days (between 20th February and 20th March) with no viper observed also decreased significantly over the years. Our study showed that three different traits of the annual phenology of a Mediterranean snake are shifting in the 20+ years of monitoring, and that there is correlational evidence that these shifts are linked to intervening climate change.

  20. Water Erosion in Relation with Soil Management System and Crop Sequence during 20 Years on an Inceptisol in South Brazil

    NASA Astrophysics Data System (ADS)

    Bertol, I.; Schick, J.; Barbosa, F. T.; Paz-Ferreiro, J.; Flores, M. T.; Paz González, A.

    2012-04-01

    Soil erosion still remains persistent at the world scale, even if big efforts have been done to control and reduce it, mainly using soil crop residues to protect soil surface. Although in South Brazil the main management system for most crops is no tillage and direct drilling, water erosion prevails as the most important soil erosion type, which is due both, to the high erosivity and the evenly distribution of rainfall over the year. Moreover, some crops are still grown under soil tillage systems consisting of ploughing, harrowing and less frequently chiselling. Starting 1992, a field experiment under natural rainfall has been conducted on an Inceptisol located in Lages, Santa Catarina State, Brazil, which objective was to assess rainfall water erosion. Two soil cover conditions and four soil management systems were studied: I) a crop rotation, which included oats (Avena strigosa), soybean (Glycine max), common vetch (Vicia sativa), maize (Zea mays), fodder radish (Raphanus sativus) and common bean (Phaseolus vulgaris) under the following soil management types: 1) ploughing plus two levelling operations (CT), chiselling plus levelling (RT) and direct drilling with no tillage (NT), and II) bare soil (BS) without crop cover tilled by ploughing plus two levelling. In more than 90% of the study cases, soil losses were collected for single rain events with erosive power, whose erosivity was calculated. Total rain recorded during the 20 year experimental period was approximately 66,400 mm, which is equivalent to roughly 105,700, MJ mm ha-1 h-1 (EI30), whereas soil losses in the BS treatment were higher than 1,700 t.ha-1. On average, soil losses under RT treatment showed a 92% reduction in relation with BS, whereas under CT the reduction in relation to BS was about 66%. Soil management by direct drilling (NT) was the most efficient system to minimize water erosion, as soil losses decreased about 98% when compared with BS. Moreover, soil management systems with a crop

  1. Primary Hyperparathyroidism with Extensive Brown Tumors and Multiple Fractures in a 20-Year-Old Woman

    PubMed Central

    Choi, Ju Hee; Kim, Kyoung Jin; Lee, Ye Jin; Kim, Sun Hwa; Kim, Sin Gon; Jung, Kwang Yoon; Choi, Dong Seop

    2015-01-01

    A brown tumor is a benign fibrotic, erosive bony lesion caused by localized, rapid osteoclastic turnover, resulting from hyperparathyroidism. Although brown tumors are one of the most pathognomonic signs of primary hyperparathyroidism, they are rarely seen in clinical practice. In this report, we present a case of 20-year-old woman with recurrent fractures and bone pain. Plain digital radiographs of the affected bones revealed multiple erosive bone tumors, which were finally diagnosed as brown tumors associated with primary hyperparathyroidism due to a parathyroid adenoma. This case shows that multiple, and clinically severe form of brown tumors can even occur in young patients. PMID:26354493

  2. Time-Periodic Solutions of Driven-Damped Trimer Granular Crystals

    DOE PAGES

    Charalampidis, E. G.; Li, F.; Chong, C.; Yang, J.; Kevrekidis, P. G.

    2015-01-01

    We consider time-periodic structures of granular crystals consisting of alternate chrome steel (S) and tungsten carbide (W) spherical particles where each unit cell follows the pattern of a 2 : 1 trimer: S-W-S. The configuration at the left boundary is driven by a harmonic in-time actuation with given amplitude and frequency while the right one is a fixed wall. Similar to the case of a dimer chain, the combination of dissipation, driving of the boundary, and intrinsic nonlinearity leads to complex dynamics. For fixed driving frequencies in each of the spectral gaps, we find that the nonlinear surface modes and the statesmore » dictated by the linear drive collide in a saddle-node bifurcation as the driving amplitude is increased, beyond which the dynamics of the system becomes chaotic. While the bifurcation structure is similar for solutions within the first and second gap, those in the first gap appear to be less robust. We also conduct a continuation in driving frequency, where it is apparent that the nonlinearity of the system results in a complex bifurcation diagram, involving an intricate set of loops of branches, especially within the spectral gap. The theoretical findings are qualitatively corroborated by the experimental full-field visualization of the time-periodic structures.« less

  3. Hydromagnetic natural convection flow between vertical parallel plates with time-periodic boundary conditions

    NASA Astrophysics Data System (ADS)

    Adesanya, S. O.; Oluwadare, E. O.; Falade, J. A.; Makinde, O. D.

    2015-12-01

    In this paper, the free convective flow of magnetohydrodynamic fluid through a channel with time periodic boundary condition is investigated by taking the effects of Joule dissipation into consideration. Based on simplifying assumptions, the coupled governing equations are reduced to a set of nonlinear boundary valued problem. Approximate solutions are obtained by using semi-analytical Adomian decomposition method. The effect of pertinent parameters on the fluid velocity, temperature distribution, Nusselt number and skin friction are presented graphically and discussed. The result of the computation shows that an increase in the magnetic field intensity has significant influence on the fluid flow.

  4. Geometric tools for solving the FDI problem for linear periodic discrete-time systems

    NASA Astrophysics Data System (ADS)

    Longhi, Sauro; Monteriù, Andrea

    2013-07-01

    This paper studies the problem of detecting and isolating faults in linear periodic discrete-time systems. The aim is to design an observer-based residual generator where each residual is sensitive to one fault, whilst remaining insensitive to the other faults that can affect the system. Making use of the geometric tools, and in particular of the outer observable subspace notion, the Fault Detection and Isolation (FDI) problem is formulated and necessary and solvability conditions are given. An algorithmic procedure is described to determine the solution of the FDI problem.

  5. The Cluster Science Archive: from Time Period to Physics Based Search

    NASA Astrophysics Data System (ADS)

    Masson, A.; Escoubet, C. P.; Laakso, H. E.; Perry, C. H.

    2015-12-01

    Since 2000, the Cluster spacecraft relay the most detailed information on how the solar wind affects our geospace in three dimensions. Science output from Cluster is a leap forward in our knowledge of space plasma physics: the science behind space weather. It has been key in improving the modeling of the magnetosphere and understanding its various physical processes. Cluster data have enabled the publication of more than 2000 refereed papers and counting. This substantial scientific return is often attributed to the online availability of the Cluster data archive, now called the Cluster Science Archive (CSA). It is being developed by the ESAC Science Data Center (ESDC) team and maintained alongside other science ESA archives at ESAC (ESA Space Astronomy Center, Madrid, Spain). CSA is a public archive, which contains the entire set of Cluster high-resolution data, and other related products in a standard format and with a complete set of metadata. Since May 2015, it also contains data from the CNSA/ESA Double Star mission (2003-2008), a mission operated in conjunction with Cluster. The total amount of data format now exceeds 100 TB. Accessing CSA requires to be registered to enable user profiles and CSA accounts more than 1,500 users. CSA provides unique tools for visualizing its data including - on-demand particle distribution functions visualization - fast data browsing with more than 15TB of pre-generated plots - inventory plots It also offers command line capabilities (e.g. data access via Matlab or IDL softwares, data streaming). Despite its reliability, users can only request data for a specific time period while scientists often focus on specific regions or data signatures. For these reasons, a data-mining tool is being developed to do just that. It offers an interface to select data based not only on a time period but on various criteria including: key physical parameters, regions of space and spacecraft constellation geometry. The output of this tool is a

  6. Thermomagnetic convection in a ferrofluid layer exposed to a time-periodic magnetic field

    NASA Astrophysics Data System (ADS)

    Matura, P.; Lücke, M.

    2009-08-01

    We have investigated the influence of a time-periodic and spatially homogeneous magnetic field on the linear stability properties and on the nonlinear response of a ferrofluid layer heated from below and from above. A competition between stabilizing thermal and viscous diffusion and destabilizing buoyancy and Kelvin forces occurs. Floquet theory is used to determine the stability boundaries of the motionless conductive state for a harmonic and subharmonic response. Full numerical simulations with a finite difference method were made to obtain nonlinear convective states. The effect of low- and high-frequency modulation on the stability boundaries as well as on the nonlinear oscillations that may occur is investigated.

  7. Finite-time position and velocity estimation adapted to noisy biased acceleration measurements from periodic motion

    NASA Astrophysics Data System (ADS)

    Estrada, Antonio; Efimov, Denis; Perruquetti, Wilfrid

    2016-09-01

    The present work focuses on the problem of velocity and position estimation. A solution is presented for a class of oscillating systems in which position, velocity and acceleration are zero mean signals. The proposed scheme considers that the dynamic model of the system is unknown. Only noisy acceleration measurements, that may be contaminated by zero mean noise and constant bias, are considered to be available. The proposal uses the periodic nature of the signals obtaining finite-time estimations while tackling integration drift accumulation.

  8. Stability analysis of a time-periodic 2-dof MEMS structure

    NASA Astrophysics Data System (ADS)

    Kniffka, Till Jochen; Welte, Johannes; Ecker, Horst

    2012-11-01

    Microelectromechanical systems (MEMS) are becoming important for all kinds of industrial applications. Among them are filters in communication devices, due to the growing demand for efficient and accurate filtering of signals. In recent developments single degree of freedom (1-dof) oscillators, that are operated at a parametric resonances, are employed for such tasks. Typically vibration damping is low in such MEM systems. While parametric excitation (PE) is used so far to take advantage of a parametric resonance, this contribution suggests to also exploit parametric anti-resonances in order to improve the damping behavior of such systems. Modeling aspects of a 2-dof MEM system and first results of the analysis of the non-linear and the linearized system are the focus of this paper. In principle the investigated system is an oscillating mechanical system with two degrees of freedom x = [x1x2]T that can be described by Mx+Cx+K1x+K3(x2)x+Fes(x,V(t)) = 0. The system is inherently non-linear because of the cubic mechanical stiffness K3 of the structure, but also because of electrostatic forces (1+cos(ωt))Fes(x) that act on the system. Electrostatic forces are generated by comb drives and are proportional to the applied time-periodic voltage V(t). These drives also provide the means to introduce time-periodic coefficients, i.e. parametric excitation (1+cos(ωt)) with frequency ω. For a realistic MEM system the coefficients of the non-linear set of differential equations need to be scaled for efficient numerical treatment. The final mathematical model is a set of four non-linear time-periodic homogeneous differential equations of first order. Numerical results are obtained from two different methods. The linearized time-periodic (LTP) system is studied by calculating the Monodromy matrix of the system. The eigenvalues of this matrix decide on the stability of the LTP-system. To study the unabridged non-linear system, the bifurcation software ManLab is employed

  9. Landsat: Planning the Next 20 Years of Earth Observation and Science

    NASA Astrophysics Data System (ADS)

    Ryker, S. J.; Larsen, M. C.; Newman, T. R.

    2013-12-01

    The Landsat series of Earth-observing satellites began 41 years ago as a partnership between the U.S. Department of the Interior (DOI) and NASA. The U.S. Geological Survey (USGS), as DOI's Earth science agency, provides Landsat's ground systems and data and develops value-added science products and applications. In 2013 the Administration committed to continue the Landsat program for the long term, and directed NASA and USGS to develop a series of spaceborne systems to provide global, continuous Landsat-quality multispectral and thermal infrared measurements for at least 20 years beyond Landsat 9. The Administration also directed the USGS to develop the program's long-term science directions, with special emphasis on making Landsat data more easily used in a wide variety of disciplines and fields of practice. With Landsats 7 and 8 on orbit, the USGS provides data every eight days for any location on the Earth's land masses. Given eight-day data collection and Landsat's 41-year historical archive, researchers and decision-makers can assess phenomena occurring at weekly to decadal time scales. With this in mind, the USGS has identified a set of Landsat-based science products that will improve applications used by natural resource managers and will contribute to the international and interagency climate monitoring community's initiative to develop consistent climate data records (CDRs) and essential climate variables (ECVs). Key Landsat-derived CDRs include surface reflectance and surface temperature, and ECV products will include measures of fire disturbance, snow covered area, surface water extent, land cover, and above-ground green biomass. These interpretive products will provide an authoritative basis for regional to continental scale identification of historical change, monitoring of current conditions, and predicting future conditions. The Administration has also assigned USGS the responsibility to analyze Landsat users' needs to inform future operational

  10. Time series modelling of increased soil temperature anomalies during long period

    NASA Astrophysics Data System (ADS)

    Shirvani, Amin; Moradi, Farzad; Moosavi, Ali Akbar

    2015-10-01

    Soil temperature just beneath the soil surface is highly dynamic and has a direct impact on plant seed germination and is probably the most distinct and recognisable factor governing emergence. Autoregressive integrated moving average as a stochastic model was developed to predict the weekly soil temperature anomalies at 10 cm depth, one of the most important soil parameters. The weekly soil temperature anomalies for the periods of January1986-December 2011 and January 2012-December 2013 were taken into consideration to construct and test autoregressive integrated moving average models. The proposed model autoregressive integrated moving average (2,1,1) had a minimum value of Akaike information criterion and its estimated coefficients were different from zero at 5% significance level. The prediction of the weekly soil temperature anomalies during the test period using this proposed model indicated a high correlation coefficient between the observed and predicted data - that was 0.99 for lead time 1 week. Linear trend analysis indicated that the soil temperature anomalies warmed up significantly by 1.8°C during the period of 1986-2011.

  11. Evolution of illustrations in anatomy: a study from the classical period in Europe to modern times.

    PubMed

    Ghosh, Sanjib Kumar

    2015-01-01

    Illustrations constitute an essential element of learning anatomy in modern times. However it required a significant evolutionary process spread over centuries, for illustrations to achieve the present status in the subject of anatomy. This review article attempts to outline the evolutionary process by highlighting on the works of esteemed anatomists in a chronological manner. Available literature suggests that illustrations were not used in anatomy during the classical period when the subject was dominated by the descriptive text of Galen. Guido da Vigevano was first to use illustrations in anatomy during the Late Middle Ages and this concept developed further during the Renaissance period when Andreas Vesalius pioneered in illustrations becoming an indispensable tool in conveying anatomical details. Toward later stages of the Renaissance period, Fabricius ab Aquapendente endeavored to restrict dramatization of anatomical illustrations which was a prevalent trend in early Renaissance. During the 18th century, anatomical artwork was characterized by the individual styles of prominent anatomists leading to suppression of anatomical details. In the 19th century, Henry Gray used illustrations in his anatomical masterpiece that focused on depicting anatomical structures and were free from any artistic style. From early part of the 20th century medical images and photographs started to complement traditional handmade anatomical illustrations. Computer technology and advanced software systems played a key role in the evolution of anatomical illustrations during the late 20th century resulting in new generation 3D image datasets that are being used in the 21st century in innovative formats for teaching and learning anatomy.

  12. Periodic boundary conditions for long-time nonequilibrium molecular dynamics simulations of incompressible flows

    NASA Astrophysics Data System (ADS)

    Dobson, Matthew

    2014-11-01

    This work presents a generalization of the Kraynik-Reinelt (KR) boundary conditions for nonequilibrium molecular dynamics simulations. In the simulation of steady, homogeneous flows with periodic boundary conditions, the simulation box deforms with the flow, and it is possible for image particles to become arbitrarily close, causing a breakdown in the simulation. The KR boundary conditions avoid this problem for planar elongational flow and general planar mixed flow [T. A. Hunt, S. Bernardi, and B. D. Todd, J. Chem. Phys. 133, 154116 (2010)] through careful choice of the initial simulation box and by periodically remapping the simulation box in a way that conserves image locations. In this work, the ideas are extended to a large class of three-dimensional flows by using multiple remappings for the simulation box. The simulation box geometry is no longer time-periodic (which was shown to be impossible for uniaxial and biaxial stretching flows in the original work by Kraynik and Reinelt [Int. J. Multiphase Flow 18, 1045 (1992)]. The presented algorithm applies to all flows with nondefective flow matrices, and in particular, to uniaxial and biaxial flows.

  13. Understanding the resilience of mail-back survey methods: An analysis of 20years of change in response rates to national park surveys.

    PubMed

    Rookey, Bryan D; Le, Lena; Littlejohn, Margaret; Dillman, Don A

    2012-11-01

    Coverage and response rate challenges facing telephone and internet surveys have encouraged scientists to reconsider mail data collection methods. Although response rates to telephone surveys have declined sharply in the last 20years, it is unclear how response rates to mail have fared during this time. This study analyzes 179 mail-back surveys of visitors to US National Parks from 1988 to 2007, which used virtually the same administration procedures throughout the period. Results show that response rates, based on only those who initially agreed to return a questionnaire, have remained at a high level with a 76% average while the number of questions and pages steadily increased. Despite this rise in response burden, rates have declined only moderately from about 80% in the late 1980s to about 70% more recently. The roles of additional contacts and survey salience in maintaining high response rates are examined. Results suggest that mail-back surveys for obtaining information from quasi-general public populations remain an effective data collection procedure.

  14. Changes in orthodontic treatment modalities in the past 20 years: exploring the link between technology and scientific evidence.

    PubMed

    Bradley, T Gerard

    2013-01-01

    STATEMENT OF THE ISSUE: Is there a link between the many perceived advances in orthodontic techniques/therapy and science in the past 20 years? The purpose of this paper is to take five topics and match the perceptions with the scientific evidence. The variety of appliances and the swings in treatment philosophy have been dramatic, including the swing from extraction to non-extraction therapy, the introduction of space-age wires, appliances that grow mandibles, the introduction and extraordinary growth of Invisalign, and reduced friction brackets to reduce treatment time, all with claims by manufacturers of better results than ever before. The focus is on faster treatment, reduced visits/appointments and superior results. Most of these 'advancements' represent what has been the 'juggernaut of technology'. Five questions are posed, and an evidence-based approach is used to critically examine the literature in these selected topics.

  15. Developmental histories of perceived racial discrimination and diurnal cortisol profiles in adulthood: A 20-year prospective study.

    PubMed

    Adam, Emma K; Heissel, Jennifer A; Zeiders, Katharine H; Richeson, Jennifer A; Ross, Emily C; Ehrlich, Katherine B; Levy, Dorainne J; Kemeny, Margaret; Brodish, Amanda B; Malanchuk, Oksana; Peck, Stephen C; Fuller-Rowell, Thomas E; Eccles, Jacquelynne S

    2015-12-01

    Perceived racial discrimination (PRD) has been associated with altered diurnal cortisol rhythms in past cross-sectional research. We investigate whether developmental histories of PRD, assessed prospectively, are associated with adult diurnal cortisol profiles. One-hundred and twelve (N=50 Black, N=62 White) adults from the Maryland Adolescent Development in Context Study provided saliva samples in adulthood (at approximately age 32 years) at waking, 30min after waking, and at bedtime for 7 days. Diurnal cortisol measures were calculated, including waking cortisol levels, diurnal cortisol slopes, the cortisol awakening response (CAR), and average daily cortisol (AUC). These cortisol outcomes were predicted from measures of PRD obtained over a 20-year period beginning when individuals were in 7th grade (approximately age 12). Greater average PRD measured across the 20-year period predicted flatter adult diurnal cortisol slopes for both Black and White adults, and a lower CAR. Greater average PRD also predicted lower waking cortisol for Black, but not White adults. PRD experiences in adolescence accounted for many of these effects. When adolescent and young adult PRD are entered together predicting cortisol outcomes, PRD experiences in adolescence (but not young adulthood) significantly predicted flatter diurnal cortisol slopes for both Black and White adults. Adolescent, but not young adult PRD, also significantly predicted lower waking and lower average cortisol for Black adults. Young adult PRD was, however, a stronger predictor of the CAR, predicting a marginally lower CAR for Whites, and a significantly larger CAR for Blacks. Effects were robust to controlling for covariates including health behaviors, depression, income and parent education levels. PRD experiences interacted with parent education and income to predict aspects of the diurnal cortisol rhythm. Although these results suggest PRD influences on cortisol for both Blacks and Whites, the key findings

  16. 20 years TraumaRegister DGU(®): development, aims and structure.

    PubMed

    2014-10-01

    The TraumaRegister DGU(®) organisational and technical development has undergone an evolution process, which started 20 years ago. Currently, the management of the registry is under the management of the "AUC - Academy for Trauma Surgery" (infrastructure) and the "Sektion NIS" (scientific responsibility). The aim of the registry was to establish an inter-hospital quality assessment tool with the option to use the increasing database for scientific evaluations of acute care. Year after year and most recently with the obligatory participation of certified hospitals the number of participating hospitals has grown as well as the registered cases per annum. Recently, even hospitals from other countries joined the registry too. Starting with six German hospitals and 260 cases in 1993, 20 years later more than 600 hospitals from eleven countries deliver over 30,000 trauma cases per year resulting in over 150,000 reported cases until 2013. In this article a historical perspective is presented of the evolution and current status of the TraumaRegister DGU(®).

  17. A 20-year data set of surface longwave fluxes in the Arctic

    SciTech Connect

    Jennifer Francis

    2004-06-15

    Creation of 20-year data set of surface infrared fluxes from satellite measurements. A reliable estimate of the surface downwelling longwave radiation flux (DLF) is a glaring void in available forcing data sets for models of Arctic sea ice and ocean circulation. We have developed a new method to estimate the DLF from a combination of satellite sounder retrievals and brightness temperatures from the TIROS Operational Vertical Sounder (TOVS), which has flown on NOAA polar-orbiting satellites continuously since late 1979. The overarching goal of this project was to generate a 20-year data set of surface downwelling longwave flux measurements from TOVS data over the Arctic Ocean. Daily gridded fields of DLF were produced with a spatial resolution of (100 km){sup 2} north of 60{sup o}N for 22.5 years rather than only 20. Surface measurements from the field station at Barrow, AK--part of the Atmospheric Radiation Measurement (ARM) Program --and from the Surface Heat Budget of the Arctic (SHEBA) were used to validate the satellite-derived fluxes and develop algorithm improvements for conditions that had resulted in systematic errors in early versions of the algorithm. The resulting data set has already been sent to two other investigators for incorporation into their research, and we will soon complete preparations to send the products to the National Snow and Ice Data Center and ARM data archive, where it can be disseminated to the scientific community.

  18. 20 years TraumaRegister DGU(®): development, aims and structure.

    PubMed

    2014-10-01

    The TraumaRegister DGU(®) organisational and technical development has undergone an evolution process, which started 20 years ago. Currently, the management of the registry is under the management of the "AUC - Academy for Trauma Surgery" (infrastructure) and the "Sektion NIS" (scientific responsibility). The aim of the registry was to establish an inter-hospital quality assessment tool with the option to use the increasing database for scientific evaluations of acute care. Year after year and most recently with the obligatory participation of certified hospitals the number of participating hospitals has grown as well as the registered cases per annum. Recently, even hospitals from other countries joined the registry too. Starting with six German hospitals and 260 cases in 1993, 20 years later more than 600 hospitals from eleven countries deliver over 30,000 trauma cases per year resulting in over 150,000 reported cases until 2013. In this article a historical perspective is presented of the evolution and current status of the TraumaRegister DGU(®). PMID:25284237

  19. Time-dependent Mott transition in the periodic Anderson model with nonlocal hybridization

    NASA Astrophysics Data System (ADS)

    Hofmann, Felix; Potthoff, Michael

    2016-08-01

    The time-dependent Mott transition in a periodic Anderson model with off-site, nearest-neighbor hybridization is studied within the framework of nonequilibrium self-energy functional theory. Using the two-site dynamical-impurity approximation, we compute the real-time dynamics of the optimal variational parameter and of different observables initiated by sudden quenches of the Hubbard-U and identify the critical interaction. The time-dependent transition is orbital selective, i.e., in the final state, reached in the long-time limit after the quench to the critical interaction, the Mott gap opens in the spectral function of the localized orbitals only. We discuss the dependence of the critical interaction and of the final-state effective temperature on the hybridization strength and point out the various similarities between the nonequilibrium and the equilibrium Mott transition. It is shown that these can also be smoothly connected to each other by increasing the duration of a U-ramp from a sudden quench to a quasi-static process. The physics found for the model with off-site hybridization is compared with the dynamical Mott transition in the single-orbital Hubbard model and with the dynamical crossover found for the real-time dynamics of the conventional Anderson lattice with on-site hybridization.

  20. On Bifurcating Time-Periodic Flow of a Navier-Stokes Liquid Past a Cylinder

    NASA Astrophysics Data System (ADS)

    Galdi, Giovanni P.

    2016-10-01

    We provide general sufficient conditions for the existence and uniqueness of branching out of a time-periodic family of solutions from steady-state solutions to the two-dimensional Navier-Stokes equations in the exterior of a cylinder. By separating the time-independent averaged component of the velocity field from its oscillatory one, we show that the problem can be formulated as a coupled elliptic-parabolic nonlinear system in appropriate and distinct function spaces, with the property that the relevant linearized operators become Fredholm of index 0. In this functional setting, the notorious difficulty of 0 being in the essential spectrum entirely disappears and, in fact, it is even meaningless. Our approach is different and, we believe, more natural and simpler than those proposed by previous authors discussing similar questions. Moreover, the latter all fail, when applied to the problem studied here.

  1. Period-independent novel circadian oscillators revealed by timed exercise and palatable meals

    PubMed Central

    Flôres, Danilo E. F. L.; Bettilyon, Crystal N.; Yamazaki, Shin

    2016-01-01

    The mammalian circadian system is a hierarchical network of oscillators organized to optimally coordinate behavior and physiology with daily environmental cycles. The suprachiasmatic nucleus (SCN) of the hypothalamus is at the top of this hierarchy, synchronizing to the environmental light-dark cycle, and coordinates the phases of peripheral clocks. The Period genes are critical components of the molecular timekeeping mechanism of these clocks. Circadian clocks are disabled in Period1/2/3 triple mutant mice, resulting in arrhythmic behavior in constant conditions. We uncovered rhythmic behavior in this mutant by simply exposing the mice to timed access to a palatable meal or running wheel. The emergent circadian behavior rhythms free-ran for many cycles under constant conditions without cyclic environmental cues. Together, these data demonstrate that the palatable meal-inducible circadian oscillator (PICO) and wheel-inducible circadian oscillator (WICO) are generated by non-canonical circadian clocks. Entrainment of these novel oscillators by palatable snacks and timed exercise could become novel therapeutics for human conditions caused by disruptions of the circadian clocks. PMID:26904978

  2. Testing aggregation hypotheses among Neotropical trees and shrubs: results from a 50-ha plot over 20 years of sampling.

    PubMed

    Myster, Randall W; Malahy, Michael P

    2012-09-01

    Spatial patterns of tropical trees and shrubs are important to understanding their interaction and the resultant structure of tropical rainforests. To assess this issue, we took advantage of previously collected data, on Neotropical tree and shrub stem identified to species and mapped for spatial coordinates in a 50ha plot, with a frequency of every five years and over a 20 year period. These stems data were first placed into four groups, regardless of species, depending on their location in the vertical strata of the rainforest (shrubs, understory trees, mid-sized trees, tall trees) and then used to generate aggregation patterns for each sampling year. We found shrubs and understory trees clumped at small spatial scales of a few meters for several of the years sampled. Alternatively, mid-sized trees and tall trees did not clump, nor did they show uniform (regular) patterns, during any sampling period. In general (1) groups found higher in the canopy did not show aggregation on the ground and (2) the spatial patterns of all four groups showed similarity among different sampling years, thereby supporting a "shifting mosaic" view of plant communities over large areas. Spatial analysis, such as this one, are critical to understanding and predicting tree spaces, tree-tree replacements and the Neotropical forest patterns, such as biodiversity and those needed for sustainability efforts, they produce.

  3. A Report to the People. 20 Years of Your National Commitment to Public Broadcasting, 1967-1987. 1986 Annual Report.

    ERIC Educational Resources Information Center

    Corporation for Public Broadcasting, Washington, DC.

    This annual report for the Corporation for Public Broadcasting (CPB) for fiscal year 1986 also summarizes the CPB's activities over the last 20 years. The front inside cover folds out to three pages and provides a chronology of the important events in CPB history from its inception in 1967 to 1987. A narrative report on the CPB's 20 years of…

  4. Enhanced Transport of Passive Tracers In A Time Periodic Two-dimensional Flow

    NASA Astrophysics Data System (ADS)

    Boffetta, G.; Cencini, M.; Espa, S.; Musacchio, S.

    , investigating systems in which the second condition is violated is much more inter- esting. With this purpose, some experiments have shown how superdiffusion arises in a two-dimensional quasi-geostrophic (planetary-type) flow, where particles can jump for very long time in the same direction performing a Levy flight (Castiglione et al., 2001 ). Moreover, two recent papers (Vulpiani, 1998; Solomon, 2001) show how, also in very simple two-dimensional, time and space periodic cellular flows,anomalous diffusive behaviours can appear. In this paper we present an experimental study of transport in an electromagnetically forced time periodic two-dimensional flow. The flow is generated by applying an electromagnetic forcing on a thin layer of an elec- trolyte solution and reveals in a square grid of alternating vortices. Time dependence can be easily obtained by changing the time dependence of the electric fields. In par- ticular, considering certain values of the imposed oscillation frequencies, particles can display very long jump. Particle Tracking Velocimetry (PTV) is used to measure the flow field. This technique is the most suitable for studying dispersion phenomena in a Lagrangian framework allowing the direct evaluation of particle displacements and related quantities (Cenedese, Querzoli; 2000). Moreover, due to the characteristics of the analyzed flow and to the improvement of the tracking procedure, we have been able to track a great number of particles for time intervals greater than the charac- teristic time-scales of the flow. In order to characterize the time correlations we will evaluate the so-called jumps probabilities with memory which represent the probabil- ities to jump in a given direction conditioned to having experienced jumps in the same direction at previous times. Such statistics will revealed very useful and suitable for detecting the onset of the aforementioned correlations. 2

  5. Compensatory mechanisms in higher-educated subjects with Alzheimer's disease: a study of 20 years of cognitive decline.

    PubMed

    Amieva, Hélène; Mokri, Hind; Le Goff, Mélanie; Meillon, Céline; Jacqmin-Gadda, Hélène; Foubert-Samier, Alexandra; Orgogozo, Jean-Marc; Stern, Yaakov; Dartigues, Jean-François

    2014-04-01

    A better knowledge of long-term trajectories of cognitive decline is a central feature of the study of the process leading to Alzheimer's dementia. Several factors may mitigate such decline, among which is education, a major risk factor for Alzheimer's disease. The aim of our work was to compare the pattern and duration of clinical trajectories before Alzheimer's dementia in individuals with low and high education within the PAQUID cohort involving 20 years of follow-up. The sample comprises 442 participants with incident Alzheimer's disease (27.2% were male)--171 with low education (mean age=86.2 years; standard deviation=5.3 years) and 271 with higher education (mean age=86.5; standard deviation=5.4)--and 442 control subjects matched according to age, sex and education. At each visit and up to the 20-year follow-up visit, several cognitive and clinical measures were collected and incident cases of Alzheimer's disease clinically diagnosed. The evolution of clinical measures in pre-demented subjects and matched controls was analysed with a semi-parametric extension of the mixed effects linear model. The results show that the first signs of cognitive decline occurred 15 to 16 years before achieving dementia threshold in higher-educated subjects whereas signs occurred at 7 years before dementia in low-educated subjects. There seemed to be two successive periods of decline in higher-educated subjects. Decline started ∼15 to 16 years before dementia with subtle impairment restricted to some cognitive tests and with no impact during the first 7 to 8 years on global cognition, cognitive complaints, or activities of daily living scales. Then, ∼7 years before dementia, global cognitive abilities begin to deteriorate, along with difficulties dealing with complex activities of daily living, the increase in self-perceived difficulties and depressive symptoms. By contrast, lower-educated subjects presented a single period of decline lasting ∼7 years, characterized by

  6. The changes of subtypes in pediatric diabetes and their clinical and laboratory characteristics over the last 20 years

    PubMed Central

    Kwon, Eun Byul; Lee, Hae Sang; Shim, Young Seok; Jeong, Hwal Rim

    2016-01-01

    Purpose We studied the changes in subtypes of diabetes mellitus (DM) in children and evaluated the characteristics of each group over the past 20 years. In addition, we also examined the correlation between the glycated hemoglobin (HbA1c) values at the time of diagnosis and lipid profiles. Methods The patients were divided into 2 groups: there were a total of 190 patients under 20 years of age firstly diagnosed with DM in Ajou University Hospital. The patients in groups I and II were diagnosed from September 1995 to December 2004 and from January 2005 to April 2014, respectively. Results The characteristics were compared between the 2 groups of patients. The result showed an increase in percentage of type 2 diabetes and maturity onset diabetes of the young (MODY) patients between the 2 groups. HbA1c and total cholesterol level had statistical significances to explain increasing the low-density lipoprotein cholesterol level among age, HbA1c, total cholesterol level, and z-scores of weight and body mass index (BMI) in type 2 diabetes. R-square was 0.074. However, z-score of BMI and total cholesterol level, not HbA1c, had statistical significances in type 1 diabetic patients. R-square was 0.323. Conclusion The increase in the proportions of both type 2 diabetes and MODY in the last 10 years needed to be reminded when diagnosing the subtypes of DM, and the dyslipidemia should be attended more as a common problem of pediatric diabetic patients. PMID:27462584

  7. Evolution of illustrations in anatomy: a study from the classical period in Europe to modern times.

    PubMed

    Ghosh, Sanjib Kumar

    2015-01-01

    Illustrations constitute an essential element of learning anatomy in modern times. However it required a significant evolutionary process spread over centuries, for illustrations to achieve the present status in the subject of anatomy. This review article attempts to outline the evolutionary process by highlighting on the works of esteemed anatomists in a chronological manner. Available literature suggests that illustrations were not used in anatomy during the classical period when the subject was dominated by the descriptive text of Galen. Guido da Vigevano was first to use illustrations in anatomy during the Late Middle Ages and this concept developed further during the Renaissance period when Andreas Vesalius pioneered in illustrations becoming an indispensable tool in conveying anatomical details. Toward later stages of the Renaissance period, Fabricius ab Aquapendente endeavored to restrict dramatization of anatomical illustrations which was a prevalent trend in early Renaissance. During the 18th century, anatomical artwork was characterized by the individual styles of prominent anatomists leading to suppression of anatomical details. In the 19th century, Henry Gray used illustrations in his anatomical masterpiece that focused on depicting anatomical structures and were free from any artistic style. From early part of the 20th century medical images and photographs started to complement traditional handmade anatomical illustrations. Computer technology and advanced software systems played a key role in the evolution of anatomical illustrations during the late 20th century resulting in new generation 3D image datasets that are being used in the 21st century in innovative formats for teaching and learning anatomy. PMID:25053471

  8. Long-time asymptotics of the periodic Toda lattice under short-range perturbations

    NASA Astrophysics Data System (ADS)

    Kamvissis, Spyridon; Teschl, Gerald

    2012-07-01

    We compute the long-time asymptotics of periodic (and slightly more generally of algebro-geometric finite-gap) solutions of the doubly infinite Toda lattice under a short-range perturbation. In particular, we prove that the perturbed lattice asymptotically approaches a modulated lattice. More precisely, let g be the genus of the hyperelliptic curve associated with the unperturbed solution. We show that, apart from the phenomenon of solitons travelling in a quasi-periodic background, the n/t-pane contains g + 2 areas where the perturbed solution is close to a finite-gap solution on the same isospectral torus. In between there are g + 1 regions where the perturbed solution is asymptotically close to a modulated lattice which undergoes a continuous phase transition (in the Jacobian variety) and which interpolates between these isospectral solutions. In the special case of the free lattice (g = 0), the isospectral torus consists of just one point and we recover the known result. Both the solutions in the isospectral torus and the phase transition are explicitly characterized in terms of Abelian integrals on the underlying hyperelliptic curve. Our method relies on the equivalence of the inverse spectral problem to a vector Riemann-Hilbert problem defined on the hyperelliptic curve and generalizes the so-called nonlinear stationary phase/steepest descent method for Riemann-Hilbert problem deformations to Riemann surfaces.

  9. Role of 3-D ultrasound in clinical obstetric practice: evolution over 20 years.

    PubMed

    Tonni, Gabriele; Martins, Wellington P; Guimarães Filho, Hélio; Araujo Júnior, Edward

    2015-05-01

    The use of 3-D ultrasound in obstetrics has undergone dramatic development over the past 20 years. Since the first publications on this application in clinical practice, several 3-D ultrasound techniques and rendering modes have been proposed and applied to the study of fetal brain, face and cardiac anatomy. In addition, 3-D ultrasound has improved calculations of the volume of fetal organs and limbs and estimations of fetal birth weight. And furthermore, angiographic patterns of fetal organs and the placenta have been assessed using 3-D power Doppler ultrasound quantification. In this review, we aim to summarize current evidence on the clinical relevance of these methodologies and their application in obstetric practice.

  10. [Meeting Report: 20 years after the First International Symposium on hepatitis C virus and related viruses].

    PubMed

    Carnero, Elena; Díez, Juana; Fortes, Purificación; Gastaminza, Pablo; Majano, Pedro; Martínez, Miguel Angel; Pérez-del-Pulgar, Sofía; Quer, Josep; López-Labrador, F Xavier

    2013-12-01

    The hepatitis C virus (HCV) was discovered by the team of Michael Houghton at Chiron Corporation in 1989 and the first symposium on HCV and related viruses was held in Venice, Italy, shortly after, in 1992. This conference was organized to advance knowledge on what then was a mysterious virus responsible for most cases of «non-A, non-B» hepatitis. During the 20 years since the first conference, the scientific quality of presentations has steadily increased, together with the tremendous advances in basic and clinical research and epidemiology. What started as a small conference on a new virus, about which there were very few data, has today become a first-in-class congress: a meeting place for basic researchers, clinicians, epidemiologists, public health experts, and industry members to present the most important advances and their application to HCV treatment and control. The nineteenth HCV symposium was held in September 2012, once again in Venice.

  11. How do animal territories form and change? Lessons from 20 years of mechanistic modelling.

    PubMed

    Potts, Jonathan R; Lewis, Mark A

    2014-06-01

    Territory formation is ubiquitous throughout the animal kingdom. At the individual level, various behaviours attempt to exclude conspecifics from regions of space. At the population level, animals often segregate into distinct territorial areas. Consequently, it should be possible to derive territorial patterns from the underlying behavioural processes of animal movements and interactions. Such derivations are an important element in the development of an ecological theory that can predict the effects of changing conditions on territorial populations. Here, we review the approaches developed over the past 20 years or so, which go under the umbrella of 'mechanistic territorial models'. We detail the two main strands to this research: partial differential equations and individual-based approaches, showing what each has offered to our understanding of territoriality and how they can be unified. We explain how they are related to other approaches to studying territories and home ranges, and point towards possible future directions. PMID:24741017

  12. RSIC after 20 years: a look back and a look ahead

    SciTech Connect

    Maskewitz, B.F.; Roussin, R.W.; Trubev, D.K.

    1983-01-01

    On the occasion of RSIC's 20th anniversary year, this review includes highlights and lessons learned. In June 1963, the first RSIC Newsletter was published, and information analyses procedures and practices were initiated. Evidence indicates that RSIC served for 20 years as the focal point for the exchange and transfer of radiation transport technology and contributed to the advancement of the state of the art. The original concept is found to be sound: operate an information analysis center by collecting, organizing, evaluating, and analyzing all relevant information and making the information available in a form readily useful to scientists and engineers. Computing technology, a computer-based literature information system, and an advisory service remain important elements of the center. Continuing interaction between the center, developers, and users of information products and services has been a key to RSIC success. A look to the future reflects optimism.

  13. From the First Stars and Galaxies to the Epoch of Reionization: 20 Years of Computational Progress

    NASA Astrophysics Data System (ADS)

    Norman, Michael L.

    2016-06-01

    I give a progress report on computational efforts to reconstruct the first billion years of cosmic evolution beginning with the formation of the first generation of stars and galaxies, culminating in the complete photoionization of the intergalactic medium. After 20 years of intense effort, the picture is falling into place through the development and application of complex multiphysics numerical simulations of increasing physical complexity and scale on the most powerful supercomputers. I describe the processes that govern the formation of the first generation of stars, the transition to the second generation of stars, the assembly of the first galaxies, and finally the reionization of the universe. I discuss how these simulations guide the interpretation of relevant observations of the high redshift (and local) universe, along with some observational predictions of these simulations which will be tested with the next generation observatories.

  14. [20 years of a sex education clinic. Are family planning centers still needed?].

    PubMed

    Alfsen, G C; Hokstad, S

    1992-02-28

    The Sexual Information Clinic in Oslo was founded more than 20 years ago. The clinic is the largest family planning centre in Norway, treating 4,000-6,000 patients per year. In recent years the treatment of venereal diseases has become the major component of the daily work. The authors describe the different groups of patients who visit the clinic. The meanage of the patients is 21 years. The high number of legal abortions among younger women and the rising incidence of sexually transmitted diseases prove the continued existence of a need for family planning centres. The authors discuss the situation of family planning centres in Norway in general and stress the importance of their work. They argue that all venereal diseases should be treated free of charge.

  15. How do animal territories form and change? Lessons from 20 years of mechanistic modelling

    PubMed Central

    Potts, Jonathan R.; Lewis, Mark A.

    2014-01-01

    Territory formation is ubiquitous throughout the animal kingdom. At the individual level, various behaviours attempt to exclude conspecifics from regions of space. At the population level, animals often segregate into distinct territorial areas. Consequently, it should be possible to derive territorial patterns from the underlying behavioural processes of animal movements and interactions. Such derivations are an important element in the development of an ecological theory that can predict the effects of changing conditions on territorial populations. Here, we review the approaches developed over the past 20 years or so, which go under the umbrella of ‘mechanistic territorial models’. We detail the two main strands to this research: partial differential equations and individual-based approaches, showing what each has offered to our understanding of territoriality and how they can be unified. We explain how they are related to other approaches to studying territories and home ranges, and point towards possible future directions. PMID:24741017

  16. Gastric metastasis of renal cell carcinoma 20 years after radical nephrectomy

    PubMed Central

    Akay, Ebru; Kala, Mehtap; Karaman, Hatice

    2016-01-01

    Renal cell carcinomas account for 2–3% of malignant neoplasms in adults. The lung, soft tissues and bone represent the most frequent sites of distant metastasis in renal cell carcinoma. Gastric metastasis is rare. Our case was a 72-year-old man with complaints of fatigue and loss of appetite. In history, he had unergone radical nephrectomy due to renal cell carcinoma in 1993. A polypoid lesion was observed in upper gastrointestinal endoscopy. Histopathology of gastric biopsy specimen was reported as renal cell carcinoma. In English literature, there are 50 cases diagnosed as gastric metastasis from renal cell carcinoma. To date, there are only 4 cases with extremely late gastric metastasis of renal cell carcinoma. Herein, we present a rare case which underwent radical nephrectomy due to renal cell carcinoma and found to have gastric metastasis at 20. year of his follow-up. PMID:27274897

  17. A General Time-Periodic Driving Approach to Realize Topological Phases in Cold Atomic Systems

    PubMed Central

    Yan, Zhongbo; Li, Bo; Yang, Xiaosen; Wan, Shaolong

    2015-01-01

    For time-reversal symmetric cold atomic insulating systems, it is found that the usual driving approach based on electromagnetic field used in solid state systems loses its power to drive them from trivial regimes to topological regimes if the driven systems still hold time-reversal symmetry (TRS). For such systems, we point out that simply varying the optical lattice potential periodically provides a general and effective way to drive them into topological regimes without breaking their symmetries. Based on this approach, we find that the time-reversal symmetric Kane-Mele model can be effectively driven from the trivial phase to topological phases named as Floquet Quantum Spin Hall insulator. Due to the existence of two gaps in the Floquet system, this novel state of matter can stably host one or two pair of gapless helical states on the same boundary, which suggests this state is not a simple analog of the Quantum Spin Hall insulator. This new driving approach to a system without TRS is also investigated. PMID:26541611

  18. Dynamical generalized Hurst exponent as a tool to monitor unstable periods in financial time series

    NASA Astrophysics Data System (ADS)

    Morales, Raffaello; Di Matteo, T.; Gramatica, Ruggero; Aste, Tomaso

    2012-06-01

    We investigate the use of the Hurst exponent, dynamically computed over a weighted moving time-window, to evaluate the level of stability/instability of financial firms. Financial firms bailed-out as a consequence of the 2007-2008 credit crisis show a neat increase with time of the generalized Hurst exponent in the period preceding the unfolding of the crisis. Conversely, firms belonging to other market sectors, which suffered the least throughout the crisis, show opposite behaviors. We find that the multifractality of the bailed-out firms increase at the crisis suggesting that the multi fractal properties of the time series are changing. These findings suggest the possibility of using the scaling behavior as a tool to track the level of stability of a firm. In this paper, we introduce a method to compute the generalized Hurst exponent which assigns larger weights to more recent events with respect to older ones. In this way large fluctuations in the remote past are less likely to influence the recent past. We also investigate the scaling associated with the tails of the log-returns distributions and compare this scaling with the scaling associated with the Hurst exponent, observing that the processes underlying the price dynamics of these firms are truly multi-scaling.

  19. A General Time-Periodic Driving Approach to Realize Topological Phases in Cold Atomic Systems

    NASA Astrophysics Data System (ADS)

    Yan, Zhongbo; Li, Bo; Yang, Xiaosen; Wan, Shaolong

    2015-11-01

    For time-reversal symmetric cold atomic insulating systems, it is found that the usual driving approach based on electromagnetic field used in solid state systems loses its power to drive them from trivial regimes to topological regimes if the driven systems still hold time-reversal symmetry (TRS). For such systems, we point out that simply varying the optical lattice potential periodically provides a general and effective way to drive them into topological regimes without breaking their symmetries. Based on this approach, we find that the time-reversal symmetric Kane-Mele model can be effectively driven from the trivial phase to topological phases named as Floquet Quantum Spin Hall insulator. Due to the existence of two gaps in the Floquet system, this novel state of matter can stably host one or two pair of gapless helical states on the same boundary, which suggests this state is not a simple analog of the Quantum Spin Hall insulator. This new driving approach to a system without TRS is also investigated.

  20. Sustained and transient attentional processes modulate neural predictors of memory encoding in consecutive time periods.

    PubMed

    Padovani, Tullia; Koenig, Thomas; Eckstein, Doris; Perrig, Walter J

    2013-07-01

    Memory formation is commonly thought to rely on brain activity following an event. Yet, recent research has shown that even brain activity previous to an event can predict later recollection (subsequent memory effect, SME). In order to investigate the attentional sources of the SME, event-related potentials (ERPs) elicited by task cues preceding target words were recorded in a switched task paradigm that was followed by a surprise recognition test. Stay trials, that is, those with the same task as the previous trial, were contrasted with switch trials, which included a task switch compared to the previous trial. The underlying assumption was that sustained attention would be dominant in stay trials and that transient attentional reconfiguration processes would be dominant in switch trials. To determine the SME, local and global statistics of scalp electric fields were used to identify differences between subsequently remembered and forgotten items. Results showed that the SME in stay trials occurred in a time window from 2 to 1 sec before target onset, whereas the SME in switch trials occurred subsequently, in a time window from 1 to 0 sec before target onset. Both SMEs showed a frontal negativity resembling the topography of previously reported effects, which suggests that sustained and transient attentional processes contribute to the prestimulus SME in consecutive time periods. PMID:24381815

  1. Multi Band Insar Analysis of Subsidence Development Based on the Long Period Time Series

    NASA Astrophysics Data System (ADS)

    Çomut, F. C.; Ustun, A.; Lazecky, M.; Aref, M. M.

    2015-12-01

    The SAR Interferometry (InSAR) application has shown great potential in monitoring of land terrain changes and in detection of land deformations such as subsidence. Longer time analysis can lead to understand longer trends and changes. Using different bands of SAR satellite (C- from ERS 1-2 and Envisat, L- from ALOS) over the study area, we achieve knowledge of movements in long-term and evaluation of its dynamic changes within observed period of time. Results from InSAR processing fit with the position changes in vertical direction based on GPS network established over the basin as an effective geodetic network. Time series (StaMPS PS+SB) of several points over Çumra County in eastern part of Konya City show a general trend of the deformation that is expected to be approximately between -13 to -17 mm/year. Northern part of Karaman is affected by faster subsidence, borders of the subsidence trough were identified from Envisat. Presenting InSAR results together with GIS information about locations and time of occurrence of sudden subsidence, urban/industrial growth in time and climate changes helps in better understanding of the situation. This way, the impact of natural and man-made changes will be shown for urban planning thanks to InSAR and GIS comparisons with hydrogeological modeling. In this study we present results of differential and multitemporal InSAR series using different bands and GIS conjunction associated with seasonal and temporal groundwater level changes in Konya Closed Basin.

  2. Effects of storage conditions on forensic examinations of blood samples and bloodstains stored for 20 years.

    PubMed

    Hara, M; Nakanishi, H; Yoneyama, K; Saito, K; Takada, A

    2016-01-01

    The effects of various storage conditions on blood identification tests, DNA degradation, and short tandem repeat (STR) typing were evaluated. Bloodstains stored at room temperature, 4 °C, -20 °C, and -80 °C for 20 years; blood samples stored at -20 °C and -80 °C for 20 years; and fresh blood samples were analyzed. Leuco-malachite-green testing, anti-human hemoglobin (Hb) testing (using immunochromatography), and tests for hemoglobin-beta (HBB) mRNA were performed as blood identification tests. DNA degradation was evaluated by quantifying the ratios of 305 and 129 base pair (bp) fragments to 41 bp fragments. STR typing was performed using an AmpFlSTR® Identifiler™ Plus PCR Amplification Kit. All samples were positive in leuco-malachite-green staining and anti-human Hb assays. HBB was not detected in blood samples stored at -20 °C or -80 °C, although this marker was detected in all bloodstains. As indicated by the ratio of 129:41 bp and 305:41 bp DNA fragments, DNA from bloodstains stored at room temperature or 4 °C were significantly degraded compared to DNA from all other samples. STR typing analyses revealed that a portion of the loci was undetected in bloodstains stored at room temperature. Therefore, to prevent DNA degradation during long-term storage, it is recommended that bloodstains and blood be stored at below -20 °C. In addition, because bloodstains are more suitable for detection of blood-specific mRNAs than blood sample, it is desirable that blood is stored as bloodstain for this method.

  3. Fault kinematics in the 1989 Loma Prieta rupture area during 20 years before that event

    SciTech Connect

    Seeber, L.; Armbruster, J.G. )

    1990-08-01

    The Loma Prieta (LP) compressional bend of the San Andreas fault zone (SAF) appears to be multi-stranded and vertically segmented; thus, faults in this segment other than the one that ruptured in 1989 may: (1) be the source of prior large events associated with this portion of the SAF and (2) be highly stressed after the 1989 LP event. The fault that ruptured in 1989 was remarkably aseismic during the preceding 20 years; seismicity occurred on some of the neighboring faults of the system, but others remained aseismic. The Lake Elsman burst of seismicity within 1.6 years of the main shock is on a set of secondary faults within the foot-wall of the rupture. The shallow ({le}5 km) portion of the SAF, morphologically and structurally characterized as steep and predominantly strike-slip, and the imbricate thrust zone to the northeast were also quiescent. These upper crustal faults may partition oblique motion accomplished by LP-like ruptures in the lower crust into fault-parallel (transcurrence) and fault-normal motion (convergence), respectively. While the overall level of seismicity in the region around LP increased over the 20 years before 1989, the level of seismicity (number of events) on the creeping portion of the SAF next to the LP segment decreased. Moreover, the level of background seismicity on this and other fault segments varied dramatically, both up and down, in conjunction with major regional earthquakes on other segments. Thus, improved models for precursory patterns of seismicity should account for mechanistically more realistic changes than simple seismicity increase or decrease everywhere around an impending rupture.

  4. Cardiac Magnetic Resonance Imaging Findings in 20-year Survivors of Mediastinal Radiotherapy for Hodgkin's Disease

    SciTech Connect

    Machann, Wolfram; Beer, Meinrad; Breunig, Margret; Stoerk, Stefan; Angermann, Christiane; Seufert, Ines; Schwab, Franz; Koelbl, Oliver; Flentje, Michael; Vordermark, Dirk

    2011-03-15

    Purpose: The recognition of the true prevalence of cardiac toxicity after mediastinal radiotherapy requires very long follow-up and a precise diagnostic procedure. Cardiac magnetic resonance imaging (MRI) permits excellent quantification of cardiac function and identification of localized myocardial defects and has now been applied to a group of 20-year Hodgkin's disease survivors. Methods and materials: Of 143 patients treated with anterior mediastinal radiotherapy (cobalt-60, median prescribed dose 40 Gy) for Hodgkin's disease between 1978 and 1985, all 53 survivors were invited for cardiac MRI. Of those, 36 patients (68%) presented for MRI, and in 31 patients (58%) MRI could be performed 20-28 years (median, 24) after radiotherapy. The following sequences were acquired on a 1.5-T MRI: transversal T1-weighted TSE and T2-weighted half-fourier acquisition single-shot turbo-spin-echo sequences, a steady-state free precession (SSFP) cine sequence in the short heart axis and in the four-chamber view, SSFP perfusion sequences under rest and adenosine stress, and a SSFP inversion recovery sequence for late enhancement. The MRI findings were correlated with previously reconstructed doses to cardiac structures. Results: Clinical characteristics and reconstructed doses were not significantly different between survivors undergoing and not undergoing MRI. Pathologic findings were reduced left ventricular function (ejection fraction <55%) in 7 (23%) patients, hemodynamically relevant valvular dysfunction in 13 (42%), late myocardial enhancement in 9 (29%), and any perfusion deficit in 21 (68%). An association of regional pathologic changes and reconstructed dose to cardiac structures could not be established. Conclusions: In 20-year survivors of Hodgkin's disease, cardiac MRI detects pathologic findings in approximately 70% of patients. Cardiac MRI has a potential role in cardiac imaging of Hodgkin's disease patients after mediastinal radiotherapy.

  5. A History of the Environmental Management Advisory Board: 20 Years of Service and Partnership - 13219

    SciTech Connect

    Ellis, Kristen; Schmitt, Elizabeth

    2013-07-01

    The Environmental Management Advisory Board (EMAB or Board) was chartered under the Federal Advisory Committee Act (FACA) in 1992 to provide the Assistant Secretary for Environmental Management (EM) with independent and external advice, information, and recommendations on corporate issues relating to accelerated site clean-up and risk reduction throughout the EM complex. Over the course of the past 20 years, the composition and focus of the Board have varied widely to address the changing needs of the program. EMAB began as the Environmental Restoration and Waste Management Advisory Committee, formed to provide advice on an EM Programmatic Environmental Impact Statement. In 1994, the Board was restructured to function more as an executive-level, limited member advisory board whose membership provides insight of leading industry experts and the viewpoints of representatives from critical stakeholder constituencies. Throughout the 20 years of its existence, EMAB has covered a wide variety of topics and produced nearly 200 recommendations. These recommendations have resulted in several policy changes and improvements within EM. Most recently, EMAB has been credited for its contribution to the EM Energy Park Initiative, forerunner of the DOE Asset Revitalization Initiative; creation of the EM Offices of Communications and External Affairs; improvement of acquisition and project management strategies and culture; and several recommendations related to the Waste Treatment Plant and the tank waste programs at Hanford and the Savannah River Site. The wealth of experience and knowledge the Assistant Secretary can leverage through utilization of the Board continues to support fulfillment of EM's mission. In commemoration of EMAB's 20. anniversary, this paper will provide further context for the evolution of the Board, the role FACA plays in its administration, and a look at the members' current objectives and EM's expectations for the future. (authors)

  6. Temporal and Spatial Trends of Mercury Speciation in the Mediterranean Sea - 20 years of measurements

    NASA Astrophysics Data System (ADS)

    Horvat, M.; Kotnik, J.; Fajon, V.; Zivkovic, I.; Begu, E.; Pirrone, N.; Sprovieri, F.

    2015-12-01

    Despite the geological mercury anomaly in the Mediterranean Basin, the concentrations of Hg Hg and its compounds are generally lower than those found in the Atlantic and Pacific waters. Temporal and spatial trends of total mercury and its species in surface and deep waters (dissolved gaseous mercury - DGM, mono and di-methylmercuy - MMHg, and DMHg) obtained during last 20 years will be presented. Total mercury Hg levels in open waters are generally very low (0.81-2.33 pM, av. 1.46 pM) and remain constant over the years. Hg speciation data showed that DGM accounts for up to 50% while MMHg accounted to up to 15% of total Hg in water. Significant spatial and temporal differences were observed for mercury speciation. The relatively high concentrations and fractions of DGM and MMHg indicate the high reactivity of Hg in open marine waters. DGM was present in surface waters mainly as Hg0 as no DMHg was detected at the surface, while towards the bottom a noticeable, but relatively small fraction of DMHg was present. It was found that DGM species were lower in surface with an increasing trend towards the bottom, especially in the tectonically active areas, indicating its geotectonic origin. In surface waters, DGM exhibited higher values in summer. MMHg profiles are mostly related to Chl-a and oxygen concentrations. This underlines the role of planktonic production and regeneration in methylation/ demethylation processes. The low MMHg concentrations found in shelf edge or coastal sediments and water over sediment indicate that coastal or shelf sediments are not a significant MMHg source for adjacent open sea waters. Anthropogenic and natural point sources show local enrichments, while natural diffusive sources influence Hg speciation over larger areas. The results allowed estimation of temporal mass balances to be evaluated for the Mediterranean Sea. Comparability of the measured results was secured by strict quality control measures over the 20 years.

  7. Effects of storage conditions on forensic examinations of blood samples and bloodstains stored for 20 years.

    PubMed

    Hara, M; Nakanishi, H; Yoneyama, K; Saito, K; Takada, A

    2016-01-01

    The effects of various storage conditions on blood identification tests, DNA degradation, and short tandem repeat (STR) typing were evaluated. Bloodstains stored at room temperature, 4 °C, -20 °C, and -80 °C for 20 years; blood samples stored at -20 °C and -80 °C for 20 years; and fresh blood samples were analyzed. Leuco-malachite-green testing, anti-human hemoglobin (Hb) testing (using immunochromatography), and tests for hemoglobin-beta (HBB) mRNA were performed as blood identification tests. DNA degradation was evaluated by quantifying the ratios of 305 and 129 base pair (bp) fragments to 41 bp fragments. STR typing was performed using an AmpFlSTR® Identifiler™ Plus PCR Amplification Kit. All samples were positive in leuco-malachite-green staining and anti-human Hb assays. HBB was not detected in blood samples stored at -20 °C or -80 °C, although this marker was detected in all bloodstains. As indicated by the ratio of 129:41 bp and 305:41 bp DNA fragments, DNA from bloodstains stored at room temperature or 4 °C were significantly degraded compared to DNA from all other samples. STR typing analyses revealed that a portion of the loci was undetected in bloodstains stored at room temperature. Therefore, to prevent DNA degradation during long-term storage, it is recommended that bloodstains and blood be stored at below -20 °C. In addition, because bloodstains are more suitable for detection of blood-specific mRNAs than blood sample, it is desirable that blood is stored as bloodstain for this method. PMID:26832383

  8. Characteristics of dissolved organic matter following 20years of peatland restoration.

    PubMed

    Höll, Bettina S; Fiedler, Sabine; Jungkunst, Hermann F; Kalbitz, Karsten; Freibauer, Annette; Drösler, Matthias; Stahr, Karl

    2009-12-15

    The changes in the amounts and composition of dissolved organic matter (DOM) following long-term peat restoration are unknown, although this fraction of soil organic matter affects many processes in such ecosystems. We addressed this lack of knowledge by investigating a peatland in south-west Germany that was partly rewetted 20 years ago. A successfully restored site and a moderately drained site were compared, where the mean groundwater levels were close to the soil surface and around 30 cm below surface, respectively. The concentrations of dissolved organic carbon (DOC) at 4 depths were measured over one year. The specific absorbance was measured at 280 nm and the fluorescence spectra were used to describe the aromaticity and complexity of DOM. The investigations showed that 20 years of peatland restoration was able to create typical peatland conditions. The rewetted site had significantly lower DOC concentrations at different depths compared to the drained site. The specific UV absorbance showed that the rewetted site had a lower level of aromatic DOM structures. The decreasing specific UV absorbance might indicate an increasing contribution of small organic molecules to DOM. It was hypothesized that the decreasing DOC concentrations and the relative enrichment of small, readily degradable organic molecules, reflect the slower decomposition of organic matter after the re-establishment of the water table. Seasonal trends provided substantial evidence for our hypothesis that reduced DOC concentrations were caused by reduced peat decomposition. During summer, the elevated DOC values were accompanied by an increase in DOM aromaticity and complexity. Our results demonstrated a close link between C mineralization and DOC production. We concluded that long-term peatland restoration in the form of the successful re-establishment of the water table might result in reduced peat decomposition and lower DOC concentrations. The restoration of peatlands seems to have a

  9. Anterior cruciate ligament injury after more than 20 years: I. Physical activity level and knee function.

    PubMed

    Tengman, E; Brax Olofsson, L; Nilsson, K G; Tegner, Y; Lundgren, L; Häger, C K

    2014-12-01

    Little is known about physical activity level and knee function including jump capacity and fear of movement/reinjury more than 20 years after injury of the anterior cruciate ligament (ACL). Seventy persons with unilateral ACL injury participated (23 ± 2 years post-injury): 33 treated with physiotherapy in combination with surgical reconstruction (ACLR ), and 37 treated with physiotherapy alone (ACLPT ). These were compared with 33 age- and gender-matched controls. Assessment included knee-specific and general physical activity level [Tegner activity scale, International Physical Activity Questionnaire (IPAQ)], knee function [Lysholm score, Knee injury and Osteoarthritis Outcome Score (KOOS)], jump capacity (one-leg hop, vertical jump, side hops), and fear of movement/reinjury [Tampa Scale for Kinesiophobia (TSK)]. Outcomes were related to degree of osteoarthritis (OA). ACL-injured had lower Lysholm, KOOS, and Tegner scores than controls (P < 0.001), while IPAQ score was similar. ACL-injured demonstrated inferior jump capacity in injured compared with noninjured leg (6-25%, P < 0.001-P = 0.010 in the different jumps), while noninjured leg had equal jump capacity as controls. ACL groups scored 33 ± 7 and 32 ± 7 of 68 on TSK. Lower scores on Lysholm and KOOS symptom were seen for persons with moderate-to-high OA than for no-or-low OA, while there were no differences for physical activity and jump capacity. Regardless of treatment, there are still negative knee-related effects of ACL injury more than 20 years later.

  10. Periodic coupling strength-dependent multiple coherence resonance by time delay in Newman-Watts neuronal networks.

    PubMed

    Wu, Yanan; Gong, Yubing; Xu, Bo

    2013-12-01

    Recently, multiple coherence resonance induced by time delay has been observed in neuronal networks with constant coupling strength. In this paper, by employing Newman-Watts Hodgkin-Huxley neuron networks with time-periodic coupling strength, we study how the temporal coherence of spiking behavior and coherence resonance by time delay change when the frequency of periodic coupling strength is varied. It is found that delay induced coherence resonance is dependent on periodic coupling strength and increases when the frequency of periodic coupling strength increases. Periodic coupling strength can also induce multiple coherence resonance, and the coherence resonance occurs when the frequency of periodic coupling strength is approximately multiple of the spiking frequency. These results show that for periodic coupling strength time delay can more frequently optimize the temporal coherence of spiking activity, and periodic coupling strength can repetitively optimize the temporal coherence of spiking activity as well. Frequency locking may be the mechanism for multiple coherence resonance induced by periodic coupling strength. These findings imply that periodic coupling strength is more efficient for enhancing the temporal coherence of spiking activity of neuronal networks, and thus it could play a more important role in improving the time precision of information processing and transmission in neural networks.

  11. Stochastic extinction of tumor cells due to synchronization effect through time periodic treatment in a tumor-immune interaction model

    NASA Astrophysics Data System (ADS)

    Aisu, Ryota; Horita, Takehiko

    The response to a time periodic treatment of the immunotherapy in a stochastic model of tumor-immune interaction is numerically investigated. Due to the effect of synchronization among the intrinsic oscillation and the treatment, an enhanced extinction of the tumor cells is observed. It suggests that compared with the static treatment, by controlling the period of the treatment, the time periodic treatment could be an effective way of treatment leading to tumor extinction.

  12. Crossing rule for a PT-symmetric two-level time-periodic system

    SciTech Connect

    Moiseyev, Nimrod

    2011-05-15

    For a two-level system in a time-periodic field we show that in the non-Hermitian PT case the level crossing is of two quasistationary states that have the same dynamical symmetry property. At the field's parameters where the two levels which have the same dynamical symmetry cross, the corresponding quasienergy states coalesce and a self-orthogonal state is obtained. This situation is very different from the Hermitian case where a crossing of two quasienergy levels happens only when the corresponding two quasistationary states have different dynamical symmetry properties and, unlike the situation in the non-Hermitian case, the spectrum remains complete also when the two levels cross.

  13. Fluctuation relations for heat engines in time-periodic steady states

    NASA Astrophysics Data System (ADS)

    Lahiri, Sourabh; Rana, Shubhashis; Jayannavar, A. M.

    2012-11-01

    A fluctuation relation for heat engines has been derived recently. In the beginning, the system is in contact with the cooler bath. The system is then coupled to the hotter bath and external parameters are changed cyclically, eventually bringing the system back to its initial state, once the coupling with the hot bath is switched off. In this work, we lift the condition of initial thermal equilibrium and derive a new fluctuation relation for the central system (heat engine) being in a time-periodic steady state (TPSS). Carnot’s inequality for classical thermodynamics follows as a direct consequence of this fluctuation theorem even in the TPSS. For the special cases of the absence of hot bath and no extraction of work, we obtain the integral fluctuation theorem for total entropy and the generalized exchange fluctuation theorem, respectively. Recently, microsized heat engines have been realized experimentally in the TPSS. We numerically simulate the same model and verify our proposed theorems.

  14. Efficiency, Power and Period of a model quantum heat engine working in a finite time

    NASA Astrophysics Data System (ADS)

    Bekele, Mulugeta; Dima, Tolasa A.; Alemye, Mekuannent; Chegeno, Warga

    We take a spin-half quantum particle undergoing Carnot type cyclic process in a finite time assisted by two heat reservoirs and an external magnetic field. We find that the power of the heat engine is maximum at a particular period of the cyclic process and efficiency at the maximum power is at least half of the Carnot efficiency. We further apply the Omega-criterion for a figure of merit representing a compromise between useful power and lost power determining the corresponding efficiency for the optimization criterion to be at least three fourth of the Carnot efficiency. The authers are thankful to the International Science programme, IPS, Uppsala, Sweden for their support to our research lab.

  15. Controllability discrepancy and irreducibility/reducibility of Floquet factorisations in linear continuous-time periodic systems

    NASA Astrophysics Data System (ADS)

    Zhou, Jun; Lu, Xinbiao; Qian, Huimin

    2016-09-01

    The paper reports interesting but unnoticed facts about irreducibility (resp., reducibility) of Flouqet factorisations and their harmonic implication in term of controllability in finite-dimensional linear continuous-time periodic (FDLCP) systems. Reducibility and irreducibility are attributed to matrix logarithm algorithms during computing Floquet factorisations in FDLCP systems, which are a pair of essential features but remain unnoticed in the Floquet theory so far. The study reveals that reducible Floquet factorisations may bring in harmonic waves variance into the Fourier analysis of FDLCP systems that in turn may alter our interpretation of controllability when the Floquet factors are used separately during controllability testing; namely, controllability interpretation discrepancy (or simply, controllability discrepancy) may occur and must be examined whenever reducible Floquet factorisations are involved. On the contrary, when irreducible Floquet factorisations are employed, controllability interpretation discrepancy can be avoided. Examples are included to illustrate such observations.

  16. Intercomparison of UT1 measurements during the MERIT campaign period. [Universal Time

    NASA Technical Reports Server (NTRS)

    Spieth, M. A.; Eubanks, T. M.; Steppe, J. A.

    1986-01-01

    Universal time (UT1) measurements obtained using VLBI, lunar laser ranging (LLR), and BIH optical astronomy are compared. The JPL Kalman filter for the earth rotation and the polar motion is utilized to smooth one data set or combine data sets for intercomparison. The differences between raw UT1 data and independently smoothed data are employed to assess the accuracy of the measured series and the sufficiency of the error budget. Systematic errors in periodic signatures and length of day estimates are analyzed. The data reveal that the techniques of LLR and VLBI agree to within their formal errors. It is determined that the residual error for the LLR is too large and the residual error estimated for the BIH data is too small.

  17. Observations of the April 2002 Storm Period with TIMED-TIDI

    NASA Astrophysics Data System (ADS)

    Niciejewski, R.; Killeen, T.; Wu, Q.; Skinner, W.; Solomon, S.; Ortland, D.; Kafkalidis, J.; Gell, D.; Gablehouse, D.; Johnson, R.

    2002-12-01

    TIDI is meeting its basic requirement, which is to measure the global wind field in the mesosphere and lower thermosphere, the core study region. Since February 2002, TIDI has been in a routine science data-taking mode. During April 2002, TIMED was positioned at a high beta angle (angle between the plane of the satellite orbit and the Earth-Sun line) resulting in a series of TIDI measurements near the dusk/dawn terminator. The field of view of TIDI allows it to obtain measurements from pole to pole, while the repetition rate of the sky-scanner allows it to obtain several scans within the auroral oval region on each orbit. This paper will discuss TIDI measurements obtained during the April 2002 storm period, including OI (5577\\x8F) intensity data and neutral wind data sets.

  18. 40 CFR 270.215 - How are time periods in the requirements in this subpart and my RAP computed?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements in this subpart and my RAP computed? 270.215 Section 270.215 Protection of Environment... HAZARDOUS WASTE PERMIT PROGRAM Remedial Action Plans (RAPs) Operating Under Your Rap § 270.215 How are time periods in the requirements in this subpart and my RAP computed? (a) Any time period scheduled to begin...

  19. 40 CFR 270.215 - How are time periods in the requirements in this subpart and my RAP computed?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements in this subpart and my RAP computed? 270.215 Section 270.215 Protection of Environment... HAZARDOUS WASTE PERMIT PROGRAM Remedial Action Plans (RAPs) Operating Under Your Rap § 270.215 How are time periods in the requirements in this subpart and my RAP computed? (a) Any time period scheduled to begin...

  20. 40 CFR 270.215 - How are time periods in the requirements in this subpart and my RAP computed?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements in this subpart and my RAP computed? 270.215 Section 270.215 Protection of Environment... HAZARDOUS WASTE PERMIT PROGRAM Remedial Action Plans (RAPs) Operating Under Your Rap § 270.215 How are time periods in the requirements in this subpart and my RAP computed? (a) Any time period scheduled to begin...

  1. 40 CFR 270.215 - How are time periods in the requirements in this subpart and my RAP computed?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements in this subpart and my RAP computed? 270.215 Section 270.215 Protection of Environment... HAZARDOUS WASTE PERMIT PROGRAM Remedial Action Plans (RAPs) Operating Under Your Rap § 270.215 How are time periods in the requirements in this subpart and my RAP computed? (a) Any time period scheduled to begin...

  2. 40 CFR 270.215 - How are time periods in the requirements in this subpart and my RAP computed?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements in this subpart and my RAP computed? 270.215 Section 270.215 Protection of Environment... HAZARDOUS WASTE PERMIT PROGRAM Remedial Action Plans (RAPs) Operating Under Your Rap § 270.215 How are time periods in the requirements in this subpart and my RAP computed? (a) Any time period scheduled to begin...

  3. The timing and duration of a sensitive period in human flavor learning: a randomized trial1234

    PubMed Central

    Mennella, Julie A; Lukasewycz, Laura D; Castor, Sara M; Beauchamp, Gary K

    2011-01-01

    Background: By using the response to protein hydrolysate formula (PHF) as a model system, we discovered the existence of a sensitive period, before 4 mo, when exposure determines the hedonic tone to flavors. Objective: We aimed to characterize the timing and duration of this sensitive period. Design: Healthy infants, whose parents had chosen formula feeding, were randomly assigned into 1 of 6 groups at age 0.5 mo: 2 control groups, one fed cow milk–based formula (CMF) and the other fed PHF for 7 mo; 2 groups fed PHF for either 1 or 3 mo beginning at 1.5 mo and CMF otherwise; and 2 groups fed PHF for 1 mo beginning at either 2.5 or 3.5 mo and CMF otherwise. Brief access taste tests were conducted monthly, and complete “meals” of both formulas occurred at the end of the study. Results: Three months of PHF exposure led to acceptance similar to that at 1 mo of exposure. Although these infants were more accepting than were infants with no exposure, they were less accepting than were infants with 7 mo of exposure, which suggests a dosing effect. The time when flavor experiences began was also significant. Among infants exposed to PHF for 1 mo, those who were first fed PHF at 3.5 mo rejected PHF relative to CMF more than did infants exposed at younger ages. Conclusion: The general principles observed are likely of broader significance, indicating a fundamental feature of mammalian development and reflecting the importance of familiarizing infants with flavors that their mothers consume and transmit to breast milk. This trial was registered at clinicaltrials.gov as NCT00994747. PMID:21310829

  4. Low-thrust roundtrip trajectories to Mars with one-synodic-period repeat time

    NASA Astrophysics Data System (ADS)

    Okutsu, Masataka; Landau, Damon F.; Rogers, Blake A.; Longuski, James M.

    2015-05-01

    Cycler trajectories-both ballistic and powered-are reported in the literature in which there are two-vehicle, three-vehicle, and four-vehicle cases. Such trajectories permit the installation of cycler vehicles which provide safe and comfortable living conditions for human space travel between Earth and Mars during every synodic opportunity. The question the present paper answers is a logical, obvious one: Does a single-vehicle, one-synodic-period cycler exist? The answer is yes: such a trajectory can be flown-but only with a high-power electric propulsion system. In our example, it is found that "stopover" trajectories that spend 30 days in orbit about Earth and 30 days about Mars, and return astronauts to Earth in one synodic period require a 90-t power generator with a power level of 11 MWe. Fortuitously, and in lieu of using chemical propulsion, the high power level of the electric propulsion system would also be effective in hauling the cargo payload via a spiral trajectory about the Earth. But because one synodic period is not enough for the cycler vehicle to fly both the interplanetary trajectories and the Earth-spiral trajectories, we suggest developing two nuclear power generators, which could alternate flying the interplanetary trajectories and the Earth-spiral trajectories. Once these power generators are launched and begin operating in space, the mass requirement in seven subsequent missions (over a period of 15 years beginning in 2022) would be modest at 250-300 metric tons to low-Earth orbit per mission. Thus two cargo launches of NASA's Space Launch System and one crew launch of the Falcon Heavy, for example, would be adequate to maintain support for each consecutive mission. Although we propose developing two sets of electric propulsion systems to account for the Earth-spiral phases, only one vehicle is flown on a heliocentric trajectory at any given time. Thus, our low-thrust stopover cycler with zero encounter velocities falls into a category of a

  5. FORENSIC SCIENCE:: 20 YEARS OF FORENSIC DENTISTRY AT THE UNIVERSITY OF ZAGREB, 1994 - 2014.

    PubMed

    Brkić, Hrvoje

    2014-06-01

    Data from available literature point to an early beginning of Forensic Dentistry in Croatia relating to a post-mortem examination of a female patient after a dental procedure in the 1930s. Later on, there were several mass casualties due to collisions and airplane crashes and a railway accident at the Zagreb Main Railway Station wherein the identity of the victims was established based on dental features. Foreign experts in forensics helped identify those victims, particularly forensic dentists because this specialty was almost unknown in our region at the time. During the twenty-year period of the development of Forensic Dentistry at the University of Zagreb, the School of Dental Medicine, the city of Zagreb and Croatia have become internationally recognised on the forensic map of the world.

  6. Estimating interevent time distributions from finite observation periods in communication networks

    NASA Astrophysics Data System (ADS)

    Kivelä, Mikko; Porter, Mason A.

    2015-11-01

    A diverse variety of processes—including recurrent disease episodes, neuron firing, and communication patterns among humans—can be described using interevent time (IET) distributions. Many such processes are ongoing, although event sequences are only available during a finite observation window. Because the observation time window is more likely to begin or end during long IETs than during short ones, the analysis of such data is susceptible to a bias induced by the finite observation period. In this paper, we illustrate how this length bias is born and how it can be corrected without assuming any particular shape for the IET distribution. To do this, we model event sequences using stationary renewal processes, and we formulate simple heuristics for determining the severity of the bias. To illustrate our results, we focus on the example of empirical communication networks, which are temporal networks that are constructed from communication events. The IET distributions of such systems guide efforts to build models of human behavior, and the variance of IETs is very important for estimating the spreading rate of information in networks of temporal interactions. We analyze several well-known data sets from the literature, and we find that the resulting bias can lead to systematic underestimates of the variance in the IET distributions and that correcting for the bias can lead to qualitatively different results for the tails of the IET distributions.

  7. Estimating interevent time distributions from finite observation periods in communication networks.

    PubMed

    Kivelä, Mikko; Porter, Mason A

    2015-11-01

    A diverse variety of processes-including recurrent disease episodes, neuron firing, and communication patterns among humans-can be described using interevent time (IET) distributions. Many such processes are ongoing, although event sequences are only available during a finite observation window. Because the observation time window is more likely to begin or end during long IETs than during short ones, the analysis of such data is susceptible to a bias induced by the finite observation period. In this paper, we illustrate how this length bias is born and how it can be corrected without assuming any particular shape for the IET distribution. To do this, we model event sequences using stationary renewal processes, and we formulate simple heuristics for determining the severity of the bias. To illustrate our results, we focus on the example of empirical communication networks, which are temporal networks that are constructed from communication events. The IET distributions of such systems guide efforts to build models of human behavior, and the variance of IETs is very important for estimating the spreading rate of information in networks of temporal interactions. We analyze several well-known data sets from the literature, and we find that the resulting bias can lead to systematic underestimates of the variance in the IET distributions and that correcting for the bias can lead to qualitatively different results for the tails of the IET distributions. PMID:26651750

  8. The Effects of Time-Periodic Shear on a Diffusion Flame Anchored to a Model Propellant

    NASA Astrophysics Data System (ADS)

    Isfahani, Amir H. G.; Zhang, Ju; Jackson, Thomas L.

    2008-11-01

    Propellants of solid rocket motors are subject to intense time-dependent shear flows and the response of the combustion field to these flows is of fundamental interest. Erosive burning (EB), the enhanced regression rate that can arise due to these flows, affects the performance of the solid rocket motor: the specific-impulse history. It is generally agreed that EB results from an increased heat transfer to the surface. The geometry is that of two quarter-planes of ammonium perchlorate (AP) and binder (or a blend of AP/binder). Three step kinetics is considered: AP decomposition and two diffusion flames, one between the virgin AP gases and binder and one between AP decomposed gases and binder. Gas and solid phases are coupled and temperature along the surface as well as the burn rate is solved for. We present an estimation of the shear parameters as a function of the motor size using a 2D planar periodic rocket (PPR) analysis without resorting to fully time-dependent three-dimensional turbulent simulations. These parameters are then used to study the change in the heat flux to the surface and the burn rate. It is shown that the burn rate is increased by more than two folds for larger amplitudes and frequencies.

  9. Estimating interevent time distributions from finite observation periods in communication networks.

    PubMed

    Kivelä, Mikko; Porter, Mason A

    2015-11-01

    A diverse variety of processes-including recurrent disease episodes, neuron firing, and communication patterns among humans-can be described using interevent time (IET) distributions. Many such processes are ongoing, although event sequences are only available during a finite observation window. Because the observation time window is more likely to begin or end during long IETs than during short ones, the analysis of such data is susceptible to a bias induced by the finite observation period. In this paper, we illustrate how this length bias is born and how it can be corrected without assuming any particular shape for the IET distribution. To do this, we model event sequences using stationary renewal processes, and we formulate simple heuristics for determining the severity of the bias. To illustrate our results, we focus on the example of empirical communication networks, which are temporal networks that are constructed from communication events. The IET distributions of such systems guide efforts to build models of human behavior, and the variance of IETs is very important for estimating the spreading rate of information in networks of temporal interactions. We analyze several well-known data sets from the literature, and we find that the resulting bias can lead to systematic underestimates of the variance in the IET distributions and that correcting for the bias can lead to qualitatively different results for the tails of the IET distributions.

  10. Time Dependence of Anodal and Cathodal Refractory Periods in Cardiac Tissue

    NASA Astrophysics Data System (ADS)

    Bennett, Jonathan A.; Roth, Bradley J.

    1997-11-01

    Cathodal and anodal make and break excitation have been observed in cardiac tissue. Make excitation occurs when a stimulus pulse is turned on and has a lower threshold than break excitation, which occurs when a stimulus pulse is turned off. Mehra et al. (PACE 3:526) observed that over time the anodal refractory period (RP) becomes longer than the cathodal RP. After implantation, damaged tissue accumulates around the electrode, thereby increasing its effective surface area. We investigate this time-dependent change numerically by stimulating cardiac tissue using small and large electrodes. The tissue is represented as a bidomain with a Beeler-Reuter membrane. Like Mehra et al., we define the RP to be the threshold interval at a strength of 8 mA. The anodal RP is longer than the cathodal RP for the large electrode, whereas it is shorter for the small electrode. However, anode break threshold for the small electrode is less than 8 mA, but for the large electrode it is greater than 8 mA. The lengthening of the anodal RP is caused by excluding the anode break excitation with the larger electrode. This result is consistent with Mehra et al., and suggests that their observation resulted from their definition of RP.

  11. Growth mechanism of photoreduced silver nanostructures on periodically proton exchanged lithium niobate: Time and concentration dependence

    SciTech Connect

    Craig Carville, N.; Denning, Denise; Rodriguez, Brian J.; Manzo, Michele; Gallo, Katia

    2013-05-14

    Photodeposition of metallic nanostructures onto ferroelectric surfaces, which have been chemically patterned using a proton exchange process, has recently been demonstrated. By varying the molar concentration of the AgNO{sub 3} solution and the illumination time, one can determine the initial nucleation sites, control the rate of nucleation and the height of silver nanostructures formed, and study the mechanisms by which these processes occurs. The nanoparticles are found to deposit preferentially in the boundary between ferroelectric and proton exchanged regions, in an area proton exchanged via lateral diffusion under the masking layer used for chemical patterning, consistent with our previous results. Using a short illumination time (3 min), we are able to determine that the initial nucleation of the silver nanostructure, having a width of 0.17 {+-} 0.02 {mu}m and a height of 1.61 {+-} 0.98 nm, occurs near the edge of the reactive ion etched area within this lateral diffusion region. Over longer illumination times (15 min), we find that the silver deposition has spread to a width of 1.29 {+-} 0.06 {mu}m, extending across the entire lateral diffusion region. We report that at a high molar concentration of AgNO{sub 3} (10{sup -2} M), the amount of silver deposition for 5 min UV illumination is greater (2.88 {+-} 0.58 nm) compared to that at low (10{sup -4} M) concentrations (0.78 {+-} 0.35 nm), however, this is not the case for longer time periods. With increasing illumination time (15 min), experiments at 10{sup -4} M had greater overall deposition, 6.90 {+-} 1.52 nm, compared to 4.50 {+-} 0.76 nm at 10{sup -2} M. For longer exposure times (30 min) at 10{sup -2} M, the nanostructure height is 4.72 {+-} 0.59 nm, suggesting a saturation in the nanostructure height. The results are discussed in terms of the electric double layer that forms at the crystal surface. There is an order of magnitude difference between the Debye lengths for 10{sup -2} and 10{sup -4} M

  12. [A 20-year follow-up study of a sample of 50 pairs of twins with neurotic-psychosomatic disorders].

    PubMed

    Muhs, A; Schepank, H; Manz, R

    1990-01-01

    As part of a research project, examination was made of a sample of 50 pairs of twins (21 pairs of identical twins, 16 pairs of non-identical twins of the same sex, and 13 pairs of male-female twins [n = 100 test persons]) between 1963 and 1969 and again recently after a period of 20 years. The index twins were drawn from among the patients who made use of the services of an out-patient psychotherapeutic clinic, and they were determined to be either psychoneurotic, character neurotic, or psychosomatically ill. The question examined was again one of nature vs. nurture. Identical twins showed a significantly higher similarity with regard to the seriousness of their neuroses and the manifestation of neurotic symptoms than did non-identical twins. Noticeable similarities existed in cases of depressive disturbances, disturbances of oral and aggressive behavior, and disturbances of interpersonal contact. With regard to the influence of variables in the environment, we examined the effect of factors in early childhood on neurotic development. Lack of a reference person, a negative attitude on the part of parents toward the child, etc., frustration within and outside the family have an effect on the manifestation of neuroses and on the course of their development. The influence of early childhood factors on the degree of neurotic disorder is still to be noted in the current point prevalence.

  13. The clinical picture of late-onset PTSD: a 20-year longitudinal study of Israeli war veterans.

    PubMed

    Horesh, Danny; Solomon, Zahava; Keinan, Giora; Ein-Dor, Tsachi

    2013-08-15

    Delayed-onset posttraumatic stress disorder (PTSD) has been under medico-legal debate for years. Previous studies examining the prevalence and clinical characteristics of delayed-onset PTSD have yielded inconclusive findings. This study prospectively examines the prevalence and clinical picture of late-onset PTSD among Israeli war veterans. It also evaluates whether or not late-onset PTSD erupts after a completely non-symptomatic period. 675 Israeli veterans from the 1982 Lebanon War, with and without antecedent combat stress reaction (CSR), have been assessed 1, 2 and 20 years post-war. They were divided into 4 groups, according to the duration of delay in PTSD onset. Participants completed self-report questionnaires tapping psychopathology, combat exposure and socio-demographics. 16.5% of the veterans suffered from late-onset PTSD. A longer delay in PTSD onset was associated with less severe psychopathology. Also, CSR was associated with a shorter delay in PTSD onset. Finally, the vast majority of veterans already suffered from PTSD symptoms prior to late PTSD onset. Our results offer further validation for the existence of delayed-onset PTSD. Delayed-onset PTSD appears to be a unique sub-type of PTSD, with an attenuated clinical picture. In addition, delayed-onset PTSD may be the result of an incubation process, wherein symptoms already exist prior to PTSD onset.

  14. [A 20-year follow-up study of a sample of 50 pairs of twins with neurotic-psychosomatic disorders].

    PubMed

    Muhs, A; Schepank, H; Manz, R

    1990-01-01

    As part of a research project, examination was made of a sample of 50 pairs of twins (21 pairs of identical twins, 16 pairs of non-identical twins of the same sex, and 13 pairs of male-female twins [n = 100 test persons]) between 1963 and 1969 and again recently after a period of 20 years. The index twins were drawn from among the patients who made use of the services of an out-patient psychotherapeutic clinic, and they were determined to be either psychoneurotic, character neurotic, or psychosomatically ill. The question examined was again one of nature vs. nurture. Identical twins showed a significantly higher similarity with regard to the seriousness of their neuroses and the manifestation of neurotic symptoms than did non-identical twins. Noticeable similarities existed in cases of depressive disturbances, disturbances of oral and aggressive behavior, and disturbances of interpersonal contact. With regard to the influence of variables in the environment, we examined the effect of factors in early childhood on neurotic development. Lack of a reference person, a negative attitude on the part of parents toward the child, etc., frustration within and outside the family have an effect on the manifestation of neuroses and on the course of their development. The influence of early childhood factors on the degree of neurotic disorder is still to be noted in the current point prevalence. PMID:2305597

  15. Analysis of Profit and Loss by Injury Severity over 20 Years at a University Level I Trauma Center.

    PubMed

    Dietch, Zachary; Young, Jeffrey S; Young, Steven D

    2016-07-01

    We examined financial data from a University Level I Trauma Center from 1994 to 2014. We sought to investigate the hypothesis that lower injury severity correlates with increased profitability. We examined data from July 1994 to December 2014. This included hospital charges, Medicare cost data, final reimbursement, and payor source. Patients were separated into Injury Severity Score (ISS) groupings: 0 to 9, 10 to 14, 15 to 24, >24, and >14. Mean and standard deviation of mean are reported. We had complete data on 27,582 patients. Overall profit per case when subtracting costs from reimbursements was $1,932/case (total profit in unadjusted dollars = $53,475,828 or $2,673,791/year). When examined by ISS, profitability was significantly different between ISS 0 to 14 and 15 to 24, and > 24. When charge data were examined, the average loss per case was -$31,313 for the 27,582 patient data set. When using cost, and not charge data, overall trauma care had a positive margin. Severely injured patients (ISS > 14) were the most profitable, with a significantly higher profit per case than all other groupings. Only through examination of cost data can realistic determinations of trauma center profitability be made. If only charge data had been examined in this study, the overall loss from the 20-year period would have been $863,675,166 and not a profit of $53,475,828. PMID:27457865

  16. Almost periodic solutions for a memristor-based neural networks with leakage, time-varying and distributed delays.

    PubMed

    Jiang, Ping; Zeng, Zhigang; Chen, Jiejie

    2015-08-01

    In this paper, we study the existence and global exponential stability of almost periodic solution for memristor-based neural networks with leakage, time-varying and distributed delays. Using a new Lyapunov function method, we prove that this delayed neural network has a unique almost periodic solution, which is globally exponentially stable. Moreover, the obtained conclusion on the almost periodic solution is applied to prove the existence and stability of periodic solution (or equilibrium point) for this delayed neural network with periodic coefficients (or constant coefficients).

  17. Timing and return period of major palaeoseismic events in the Shillong Plateau, India

    NASA Astrophysics Data System (ADS)

    Sukhija, B. S.; Rao, M. N.; Reddy, D. V.; Nagabhushanam, P.; Hussain, Syed; Chadha, R. K.; Gupta, H. K.

    1999-07-01

    The close temporal occurrence of four great earthquakes in the past century, including the great Assam earthquake of 1897 in the Shillong Plateau, necessitated examination of the palaeoseismicity of the region. The results from such investigation would definitely aid in addressing the problem of the earthquake hazard evaluation more realistically. Our recent palaeoseismological study in the Shillong Plateau has led us to identify and provide geological evidence for large/major earthquakes and estimate the probable recurrence period of such violent earthquakes in parts of the Shillong Plateau and the adjoining Brahmaputra valley. Trenching along the Krishnai River, a tributary of the River Brahmaputra, has unravelled very conspicuous and significant earthquake-induced signatures in the alluvial deposits of the valley. The geological evidence includes: (1) palaeoliquefaction features, like sand dykes and sand blows; (2) deformational features, like tilted beds; (3) fractures and syndepositional deformational features, like flame structures caused by coeval seismic events. Chronological constraints of the past large/major earthquakes are provided from upper and lower radiocarbon age bounds in the case of the palaeoliquefaction features, and the coeval timing of the palaeoseismic events is obtained from the radiocarbon dating of the organic material associated with the deformed horizon as well as buried tree trunks observed wide distances apart. Our palaeoseismic measurements, which are the first from the area, indicate that the Shillong Plateau has been struck by large/major earthquakes around 500±150, 1100±150 and >1500±150 yr BP, in addition to the well-known great seismic event of 1897, thereby the 14C dates indicate a recurrence period of the order of 500 yr for large earthquakes in the Shillong Plateau.

  18. Identification of Under-Detected Periodicity in Time-Series Microarray Data by Using Empirical Mode Decomposition

    PubMed Central

    Chen, Chaang-Ray; Shu, Wun-Yi; Chang, Cheng-Wei; Hsu, Ian C.

    2014-01-01

    Detecting periodicity signals from time-series microarray data is commonly used to facilitate the understanding of the critical roles and underlying mechanisms of regulatory transcriptomes. However, time-series microarray data are noisy. How the temporal data structure affects the performance of periodicity detection has remained elusive. We present a novel method based on empirical mode decomposition (EMD) to examine this effect. We applied EMD to a yeast microarray dataset and extracted a series of intrinsic mode function (IMF) oscillations from the time-series data. Our analysis indicated that many periodically expressed genes might have been under-detected in the original analysis because of interference between decomposed IMF oscillations. By validating a protein complex coexpression analysis, we revealed that 56 genes were newly determined as periodic. We demonstrated that EMD can be used incorporating with existing periodicity detection methods to improve their performance. This approach can be applied to other time-series microarray studies. PMID:25372711

  19. The last interglacial period on the Pacific Coast of North America: Timing and paleoclimate

    USGS Publications Warehouse

    Muhs, D.R.; Simmons, K.R.; Kennedy, G.L.; Rockwell, T.K.

    2002-01-01

    New, high-precision U-series ages of solitary corals (Balanophyllia elegans) coupled with molluscan faunal data from marine terraces on the Pacific Coast of North America yield information about the timing and warmth of the last interglacial sea-level highstand. Balanophyllia elegans takes up U in isotopic equilibrium with seawater during growth and shortly after death. Corals from the second terrace on San Clemente Island (offshore southern California), the third terrace on Punta Banda (on the Pacific Coast of northern Baja California), and the Discovery Point Formation on Isla de Guadalupe (in the Pacific Ocean offshore Baja California) date to the peak of the last interglacial period and have U-series ages ranging from ca. 123 to 114 ka. The first terrace on Punta Banda has corals with ages ranging from ca. 83 to 80 ka, which corresponds to a sea-level highstand formed in the late last interglacial period. U-series analyses of corals from the Cayucos terrace (central California) and the Nestor terrace at Point Loma (southern California) show that these fossils have evidence of open-system history, similar to what has been reported by other workers for the same localities. Nevertheless, a model of continuous, secondary U and Th uptake shows that two ages of corals are likely present at these localities, representing the ca. 105 and ca. 120 ka sea-level highstands reported elsewhere. U-series ages of last interglacial corals from the Pacific Coast overlap with, but are on average younger than the ages of corals from Barbados, the Bahamas, and Hawaii. This age difference is explained by the nature of the geomorphic response to sea-level change: fringing or barrier reefs on low-latitude coastlines have an accretionary growth style that keeps pace with rising sea level, whether on a tectonically rising or stable coastline. In contrast, midlatitude, high-energy coastlines are sites of platform cutting during the early part of a sea-level high stand and terrace

  20. Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods.

    PubMed

    Tovey, Euan R; Liu-Brennan, Damien; Garden, Frances L; Oliver, Brian G; Perzanowski, Matthew S; Marks, Guy B

    2016-01-01

    Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical